       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

                 ERNIE BALL, INC.,
                  Plaintiff-Appellee,

                           v.

                   EARVANA, LLC,
                 Defendant-Appellant.
                ______________________

                      2012-1276
                ______________________

   Appeal from the United States District Court for the
Central District of California (Riverside) in No. 06-CV-
0384, Judge Jacqueline H. Nguyen.
                 ______________________

               Decided: January 24, 2013
                ______________________

    G. HENRY WELLES, Best Best & Krieger, LLP, of Indi-
an Wells, California, for plaintiff-appellee. With him on
the brief was KIRA L. KLATCHKO.

    CHRISTIAN E. IVERSEN, of Paso Robles, California, for
defendant-appellant.
                ______________________
2                            ERNIE BALL, INC.   v. EARVANA, LLC


 Before NEWMAN, LOURIE, and O'MALLEY, Circuit Judges.
LOURIE, Circuit Judge.
       Defendant-Appellant Earvana, LLC (“Earvana”)
appeals from the final judgment of the United States
District Court for the Central District of California hold-
ing U.S. Patent 6,433,264 (the “’264 patent”), assigned to
Plaintiff-Appellee Ernie Ball, Inc. (“Ernie Ball”), valid and
enforceable and holding Earvana liable for infringement.
Ernie Ball, Inc. v. Earvana, LLC, No. 5:06-cv-00384-JHN-
OPx, 2011 WL 201816, 2011 U.S. Dist. LEXIS 5831 (C.D.
Cal. Jan. 21, 2011). Because we conclude that the assert-
ed claims of the ’264 patent are invalid under 35 U.S.C.
§ 112, we reverse.
                       BACKGROUND
      Ernie Ball and Earvana compete in the market for
guitar parts designed to optimize the intonation along
each of the instrument’s strings. As depicted below,
conventional guitars have a body (12), an elongated
neck (28), a bridge (22), a nut (42), a series of frets (34)
extending across the neck perpendicular to its length, and
a number of strings (40) extending along the neck.
 ERNIE BALL, INC.   v. EARVANA, LLC                        3




’264 patent fig. 1. The nut and the bridge each typically
include slots or saddle positions for receiving each string,
and those opposing saddle positions together define the
effective length of each string. The strings are tuned to a
desired pitch, which varies with the string’s construction,
diameter, tension, and length. Once the strings have
been tuned, a user can derive various chords and notes by
pressing the strings down at selected fret locations along
the neck. Even after tuning, however, guitar players have
recognized that the strings on a conventional guitar may
not produce the correct intonation at each fret. Various
technologies have been introduced to compensate for such
tonal imperfections by varying the effective length of each
string through adjustments to the position or configura-
tion of the nut and/or the bridge. See id. col. 1 l. 11–col. 2
l. 43.
4                           ERNIE BALL, INC.   v. EARVANA, LLC


       One such approach is disclosed in Earvana’s U.S.
Patent 5,481,956 (hereafter “LoJacono”), 1 relating to a
compensated nut for achieving proper intonation along
each string. Conventional guitar nuts have saddle posi-
tions disposed in a uniform linear arrangement running
across the nut parallel to the frets. In contrast, LoJacono
describes an adjustable compensated nut (10) that in-
cludes separate, independently adjustable saddle mem-
bers (20) for each string, as below.




LoJacono figs. 8, 9. By adjusting the positions of the
individual saddle members, the strings’ upper termina-
tion points can be shifted toward or away from the bridge,
thus slightly altering the effective playable length of each
string and allowing the optimal intonation to be achieved
and maintained. See id. col. 7 ll. 5–50. Furthermore,
because the individual strings generally require different
levels of compensation, LoJacono notes that the saddle
members will assume an offset or undulating pattern,
termed a “sinusoidal configuration,” once they have been
positioned using the disclosed tuning methods:


      1   U.S. Patent 5,481,956 issued to Richard J.
LoJacono and James D. Walseth on January 9, 1996.
 ERNIE BALL, INC.   v. EARVANA, LLC                       5


