TW200951532A - Image-forming lens set - Google Patents

Abstract

An image-forming lens set is disclosed, which comprises a fixed diaphragm and an optical set. The optical set comprises a first lens, a second lens, a third lens and a fourth lens which are arranged from an object side to an image side according to the following order: the diaphragm; the first lens, having positive diopter with a convex surface facing toward the object side; the second lens, which is a meniscus lens having a negative diopter with a concave surface facing toward the object side; the third lens, having positive diopter with a convex surface facing toward the object side; and the fourth lens having negative diopter with a concave surface facing toward the object side. According to the design that the second and fourth lens have concave surfaces facing toward the object side, and the third lens has convex surface facing toward the object side, the system sensitivity can be reduced so as to effectively control tolerance range, thereby providing a high-resolution and high-yield image-forming lens set.