| 摘要 |
An optical pickup lens for focusing a light beam from a laser light source on an optical information recording medium is a single lens. The optical pickup lens has two surfaces, and a surface R2 opposite to a surface R1 closer to the laser light source has a continuous shape. When the surface R2 has radii h1, h2 and h3 (h1<h2<h3) from an optical axis to a lens periphery, and where sags in the radii h1, h2 and h3 are sag1, sag2 and sag3, and differentials in the sags are &Dgr;sag1, &Dgr;sag2 and &Dgr;sag3, respectively, 0>&Dgr;sag1>&Dgr;sag2 and &Dgr;sag2<&Dgr;sag3 are satisfied. |
