| 摘要 |
PURPOSE:To obtain an optical disk device which has two light sources and can obtain a stable reproduced signal and control signal, by making use of the difference of polarizing directions and wavelengths between two semiconductor laser beams to synthesize these two laser beams to that they are put approximately on the optical axis of an aperture lens and then separating and detecting the reflected light of the laser beams. CONSTITUTION:The light beam of wavelength lambda1 given from a semiconductor laser 10 is reflected by a BPF15 via a condenser lens 11, a prism 12, a polarized beam splitter PBS13 and a lambda/4 plate 14 and then focused on a disk 5 through a PBS17, a lambda/4 plate 17 and an aperture lens 4 to be used for recording and erasion of signals. The reflected light of the light beam is reflected by the PBS13 and turned into a light beam 10b. While the S polarized beam of wavelength lambda2 given from a light source 18 is reflected by the PBS13 via a condenser lens 19 and focused on the disk 5 through the plate 17 and the lens 4. The reflected light of the focused beam is supplied to focusing and tracking control detectors 22 and 24 via a split mirror 20 after passing through the PBS13 and the BPF15. |
