In Board of Regents of the University of Texas System v. BENQ America, No. 2007-1497 (July 24, 2008), the U.S. Court of Appeals for the Federal Circuit recently affirmed the trial court’s decision that BENQ America, Motorola Corp., and a number of other handset manufacturers (collectively “BENQ”) did not infringe U.S. Patent No. 4,674,112 (the ‘112 patent). At issue before the Federal Circuit was whether the trial court correctly construed the claim term “syllabic element” to mean a narrower “one-syllable element” instead of a broader “word or a part of a word” with no limit on the number of syllables comprising it. Since the Federal Circuit agreed that the claim term “syllabic element” was correctly construed by the trial court to mean a “one-syllable element,” BENQ did not infringe the ‘112 patent.
The ‘112 patent is directed towards an apparatus and method that enables “non-verbal entry” and transmission of one or more words using a standard, touch-tone telephone. For each letter of the word to be transmitted, a user depresses a single key on a telephone’s keypad. Because each key available on the standard telephone keypad represents more than one letter, the user’s input sequence will be inherently ambiguous. In order to resolve the ambiguity and correctly identify the inputted word, the method compares this sequence against a “vocabulary” of words or syllabic elements. While it is easier for the system to compare the inputted word to a vocabulary of words, the system can instead enable an expanded word recognition capability by using a vocabulary of syllabic elements.
To construe the claim term “syllabic element,” the Federal Circuit looked to the intrinsic record—that is, (1) the actual language of the claims, (2) the specification of the ‘112 patent, and (3) the prosecution history of the ‘112 patent. First, the claim language itself recited that “each pre-programmed code [is] representative of a syllabic element” and “a representation of the word [is formed] from the one or more syllabic elements.” From this, the Federal Circuit concluded that a word is comprised of one or more “syllabic elements.”
Second, the Federal Circuit noted that the specification of the ‘112 patent repeatedly distinguishes between a “word” and a “syllabic element” and indicates that a word is comprised of syllabic elements. Indeed, the specification of the ‘112 patent consistently illustrates that the terms “word” and “syllabic element” are not coextensive in scope, as provided below:
[S]yllabic elements . . . are used to reconstruct the word. (Abstract of ‘112 patent).
[T[he apparatus recognizes a particular word in terms of “syllabic elements.” (‘112 patent Col. 1, lines 65-66).
In the preferred embodiment, “syllabic elements” are stored in memory and combined to create words. For example, the “CON” letter group in contest, silicon, conference contact, etc. is such a stored syllabic element. Thus, the vocabulary stored in the preferred embodiment includes common lettergroups, suffixes, prefixes, single letters, and a few complete words, genericly [sic] to as “syllabic elements.” (‘112 patent, Col. 5, lines 5-12).
Third, the Federal Circuit found that the prosecution history of the ‘112 patent likewise distinguishes between a “syllabic element” and a “word.” In particular, the original independent claim recited matching with an alphabetic character string, while one of its dependent claims specified that this string comprised a word. However, when the Examiner identified a prior art reference that showed matching with a word, the patentee amended the claim to require matching with “syllabic elements” and canceled the dependent claim that required matching with words. Thus, the Federal Circuit reasoned that the cancellation of the dependent claim indicated that “syllabic elements” do not include all words.
Based upon the claim language, specification, and prosecution history of the ‘112 patent, the Federal Circuit construed “syllabic element” to be “a one-syllable letter group that either comprises a word or can be combined with other one-syllable letter groups to form a word.” Because BENQ’s vocabulary only included complete words, the Federal Circuit agreed with the trial court that BENQ did not infringe the ‘112 patent.
This case serves as a reminder that the claims of a patent will generally be construed in view of the intrinsic evidence, including the specification and prosecution history of the patent. Accordingly, patent applicants should carefully consider how statements made in the specification and prosecution history may impact the scope of their claims.