Federal Circuit Reverses District Court’s Indefiniteness Ruling For Applying Incorrect Legal Standard
On January 27, 2022, the Court of Appeals for the Federal Circuit (“CAFC”) reversed the judgment of the United States District Court for the Northern District of California finding certain claims invalid on the ground of claim indefiniteness under 35 U.S.C. § 112(b), because the district court erred by applying an incorrect legal standard. Nature Simulation Sys. Inc. v. Autodesk, Inc., __ F.4th __ (Fed. Cir. Jan. 27, 2022).
Nature Simulation Systems, Inc. (“NSS”) sued Autodesk, Inc. (“Autodesk”) for infringement of two patents directed to a computer-implemented method for building three-dimensional geometric models using a computation method called “Boolean operation.” The particular “Boolean operation” method claimed in the patents is a modification of a prior art “Watson method.” The claimed method purports to provide flexibility and simplicity over the prior art.
Autodesk, supported by an expert declaration, sought the construction of two claim terms: (1) “searching neighboring triangles of the last triangle pair that holds the last intersection point” and (2) “modified Watson method.” The district court conducted a claim construction hearing and subsequently held the claims invalid, after finding these two claim terms indefinite. In so holding, the district court explained that a claim term is indefinite, as a matter of law, if there are any “unanswered questions” about the term, specifically referring to a conflict between the opinion of Autodesk’s expert and the patent examiner’s resolution of an indefiniteness rejection during original prosecution of the patents. The district court recited several “unanswered questions” raised by Autodesk’s expert, and further stated—in response to NSS’s argument that those questions are answered in the patent specification—that the definiteness requirement is not met if the questions are not answered in the claims themselves.
The CAFC, citing the Supreme Court’s seminal Nautilus opinion on indefiniteness, set forth the correct legal standard—i.e., that § 112 requires a patent’s claims, viewed in light of the specification and prosecution history, to inform those skilled in the art about the scope of the invention with reasonable certainty, recognizing that, while the definiteness requirement mandates clarity, absolute precision is unattainable. See Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898, 910 (2014).
The CAFC criticized the district court’s analysis for applying an incorrect standard of “unanswered questions” and a flawed analysis of validity. Specifically, the CAFC explained that the district court declined to consider information in the specification that was not included in the claims, and, critically, that the district court misperceived the function of patent claims, which is to point out what the invention is in such a way as to distinguish it from what was previously known (i.e., from the prior art), and to define the scope of protection afforded by the patent. The CAFC further explained that, in this case, the prosecution history is significant because the patent examiner had initially rejected the claims for indefiniteness and subsequently required additional definition with respect to the claim limitations at issue here. In fact, the subsequently-made amendments were “examiner’s amendments” that were done in consultation between the applicant and examiner. The CAFC criticized the district court for failing to give proper weight to that prosecution history. The CAFC explained that a certain level of deference should have been given to the examiner’s amendment because it should be presumed that an examiner, as an official agency actor, would not introduce an indefinite term into a claim when he or she chooses to amend the claim for the very purpose of putting the application in a condition for allowance.
In concluding, the CAFC explained that the subject matter of the patents at issue was an improvement on known methods (e.g., the Watson method), and that there was no dispute that the specification describes and enables practice of the claimed method. The claims, as amended during prosecution, were held by the examiner to distinguish the claimed method from the prior art and to define the scope of the patented subject matter. In reversing and remanding, the CAFC found that the district court made no contrary findings, and that indefiniteness under 35 U.S.C. § 112 was not established as a matter of law.
It should be noted, however, that Judge Dyk dissented from the majority because, in his view, the district court did, in fact, apply the correct legal standard under Nautilus, and simply illustrated its reasoning through its “unanswered questions” analysis. Judge Dyk further opined that, under the de novo standard of review, he would have found the claims indefinite because the term “modified Watson method” does not have an ordinary and customary meaning to a person of ordinary skill in the art. In his view, the majority side-stepped the reasonable-certainty Nautilus analysis by placing too much weight on the fact that a patent examiner had added the claim language.