The appeal came from the US District Court for the Northern District of California, where Technology Properties asserted an oscillator patent against Huawei, ZTE, Samsung, LG and Nintendo in five separate complaints.
All parties stipulated non-infringement, but Technology Properties appealed against the district court’s claim construction.
On appeal, the Federal Circuit consolidated all five cases. Technology Properties argued that the district court erred in its construction that the “entire oscillator” must include the limitation “whose frequency is not fixed by any external crystal”.
But the Federal Circuit disagreed, upholding the district court’s construction in one respect.
The Californian district court also originally held that construction of entire oscillator must include the limitation that does not require a control signal.
The Federal Circuit said that this statement does not “disclaim an entire oscillator receiving a command input for any purpose”.
“Every time the patentee mentioned a ‘control signal’ or ‘command input,’ it did so only in the context of using a command input to modify the frequency of the CPU clock.”
“We hold that an ‘entire oscillator’ is one ‘that does not require a command input to change the clock frequency'," the Federal Circuit said.
While the court said this minor modification “likely does not affect the outcome” of the case, “because the parties stipulated to non-infringement under the district court’s construction, the proper course of action is for us to vacate and remand”.