| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup apparatus which can detect accurately information recorded in an optical information recording medium utilizing efficiently light beams emitted from a plurality of light sources. <P>SOLUTION: The optical pickup apparatus is provided with an optical axis compensating section 20 arranged between a condenser lens 32 and a photodiode 30. The optical axis compensating section 20 has a diffraction optical element of a binary type and liquid crystal arranged so as to contact tightly to a binary stage part of the diffraction optical element. Refractive index of the liquid crystal is adjusted by a liquid crystal circuit in accordance with a laser beam emitted from the laser light source. The liquid crystal circuit adjusts the refractive index of the liquid crystal so as to improve refraction efficiency of the laser beam in the refractive optical element. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
