Case: 23-1715    Document: 64     Page: 1   Filed: 07/28/2025




   United States Court of Appeals
       for the Federal Circuit
                  ______________________

       JIAXING SUPER LIGHTING ELECTRIC
        APPLIANCE, CO., LTD., OBERT, INC.,
                Plaintiffs-Appellees

                             v.

 CH LIGHTING TECHNOLOGY CO., LTD., ELLIOTT
  ELECTRIC SUPPLY, INC., SHAOXING RUISING
            LIGHTING CO., LTD.,
              Defendants-Appellants
             ______________________

                        2023-1715
                  ______________________

    Appeal from the United States District Court for the
 Western District of Texas in No. 6:20-cv-00018-ADA, Judge
 Alan D. Albright.
                   ______________________

                  Decided: July 28, 2025
                  ______________________

     MATTHEW COOK BERNSTEIN, Perkins Coie LLP, San Di-
 ego, CA, argued for plaintiffs-appellees. Also represented
 by EVAN SKINNER DAY, ABIGAIL A. GARDNER, JOSEPH P.
 REID; DAN L. BAGATELL, Hanover, NH.

    JEFFREY A. LAMKEN, MoloLamken LLP, Washington,
 DC, argued for defendants-appellants. Also represented by
 CALEB HAYES-DEATS, LUCAS M. WALKER; ALEXANDRA C.
 EYNON, SWARA SARAIYA, New York, NY.
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 2         JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.
                           CH LIGHTING TECHNOLOGY CO., LTD.


                   ______________________

      Before DYK, CHEN, and HUGHES, Circuit Judges.
 DYK, Circuit Judge.
     Jiaxing Super Lighting Electric Appliance Co., Ltd.
 and its North American affiliate Obert, Inc. (collectively,
 “Super Lighting”) brought suit against CH Lighting Tech-
 nology Co., Ltd., Elliott Electric Supply, Inc., and Shaoxing
 Ruising Lighting Co., Ltd. (collectively, “CH Lighting”) for
 infringement of U.S. Patent Nos. 10,295,125 (the “’125 pa-
 tent”), 10,352,540 (the “’540 patent”), and 9,939,140 (the
 “’140 patent”). Before trial, CH Lighting conceded infringe-
 ment of the ’125 and ’540 patents. At trial, the district
 court granted Super Lighting’s motions to exclude evidence
 relating to the validity of the asserted claims of the ’125
 and ’540 patents and subsequently granted Super Light-
 ing’s motion for judgment as a matter of law (“JMOL”) that
 the ’125 and ’540 patents were not invalid on the ground of
 an on-sale bar. A jury found the ’140 patent infringed and
 not invalid and awarded damages for infringement of
 claims of the three patents. CH Lighting appeals.
     We conclude as follows. First, the district court erred
 in granting JMOL that the ’125 and ’540 patents were not
 invalid because it erroneously prevented CH Lighting from
 presenting evidence of their invalidity; the district court
 was required to hold a new trial as to the invalidity of the
 ’125 and ’540 patents. Second, with respect to the ’140 pa-
 tent, substantial evidence supports the jury’s verdicts of in-
 fringement and no invalidity. Third, the district court
 should assess the reliability of Ms. Kindler’s testimony con-
 sistent with this court’s recent en banc decision in EcoFac-
 tor and under Rule 702 of the Federal Rules of Evidence.
 Accordingly, a new trial is required as to the validity of the
 ’125 and ’540 patents and as to damages for infringement
 of all three patents.       We accordingly affirm-in-part,
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 JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.            3
 CH LIGHTING TECHNOLOGY CO., LTD.


 reverse-in-part, vacate-in-part, and remand for further
 proceedings consistent with this opinion.
                         BACKGROUND
                               I
     Super Lighting owns the three asserted patents, which
 relate generally to light-emitting diode (“LED”) tube
 lamps. LED tube lamps resemble traditional incandescent
 and fluorescent tube lamps and can operate in fluorescent
 light fixtures. LED tube lamps typically comprise a lamp
 tube, an LED light strip, two end caps, and a power source
 that supplies external electricity to one or both of the end
 caps. LED tube lamps are more energy efficient and last
 longer than their incandescent and fluorescent counter-
 parts.
     The ’125 and ’540 patents (together, the “tube patents”)
 both relate to purported structural improvements in LED
 tube lamps. The ’125 patent discloses an LED tube lamp
 in which a flexible printed circuit board is mounted directly
 onto the tube’s inner surface.1 Claim 1 is the only claim of
 the ’125 patent that is the subject of this appeal and recites:
     1. An LED tube lamp, comprising:
         a lamp tube;



