| 摘要 |
PURPOSE:To make the accuracy of readout address information constant at all times, by controlling the pickup feeding speed so as to make it fast at the inner circumference of a disc, and slow at the outer circumference by the position information of a pickup device. CONSTITUTION:A photoelectric converting element 4 connected to a DC power supply 1 and a light emitting diode 2 fitted in a case 3 of the pickup detect a radial position of the pickup on an information recording disc. Depending on the output voltage from the position detecting means, a voltage controlled type oscillation circuit 8 changes the oscillating frequency. A monostable multivibrator 10 shaping the output signal from the circuit 8 to a pulse train having a prescribed pulse width generates pulses controlling the feeding speed of the pickup. This pulse is applied to a pickup feeding motor 15 via a driver 14 to drive a motor. |
