Rambus Inc. v. Rea , 731 F.3d 1248 ( 2013 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    RAMBUS INC.,
    Appellant,
    v.
    TERESA STANEK REA, Acting Director, United
    States Patent and Trademark Office,
    Appellee.
    ______________________
    2012-1634
    ______________________
    Appeal from the United States Patent and Trademark
    Office, Board of Patent Appeals and Interferences in
    Reexamination No. 95/001,134.
    ______________________
    Decided: September 24, 2013
    ______________________
    JAMES R. BARNEY, Finnegan, Henderson, Farabow,
    Garrett & Dunner, LLP, of Washington, DC, argued for
    appellant. With him on the brief were J. MICHAEL JAKES
    and MOLLY R. SILFEN.
    WILLIAM LAMARCA, Associate Solicitor, United States
    Patent and Trademark Office of Alexandria, Virginia,
    argued for appellee. With him on the brief were NATHAN
    K. KELLEY, Deputy Solicitor, and COKE MORGAN STEWART,
    Associate Solicitor.
    2                                       RAMBUS INC.   v. REA
    ______________________
    Before MOORE, LINN, and O’MALLEY, Circuit Judges.
    MOORE, Circuit Judge.
    Rambus Inc. appeals from the decision of the Board of
    Patent Appeals & Interferences (Board) holding invalid
    various claims of 
    U.S. Patent No. 6,260,097
     (’097 patent)
    for anticipation and obviousness. Rambus challenges the
    Board’s claim construction and its obviousness decision.
    Because the Board correctly construed the claims but
    erred in its obviousness decision, we affirm-in-part,
    vacate-in-part, and remand.
    BACKGROUND
    This case relates to memory circuits known as dynam-
    ic random-access memory (DRAM). Conventional memory
    circuits transfer all of the data upon request, asynchro-
    nously. Each transfer can tie up the computer system for
    extended periods of time and create a “bottleneck” that
    slows down computer operations.
    The ’097 patent solves this problem using a synchro-
    nous memory system to transfer the data. In synchronous
    systems, a clock signal that alternates between a digital
    value of 0 and 1 synchronizes the operations within the
    system. The change in the clock signal from a 0 to a 1 is
    referred to as the “rising edge” of the clock, and the
    change in the signal from a 1 to a 0 is referred to as the
    “falling edge” of the clock. Figure 14 of the ’097 patent
    depicts an exemplary clock signal:
    In conventional synchronous memory systems, the da-
    ta transmitted to the memory ties up the system for a full
    cycle of the clock signal. In contrast, the ’097 patent
    RAMBUS INC.   v. REA                                     3
    claims what Rambus refers to as the “dual-edge / double-
    data-rate” functionality because the system transfers data
    at twice the rate by employing both the rising and falling
    edges of the clock signal. Specifically, the invention
    separates the data into multiple portions and then trans-
    fers a portion during the rising edge of the clock signal
    and a portion during the falling edge of the clock signal.
    ’097 patent, at [57]. Claim 1 of the ’097 patent is repre-
    sentative of the claims at issue:
    A method of controlling a synchronous memory
    device . . . compris[ing]:
    issuing a write request to the memory device . . . ;
    providing a first portion of data to the memory
    device synchronously with respect to a rising edge
    transition of an external clock signal; and
    providing a second portion of data to the memory
    device synchronously with respect to a falling
    edge transition of the external clock signal.
    ’097 patent claim 1 (emphases added). The United States
    Patent and Trademark Office (PTO) initiated an inter
    partes reexamination of the ’097 patent claims and ulti-
    mately found that the reexamined claims were not pa-
    tentable over two references: Unexamined Japanese
    Patent Application No. 56-88987 (Inagaki) and the Intel
    iAPX system manual and specification (iAPX).
    The following facts regarding Inagaki and iAPX are
    not in dispute. Inagaki discloses a memory system that
    transmits one bit during each half-cycle of the external
    clock. J.A. 2955–58. The half-cycle system disclosed in
    Inagaki is a modification of a conventional full-cycle
    system. 
    Id.
     Inagaki achieves the half-cycle functionality
    by generating two clock signals based on the rising and
    falling edge of the external clock. 
    Id.
