| 摘要 |
PURPOSE:To enable accurate tracking, by obtaining a signal being the reference of a rotating speed from a disc recording medium having spiral track and controlling the movement of the head. CONSTITUTION:A reference clock signal is recorded on a disc recording medium 1 with a prescribed period at the external circumference in advance. This signal is detected at a detection head 10 and after it is amplified at an amplifier 2, it is converted into a pulse signal at a wave shape circuit 3. A pulse motor 5 is driven with the output of a motor drive circuit 4, the pulse motor 5 is directly coupled with the feed mechanism of screw type, and recording/playback head provided at the tip of an arm 8 is operated by operating a carriage 7 toward the arrow. Thus, accurate tracking is performed. |