     1   This is in contrast to LED tube lamps’ usual struc-
 tural configuration, in which the lamp’s circuit board is
 supported on aluminum rails encased in plastic insulating
 sleeves. This configuration apparently has several draw-
 backs, since the plastic sleeves may change color as they
 age—thereby affecting lighting quality—and the rails can
 block transmission of light in certain directions. According
 to the ’125 patent’s specification, relocating the circuit
 board to the tube’s inner circumference improves bright-
 ness and light quality.
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 4          JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.
                            CH LIGHTING TECHNOLOGY CO., LTD.


         two end caps, each of the two end caps cou-
         pled to a respective end of the lamp tube;
         a power supply disposed in one or two end
         caps;
         an LED light strip disposed on an inner cir-
         cumferential surface of the lamp tube, the
         LED light strip comprising a mounting re-
         gion and a connecting region, the mounting
         region for mounting a plurality of LED
         light sources, the connecting region having
         at least two soldering pads, and the mount-
         ing region and the connecting region being
         electrically connected to the plurality of
         LED light sources and the power supply;
         and
         a protective layer disposed on a surface of
         the LED light strip, the protective layer
         having a plurality of first openings to ac-
         commodate the plurality of LED light
         sources and at least two second openings to
         accommodate the at least two soldering
         pads.
 ’125 patent, col. 99 ll. 7–24.
     The ’540 patent builds on the ’125 patent by including
 a diffusion film that can be placed on the tube lamp to pro-
 vide a uniform glow.2 Claims 13 and 14 are the only claims




     2    Since LEDs are spot light sources, the light emitted
 by them does not necessarily contribute to uniform illumi-
 nance of the entire tube lamp without optical manipula-
 tion. The ’540 patent’s specification states that using a
 diffusion film is a useful measure “to avoid grainy visual
 effects.” ’540 patent col. 2 l. 15.
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 JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.         5
 CH LIGHTING TECHNOLOGY CO., LTD.


 of the ’540 patent that are the subject of this appeal and
 recite:
    13. An LED tube lamp, comprising:
        a tube, comprising:
            a main body; and
            two rear end regions respectively at
            two ends of the main body;
        two end caps respectively sleeving the two
        rear end regions, each of the end caps com-
        prising:
            a lateral wall substantially coaxial
            with the tube, the lateral wall
            sleeving the respective rear end re-
            gion;
            an end wall substantially perpen-
            dicular to the axial direction of the
            tube; and
            two pins on the end wall for receiv-
            ing an external driving signal;
        an LED light strip disposed on an inner cir-
        cumferential surface of the main body with
        a plurality of LED light sources mounted
        thereon;
        a power supply comprising a circuit board
        and configured to drive the plurality of
        LED light sources, the circuit board dis-
        posed inside one of the rear end regions and
        one of the end caps;
        an adhesive disposed between each of the
        lateral wall and each of the rear end re-
        gions; and
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 6          JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.
                            CH LIGHTING TECHNOLOGY CO., LTD.


         a diffusion film disposed on the glass lamp
         tube so that light emitted from the LED
         light sources passing through the inner
         surface of the glass lamp tube and then
         passing through the diffusion film on the
         glass lamp tube.
     14. The LED tube lamp of claim 13, wherein a por-
     tion of the circuit board, one of the rear end regions,
     the adhesive and one of the lateral wall are stacked
     sequentially in a radial direction of the LED tube
     lamp.
 ’540 patent, col. 18 ll. 19–49.
      The ’140 patent relates to a shock-prevention system
 for use while installing LED tube lamps. Because many
 LED tube lamps have metallic pins at both ends, a person
 installing an LED lamp could receive a potentially lethal
 electric shock by touching the pins on the opposite end of
 the lamp when one end of the tube is inserted into a live
 outlet. The ’140 patent discloses a system that controls the
 flow of current in the lamp using a pulse generating circuit
 and detection determining circuit. The pulse generating
 circuit produces a pulse signal, and the detection determin-
 ing circuit determines that a person is touching the lamp if
 it senses high impedance. Both the detection determining
 circuit and the pulse signals can control the switch circuit
 to turn off or on. Claim 1 of the ’140 patent is exemplary3
 and recites:
     1. An installation detection circuit configured in a
     light-emitting diode (LED) tube lamp configured to
     receive an external driving signal, the installation
     detection circuit comprising:



     3   CH Lighting was found to infringe claims 1, 4, 5,
 24, 28, and 31 of the ’140 patent.
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 JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.         7
 CH LIGHTING TECHNOLOGY CO., LTD.