     The two internal
    clock signals, in turn, synchronize the transfer of data
    during the two halves of the system clock cycle. 
    Id.
    4                                         RAMBUS INC.   v. REA
    The iAPX manual and specification disclose a system
    that transfers data based on the rising or falling edges of
    two system clocks. J.A. 3285, 3331. The system, howev-
    er, utilizes the full clock cycle for each data transfer. 
    Id.
    Thus, because the iAPX system employs a full clock cycle
    to transfer data to the memory device, the system cannot
    use both edges of the clock signal to synchronize the
    transfer of data portions to memory. However, Inagaki
    discloses a mechanism for converting a conventional full-
    cycle system into a half-cycle system. J.A. 2955–58.
    The examiner rejected claims 1, 2, 7, 8, 10, and 14 as
    anticipated by Inagaki and rejected claims 1–5, 7, 8, 10–
    12, 14, 26, 28–32, and 35 as obvious in light of the iAPX
    system in view of Inagaki. The Board upheld the examin-
    er’s rejections. Rambus appeals. We have jurisdiction
    under 
    28 U.S.C. § 1295
    (a)(4)(A).
    DISCUSSION
    I. Applicable Law
    We review the Board’s factual findings for substantial
    evidence and its legal conclusions de novo. In re Kotzab,
    
    217 F.3d 1365
    , 1369 (Fed. Cir. 2000). Whether a claim
    would have been obvious under 
    35 U.S.C. § 103
    (a) is a
    legal conclusion based on underlying factual determina-
    tions. 
    Id.
     The factual determinations include (1) the
    scope and content of the prior art; (2) the differences
    between the claims and the prior art; (3) the level of
    ordinary skill in the art; and (4) objective evidence of
    nonobviousness. Graham v. John Deere Co. of Kansas
    City, 
    383 U.S. 1
    , 17–18 (1966). “[W]hether there is a
    reason to combine prior art references is a question of
    fact.” Kinetic Concepts, Inc. v. Smith & Nephew, Inc., 
    688 F.3d 1342
    , 1367 (Fed. Cir. 2012).
    “[C]laim construction by the PTO is a question of law
    that we review de novo . . . .” In re Baker Hughes Inc., 
    215 F.3d 1297
    , 1301 (Fed. Cir. 2000). “While claims are
    RAMBUS INC.   v. REA                                     5
    generally given their broadest possible scope during
    prosecution, the Board’s review of the claims of an expired
    patent is similar to that of a district court’s review.” In re
    Rambus Inc., 
    694 F.3d 42
    , 46 (Fed. Cir. 2012) (citations
    omitted).
    II. Anticipation
    The Board upheld the examiner’s finding that Inagaki
    anticipates a number of the ’097 patent claims. As part of
    that decision, the Board construed the terms “external
    clock signal” and “write request.” Rambus challenges the
    Board’s construction of these claim terms.
    A. “External Clock Signal”
    The Board held that the “external clock signal” only
    requires the clock to be periodic during the data input
    phases, as opposed to being periodic for all system opera-
    tions. Rambus, Inc. v. Nvidia Corp., No. 2012-000171
    (B.P.A.I. June 11, 2012) (“Board Opinion”). It reached
    this construction based on the established industry mean-
    ing of the term “clock” and the failure of the specification
    to disclose “a computer clock that runs forever or that
    cannot be turned off.” 
    Id. at 7-8
    .
    Rambus contends that the intrinsic record requires
    the “external clock signal” to be continuously periodic. It
    argues that the claims contain this requirement because
    they recite a “synchronous memory device,” and a clock
    signal synchronizes all operations in a synchronous
    device.   Rambus contends that, consistent with the
    claims, the specification only discloses a periodic clock
    signal. Lastly, Rambus argues that, during prosecution of
    a related patent, the inventors distinguished the prior art
    on the basis that it did not teach a periodic clock signal.
    The PTO counters that the claim language requires
    only that the memory device receive data “synchronously
    with respect to a rising edge transition” and the “falling
    edge transition” of “an external clock signal.” According
    6                                         RAMBUS INC.   v. REA
    to the PTO, this language shows that the “external clock
    signal” synchronizes data transfer and need not be period-
    ic for all time.
