During the en banc rehearing, both parties argued that the court should revise its de novo standard of review in claim construction cases. But while Lighting Ballast wants the Federal Circuit to drop the de novo standard altogether and defer to a district court’s interpretation of the claim, appellee Universal Lighting Technologies argued that the Federal Circuit should only defer to the district court’s interpretation when considering disputed issues of historical fact.
The case involves Lighting Ballast’s patents for control and protection circuits for electronic lighting ballasts commonly used in fluorescent lighting. A jury at the District Court for the Northern District of Texas found that Universal Lighting Technologies had infringed the patents.
In January, the Federal Circuit reversed the jury decision, concluding that claim construction is a matter of law rather than fact and can therefore be decided without deference to the district court’s interpretation.
The case will also have implications for the USPTO’s Patent Trial and Appeal Board and Inter Partes Review and Post Grant Review proceedings, which at present apply the “broadest reasonable interpretation” standard under the America Invents Act. District courts use a higher claim construction standard.
