| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging lens which is compact, has long back focus and is excellent in mass productivity though it has excellent optical performance, and to provide an imaging unit and an imaging apparatus each using the imaging lens. SOLUTION: The imaging lens is constituted by arranging an aperture diaphragm IR, a 1st lens G1 having positive refractive power, a 2nd lens G2 having negative refractive power, a 3rd lens G3 having positive refractive power and a 4th lens G4 having negative refractive power in order from an object side. The 2nd lens, the 3rd lens and the 4th lens are composed of resin material, and the imaging lens 1 satisfies following conditional expressions (1), (2) and (3). (1): f/f1<1.5 (2): -2.5<¾f/f2¾<-1.5 (3): 15<νd3-νd2, wherein f means the focal distance of an entire lens system, f1 means the focal distance of the 1st lens, f2 means the focal distance of the 2nd lens,νd2 means the Abbe number of the 2nd lens on a d-line, andνd3 means the Abbe number of the 3rd lens on the d-line. COPYRIGHT: (C)2006,JPO&NCIPI
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