    We agree with the PTO. The claimed clock signal
    synchronizes data transfer to the memory device. The
    claimed method provides a first portion of data “synchro-
    nously with respect to a rising edge transition of an
    external clock signal” and then provides a second portion
    of data “synchronously with respect to a falling edge
    transition of the external clock signal.” ’097 patent claim
    1. Thus, while the “external clock signal” must be period-
    ic during data transfer, nothing in the claim language
    requires the signal to be periodic for all time. The specifi-
    cation also shows that the external clock signal is periodic
    during the transfer of data. 
    Id.
     fig. 14. Nothing in the
    specification limits the external clock signal to a clock
    that is periodic for all time. Nor does the prosecution
    history upon which Rambus relies require a narrower
    construction. There, consistent with the plain language of
    the claims, the inventors explained that the “external
    clock signal” is “a periodic signal used to orchestrate
    timing events.” J.A. 2700 n.2 (emphasis omitted). Ac-
    cordingly, we conclude that the Board properly construed
    the term “external clock signal.”
    B. “Write Request”
    The Board concluded that the claimed “write request”
    could include “the state of a signal,” which is usually
    represented by a single bit. Board Opinion at 11–13. The
    Board held that its construction comported with our
    holding in a prior case involving the same family of pa-
    tents as the ’097 patent, Rambus Inc. v. Infineon Technol-
    ogies AG, 
    318 F.3d 1081
    , 1093 (Fed. Cir. 2003). In that
    case, we construed the term “write request” to mean “a
    series of bits used to request a write of data.” 
    Id.
    Rambus argues that the Board erroneously construed
    “write request” to cover conventional, transition-based
    RAMBUS INC.   v. REA                                    7
    control signals and disregarded our construction from
    Infineon. It asserts that the specification clearly shows
    that a “write request” includes multiple bits because each
    request carries at least two pieces of information.
    The PTO responds that the Board properly declined to
    limit the term “write request” to a sequence of multiple
    bits. It argues that the plain and ordinary meaning of the
    term allows for a one-bit signal. The PTO also points to
    the specification’s disclosure of an embodiment in which a
    single bit determines whether the system requests a read
    operation or a write operation. Lastly, the PTO argues
    that the Board’s construction is not inconsistent with the
    construction in Infineon because that case did not decide
    if such a “series of bits” could include one bit or a signal.
    We agree with the PTO that the Board correctly con-
    strued “write request.” As an initial matter, we do not
    find that the Board disregarded our construction in In-
    fineon. In Infineon, the dispute centered on the accused
    infringer’s contention that the claimed “request” must
    include both address and control information. 
    318 F.3d at 1091
    . We rejected that argument. 
    Id.
     at 1091–93. At no
    point did we resolve the claim-scope dispute presented in
    this appeal: whether the “write request” can be a single
    bit. Indeed, it appears that the parties in Infineon did not
    dispute the “series of bits” portion of the district court’s
    claim construction, 
    id.
     at 1091–92, and we generally
    “decline to raise an issue sua sponte that the parties have
    not presented,” WMS Gaming Inc. v. Int’l Game Tech.,
    
    184 F.3d 1339
    , 1347 n.2 (Fed. Cir. 1999).
    We conclude that “write request” is not limited to a
    multiple-bit request. The plain language of the claim
    does not contain that requirement. The claims require a
    “write request” be issued to the memory device and that,
    in response to the request, the device sample portions of
    data. ’097 patent claim 1. Moreover, the specification
    expressly discloses that “write request” can be embodied
    8                                         RAMBUS INC.   v. REA
    in a single bit. ’097 patent col. 9 ll. 38–64. The specifica-
    tion discloses a preferred embodiment in which a single
    bit acts as a “Read/Write switch”: if its value is a 1, the
    system requests a read; if its value is a 0, the system
    requests a write. 
    Id.
     “A claim construction that excludes
    the preferred embodiment ‘is rarely, if ever, correct and
    would require highly persuasive evidentiary support.’”
    Adams Respiratory Therapeutics, Inc. v. Perrigo Co., 
    616 F.3d 1283
    , 1290 (Fed. Cir. 2010) (quoting Vitronics Corp.
    v. Conceptronic, Inc., 
    90 F.3d 1576
    , 1583–84 (Fed. Cir.