        a pulse generating circuit configured to
        output one or more pulse signals; wherein
        the installation detection circuit is config-
        ured to detect during at least one of the one
        or more pulse signals whether the LED
        tube lamp is properly installed on a lamp
        socket, based on detecting a signal gener-
        ated from the external driving signal; and
        a switch circuit coupled to the pulse gener-
        ating circuit, wherein the one or more pulse
        signals control turning on and off of the
        switch circuit;
        wherein the installation detection circuit is
        further configured to:
        when it is detected during one of the one or
        more pulse signals that the LED tube lamp
        is not properly installed on the lamp socket,
        control the switch circuit to remain in an
        off state to cause a power loop of the LED
        tube lamp to be open; and
        when it is detected during one of the one or
        more pulse signals that the LED tube lamp
        is properly installed on the lamp socket,
        control the switch circuit to remain in a
        conducting state to cause the power loop of
        the LED tube lamp to maintain a conduct-
        ing state,
        wherein the signal generated from the ex-
        ternal driving signal is a sampling signal
        on the power loop, the installation detec-
        tion circuit further comprises a detection
        determining circuit configured to detect the
        sampling signal for determining whether
        the LED tube lamp is properly installed on
        the lamp socket, and the power loop
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 8          JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.
                            CH LIGHTING TECHNOLOGY CO., LTD.


         includes the switch circuit and the detec-
         tion determining circuit, and
         wherein the pulse generating circuit is con-
         figured to output one or more pulse signals
         independent of whether the detection de-
         termining circuit detects the sampling sig-
         nal.
 ’140 patent, col. 58 l. 61–col. 59 l. 32.
                                II
     On January 10, 2020, Super Lighting brought suit
 against CH Lighting for infringement of the three asserted
 patents in the U.S. District Court for the Western District
 of Texas. Before trial, CH Lighting stipulated to infringe-
 ment for all accused products except the “LT2600 chips,”
 which it contended did not infringe the ’140 patent’s
 claims. At trial, the parties disputed the validity of the
 tube patents (the ’125 and ’540 patents); CH Lighting ar-
 gued that the America Invents Act’s (“AIA”) on-sale bar
 provision rendered the tube patents invalid. The district
 court excluded evidence offered by CH Lighting to show
 that three LED tube lamp products (the “prior art tubes”)
 were on sale before the effective filing dates of the tube pa-
 tents.    Nonetheless, CH Lighting’s invalidity expert
 Dr. Lebby testified that the prior art tubes embodied the
 tube patents’ claims and were on sale before the tube pa-
 tents’ effective filing dates.
     After the presentation of CH Lighting’s invalidity de-
 fense, the district court granted Super Lighting’s
 Rule 50(a) motion for JMOL that the tube patents were not
 invalid on the ground of an on-sale bar, holding that
 Dr. Lebby’s testimony alone did not constitute sufficient
 evidence upon which a reasonable jury could find that the
 prior art tubes embodying the claimed inventions were on
 sale prior to the tube patents’ 2015 effective filing dates.
 The district court also denied CH Lighting’s Rule 50(a)
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 JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.         9
 CH LIGHTING TECHNOLOGY CO., LTD.


 motion for JMOL that the claims of the asserted patents
 were invalid. On November 4, 2021, the jury returned a
 verdict finding that the ’140 patent was infringed and not
 shown to be invalid, ultimately awarding $13,872,872 to
 Super Lighting for infringement of the three asserted pa-
 tents.
     After trial, CH Lighting filed a renewed Rule 50(b) mo-
 tion for JMOL that the three patents were invalid and that
 the LT2600 chips did not infringe the ’140 patent. CH
 Lighting also filed a Rule 59(a) motion for a new trial, ar-
 guing that a new trial was warranted as to the validity of
 the tube patents because the district court erred in exclud-
 ing evidence showing that the prior art tubes were on sale
 before the tube patents’ effective filing dates. CH Lighting
 additionally argued in its Rule 59(a) motion that a new
 trial was warranted for damages because the district court
 improperly admitted the testimony of Super Lighting’s
 damages expert Ms. Kindler over CH Lighting’s Daubert
 objection and because her testimony was legally insuffi-
 cient to prove damages. The district court denied both of
 CH Lighting’s motions and also granted Super Lighting’s
 motion for enhanced damages, doubling the jury’s damages
 verdict. CH Lighting now appeals. We have jurisdiction
 pursuant to 

(a)(1).
                        DISCUSSION
     We review the grant of JMOL de novo. ACCO Brands,
 Inc. v. ABA Locks Mfr. Co., 

 (Fed. Cir.
 2007). We review the denial of a motion for a new trial for
 abuse of discretion. Power Mosfet Techs., L.L.C. v. Siemens
 AG, 

 (Fed. Cir. 2004). Evidentiary rul-
 ings are reviewed for abuse of discretion. Seigler v. Wal-
 Mart Stores Texas, L.L.C., 

, 476 (5th Cir.
 2022). We review a district court’s decision on the admis-
 sion of expert testimony for abuse of discretion. Ericsson,
 Inc. v. D-Link Sys., Inc., 

 (Fed. Cir.
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 10         JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.
                            CH LIGHTING TECHNOLOGY CO., LTD.