   When all the guitar strings are properly tuned . . .
   the saddle [members] will define a substantially
   sinusoidal configuration, indicated by line A—A,
   positioned over the juxtaposed saddle nuts . . . .
   [T]he configuration of sinusoidal line A—A will
   change according to different designs of various
   name brand guitar and their associated types of
   guitar strings . . . .
Id. col. 8 ll. 3–10 (emphasis added); see also id. figs. 2
(showing exemplary line A—A), 7, 8 (showing additional
adjusted configurations).
       LoJacono also discloses the possibility of using
fixed (non-adjustable) compensated nuts set to a prede-
fined “sinusoidal configuration.” Id. col. 8 ll.13–31. The
specification cautions, however, that fixed compensated
nuts would be compatible only with an intended combina-
tion of guitar model and string type and thus might be
disfavored by users accustomed to switching between
different guitar strings.
       Approximately three years after the LoJacono pa-
tent issued, Ernie Ball filed U.S. Patent Application
09/199,747 (the “’747 application”), which became the ’264
patent now before us on appeal. The ’264 patent discloses
and claims a fixed compensated nut (42) having a number
of individual “intonation portions,” such as cut-outs (64),
provided in the front side (52) of the nut, as illustrated
below.
6                           ERNIE BALL, INC.   v. EARVANA, LLC




’264 patent figs. 2, 5. The individual cut-outs “have gener-
ally the same configuration but different dimensions
depending, for example, upon the desired pitch and into-
nation of the corresponding string.” Id. col. 6 ll. 38–41.
Like the adjustable saddle members disclosed by LoJaco-
no, the varying depths of the cut-outs define the upper
termination point and thus the effective length of each
string. According to the ’264 patent, however, the fixed
design is comparatively “simple to manufacture because it
consists of a single, solid component” and results in a
more reliable instrument because it “does not require any
adjustments and it does not go out of tune.” Id. col. 3 ll.
36–43.
   The ’264 patent includes 29 claims directed to com-
pensated nuts, stringed instruments containing compen-
 ERNIE BALL, INC.   v. EARVANA, LLC                       7


sated nuts, and a method of making such instruments.
For example, claim 1 recites:
    A compensated nut for a stringed instrument, the
    stringed instrument having one or more strings, a
    body and a neck, the nut comprising:
    an elongated body having a length sufficient to ex-
          tend across at least a portion of the neck of
          the stringed instrument; and
    one or more fixed intonation portions on a front
          side of the elongated body, the intonation
          portions having different dimensions ac-
          cording to the desired pitch compensation
          for each string and being configured such
          that a line extending through the one or
          more fixed intonation portions does not form
          a sinusoidal arc.
Id. col. 9 ll. 44–55 (emphasis added). As originally filed,
neither the written description nor the claims of the ’747
application contained any mention of whether or not the
intonation portions are arranged in a sinusoidal configu-
ration. In fact, the word “sinusoidal” appears only once in
the original ’747 application (and only once in the written
description of the corresponding ’264 patent), in a brief
description of the LoJacono reference as prior art. See id.
col. 2 ll. 8–27 (“U.S. Patent No. 5,481,956 . . . discloses a
guitar tuning apparatus . . . . [T]he nut has a sinusoidal
configuration with a plurality of adjustable nut saddle
members mounted in a nut frame.”). Nevertheless, dur-
ing prosecution all of the independent claims of the ’747
application were amended to add limitations requiring
that the intonation portions be provided in non-sinusoidal
configurations in response to repeated obviousness rejec-
tions over LoJacono. The examiner allowed the claims as
8                          ERNIE BALL, INC.   v. EARVANA, LLC


