| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device in which a tracking servo control characteristic can be improved by reducing an offset component in a push-pull signal caused by a sub-beam. <P>SOLUTION: In a light guide means of an optical pickup device, light reflected from an optical recording medium is diffracted by a first diffraction element, diffracted light traveling toward to a plurality of light receiving regions of a light receiving element is generated, light emitted from a light source is diffracted by a second diffraction element provided on an optical path between the light source and the first diffraction element, at least zeroth order diffracted light and ± first-order diffracted light are generated, light quantity of the ± first-order diffracted light made incident on respective light receiving regions of the light receiving element is adjusted by making one diffraction efficiency of the ± first-order diffracted light higher than the other diffraction efficiency of the ± first-order diffracted light. <P>COPYRIGHT: (C)2009,JPO&INPIT |
