OPTICAL PICKUP DEVICE, RECORDING/REPRODUCING DEVICE, PROVIDED WITH THE OPTICAL PICKUP DEVICE OPTICAL ELEMENT, INFORMATION RECORDING/REPRODUCING METHOD, OPTICAL SYSTEM, LENS, DIFFRACTION OPTICAL SYSTEM FOR OPTICAL DISK, REPRODUCING DEVICE AND OBJECTIVE LENS FOR OPTICAL PICKUP

摘要

PROBLEM TO BE SOLVED: To provide an optical pickup device correcting aberration with simple constitution, a recording/reproducing device provided with the optical pickup device, an optical element, an information recording/reproducing method, an optical system, a lens, a diffraction optical system for an optical disk, a reproducing device and an objective lens for the optical pickup device. ;SOLUTION: In this optical pickup device containing an optical surface provided with a diffraction zonal lens on the refraction surface of the objective lens 1, and actions of a diffraction surface and a refraction surface are canceled for three wavelengths light sources 11, 12, 13 different from each other, and a spherical aberration is corrected. Further, related to the beams from three wavelengths light sources 11, 12, 13 by using 1st order diffraction beams as the diffraction beams, a loss of a light quantity is reduced. Further, the objective lens is provided with a diffraction pattern on at least one surface, and when luminous flux from the light sources of different wavelengths are converged on an information recording surface, the 1st order diffraction beams from the diffraction pattern are used together in the reproduction of plural recording media. By the condition of the recording media, the used diffraction beams are +1st order diffraction beams together or -1st order diffraction beam together.;COPYRIGHT: (C)2001,JPO