| 摘要 |
<P>PROBLEM TO BE SOLVED: To stably control recording and reproduction using an electro-optical element to eliminate adverse effect of noise for a light source in reproduction, to process receiving signals without deterioration in response speed, and to correct deterioration due to wave aberration, and to stably perform processing of information recording/reproduction to/from an information recording medium. <P>SOLUTION: Transmissivity of an optical beam is set low by the first region of a first electro-optic element 3, thereby enabling semiconductor laser 1 output to be set high in reproduction, reducing effect of return light, and stabilizing light emission of the semiconductor laser 1 to reduce noise. In addition, by the third region of a second electro-optic element 9, light quantity from an information recording medium 8 is unchanged in reproduction; the transmissivity of the optical beam is set low in recording, enabling the light quantity to be controlled to a light receiving element 11, attaining common gain, and performing aberration compensation by the second and fourth regions of the first and second electro-optic elements 3, 9. Thus, the processing of information recording/reproduction can be stably carried out for the information recording medium. <P>COPYRIGHT: (C)2003,JPO |
