| 摘要 |
PROBLEM TO BE SOLVED: To simplify an optical information reproducing device by reducing the number of optical parts and to adjust a tracking error signal in accordance with a characteristic of an optical disk. SOLUTION: A light spot 30 is divided vertically to the track into a middle area and end areas by a 1st dividing means 22, and is moreover divided parallel to the track by a 2nd dividing means 31. Then, outputs of photocells in the end areas of a photodetector 5 are calculated by an light spot deviation signal detecting means 23, a tracking error generating means 24 and an offset correcting means 8 to control an objective lens 3 in position. Then, an output of a photocell in the middle area is calculated in the same manner to perform tracking control by a tracking control means 9. Since the light spot 30 is divided by the 1st and 2nd dividing means 22 and 31, the light is not separated by its main spot and side spots, etc., and a high speed access is feasible, and such parts as a diffraction grating, etc., are unnecessitated, and also the constitution is simplified. |