 2014). A district court necessarily abuses its discretion if
 its decision rests on an erroneous view of the law. Gensetix,
 Inc. v. Bd. of Regents of Univ. of Tex. Sys., 

,
 1324 (Fed. Cir. 2020).
      I. The On-Sale Bar as to the ’125 and ’540 Patents
      We first address the invalidity issue with respect to the
 tube patents. Under the AIA’s on-sale bar provision, which
 governs here, “[a] person shall be entitled to a patent un-
 less[] . . . the claimed invention was . . . on sale[] . . . before
 the effective filing date of the claimed invention.”
 

(a). The effective filing date for the ’125 pa-
 tent is September 25, 2015, and the effective filing date for
 the ’540 patent is December 5, 2015. To trigger the on-sale
 bar provision, the offer for sale must embody the claims of
 the asserted patent. Helsinn Healthcare S.A. v. Teva
 Pharms. USA, Inc., 

 (Fed. Cir. 2017),
 aff’d, 

 (2019). The invention must be the sub-
 ject of a commercial offer for sale and be ready for patent-
 ing. Pfaff v. Wells Elecs., Inc., 

 (1998).
 Whether an invention was on sale is a question of law that
 we review de novo based on underlying facts. Crown Pack-
 aging Tech., Inc. v. Belvac Prod. Mach., Inc., 

,
 924 (Fed. Cir. 2024).
                                 A
     CH Lighting argues that the district court erred in
 granting JMOL that the tube patents were not invalid un-
 der the on-sale bar. Based on photographs of teardowns of
 the tubes, the tubes’ specification sheets, and related docu-
 mentation, Dr. Lebby testified as to the prior art tubes:
 (1) Cree LED T8-48-21L-40K (“Cree tube”), (2) MaxLite
 G Series L18T8DF440-G (“MaxLite tube”), and (3) Philips
 InstantFit LED T816.5W/48-3500 (“Philips tube”). For
 each relevant prior art tube, Dr. Lebby testified that the
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 JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.          11
 CH LIGHTING TECHNOLOGY CO., LTD.


 tube satisfied the tube patents’ claim limitations,4 that the
 tube patents’ effective filing dates were in 2015, and that
 “from the evidence [he had] seen so far in this case” the
 prior art tubes were “on sale in 2014.” J.A. 10178 (282:19–
 23) (Cree tube); accord J.A. 10179 (285:20–24) (MaxLite
 tube), J.A. 10180 (289:18–23) (Philips tube).
     Super Lighting did not dispute that Dr. Lebby’s testi-
 mony was sufficient to establish that the prior art tubes
 embodied the claimed inventions, and there is also no con-
 tention that the prior art tubes were not ready for patent-
 ing.5 But Super Lighting contended before the district
 court that Dr. Lebby did not have personal knowledge that
 the prior art tubes were on sale before the tube patents’
 effective filing dates and that his conclusory testimony was
 thus not supported by record evidence. The district court
 agreed, as do we, that CH Lighting was required to present
 competent evidence that the tubes were on sale, and the
 district court did not err in concluding that Dr. Lebby’s tes-
 timony alone did not suffice to establish that the prior art
 tubes were on sale before the tube patents’ effective filing


     4   The Cree and Philips tubes were asserted only
 against the ’125 patent, while the MaxLite tube was as-
 serted against both tube patents.
     5   The district court appears to have taken issue with
 CH Lighting’s failure to properly authenticate the prior art
 tubes’ photographs, but even a lay witness authenticating
 a photograph need not “see the picture taken” so long as
 the witness “recognizes and identifies the object depicted.”
 United States v. Okulaja, 

, 345 (5th Cir. 2021).
 While the district court also appears to have faulted CH
 Lighting for failing to secure admission of the prior art
 tubes’ photographs into evidence, this, too, would fail to
 support JMOL because Dr. Lebby testified without objec-
 tion that he relied on these photographs and what they de-
 picted.
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 12         JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.
                            CH LIGHTING TECHNOLOGY CO., LTD.


 dates. See Wi-LAN Inc. v. Sharp Elecs. Corp., 

, 1376 (Fed. Cir. 2021) (affirming a district court’s ex-
 clusion of expert testimony that was not based on evidence
 in the record upon which experts would reasonably rely).
                               B
     CH Lighting alternatively argues that the district
 court’s JMOL decision as to the tube patents’ validity
 should be vacated and that a new trial on this issue is re-
 quired because the district court abused its discretion in
 excluding relevant evidence that was sufficient to establish
 that the prior art tubes were on sale before the tube pa-
 tents’ effective filing dates. CH Lighting’s argument is two-
 fold.
      First, CH Lighting argues that the district court
 abused its discretion in granting Super Lighting’s motion
 to exclude MaxLite representative Mr. Marsh, who would
 have authenticated the “MaxLite documents.”                The
 MaxLite documents purportedly showed that the MaxLite
 tube was on sale prior to the tube patents’ 2015 effective
 filing dates. On their face, the MaxLite documents appear
 to be offers for sale, disclosing the MaxLite tube’s specifi-
 cations and providing ordering codes. See J.A. 1189–90.
 Dr. Lebby relied on the MaxLite documents in his expert
 report in support of his finding that the MaxLite tube was
 on sale prior to the tube patents’ effective filing dates.
     Because Dr. Lebby himself could not authenticate the
 MaxLite documents, CH Lighting originally listed
 Mr. Baheti and an unnamed “MaxLite Representative” as
 witnesses, but Mr. Baheti was later unable to attend trial
 due to a conflict. CH Lighting then identified Mr. Marsh
 as the MaxLite representative who would authenticate the
 MaxLite documents. Despite the district court’s initial
 statement that it “[did] not have an issue with the intro-
 duction of [Mr. Marsh] for the sole purpose of authenticat-
 ing a pre-identified set of documents . . . . [absent] real and
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 JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.         13
 CH LIGHTING TECHNOLOGY CO., LTD.


