Functional Claim Language In View of Recent CAFC Decisions

Functional Claim Language In View of Recent CAFC Decisions

Author: Nicholas R. Mattingly

The recent en banc opinion in Williamson v. Citrix (Fed. Cir. 2015) highlights the dangers of functional claiming in computer-implemented inventions.  On June 16, 2015, the Federal Circuit decided en banc to overrule precedent that characterizes as “strong” the presumption that that a limitation lacking the word “means” is not subject to § 112(f).

Applying a different standard, which is discussed below, the court found the term “distributed learning control module” is subject to § 112(f) and is invalid as indefinite under § 112(b).  Just under a year ago in November 2014, the court, in Williamson v. Citrix, reached the opposite conclusion with respect to whether the claim term invoked § 112(f).

Recent CAFC decisions have also touched on the dangers involved with using functional claim limitations. In EON Corp v. AT&T (Fed. Cir. 2015), the CAFC affirmed invalidity based on indefiniteness for failing to disclose software algorithms corresponding to means-plus-function language.  In Robert Bosch, LLC v. Snap-On Inc. (Fed. Cir. 2014), the court affirmed claim limitations as indefinite after determining that the claims invoke 35 U.S.C. § 112(f), even though the phrase “means” was not explicitly recited in the claims.

Principles of Law

Use of the word “means” in a claim creates a rebuttable presumption that the applicant intended to invoke § 112(f).  Failure to use the word “means” creates a rebuttable presumption that the applicant did not intend the claims to be governed by § 112(f).

Prior to the en banc opinion in Williamson v. Citrix, the presumption against invocation was characterized as ”strong.”  Now, the standard “is whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure.”  If the words of the claim do not meet the standard, then § 112(f) applies.  The en banc opinion expressly overrules the characterization of the presumption as “strong.”

The above-recited standard is not a “new” one.  Rather, it was the standard used prior to Lighting World, Inc. v. Birchwood Lighting, Inc. (Fed. Cir. 2004).  Lighting World marked the first time a different standard was applied to the presumption flowing from the absence of the word “means” and held that the presumption flowing from the absence of the term “means” was a “strong one that is not readily overcome.”  The en banc opinion reasoned that

the characterization is unwarranted, is uncertain in meaning and application, and has the inappropriate practical effect of placing a thumb on what should otherwise be a balanced analytical scale.  It has shifted the balance struck by Congress in passing § 112, para. 6 and has resulted in a proliferation of functional claiming untethered to § 112, para. 6 and free of the strictures set forth in the statute.

The en banc opinion also overrules the raised bar of presumption set forth in Flo Healthcare Solutions, LLC v. Kappos (Fed. Cir. 2012).  Flo Healthcare Solutions declared that “[w]hen the claim drafter has not signaled his intent to invoke [§ 112(f)] by using the term ‘means,’ [the CAFC] is unwilling to apply that provision without a showing that the limitation essentially is devoid of anything that can be construed as structure.”  The en banc decision overruled the requirement of a “showing that the limitation essentially is devoid of anything that can be construed as structure.”  The principle remains that the presumption that § 112(f) does not apply 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.”

Stated another way, the presumption may be overcome by using a term instead of “means” that is “a nonce word or a verbal construct that is not recognized as the name of structure.”  Generic terms such as “mechanism,” “element,” “device,” and other nonce words that reflect nothing more than verbal constructs may be used in a claim in a manner that is tantamount to using the word “means” because they “typically do not connote sufficiently definite structure” and therefore may invoke § 112(f).

On the other hand, claim language that further defines a term that otherwise would be a nonce word can denote sufficient structure to avoid construction under § 112(f). A claim limitation that contains a term that is used in common parlance or by persons of skill in the art to designate structure, even if the term covers a broad class of structures and even if the term identifies the structures by their function can also denote sufficient structure. For example, “digital detector” was found to recite sufficient definite structure to avoid the invocation.  “Digital detector” had a known meaning to those having ordinary skill in the art as a type of “detector” and dictionary definitions connoted structure, including a rectifier or demodulator.

