| 摘要 |
PROBLEM TO BE SOLVED: To achieve wider angle and miniaturization after securing a high performance. SOLUTION: There are arranged in order from an object side to an image side: a first lens group G1 having positive refractive power and always fixing positions; a second lens group G2 which has negative refractive power and can be moved to an optical axis direction mainly for variable magnification; a third lens group G3 having positive refractive power and always fixing positions; and a fourth lens group G4 which has positive refractive power and can be moved to an optical axis direction for correction and focusing of focal positions due to variable magnification. The first lens group arranges concave lenses, a cemented lens having positive refractive power, and convex lenses in order from an object side to an image side. COPYRIGHT: (C)2011,JPO&INPIT |
