Patent ID: 7986593
Filing Date: 2011-07-26
Classification: G11B

Abstract:
1. An optical integrated device comprising: a light source to emit a light beam; a light splitting-and-guiding section to split a reflected light beam into two end light beams, a connection light beam, and a residual light beam, and to guide the two end light beams and the connection light beam in directions different from a direction of the residual light beam, the reflected light beam being a portion of the light beam reflected from an optical disc including a track extending in a tangential direction, the two end light beams passing through two end regions of a cross section of the reflected light beam, the two end regions being positioned at ends of the cross section in the tangential direction and on opposite sides of the cross section in a radial direction of the optical disc, the connection light beam passing through a connection region of the cross section, the connection region connecting the end regions to each other, the residual light beam passing through a residual region of the cross section, the residual region being a region excluding the two end regions and the connection region; and a light receiving section to receive the two end light beams and the connection light beam with a plurality of photodetection devices divided, in the tangential direction, into at least two regions within a range in which the connection light beam is incident, to receive the residual light beam with a plurality of photodetection devices divided, in the tangential direction, into a plurality of regions having widths at least corresponding to portions on which the two end light beams are incident, and to output a detection signal in accordance with an amount of light received with each of the photodetection devices.