| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup device that can realize a high-precision tilt detection, without arranging a new detecting member, by setting a mechanism not accompanied by an offsetting composition generated due to deviation of optical axes. SOLUTION: Since, by using a mechanism in which the spot on a photodetector 8 does not move even if an objective lens 5 is transferred, three spots with the main beam Bm and a side beam Bs form an image through the same objective lens 5, it enables that an effect due to optical axis deviation is not included in the offset by tilting. As a result, this offset is generated by the tilt and, by receiving from the photodetector 8 the total light quantity of the three spots with the main beam Bm and the side beam Bs, the tilt signal (offset signal) quantity can be extracted in an error signal detecting circuit 10.
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