Patent ID: 7965613
Filing Date: 2011-06-21
Classification: G11B

Abstract:
1. An image reader comprising: a rotation unit that rotates an optical disk; an irradiation unit that is movable in a radial direction of the optical disk and irradiates the optical disk rotated by the rotation unit with laser light; a feeding unit that transports the irradiation unit in the radial direction while the rotation unit rotates the optical disk; a gradation level determination unit that receives reflection light of the laser light applied to the optical disk by the irradiation unit and determines a gradation level for each predetermined dot region along a circumferential direction of the optical disk in response to an amount of the received reflection light; an output unit that outputs pixel data indicating the gradation level for each dot region determined by the gradation level determination unit; and a position information acquisition unit that acquires position information indicating a read start position and a read termination position in the radial direction of the optical disk, wherein the feeding unit transports the irradiation unit from the read start position to the read termination position indicated by the position information acquired by the position information acquisition unit by a predetermined feed width in the radial direction each time the optical disk makes one revolution, and wherein the gradation level determination unit receives the reflection light of the laser light applied to the optical disk by the irradiation unit over a time period during which the optical disk makes one revolution.