| 摘要 |
PROBLEM TO BE SOLVED: To give disks with different thickness and recording material compatibility and to make possible recording/reproducing on respective disks under optimum optical environment by using light sources with different wavelengths according to the disks. SOLUTION: This optical pickup is composed of following elements, means. First, second light sources 11, 21 generate respectively the light with different wavelengths, and an objective lens 60 converges respectively the light radiated from the first, second light sources on the disks 70, 80 with different thickness. An optical path control means contains a beam splitter 30, and controls an optical path so that the light radiated from the first, second light sources are made incident on the objective lens. A collimate lens 50 of a radiation angle adjustment means adjusts the radiation angles of the first, second light sources 11, 21 for limit-adjusting the effective numerical aperture of the objective lens 60. First, second detectors 12, 22 light-receive respective reflection light reflected from the disks 70, 80 with different thickness to detect electric signals. |
