| 摘要 |
PROBLEM TO BE SOLVED: To effectively restrain curve of an image face and to realize a sufficiently wider angle while preventing increases in lens diameter, a yield drop during manufacture, degradation in optical performance resulting from the wider angle, and so on. SOLUTION: A first lens group G1 includes a first aspherical lens L1 disposed on the front Ff side and at least two or more negative single lenses L2 and L3 disposed in succession on the rear Fr side. A second lens group G2 includes at least one or more positive single lenses L4 and L5. A third lens group G3 includes, in order from the front Ff side: a second aspherical lens L6 the refractive index N0 of which satisfies 1.45<N0<1.65; a first cemented lens LC1 in which a positive lens L7 and a negative lens L8 are cemented so that the center of the curvature of a cemented face C1 is on the front Ff side; at least two or more positive single lenses L9 and L10; and a second cemented lens LC2 in which a negative meniscus lens L11 and a positive lens L12 are cemented so that the center of the curvature of a cemented face C2 is on the rear Fr side. COPYRIGHT: (C)2007,JPO&INPIT
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