摘要 |
PURPOSE:To obtain a linear output of an optical deflector over the entire surface of a source disk by storing the data on the deflector drive input voltage for writing address information and a groove in response to the position of the radius of the disk and reading the data based on a detected write position to control the drive voltage of the deflector. CONSTITUTION:An actuator 7 is set at its start position, and the distance between the revolving center of a source disk 1 and the write start position is informed to a counter 11. Then the actuator 7 moves gradually toward the outer circumference side of the disk 1 along the radius direction, and the position of the actuator 7 is detected by a laser length measurement device 6. A position pulse is sent to the counter 11 every time the actuator 7 has reached each split point. For the value of the counter 11, the desired correction data is read out and sent to DAC14 and 15 and then delivered from amplifiers 16 and 17 by giving accesses to memories 12 and 13 since a number (i) is shown. While a selection signal 19 is sent to a changeover switch 18 to show writing of the address information or a groove. Then the output of an amplifier 16 or 17 is transmitted in the form of the drive input voltage Ei of an optical deflector. Thus a linear output of the deflector is obtained to a distance. This attains the uniform writing over the entire surface of the disk 1. |