Network-1 Technologies, Inc. v. Hewlett-Packard Company ( 2020 )


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  • Case: 18-2338    Document: 73      Page: 1   Filed: 09/24/2020
    United States Court of Appeals
    for the Federal Circuit
    ______________________
    NETWORK-1 TECHNOLOGIES, INC.,
    Plaintiff-Appellant
    v.
    HEWLETT-PACKARD COMPANY, HEWLETT
    PACKARD ENTERPRISE COMPANY,
    Defendants-Cross-Appellants
    ______________________
    2018-2338, 2018-2339, 2018-2395, 2018-2396
    ______________________
    Appeals from the United States District Court for the
    Eastern District of Texas in Nos. 6:11-cv-00492-RWS, 6:13-
    cv-00072-RWS, Judge Robert Schroeder, III.
    ______________________
    Decided: September 24, 2020
    ______________________
    GREGORY S. DOVEL, Dovel & Luner, LLP, Santa Mon-
    ica, CA, argued for plaintiff-appellant. Also represented by
    SEAN LUNER, RICHARD ELGAR LYON, III; JEFFREY A.
    LAMKEN, MoloLamken LLP, Washington, DC.
    MARK ANDREW PERRY, Gibson, Dunn & Crutcher LLP,
    Washington, DC, argued for defendants-cross-appellants.
    Also represented by OMAR FAROOQ AMIN; HERSH H. MEHTA,
    Morgan, Lewis & Bockius LLP, Chicago, IL; NATALIE A.
    BENNETT, Washington, DC.
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    2        NETWORK-1 TECHNOLOGIES, INC. v. HEWLETT-PACKARD
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    ANDREW M. MASON, Klarquist Sparkman, LLP, Port-
    land, OR, for amicus curiae T-Mobile USA, Inc. Also rep-
    resented by SARAH ELISABETH JELSEMA, JOHN D.
    VANDENBERG; SARAH J. KALEMERIS, Winston & Strawn
    LLP, Chicago, IL.
    ______________________
    Before PROST, Chief Judge, NEWMAN and BRYSON,
    Circuit Judges.
    PROST, Chief Judge.
    Network-1 Technologies, Inc. (“Network-1”) appeals a
    final judgment of the United States District Court for the
    Eastern District of Texas. Network-1 sued Hewlett-Pack-
    ard (“HP”), alleging infringement of U.S. Patent
    No. 6,218,930 (“the ’930 patent”). HP argued in response
    that the ’930 patent is invalid, and that HP did not in-
    fringe. The jury found the patent not infringed and invalid.
    Following post-trial motions, the district court denied Net-
    work-1’s request for a new trial on infringement but
    granted Network-1’s motion for judgment as a matter of
    law (“JMOL”) on validity.
    Network-1 appeals the district court’s final judgment
    that HP does not infringe the ’930 patent, arguing the dis-
    trict court erred in its claim construction. HP cross-ap-
    peals the district court’s determination that HP was
    estopped from raising certain validity challenges under
    35 U.S.C. § 315(e)(2) based on HP’s joinder to an inter
    partes review (“IPR”) before the Patent Trial and Appeal
    Board (“Board”). On cross-appeal, HP also argues that
    Network-1 improperly broadened claim 6 of the ’930 patent
    during reexamination.
    For the reasons explained below, we affirm-in-part, re-
    verse-in-part, vacate, and remand. Specifically, as to Net-
    work-1’s appeal, we affirm-in-part and reverse-in-part the
    district court’s claim construction and remand to the dis-
    trict court. As to HP’s cross-appeal, we vacate the district
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    court’s JMOL on validity and remand. And finally, we af-
    firm the district court’s decision with respect to improper
    claim broadening.
    FACTUAL BACKGROUND
    I. The ’930 Patent
    The ’930 patent is titled “Apparatus and Method for Re-
    motely Powering Access Equipment over a 10/100 Switched
    Ethernet Network.” It discloses an apparatus and methods
    for allowing electronic devices to automatically determine
    if remote equipment is capable of accepting remote power
    over Ethernet. See ’930 patent col. 1 ll. 13–17. According
    to the patented method, a “low level current” is delivered
    over a data signaling pair to an access device (also called
    remote equipment or remote access equipment).
    Id. at
     col. 2 ll. 8–10. After the low level current is sent, a network
    switch senses the resulting “voltage level” on the data sig-
    naling pair.
    Id. at
    col. 1 l. 65–col. 2 l. 14. If the device can
    accept remote power, the sensed voltage level will match a
    “preselected condition” of the voltage, such as a particular
    “varying voltage” level.
    Id. at
    col. 2 ll. 10–14, col. 3 ll. 2–
    17. Upon detecting the preselected condition, the network
    switch will increase the current from the low level to a
    higher level sufficient to allow the “remote equipment [to]
    become[] active.”
    Id. at
    col. 3 ll. 17–22. If the preselected
    condition of the voltage is not detected, the network switch
    will determine that the device cannot accept remote power
    and will not transmit a higher current.
    Id. at
    col. 3 ll. 3–
    11.
    The ’930 patent issued in April 2001 with 9 claims, in-
    cluding two independent claims: claims 1 and 6. Claim 6
    is representative of the issues on appeal. Claim 6 recites:
    6. Method for remotely powering access equipment
    in a data network, comprising,
    providing a data node adapted for data switching,
    an access device adapted for data transmission, at
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    least one data signaling pair connected between
    the data node and the access device and arranged
    to transmit data therebetween, a main power
    source connected to supply power to the data node,
    and a secondary power source arranged to supply
    power from the data node via said data signaling
    pair to the access device,
    delivering a low level current from said main
    power source to the access device over said data sig-
    naling pair,
    sensing a voltage level on the data signaling pair in
    response to the low level current, and
    controlling power supplied by said secondary
    power source to said access device in response to
    a preselected condition of said voltage level.
