Optical lens, optical pickup apparatus, and optical disk apparatus using the same

摘要

Providing an objective lens capable of achieving reliable centering during formation, allowing high-precision formation, and improving durability of a manufacturing apparatus, and providing an optical pickup apparatus and an optical disk apparatus using that objective lens. According to the present invention, an objective lens is formed so as to satisfy condition 0.3<=Z/D<=0.5, where Z is a sag amount equivalent to a length of a convexly curved optical surface along an optical axis, and D is an optically effective diameter equivalent to a length which is optically effective for the optical surface and is orthogonal to the optical axis. It is possible to reliably perform centering during fabrication of the objective lens and allow high-precision formation for decreasing the lens aberration.