  United States Court of Appeals
      for the Federal Circuit
               __________________________

 MEYER INTELLECTUAL PROPERTIES LIMITED
      AND MEYER CORPORATION, U.S.,
             Plaintiffs-Appellees,
                            v.
                    BODUM, INC.,
                  Defendant-Appellant.
               __________________________

                       2011-1329
               __________________________

    Appeal from the United States District Court for the
Northern District of Illinois in case no. 06-CV-6329, Judge
Milton I. Shadur.
               _________________________

                Decided: August 15, 2012
               _________________________

    JOSHUA C. KRUMHOLZ, Holland & Knight, LLP, of Bos-
ton, Massachusetts, argued for plaintiffs-appellees. Of
counsel on the brief were R. DAVID DONOGHUE and DANIEL
L. FARRIS, of Chicago, Illinois.

    ROBERT S. RIGG, Vedder Price, P.C., of Chicago, Illi-
nois, argued for defendant-appellant. With him on the
brief were DAVID E. BENNETT, and WILLIAM J. VOLLER, III.
               __________________________
MEYER INTELL PROP   v. BODUM                               2


   Before DYK, MOORE, and O’MALLEY, Circuit Judges.
  Opinion for the court filed by Circuit Judge O’Malley.
               Circuit Judge Dyk concurs.
O’MALLEY, Circuit Judge.
     In this patent case, Meyer Intellectual Properties
Limited and Meyer Corporation, U.S. (collectively,
“Meyer”) filed suit against Bodum, Inc. (“Bodum”) in the
United States District Court for the Northern District of
Illinois, alleging that Bodum infringed two of Meyer’s
patents, both of which are directed to a method for froth-
ing milk: U.S. Patent Nos. 5,780,087 (“the ’087 Patent”)
and 5,939,122 (“the ’122 Patent”) (collectively, “the pat-
ents-in-suit”). Bodum counterclaimed for declaratory
judgment of noninfringement and invalidity.
    The district court granted Meyer’s motions for sum-
mary judgment that Bodum’s products infringed the
patents-in-suit. Before proceeding to trial, the district
court granted Meyer’s motions in limine prohibiting
Bodum from: (1) introducing and relying on certain prior
art; (2) presenting certain testimony relating to that prior
art; and (3) introducing any evidence to support its ineq-
uitable conduct claims. The jury returned a verdict in
favor of Meyer, finding that the patents-in-suit were not
proven to be invalid, finding that Bodum’s infringement
was willful, and awarding Meyer damages in the amount
of $50,000.     The district court subsequently denied
Bodum’s post-trial motions for judgment as a matter of
law (“JMOL”) and granted Meyer’s motion requesting
enhanced damages and attorney fees.
    Bodum appeals from the district court’s final judg-
ment awarding damages and attorney fees to Meyer in
the amount of $906,487.56. Judgment, Meyer Intellectual
Props. Ltd. v. Bodum, Inc., No. 06-cv-6329 (N.D. Ill. Feb.
3                              MEYER INTELL PROP   v. BODUM


16, 2011), ECF No. 237. On appeal, Bodum challenges
several of the court’s rulings. Specifically, Bodum chal-
lenges the district court’s decisions: (1) granting summary
judgment in favor of Meyer on infringement; (2) granting
Meyer’s motions in limine precluding Bodum from pre-
senting certain prior art and testimony at trial;
(3) denying Bodum’s motion for JMOL that Bodum did
not willfully infringe the patents-in-suit; (4) enhancing
damages and awarding attorney fees in Meyer’s favor;
and (5) denying Bodum’s renewed motion for JMOL and
motion to alter the court’s infringement decisions. For the
reasons explained below, we reverse-in-part, vacate-in-
part, and remand.
                      BACKGROUND
                 A. Factual Background
                 1. The Patents-in-Suit
    Frank Brady (“Brady”) is the sole inventor of the ’087
and ’122 Patents. For approximately ten years, from 1986
to 1996, Brady was an independent sales representative
for Bodum, a company that designs and sells housewares
products, including coffee makers, milk frothers, and
other kitchen products. Tr. of Proceedings held on Nov.
12, 2010, Meyer Intellectual Props. Ltd. v. Bodum, Inc.,
No. 06-6329 (N.D. Ill. Apr. 29, 2011), ECF No. 268 at
683:14-23. In that capacity, and as the Chief Executive
Officer of Brady Marketing Company, Inc., Brady mar-
keted and sold a number of Bodum’s household products,
including Bodum’s French press coffee makers. Brady
explained that he first conceived of a frother using aera-
tion instead of steam in the mid-1990s, and that he intro-
duced it for sale at a trade show in May 1996. Tr. of
Proceedings held on Nov. 10, 2010, Meyer Intellectual
Props. Ltd. v. Bodum, Inc., No. 06-6329 (N.D. Ill. Apr. 29,
2011), ECF No. 267 at 466:3-467:2. Around that same
MEYER INTELL PROP   v. BODUM                             4


time, Brady began selling his frothers through his com-
pany BonJour, Inc. (“BonJour”).
    On September 23, 1996, Brady filed a patent applica-
tion directed to a “Method for Frothing Liquids.” That
application became the ’087 Patent, which issued on July
14, 1998. During prosecution of the application that
resulted in the ’087 Patent, the PTO examiner initially
rejected Claim 1 as anticipated by a prior art reference:
U.S. Patent No. 5,580,169 (“the Ghidini Patent”). In
response, Brady amended the claim to provide: (1) a
dimensional limitation requiring that the container have
a height that is at least two times the diameter; and (2) a
plunger with a screen and a spring, where the spring is
“positioned about the circumference of the plunger body
such that the spring is biased to hold the screen in place
in contact with, though not sealably connected to, the
container.” With these changes, Claim 1 of the ’087
Patent was allowed.
    While the application that resulted in the ’087 Patent
was pending, Brady filed a continuation application that
later became the ’122 Patent. The ’122 Patent issued on
August 17, 1999.
    The patents-in-suit, which share a common specifica-
tion, are directed to a method for frothing liquids such as
milk. Specifically, the patents relate to “an apparatus
and method for frothing, which allows the user to obtain
foamy, frothed milk without the use of a complicated
steamer device.” ’087 Patent col.1 ll.5-10; ’122 Patent
col.1 ll.8-12. 1 The “Background of the Invention” explains
that, at the time the application was filed, “[m]ost of the

   1    Despite the reference to an “apparatus” in the
opening sections of the ’122 Patent, there are no appara-
tus claims in that patent; only method claims are at issue
here.
5                                MEYER INTELL PROP   v. BODUM


prior art foaming devices [were] complicated machines
which involve the use of steam to aerate or foam the
liquid.” ’087 Patent col.1 ll.12-15. The background sec-
tion concludes with the statement that, “[w]hat is needed,
and is lacking in the prior art, is a device to froth liquids,
such as milk, which is simple to use, has no need for
electricity or steam, and is relatively easy to clean and
store.” Id. at col.1 ll.64-67.
     Generally speaking, the claims disclose four steps:
(1) providing a container that has a height to diameter
aspect ratio of 2:1; (2) pouring liquid (e.g., milk) into the
container; (3) introducing a plunger that includes at least
a rod and plunger body with a screen; and (4) pumping
the plunger to aerate the liquid. ’087 Patent col.5 ll.20 –
col.6 ll.8.
              2. Bodum’s Accused Products
     Meyer accuses three of Bodum’s milk frothers of in-
fringement: (1) the Chambord Frother Model No. 1964;
(2) the Aerius Frother Model No. 1364; and (3) the Shin
Bistro Frother Model No. 10492. Bodum began selling a
first generation of accused milk frothers – referred to as
the Version 1 frothers – in 1999. The Version 1 frothers
departed from Bodum’s previous non-electric milk froth-
ers in that: (1) the carafe was taller and thinner; and
(2) the plunger had a different construction involving a
mesh and spring design. The following images show a
comparison between Bodum’s Version 1 Chambord
Frother and the Figures from Meyer’s ’087 Patent:
MEYER INTELL PROP   v. BODUM   6
7                             MEYER INTELL PROP   v. BODUM




                 B. Procedural History
   In May 2005, Brady sold his company – BonJour – to
Meyer. In the sale, BonJour transferred its intellectual
property rights to Meyer, and it is undisputed that Meyer
owns the patents-in-suit.
     On November 20, 2006, Meyer filed suit against
Bodum in the Northern District of Illinois, alleging in-
fringement of the patents-in-suit. In the Complaint,
Meyer alleged that Bodum “has been and still is using,
selling, offering for sale and/or importing one or more
milk frother products for frothing liquids that infringe,
directly, indirectly, contributorily and/or by inducement”
the ’087 Patent and the ’122 Patent. Complaint, Meyer
Intellectual Props. Ltd. v. Bodum, Inc., No. 06-cv-6329
MEYER INTELL PROP   v. BODUM                               8


