| 摘要 |
PURPOSE:To select a required disk and to reduce the dispersion of access time even at the time of large capacity by arranging the shaft direction for plural laminated disks in parallel with the optical axis of a fixed optical system and making a light beam from a light source incident upon the disk side by a mirror selecting mechanism. CONSTITUTION:Pickup parts 2 are arranged among plural optical disks 3 fitted around the shaft 5 and light beams 18 of the fixed optical system 1 is set up in parallel with the shaft 5. At the selection of a disk 3-2 e.g., mirrors 4-1, 4-3 in a mirror selector 6 are receded, light beams 18 from the light source 16 are made incident upon a pickup part 2-2 by a mirror 4-2 and the reflected lights from the disk 3-2 are made incident upon a detecting part 17 through the reverse course to read out data recorded on the optical disk. Since each mirror 4 is constituted mirrors 9, 10 with 45 deg. inclination, input and output beams always intersect with each other at 90 deg.. Consequently, a required optical disk can be accurately selected and the dispersion of the access time for the large capacity can be reduced. |
