Dual-focus objective lens of optical pickup

摘要

A dual-focus objective lens for an optical pickup which is compatible with both 0.6 mm and 1.2 mm disks is compensated in its aberration with respect to a light spot on a recording plane of the loaded disk and is composed of a first lens and a second lens. The loaded positions of the 0.6 mm disk and 1.2 mm disk in view of the second lens are different from each other. An optical pickup having the dual-focus objective lens can reproduce a signal with a high signal-to-noise ratio and has improved light efficiency. Also, an optical pickup enabling recording as well as reproduction is obtained.