| 摘要 |
Disclosed is an optical storage device for reading information from an optical storage medium by an optical head. The optical storage device comprises an optical head including a track actuator for scanning on the skew across tracks on the optical storage medium by the laser beam, and a divided-by-4 light receiving unit for receiving the laser beam from the optical storage medium, a moving motor for moving the optical head, a first signal processing unit for calculating a track error signal on the basis of an output of the divided-by-4 light receiving unit, a second signal processing unit for calculating a shift signal of the objective lens from the output of the divided-by-4 light receiving unit, and a control unit for controlling the track actuator or the moving motor by the track error signal, and controlling the track actuator or the moving motor so that the laser beam passing through the objective lens is located at the center of the objective lens. With this construction, a lens position can be detected, and hence a lens position sensor becomes unnecessary. <IMAGE> |
