Patent owner comments can narrow scope of patents, says Federal Circuit
Statements made by a patent owner during an inter partes review (IPR) can be used to narrow the scope of the patent in court proceedings, according to the US Court of Appeals for the Federal Circuit.
In a decision handed down yesterday, the court affirmed that Apple had not infringed a patent.
Software company Aylus Networks appealed against a grant of summary judgment by the US District Court for the Northern District of California. The court had found that Apple’s AirPlay feature didn’t infringe a patent owned by Aylus.
AirPlay is Apple’s wireless streaming feature.
The patent, US number RE 44,412, “provides systems and methods for implementing digital home networks having a control point located on a wide area network”.
Aylus had sued Apple for infringement and Apple responded by filing two separate petitions for IPR, each challenging different claims of the patent.
The Patent Trial and Appeal Board (PTAB) instituted an IPR proceeding challenging all claims of the ‘412 patent.
The software company then filed a notice in the district court to dismiss with prejudice its infringement contentions on all of the asserted claims, except for claims 2 and 21.
Apple subsequently filed a motion for summary judgment of non-infringement of the two claims, which the court granted.
The court had relied on statements made by Aylus in its preliminary responses to Apple’s IPR petitions, finding that the statements were “akin to prosecution disclaimer”.
Prosecution disclaimers preclude patentees from “recapturing through claim interpretation specific meanings disclaimed during prosecution”, said the court.
Aylus appealed to the Federal Circuit, arguing that statements made during an IPR can’t be relied on to support a finding of prosecution disclaimer.
The company also claimed that its statements did not “constitute a clear and unmistakable disclaimer of claim scope”.
The doctrine arose in the context of pre-issuance prosecution, but it’s also been applied by the court in other post-issuance proceedings before the US Patent and Trademark Office (USPTO) and in re-examination proceedings.
“It follows that we should apply the doctrine in IPR proceedings before the USPTO,” said Circuit Judge Kara Stoll.
She added: “Extending the prosecution disclaimer doctrine to IPR proceedings will ensure that claims are not argued one way in order to maintain their patentability and in a different way against accused infringers.”
The court also found that Aylus’s statements constituted a “clear and unmistakable” surrender of methods covered in the claims.
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