Eidos Display, LLC v. Au Optronics Corporation , 779 F.3d 1360 ( 2015 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    EIDOS DISPLAY, LLC, EIDOS III, LLC,
    Plaintiffs-Appellants
    v.
    AU OPTRONICS CORPORATION, AU OPTRONICS
    CORPORATION AMERICA, CHI MEI INNOLUX
    CORPORATION, CHI MEI OPTOELECTRONICS
    USA INC., CHUNGHWA PICTURE TUBES, LTD.,
    HANNSTAR DISPLAY CORPORATION,
    HANNSPREE NORTH AMERICA, INC.,
    Defendants-Appellees
    ______________________
    2014-1254
    ______________________
    Appeal from the United States District Court for the
    Eastern District of Texas in No. 6:11-cv-00201-LED-JDL,
    Chief Judge Leonard Davis.
    ______________________
    Decided: March 10, 2015
    ______________________
    ROBERT TYLER GOODWYN, McKenna Long & Aldridge
    LLP, Washington, DC, argued for plaintiffs-appellants.
    Also represented by GASPARE JOSEPH BONO, CASS WALKER
    CHRISTENSON, ROBERT C. NISSEN.
    CHRISTOPHER BENSON, Austin, TX, argued for defend-
    ants-appellees. Defendant-appellee Chunghwa Picture
    2            EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION
    Tubes, Ltd., also represented by DANIEL LEVENTHAL, PAUL
    ANDREW DYSON, ERIC B. HALL, Norton Rose Fulbright,
    Houston, TX. Defendants-appellees AU Optronics Corpo-
    ration, AU Optronics Corporation America, also repre-
    sented by MARVIN CRAIG TYLER, BRIAN A. DIETZEL,
    GEOFFREY WILLIAM HEAVEN, Wilson, Sonsini, Goodrich &
    Rosati, PC, Austin, TX. Defendants-appellees Chi Mei
    Innolux Corporation, Chi Mei Optoelectrics, USA Inc.,
    Hannspree North America, Inc., Hannstar Display Corpo-
    ration, also represented by MING-TAO YANG, JACOB ADAM
    SCHROEDER, Finnegan, Henderson, Farabow, Garrett &
    Dunner, LLP, Palo Alto; EDWARD ROBERT YOCHES, Wash-
    ington, DC.
    ______________________
    Before WALLACH, TARANTO, and CHEN, Circuit Judges.
    CHEN, Circuit Judge.
    Plaintiff-Appellants Eidos Display, LLC and Eidos III,
    LLC (Eidos) appeal from the district court’s grant of a
    motion for summary judgment, finding the asserted claim
    of U.S. Patent No. 5,879,958 (the ’958 patent) to be invalid
    as indefinite. Because the claim, when read in light of the
    specification and prosecution history, informed with
    reasonable certainty those skilled in the art at the time
    the patent was filed about the scope of the claimed inven-
    tion, we reverse the district court’s grant of summary
    judgment of indefiniteness, and remand to the district
    court for further proceedings consistent with our decision.
    BACKGROUND
    Eidos alleges AU Optronics Corporation, AU Optron-
    ics Corporation America, Chi Mei Innolux Corporation,
    Chi Mei Optoelectronics USA Inc., Chunghwa Picture
    Tubes, Ltd., Hannstar Display Corporation, and
    Hannspree North America, Inc. (collectively, “Display
    Manufacturers”) infringe claim 1 of the ’958 patent. The
    ’958 patent is directed toward manufacturing processes
    EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION          3
    for an electro-optical device, such as a liquid crystal
    display (LCD).
    The specification of the ’958 patent contains 17 em-
    bodiments, each identified by a letter (A through H, J,
    and L through S). Each embodiment describes a manu-
    facturing process that reduces the number of photolitho-
    graphic steps in creating an LCD panel compared to prior
    art processes, lowering the production cost and improving
    yield and production efficiency. ’958 patent, 1:19–3:37
    (describing the prior art as containing seven photolitho-
    graphic steps), 4:39–14:18 (describing the invention as
    containing four or five photolithographic steps), 14:31–37
    (comparing the invention to the prior art). Each embodi-
    ment is broken down into a series of “forming” steps that
    deposit material, such as metal, insulator, or passivation
    material, on the substrate or previous layers, as well as a
    series of “photolithographic” steps that etch or remove
    portions of previously-formed material. For example, the
    seventh embodiment, identified by the letter “G,” contains
    five forming steps—G1, G3, G5, G7, and G9—sequentially
    interspersed with five photolithographic steps—G2, G4,
    G6, G8, and G10. 