(N.D. Ill. Nov. 20, 2006), ECF No. 1. Meyer amended its
complaint a year later, in November 2007, to add a claim
for willful infringement.
     On January 19, 2007, Bodum: (1) filed an answer as-
serting an affirmative defense of inequitable conduct; and
(2) counterclaimed seeking a declaration that the asserted
claims of the patents-in-suit are invalid and not infringed.
     Roughly six months after it was served with the com-
plaint, Bodum ceased manufacturing its Version 1 froth-
ers and transitioned to Version 2 frothers with a new
plunger design. Bodum did not change the name or
designation of its frother products. According to Bodum,
“[u]nlike the Version 1 plunger, the Version 2 plunger
does not have a spring or other biasing element that holds
the screen against the inside wall of the container or
housing, and the screen does not extend beyond the
diameter of the plunger plate.” Appellant Br. 9. Instead,
the Version 2 plunger contains an O-ring around the
circumference of the plunger body. Bodum subsequently
removed the O-ring from the Version 2 frother and began
selling the new design as Version 3 in July 2008.
                  1. Claim Construction
    On May 14, 2008, the district court issued its claim
construction order. Meyer Intellectual Props. Ltd. v.
Bodum, Inc., 552 F. Supp. 2d 810 (N.D. Ill. 2008) (“Claim
Construction Order”). In that order, the court noted that
the parties “agree[d] on which claims are in dispute and
have submitted a joint letter identifying the disputed
language.” Id. at 812. Consistent with the parties’ re-
quest, the court limited its construction to certain lan-
guage in Claim 1 of the ’087 Patent and Claims 1 and 10
of the ’122 Patent. The bulk of the court’s claim construc-
tion order is not relevant to resolution of this appeal so we
do not discuss it in any detail. Notably, however, the
9                              MEYER INTELL PROP   v. BODUM


parties did not ask the court to construe the phrase “pro-
viding a container” as it is used in Claim 1 of the patents-
in-suit at this stage of the proceedings. See ’087 Patent
col.5 ll.23-25 (“providing a container characterized by a
height and a diameter, the height being at least two times
the diameter”).
                 2. Summary Judgment
     On September 2, 2008, Meyer moved for partial sum-
mary judgment, arguing that, by providing its Version 1
frothers along with instructions for their use, Bodum
induced others – specifically Meyer’s own expert Albert
Karvelis – to infringe the patents-in-suit. In response,
Bodum argued that: (1) Meyer failed to provide sufficient
evidence of an intent to induce infringement; (2) Bodum
could not induce infringement because it believed in good
faith that the Meyer patents are invalid; (3) Bodum could
not be liable for inducement because no single third party
could perform all the steps in the patented claims, not
even Mr. Karvelis; and (4) even if Mr. Karvelis had per-
formed all of the steps of the method claims, his acts could
not be acts of “infringement” since he was acting under an
implied license created by the umbrella of the parties’
litigation.
    Two things are notable about the parties’ summary
judgment filings. First, Meyer presented no evidence that
anyone other than its own expert had directly “infringed”
the ’087 and ’122 Patents. Second, both parties discussed
what it meant to “provide a container” for frothing
though, again, neither expressly sought construction of
that term.
    On February 11, 2009, the district court granted
Meyer’s motion for partial summary judgment, finding
that Bodum had induced infringement of certain claims in
the ’087 and ’122 Patents by its sales of the Version 1
MEYER INTELL PROP   v. BODUM                            10


frothers. Meyer Intellectual Props. Ltd. v. Bodum, Inc.,
597 F. Supp. 2d 790 (N.D. Ill. 2009) (“Summary Judgment
Version 1”).
    Meyer then filed a second motion for partial summary
judgment, this time arguing that Bodum’s sale of its
Version 2 and 3 frothers both directly infringed and
induced infringement of the ’122 Patent. 2 The court
granted summary judgment of direct infringement and
inducement as to the Version 2 frothers, but found genu-
ine issues of material fact as to literal infringement with
respect to the Version 3 frothers. Meyer Intellectual
Props. Ltd. v. Bodum, Inc., 674 F. Supp. 2d 1015, 1022
(N.D. Ill. 2009) (“Summary Judgment Version 2”). The
court began by noting that the ’122 Patent includes a
limitation that “substantially no liquid passes between
the circumference of the plunger body and the inside wall
of the container.” Id. at 1017. Although Bodum at-
tempted to design around this limitation by removing the
O-ring from the Version 2 frother so that a greater
amount of liquid could pass between the plunger and the
container, Bodum “mistakenly produced and sold frothers
with O-rings (“Version 2 frothers”) during a period that
began about July 2007 and ran through June 2008.” Id.
     Bodum argued that it could not be liable for infringe-
ment because Meyer did not offer evidence that Bodum
itself performed each step of the method and Meyer
offered no evidence that its customers did so. The court
rejected this argument and reiterated its view that, if
Meyer’s patents are valid, Bodum’s production and sale of
the Version 2 frothers infringe directly and induce others
to infringe.


   2    Meyer did not assert the ’087 Patent against ei-
ther the Version 2 or Version 3 frothers.
11                               MEYER INTELL PROP   v. BODUM


                   3. Motions in Limine
     In April 2010, Meyer filed several motions in limine.
Specifically, Meyer sought to: (1) bar Bodum’s proffered
expert, Robert John Anders (“Anders”), from testifying
regarding his opinion that the patents-in-suit are invalid
as obvious under 35 U.S.C. § 103; (2) prevent Bodum from
relying on evidence it claims constitutes prior art, includ-
ing documents Anders referred to in his report;
(3) preclude Bodum from presenting any evidence regard-
ing its inequitable conduct defense; and (4) prevent
Bodum from introducing what Meyer characterized as
previously undisclosed prior art references.
    In a series of decisions, the district court granted all of
Meyer’s motions, limiting significantly the evidence
Bodum could introduce at trial. First, the court issued an
order excluding Anders’ opinion on obviousness and
preventing him from testifying on that subject because he
“advance[d] his opinion as a mere ipse dixit: ‘Trust me – I
know obviousness when I see it, and this is it.’” Meyer
Intellectual Props. Ltd. v. Bodum, Inc., 715 F. Supp. 2d
827, 830 (N.D. Ill. 2010).
     Next, the district court issued an order barring
Bodum from using prior art evidence not contained in
Anders’ report. Meyer Intellectual Props. Ltd. v. Bodum,
Inc., No. 06-cv-6329, 2010 U.S. Dist. LEXIS 56168 (N.D.
Ill. June 7, 2010). Looking at Anders’ report, the court
found that it was divided into three sections – A, B, and C
– and that, although Anders identified fifty-six items in
Part A “as matters that [he] reviewed en route to his
arrival at the opinions that he then sets out in Parts B
and C,” his “ensuing opinions themselves focused solely on
just two of those many items as the actual predicates for
his stated conclusions.” Id. at *4. In other words, the
court found that Anders limited the universe of prior art
MEYER INTELL PROP   v. BODUM                             12


and that Bodum’s lawyers could not expand that scope.
Finally, the court granted Meyer’s motion to preclude
Bodum from arguing that Brady engaged in inequitable
conduct in obtaining the patents-in-suit. Specifically, the
court found that Bodum’s “inequitable conduct charge . . .
failed to meet the demanding requirements” of material-
ity and intent. Id. at *6-9.
    Bodum moved the court to reconsider both of its or-
ders granting Meyer’s motions in limine. In relevant
part, Bodum argued that: (1) during discovery, Bodum
identified and disclosed much of the contested prior art in
its Second Supplemental Answers to Plaintiffs’ Interroga-
tories 2 and 3; (2) it was improper for the court to use the
Anders’ report to limit the scope of prior art upon which
Bodum could rely at trial; (3) the Anders’ report is a
single report with three component parts which should be
read together; and (4) even if Bodum were limited to the
references upon which Anders expressly relied, those
references included a drawing of a Bodum French press
container with dimensions which matched those disclosed
in Meyer’s ’122 Patent.
    In a decision dated October 7, 2010, the court denied
Bodum’s motion to reconsider. First, the court reiterated
that Anders “considered a great deal of potentially rele-
vant material and, having done so, settled on just two
items as the relevant prior art.” Meyer Intellectual Props.
Ltd. v. Bodum, Inc., No. 06-cv-6329, 2010 U.S. Dist.
LEXIS 107169, at *3 (N.D. Ill. Oct. 7, 2010). Second, the
court stated that:
   It simply will not do for Bodum to take an end run
   around its own chosen expert’s opinion by adduc-
   ing testimony from its own people, Jorgen Bodum
   and Thomas Perez, as to other items that they
   consider prior art, whether that testimony is ten-
13                              MEYER INTELL PROP   v. BODUM


     dered under the rubric of Evid. R. 702 (the rule
     governing “expert” testimony) or of Evid. R. 701
     (the rule that gives room for opinion testimony by
     lay witnesses).
Id. Accordingly, the court limited Bodum to only two of
the references identified in Anders’ report: (1) United
States Reissued Patent, No. RE37,137 (“the Ghidini
Reissue Patent”); and (2) a Bodum French Press con-
tainer.
                       4. Jury Trial
    Beginning on November 8, 2010, the court conducted
a jury trial to address three issues: (1) invalidity based on
obviousness; (2) whether Bodum’s infringement of the
asserted claims was willful; and (3) damages.
     On November 10, 2010, near the end of Meyer’s case-
in-chief, Meyer moved the court to preclude Bodum from
introducing and using a modern version of the Bodum 3-
Cup French Press as prior art on grounds that: (1) Bodum
had no corroborating evidence tying the modern version to
that which allegedly pre-dated the Meyer patents; and
(2) it was an attempt to backdoor the court’s prior rulings
limiting the prior art on which Bodum could rely. The
district court granted the motion on the second ground,
and the Bodum 3-Cup French Press was not introduced as
an exhibit at trial.
    Also at the end of Meyer’s case-in-chief, Bodum filed a
motion for JMOL that it did not willfully infringe the
asserted patents. The district court denied that motion on
the record on November 15, 2010.
    On November 17, 2010, the jury returned a verdict in
favor of Meyer, finding that the patents-in-suit were not
invalid and that Bodum’s infringement was willful. The
MEYER INTELL PROP   v. BODUM                              14


