Patent Number: 7,786,368

Title: Actuator unit for performance operator, keyboard musical instrument and actuator unit assembly

Abstract: An actuator unit includes: a performance operator drive device including a movable member that mechanically drives the performance operator member; an optical pattern having a pattern to cause an amount of light reflection or light transmission to gradually vary in accordance with movement of the movable member; and an optical sensor that irradiates light toward the optical pattern and receives light reflected from or transmitted through the optical pattern. One of the optical pattern and the optical sensor is provided to move in interlocked relation to the movable member, and the amount of the reflected light or transmitted light, based on the optical pattern, is detected by the optical sensor, so that a moving position of the movable member is detected on the basis of the detected amount of the reflected or transmitted light.

Inventors: Muramatsu; Shigeru (Shizuoka-ken, JP)

Assignee: Yamaha Corporation

International Classification: G10H 1/18 (20060101)

Expiration Date: 8/31/12018