    Id. at 8:33–67.
    The specification de-
    scribes the manufacturing process for each disclosed
    embodiment with reference to the figures. For example,
    figures 54 through 63 depict the process steps of the G
    embodiment. 
    Id. at 18:9–44,
    35:31–36:65.
    The circuitry in the LCD devices formed by the pa-
    tented manufacturing processes is the same as circuitry
    formed by a prior art manufacturing process. 
    Id. at 1:16–
    18. An example of such a prior art circuit is found in
    figure 169, reproduced below. 
    Id. 1 Figure
    169 shows a
    matrix with source wiring (S1, S2, S3, . . . Sn) forming the
    vertical lines and gate wiring (G1, G2, G3, . . . Gn) form-
    1    Line 16 of column 1 erroneously refers to “FIG.
    169” as “FIG. 165.”
    4           EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION
    ing the horizontal lines. 
    Id. at 1:19–23.
    The source
    wiring is connected to a signal supply circuit to provide
    image data, and the gate wiring is connected to a scan-
    ning circuit to provide control signals. Id.; Appellants’ Br.
    at 6–7.
    Important to this appeal, the electrical connection be-
    tween a source wire and the signal supply circuit is called
    a source wiring connection terminal. The electrical con-
    nection between a gate wire and the scanning circuit is
    called a gate wiring connection terminal. In an LCD
    panel, there are many individual source and gate wires,
    each with a connection terminal located at the end of the
    wire. Appellants’ Br. at 7 (citing Eidos Display, LLC v.
    AU Optronics Corp., No. 6:11-cv-201 LED-JDL, 
    2013 WL 1559729
    , at *5 (E.D. Tex. Apr. 12, 2013)). During the
    relevant LCD manufacturing process, a non-conductive
    passivation film is formed on top of the wiring and con-
    nection terminals. See ’958 patent, 58:34–36 (Step G7).
    The passivation film is then etched away to allow the
    scanning and signal supply circuits to connect to the
    terminals. See 
    id. at 58:37–41
    (Step G8). Experts for
    EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION          5
    both parties agree that, at the time of the ’958 patent, the
    only industry practice for this manufacturing process was
    to create individual holes, referred to as “contact holes,”
    through the passivation film to each connection terminal.
    While a single contact hole shared by all the connection
    terminals may have been technically possible, no expert
    was aware of any example or teaching where such a
    contact hole was ever created, and neither party put any
    such teaching into the record, if such a teaching exists.
    The asserted claim 1 is the only issued claim in the
    ’958 patent and recites:
    1. A method for producing an electro-optical de-
    vice in which an electro-optical material is put be-
    tween a pair of substrates opposed to each other,
    at least a portion of opposing surfaces of the sub-
    strates is insulative, a plurality of source wirings
    and a plurality of gate wirings are formed crossing
    each other on the surface of one of said pair of
    substrates and a transparent pixel electrode and a
    thin film transistor are formed at each of the
    crossing points between the source wirings and
    the gate wirings, wherein the method comprises:
    a step G1 of forming a first metal film on the sur-
    face of said one substrate,
    a first photolithographic step G2 of patterning the
    first metal film to form a gate electrode and a gate
    wiring,
    a step G3 of forming a first insulator film, a semi-
    conductor film and an ohmic contact film on the
    surface of said one substrate after the first photo-
    lithographic step,
    a second photolithographic step G4 of patterning
    the semiconductor active film and the ohmic con-
    tact film to form a semiconductor portion above
    6           EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION
    the gate electrode in a state isolated from other
    portions,
    a step G5 of forming a second metal film on the
    surface of said one substrate after the second pho-
    tolithographic step,
    a third photolithographic step G6 of patterning
    the second metal film and the ohmic contact film
    to form a source electrode, a drain electrode and a
    channel portion,
    a step G7 of forming a passivation film on the sur-
    face of said one substrate after the third photo-
    lithographic step, and
    a fourth photolithographic step G8 of patterning
    the passivation film to form a contact hole reach-
    ing the gate wiring, a contact hole reaching the
    drain electrode and a contact hole for source wir-
    ing and gate wiring connection terminals,
    a step G9 of forming a transparent conductive film
    on the surface of said one substrate after the
    fourth photolithographic step, and
    a fifth photolithographic step G10 of patterning
    the transparent conductive film to form a trans-
    parent pixel electrode.
