Case: 19-1622    Document: 59    Page: 1   Filed: 06/25/2020




   United States Court of Appeals
       for the Federal Circuit
                  ______________________

                SHOES BY FIREBUG LLC,
                       Appellant

                            v.

      STRIDE RITE CHILDREN'S GROUP, LLC,
                     Appellee
              ______________________

                   2019-1622, 2019-1623
                  ______________________

     Appeals from the United States Patent and Trademark
 Office, Patent Trial and Appeal Board in Nos. IPR2017-
 01809, IPR2017-01810.
                  ______________________

                  Decided: June 25, 2020
                  ______________________

     WILLIAM ALCIATI, Gardella Grace PA, Washington, DC,
 for appellant.

    GAETAN GERVILLE-REACHE, Warner Norcross & Judd
 LLP, Grand Rapids, MI, for appellee. Also represented by
 ROBERT MICHAEL AZZI.
                ______________________

   Before LOURIE, MOORE, and O’MALLEY, Circuit Judges.
 LOURIE, Circuit Judge.
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 2       SHOES BY FIREBUG LLC   v. STRIDE RITE CHILDREN'S GROUP



     Shoes by Firebug LLC (“Firebug”) appeals from two fi-
 nal written decisions of the United States Patent and
 Trademark Office Patent Trial and Appeal Board (“the
 Board”) holding claims 1–10 of U.S. Patent 8,992,038 (“’038
 patent”) and claims 1–10 of U.S. Patent 9,301,574 (“’574
 patent”) unpatentable as obvious. See Stride Rite Chil-
 dren’s Grp., LLC v. Shoes by Firebug LLC, No. IPR2017-
 01809, 2019 WL 236242 (P.T.A.B. Jan. 16, 2019) (“-1809
 Decision”); Stride Rite Children’s Grp., LLC v. Shoes By
 Firebug LLC, No. IPR2017-01810, 2019 WL 237069
 (P.T.A.B. Jan. 16, 2019) (“-1810 Decision”). Because the
 Board did not err in its conclusion that the claims would
 have been obvious over the prior art, we affirm.
                          BACKGROUND
     Firebug owns the ’038 and ’574 patents (collectively the
 “Firebug patents”), which are generally directed to illumi-
 nation systems for footwear. ’038 patent col. 1 ll. 10–12. 1
 According to the patents, while light-up shoes are not new
 to the footwear industry, there is a wide variety of struc-
 tural designs for illuminated footwear. In some designs,
 the light sources are external to the footwear, while in oth-
 ers the lights are integrated into the shoes. The Firebug
 patents purport to disclose an improved structure for inter-
 nally illuminated footwear. The patents describe footwear
 comprising a sole and an upper portion having three lay-
 ers—a liner, which is the innermost layer, an interfacing
 layer, and a light-diffusing layer. Id. col. 2 l. 45–col. 3 l. 8.
 The light sources are connected to the interfacing layer be-
 tween the interfacing layer and the light diffusing layer.
 Id. col. 2 l. 65–col. 3 l. 1. The interfacing layer is a reflec-
 tive layer that maximizes the amount of light that exits
 through the light-diffusing layer and is ultimately visible


     1    Because the ’038 and ’574 patents share a substan-
 tially identical written description, all citations are to the
 ’038 patent unless specified otherwise.
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 to an observer. Id. col. 3 ll. 3–5. Claim 1 of the ’038 patent
 is illustrative:
     1. An internally illuminated textile footwear com-
     prises:
     a footwear;
     the footwear comprises a sole and an upper;
     an illumination system;
     the illumination system comprises a power source
     and a plurality of illumination sources;
     a liner;
     a structure;
     the structure comprises an interfacing layer and a
     batting;
     the structure being adjacently connected to the up-
     per;
     the structure being positioned between the liner
     and the upper;
     the interfacing layer being positioned adjacent to
     the liner;
     the batting being adjacently connected to the inter-
     facing layer opposite the liner;
     the interfacing layer being reflective;
     the batting being light diffusing;
     the plurality of illumination sources being adja-
     cently connected to the interfacing layer;
     the plurality of illumination sources being posi-
     tioned between the interfacing layer and the bat-
     ting;
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 4     SHOES BY FIREBUG LLC    v. STRIDE RITE CHILDREN'S GROUP



