| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem of a possibility that due to the occurrence of offsetting in a tracking error signal caused by a change in a positional relation between a photodetector and an optical spot due to a temperature change or the like, a tracking servo is removed to cause offsetting in an optical pickup. <P>SOLUTION: The optical pickup includes a beam separation means in front of a cylindrical lens, and divides the optical spot into two in a groove diffraction light direction to form an image in a photodetector 11. Thus, even when a change occurs in positional relation between the photodetector 11 and the optical spot 21, the occurrence of offsetting in a tracking error signal is prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT |
