Claim Not Anticipated By Prior Art Where Missing Limitation In Reference Allegedly Would Have Been Apparent To Skilled Artisan

  • April 29, 2017

By: Thomas M. Sullivan

Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co.

In Nidec, the Federal Circuit held that a claim in inter partes review was not anticipated where the prior art reference failed to disclose a claim limitation, despite a finding by the Patent Trial and Appeal Board that a person of ordinary skill in the art would “at once envisage” the missing limitation.

Nidec held a patent directed to controlling torque of an electromagnetic motor. The patented controller receives various inputs including torque demand and rotor position or speed, and outputs motor control values, which can either be expressed relative to a stationary frame of reference, or a rotating frame of reference. The Board found that the challenged claims required the controller to output a control value relative to the position of the rotor, which is to say the rotating frame of reference.

Broad Ocean challenged the patent as allegedly anticipated by a single prior art reference. Broad Ocean conceded that the outputs of the prior art controller produced control signals in the stationary frame of reference. However, the Broad Ocean argued, and the Board agreed, that the claims were still anticipated because a person of ordinary skill in the art would have at once envisaged the claimed arrangement. The Board held the challenged claims to be unpatentable. Nidec appealed.

The Federal Circuit held that the Board misapplied prior precedent regarding anticipation. Where, for example, a prior art reference taught that any of five binding agents could be combined with any of three coating techniques, a challenged claim could still be anticipated even if the prior art did not disclose the exact combination that was later claimed, so long as the combination would have been immediately apparent from reading the reference. In other words, the disclosure of a limited number of combination possibilities discloses one of the possible combinations. But the Board was not permitted to “fill in missing limitations” with what allegedly would have been apparent to a skilled artisan. Because the rotating frame of reference limitation was not found in the prior art reference at all, the Board’s finding of anticipation was not supported by substantial evidence.

Key Takeaway:

A finding of anticipation may be supported where a skilled artisan could at once envisage a particular combination out of a limited number of possible combinations, but it may not be grounded in a determination that a skilled artisan would at once envisage the addition or substitution of a limitation not disclosed in the reference.


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