  United States Court of Appeals
      for the Federal Circuit
                ______________________

     SCA HYGIENE PRODUCTS AKTIEBOLAG
          SCA PERSONAL CARE, INC.,
              Plaintiffs-Appellants

                           v.

     FIRST QUALITY BABY PRODUCTS, LLC,
         FIRST QUALITY HYGIENIC, INC.,
       FIRST QUALITY PRODUCTS, INC. AND
     FIRST QUALITY RETAIL SERVICES, LLC,
               Defendants-Appellees
              ______________________

                      2013-1564
                ______________________

   Appeal from the United States District Court for the
Western District of Kentucky in No. 10-CV-0122, Chief
Judge Joseph H. McKinley, Jr.
                ______________________

              Decided: September 18, 2015
                ______________________

   MARTIN J. BLACK, Dechert LLP, Philadelphia, PA, ar-
gued for plaintiffs-appellants. Also represented by TERI-
LYNN A. EVANS, KEVIN MARK FLANNERY, SHARON K.
GAGLIARDI.

   KENNETH GEORGE, Amster Rothstein & Ebenstein
LLP, New York, NY, argued for defendants-appellees.
2    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



Also represented by MARK BERKOWITZ, SANDRA ADELE
HUDAK, CHARLES R. MACEDO.

   J. DEREK VANDENBURGH, Carlson, Caspers, Vanden-
burgh, Lindquist & Schuman, P.A., Minneapolis, MN, for
amicus curiae The Toro Company. Also represented by
JOSEPH W. WINKELS.

     RICHARD DELUCIA, Kenyon & Kenyon LLP, New York,
NY, for amicus curiae Medinol Ltd. Also represented by
MARK ALEXANDER CHAPMAN, ELIZABETH GARDNER,
ALOYSIUS ANTONY PFEFFER, JOSEPH MATTHEW PURCELL,
JR., ERIC SCHREIBER; RICHARD H. PILDES, New York, NY.

    GREGORY A. CASTANIAS, Jones Day, Washington, DC,
for amicus curiae Intellectual Property Owners Associa-
tion. Also represented by CAROLINE EDSALL, ISRAEL SASHA
MAYERGOYZ; PHILIP STATON JOHNSON, Johnson & John-
son, New Brunswick, NJ; KEVIN H. RHODES, 3M Innova-
tive Properties Company, St. Paul, MN; HERBERT CLARE
WAMSLEY, JR., Intellectual Property Owners Association,
Washington, DC.

   ANDREW JOHN DHUEY, Berkeley, CA, for amicus curi-
ae Morris Reese.

    MICHAEL J. FARNAN, Farnan LLP, Wilmington, DE,
for amicus curiae ART+COM Innovationpool GmbH.

    ARIEL LAVINBUK, Robbins, Russell, Englert, Orseck,
Untereiner & Sauber LLP, Washington, DC, for amici
curiae Stephanos Bibas, Samuel L. Bray, John F. Duffy.
Also represented by MICHAEL E. KENNEALLY.

    NANCY MERTZEL, Schoeman Updike Kaufman & Stern
LLP, New York, NY, for amicus curiae American Intellec-
tual Property Law Association. Also represented by
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS   3



DENISE WHELTON DEFRANCO, Finnegan, Henderson,
Farabow, Garrett & Dunner, LLP, Boston, MA.

   STEVEN C. SEREBOFF, SoCal IP Law Group LLP,
Westlake Village, CA, for amicus curiae Conejo Valley
Bar Association. Also represented by MARK ANDREW
GOLDSTEIN, MEENAKSHI KALA SARVAIYA.

    PHILIP J. WARRICK, Klarquist Sparkman, LLP, Port-
land, OR, for amici curiae Garmin International, Inc.,
Limelight Networks, Inc., LinkedIn Corporation, Mentor
Graphics Corporation, Newegg Inc., SAP America, Inc.,
SAS Institute Inc., Symmetry LLC, Xilinx, Inc. Also
represented by JOHN D. VANDENBERG.

    MITCHELL M. WONG, Ashmasons LLP, New York, NY,
for amicus curiae Ashmasons LLP.

    JOHN THORNE, Kellogg, Huber, Hansen, Todd, Evans
& Figel, PLLC, Washington, DC, for amici curiae Dell
Inc., CTIA The Wireless Association, Hewlett-Packard
Company, Intel Corporation, Xerox Corporation. Also
represented by AARON M. PANNER, GREGORY G. RAPAWY.

   SUZANNE MICHEL, Google Inc., Washington, DC, for
amicus curiae Google Inc.

   DEREK SHAFFER, Quinn Emanuel Urquhart & Sulli-
van, LLP, Washington, DC, for amicus curiae Marvell
Semiconductor, Inc.

    EUGENE M. GELERNTER, Patterson Belknap Webb &
Tyler LLP, New York, NY, for amici curiae Johnson &
Johnson, Cordis Corporation. Also represented by
GREGORY DISKANT, SCOTT B. HOWARD.
4    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



    VERA RANIERI, Electronic Frontier Foundation, San
Francisco, CA, for amici curiae Electronic Frontier Foun-
dation, Public Knowledge.

    KEVIN J. CULLIGAN, Goodwin Procter LLP, New York,
NY, for amicus curiae Askeladden, L.L.C. Also represent-
ed by JOHN P. HANISH; BRIAN TIMOTHY BURGESS, WILLIAM
M. JAY, Washington, DC.

    DOUGLAS A. MIRO, Ostrolenk Faber LLP, New York,
NY, for amicus curiae Universal Remote Control, Inc. Also
represented by ALAN FEDERBUSH.

    MICHAEL SONGER, Crowell & Moring, LLP, Washing-
ton, DC, for amicus curiae AT&T Mobility II LLC. Also
represented by VINCENT JOHN GALLUZZO.

    GREER N. SHAW, Snell & Wilmer, LLP, Los Angeles,
CA, for amicus curiae T-Mobile USA, Inc. Also represent-
ed by TRISHA FARMER, Phoenix, AZ.

    DOMINIC P. ZANFARDINO, Brinks Gilson & Lione, Chi-
cago, IL, for amicus curiae Cook Medical LLC. Also repre-
sented by CYNTHIA A. HOMAN, ANDREW S. MCELLIGOTT.

    BRETT L. FOSTER, Holland & Hart LLP, Salt Lake
City, UT, for amicus curiae Hydro Engineering, Inc. Also
represented by DAWN M. DAVID, MARK A. MILLER.

    MARK CHRISTOPHER FLEMING, Wilmer Cutler Picker-
ing Hale and Dorr LLP, Boston, MA, for amicus curiae
Roche Molecular Systems, Inc. Also represented by
ROBERT J. GUNTHER, JR., OMAR KHAN, New York, NY.

   MATTHEW WOLF, Arnold & Porter LLP, Washington,
DC, for amici curiae Briggs & Stratton Corp., Harley-
Davidson Motor Company, Inc., Jockey International,
SCA HYGIENE PRODUCTS    v. FIRST QUALITY BABY PRODUCTS     5



Inc., Rockwell Automation, Inc., Wisconsin Manufacturers
& Commerce.
                 ______________________
  Before PROST, Chief Judge, NEWMAN, LOURIE, DYK,
MOORE, O’MALLEY, REYNA, WALLACH, TARANTO, CHEN, and
              HUGHES, Circuit Judges. ∗
Opinion for the court filed by Chief Judge PROST in which
 Circuit Judges NEWMAN, LOURIE, DYK, O’MALLEY, and
                        REYNA join.
 Opinion concurring-in-part, dissenting-in-part filed by
 Circuit Judge HUGHES in which Circuit Judges MOORE,
           WALLACH, TARANTO, and CHEN join.
PROST, Chief Judge.
    We convene en banc to resolve whether, in light of the
Supreme Court’s recent decision in Petrella v. Metro-
Goldwyn-Mayer, Inc., 134 S. Ct. 1962 (2014), laches
remains a defense to legal relief in a patent infringement
suit. We conclude that Congress codified a laches defense
in 35 U.S.C. § 282(b)(1) that may bar legal remedies.
Accordingly, we have no judicial authority to question the
law’s propriety. Whether Congress considered the quan-
dary in Petrella is irrelevant—in the 1952 Patent Act,
Congress settled that laches and a time limitation on the
recovery of damages can coexist in patent law. We must
respect that statutory law.
    Nevertheless, we must adjust the laches defense in
one respect to harmonize it with Petrella and other Su-
preme Court precedent. We emphasize that equitable
principles apply whenever an accused infringer seeks to
use laches to bar ongoing relief. Specifically, as to injunc-


    ∗
          Circuit Judge Stoll did not participate in this de-
cision.
6     SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



tions, considerations of laches fit naturally within the
eBay framework. In contrast, Menendez v. Holt, 128 U.S.
514 (1888), and Petrella counsel that laches will only
foreclose an ongoing royalty in extraordinary circum-
stances.
                      I. BACKGROUND
    The present dispute arose out of litigation concerning
adult incontinence products. SCA alleges that First
Quality, a competitor in the adult incontinence products
market, infringes U.S. Patent No. 6,375,646 (’646 patent).
SCA first contended that First Quality’s Prevail® All
Nites™ product infringes the ’646 patent in a letter sent
to First Quality on October 31, 2003. The correspondence
explained:
    It has come to our attention that you are making,
    selling and/or offering for sale in the United
    States absorbent pants-type diapers under the
    name Prevail® All Nites™. We believe that these
    products infringe claims of [the ’646 patent].
    We suggest that you study [the ’646 patent]. If
    you are of the opinion that the First Quality Pre-
    vail® All Nites™ absorbent pants-type diaper
    does not infringe any of the claims of this patent,
    please provide us with an explanation as to why
    you believe the products do not infringe. If you
    believe that the products do infringe, please pro-
    vide us with your assurance that you will imme-
    diately stop making and selling such products.
J.A. 544.
    First Quality responded on November 21, 2003 and
claimed the patent was invalid:
    As you suggested, we studied [the ’646
    tent]. . . . In addition, we made a cursory review of
    prior patents and located U.S. Patent No.
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    7



   5,415,649, (“the ’649 Patent”), which was filed in
   the United States on October 29, 1991 and is
   therefore prior to your client’s ’646 Patent. A re-
   view of Figs. 3 and 4 of the prior ’649 Patent re-
   veals the same diaper construction claimed by
   the ’646 Patent. Thus, the prior ’649 Patent inval-
   idates your client’s ’646 Patent. As you know, an
   invalid patent cannot be infringed.
J.A. 547. SCA and First Quality ceased communications
regarding the ’646 patent after First Quality’s response.
However, on July 7, 2004, SCA requested reexamination
of the ’646 patent in light of the ’649 patent. SCA did not
notify First Quality of the reexamination because, in
SCA’s view, U.S. Patent and Trademark Office (“PTO”)
reexaminations are public and First Quality could follow
the proceedings itself. Yet, from First Quality’s point of
view, SCA dropped its infringement allegations against
First Quality after First Quality argued the patent was
invalid in the November 21st letter.
     The PTO instituted reexamination on the ’646 patent
and, on March 27, 2007, confirmed the patentability of all
twenty-eight original claims and issued several other
claims SCA added during reexamination. Meanwhile,
First Quality invested heavily in its protective underwear
business. In 2006, First Quality expanded its line of adult
incontinence products. In 2008, First Quality acquired
Tyco Healthcare Retail Group LP, which had several lines
of competing products, and in 2009 First Quality spent
another $10 million to purchase three more lines of pro-
tective underwear products. SCA was aware of First
Quality’s activities, but never mentioned the ’646 patent
to First Quality during this time.
    On August 2, 2010—over three years after reexami-
nation concluded—SCA filed a complaint alleging that
First Quality infringes the ’646 patent. Service of the
complaint was the first time in nearly seven years that
8     SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



SCA had communicated with First Quality regarding
the ’646 patent. The district court proceeded with discov-
ery and issued a claim construction order. First Quality
then moved for partial summary judgment of nonin-
fringement and for summary judgment of laches and
equitable estoppel. The district court granted First
Quality’s motion as to laches and equitable estoppel and
dismissed the noninfringement motion as moot.
    SCA appealed, and on September 17, 2014, a panel of
this court affirmed the district court’s opinion on laches,
but reversed as to equitable estoppel. See SCA Hygiene
Prods. Aktiebolag v. First Quality Baby Prods., LLC, 767
F.3d 1339 (Fed. Cir. 2014) (“Panel Opinion”). On laches,
the panel rejected SCA’s argument that the Supreme
Court’s Petrella decision abolished laches in patent law,
reasoning instead that the panel was bound by this
court’s prior en banc opinion in A.C. Aukerman Co. v. R.L.
Chaides Construction Co., 960 F.2d 1020 (Fed. Cir. 1992)
(en banc), and that Petrella left Aukerman intact. Panel
Opinion at 1345. As to the delay element, the panel
opinion held that while “SCA was not required to provide
notice of the reexamination to First Quality,” “SCA re-
mained silent for more than three years after the patent
came out of reexamination.” Id. at 1346. “Given the
circumstances, SCA should have been prepared to reas-
sert its rights against First Quality shortly after the ’646
patent emerged from reexamination.” Id. Therefore, the
panel concluded that “SCA has failed to raise a genuine
issue of material fact regarding the reasonability of its
delay.” Id.
    With respect to the prejudice element of laches, the
panel affirmed the district court’s analysis. Specifically,
the panel agreed that First Quality made a number of
significant capital expenditures in its adult incontinence
business, and that First Quality likely would have “re-
structured its activities to minimize infringement liability
if SCA had brought suit earlier.” Id. at 1347. Because
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    9



SCA did not present any contrary evidence, the panel held
that “SCA has not identified any evidence that raises a
genuine issue of material fact regarding First Quality’s
presumed economic prejudice.” Id. at 1348. And although
the district court did not explicitly weigh the equities in
determining that laches applied, the panel concluded the
error was harmless. Id. Thus, the panel affirmed the
district court’s grant of summary judgment on laches. 1
    SCA subsequently filed a petition for rehearing en
banc, asking this court to reconsider Aukerman in light of
Petrella. On December 30, 2014, this court granted SCA’s
petition and posed the following two en banc questions:
   (a) In light of the Supreme Court’s decision in
       Petrella v. Metro-Goldwyn-Mayer, 134 S. Ct.
       1962 (2014) (and considering any relevant dif-
       ferences between copyright and patent law),
       should this court’s en banc decision in A.C.
       Aukerman Co. v. R.L. Chaides Constr. Co., 960
       F.2d 1020 (Fed. Cir. 1992), be overruled so
       that the defense of laches is not applicable to
       bar a claim for damages based on patent in-
       fringement occurring within the six-year
       damages limitations period established by 35
       U.S.C. § 286?