     the upper being perimetrically connected to the
     sole;
     the liner being positioned interior to the upper;
     the upper being light diffusing;
     the illumination system being housed within the
     footwear;
     the plurality of illumination sources emitting light,
     wherein the light first entering the batting and be-
     ing diffused by the batting, the light diffused by the
     batting exits the batting, enters the upper, diffused
     again by the upper and then exits the upper, the
     twice diffused light creating a visual impression of
     internal radiant illumination across an outer sur-
     face area of the upper.
 ’038 patent col. 7 ll. 26–57 (emphasis added).
      Claim 1 of the ’574 patent recites similar subject mat-
 ter, with slight differences relevant to this appeal.
     1. An internally illuminated textile footwear com-
     prises:
     a sole and an upper;
     an illumination system;
     the illumination system comprises a power source
     and a plurality of illumination sources;
     a liner;
     an interfacing layer;
     the interfacing layer being adjacently connected to
     the upper;
     the interfacing layer being positioned between the
     liner and the upper;
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     the plurality of illumination sources being adja-
     cently connected to the interfacing layer;
     the plurality of illumination sources being posi-
     tioned between the interfacing layer and the upper;
     the upper being perimetrically connected to the
     sole;
     the liner being positioned interior to the upper;
     the upper being a light diffusing section;
     the illumination system being housed within the
     footwear; and
     the plurality of illumination sources emitting light,
     wherein the light enters the light diffusing section,
     then exits the upper as diffused light, creating a
     visual impression of internal radiant illumination
     across an outer surface of the upper.
 ’574 patent col. 9 l. 47–col. 10 l. 5 (emphasis added).
      Stride Rite Children’s Group, LLC (“Stride Rite”) is a
 competitor to Firebug in the children’s footwear market.
 Firebug asserted the ’038 and ’574 patents against Stride
 Rite in the United States District Court for the Eastern
 District of Texas. See Complaint, Shoes by Firebug LLC v.
 Stride Rite Children’s Grp., LLC, No. 4:16-cv-00899 (E.D.
 Tex. Nov. 22, 2016), ECF No. 1. Stride Rite in response
 filed petitions for inter partes review of claims 1–10 of the
 ’038 patent and claims 1–10 of the ’574 patent, alleging
 that the challenged claims would have been obvious over
 U.S. Patent 5,894,686 (“Parker”) in view of U.S. Patent
 App. Pub. 2011/0271558 (“Rosko”) and other references.
     Parker teaches a light distribution system for use on
 the upper portion of a shoe and discloses a layer of woven
 or non-woven optical fibers disposed on a “back reflector,”
 which reflects light from the optical fibers back through the
 outer layer of the shoe. Parker, col. 4 ll. 18–34. Rosko
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 discloses a multi-layered lighting panel for footwear that
 uses an array of light-emitting diodes disposed in a “light
 diffuser” for illumination. Rosko ¶ 23. Stride Rite con-
 tended that the challenged claims would have been obvious
 because a skilled artisan would have substituted Parker’s
 fragile optical fiber layer with Rosko’s LED-based light dif-
 fuser to reduce cost and improve the structural integrity of
 the footwear.
      The Board instituted trial on both petitions and issued
 a final written decision in each proceeding concluding that
 the challenged claims are unpatentable as obvious. In both
 decisions, the Board determined that the preamble of claim
 1 of each of the Firebug patents, which is the only inde-
 pendent claim at issue in each IPR, does not limit the chal-
 lenged claims. -1809 Decision, 2019 WL 236242, at *6; -
 1810 Decision, 2019 WL 237069, at *8. The Board con-
 cluded that the references otherwise render the challenged
 claims obvious and the disclosure of the references is not
 outweighed by Firebug’s evidence of secondary considera-
 tions of nonobviousness. -1809 Decision at *23–24; -1810
 Decision at *24.
    Firebug timely appealed the Board’s decisions.        We
 have jurisdiction under 28 U.S.C. § 1295(a)(4)(A).
                         DISCUSSION
     Firebug presents two principal arguments on appeal.
 First, it argues that the Board erred in determining that
 the preambles of claim 1 of both the ’038 and ’574 patents
 do not limit the claims. Second, it argues that the Board
 erred in concluding that the challenged claims would have
 been obvious in light of the prior art and Firebug’s evidence
 of secondary considerations of nonobviousness. We ad-
 dress Firebug’s arguments in turn.
                    I. Claim Construction
     “Claim construction is a question of law that may in-
 volve underlying factual questions.” Amgen Inc. v. Amneal
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 SHOES BY FIREBUG LLC   v. STRIDE RITE CHILDREN'S GROUP         7



