DESIGN METHOD OF OBJECTIVE OPTICAL ELEMENT USED FOR OPTICAL PICKUP APPARATUS, OBJECTIVE OPTICAL ELEMENT, AND OPTICAL PICKUP APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a design method of an objective optical element included in an optical pickup apparatus satisfying the required performance/specifications and to provide the objective optical element and the optical pickup apparatus.

SOLUTION: This invention relates to the design method of the objective optical element included in the optical pickup apparatus applying information reproduction or the like to first and second optical information recording media whose protective substrate thicknesses differ from each other by using at least two kinds of light sources whose wavelengths differ from each other. An optical functional side of the objective optical element is divided into a central area used for the two kinds of the optical information recording media and a peripheral area used mainly for the first optical information recording medium, in the central area, when a condition of Expression (1) holds and a maximum tracking amount is 0.5 mm, magnifications m(D), m(C) with respect to the first and second optical information recording media are selected so that a ternary coma aberration CM 3 caused thereby satisfies a condition (a), wherein Expression (1): -0.12COPYRIGHT: (C)2004,JPO