| 摘要 |
PROBLEM TO BE SOLVED: To provide a composite optical unit which may be reduced in cost, is dealable with an optical device using plural light sources of different wavelengths even with one composite optical device and is applicable to an optical pickup as well. SOLUTION: This composite optical unit has a housing 51 mounted at the optical pickup 100. A semiconductor laser 52, a photodetecting member 54 and a composite optical member 55 are integrally mounted and fixed to the housing 51. The semiconductor laser 52 has a laser diode 53 for emitting a laser beam 53' for DVDs. The composite optical member 55 is provided with an incident surface 55a on which the light emitted from the semiconductor laser 52 is made incident, an exit surface 55b from which the light is emitted, a diffraction grating 55f which is disposed on the exit surface 55b and diffracts the return light reflected by an optical disk D disposed on the exit surface 55b, a reflection surface 55d' which reflects the light diffracted by the diffraction grating 55f and an exit surface 55e' which emits the light reflected by the reflection surface 55d' to the photodetecting member 54. |
