| 摘要 |
PURPOSE:To attain quick and accurate search, by stopping a tracking servo in the shifting state of a pickup by an output driving signal of a counting means stopping the shift of the pickup in response to the distance data. CONSTITUTION:Position calculating circuits 158, 159 calculate the distance data with the absolute address of the pickup 142 of a present address memory 153 and the absolute address of the objective position outputted from an adder 157. An output of a subtraction circuit 160 is the distance data between the pickup position and the objective position. Since the pickup is shifted by the distance, no readout of address is required during the shift. Further, a switch circuit 147 is turned off to stop the tracking servo during the shift. When the said distance is long, the pickup is shifted largely with the driving signal from a level shaping circuit 166, and when the distance is within a prescribed range, the pickup is shifted to the objective position with the kick pulse. |