    1996)). There is no such evidentiary support here, and
    Rambus points to nothing in the intrinsic record that
    limits the claims to multi-bit requests. We conclude that
    the Board properly construed “write request.”
    *****
    Because the Board correctly construed the “external
    signal” and “write request” limitations, we affirm the
    Board’s finding that Inagaki anticipates claims 1, 2, 7, 8,
    10, and 14 of the ’097 patent.
    III. Obviousness
    The Board held that the reexamined claims would
    have been obvious in view of iAPX in combination with
    Inagaki. The Board concluded that one of skill in the art
    could have modified the existing circuitry in the iAPX
    system to use both edges of the clock signal to transfer
    data at twice the rate based on Inagaki. Board Opinion at
    21–28. The Board’s particular findings, however, differed
    from those of the examiner. The examiner found that one
    of skill in the art would have been motivated to modify
    the iAPX system to transfer data on both the rising and
    falling edges of the clock signal because the system “does
    not show that all edges are used.” J.A. 1113. All parties
    appear to agree on appeal that this fact finding was
    erroneous and that iAPX employs both the rising and
    falling edges.
    RAMBUS INC.   v. REA                                       9
    The Board found that a skilled artisan “easily could
    have modified the iAPX system in view of Inagaki’s clock-
    ing scheme by dropping, instead of replacing, many
    functions.” Board Opinion at 24. It found that a skilled
    artisan could have achieved data transfer on both clock
    edges by using a slower clock in Inagaki as a “trigger” for
    the faster clocks disclosed in iAPX. 
    Id.
     at 24–25. The
    Board provided a number of reasons why skilled artisans
    would modify the iAPX system to hold data for less than
    one full cycle, enabling it to transfer data on both the
    rising and falling edges of its clocks. 
    Id.
     at 25–27.
    The Board then addressed Rambus’s objective evi-
    dence of nonobviousness, concluding that it lacked a
    nexus to the ’097 patent claims. 
    Id.
     at 28–32. The Board
    found that Rambus’s evidence was not commensurate
    with the scope of the claims and related to claim limita-
    tions that were disclosed in the prior art. 
    Id.
     The Board
    found that Rambus’s licensing evidence lacked a nexus
    because “it is well established that competitors have
    many reasons for taking licenses which are not necessari-
    ly related to unobviousness (i.e., litigation costs, etc.).” Id.
    at 30.
    Rambus argues that the Board erred in its obvious-
    ness decision. It contends that the Board erroneously
    placed the burden on Rambus to demonstrate nonobvi-
    ousness. It asserts that, rather than rely on the examin-
    er’s flawed findings, the Board relied on unsubstantiated
    conjecture that one could combine iAPX and Inagaki into
    an operable system. Rambus contends that the reference
    actually teaches away from using both clock edges to
    transfer data. It argues that strong objective evidence of
    nonobviousness, including praise for the dual-edge func-
    tionality in industry publications and the licensing of the
    ’097 patent, supports a conclusion that the claims would
    not have been obvious.
    10                                       RAMBUS INC.   v. REA
    The PTO counters that the Board properly held that
    the claims would have been obvious. It contends that the
    only claim limitation that iAPX does not disclose is the
    synchronous writing of data to memory during the rising
    and falling edges of a clock signal. It argues that Inagaki
    expressly discloses that missing feature. The PTO argues
    that a skilled artisan would have combined iAPX and
    Inagaki because, even if the combination required further
    modifications to the combined system, both references
    seek to increase the speed and efficiency of memory-
    writing operations. Regarding Rambus’s arguments that
    the Board improperly relied on its own conjecture, the
    PTO asserts that the Board is entitled to make its own
    fact findings when interpreting prior art references and is
    permitted to rely on common sense.
    The PTO contends that Rambus’s objective evidence of
    nonobviousness cannot overcome the strong showing of
    obviousness. It asserts that Rambus’s evidence lacks a
    nexus to the ’097 patent claims because the claims do not
    require a specific clock speed. The PTO further argues
    that Rambus’s patent licenses were not cogent evidence of
    commercial success because they involved a portfolio of
    patents, not simply the ’097 patent. It argues that Ram-
    bus never showed that the value exchanged in the licens-
    es was tied to the value of the invention claimed in the
    ’097 patent, as opposed to the other patents in the portfo-
    lio or the licensees’ desire to avoid litigation costs.