    
    Id. at 58:5–47
    (emphasis added to highlight the limitation
    at issue on appeal).
    During Markman proceedings in front of the magis-
    trate judge, the primary claim construction dispute fo-
    cused on the last portion of step G8, “a contact hole for
    source wiring and gate wiring connection terminals.”
    Eidos Display, 
    2013 WL 1559729
    , at *4. Eidos argued
    that the disputed limitation requires separate and dis-
    tinct contact holes for the source wiring connection termi-
    nals and gate wiring connection terminals, consistent
    with the standard industry practice and the specification,
    EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION          7
    whereas Display Manufacturers argued that the plain
    language of the disputed limitation requires a shared
    contact hole for all connection terminals. 
    Id. The magis-
    trate judge reviewed the claim language, specification,
    and the record in the then-ongoing ex parte reexamina-
    tion, and determined that the dispute “[wa]s not ripe for
    claim construction, as the dispute [as] presented cen-
    ter[ed] around theories of invalidity pursuant to
    35 U.S.C. § 112.” 
    Id. at *6.
         Defendants Chi Mei Innolux Corporation and Chi Mei
    Optoelectronics USA Inc. (collectively, “Innolux”) then
    filed a motion for summary judgment alleging nonin-
    fringement, in which they argued for a third construction
    of the disputed limitation, that two different structures be
    formed: 1) a contact hole for source wiring and 2) the gate
    wiring connection terminals, with no corresponding
    contact hole or holes. The district court declined to adopt
    Innolux’s proposed construction, and instead ordered
    briefing as to whether the disputed limitation was defi-
    nite. Display Manufacturers subsequently filed a motion
    for summary judgment asserting indefiniteness. Eidos, in
    its response to Display Manufacturers’ motion, proposed a
    fourth construction of the disputed limitation: that the
    structure for the limitation could be formed as either a
    single contact hole as Display Manufactures proposed, or
    as separate contact holes as Eidos originally proposed.
    Joint Appendix (J.A.) 33.
    The magistrate judge rejected all four proposed con-
    structions of the disputed limitation. Regarding the first,
    second, and fourth proposed constructions, the magistrate
    judge determined that the specification failed to support
    that “a contact hole for source wiring and gate wiring
    connection terminals” could be formed as either separate
    contact holes or a shared contact hole. The magistrate
    judge dismissed Innolux’s proposed construction because
    it required connection terminals to be formed from an
    insulating material, whereas the specification requires
    8           EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION
    the terminals to be made of a conductive material. The
    magistrate judge recommended that the district court
    grant the motion for summary judgment on indefiniteness
    because “the Court is unable to arrive at a construction
    that would allow a person of ordinary skill in the art to
    determine what is claimed when the claim is read in light
    of the specification.” J.A. 34 (citation omitted). The
    district court issued an order adopting the magistrate
    judge’s recommendation and granting the motion for
    summary judgment of indefiniteness. J.A. 22.
    Eidos appealed and we have jurisdiction pursuant to
    28 U.S.C. § 1295(a)(1).
    DISCUSSION
    A patent must “conclude with one or more claims par-
    ticularly pointing out and distinctly claiming the subject
    matter which the applicant regards as [the] invention.”
    35 U.S.C. § 112, ¶ 2 (2006). 2 Keeping in mind that “pa-
    tents are not addressed to lawyers, or even to the public
    generally, but rather to those skilled in the relevant art,”
    the patent claims “must be precise enough to afford clear
    notice of what is claimed, thereby appris[ing] the public of
    what is still open to them.” Nautilus, Inc. v. Biosig In-
    struments, Inc., 
    134 S. Ct. 2120
    , 2129 (2014) (internal
    quotation marks omitted). A claim fails to satisfy this
    statutory requirement and is thus invalid for indefinite-
    ness if its language, when read in light of the specification
    and prosecution history, “fail[s] to inform, with reasonable
    2   Paragraph 2 of 35 U.S.C. § 112 was replaced with
    newly designated § 112(b) when § 4(c) of the America
    Invents Act (AIA), Pub. L. No. 112-29, took effect on
    September 16, 2012. Because the applications resulting
    in the patents at issue in this case were filed before that
    date, we will refer to the pre-AIA version of § 112.
    EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION          9
    certainty, those skilled in the art [at the time the patent
    was filed] about the scope of the invention.” 
