Symantec Corp. v. Computer Associates International Inc. ( 2008 )


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  •  United States Court of Appeals for the Federal Circuit
    2007-1201, -1239
    SYMANTEC CORPORATION,
    Plaintiff/Counterclaim Defendant-
    Appellant,
    and
    HILGRAEVE, INCORPORATED,
    Plaintiff/Counterclaim Defendant,
    v.
    COMPUTER ASSOCIATES INTERNATIONAL, INC.,
    Defendant/Counterclaimant-
    Cross Appellant,
    and
    RICHARD B. LEVIN,
    Counterclaimant-Cross Appellant.
    David A. Nelson, Latham & Watkins LLP, of Chicago, Illinois, argued for
    plaintiff/counterclaim defendant-appellant. With him on the brief was Mark A. Flagel, of
    Los Angeles, California. On the brief were Daniel A. Boehnen, George I. Lee, and
    Jeffrey A. Steck, McDonnell Boehnen Hulbert & Berghoff LLP, of Chicago, Illinois. Of
    counsel on the brief was Joseph Fitzgerald, Symantec Corp., of Cupertino, California.
    Michael A. Nicodema, Greenberg Traurig LLP, of New York, New York, argued
    for defendant/counterclaimant-cross appellant. With him on the brief was Gaston
    Kroub.
    Gerry J. Elman, Elman Technology Law, P.C, of Swarthmore, Pennsylvania, for
    counterclaimant-cross-appellant.
    Appealed from: United States District Court for the Eastern District of Michigan
    Chief Judge Bernard A. Friedman
    United States Court of Appeals for the Federal Circuit
    2007-1201, -1239
    SYMANTEC CORPORATION,
    Plaintiff/Counterclaim
    Defendant-Appellant,
    and
    HILGRAEVE, INCORPORATED,
    Plaintiff/Counterclaim Defendant,
    v.
    COMPUTER ASSOCIATES INTERNATIONAL, INC.,
    Defendant/Counterclaimant-
    Cross Appellant,
    and
    RICHARD B. LEVIN,
    Counterclaimant-Cross Appellant.
    Appeals from the United States District Court for the Eastern District of Michigan in case
    no. 02-CV-73740, Chief Judge Bernard A. Friedman.
    ___________________________
    DECIDED: April 11, 2008
    ___________________________
    Before GAJARSA, LINN, and DYK, Circuit Judges.
    DYK, Circuit Judge.
    In this patent infringement suit, appellant Symantec Corporation (“Symantec”)
    appeals from the district court’s grant of summary judgment of non-infringement of
    claims 1-20 of the asserted patent, 
    U.S. Patent No. 5,319,776
     (“the ’776 patent”).
    Symantec Corp. v. Computer Assocs. Int’l, Inc., No. 02-CV-73740-DT (E.D. Mich. Aug.
    31, 2006) (reports and recommendations of magistrate judge). 1 Computer Associates
    International, Inc. (“CA”), the accused infringer, cross-appeals from the district court’s
    grant of summary judgment on: (1) the defense of laches; (2) inequitable conduct; (3)
    invalidity over the prior art; and (4) inventorship. 
    Id.
     Richard B. Levin (“Levin”) cross-
    appeals from the district court’s grant of summary judgment that he was not a co-
    inventor of the ‘776 patent. 
    Id.
    Because we find that the district court erred in its construction of the claim terms
    “a method of screening data as it is being transferred,” “destination storage medium,”
    “computer,” and “computer system,” we vacate and remand as to non-infringement and
    invalidity. We dismiss CA’s cross-appeal as to laches as improper, but we treat laches
    as an alternative ground for affirming the judgment.         We affirm the district court’s
    decision on laches, inequitable conduct, and inventorship.
    BACKGROUND
    The ’776 patent is here for the third time. The patent is directed to the “In Transit
    Detection of Computer Virus with Safeguard,” and is described in detail in our earlier
    opinions. See Hilgraeve Corp. v. McAfee Assocs., Inc., 
    224 F.3d 1349
    , 1350-52 (Fed.
    Cir. 2000) (“Hilgraeve I”); Hilgraeve Corp. v. Symantec Corp., 
    265 F.3d 1336
    , 1338-41
    1
    The citations are to the reports and recommendations of the magistrate
    judge. The district court adopted these reports and recommendations in their entirety
    by order. Symantec, No. 02-CV-73740-DT (E.D. Mich. Jan. 23, 2007) (order accepting
    and adopting magistrate judge’s reports and recommendations).
    2007-1201, -1239                             2
    (Fed. Cir. 2001) (“Hilgraeve II”). Briefly, the ’776 patent discloses a method of scanning
    for and detecting computer viruses embedded in data files that are downloaded or
    copied from a remote server (e.g., via the internet) onto a computer. Critically, the
    claimed virus-scan operates before the downloaded or copied data files are accessible
    to the computer’s operating system, thereby allowing the software to block access to
    those files early enough to prevent the embedded viruses from spreading and infecting
    the computer. The ’776 patent includes claims 1-20, of which claim 1 and claim 18 are
    independent. Claim 1 is representative:
    1.     In a system for transferring digital data for storage in a computer
    storage medium, a method of screening the data as it is being transferred
    and automatically inhibiting the storage of screened data containing at
    least one predefined sequence, comprising the steps of:
    causing a quantity of digital data resident on a source storage medium to
    be transferred to a computer system having a destination storage medium;
    receiving and screening the transferred digital data prior to storage on the
    destination storage medium to determine if at least one of a plurality of
    predefined sequences are present in the digital data received; and
    in response to said screening step:
    (a) automatically causing the screened digital data to be stored on
    said destination storage medium if none of the plurality of
    predefined sequences are present, and
    (b) automatically inhibiting the screened digital data from being
    stored on said destination storage medium if at least one
    predefined sequence is resent.
    ’776 patent, col.17 ll.9-29 (emphases added).
    In the ’776 patent’s two prior appearances before this court, the central issue was
    whether the accused virus-scanning products scanned incoming data files prior to
    storage. In Hilgraeve I, Hilgraeve, the original assignee of the ’776 patent, brought a
    2007-1201, -1239                            3
    patent infringement suit against McAfee Associates (“McAfee”) for its VirusScan
    product.   
