| 摘要 |
PURPOSE:To shift a pick-up to an address position of a desired disk by installing a position detector and a switch to be detected, recording an address at a prescribed number of tracks of a disk for the disk in the initial condition and after that, relating a detecting position of a pick-up to the address. CONSTITUTION:A pair of photodetectors 5 are fitting at a linear motor 4, a scale 6 is installed and plural slits are provided at the interval of 20mum. In an initialized action condition, a limit switch 7 is on, and then, only a prescribed quantity 100mum is shifted in the outer circumferential direction of a light disk 1. In the shifting, the contents of a scale counter 12 become five. A pick-up 2 is shifted in the outer circumferential direction and an address is successively recorded to an address area 1b of respective tracks of the light disk 1. When the initialized action ends, only the prescribed quantity 300mum is shifted in the outer circumferential direction of the light disk 1, and at this time, the contents of the scale counter 12 become 15. An address reading part 11 reads the address from the signal which the pick-up 2 reproduces from the light disk 1. |