    Id. at 2124.
    3
    We review the grant of summary judgment of indefi-
    niteness de novo, applying the same standard used by the
    district court. Ethicon Endo-Surgery, Inc. v. U.S. Surgi-
    cal Corp., 
    149 F.3d 1309
    , 1315 (Fed. Cir. 1998). We
    review the district court’s ultimate indefiniteness deter-
    mination de novo. Interval Licensing LLC v. AOL, Inc.,
    
    766 F.3d 1364
    , 1370 (Fed. Cir. 2014). The indefiniteness
    inquiry here is intertwined with claim construction, see
    Atmel Corp. v. Info. Storage Devices, Inc., 
    198 F.3d 1374
    ,
    1379 (Fed. Cir. 1999), which, because the meaning of the
    claim at issue is clear in view of the intrinsic record and
    undisputed facts, we also review de novo, see Teva Pharm.
    USA, Inc. v. Sandoz, Inc., 
    135 S. Ct. 831
    , 840–42 (2015).
    To the extent the district court considered extrinsic evi-
    dence in its claim construction order or summary judg-
    ment order, that evidence is ultimately immaterial to the
    outcome because the intrinsic record is clear. See Phillips
    v. AWH Corp., 
    415 F.3d 1303
    , 1318 (Fed. Cir. 2005) (en
    banc) (“[A] court should discount any expert testimony
    that is clearly at odds with the claim construction man-
    dated by the claims themselves, the written description,
    and the prosecution history, in other words, with the
    written record of the patent.” (internal quotation marks
    omitted)). We reverse the district court’s finding of indef-
    initeness because Eidos’ proposed construction for the
    3   The district court granted summary judgment on
    January 22, 2014, without the benefit of the Supreme
    Court’s guidance in Nautilus. The magistrate judge
    recommended that summary judgment of indefiniteness
    be granted because he determined, under the pre-
    Nautilus standard, that the asserted claim was “insolubly
    ambiguous.” J.A. 34 (citing Honeywell Int’l v. Int’l Trade
    Comm’n, 
    341 F.3d 1332
    , 1338–39 (Fed. Cir. 2003)).
    10          EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION
    disputed limitation reflects how a person of ordinary skill
    in the art at the time of the invention would have under-
    stood the limitation after reading the intrinsic record. See
    
    id. at 1312–18.
        The limitation-at-issue, “a contact hole for source wir-
    ing and gate wiring connection terminals,” by itself, might
    suggest to someone unknowledgeable in the field of LCD
    manufacturing that one contact hole is formed for all the
    source wiring connection terminals and gate wiring
    connection terminals, as the Display Manufacturers
    argue. But the limitation, by itself, might also indicate
    that many contact holes are formed for the connection
    terminals. To analogize, a person familiar with cars,
    when reading the sentence “I am going to create an elec-
    tric car for the United States and United Kingdom,”
    would likely expect different electric cars to be created,
    one set with the steering wheel located on the left for
    driving in the United States, and another set with the
    steering wheel on the right for driving in the United
    Kingdom. The intrinsic record here makes sufficiently
    clear that a person of ordinary skill in the art—someone
    with knowledge of LCD manufacturing—after considering
    the limitation “in the context of the particular claim in
    which the disputed term appears, [and] in the context of
    the entire patent, including the specification,” 
    Phillips, 415 F.3d at 1313
    , would understand the limitation-at-
    issue to call for separate, different contact holes for the
    source wiring connection terminals and gate wiring
    connection terminals, rather than one shared contact
    hole. 4
    4  During reexamination of the ’958 patent, the ex-
    aminer concluded that the limitation-at-issue “implicitly
    requires separate contact holes for the source wiring and
    gate wiring connection terminals.” J.A. 6079–80.
    EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION         11
    As an initial matter, no party disputes that the state
    of the art for manufacturing LCD panels always had been
    to form contact holes for source wiring connection termi-
    nals that are separate from contact holes for gate wiring
    connection terminals.       Consistent with that well-
    established practice, the specification teaches that each
    connection terminal for the electro-optical device would
    receive its own contact hole, for two reasons.
    First, nothing in the 172 figures or 58 columns of the
    ’958 patent describes how a person of ordinary skill in the
    art would deviate from the known industry practice to
    create a novel shared contact hole for all the connection
    terminals. If the patentee wanted to deviate from the
    standard practice and claim a novel shared contact hole,
    some teaching of how to depart from the common practice
    would not only be expected, but is required. See 35 U.S.C.