    224 F.3d at 1350
    .     The district court granted summary judgment of non-
    infringement to McAfee, and Hilgraeve appealed. 
    Id.
     In that appeal, the parties did not
    dispute the construction of the claim term “storage,” which the district court had
    construed as occurring “when the incoming digital data is sufficiently present on the
    destination storage medium, and accessible by the operating system or other programs,
    so that any viruses contained in the data can spread and infect the computer system.”
    
    Id. at 1351
    .
    In Hilgraeve II, Hilgraeve asserted the same ’776 patent in a separately filed
    action against Symantec.     265 F.3d at 1338.      The district court granted summary
    judgment of non-infringement to Symantec, and Hilgraeve appealed. Id. On appeal,
    Hilgraeve challenged the district court’s construction of the term “storage,” which
    differed from the construction in Hilgraeve I because it did not include the “accessible by
    the operating system or other programs” language. Id. at 1341. Symantec argued that
    the term should be construed to occur “when the data become physically present (i.e.,
    magnetically recorded) on the storage medium.”           Id.   We rejected Symantec’s
    construction and adopted Hilgraeve’s construction (which was identical to the district
    court’s construction in Hilgraeve I) of “storage,” holding that “storage” occurred “when
    the incoming digital data [are] sufficiently present on the destination storage medium
    and accessible by the operating system or other programs so that any viruses contained
    in the data can spread and infect the computer system.” Id. at 1342.
    Subsequent to our decision in Hilgraeve II, Symantec settled its dispute with
    Hilgraeve, and, as part of that settlement, purchased Hilgraeve’s interest in the ‘776
    2007-1201, -1239                            4
    patent. Hilgraeve had previously filed a new infringement action against CA, alleging
    infringement of claims 1-20 of the ’776 patent.        The district court then substituted
    Symantec as the plaintiff.
    CA, the accused infringer here, develops and sells a number of antivirus software
    products. The accused products are: (1) the eTrust EZ and eTrust products (collectively
    “the EAV products”), which employ both an incoming and outgoing scan mode; (2) the
    ARCserve product, which is designed to restore data from a backup media where the
    data had previously been archived; and (3) the Gateway products, which operate as a
    proxy between a user’s personal computer and an unattended gateway computer.
    CA’s initial pleadings denied infringement and asserted affirmative defenses and
    counterclaims for invalidity and non-infringement.       Subsequently, CA amended its
    pleadings to add affirmative defenses (including a defense of laches) and counterclaims
    for unenforceability of the ’776 patent due to inequitable conduct, and for invalidity of the
    ’776 patent under 
    35 U.S.C. § 256
     for failing to name alleged co-inventor Levin. The
    district court also granted Levin’s motion to intervene as a party and assert a claim for
    co-inventorship of the ’776 patent.
    As discussed below, the district court construed the terms “a method of
    screening the data as it is being transferred,” “computer system,” and “destination
    storage medium”—the critical claim terms on appeal—in an order dated March 16,
    2005. Based on its constructions of those terms, it granted summary judgment to CA of
    non-infringement on the EAV products and the ARCserve product. Although it did not
    grant summary judgment on the Gateway products, the parties stipulated to non-
    infringement of the Gateway products under the district court’s claim construction. The
    2007-1201, -1239                             5
    district court also granted summary judgment to Symantec on invalidity, holding that the
    ’776 patent was not anticipated or obvious in view of several prior art references.
    Finally, in separate orders, the district court granted summary judgment to Symantec
    on: CA’s affirmative defense of laches; CA’s claim that the ’776 patent was
    unenforceable based on inequitable conduct; and CA and Levin’s claim that Levin was a
    joint inventor of the ’776 patent. Symantec timely appealed; CA and Levin timely cross-
    appealed. We have jurisdiction pursuant to 
    28 U.S.C. § 1295
    (a)(1), except as to CA’s
    improper cross-appeal on the issue of laches.
    DISCUSSION
    We review summary judgment decisions without deference, reapplying the
    standard used by the district court. Innogenetics, N.V. v. Abbott Labs., 
    512 F.3d 1363
    ,
    1378 (Fed. Cir. 2008).    “Under that standard, summary judgment must be granted
    when, drawing all reasonable inferences in favor of the non-movant, there is no genuine
    issue as to any material fact and no reasonable jury could return a verdict for the non-
    movant.” 
    Id.
    I
    A
    Symantec’s primary challenge is to the district court’s determination that the term
    “a method of screening the data as it is being transferred,” appearing in the preambles
    to the claims, was a claim limitation, and its construction of that phrase to mean “a
    method of screening the data while it is being moved or copied and before the data is
    stored to the computer storage medium.”         J.A. at 15.   These determinations bear
    2007-1201, -1239                           6
    directly on the infringement analysis of each of the accused CA products. The dispute
    centers on whether the claims cover methods that do not screen data until after that
    data is written to a storage medium but do conduct screening “prior to storage,” i.e.,
    before the data is accessible to the operating system or to other computer programs.
    Under the district court’s construction, antivirus programs that screen data at any
    time after that data is written to the storage medium (e.g., the computer’s hard drive),
    but before it becomes accessible to the operating system or to other computer
    programs, fall outside the scope of the “as it is being transferred” limitation, even if
    screening is completed entirely before the data becomes accessible. This construction,
    Symantec argues, is in direct conflict with our earlier decision in Hilgraeve II, where we
    construed the term “storage” to occur “when the incoming digital data is sufficiently
    present on the destination storage medium and accessible by the operating system or
    other programs so that any viruses contained in the data can spread and infect the
    computer system.”     265 F.3d at 1342.         That construction of the term “storage,”
    Symantec argues, would have no meaning if the claim term “a method of screening data
    as it is being transferred” were construed to mean that the virus scanning must occur
    entirely before any data is written to the storage medium.
