| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical information reproducing device capable of shifting an objective lens highly precisely and obtaining a reproduction signal excellent in S/N without regulating the direction of luminous flux made incident on a mirror. <P>SOLUTION: The shift amount of the objective lens 214 is detected at the time when the objective lens 214 is shifted to the radial direction of a hologram disk 216. Also, the luminous flux to be imaged on a photodetector (CMOS) 219 according to the shift amount of the objective lens 214 is moved to the vertical direction with respect to the incident direction. To move the luminous flux on the photodetector 219, an opening 217 or a mask element is used to move it according to the shift operation of the objective lens 214. Alternatively, the opening or the mask element and photodetector can be moved. <P>COPYRIGHT: (C)2008,JPO&INPIT |