    We agree with Rambus that the Board committed
    multiple errors in its obviousness decision. Due to these
    errors, we vacate the Board’s decision and remand for
    further proceedings. We address each of these errors
    below.
    A. Burden of Proof
    The Board erroneously placed the burden on Rambus
    to prove that its claims were not obvious. In reexamina-
    tion proceedings, “a preponderance of the evidence must
    RAMBUS INC.   v. REA                                   11
    show nonpatentability before the PTO may reject the
    claims of a patent application.” Ethicon, Inc. v. Quigg,
    
    849 F.2d 1422
    , 1427 (Fed. Cir. 1988); see also In re Jung,
    
    637 F.3d 1356
    , 1365–66 (Fed. Cir. 2011) (explaining that
    while “the applicant must identify to the Board what the
    examiner did wrong, . . . the examiner retains the burden
    to show invalidity”). The Board instead concluded that
    “Rambus ha[d] not demonstrated that skilled arti-
    sans . . . would not have been able to arrive at the broadly
    claimed invention.” Board Opinion at 27; see also id. at
    24 (holding that “Rambus fail[ed] to present evidence that
    skilled artisans would have been unable to modify” iAPX
    to achieve the claimed invention). That was legal error.
    B. New Fact Findings
    The Board also exceeded its limited role to “review of
    the examiner’s decisions during prosecution.” In re Ste-
    pan Co., 
    660 F.3d 1341
    , 1344 (Fed. Cir. 2011). Under the
    Administrative Procedure Act, the PTO must ensure that
    the parties before it are “fully and fairly treated at the
    administrative level.” In re Leithem, 
    661 F.3d 1316
    , 1319
    (Fed. Cir. 2011). Namely, the PTO must “provide prior
    notice to the applicant of all ‘matters of fact and law
    asserted’ prior to an appeal hearing before the Board.”
    Stepan, 
    660 F.3d at 1345
     (quoting 
    5 U.S.C. § 554
    (b)(3)).
    This framework limits the Board’s ability to rely on
    different grounds than the examiner. The Board may not
    “rel[y] on new facts and rationales not previously raised to
    the applicant by the examiner.” Leithem, 
    661 F.3d at 1319
    . Of course, the Board is not required to “recite and
    agree with the examiner’s rejection in haec verba” in order
    to ensure that the PTO has provided adequate notice. 
    Id.
    And the Board may elaborate on the examiner’s findings,
    so long as the appellant had an adequate opportunity to
    respond to the Board’s findings during the PTO proceed-
    ing. In re Adler, 
    723 F.3d 1322
    , 1328 (Fed. Cir. 2013).
    The ultimate criterion is whether the appellant has had
    12                                       RAMBUS INC.   v. REA
    before the PTO a “fair opportunity to react to the thrust of
    the rejection.” Jung, 
    637 F.3d at 1365
     (quoting In re
    Kronig, 
    539 F.2d 1300
    , 1302–03 (CCPA 1976)) (internal
    quotation marks omitted). If that condition is not met,
    the Board must designate its decision a new ground of
    rejection and provide the appellant with an opportunity to
    respond.    See Stepan, 
    660 F.3d at 1346
    ; 
    37 C.F.R. § 41.77
    (b). Failure to do so violates the appellant’s notice
    rights and warrants vacatur of the Board’s decision.
    Stepan, 
    660 F.3d at 1346
    . Whether the Board relied on a
    new ground of rejection is a legal issue that we review de
    novo. 
    Id. at 1343
    .
    The Board erred when it supplied its own reasons to
    combine iAPX and Inagaki. The examiner issued a specif-
    ic finding—that one of skill in the art would have been
    motivated to modify the iAPX system to transfer data on
    both the rising and falling edges of the clock signal be-
    cause the system “does not show that all edges are used.”
