| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device which handles a plurality of kinds of information recording media without increasing the size and the cost and which forms an optimum optical spot for the media. <P>SOLUTION: Luminous fluxes emitted form a plurality of light sources LD1 and LD2 are respectively made into approximately parallel light beams by an optical element 52. Then, the beam radius of at least one of the luminous fluxes is changed by beam radius changing means (DP2, DP3, RM1, BE and RM2) and the light beams are converged onto a recording surface of a corresponding information recording medium 15 through an objective lens 60. When the luminous flux emitted from the light source is made incident on the lens 60 without changing the beam radius and the RIM at the taken-in luminous flux is deviated from an ideal value of the wavelength of the flux, the beam radius of the luminous flux at its wavelength is changed by the beam radius changing means and the RIM at the taken-in luminous flux is made close to the ideal value at its wavelength. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