    ’930 patent claim 6 (emphases added to terms challenged
    on appeal).
    On appeal, Network-1 contends that the district court
    erroneously construed the claim terms “main power
    source” and “low level current.” On cross-appeal, HP con-
    tends that Network-1 improperly broadened the term “sec-
    ondary power source” during reexamination.
    II. The Reexamination Proceedings
    After it issued, and concurrent with the underlying dis-
    trict court action, the ’930 patent was reexamined twice be-
    fore the U.S. Patent and Trademark Office. The first
    reexamination, No. 90/012,401 (“the ’401 reexamination”),
    concluded in October 2014. See J.A. 333–35. It confirmed
    the patentability of claims 6, 8, and 9, and resulted in the
    issuance of claims 10–23. Relevant to HP’s cross-appeal,
    claims 15 and 16 were added depending from original
    claim 6.
    Claim 15 recites: “Method according to claim 6,
    wherein said secondary power source is the same source
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    of power as said main power source.” ’930 patent, Ex Parte
    Reexamination Certificate, col. 1 ll. 39–41 (emphasis
    added).
    Claim 16 recites: “Method according to claim 6,
    wherein said secondary power source is the same physi-
    cal device as the main power source.”
    Id. at
    col. 1 ll. 42–44
    (emphasis added).
    The second reexamination, No. 90/013,444, concluded
    in November 2015. It confirmed the patentability of claims
    6 and 8–23. See J.A. 336–37.
    PROCEDURAL BACKGROUND
    This case has a long and complicated history, which be-
    gan in 2011 when Network-1 sued a number of defendants,
    including HP, for infringement of the ’930 patent in the
    U.S. District Court for the Eastern District of Texas. After
    several stays, the district court finally reached the under-
    lying final judgment in 2018. We discuss the relevant
    background here.
    I. The Avaya IPR
    After Network-1 filed its complaint in the district court,
    another defendant, Avaya Inc. (“Avaya”), petitioned for
    IPR of the ’930 patent. The district court stayed its pro-
    ceedings pending IPR. The Board partially instituted
    Avaya’s petition. See Avaya Inc. v. Network-1 Sec. Sols.,
    Inc., No. IPR2013-00071, Paper 18, 
    2013 WL 8595554
     (P.T.A.B. May 24, 2013) (“the Avaya IPR”). Specifically,
    the Board instituted review of claims 6 and 9 of the ’930
    patent based on two grounds: (1) anticipation under
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    35 U.S.C. § 102(b) by Matsuno 1; and (2) obviousness under
    35 U.S.C. § 103(a) by De Nicolo 2 and Matsuno.
    Id. at
    *16.
    Following institution, HP, together with other petition-
    ers, filed an IPR petition and motion to join the Avaya IPR.
    HP’s petition included grounds different from those that
    had already been instituted. The Board denied HP’s re-
    quest. HP, with others, thereafter filed a second IPR peti-
    tion and motion to join the Avaya IPR, this time including
    only the grounds already instituted. The Board granted
    HP’s request, and HP was joined as a party to the Avaya
    IPR. At the time that HP filed its second IPR petition,
    more than one year had passed since the district court com-
    plaint had been served, and therefore, HP was time-barred
    under 35 U.S.C. § 315(b) from having its own petition in-
    stituted. But because § 315(b) creates an exception from
    the time bar for joinder under 35 U.S.C. § 315(c), HP was
    nonetheless able to join.
    In its final written decision, the Board held that nei-
    ther claim 6 nor claim 9 was unpatentable over the insti-
    tuted grounds. We affirmed. See Avaya Inc. v. Network-1
    Techs., Inc., 612 F. App’x 613 (Fed. Cir. 2015).
    II. The District Court Action
    After more stays, Network-1 continued its suit in the
    district court. In 2017, the district court issued its con-
    struction of disputed claim terms, including “low level cur-
    rent” and “main power source.” See Network-1 Techs., Inc.
    v. Alcatel-Lucent USA, Inc., ET, No. 6:11-cv-492, Report
    and Recommendation of the Magistrate Judge, D.I. 693,
    at 12 (E.D. Tex. Nov. 4, 2016) (J.A. 24–48); see also Net-
    work-1 Techs., Inc. v. Alcatel-Lucent USA, Inc., ET, No.
    1   Japanese Unexamined Patent Application Publica-
    tion No. H10-13576, published Jan. 16, 1998 (“Matsuno”).
    2   U.S. Patent No. 6,115,468, filed Mar. 26, 1998,
    issued Sept. 5, 2000 (“De Nicolo”).
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    6:11-cv-492, Order Adopting Report and Recommendation
    of U.S. Magistrate Judge, D.I. 860, at 1, 5–7 (E.D. Tex.
    May 2, 2017) (J.A. 49–68). Together with its claim con-
    struction, in relevant part, the district court denied HP’s
    summary judgment motion that argued claim 6 was imper-
    missibly broadened through the ’401 reexamination.
    J.A. 40–42, 57–59.
    This case finally proceeded to trial in November 2017.