    On appeal, CA does not dispute the binding effect of our earlier construction of
    the term “storage” in Hilgraeve II. Instead, CA contends that our earlier panel decision
    did not address the claim term “a method of screening data as it is being transferred,”
    appearing in the preamble, now at issue. That term, it argues, is a separate claim
    limitation that was added independently to overcome prior art virus-detection methods.
    2007-1201, -1239                            7
    Claim construction is a question of law that we review without deference. Cybor
    Corp. v. FAS Techs., Inc., 
    138 F.3d 1448
    , 1456 (Fed. Cir. 1998) (en banc).
    Because the disputed term appears in the preamble to claim 1, we must first
    determine whether it is in fact a separate limitation. In general, a preamble is construed
    as a limitation “if it recites essential structure or steps, or if it is ‘necessary to give life,
    meaning, and vitality’ to the claim.” Catalina Mktg. Int’l, Inc. v. Coolsavings.com, Inc.,
    
    289 F.3d 801
    , 808 (Fed. Cir. 2002) (quoting Pitney Bowes, Inc. v. Hewlett-Packard Co.,
    
    182 F.3d 1298
    , 1305 (Fed. Cir. 1999)). A preamble is not limiting, however, “’where a
    patentee defines a structurally complete invention in the claim body and uses the
    preamble only to state a purpose or intended use for the invention.’” 
    Id.
     (quoting Rowe
    v. Dror, 
    112 F.3d 473
    , 478 (Fed. Cir. 1997)). In Catalina, we identified several
    guideposts to aid in determining whether a preamble should be given limiting weight.
    For example, “clear reliance on the preamble during prosecution to distinguish the
    claimed invention from the prior art transforms the preamble into a claim limitation
    because such reliance indicates use of the preamble to define, in part, the claimed
    invention.” 
    Id.
     Absent clear reliance on the preamble in the prosecution history, or in
    situations where it is necessary to provide antecedent basis for the body of the claim,
    the preamble “generally is not limiting.” Id. at 809. Thus, in general, the purpose of a
    claim preamble is to give context for what is being described in the body of the claim; if
    it is reasonably susceptible to being construed to be merely duplicative of the limitations
    in the body of the claim (and was not clearly added to overcome a rejection), we do not
    construe it to be a separate limitation.
    2007-1201, -1239                               8
    Here, the only basis for the district court’s departure from the general rule was
    the notion that the “as it is being transferred” language was added separately from the
    “prior to storage” limitation to overcome the prior art. However, the district court erred in
    its description of the prosecution history. The prosecution history is clear that both
    terms were added concurrently to overcome the same prior art. The “as it is being
    transferred” language did not have its own independent significance. The prosecution
    history fails to demonstrate “clear reliance on the preamble during prosecution to
    distinguish the claimed invention from the prior art.” See id. at 808. 2
    CA argues alternatively that the district court’s construction was nonetheless
    correct because the “as it is being transferred” term and the “prior to storage” term
    cannot have the same meaning—they must each be given a distinct construction.
    Although CA is correct that when construing terms in the body of a claim, the general
    assumption is that different terms have different meanings, Applied Medical Resources
    Corp. v. United States Surgical Corp., 
    448 F.3d 1324
    , 1333 n.3 (Fed. Cir. 2006), the
    same generally is not true for terms in the preamble. The use of different language in
    the preamble than in the body of the claims does not suggest that the preamble
    imposes a limitation. Rather it is assumed that the preamble language is duplicative of
    the language found in the body of the claims or merely provides context for the claims,
    2
    CA also argues that the “prior to storage” requirement was already in the
    claim before amendment because the claim referred to “inhibiting the digital data of said
    transmission from being stored on said destination storage medium if at least one
    predefined sequence is present.” J.A. at 7439. Even if the original claim language could
    be construed to include the “prior to storage” limitation, the applicant chose not to rely
    on that language, and added additional specific “prior to storage” language to overcome
    the prior art. Under these circumstances, we must assume that the additional language
    had significance in distinguishing the prior art.
    2007-1201, -1239                             9
    absent any indication to the contrary in the claims, the specification or the prosecution
    history. Here, there is nothing in the claims, the specification or the prosecution history
    that suggests that the preamble language “as it is being transferred” has any different
    meaning than “prior to storage.” 3
    Indeed, if the term “as it is being transferred” is to be read consistently with our
    prior construction of the term “storage,” the claim term “as it is being transferred” can
    only mean that virus scanning occurs “prior to storage.” 4 Any other construction of that
    term would vitiate the meaning that we previously gave to the term “storage” in
    Hilgraeve I and Hilgraeve II. See Kimberly-Clark Corp. v. Fort Howard Paper Co., 
    772 F.2d 860
    , 863 (Fed. Cir. 1985) (“[S]tatements in opinions of this court must be read
    harmoniously with prior precedent, not in isolation.”). There would simply be no reason
    to construe “storage” to mean that scanning can occur after it is written to the computer
    but before it is accessible to other programs if the term “as it is being transferred”
    requires scanning to occur completely before any data is written to the computer.
    We conclude that the term “as it is being transferred” simply means “prior to
    storage.” Given our previous construction of the term “storage” in Hilgraeve II, the term
    “as it is being transferred” must mean “before the incoming digital data is sufficiently
    3
    CA relies on expert testimony that the preamble and the body of the claim
    should be interpreted as requiring separate limitations. That testimony does not,
    however, identify an accepted meaning in the field. To the extent that the testimony
    merely gives the expert’s opinion as to claim construction, we attribute it no weight. See
    Sinorgchem Co., Shandong v. Int’l Trade Comm'n, 
    511 F.3d 1132
    , 1137 n.3 (Fed. Cir.
    2007).
    4
    This appears to have been our assumption in Hilgraeve I, where we
    stated: “The claimed invention scans a body of data during its transfer, i.e., before
    storage of the data with potential viruses on the destination storage medium.” 
    224 F.3d at 1350
    .
    2007-1201, -1239                            10
    present on the destination storage medium and accessible by the operating system or
    other programs so that any viruses contained in the data can spread and infect the
    computer system.” 5 Under these circumstances, the language in the preamble does not
    impose a separate claim limitation.