 Pharm. LLC, 945 F.3d 1368, 1375 (Fed. Cir. 2020) (citing
 Teva Pharm. USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 332
 (2015)). Where, as here, the lower tribunal’s construction
 is based solely on evidence intrinsic to the patent, we re-
 view the construction de novo. Shire Dev., LLC v. Watson
 Pharm., Inc., 787 F.3d 1359, 1364 (Fed. Cir. 2015) (citing
 Teva, 574 U.S. at 330–33).
     Firebug argues that the Board erred in determining
 that the preamble of claim 1 of each of the Firebug patents,
 which recites “[a]n internally illuminated textile footwear
 comprises,” does not limit the claims. Specifically, Firebug
 argues that the preamble limits the scope of the claims to
 “textile footwear.” According to Firebug, when the pream-
 ble’s requirement of textile footwear is read together with
 the claims’ limitation that the upper is light diffusing, the
 claims necessarily require that the light diffusing portion
 of the upper—that is, the portion of the outermost layer of
 the footwear that is illuminated—be textile. Firebug ar-
 gues that neither Parker nor Rosko disclose internally illu-
 minated footwear having a textile light diffusing layer and
 therefore the references do not render the claims obvious.
     Stride Rite responds that the preambles do not limit
 any of the challenged claims because the bodies of the
 claims recite structurally complete articles, and the pream-
 ble merely states an intended use of the claimed structure.
 However, according to Stride Rite, even if the preambles do
 limit the claims to require textile footwear, the Board’s
 claim construction error was harmless because the Board
 alternatively found that the prior art discloses footwear
 with a textile upper, and that finding is supported by sub-
 stantial evidence.
     Whether a claim preamble is considered to be a limit-
 ing part of the claim matters, inter alia, because, if it is not,
 the scope of the claim is broader, but the claim is vulnera-
 ble to more potentially-invalidating prior art. Here, we
 agree with Firebug that the preamble of claim 1 of the ’574
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 8      SHOES BY FIREBUG LLC   v. STRIDE RITE CHILDREN'S GROUP



