| 摘要 |
PROBLEM TO BE SOLVED: To provide a wide-angle imaging lens having optical performance capable of coping with an imager that has a view angle of≥90°, a brightness of≤F2.8, and≥100 million pixels. SOLUTION: The wide-angle imaging lens is a triplet lens composed of a positive first lens, a negative second lens, and a positive third lens. The wide-angle imaging lens is designed so that the refracting forces of these lenses satisfy the following conditions (1) to (4), a distance between the second lens and the third lens satisfies the following condition (5), and also the material of each lens satisfies given conditions. The condition (1) is 15<f1/f<30, condition (2) is -3<f2/f<-1.5, condition (3) is 1.2<f3/f<2.5, condition (4) is 0.15<f2/f1<-0.07, and condition (5) is 2.5<D23/f<5.0. In all the conditions, f denotes the focal distance of the entire lens system, f1 denotes the focal distance of the first lens, f2 denotes the focal distance of the second lens, f3 denotes the focal distance of the third lens, and D23 denotes a distance between the second and third lenses. COPYRIGHT: (C)2006,JPO&NCIPI
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