OBJECTIVE LENS, OPTICAL PICKUP, AND OPTICAL DISC DRIVE

摘要

An objective optical lens is provided with an optical pickup apparatus for recording and/or reproducing information converging light on first to third optical information recording media and the objective lens is commonly used for the first to third optical information recording media and is formed by single lens. At least one optical surface of the objective lens is formed by being divided into at least two regions including a central region and a peripheral region. The central region has a first diffractive structure and the objective lens converges diffracted light fluxes with same diffraction order among diffracted light fluxes of the first - third light fluxes generated in the first diffractive structure onto information recording surfaces of the first to third optical information recording media, respectively. The peripheral region has a second diffractive structure and the objective lens converges diffracted light fluxes with different diffraction order among diffracted light fluxes of the first and second light fluxes generated in the second diffractive structure onto information recording surfaces of the first and second optical information recording media, respectively.