| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which is made smaller in size than the conventional one, and which can secure about 2.8 to 3.0 as a zoom ratio. SOLUTION: In the zoom lens, a first group G1 having negative refractive power, a second group G2 having negative refractive power, a third group G3 having positive refractive power, and a fourth group G4 having positive refractive power are arranged in this order from an object side, and the second group G2, the third group G3 and the fourth group G4 move on an optical axis when performing variable power operation between a wide angle end and a telephoto end. The first group G1 is constituted of one negative lens which has a concave surface on an image side. In the second group G2, a negative meniscus lens turning its convex surface to the object side, and a positive meniscus lens turning its convex surface to the object side are arranged in this order from the object side. In the third group G3, an aperture stop, a biconvex lens, and a cemented lens comprising a biconvex lens and a biconcave lens are arranged in this order from the object side. The fourth group G4 is constituted of one positive meniscus lens turning its convex surface to the image side. COPYRIGHT: (C)2009,JPO&INPIT
|
