Case: 23-2117   Document: 72     Page: 1   Filed: 08/08/2025




   United States Court of Appeals
       for the Federal Circuit
                 ______________________

  MONDIS TECHNOLOGY LTD., HITACHI MAXELL,
  LTD., NKA MAXELL HOLDINGS, LTD., MAXELL,
                      LTD.,
              Plaintiffs-Appellants

                            v.

  LG ELECTRONICS INC., LG ELECTRONICS USA,
                      INC.,
           Defendants-Cross-Appellants
             ______________________

                  2023-2117, 2023-2116
                 ______________________

     Appeals from the United States District Court for the
 District of New Jersey in No. 2:15-cv-04431-SRC-CLW,
 Judge Stanley R. Chesler.
                 ______________________

                 Decided: August 8, 2025
                 ______________________

    MARTIN JAY BLACK, Dechert LLP, Philadelphia, PA, ar-
 gued for plaintiffs-appellants. Also represented by
 JEFFREY EDWARDS, BRIAN GOLDBERG; JEFFREY B. PLIES,
 Austin, TX.

     MICHAEL JOHN BALLANCO, Fish & Richardson P.C.,
 Washington, DC, argued for defendants-cross-appellants.
 Also represented by CHRISTIAN A. CHU, MICHAEL J.
 MCKEON, ROBERT ANDREW SCHWENTKER.
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 2           MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.




                  ______________________

     Before TARANTO, CLEVENGER, and HUGHES, Circuit
                        Judges.
 HUGHES, Circuit Judge.
     This is an appeal from a judgment issued by the United
 States District Court for the District of New Jersey pursu-
 ant to a jury verdict and a subsequent denial of motion for
 judgment as a matter of law. The jury determined that 

 was not proven invalid and that LG
 Electronics Inc. and LG Electronics U.S.A., Inc.’s accused
 products infringed the patent. Because we hold the ’180 pa-
 tent is invalid for lack of an adequate written description,
 we reverse.
                               I
     The present appeal arises from a dispute between Ap-
 pellants Mondis Technology Ltd., Hitachi Maxell, Ltd.,
 n/k/a/ Maxell Holdings, Ltd., and Maxell, Ltd. (collectively,
 Mondis), owners of 

 and Cross-
 Appellants LG Electronics, Inc. and LG Electronics U.S.A.,
 Inc. (collectively, LG), over allegations that LG manufac-
 tured and sold televisions that infringed claims 14 and 15
 of the ’180 patent.
                              A
      The ’180 patent, which issued on January 6, 2009, is
 titled “Display Unit with Communication Controller and
 Memory for Storing Identification Number for Identifying
 Display Unit.” The patent describes a system for control-
 ling a specific display unit, such as a computer monitor,
 that is configured to receive video signals from an external
 source, such as a computer. The display unit’s memory
 stores one or more identification numbers. 

 Fig. 2. A
 computer may request control of a newly connected display
 unit by transmitting the computer’s individualized identi-
 fication number, which the display unit then compares to a
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 MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.                 3



 stored list of known identification numbers. 

 5:38–42. If
 the computer’s identification number matches a registered
 identification number in the display unit’s memory, the
 computer can control aspects of the display unit, such as
 its brightness and contrast. 

 5:43–47. If there is no
 matching identification number, the computer cannot con-
 trol the display unit. 

 Fig. 3. Alternatively, the com-
 puter can store registered identification numbers for
 specific display units and gain control of a display unit by
 matching the display unit’s identification number against
 its stored list. 

 5:61–6:4.
      In either configuration, each identifier is associated
 with a specific computer or a specific display unit. The pa-
 tent consistently describes a one-to-one relationship in
 which one identification number corresponds to one device.
 For example, the patent provides that “the microcomputer
 7 in the display device 6 waits for sending of the identifica-
 tion number assigned to the computer 1, that is, the so-
 called ID number from the computer 1.” 

 5:35–38. After
 this registration process, “the computer 1 is allowed to con-
 trol the display device 6.” 

