| 摘要 |
PURPOSE:To eliminate an error of the present position by calculating the number of revolutions of a rotary spindle of a turntable to obtain a diameter to be fed and correcting the feed pitch from the difference between said diameter and the present position of a light beam. CONSTITUTION:The diameter information read out of a linear scaler 3 attached to a feed stage 2 is converted into the binary data by an address converter 4 and then supplied to the addresses of memories 6 and 12 to control the preset value of a down- counter 10. The counter 10 performs down-counting of an oscillator 17 and produces a target frequency. The phase error signal between said target frequency and the output obtained by dividing the 1-rotation pulse is converted into a DC control signal to give the phase control to a feed motor 21. While a preset counter 18 presets the diameter information of a start mode with interlocking of a switch 23. Hereafter the output of a divider 19 is integrated to produce the digital data on the present logic diameter. This logic diameter is compared with the present diameter information by a subtractor 9 to obtain the error data. This error data is added to the division ratio control data given from the memory 6. Then the target frequency data is corrected, and the motor 21 is controlled. Thus the recording is possible in response to the logical value. |
