| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device and an optical recording and reproducing device which suppress a tracking error signal offset caused at a boundary between an unrecorded area and a recorded area. <P>SOLUTION: A three-beam diffraction grating is divided into two areas. A division line that divides the diffraction grating into two areas has a step in the direction almost vertical to a groove period structure, the part of the division line in the step has a staircase shape. The phase difference in the groove period structure between one area and the other area separated by the division line is about 180 degrees. <P>COPYRIGHT: (C)2010,JPO&INPIT |
