Tokyo Keiso Company v. SMC (08-1045)
Tokyo Keiso owns U.S. Patent No. 5,458,004, which is directed to a volume flow meter. Tokyo Keiso sued SMC for infringement of claims 1, 2 and 5 of the patent. However, on summary judgment, the district court determined that the asserted claims were obvious and thus invalid.
On appeal, the Federal Circuit affirmed the district court. The court recognized that most of the claim limitations in the Keiso patent were conceded in the specification of the patent as being prior art. “A statement in a patent that something is in the prior art is binding on the applicant and patentee for determinations of anticipation and obviousness.” Using this principle, the court determined that the asserted claims were obvious when the admitted prior art was considered along with the teachings of another patent.