| US 7,538,955 B2 | ||
| Imaging lens | ||
| Tomohiro Saito, Kawaguchi (Japan) | ||
| Assigned to Enplas Corporation, Saitama (Japan) | ||
| Filed on Sep. 28, 2007, as Appl. No. 11/904,842. | ||
| Prior Publication US 2008/0094732 A1, Apr. 24, 2008 | ||
| Int. Cl. G02B 3/02 (2006.01) | ||
| U.S. Cl. 359—716 [359/772; 359/791] | 7 Claims |
| 1. 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 first lens that is a meniscus lens having a positive power whose
convex surface faces the object side, a diaphragm, a second lens that is a meniscus lens having a positive power whose convex
surface faces the image surface side, and a third lens that is a biconcave lens having a negative power, wherein a condition
expressed by the following expression (1) is to be satisfied:
0.11<d4/fl≤0.25 (1)
where,
d4: distance between the second lens and the third lens on the optical axis
fl: focal distance of the entire lens system.
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