 patent is limiting but conclude that the preamble of claim
 1 of the ’038 patent is not. However, we agree with Stride
 Rite that even though the preamble is limiting with respect
 to the challenged claims of the ’574 patent, the Board’s al-
 ternative determination that the references nevertheless
 disclose the limitation is supported by substantial evi-
 dence. Thus, our conclusion does not upset the Board’s
 overall conclusion of obviousness.
      “Whether to treat a preamble as a limitation is a deter-
 mination ‘resolved only on review of the entire[] . . . patent
 to gain an understanding of what the inventors actually in-
 vented and intended to encompass by the claim.’” Catalina
 Mktg. Int’l, Inc. v. Coolsavings.com, Inc., 289 F.3d 801, 808
 (Fed. Cir. 2002) (quoting Corning Glass Works v. Sumitomo
 Elec. U.S.A., Inc., 868 F.2d 1251, 1257 (Fed. Cir. 1989)) (al-
 terations in original). “In general, a preamble limits the
 invention if it recites essential structure or steps, or if it is
 ‘necessary to give life, meaning, and vitality’ to the claim.”
 Id. (quoting Pitney Bowes, Inc. v. Hewlett-Packard Co., 182
 F.3d 1298, 1305 (Fed. Cir. 1999)). “Conversely, a preamble
 is not limiting ‘where a patentee defines a structurally com-
 plete invention in the claim body and uses the preamble
 only to state a purpose or intended use for the invention.’”
 Id. (quoting Rowe v. Dror, 112 F.3d 473, 478 (Fed. Cir.
 1997)). “No litmus test defines when a preamble limits
 claim scope,” id. (citing Corning Glass, 868 F.2d at 1257),
 but “dependence on a particular disputed preamble phrase
 for antecedent basis may limit claim scope because it indi-
 cates a reliance on both the preamble and claim body to
 define the claimed invention.” Id. (citing Bell Commc’ns
 Research, Inc. v. Vitalink Commc’ns Corp., 55 F.3d 615, 620
 (Fed. Cir. 1995)).
     We conclude that the body of claim 1 of the ’038 patent
 recites a structurally complete invention, and therefore the
 preamble’s recitation of an “internally illuminated textile
 footwear” is merely an intended purpose that does not limit
 the claims. Notably, the first limitation of the body of
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 claim 1 of the ’038 patent reintroduces “a footwear” which
 “comprises a sole and an upper.” The preamble, then, can-
 not be said to provide essential structure or necessary
 meaning to the claimed invention because the same ele-
 ment—the footwear—is independently recited in the body
 of the claim. The body does not go on to expressly impose
 any further limitation on the footwear requiring use of a
 specific material, nor is a requirement of textile footwear
 implicitly necessary to the invention. Indeed, the written
 description itself discloses numerous materials other than
 textile suitable for footwear manufacture, including
 “leather, synthetics, [and] plastics.” ’038 patent col. 1
 ll. 18–19.
     Firebug argues that the written description treats the
 use of textile footwear as an important aspect of the disclo-
 sure, and therefore the recitation of “textile footwear” in
 the preamble should be treated as limiting. The written
 description explains that “[t]he present invention focuses
 on the adoption and improvement of internally illuminated
 footwear . . . by providing a light diffusing textile upper.”
 ’038 patent col. 1 ll. 37–39. In addition to the general dis-
 favor of importing language from the written description
 into the claims, see SuperGuide Corp. v. DirecTV Enters.,
 Inc., 358 F.3d 870, 875 (Fed. Cir. 2004), we disagree with
 Firebug that the use of textile footwear is essential to real-
 izing the stated purpose of the invention. Internal illumi-
 nation is achieved by the multilayer design recited in the
 claims in which the light sources are integrated into the
 footwear between the interior interfacing layer and the ex-
 terior light diffusing layer. Of course, the light diffusion
 layer must be light permeable to allow light to escape the
 footwear, but this suggests that light permeability, not the
 use of a particular material, is the critical characteristic of
 the upper.
      The written description and the body of claim 1 accord
 with this understanding. The patent explains that “[t]ex-
 tile materials . . . are just one possible material type which
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 10    SHOES BY FIREBUG LLC   v. STRIDE RITE CHILDREN'S GROUP



