PURPOSE: To execute high-density recording without being affected by the fluctuation in pit shape by irradiating the optical disk with the 1st laser beam and the 2nd laser beam while these laser beams are shifted zigzag in a track direction with half the size of the spacing between the guide tracks as a limit.
CONSTITUTION: The 1st laser beam 5a from a laser diode 1a and the 2nd laser beam 5b from a 2nd laser diode 1b are guided to the recording medium surface of the optical disk 7. The irradiation points of the beams 5a, 5b are relatively parted in the radial direction and the radial directions are shifted with half the size of the spacing between the tracks as the limit. The reflected light beams of the beams 5a, 5b from the optical disk 7 are made incident to detectors 8a, 8b. A switch 11 is closed and the laser beams 5a, 5b are subjected to servo control so as to be brought to the positions symmetrical with the track center at the time of data recording. The switch 11 is opened and only the laser beam 5a is so servo-controlled as to coincide with the track center at the time of data reproducing.
TERAO MOTOYASU
TSUYOSHI TOSHIAKI
YASUOKA HIROSHI
| JPS63222329A | 1988-09-16 | |||
| JPS59142755A | 1984-08-16 | |||
| JPH0253223A | 1990-02-22 | |||
| JPS6425320A | 1989-01-27 |
Next Patent: OPTICAL DISK