| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical head device in which visual field characteristics and temperature characteristics are improved having the shape suitable for miniaturization. SOLUTION: The direction of the dividing lines, which divide a focus control light receiving region, is approximately set parallel to the tracking direction projected on the region and the displacement direction of the light receiving spot caused by the displacement of an objective lens 7 is set parallel to the direction of the lines to improve the visual field characteristic. Moreover, the arranging direction of gratings 5a of a diffraction gratings 5 is set to the up and down direction, the arranging direction of a light emitting element 1 and a light receiving element 3 is set to the up and down direction and the displacement direction of the spot caused by the change in temperature is set parallel to the direction of the lines of the region to improve the temperature characteristic. |