jury awarded damages to Meyer in the requested amount
of $50,000.
                  5. Post-Trial Motions
    Following the jury verdict, Meyer filed a motion ask-
ing the court to: (1) award treble damages pursuant to 35
U.S.C. § 284; (2) declare this case exceptional within the
meaning of 35 U.S.C. § 285; and (3) award Meyer its
attorney fees in the amount of $756,487.56. In a decision
dated February 16, 2011, the district court granted
Meyer’s motion, increased the jury’s damage award to
$150,000, and awarded Meyer its full attorney fees.
Meyer Intellectual Props. Ltd. v. Bodum, Inc., 764 F.
Supp. 2d 1004 (N.D. Ill. 2011) (“Decision Awarding Attor-
ney Fees”).
     Bodum subsequently filed two post-trial motions.
First, Bodum filed a renewed motion for JMOL, again
asking the court to find that Bodum did not willfully
infringe the patents-in-suit. In that motion, Bodum
argued that: (1) it did not have knowledge of the ’087 and
’122 Patents prior to the filing of the complaint; (2) Meyer
failed to move for a preliminary injunction, and thus could
not show willful infringement under In re Seagate Tech-
nology, LLC, 497 F.3d 1360 (Fed. Cir. 2007) (en banc);
(3) Bodum’s efforts to design around the patents-in-suit
demonstrate that it was not objectively reckless; and
(4) Bodum raised substantial questions of non-
infringement and invalidity.
    Second, Bodum moved the court pursuant to Rule
59(e) of the Federal Rules of Civil Procedure to alter its
previous decisions granting summary judgment of in-
fringement. In that motion, Bodum asked the court to
revisit its prior decisions in light of this court’s December
2010 decision in Akamai Technologies, Inc. v. Limelight
Networks, Inc., 629 F.3d 1311 (Fed. Cir. 2010), vacated,
15                             MEYER INTELL PROP   v. BODUM


419 F. App’x 989 (Fed. Cir. 2011). Specifically, in light of
Akamai, Bodum argued that the court should withdraw
its findings of direct infringement because: (1) Meyer
failed to show that Bodum performed every step of the
asserted claims; (2) the claims are incapable of being
directly infringed by a single third party; and (3) there is
no direct infringement under a divided infringement or
joint infringement theory because Bodum’s customers are
not agents of Bodum, and are not obligated to use the
frothers in any particular way.
    The district court conducted a hearing on March 14,
2011, and denied both of Bodum’s post-trial motions on
the record. First, the court denied Bodum’s renewed
JMOL for the reasons previously stated on the record at
the conclusion of Meyer’s case in chief. With respect to
Bodum’s Rule 59(e) motion, the district judge explained
that he reviewed Akamai and noted that “joint liability
may be found when one party ‘controls or directs’ the
activities of another party.” Tr. of Proceedings held on
Mar. 14, 2011, Meyer Intellectual Props. Ltd. v. Bodum,
Inc., No. 06-cv-6329 (N.D. Ill. Apr. 29, 2011), ECF No.
272, at 4:19-21. The judge then stated that the patented
method here “has only one intended goal. That is the
production of froth liquid such as milk. And the devices
marketed by Bodum have exactly that function. This isn’t
a matter of purchasers that – that where the devices that
Bodum’s customers choose among several possible means
of accomplishing a purpose.” Id. at 6:1-7. The court
concluded that it “would be a solipsism if you permitted
an escape for a party that practices the method up to the
point of its ultimate utilization . . . .” Id. at 7:11-16.
Accordingly, the court found no basis to reverse its prior
rulings granting summary judgment in Meyer’s favor.
MEYER INTELL PROP   v. BODUM                              16


    Bodum timely appealed several of the district court’s
decisions to this court. We have jurisdiction pursuant to
28 U.S.C. § 1295(a)(1).

                        DISCUSSION
     On appeal, Bodum argues that the district court erred
when it: (1) granted summary judgment of direct in-
fringement and inducement of the asserted method
claims, despite the lack of evidence that any one party –
including Bodum – actually performed each step of the
asserted claims; (2) made several evidentiary rulings that
made it impossible for Bodum to present its case;
(3) dismissed Bodum’s affirmative defense of inequitable
conduct on a motion in limine; and (4) denied Bodum’s
JMOL of no willful infringement. We address each of
these issues in turn.
                     A. Infringement
     The district court issued two separate decisions grant-
ing summary judgment that Bodum directly infringed and
induced infringement of the patents-in-suit. First, with
respect to Bodum’s Version 1 frothers, the court found
that: (1) Bodum conceded direct infringement; and
(2) whenever a Bodum customer uses its milk frother and
follows the instructions contained therein, that customer
directly infringes the patents-in-suit, and Bodum induces
the same as a matter of law. Summary Judgment Ver-
sion 1, 597 F. Supp. 2d at 794, 798-99. Bodum moved the
district court to clarify its decision, arguing that it could
not be a direct infringer because it only practices the first
step of the claim – “providing a container” – and its cus-
tomers could not be direct infringers because, while they
practice each of the other steps, they do not practice the
“providing” step. The district court judge conducted a
status hearing and explained to Bodum that:
17                              MEYER INTELL PROP   v. BODUM


     I took a look at the box that contains this plunger.
     And everything that you have done is everything
     except hold the customer’s hand on the plunger. I
     mean you know, you have given the direct – you
     have got essentially a one purpose invention. And
     you have done everything, including the first step
     to practice the thing, because again all that you
     lack is putting your client’s hot hand on the
     plunger, because you instructed the customer,
     “Here is how you use the thing.”
Tr. of Proceedings held on May 1, 2009, Meyer Intellectual
Props. Ltd. v. Bodum, Inc., No. 06-cv-6329 (N.D. Ill. May
5, 2011), ECF No. 273 at 5:12-20. Accordingly, the court
denied Bodum’s motion to clarify.
    The district court subsequently granted Meyer’s mo-
tion for summary judgment that Bodum’s sale of the
Version 2 frothers infringe the claims of the ’122 Patent,
finding that: (1) Bodum must have tested its products
before putting them on the market; and (2) ”[t]hough
Meyer does not provide evidence of specific instances of
direct infringement by Bodum’s customers, such proof is
not required because . . . Version 2 ‘necessarily infringes’
the patented method when operated as directed.” Sum-
mary Judgment Version 2, 674 F. Supp. 2d at 1018, 1021. 3
    We review the district court’s grant of summary
judgment without deference, drawing all reasonable
inferences in favor of the nonmoving party. King Pharm.,
Inc. v. Eon Labs., Inc., 616 F.3d 1267, 1273 (Fed. Cir.
2010). Summary judgment is appropriate when there are

     3   After trial, the court denied Bodum’s Rule 59(e)
motion to alter the court’s prior summary judgment
decisions, reiterating that Bodum’s products have one
goal – to froth milk – and that Bodum cannot avoid liabil-
ity by claiming that it does not use the device.
MEYER INTELL PROP   v. BODUM                             18


no genuine issues of material fact and the moving party is
entitled to judgment as a matter of law. Fed. R. Civ. P.
56. Evaluating a district court decision granting sum-
mary judgment of infringement requires two steps:
(1) claim construction; and (2) comparison of the properly
construed claims to the accused product or process.
Abbott Labs. v. Sandoz, Inc., 566 F.3d 1282, 1288 (Fed.
Cir. 2009).
    Where, as here, the asserted patent claims are
method claims, the sale of a product, without more, does
not infringe the patent. i4i Ltd. P’ship v. Microsoft Corp.,
598 F.3d 831, 850 (Fed. Cir. 2010) (citation omitted).
Instead, direct infringement of a method claim requires a
showing that every step of the claimed method has been
practiced. Lucent Techs., Inc. v. Gateway, Inc., 580 F.3d
1301, 1317 (Fed. Cir. 2009).
    Under 35 U.S.C. § 271(b), a party who “actively in-
duces infringement of a patent shall be liable as an in-
fringer.” To prevail on an inducement claim, a patentee
must establish that: (1) there has been direct infringe-
ment; (2) the defendant, with knowledge of the patent,
actively and knowingly aided and abetted such direct
infringement. DSU Med. Corp. v. JMS Co., 471 F.3d
1293, 1305 (Fed. Cir. 2006) (en banc).       It is well-
established that a finding of direct infringement is a
prerequisite to a finding of inducement. Ricoh Co. v.
Quanta Computer Inc., 550 F.3d 1325, 1341 (Fed. Cir.
2008) (“[A] finding of inducement requires a threshold
finding of direct infringement.”).
    On appeal, Bodum argues both that the district court
assumed that acts of direct infringement occurred when
there was no evidence in the record that they did and that
the district court misapplied the law with respect to
inducement in the context of method claims. According to
19                             MEYER INTELL PROP   v. BODUM


