| 摘要 |
PROBLEM TO BE SOLVED: To condense reflected light of two kinds of wavelengths correspondent to each different optical disk in nearly the same location on a photodetector. SOLUTION: In an optical pickup composed of an emitting optical system to condense light on an optical disk 6 consisting of two kinds of light sources consisting of a laser chip 101 having a wavelength λ1 and a laser chip 102 having a wavelength λ2 (#l1<λ2), a collimator lens 2, a half mirror 3, a rising mirror 4, and an objective lens 5, and a detecting optical system to receive reflected light from the optical disk 6 on the photodetector 10 through the objective lens 5, the rising mirror 4, the half mirror 3 to pass light from the rising mirror 4, a condensing lens 8 and a cylindrical lens 9, each reflected light of two wavelengths correspondent to the optical disk 6 condenses on nearly the position of the photodetector 10 by disposing a correction prism 7 to the detecting optical system. |
