United States Court of Appeals 

for the Federal Circuit ______________________ 

ENOCEAN GMBH,

Appellant,

v.

FACE INTERNATIONAL CORPORATION,

Appellee.

______________________ 

2012-1645

______________________ 

Appeal from the United States Patent and Trademark 

Office, Board of Patent Appeals and Interferences, in 

Interference No. 105,755.

______________________ 

Decided: January 31, 2014

______________________ 

GEORGE E. QUILLIN, Foley & Lardner LLP, of Washington, DC, argued for appellant. 

DUNCAN G. BYERS, Byers Law Group, of Norfolk, Virginia, argued for appellee.

______________________ 

Before RADER, Chief Judge, LOURIE and PROST, Circuit 

Judges.
2 ENOCEAN GMBH v. FACE INTERNATIONAL CORP

PROST, Circuit Judge. 

EnOcean GmbH (“EnOcean”) appeals from an order of 

the U.S. Patent and Trademark Office (“PTO”), Board of 

Patent Appeals and Interferences (“Board”), finding all of 

EnOcean’s claims involved in Patent Interference No. 

105,755 with Face International Corporation (“Face”) 

unpatentable over a combination of prior art that includes 

PCT Application No. PCT/GB01/00901 to Burrow (“Burrow reference”). See J.A. 50. Because the Board erred in 

treating certain EnOcean claims as means-plus-function 

claims and in finding that certain EnOcean claim limitations lack support in its priority German and PCT applications, we vacate-in-part1 the Board’s order with respect 

to EnOcean’s claims and motions, and we remand for 

further proceedings.

I. BACKGROUND

EnOcean owns the rights to U.S. Patent Application

No. 10/304,121 (“EnOcean application”), which contains 

claims to a self-powered switch. The switch can be used 

to turn on and off lights, appliances, and other devices 

without a battery or a connection to an electrical outlet. 

The named inventors on the EnOcean Application 

originally filed a patent application disclosing their new 

switch in Germany on May 24, 2000 (DE 10025 561.2), 

and on May 21, 2001 they filed a PCT application with a 

similar disclosure. See PCT Application No. 

PCT/DE01/01965. 

Following EnOcean’s formal suggestion, the Board declared an interference on June 25, 2010 between EnOcean 

1 Since Face has not appealed the Board’s finding 

that all of its claims involved in the interference are 

unpatentable as obvious, the portion of the Board’s opinion that relates to Face’s claims remains intact. 

 
ENOCEAN GMBH v. FACE INTERNATIONAL CORP 3

and Face, the real party of interest in U.S. Patent No. 

7,084,529, which also claims a self-powered switch. 

Subsequently, the Board found that all the involved Face 

claims were unpatentable under 35 U.S.C. § 103 in view 

of the Burrow reference in combination with several other 

references. J.A. 41. Face has not appealed this determination.

Under 37 C.F.R. § 41.207(c),2 the Board next applied a 

presumption that EnOcean’s claims would be unpatentable for the same reasons that Face’s claims were unpatentable. J.A. 45. EnOcean’s sole argument for 

rebutting the presumption required a determination that 

EnOcean’s involved claims could benefit from the filing 

date of its German and PCT applications, thereby eliminating the Burrow reference from the realm of prior art.3 

However, the Board found that EnOcean’s disclosure of a 

“receiver” in its German application did not support the 

2 Section 41.207(c) states: “When a motion for 

judgment of unpatentability against an opponent’s claim 

on the basis of prior art is granted, each of the movant’s 

claims corresponding to the same count as the opponent’s 

claim will be presumed to be unpatentable in view of the 

same prior art unless the movant in its motion rebuts this 

presumption.” 

3 The Burrow reference is a published PCT application with a publication date of September 13, 2001 and an 

international filing date of March 5, 2001. Since the 

Burrow reference was filed on or after November 29, 

2000, designated the United States, and was published in 

English, it is available as prior art as of its PCT filing 

date. 35 U.S.C. § 102(e)(2) (2002). The Burrow reference 

is an intervening reference because its filing date of 

March 5, 2001 falls between the U.S. filing date of the 

EnOcean Application (November 25, 2002) and the filing 

date of the German application (May 24, 2000). 

 
4 ENOCEAN GMBH v. FACE INTERNATIONAL CORP

“means for receiving” limitation in the EnOcean application’s claims 37, 38, and 43-45 (“means-plus-function

claims”). J.A. 46-47. The Board also found that the 

EnOcean application’s claims 29, 30, 32, 33, 39, 40, and 41 

(“receiver claims”) were means-plus-function claims, 

despite the fact that they all lack “means for” language. 