    At trial, Network-1 argued that HP infringed claims 6, 13,
    14, 17, 20, and 22 of the ’930 patent (“the asserted claims”)
    by selling particular Power over Ethernet (“PoE”) switches.
    HP argued that each of the asserted claims was rendered
    obvious by both public use of “the Fisher system,” which
    was a PoE system developed by David Fisher, and by the
    patents and printed publications referred to as “the Fisher
    patents,” 3 Woodmas, 4 and Chang. 5 See J.A. 78.
    Using a general verdict form, the jury found that HP
    did not infringe any asserted claim of the ’930 patent.
    J.A. 70. The jury also found that HP had shown that all
    asserted claims of the ’930 patent are invalid. J.A. 71.
    Following the jury’s verdict, Network-1 filed, in rele-
    vant part, a motion for a new trial related to infringement,
    and a motion for JMOL and motion for a new trial related
    3   U.S. Patent No. 5,994,998, filed May 29, 1997, is-
    sued Nov. 20, 1999; U.S. Patent No. 6,710,704, filed Oct.
    28, 2002, issued Mar. 23, 2004; International Publication
    No. WO 98/54843, published Dec. 3, 1998 (collectively, “the
    Fisher patents”).
    4   U.S. Patent No. 5,345,592, filed Apr. 8, 1992, is-
    sued Sept. 6, 1994 (“Woodmas”).
    5   U.S. Patent No. 5,991,885, filed June 11, 1997, is-
    sued    Nov. 23,     1999;   International     Publication
    No. WO 98/57248, published Dec. 17, 1998 (collectively,
    “Chang”).
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    to validity. The district court denied the motion for a new
    trial on infringement. Applying its construction of the
    claim terms “low level current” and “main power source,”
    the district court concluded that the jury’s verdict was not
    against the great weight of the evidence that HP’s accused
    devices did not meet either limitation. See J.A. 92–97.
    As to the ’930 patent’s validity, however, the district
    court granted Network-1’s motion for JMOL. The district
    court concluded that because of HP’s joinder to the Avaya
    IPR, HP should have been estopped under 35 U.S.C.
    § 315(e) from raising the remaining obviousness chal-
    lenges, which it determined “reasonably could have been
    raised” in the Avaya IPR. J.A. 91. 6 The district court did
    not conditionally rule on HP’s motion for a new trial with
    respect to validity.
    Network-1 appealed. HP cross-appealed. We have ju-
    risdiction under 28 U.S.C. § 1295(a)(1).
    DISCUSSION
    On appeal, Network-1 challenges the district court’s
    denial of a new trial on infringement based on its argument
    that the district court erred in its claim construction.
    On cross-appeal, HP challenges the district court’s
    JMOL on validity, arguing that the district court erred in
    concluding that HP is estopped from raising its obvious-
    ness challenges because it joined the Avaya IPR. HP fur-
    ther challenges the district court’s denial of summary
    6   With respect to the Fisher system, the district
    court concluded that HP failed to show that the Fisher sys-
    tem constitutes prior art. See J.A. 79–87. On cross-appeal,
    HP does not challenge the district court’s conclusion that
    the Fisher system does not constitute prior art. Appellee’s
    Br. 62 n.2.
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    judgment, arguing that the asserted claims of the ’930 pa-
    tent were improperly broadened during reexamination.
    We address these issues in turn.
    I. Claim Construction
    Network-1 argues that the district court incorrectly
    construed the claim terms “low level current” and “main
    power source,” and that this error entitles it to a new trial
    on infringement. HP argues in response that the district
    court’s claim construction should be affirmed, but that even
    if it is not, Network-1 was not prejudiced by the erroneous
    claim construction.
    For the below-described reasons, we conclude that the
    district court correctly construed “low level current” but
    erred in its construction of “main power source,” and as a
    result of that error, Network-1 is entitled to a new trial on
    infringement. We therefore vacate the district court’s judg-
    ment of non-infringement and remand for a new trial to
    determine whether HP infringes the asserted claims based
    on the correct construction of “main power source.”
    A
    We review the district court’s ultimate construction of
    the claim language de novo. Teva Pharms. USA, Inc. v.
    Sandoz, Inc., 
    574 U.S. 318
    , 331 (2015). “[W]hen the district
    court reviews only evidence intrinsic to the patent (the pa-
    tent claims and specifications, along with the patent’s pros-
    ecution history), the judge’s determination will amount
    solely to a determination of law, and [we] will review that
    construction de novo.”
    Id. To the extent
    that subsidiary
    factfinding is required for claim construction analysis, we
    review such factfinding for clear error.
    Id. at
    332.
    
         Claim terms “are generally given their ordinary and
    customary meaning,” which is “the meaning that the term
    would have to a person of ordinary skill in the art in ques-
    tion at the time of the invention.” Phillips v. AWH Corp.,
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    415 F.3d 1303
    , 1312–13 (Fed. Cir. 2005) (en banc) (internal
    quotation marks and citations omitted). “[T]he claims
    themselves provide substantial guidance as to the meaning
    of particular claim terms” and “the specification is the sin-
    gle best guide to the meaning of a disputed term.”
    Id. at
    1314–15 (internal quotation marks and citations omit-
    ted).
    As the party seeking to disturb the non-infringement
    judgment, Network-1 “must establish that [the challenged
    jury] instructions were legally erroneous, and that the er-
    rors had prejudicial effect.” SSL Servs., LLC v. Citrix Sys.,
    
    769 F.3d 1073
    , 1085 (Fed. Cir. 2014) (quoting Ecolab Inc.
    v. Paraclipse, Inc., 
    285 F.3d 1362
    , 1373 (Fed. Cir. 2002)).
