| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact and high-performance variable power optical system contriving the harmony (balance) of the moving amounts of respective lens group in variable power and restraining its entire length. SOLUTION: The variable power optical system has: at least a first lens group GR1 having positive power; a second lens group GR2 having negative power; and a third lens group GR3 having positive power from an object side to an image side, and the first lens group GR1 includes an optical prism PR to change an optical axis. The variable power optical system satisfies a following conditional expression (1). 0.1<¾f2/√(fw×ft)¾<0.45, provided that f2: the focal length of the second lens group, fw: the focal length of the variable power optical system in a wide angle end state, and ft: the focal length of the variable power optical system in a telephoto end state. COPYRIGHT: (C)2007,JPO&INPIT
|
