広角レンズ、撮像レンズユニット、カメラおよび情報装置

Japanese Patent JP5601584

B2

PROBLEM TO BE SOLVED: To provide a small-size and high-performance wide-angle lens of two positive-positive groups type constituted of two groups of floating focus type.SOLUTION: The wide-angle lens is sequentially disposed with, in order from an object side to an image side: a first lens group G1 having a positive refractive power; and a second lens group G2 having a positive refractive power. The first lens group G1 includes: a negative meniscus lens L1 with a convex surface facing the object side; a biconvex lens L2; and a biconcave lense L3, and the second lens L2 and the third lens L3 are cemented together. The second lens group G2 includes a fourth lens L4 of a positive meniscus lens, the fifth lens L5 of a biconcave lens, a sixth lens L6 of a biconvex lens, and a seventh lens L7 of a biconvex lens. Among them, the fifth lens L5 and the sixth lens L6 are cemented together. The focal length F of the entire lens system at a telephoto end, and a back focus BF at the telephoto end satisfy the following conditions: (1) 4.0