| 摘要 |
PROBLEM TO BE SOLVED: To record/reproduce plural kinds of optical disks such as an optical disk whose positions of information recording surfaces are different to each other in the direction of thickness and an optical disk having wavelength dependency, with the same optical pickup. SOLUTION: This optical pickup is composed of more than two laser diodes 1, 2 having different emitting wavelengths, collimator lenses 3, 3' making light beams transmitted from the laser diodes parallel beams, an objective lens 5 converging the laser beam 12 on an information recording surface 10, a filter 6 coated in a dichroic manner and fixed to the objective lens 5 or its supporting member, a photodiode 7 for signal converting the reflected return light beam and a prism 4 refracting the light beams transmitted from more than two laser diodes 1, 2 on the same optical path and refracting the reflected return beam by the information recording surface 10 toward the photodiode 7. |