    “It is well established that when an incorrect jury in-
    struction—such as an incorrect claim construction—re-
    moves from the jury a basis on which the jury could
    reasonably have reached a different verdict, the verdict
    should not stand.” Cardiac Pacemakers, Inc. v. St. Jude
    Med., Inc., 
    381 F.3d 1371
    , 1383 (Fed. Cir. 2004); see also
    Avid Tech., Inc. v. Harmonic, Inc., 
    812 F.3d 1040
    , 1042
    (Fed. Cir. 2016). An erroneous claim construction on one
    element is harmless “only if a reasonable jury would have
    been required by the evidence to find non-infringement
    even without the error.” 
    Avid, 812 F.3d at 1047
    .
    B
    The district court construed “low level current” as “a
    non-data-signal current that is sufficient to begin start up
    of the access device but that is not sufficient to sustain the
    start up.” J.A. 35; see also J.A. 53–55. The district court
    explained that it was construing the disputed phrase to
    give meaning to the constituent term “low.” See J.A. 34. It
    stated that while the current must be sufficient to “begin
    start up,” the current need not “cause start up,” and thus
    it construed the term to eliminate “any implication that the
    current must be sufficient to result in a completed start-
    up.” J.A. 34 (citing ’930 patent col. 3 ll. 12–17).
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    On appeal, Network-1 argues that the district court
    erred by construing the phrase “low level current” to have
    a lower bound. Network-1 agrees that, in the context of the
    ’930 patent, the phrase “low level current” describes cur-
    rent that cannot “sustain start up” but argues that it was
    error for the district court to additionally require that the
    current be sufficient to begin start up. See Appellant’s
    Br. 27. Relying on extrinsic evidence related to the word
    “low,” including dictionary definitions, grammar refer-
    ences, and claim constructions adopted for unrelated pa-
    tents, Network-1 argues that the term points in one
    direction and should be construed to have a single refer-
    ence point. Network-1 asserts that the correct reference
    point with respect to the ’930 patent is the upper boundary
    requiring that the current not exceed the level needed to
    operate the device. We disagree.
    We conclude that the district court correctly construed
    “low level current.” As an initial matter, there is no dispute
    that the word “low” in the claim phrase “low level current”
    operates to limit the upper boundary of the current level.
    See Appellant’s Br. 26–29; Appellee’s Br. 36–37. Indeed,
    the ’930 patent explicitly describes a low level current with
    an upper boundary that is “unable to sustain start up.” See
    ’930 patent col. 3 ll. 14–16; see also
    id. at
    col. 3 ll. 2–13. But
    the claim phrase is not limited to the word “low,” and the
    claim construction analysis should not end just because one
    reference point has been identified. To be sure, the claim
    phrase “low level current” does not preclude a lower bound
    by use of the word “low.” Rather, in the same way the
    phrase should be construed to give meaning to the term
    “low,” the phrase must also be construed to give meaning
    to the term “current.”
    The intrinsic record of the ’930 patent confirms that the
    district court correctly construed the phrase to require a
    lower boundary of current. See 
    Phillips, 415 F.3d at 1315
    .
    Claim 6 recites “delivering a low level current” to an access
    device to detect whether the device can accept remote
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    power. ’930 patent col. 4 ll. 49–67 (emphasis added); see
    also
    id. at
    col. 2 ll. 8–14. The express language of the claim
    thus requires that at least some level of current be deliv-
    ered. Even Network-1 admits that the term “current” nec-
    essarily requires some flow of electric charge because “[i]f
    there is no flow, there is no ‘current.’” See Appellant’s Br.
    33–34.
    The specification of the ’930 patent discloses the lower
    boundary of current. It explains that an access device ca-
    pable of accepting remote power will signal a varying volt-
    age level and teaches “[t]he varying level is created by the
    remote power supply beginning to start up but the low cur-
    rent level is unable to sustain the start up.” ’930 patent
    col. 3 ll. 14–16 (emphasis added); see also
    id. at
    col. 3 ll. 2–
    13. Thus, consistent with the district court’s construction,
    the ’930 patent teaches that the delivered “low level cur-
    rent” is current that is sufficient to begin start-up.
    Accordingly, we conclude that the district court did not
    err in its construction of “low level current.”
    C
    The district court construed “main power source” as “a
    DC power source,” and thereby excluded AC power sources
    from its construction. J.A. 50–51. 7 In reaching its decision,
    the court relied on HP’s expert testimony that a network
    device would either fail to function or would be damaged if
    it received AC power. J.A. 50–51. The court therefore con-
    cluded that embodiments using AC power are inoperable
    and construed “main power source” to exclude such embod-
    iments. J.A. 50–51 (“A construction that renders the
    claimed invention inoperable should be viewed with ex-
    treme skepticism.” (quoting Talbert Fuel Sys. Pats. Co. v.
    7  “DC” refers to direct current and “AC” refers to al-
    ternating current.
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    Unocal Corp., 
    275 F.3d 1371
    , 1376 (Fed. Cir. 2002))); see
    also J.A. 30–31.
