Imaging lens
AssigneeEnplas Corporation
InventorTomohiro Saito
Life of this patent
Estimating the term…
Abstract
It is to provide an imaging lens that can improve optical performance while reducing size and weight. An imaging lens includes, in order from an object side to an image surface side, a diaphragm, a first lens that is a biconvex lens, and a second lens that is a lens having a negative power whose concave surface faces the object side, wherein conditions expressed by the following expressions are to be satisfied: −0.3≦r1/r2<−0.1 and 0.8≦f1/FL≦0.98 (where, r1: center radius curvature of the object side face of the first lens, r2: center radius curvature of the image surface side face of the first lens, f1: focal distance of the first lens, and FL: focal distance of the entire lens system).
Claims5
An imaging lens used for forming an image of an object on an image-taking surface of an image sensor element consisting of:
- in order from an object side to an image surface side, a diaphragm, a first lens that is a biconvex lens, and a second lens that is a lens having a negative power whose concave surface faces the object side, wherein conditions expressed by the following expressions (1), (2) and (5) are to be satisfied:
- −0.3≦r1/r2<−0.1 (1)
- 0.8≦f1/FL≦0.98 (2)
- 0.1≦d1/FL≦0.3 (5)
- where,
- r1:
- center radius curvature of the object side face of the first lens
- r2:
- center radius curvature of the image surface side face of the first lens
- f1:
- focal distance of the first lens
- FL:
- focal distance of the entire lens system
- d1:
- center thickness of the first lens.
Dependencies are inferred from the claim text.