Patent ID: 7969852
Filing Date: 2011-06-28
Classification: G11B

Abstract:
1. An optical pickup apparatus comprising: a first light source emitting a light flux with a wavelength λ a second light source emitting a light flux with a wavelength λ a light-converging optical system comprising a coupling lens and an objective lens; and a photodetector, wherein the optical pickup apparatus is capable of recording and/or reproducing information by converging a light flux from the first light source with the light-converging optical system on an information recording surface of a first optical information recording medium through a protective layer with a thickness of t wherein the optical apparatus is capable of recording and/or reproducing information by converging a light flux from the second light source with the light-converging optical system on an information recording surface of a second optical information recording medium through a protective layer with a thickness of t wherein the optical pickup apparatus satisfies following expressions (1), (2), and (3): where L L m m M M