OPTICAL PICKUP DEVICE FOR HOLOGRAM, OPTICAL INFORMATION RECORDING AND REPRODUCING DEVICE AND OPTICAL INFORMATION REPRODUCING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an optical pickup device capable of attaining high-speed reproduction and detecting an angle error signal to obtain a best reproduction signal, in a two-beam angle multiple system.SOLUTION: An optical pickup device 100 for hologram includes: an optical axis branch element 36 for blanching a reference beam into two beams whose propagation directions are different from each other and whose polarization states are substantially orthogonal to each other; angle variable elements 38, 40 for changing an incident angle of the reference beam radiated to an optical information recording medium 200; an imaging device 41 for detecting a diffraction beam generated from a recorded area when radiating the reference beam to the optical information recording medium, and making the diffraction beam into a reproduction signal; photodetectors 54, 63 for detecting the diffraction beam generated from the recorded area when radiating the reference beam to the optical information recording medium. Using a signal detected by the photodetector 54, 63, an angle error signal for controlling the angle variable element 38 is generated.