Bodum, because there was no evidence that any single
party, including Bodum itself, actually performed each
step of the asserted method claims, there can be no find-
ing of direct infringement or inducement. Since this
court’s decision in Akamai has been vacated pending en
banc review, Bodum relies upon our decision in BMC
Resources, Inc. v. Paymentech, L.P., 498 F.3d 1373 (Fed.
Cir. 2007) to support its argument.
    Meyer responds that: (1) as the district court held,
Bodum waived its direct infringement argument with
respect to Version 1; and (2) Bodum’s own witnesses
admitted actual use of Bodum’s Version 1 and Version 2
frothers during testing of the frothers. Notably, Meyer
abandons its argument that a finding of infringement can
be premised on the acts of its own expert during the
course of litigation. Meyer neither cites nor discusses
BMC in its brief to this court. 4
    For the reasons discussed below, we conclude that the
district court erred in granting summary judgment of
infringement with respect to both the Version 1 and
Version 2 frothers because the record was inadequate to
support such a conclusion as a matter of law. In reaching
this conclusion, we find no reason to discuss or apply this
court’s case law on divided infringement or to await its
clarification en banc because we find that, properly con-

     4  On appeal, Bodum separately argues that its Ver-
sion 2 frother cannot infringe because it does not have a
spring biasing screen, as is required in Claims 19 and 23
of the ’122 Patent. In response, Meyer argues that:
(1) there is no spring limitation in Claims 19 or 23 of the
’122 Patent; and (2) the O-ring present in the Version 2
frother is the equivalent of the spring specified in certain
claims of the patents-in-suit. Appellees’ Br. 54-55. Be-
cause we find issues of material fact with respect to direct
infringement and inducement, we need not address
Bodum’s additional arguments at this stage.
MEYER INTELL PROP   v. BODUM                              20


strued, each step of the method claims could be performed
by a single user.
                        1. Waiver
    First, we disagree with the district court’s finding that
Bodum conceded direct infringement as to its Version 1
frother. In its initial motion seeking summary judgment,
Meyer’s sole argument with respect to direct infringement
was that “literal and direct infringement exists by one,
such as Meyer’s expert, Albert Karvelis, when practicing
the method prescribed in Bodum’s instructions while
using Bodum’s accused milk frothers.” Mem. in Supp. of
Pls.’ Mot. for Partial Summ. J., Meyer Intellectual Props.
Ltd. v. Bodum, Inc., No. 06-cv-6329, (N.D. Ill. Sept. 2,
2008), ECF No. 90 at 8 (emphasis added). Meyer did not
argue that anyone other than Mr. Karvelis practiced each
step of the claimed method by using Bodum’s Version 1
frother. Nor did Meyer offer evidence of or even argue
that anyone at Bodum ever practiced every step of the
method claim or that there was any known customer who
did so.
    In response, Bodum both rejected the notion that Mr.
Karvelis’ actions could constitute acts of infringement and
argued that no single person or entity – not even Mr.
Karvelis – could perform all steps of the method claim
because Bodum itself practiced the “providing a con-
tainer” step, and only that step. Recognizing that induced
infringement requires proof of both direct infringement
and that the alleged inducer knowingly aided and abetted
that direct infringement, Bodum argued that:
    Meyer’s allegation of direct infringement is im-
    proper for at least the reason that, as drafted, no
    one party can directly infringe any of the inde-
    pendent method claims. Only Bodum performs
    the first step of each independent claim, the step
21                             MEYER INTELL PROP   v. BODUM


     of providing a container or housing associated
     with its Accused Products. The remaining steps
     are each performed only by Bodum’s customers.
     As a result there is no direct infringement and
     consequently, no inducement.
Def.’s Mem. in Opp’n, Meyer Intellectual Props. Ltd. v.
Bodum, Inc., No. 06-cv-6329, (N.D. Ill. Nov. 21, 2008),
ECF No. 99 at 13. Given this language, we find that the
district court erred in concluding that Bodum “raise[d] no
defense to the argument that its products directly in-
fringed the Meyer Patents.” Summary Judgment Version
1, 597 F. Supp. 2d at 794. In these circumstances, we
agree with Bodum that no waiver occurred.
                 2. Claim Construction
    Resolution of the parties’ dispute turns, in large part,
on the construction of the term “providing” as it is used in
the patent claims. Claim construction is an issue of law
subject to de novo review on appeal. See Cybor Corp. v.
FAS Techs., Inc., 138 F.3d 1448, 1456 (Fed. Cir. 1998) (en
banc).
     To ascertain the scope and meaning of the asserted
claims, we look to the claim language, the specification,
the prosecution history, and any relevant extrinsic evi-
dence. Phillips v. AWH Corp., 415 F.3d 1303, 1315-17
(Fed. Cir. 2005) (en banc). As a general rule, a claim term
is given the plain and ordinary meaning as understood by
a person of ordinary skill in the art at the time of inven-
tion. Id. at 1312-13.
    Although claim construction begins with the language
of the claims themselves, the claims “must be read in view
of the specification, of which they are a part.” Markman
v. Westview Instruments, Inc., 52 F.3d 967, 979 (Fed. Cir.
1995) (en banc). Indeed, the specification “is the single
MEYER INTELL PROP   v. BODUM                             22


best guide to the meaning of a disputed term” and it “acts
as a dictionary when it expressly defines terms used in
the claims or when it defines terms by implication.”
Phillips, 415 F.3d at 1321 (quoting Vitronics Corp. v.
Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)).
We have also recognized that dictionaries “are often
useful to assist in understanding the commonly under-
stood meaning of words.” Id. at 1322. As such, we have
held that judges are free to rely on dictionary definitions
when construing claims, “so long as the dictionary defini-
tion does not contradict any definition found in or ascer-
tained by a reading of the patent documents.” Id. at 1322-
23 (quoting Vitronics, 90 F.3d at 1584 n.6).
     As noted, representative Claim 1 of the ’087 Patent
generally discloses four steps: (1) providing a container
with a 2:1 height to diameter ratio; (2) pouring milk into
the container; (3) introducing a plunger; and (4) pumping
the plunger to aerate the liquid. The parties’ summary
judgment arguments, and the district court’s ruling
thereon, focused on the first step: “providing a container.”
It is undisputed that the patents-in-suit do not explicitly
define the term “providing.”
    During claim construction, neither party asked the
court to construe the term “providing.” Although claim
construction is a question of law, we are generally hesi-
tant to construe claim terms for the first time on appeal.
Wavetronix v. EIS Elec. Integrated Sys., 573 F.3d 1343,
1355 (Fed. Cir. 2009). Under the circumstances of this
case, however, we find it appropriate to do so. While the
parties specifically addressed the meaning and scope of
this term in their summary judgment briefing to the
district court, the court did not formally construe the
claim term because it found no reason to do so. Instead,
the court found that Bodum could be liable for induced
infringement even if it, and only it, performed the provid-
23                             MEYER INTELL PROP   v. BODUM


ing step because Bodum thereafter directed its customers
on how to perform the remaining steps of the claim.
Because the record is sufficiently developed to enable us
to construe the term, and because the parties’ debate
really focuses on the scope, rather than the meaning of
the claim terms, we choose to address the question the
trial court sidestepped.
     In opposition to Meyer’s motion for summary judg-
ment, Bodum supplied the following dictionary definition
for the word “provide”: “1. To furnish; supply. 2. To make
available; afford. 3. To set down as a stipulation. 4.
Archaic: To make ready ahead of time; prepare.” Am.
Heritage College Dictionary 1102 (3d ed. 2000). Bodum
argued that, because it supplies, furnishes, and otherwise
makes the accused products available for sale, it is the
only party that can carry out the providing step. In its
reply, Meyer agreed that providing should be given its
common ordinary meaning, but argued that “there is no
limitation in the claims on who does the ‘providing,’ and
none exists. Bodum can do the providing or the end user
completing the claimed method steps can do the provid-
ing. In either event, direct infringement occurs.” Reply in
Supp. of Pls.’ Mot. for Partial Summ. J., Meyer Intellectual
Props. Ltd. v. Bodum, Inc., No. 06-cv-6329, (N.D. Ill. Dec.
5, 2008), ECF No. 105 at 13.
    In its decision granting summary judgment as to
Bodum’s Version 1 frothers, the district court acknowl-
edged Bodum’s proffered dictionary definition and its
argument that, because an end user “cannot ‘provide’ the
container as called for by the claims,” Bodum does not
induce infringement. Summary Judgment Version 1, 597
F. Supp. 2d at 798. Rather than analyze the scope of the
term “providing,” however, the district court found that,
even under Bodum’s definition, Bodum’s argument fails
because “it impermissibly distorts the fundamental con-
MEYER INTELL PROP   v. BODUM                            24


