| 摘要 |
PURPOSE:To retrieve a desired track in high speed stably by giving a moving start signal to a moving stand and also making a control means inoperative by means of a signal giving a delay to the moving start signal and counting a track crossing signal after the moving stand starts actually the movement by means of a counter means. CONSTITUTION:When a signal delayed by a delay circuit 85 of a counter circuit 74 is inputted to an information processing controller 78, the controller 78 outputs a signal to a switch 63 so as to make the tracking control and the moving control inoperative. Then the moving stand 71 crosses a light beam 2 while being moved by a linear motor 69, a signal as the result of the light beam 2 crossing a track on a recording medium 7 is outputted at an output of a differential amplifier 60, the counter circuit 74 counts the clock, a signal generating circuit 75 generates a signal in response to the counter output so as to control the moving speed of the moving stand 71. The counter circuit 74 counts the track number crossed by the light beam 2 on the recording medium 57, coarse and minute retrieval is attained and a desired track is retrieved. |
