This is a discussion of the new Federal Circuit Decision Microsoft v. Enfish appealing a PTAB final decision.
In the prior parallel decision – Enfish v. Microsoft, 822 F.3d 1327 (Fed. Cir. 2016), the Federal Circuit reversed a district court ruling that Enfish’s asserted software claims were ineligible under § 101 and also vacated the lower court’s holding that some of the claims were invalid as anticipated. U.S. Patent Nos. 6,151,604 and 6,163,775 (inventions relating to a “self-referential” database).
Enfish sued Microsoft for infringement in 2012. In addition to its litigation defenses, Microsoft marshaled a collateral attack on the patents with five petitions with the US Patent Office for inter partes review of the ’604 and ’775 patents.
After instituting review, the Patent Trial and Appeal Board found some of the patent claims invalid as anticipated/obvious. On appeal, PTAB factual findings are generally given deference but legal conclusions are reviewed without deference. After reviewing the claim construction and rejections, the Federal Circuit affirmed in a non-precedential decision.
Collateral Attacks: These collateral attacks work well to cancel patent claims with obviousness arguments that would have been unlikely to be accepted by a trial court or jury. This is a pointed example here since the previously rejected district court’s judgment was based upon a more simplistic Section 101 analysis that is easier for the Federal Circuit to overturn.
Not Amenable to Construction: The most interesting aspect of the decision is hidden in a single sentence statement: “As to claims 1–26 and 30 of both patents—which are not at issue before us—the Board terminated proceedings after concluding that those claims were not amenable to construction.”
In its final judgment, the Board explained that those claims include a means-plus-function element (“means for configuring said memory according to a logical table“) but that no embodiments of the element were provided in the specification. And, although a person of skill in the art may know how to construct the element, our 112(f) jurisprudence requires embodiments in the specification and does not allow a patentee to “rely on the knowledge of one skilled in the art to address the deficiencies” See Function Media, LLC v. Google Inc., 708 F.3d 1310 (Fed. Cir. 2013). The statute states permits means-plus-function claims but also provides a guide for narrowly construing those claims.
35 U.S.C. 112(f) ELEMENT IN CLAIM FOR A COMBINATION.—An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
In both patent prosecution and district court litigation, failure to properly disclose structural embodiments for a means-plus-function limitation results in the claim being held invalid as indefinite since the limitation’s scope cannot be properly construed. In the inter partes review situation, however, the Board’s power is limited to cancelling patents on novelty or obviousness grounds. As such, the Board simply terminated the IPR trial with respect to these non-construable claims. The Board writes:
In the circumstance when the specification of the challenged patent lacks sufficient disclosure of structure under 35 U.S.C. § 112, sixth paragraph, the scope of the claims cannot be determined without speculation and, consequently, the differences between the claimed invention and the prior art cannot be ascertained. For the reasons given, we determine that independent claims 1, 11, and 15 are not amenable to construction and, thus, we terminate this proceeding with respect to claims 1, 11, and 15 under 37 C.F.R. § 42.72.
No Appeal of Termination: Neither party appealed the termination, although the Federal Circuit previously held that its appellate jurisdiction over these cases is limited to appeals of “final written decision[s] with respect to the patentability of any patent claim challenged by the petitioner …” A termination decision was seen as essentially an extension of the institution decision that is not itself appealable.
Of course, the original Federal Enfish decision mentioned above also addressed this indefiniteness issue and held that the claims were not indefinite because sufficient structure was disclosed — holding that the scant description was adequate because “the sufficiency of the structure is viewed through the lens of a person of skill in the art and without need to ‘disclose structures well known in the art.’ I guess that this means that those claims are OK.