At the Federal Circuit - Means-Plus-Function Plus Priority: The Federal Circuit’s Decision in EnOcean GmbH

While interference activity at the U.S. Patent and Trademark Office (USPTO) is winding down due to enactment of the America Invents Act, interferences are still yielding precedent. In a recent appeal from an interference, the Federal Circuit addressed the issues of means-plus-function claiming and the benefit of priority to foreign parent applications. The Federal Circuit’s decision inEnOcean GmbH v. Face International Corp., No. 2012-1645,slip op.(Fed. Cir. Jan. 31, 2014), includes holdings on both issues that practitioners should bear in mind when preparing and prosecuting applications.

The underlying interference involved a patent application filed by EnOcean GmbH and a patent issued to Face International Corporation. Both EnOcean’s application and Face’s patent included claims directed to a self-powered switch that could be used to turn on and off lights, appliances, and other devices without the need for a battery or external power. EnOcean’s application was originally filed in Germany on May 24, 2000, and a similar PCT application was filed on May 21, 2001.

On June 25, 2010, the Board of Patent Appeals and Interferences (the “Board,” now known as the Patent Trial and Appeal Board) declared an interference between EnOcean’s application and Face’s patent. The Board found that all of Face’s claims were invalid under 35 U.S.C. §103(a) based in part on a published PCT application to Burrow. The Board then applied the presumption under 37 C.F.R.§ 41.207(c)that EnOcean’s corresponding claims were unpatentable over Burrow for the same reasons. EnOcean responded by arguing that its application benefited from the priority dates of its German and PCT parent applications, both of which antedated Burrow.

The Board rejected EnOcean’s priority claim and held that its claims were obvious in view of Burrow.In particular,the Board found that the disclosure of a “receiver” in EnOcean’s parent German and PCT applications did not support EnOcean’s claims reciting a “means for receiving” as required by 35 U.S.C. §112, ¶6 (now 35 U.S.C. §112(f)). The Board also found that certain other claims reciting a “receiver” without the term “means” were also means-plus-function claims, and that the parent German and PCT applications failed to support them as well. Concluding that EnOcean’s application could not claim priority to the parent applications, it held EnOcean’s claims obvious based in part on Burrow. EnOcean appealed.

On appeal, the Federal Circuit first addressed EnOcean’s claims reciting a “receiver” without the term “means.” For example, claim 37 recited “a signalreceiver for receivinga first electromagnetic signal transmitted by said first signal transmitter.” Slip op. at 6. The Federal Circuit began by noting that these claims presumptively were not means-plus-function claims because they did not recite the term “means.” While the Federal Circuit noted that the presumption could be overcome, it concluded that it was not overcome in this case, and that “receiver” claims were not means-plus-function claims. In particular, the Federal Circuit referenced the Board’s finding that a “skilled worker would have been familiar with the design and principles of the types of components utilized in the claimed invention, including . . . receivers.”Id. at 7 (citation omitted). The Federal Circuit also cited the scientific literature and expert declarations of record, which supported EnOcean’s position that a person of ordinary skill in the art would have been able to understand the structure connoted by the recited “receiver.”

The Federal Circuit next considered whether EnOcean’s claims—some of which recited “means” and some of which did not—were entitled to claim priority to the parent German and PCT applications. The Federal Circuit noted that the only portion of the German application that referred to a “receiver” stated:

In this case, a typical scenario is that all the switches, for example light switches, upon actuation, emit one or a plurality of radio frequency telegrams which are received by a single receiverand the latter initiates the corresponding actions (lamp on/off, dimming of lamp, etc.).

Id. at 10 (citation omitted). In view of this disclosure, the Federal Circuit disagreed with the Board’s conclusion that the German application provided insufficient disclosure for the later-filed “means for receiving” and “receiver” claims. The Federal Circuit rejected the Board’s test that the German application must “expressly describe the structure of the receiver” in order to provide adequate written-description support.Id. (ciation omitted). Further, the Federal Circuit agreed with EnOcean that “a person of ordinary skill in the art could understand the bounds of the invention merely by reading the term ‘receiver,’ which is present in EnOcean’s German and PCT applications.”Id. at 11. Because “the inventors did not invent the receiver, and the Board found that the structure was well known as of the filing date, the inventors were ‘not obliged . . . to describe . . . the particular appendage to which the improvement refers, nor its mode of connection with the principal machine,’”id. (citation omitted). Accordingly, the Federal Circuit found that the Board erred in concluding that both types of EnOcean’s claims were not entitled to priority. The Federal Circuit thus vacated-in-part the Board’s decision (to the extent it related to EnOcean’s “means” and “receiver” claims) and remanded the case to the Board.

Practitioners should keep in mind the Federal Circuit’s holdings both when drafting applications and during prosecution. First, when drafting a specification and claims, practitioners should understand that there is a presumption of means-plus-function treatment based on use of the term “means” in claims. Therefore, practitioners should carefully consider whether to use the term “means” in a claim and, when using it, draft a specification describing various types of structure for that “means” element. Practitioners should also continue to fully describe their inventions in all priority applications. While the claims at issue inEnOcean were found to properly claim priority, draftspersons should prepare specifications and claims with an eye toward avoiding potential disputes about the adequacy of disclosure. These same lessons apply during prosecution as well. Throughout prosecution, when faced with decisions about whether to amend claims and, if so, what language to use, practitioners should be cognizant of the implications of means-plus-function claiming. Practitioners should also consider the implications of priority claims to parent applications if claim amendments are made that change the scope of the claims. Practitioners should also keep in mind that patent offices outside the United States often have stricter requirements than those expressed by the Federal Circuit in this case.