 can be used for the light diffusing section,” ’038 patent
 col. 4 ll. 46–50, and the body of claim 1 requires only that
 “the upper be[] light diffusing” without limiting the scope
 of the claim to a particular material. Id. col. 7 ll. 49. Ac-
 cordingly, because the body of claim 1 of the ’038 patent
 recites a structurally complete article and the use of textile
 material is not otherwise necessary to the claimed inven-
 tion, we conclude that the preamble of claim 1 does not
 limit claims 1–10 of the ’038 patent.
      Unlike claim 1 of the ’038 patent, claim 1 of the ’574
 patent does not reintroduce “footwear” in the body of the
 claim but instead relies on the instance of “footwear” intro-
 duced in the preamble for “antecedent basis.” Claim 1 of
 the ’574 patent recites an illumination system comprising
 “a power source and a plurality of illumination sources.”
 The first and only reference to footwear in the body of claim
 1 appears in a limitation describing the configuration of the
 illumination system (“the illumination system being
 housed within the footwear”) and relies on the footwear re-
 cited in the preamble for an antecedent basis for further
 limitations in the claim. While antecedent basis alone is
 not determinative of whether a preamble is limiting, use of
 preamble terms to define positive limitations in the body of
 claims can evince an inventor’s intent that the preamble
 limit the scope of the claim. That is the case here. Because
 the claim requires that the illumination system be housed
 in the textile footwear recited in the preamble, the pream-
 ble is essential to understanding the structural limitations
 of the illumination system. Accordingly, rather than
 merely reciting an intended purpose of the claimed inven-
 tion, we conclude that the preamble of claim 1 of the ’574
 patent limits the scope of claims 1–10 of the ’574 patent to
 require the use of a textile upper.
     However, although the Board erred in omitting the pre-
 amble from its claim construction of the ’574 patent, we
 conclude that the Board’s alternative fact findings that the
 references disclose the use of textile footwear are supported
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 SHOES BY FIREBUG LLC   v. STRIDE RITE CHILDREN'S GROUP    11



 by substantial evidence and that the Board’s error was
 therefore harmless. See In re Watts, 354 F.3d 1362, 1369
 (Fed. Cir. 2004) (“[T]he harmless error rule applies to ap-
 peals from the Board.”) (citing In re McDaniel, 293 F.3d
 1379, 1385–86 (Fed. Cir. 2002); Gechter v. Davidson, 116
 F.3d 1454, 1457 (Fed. Cir. 1997)). The Board noted that
 although it did not construe the preamble as limiting,
 Rosko “suggests using a woven, porous material in a light
 diffusing, internally illuminated part of footwear.” -1810
 Decision, 2019 WL 237069, at *8 n.16. Specifically, Rosko
 suggests constructing its display panel from a woven, po-
 rous material—such as textile—and provides a rationale
 for doing so: according to Rosko, “[s]uch material would fur-
 ther assist in diffusing light because its porosity would
 tend to spread, disperse, and diffuse light.” Rosko ¶ 22. We
 note also that the ’574 patent itself acknowledges that tex-
 tiles have been used in the production of footwear “over
 many decades.” ’574 patent col. 1 ll. 19–22. The disclosure
 of Rosko and statements of the ’574 patent constitute sub-
 stantial evidence supporting the Board’s determination
 that the use of a textile light diffusing section would have
 been obvious. Thus, although we agree with Firebug that
 the preamble of claim 1 of the ’574 patent limits the chal-
 lenged claims to require textile footwear, we conclude that
 the Board’s ultimate conclusion of obviousness is correct
 under the proper claim construction and that the Board’s
 error was therefore harmless.
                        II. Obviousness
      Obviousness is a question of law that “lends itself to
 several basic factual inquiries,” Graham v. John Deere Co.,
 383 U.S. 1, 17–18 (1966) (citing Great Atl. & Pac. Tea Co.
 v. Supermarket Equip. Corp., 340 U.S. 147, 155 (1950)), in-
 cluding the scope and content of the prior art, the level of
 ordinary skill in the art, differences between the prior art
 and the claimed invention, and any relevant secondary con-
 siderations. Id. “We review the PTAB’s factual findings
 for substantial evidence and its legal conclusions de novo.”
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 12    SHOES BY FIREBUG LLC   v. STRIDE RITE CHILDREN'S GROUP