cept of patent infringement.” Id. Specifically, the court
held that, “[w]hen any end user ‘uses’ a Bodum milk
frother – a container – that has been ‘provided’ by Bodum,
and in doing so follows Bodum’s instructions detailing the
steps to be taken in such use of the frother . . . it thus
directly infringes the Meyer Patents.” Id. at 798-99.
Notably, however, nothing in the district court’s decision
suggests that Bodum is the only party that can “provide”
the container for use.
    After careful review of the intrinsic evidence, we find
that nothing in the claim language or the patent specifica-
tion limits the “providing” step to a specific party. Under
Bodum’s proffered dictionary definition, it is clear that
Bodum “furnishes” or “supplies” the container by manu-
facturing and selling its milk frothers. It is also clear
under that same definition, however, that anyone who
takes a Bodum frother from the kitchen cabinet and
places it on the counter before filling it with milk can
satisfy the “providing” step. That person has undoubtedly
made the container available for use and prepared it for
frothing. Accordingly, we construe the term “providing” to
mean “furnishing, supplying, making available, or prepar-
ing” and find that anyone – Bodum or the end user of its
products – can satisfy the providing step. Given this
construction, we find that the claims at issue here are
drawn to actions that can be performed by a single party.
                 3. Direct Infringement
    Having concluded that a single party is capable of in-
fringing the patents-in-suit, we move to the parties’
arguments regarding infringement. We turn first to the
issue of direct infringement. As noted, in its motion for
summary judgment with respect to Bodum’s Version 1
frother, Meyer’s only evidence of direct infringement was
the activities of Meyer’s own expert. On appeal, Bodum
25                             MEYER INTELL PROP   v. BODUM


argues that Meyer did not introduce any evidence that
either Bodum or its customers used the claimed method.
Meyer responds that Bodum’s witnesses conceded use.
Again, Meyer does not argue that there was evidence of
customer infringement. For the reasons explained below,
we agree with Bodum that the district court’s judgments
of infringement as to both the Version 1 and Version 2
frothers suffer from the same deficiency: there was no
evidence of direct infringement in the record.
     As to the Version 1 frothers, the district court relied
only on its conclusion that Bodum had conceded direct
infringement, though the court never explained to whom
that concession pertained. Because we find that Bodum
made no such concession, Meyer points to no other evi-
dence of direct infringement as to the Version 1 frothers,
and we find none in the underlying summary judgment
papers, we conclude that the trial court erred in finding
direct infringement as a matter of law as to those froth-
ers.
    In its decision granting Meyer summary judgment
with respect to the Version 2 frothers, the district court
rejected Bodum’s argument that Meyer failed to prove
direct infringement. Specifically, the court found it unbe-
lievable that “an established company such as Bodum
would have placed Version 2 and later Version 3 on the
market for public sale, and would have kept those prod-
ucts on the market for substantial periods of time, with-
out having first confirmed for itself that each product
would perform its allotted task . . . .” Summary Judgment
Version 2, 674 F. Supp. 2d at 1018. In other words, the
court assumed that Bodum must have tested its products.
Given this assumption, the court concluded that Bodum’s
use of the ’122 Patent method “has been established as a
matter of law.” Id.
MEYER INTELL PROP   v. BODUM                             26


     We find it troubling that the district court based its
direct infringement analysis on what it assumed hap-
pened, rather than on actual evidence of record. This
assumption contradicts our well-established law that a
patentee must prove infringement by a preponderance of
the evidence. See Siemens Med. Solutions USA, Inc. v.
Saint-Gobain Ceramics & Plastics, Inc., 637 F.3d 1269,
1279 (Fed. Cir. 2011) (“Patent infringement, whether
literal or by equivalence, is an issue of fact, which the
patentee must prove by a preponderance of the evi-
dence.”). And, by assuming testing without any evidence
in the record, the court improperly drew an inference in
favor of Meyer and against Bodum. Because factual
inferences must be drawn in favor of the nonmoving party
on summary judgment, we find that the district court’s
decision cannot stand. See IMS Tech., Inc. v. Haas Auto-
mation, Inc., 206 F.3d 1422, 1429 (Fed. Cir. 2000) (noting
that, on summary judgment, “[w]e view the evidence in a
light most favorable to the non-movant, and draw all
reasonable inferences in its favor”).
     For the first time on appeal, Meyer cites to deposition
testimony from Bodum’s President, Thomas Perez, as
evidence that Bodum used the claimed method in testing
and developing its frothers. Specifically, Meyer points to
Perez’s testimony that Bodum’s design team always tests
each of its products. Bodum argues that Meyer’s reliance
on this testimony is misplaced because the portions cited
were neither submitted with the motions for summary
judgment nor introduced at trial. In addition, Bodum
points to the testimony of Jorgen Bodum, Bodum’s Chief
Executive Officer (hereinafter referred to as “Jorgen”),
that he conducts product development with his design
team which consists of five people in Hong Kong and
fifteen people in Switzerland. In other words, there is no
27                             MEYER INTELL PROP   v. BODUM


evidence that Bodum used or tested its milk frother
products in the United States.
    We agree with Bodum that Meyer cannot for the first
time on appeal introduce deposition testimony that was
not before the district court when it was deciding the
motions for summary judgment. And, given Jorgen’s trial
testimony that Bodum’s product development team is
located in Hong Kong and Switzerland, Meyer has not –
at this stage – shown any instances of direct infringement
in the United States. Because direct infringement of a
method claim requires that each of the claimed steps are
performed within the United States, the evidence of
record is insufficient as a matter of law to support the
court’s decision granting summary judgment. See NTP,
Inc. v. Research in Motion, Ltd., 418 F.3d 1282, 1318 (Fed.
Cir. 2005) (“We therefore hold that a process cannot be
used ‘within’ the United States as required by section
271(a) unless each of the steps is performed within this
country.”).
     Based on the foregoing, we find that Meyer failed to
point to specific instances of direct infringement and
failed to offer any evidence that someone at Bodum used
its Version 1 and Version 2 frothers. Accordingly, we find
that there are genuine issues of material fact as to
whether anyone at Bodum practiced each step of the
asserted method claims.
    We now turn to the trial court’s conclusion that
Bodum intended that its customers would use the frothers
to produce froth liquid and that the act of frothing there-
after would constitute direct infringement. While it may
be true that Bodum’s customers may be characterized as
direct infringers under our now-controlling construction of
the providing step, Meyer never argued at the summary
judgment stage that they were, and it does not make that
MEYER INTELL PROP   v. BODUM                            28


argument here. Indeed, Meyer presented no evidence in
support of its motion for summary judgment regarding
either product sales or customer use; it relied only on Mr.
Karvelis’ testing of the product. Judgment as a matter of
law on such a sparse record is simply not appropriate.
     Because we conclude that genuine issues of material
fact remain, we reverse the district court’s grant of sum-
mary judgment with respect to Bodum’s Version 1 and
Version 2 frothers and remand for further consideration
in light of our construction of the term “providing.”
                 B. Evidentiary Rulings
     We turn next to Bodum’s challenges to the district
court’s evidentiary rulings. On appeal, Bodum argues
that the district court improperly: (1) excluded Bodum’s
primary prior art, including Bodum’s 3-Cup French Press;
(2) barred Bodum’s expert witness – Anders – from testi-
fying that the asserted patents were invalid for obvious-
ness; and (3) precluded Jorgen from testifying about the
Bodum 3-Cup French Press. Given these rulings, Bodum
argues that it was stripped of its ability to present its
obviousness defense at trial.
    We review the district court’s decision to exclude evi-
dence under the law of the relevant regional circuit.
Research Corp. Techs. v. Microsoft Corp., 536 F.3d 1247,
1255 (Fed. Cir. 2008) (“The Federal Circuit applies its
own law with respect to issues of substantive patent law
and certain procedural issues pertaining to patent law,
but applies the law of our sister circuits to non-patent
issues.”) (citation omitted). The Seventh Circuit – the
pertinent regional circuit in this case – reviews eviden-
tiary rulings for an abuse of discretion. Von Der Ruhr v.
Immtech Int’l, Inc., 570 F.3d 858, 862 (7th Cir. 2009)
(noting that “decisions regarding the admission and
29                             MEYER INTELL PROP   v. BODUM


exclusion of evidence are peculiarly within the compe-
tence of the district court”) (citation omitted).
     In the Seventh Circuit, appellate review of eviden-
tiary rulings is limited to determining “whether an ‘error
in either the admission or the exclusion of evidence’ was
made which affected ‘the substantial rights’ of the plain-
tiffs.” Nachtsheim v. Beech Aircraft Corp., 847 F.2d 1261,
1266 (7th Cir. 1988) (quoting Fed. R. Civ. P. 61). Gener-
ally speaking, “the test of whether a substantial right of a
party has been affected is whether the error in question
affected the outcome of the case.” 2 Jack B. Weinstein &
Margaret A. Berger, Weinstein’s Federal Evidence
§ 103.41[2] (Joseph M. McLaughlin, ed., Matthew Bender
2d ed. 2011).
    More recently, the Seventh Circuit held that “[n]o er-
ror in either the admission or exclusion of evidence is
ground[s] for . . . vacating, modifying, or otherwise dis-
turbing a judgment or order, unless refusal to take such
action appears to the court inconsistent with substantial
justice.” Thompson v. City of Chicago, 472 F.3d 444, 455
(7th Cir. 2006) (quoting Goodman v. Illinois Dept. of Fin.
& Prof. Reg., 430 F.3d 432, 439 (7th Cir. 2005)). The
court recognized that “[e]ven an erroneous evidentiary
ruling can be deemed harmless if the record indicates that
the same judgment would have been rendered regardless
of the error.” Id. (quoting Goodman, 430 F.3d at 439).
Accordingly, Bodum must show both that the district
court erred in excluding evidence and that the exclusion
prejudiced its substantial rights.
     For the reasons explained below, we find that the dis-
trict court abused its discretion in granting Meyer’s
motions in limine and that these evidentiary errors were
prejudicial because they prevented Bodum from present-
ing its obviousness defense. Accordingly, we vacate and
MEYER INTELL PROP   v. BODUM                              30