    B
    Symantec also challenges the district court’s construction of the terms
    “computer” and “computer system.” The district court construed these terms to mean a
    “personal computer or workstation.” In doing so, the district court rejected Symantec’s
    proposed construction that “computer system” meant “any combination of hardware,
    software, documentation, and manual procedures that are combined to perform a
    specific function.”   J.A. at 16.   Based on the district court’s claim construction, the
    parties stipulated that the Gateway products do not infringe the asserted claims.
    The dispute here centers on whether the term “computer system” is properly
    limited to a single computer, or whether it covers a network of multiple computers. The
    district court explained that its construction limited the term “computer system” to a
    single personal computer or workstation. The district court premised its construction on
    the preferred embodiment’s use of a single computer, which as the court noted,
    “constitutes the complete description of the computer system.” The district court also
    relied on expert testimony that the term “computer system,” as used in the specification,
    referred to a single computer.
    5
    Although implicit in the requirement that the screening is performed on
    “incoming digital data,” we note that the claims do not cover methods of screening data
    for viruses before that data has left the source storage medium.
    2007-1201, -1239                            11
    On appeal, Symantec contends that the district court improperly limited the
    claims to cover only the preferred embodiment. The specification does not limit the
    invention to the preferred embodiment, and the ordinary meaning of the term “computer
    system,” according to Symantec, includes both a single computer and a system of
    multiple, interconnected computers.
    We agree with Symantec that the district court’s construction of the terms
    “computer” and “computer system” unduly limits the scope of the claims to a single
    personal computer. The claims “must be read in view of the specification, of which they
    are a part.” Phillips v. AWH Corp., 
    415 F.3d 1303
    , 1315 (Fed. Cir. 2005) (en banc). In
    Phillips, we characterized the specification as “the single best guide to the meaning of a
    disputed term.” 
    Id.
     We find nothing in the specification that would limit the meaning of
    the term “computer” or “computer system” to a single computer. The terms are not
    expressly defined in the specification, and there is nothing in the specification that
    suggests that it adopted a special definition of those terms. 6     Moreover, the expert
    testimony that the district court cites does not support the district court’s construction.
    That testimony simply recites how each expert would construe the term “computer
    system” based on his own reading of the specification. Such expert testimony, which
    does not identify the “accepted meaning in the field” to one skilled in the art, is
    unhelpful. Sinorgchem, 
    511 F.3d at
    1137 n.3 (according little or no weight to expert
    testimony about the meaning of specification terms where the expert failed to present
    6
    Although the preferred embodiment utilizes a single computer, this is not a
    case where the specification consistently refers to the invention as involving a single
    computer. See Ormco Corp. v. Align Tech., Inc., 
    498 F.3d 1307
    , 1313 (Fed. Cir. 2007).
    2007-1201, -1239                            12
    evidence of the generally accepted meaning of those terms to persons of ordinary skill
    in the art).
    Because the specification does not reveal any special definition for the terms
    “computer” or “computer system,” we must construe those terms according to their
    ordinary meaning. In Phillips, we explained that “the words of a claim ‘are generally
    given their ordinary and customary meaning.’” 415 F.3d at 1312. We clarified that the
    relevant meaning is “the meaning that the term would have to a person of ordinary skill
    in the art in question at the time of the invention.” Id. at 1313. Dictionaries are “among
    the many tools that can assist the court in determining the meaning of particular
    terminology to those of skill in the art of the invention.” Id. at 1318. Here, it is clear that
    the ordinary meaning of the terms “computer” or “computer system” as understood by a
    person of ordinary skill in the art at the time of the invention is not limited to a single
    computer or workstation. The Dictionary of Computing at that time defined the term
    “system,” in relevant part, as:
    Anything we choose to regard (a) as an entity and (b) as comprising a set
    of related components. In computing the word is widely used with many
    shades of meaning. Most commonly, however, it may refer to a related
    set of hardware units, or programs, or both. The hardware contents of a
    computer room may be spoken of as “the system,” and so may a range of
    manufacturer’s equipment[.]
    Dictionary of Computing 375 (2d ed. 1986). By contrast, the same dictionary defined
    the term “stand-alone” as “[d]enoting a computer system or subsystem that is capable of
    operation without being connected to any other computer system or subsystem.” Id. at
    360. In other words, a stand alone computer is only one type of computer or computer
    system. We therefore conclude that the ordinary meaning of the terms “computer” and
    “computer system” to one of ordinary skill in the art in 1990 was not limited to a single,
    2007-1201, -1239                              13
    stand-alone computer or workstation and that the district court erred by unduly limiting
    its construction of those terms.
    Because we find that the terms “computer” and “computer system” are not limited
    to a single computer, we must vacate and remand to the district court on the issue of
    infringement of CA’s Gateway products. Given our construction of these terms, on
    remand, the district court should determine whether the combination of computers used
    in the Gateway system performs all the claimed method steps.
    C
    Symantec also contends that the district court erred in construing the term
    “destination storage medium” to mean “a computer storage medium that is the target of
    the transfer of data as a result of the causing step.” This construction, when read
    together with the district court’s construction of the terms “computer” and “computer
    system,” which we rejected above, effectively limited the term “destination storage
    medium” to encompass only a storage system residing within a stand-alone computer,
    such as a computer’s hard drive. Such a limitation had the effect of excluding from the
    claim’s scope any peripheral devices, such as floppy drives or thumb drives.
    The district court reasoned that construing “destination storage medium” to
    include peripheral devices would be inconsistent with its construction of the term
    “computer system,” since such a construction would “permit the invention to operate
    outside of the computer system.”      J.A. at 18.   Under the correct construction of
    “computer system,” there is no reason that “destination storage medium” must be
    limited to a computer hard drive.     Under our construction of “destination storage
    medium,” peripheral devices, such as floppy drives and thumb drives, are properly
    2007-1201, -1239                          14
    within the scope of that term.    In addition, we note that the inclusion of peripheral
    devices within the scope of the term “destination storage medium” is consistent with the
    broad construction we gave that term in Hilgraeve II: “‘storage medium’ refers to any
    storage medium of the computer system, if the data, when stored on the medium, are
    accessible to the operating system or other programs, such that viruses in the data can
    spread and infect the computer system.” 265 F.3d at 1342 n.1.
