Patent ID: 6370103
Filing Date: 2002-04-09
Classification: G02B,G11B

Abstract:
An optical pickup apparatus for reproducing information from one of different kinds of optical information recording medium, each having a transparent substrate in different thickness, or for recording information onto one of said different kinds of optical information recording medium, said optical pickup apparatus comprising:(a) a first light source for emitting light flux; (b) a converging optical system having an optical axis, a ring-zonal diffraction section, and a refracting surface including a first divisional portion, a second divisional portion and a third divisional portion, wherein the third divisional portion is farther from the optical axis than the first divisional portion, and the second divisional portion is provided between the first divisional portion and the third divisional portion; and (c) an image sensor, wherein the first divisional portion and the third divisional portion are capable of converging the light flux on a first information recording plane of a first optical information recording medium having a first transparent substrate of thickness t1, to reproduce information recorded in the first optical information recording medium or recording information on the first optical information recording medium, wherein the first divisional portion and the second divisional portion are capable of converging the light flux on a second information recording plane of a second optical information recording medium having a second transparent substrate of thickness t2, to reproduce information recorded in the second optical information recording medium or recording information on the second optical information recording medium, wherein t2 is greater than t1, and wherein the image sensor is capable of receiving light flux reflected from the first information recording plane or the second information recording plane.