| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical head device using a polarization hologram optical element and an optical disk device using the optical head device, which reduce noise mixed in an RF (Radio Frequency) signal without imposing restriction on the number of photodetectors for acquiring a servo signal. <P>SOLUTION: The optical disk device 10 includes: a signal processing section 11 as a signal processing means; a servo circuit 12 as a servo means; and an optical head device 20. The optical head device 20 includes a light source 21; a PBS (Polarizing Beam Splitter) 22; a CL(Collimating Lens) 23; a HOE(Holographic Optical Element) 24 as a diffraction means; an objective lens 25; a correcting lens 26; and a photodetection section 27 as a photodetection means. The optical head device 10 utilizes first order diffraction light by the HOE 24 for an FE (focus error) signal and TE(tracking error) signal, while utilizes zero-order diffraction light which travels straight on the HOE 24 for the RF signal. <P>COPYRIGHT: (C)2009,JPO&INPIT |