remand for a new trial to address whether the asserted
claims are invalid as obvious.
                       1. Prior Art
    As previously noted, the district court granted
Meyer’s motions in limine and limited the universe of
prior art on which Bodum could rely. In particular, the
court found that: (1) Bodum’s discovery responses “identi-
fied a not particularly extensive group of [prior art]
items”; and (2) Anders reviewed the fifty-six items listed
in Part A of his report but then “focused solely on just two
of those many items as the actual predicates for his stated
conclusions.” Meyer v. Bodum, 2010 U.S. Dist. LEXIS
56168, at *2-4. In its proposed list of exhibits in the Final
Pretrial Order, however, Bodum included what the court
characterized as a “laundry list” of prior art exhibits.
Because it found that Bodum’s discovery responses and
expert report narrowed the relevant prior art, the court
found that Bodum could rely only on two items of prior art
at trial: the Reissue Ghidini Patent and the Bodum
French 3-Cup French Press. As discussed below, more-
over, at trial, the court further limited Bodum’s introduc-
tion of evidence to exclude the Bodum 3-Cup French
Press.
    Bodum explains that, prior to trial, its invalidity posi-
tion was that each claim of the ’087 and ’122 Patents is
made obvious by a combination of the Bodum 3-Cup
French Press and the Reissue Ghidini Patent. 5 According

    5     Bodum was not allowed to use the Ghidini Reis-
sue Patent as prior art because it did not pre-date the
patents-in-suit. It was, however, permitted to use the
original Ghidini patent – United States Patent No.
5,580,169 (“the ’169 Patent”) – which predated the as-
serted patents, and both Ghidini Patents were admitted
at trial.
31                              MEYER INTELL PROP   v. BODUM


to Bodum, its 3-Cup French Press “teaches all of the
elements required in the ’087 and ’122 Patents with the
exception of using a coffee press as a frother,” and the
Reissue Ghidini Patent teaches a method for frothing
milk in a container with a plunger assembly. Appellant’s
Br. 17. Bodum contends that, had it been permitted to
offer the wrongfully excluded exhibits, “it would have
been clear to the jury that the combination of at least the
Bodum 3-Cup French Press and the Reissue Ghidini
Patent show all of the features of the claimed invention.”
Id. at 20.
    On appeal, Bodum argues that the district court erred
when it excluded its 3-Cup French Press as well as the
other prior art that was disclosed both during discovery
and in Anders’ report. In response, Meyer argues that
Bodum’s prior art was not properly disclosed and that the
relevant scope of prior art was narrowed by Bodum’s own
expert. We disagree with Meyer.
     We turn first to the district court’s exclusion of prior
art that Bodum disclosed in its interrogatory responses.
During discovery, Meyer asked Bodum to identify and
explain the factual bases for Bodum’s claim that the
patents at issue were invalid. In its Second Supplemental
Answers to Interrogatories 2 and 3, Bodum identified,
among other things, its prior Chambord French Press
products, the Insta-Brewer French Press coffee maker,
which “includes a container that is at least twice as tall as
it is wide and includes a plunger structure,” advertise-
ments for the Insta-Brewer showing that it was available
for sale in 1965, a still frame image from the movie “The
Ipcress File” which showed use of the Insta-Brewer in
1965, the file history of the Reissue Ghidini Patent, and
catalogs showing that the Bodum 3-Cup French Press was
offered for sale in the United States prior to 1995. In-
deed, at oral argument, counsel for Meyer conceded that,
MEYER INTELL PROP   v. BODUM                               32


at a minimum, the following prior art was disclosed in
Bodum’s interrogatory responses: “certainly the 3 cup was
in there, the Ghidini Patent was in there, there was also,
I think, a digital image from a movie, there was also a
catalog.” See Oral Argument at 17:45, available at
http://www.cafc.uscourts.gov/oral-argument-
recordings/2011-1329/all.
     Turning to the prior art discussed in Anders’ report,
careful review of Part C reveals that Anders’ opinion on
obviousness was not, as the district court found, limited to
just two pieces of prior art. Indeed, Part C of the report
specifically references: (1) the Ghidini Reissue Patent;
(2) the Bodum French Press; and (3) the “drawing of a
Bodum French press container dated 6.2.84 with Bates
number B01781 shows a container having a height that is
two times the diameter.” J.A. 4378. The district court
trifurcated Anders’ report and found that the list of
documents included in Part A were not relied upon with
respect to obviousness because they were not substan-
tively discussed in Part C. The fact remains, however,
that those references in Part A – including the Bodum
Chambord 3-cup coffee maker and catalog pages of Bodum
products – were included in the expert report and were,
thus, provided to Meyer.
    Even assuming we agree with the district court that
Anders relied only on the specific prior art listed in Part C
for his obviousness opinion, the district court still erred in
using the Anders’ report to limit Bodum’s ability to pre-
sent, through other witnesses at trial, prior art that was
previously disclosed during discovery. If anything, the
scope and content of Anders’ report should operate only to
limit his testimony at trial – not the testimony of any
other witnesses.
33                             MEYER INTELL PROP   v. BODUM


    Meyer concedes that it received Bodum’s interroga-
tory responses, and thus was on notice of Bodum’s intent
to use the prior art included therein. 6 Meyer nonetheless
contends the court was correct to prohibit reliance on that
art at trial, however. During oral argument, counsel for
Meyer explained that, although it knew about the prior
art in Bodum’s discovery responses, “there was a further
narrowing as to what the case was going to be . . . in the
expert report.” Oral Argument at 19:40. Counsel ex-
plained that the district court ultimately precluded
Bodum’s expert from testifying as to obviousness, and
that the court “felt that this [other prior art disclosed
during discovery] should not come in without expert
testimony coming in with it because it was just going to
lead to speculation from the jury.” Id. at 23:54.
    Where, as here, the technology involved is simple, we
can think of no explanation for excluding prior art that
was disclosed in interrogatory responses but was not
relied upon in an expert report. As this court recently
reiterated, “[t]here is no invariable requirement that a
prior art reference be accompanied by expert testimony.”
In re Brimonidine Patent Litig., 643 F.3d 1366, 1376 (Fed.
Cir. 2011) (citation omitted). It is well-established, more-
     6  In its decision, the district court stated that
Bodum never supplemented its initial discovery responses
and that “Bodum’s initial response has set the outer
boundaries of the potential ‘prior art’ universe.” Meyer,
2010 U.S. Dist. LEXIS 56168, at *2. To the contrary,
however, Meyer admits in its briefing in support of its
motion in limine that it received, and was relying upon,
Bodum’s Second Supplemental Answers to Plaintiffs’
Interrogatories Nos. 2 and 3 dated March 18, 2009. Mem.
in Supp. of Pls.’ Mot. in Limine, Meyer Intellectual Props.
Ltd. v. Bodum, Inc., No. 06-cv-6329 (N.D. Ill. Apr. 29,
2010), ECF No. 167, at 2 n.1. As such, the district court
erred in finding that Bodum did not supplement its dis-
covery responses.
MEYER INTELL PROP   v. BODUM                             34


over, that, where the technology involved is easily under-
standable, expert testimony is not required. Wyers v.
Master Lock Co., 616 F.3d 1231, 1242 (Fed. Cir. 2010); see
also Centricut, LLC v. Esab Group, Inc., 390 F.3d 1361,
1369 (Fed. Cir. 2004) (“In many patent cases expert
testimony will not be necessary because the technology
will be ‘easily understandable without the need for expert
explanatory testimony.’” (citation omitted)).
    The district court’s evidentiary errors improperly nar-
rowed the scope of prior art that Bodum could introduce
at trial and prevented Bodum from using its primary
piece of prior art – the Bodum 3-Cup French Press.
Because we find that the court’s erroneous evidentiary
rulings prejudiced Bodum’s ability to present its invalid-
ity defense, we vacate and remand for a new trial on
obviousness.
                    2. Expert Testimony
    Bodum next argues that the district court erred in
granting Meyer’s motion to exclude Anders’ testimony. In
response, Meyer contends that Anders offered a conclu-
sory opinion with no explanation or support and that the
district court properly excluded his testimony under Rule
26(a) of the Federal Rules of Civil Procedure. 7
    Rule 26(a) requires disclosure of a written expert re-
port that contains “a complete statement of all opinions

