Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co. Ltd.
March 14, 2017
Federal Circuit No. 2016-1900
Author: Andrew Yeretsky
In a precedential opinion reversing the Patent Trial and Appeal Board ("the Board") in IPR2014-01122, the Federal Circuit held that the claims of U.S. Patent 7,208,895 are not anticipated by Kusaka (U.S. Patent 5,569,995). In particular, the Federal Circuit held that the Board had improperly applied the holding of Kennametal, Inc. v. Ingersoll Cutting Tool Co., 780 F.3d 1376, 1381 (Fed. Cir. 2015).
The claims at issue are directed to a system for controlling the torque of an electromagnetic motor. According to claim 12, the method includes "combining the IQr demand and the dr-axis injection current to produce an IQdr demand." Both parties agreed that the "IQdr demand" signal must be in the rotating frame of reference before being converted to the stationary frame of reference.
The alleged anticipatory reference, Kusaka, did not disclose phase reference currents in the rotating frame of reference. However, citing Kennametal, the Board held that Kusaka still anticipated claim 12 because a person of skill in the art would "at once envisage" the missing limitation.
The Federal Circuit, reversing the Board, stated that Kennametal does not stand for the proposition that a reference missing a limitation can anticipate a claim if a skilled artisan viewing the reference would "at once envisage" the missing limitation. Rather, the relevant question in Kennametal is whether the disclosure of a limited number of combination possibilities discloses one of the possible combinations. The Federal Circuit then explained that "Kennametal does not permit the Board to fill in missing limitations simply because a skilled artisan would immediately envision them."