US Patent 11574615 Keyboard apparatus and load application method

Provided is a keyboard apparatus including: a hammer, having a mass body on one end side, rotating in a first direction by being pushed on the other end side when a key is pressed; and a load application member, applying, to the hammer, at least one of a first load directed in the first direction and a second load directed in a second direction opposite the first direction. The first load is a load that gradually increases as approaching a terminal position of the key in key pressing. The second load is a load that gradually decreases as approaching the terminal position.