The Patent and Trial Appeal Board invoked the doctrine of prosecution history disclaimer to construe the claims at issue narrowly for the inter partes review of U.S. Patent No. 5,884,033; and thus, concluding that the claims had not been shown to be unpatentable in light of prior art. The Board rejected the Petitioner’s additional arguments that the claims as construed were not adequately described in the specification. The Board noted that it was not proper for it to consider whether the claims as construed were valid under 35 U.S.C. §112, first paragraph.

Apple petitioned for inter partes review of claims 1, 2, 9, 15 and 23 of OpenTV’s U.S. Patent No. 5,884,003. The claims were directed to methods for filtering material transmitted over the Internet, such as techniques that block access to materials that users might find objectionable. After institution, the Patentee requested that the Board reconsider the claim construction adopted at institution of the IPR.

Claim 1 recites:

  1. A method for communicating with servers over the Internet to prevent or allow access to Internet sites, the method comprising computer-implemented steps of:
    1. opening a data stream to send a message through an interface to an Internet server;
    2.  maintaining a database of filtering information comprising a table of filters, said table comprising
      1. filters specifying immediate action, and
      2. filters specifying deferred action;
    3. comparing information in the message to filtering information in at least one of said filters specifying immediate action and said filters specifying deferred action; and
    4. determining whether to prevent or allow the outgoing transmission of the message based on the comparison.

At issue was the construction of the terms “filters specifying immediate action” and “filters specifying deferred action.” Ordinarily, the Board interprets claims of an unexpired patent using the broadest reasonable construction standard. Cuozzo Speed Techs., LLC v. Lee, 136 S. Ct. 2131, 2144-45 (2016). However, in its institution decision the Board had elected to construe the terms in the ‘033 Patent according to the Phillips standard applied by the District Courts. The Board did so in light of the fact that the ‘033 Patent was expected to expire prior to the statutory deadline for the Board’s final written decision.

The Patent Owner urged the Board to adopt a claim construction that had been rendered in a related District Court proceeding. See OpenTV, Inc. v. Apple, Inc., Case No. 3:14-cv-01622-HSG (N.D. Cal.).¹ The District Court had construed the two filter terms at issued to require their operation “between the presentation and application levels” of the ISO protocol model. In instituting inter partes review, the Board declined to adopt the District Court’s construction.

Following institution, however, the Patent Owner urged adoption of this aspect of the District Court’s earlier construction. In its final written decision, the Board agreed to adopt these added requirements based upon a further review of the patent’s prosecution history.

The Board observed that when a patent applicant unequivocally and unambiguously disavows a certain meaning to obtain a patent, the doctrine of prosecution history disclaimer narrows the meaning of the claim consistent with the scope of the claim surrendered. Decision at 9 (citing Biogen Idec. Inc. v. GlaxoSmithKline LLC, 713 F.3d 1090, 1095 (Fed. Cir. 2013)). During prosecution of the ‘033 Patent, the Applicant introduced the filter limitations via amendment in response to rejections under 35 U.S.C. § 102 or § 103 in view of Shwed U.S. Patent No. 5,606,668. In the remarks describing how the amendment distinguished the Shwed reference from the then-pending claims, the Applicant stated that “the packet filters of [Shwed] operate between the network interface hardware (level 2) and the network software (level 3). Applicant’s filtering methods, by contrast, operate between the presentation and applications levels (layers 6 and 7, respectively) of the seven-level ISO protocol model.” (See p. 7 of Amendment dated Jan. 7, 1998; file history ‘033 Patent.)

The Board observed that the U.S. Supreme Court had suggested that the Board would exceed its statutory authority were it to find a claim invalid under Section 112.

The Board reasoned that this statement was a clear and unmistakable disclaimer for the following reasons: (i) the amendment was made to distinguish the cited art, and the Applicant specifically stated that the amendment distinguished the claims over the Shwed reference because the filters of the invention operate at layers 6 and 7; and (ii) the Applicant’s remarks clearly were directed at the inserted claim language regarding the filters rather than other aspects of the technique. The Board concluded that there was no ambiguity that the Applicants intended to limit the claim-recited filters to those that operate between layers 6 and 7 of the ISO protocol.

The Petitioner, in response, argued that such a construction lacks written descriptive support in the patent’s specification and should be rejected for that reason. Initially, the Board noted that “written description” issues are not issues that the Board may consider in inter partes review. The Board observed that the U.S. Supreme Court had suggested that the Board would exceed its statutory authority were it to find a claim invalid under Section 112.

The Petitioner argued that the Board’s claim construction would contravene the axiom that claims are to be construed to preserve their validity. In answer, the Board noted that the Federal Circuit had “admonished against judicial rewriting of claims to preserve validity.” The Board noted that application of the axiom in claim construction was reserved only to situations in which the claim remains ambiguous even after the application of all other available tools of claim construction. In this case, the Board further determined the axiom had no application because the prosecution history clearly evidenced that the Applicant had unmistakably disclaimed filters that operate at layers other than Layers 6 and 7 of the IOS protocol model.

When the Phillips standard is applied, a clear and unmistakable disclaimer in the prosecution history will control claim construction regardless of whether the written description for the construed claims is in question. In this case, the disclaimer allowed the Patentee to distinguish the art cited in the IPR petition, and the claims at issue were determined to be patentable. Prosecution disclaimers will be considered by the Board during claim construction of an expired patent, despite their effect on the allowance of the claims during prosecution and their support in the specification.