| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device which can improve the resolution of a regenerative signal without increasing the number of parts and can omit position adjustment of diffraction gratings in assembling the optical pickup device. <P>SOLUTION: The optical pickup device is equipped with a semiconductor laser 1, the diffraction grating 3, an objective lens 5 and a push-pull signal detector 10. The diffraction grating 3 diffracts the light emitted from the semiconductor laser 1 to 0 order diffracted light and a pair of ±lst order diffracted light. The diffraction grating 3 is so set that the decreasing rate of the intensity of the 0 order diffracted light becomes smaller the nearer the peripheral part from near the optical axis and on the other hand the intensity of each of the pair of the ±lst order diffracted light becomes smaller. The 0 order diffracted light is shaped flat in intensity distribution and the pair of the ±lst order diffracted light become greater in the light intensity of the luminous flux near the optical axis as compared to the luminous flux of the outer edge. Consequently, the resolution of the regenerative signal can be improved and in addition the position adjustment of the diffraction grating can be omitted in assembly. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