    § 112 (“The specification shall contain a written descrip-
    tion of the invention, and the manner and process of
    making and using it, in such full, clear, concise, and exact
    terms as to enable any person skilled in the art . . . to
    make and use the same . . . .”).
    Second, the only description corresponding to “a con-
    tact hole for source wiring and gate wiring connection
    terminals” in the specification teaches that separate
    contact holes are formed for the different connection
    terminals. This teaching is evident when considering the
    history of the ’958 patent, in particular the patent appli-
    cation to which the ’958 patent claims priority, applica-
    tion number 08/459,925. See Masco Corp. v. United
    States, 
    303 F.3d 1316
    , 1324 (Fed. Cir. 2002) (“The prose-
    cution history of a parent application may be considered
    in construing claim terms.” (citing Elkay Mfg. Co. v. Ebco
    Mfg. Co., 
    192 F.3d 973
    , 980 (Fed. Cir. 1999) (“When
    multiple patents derive from the same initial application,
    the prosecution history regarding a claim limitation in
    any patent that has issued applies with equal force to
    subsequently issued patents that contain the same claim
    12          EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION
    limitation.”))). The ’925 application originally contained
    seventeen independent claims, J.A. 9419–49, which were
    subject to a seventeen-species restriction, J.A. 9516. The
    specification in the ’925 application, which is substantial-
    ly the same as the specification in the ’958 patent, con-
    tains seventeen embodiments that match with and
    describe the seventeen original independent claims. The
    limitation-at-issue, “a contact hole for source wiring and
    gate wiring connection terminals,” appeared in five of the
    original claims; claim 3 (embodiment B), claim 4 (embod-
    iment C), claim 5 (embodiment D), claim 7 (embodiment
    F), and claim 8 (embodiment G). Original claim 8 ulti-
    mately became claim 1 of the patent before us—the ’958
    patent. Although the portion of the specification describ-
    ing embodiment G does not explain in detail this particu-
    lar photolithographic step, the portion describing
    embodiment D, which claims this step using identical
    claim language, explicitly describes this photolithographic
    step as forming “a contact hole [] for a source wiring
    connection terminal and a contact hole for a gate wiring
    connection terminal.” ’958 patent, 31:42–53. Both parties
    agree that, as recited in original claim 5 (which corre-
    sponds to embodiment D), “a contact hole for source
    wiring and gate wiring connection terminals” requires
    separate contact holes for each connection terminal,
    consistent with Eidos’ proposed construction. 
    Id. at 31:50–53.
    After reviewing the specification as well as the
    claims originally filed with the Patent Office, we see no
    reason to ascribe a different meaning to the same limita-
    tion in original claim 8, i.e., claim 1 of the ’958 patent.
    See 
    Phillips, 415 F.3d at 1314
    (“Because claim terms are
    normally used consistently throughout the patent, the
    usage of a term in one claim can often illuminate the
    meaning of the same term in other claims.”).
    Even without considering the priority application, the
    specification makes clear that the limitation-at-issue
    requires formation of separate contact holes. Again, with
    EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION          13
    respect to embodiment D, the specification, at one point,
    describes “a fourth photolithographic step D8 of pattern-
    ing the passivation film to remove a portion of the pas-
    sivation film, . . . forming a contact hole for source wiring
    and gate wiring connection terminals.” ’958 patent, 7:11–
    22 (emphasis added). And, as already stated, the specifi-
    cation later clarifies that “photolithographic step D8”
    entails forming “a contact hole [] for a source wiring
    connection terminal and a contact hole for a gate wiring
    connection terminal.” 
    Id. at 31:42–53.
    The specification
    thus equates the limitation-at-issue with forming separate
    contact holes for the source wiring connection terminal
    and the gate wiring connection terminal. Nothing in the
    specification suggests why the identical phrase recited in
    the claimed “fourth photolithographic step G8” should be
    read differently from the described “fourth photolitho-
    graphic step D8.” Instead, a person of ordinary skill in
    the art would understand that the phrase, “a contact hole
    for source wiring and gate wiring connection terminals,”
    when used repeatedly throughout the patent, would be
    given a consistent meaning. See Energy Transp. Grp.,
    Inc. v. William Demant Holding A/S, 
    697 F.3d 1342
    ,
    1349–50 (Fed. Cir. 2012) (using the description of a word
    in the specification for a different structure to inform the
    meaning of the same word in the claim because “claim
    terms are normally used consistently throughout the
    patent” (quoting 
    Phillips, 415 F.3d at 1314
    )).
