| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a compact, thin and low-cost optical pickup device having good environmental change resistance characteristics such as a temperature change even in using a short wavelength laser including a blue laser. <P>SOLUTION: This device is provided with an optical path conversion means arranged in a photodetection optical system to convert a light advancing direction for each of at least four areas divided by a line for dividing the inner and outer sides of a reflected light from an optical recording medium around an optical axis and a straight line including the optical axis, and a photodetecting means arranged in the photodetection optical system and provided with at least four photodetection parts arranged along a straight line parallel to the straight line including the optical axis for dividing the optical path conversion means. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
