Condenser lens

Abstract

Abstract PURPOSE:To obtain an objective lens suitable for an optical reproducing device where the objective lens itself is shaked to perform tracking, by satisfying prescribed conditions in respect to a biconvex single lens consisting of the first and the second axially symmetric general aspherical surfaces. CONSTITUTION:A biconvex single lens is constituted which consists of the first and the second axially symmetric general aspherical surfaces expressed with formula (1) in the system of orthogonal coordinates of (x), (y), and (z) axes where the optical axis is the (z) axis and apexes of the first and the second surfaces, to which a parallel light is made incident, are the origin, and conditions of formulas (2) and (3) are satisfied. Thus, since the lens is small-sized and lightweight and the aberration near the optical axis is corrected well, an objective lens is obtained which is suitable for an optical reproducing device where the objective lens itself is shaked to perform tracking.

Inventors

• 👤 Shigeo Kubota

Bibliographic Details