Keyboard musical instrument hammer movement detection apparatus

Abstract

A hammer movement detection device for detecting the movement of a hammer which strikes strings provided for each key of a keyboard musical instrument. The hammer movement detection device radiates light onto a hammer shank which moves with the hammer and detects at least the displacement of the hammer shank based on the light reflected from the hammmer shank. The movement detection device may be attached to a shank rail which supports the hammer shank in a freely rotatable manner. The hammer movement detection device may be supported using a fixed member which is supported above the hammer shank and below the pin board which is connected to the frame which supports the strings which are struck by the hammer.

Dependencies are inferred from the claim text.