    II
    Next, Symantec argues that the district court improperly granted summary
    judgment of non-infringement on the EAV products based on a finding that CA does not
    induce infringement of the ‘776 patent. The district court held that the EAV products
    failed to meet both the “as it is being transferred” claim limitation and the “causing a
    quantity of digital data resident on a source storage medium to be transferred” claim
    limitation. As we have already found that the former was based on an erroneous claim
    construction, we now need only address the latter claim limitation.
    Before the district court, there was no dispute that the EAV products do not
    “cause[] a quantity of digital data resident on a source storage medium to be
    transferred,” as required by claim 1.    Instead, as the district court found, the EAV
    products work in conjunction with a downloading or copying program, such as an
    internet browser. The EAV products perform the anti-virus scanning; the downloading
    program performs the downloading. Symantec argued that CA induces its customers to
    infringe the ‘776 patent by promoting its EAV products to be used in an infringing
    manner in conjunction with a downloading program. The district court rejected this
    2007-1201, -1239                           15
    argument. It held that Symantec could not establish active inducement because it did
    not show that any third party directly infringed the ‘776 patent using the EAV products.
    
    35 U.S.C. § 271
    (b) provides that “[w]hoever actively induces infringement of a
    patent shall be liable as an infringer.” “In order to succeed on a claim of inducement,
    the patentee must show, first that there has been direct infringement,” and “second, that
    the alleged infringer knowingly induced infringement and possessed specific intent to
    encourage another's infringement.” MEMC Elec. Materials, Inc. v. Mitsubishi Materials
    Silicon Corp., 
    420 F.3d 1369
    , 1378 (Fed. Cir. 2005) (quoting Minn. Mining & Mfg. Co. v.
    Chemque, Inc., 
    303 F.3d 1294
    , 1304-05 (Fed. Cir. 2002)). We recently clarified en
    banc that the specific intent necessary to induce infringement “requires more than just
    intent to cause the acts that produce direct infringement. . . . [T]he inducer must have an
    affirmative intent to cause direct infringement.” DSU Med. Corp. v. JMS Co., 
    471 F.3d 1293
    , 1306 (Fed. Cir. 2006) relevant section (en banc). Thus, “inducement requires
    evidence of culpable conduct, directed to encouraging another's infringement, not
    merely that the inducer had knowledge of the direct infringer's activities.” 
    Id.
    On appeal, Symantec asserts that it produced ample evidence to establish that
    the EAV products have no utility apart from screening downloaded or copied data files.
    That is, the EAV products operate only when a user downloads or copies a file onto his
    computer, and the downloading or copying must happen via a downloading or copying
    software program. In particular, Symantec points out that the EAV product manual
    establishes that CA promotes its use of the EAV product in combination with a
    downloading program in an infringing manner. The manual states that “[t]he Realtime
    Monitor scans programs on a workstation or server each time a file is executed,
    2007-1201, -1239                             16
    accessed, or opened.” J.A. at 6213. In its discussion of the internet, the manual states
    that “[t]he newest source of infections is the Internet. . . . This feature works with
    browsers from Netscape and Microsoft.” Id. at 6214. In response, CA maintains that
    Symantec has not shown any evidence of direct infringement because it has not shown
    that any CA customer actually performs all of the claimed method steps. Absent such a
    showing, CA contends that the district court properly granted summary judgment.
    We find that there are genuine issues of material fact as to whether CA induced
    its customers to infringe the ‘776 patent. We agree with Symantec that CA encouraged
    customers to engage in direct infringement by using the EAV products in conjunction
    with a downloading program. This is not a case where the customers may be using the
    product in either an infringing way or a non-infringing way; CA’s customers can only use
    the EAV products in an infringing way. Under these circumstances, Symantec has
    produced sufficient circumstantial evidence of direct infringement to create a genuine
    issue of material fact, even though Symantec has not produced evidence that any
    particular customer has directly infringed the ‘776 patent.        Direct evidence of
    infringement, as opposed to circumstantial evidence, is not necessary.             See
    Chiuminatta Concrete Concepts, Inc. v. Cardinal Indus., Inc., 
    145 F.3d 1303
    , 1312 (Fed.
    Cir. 1998) (finding that Cardinal's advertisements conceded the ability of the accused
    device to practice the claimed method, and encouraged such use); Moleculon Research
    Corp. v. CBS, Inc., 
    793 F.2d 1261
    , 1272 (Fed. Cir. 1986) (rejecting the argument that
    “proof of inducing infringement or direct infringement requires direct, as opposed to
    circumstantial evidence”).
    2007-1201, -1239                          17
    We therefore vacate and remand the district court’s summary judgment finding of
    non-infringement with respect to the EAV products. 7       On remand, the district court
    should consider whether the specific intent requirement set forth in DSU, which was
    decided after the grant of summary judgment in this case, was met.
    III
    On cross-appeal, CA challenges the district court’s summary judgment finding
    that the doctrine of laches does not bar Symantec’s recovery for CA’s alleged patent
    infringement prior to the filing of suit. At the outset, we dismiss CA’s laches claim as an
    improper cross-appeal.        “A party may cross-appeal if adversely affected by the
    appealed judgment in some particular which it seeks to have modified.” TypeRight
    Keyboard Corp. v. Microsoft Corp., 
    374 F.3d 1151
    , 1156 (Fed. Cir. 2004) (internal
    quotation marks omitted). A cross-appeal may only be filed “when a party seeks to
    enlarge its own rights under the judgment or to lessen the rights of its adversary under
    the judgment.” Bailey v. Dart Container Corp., 
    292 F.3d 1360
    , 1362 (Fed. Cir. 2002).
    Thus, a properly filed cross-appeal requires that, upon acceptance of appellee’s
    argument, our determination would result in a reversal or modification of the judgment
    rather than an affirmance. See 
    id.