   1     On equitable estoppel, the panel reversed the dis-
trict court’s grant of summary judgment because compet-
ing inferences could be drawn as to the meaning of SCA’s
silence regarding the ’646 patent. Panel Opinion at 1350.
The panel also held that a dispute of material fact re-
mained over whether First Quality relied on SCA’s al-
leged misleading communication because First Quality
could have relied on its own belief that the ’646 patent
was invalid or simply ignored the ’646 patent. Id. at
1350–51.
10     SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



     (b) In light of the fact that there is no statute of
         limitations for claims of patent infringement
         and in view of Supreme Court precedent,
         should the defense of laches be available un-
         der some circumstances to bar an entire in-
         fringement suit for either damages or
         injunctive relief? See, e.g., Lane & Bodley Co.
         v. Locke, 150 U.S. 193 (1893).
SCA Hygiene Prods. Aktiebolag v. First Quality Baby
Prods., LLC, No. 2013-1564, 2014 WL 7460970, at *1
(Fed. Cir. Dec. 30, 2014) (granting en banc review).
Following briefing, including numerous amicus briefs, we
held oral argument on June 19, 2015.
     We have jurisdiction under 28 U.S.C. § 1295(a)(1).
          II. VIABILITY OF LACHES AFTER PETRELLA
                              A
    SCA contends that, after the Supreme Court’s deci-
sion in Petrella, laches is no longer available as a defense
to patent infringement within the six-year damages
recovery period. We last addressed our laches law en
banc in Aukerman. There, we set out five rules regarding
the laches defense:
     1. Laches is cognizable under 35 U.S.C. § 282
        (1988) as an equitable defense to a claim for
        patent infringement.
     2. Where the defense of laches is established, the
        patentee’s claim for damages prior to suit may
        be barred.
     3. Two elements underlie the defense of laches:
        (a) the patentee’s delay in bringing suit was
        unreasonable and inexcusable, and (b) the al-
        leged infringer suffered material prejudice at-
        tributable to the delay. The district court
        should consider these factors and all of the ev-
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    11



       idence and other circumstances to determine
       whether equity should intercede to bar pre-
       filing damages.
   4. A presumption of laches arises where a pa-
      tentee delays bringing suit for more than six
      years after the date the patentee knew or
      should have known of the alleged infringer’s
      activity.
   5. A presumption has the effect of shifting the
      burden of going forward with evidence, not the
      burden of persuasion.
Aukerman, 960 F.2d at 1028.
    Four different portions of Aukerman’s reasoning are
especially relevant to this case. First, we determined in
Aukerman that laches was codified in 35 U.S.C. § 282.
Aukerman explained that, “[a]s a defense to a claim of
patent infringement, laches was well established at the
time of recodification of the patent laws in 1952.” Id. at
1029. We also credited P.J. Federico’s Commentary on the
New Patent Act for its observation that the second para-
graph of § 282 includes “equitable defenses such as lach-
es, estoppel and unclean hands.”         Id. (quoting P.J.
Federico, Commentary on the New Patent Act, 35 U.S.C.A.
1, 55 (West 1954) (hereinafter Federico Commentary)).
     Second, Aukerman addressed the argument that lach-
es conflicts with 35 U.S.C. § 286, which limits recovery of
damages to the six years prior to the complaint. We
explained that “[i]n other areas of our jurisdiction, laches
is routinely applied within the prescribed statute of
limitations period for bringing the claim.” Id. at 1030
(citing Cornetta v. United States, 851 F.2d 1372 (Fed. Cir.
1988) (en banc) (military pay); Reconstruction Finance
Corp. v. Harrisons & Crosfield Ltd., 204 F.2d 366 (2d
Cir.), cert. denied, 346 U.S. 854 (1953) (breach of con-
tract)). Moreover, we observed that § 286 (or a virtually
12    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



identical analogue) “has been in the patent statute since
1897,” and that, “[w]ithout exception, all circuits recog-
nized laches as a defense to a charge of patent infringe-
ment despite the reenactment of the damages limitation
in the 1952 statute.” Id. Aukerman also noted that
“section 286 is not a statute of limitations in the sense of
barring a suit for infringement.” Id. Rather, “the effect of
section 286 is to limit recovery to damages for infringing
acts committed within six years of the date of the filing of
the infringement action.” Id. Finally, we reasoned that
laches and a statute of limitations are not inherently
incompatible. “By section 286, Congress imposed an
arbitrary limitation on the period for which damages may
be awarded on any claim for patent infringement. Lach-
es, on the other hand, invokes the discretionary power of
the district court to limit the defendant’s liability for
infringement by reason of the equities between the par-
ticular parties.” Id. (emphasis in original).
    Third, we rejected the argument “that laches, by rea-
son of being an equitable defense, may be applied only to
monetary awards resulting from an equitable accounting,
not to legal claims for damages.” Aukerman, 960 F.2d at
1031. According to the Aukerman court, the merger of
law and equity courts allowed laches to bar legal relief.
When in 1915 Congress enacted 28 U.S.C. § 398—which
authorized parties to plead equitable defenses at law
without having to file a separate bill in equity—“laches
became available to bar legal relief, including patent
damage actions.” Id. We also found persuasive the fact
that Federal Rule of Civil Procedure 8(c) recognizes laches
as a defense in civil actions. Id.
    Fourth, Aukerman considered whether laches bars re-
covery of pre-filing damages only, or whether it precludes
the entire suit. In ruling that laches prohibits recovery of
pre-filing damages only, Aukerman relied on the Supreme
Court’s Menendez decision. Aukerman quoted the follow-
ing portion of Menendez:
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS       13



    Mere delay or acquiescence cannot defeat the
    remedy by injunction in support of the legal right,
    unless it has been continued so long[,] and under
    such circumstances[,] as to defeat the right it-
    self. . . . Acquiescence[,] to avail[,] must be such
    as to create a new right in the defendant. . . .
    So far as the act complained of is completed, ac-
    quiescence may defeat the remedy on the principle
    applicable when action is taken on the strength of
    encouragement to do it[;] but so far as the act is in
    progress[,] and lies in the future, the right to the
    intervention of equity is not generally lost by pre-
    vious delay, in respect to which the elements of an
    estoppel could rarely arise.
Aukerman, 960 F.2d at 1040 (quoting Menendez, 128 U.S.
at 523–24.) Aukerman was motivated by preserving the
distinction between laches—which bars only pre-suit
damages—and equitable estoppel—which bars the entire
suit. Id. Estoppel, which does not necessarily involve
delay in bringing suit, requires “statements or conduct of
the patentee which must ‘communicate . . . in a mislead-
ing way’ . . . that the accused infringer will not be dis-
turbed by the plaintiff patentee in the activities in which
the former is currently engaged.” Id. at 1042. Aukerman
explained that the “stated difference in the effect of laches
and estoppel has served well to emphasize that more is
required in the overall equities than simple laches if an
alleged infringer seeks to wholly bar a patentee’s claim.”
Id. at 1040. The court dismissed a rule by which laches
could bar all relief “in egregious circumstances.” Id.
    For over two decades, Aukerman governed the opera-
tion of laches in patent cases. However, last year in
Petrella the Supreme Court held that laches was not a
defense to legal relief in copyright law. Petrella calls
portions of Aukerman’s reasoning into question, necessi-
tating our present en banc reconsideration of laches.
14    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



    Petrella involved an assertion that Metro-Goldwyn-
Mayer’s (“MGM”) critically-acclaimed 1980 film Raging
Bull infringed a copyright in a 1963 screenplay authored
by Frank Petrella. Frank Petrella’s daughter, Paula
Petrella (“Petrella”), renewed the copyright in 1991, but
did not contact MGM until seven years later. Petrella,
134 S. Ct. at 1971. Over the next two years, Petrella and
MGM exchanged letters concerning Petrella’s copyright
claim. Id. Petrella then went silent, and did not file suit
until January 6, 2009, about nine years after her last
correspondence with MGM. Id. To dispose of the suit,
MGM moved for summary judgment of laches, which the
district court granted and the Ninth Circuit affirmed.
     However, the Supreme Court reversed, holding that
laches is no defense to a copyright infringement suit
brought within the Copyright Act’s statutory limitations
period. Fundamentally, the Supreme Court reasoned that
“the copyright statute of limitations, § 507(b), itself takes
account of delay,” crowding out the judiciary’s power to
decide whether a suit is timely. Id. at 1973. According to
the Court, “[l]aches . . . originally served as a guide when
no statute of limitations controlled the claim.” Id. at
1975. Historically, “laches is a defense developed by
courts of equity; its principal application was, and re-
mains, to claims of an equitable cast for which the Legis-
lature has provided no fixed time limitation.” Id. at 1973.
Laches is thus “gap-filling, not legislation-overriding.” Id.
at 1974. In this respect, separation of powers concerns
drove the result in Petrella. Petrella consequently held
that “in face of a statute of limitations enacted by Con-
gress, laches cannot be invoked to bar legal relief.” Id.
Therefore, under Petrella, “[t]o the extent that an in-
fringement suit seeks relief solely for conduct occurring
within the limitations period . . . courts are not at liberty
to jettison Congress’ judgment on the timeliness of suit.”
Id. at 1967.
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS   15