 Redline Detection, LLC v. Star Envirotech, Inc., 811 F.3d
 435, 449 (Fed. Cir. 2015) (citing Rambus Inc. v. Rea, 731
 F.3d 1248, 1251 (Fed. Cir. 2013)). A finding is supported
 by substantial evidence if a reasonable mind might accept
 the evidence as adequate to support the finding. Consol.
 Edison Co. v. NLRB, 305 U.S. 197, 229 (1938). “If two ‘in-
 consistent conclusions may reasonably be drawn from the
 evidence in record, the PTAB’s decision to favor one conclu-
 sion over the other is the epitome of a decision that must
 be sustained upon review for substantial evidence.’” Elbit
 Sys. of Am., LLC v. Thales Visionix, Inc., 881 F.3d 1354,
 1356 (Fed. Cir. 2018) (quoting In re Cree, Inc., 818 F.3d 694,
 701 (Fed. Cir. 2016) (internal brackets omitted)).
                    A. “Interfacing layer”
      Independent of its claim construction argument, Fire-
 bug also challenges the Board’s conclusion that the claims
 otherwise would have been obvious over the references.
 Specifically, Firebug argues that the combination of Parker
 and Rosko fails to disclose the claimed interfacing layer be-
 cause the “back reflector” of Parker is a permanently fixed
 coating of Parker’s optical fibers and would not be retained
 if the optical fibers were replaced by Rosko’s LEDs, as pro-
 posed by Stride Rite.
     Stride Rite counters that the Board’s determination
 that the combination of Parker and Rosko discloses the in-
 terfacing layer is supported by substantial evidence. Stride
 Rite points to the testimony of its expert, Lenny Holden,
 that a skilled artisan would have substituted Rosko’s LEDs
 for the optical fibers of Parker, resulting in the claimed
 structure.
      We agree with Stride Rite that the Board’s conclusion
 is supported by substantial evidence. The challenged
 claims require that the interfacing layer be “adjacently con-
 nected” to the light diffusing layer, with the illumination
 sources positioned between the two layers. ’038 patent
 col. 7 ll. 39–40; ’574 patent col. 9 ll. 55–56. Parker’s back
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 of the shoe in Parker and decrease material costs.” J.A.
 2607 ¶ 87.
      In its response, Firebug argued that Parker’s back re-
 flector is an optical layer associated with the optical fibers
 that would have no function in the absence of the optical
 fibers and that there would be no reason to retain Parker’s
 back reflector because the light diffusers of Rosko already
 include a reflective sheet. J.A. 2926–27.
     After weighing the parties’ positions, the Board deter-
 mined that Stride Rite’s proposed combination of Parker
 and Rosko accounted for the claimed interfacing layer and
 that Stride Rite had articulated sufficient reasons to com-
 bine the known elements in the claimed arrange-
 ment. -1809 Decision, 2019 WL 236242, at *23; -1810
 Decision, 2019 WL 237069, at *24.
     Firebug argues that we must reverse the Board be-
 cause its finding is not supported by substantial evidence.
 We disagree. The Board was presented with two alterna-
 tive theories as to whether a skilled artisan would or would
 not have substituted Rosko’s LEDs for Parker’s optical fi-
 bers as proposed by Stride Rite. Our task is not to deter-
 mine which theory we find more compelling. “[I]t is not for
 us to second-guess the Board’s assessment of the evidence.”
 Velander v. Garner, 348 F.3d 1359, 1378 (Fed. Cir. 2003).
 Rather, the only question before us is whether the conclu-
 sion adopted by the Board is supported by substantial evi-
 dence. Here, we conclude that it is.
     Parker and Rosko both suggest that LEDs would be a
 suitable alternative for optical fibers. Parker discloses
 LEDs as one possible light source for its optical fibers, Par-
 ker, col. 4 ll. 63–64, while Rosko explains that, although its
 light source “is typically a light-emitting diode . . . any
 source of light may be used such as . . . optic fiber.” Rosko
 ¶ 23. And as noted by the Board, Holden explained that at
 the time of the invention optical fibers were known to be
 more expensive than LEDs and that the use of LEDs would
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 result in more durable footwear. As to the back reflector,
 the Board credited Holden’s testimony that a person of skill
 would have retained the back reflector for use with the sub-
 stituted LEDs “to maximize the distribution of light.” J.A.
 2604 ¶ 83. This testimony accords with the disclosure of
 Parker, which explains that the purpose of the back reflec-
 tor is to redirect light back through the light source “such
 that light is emitted from only the front side of the light
 emitting portion.” Parker, col. 4 ll. 30–34. Based on the
 disclosure of the references and Holden’s testimony, we
 conclude that the Board’s determination that a skilled ar-
 tisan would have been motivated to combine Parker and
 Rosko in the manner proposed by Stride Rite, and that the
 combination discloses the claimed limitations of the inter-
 facing layer, is supported by substantial evidence.
      None of Firebug’s arguments on appeal demonstrate
 otherwise. First, Firebug argues that, because Parker’s
 back reflector is a coating of the optical fibers, the reflector
 is coextensive with the light source. Thus, according to
 Firebug, if the optical fibers were replaced with discrete
 LEDs, the back reflector would similarly coextend with the
 LEDs themselves and would not extend beyond or between
 the light sources to be “adjacently connected” to the light
 diffusing layer. Appellant’s Br. 46–47. Ultimately, Fire-
 bug’s argument improperly asks us to perform fact-finding.
 We are not in a position to evaluate the correctness of Fire-
 bug’s argument, but rather must determine whether the
 Board’s conclusion was supported by the evidence pre-
 sented. Holden testified that a skilled artisan would have
 been motivated to retain Parker’s back reflector for the rea-
 sons discussed above and presented a modified structure in
 which the back reflector extended beyond and between the
 individual LEDs. Further, Figure 2 of Parker illustrates
 the illumination section—including its associated back re-
 flector—extending beyond the viewing window through
 which reflected light would be visible. In light of this evi-
 dence, the Board’s determination that a person of skill
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 16    SHOES BY FIREBUG LLC   v. STRIDE RITE CHILDREN'S GROUP



