| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive and simple tilt detecting system capable of mainly detecting a DC-like tilt quantity in the state of focusing on the information surface of an optical disk without necessitating a tilt sensor separately. SOLUTION: Reflected light is received by a quadripartite light receiving element divided by orthogonal dividing lines in the state of focusing a reproduced beam spot on the information surface of the optical disk, and the absolute value of the difference of two added results obtained by adding the output of the light receiving element being the opposite angle of the quardripartite light receiving element is outputted. The tilt quantity is obtained based on amplitude or the minimum value of the absolute value of the output signal obtained when irradiating light scans in the direction orthogonal to a track.
|
