MOTION SENSOR FOR A PIANO KEY MOTION ANALYSIS SYSTEM

摘要

A motion sensor device particularly suitable for use under a piano keyboard in an opto-electronic piano key motion analysis system. The device comprises a body (24, 26) attachable to the piano under the keys thereof, and at least one element (12) that is movable relative to the body (24, 26) and has one end (11) contacting the underside of a piano key. The mutually contacting surfaces of the movable element (12) and the key include a magnetic element (14, 16) and a corresponding magnetic or magnetisable element (14, 16) whose mutual pull is determined in such a way that the end (11) of said movable element (12) remains in contact with the key during normal use.