J.A. 43-46. The Board explained that the word “receiver” 

is defined in the claims solely in terms of functional 

language, thus creating no difference between a “receiver” 

and “signal receiving means.” J.A. 43-44. Therefore, the 

Board accorded no benefit of priority to the receiver 

claims as well, and it found all of EnOcean’s claims unpatentable under § 103 for the same reasons that Face’s 

claims were unpatentable. J.A. 45. The Board then 

dismissed all other pending motions of both parties as 

moot. J.A. 6-7. EnOcean timely appealed. We have

jurisdiction under 28 U.S.C. § 1295(a)(4).

II. DISCUSSION

This appeal concerns two sets of EnOcean’s claims, 

the receiver claims and the means-plus-function claims, 

and presents two main issues: (1) whether the Board 

erred in finding that the receiver claims invoke § 112, ¶ 6; 

and (2) whether the Board erred in finding that both sets 

of claims are not entitled to claim priority to the German 

and PCT applications. We address each issue in turn. 

A. Whether the Receiver Claims Invoke § 112, ¶ 6

It is well established that the use of the term “means” 

triggers a rebuttable presumption that § 112, ¶ 6 governs 

the construction of the claim term. Inventio AG v. 

ThyssenKrupp Elevator Ams. Corp., 649 F.3d 1350, 1356 

(Fed. Cir. 2011) (citing TriMed, Inc. v. Stryker Corp., 514 

F.3d 1256, 1259 (Fed. Cir. 2008)). Conversely, where, as 

here, the claim language does not recite the term 

“means,” we presume that the limitation does not invoke 

§ 112, ¶ 6. Id. (citing Personalized Media Commc’ns, LLC 

v. Int’l Trade Comm’n, 161 F.3d 696, 703-04 (Fed. Cir. 
ENOCEAN GMBH v. FACE INTERNATIONAL CORP 5

1998)). However, this presumption can be overcome if the 

challenger demonstrates that “the claim term fails to 

‘recite sufficiently definite structure’ or else recites ‘function without reciting sufficient structure for performing 

that function.’” Id. (citing CCS Fitness v. Brunswick 

Corp., 288 F.3d 1359, 1369 (Fed. Cir. 2002)). The correct 

inquiry is “whether skilled artisans, after reading the 

patent, would conclude that a claim limitation is so devoid 

of structure that the drafter constructively engaged in 

means-plus-function claiming.” Inventio, 649 F.3d at 

1357. Therefore, “[u]ltimately, whether claim language 

invokes § 112, ¶ 6 depends on how those skilled in the art 

would understand the structural significance of that claim 

language.” Id. at 1360. 

Whether a claim limitation invokes means-plusfunction claiming under 35 U.S.C. § 112, ¶ 6 (now 35 

U.S.C. § 112(f)), is an exercise in claim construction which 

we review without deference. Power Integrations, Inc. v. 

Fairchild Semiconductor Int’l, Inc., 711 F.3d 1348, 1355

(Fed. Cir. 2013) (citing Inventio, 649 F.3d at 1356).4 We 

set aside factual findings of the Board “that are unsupported by substantial evidence.” Falkner v. Inglis, 448 

F.3d 1357, 1363 (Fed. Cir. 2006).

Here, EnOcean challenges the Board’s construction 

that its receiver claims invoke § 112, ¶ 6. The receiver 

claims include the following limitations:

4 Face argues that the Board’s construction is entitled to deference if the PTO’s interpretation is reasonable 

in light of all the evidence before the Board. See In re 

Suitco Surface, Inc., 603 F.3d 1255, 1259 (Fed. Cir. 2010). 

Although we apply de novo review to the Board’s claim 

construction, in this case a more deferential standard of 

review would not change the outcome.

 
6 ENOCEAN GMBH v. FACE INTERNATIONAL CORP

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;” 

EnOcean application, claims 37, 38, 43, and 45 (emphases 

added). Notably, these claims all lack the word “means,” 

thus entitling them to a presumption that they are not 

means-plus-function claims. Despite the benefit of this 

presumption, the Board concluded that “the recited ‘receiver’ element of the involved EnOcean claims invokes 

§ 112, ¶ 6.” J.A. 47. The Board found “that there is no 

distinction in meaning between ‘receiver’ and ‘signal 

receiving means,’” and stated that “the receiver of the 

EnOcean claims is defined in the claims solely in terms of 

functional language.” Id. 