 substantial prejudice . . . by the substitution of this wit-
 ness,” J.A. 1200, the court later changed course and, at Su-
 per Lighting’s urging, refused to allow Mr. Marsh to
 authenticate the documents because CH Lighting “did not
 give sufficient notice to [Super Lighting] that [Mr. Baheti]
 would be performing this task,” J.A. 1212 (27:25–28:1), of
 authenticating the MaxLite documents.               Because
 Mr. Marsh was the substitute witness for Mr. Baheti, the
 district court excluded him from testifying as to the
 MaxLite documents.
      In excluding Mr. Marsh from authenticating the
 MaxLite documents, the district court did not identify any
 rule or order requiring parties to identify in advance which
 witnesses would authenticate documents. This is unsur-
 prising, as no Federal Rule or local rule requires such iden-
 tification. Because there is no such requirement, we
 conclude that the exclusion of Mr. Marsh’s testimony was
 an abuse of discretion. Although we recognize that district
 courts have wide latitude to make determinations about
 the admissibility of evidence at trial, we perceive no rea-
 sonable basis for the district court’s decision here to ex-
 clude a competent witness from authenticating documents
 previously identified as trial exhibits. The district court’s
 exclusion of Mr. Marsh’s authenticating testimony re-
 sulted in the exclusion from evidence of the MaxLite docu-
 ments relied upon by Dr. Lebby. This error was prejudicial
 because Dr. Lebby relied on the MaxLite documents in his
 expert report for his finding that the MaxLite tube was on
 sale prior to the tube patents’ effective filing dates. See
 J.A. 11143 ¶ 783; J.A. 11200 ¶ 1004.
     Second, CH Lighting also argues that the district court
 abused its discretion by excluding an internal Super Light-
 ing presentation (“DX-41”), which it argued showed that
 Super Lighting had acquired the Cree and Philips tubes
 before the effective filing dates of the ’125 patent, showing
 that these prior art tubes were already on sale. The district
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 14         JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.
                            CH LIGHTING TECHNOLOGY CO., LTD.


 court granted Super Lighting’s motion to exclude DX-41,
 agreeing with Super Lighting that the presentation was di-
 rected to CH Lighting’s inequitable conduct defense (which
 CH Lighting dropped prior to trial). However, CH Light-
 ing’s counsel stated that they “[did not] offer this document
 for any inequitable conduct purpose,” J.A. 10113 (22:23–
 24), and intended to use the presentation only to demon-
 strate that “these third-party products of Cree, as well as
 Philips, were available on the market because Super Light-
 ing was able to have” them in its possession, J.A. 10114
 (25:7–9). Dr. Lebby’s expert report only addressed invalid-
 ity (and not inequitable conduct), and in a portion of his
 expert report entitled “Plaintiff’s Awareness of the Prior
 Art,” Dr. Lebby attached slides from DX-41 depicting tubes
 from Cree and Philips, stating that “the arrangement of
 electronic components set forth in . . . the ’125 patent[]
 [were] apparent in the circuit diagram[s] and photos.”
 J.A. 11253; J.A. 11255 ¶ 1185 (Cree); J.A. 11257 ¶ 1192
 (Philips). Dr. Lebby was thus prepared to testify that Su-
 per Lighting “was in possession” of the tubes “prior to the
 priority date[] asserted for . . . the ’125 patent,” suggesting
 that they were on sale.            J.A. 11255 ¶ 1183 (Cree);
 J.A. 11257 ¶ 1190 (Philips).
      We agree with CH Lighting that the district court’s ex-
 clusion of DX-41 was also an abuse of discretion. The dis-
 trict court’s initial justification that DX-41 “only deal[t]
 with inequitable conduct,” J.A. 10050 (7:12–14), is contra-
 dicted by the record. Both Dr. Lebby in his expert report
 and CH Lighting’s counsel before the district court repre-
 sented that DX-41 was relevant to the on-sale bar.
 Dr. Lebby’s report expressly discussed DX-41 with regard
 to the public availability of the prior art tubes. Because
 Dr. Lebby’s expert report clearly identified the slides in his
 invalidity findings and stated that the ’125 patent’s claims
 were “apparent in the circuit diagram and photos,”
 J.A. 11255 ¶ 1185; J.A. 11257 ¶ 1192, we conclude that the
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 CH LIGHTING TECHNOLOGY CO., LTD.