    In addition, the Petrella Court conceded that “there
has been, since 1938, only one form of action—the civil
action.” Petrella, 134 S. Ct. at 1974 (internal quotation
marks omitted). But, the Court responded, “the substan-
tive and remedial principles [applicable] prior to the
advent of the federal rules [have] not changed.” Id. (al-
terations in original) (internal quotation marks omitted).
“Both before and after the merger of law and equity in
1938, this Court has cautioned against invoking laches to
bar legal relief.” Id. at 1973.
     Petrella also addressed the extent to which laches
should affect equitable relief. The Court explained: “In
extraordinary circumstances, however, the consequences
of a delay in commencing suit may be of sufficient magni-
tude to warrant, at the very outset of the litigation, cur-
tailment of the relief equitably awardable.” Id. at 1977.
Petrella then contrasted a Sixth Circuit case involving a
copyrighted architectural design and the facts in Petrella.
In the Sixth Circuit case, Chirco v. Crosswinds Communi-
ties, Inc., 474 F.3d 227 (6th Cir. 2007), the plaintiffs
“would not be entitled to an order mandating destruction
of the housing project” embodying the copyrighted design
because “the plaintiffs knew of the defendants’ construc-
tion plans before the defendants broke ground, yet failed
to take readily available measures to stop the project; and
the requested relief would work an unjust hardship upon
the defendants and innocent third parties.” Petrella, 134
S. Ct. at 1978 (emphasis in original) (internal quotation
marks omitted). In Petrella, however, “Petrella notified
MGM of her copyright claims before MGM invested mil-
lions of dollars in creating a new edition of Raging Bull.
And the equitable relief Petrella seeks—e.g., disgorge-
ment of unjust gains and an injunction against future
infringement—would not result in total destruction of the
film, or anything close to it.” Id. (emphasis in original)
(internal quotation marks omitted). Furthermore, the
Court reasoned that “[a]llowing Petrella’s suit to go
16    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



forward will put at risk only a fraction of the income
MGM has earned during that period and will work no
unjust hardship on innocent third parties, such as con-
sumers who have purchased copies of Raging Bull. The
circumstances here may or may not (we need not decide)
warrant limiting relief at the remedial stage, but they are
not sufficiently extraordinary to justify threshold dismis-
sal.” Id. (citation omitted).
     Nonetheless, the Supreme Court continued: “Should
Petrella ultimately prevail on the merits, the District
Court, in determining appropriate injunctive relief and
assessing profits, may take account of her delay in com-
mencing suit.” Id. The Court then laid out several con-
siderations for the district court. In particular, the “court
should closely examine MGM’s alleged reliance on Pet-
rella’s delay.” Id. “This examination should take account
of MGM’s early knowledge of Petrella’s claims, the protec-
tion MGM might have achieved through pursuit of a
declaratory judgment action, the extent to which MGM’s
investment was protected by the separate-accrual rule,
the court’s authority to order injunctive relief on such
terms as it may deem reasonable, and any other consider-
ations that would justify adjusting injunctive relief or
profits.” Id. at 1978–79 (internal quotation marks and
citation omitted). In conclusion, the Court assured that,
“on the facts thus far presented,” Petrella would remain
entitled to an ongoing royalty. Id. at 1979 (“Whatever
adjustments may be in order in awarding injunctive relief,
and in accounting for MGM’s gains and profits, on the
facts thus far presented, there is no evident basis for
immunizing MGM’s present and future uses of the copy-
righted work, free from any obligation to pay royalties.”).
    Finally, the Supreme Court in Petrella recognized
that Congress could provide for a laches defense, noting,
as an example, that it had done so in the Lanham Act,
governing trademarks. Id. at 1974 n.15. The Court took
no position on whether its decision extends to the patent
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS      17



context, remarking that “based in part on § 282 and
commentary thereon, legislative history, and historical
practice, the Federal Circuit has held that laches can bar
damages incurred prior to the commencement of suit, but
not injunctive relief. We have not had occasion to review
the Federal Circuit’s position.” Id. (citation omitted).
     Still, Petrella clearly casts doubt on several aspects of
Aukerman. The following sections reexamine the availa-
bility of laches to bar recovery of damages incurred within
the six-year limitations period.
                              B
     First, we consider the character of 35 U.S.C. § 286.
Section 286 states, in relevant part: “Except as otherwise
provided by law, no recovery shall be had for any in-
fringement committed more than six years prior to the
filing of the complaint or counterclaim for infringement in
the action.” 35 U.S.C. § 286. The parties and amici
fervently debate whether § 286 is a statute of limitations
or a damages limitation. By its terms, § 286 is a damages
limitation. The statute does not preclude bringing a
claim—instead, it limits a patentee’s damages recovery to
compensation for only the last six years of infringement.
See Standard Oil Co. v. Nippon Shokubai Kagaku Kogyo
Co., 754 F.2d 345, 347–48 (Fed. Cir. 1985).
    However, this distinction is irrelevant to the resolu-
tion of this case under Petrella. As discussed above at
II.A, Petrella focuses on the fact that, in enacting a stat-
ute of limitations, Congress has spoken on the timeliness
of copyright infringement damages claims. Thus, the
question under Petrella is whether Congress has pre-
scribed a time period for recovery of damages. Section
286 is one such prescription. In § 286, Congress provided
a six-year time period for recovery of damages. Given
that laches also considers the timeliness of damages
claims, § 286—a damages-barring time provision—
invokes Petrella’s logic at least as much as, and perhaps
18       SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



more than, a statute of limitations. Petrella, 134 S. Ct. at
1973 (“[T]he copyright statute of limitations, § 507(b),
itself takes account of delay.”). Moreover, because patent
infringement is a continuous tort, there is no relevant
functional difference between a damages limitation and a
statute of limitations. We therefore see no substantive
distinction material to the Petrella analysis between § 286
and the copyright statute of limitations considered in
Petrella.
                                C
    Next, we determine that Congress codified a laches
defense in 35 U.S.C. § 282(b)(1). Section 282(b) 2 provides:
     The following shall be defenses in any action in-
     volving the validity or infringement of a patent
     and shall be pleaded:
          (1) Noninfringement, absence of liability for
              infringement or unenforceability.
          (2) Invalidity of the patent or any claim in suit
              on any ground specified in part II as a con-
              dition for patentability.
          (3) Invalidity of the patent or any claim in suit
              for failure to comply with—
              (A) any requirement of section 112, except
                  that the failure to disclose the best



     2  This version of § 282(b) incorporates amendments
by the America Invents Act that, due to later effective
dates, are inapplicable to the instant case. See Pub. L.
112–29, § 15(a), (c), 125 Stat. 284, 328; § 20(g), (j)(1), (l),
125 Stat. 284, 334–35 (2011). Those amendments, how-
ever, would not affect our decision today. For conven-
ience, therefore, we use the current version of the statute.
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    19



               mode shall not be a basis on which any
               claim of a patent may be canceled or
               held invalid or otherwise unenforcea-
               ble; or
           (B) any requirement of section 251.
       (4) Any other fact or act made a defense by
           this title.
By its plain terms, § 282 broadly sets out defenses availa-
ble in a patent infringement or validity suit. Rather than
enumerate specific defenses, subsection (1) lists categories
of defenses—“[n]oninfringement, absence of liability for
infringement or unenforceability.” Subsections (2) and (3)
follow this pattern, referring to invalidity based on “any
ground specified in part II as a condition for patentabil-
ity,” “any requirement of section 112,” and “any require-
ment of section 251.” And § 282(b) concludes with a
catch-all provision in subsection (4): “[a]ny other fact or
act made a defense by this title” is a defense within
§ 282(b).
    The House and Senate Reports on § 282 confirm that
Congress intended § 282 to have broad reach. Only one
sentence in each Report describes § 282(b), but both
endorse an expansive interpretation of the subsection.
The Senate Report explains that “[t]he five defenses
named in R. S. 4920 are omitted and replaced by a broad-
er paragraph specifying defenses in general terms.” S.
Rep. No. 82-1979 at 8–9 (1952), 1952 U.S.C.C.A.N. 2394,
2422. Likewise, the House Report clarifies that “[t]he
defenses to a suit for infringement are stated in general
terms, changing the language in the present statute, but
20       SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



not materially changing the substance.” 3 H.R. Rep. No.
82-1923, at 10 (1952).
    Contemporary commentary by “P. J. Federico, a prin-
cipal draftsman of the 1952 recodification,” Diamond v.
Chakrabarty, 447 U.S. 303, 321 (1980), reveals that the
“broader” and “general” § 282 codified the laches defense.
Federico’s Commentary on the New Patent Act, which
appears as a prologue to Title 35 in West’s initial publica-
tion of the statute, states:
     The defenses which may be raised in an action in-
     volving the validity or infringement of a patent
     are specified in general terms, by the second par-
     agraph of section 282, in five numbered items.
     Item 1 specifies “Noninfringement, absence of lia-
     bility for infringement, or unenforceability” (the
     last word was added by amendment in the Senate
     for greater clarity); this would include the defens-
     es such as that the patented invention has not
     been made, used or sold by the defendant; license;
     and equitable defenses such as laches, estoppel
     and unclean hands.”
Federico Commentary (emphases added).
    The dissent criticizes our reliance on Federico, Dis-
sent at 9–10, but the Supreme Court has trusted Federico
as an authority on the Patent Act at least thrice. See


     3  The dissent asserts that the words “not materially
changing the substance” indicate that § 282 is no broader
than R. S. 4920. Dissent at 8. But by the statutes’ plain
terms that contention is wrong. R. S. 4920 enumerated
five specific defenses. Even putting aside § 282(b)(1) and
the catch-all provision in §282(b)(4), § 282(b)(2) and (b)(3)
clearly broaden the statutory defenses available to ac-
cused infringers.
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    21



Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520
U.S. 17, 28 (1997) (citing 2 D. Chisum, Patents § 8.04[2],
pp. 63–64 (1996) (discussing Federico Commentary));
Diamond, 447 U.S. at 321 (citing Hearings on H.R. 3760
before Subcommittee No. 3 of the House Committee on the
Judiciary, 82d Cong., 1st Sess., 37 (1951) (statement of P.
J. Federico)); Aro Mfg. Co. v. Convertible Top Replacement
Co., 365 U.S. 336, 342 n.8 (1961) (citing Federico Com-
mentary). Moreover, we and our predecessors have relied
on the Federico Commentary countless times as “an
invaluable insight into the intentions of the drafters of
the Act.” Symbol Techs., Inc. v. Lemelson Med., 277 F.3d
1361, 1366 (Fed. Cir. 2002); see, e.g., Antares Pharma, Inc.
v. Medac Pharma Inc., 771 F.3d 1354, 1360 (Fed. Cir.
2014); Slip Track Sys., Inc. v. Metal-Lite, Inc., 304 F.3d
1256, 1264 n.2 (Fed. Cir. 2002); BIC Leisure Prods., Inc. v.
Windsurfing Int’l, Inc., 1 F.3d 1214, 1220 (Fed. Cir. 1993);
Albert v. Kevex Corp., 729 F.2d 757, 761 (Fed. Cir. 1984);
Application of Hogan, 559 F.2d 595, 603 (C.C.P.A. 1977);
Application of Harry, 333 F.2d 920, 924 n.2 (C.C.P.A.
1964). In addition, Judge Rich, who was deeply involved
in crafting the Patent Act, described Federico in a concur-
ring opinion as “[t]he key person” in drafting the Patent
Act. Paulik v. Rizkalla, 760 F.2d 1270, 1277 (Fed. Cir.
1985) (Rich, J., concurring). According to Judge Rich,
Federico “not only wrote the first draft of the Act himself
and actively participated for the next two years in every
detail of its revisions but, having been made a special
consultant to the House subcommittee in charge of the
project, he was also a principal author of House Report
No. 1923 on the bill, which was virtually copied by the
Senate Judiciary Committee as its report No. 1979, and
the author of the section-by-section Revisors Notes.” Id.
Judge Rich also reveals that the Federico Commentary
was solicited by the West Publishing Company for publi-
cation with the new Title 35:
22     SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



     After enactment of the law, West Publishing
     Company asked Federico to write a commentary
     on it for publication in U.S.C.A., which he did, and
     it was published in 1954 in the first of the vol-
     umes containing the new Title 35. Federico also
     submitted drafts of the commentary to Ashton
     and the Drafting Committee for suggestions . . . .
Id. (footnote omitted). We therefore consider the Federico
Commentary to be a sufficiently reliable source on the
meaning of § 282.
     To summarize, § 282 uses inclusive language, the leg-
islative history characterizes § 282 as “broader” and
“general,” and the Federico Commentary explicitly states
that § 282 includes laches. The dissent does not point to
anything that contradicts our understanding of § 282.
Accordingly, we conclude that Congress codified a laches
defense in § 282.
     Notably, our construction of § 282 to include laches is
neither novel, nor a direct response to Petrella. Rather,
for decades we have held that laches was codified in § 282,
including once sitting en banc in Aukerman. See Auker-
man, 960 F.2d at 1029; Symbol, 277 F.3d at 1366; Mylan
Pharm., Inc. v. Thompson, 268 F.3d 1323, 1331 (Fed. Cir.
2001); J.P. Stevens & Co. v. Lex Tex Ltd., 747 F.2d 1553,
1561 (Fed. Cir. 1984). Nothing in Petrella casts doubt on
our longstanding construction of the Patent Act.
                              D
    Having determined that Congress codified a laches
defense in § 282, we now reach the critical question: does
laches as codified in the 1952 Patent Act bar recovery of
legal relief? If laches as codified in § 282 is a defense
against only equitable relief, Petrella prohibits judicial
application of laches to bar legal damages. If, however,
laches as codified operates as a defense to both legal and
equitable relief, patent law’s statutory scheme—like the
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    23



Lanham Act, see Petrella, 134 S. Ct. at 1974 n.15—does
not implicate Petrella. In that case, § 282 obligates us to
apply laches as a defense to legal relief, notwithstanding
§ 286’s time limitation on the recovery of damages.
     Turning to the content of the laches defense in § 282,
the text of § 282 provides little guidance. Because § 282
does not enumerate specific defenses, the statutory text
says nothing on the applicability of laches to legal relief.
Similarly, the legislative history is silent on the meaning
of laches, and Federico does no more than mention laches’
codification in § 282.
    In these circumstances, the Supreme Court counsels
that “[w]hen a statute covers an issue previously governed
by the common law, we must presume that Congress
intended to retain the substance of the common law.”
Kirtsaeng v. John Wiley & Sons, Inc., 133 S. Ct. 1351,
1363 (2013) (internal quotation marks omitted). 4 This


