Patent ID: 6366542
Filing Date: 2002-04-02
Classification: G02B,G11B

Abstract:
An optical pickup apparatus to conduct reproducing and/or recording information of an optical information recording medium, comprising:a light source to emit a light flux having a wavelength of &lgr; (nm); a converging optical system to converge the light flux emitted from the light source onto a information recording surface of the optical information recording medium, the converging optical system having an objective lens; and an optical detector to receive reflected light from the optical information recording medium; wherein the objective lens is a plastic lens, has a diffracting section on at least one surface thereof and satisfies the following conditional formula: 0.3&lE;&phgr;R/&phgr;&lE;1.5 where &phgr;R represents a refracting power of the objective lens on wavelength &lgr; (nm) of the light source and &phgr; represents a power of the objective lens in wavelength &lgr; nm of the light source.