Federal Circuit Finds Claim Terms “Computer” And “Passive Link” Indefinite
IP Litigation
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  • Federal Circuit Finds Claim Terms “Computer” And “Passive Link” Indefinite

    On February 10, 2021, the Court of Appeals for the Federal Circuit (“CAFC”) issued an opinion affirming a decision by the United States District Court for the District of Delaware, invalidating all asserted claims of appellant’s four related patents under 35 U.S.C. § 112.  Infinity Computer Products v. Oki Data Americas Inc., __ F.3d __ (Fed. Cir. Feb. 10, 2021).  In its decision, the CAFC ruled that the asserted claims were rendered indefinite by conflicting statements made by appellant during prosecution of the asserted patents.

    A patent is invalid for indefiniteness under 35 U.S.C. § 112 “if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”  NautilusIncvBiosig InstrumentsInc., 572 U.S. 898, 901 (2014).

    In the district court, appellant asserted certain claims of four related patents involving the use of a fax machine as a printer or scanner for a personal computer.  Claim 1 of the asserted ’811 patent—which the parties agreed was representative—recites a “method of creating a scanning capability from a facsimile machine to a computer, with scanned image digital data signals transmitted … via a passive link between the facsimile machine and the computer … [and] received directly into the computer … via the passive link.”

    Appellee argued before the district court that the terms “passive link” and “computer” are indefinite, because appellant took materially inconsistent positions regarding the extent of the claimed “passive link” during prosecution—alternately claiming this link ends at an I/O bus inside the computer to distinguish a first prior art reference (“Perkins”) during initial examination, and at the port on the external surface of the computer to antedate a second prior art reference during reexamination.  The district court agreed with appellee, concluded that the endpoint of the “passive link” and the beginning of the “computer” were not reasonably certain based on appellant’s conflicting representations, and entered a final judgment of invalidity.

    On appeal, the CAFC first examined the claim language and specification of the ’811 patent and concluded they do not provide reasonable certainty as to where the “passive link” ends.  The CAFC noted that the term “passive link” does not appear in the ’811 patent specification.  Rather, it was first introduced during prosecution to distinguish Perkins.  Specifically, with respect to Perkins, appellant argued that a “passive link” does not allow for intervening circuitry, e.g., a fax modem card, inserted inside the case of the computer and residing between the fax machine and the internal I/O bus of the computer.  Unlike Perkins, appellant argued, data transmitted “through a passive link . . . passes directly to the I/O Bus and is processed by the receiving circuits . . . of the computer.”  The CAFC determined that this position would lead one of ordinary skill to believe a “passive link” does not end at the computer’s external connection port but rather extends to the I/O bus inside the computer.

    During reexamination, however, appellant took the exact opposite position, contending that a fax modem card inserted in the computer could lie between the end of the “passive link” and the computer’s internal I/O bus.  The CAFC determined that this argument would lead one of ordinary skill to believe a “passive link” ends at the computer’s external connection port.  The CAFC then concluded that appellant’s contradictory positions resulted in a failure to provide public notice of what the patentee had claimed. 

    The CAFC then considered and dismissed appellant’s various arguments on appeal.  Appellant first argued that the passive link is the physical cable spanning the fax machine and the computer and that its prosecution statements should be interpreted to mean that the data flowing through the passive link, rather than the passive link itself, proceeds uninterrupted to the computer I/O bus.  The CAFC disagreed, observing that, to distinguish Perkins’s internal-card embodiment, the passive link could not be merely a cable that ends at the computer’s port.  And, the CAFC noted it “hold[s] patentees to the actual arguments made, not the arguments that could have been made” during prosecution.

    The CAFC also rejected an express definition of “passive link” provided by appellant during prosecution for failing to address the point in question: the end point of the “link.”  The CAFC also dismissed expert testimony that appellant offered in district court as to the meaning of “passive link.”  According to the CAFC, this extrinsic evidence was unhelpful in view of the clear prosecution history.

    Next, the CAFC dismissed appellant’s argument that the district court should not have held the claims indefinite based on a “single statement” during prosecution.  While not agreeing that the district court relied on only a single statement, the CAFC noted that even a single statement can be sufficient.  The CAFC also found it immaterial that appellant also distinguished Perkins on another ground.

    Last, while the CAFC recognized that, in a vacuum, it might seem odd to hold “computer” indefinite, its holding does not reside in the terms “passive link” or “computer” on their own, but rather in the relationship between the two and appellant’s own conflicting statements respecting these terms. 
    CATEGORY: Section 112