| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical recording and reproducing device which can raise the utilization efficiency of light of an optical system and also which has a constant control characteristic. <P>SOLUTION: The optical recording and reproducing device is provided with a light source which emits light, a condensing means for converging light to be incident on an effective aperture among the light emitted from the light source, a light shielding means for shading the other light heading toward the outside of the effective aperture of the condensing means among the light emitted from the light source, a first diffraction means for diffracting the light transmitted through the aperture of the condensing means among reflected rays of light reflected from the recording medium and a first photodetecting means which detects rays of light diffracted by the first diffraction means and outputs an electric signal. <P>COPYRIGHT: (C)2004,JPO |