    On appeal, Network-1 argues that the claim phrase
    “main power source” should be construed consistent with
    the ordinary meaning of “power source” to include both AC
    and DC power sources. See Appellant’s Br. 46. Network-1
    acknowledges that certain embodiments with AC power
    sources require power from the main power source to be
    converted to DC power before being received by the net-
    work device, but Network-1 argues that nothing in the
    ’930 patent precludes such embodiments. To the contrary,
    Network-1 asserts that the intrinsic record supports a con-
    struction that includes both types of power sources. We
    agree and reverse the district court’s construction of main
    power source.
    We conclude that the correct construction of “main
    power source” includes both AC and DC power sources.
    There is no dispute that the ordinary meaning of “power
    source” includes both AC and DC power sources. Appel-
    lant’s Br. 45–49; see Appellee’s Br. 47. And neither the
    claims nor the specification of the ’930 patent require a de-
    parture from this ordinary meaning. Starhome GmbH v.
    AT & T Mobility LLC, 
    743 F.3d 849
    , 857 (Fed. Cir. 2014)
    (“In the absence of an express intent to impart a novel
    meaning to claim terms, an inventor’s claim terms take on
    their ordinary meaning.”).
    Claim 6 recites a “main power source” that is “con-
    nected to supply power to the data node” and that “de-
    liver[s] a low level current . . . to the access device.”
    ’930 patent col. 4 ll. 56–57, ll. 60–61; see also
    id. at
    col. 1
    ll. 64–65, col. 2 ll. 8–9. Nowhere do the claims suggest that
    the “main power source” should be limited to DC power
    sources.
    The specification likewise never expresses a preference
    for DC power sources, much less a suggestion that DC
    power is an “essential” feature of the main power source.
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    See GE Lighting Sols., LLC v. AgiLight, Inc., 
    750 F.3d 1304
    , 1309–10 (Fed. Cir. 2014). Indeed, far from limiting
    the plain language of the claims to a DC power source, the
    specification states that the power source may be a “con-
    ventional main power supply,” which according to the ordi-
    nary meaning would include both AC and DC power
    sources. ’930 patent col. 2 ll. 52–53. This reading of the
    specification is further confirmed by the ’930 patent’s dis-
    closure of a preferred embodiment, which is shown in Fig-
    ures 1 and 3. See MBO Labs., Inc. v. Becton, Dickinson &
    Co., 
    474 F.3d 1323
    , 1333 (Fed. Cir. 2007) (“A claim inter-
    pretation that excludes a preferred embodiment from the
    scope of the claim is rarely, if ever, correct.” (internal cita-
    tion omitted)). In Figure 1, power source 16 is identified as
    a “conventional” power supply, and in Figure 3, main power
    supply 70 is specifically depicted as a traditional AC power
    outlet. ’930 patent col. 2 ll. 52–53, Fig. 3.
    Despite the express disclosures of the ’930 patent, the
    district court construed “main power source” to exclude AC
    power sources on the basis of expert testimony that receipt
    of AC power by a network device would render it inopera-
    ble. J.A. 30–31, 50–51. This is error for two reasons. First,
    even though the network device cannot receive AC power,
    the record establishes that “data nodes” or network
    switches were commonly used to convert AC power to DC
    power as needed to power the network device. Indeed, we
    need not look beyond the specification of the ’930 patent.
    In the preferred embodiment, as shown in Figure 1, a data
    node exists between main power source 16 and the remote
    equipment. And in Figure 3, an 8-port switch is shown con-
    nected to the AC power outlet such that the AC power is
    converted to DC power before reaching the network device.
    ’930 patent col. 2 l. 29, col. 3 ll. 59–60, Figs. 1 & 3. Even
    HP’s expert Dr. Neikirk explained that Figure 3 illustrates
    “‘the main power supply 70’ receiving power from a typical
    AC wall socket, and in turn suppl[ying] operational power
    via the ‘Main Power Distribution Bus’ to the data
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    switches.” J.A. 1049 ¶ 35. Nothing in the claims of the
    ’930 patent precludes the conversion of AC power to DC
    power, and it was error for the district court to add such a
    limitation.
    Second, the district court erred by adding a limitation
    to the claims to carve out certain inoperable embodiments.
    To be sure, we have stated that we skeptically view a con-
    struction that renders all embodiments inoperable, but we
    have instructed that it is nonetheless improper to add lim-
    itations to constructions to exclude only certain inoperable
    embodiments. Cordis Corp. v. Medtronic AVE, Inc.,
    
    511 F.3d 1157
    , 1174 (Fed. Cir. 2008). In this case, the dis-
    trict court’s construction not only excluded inoperable em-
    bodiments that do not convert AC to DC power, but also
    excluded operable embodiments, like the preferred embod-
    iment. See MBO 
    Labs., 474 F.3d at 1333
    .
    Accordingly, we conclude that the district court erred
    in its construction of “main power source.”
    D
    We now consider the effect of the district court’s erro-
    neous construction of “main power source” on the jury’s ver-
    dict of non-infringement. Network-1 argues that if the
    district court erred in its construction of either claim term,
    that error was prejudicial, and it is entitled to a new trial
    on infringement. HP argues in response that to the extent
    either term was misconstrued, such error was harmless
    and the judgment of non-infringement should not be dis-
    turbed. We conclude that Network-1 established that it
    was prejudiced by the district court’s erroneous claim con-
    struction of “main power source” and is entitled to a new
    trial on infringement.