     Here, the district court granted summary judgment
    of non-infringement on CA’s EAV products. CA argues on appeal that the doctrine of
    laches precludes Symantec from recovering damages on those products for any period
    before the filing of suit.   Thus, even if we were to agree with CA that laches precludes
    Symantec’s recovery over the EAV products, our determination would have no effect on
    7
    We note that the district court appeared to confuse the test for inducement
    with the test for the doctrine of equivalents. The two concepts are not related.
    2007-1201, -1239                             18
    the district court’s judgment.   We therefore dismiss as improperly filed CA’s laches
    cross-appeal. 8
    However, we may consider CA’s laches arguments as an alternative ground for
    sustaining the judgment of non-infringement. TypeRight Keyboard, 
    374 F.3d at 1160
    (“Even though we lack jurisdiction over the cross-appeal, [the appellee] may still defend
    the judgment on other grounds.”). We find that the district court did not err in dismissing
    CA’s laches defense on summary judgment.
    A defendant, in order to invoke the defense of laches, must prove: “(1) [that] the
    plaintiff delayed filing suit for an unreasonable and inexcusable length of time from the
    time the plaintiff knew or reasonably should have known of its claim against the
    defendant, and (2) [that] the delay operated to the prejudice or injury of the defendant.”
    A.C. Aukerman Co. v. R.L. Chaides Constr. Co., 
    960 F.2d 1020
    , 1032 (Fed. Cir. 1992)
    (en banc). A presumption of laches arises “upon proof that the patentee delayed filing
    suit for more than six years after actual or constructive knowledge of the defendant’s
    alleged infringing activity.” 
    Id. at 1035-36
    . We review a district court's determination on
    the issue of laches for an abuse of discretion. 
    Id. at 1039
    .
    The ‘776 patent issued to Hilgraeve on June 7, 1994.            In June 1995, an
    independent software company called Cheyenne Software began marketing a real-time
    antivirus software product called Inoculan. Hilgraeve sent a warning letter to Cheyenne
    dated October 5, 1996, regarding possible infringement. On November 6, 1996, CA
    8
    CA’s other cross-appeals, directed to inequitable conduct, invalidity over
    the prior art, and inventorship, are proper because they would expand the scope of the
    judgment. In TypeRight Keyboard, we explained that “where the appellee urges
    invalidity as a new ground on which to support a judgment of non-infringement . . . a
    2007-1201, -1239                            19
    acquired Cheyenne Software, and thereafter allegedly “re-branded” the Inoculan
    product into one of its eTrust antivirus products. Hilgraeve filed the present suit against
    CA on September 18, 2002, and, as discussed above, Symantec later acquired
    Hilgraeve’s interest in the ‘776 patent and was substituted as the plaintiff in the present
    suit.
    Before the district court, CA argued that Symantec should be charged with the
    period of delay attributable to Hilgraeve when it stepped in as the plaintiff in the present
    suit. CA asserted that Cheyenne’s open and notorious marketing of Inoculan in June
    1995 established Hilgraeve’s constructive knowledge of Cheyenne’s infringing use, and
    that, regardless, the October 5, 1996, warning letter established Hilgraeve’s actual
    knowledge of Cheyenne’s infringing use.          Finally, CA argued that by establishing
    Hilgraeve’s knowledge of Cheyenne’s alleged infringement, it was also establishing
    Hilgraeve’s knowledge with respect to the accused CA products at issue here, since CA
    “re-branded” the Inoculan product into one of its own.
    The district court held that Hilgraeve’s alleged knowledge of Inoculan, either
    constructive or actual, was insufficient as a matter of law to establish Hilgraeve’s
    knowledge of the alleged infringing CA products. In doing so, it did not reach the
    question of whether Symantec should be charged with Hilgraeve’s knowledge. Rather,
    it concluded that CA had failed to show evidence establishing that Inoculan was the
    same or similar to the products in suit. We agree that laches would only apply if the
    products were the same or similar, see Watkins v. Northwestern Ohio Tractor Pullers
    Association, Inc., 
    630 F.2d 1155
    , 1164 (6th Cir. 1980), and that CA has presented
    cross-appeal is necessary since a judgment of invalidity is broader than a judgment of
    2007-1201, -1239                            20
    insufficient evidence that Inoculan is the same or similar to any of the products in suit. 9
    On appeal, CA does not point to any such evidence but contends that Symantec’s
    October 5, 1996, warning letter to CA, urging that it had committed willful infringement,
    must be interpreted as an admission that Inoculan was a precursor to one of the CA
    products at issue here. We cannot agree. Willful infringement requires an objective
    showing that the alleged actions constituted infringement of a valid patent, “determined
    by the record developed in the infringement proceeding.” In re Seagate Tech., LLC,
    
    497 F.3d 1360
    , 1371 (Fed. Cir. 2007). An allegation of willful infringement does not
    assume any similarity between Inoculan and the products in suit. We therefore find that
    the district court did not err in granting summary judgment to Symantec on CA’s laches
    defense.
    IV
    Levin (and CA) asserts that he is an omitted co-inventor of the ‘776 patent. 10 To
    show co-inventorship, Levin is required to prove his contribution to the conception of the
    claims by clear and convincing evidence. See Ethicon, Inc. v. U.S. Surgical Corp., 
    135 F.3d 1456
    , 1461 (Fed. Cir. 1998). An alleged co-inventor’s testimony, standing alone,
    cannot rise to the level of clear and convincing evidence; he must supply evidence to
    corroborate his testimony.   
    Id.
     In Gemstar-TV Guide International, Inc. v. International
    Trade Commission, 
    383 F.3d 1352
     (Fed. Cir. 2004), we explained that “[w]hether the
    non-infringement.” 
    374 F.3d at
    1157 n.4.
    9
    Relying on an expert’s affidavit, CA asserts that the latest products at
    issue here utilize the same “antivirus engine technology” as that used in the original
    Inoculan product. This is hardly the same as demonstrating that the earlier product
    embodied the same claimed features as the accused product.
    10
    Levin licensed any interest he may have in the ’776 patent to CA.