    J.A. 1113. The PTO does not dispute that this finding
    was erroneous. iAPX quite clearly employed both the
    rising and falling edges of the clock signal. Recognizing
    this problem, the Board instead found that a skilled
    artisan would have been able to drop functionality that
    iAPX discloses as occurring during the rising and falling
    edges of the clock. Board Opinion at 23–24. It also pro-
    vided additional ways to combine iAPX and Inagaki to
    create a half-cycle system that could transfer data on both
    the rising and falling edges of its clocks. 
    Id.
     at 24–27.
    These findings were completely new; the Board did not
    elaborate on the examiner’s findings with “more detail.”
    See Adler, 723 F.3d at 1328. While the Board’s findings
    may ultimately be correct, we will not affirm a Board
    rejection, like this one, which essentially provides a new
    motivation to combine the references.
    The Board has a procedure for issuing a new ground
    of rejection in appeals of inter partes reexaminations. 
    37 C.F.R. § 41.77
    (b). This procedure ensures that appellants
    RAMBUS INC.   v. REA                                  13
    have an appropriate opportunity to respond and, if neces-
    sary, supplement the record before the examiner. We
    cannot let the Board shortcut this procedure and deprive
    appellants of their due process rights. To be clear, we are
    not passing judgment on the merits of the Board’s find-
    ings regarding the motivation to combine.
    C. Objective Evidence of Nonobviousness
    We also agree with Rambus that the Board erred in
    its treatment of objective evidence of nonobviousness.
    Such objective evidence can establish that “an invention
    appearing to have been obvious in light of the prior art
    was not.” Stratoflex, Inc. v. Aeroquip Corp., 
    713 F.2d 1530
    , 1538 (Fed. Cir. 1984). In some cases, that evidence
    is “the most probative and cogent evidence in the record.”
    
    Id.
     It helps “turn back the clock and place the claims in
    the context that led to their invention.” Mintz v. Dietz &
    Watson, Inc., 
    679 F.3d 1372
    , 1378 (Fed. Cir. 2012). “For
    objective evidence . . . to be accorded substantial weight,
    its proponent must establish a nexus between the evi-
    dence and the merits of the claimed invention.” In re Kao,
    
    639 F.3d 1057
    , 1068 (Fed. Cir. 2011) (quoting Wyers v.
    Master Lock Co., 
    616 F.3d 1231
    , 1246 (Fed. Cir. 2010))
    (emphasis omitted) (internal quotation marks omitted).
    The Board erred when it found that Rambus’s objec-
    tive evidence of nonobviousness lacked a nexus because it
    related to unclaimed features. Rambus presented uncon-
    tested evidence of long-felt need and industry praise due
    to the claimed dual-edge data transfer functionality
    claimed in the ’097 patent. For example, an article in the
    Microprocessor Report stated that Rambus “ha[d] un-
    veiled its radical new processor-to-memory interface and
    DRAM architecture, which promise to create the most
    significant change in processor/memory system architec-
    ture since the introduction of the DRAM two decades
    ago.” J.A. 2633. The article explains that the technology
    “operat[es] with a 250-MHz clock and transfer[s] a byte of
    14                                       RAMBUS INC.   v. REA
    data on each clock edge,” an approach that was “some-
    what counter-intuitive.” 
    Id.
     A press release issued by
    Micron Technology, Inc., a Rambus competitor, referred to
    the dual-edge data transfer functionality as a “revolution-
    ary and pioneering technology” that “vastly improv[ed]”
    the performance of memory chips. J.A. 1711. The Board
    did not address any of this evidence.
    The Board also erroneously found that Rambus’s evi-
    dence relating to high-speed memory systems was not
    commensurate with the scope of the claims because the
    claims “do not recite a specific clock speed and therefore
    embrace slow memory devices.” Board Opinion at 29–30.
    Such a strict requirement was improper. Objective evi-
    dence of nonobviousness need only be “reasonably com-
    mensurate with the scope of the claims,” and we do not
    require a patentee to produce objective evidence of nonob-
    viousness for every potential embodiment of the claim.
