Patent ID: 6721242
Filing Date: 2004-04-13
Classification: G11B

Abstract:
An optical pickup comprising:a semiconductor laser which emanates an optical beam; an optical dividing element which divides the optical beam into at least three optical beams, the at least three optical beams including 0 order light and Â±1st order diffraction light; an optical lens which irradiates optical spots of the three optical beams on an optical disk; and an optical detector which has a first receiving area which receives 0 order light reflected by the optical disk, a second receiving area which receives Â±1st order diffraction light reflected by the optical disk and a third receiving area which receives âˆ’1st order diffraction light reflected by the optical disk, the second and the third receiving areas being divided into four light receiving surfaces delimited by a first direction corresponding to a radius direction of the disk and a second direction corresponding to a track direction of the disk, the optical detector providing an output of a sum signal of an output from the light receiving surfaces of the second and the third receiving areas which are located at corresponding positions with respect to both of the first and the second directions.