PTAB’s predecessor failed to interpret patent claims broadly, says CAFC

The US Court of Appeals for the Federal Circuit has vacated a decision to invalidate a patent after finding that a patent appeals board failed to interpret claims under the ‘broadest reasonable construction’ standard.

In a unanimous decision yesterday, August 12, the federal circuit remanded the dispute over the validity of a patent owned by technology company Power Integrations.

The dispute started in 2006 after the US Patent and Trademark Office (USPTO) granted an ex parte re-examination of patent number 6,249,876, which is titled “Frequency jittering control for varying the switching frequency of a power supply”.

Power Integrations’s competitor Fairchild Semiconductor International had requested the re-examination.

The USPTO’s decision followed Power Integrations’s successful litigation against Fairchild. A jury at the US District Court for the District of Delaware found that the patent was valid and wilfully infringed.

Unlike the district court, the Board of Patent Appeals and Interferences (BPAI), the Patent Trial and Appeal Board’s predecessor, construed the term ‘coupling’ from the patent’s claims to mean “join devices into a single circuit”, and did not preclude the presence of intervening components.

The BPAI invalidated the patent on the grounds of anticipation.

Power Integrations’s request for a further re-hearing at the BPAI was denied in May 2011. The company filed a lawsuit against the USPTO challenging the decision.

The federal circuit, in yesterday’s decision, requested the re-hearing of the patent’s validity to be heard again.

Judge Haldane Robert Mayer, writing the opinion, said the “board fundamentally misconstrued Power Integrations’s principal claim construction argument and failed to provide a full and reasoned explanation of its decision to reject” the validity of the patent on grounds of anticipation.

Mayer pointed to the failure of the BPAI to interpret the term ‘coupled’ according to the “broadest reasonable construction ... instead, the board devoted a substantial portion of its analysis to resolving the question of whether the term ‘coupled’ requires a direct connection between the counter and the digital analogue converter”.

“A significant portion of the board’s opinion is devoted to rejecting an argument that Power Integrations not only never made, but instead expressly disavowed ... it failed to adequately evaluate Power Integrations’s primary argument, which is that the ‘coupled’ limitation requires that the counter pass control signals, voltage, or current to the digital to analogue converter to control it,” he concluded.

Neither Howard Pollack, principal at law firm Fish & Richardson and representing Power Integrations, nor the USPTO had responded to a request for comment at the time of publication, but we will update the story should either party get in touch.