ALEXANDRIA, Va., April 15 -- United States Patent no. 12,603,620, issued on April 14, was assigned to Yamaha Corp. (Hamamatsu, Japan).
"Class-D amplifier" was invented by Shinya Mizoshiri (Hamamatsu, Japan) and Masao Noro (Hamamatsu, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A class-D amplifier that amplifies an input signal comprises a control circuit configured to generate a control signal that varies in accordance with a level of the input signal, a first generating circuit configured to generate a first pulse, and a second generating circuit configured to generate a second pulse. A pulse width of the first pulse becomes narrower as the signal level of the input signal becomes smaller, and the ...