ALEXANDRIA, Va., March 24 -- United States Patent no. 12,587,791, issued on March 24, was assigned to AAC Microtech (Changzhou) Co. Ltd. (Changzhou, China).
"Sound-generating device" was invented by Zhang Ren (Changzhou, China) and Zhiwei Zhong (Changzhou, China).
According to the abstract* released by the U.S. Patent & Trademark Office: "A sound-generating device, including a cone frame, a vibration system fixed to the cone frame, and a magnetic circuit system fixed to the cone frame and configured to drive the vibration system to vibrate. The vibration system includes a diaphragm, a first voice coil, a second voice coil and a third voice coil, where the first, second and third voice coils are arranged spaced apart, and are configured to...