   7    On appeal, Meyer also argues that the district
court relied on Rule 702 of the Federal Rules of Evidence
in excluding Anders, and that this court can only reverse
the district court’s ruling if it is “manifestly erroneous.”
Appellees’ Br. 34-35. Notably, however, Meyer moved to
bar Anders’ testimony solely under Rule 26 – not Rule
702. And, although the district court’s decision briefly
mentions Rule 702, the court focuses its analysis on Rule
26(a)(2)(B)(i).
35                               MEYER INTELL PROP   v. BODUM


the witness will express and the basis and reasons for
them.” Fed. R. Civ. P. 26(a)(2)(B)(i). The purpose of this
rule is “to convey the substance of the expert’s opinion . . .
so that the opponent will be ready to rebut, to cross-
examine, and to offer a competing expert if necessary.”
Walsh v. Chez, 583 F.3d 990, 994 (7th Cir. 2009).
     In the patent context, an expert report that merely
lists a number of prior art references and concludes that
one skilled in the art would find the claims obvious is
deficient under Rule 26. Innogenetics, N.V. v. Abbott
Labs., 512 F.3d 1363, 1373 (Fed. Cir. 2008). In Innogenet-
ics, for example, we found that the expert’s report failed to
“state how or why a person ordinarily skilled in the art
would have found the claims . . . obvious in light of some
combination of those particular references.” Id. Given
this deficiency, we affirmed the district court’s decision
precluding the expert’s vague and conclusory testimony
regarding obviousness. Id. at 1374.
     Here, the district court found that Anders’ report
failed to comply with Rule 26, and that Anders advanced
“his opinion as a mere ipse dixit . . . .” Meyer, 715 F.
Supp. 2d at 830. In reaching this decision, the district
court relied heavily on Innogenetics, suggesting that it
“might well have been written for this case.” Id. We
disagree. Unlike the situation in Innogenetics, here,
Anders’ report does more than merely list prior art refer-
ences and provide a conclusion of obviousness.
    First, Anders defined a person of ordinary skill in the
art as someone who has “an undergraduate degree in
industrial design or mechanical engineering, with one to
three years experience” or, in the alternative, “a person
without a degree but with five or more years of practical
experience in the consumer products or housewares
industry.” Expert Report of Robert John Anders, Meyer
MEYER INTELL PROP   v. BODUM                             36


Intellectual Props. Ltd. v. Bodum, Inc., No. 06-cv-6329
(N.D. Ill. Nov. 16, 2010), ECF No. 217 at 27. Anders then
provided detailed claim charts comparing the asserted
claims to the relevant prior art. As previously noted, the
claim charts in Part C of Anders’ report identify three
items of prior art: (1) the Ghidini Reissue Patent; (2) the
Bodum French Press; and (3) the “drawing of a Bodum
French press container dated 6.2.84” with a height that is
two times the diameter.
    In his report, Anders explained that “a designer of or-
dinary skill in the art at the time of the claimed invention
would have been familiar with the methods for aerating
milk based liquids as well as with the structure of the
French press apparatus, and thus the combination would
have been obvious to said designer.” Id. at 29. In Anders’
opinion, all Brady did was “copy an old apparatus which
was also known to be capable of frothing milk . . . and
fabricate a ‘method’ that was in fact also old and well
known and detailed in the prior art patents.” Id. Given
these circumstances, Anders concluded that the patents-
in-suit are invalid for obviousness.
    Careful review of Anders’ report reveals that it con-
tains a sufficiently detailed statement of his opinions and
the bases for his conclusions. This is particularly true
given that the technology involved in this case – using a
plunger to froth milk in a container – is not complex.
According to Anders, the patents-in-suit are obvious
because one skilled in the art would have been motivated
based on familiarity with the prior art to combine the
known method for aerating milk in a frother with the
structure of a French press. In other words, Anders
invoked the common sense of one skilled in the art as
evidence of motivation to combine prior art references.
Given the technology involved, we find no fault in Anders’
reliance on common sense in rendering his obviousness
37                             MEYER INTELL PROP   v. BODUM


opinion. Indeed, this court has specifically recognized
that the common sense of one skilled in the art can play a
role in the obviousness analysis. See Perfect Web Techs.,
Inc. v. InfoUSA, Inc., 587 F.3d 1324, 1329 (Fed. Cir. 2009)
(holding that “an analysis of obviousness . . . may include
recourse to logic, judgment, and common sense available
to the person of ordinary skill [which] do[es] not necessar-
ily require explication in any reference or expert opin-
ion”).
     Because the technology involved is simple and com-
mon sense would motivate one of skill in the art to make
the combination, Anders’ report is sufficiently detailed.
Accordingly, we conclude that the district court abused its
discretion when it excluded Anders’ testimony. We fur-
ther find that the exclusion of Anders’ testimony was not
harmless because it impaired Bodum’s ability to present
its obviousness defense. And, as Bodum points out in its
brief, while Meyer’s expert was permitted to testify as to
why the patent was not obvious, the exclusion of Anders’
testimony made it look as though Bodum had no rebuttal.
                    3. Lay Testimony
    Prior to trial, the district court ruled that Bodum
could not introduce testimony from lay witnesses to
expand the scope of prior art on which its expert relied.
Although Bodum intended to have Jorgen introduce and
authenticate a Bodum 3-Cup French Press at trial, the
district court ultimately prohibited any such testimony on
grounds that it was an impermissible attempt to “back-
door” the court’s prior orders excluding prior art.
    On appeal, Bodum argues that the district court erred
in refusing to let Jorgen testify to issues that were within
his personal knowledge, including the Bodum 3-Cup
French Press and catalogs and drawings depicting the
features of that device prior to the filing of the applica-
MEYER INTELL PROP   v. BODUM                              38


tions that resulted in the patents-in-suit. In response,
Meyer argues that the district court acted within its
discretion in refusing to let Jorgen testify be-
cause uncorroborated testimony from interested parties is
insufficient to invalidate a patent under the so-called
Barbed Wire doctrine.
     The     “Barbed   Wire    doctrine”   provides   that
“[c]orroboration is required of any witness whose testi-
mony alone is asserted to invalidate a patent.” TypeRight
Keyboard Corp. v. Microsoft Corp., 374 F.3d 1151, 1159
(Fed. Cir. 2004) (citation omitted); see also Checkpoint
Sys., Inc. v. All-Tag Sec. S.A., 412 F.3d 1331, 1339 (Fed.
Cir. 2005) (“The law has long looked with disfavor upon
invalidating patents on the basis of mere testimonial
evidence absent other evidence that corroborates that
testimony.”) (citation omitted). We have explained that
this requirement “arose out of a concern that inventors
testifying in patent infringement cases would be tempted
to remember facts favorable to their case by the lure of
protecting their patent or defeating another’s patent.”
Mahurkar v. C.R. Bard, Inc., 79 F.3d 1572, 1577 (Fed.
Cir. 1996); see also Barbed Wire Patent, 143 U.S. 275, 284
(1892) (recognizing that testimony regarding invalidity
can be “unsatisfactory” given “the forgetfulness of wit-
nesses, their liability to mistakes, their proneness to
recollect things as the party calling them would have
them recollect them, aside from the temptation to actual
perjury . . . .”).
    Bodum argues that the Barbed Wire doctrine does not
apply here because: (1) the district court did not rely on it
in excluding the testimony; and (2) Bodum is not relying
on oral testimony alone to prove invalidity. We agree
with Bodum on both points.
39                              MEYER INTELL PROP   v. BODUM


    First, as noted, the district court excluded Jorgen’s
testimony on grounds that its proffer was an attempt to
“backdoor” the judge’s prior ruling excluding Anders’
expert testimony. Meyer, 2010 U.S. Dist. LEXIS 107169,
at *3. Nowhere in that order did the court cite to or rely
upon the Barbed Wire doctrine. When counsel for Meyer
invoked the Barbed Wire doctrine on the record during
trial, the court reiterated its earlier order limiting
Bodum’s prior art and simply stated that: “whether it
happens to be supported or not by the barbed wire theory,
which I think tends to sort of, in a way, corroborate it, is
really not the point. So I am not permitting it.” Tr. of
Proceedings held on Nov. 10, 2010, Meyer Intellectual
Props. Ltd. v. Bodum, Inc., No. 06-cv-6329 (N.D. Ill. Apr.
29, 2011), ECF No. 267 at 459:13-460:17. Accordingly, the
record reveals that the district court did not base its
decision on the Barbed Wire doctrine.
    Second, Meyer’s reliance on the Barbed Wire doctrine
is misplaced because Bodum did not seek to rely on uncor-
roborated oral testimony to establish invalidity. Instead,
Bodum proffered Jorgen to testify that the version of the
Bodum 3-Cup French Press it sought to introduce into
evidence was an accurate example of the product as it
existed prior to the patents-in-suit. According to Bodum,
Jorgen would have testified that the design of the Bodum
3-Cup French Press has not changed in any material
respect since 1982, and that it includes: (1) a carafe with a
2:1 height to diameter ratio; and (2) a plunger mechanism
almost identical to that disclosed in the patents-in-suit.
    To corroborate Jorgen’s testimony, Bodum intended to
offer drawings of the carafe and pages from its catalogs –
all of which predated the patents-in-suit. According to
Bodum, the drawings and catalogs show that the Bodum
3-Cup French Press has the dimensional requirements
and plunger disclosed in the patents-in-suit, and that
MEYER INTELL PROP   v. BODUM                             40


