| 摘要 |
PURPOSE:To eliminate the mixture of noise, by returning the reflected beam of the light irradiated to the recording medium from the light source to the semiconductor laser light source and thus obtaining the reproduced signal based on the reproduced beam which received a self-coupling. CONSTITUTION:The radiation laser beam given from the semiconductor laser light source 1 is irradiated to the optical recording medium 4, and this reflected beam is returned to the source 1. And then the reproduced signal is obtained based on the reproduced beam which received a self-coupling. In such device, the lambda/4 plate 7 is distributed into the optical path between the source 1 and the medium 4, and the angle formed with the optical axis of the plate 7 and the polarized wave axis of the radiation laser beam is selected. Thus the reproduced beam has substantially the signal oscillation mode. |
