【発明の名称】複写用レンズ

Japanese Patent JP2859418

B2

A copying lens system of a three-unit/three-element composition that can be made from relatively inexpensive optical materials and which exhibits satisfactory performance at copying ratios ranging from about 0.5 to 2.0. The lens system includes, in order from the object side, a first lens of positive meniscus having a convex surface directed to the object, a negative second lens having a concave surface on both sides, and a positive third lens having a convex surface on both sides. The lens system satisfies the following conditions: (1) 1.70