| 摘要 |
PURPOSE:To improve durability, detecting accuracy and stability, by employing a light source, a movable piece provided with two logs inclined to the direction of displacement and at least two light receiving elements. CONSTITUTION:A movable piece 4 interrupts a part of light flux irradiating a light receiving element 2 and further, it is fixed to the displacing end with a configuration provided with two legs P1,P2 having the same symmetrical inclination to the direction of displacement. Independent from a position of the movable piece 4, the light receiving element 3 is irradiated with a constant ratio of light of the flux from the light source 1. A comparator 5a supplies an electric current to the source 1 in such a way that output and reference voltage 7 of the element 3 coincides always. Thus, a signal light receiving element 3 compensates temperature characteristic and time aging, an the same time, the other element 2 can detect a stable and continuous position signal detect a stable and continuous position signal to a and further, the detecting accuracy can be held constant regardless of the direction in which a vibration is started. |
