| 摘要 |
<P>PROBLEM TO BE SOLVED: To generate a stabilized tracking error signal by a DPP method. <P>SOLUTION: The optical integrated unit 17 is provided with a semiconductor laser 18 for irradiating an optical disk 12 with a light, a 3-beam diffraction grating 1 for branching the light of the semiconductor laser 18 into a main beam, a fist subbeam A, and a second subbeam B, a photodetector 8 for detecting a return light from the optical disk 12, a radially dividing diffraction grating 2 for dividing the return light at least in the radial direction of the optical disk 12, and a tangentially dividing diffracting grating 3 for dividing the return light at least tangentially of the optical disk 12. The radially dividing diffraction grating 2 and the tangentially dividing diffraction grating 3 are arranged to be apart from each other by a predetermined distance. The radially dividing diffraction grating 2 and the tangentially dividing diffraction grating 3 are capable of separately dividing the return light. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
