| 摘要 |
<P>PROBLEM TO BE SOLVED: To eliminate the difficulty of properly detecting a control signal during recording and reproducing caused by simultaneously entry of reflected light from a recording layer of performing current recording and reproducing and reflected light from the other recording layer not performing current recording and reproducing to a photodetector when data is recorded and reproduced on an information recording medium having a plurality of information recording layers. <P>SOLUTION: When light reflected on an information recording medium is made incident on a photodetector, a polarizing direction of 0-order diffracted light and a polarizing direction of first-order diffracted light are made to be orthogonal to each other by using a polarized hologram element. This achieves an optical pickup device capable of reducing the influence of interferences of light from other recording layers, obtaining an appropriate control signal, and having good recording performance. The polarizing direction of the 0-order diffracted light and the polarizing direction of the first-order diffracted light are made to be orthogonal to each other by using the polarized hologram element. Thus, the optical pickup device is miniaturized and thinned. <P>COPYRIGHT: (C)2011,JPO&INPIT |
