ALEXANDRIA, Va., June 19 -- United States Patent no. 12,335,708, issued on June 17, was assigned to AAC Microtech (Changzhou) Co. Ltd. (Changzhou, China).
"Sound device" was invented by Li Ren (Changzhou, China) and Shengjie Hua (Changzhou, China).
According to the abstract* released by the U.S. Patent & Trademark Office: "A sound device include a frame, a first vibration system, and a magnetic circuit system. The first vibration system includes a first vibrating diaphragm and a first voice coil. The magnetic circuit system includes a magnetic yoke, a main magnetic steel set, and auxiliary magnetic steel sets. One side, away from the magnetic yoke body, of each of the magnetic yoke extending portions is recessed to form positioning holes....