SWITCH, KEYBOARD INSTRUMENT PROVIDED WITH THE SAME, AND LIGHT EMISSION CONTROL CIRCUT

摘要

A switch according to the present invention includes: a substrate; a touch sensor; a light guide plate; a light emitting unit; and a control unit. The light guide plate has a surrounding side surface chamfered so that a light entering into the surrounding side surface of the light guide plate diffusely reflects inside the light guide plate. The light emitting unit is arranged at a position facing the surrounding side surface of the light guide plate. The light emitting unit is configured to emit the light to the surrounding side surface of the light guide plate.