US 5,668,669 A · Compact wide-angle objective lens

Abstract

A wide-angle objective lens is comprised, from the object side, of a first lens component which is a negative meniscus lens having its convex surface facing the object side, a second lens component which is a meniscus lens having its convex surface facing the object side and having positive refractive power, a third lens component which is a cemented meniscus lens comprising a positive lens and a negative lens cemented together and having its convex surface facing the object side and having positive refractive power, a fourth lens component which is a positive meniscus lens having its concave surface facing the object side, and a fifth lens component which is a negative meniscus lens having its concave surface facing the object side. The wide-angle objective lens has a stop disposed between the second lens component and third lens component, and satisfies predetermined conditions.

Claims7

Dependent claims

A wide-angle objective lens system comprising, in the order from an object side:

a first negative lens component having a concave surface facing an image side;
a second lens component having positive refractive power and having a convex surface facing the object side;
a third lens component having a convex surface facing the object side;
a fourth lens component including a positive meniscus single lens having a concave surface facing the object side;
and
a fifth lens component including a negative meniscus single lens having a concave surface facing the object side,
wherein said lens system satisfies the following condition:
0. 40.ltoreq.D/f.ltoreq.1.00
where
f:
the focal length of the entire lens system,
D:
the total thickness of the lens system.

10 more elements

Dependencies are inferred from the claim text.

Compact wide-angle objective lens

Life of this patent

Compact wide-angle objective lens

Life of this patent

Abstract

Claims7