| 摘要 |
<P>PROBLEM TO BE SOLVED: To cope with recording on a DVD-R disk, while forming prescribed 3 beams for both DVD and CD without generating unnecessary diffracted light and making a servo signal detectable, even when temperature of a semiconductor laser section changes and oscillation wavelength changes in an optical pickup device which takes a configuration arranging diffraction-grating for forming 3 beams in a common optical path of optical beams of the DVD and the CD corresponding to a DVD optical beam and a CD optical beam. <P>SOLUTION: The optical pickup device which generates at least a tracking error signal for a DVD-R disk by a differential push pull method by utilizing that a diffraction angle of a diffraction-grating is proportional to wavelengths and setting disk radial direction spot spacing of a DVD optical beam on an optical disk as nearly as 0.37 μm, and generates at least a tracking error signal for a CD-ROM disk by a three spot method, is used. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