    At trial, HP contested infringement based on the ele-
    ments “low level current” and “main power source.” With
    respect to “main power source,” the record shows that the
    jury was instructed to apply the erroneous construction,
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    that Network-1 elicited testimony showing that the main
    power source for certain HP products originates at an AC
    input, J.A. 2291, 2056, and that HP relied on evidence of
    non-infringement, at least in part, based on the fact that
    these products are not within the scope of the ’930 patent
    because they use an AC input, J.A. 2056–57, 2065–66. The
    jury found that HP did not infringe the asserted claims of
    the ’930 patent. Because the general verdict form does not
    indicate the basis for the jury’s decision, where the evi-
    dence shows that HP relied on the district court’s erroneous
    construction for its argument that it does not infringe the
    asserted claims, we conclude that Network-1 has estab-
    lished that it was prejudiced by the claim construction.
    J.A. 69–70.
    HP argues that the erroneous claim construction was
    harmless because HP presented conclusive evidence that
    no accused product meets the claim limitation “delivering
    a low level current from said main power source.” Appel-
    lee’s Br. 25–26 (emphases in original). More particularly,
    HP argues that the record shows that its products deliver
    detection current from a PoE chip, not an AC or DC power
    source. But HP’s argument relies on an element that is not
    in the claims—namely, that current be delivered directly
    from the main power source to the access device. Indeed,
    the district court expressly rejected HP’s attempt to import
    such a limitation during claim construction. See J.A 39–40.
    And in any case, Network-1 presented evidence at trial
    showing that HP’s products practice this claim limitation.
    See, e.g., J.A. 1790–95, 2480–81, 2724. We therefore reject
    HP’s argument that the non-infringement verdict may be
    affirmed on appeal.
    Accordingly, we affirm the district court’s construction
    of “low level current,” reverse the district court’s construc-
    tion of “main power source,” and remand to the district
    court for proceedings consistent with this opinion.
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    II. Statutory Estoppel
    We now turn to HP’s cross-appeal. HP argues that the
    district court erroneously granted JMOL with respect to
    the ’930 patent’s validity based on its determination that
    HP was estopped under 35 U.S.C. § 315(e) from presenting
    obviousness challenges as a consequence of its joinder to
    the Avaya IPR. We agree that HP is not estopped. We
    therefore vacate the district court’s judgment and remand
    to the district court for proceedings consistent with this
    opinion.
    A
    We review “decisions on motions for JMOL, motions for
    a new trial, and evidentiary rulings under the law of the
    regional circuit.” SSL 
    Servs., 769 F.3d at 1082
    . The Fifth
    Circuit reviews decisions on motions for JMOL “de novo,
    reapplying the JMOL standard.” Summit 6, LLC v. Sam-
    sung Elecs. Co., 
    802 F.3d 1283
    , 1293 (Fed. Cir. 2015) (citing
    Ford v. Cimarron Ins. Co., 
    230 F.3d 828
    , 830 (5th Cir.
    2000)). In the Fifth Circuit, a jury verdict may only be re-
    versed by JMOL if substantial evidence does not support
    the verdict. Versata Software, Inc. v. SAP Am., Inc.,
    
    717 F.3d 1255
    , 1261 (Fed. Cir. 2013). “Thus, a JMOL may
    only be granted when, ‘viewing the evidence in the light
    most favorable to the verdict, the evidence points so
    strongly and overwhelmingly in favor of one party that the
    court believes that reasonable jurors could not arrive at
    any contrary conclusion.’”
    Id. (quoting Dresser–Rand Co.
     v. Virtual Automation, Inc., 
    361 F.3d 831
    , 838 (5th Cir.
    2004)).
    B
    Following trial, the district court granted Network-1’s
    motion for JMOL on validity of the ’930 patent. The district
    court concluded that as a result of HP’s joinder to the
    Avaya IPR, HP was estopped under 35 U.S.C. § 315(e) from
    raising obviousness challenges not based on the Fisher
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    system. J.A. 91. According to the district court, in contrast
    to the Fisher system, which was not a patent or printed
    publication that HP “reasonably could have raised” in the
    IPR, HP could have reasonably raised its remaining inva-
    lidity arguments during the IPR—i.e., the Fisher patents,
    Woodmas, and Chang. J.A. 88–89, 91 (quoting 35 U.S.C.
    § 315(e)(2)). In reaching this conclusion, the district court
    specifically rejected HP’s argument that it could not have
    raised new grounds in the Avaya IPR because it was a
    joined party. The district court stated that “the fact that
    HP sought joinder with Avaya’s IPR does not mean that HP
    could not have reasonably raised different grounds from
    those raised by Avaya.” J.A. 91. The district court further
    stated that allowing HP to raise arguments “that it elected
    not to raise during the IPR would give it a second bite at
    the apple and allow it to reap the benefits of the IPR with-
    out the downside of meaningful estoppel.” J.A. 91 (internal
    quotations omitted). The district court therefore granted
    JMOL on validity without considering the merits of HP’s
    invalidity arguments. J.A. 91 & n.6.
    HP argues that, in granting Network-1’s motion for
    JMOL on invalidity, the district court misapplied the es-
    toppel provision under 35 U.S.C. § 315(e)(2). Specifically,
    HP argues that no validity ground that it raised at trial
    “reasonably could have [been] raised” through its joinder to
    the Avaya IPR. See J.A. 88–91. We agree with HP. HP’s
    joinder to the Avaya IPR and the estoppel consequences of
    that joinder are governed by the America Invents Act
    (“AIA”), which established IPR proceedings. According to
    the AIA, under 35 U.S.C. § 315(c), HP was permitted to join
    the Avaya IPR “as a party” even though HP was time-
    barred under § 315(b) from bringing its own petition. But,
    as we held in Facebook, Inc. v. Windy City Innovations,
    LLC, the joinder provision does not permit a joining party
    to bring into the proceeding new grounds that were not al-
    ready instituted. Facebook, Inc. v. Windy City Innovations,
    LLC, __ F.3d __, No. 18-1400, 
    2020 WL 5267975
    , at *9–10
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    (Fed. Cir. Sept. 4, 2020). Rather, it may only join the al-
    ready-instituted proceeding as a party.