 would be motivated to retain the back reflector in its gen-
 eral size and shape when Rosko’s LEDs are substituted for
 Parker’s optical fibers is not unreasonable.
     Second, Firebug argues that the Board improperly dis-
 regarded its argument, supported by the declaration of
 Firebug’s owner and the named inventor Roy Smith, that
 Stride Rite’s modified structure would not survive the
 “lasting” process—the process in which upper material is
 formed into the shape of a shoe—because the back reflector
 would be too weak. Appellant’s Br. 49–51. On the con-
 trary, the Board considered the argument but found it un-
 persuasive because it was predicated on Firebug’s
 contention that the reflective layer would be made of a thin
 layer “such as foil.” -1809 Decision, 2019 WL 236242, at
 *18; -1810 Decision, 2019 WL 237069, at *18. The Board
 also discounted Smith’s testimony because he “had not ex-
 perimented with foil, admitted that lasting forces can be
 applied by hand, and admitted that components that are
 glued together can survive the lasting process.” Id. Addi-
 tionally, Holden testified that Stride Rite’s proposed modi-
 fication would in fact increase the durability of the
 footwear. J.A. 2607 ¶ 87. The Board was within its discre-
 tion to weigh the credibility of expert testimony, see Yorkey
 v. Diab, 601 F.3d 1279, 1284 (Fed. Cir. 2010) (citing Ve-
 lander, 348 F.3d at 1371), and Firebug has not otherwise
 demonstrated that the Board’s determination is unsup-
 ported by substantial evidence.
                B. Secondary Considerations
     Firebug also argues that the Board improperly failed to
 consider certain portions of Firebug’s evidence of secondary
 considerations of nonobviousness. Specifically, Firebug ar-
 gues that the Board erred by failing to consider two license
 agreements that include the ’038 and ’574 patents as well
 as the testimony of Ralph Shanks, who negotiated the li-
 censes on behalf of the licensee. According to Firebug, the
 licenses and associated testimony from Shanks establish a
Case: 19-1622    Document: 59      Page: 17   Filed: 06/25/2020




