Optical pickup apparatus and objective lens

摘要

An objective lens (160) of an optical pickup apparatus converges a divergent light flux onto an information recording surface. The following conditional formula is satisfied: <DF> delta SA1/ delta U . delta U + delta SA2/ delta T . delta T </= 0.07 lambda rms </DF> where lambda represents a wavelength of a light source, delta SA1/ delta U represents a change of a spherical aberration for an object-to-image distance change delta U ( delta U </= 0.5mm) and delta SA2/ delta T represents a change of spherical aberration for a temperature change delta T ( delta T </= 30 DEG C), the object-to-image distance is a distance between the light source (a light emitting point) and the information recording surface. <IMAGE>