The court also considers the specification to inform the analysis of whether the claim recites sufficiently definite structure to overcome a presumption that § 112(f) governs the claim.  For example, in Inventio AG v. Otis Elevator Co., the claim terms “modernizing device” and “computing unit” when read in light of the specification connoted sufficient, definite structure to one of skill in the art to preclude application of § 112(f).

The USPTO applies § 112(f) to a claim limitation if it meets the following 3-prong analysis:

  • (A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder for performing the claimed function;

  • (B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” or another linking word or phrase, such as “configured to” or “so that”; and

  • (C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.

If § 112(f) applies to a claim limitation, then the claim is reviewed for indefiniteness in accordance with § 112(b) to determine whether the corresponding structures, materials, or acts that perform the claimed function are disclosed in the specification. If the corresponding structure is not adequately disclosed, then the claim will be indefinite under § 112(b).  The trade-off for allowing means-plus function claiming is that the specification must contain sufficient descriptive text by which a person of skill in the field of the invention would know and understand what structure corresponds to the limitation invoking § 112(f).

In computer-implemented inventions, the corresponding structure must be an algorithm, disclosed as one or more flow charts supported by a written description of each step.  In particular, as stated in Aristocrat Techs. Australia Pty Ltd. v. Int’l Game Tech, the corresponding structure must include the algorithm needed to transform the general purpose computer or processor disclosed in the specification into the special purpose computer programmed to perform the disclosed algorithm.

The “specification can express the algorithm in any understandable terms including as a mathematical formula, in prose, or as a flow chart, or in any other manner that provides sufficient structure.”  An algorithm is defined, for example, as “a finite sequence of steps for solving a logical or mathematical problem or performing a task.”

Structure disclosed in the specification qualifies as “corresponding structure” if the intrinsic evidence clearly links or associates that structure to the function recited in the claim.  Therefore, “if a person of ordinary skill in the art would be unable to recognize the structure in the specification and associate it with the corresponding function in the claim, a means-plus-function clause is indefinite.”

With respect to adequate disclosure in the specification, simply disclosing a computer as the structure designated to perform a particular function does not limit the scope of the claim to “the corresponding structure, material, or acts,” that perform the function, as required by section § 112.

In Eon Corp., finding the claims indefinite, the CAFC distinguished the case from that of In re Katz, which held that a standard microprocessor can serve as sufficient structure for “functions [that] can be achieved by any general purpose computer without special programming.” In Katz, claim terms involving basic “processing,” “receiving,” and “storing” functions were not necessarily indefinite because a general purpose computer need not “be specially programmed to perform the recited function.”  The court called this exception a narrow one.  The claims in Eon Corp. were indefinite since a general purpose microprocessor could not perform the functions claimed, such as “causing selected themes to automatically display a second menu.”

In Noah Sys. Inc. v. Intuit Inc., the CAFC reiterated that the test for definiteness asks whether one skilled in the art would understand the bounds of the claim when read in light of the specification.” However, the testimony of one of ordinary skill in the art cannot supplant the total absence of structure from the specification.”

In addition, relying on the proposition that the algorithm, which is lacking in the specification, is known to one of ordinary skill in the art does not save the claim from indefiniteness.” Further, a bare statement that known techniques or methods can be used does not meet the standard for adequately disclosing structure. The CAFC in Triton Tech of Tex., LLC v. Nintendo of Am., Inc. upheld indefiniteness of a claim stating that “the district court correctly recognized that ‘[a]lthough a person of skill in the art might be able to choose an appropriate numerical integration algorithm and program it onto a microprocessor, the [p]atent discloses no algorithm at all.’”  So, extrinsic evidence in the form of dictionaries may be used as evidence to determine whether a term connotes structure to avoid the invocation a claim under § 112(f), but testimony alone will not cure indefiniteness of the claim under § 112(b) if the algorithm is not disclosed.