   4    While the doctrine of laches in the patent context
is not strictly a matter of common law, as the patent law
is statutory, the Supreme Court has treated uniform
interpretations of statutes involving judicially created
doctrines as invoking common law adoption principles. In
United States v. Texas, 507 U.S. 529, 533 (1993), the
Supreme Court considered whether the statutory scheme
there implicitly allowed for the federal government to
recover prejudgment interest for money owed by state
governments. The statute itself was silent on the issue,
only expressly requiring individuals to pay prejudgment
interest. The Court determined that there was a common
law tradition of the federal government being able to
recover prejudgment interest for money owed it by the
states, and therefore that the statute implicitly allowed
for the federal government to recover prejudgment inter-
est against the states. Indeed, the Court rejected an
24    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



presumption applies where “Congress has failed expressly
or impliedly to evince any intention on the issue.” Astoria
Fed. Sav. & Loan Ass’n v. Solimino, 501 U.S. 104, 110
(1991); see also Isbrandtsen Co. v. Johnson, 343 U.S. 779,
783 (1952) (“Statutes which invade the common law . . .
are to be read with a presumption favoring the retention
of long-established and familiar principles, except when a
statutory purpose to the contrary is evident.”). “In order
to abrogate a common-law principle, the statute must
speak directly to the question addressed by the common
law.” United States v. Texas, 507 U.S. 529, 534 (1993)
(internal quotation marks omitted).
     This canon of construction is especially applicable
here. Congress’s purpose in enacting the Patent Act was
to codify the prevailing law wholesale, except where
changes were expressly noted. The House Report reveals
that, while a preliminary draft of the Patent Act “included
a collection of a large number of proposed changes in the
law,” “[a]s a result of the comments received, it was
decided not to include most of the proposed changes in a
bill but to defer them for later consideration, and to limit
the bill to the main purpose of codification and enactment
of title 35 into law, with only some minor procedural and
other changes deemed substantially noncontroversial and
desirable.” H.R. Rep. No. 82-1923, at 3. Consequently,
“the principal purpose of the bill [was] the codification of
title 35 . . . .” Id. at 5; S. Rep. No. 82-1979 at 4, 1952



argument that the presumption favoring the common law
only applies “with respect to state common law or federal
maritime law.” Id. at 534. See also Singer, Norman &
Singer, J.D., 2B Statutes and Statutory Construction
§ 50:1 (7th ed. 2007) (“All legislation is interpreted in
light of the common law and the scheme of jurisprudence
existing at the time of its enactment.”).
SCA HYGIENE PRODUCTS    v. FIRST QUALITY BABY PRODUCTS      25



U.S.C.C.A.N. at 2397. While “there [were] a number of
changes in substantive statutory law,” “these [were]
explained in some detail in the revision notes,” and “[t]he
major changes or innovations in the title consist of incor-
porating a requirement for invention in § 103 and the
judicial doctrine of contributory infringement in § 271.”
H.R. Rep. No. 82-1923, at 5; S. Rep. No. 82-1979 at 4,
1952 U.S.C.C.A.N. at 2397. No changes to laches doctrine
were mentioned in the revision notes. Finally, “just
before the bill was passed in the Senate, Senator Salton-
stall asked on the floor, ‘Does the bill change the law in
any way or only codify the present patent laws?’ Senator
McCarran, Chairman of the Judiciary Committee which
had been in charge of the bill for the Senate, replied, ‘It
codifies the present patent laws.’” Aro Mfg. Co. v. Con-
vertible Top Replacement Co., 365 U.S. 336, 350 n.2 (1961)
(Black, J., concurring) (quoting 98 Cong. Rec. 9323 (July
4, 1952)); see also Dawson Chem. Co. v. Rohm & Haas Co.,
448 U.S. 176, 203 (1980) (quoting the same). Therefore, if
anything, Congress intended to adopt the laches patent
common law when it included laches in § 282.
    As outlined above, Congress remained silent on the
content of the laches defense. 5 Section 282 therefore
retains the substance of the common law as it existed at
the time Congress enacted the Patent Act. See Astoria,
501 U.S. at 109 (“[L]egislative repeals by implication will
not be recognized . . . .”). See generally Symbol, 277 F.3d
at 1366 (“There is nothing in the legislative history to
suggest that Congress did not intend to carry forward the
defense of prosecution laches . . . .”); Transco Prods. Inc. v.



    5   If we can infer anything from what Congress said,
it is that Congress intended to “not materially chang[e]
the substance” of the § 282 defenses. H.R. Rep. No. 82-
1923, at 10.
26    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



Performance Contracting, Inc., 38 F.3d 551, 557 (Fed. Cir.
1994) (“The legislative history of section 120 does not
indicate any congressional intent to alter the Supreme
Court’s interpretation of continuing application prac-
tice.”). Accordingly, we must review the case law prior to
1952 to determine whether courts applied laches to bar
legal relief.
    Some initial background information is necessary to
place the case law in context. Traditionally, patentees
could seek an injunction and an accounting of profits—
both equitable remedies—by filing a bill in equity courts.
Alternatively, patentees could seek compensatory damag-
es by filing an action at law. In 1870, however, Congress
gave equity courts the authority to award legal damages
in patent cases. Patent Act of 1870, ch. 230, § 55, 16 Stat.
198, 206 (1870). Forty-five years later, in 1915, Congress
passed a general statute (§ 274b) providing that “in all
actions at law equitable defenses may be interposed by
answer, plea, or replication without the necessity of filing
a bill on the equity side of the court.” Act of March 3,
1915, ch. 90, § 274b, 38 Stat. 956 (1915). Prior to this
statute, parties wishing to raise equitable defenses in an
action at law had to file a separate bill in equity seeking
to enjoin the legal action. See, e.g., Kessler v. Eldred, 206
U.S. 285 (1907). Section 274b did not change substantive
law. See Enelow v. N.Y. Life Ins. Co., 293 U.S. 379, 382
(1935), overruled on other grounds by Gulfstream Aero-
space Corp. v. Mayacamas Corp., 485 U.S. 271 (1988).
Rather, “[t]he net effect of [§§ 274a and 274b] was to allow
transfer of action begun on either side of the court to the
other side, without the necessity of commencing a new
action, to permit determination of law questions arising in
equity actions in those actions, and to allow equitable
defenses to be offered and equitable relief to be granted in
an action at law.” City of Morgantown v. Royal Ins. Co.,
337 U.S. 254, 256–57 (1949). Beginning in 1915, then,
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS     27



accused infringers were not procedurally foreclosed from
pleading a laches defense in an action at law.
    The merger of law and equity was completed with the
advent of the Federal Rules of Civil Procedure in 1938.
“[T]here has been, since 1938, only ‘one form of action—
the civil action.’” 6 Petrella, 134 S. Ct. at 1974 (quoting
Fed. R. Civ. P. 2). Prior to 1938, where the requirements
for equitable jurisdiction were satisfied, patentees often
alleged patent infringement in a bill in equity, as equita-
ble courts could provide the powerful remedies of an
accounting of profits and an injunction, which were una-
vailable in actions at law, in addition to compensatory
damages. After the Federal Rules of Civil Procedure were
implemented, patentees no longer needed to choose.
     Finally, in the Patent Act of 1946, Congress eliminat-
ed accounting of profits as a remedy for patent infringe-
ment (except for design patents). See Act of Aug. 1, 1946,
Pub. L. No. 79-587, 60 Stat. 778; see also Kori Corp. v.
Wilco Marsh Buggies & Draglines, Inc., 761 F.2d 649, 654
(Fed. Cir. 1985) (“The 1946 amendment to the damages
provisions effectively eliminated this double recovery.”).
“After the 1946 amendment . . . R.S. 4921 provided that
‘the complainant shall be entitled to recover general
damages which shall be due compensation for making,
using, or selling the invention, not less than a reasonable
royalty therefor . . . .’” Kori, 761 F.2d at 654 (quoting Act
of Aug. 1, 1946, Pub. L. No. 79-587, 60 Stat. 778). The
prior availability of an equitable accounting of profits in
patent infringement cases is relevant because, in cases
litigated between 1870 and 1946, the patentee often
sought both compensatory damages and an accounting of


    6   The christening of the Federal Rules of Civil Pro-
cedure did not alter any substantive law. Petrella, 134 S.
Ct. at 1974.
28       SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



profits. Id. Moreover, “[f]ollowing the 1870 Patent Act,
courts regularly used the terms ‘account’ and ‘accounting’
to refer to the special master’s determination of both an
adjudged infringer’s profits and a patentee’s damages.”
Robert Bosch, LLC v. Pylon Mfg. Corp., 719 F.3d 1305,
1310 (Fed. Cir. 2013). For this reason, it is in many cases
difficult to determine whether a court applied laches to
bar purely equitable relief, or whether, in using the term
“accounting,” a court also prohibited legal relief. That
said, equity courts’ grouping of legal and equitable relief
under a single name—accounting—could explain a unique
willingness in patent law to apply laches to bar a tradi-
tionally legal remedy.
    With all of the foregoing in mind, we now turn to the
pre-1952 case law on laches. Upon review, the case law
demonstrates that, by 1952, courts consistently applied
laches to preclude recovery of legal damages. Nearly
every circuit recognized that laches could be a defense to
legal relief prior to 1952. See, e.g., Banker v. Ford Motor
Co., 69 F.2d 665 (3d Cir. 1934); Hartford-Empire Co. v.
Swindell Bros., 96 F.2d 227 (4th Cir. 1938); Ford v. Huff,
296 F. 652 (5th Cir. 1924); France Mfg. Co. v. Jefferson
Elec. Co., 106 F.2d 605 (6th Cir. 1939); Brennan v. Hawley
Prods. Co., 182 F.2d 945 (7th Cir. 1950); Middleton v.
Wiley, 195 F.2d 844 (8th Cir. 1952). 7 In fact, the only two
pre-1952 circuit courts that considered SCA’s argument—
that laches operates as a defense to equitable relief only—
expressly held that laches can also bar legal remedies.
See Ford, 296 F. at 658; Banker, 69 F.2d at 666.




     7  Significantly, the cases cited as examples here do
not include the numerous cases that apply laches to bar
an “accounting.” Because of the term’s inherent ambigui-
ty (described above in text), we do not rely on such cases.
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    29



    The Ford case was both early and influential. In
Ford, the patentee, Huff, was employed by defendant
Henry Ford as an electrical and mechanical engineer.
Ford, 296 F. at 654. Huff and Ford agreed that Huff
would invent a magneto for an automobile flywheel and
assign the patent rights to Ford, and Ford would pay a
reasonable royalty for the invention’s use. Id. Huff
subsequently invented the magneto and assigned the
patent rights to Ford. Id. While Ford paid Huff $10,000
in installments upon Ford manufacturing the first 20,000
magnetos, Ford made no further royalty payments. Id.
     Huff did not bring suit against Ford until fourteen
years after the invention, ten years after he left the Ford
Motor Company, and eight years after the patents issued.
Id. at 655. The court found that Ford had established
both laches and equitable estoppel—laches from the
delay, and equitable estoppel from Huff’s acceptance of
Ford’s $10,000 payment. Id. at 657. The court then
considered whether the laches and equitable estoppel
defenses could be brought in a suit at law. Citing § 274b
and Liberty Oil Co. v. Condon National Bank, 260 U.S.
235 (1922), the Fifth Circuit stated that “a defendant in
an action at law who files a plea setting up an equitable
defense is given the same rights as if he had set them up
in a bill in equity.” Id. at 658. The court reasoned that “a
bill in equity disclosing the state of facts alleged in the
plea in question would show that defendant was entitled
to prevent the enforcement of the claim asserted by this
suit on the ground that plaintiff’s conduct had been such
as to deprive him of the right to enforce that claim.” Id.
Therefore, because the laches and equitable estoppel
defenses could be pleaded in a bill in equity to enjoin the
patentee’s suit at law for patent infringement, § 274b
30       SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



allowed the defenses to be pleaded directly in the legal
suit. 8
    The only other case to expressly consider the argu-
ment that laches cannot preclude legal relief is Banker.
In Banker, which involved only laches and not equitable
estoppel, the Third Circuit employed similar methodology
to Ford. Specifically, Banker held that “[h]ad the appel-
lant’s suit been in equity, the evidence would have been
ample for holding that recovery was barred because of
laches.” Banker, 69 F.2d at 666. Nevertheless, “[t]he
appellant admit[ted] the authority of the cited cases if
applied in equity, but contend[ed] that they [were] inap-
plicable to actions at law.” Id. The court quickly dis-
pensed with that contention, however. Relying on Ford,
Banker concluded that § 274b “authorizes equitable
defenses in actions at law theretofore applicable only in
equity.” Id.
    A plethora of other cases assumes laches to preclude
legal relief without discussion. See, e.g., Hartford-Empire
Co. v. Swindell Bros., 96 F.2d 227 (4th Cir. 1938); France
Mfg. Co. v. Jefferson Elec. Co., 106 F.2d 605 (6th Cir.
1939); Brennan v. Hawley Prods. Co., 182 F.2d 945 (7th
Cir. 1950); Universal Coin Lock Co. v. Am. Sanitary Lock