 district court’s exclusion constitutes reversible error. See
 Meyer Intell. Properties Ltd. v. Bodum, Inc., 

 (Fed. Cir. 2012) (concluding that an exclusion was not
 harmless “because it impaired [the party’s] ability to pre-
 sent its [invalidity] defense”).
     The district court later adopted an alternative ra-
 tionale for DX-41’s exclusion, crediting Super Lighting’s
 new argument that it should be excluded because the tubes
 included in DX-41 were of a different wattage from the
 Cree and Philips tubes analyzed by Dr. Lebby. This justi-
 fication fares no better. Dr. Lebby was prepared to testify
 that the tubes whose circuit diagrams were depicted in DX-
 41 embodied the claimed invention. Nothing in the record
 suggests that a difference in wattage would have any bear-
 ing on the application of the on-sale bar to the ’125 patent.
 We agree with CH Lighting that the fact that the tubes de-
 scribed in the Super Lighting presentation were of a differ-
 ent wattage from the prior art tubes did not preclude DX-
 41’s admissibility; it was for the jury to determine whether
 to credit Dr. Lebby’s testimony.
     We accordingly reverse the district court’s grant of
 JMOL to Super Lighting and remand for a new trial on the
 invalidity of the tube patents because of the district court’s
 erroneous exclusion of Mr. Marsh’s authenticating testi-
 mony, the MaxLite documents, and DX-41.6




     6    CH Lighting also argues that the trial court abused
 its discretion in refusing to admit into evidence the physi-
 cal prior art tubes on which Dr. Lebby based his opinions,
 on the ground that he did not actually examine the physical
 tubes in formulating his report. Because Dr. Lebby based
 his expert report only on photographs of the tubes, we see
 no error in the exclusion of the physical tubes, which in any
 case would not prove the applicability of the on-sale bar.
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 16          JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.
                             CH LIGHTING TECHNOLOGY CO., LTD.


      II. Anticipation and Infringement of the ’140 Patent
     We next address CH Lighting’s argument that Interna-
 tional Patent Application WO 2012/066822 (“Ono”) antici-
 pates the asserted claims of the ’140 patent or that, in the
 alternative, the LT2600 chips do not infringe the ’140 pa-
 tent’s claims. A patent claim is anticipated only “if each
 and every limitation is found either expressly or inherently
 in a single prior art reference.” Celeritas Techs., Ltd.
 v. Rockwell Int’l Corp., 

 (Fed. Cir.
 1998). Anticipation must be proven by clear and convinc-
 ing evidence. Microsoft Corp. v. i4i Ltd. P’ship, 

 (2011). “Anticipation is a question of fact, reviewed
 for substantial evidence when tried to a jury.” Finisar
 Corp. v. DirecTV Grp., Inc., 

 (Fed. Cir.
 2008). The jury’s determination of infringement is re-
 viewed for substantial evidence. Omega Pats., LLC
 v. CalAmp Corp., 

 (Fed. Cir. 2019).
      At trial, both parties agreed that Ono is a prior-art
 shock prevention system that functions similarly to the
 ’140 patent’s invention in most respects. The jury con-
 cluded that Ono did not anticipate the claims of the ’140 pa-
 tent. On the issue of invalidity, both CH Lighting’s
 invalidity expert Dr. Zane and Super Lighting’s invalidity
 expert Dr. Phinney acknowledged that the only issue for
 the jury to resolve was whether Ono discloses “pulse sig-
 nals [that] control turning [the switch circuit] on and off,”
 as required by the ’140 patent’s claims. ’140 patent, col. 59
 ll. 6–7.
     Dr. Zane testified that the pulses in Ono controlled the
 switch because Ono’s “pulse generating circuit generates
 the signal, which is what the detection circuit directly re-
 sponds to, which is what controls the on and off of the
 switch.” J.A. 10158 (203:14–17). Dr. Phinney testified
 that the pulses did not control the switch because Ono
 “provid[es] pulses that . . . detect the impedance . . . of the
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 installation[,] [and that] it’s really the . . . response of that
 pulse . . . that determines whether or not the switch turns
 on.” J.A. 10221 (91:13–19) (emphasis added). As the dis-
 trict court concluded, the jury was free to credit Dr. Phin-
 ney’s testimony that Ono’s pulses did not control turning
 the switch on and off because the pulse signals did not do
 so directly. Accordingly, its verdict of no invalidity is sup-
 ported by substantial evidence.
     We also disagree with CH Lighting’s argument that the
 jury’s verdict of no invalidity is incompatible with its ver-
 dict of infringement.       CH Lighting urges that the
 LT2600 chips cannot infringe because, as in Ono, the
 LT2600 chips control turning the switch on and off in re-
 sponse to detecting impedance during the pulse generation
 step. The problem with CH Lighting’s argument is that
 Super Lighting’s expert Dr. Phinney testified that, unlike
 in Ono, the LT2600 chips’ pulses do also control the switch
 as required by the ’140 patent’s claims. The jury was also
 free to credit Super Lighting’s other expert Dr. D’Andrade’s
 unrebutted testimony that the switches disclosed
 “pulses . . . that turn on and off a semiconductor switch.”
 J.A. 10094 (181:1–2). The jury’s finding of infringement is
 thus supported by substantial evidence and is not incon-
 sistent with its finding of no invalidity.
     III. Super Lighting’s Failure to Present Competent
                     Damages Evidence
     CH Lighting argues that the district court abused its
 discretion in denying its Daubert motion and its motion for
 a new damages trial because Ms. Kindler’s expert testi-
 mony violated Rule 702 of the Federal Rules of Evidence.
     As a preliminary matter, having reversed the district
 court’s grant of JMOL as to invalidity of the tube patents
 and ordering a new trial on this issue, a new trial as to
 damages is appropriate because “the jury rendered a single
 verdict on damages, without breaking down the damages
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                           CH LIGHTING TECHNOLOGY CO., LTD.