 SHOES BY FIREBUG LLC   v. STRIDE RITE CHILDREN'S GROUP   17



 nexus between Firebug’s products and the challenged
 claims, which the Board otherwise found lacking. Appel-
 lant’s Br. 57.
     Stride Rite responds that even if nexus is presumed be-
 tween Firebug’s products and the challenged claims, the
 Board’s determination that Firebug’s evidence of secondary
 considerations is entitled to little weight is supported by
 substantial evidence.
     We agree with Stride Rite. The agreements presented
 by Firebug license eight patents, two patent applications,
 and one trademark to APTC LLC. J.A. 2858–79. Because
 the licenses include numerous intellectual property rights
 in addition to the ’038 and ’574 patents, the agreements on
 their face do not establish a nexus between the commercial
 interest in Firebug’s products and the claims of the ’038
 and ’574 patents. To remedy this deficiency, Firebug relies
 on the testimony of Shanks, who negotiated the license on
 behalf of APTC, that “[i]t was the ability of the Firebug
 shoes to illuminate from within that served as the primary
 driver for the license agreement.” J.A. 2180 ¶9. However,
 we need not determine whether the Board erred in deter-
 mining that Firebug had not established nexus because the
 Board alternatively found that, even if nexus is presumed,
 Firebug’s evidence of secondary considerations is weak,
 and that conclusion is supported by substantial evidence.
      Before the Board, Firebug primarily argued that evi-
 dence of industry praise, commercial success, and copying
 supports a conclusion of nonobviousness. Firebug’s evi-
 dence of industry praise rested primarily on declarations
 from Paul Barcroft, a Firebug salesman and shoe-industry
 veteran, and Smith, owner of Firebug and named inventor
 of the challenged patents. The Board struck Barcroft’s dec-
 laration because he refused to be deposed and determined
 that Smith’s testimony was entitled to little weight because
 it comprised only characterizations by the inventor of
 statements of industry reaction allegedly reported to him
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 18    SHOES BY FIREBUG LLC   v. STRIDE RITE CHILDREN'S GROUP



 by others. -1809 Decision, 2019 WL 236242, at *21; -1810
 Decision, 2019 WL 237069, at *21. Smith also testified that
 C.P. International, a footwear manufacturer and Firebug
 licensee, reported $1.3 million in sales of Firebug’s prod-
 ucts in 2014. The Board similarly discounted the weight
 given to this evidence because Smith admitted that the fig-
 ure includes products not covered by the challenged pa-
 tents. -1809 Decision at *22; -1810 Decision at *22.
 Finally, the Board gave little weight to Firebug’s proffered
 evidence of copying because it did not demonstrate that
 Stride Rite had access to a sample of Firebug’s boot that it
 could reverse engineer. -1809 Decision at *23; -1810 Deci-
 sion at *23.
     Given the weakness of the evidence considered by the
 Board, the two license agreements argued by Firebug on
 appeal have little impact on the overall weighing of second-
 ary considerations. The licenses include trademarks and
 patents other than the challenged patents, and the only ev-
 idence offered by Firebug to tie the agreements to the
 claimed features is Shanks’s testimony of comments alleg-
 edly made to him by various industry representatives. Ac-
 cordingly, we conclude that the license agreements are
 entitled to limited weight and, weighing Firebug’s evidence
 of secondary considerations of nonobviousness, we discern
 no error in the Board’s ultimate conclusion of obviousness.
                        CONCLUSION
     We have considered Firebug’s remaining arguments
 but find them unpersuasive. For the foregoing reasons, the
 decisions of the Board are affirmed.
                        AFFIRMED