amended, stating that “[t]he prior art does not teach the
fixed intonations with different dimensions providing a
line that does not form a sinusoid arc as recited by the
applicant.”
       In 2006, Ernie Ball filed suit against Earvana al-
leging infringement of claims 1–4, 6–10, and 21–23 of the
’264 patent and asserting state law claims for unfair
competition. Earvana’s answer raised 27 separate affirm-
ative defenses and asserted counterclaims alleging nonin-
fringement, unenforceability due to inequitable conduct,
and invalidity under 35 U.S.C. §§ 102, 103, and 112.
       The case was initially assigned to District Judge
Florence-Marie Cooper, who granted partial summary
judgment in favor of Ernie Ball, finding that Earvana had
infringed the ’264 patent and rejecting Earvana’s counter-
claims for invalidity and inequitable conduct. Ernie Ball,
Inc. v. Earvana, LLC, No. 5:06-cv-00384-FMC-OPx (C.D.
Cal. July 20, 2009), ECF No. 90 (“Summary Judgment”).
Upon reconsideration, Judge Cooper modified her sum-
mary judgment order to permit Earvana’s inequitable
conduct counterclaim to be presented at trial. Ernie Ball,
Inc. v. Earvana, LLC, No. 5:06-cv-00384-FMC-OPx (C.D.
Cal. Sept. 16, 2009), ECF No. 96. While the case re-
mained pending, Judge Cooper passed away on January
15, 2010, and the matter was reassigned to then-District
Judge Jacqueline H. Nguyen. 2
       Adopting all prior rulings in the case, Judge Ngu-
yen conducted a bench trial in November 2010 to resolve
the issue of inequitable conduct along with Ernie Ball’s

      2    Judge Nguyen served as a District Judge from
December 4, 2009, until May 14, 2012, when she assumed
her current duties as a Circuit Judge on the United States
Court of Appeals for the Ninth Circuit.
 ERNIE BALL, INC.   v. EARVANA, LLC                      9


unfair competition claims. Following trial, the district
court determined that (i) Earvana failed to establish that
Ernie Ball engaged in inequitable conduct in obtaining
the ’264 patent, (ii) Ernie Ball was entitled to a reasona-
ble royalty to compensate for Earvana’s adjudged in-
fringement of the ’264 patent, and (iii) Earvana was not
liable for unfair competition. Ernie Ball, Inc. v. Earvana,
LLC, No. 5:06-cv-00384-JHN-OPx, 2010 U.S. Dist. LEXIS
123517 (C.D. Cal. Nov. 8, 2010). The district court subse-
quently awarded $165,016.80 in damages and permanent-
ly enjoined Earvana from further infringing the ’264
patent. Ernie Ball, Inc. v. Earvana, LLC, No. 5:06-cv-
00384-JHN-OPx (C.D. Cal. Jan. 25, 2011), ECF No. 138.
       Earvana initially filed its appeal in the United
States Court of Appeals for the Ninth Circuit, which
concluded that this case “arises under patent law” and
therefore lies outside of its appellate jurisdiction. Ernie
Ball, Inc. v. Earvana, LLC, No. 11-55532 (9th Cir. Mar.
14, 2012). The Ninth Circuit transferred the appeal to
this court, and we have jurisdiction pursuant to 28 U.S.C.
§ 1295(a)(1).
                          DISCUSSION
                               I.
       On appeal, Earvana disputes various aspects of the
district court’s judgment, including its holdings on claim
construction, validity, infringement, and inequitable
conduct. Before addressing the merits, we must note that
the parties make no more than passing reference to any
particular claim, generically structuring their arguments
on claim construction, infringement, and validity as if
they applied to the ’264 patent as a whole, rather than, as
they must, to one or more of its discrete claims. See, e.g.,
Appellant’s Br. 29 (“[P]ursuant to 35 U.S.C. §§102, 103,
10                           ERNIE BALL, INC.   v. EARVANA, LLC


