PURPOSE: To eliminate the possibility of wrong operation by passing a light quantity, corresponding to the width size of a window hole, through a rotary disc for operation when the suitable place of the curved-state window holes conforms to the optical axis of an optical fiber cable by rotating the rotary disc for operation.
CONSTITUTION: Plural window holes 31, 32, and 33 of a rotary disc 3 for operation and the optical axis of an optical fiber cable (outward side) 21 are not conformed in a normal condition. When the largest window hole 31 is made to align with the optical axis of the optical fiber cable 21 by rotating the rotary disc 3 for operation, the maximum light quantity of light passes the rotary disc (window hole 31) 3 for operation, and the light is received with a light receiving element 4 via a optical fiber cable 22 on an inward side. When the smallest window hole 33 is made to align with the optical axis of the optical fiber cable 21, the smallest light quantity of the light passes the rotary disc 3 (window hole 33) for operation, and the light is received by the light receiving element 4. This realizes stage switches corresponding to the number of window holes to prevent wrong operation.
OKAUCHI TERUO
HISHIKI ICHIRO
