| 摘要 |
PROBLEM TO BE SOLVED: To obtain track error signals matching with a CD and a high density disk through automatically switching. SOLUTION: An output from a laser 1 of an optical disk device is made five beams B0-B2 of 1st-order light, 2nd-order light together with zero-order light by a diffraction grating 2, and the track error signals TL, TH are obtained from a light spot by a 1st-order diffracted beam in the case of the high density disk, and from the light spot, by a 2nd-order diffracted beam in the case of the CD for the track of the optical disk 5, and the disk is decided by a comparator 11. Thus, correct track error signals are obtained automatically respectively for respective disks. |