     8  Subsequently, the Supreme Court in Enelow—
which held that § 274b changed no substantive law—cited
Ford in the context of an injunction staying a legal action
pending resolution of an equitable defense. Enelow, 293
U.S. at 383. Although unclear, Enelow arguably approved
of Ford’s § 274b methodology. Id. (explaining that, under
§ 274b, “the court, exercising what is essentially an equi-
table jurisdiction, in effect grants or refuses an injunction
restraining proceedings at law precisely as if the court
had acted upon a bill of complaint in a separate suit for
the same purpose”).
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    31



Co., 104 F.2d 781 (7th Cir. 1939); George J. Meyer Mfg.
Co. v. Miller Mfg. Co., 24 F.2d 505 (7th Cir. 1928); Wolf,
Sayer & Heller v. U.S. Slicing Mach. Co., 261 F. 195 (7th
Cir. 1919); Middleton v. Wiley, 195 F.2d 844 (8th Cir.
1952). 9 In addition, the Supreme Court in Lane & Bodley
Co. v. Locke mentions monetary compensation, but does
not state whether the recovery was legal or equitable in
nature. 150 U.S. 193, 194 (1893) (“[T]he circuit court
found in favor of the complainant, and, after reference to
and report by a master, rendered a final decree against
the defendant for the sum of $3,667.37, with interest and
costs.”). Countless other cases refer to an accounting, and
thus remain ambiguous as to whether they barred legal
relief. See, e.g., Union Shipbuilding Co. v. Bos. Iron &
Metal Co., 93 F.2d 781 (4th Cir. 1938); Gillons v. Shell Co.
of Cal., 86 F.2d 600 (9th Cir. 1936); Window Glass Mach.
Co. v. Pittsburgh Plate Glass Co., 284 F. 645, 647 (3d Cir.
1922); A.R. Mosler & Co. v. Lurie, 209 F. 364 (2d Cir.
1913). Significantly, neither SCA, nor the amici, nor the
dissent, can identify a single appellate-level patent in-
fringement case stating—much less holding—that laches
is inapplicable to legal damages.




   9    SCA and some amici contend that the Middleton
case holds that laches cannot preclude legal relief. But
Middleton merely states that the elements of laches were
not proven in that case. As Middleton reasoned, delay,
without prejudice, is insufficient. Middleton, 195 F.2d at
847. Moreover, the Middleton court ruled that application
of laches would have been inequitable because the ac-
cused infringers “knowingly and deliberately were using
for their own benefit the owner’s patented equipment
without authority, legal excuse or payment of royalty.”
Id.
32    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



     Finally, the Walker patent treatise supports the con-
clusion that laches can preclude legal remedies. The 1937
version of the Walker treatise was published before many
of the cases discussed above. 4 Walker, on Patents (Del-
ler’s ed. 1937). Nonetheless, although it does not list
laches among the defenses in actions at law, see id.
§§ 656, 687–88, Walker elsewhere explains that “[w]here
a plaintiff is chargeable with laches, he cannot recover the
damages he has suffered nor the profits defendant has
gained.” Id. § 880B (citing George Meyer, 24 F.2d 505).
Moreover, Walker’s 1951 Supplement states that “[l]aches
and estoppel are equitable defenses, and may be inter-
posed in an action at law.” 4 Walker, on Patents at 106
(Supp. 1951) (addressing § 575) (citing Mather v. Ford
Motor Co., 40 F. Supp. 589 (E.D. Mich. 1941)).
     In sum, the case law strongly supports the availabil-
ity of laches to bar legal relief. Section 282 codified what-
ever laches doctrine existed when Congress enacted the
Patent Act in 1952. Although the development occurred
over time, by 1952 nearly every circuit had approved of
the proposition that laches could bar legal relief for patent
infringement, and no court had held to the contrary. The
Walker treatise—in 1937 and then more authoritatively
in 1951—agreed that laches precludes recovery of legal
damages. The laches doctrine codified in § 282 must have
meaning, and, absent any direction from Congress, it
takes on its common law meaning. Following a review of
the relevant common law, that meaning is clear: in 1952,
laches operated as a defense to legal relief. Therefore, in
§ 282, Congress codified a laches defense that barred
recovery of legal remedies.
    The dissent suggests that this significant court of ap-
peals authority allowing a laches defense to patent dam-
ages actions should not be deemed incorporated into the
1952 Act because “[a]ny analysis of what the common law
was at a certain point in time must start with Supreme
Court precedent” which established a “general principle”
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS   33



that laches does not bar a claim for legal relief. Dissent
at 10, 12. The dissent also suggests that circuit authority
allowing the laches defense in equity actions is not perti-
nent to congressional intent. Id. at 13. The dissent is
incorrect on both counts. In contrast to other areas, in
patent law before 1952 there was no sharp distinction
between legal and equitable actions for damages or in the
defenses that were available.        See supra pp. 23–
25. Patent damages actions were unlike typical damages
actions in that the 1870 statute allowed the recovery of
damages in either an action at law or in equity, see 16
Stat. 206 (1870), and the 1897 statute of limitations
applied to both legal and equitable actions, see 29 Stat.
694 (1897), as did the laches defense. Furthermore, the
Chairman of the Judiciary Committee clarified on the
Senate floor just before the Patent Act was passed that
the 1952 Act “codifie[d] the present patent laws.’” 98
Cong. Rec. 9323 (emphasis added); see also supra pp. 21–
22. If Congress looked to the common law, it likely looked
to the common law of patents10 rather than to more
general principles.



   10    The two patent cases cited by the dissent—both
trial court cases from a single jurisdiction—are unhelpful.
In the first, City of Concord v. Norton, 16 F. 477 (C.C.D.
Mass. 1883), after noting that the equitable defense of
estoppel was available at law and at equity, the court
found that equitable estoppel was not established. Id. at
479. The court then stated that if laches had been al-
leged, it would not have been available because “for laches
the remedy at law is found in the statute of limita-
tions.” Id. at 480. It is difficult to know what was meant
by this dictum because at this time no statute of limita-
tions existed in patent law. The second, Thorpe v. Wm.
Filene’s Sons Co., 40 F.2d 269, 270 (D. Mass. 1930), simp-
34    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



                             E
     The fact that § 286 speaks to the timeliness of dam-
ages claims does not alter the outcome. Petrella funda-
mentally concerns separation of powers. That is, Petrella
eliminates copyright’s judicially-created laches defense
because Congress, through a statute of limitations, has
already spoken on the timeliness of copyright infringe-
ment claims, so there is no room for a judicially-created
timeliness doctrine. See Petrella, 134 S. Ct. at 1974
(describing laches as “gap-filling, not legislation-
overriding”). The statutory scheme in patent law, howev-
er, is different. While Congress has spoken on the timeli-
ness of patent damages claims, Congress also codified a
laches defense in § 282. Thus, because § 286 provides for
a time limitation on the recovery of legal remedies, and
§ 282 provides for laches as a defense to legal relief, the
separation of powers concern is not present. See id. at
1974 n.15 (noting that laches is preserved in trademark
law because the Lanham Act “expressly provides for
defensive use of ‘equitable principles, including laches’”).
Laches therefore remains a viable defense to legal relief
in patent law.
    Despite whatever tension may exist between the
§ 286 damages limitation and the § 282 laches defense,
“we have no authority to substitute our views for those
expressed by Congress in a duly enacted statute.” Mobil
Oil Corp. v. Higginbotham, 436 U.S. 618, 626 (1978). If,
in light of this issue’s newfound salience, Congress de-


ly did not address whether patent law was different from
other areas. Moreover, because a plethora of court of
appeals-level case law concludes that laches may bar legal
relief, we need not list the many district court cases, such
as Mather, 40 F. Supp. at 591–92, that accord with our
reasoning.
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS      35



cides that the § 286 damages limitation and the § 282
laches defense are incompatible, it can change the law.
As a court, however, we must apply the law as enacted,
which means that the § 286 damages limitation and the
§ 282 laches defense must continue to coexist.
                              F
     Finally, one major difference between copyright and
patent law bears mention: copyright infringement re-
quires evidence of copying, but innocence is no defense to
patent infringement. Compare N. Coast Indus. v. Jason
Maxwell, Inc., 972 F.2d 1031, 1033 (9th Cir. 1992) (“If the
plaintiff copyright holder survives the first step, i.e., it
establishes that it owns a valid copyright, then the plain-
tiff must establish infringement by showing both access to
its copyrighted material on the part of the alleged infring-
er and substantial similarity between the copyrighted
work and the alleged infringing work.”), and Eden Toys,
Inc. v. Marshall Field & Co., 675 F.2d 498, 501 (2d Cir.
1982) (“Evidence of independent creation may be intro-
duced by a defendant to rebut a plaintiff’s prima facie
case of infringement.”), with Commil USA, LLC v. Cisco
Sys., Inc., 135 S. Ct. 1920, 1926 (2015) (“Direct infringe-
ment is a strict-liability offense.”). Because copyright
infringement requires proof of access, a potential defend-
ant is typically aware of a risk that it is infringing and
can estimate its exposure when making its initial invest-
ment decision. See Dell Br. 26–27; Roche Br. 19–21. The
potential defendant can also accumulate evidence of
independent creation to protect its investment. Thus, in
Petrella—as in a typical copyright suit—“[a]llowing Pet-
rella’s suit to go forward will put at risk only a fraction of
the income MGM has earned during that period and will
work no unjust hardship on innocent third parties . . . .”
Petrella, 134 S. Ct. at 1978.
   In patent law, however, the calculus is different. For
example, in the medical device industry, a company may
36        SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



independently develop an invention and spend enormous
sums of money to usher the resultant product through
regulatory approval and marketing, only to have a pa-
tentee emerge six years later to seek the most profitable
six years of revenues. See Roche Br. 19–23; IPO Br. 19.
In the high tech industry, amici advise that businesses
receive demand letters every day—many of which assert
unmeritorious claims—and it is often impractical for
companies to determine which claims have merit. See
Dell Br. 23–27. Independent invention is no defense in
patent law, so without laches, innovators have no safe-
guard against tardy claims demanding a portion of their
commercial success. Consequently, “there is a recurring
risk that a stale patent claim will inflict significant hard-
ship on a defendant who has lost the meaningful ability to
choose between alternative technologies and whose in-
vestment in research, development, and further innova-
tion may be jeopardized.” Dell Br. 27. This risk likely
explains why the amici in this case—encompassing indus-
tries as diverse as biotechnology, electronics, manufactur-
ing, pharmaceuticals, software, agriculture, apparel,
health     care,   telecommunications,      and     finance—
overwhelmingly support retaining laches in patent law. 11



     11  See, e.g., Brief of Amicus Curiae Roche Molecular
Systems, Inc. in Support of Defendants-Appellees; Brief of
Dell Inc. et al. as Amicus Curiae in Support of Defend-
ants-Appellees; Brief of Intellectual Property Owners
Ass’n as Amicus Curiae in Support of Defendants-
Appellees; Corrected Brief of Amici Curiae Briggs &
Stanton Corp., Harley-Davidson Motor Co., Inc., Jockey
Int’l, Inc., Rockwell Automation, Inc. and Wisconsin Mfrs.
& Commerce in Support of Defendants-Appellees; Brief of
Amicus Curiae Hydro Engineering, Inc. on Rehearing En
Banc in Support of Defendants-Appellees; Brief of Amici
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    37



      III. LACHES’ APPLICATION TO ONGOING RELIEF
     The second question for en banc review concerns the
extent to which laches can limit recovery of ongoing relief.
Aukerman held that laches could not bar prospective
relief. Aukerman, 960 F.2d at 1041. Reexamination of
that rule is necessary in light of Petrella and the Supreme
Court’s decision in eBay Inc. v. MercExchange, L.L.C., 547
U.S. 388 (2006). There are two parts to this inquiry:
whether laches can bar permanent injunctive relief and
whether it can bar an ongoing royalty for continuing
infringing acts.
    When a court orders ongoing relief, the court acts
within its equitable discretion. See eBay, 547 U.S. at
391–92; Paice LLC v. Toyota Motor Corp., 504 F.3d 1293,
1316 (Fed. Cir. 2007). As eBay instructs, equitable “dis-
cretion must be exercised consistent with traditional
principles of equity, in patent disputes no less than in
other cases governed by such standards.” eBay, 547 U.S.
at 394. With respect to injunctions, this means following
eBay’s familiar four-factor test:
   A plaintiff must demonstrate: (1) that it has suf-
   fered an irreparable injury; (2) that remedies
   available at law, such as monetary damages, are
   inadequate to compensate for that injury; (3) that,
   considering the balance of hardships between the
   plaintiff and defendant, a remedy in equity is




