US Patent 7564765 Optical pickup device and optical disk apparatus

An optical pickup device includes: a light source; a light receiving sensor, having main tracking light detection faces and sub-tracking light detection faces; and a hologram, having tracking areas that are divided into main tracking areas and sub-tracking areas along division lines in the tangential direction. In the hologram, each of the tracking areas is alternately divided into the main tracking areas and the sub-tracking areas along the division lines in the radial direction, and the same width is employed in the radial direction for the main tracking areas and the sub-tracking areas.