OBJECTIVE LENS OPTICAL SYSTEM, LUMINOUS FLUX DIVIDING ELEMENT, AND OPTICAL PICKUP OPTICAL SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an objective lens optical system having high out-of-axis performance, a luminous flux dividing element, and an optical pickup optical system, capable of performing recording/reproducing in an optical recording medium different in thickness by using luminous fluxes of equal wavelengths.;SOLUTION: The luminous flux dividing element 1 is disposed on the incident side of an objective lens 2 for converging a luminous flux of a wavelength λ on the information recording surface of a first optical recording medium having a transparent substrate of a thickness t1, and converging a luminous flux of a wavelength λ on the information recording surface of a second optical recording medium having a transparent substrate of a thickness t2(t1≠t2). Each of the incident and exit surfaces of the luminous flux dividing element 1 is divided into a first optical recording medium area 11 and a second optical recording medium area 12. In the second optical recording medium area 12, the incident and exit surfaces both have positive or negative power.;COPYRIGHT: (C)2009,JPO&INPIT