    The limitation-at-issue also appears in original claims
    3, 4, and 7 of the ’925 application, J.A. 9421–25, 9429–30,
    and in the corresponding embodiments B, C, and F of the
    specification, ’958 patent, 5:38–6:8, 6:9–49, 7:64–8:32.
    Display Manufacturers argue that the lack of description
    for the limitation-at-issue in embodiments B, C, F, and G,
    as described in the specification, is evidence that the
    structure in those embodiments is different than in em-
    bodiment D. We disagree. As set forth above, the rela-
    tionship between the specification description for
    14          EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION
    embodiment D and original claim 5 establishes the proper
    understanding for the same claim limitation recited in the
    other original claims of the ’925 application, i.e., claim 3
    (embodiment B), claim 4 (embodiment C), claim 7 (embod-
    iment F), and claim 8 (embodiment G).
    The district court dismissed the teachings of the D
    embodiment because structures formed in Step D8, as
    recited in original claim 5 of the ’925 application and in
    the specification, do not precisely mirror the structures
    formed in the claimed Step G8. J.A. 29. The magistrate
    judge noted that, in addition to the “contact hole for
    source wiring and gate wiring connection terminals,” Step
    G8 forms a contact hole reaching the gate wiring and a
    contact hole reaching the drain electrode, whereas, in the
    D embodiment, the contact hole reaching the gate wiring
    is formed during Step D4, and a contact hole reaching the
    drain electrode is not mentioned. J.A. 29–30. Relatedly,
    Display Manufacturers argue that the different embodi-
    ments have a different number of steps and have a differ-
    ent sequence in which the patterns are etched, which they
    argue results in “a fundamentally different approach to
    manufacturing a [device].” Appellees’ Br. at 8–9. Differ-
    ent embodiments, however, are expected to have differ-
    ences, and neither the magistrate judge nor Display
    Manufacturers explain how the noted differences in the
    structures of the embodiments impact the structure of the
    limitation-at-issue or impact how a person of ordinary
    skill in the art would have understood the limitation.
    Instead, the embodiments all similarly describe manufac-
    turing processes for an electro-optical device using a
    reduced number of photolithographic steps over the prior
    art, and the structure for the limitation-at-issue is formed
    in the same context in each embodiment—in a “photolith-
    ographic step [] of patterning the passivation film.” ’958
    patent, 6:4–5, 6:43–44, 7:11–12, 8:23–24, 8:57–58. This
    similar context of the limitation-at-issue, in similar
    embodiments, supports the conclusion that a person of
    EIDOS DISPLAY, LLC   v. AU OPTRONICS CORPORATION        15
    ordinary skill in the art would adopt the same under-
    standing for the same limitation recited in claim 1 of the
    ’958 patent.
    Finally, Display Manufacturers argue that permitting
    separate contact holes to be covered by the limitation “a
    contact hole for source wiring and gate wiring connection
    terminals” would require rewriting the limitation, which
    is impermissible except in certain situations. Appellees’
    Br. at 29 (citing Source Vagabond Sys., Ltd. v. Hydrapak,
    Inc., 
    753 F.3d 1291
    , 1301 (Fed. Cir. 2014)). Determining
    how a person of ordinary skill in the art would under-
    stand the limitation, however, is different from rewriting
    the limitation. Here, because a person of ordinary skill in
    the art would understand that the limitation “a contact
    hole for source wiring and gate wiring connection termi-
    nals” means separate contact holes for source wiring
    connection terminals and gate wiring connection termi-
    nals, adopting such a construction is not rewriting the
    claim limitation.
    ***
    The ’958 patent teaches a person of ordinary skill in
    the art that “a contact hole for source wiring and gate
    wiring connection terminals” is formed by etching sepa-
    rate contact holes for the source wiring connection termi-
    nals and for the gate wiring connection terminals, as
    described in the specification and prosecution history.
    Therefore, the limitation “a contact hole for source wiring
    and gate wiring connection terminals” in claim 1 of the
    ’958 patent is not indefinite under 35 U.S.C. § 112, ¶ 2.
    We reverse the judgment of indefiniteness and remand to
    the district court for further proceedings consistent with
    this opinion.
    REVERSED AND REMANDED
    COSTS
    Each party shall bear its own costs.