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Federal Circuit Holds District Court Used Wrong Indefiniteness Standard, Reverses Invalidity Ruling

Publications / Jan 30, 2022

Article written by Clyde Shuman

The U.S. Court of Appeals for the Federal Circuit held that a district court used the incorrect legal standard for claim indefiniteness, reversing the district court’s finding that two patents related to methods of packaging computer-aided data for three-dimensional objects were invalid as indefinite. Nature Simulation Systems Inc. v. Autodesk, Inc., Appeal No. 2020-2257.

By way of background, the patents at issue were for a computer-implemented method for building three-dimensional objects employing a computation method called “Boolean operation.” The patents cited two prior art methods: the Delaunay method of triangulation (“Delaunay triangulation”), and the Watson method, an algorithm for computing a Delaunay triangulation, described in a paper written by Watson. The patents state that the “modified Watson method” described therein provides simplicity and flexibility compared with prior methods, and is easier to program and implement.

Following a Markman hearing, the district court ruled that two disputed claim terms—“searching neighboring triangles of the last triangle pair that holds the last intersection point” and “modified Watson method”—were indefinite, rendering the claims invalid. The district court did not define the two terms, instead holding that a claim term is indefinite, as a matter of law, if there are any “unanswered questions” about the term. The court referred to the conflict between the opinion of Autodesk’s expert, and the patent examiner’s resolution of indefiniteness. The district court held that, even if Autodesk’s several “unanswered questions” were answered in the patent specification, this did not satisfy the definiteness requirement, which require that the questions be answered in the claims themselves.

NSS appealed, arguing that the district court applied the incorrect legal standard.

On appeal, the Federal Circuit, citing its own precedent, noted the rule that when the meaning or scope of a patent claim is disputed, the court must construe the claim as a matter of law, looking first to the intrinsic record, the claim  language, specification and prosecution history, and extrinsic evidence concerning, inter alia relevant scientific principles and the state of the art. Here, however, the Court found that the district court did not construe the claims, did not consider the intrinsic and extrinsic evidence, and did not resolve the meaning and scope of the challenged claims. Rather, per the Court, the district court applied an incorrect standard of “unanswered questions” and a flawed analysis of validity. The Federal Circuit further found that, in response to NSS’s argument that the “unanswered questions” were answered in the specification, the lower court held that definiteness requires that the questions are answered in “the claim language, standing alone,” as stated in Autodesk’s expert’s declaration.

The Federal Circuit said that “claim language, standing alone” is not the correct standard, and is contrary to precedent. Rather, patent claims are viewed and understood in light of the specification, the prosecution history, and other relevant evidence, as “would have allowed a skilled artisan to know the scope of the claimed invention with reasonable certainty.”

The Court specifically noted that the patent specification describes, and the claim recites, that the intersection line is built from the intersection points around the objects being compared, “searching neighboring triangles of the last triangle pair that holds the last intersection point to extend the intersection line until the first intersection point is identical to the last intersection point of the intersection line ensuring that the last line gets closed or until all triangles are traversed.” Further, Figure 13 of the patent is a flowchart of “Delaunay mesh modified Watson method that created the sequence” shown in Figure 12. The Court also found that the specification describes the Watson and Delaunay prior art, in text and drawings to show how they are used and modified in the subject invention. The Court expressly found that Autodesk’s expert acknowledged this prior art in his declaration.

However, the district court declined to consider information in the specification that was not included in the claims. Per the Federal Circuit, the district court thus “misperceived the function of patent claims.” Quoting precedent, the Court said that claims “are not technical descriptions of the disclosed inventions but are legal documents like the descriptions of lands by metes and bounds in a deed which define the area conveyed but do not describe the land.”

Turning to the prosecution history, the Federal Circuit noted that the examiner had initially rejected the claims as indefinite, specifically citing the clause “extending intersection lines until they get closed by searching neighboring triangles.” However, the applicant, in consultation with the examiner, amended this claim term and the examiner subsequently withdrew the indefiniteness rejection relating to the intersection lines. The Court also noted that the applicant and the examiner also interacted to amend the term “modified Watson method,” citing an Examiner’s Amendment mentioned in the Notice of Allowance.

However, the district court rejected the examiner’s conclusion as to indefiniteness, stating that the amendments did not answer “the questions posed by” Autodesk’s expert. The Federal Circuit found that the district court gave no weight to the prosecution history showing the resolution of indefiniteness by adding the designated technologic limitations to the claims, did not discuss the Examiner’s Amendment, and held that since the expert’s questions were not answered, the claims are invalid.

The Federal Circuit held that this was in error, noting that actions by examiners are entitled to appropriate deference as official agency actions, for examiners are deemed to be experienced in the relevant technology as well as the statutory requirements for patentability. The Court found that the subject matter at issue was an improvement on the known Watson and Delaunay methods, and partakes of known usages for established technologies. Analogizing to its 2017 decision in Presidio Components, Inc. v. Am. Tech. Ceramics Corp., 875 F.3d 1369 (Fed. Cir. 2017), the Court said: “It is not disputed 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. The district court made no contrary findings.”

Judge Dyk dissented, writing that the fact that a patent examiner introduced the indefinite language does not absolve the claims from the requirements of 35 U.S.C. § 112. Per Judge Dyk, the district court read the claims in light of the patent specification to determine if it would inform those skilled in the art about the scope of the invention with reasonable certainty, which is what is required under Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898, 910 (2014).

Judge Dyk noted that it was undisputed that the term “modified Watson method” does not have, and did not have at the time the patents were issued, an ordinary and customary meaning to a person of ordinary skill in the art. Judge Dyk further faulted the majority’s reliance on Figures 12 and 13, pointing out that the claim adds express limitations not found in those figures. Even more significant, per Judge Dyk, nothing in the specification defines what these additional limitations mean. The only expert evidence on these limitations in the record is by Autodesk’s expert, who testified that these limitations are “not describe[d]” in the patent, “ambiguous” and “unclear,” and “inconsistent with” Figure 13 and the accompanying text.

Addressing the majority’s discussion of the examiner’s amendments, Judge Dyk wrote that “the test for definiteness is whether the claims ‘inform those skilled in the art about the scope of the invention with reasonable certainty,’ not whether the claim language was added by a patent examiner or was not indefinite to the examiner.”