| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens system which is widened to a half-angle of view of about 40°while attaining miniaturization and cost reduction and improving operability and has a variable power ratio (zoom ratio) of about twice. SOLUTION: The zoom lens system is constituted of three lenses, i.e. a 1st lens having negative power, a 2nd lens having positive power and a 3rd lens having positive power which are arranged successively from the object side. At the time of zooming from a short focal distance end to a long focal distance end, the 2nd lens and the 3rd lens are moved along an optical axis while fixing the 1st lens and the moving direction of the 2nd lens is set to an advancing direction from the image side to the object side. COPYRIGHT: (C)2005,JPO&NCIPI
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