Curiae AT&T Mobility II LLC and T-Mobile USA, Inc. in
Support of Defendants-Appellees; Brief of Amici Curiae
Johnson & Johnson and Cordis Corp. in Support of De-
fendants-Appellees; Brief of Amici Curiae Garmin Int’l,
Inc. et al. on Rehearing En Banc Supporting Defendants-
Appellees.
38    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



     warranted; and (4) that the public interest would
     not be disserved by a permanent injunction.
Id. at 391.
     Consideration of laches fits naturally into this frame-
work. As noted in Petrella, “the District Court, in deter-
mining appropriate injunctive relief . . . may take account
of [the plaintiff’s] delay in commencing suit.” Petrella,
134 S. Ct. at 1978; see also Menendez, 128 U.S. at 523
(“Mere delay or acquiescence cannot defeat the remedy by
injunction in support of the legal right, unless it has been
continued so long, and under such circumstances, as to
defeat the right itself.”). Many of the facts relevant to
laches, such as the accused infringer’s reliance on the
patentee’s delay, fall under the balance of the hardships
factor. Id. Unreasonable delay in bringing suit may also
be relevant to a patentee’s claim that continued infringe-
ment will cause it irreparable injury. More than any-
thing, district courts should consider all material facts,
including those giving rise to laches, in exercising its
discretion under eBay to grant or deny an injunction. See
eBay, 547 U.S. at 394.
    The Aukerman court, relying on Menendez, based its
conclusion that laches may only bar pre-suit damages on
the necessity of maintaining a distinction between laches
and equitable estoppel. Aukerman, 960 F.2d at 1040–41.
But Menendez does not create a bright-line rule favoring
injunctions. In fact, Menendez repeatedly allows for the
possibility that laches could foreclose injunctive relief.
For example, an injunction may be inequitable when the
delay “has been continued so long, and under such cir-
cumstances, as to defeat the right itself.” Menendez, 128
U.S. at 523; see also id. at 524 (“[S]o far as the act is in
progress, and lies in the future, the right to the interven-
tion of equity is not generally lost by previous delay, in
respect to which the elements of an estoppel could rarely
arise.”) (emphasis added); id. at 524–25 (“Delay in bring-
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS      39



ing suit there was, and such delay as to preclude recovery
of damages for prior infringement; but there was neither
conduct nor negligence which could be held to destroy the
right to prevention of further injury.”) (emphasis added). 12
Likewise, eBay clarifies that a patentee is not automati-
cally entitled to an injunction—the patentee must prove
that the equities favor an injunction. eBay, 547 U.S. at
392 (“[I]njunctive relief may issue only in accordance with
the principles of equity.”) (internal quotation marks
omitted). Laches, an equitable defense, belongs in that
calculus. We, accordingly, reject Aukerman’s bright line
rule regarding the interplay between laches and injunc-
tive relief.
    With respect to ongoing royalties, while the principles
of equity apply, equity normally dictates that courts
award ongoing royalties, despite laches. Menendez, an
influential case contrasting laches and equitable estoppel
in the trademark context, guides us here. According to
Menendez, delay in exercising a patent right, without
more, does not mean that the patentee has abandoned its
right to its invention. Rather, the patentee has aban-
doned its right to collect damages during the delay.
Equitable estoppel, on the other hand, is different—the
patentee has granted a license to use the invention that
extends throughout the life of the patent:
    Acquiescence, to avail, must be such as to create a
    new right in the defendant. . . . But there is noth-
    ing here in the nature of an estoppel; nothing
    which renders it inequitable to arrest at this stage


    12  While these passages contemplate that estoppel
will be the primary situation where delay can bar an
injunction, they also allow for the possibility that the facts
surrounding delay can be so extreme—without establish-
ing estoppel—as to preclude an injunction.
40    SCA HYGIENE PRODUCTS     v. FIRST QUALITY BABY PRODUCTS



     any further invasion of complainants’ rights.
     There is no pretense of abandonment. That would
     require proof of non-user by the owner, or general
     surrender of the use to the public. . . . Delay in
     bringing suit there was, and such delay as to pre-
     clude recovery of damages for prior infringement;
     but there was neither conduct nor negligence
     which could be held to destroy the right to preven-
     tion of further injury.
Menendez, 128 U.S. at 524–25.
    Petrella also briefly considered the propriety of ongo-
ing royalties. Although Petrella did not supply its reason-
ing, it found that, “on the facts thus far presented, there
[was] no evident basis for immunizing MGM’s present and
future uses of the copyrighted work, free from any obliga-
tion to pay royalties.” Petrella, 134 S. Ct. at 1979. As did
Aukerman, moreover, Menendez and Petrella caution
against erasing the distinction between laches and estop-
pel. As Petrella stated, “the doctrine of estoppel may bar
the copyright owner’s claims completely, eliminating all
potential remedies. The test for estoppel is more exacting
than the test for laches, and the two defenses are differ-
ently oriented. The gravamen of estoppel . . . is mislead-
ing and consequent loss. Delay may be involved, but is
not an element of the defense. For laches, timeliness is
the essential element.” Petrella, 134 S. Ct. at 1977 (cita-
tions omitted). For that reason, absent egregious circum-
stances, when injunctive relief is inappropriate, the
patentee remains entitled to an ongoing royalty.
    In sum, we must recognize “the distinction be-
tween . . . estoppel and laches . . . .” Id. (first alteration in
original). Whereas estoppel bars the entire suit, laches
does not. As outlined above, laches in combination with
the eBay factors may in some circumstances counsel
against an injunction. However, a patentee guilty of
laches typically does not surrender its right to an ongoing
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS     41



royalty. Menendez, 128 U.S. at 523–25. Paramount in
both these inquiries are the flexible rules of equity and, as
a corollary, district court discretion. “[A] major departure
from the long tradition of equity practice should not be
lightly implied.” eBay, 547 U.S. at 391 (quoting Wein-
berger v. Romero-Barcelo, 456 U.S. 305, 320 (1982)).
                      V. CONCLUSION
     For the foregoing reasons, laches remains a defense
to legal relief in a patent infringement suit after Petrella.
Laches bars legal relief, and courts must weigh the facts
underlying laches in the eBay framework when consider-
ing an injunction. However, absent extraordinary cir-
cumstances, laches does not preclude an ongoing royalty.
    Finally, we reinstate the panel opinion’s reversal of
the district court’s grant of summary judgment on equita-
ble estoppel and adopt its reasoning. We thus remand to
the district court for proceedings consistent with this
opinion.
            REVERSED AND REMANDED
  United States Court of Appeals
      for the Federal Circuit
                 ______________________

     SCA HYGIENE PRODUCTS AKTIEBOLAG
          SCA PERSONAL CARE, INC.,
              Plaintiffs-Appellants

                            v.

     FIRST QUALITY BABY PRODUCTS, LLC,
         FIRST QUALITY HYGIENIC, INC.,
       FIRST QUALITY PRODUCTS, INC. AND
     FIRST QUALITY RETAIL SERVICES, LLC,
               Defendants-Appellees
              ______________________

                       2013-1564
                 ______________________

   Appeal from the United States District Court for the
Western District of Kentucky in No. 10-CV-0122, Chief
Judge Joseph H. McKinley, Jr.
                ______________________

HUGHES, Circuit Judge, concurring-in-part, dissenting-in-
part, with whom MOORE, WALLACH, TARANTO, and CHEN,
Circuit Judges, join.
    Patent law is governed by the same common-law prin-
ciples, methods of statutory interpretation, and procedur-
al rules as other areas of civil litigation. Today, the
majority adopts a patent-specific approach to the equita-
ble doctrine of laches. In doing so, the majority overlooks
Congress’ intent and Supreme Court precedent, which
demonstrate that laches is no defense to a claim for
2       SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



damages filed within the statutory limitations period
established by 35 U.S.C. § 286.
    In Petrella v. Metro-Goldwyn-Mayer, Inc., 134 S. Ct.
1962, 1974 (2014), the Supreme Court emphasized that it
had never approved the use of laches to bar a claim for
legal damages brought within a statutory limitations
period. The majority reasons that Petrella is not control-
ling here because Congress specifically incorporated
laches as a defense to legal damages into the Patent Act
of 1952. But the majority has no sound basis for finding
that Congress intended to displace the uniform limita-
tions period in § 286 with the case-specific doctrine of
laches. The majority’s key logic—that Congress adopted
the view of some lower courts that laches could bar legal
relief in patent cases—requires us to presume that Con-
gress ignored the Supreme Court. For in 1952, the Su-
preme Court had already recognized the common-law
principle that laches cannot bar a claim for legal damag-
es. I know of no precedent for inferring a congressional
departure from a common-law principle recognized by the
highest court based solely on aberrational lower-court
decisions.
    The Supreme Court has repeatedly cautioned this
court not to create special rules for patent cases. In light
of the Supreme Court’s clear, consistent, and long-
standing position on the unavailability of laches to bar
damages claims filed within a statutory limitations peri-
od, we should not do so here. I respectfully dissent-in-
part. 1




    1  I agree with the majority that laches is available
to bar equitable relief. I therefore join Part III of the
majority opinion.
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS     3



                             I
    The Supreme Court in Petrella held that when Con-
gress enacts a statutory limitations period, courts cannot
invoke the equitable doctrine of laches to bar claims for
legal relief filed within that period. 134 S. Ct. at 1967.
The Supreme Court reasoned that a statutory limitations
period expresses Congress’ judgment on the timeliness of
a claim. Id. Because the statutory limitations period
“itself takes account of delay,” courts cannot further
regulate the timeliness of a claim using the doctrine of
laches. Id. at 1973. The Supreme Court found that the
conflict between these two delay-based limitations creates
a separation of powers problem, and concluded that
“courts are not at liberty to jettison Congress’ judgment
on the timeliness of suit.” Id. at 1967.
     The Supreme Court further explained that “laches is a
defense developed by courts of equity; its principal appli-
cation was, and remains, to claims of an equitable cast for
which the Legislature has provided no fixed time limita-
tion.” Id. at 1973 (citing 1 D. Dobbs, Law of Remedies
§ 2.4(4), p. 104 (2d ed. 1993)). This principle has a strong
historical pedigree: “[b]oth before and after the merger of
law and equity in 1938, [the Supreme Court] has cau-
tioned against invoking laches to bar legal relief.” Id. at
1973. The Supreme Court cited several of its decisions as
proof, including two cases decided prior to 1952. See id.
(citing Holmberg v. Armbrecht, 327 U.S. 392, 395, 396
(1946); United States v. Mack, 295 U.S. 480, 489 (1935)).
Although some regional-circuit cases have departed from
this principle, the Supreme Court found “no case in which
[the Supreme Court] has approved the application of
laches to bar a claim for damages brought within the time
allowed by a federal statute of limitations.” Id. at 1974.
    Like the statute of limitations considered in Petrella,
the statutory limitations period in § 286 of the Patent Act
expresses Congress’ judgment on the timeliness of claims
4    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



for damages. See 35 U.S.C. § 286. Section 286 prohibits
recovery of damages when a claim is filed more than six
years after the associated patent infringement occurs, but
allows recovery of damages when a claim is filed within
that six-year window. Cf. Petrella, 134 S. Ct. at 1973
(observing that under the Copyright Act’s statute of
limitations, “a successful plaintiff can gain retrospective
relief only three years back from the time of suit”). I
agree with the majority that, with respect to claims for
damages and the conflict with laches, there is no func-
tional difference between § 286 and a statute of limita-
tions. See Maj. Op. at 17–18. The Supreme Court’s
decision in Petrella, therefore, strongly suggests that
laches is not available to further regulate the timeliness
of damages claims in patent-infringement cases.
     To overcome this conclusion, we would have to find
compelling evidence that Congress incorporated laches
into the Patent Act as an additional time-bar on claims
for legal damages. The Supreme Court has required clear
evidence to justify inferring a congressional departure
from traditional common-law principles, such as the
principle recognized in Petrella that laches does not apply
to claims for legal relief. See, e.g., Nken v. Holder, 556
U.S. 418, 433 (2009) (applying the “presumption favoring
the retention of long-established and familiar principles,
except when a statutory purpose to the contrary is evi-
dent”); Weinberger v. Romero-Barcelo, 456 U.S. 305, 320
(1982) (“[A] major departure from the long tradition of
equity practice should not be lightly implied.”). Addition-
ally, the Supreme Court has made abundantly clear that
there must be a particular justification in the statute
before this court may announce special rules for patent
cases that depart from the rules for other areas of civil
litigation. See, e.g., Teva Pharm. USA, Inc. v. Sandoz,
Inc., 135 S. Ct. 831, 836–40 (2015); Octane Fitness, LLC v.
ICON Health & Fitness, Inc., 134 S. Ct. 1749, 1758 (2014);
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS      5



