| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device and optical disk drive which obtains a good tracking error signal to a plurality of kinds of optical disks with different track pitches. <P>SOLUTION: The optical pickup device which records and reproduces information to a plurality of optical disks of different track pitches is provided with: a light source 31 emitting an optical beam of predetermined wavelength; a diffraction element 32 which diffracts the optical beam emitted from the light source into a predetermined direction and splits it into a main beam and a side beam; an objective lens 33 which condenses the split main beam and side beam to a recording layer of the optical disk 2; and an optical detector 34 which has a main receiver receiving the main beam and a sub receiver receiving the side beam among return lights from the optical disk. A part of an area on the diffraction element 32 corresponding to an entrance pupil of the objective lens 33 is restricted in diffraction to a predetermined direction so that the diffraction element may lower a cutoff frequency of a sub spot in the radial direction formed by side beam. <P>COPYRIGHT: (C)2009,JPO&INPIT |
