Patent ID: 8445765

Claim:
A keyboard device, comprising: a key, supported by a chassis in a free-rotation manner; a hammer, displaced rotationally corresponding to a key-pressing operation or a key-releasing operation of the key to provide an action load to the key; a protrusion, projected at a specific position on the hammer or the key, and displaced corresponding to the key-pressing operation or the key-releasing operation; a sliding surface, formed on any one of the chassis, the key, and the hammer, and having a flat surface or a curved surface inclined to a direction which is along a sliding direction of the protrusion in the key-pressing operation and gradually departs from a base portion of the protrusion, and where the protrusion slides thereon in the key-pressing operation or the key-releasing operation; and a bump portion, formed in continuation with the flat surface or the curved surface, and raising up from the sliding surface towards a direction which is along a sliding direction of the protrusion in the key-pressing operation and approaches the base portion of the protrusion.