 attributable to each patent.”        Verizon Servs. Corp.
 v. Vonage Holdings Corp., 

 (Fed. Cir.
 2007). We briefly address CH Lighting’s arguments re-
 garding Ms. Kindler’s testimony because this legal issue is
 likely to reoccur on remand. See, e.g., LaserDynamics, Inc.
 v. Quanta Comput., Inc., 

 (Fed. Cir. 2012);
 Trans-World Mfg. Corp. v. Al Nyman & Sons, Inc.,
 

 (Fed. Cir. 1984).
     The admissibility of expert testimony is governed by
 the Federal Rules of Evidence and the principles laid out
 by the Supreme Court in Daubert v. Merrell Dow Pharma-
 ceuticals, Inc., 

 (1993). The proponent of ex-
 pert testimony must demonstrate to the court that it is
 more likely than not that the testimony “is based on suffi-
 cient facts or data,” “is the product of reliable principles
 and methods,” and “reflects a reliable application of the
 principles and methods to the facts of the case.” Fed. R.
 Evid. 702. The trial court must responsibly exercise its
 gatekeeping role to “ensure that any and all scientific tes-
 timony or evidence admitted is not only relevant, but reli-
 able.” Daubert, 

.
     At trial, Ms. Kindler relied on Super Lighting’s previ-
 ous portfolio licenses with Technical Consumer Products
 (“TCP license”) and Lunera Lightning, Inc. (“Lunera li-
 cense”)—along with evidence from Super Lighting—to pro-
 pose a per-unit royalty based on a hypothetical negotiation.
 The TCP licensing agreement involved a 30-cent per-unit
 royalty, and the Lunera license involved a flat 5% fee
 (which she calculated would translate to a per-unit royalty
 fee between 35 and 45 cents). Although the Lunera and
 TCP licenses granted a license to Super Lighting’s entire
 patent portfolio, Ms. Kindler opined that three particular
 patents comparable to the asserted patents drove the nego-
 tiations. Specifically, Ms. Kindler observed that a “subset
 of patents” comparable to the three asserted patents “drove
 th[e] negotiation” with TCP, see J.A. 10121 (54:11–12),
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 based solely on a document sent from Super Lighting to
 TCP alleging that TCP might be infringing 15 of Super
 Lighting’s patents, see J.A. 10121 (54:20–21); J.A. 21732–
 33, and similarly, that patents comparable to the asserted
 patents were “very important patents to Super Lighting’s
 portfolio” during the Lunera negotiation, see J.A. 10123
 (61:2–3), based solely on discussions with Super Lighting
 personnel.
      In its pretrial Daubert motion and motion for a new
 trial, CH Lighting argued that Ms. Kindler’s testimony
 was not reliable and that she failed to apportion the license
 fees to account for licensed patents that were not asserted.
 The district court denied CH Lighting’s Daubert motion
 without explanation. Our recent en banc decision in Eco-
 Factor, Inc. v. Google LLC, 

 (Fed. Cir. 2025),
 noted that “[a]n absence of reviewable reasoning may be
 sufficient grounds for this court to conclude the district
 court abused its discretion.” 

