| 摘要 |
<P>PROBLEM TO BE SOLVED: To secure good reproduced signal quality even when the dimensional accuracy of a housing, etc., is alleviated to the extent of general tolerance and assembly accuracy is alleviated by making a conjugate relation adjustable so that reflected light from an optical recording medium focus on the light receiving pattern of a light receiving element. <P>SOLUTION: An interval LB between each light receiving part 18a with a first wavelength and a light receiving part 18b with a second wavelength of a photodetector 18 which is a light receiving part is set to be about 1.1 to 1.6 times of an interval LA between a light emitting point 11d with the first wavelength and a light emitting point 11e with the second wavelength of a semiconductor laser 11 which is a light source. A sensor lens 17 having a negative refractive index is provided at the preceding stage of the photodetector 18, and the conjugate relation between the light source and the light receiving part is adjusted by adjusting the position of the sensor lens 17 in an optical axis direction. Thereby, the reflected light from the optical recording medium is accurately focused on the light receiving part corresponding to the wavelength. <P>COPYRIGHT: (C)2003,JPO |