    Id. Following a final
    written decision in an IPR, the AIA
    provides for statutory estoppel under 35 U.S.C. § 315(e) to
    limit the invalidity challenges that an IPR petitioner may
    bring in a separate action involving the same patent
    claims. With respect to district court actions, § 315(e)(2)
    states:
    CIVIL ACTIONS AND OTHER PROCEEDINGS.—The peti-
    tioner in an inter partes review of a claim in a pa-
    tent under this chapter that results in a final
    written decision under section 318(a) . . . may not
    assert in . . . a civil action arising in whole or in
    part under section 1338 of title 28 . . . that the
    claim is invalid on any ground that the petitioner
    raised or reasonably could have raised during that
    inter partes review.
    35 U.S.C. § 315(e)(2) (emphases added). Thus, according to
    the statute, a party is only estopped from challenging
    claims in the final written decision based on grounds that
    it “raised or reasonably could have raised” during the IPR.
    Because a joining party cannot bring with it grounds other
    than those already instituted, that party is not statutorily
    estopped from raising other invalidity grounds.
    In this case, the Board instituted two grounds in the
    Avaya IPR, which challenged claims 6 and 9 of the ’930 pa-
    tent based on Matsuno and De Nicolo. HP did not timely
    petition for IPR but relied on the joinder exception to the
    time bar under § 315(b). HP first filed a motion to join the
    Avaya IPR with a petition requesting review based on
    grounds not already instituted. The Board correctly denied
    HP’s request. The Board, however, granted HP’s second
    joinder request, which petitioned for only the two grounds
    already instituted. When the Board reached a final written
    decision in the Avaya IPR, because HP was a petitioner in
    that proceeding, HP was statutorily estopped from raising
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    invalidity grounds based on Matsuno and De Nicolo
    against claims 6 and 9 in a district court action. HP, how-
    ever, was not estopped from raising other invalidity chal-
    lenges against those claims because, as a joining party, HP
    could not have raised with its joinder any additional inva-
    lidity challenges. Thus, contrary to the district court’s sug-
    gestion, permitting HP to challenge the asserted claims of
    the ’930 patent as obvious over the Fisher patents, Wood-
    mas, and Chang does not give HP a “second bite at the ap-
    ple” to challenge the ’930 patent, J.A. 91, because HP could
    not have raised such a challenge in the Avaya IPR.
    Accordingly, we conclude that HP was not statutorily
    estopped under § 315(e) from challenging the asserted
    claims of the ’930 patent based on the Fisher patents,
    Woodmas, and Chang, which were not raised in the Avaya
    IPR and which could not have reasonably been raised by
    HP. We therefore vacate the district court’s JMOL decision
    on validity with respect to estoppel.
    C
    Because we conclude that the district court erred in
    granting JMOL of validity for Network-1 on the basis that
    HP was statutorily estopped from raising certain invalidity
    challenges, we vacate that decision.
    HP argues that if we vacate the district court’s JMOL
    on validity, substantial evidence supports the jury’s verdict
    of invalidity, and thus the jury’s verdict should be rein-
    stated. In response, Network-1 argues that even if we re-
    verse on estoppel, we cannot resolve this case on appeal
    because there is an outstanding new-trial motion that the
    district court must decide. Indeed, the district court failed
    to conditionally rule on Network-1’s motion for a new trial
    on validity even though it was required to do so by Federal
    Rule of Civil Procedure 50(c). See J.A. 78–91, 9260–65. We
    decline to consider Network-1’s motion in the first instance.
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    We therefore remand to the district court for further pro-
    ceedings consistent with this opinion.
    III. Claim Broadening
    On cross-appeal, HP also argues that claim 6 and the
    other asserted claims are invalid under 35 U.S.C. § 305 be-
    cause Network-1 improperly broadened claim 6 through
    the addition of claim 15 and 16 in the ’401 reexamination.
    We disagree and affirm the district court’s judgment that
    the asserted claims were not improperly broadened.
    A
    A patentee is not permitted to enlarge the scope of a
    patent claim during reexamination. 35 U.S.C. § 305. The
    broadening inquiry under § 305 involves two steps: (1) “an-
    alyz[ing] the scope of the claim prior to reexamination” and
    (2) “compar[ing] it with the scope of the claim subsequent
    to reexamination.” Creo Prods., Inc. v. Presstek, Inc., 
    305 F.3d 1337
    , 1344 (Fed. Cir. 2002). A claim “is broader in
    scope than the original claims if it contains within its scope
    any conceivable apparatus or process which would not have
    infringed the original patent.” See Predicate Logic, Inc. v.
    Distributive Software, Inc., 
    544 F.3d 1298
    , 1303 (Fed. Cir.
    2008).
    “Whether amendments made during reexamination
    enlarge the scope of a claim is a matter of claim construc-
    tion,” Creo 
    Prods., 305 F.3d at 1344
    , which we review de
    novo, while giving deference to subsidiary factual determi-
    nations, Teva 
    Pharms., 574 U.S. at 331
    .