 5:43–44. Similarly, for the
 alternative configuration where the computer verifies the
 display unit, “an ID number is sent to the computer 1 from
 the display device 6 so that the computer 1 identifies that
 the display device 6 . . . is connected,” and “[b]y doing this,
 the computer 1 communicates with a specific display device
 6.” 

 5:62–6:6. And “[w]hen an identification number is
 set to each device, a value which is set by the above control
 will not be lost by a careless operation of a user.” 

 10:28–
 30.
     As initially filed, application claim 40 (which issued as
 claim 14) recited:
     40. A display unit for displaying an image based on
     video signals inputted from an externally con-
     nected video source, comprising:
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 4             MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.




        a video circuit adapted to display an image
        based on the video signals sent by the ex-
        ternally connected video source;
        a memory in which at least display unit in-
        formation is stored, said display unit infor-
        mation including an identification
        number for identifying said display
        unit and characteristic information of said
        display unit; and
        a communication controller capable of bi-
        directionally communicating with said
        video source;
        wherein said communication controller is
        capable of communicating said display unit
        information other than said characteristic
        information to said video source.
 J.A. 18192–93 (emphasis added) (cleaned up).
     On June 4, 2002, Mondis amended the claim by insert-
 ing the phrase “at least a type of” to overcome a prior art
 rejection. As amended, claim 14 recites:
     14. A display unit for displaying an image based on
     video signals inputted from an externally con-
     nected video source, comprising:
         ...
        information including an identification
        number for identifying at least a type
        of said display unit and characteristic in-
        formation of said display unit; and
         ....
 ’180 patent, claim 14 (emphasis added). Claim 15, which
 depends on claim 14, recites:
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 MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.                5



     15. The display unit according to claim 14, wherein
     said display unit information is sent to said video
     source in response to power on of at least one of said
     display unit and said video source.
 

 claim 15.
                               B
     In 2014, Mondis filed a complaint against LG in the
 Eastern District of Texas alleging infringement of the ’180
 patent and four other patents in the same family. Compl.
 at ¶ 1, 10–14, Mondis Tech. Ltd. v. LG Elecs., Inc., No. 2:14-
 CV-702-JRG (E.D. Tex. June 21, 2014), ECF No. 1. The
 case was then transferred to New Jersey, where it was
 stayed pending reexamination by the Patent Office. Mon-
 dis Tech. Ltd. v. LG Elecs., Inc., No. 2:14-CV-702-JRG,
 

 (E.D. Tex. June 3, 2015), ECF No. 56
 (order granting motion to transfer); Mondis Tech. Ltd. v.
 LG Elecs., Inc., No. 2:15-CV-04431-SRC-CLW, (D.N.J.
 Nov. 12, 2015), ECF No. 121 (order granting motion to
 stay). After some claims of the ’180 patent survived reex-
 amination, Mondis voluntarily cancelled all claims of the
 other four patents subject to reexamination. J.A. 1060. The
 district court litigation proceeded, relevant here, on claims
 14 and 15 of the ’180 patent.
      A jury trial took place in April 2019. LG challenged
 claims 14 and 15 as invalid for lacking written description
 for the limitation “said display unit information including
 an identification number for identifying at least a type of
 said display unit and characteristic information of said dis-
 play unit” (the type limitation). LG argued that while the
 originally filed patent supported the original claim of an
 identification number for identifying said display unit, it
 did not support the amended claim’s requirement of iden-
 tifying a type of said display unit. Mondis did not present a
 rebuttal case regarding written description during trial.
 J.A. 20744, 744:3–6.
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 6           MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.