. Though the dis-
 trict court briefly elaborated in its decision denying a new
 trial, it should have conducted a more exacting analysis of
 Ms. Kindler’s testimony.
     We recently considered the issue of patent damages ex-
 perts’ reliability under Rule 702 in EcoFactor, in which we
 explained that testimony as to a hypothetical negotiation
 that is based on prior licenses must be supported by suffi-
 cient facts or data. In EcoFactor, the patentee’s damages
 expert, Mr. Kennedy, calculated a reasonable royalty based
 on nonbinding “whereas” clauses included in three prior
 lump-sum settlement agreements. See 137 F.4th at 1341.
 Each “whereas” clause recited that the patentee “agreed to
 the payment set forth in this Agreement based on what [the
 patentee] believes is a reasonable royalty calculation. Id.
 (emphasis omitted). The only other evidence Mr. Kennedy
 relied on was the patentee’s CEO’s testimony stating that
 those lump sums were calculated based on a per-unit roy-
 alty rate. However, “[w]hen asked about the basis for his
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                           CH LIGHTING TECHNOLOGY CO., LTD.


 understanding of the lump-sum calculations, [patentee’s
 CEO] testified that neither he nor anyone else at EcoFactor
 had been given access” to the relevant sales data that could
 be used to determine the agreed-upon lump sums using the
 purported per-unit royalty rate. Id. at 1344.
     We held that neither the settlement agreements nor
 the patentee’s CEO’s testimony was sufficient to support
 Mr. Kennedy’s conclusions. We explained that the settle-
 ment agreements when considered in their entirety could
 not support his conclusion, since they expressly disavowed
 any binding effect of the “whereas” clauses and otherwise
 provided no indication that the licensees agreed to a roy-
 alty rate or shared the patentee’s belief recited in the
 whereas clauses. Id. at 1343. The patentee’s CEO’s testi-
 mony fared no better, we explained, because it “referenced
 no evidentiary support” and “relied entirely on his asserted
 ‘general understanding of the space.’” Id. at 1344 (citation
 omitted). We concluded that “[i]n the absence of any evi-
 dence, [his] testimony amount[ed] to an unsupported asser-
 tion from an interested party.” Id.
      On remand, the district court should consider the reli-
 ability of Ms. Kindler’s expert testimony in light of EcoFac-
 tor, with a particular focus on whether “she reasonably
 rel[ied] on [the] kinds of facts or data in forming an opin-
 ion” that would be reasonably relied upon by an expert in
 her field. Fed. R. Evid. 703. See, e.g., EcoFactor, 137 F.4th
 at 1344 (finding the patentee’s CEO’s testimony insuffi-
 cient to sustain Mr. Kennedy’s methodology because the
 CEO “reference[d] no evidentiary support” and because
 “[his] claim regarding calculation of the lump-sum
 amounts is not supported by any record evidence”).
     In the context of patent damages, we have repeatedly
 explained that the damages expert must apportion among
 licenses. Apple Inc. v. Wi-LAN Inc., 

, 971
 (Fed. Cir. 2022). We have explained that expert testimony
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 CH LIGHTING TECHNOLOGY CO., LTD.


 should be excluded when it fails to allocate license fees
 among the licensed patents covered by an agreement. MLC
 Intell. Prop., LLC v. Micron Tech., Inc., 

,
 1374–75 (Fed. Cir. 2021) (affirming a Daubert exclusion of
 a damages expert who relied on an “agreement grant[ing]
 a license to a portfolio of forty-one U.S. and international
 patents and patent applications[] [when] only one of those
 forty-one patents [was] at issue in the hypothetical negoti-
 ation”); Omega Pats., LLC v. CalAmp Corp., 

,
 1380 (Fed. Cir. 2021) (vacating a damages award when the
 patentee’s expert “failed to adequately account for substan-
 tial distinguishing facts between the proffered licenses and
 a hypothetical negotiation over a single-patent license to
 the [asserted] patent” (internal quotation marks and cita-
 tion omitted)). On remand, the trial court must consider
 whether Super Lighting properly apportioned damages.
     If there is a problem with Ms. Kindler’s damages testi-
 mony, her testimony cannot be justified simply because she
 made a series of blanket upward and downward adjust-
 ments based on such factors as the level of competition be-
 tween the parties and changes in the price of LED tubes.
 See J.A. 10121 (55:12–17) (“[T]here are other differences in
 the [licenses] that are counterbalancing differences[,] [s]o
 to the extent that the broader license agreement would
 have resulted in a higher royalty payment, there’s other
 counterbalancing factors . . . that would go the other way
 that we have to take into account.”). See Apple, 25 F.4th
 at 972–74 (concluding that a damages expert’s flat
 25% discount for five unasserted patents covered by a pre-
 vious licensing agreement was unreliable).
     In a new trial on damages, these concerns may form
 the basis for a Daubert motion.
                        CONCLUSION
     For the foregoing reasons, we affirm the jury’s verdict
 of validity and infringement of the ’140 patent. We reverse
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 22          JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v.
                             CH LIGHTING TECHNOLOGY CO., LTD.


 the district court’s grant of JMOL that the tube patents
 were not invalid, vacate the jury’s award of damages, and
 remand for a new trial on the tube patents’ validity and
 damages.
      AFFIRMED-IN-PART, REVERSED-IN-PART,
        VACATED-IN-PART, AND REMANDED
                             COSTS
 No costs.