    2007-1201, -1239                            21
    co-inventor's testimony has been sufficiently corroborated is evaluated under a ‘rule of
    reason analysis,’ which requires that an ‘evaluation of all pertinent evidence must be
    made so that a sound determination of the credibility of the inventor's story may be
    reached.’” Id. at 1382 (quoting Price v. Symsek, 
    988 F.2d 1187
    , 1195 (Fed. Cir. 1993)).
    Corroborating evidence may be in the form of “records made contemporaneously with
    the inventive process,” “[c]ircumstantial evidence of an independent nature,” or “oral
    testimony from someone other than the alleged inventor.” 
    Id.
    Before the district court, Levin submitted a declaration stating that he gave
    Matthew H. Gray (“Gray”), one of the named inventors of the ‘776 patent, the idea for
    the in-transit virus scan method in a February 12, 1990, telephone call. To corroborate
    his declaration, Levin submitted Gray’s day planner, which reflected Gray’s notes
    confirming that the disputed telephone call took place.         Levin points out that Gray
    testified that the day planner entry that reflected his conversation with Levin was
    “relat[ed] to the ’776 patent.” J.A. at 10,064. In addition, Levin relied on the lack of
    evidence showing Gray’s conception of the in-transit virus scan invention, which he
    argued further corroborated his own testimony.
    The district court found that the day planner entry was insufficient as
    corroborating evidence. That entry, according to the district court, “at most shows only
    that [Levin and Gray] discussed the then-current state of the art”; it “fail[ed] to explicitly
    identify [Levin’s] contribution.” J.A. at 87-88. We agree with the district court that, at
    most, the day planner entry establishes that Gray and Levin spoke about the then-
    current state of anti-virus programs; it does not establish that Levin contributed to the
    idea. That entry, listing an “IBM SCAN program,” a “Computer Virus Handbook,” “Jim
    2007-1201, -1239                             22
    McAffey’s Virus Scan,” and “Levin’s Checkup Antivirus System,” J.A. at 1841, suggests
    only that Gray simply called Levin to discuss the state of the prior art.
    The district court also found that any evidence tending to call into question Gray’s
    contribution to the invention was irrelevant to the question of whether Levin made any
    contribution. Again, we agree with the district court that the evidence regarding Gray’s
    contribution was not relevant to the question of Levin’s contribution. This is particularly
    so because Gray was not the sole inventor here; even though he may have lacked
    technical expertise, there is no suggestion that his co-inventors also lacked any
    technical expertise. This case is thus distinguishable from Ethicon, where we held that
    a sole inventor’s lack of technical expertise corroborated another’s claim of co-
    inventorship. 
    135 F.3d at 1464-65
    .
    Levin’s declaration itself is insufficient because it lacks corroboration.      We
    therefore affirm the district court’s conclusion that Levin has failed to establish a
    genuine issue of material fact that he was a co-inventor of the ’776 patent.
    V
    CA appeals the district court’s summary judgment determination that Hilgraeve
    did not commit inequitable conduct before the Patent Office in procuring the ’776 patent.
    CA alleges that Hilgraeve made three separate false and material misrepresentations to
    the Patent Office: (1) Gray’s April 18, 1990, declaration that he was an inventor of the
    ’776 patent; (2) Gray’s August 12, 1990, declaration to overcome prior art; and (3) co-
    inventor Donald Wakelin’s April 18, 1990, declaration that he understood the claims of
    the patent application.
    2007-1201, -1239                             23
    Patent applicants “have a duty to prosecute patent applications in the Patent
    Office with candor, good faith, and honesty.” Honeywell Int’l Inc. v. Universal Avionics
    Sys. Corp., 
    488 F.3d 982
    , 999 (Fed. Cir. 2007).        A breach of this duty constitutes
    inequitable conduct and renders the entire patent unenforceable.         
    Id.
       In order to
    establish inequitable conduct, the party challenging the patent is required to establish by
    clear and convincing evidence that the patent applicant “(1) either made an affirmative
    misrepresentation of material fact, failed to disclose material information, or submitted
    false material information, and (2) intended to deceive the U.S. Patent and Trademark
    Office.” Cargill, Inc. v. Canbra Foods, Ltd., 
    476 F.3d 1359
    , 1363 (Fed. Cir. 2007).
    “Once threshold findings of materiality and intent are established, the trial court must
    weigh them to determine whether the equities warrant a conclusion that inequitable
    conduct occurred.” Purdue Pharma L.P. v. Endo Pharmaceuticals Inc., 
    438 F.3d 1123
    ,
    1128 (Fed. Cir. 2006).
    Information is material when “a reasonable examiner would consider it important
    in deciding whether to allow the application to issue as a patent.” eSpeed, Inc. v.
    BrokerTec USA, L.L.C., 
    480 F.3d 1129
    , 1136 (Fed. Cir. 2007) (quoting A.B. Dick Co. v.
    Burroughs Corp., 
    798 F.2d 1392
    , 1397 (Fed. Cir. 1986)). Moreover, we have found that
    “[f]alse statements are more likely material when embodied in declarations or affidavits
    submitted to the PTO.” 
    Id.
    CA’s first inequitable conduct claim arises out of the April 18, 1990, declaration
    that Gray signed and submitted with the patent application that led to the ‘776 patent. In
    the declaration, Gray submitted that he was “an original, first and joint inventor . . . of
    the subject matter which is claimed and for which a patent is sought.” J.A. at 1828-30.
    2007-1201, -1239                            24
    CA asserts that Gray’s declaration was a false statement because the idea for the in
    transit virus-detection method was Levin’s. Even if Levin somehow contributed to the
    invention (which, as noted above, has not been established), that fact alone would not
    establish that Gray did not also contribute to the invention. CA also relies on Gray’s
    inability at trial to identify with specificity the contribution that he made to the invention.
    We agree with the district court that Gray’s inability to identify with precision his
    contribution, nearly fourteen years later, does not show anything more than that Gray
    simply could not recall, particularly since Gray and a co-inventor, John Hile, both
    testified in general terms that Gray came up with the idea. 11 Finally, CA contends that
    Gray’s lack of technical expertise establishes that Gray was not an inventor.                We
    disagree. Gray was not the sole inventor of the claimed method. Indeed, Gray worked
    with the other inventors who did have technical expertise to design the invention. For
    these reasons, we find that the district court did not err in granting summary judgment
    that CA has failed to present a genuine issue of material fact that Gray was not the
    inventor.