     On April 9, 2019, the jury found the two asserted
 claims of the ’180 patent not invalid and infringed. J.A.
 193–94. On April 12, 2019, the jury returned a verdict find-
 ing willful infringement and awarding $45,000,000 in dam-
 ages to Mondis. J.A. 216–17.
      LG filed a motion for Judgment as a Matter of Law
 challenging, among other things, the jury’s finding of writ-
 ten description support. On September 24, 2019, the dis-
 trict court denied LG’s motion without identifying support
 for the type limitation in the patent’s specification.
 J.A. 221–24. Instead, the district court relied on the pre-
 sumption of validity and its determination that the jury
 was free to disregard LG’s expert’s testimony because he
 was impeached when testifying about noninfringement to
 determine that “[t]he jury reached the conclusion that the
 claims were valid based on the failure of the patent chal-
 lenger’s evidence to clearly and convincingly establish the
 contrary.” J.A. 223. The district court accordingly upheld
 the jury’s findings on invalidity, infringement, and willful-
 ness, but vacated the damages award and ordered a retrial
 on damages.
     After a damages retrial that began on February 6,
 2023, the retrial jury awarded damages of $14,300,000 to
 Mondis. J.A. 506. On June 1, 2023, the district court denied
 LG’s post-trial motions related to damages, denied Mondis’
 motion for enhanced damages and attorneys’ fees, and
 granted-in-part Mondis’ motion for pre-judgment and post-
 judgment interest. Mondis Tech. Ltd v. LG Elecs., Inc., No.
 2:15-CV-4431-SRC-CLW, 

 (D.N.J.
 June 1, 2023).
      Both LG and Mondis timely filed notices of appeal. On
 appeal, Mondis argues: (1) the district court erred in vacat-
 ing the original $45 million damages verdict, (2) the dis-
 trict court erred in creating a supposed “no new evidence”
 rule during retrial, (3) the district court erred in denying
 enhanced damages, (4) the district court erred in denying
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 MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.               7



 attorneys’ fees, and (5) the district court erred in determin-
 ing prejudgment interest. On cross-appeal, LG argues:
 (1) the district court erroneously denied its motion for
 JMOL of invalidity for lack of written description, (2) the
 district court erroneously denied its motion for JMOL of
 noninfringement, and (3) no reasonable jury could have
 found the damages award at retrial. We have jurisdiction
 over the appeal and cross-appeal pursuant to 

(a)(1).
                               II
     We review a district court’s denial of JMOL under the
 regional circuit law. Summit Tech., Inc. v. Nidek Co.,
 

 (Fed. Cir. 2004). In the Third Circuit,
 denial of JMOL is reviewed for “whether there is evidence
 upon which a reasonable jury could properly have found its
 verdict.” TransWeb, LLC v. 3M Innovative Props. Co.,
 

 (Fed. Cir. 2016) (quoting Gomez v. Al-
 legheny Health Servs., 

, 1083 (3d Cir. 1995)).
 “JMOL ‘should be granted only if, viewing the evidence in
 the light most favorable to the nonmovant and giving it the
 advantage of every fair and reasonable inference, there is
 insufficient evidence from which a jury reasonably could
 find’ for the nonmovant.” Id. (quoting Lightning Lube, Inc.
 v. Witco Corp., 

 (3d Cir. 1993)). Patents
 are presumed to be valid and overcoming this presumption
 requires clear and convincing evidence. Ariad Pharms.,
 Inc. v. Eli Lilly & Co., 

 (Fed. Cir. 2010)
 (en banc).
                              III
     A patent’s specification “shall contain a written de-
 scription of the invention.” 

 ¶ 1 (pre-AIA).
 “[T]he hallmark of written description is disclosure.” Ariad,
 

. To satisfy the written description re-
 quirement an applicant need not expressly “recite the
 claimed invention in haec verba,” but a patent’s specifica-
 tion must “reasonably convey[] to those skilled in the art
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 8            MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.




 that the inventor had possession of the claimed subject
 matter as of the filing date.” 

 at 1351–52. And “[w]hile it
 is legitimate to amend claims or add claims to a patent ap-
 plication purposefully to encompass devices or processes of
 others, there must be support for such amendments or ad-
 ditions in the originally filed application.” PIN/NIP, Inc. v.
 Platte Chem. Co., 

 (Fed. Cir. 2002).
     Compliance with the written description requirement
 of 

, ¶ 1 is a question of fact, and “we review
 a jury’s determinations of facts relating to compliance with
 the written description requirement for substantial evi-
 dence.” Ariad, 

 (quoting PIN/NIP,
 

). LG had the burden of persuasion on this
 fact, needing clear and convincing evidence. 

