By Dennis Crouch
EnOcean v. Face Int’l. (Fed. Cir. 2014)
This interference appeal is focused on interpreting the “functional” claim term “receiver” and relates directly to recent Patently-O discussions on the topic of means-plus-function claim terms compared with bare non-MPF functional claim terms. See Crouch, Functional Claim Language in Issued Patents (2014). Here, the court finds, roughly, that a claim term with a smidgen of structure should be seen as a structural limitation rather than one governed by 35 U.S.C. §112¶6. The case is also relevant to the still pending en banc case of Lighting Ballast where the Federal Circuit is set to decide whether a “voltage source means” limitation should be considered a means-plus-function limitation.
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Inter Partes Reviews have quickly taken-on the procedural appearance and nature of their PTO-trial predecessor interference proceedings. This interference case involves a competition between EnOcean and Face Int’l over a “self-powered light switch” that can be used to remotely trigger a relay using a piezoelectric element. Many think of an interference as a fight over who gets the patent. Some cases follow that model, but many others (such as this one) are really just one party trying to block the other’s patent. Interferences also have a tradition of being quite messy and I expect that tradition to continue in the Board’s new review and derivation proceedings.
Here, EnOcean’s patent application claims priority back to a May 2000 German application with later filed PCT and US national stage applications. Face’s priority only goes to 2001, but Face’s patent issued in 2006 while EnOcean has been battling with the PTO this whole time. After Face’s patent was issued, EnOcean amended its claims to match those of Face and requested an interference.
In the interference, EnOcean identified a set of prior art (other than its own application) that, in combination invalidated Face’s patent. Considering that evidence, the PTO Board found Face’s patent claims invalid as obvious. The Board also found that EnOcean’s amended claims were not sufficiently disclosed in the 2000 priority document and that EnOcean’s claims were therefore invalid as obvious (since they didn’t have an early priority date).
The case against priority was interesting. Many of EnOcean’s patent claims include the term “receiver” as follows:
- Claim 37: “a signal receiver for receiving a first electromagnetic signal transmitted by said first signal transmitter;”
- Claim 38: “a receiver for receiving a first radiofrequency signal transmitted by said first signal transmitter;”
- Claim 43: “a receiver adapted to receiving a radiofrequency telegram transmitted by said radio frequency transmission stage;”
- Claim 45: “a receiver adapted to receiving a radiofrequency telegram transmitted by said first radio frequency transmission stage;”
But, the German priority document’s only reference to a receiver came from a single sentence, as translated:
[A] typical scenario is that all the switches … upon actuation, emit one or a plurality of radio frequency telegrams which are received by a single receiver and the latter initiates the corresponding actions (lamp on/off, dimming of lamp, etc.).
(In German, the original application uses the term “empfänger.”)
In interpreting the “receiver” limitation, the Board found that it was purely functional and thus should be interpreted as a means-plus function element governed by 35 U.S.C. §112¶6. In other claims found in the patent, EnOcean had used the phrases “signal receiving means” and “means for receiving” and the PTO Board found those terms synonymous with “receiver.” Under the statute, a means-plus-function claim term must have corresponding structure described in the specification. Since, the original German application did not include any structural discussion of a receiver or how it might work, the Board held that the US patent could not properly claim priority to the German application.
In the Appeal, the Federal Circuit has vacated – agreeing with EnOcean that its claim term “receiver” is not so functional as to be a means-plus-function claim. The court began its analysis with the black-letter precedent that “means” is a magical word. When it is used, courts should presume that the applicant intended for the term to be interpreted under 112¶6, and that the opposite presumption should be made (not 112¶6) if the magic word “means” is absent. Here, because the receiver term is not accompanied by the magical word “means,” we begin with a presumption that it is not to be interpreted under 112¶6.
After finding its beginning presumption, the court then determined that one of skill in the art would see sufficient structure from the term.
Indeed, the record indicates that the term “receiver” conveys structure to one of skill in the art—the Board itself made a factual finding that that the “skilled worker would have been familiar with the design and principles of the types of components utilized in the claimed invention, including . . . receivers.”
We also come to this conclusion, in part, because EnOcean has provided extensive evidence demonstrating that the term “receiver” conveys known structure to the skilled person. . . . Further, we are not persuaded by Face’s arguments that the term “receiver” is simply too broad to recite sufficiently definite structure. We have stated previously that just because “the disputed term is not limited to a single structure does not disqualify it as a corresponding structure, as long as the class of structures is identifiable by a person of ordinary skill in the art. Linear Tech. Corp. v. Impala Linear Corp., 379 F.3d 1311, 1322 (Fed. Cir. 2004).
What the court didn’t do here was describe what a receiver is structurally (or how has that changed over the past three decades). As part of its analysis, the court rejected the Board’s conclusion that “that there is no distinction in meaning between ‘receiver’ and ‘signal receiving means,’” since “the receiver of the EnOcean claims is defined in the claims solely in terms of functional language.”
Connecting all the dots, the court then found that the one-liner original receiver disclosure provided sufficient structure to support both the means-plus-function claim elements (receiving means) and the non-MPF receiver.
The decision here is not overly surprising and follows a number of other Federal Circuit decisions where a smidgen of structural understanding was sufficient to remove a claim term from 112¶6 analysis. Notably amongst these is the Linear Tech decision cited above where the court found the claimed “circuit for monitoring a signal” recited sufficient structure to avoid 112¶6 analysis.