Indefiniteness for Multiple Plausible Claim Constructions
The Board stated that "we employ a lower threshold of ambiguity when reviewing a pending claim for indefiniteness than those used by post-issuance reviewing courts. In particular, rather than requiring that the claims are insolubly ambiguous, we hold that if a claim is amenable to two or more plausible claim constructions, the USPTO is justified in requiring the applicant to more precisely define the metes and bounds of the claimed invention by holding the claim unpatentable under 35 U.S.C. § 112, second paragraph, as indefinite. " Miyazaki, slip op. at 11-12.
The Board remarkably departs from more than a century of precedent that permits plural interpretations . . . A unique aspect of the Board's opinion is that it provides a ground for invalidity under 35 USC § 112, ¶ 2, that is applicable only in the case of a pending application and not a granted patent. Presumably, a perfectly valid claim in a granted patent that is put through a reissue proceeding to consider a different issue would now be subject to rejection under 35 USC § 112, ¶ 2.
The Board's rationale for its departure: "The USPTO, as the sole agency vested with the authority to grant exclusionary rights to inventors for patentable inventions, has a duty to guard the public against patents of ambiguous and vague scope. Such patents exact a cost on society due to their ambiguity that is not commensurate with the benefit that the public gains from disclosure of the invention. The USPTO is justified in using a lower threshold showing of ambiguity to support a finding of indefiniteness under 35 U.S.C. § 112, second paragraph, because the applicant has an opportunity and a duty to amend the claims during prosecution to more clearly and precisely define the metes and bounds of the claimed invention and to more clearly and precisely put the public on notice of the scope of the patent." Id., slip op. at 12.