(July 13, 2017, 10:50 AM EDT) -- ALEXANDRIA, Va. — A patent covering a system that supplies digital signals in a variety of formats to accommodate different types of external units, assigned by its inventors to Sony Corp., would have been obvious to a person of ordinary skill in the art, several petitioners allege in a July 11 filing with the Patent Trial and Appeal Board (ARRIS International plc, et al. v. Sony Corporation, No. IPR2017-01699, PTAB)....