United States: What A Difference A Few Letters Make – Judge Donato Strikes Patent Claim Over Ambiguous Typo, While Sparing Another Through Claim Construction

Last Updated: September 7 2015
Article by Diana Rutowski and Daniel Justice

Order Re: Claim Construction and Invalidity, Altera Corp. v. PACT XPP Tech., AG, Case No. 14-cv-02868-JD (Judge James Donato)

When filing a patent application, make sure to cross your t's and dot your i's—and also check for typos and ambiguous antecedents. In a recent order addressing claim construction and a motion for summary judgment on indefiniteness, Judge Donato invalidated a patent claim based on a typographical error, and nearly invalidated a claim for an ambiguous antecedent.

In Altera Corp. v. PACT XPP Tech., AG, Altera sought a declaration that it does not infringe on several of PACT's patents involving reconfigurable semiconductor devices, such as field programmable gate arrays (i.e., an integrated circuit a customer can configure post-manufacturing). After construing a number of claim terms, Judge Donato addressed Altera's motion for summary judgment on indefiniteness, in which Altera argued certain claims were rendered indefinite, and therefore invalid, by ambiguous claim terms—namely, "the unit" and "haltered."

Turning to the first term, one claim-at-issue recites "a unit," a separate instance of "a unit," and "multiple units" before referring to "the unit."1 Altera argued that "the unit" rendered the claim indefinite, asking whether it referred back to the first instance of "a unit," the second instance, or the phrase "multiple units"?. Judge Donato first noted that the USPTO's Manual of Patent Examining Procedure ("MPEP") suggests claims can sometimes be rendered indefinite by ambiguous antecedents. He also noted, however, that the MPEP does not have the force of law, and that indefiniteness rejections by the USPTO arise in a different posture from indefiniteness challenges to an issued patent. Notably, a USPTO examiner may issue an indefiniteness rejection to merely clarify a proposed claim, as opposed to finding it invalid. In contrast, a Court applies the standard indefiniteness test that asks whether "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."

Applying this standard, Judge Donato agreed with PACT's argument that "the unit" referred to the first instance of "a unit" based on his construction of "at least one of . . . and . . ." Construing this term earlier in the opinion, Judge Donato rejected the presumption in SuperGuide Corp. v. DirecTV Enters., Inc., 358 F.3d 870, 886 (Fed. Cir. 2004) that "at least one of" applies to each element of the list and that "and" is read conjunctively, instead relying on intrinsic evidence to arrive at the construction: "at least one of ... and/or ...." In the claim at issue, the second instance of "a unit" appeared in such a list (i.e. "at least one of As, Bs, and/or [a unit having] Cs"). Given this construction, it is possible that an embodiment of the claim would not include "a unit having Cs." In those situations, "the unit" would not have an antecedent basis at all. Further, Judge Donato found that the singular "the unit" could not refer back to the plural "multiple units." Thus, Judge Donato found "the unit" must refer back to the first instance of "a unit" and did not find this claim to be indefinite.

With respect to the second term, "haltered,"2 both parties agreed it made no sense in the context of the claim. On the one hand, Altera argued it was unclear whether the intended term was "halted" or "altered." On the other, PACT argued the intended term was "halted." In addressing the typographical error, Judge Donato found that a district court can fix a typographical error in a patent claim even when no certificate of correction has been issued, only when (1) the correction is not subject to reasonable debate considering the claim language and the specification, and (2) the prosecution history does not suggest a different interpretation of the claims. He also found that unlike the UPSTO, which can review the entire intrinsic record, district courts are limited to correcting obvious errors evident from the face of the patent itself. District courts may only look to the prosecution history to determine if it weighs against a proposed correction. PACT pointed to the prosecution history of the patent at issue and the specification of a related patent, to support its argument for its correction to "halted." Since neither of these come from the face of the patent, Judge Donato could not use either as a basis to correct the claim.

PACT's expert also opined that a POSITA would understand that the claim should read "halted" and not "haltered." To support this proposition, the expert pointed to the abstract, arguing that the whole point of the invention was to allow reconfiguration of certain cells or cell groups without "halting" or "deactivating" neighboring cells. Judge Donato found, however, it was not enough that PACT's interpretation was the more likely interpretation; rather, it had to be "obvious" and "not subject to reasonable debate." He found PACT could not meet this standard because Altera was able to point to portions of the specification that stated neighboring cells must not be "affected"—a term closer in meaning to "altered" than to "halted."  Consequently, he found that whether the intended term was "halted" or "altered" was subject to reasonable debate and thus found the claim invalid for indefiniteness. When it comes to claim language, a few letters can make all the difference.


1. "A bus system, comprising:

a plurality of at least one of individual lines, buses, and subbuses within at least one of a unit including at least one of a data flow processor (DFP), a field programmable gate array (FPGA), a dynamically programmable gate array (DPGA), and a unit having a multi-dimensional programmable cell architecture, the plurality of at least one of the individual lines, buses and subbuses being bundled,

wherein the plurality of at least one individual lines, buses and subbused at least one of combines multiple units and connects at least one of memories and peripherals, and wherein standard bus systems are used, and

wherein the unit includes additional ordinary connections in a manner customary with at least one of the DFP, the FGPA, and the DPGA."

2. ". . . at least some of the plurality of computing cells being configured as a function of the at least one configuration signal during operation of the massively parallel data processing apparatus such that others of the plurality of computing cells not being configured are not haltered or impaired in their operations."

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