Williamson v. Citrix Online, LLC (Fed. Cir. 2015) (en banc)

In the November 2014 opinion of Williamson v. Citrix, the majority held that the district court erred in concluding that “distributed learning control module” was a means-plus-function claim term subject to § 112(f).  In Williamson v. Citrix (en banc) the CAFC substituted the previous opinion with the en banc opinion overruling precedent that characterizes as “strong” the presumption that a limitation lacking the word “means” is not subject to § 112(f).

Applying the above-recited standard in the en banc opinion, the court found that the term “distributed learning control module” was subject to § 112(f) and indefinite under § 112(b).

Claim 8 of U.S. Pat. No. 6,155,840 sets forth, inter alia:

a distributed learning control module for receiving communications transmitted between the presenter and the audience member computer systems and for relaying the communications to an intended receiving computer system and for coordinating the operation of the streaming data module.

The analysis of whether the term invokes § 112(f) begins with pointing out that the full term of the claim must be considered and not merely the introductory phrase, “distributed learning control module.”  The opinion states that, as claimed, the full term is a format consistent with traditional means-plus-function claim limitations.  The court reasoned that the term “means” is replaced with the term “module” and the claim recites functions performed by the “distributed learning control module.”

In the context of § 112, “module” is a well-known nonce word that can operate as a substitute for “means.”  The word “module” in claim 8 does not provide any indication of structure because it sets forth the same black box recitation of structure for providing the same specified function as if the term “means” had been used.

Dictionary definitions were not considered whatsoever in the en banc opinion to determine whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure.  Rather, the en banc opinion reasoned that the term “module” was a generic “black box” term that performed the recited computer-implemented functions and the prefix “distributed learning control” do not depart structure into the term “module.” The court notes that “module” is simply a generic description for software or hardware that performs a specified function.

 

Although the “distributed learning control module” is described in a certain level of detail in the written description, the written description failed to impart any structural significance to the term. The specification of the ‘840 patent supports that the distributed learning control module operates as a functional unit of the distributed learning server and coordinates the operation of the streaming data module through input from the presenter computer system. The specification also makes clear that the distributed learning control module includes software that runs on a portion of the distributed learning server.

 

Consider the portions of the specification related to Figs. 2 and 3, which the court relied on in their original conclusion that § 112(f) does not apply. Fig. 2 of the ‘840 patent is reprinted below.

Fig. 2 is a high-level block diagram illustrating a typical computer system 200 for implementing the distributed learning server (DLS) 102, on which the claimed distributed learning control module is implemented.  Fig. 3 (reprinted below) shows a block diagram illustrating the functional units of the DLS 102, including a distributed learning control module (DLCM) 310, a classroom environment module 312, and a streaming data module 314. The specification states that the DLCM 310 controls the communications among the various computer systems 106, 108 in the distributed learning system 100 and manages the other modules in the DLS 102.

However, the written description fails to impart any structure significance to the term learning control module.  The court did not find anything that lead them to construe the expression as the name of a sufficiently definite structure to avoid the invocation of § 112(f).

 

Looking back to the language of the claim, one fault pointed out by the court was that the claim does not describe how the “distributed learning control module” interacts with other components in the distributed learning [control] server in a way that might inform the structural character of the limitation in question or otherwise impart structure to the “distributed learning control module.”  Note that in claim 8, the distributed learning server comprises the “distributed learning control module.”

Further, the en banc opinion reiterates the principle that mere testimony declaring that one having ordinary skill in the art, reading the specification, would know how to program a computer to perform the recited functions, does not replace structure where none is otherwise disclosed.

 

Having found that the term invokes § 112(f), the decision continues with analyzing whether the specification discloses sufficient structure that corresponds to the claimed function.  The district court identified three functions in the claim: 1) receiving communications transmitted between the presenter and the audience member computer systems; 2) relaying the communications to an intended receiving computer system; and 3) coordinating the operation of the streaming data module.

