| 摘要 |
PROBLEM TO BE SOLVED: To realize an optical pickup device that makes both a DVD and CD systems able to perform three-beam track detection independently of each other, that can prevent reduction in reproducing speed and generation of a flare, and that can provide highly precise adjustability as well as a high speed recording and reproduction. SOLUTION: This optical pickup device, in which luminous fluxes of semiconductor lasers 1, 2 as a plurality of light sources different in wavelength are emitted to the recording face of an optical recording medium 9 and the writing, erasure or reproduction of information are carried out while return optical fluxes reflected by the recording face are received by a light receiving means 10, is provided with a plurality of three-beam forming gratings 3, 4 for track detection, then at least one of them is a polarizing grating in which diffraction efficiency is dependent on the polarization direction of incident light, and that it is rotatably adjustable. In other words, by making at least one of the three- beam forming gratings 3, 4 a polarizing grating, the reduction in the signal detecting quantity and the generation of flare can be suppressed. |
