| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup device which can obtain a tilt error signal by devising a photodetector part. SOLUTION: In the optical pickup device in which a laser beam L from a laser element 50 is concentrated by an objective lens 58 to form a fine spot on a recording medium D and which is made so as to divide the reflected laser beam from the recording medium into a plurality of light fluxes consisting of a main beam and a plurality of sub beams through a beam splitter 56, a convergence lens 60, and a hologram element 62, to be received by a multi- divided type photodetector part 64, the multi-divided type photodetector part is formed by a plurality of main element blocks 70C for the main beam arranged in a row at the central part and a plurality of sub element blocks 70B for sub beams respectively arranged in rows on both sides of the main element blocks. A part of the sub element blocks is divided into a plurality of element pieces 80. It is constituted so that the tilt error detection signal is obtained on the basis of the output from each element piece. |
