| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device which suppresses jitter generation due to leakage of a side beam of a DVD and has satisfactory recording reproducing characteristics for both a DVD and a CD. <P>SOLUTION: The optical pickup device has two-wavelength semiconductor laser 1 as a light source; a light receiving sensor 11 as a light receiving means; a diffraction grating 2, arranged between the two-wavelength semiconductor laser 1 and an optical disc 10, in which multiple parallel grooves for dividing the light from the two-wavelength semiconductor laser 1 into three beams is formed in a direction where the three beams are aligned in the direction toward a tangential line with a minute angle for circumference of the optical disc 10; and an optical system, arranged between the diffraction grating 2 and the optical disc 10, for both condensing the light from the two-wavelength semiconductor laser 1 to the optical disc 10 and leading the reflected light from the optical disc 10 to the light receiving sensor 11. The diffraction grating 2 has two areas where phases of peaks and bottoms of the groove are shifted, its boundary is made to pass through the center of the light from the two-wavelength semiconductor laser 1 and parallel to the direction toward the tangential line of the circumference of the optical disc 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
