| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens that requires no start-up time to use, as seen in a collapsible lens barrel, is preferable in terms of waterproof and dust-proof, is easily configured for bending the optical path of an optical system by means of a reflecting optical element in order to make a camera thinner in the direction of its depth, has high optical specification performance such as zoom ratio, viewing angle, F-value, fewer aberrations, and can be shortened after the bending of the optical path. SOLUTION: The zoom lens includes, in order from the object side: a first lens group that has a reflecting optical element having a reflecting face for bending an optical path and serves as the lens group closest to the object side and fixed when power is varied; a second lens group that has negative refractive power and serves as a first moving lens group moved on the optical axis when power is varied; a third lens group that has positive refractive power and serves as a second moving lens group moved on the optical axis when power is varied; and a lens group closest to the image side. When power is varied from the wide-angle end to the tele-photo end during focusing on an infinity distant object, the second lens group is reciprocated so as to have a projecting locus to the image side. COPYRIGHT: (C)2009,JPO&INPIT
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