On appeal, EnOcean challenges the Board’s determination that its receiver claims invoke § 112, ¶6. EnOcean 

argues that the claim limitation “receiver” is reasonably 

well understood in the art as a name for a structure which 

performs the recited function. See Greenberg v. Ethicon 

Endo-Surgery, Inc., 91 F.3d 1580, 1583 (Fed. Cir. 1996) 

(applying this test to the claim term “detent mechanism”). 

EnOcean points to external evidence and expert testimony to support this assertion. 

Face responds by arguing that the claimed “receiver” 

is defined only in terms of the function that it performs 

(i.e., receiving), not its structure. Citing Blackboard, Inc.
ENOCEAN GMBH v. FACE INTERNATIONAL CORP 7

v. Desire2Learn, Inc., it argues that a receiver is “essentially a black box that performs a recited function,” because “how it does so is left undisclosed.” 574 F.3d 1371, 

1383 (Fed. Cir. 2009). 

We agree with EnOcean. The term “receiver” (i.e., the 

absence of the term means) presumptively connotes 

sufficiently definite structure to those of skill in the art. 

See Personalized Media, 161 F.3d at 703-04. And in this 

case, Face has not overcome that presumption. 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.” J.A. 18. 

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. See, e.g., J.A. 1772-73, 1947 (scientific 

literature demonstrating that the term “receiver” was 

well understood in the art); J.A. 1199-1220, 1377-87, 

1434-35, 1654-64 (expert declarations addressing how 

well known the term “receiver” was); see also Inventio, 649 

F.3d at 1356 (calling for courts to consider relevant extrinsic evidence to determine whether a claim term invokes § 112, ¶ 6). 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); see also Power Integrations, 711 

F.3d at 1365 (“[W]e require only that the claim term be 

used in common parlance or by ordinarily skilled artisans 

to designate sufficiently definite structure, even if the 
8 ENOCEAN GMBH v. FACE INTERNATIONAL CORP

term covers a broad class of structures.”) (internal citation 

omitted). Given the demonstrated familiarity that one of 

skill in the art would have with a “receiver” and the 

Board’s own factual finding that a skilled worker would 

know what a “receiver” is, we hold that in this case the 

term is not the “black box that performs a recited function” that Face would have us believe it is. 

This conclusion is also well supported by our precedent. We have found sufficient structure in claim terms 

to avoid invoking § 112, ¶ 6 in several similar cases. See, 

e.g., Flo Healthcare Solutions, LLC v. Kappos, 697 F.3d

1367, 1374-75 (Fed. Cir. 2012) (holding that “height 

adjustment mechanism” imparts sufficient structure so 

that the presumption against applying § 112, ¶ 6 is not 

overcome); Inventio, 649 F.3d at 1353, 1359-60 (holding

that “computing unit . . . for . . . evaluating . . .” is not a 

means-plus-function limitation because the term connotes 

a computer or other data processing device); Linear Tech.,

379 F.3d at 1320-21 (holding that term “circuit” itself in 

claim term “‘circuit’ for ‘monitoring a signal from the 

output terminal to generate a first feedback signal’” 

connotes structure); Personalized Media Commc’ns, 161 

F.3d at 704 (holding that claim term “digital detector”

recited sufficient structure to avoid § 112, ¶ 6); Greenberg, 

91 F.3d at 1583-84 (holding that § 112, ¶ 6 did not apply 

to the term “detent mechanism,” because “the noun ‘detent’ denotes a type of device with a generally understood 

meaning in the mechanical arts, even though the definitions are expressed in functional terms.”). For the foregoing reasons, we conclude that the Board erred in finding 

that the EnOcean application’s receiver claims invoked 

§ 112, ¶ 6. 

B. Whether the Board Erred in Determining Priority

Turning to the priority issue, we now examine whether the means-plus-functions claims and/or the receiver 

claims are entitled to claim the benefits of the earlier 
ENOCEAN GMBH v. FACE INTERNATIONAL CORP 9

German and PCT applications’ priority dates. This inquiry is crucial because, as the Board correctly noted, to 

overcome the date of the Burrow reference, EnOcean 

must establish that its claims are entitled to an earlier

priority date. J.A. 43.

“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.’” Anascape, Ltd. v. Nintendo 

of Am. Inc., 601 F.3d 1333, 1335 (Fed. Cir. 2010) (citing 

Lockwood v. Am. Airlines, Inc., 107 F.3d 1565, 1572 (Fed.

Cir. 1997)). We review de novo the Board’s legal conclusions regarding priority. Eaton v. Evans, 204 F.3d 1094, 

1097 (Fed. Cir. 2000). 

