| 摘要 |
PROBLEM TO BE SOLVED: To provide a wide angle lens that is compact, while achieving the excellent compensation of aberration, yielding high performance, and especially securing long back focus such that the angle of view is about 70°. SOLUTION: The wide angle lens is constituted by successively arranging a first lens L1 being a negative meniscus type lens whose powerful concave surface faces to an image side, a second lens L2 being a negative lens, a third lens L3 being a positive lens, a cemented lens L45 constituted by laminating a fourth lens L4 being a positive lens and a fifth lens L5 being a negative lens, and a sixth lens L6 being a positive lens from an object side. As for the operating functions of the lenses, the first and the second lenses L1 and L2 constitute a first lens group G1 having negative refractive power, the third, the fourth and the fifth lenses L3, L4 and L5 constitute a second lens group G2 having positive refractive power, and the sixth lens L6 constitutes a third lens group G3 having positive refractive power. An aperture diaphragm S is arranged to intervene between the third and the fourth lenses L3 and L4. COPYRIGHT: (C)2004,JPO
|