and 112, Ernie Ball’s [’264] patent is invalid for several
reasons . . . .”); id. at 31 (“[T]he [LoJacono] patent antici-
pates the configurations of the compensated nuts created
by Ernie Ball . . . .”); Appellee’s Br. 17 (“Earvana admitted
it manufactured and sold compensated nuts that in-
fringed upon all the elements of the ’264 patent . . . .”). As
is black letter law, the claims define the exclusive rights
conferred by a patent, and the validity and infringement
of those rights must be evaluated on a claim by claim
basis. E.g., Amazon.com, Inc. v. Barnesandnoble.com,
Inc., 239 F.3d 1343, 1351 (Fed. Cir. 2001); SRI Int’l v.
Matsushita Elec. Corp. of Am., 775 F.2d 1107, 1121 (Fed.
Cir. 1985) (en banc).
       Confronted by the same ambiguity, the district
court appears to have treated claim 1 as representative of
all of the asserted claims. See Summary Judgment, slip
op. at 15. Neither party has criticized the district court’s
focus on claim 1, and we interpret their arguments on
appeal as adopting that approach. See Appellee’s Br. 18
(framing blanket claim construction arguments with
reference to claim 1). Accordingly, we too will treat claim
1 of the ’264 patent as representative of asserted claims
1–4, 6–10, and 21–23 for purposes of this appeal.
                             II.
    Claim construction is a matter of law, reviewed de
novo on appeal. Cybor Corp. v. FAS Techs., Inc., 138 F.3d
1448, 1456 (Fed. Cir. 1998) (en banc). The parties to this
case dispute the meaning of the term “sinusoidal” as used
in the claims of the ’264 patent—specifically, whether the
intonation portions of the accused Earvana products are
“configured such that a line extending through the one or
more fixed intonation portions does not form a sinusoidal
arc,” see ’264 patent col. 9 ll. 53–55, and whether the prior
 ERNIE BALL, INC.   v. EARVANA, LLC                      11


art disclosures of LoJacono anticipate or render obvious
the properly construed claims of the ’264 patent.
    The district court perceived the ordinary meaning of
“sinusoidal” to indicate a configuration conforming to the
shape of a sine wave or arc. Apparently finding no guid-
ance in the ’264 patent itself, the court turned to the prior
art LoJacono patent for insight into the proper construc-
tion. The court noted a “significant possibility” that
LoJacono could be read to use the term “sinusoidal” as
“indicat[ing] any configuration not conforming to a
straight line,” but it concluded that, on balance, LoJacono
supported interpreting the term “sinusoidal” in the claims
of the ’264 patent according to its more restrictive plain
meaning. The district court therefore construed “sinusoi-
dal” to mean “a configuration that strictly conforms to the
shape of a sine wave or arc.” Summary Judgment, slip
op. at 10–14. Paradoxically, the district court’s narrow
construction of “sinusoidal” in view of the prior art had
the practical effect of conferring expansive scope on Ernie
Ball’s overarching claims, which incorporate the term in a
negative limitation (i.e., the claims require configurations
that are not sinusoidal). Accordingly, under the district
court’s construction, the asserted claims cover fixed
compensated nuts having any configuration that does not
strictly conform to the shape of a sine wave or arc.
    Earvana, relying primarily on LoJacono, contends on
appeal that “sinusoidal” should not be so narrowly con-
strued and should instead encompass any non-linear
arrangement of termination points that results from
individually compensating each string. For its part, Ernie
Ball acknowledges that the specification of the ’264 patent
does not explain what qualifies as a non-sinusoidal nut
configuration but argues that one of ordinary skill in the
12                           ERNIE BALL, INC.   v. EARVANA, LLC


art would nonetheless understand the ordinary meaning
of the term.
        We conclude that the district court’s construction of
the term “sinusoidal” was correct. The plain meaning of
“sinusoidal” connotes conformity with a mathematically
defined curve derived from the trigonometric sine func-
tion, 3 and neither the specification nor the prosecution
history of the ’264 patent clearly sets forth a different
definition. See Vitronics Corp. v. Conceptronic, Inc., 90
F.3d 1576, 1582 (Fed. Cir. 1996) (“[W]ords in a claim are
generally given their ordinary and customary meaning,
[but] a patentee may choose to be his own lexicographer
and use terms in a manner other than their ordinary
meaning, as long as the special definition of the term is
clearly stated in the patent specification or file history.”).
       The specification of the ’264 patent provides little
guidance. The word “sinusoidal” appears in the specifica-
tion only once—in a passage describing the subject matter
of the LoJacono patent. See ’264 patent col. 2 l. 16. As for
the prosecution history, the limitation excluding “sinusoi-
dal” configurations from claim 1 was introduced by
amendment after several years of prosecution and repeat-
ed rejections based on LoJacono. In comments accompa-
nying the amendment, Ernie Ball argued that LoJacono
disclosed compensated nuts having a sinusoidal configu-
ration and “taught away from any fixed nut that was not
sinusoidal” such as those specified in the amended claims
of the ’747 application. In essence, Ernie Ball equated
“sinusoidal,” as used in the amended claims, with “that

