Patent ID: 7173895

Claim:
An optical pickup apparatus for recording and/or reproducing information for an optical information recording medium, comprising: a first light source configured to emit a first light flux having a first wavelength for recording and/or reproducing a second optical information recording medium provided with a transparent substrate having a thickness of t 1 ; a second light source configured to emit a second light flux having a second wavelength longer than the first wavelength, for recording and/or reproducing a first optical information recording medium provided with a transparent substrate having a thickness of t 1 ; a third light source configured to emit a third light flux having a third wavelength longer than the second wavelength, for recording and/or reproducing a third optical information recording medium provided with a transparent substrate having a thickness of t 2 thicker than t 1 ; an objective lens configured to converge the first light flux emitted from the first light source onto an information recording plane of the second optical information recording medium when recording and/or reproducing information is conducted for the second optical information recording medium, to converge the second light flux emitted from the second light source onto an information recording plane of the first optical information recording medium when recording and/or reproducing information is conducted for the first optical information recording medium, and to converge the third light flux emitted from the third light source onto an information recording plane of the third optical information recording medium when recording and/or reproducing information is conducted for the third optical information recording medium; and a photodetector configured to receive a reflected light flux modulated by the information recording plane.