.
      LG contends that the written description does not sup-
 port the claim limitation “identification number for identi-
 fying at least a type of said display unit,” which we refer to
 as the type limitation. LG’s Opening Br. 10. We agree with
 LG that no reasonable jury could find the patent’s written
 description conveys to a relevant artisan that the inventors
 possessed the type limitation. We hold that the jury’s find-
 ing that LG failed to show inadequate written description
 for the asserted claims lacked substantial evidence support
 on the record.
                               A
     As a threshold matter, Mondis argues that because of
 the presumption of validity, it was not required to provide
 any evidence to prove there was adequate written descrip-
 tion support. Under 

(a), a “patent shall be
 presumed valid.” Throughout litigation “the presumption
 of validity remains intact and the ultimate burden of prov-
 ing invalidity remains with the challenger.” Pfizer, Inc. v.
 Apotex, Inc., 

 (Fed. Cir. 2007) (quoting
 Mas-Hamilton Grp. v. LaGard, Inc., 

 (Fed. Cir. 1998)).
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 MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.               9



      There are situations where, because “[a] patent [is] pre-
 sumed valid at birth, . . . a patentee need submit no evi-
 dence in support of a conclusion of validity by a court or a
 jury.” Orthokinetics, Inc. v. Safety Travel Chairs, Inc.,
 

 (Fed. Cir. 1986) (emphasis in original).
 However, sometimes the patent itself is clear enough that
 it establishes inadequacy of support in the written descrip-
 tion for the full scope of the claimed invention unless there
 is contrary evidence. See Centocor Ortho Biotech, Inc. v. Ab-
 bott Lab’ys, 

 (Fed. Cir. 2011) (“A patent
 also can be held invalid for failure to meet the written de-
 scription requirement based solely on the face of the patent
 specification.”); PIN/NIP, 304 F.3d at 1247–48 (holding
 that a patent can be held invalid for failure to meet the
 written description requirement, based solely on the lan-
 guage of the patent specification); Univ. of Rochester v.
 G.D. Searle & Co., 

 (Fed. Cir. 2004)
 (“[The] argument that a patent may not be held invalid on
 its face is contrary to our case law.”). That is so here, as
 confirmed by the testimony of Mondis’ own expert on the
 key point.
      When the patent was initially filed, claim 14 (then-
 numbered as claim 40) recited “an identification number
 for identifying said display unit.” J.A. 18193 (emphasis
 added). Mondis amended the claim to overcome a prior art
 rejection. J.A. 18203–04; J.A. 18209–10. As issued, claim
 141 of the patent recites “an identification number for iden-
 tifying at least a type of said display unit.” ’180 patent,
 claim 14 (emphasis added). This amendment changed the
 nature of the claim’s identification number from one iden-
 tifying a specific display unit to one identifying a type of
 display unit. LG contends that the amended type limitation




     1  Claim 15 depends on claim 14 and includes the
 same limitation.
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 10             MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.




 lacks written description support from the originally filed
 patent.
      It is undisputed that the patent does not expressly dis-
 close the type limitation.2 The patent’s specification recites
 the phrase “type of display device” only once in its back-
 ground section, 

 1:41–44, but this use does not provide
 written description support because it refers to a prior-art
 multi-scan monitor rather than the claimed invention. See
 Tronzo v. Biomet, Inc., 

