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Computer-Implemented Algorithm Recited in Prose Discloses Adequate Structure for Means-Plus-Function Element

November 04, 2011

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Last Month at the Federal Circuit - December 2011

Judges: Rader, Newman (author), Prost

[Appealed from: E.D. Tex., Judge Davis]

In Typhoon Touch Technologies, Inc. v. Dell, Inc., No. 09-1589 (Fed. Cir. Nov. 4, 2011), the Federal Circuit affirmed the district court’s construction of four claim terms but reversed its judgment of indefiniteness for a means-plus-function element.

Typhoon Touch Technologies, Inc. (“Typhoon”) sued a number of manufacturers and sellers of laptop computers and other tablet-like devices, alleging infringement of its U.S. Patent Nos. 5,379,057 (“the ’057 patent”) and 5,675,362 (“the ’362 patent”). The ’057 patent and the related ’362 patent are both titled “Portable Computer with Touch Screen and Computer System Employing Same.” The ’057 and ’362 patents disclose a “portable, self-contained, general-purpose, keyboardless computer” with a “touch screen display for data entry purposes,” reciting the deficiencies of portable devices that require a keyboard.

The district court found four of the claim elements required that an infringing device must actually perform, or be configured or programmed to perform, each of the claimed functions, resulting in a judgment of noninfringement for all defendants. Finding a fifth claim element invalid for indefiniteness, the district court held that the element lacked sufficient structure, under means-plus-function claiming, by failing to recite an algorithm for the claimed function. Typhoon appealed.

Taking up first the four constructions that resulted in a judgment of noninfringement, the Federal Circuit considered the element of a “memory for storing at least one data collection application configured to determine contents and formats of said inquiries displayed on said screen.” The district court found this clause required a memory actually configured or programmed to store the data collection application. Typhoon argued, on appeal, that requiring an infringing device to be configured or programmed to perform the memory-storing function incorrectly included a “use” limitation in an apparatus claim. Rather, Typhoon argued that a device may infringe if it is merely capable of performing each claimed function, even though it is not so configured or programmed. The Court, however, relied on the specification as the primary source for determining the invention, which recited that “[t]he memory of the portable computer stores a data collection application.” Slip op. at 8 (citation omitted). On this basis, the Court found no error in the district court’s construction that the “memory for storing” clause required a device actually configured or programmed to store the data collection application.

Next, the Court considered the district court’s construction of “processor for executing said data collection application.” Again, the district court construed this clause as requiring a processor actually configured or programmed to execute the data collection application rather than merely being capable of executing the data collection application. Reviewing the district court’s construction, the Court noted the inconsistencies between Typhoon’s current position and the prosecution history. In response to a rejection, the applicant narrowed the claims to executing data collection applications. Based on the specification and this disclosure, the Court agreed with the district court’s construction, binding the patentee to representations made during the prosecution of the patents.

Third, the Court considered the element of a “run-time utility operating in conjunction with said processor to execute said application and said libraries to facilitate data collection operations.” The district court found the “operating in conjunction” phrase needed no construction because the meaning was clear. Once again, Typhoon argued that the district court incorrectly deemed the claimed element required that the utility operates in conjunction with the processor rather than being merely capable of doing so. Looking to the specification again, the Court found it recited a “portable computer . . . specifically adapted for facilitated data collection and recordation.” This language satisfied the Court that the district court did not err in construing the “operating in conjunction” phrase as requiring the utility be configured or programmed to operate in conjunction with the processor.

Fourth, the Court considered the district court’s construction of “keyboardless” as meaning “without a mechanically integrated keyboard.” On appeal, Typhoon argued this definition of “keyboardless” was too restrictive, because “keyboardless” meant the device did not require a separate keyboard. The infringing devices, Typhoon argued, could have a separate keyboard if a touch screen rendered the keyboard unnecessary. The Court therefore considered whether the patentee ascribed a special meaning to the term “keyboardless” other than the ordinary meaning “without a keyboard.” Looking again to the patentee’s own language in the specification, the Court distinguished a mechanically integrated keyboard from a “hooked up” peripheral keyboard. The Court found that the ’057 and ’362 patents described no device having a mechanically integrated keyboard. Instead, the specification proposed that an external keyboard may be “hooked up.” And while the specification criticized mechanical keyboards as laborious or tedious, it touted the advantages of touch-screen keyboards. With these representations made in the specification, the Court affirmed the district court’s construction of “keyboardless” as “without a mechanically integrated keyboard.”

Because Typhoon stipulated to noninfringement on the district court’s construction of these four claim terms, the Federal Circuit affirmed the noninfringement judgment.

The Federal Circuit then considered the fifth claim element, which the district court found indefinite and invalid. In the phrase “means for cross-referencing said responses with one of said libraries of said possible responses,” the district court found this means-plus-function element lacked an “algorithm” adequate to provide structure for the function. The Federal Circuit explained that an algorithm “encompasses ‘in essence a series of instructions for the computer to follow,’ whether in mathematical formula, or a word description of the procedure to be implemented by a suitably programmed computer.” Id. at 15 (citation omitted). Because “algorithm” has broad meaning in computer systems, a patentee can express it as a mathematical formula, in prose, as a flowchart, or any other manner that provides sufficient structure “for a person of skill in the field to provide an operative software program for the specified function.” Id. at 16.

Here, the Court found that the patentee did disclose a four-step algorithm for its computer-implemented cross-referencing function, described in prose as (1) entering a response; (2) searching for the entered response in a library of responses; (3) determining whether a match exists in the library; and (4) executing an action if a match exists. And in rejecting the finding of indefiniteness, the Federal Circuit explained that the district court placed too much weight on Typhoon’s statement that the specification did not explicitly disclose the specific algorithm for cross-referencing. The Court found that this did not constitute a “concession,” for a patentee need not disclose computer code nor a mathematical algorithm in the specification. “[I]t suffices if the specification recites in prose the algorithm to be implemented by the programmer.” Id. at 18-19. Accordingly, the Federal Circuit found that the four-step written algorithm disclosed adequate structure for the means-plus-function element and reversed the district court’s finding of invalidity for indefiniteness.

Thus, the Court affirmed the district court’s finding of noninfringement and reversed the district court’s finding of invalidity for indefiniteness.

Summary authored by Lauren J. Dreyer, law clerk at Finnegan.