| 摘要 |
PURPOSE:To obtain a tracking error signal accurately by providing the 1st comparing means which compares a reproduced signal with a specific level to obtain a waveform-shaped output and the 2nd comparing means which compares a high frequency component with a specific reference level, and obtaining a switching output according to the operation modes of said comparing means. CONSTITUTION:The cascade circuit of a high-pass filter 16 and a level comparator 17 is provided separately in parallel to an ATC circuit 10, and the output of the ATC circuit 10 and that of the level comparator 17 are inputted to a switch circuit 8. This switching circuit 8 is controlled by a device operation mode specifying signal to send the output of the ATC circuit 10 in normal reproduction mode and the output of the level comparator 17 in fast-forward mode selectively to differentiating circuits 9 and 11. |
