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Fresh From the Bench: Recent Patent Cases From the Federal Circuit

February 3, 2014


Every week or so we will continue to provide summaries of cases we think clients and others might find of interest. If you have any questions about the information provided in these case summaries or wish to discuss them further, please contact Peter Heuser at 503-796-2424 or

EnOcean GmbH v. Face Int'l. Corp., Fed. Cir. No. 2012-1645 (1/31/2014)

The Federal Circuit reiterated the test to be applied in determining whether claims that don't use "means for" language should nonetheless be construed under § 112, ¶ 6. Here the panel unanimously determined that § 112, ¶ 6 did not apply because there was an adequate description of the structure through the use of the claim term "receiver." The panel also held that "means for receiving" and "signal receiving means" were supported in applicant's prior German application because that application provided sufficient detail to one skilled in the art, thus removing as a reference a patent that otherwise would have been invalidating.

EnOcean's application included claims to a switch used to turn on and off lights and home appliances. In 2000 EnOcean filed a patent application in Germany. A U.S. application was subsequently filed and an interference was declared between EnOcean and Face. The PTO then determined that both the Face and EnOcean claims were unpatentable in view of a patent to Burrow. EnOcean argued it was entitled to the filing date of its German application, which pre-dated Burrow. The Board disagreed, holding that EnOcean's disclosure of a "receiver" in its German application did not support the "means for receiving" or "signal receiving means" limitations in its U.S. claims ("means claims"). The Board also found that the other claims ("receiver claims") were means-plus-function claims, despite the fact that they did not recite "means for" language. The Board explained that the word "receiver" was defined in the claims solely in terms of functional language, thus creating no difference between a "receiver" and "signal receiving means." The Board then accorded no benefit of priority to either the means claims or the receiver claims because the German priority application did not "expressly describe the structure of the receiver."

The issues to be decided by the Circuit panel were: (1) whether the claims that recite "receiver" but do not include "means for" language should nonetheless invoke § 112, ¶ 6; and (2) whether the receiver claims and the means claims should be entitled to the priority of the German application, which did not provide any real description of what was meant by "receiver.".

There is sufficient structure in "receiver" that § 112, ¶ 6 is not invoked.

The panel first noted that the use of the term "means" triggers a rebuttable presumption that § 112, ¶ 6 governs the claim term. Conversely, where the claim language does not recite "means," it is presumed that the limitation does not invoke § 112, ¶ 6. However, this presumption can be overcome "if the claim term fails to recite sufficiently definite structure or else recites function without reciting sufficient structure for performing that function." The correct inquiry is "whether skilled artisans, after reading the patent, would conclude that a claim limitation does not use 'means' is so devoid of structure that the drafter constructively engaged in means-plus-function claiming."

The receiver claims recite "a signal receiver for receiving" and "a receiver adapted to receiving" a signal. Because these phrases lack the word "means," they are entitled to a presumption that they are not means-plus-function claims. EnOcean argued that the claim limitation "receiver" is reasonably well understood in the art as a name for a structure that performs the recited function. Face responded by arguing that the claimed "receiver" is defined only in terms of the function that it performs (i.e., receiving), and not its structure.

The panel agreed with EnOcean, noting that the term "receiver" (i.e., without the term "means") sufficiently defines the structure to those in the art and therefore should not invoke § 112, ¶ 6. In so holding, the panel noted that the language was similar to that used in some of its precedents where the presumption against applying § 112, ¶ 6 was not overcome: "height adjustment mechanism," "computing unit . . . for . . . evaluating," the term "circuit" in the phrase "circuit for monitoring a signal from the output terminal to generate a first feedback signal," "digital detector," and "detent mechanism."

The claims are entitled to priority since disclosure of a "receiver" is sufficiently clear to one in the art.

Turning to the priority issue, the panel determined that just because it concluded that the term "receiver" in EnOcean's receiver claims connotes enough structure to avoid invoking § 112, ¶ 6 does not necessarily mean that the disclosure of a "receiver" in the German application connotes enough structure to support EnOcean's "means" claims for purposes of claiming priority. Nonetheless, it came to that conclusion here. In examining whether the means claims and/or the receiver claims are entitled to claim the benefits of the earlier German application's priority date, it is not necessary, as stated by the Board, that the priority document expressly describe the structure of the receiver. Instead, according to the panel, the test is: "To obtain the benefit of the filing date of a parent application, the claims of the later-filed application must be supported by the written description in the parent in sufficient detail that one skilled in the art can clearly conclude that the inventor invented the claimed invention as of the filing date sought."

The panel determined that the following language in the German application demonstrates that one of ordinary skill could understand the bounds of the invention merely by reading the term "receiver" in that description:

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 receiver and the latter initiates the corresponding actions (lamp on/off, dimming of lamp, etc.).

Therefore, the panel concluded that both the receiver claims and the means claims were entitled to claim the benefit of the German application's priority date, thus removing the Burrow patent as a prior art reference.

This case reminds us that just because we don't use "means" language in a claim doesn't mean our claim won't be construed as a means-plus-function claim and therefore be narrowly construed to cover only what is disclosed in the specification and equivalents thereof. It also lowers the bar on proving that a party is entitled to an early priority date when means language is and is not used in the subject application.


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