    B
    HP argues that dependent claims 15 and 16 added dur-
    ing the ’401 reexamination resulted in improper claim
    broadening of claim 6 and asserted dependent claims. In
    relevant part, prior to reexamination, claim 6 of the
    ’930 patent was construed in two separate district court ac-
    tions to require the “secondary power source” to be
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    physically separate from the “main power source.” See J.A.
    59–62; see also J.A. 40–42. Subsequently, during the ’401
    reexamination, Network-1 added claims 15 and 16, which
    depended from claim 6 and respectively added the limita-
    tions that the secondary power source “is the same source
    of power” and “is the same physical device” as the main
    power source. ’930 patent, Ex Parte Reexamination Certif-
    icate, col. 1 ll. 39–44.
    After claims 15 and 16 issued at the conclusion of the
    ’401 reexamination, HP moved in the underlying district
    court action for summary judgment of invalidity under
    35 U.S.C. § 305 for improper claim broadening. Network-1
    subsequently filed a statutory disclaimer under 35 U.S.C.
    § 253 of claims 15 and 16. See J.A. 5075. Ultimately, the
    district court denied HP’s motion, finding that claim 6 had
    not been improperly broadened. J.A. 59–62; see also
    J.A. 40–42. In the same order, the district court also con-
    strued the claim term “secondary power source” consistent
    with the earlier district court actions to require that the
    “secondary power source be physically separate from the
    driving points of the main power source.” J.A. 52–53; see
    also J.A. 32–33.
    We do not agree that claim 6 is invalid for improper
    broadening based on the addition of claims 15 and 16. Our
    broadening inquiry begins and ends with claim 6. Claim 6
    was not itself amended during the ’401 reexamination.
    And as HP admits, “[t]he district court’s construction [after
    reexamination] is consistent with how the [earlier district]
    courts construed this term [pre-reexamination].” Appel-
    lee’s Br. 15. Neither party appeals that construction.
    There can be no dispute, therefore, that the scope of claim 6
    was not changed as a result of the ’401 reexamination.
    Where the scope of claim 6 has not changed, there has not
    been improper claim broadening, and HP’s argument fails.
    See Creo 
    Prods., 305 F.3d at 1344
    .
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    Furthermore, our precedent is clear that “dependent
    claims cannot broaden an independent claim from which
    they depend.” Enzo Biochem Inc. v. Applera Corp., 
    780 F.3d 1149
    , 1156–57 (Fed. Cir. 2017). Thus, even were de-
    pendent claims 15 and 16 broader than unamended, inde-
    pendent claim 6, the remedy would not be to find claim 6
    invalid as broadened, but to invalidate added claims 15 and
    16. See MBO Labs., Inc. v. Becton, Dickinson & Co., 
    602 F.3d 1306
    , 1319 (Fed. Cir. 2010). We need not determine
    whether claims 15 and 16 are invalid because they are not
    asserted and because those claims have already been can-
    celed through Network-1’s statutory disclaimer.
    Despite the clarity of our caselaw, HP principally relies
    on ArcelorMittal France v. AK Steel Corp., 
    786 F.3d 885
     (Fed. Cir. 2015), to argue that claim 6 was improperly
    broadened and should be invalidated. In that case, we con-
    cluded that the patentee had improperly broadened inde-
    pendent claim 1 through reissue by adding a number of
    dependent claims. See 
    ArcelorMittal, 786 F.3d at 890
    . HP
    quotes our explanation that one of the new dependent
    claims had “the practical effect of expanding the scope of
    claim 1 to cover claim scope expressly rejected by a previ-
    ous claim construction ruling.” Appellee’s Br. 70 (quoting
    
    ArcelorMittal, 786 F.3d at 890
    ). HP also emphasizes that
    in ArcelorMittal, we held invalid for improper broadening
    under 35 U.S.C. § 251 not only the newly added claims but
    also claim 1 itself. Appellee’s Br. 70. HP argues that the
    facts in ArcelorMittal are “nearly identical” to this case,
    and that claim 6 is invalid because claims 15 and 16 have
    “the practical effect of expanding” the scope of claim 6.
    Id. HP is wrong.
         ArcelorMittal is inapposite. In that case, the patentee
    had stipulated that all reissued claims, including claim 1,
    were broader than the original claims. 
    ArcelorMittal, 786 F.3d at 890
    . Thus, in ArcelorMittal, there was no dispute
    that the claims had been broadened. Furthermore, we did
    not hold, as HP suggests, see Appellee’s Br. 70–71, that a
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    dependent claim added during reissue (or reexamination)
    may broaden and therefore invalidate an unamended, in-
    dependent claim. To the contrary, we rejected “the argu-
    ment that a defective reissue application invalidates . . .
    [the] original claims carried over from the original applica-
    tion.” 
    ArcelorMittal, 786 F.3d at 891
    (quoting Hewlett–
    Packard Co. v. Bausch & Lomb, Inc., 
    882 F.2d 1556
    , 1566
    (Fed. Cir. 1989)).
    Accordingly, we affirm the district court’s conclusion
    that claim 6 and the other asserted claims are not invalid
    due to improper claim broadening.
    CONCLUSION
    We have considered the parties’ remaining arguments
    and find them unpersuasive. For the reasons described
    above, we affirm-in-part, reverse-in-part, vacate, and re-
    mand.
    AFFIRMED-IN-PART, REVERSED-IN-PART,
    VACATED, AND REMANDED
    COSTS
    The parties shall bear their own costs.