US 7,072,123 B2 · Imaging lens including three lens components

Abstract

An imaging lens includes, in order from the object side: a first lens component with a convex surface on the object side near the optical axis; a second lens component with a meniscus shape and a concave surface on the object side near the optical axis; and, a third lens component of positive refractive power with a convex surface on the object side. The first and second lens components may include aspheric surfaces and be made of plastic, and the third lens component may be made of glass. A stop may be placed on the object side of the first lens component or between the first lens component and the second lens component. Each lens component that forms the imaging lens may consist of a lens element. Specified conditions are satisfied in order to reduce aberrations and to insure that a sufficient back focus is provided.

Claims20

Dependent claims

An imaging lens comprising, arranged along an optical axis in order from the object side:

a first lens component having positive refractive power, having a convex surface on the object side near the optical axis, being made of plastic, and having at least one aspheric surface;
a second lens component having a meniscus shape with a concave surface on the object side, being made of plastic, and having at least one aspheric surface;
a third lens component having positive refractive power and a convex surface on the object side;
wherein
the following condition is satisfied:
−1.0<f/Rg3r<0.4
where
f is the focal length of the imaging lens, and
Rg3r is the radius of curvature of the image-side lens surface of the third lens component.

6 more elements

Dependencies are inferred from the claim text.

Imaging lens including three lens components

Life of this patent

Imaging lens including three lens components

Life of this patent

Abstract

Claims20