Patent ID: 6212152
Filing Date: 2001-04-03
Classification: G11B

Abstract:
An optical information detecting apparatus optically detecting information recorded on a recording medium, said optical information detecting apparatus being adapted to hold said recording medium and comprising:a beam source;a first optical system focusing an optical beam produced by said beam source on a recording surface of said recording medium;a photodetection unit; anda second optical system directing an optical beam, produced as a result of irradiation of said optical beam on said recording surface, to said photodetection unit,said second optical system including a beam dividing element disposed so as to incident said produced optical beam, said beam dividing element extracting, from said produced optical beam, a plurality of optical beam elements traveling generally parallel with each other in said reflection optical beam, by dividing said produced optical beam such that said plurality of optical beam elements reach said photodetection unit along respective optical paths,wherein said photodetection unit includes first and second photodetectors on respective optical paths of first and second optical beam elements included in said produced optical beam for detecting an information signal recorded on a land formed on said recording surface of said recording medium and wherein said photodetection unit includes third and fourth photodetectors on respective optical paths of third and fourth optical beam elements includes in said produced optical beam for detecting an information signal recorded on a groove formed on said recording surface of said recording medium.