| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device that can reliably output the signals of the pickup itself and the signals containing the information required to control the objective lens position. <P>SOLUTION: The return light flux reflected on the recording surface of an information recording medium 15 is received by photosensors 59 through an optical element which includes at least one diffraction element 53 whose diffraction efficiency less depends on the incidence angle of the return light flux. Each optical sensor outputs the signals matching the light amount it receives. Since the average level of at least one of those output signals is made to take a desired value, it is possible to output the signals suitable for a push- pull circuitry. <P>COPYRIGHT: (C)2004,JPO |
