| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device capable of performing satisfactory recording and reproduction to two kinds of recording media regardless of reproducing wavelengths and the substrate thicknesses of the recording media. <P>SOLUTION: The optical pickup device is provided with a semiconductor laser 1a emitting the light of a wavelength λ1 and a semiconductor laser 1b emitting the light of a wavelength λ2 different from the wavelength λ1 and the device performs the recording or the reproduction of information to an optical disk 13a by forming a converged light spot SPa on the disk 13a while making the light of the wavelength λ1 pass through an objective lens 11 and the device performs the recording or the reproduction of information to an optical disk disk 13b whose substrate thickness is different from that of the optical disk 13a by forming a converged light spot SPb on the disk 13b while making the light of the wavelength λ2 pass through the objective lens 11. Then, a diffraction element 10 which is formed by joining two materials whose wavelength dependence of refractive indexes are difference with each other and which has grid geometry at its joined surface, is provided among the semiconductor lasers 1a, 1b and the objective lens 11. <P>COPYRIGHT: (C)2004,JPO |