    Kao, 
    639 F.3d at 1068
    ; In re Glatt Air Techniques, Inc.,
    
    630 F.3d 1026
    , 1030 (Fed. Cir. 2011) (“[W]e have consist-
    ently held that a patent applicant ‘need not sell every
    conceivable embodiment of the claims in order to rely
    upon evidence of commercial success.’”) (quoting In re
    DBC, 
    545 F.3d 1373
    , 1384 (Fed. Cir. 2008)). Moreover,
    Rambus’s evidence shows beyond dispute that the claimed
    dual-edge data transfer functionality is what enabled the
    praised high-speed transfer of data. A Byte Magazine
    article explained that, “by using both edges of a 250-MHz
    clock,” Rambus’s memory chips “will deliver a tenfold
    increase in component throughput.” J.A. 2623. The
    Electronic Engineering Times likewise described the dual-
    edge functionality as “designed to burst the bottleneck
    between processors and DRAMs in desktop systems.” J.A.
    2624–25. The Board did not point to any contrary evi-
    dence, and we have not found any in the record.
    Nor is there substantial evidence to support the
    Board’s finding that Rambus’s licensing evidence lacked a
    nexus to the reexamined claims. Rambus’s undisputed
    RAMBUS INC.   v. REA                                   15
    evidence linked its commercial success to the claimed
    dual-edge data transfer functionality. For example, an
    Electronic Engineering Times article relayed that Fujitsu
    Ltd., NEC Corp., and Toshiba Corp. had paid “substantial
    license fees to participate in the technology.” J.A. 2624.
    The article noted that a “key part” of Rambus’s licensed
    memory technology is the memory bus that “moves one
    byte on each clock edge.” J.A. 2625. By the mid-1990s,
    Rambus also obtained licenses from Hitatchi, Ltd., Oki
    Electric Industry Co., Lucky Goldstar, and Intel Corp.
    J.A. 2099. The Board held that this evidence lacked a
    nexus because “competitors have many reasons for taking
    licenses which are not necessarily related to unobvious-
    ness,” Board Opinion at 30, but this finding lacks any
    supporting evidence. Similarly, there is no evidence in
    the record to support the PTO’s assertion that the com-
    mercial value of the licenses stemmed from other licensed
    Rambus patents. Indeed, the only evidence before the
    Board points to a contrary conclusion.
    The Board’s finding that all of Rambus’s evidence
    lacked a nexus because dual-edge functionality was
    already disclosed in Inagaki, and therefore “not novel,” is
    also erroneous. 
    Id.
     at 29–30. While objective evidence of
    nonobviousness lacks a nexus if it exclusively relates to a
    feature that was “known in the prior art,” Ormco Corp. v.
    Align Tech., Inc., 
    463 F.3d 1299
    , 1312 (Fed. Cir. 2006), the
    obviousness inquiry centers on whether “the claimed
    invention as a whole” would have been obvious, 
    35 U.S.C. § 103
    . Rambus’s objective evidence of nonobvious-
    ness was not limited to the dual-edge functionality in
    Inagaki that transferred a single bit each half-cycle of an
    external clock. See J.A. 2955–58. At least some of Ram-
    bus’s objective evidence of nonobviousness pertained to
    Rambus’s overall memory device architecture. On re-
    mand, the Board should be careful to parse the evidence
    that relates only to the prior art functionality and the
    evidence that touted Rambus’s patented design as a
    16                                       RAMBUS INC.   v. REA
    whole. We decline to make these fact findings for the first
    time on appeal. We leave it to the PTO, for the ’097
    patent claims that remain on remand, to determine if
    Rambus’s objective evidence of nonobviousness pertains to
    the Rambus device or simply to the dual-edge functionali-
    ty disclosed in Inagaki.
    *****
    The Board erred when it failed to provide Rambus an
    opportunity to respond to its new grounds for rejecting the
    claims as obvious. The Board also erred in its analysis of
    Rambus’s objective evidence of nonobviousness. Due to
    these errors, we vacate the Board’s decision that claims
    3–5, 11, 12, 26, 28–32, and 35 are unpatentable. We
    express no opinion, however, as to whether those claims
    should issue.
    CONCLUSION
    For the foregoing reasons, we affirm-in-part and va-
    cate-in-part the Board’s decision and remand for further
    proceedings.
    AFFIRMED-IN-PART, VACATED-IN-PART, AND
    REMANDED
    COSTS
    Costs to Appellant.