      3     The sine function is commonly represented by
the mathematical formula y = A(sin(Bx + C)) + D, where
the variables A, B, C, and D dictate the resulting curve’s
amplitude, frequency, phase shift, and vertical shift,
respectively.
 ERNIE BALL, INC.   v. EARVANA, LLC                      13


which is not disclosed by LoJacono,” however understood.
As the district court recognized, however, and despite
Earvana’s arguments to the contrary, LoJacono itself
provides no clear definition of “sinusoidal” in the context
of compensated guitar nuts.
       Accordingly, we conclude that one of ordinary skill
in the art reading the ’264 patent in view of the relevant
intrinsic record would rely on the term’s ordinary mean-
ing and would therefore understand the term “sinusoidal,”
as used in claim 1, to indicate “a configuration that strict-
ly conforms to the shape of a sine wave or arc.”
                              III.
       Earvana argues that, even if the district court’s
construction of “sinusoidal” was correct, it does not in-
fringe the claims of the ’264 patent. We do not reach that
issue, however, as, having examined the ’264 patent, its
claims, and its prosecution history in construing the
contested claim term, we hold that the asserted claims are
invalid as a matter of law for failure to satisfy the re-
quirements of § 112.
       Before the district court, Earvana consistently ar-
gued that “the ’264 patent is invalid” pursuant to §§ 102,
103, and 112. Unfortunately, the dialogue on validity
essentially ended there. The parties’ submissions never
evolved beyond the most barren generalities, character-
ized by cursory recitations of statutory bases for invalidity
and untethered debate about the LoJacono reference. As
a result, the arguments on both sides lacked fundamental
details at every turn—for example, which claims were
challenged under each section, which limitations of those
claims were in dispute, and which specific provisions of
§ 112 were at issue, to name a few—leaving the district
14                           ERNIE BALL, INC.   v. EARVANA, LLC


court to guess at which of many possible validity issues
were material to resolving the dispute.
       The parties’ lack of focus, not surprisingly, is re-
flected in the district court’s judgment on invalidity; its
entire analysis spans only a single paragraph:
     Defendant’s invalidity counterclaim is premised
     upon its contention that [LoJacono] and ’264 pa-
     tent disclose the same invention, and because the
     [LoJacono] patent was issued first, the ’264 patent
     should be invalidated for anticipation and obvi-
     ousness pursuant to 35 U.S.C. § 102, 103, 112.
     However, as previously discussed in the Court’s
     claim construction of “sinusoidal configuration,”
     [LoJacono] and the ’264 patent are distinct and
     cover different subject matter. [LoJacono’s] speci-
     fication and claims are limited to a guitar nut
     whose intonation portions have a defined sinusoi-
     dal configuration while the ’264 patent’s intona-
     tion portions do not form a sinusoidal arc. The
     Court therefore does not find Plaintiff’s ’264 pa-
     tent to be invalid for anticipation or obviousness.
Summary Judgment, slip op. at 16. Notably, the district
court’s discussion fails even to address § 112, much less
analyze the validity of any claim in view of that section’s
multiple substantive requirements. Given the uncompli-
cated subject matter of the instant patent and the prior
art patent, however, it is clear from the record that the
asserted claims fail the definiteness requirement of § 112,
¶ 2. 4

       4     Paragraph 2 of 35 U.S.C. § 112 was replaced
with newly designated §§ 112(b) when § 4(c) of the Leahy-
Smith America Invents Act (“AIA”), Pub. L. No. 112-29,
took effect on September 16, 2012. Because this case was
 ERNIE BALL, INC.   v. EARVANA, LLC                      15