 (Fed. Cir. 1998)
 (reversing JMOL denial where cited patent passage was
 “reviewing the prior art and did not describe the inven-
 tion”). Instead, the patent consistently discloses an identi-
 fier that is associated with a specific computer. See, e.g.,
 ’180 patent, 5:35–38 (“[T]he microcomputer 7 in the display
 device 6 waits for sending of the identification number as-
 signed to the computer 1, that is, the so-called ID number
 from the computer 1.”), 5:43–44 (“[T]he computer 1 is al-
 lowed to control the display device 6[.]”), 5:62–6:6 (“[A]n ID
 number is sent to the computer 1 from the display device 6
 so that the computer 1 identifies that the display device
 6 . . . is connected,” and “[b]y doing this, the computer 1
 communicates with a specific display device 6.”), 7:18–20
 (“Each of the display devices 6B, 6C, and 6D has . . . a reg-
 istered ID number.”).
     Additionally, LG’s expert, Dr. Stevenson, testified that
 the patent does not disclose an identification number to
 identify a type of display unit. J.A. 20616–17,
 616:24–617:10; J.A. 20570–71, 570:24–571:1. Mondis ar-
 gues that the jury was free to dismiss Dr. Stevenson’s



      2  At oral argument, counsel for Mondis agreed that
 the specification does not disclose the actual words “type
 identifier.” See Oral Arg. at 15:20–17:15, No. 23-2117,
 available at https://oralarguments.cafc.uscourts.gov/de-
 fault.aspx?fl=23-2117_04072025.mp3.
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 MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.              11



 credibility on written description because he was im-
 peached.3 Mondis’ Reply Br. 41–42. But even assuming
 Dr. Stevenson’s credibility was impaired through impeach-
 ment, Mondis’ expert, Mr. Lamm, also testified that the
 specification “does not expressly recite an identification
 number for identifying a type of display unit.” J.A.
 20417–18, 417:24–418:2.
     To satisfy the written description requirement, the pa-
 tent specification’s disclosures must demonstrate to a
 skilled artisan that the inventors possessed the invention,
 including, in this case, the type limitation. See Ariad,
 

 (requiring an “objective inquiry into the
 four corners of the specification”). Based only on the patent
 and Mr. Lamm’s testimony, any reasonable jury perform-
 ing this objective inquiry into the four corners of the patent
 would have to find that the inventors only possessed and
 disclosed identifying a specific display unit.
      It would not automatically be fatal that the type limi-
 tation was not expressly disclosed as long as substantial
 evidence showed that the patent disclosed identifying a
 type of display unit in some less express way. And Mondis
 argues that (1) Mr. Lamm’s testimony, (2) Dr. Stevenson’s
 admissions, and (3) the prosecution history each provide
 substantial evidence to support the jury’s finding on valid-
 ity. We address each in turn.
                               1
     Mondis argues that there was “written description sup-
 port for a type ID based on Mr. Lamm’s description of the


     3   We do not reach whether (1) Dr. Stevenson was im-
 peached while testifying about infringement, and (2) if he
 was impeached, whether his impeached noninfringement
 testimony can impair his invalidity testimony because we
 can resolve the issue on appeal without relying on his tes-
 timony.
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 12             MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.




 patent and the plain words of the specification.” Mondis’
 Reply Br. 44. The specification describes an embodiment
 where an ID number is sent from the display to a computer:
      Namely, an ID number is sent to the computer 1
      from the display device 6 so that the computer 1
      identifies that the display device 6 having a com-
      munication function is connected and the computer
      1 compares the ID number with the ID number reg-
      istered in the computer 1.
 ’180 patent, 5:62–67. Mondis argues that “Mr. Lamm pre-
 sented this passage to the jury and explained that the com-
 munication function comprised a ‘video format the display
 is capable of receiving.’” Mondis’ Reply Br. 44 (quoting J.A.
 20291, 291:3–4). Mondis claims that “[t]his display ID
 number plainly identifies a display type in accord with the
 ordinary meaning of the word ‘type,’ because the ID distin-
 guishes between two groups of displays based on their com-
 mon characteristics, i.e. those that support a
 ‘communication function’ (video format) and those that do
 not,” and that, “[g]iven the specification’s description of a
 display ID being used to differentiate classes of displays
 with different capabilities, the jury was entitled to draw
 the reasonable inference that a display type ID was dis-
 closed.” 