The Board first found, and EnOcean does not dispute, 

that claims 29, 30, 32, 33, 39, and 41 are means-plusfunction claims. J.A. 44. A portion of EnOcean’s exemplary claim 29 is reproduced below:

29. A switching system comprising: 

. . .

signal reception means for receiving a first electromagnetic signal transmitted by said first signal 

transmission means; 

said signal reception means being adapted to generate a second signal in response to said first electromagnetic signal transmission means; . . . .

EnOcean application, claim 29 (emphases added). The 

Board then looked to the German application and found 

that it “makes only passing reference to the signal reception means.” J.A. 45. The German application’s only 

reference to a receiver states:
10 ENOCEAN GMBH v. FACE INTERNATIONAL CORP

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.). 

J.A. 1276 (emphasis added). Based on that disclosure, the 

Board found that “the PCT and German applications [do 

not] describe the structure, materials, acts or the equivalents corresponding to the claimed signal reception 

means.” J.A. 46. In making its finding, the Board required that the priority documents “expressly describe the 

structure of the receiver.” J.A. 45. 

Merely because we concluded above that the term “receiver” in EnOcean’s receiver claims connotes enough 

structure to avoid invoking § 112, ¶ 6 does not necessarily 

mean that we must conclude that the disclosure of “a 

single receiver” connotes enough structure to support 

EnOcean’s means-for-receiving claims for purposes of 

claiming priority. Compare Inventio, 649 F.3d at 1360 

(“Ultimately, whether claim language [lacking ‘means 

for’] invokes § 112, ¶ 6 depends on how those skilled in 

the art would understand the structural significance of 

that claim language.”), with Lucent Techs., Inc. v. Gateway, Inc., 543 F.3d 710, 719 (Fed. Cir. 2008) (citing Biomedino, LLC v. Waters Techs. Corp., 490 F.3d 946, 952 

(Fed. Cir. 2007)) (stating that for purposes of claiming 

priority to an earlier application, “[t]he understanding of 

one of skill in the art does not relieve the patentee of the 

duty to disclose sufficient structure to support meansplus-function claim terms”).

Nonetheless, we do come to that conclusion. “Sufficient structure must simply ‘permit one of ordinary skill 

in the art to know and understand what structure corresponds to the means limitation’ so that he may ‘perceive 

the bounds of the invention.’” In re Aoyama, 656 F.3d 
ENOCEAN GMBH v. FACE INTERNATIONAL CORP 11

1293, 1298 (Fed. Cir. 2011). For the reasons articulated 

in section II.A, supra, EnOcean has demonstrated 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. In requiring that the German and PCT 

applications “expressly describe the structure of the 

receiver,” the Board applied an incorrect standard. J.A. 

45. Since 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.” Webster Loom Co. v. Higgens, 105 

U.S. 580, 586 (1881). “This enables patents to remain 

concise statements of what is new, not cumbersome 

repetitions of what is already known and readily provided 

by reference.” Pressure Prods. Med. Supplies, Inc. v. 

Greatbatch Ltd., 599 F.3d 1308, 1324 (Fed. Cir. 2010). 

Thus, we conclude that the Board erred in finding on this 

basis that the EnOcean application’s means-plus-function

claims were not entitled to claim the benefit of the German and PCT applications’ priority dates. 

The Board stated that it applied the same priority

analysis to EnOcean’s receiver claims as it applied to 

EnOcean’s means-plus-function claims and subsequently

concluded that the receiver claims were also not entitled 

to the benefit of the German and PCT applications’ priority dates. J.A. 44. Therefore, we also conclude that the 

Board erred in finding that the receiver claims were not 

entitled to claim the benefit of the German and PCT 

applications’ priority dates.

III. CONCLUSION

For the foregoing reasons, we hold: (1) that the receiver claims in EnOcean’s application do not invoke § 112, 

¶ 6; (2) that the “means for receiving” limitations found in 
12 ENOCEAN GMBH v. FACE INTERNATIONAL CORP

EnOcean’s means-plus-function claims are adequately 

supported by the written descriptions found in the German and PCT applications for purposes of claiming priority; and (3) that the “receiver” limitations found in 

EnOcean’s receiver claims are adequately supported by 

the written descriptions found in the German and PCT 

applications for purposes of claiming priority. We therefore vacate-in-part the Board opinion to the extent it 

relates to EnOcean’s receiver and means-plus-function

claims. We also vacate the Board’s dismissal of 

EnOcean’s remaining motions and remand with instructions to the Board to consider all outstanding EnOcean 

motions in view of this opinion. 

VACATED-IN-PART AND REMANDED