OPTICAL HEAD AND OPTICAL DISK DEVICE USING IT

摘要

PROBLEM TO BE SOLVED: To provide an optical head and an optical disk device capable of coping with various optical disks different in disk thickness and recording material and also capable of performing stable and excellent recording/ reproducing to the optical disks different in track structure. SOLUTION: A diffraction grating having a cross type parting line is arranged among a first light source and a second light source which have different wavelengths respectively, an object lens for condensing a luminous flux radiated from the first light source and the second light source onto various optical disks different in disk thickness or the like and recording material, and a photodetector which receives reflected light from the optical disk and detects an electric signal. A reflected luminous flux from the optical disk is quadri-divided by the diffraction grating, diffracted light which is diffracted and separated in respective regions is guided to respective independent light receiving surface on the photodetector, and a tracking error signal by a detecting method in accordance with disk structure and a focus error signal by a knife edge system are detected.