ALEXANDRIA, Va., March 17 -- United States Patent no. 12,581,242, issued on March 17, was assigned to ALPS ALPINE Co. LTD. (Tokyo).
"Speaker" was invented by Katsuhiko Egami (Fukushima, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A through hole is formed in an inner-side yoke making up a magnetic circuit portion, passing therethrough following a vibration direction of a vibration unit, and circuit boards are disposed in the through hole. The circuit boards are disposed with board surfaces thereof following the vibration direction of the vibration unit. Also, an opening area of a middle space across which the circuit boards oppose each other is larger than opening areas of side spaces. Accordingly, f...