    CA’s second inequitable conduct claim arises from an August 12, 1992,
    declaration submitted by Gray to the PTO in response to an office action.                Gray’s
    declaration was submitted together with a number of prior art references.                 In the
    declaration, Gray described the state of the prior art with specific reference to the
    attached publications and identified the “significant advantages over the existing virus
    11
    CA appears to argue that Gray testified that the notes in the day planner
    described the invention, and that, since the notes summarized the Levin telephone call,
    the idea must have originated with Levin. Gray’s testimony, however, was that the day
    planner entry was evidence of the date of conception, and not of the idea itself.
    2007-1201, -1239                               25
    scanning, detecting and eliminating software” that his invention achieved. J.A. at 3866.
    In paragraph 1 of the declaration, Gray stated that he “ha[d] practiced in the field of
    computer software and, more particularly, in the area of computer communications
    software for 10 years . . . [and that a]s a consequence, [Gray had] become intimately
    familiar with the state of the art as it relates to computer viruses, computer virus
    detection, and computer virus prevention.” Id. at 3863. CA claims that this declaration
    was false and misleading, because Gray was a marketing person, not a software
    person with technical expertise.
    CA does not assert that the substance of the declaration itself was either false or
    misleading. The sole argument is that Gray’s description of his own qualifications is
    misleading. The district court found that Gray’s lack of technical expertise alone was
    insufficient to establish that his declaration was a misrepresentation. We agree. There
    is nothing in the record that indicates that Gray was not “intimately familiar with the state
    of the art,” and the mere fact that he was not a technical person does nothing to refute
    that. 12
    CA also relies on paragraph 4 of that declaration, where Gray stated that he “set
    out to develop an algorithm which would determine whether a file was infected with a
    virus during [a] transfer and to stop the transfer before the virus was copied into the
    system.” Id. at 3864. CA asserts that this claim was also false and misleading, since
    12
    When questioned as to whether “[s]itting here today, [Gray had] any
    knowledge concerning the state of the art in connection with computer software design
    and development,” Gray stated: “I don’t believe there’s any point in time when I would
    have been so bold as to claim I had knowledge of the state of the art of anything.” J.A.
    at 9993. We do not read that statement as contradicting the statement he made in the
    declaration concerning his earlier knowledge of virus screening technology, but rather to
    relate to his lack of knowledge of computer software design and development generally.
    2007-1201, -1239                               26
    Gray later testified that he did not develop the mathematical algorithm, but rather that
    one of the co-inventors, Donald Wakelin, developed the algorithm. Gray’s assertion that
    he “set out to develop an algorithm” is not the same as asserting that he actually
    developed the algorithm himself. Again, we see no basis for a misrepresentation claim.
    We conclude that CA has not established a genuine question of material fact that Gray’s
    August 12, 1992, declaration was false or misleading.
    CA’s final inequitable conduct claim arises from Wakelin’s April 18, 1990,
    declaration submitted with the original application, where he stated that he had
    “reviewed and underst[ood] the contents of the . . . specification, including the
    claims . . . .” Id. at 1828. That declaration, according to CA, was false and misleading
    because Wakelin allegedly did not understand the claims of the patent.              Instead,
    Wakelin testified that he only understood the claims in general terms, that “the
    statements in claim one are so vague as to be practically unintelligible,” id. at 10006,
    and that he didn’t “really understand what these claims are saying.” Id. at 10007. The
    district court found that, even if Wakelin did not fully understand the claims of the patent,
    that alone was not sufficient to establish a threshold level of materiality. We agree. As
    the district court stated, “Wakelin’s failure to fully understand the language of the claim
    contents should not be confused for failure to understand the meaning of the claims,
    which would likely be considered material by a ‘reasonable examiner.’” Id. at 124.
    VI
    Finally, we must address CA’s counterclaims for invalidity. Our constructions of
    the terms “computer,” “computer system,” and “destination storage medium” require us
    to vacate and remand the district court’s summary judgment finding that the Photonix
    2007-1201, -1239                             27
    and the Mac prior art references did not render the claims invalid. This is because the
    same    construction    governs     for    validity   determinations   as   for   infringement
    determinations. Yoon Ja Kim v. ConAgra Foods, Inc., 
    465 F.3d 1312
    , 1324 (Fed. Cir.
    2006). Here, the district court distinguished the ’776 patent claims over Photonix and
    the Mac prior art based on the conclusion that both of these antivirus programs ran on
    an Apple II GS computer, which itself only used peripheral devices (i.e., a floppy drive)
    because it did not include a hard drive. 13 The district court also concluded, with respect
    to the invalidity of the claims based on the Mac prior art, that “the Macintosh programs
    do not store the actual screened digital data after screening, but only a reference to the
    screened data,” and therefore did not meet the claim limitation “automatically store the
    transferred digital data.” J.A. at 184-85. The district court’s decision in this respect is
    somewhat unclear as are the parties’ briefs on this point. The district court’s holding
    may well be intertwined with its holding that the Apple II GS computer, on which the
    Mac programs operated, did not have a destination storage medium.                  Under the
    circumstances, we decline to address the issue at this time. Hopefully the nature of the
    district court’s decision will be clarified on remand.
    CONCLUSION
    We hold that the district court erred in its construction of the claim terms “a
    method of screening data as it is being transferred,” “destination storage medium,”
    “computer,” and “computer system.”          We therefore vacate and remand as to non-
    infringement and invalidity. We affirm the district court’s decision on laches, inequitable
    conduct, and inventorship.
    13
    The district court appeared not to address claims 18-20, and on remand
    2007-1201, -1239                               28
    The judgment of the district court is AFFIRMED-IN-PART and VACATED-IN-
    PART and REMANDED.
    No costs.
    should treat them separately.
    2007-1201, -1239                      29