| 摘要 |
PURPOSE:To detect assuredly flaws on a recording medium with simple constitution and to prevent stylus skips completely, by fixing the position of a light spot with a different interpolation signal for a period during which flaws exist. CONSTITUTION:The focus and tracking error arithmetic circuits 41 and 47 are provided along with focus and tracking actuators 46 and 52, respectively. The output signal of a sum signal arithmetic circuit 53 is kept approximately at a constant level and then increased if a flaw is detected. When a flaw is detected, a level deciding circuit 54 delivers a flaw detecting signal. This detecting signal actuates holding circuits 43 and 49 to hold a differential signal of focus and tracking error signals, i.e., a signal showing the speed information at a moment when a flaw is detected. The speed information is converted into position information by integration circuits 44 and 50 drive actuators 46 and 52. As a result, a focusing lens is kept at a fixed position. |