 at 44–45 (emphasis in original).
     The full portion of Mr. Lamm’s testimony that Mondis
 relies on states:
      This is column 5, line 62 through 67, and it basi-
      cally says the ID number identifies that the display
      device having a communication function is con-
      nected. And in this case the communication func-
      tion that they’re talking about is an actual video
      format. So, the ID number is defining what video
      format the display is capable of receiving.
 J.A. 20290–91, 290:23–291:4. Not only was this testimony
 about infringement rather than validity, it was also silent
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 MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.             13



 about the type limitation. Mondis never presented any ev-
 idence to the jury connecting this “communication func-
 tion” to the type limitation that would allow a reasonable
 jury to find written description support.
      And the plain words of this portion of the specification
 demonstrate that the patent discloses a specific display
 unit, not the type limitation. The sentence in the patent
 that immediately follows the excerpt discussed by
 Mr. Lamm, which Mondis did not present to the jury,
 states that “[b]y doing this, the computer 1 communi-
 cates with a specific display device 6 and can exercise
 control such as changing the color temperature of an image
 displayed on the display device 6 or changing the display
 size depending on the application software.” ’180 patent,
 6:5–9 (emphasis added). This passage only indicates that
 the display device transmits to the computer an identifica-
 tion number identifying a specific display unit so that the
 computer may control the display device if the specific dis-
 play unit’s identification number is registered with the
 computer. It does not provide written description support
 for the type limitation.
     Thus, neither Mr. Lamm’s testimony nor the plain
 words of the specification in the portions that he cited in
 his testimony provide substantial evidence to support the
 jury’s finding on validity.
                              2
     Mondis also argues that Dr. Stevenson made admis-
 sions that provide substantial evidence to support the
 jury’s finding on validity. Specifically, Mondis contends
 that Dr. Stevenson’s noninfringement testimony provides
 substantial evidence that serial numbers (1) could be used
 to identify a particular display unit, and (2) could hypo-
 thetically be a type 

     The written description “test requires an objective in-
 quiry into the four corners of the specification from the
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 14             MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.




 perspective of a person of ordinary skill in the art.” Ariad,
 

. And “we have repeatedly stated that ac-
 tual ‘possession’ or reduction to practice outside of the spec-
 ification is not enough.” 

. It is the specification
 itself that must demonstrate possession.
     As an initial matter, Mondis does not identify any ref-
 erence to serial numbers in the specification. The patent’s
 specification does not use the term serial numbers, does not
 discuss serial numbers, and does not describe a serial num-
 ber that identifies a display unit type.
      Further, Dr. Stevenson’s testimony does not provide
 substantial evidence for adequate written description.
 Dr. Stevenson’s testimony was regarding noninfringement.
 He never testified that in reading the patent’s specifica-
 tion, he or a relevant artisan would understand the type
 limitation to include serial numbers. Instead, he was pre-
 sented with a hypothetical serial number and testified that
 it could potentially be a type identifier in some circum-
 stances. But when asked whether a “serial number would
 be an identification number for identifying a type of display
 unit,” J.A. 20682, 682:2–4, Dr. Stevenson testified that “no
 one has made that allegation,” J.A. 20682, 682:5. Dr. Ste-
 venson explained that this would require hypothetically
 mapping the serial number onto the model number to see
 if the serial number could be used to “figure out the model
 number.” J.A. 20682, 682:5–8.
      There was no testimony from which a skilled artisan
 would have concluded that such mapping of serial number
 onto model number is disclosed or suggested in the patent
 itself. And there is nothing in the patent describing a serial
 number that identifies any type of display unit. Dr. Steven-
 son’s noninfringement testimony about a hypothetical se-
 rial number does not address whether a person of ordinary
 skill in the art would find support in the specification for
 the type limitation.
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 MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.            15



     Thus, Dr. Stevenson’s testimony does not provide sub-
 stantial evidence to support the jury’s finding on validity.
                              3
     Lastly, Mondis argues that the prosecution history pro-
 vides substantial evidence to support the jury’s finding on
 validity because the type limitation was added to overcome
 a prior art rejection. Mondis contends that when a claim
 amendment is allowed without objection, it “is entitled to
 an especially weighty presumption of correctness.” Mondis’
 Reply Br. 47 (quoting Commonwealth Sci. & Indus. Rsch.
 Org. v. Buffalo Tech., Inc. (USA), 

 (Fed. Cir. 2008) (internal citation omitted)). Thus, Mondis
 argues that when the examiners allowed the amendment,
 they agreed to the type limitation because they understood
 that it was supported by written description.
     Commonwealth Science holds that there is a “presump-
 tion of validity based on the PTO’s issuance of the patent
 despite the amendments.” 