eBay Inc. v. MercExchange, LLC, 547 U.S. 388, 391
(2006).
                             II
    The majority brushes aside the teachings of Petrella
and finds based on vague legislative history and muddled
case law that Congress intended to depart from the com-
mon-law principle that laches only bars equitable relief
where a statutory limitations period applies. See Maj. Op.
at 18–35. Two flaws pervade the majority’s analysis.
First, the majority interprets 35 U.S.C. § 282 in isolation,
without regard to Congress’ intent expressed in § 286.
Second, in addition to misreading the pre-1952 cases it
cites, the majority limits the scope of its review to favora-
ble patent cases. The majority ignores Supreme Court
precedent and other federal court decisions holding that
laches does not bar claims for legal relief filed within a
statutory limitations period.      Properly analyzed, we
cannot reasonably infer from the Patent Act that Con-
gress intended to depart from this common-law principle.
                             A
     The majority finds that Congress incorporated laches
into § 282 because Congress chose to use broad language
in that section; and because an executive-branch official
said so. See Maj. Op. at 18–22. Although the majority
does not identify which particular term encompasses a
defense of laches, the only possible candidates are “[n]on-
infringement, absence of liability for infringement or
unenforceability.” 35 U.S.C. § 282(b)(1). The remaining
subsections refer specifically to other provisions of the
Patent Act, none of which allude to laches. See id. at
(b)(2)–(4). First Quality and several amici argue that
laches falls within the term “unenforceability” in particu-
lar.
    The language in § 282(b)(1) is ambiguous at best, and
contains no hint of a special version of laches that applies
6    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



to legal relief within a statutory limitations period. The
terms “absence of liability” and “unenforceability” do not
precisely refer to any particular defenses to patent-
infringement suits. Although the plain meaning of these
terms does not conclusively rule out the defense of laches,
it does not necessarily include a defense of laches either.
The majority seems to think that the indeterminate
breadth of these terms helps its case, making it more
likely that laches falls somewhere within their scope,
whatever that may be. See Maj. Op. at 18–20. But statu-
tory interpretation cannot turn on this kind of guesswork.
And even if laches were implicit in § 282, that would not
be enough, for the question is whether Congress pre-
scribed a variant form of laches in the Patent Act that
applies to claims for legal relief.
    The majority disregards an important tool of statutory
interpretation that shows Congress did not adopt such a
defense. It is a “fundamental canon of statutory construc-
tion that the words of a statute must be read in their
context and with a view to their place in the overall
statutory scheme.” King v. Burwell, 135 S. Ct. 2480, 2492
(2015) (quoting Utility Air Regulatory Grp. v. Envtl. Prot.
Agency, 134 S. Ct. 2427, 2441 (2014)) (internal quotation
marks omitted); see also La. Pub. Serv. Comm’n v. Fed.
Commc’n Comm’n, 476 U.S. 355, 370 (1986) (noting the
“familiar rule of construction that, where possible, provi-
sions of a statute should be read so as not to create a
conflict”). Here, the statutory limitations period in § 286
informs the scope of § 282. Section 286 expresses Con-
gress’ judgment on the timeliness of damages claims: a
patent owner may recover damages when a claim is filed
within six years of infringement, but no later. If § 282
includes a defense of laches that applies to claims for
damages, it would conflict with this judgment. Laches
could bar a patent owner from recovering damages even
though its claim was filed within the clearly defined six-
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    7



year period established by § 286. The extent of this
conflict is highlighted by the Supreme Court’s reasoning
in Petrella. Notwithstanding the additional elements of
laches beyond mere delay, the Supreme Court held that
laches and the statute of limitations were in such conflict
that applying laches created a separation of powers
problem. See Petrella, 134 S. Ct. at 1967, 1973. Congress’
decision to create a fixed statutory limitations period in
§ 286 therefore strongly suggests that it did not intend to
codify a defense of laches that further regulates the
timeliness of damages claims.
    The legislative history of § 286 further proves the
point. Between 1874 and 1897, the federal patent statute
did not contain a limitations period of any kind. See
Campbell v. Haverhill, 155 U.S. 610, 613–14 (1895).
Federal courts therefore relied on analogous state stat-
utes of limitations to determine the timeliness of claims.
See id. at 618, 620. Congress found this approach prob-
lematic, and in 1897 enacted the predecessor to § 286 to
“create a uniform statute of limitations.” H.R. Rep. No.
54-940, at 2 (1896); see Rev. Stat. § 4921 (1897). 2 If we
read § 282 to incorporate the flexible, case-specific doc-
trine of laches as to legal damages, that section would


   2      Section 286 and its predecessor contain virtually
identical language. Compare 35 U.S.C. § 286 (“[N]o
recovery shall be had for any infringement committed
more than six years prior to the filing of the complaint or
counterclaim for infringement in the action.”), with Rev.
Stat. § 4921 (1897) (“But in any suit or action brought for
the infringement of any patent there shall be no recovery
of profits or damages for any infringement committed
more than six years before the filing of the bill of com-
plaint or the issuing of the writ in such suit or ac-
tion . . . .”).
8     SCA HYGIENE PRODUCTS    v. FIRST QUALITY BABY PRODUCTS



“tug against the uniformity Congress sought to achieve.”
Petrella, 134 S. Ct. at 1975 (noting a similar conflict with
the statute of limitations in the Copyright Act). Thus, to
be consistent with the purpose of § 286, we cannot inter-
pret § 282 to incorporate a defense of laches that bars
legal relief otherwise permitted under § 286.
    The House and Senate Reports from 1952 also contra-
dict the majority’s interpretation. Both sources explain
that § 282 restates statutory defenses “in general terms,
changing the language in the present statute, but not
materially changing the substance.” H.R. Rep. 82-1923 at
10 (1952); S. Rep. 82-1979 at 9 (1952). This declaration
shows that Congress intended to preserve what the lan-
guage of the pre-1952 statutes fairly conveys. And noth-
ing in the pre-1952 statutes suggests an authorization of
laches as a bar to legal damages requested within a
limitations period. The pre-1952 provision enumerating
defenses applicable to an infringement suit, whether for
legal or equitable relief, does not refer directly or indirect-
ly to laches. See 35 U.S.C. § 69 (1946) (codifying Rev.
Stat. § 4920 as amended). The provision authorizing
remedies refers to “the course and principles of courts of
equity” (which includes laches) in the portion addressing
injunctions, but does not mention equitable defenses in
the portion addressing damages. 35 U.S.C. § 70 (1946)
(codifying Rev. Stat. § 4921 as amended). In the absence
of any prior statutory authorization of laches as a bar to
legal damages, the majority relies on pre-1952 “common
law.” But nothing in the legislative history reflects con-
gressional recognition of any pre-1952 case law on the
subject of laches, let alone approval of such case law as
went beyond what the pre-1952 statutes authorized on
their face. The key 1952 legislative history on § 282 thus
runs counter to the majority’s conclusion that Congress
intended this section to incorporate laches as defense to
legal damages.
SCA HYGIENE PRODUCTS    v. FIRST QUALITY BABY PRODUCTS        9



    The majority’s only evidence that Congress intended
to incorporate a defense of laches at all in § 282 is a lone
statement in P.J. Federico’s Commentary on the New
Patent Act. But Mr. Federico’s reference to “laches” does
not suggest that Congress incorporated a distinctive
version of laches that, contrary to its traditional role at
common law, bars a claim for legal damages filed within a
statutory limitations period. This statement therefore
cannot support the majority’s conclusion. Indeed, the only
interpretation of this statement that is consistent with
§ 286 is that Mr. Federico was referring to laches as a
defense to equitable relief only. And in any event, an
inference that Congress departed from a common-law
principle could not properly rest entirely on a statement
made two years after the enactment of the Patent Act by
one person who, though central to its drafting, was not a
member of Congress voting on the measure. 3
    In Petrella, the Supreme Court was presented with a
similarly vague reference to “laches” in Federal Rule of
Civil Procedure 8(c), which lists the affirmative defenses
available in a civil action. See 134 S. Ct. at 1974–75. In
light of the statute of limitations and the traditional role
of laches, however, the Supreme Court found that this
reference does not establish laches as a defense to damag-
es claims. Id. So too here. Mr. Federico’s lone post-hoc


    3   The Supreme Court has found that a post-hoc
statement, even from members of Congress, “does not
qualify as legislative ‘history,’ . . . [and] is consequently of
scant or no value” for statutory interpretation. Graham
Cty. Soil & Water Conservation Dist. v. U.S. ex. rel. Wil-
son, 559 U.S. 280, 298 (2010) (discrediting a letter from
the primary sponsors of the bill in Congress); see also
Consumer Prod. Safety Comm’n v. GTE Sylvania, Inc.,
447 U.S. 102, 117–18, 120 (1980).
10   SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



reference to laches is entirely insufficient as a matter of
statutory construction to conclude that Congress intended
to incorporate laches as a defense to claims for legal
damages, particularly in light of the contrary and clear
language of § 286.
                            B
    To find that Congress intended to codify laches as a
defense to claims for legal damages, the majority relies on
the canon of statutory interpretation that “[w]hen a
statute covers an issue previously governed by the com-
mon law, we must presume that Congress intended to
retain the substance of the common law.” Kirtsaeng v.
John Wiley & Sons, Inc., 133 S. Ct. 1351, 1363 (2013)
(internal quotation marks omitted). But the presumption
that Congress intended to retain an aspect of the common
law only applies where the common-law principle is
sufficiently “well established.” Astoria Fed. Sav. & Loan
Ass’n v. Solimino, 501 U.S. 104, 108 (1991); see also
Isbrandtsen Co. v. Johnson, 343 U.S. 779, 783 (1952)
(explaining that Congress is presumed to retain “long-
established and familiar” common-law principles). If the
case law on a particular issue is conflicting, we cannot
infer from Congress’ silence which approach Congress
intended to adopt. Cf. Metro. Stevedore Co. v. Rambo, 515
U.S. 291, 299 (1995) (declining to infer ratification of
judicial interpretation of a statute when these interpreta-
tions were largely dicta and “were not uniform in their
approach”). Here, contrary to the majority’s narrow
analysis of regional-circuit cases, the pre-1952 case law
did not clearly establish that a plaintiff’s laches may
preclude recovery of legal damages.
                            1
    Any analysis of what the common law was at a certain
point in time must start with Supreme Court precedent.
See, e.g., Astoria, 501 U.S. at 107–08 (relying on Supreme
Court precedent for common-law rules of collateral estop-
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS       11



pel and res judicata). For even if there were differing
views in the lower courts, it would be nearly impossible to
conclude that there was a uniform understanding of the
common law that was inconsistent with Supreme Court
precedent. In our judicial system, the Supreme Court’s
understanding is controlling.
     Prior to 1952, the Supreme Court decided several cas-
es holding that laches cannot bar a claim for legal relief
filed within a statutory limitations period. See Holmberg,
327 U.S. at 395 (“If Congress explicitly puts a limit upon
the time for enforcing a right which it created, there is an
end of the matter. The Congressional statute of limita-
tion is definitive.”); Mack, 295 U.S. at 489 (“Laches within
the term of the statute of limitations is no defense at
law.”); Cross v. Allen, 141 U.S. 528, 537 (1891) (“So long
as the demands secured were not barred by the statute of
limitations, there could be no laches in prosecuting a suit
upon the mortgages to enforce those demands.”). Further,
the Supreme Court made clear that laches is unavailable
not only in an action at law, but also in a suit in equity to
enjoin an action at law. See Wehrman v. Conklin, 155
U.S. 314, 326–27 (1894). The Supreme Court explained
that a court of equity may enjoin an action at law only if
the plaintiff’s delay is accompanied by further conduct
that meets the requirements for equitable estoppel:
    Though a good defense in equity, laches is no de-
    fense at law. If the plaintiff at law has brought his
    action within the period fixed by the statute of
    limitations, no court can deprive him of his right
    to proceed. If the statute limits him to 20 years,
    and he brings his action after the lapse of 19 years
    and 11 months, he is as much entitled, as [a] mat-
    ter of law, to maintain it, as though he had
    brought it the day after his cause of action ac-
    crued, though such delay may properly be consid-
    ered by the jury in connection with other facts
    tending to show an estoppel.
12       SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



Id.; see also McClintock on Equity § 28, p. 75 (2d ed. 1948)
(“The majority of the courts which have considered the
question have refused to enjoin an action at law on the
ground of the laches of the plaintiff at law.”). In sum, as
noted in Petrella, the Supreme Court has never “approved
the application of laches to bar a claim for damages
brought within the time allowed by a federal statute of
limitations.” 134 S. Ct. at 1974. 4
    Moreover, several lower courts before 1952 likewise
applied this general principle in patent-infringement
cases to conclude that laches does not bar a claim for legal
relief. In City of Concord v. Norton, 16 F. 477, 477 (C.C.D.
Mass. 1883), the plaintiffs filed a bill in equity to enjoin
the defendant’s action at law based on laches. The court
held that although equitable estoppel is available to bar a
claim for legal relief, laches is not. Id. at 480. “[F]or
laches the remedy at law is found in the statute of limita-
tions, and if that statute is inadequate there is no other
remedy.” Id. Similarly, in Thorpe v. Wm. Filene’s Sons
Company, 40 F.2d 269, 269 (D. Mass 1930), the court
recognized that laches “has no application to actions at
law. A plaintiff’s conduct may, however, have been of



