| 摘要 |
PURPOSE:To obtain a signal corresponding to the moving direction without using a means for detecting the moving direction of a head, by providing an optical scale having a pattern where a part transmitting a light from a light emitting element and a part shielding the light are alternately arranged. CONSTITUTION:An optical scale 15 has a pattern where a part transmitting light and a part shielding light are alternately arranged, and the scale 15 moves toward (a) or (b) together with an optical head 13 and the position of the optical head 13 is detected with a position detector 17 fixed on a base 16. In this case, the position detector 17 detects the position of the optical head 13 with a so- called overlapped lattice type detection system. With this constitution, the position of the head can be detected by only adding a simple circuit without using a means for detecting the moving direction of the head. |
