| 摘要 |
PURPOSE:To reduce the cost and to attain miniaturization of the device by compensating electrically the asymmetry of a tracking error signal due to radial skew to eliminate the need for an adjusting mechanism of a mechanical radial skew. CONSTITUTION:A correction circuit 16 consists of inversion amplifiers A1, A2, diodes D1, D2, resistors R1-R6 and a variable resistor VR, and an input voltage is converted into a current by an input resistor R1. The variable resistor VR consists of the resistor R3 and a series resistor Rx. In selecting resistors as R1=R2=R4=R5=R6, the amplitude of the output voltage is the same as the input voltage when the input is positive and is a ratio of Rx/R1 when the input voltage is negative to vary it by the adjustment of the VR. Then the amplitude of the half cycle of the output waveform is varied between alternate long and short dash lines and alternate long and two-short dash lines in response to the change in the resistance of the variable resistor VR. |