     4  The majority implies that the Supreme Court’s
decision in Lane & Bodley Co. v. Locke, 150 U.S. 193
(1893), is to the contrary. See Maj. Op. at 31. In that
case, the Supreme Court found that laches barred a claim
brought in equity. Lane & Bodley, 150 U.S. at 201. As
the majority notes, the Supreme Court does not say
whether the monetary relief barred by laches was legal or
equitable in nature. And the Supreme Court decided
Lane & Bodley before the statutory limitations period for
damages claims was enacted. It therefore does not say
anything about whether laches may bar a claim for legal
damages governed by a statute of limitations.
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS    13



such character as . . . to make it unconscionable for him to
maintain it. This is estoppel and is recognized in equity
as sufficient ground for enjoining an action at law.”
    These decisions alone defeat the conclusion that
“courts consistently applied laches to preclude recovery of
legal damages” prior to 1952. Maj. Op. at 28. To say that
a rule was “well established” when the Supreme Court
clearly and repeatedly held otherwise is to give insuffi-
cient recognition to the hierarchy of federal courts. Fur-
ther, laches is a general equitable defense, not a defense
specific to patent infringement. For the purposes of a
common-law incorporation theory, therefore, the role of
laches in other areas of civil litigation is of a piece with
the role of laches in patent cases. 5 We cannot assume
that Congress would have ignored Supreme Court prece-
dent on the issue and focused solely on regional-circuit
decisions in patent cases.
                             2
    Even if we could focus solely on regional-circuit law,
the cases cited by the majority do not themselves show
that there was a uniformly well-established rule that



   5    The majority argues that a Senate floor statement
claiming that the Patent Act “codifie[d] the present patent
laws,” 98 Cong. Rec. 9323, justifies its narrow focus on the
role of laches in patent cases only. See Maj. Op. at 33.
But unlike the doctrine of contributory infringement, a
judicial doctrine expressly incorporated into the Patent
Act of 1952, laches is not a patent law specific to patent
cases. It is a general equitable defense to liability. Con-
gress’ codification of “patent laws” therefore does not
support an assumption that Congress only looked to the
application laches in patent cases, and not to fundamental
equitable principles announced by the Supreme Court.
14    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



laches is available to bar legal damages otherwise permit-
ted by § 286. Nearly all of these decisions either apply
laches under a misinterpretation § 274(b) of the Judicial
Code, mention laches in dicta, or apply laches to bar a
claim brought in equity. The discussion of laches in these
cases does not clearly demonstrate that in 1952 laches
was available to bar a claim for legal damages in a civil
action.
    The majority primarily relies on two cases that ad-
dress the availability of equitable relief under § 274(b) of
the Judicial Code. See Ford v. Huff, 296 F. 652 (5th Cir.
1924); Banker v. Ford Motor Co., 69 F.2d 665 (3d Cir.
1934). Section 274(b) stated that “in all actions at law
equitable defenses may be interposed by answer, plea, or
replication without the necessity of filing a bill on the
equity side of the court.” Act of March 3, 1915, ch. 90,
§ 274(b), 38 Stat. 956 (1915). As the court in Ford recog-
nized, however, § 274(b) simply eliminated procedural
barriers to requesting equitable relief in actions at law—
obviating the need to file separately in a court of equity—
but did not change the substantive and remedial princi-
ples of law and equity. See 296 F. at 658 (finding that
under § 274(b), “a defendant in an action at law who files
a plea setting up an equitable defense is given the same
rights as if he had set them up in a bill in equity”). The
Supreme Court subsequently confirmed that “the proce-
dure was simplified, but the substance of the authorized
intervention of equity was not altered.” Enelow v. N.Y.
Life Ins. Co., 293 U.S. 379, 382 (1935); cf. Stainback v. Mo
Hock Ke Lok Po, 336 U.S. 368, 383 n.26 (1949) (“Notwith-
standing the fusion of law and equity by [Fed. R. Civ. P.
2], the substantive principles of Courts of Chancery
remain unaffected.”). And under Supreme Court prece-
dent, it was a substantive principle of law and equity that
laches alone was not a sufficient basis for a court of equity
to enjoin an action at law. See Wehrman, 155 U.S. at
326–27. Section 274(b) therefore does not authorize
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS      15



courts to bar a claim for damages in an action at law
based on a defense of laches.
    The holding in Ford is consistent with this under-
standing of § 274(b). The court found that the plaintiff’s
claim was barred under a theory of equitable estoppel,
which is an appropriate ground for enjoining an action at
law for damages. See Dickerson v. Colgrove, 100 U.S. 578,
582–83 (1879). Equitable estoppel requires a showing
that the defendant relied on a misleading communication
by the plaintiff that is inconsistent with his present claim.
See A.C. Aukerman Co. v. R.L. Chaides Constr. Co., 960
F.2d 1020, 1041 (Fed. Cir. 1992) (en banc). The plaintiff
in Ford had accepted payment “under circumstances
calculated to lead defendant to believe or understand that
such payment was accepted by plaintiff in full satisfaction
and discharge of all claims by him.” 296 F. at 657. Not-
ing that “[t]he effect of one being estopped to enforce a
claim is that his plight is substantially the same as it
would have been if the claim had never existed,” the court
held that the plaintiff’s action at law was barred. Id. at
657–58. The disposition in Ford thus rested on a theory
of equitable estoppel, consistent with substantive equita-
ble principles and § 274(b). See Thorpe, 40 F.2d at 270
(finding that in Ford, “while the word ‘laches’ is used, the
decision clearly rested upon the ground of estoppel”). Any
mention of laches was mere dictum, and certainly cannot
be read to contradict Supreme Court precedent holding
that laches does not bar a claim for damages in an action
at law. See Jama v. Immigration & Customs Enf’t, 543
U.S. 335, 351 n.12 (2005) (“Dictum settles nothing, even
in the court that utters it.”).
    The Third Circuit in Banker, however, took Ford be-
yond its holding and applied laches in an action at law
based on a misinterpretation of § 274(b). Although the
court cited Ford for its interpretation of § 274(b), the court
went further and held that this provision “authorizes
equitable defenses in actions at law theretofore applicable
16    SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



only in equity.” Banker, 69 F.2d at 666. The Third Cir-
cuit found that “[had] the appellant’s suit been in equity,
the evidence would have been ample for holding that
recovery was barred because of laches.” Id. For support,
the Third Circuit relied on cases in which courts of equity
applied laches to preclude a claim for an injunction and
an accounting. Id. But it does not follow from these cases
in equity that laches may also be grounds for enjoining a
claim to legal damages in an action at law. Moreover, by
1952, the Supreme Court had established that laches
cannot be invoked for this purpose, see Wehrman, 155
U.S. at 326–27, and that § 274(b) does not change sub-
stantive principles of law and equity, see Enelow, 293 U.S.
at 382. In light of the Third Circuit’s flawed analysis, as
highlighted by Supreme Court decisions, Banker does not
support a well-established rule in 1952 that laches may
preclude a claim for legal damages in patent-infringement
cases, notwithstanding the statutory limitations period.
Neither do the cases relying on Banker without discus-
sion. See, e.g, Universal Coin Lock Co. v. Am. Sanitary
Lock Co., 104 F.2d 781, 781 (7th Cir. 1939).
    Several other cases cited by the majority involve
courts of equity barring a plaintiff’s suit due to laches. In
one of these cases, the precluded relief included damages.
See George J. Meyer Mfg. Co. v. Miller Mfg. Co., 24 F.2d
505 (7th Cir. 1928). Others applied laches to bar a re-
quest for an “accounting,” which we have said was some-
times—but only sometimes—used to refer to damages.
See, e.g., Wolf, Sayer & Heller v. U.S. Slicing Mach. Co.,
261 F. 195 (7th Cir. 1919); Hartford-Empire Co. v. Swin-
dell Bros., 96 F.2d 227 (4th Cir. 1938); Union Shipbuild-
ing Co. v. Boston Iron & Metal Co., 93 F.2d 781 (4th Cir.
1938); France Mfg. Co. v. Jefferson Elec. Co., 106 F.2d 605
(6th Cir. 1939); Gillons v. Shell Co. of Cal., 86 F.2d 600
(9th Cir. 1936); Window Glass Mach. Co. v. Pittsburgh
Plate Glass Co., 284 F. 645 (3d Cir. 1922); A.R. Mosler &
Co. v. Lurie, 209 F. 364 (2d Cir. 1913).
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS     17



     These cases do not support the conclusion that laches
was well understood to bar legal damages in 1952. Courts
of equity had discretion to dismiss a claim on equitable
grounds such as laches or unclean hands. Because the
patent statute required courts of equity to award damages
upon a finding of infringement, see Patent Act of 1870, ch.
230, § 55, 16 Stat. 198, 206 (1870), the court’s equitable
discretion to reject a patent-infringement claim allowed it
to bar legal damages in that equity court. But a plaintiff
also had the option to seek damages in a court of law.
And it was well established that, although a court of
equity could refuse to grant damages itself, it could not
enjoin a court of law from doing so. See, e.g., Wehrman,
155 U.S. at 326–27. Thus, laches could only bar a plain-
tiff from recovering damages in a particular forum. It was
not sufficient to deny a remedy altogether.
    That principle necessarily endures after the merger of
law and equity. See Stainback, 336 U.S. at 383. In the
post-merger system, therefore, prior case law applying
laches to bar damages in a court of equity does not sud-
denly extend to all claims for damages. Plaintiffs are still
entitled to damages that would have been available in a
court of law, to which laches was no defense.
     The majority’s remaining support is minimal. See,
e.g., Brennan v. Hawley Prods. Co., 182 F.2d 945, 948–49
(7th Cir. 1950) (applying laches to bar all relief without
mention of the statutory limitations period, citing Univer-
sal Coin Lock, 781 F.2d at 781, and cases applying laches
to bar relief in a court of equity). Particularly in light of
the Supreme Court’s repeated holding that laches cannot
preclude a claim for legal damages governed by a statuto-
ry limitations period, these outliers are not sufficient to
show a clear or well-established common-law rule to the
contrary. To the extent that Congress codified laches,
therefore, it was as a defense to equitable relief only, not
as a defense to legal relief otherwise permitted under
§ 286.
18     SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS



                               C
    The majority’s policy concerns do not alter this con-
clusion. The majority argues that, because a copyright
holder must prove a defendant’s access to a work to
establish infringement, potential defendants are more
likely to know they are at risk of being sued. See Maj. Op.
at 35. But innocence is no defense to direct patent in-
fringement, and thus a defendant is less likely to be
aware of its potential liability for infringement. See id. at
35–36. The majority argues that a defense of laches is
therefore more useful to defendants in patent-
infringement suits. See id. at 36.
    The Supreme Court’s decision in Petrella did not de-
pend on policies specific to copyright law. It turned on the
conflict between laches and a statutory limitations period,
and the longstanding principle that laches cannot bar a
claim for legal relief. See 134 S. Ct. at 1967, 1973–74.
That innocence is not a defense to direct patent infringe-
ment does not make this reasoning any less applicable.
    In any event, the majority’s policy concerns are not
the only consequences at stake. Patent owners often have
good reason for delaying suit. As the Seventh Circuit
observed:
     Frequently the position of the patentee (financial
     and otherwise) prevents the institution of suits.
     The patent litigation is often prolonged and ex-
     pensive. Moreover from the very nature of the
     thing he cannot be fully cognizant of all infringe-
     ments that occur throughout the length and
     breadth of this country. . . . Then, also, the validi-
     ty of his patent and the infringement thereof may
     be, as here, disputed. These defenses present
     mixed questions of fact and law concerning which
     there is necessarily some doubt and uncertainty.
SCA HYGIENE PRODUCTS   v. FIRST QUALITY BABY PRODUCTS   19



George J. Meyer Mfg. Co., 24 F.2d at 507. Resolving these
competing policy concerns is precisely the type of judg-
ment left for Congress. Congress was well-aware of the
nature of patent infringement in 1952, and it must be
presumed that Congress took these concerns into account
when it established the six-year limitations period for
bringing a claim for damages. We should not undermine
Congress’ judgment in 1952 according to our own assess-
ment of the current policy landscape.
                            III
    The Supreme Court in Petrella reiterated the princi-
ple that laches does not apply to claims for legal relief
governed by a statutory limitations period. The evidence
of congressional intent and the pre-1952 case law is
insufficient to justify departing from this principle in
patent-infringement cases.       Following the Supreme
Court’s longstanding precedent, I read § 286 to express
Congress’ exclusive judgment on the timeliness of a claim
for damages. Laches is not available as a further defense.
Accordingly, I respectfully dissent-in-part.
