OPTICAL PICKUP DEVICE, OBJECTIVE OPTICAL ELEMENT, AND OPTICAL INFORMATION RECORDING/ REPRODUCING DEVICE

摘要

Provided are an optical pickup device, an objective optical element, and an optical information recording/reproducing device capable of recording and/or reproducing information to/from optical discs of different types in a compatible manner. The optical pickup device includes a first light source for emitting a first light flux, a second light source for emitting a second light flux, a third light source for emitting a third light flux, and an objective optical element. The objective optical element has an optical surface having at least two areas, i.e., a central area and a peripheral area around the central area. The central area has a first optical path difference giving structure and the peripheral area has a second optical path difference giving structure. The objective optical element gathers the light fluxes passing through the central area and the peripheral area of the objective optical element so as to respectively record and/or reproduce information onto/from an information recording surface of a predetermined optical disc. Furthermore, a focal distance of the objective optical element with respect to the third light flux satisfies a predetermined condition.