Patent ID: 6894955
Filing Date: 2005-05-17
Classification: G11B

Abstract:
1. An information write device comprising: optical system means for radiating information recording tracks and guide tracks with at least two light spots; optical detector means for detecting each of reflected beams of light generated by the radiation of each of said light spots; a pickup for moving said optical system means along a direction of arrangement of said information recording tracks and said guide tracks; signal generating means for generating each of push-pull signals in accordance with each of detection signals outputted from the optical detector means when said pickup moves along the direction of arrangement of said information recording tracks and said guide tracks; and operational means for generating a contrast signal, having contrast information in the direction of arrangement of said information recording tracks and said guide tracks, by adding the push-pull signals corresponding to said at least two light spots; wherein said optical system means allows one of said at least two light spots to radiate said information recording track and at the same time the other light spot to radiate a portion displaced from the center of said information recording track or said guide track, and wherein said optical system means further includes at least one additional light spot, non-collinear with said at least two light spots.