| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a simple structured and downsized optical pickup apparatus wherein reproduction of different type disks is made and the number of optical component items is small. <P>SOLUTION: An OPU head 11 has: a light source 111; a switching hologram (SH) unit 112 showing a diffraction state corresponding to a recording medium M; a mirror 113 turning light diffracted by the SH unit 112 toward the recording medium M side; a quarter wave plate 114 giving retardation to the light reflected by the mirror 113 (the light diffracted by the SH element) to form circularly polarized light; an objective lens 115 condensing the obtained circularly polarized light on the recording medium M; and a condenser lens 116 condensing light reflected by the recording medium M on a photo detector 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