       While Earvana has not specifically pointed to the
definiteness requirement of § 112, ¶ 2, it did challenge the
asserted claims as invalid under § 112 in the district
court, and it maintains that assertion on appeal. The
definiteness requirement “is drawn from the court’s
performance of its duty as the construer of patent claims.”
Atmel Corp. v. Info. Storage Devices, 198 F.3d 1374, 1378
(Fed. Cir. 1999); see also Eplus, Inc. v. Lawson Software,
Inc., 700 F.3d 509 (Fed. Cir. 2012) (“[I]ndefiniteness is a
question of law and in effect part of claim construction.”).
“The reviewing tribunal must determine whether a person
experienced in the field of the invention would under-
stand the scope of the claim when read in light of the
specification.” Energizer Holdings, Inc. v. Int’l Trade
Comm’n, 435 F.3d 1366, 1369 (Fed. Cir. 2006). We there-
fore address definiteness as a pure legal question where,
as here, in discharging our “duty as the construer of
patent claims” we reach the inescapable conclusion that
the claims at issue cannot satisfy the definiteness stand-
ard.
       Claim 1 requires “that a line extending through the
one or more fixed intonation portions does not form a
sinusoidal arc.” ’264 patent col. 9 ll. 53–55. While the
district court reasonably interpreted the term “sinusoidal”
according to its plain meaning as “a configuration that
strictly conforms to the shape of a sine wave or arc,” that
construction does not resolve the fundamental problem
facing anyone attempting to divine the very broad bound-
aries of claim 1: the intonation portions of any compen-
sated nut represent only a handful of discrete points that
cannot unambiguously define a single line extending
therethrough. For example, even an embodiment dis-

filed before that date, we will refer to the pre-AIA version
of § 112.
16                           ERNIE BALL, INC.   v. EARVANA, LLC


closed in the ’264 patent 5 that Ernie Ball characterizes as
having a “stair step or triangular wave configuration”
within the scope of claim 1 could appear either to be
infringing (i.e., the line “does not form a sinusoidal arc”)
or noninfringing (i.e., the line forms a sinusoidal arc)
depending on which of the many possible lines through
the intonation portions one chooses to draw. The first line
depicted below is non-sinusoidal, whereas the second is
sinusoidal:




As illustrated, the disclosed points can be connected using
various undulating lines, including at least one sinusoidal
line with a constant frequency and amplitude and at least
one non-sinusoidal line without. Even intonation portions
arranged in the simplest possible configuration—a

      5     The ’264 patent discloses a fixed compensated
nut for a six-string guitar, configured with the following
compensation amounts for each string (in inches): 0.042,
0.020, 0.018, 0.029, 0.018, and 0.011. ’264 patent col. 8 ll.
39–52.
 ERNIE BALL, INC.   v. EARVANA, LLC                     17


straight line across the nut—could be connected using a
sinusoidal or a non-sinusoidal line, as depicted below.




    In short, it is impossible to tell based on the set of
discrete points defined by the intonation portions of a
given compensated guitar nut whether “a line” extending
through those points does or does not form a sinusoidal
arc because those points provide no information regarding
the line’s shape or position as it traverses the intervening
spaces. As a result, the question whether a fixed compen-
sated nut with any particular arrangement of intonation
portions would infringe claim 1 of the ’264 patent depends
on which among a limitless number of possible lines
extending through those intonation portions one has in
mind at any given time. In other words, ascertaining the
scope of claim 1 reduces to a matter of subjective percep-
tion.
    “When faced with a purely subjective phrase . . . a
court must determine whether the patent’s specification
supplies some standard for measuring the scope of the
phrase.” Datamize, LLC v. Plumtree Software, Inc., 417
F.3d 1342, 1351 (Fed. Cir. 2005). Here, the ’264 patent
offers no objective way to discern the appropriate (sinus-
oidal or non-sinusoidal) line extending through the into-
nation portions of a nut for purposes of determining
infringement. As in Datamize, claim 1 thus “fails to
delineate the scope of the invention using language that
adequately notifies the public of the patentee’s right to
18                          ERNIE BALL, INC.   v. EARVANA, LLC


exclude.” Id. at 1353. Accordingly, claim 1 is invalid for
failure to satisfy § 112, ¶ 2. In addition, because the
parties have treated claim 1 as representative of all of the
asserted claims, and because each of those claims suffers
from a similar lack of clarity, we conclude those claims
are also invalid as indefinite.
                       CONCLUSION
       Because we conclude that asserted claims 1–4, 6–
10, and 21–23 of the ’264 patent are invalid on grounds of
indefiniteness, we need not reach the parties’ remaining
arguments concerning validity, inequitable conduct,
infringement, or damages. For the foregoing reasons, we
reverse the final judgment of the district court.


                       REVERSED