those features were present in the model that pre-dated
Meyer’s patents. Although Meyer convinced the district
court that Bodum’s reliance on the catalogs and drawings
was an attempt to establish those documents as prior art
to get around the court’s prior orders limiting the scope of
prior art admissible at trial, it is clear that Bodum was
relying on those documents to corroborate Jorgen’s testi-
mony – not as independent prior art. Given this corrobo-
rating evidence, the Barbed Wire doctrine would not have
barred Jorgen’s testimony.
     Finally, we agree with Bodum that, given the simplic-
ity of the technology involved, the jury could have consid-
ered the Bodum 3-Cup French Press, other documents
disclosed during discovery, and lay testimony to reach its
decision regarding obviousness. This is not a situation
where Bodum sought to have a lay witness give his own
opinion regarding invalidity. Indeed, as counsel for
Bodum explained to the district court: “we are not asking
them to give an opinion. Mr. Bodum is going to testify
about facts. Was this [3-Cup French Press] on sale? Yes.
Is it – was it sold in 1982? Yes.” Tr. of Proceedings held
on Nov. 10, 2010, Meyer Intellectual Props. Ltd. v. Bodum,
Inc., No. 06-cv-6329 (N.D. Ill. Apr. 29, 2011), ECF No. 267
at 460:18-20. In these circumstances, we see no problem
with having Bodum’s CEO of thirty-six years testify to
factual matters within his personal knowledge where
those facts are supported by corroborating documentation.
    Accordingly, we hold that the district court erred in
granting Meyer’s motion in limine barring Jorgen Bodum
from testifying as to the Bodum 3-Cup French Press and
the related drawings and catalogs. This error – coupled
with each of the district court’s evidentiary errors dis-
cussed above – had the cumulative effect of preventing
Bodum from presenting the substance of its obviousness
defense. The district court’s exclusion of Bodum’s primary
41                              MEYER INTELL PROP   v. BODUM


exhibits and related testimony resulted in a one-sided
trial and we find that the court’s errors were not harm-
less. On remand, the court should permit Jorgen to
testify as to those matters within his personal knowledge
with the corroborating documentation Bodum has identi-
fied and previously disclosed during discovery.
                 C. Inequitable Conduct
    Prior to trial, the district court granted Meyer’s mo-
tion in limine to bar Bodum from presenting evidence in
support of its inequitable conduct defense. Specifically,
the court found that Bodum “failed to meet the demand-
ing requirements” to prove inequitable conduct. Meyer,
2010 U.S. Dist. LEXIS 56168, at *9. Bodum filed a mo-
tion asking the court to reconsider its decision. In that
motion, Bodum argued that the court erred in transform-
ing Meyer’s request to limit evidence into a motion for
summary judgment of no inequitable conduct without
giving Bodum a chance to introduce all evidence that
would be relevant to the court’s decision. The court
denied Bodum’s motion to reconsider in a minute entry on
August 4, 2010, and Bodum was barred from presenting
any evidence regarding inequitable conduct at trial.
    On appeal, Bodum argues that the district court erred
by dismissing its affirmative defense of inequitable con-
duct on a motion in limine. In response, Meyer argues
that, even if the district court erred, that error was harm-
less because there is no right to a jury trial on inequitable
conduct.
    As previously noted, the exclusion of evidence on a
motion in limine is an evidentiary ruling reviewed for an
abuse of discretion. Mid-America Tablewares, Inc. v.
Mogi Trading Co., 100 F.3d 1353, 1362 (7th Cir. 1996).
The Seventh Circuit has held that a motion in limine is
not the appropriate vehicle for weighing the sufficiency of
MEYER INTELL PROP   v. BODUM                             42


the evidence. Specifically, in Mid-America, the court
stated that, while argument regarding the sufficiency of
the evidence “might be a proper argument for summary
judgment or for judgment as a matter of law, it is not a
proper basis for a motion to exclude evidence prior to
trial.” Id. at 1362-63 (affirming the district court’s deci-
sion denying a motion in limine to exclude evidence of lost
profits and noting that the “determination as to whether
future profits were within the contemplation of the par-
ties when contracting necessarily turns on the specific
facts established at trial”).
    After careful review of the record, we conclude that
the district court erred in addressing the sufficiency of
Bodum’s inequitable conduct defense on an evidentiary
motion. We agree with Bodum that the district court
essentially converted Meyer’s motion in limine into a
motion for summary judgment. In doing so, the court did
not allow for full development of the evidence and de-
prived Bodum of an opportunity to present all pertinent
material to defend against the dismissal of its inequitable
conduct defense. Although both parties argue the merits
of Bodum’s inequitable conduct defense on appeal, we
need not address those arguments at this stage. Because
we conclude that it was procedurally improper for the
court to dispose of Bodum’s inequitable conduct defense
on a motion in limine, we reverse the court’s decision and
remand for further proceedings.
                      D. Willfulness
    The jury found in favor of Meyer on the issue of will-
fulness. After the jury verdict, Bodum filed a renewed
motion for JMOL that it did not willfully infringe the
patents-in-suit. On March 14, 2011, the district court
denied Bodum’s motion in an oral ruling on the record
and entered a minute entry to that effect. The court later
43                               MEYER INTELL PROP   v. BODUM


granted Meyer’s motion to enhance damages and award
Meyer its attorney fees, stating that: (1) ”the jury’s find-
ing of willfulness implies that Bodum was aware of
Meyer’s products and, as already indicated, Bodum copied
those products in every relevant way”; and (2) there was
“serious trial misconduct on Bodum’s part” including that
“Bodum moved to allow their lay witnesses to testify
about asserted prior art that this Court had previously
excluded because those items had not been designated as
relevant prior art by Bodum’s retained expert.” Decision
Awarding Attorney Fees, 764 F. Supp. 2d at 1008-09.
    On appeal, Bodum argues both that the court erred in
denying its motion for JMOL of no willful infringement,
and that enhanced damages and attorney fees are not
warranted. Given our decision to remand this case for a
new trial to address infringement and invalidity, we
vacate the jury’s verdict of willfulness and the district
court’s decision denying Bodum JMOL that it did not
willfully infringe the patents-in-suit. On remand, Bard
Peripheral Vascular, Inc. v. W.L. Gore & Associates, Inc.,
682 F.3d 1003 (Fed. Cir. 2012), may be a helpful starting
place for any future analysis of willfulness.
    Because we vacate the jury’s finding of willfulness, we
also vacate the district court’s decision awarding en-
hanced damages to Meyer. See i4i, 598 F.3d at 858 (“A
finding of willful infringement is a prerequisite to the
award of enhanced damages.”). With respect to attorney
fees, the district court based its decision, at least in part,
on the willfulness verdict and Bodum’s alleged litigation
misconduct in its presentation of evidence. Because we
have herein reversed the district court’s evidentiary
rulings and vacated the willfulness verdict, we also vacate
the award of attorney fees.
MEYER INTELL PROP   v. BODUM                            44


                       CONCLUSION
   For the foregoing reasons, we:
    (1)   reverse the district court’s decision
          granting summary judgment that
          Bodum’s Version 1 frother infringed the
          patents-in-suit;
    (2)   reverse the district court’s decision
          granting summary judgment that
          Bodum’s Version 2 frother infringed the
          ’122 Patent;
    (3)   reverse the district court’s decisions pre-
          cluding Bodum from introducing prior
          art that was disclosed during discovery
          and preventing Jorgen Bodum from tes-
          tifying as to the Bodum 3-Cup French
          Press and other prior art evidence;
    (4)   reverse the district court’s decision bar-
          ring Bodum’s expert from testifying on
          the issue of obviousness;
    (5)   reverse the district court’s decision pre-
          cluding Bodum from introducing any
          evidence of inequitable conduct;
    (6)   vacate the district court’s decision deny-
          ing Bodum JMOL that it did not will-
          fully infringe the patents-in-suit and
          therefore vacate the jury’s verdict of
          willfulness; and
    (7)   vacate the district court’s decision en-
          hancing damages and awarding attor-
          ney fees to Meyer.
    This case is remanded for further proceedings consis-
tent with this opinion.
45                         MEYER INTELL PROP   v. BODUM


     REVERSED-IN-PART, VACATED-IN-PART, and
                  REMANDED
                       COSTS
     Costs to Bodum.
  United States Court of Appeals
      for the Federal Circuit
               __________________________

 MEYER INTELLECTUAL PROPERTIES LIMITED
      AND MEYER CORPORATION, U.S.,
             Plaintiffs-Appellees,
                            v.
                    BODUM, INC.,
                  Defendant-Appellant.
               __________________________

                       2011-1329
               __________________________

    Appeal from the United States District Court for the
Northern District of Illinois in case no. 06-CV-6329, Judge
Milton I. Shadur.
               __________________________

DYK, Circuit Judge, concurring.
    While I agree with and join the thorough majority
opinion, in looking at this case from a broader perspec-
tive, one cannot help but conclude that this case is an
example of what is wrong with our patent system. The
patents essentially claim the use of a prior art French
press coffee maker to froth milk. Instead of making coffee
by using the plunger to separate coffee from coffee
grounds, the plunger is depressed to froth milk. The idea
of frothing cold milk by the use of aeration rather than
steam is not new as reflected in the prior art Ghidini
patent. Under the Supreme Court’s decision in KSR
International Co. v. Teleflex, Inc., 550 U.S. 398, 420
MEYER INTELL PROP   v. BODUM                               2


(2007), and its predecessors, it would be reasonable to
expect that the claims would have been rejected as obvi-
ous by the examiner, and, if not, that they would have
been found obvious on summary judgment by the district
court. But no such thing. The parties have spent hun-
dreds of thousand of dollars and several years litigating
this issue, and are invited by us to have another go of it in
a second trial. Such wasteful litigation does not serve the
interests of the inventorship community, nor does it fulfill
the purposes of the patent system.