. It does not
 hold that the examiner’s allowance of claims by itself pro-
 vides substantial evidence that the claims comply with the
 requirements of § 112. See, e.g., AK Steel Corp. v. Sollac &
 Ugine, 

 (Fed. Cir. 2003) (“[W]e dispel
 the notion that the failure of the PTO to issue an enable-
 ment rejection automatically creates an ‘especially weighty
 presumption’ of compliance with 

.”). If it
 did, there would rarely be a situation where an issued pa-
 tent could later be invalidated for lack of written descrip-
 tion.
     Nevertheless, even if the allowance of amendments
 could be substantial evidence of written description, that
 would not be the case here. The examiner’s interview sum-
 mary explains that the claim was rejected over prior art.
 Thus, the claim was amended to “specify identification
 number as a ‘type’ of display unit which examiner agree[d]
 will read over the previous art applied regarding to the
 claims.” J.A. 15102 (emphasis omitted). There is no
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 16             MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.




 evidence the examiner considered whether the specifica-
 tion contained written description support for this amend-
 ment. The evidence only shows that the examiner allowed
 the claim as amended because it included a feature that
 was not in the identified prior art. This is not substantial
 evidence that the patent contains written description sup-
 port for the type limitation.
     Thus, the fact that the examiner allowed the amend-
 ment is not substantial evidence that supports the jury’s
 finding on validity.
                               B
     Even if we assume the jury was free to disregard
 Dr. Stevenson’s testimony, the only evidence before the
 jury regarding written description was the patent—which
 does not disclose the type limitation—and Mr. Lamm’s tes-
 timony that the patent does not disclose the asserted
 claims’ type limitation. Because Mondis neither redirected
 Mr. Lamm on his testimony that the patent does not ex-
 pressly disclose the type limitation, nor called him in re-
 buttal, there was no evidence in the record that would
 allow a reasonable jury to determine that a person of ordi-
 nary skill in the art would understand that the patent dis-
 closed the type limitation. The patent and Mr. Lamm’s
 testimony established that the inventors only possessed
 and disclosed identifying a specific display unit.
      Substantial evidence does not support the jury’s find-
 ing that the ’180 patent disclosed sufficient information to
 show the inventors possessed the claim limitation “an iden-
 tification number for identifying at least a type of said dis-
 play unit.” We hold that claims 14 and 15 of the ’180 patent
 are invalid for lack of an adequate written description.
                               IV
     Because we conclude that claims 14 and 15 of the ’180
 patent are invalid for lack of an adequate written descrip-
 tion, the issue of infringement is moot. Lough v. Brunswick
Case: 23-2117    Document: 72      Page: 17    Filed: 08/08/2025




 MONDIS TECHNOLOGY LTD. v. LG ELECTRONICS INC.              17



 Corp., 

 (Fed. Cir. 1996) (“No further
 public interest is served by our resolving an infringement
 question after a determination that the patent is invalid.”).
 Similarly, because we conclude that the asserted claims are
 invalid, the remaining issues involving the damages re-
 trial, the district court’s failure to declare the case excep-
 tional, the district court’s refusal to enhance damages, and
 the district court’s award of interest are also moot. LG is
 entitled to entry of judgment in its favor.
                               V
     We have considered Mondis’ remaining arguments and
 find them unpersuasive. We reverse the district court’s
 holding that claims 14 and 15 of the ’180 patent are not
 invalid for lack of an adequate written description. Those
 claims are invalid. We reverse the denial of judgment as a
 matter of law.
                        REVERSED
                            COSTS
 Costs to Appellee/Cross-Appellant LG.