 

The opinion focused on whether adequate structure corresponding to the “coordinating” function is disclosed in the specification.  After determining that a special purpose computer is required to perform the function, the court searched for an algorithm for performing the function, but did not find one.  The court rejected Williamson’s argument that the distributed learning control module controls communications among the various computer systems and that the “coordinating” function provides a presenter with streaming media selection functionality.  The disclosures relied upon by Williamson were thought of by the court as merely functions of the distributed learning control module and opined that the specification does not set forth an algorithm for performing the claimed functions.

 

Indeed, none of Figs. 1-5 or the written description disclose an algorithm for coordinating the operation of the streaming data module.  As a result, the claim is indefinite under § 112(b) and therefore invalid.

 

Robert Bosch, LLC v. Snap-On Inc (Fed. Cir. 2014)

 

In October 2014, the Federal Circuit decided Robert Bosch, LLC v. Snap-On Inc upholding indefiniteness, affirming that both claim terms “program recognition device” and “program loading device” are means-plus-function terms and the specification does not disclose the requisite corresponding structures.  Therefore, the claims were held invalid as indefinite.

Claim 1 of U.S. Pat. No. 6,782,313 sets forth, inter alia:

a program recognition and program loading device,
wherein a program version contained in a connected control unit is queried and recognized by means of the program recognition device, and, if the program available in the motor vehicle and recognized via the diagnostic/test plug is not stored there in a latest and most current version, a respective most current version is loaded by the program loading device into a program storage device of the pertinent control unit of the motor vehicle…

 

Turning to the analysis of whether the terms invoke § 112(f), the court asked “if the claim language, read in light of the specification, recites sufficiently definite structure to avoid” § 112(f). The court elaborated the issue, adding “the question is whether the claim language names particular structures or, instead, refers only to a general category of whatever may perform specified functions.”

 

 In particular, the court stated that the word “device” has been found to be non-structural in other precedent.  In addition, the other words of the phrase do nothing more than identify functions for the “device” to perform.  Bosch argued that the terms “program recognition device” and “program loading device” both name physical electronic structures with physical connections to other components discussed in the ‘313 patent.  However, the court noted that the patent merely explains the device’s function and does not provide structural guidance whatsoever of the program recognition device itself.  The ‘313 patent is silent on what such a “program loading device” consists of.

 

The decision also mentions Inventio, in which the claimed “computing unit” and “modernizing device” were held to connote sufficiently definite structure, thereby avoiding an invocation of § 112(f).  In Inventio, the CAFC stated that the claims indicate that the “modernizing device” functions as an electrical circuit that receives signals, processes signals, and outputs signals to other components in the patented system.  The court, in Inventio, also considered the specification, which depicts the modernizing device and its internal components, namely, the processor, signal generator, converter, memory, and signal receiver elements. Fig. 3 of the patent-in-suit of Inventio is printed below, which shows the components of the modernizing device.

 

 

The written description of the patent in Inventio also shows how the elements are connected together and to the elevator control and computing unit components of the elevator system.  Accordingly, in Inventio, the claims recited sufficient structure to perform the recited function, which was also supported by the depiction of the components and connections thereof in the specification.

 

On the other hand, the court distinguished Bosch’s claims from Inventio since the claims involved functional terms and there is no language in the specification or dependent claims that defines the terms to refer to structures.

 

The court found the specification silent about any interaction between the “program recognition device” and other components of the system, including the external diagnostic tester. As stated by the CAFC, “the specification does not teach how the “program recognition device” receives and processes signals, as the words “signal” and “process” are not even in the specification.”  The same rationale was used with respect to the term “program loading device.”

 

Finding the presumption against invocation of § 112(f) was overcome, the court turned to whether the claim terms were indefinite, as required.  However, the court easily found the claims indefinite since there was no guidance about the structure of the program recognition device or program loading device.  As a result, all claims were held invalid.