| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which achieves a high variable power ratio of over 5 times without causing upsizing in an optical axis direction. SOLUTION: The zoom lens 1 is constituted by arranging a first lens group GR1 having positive refractive power, a second lens group GR2 having negative refractive power, a third lens group GR3 having positive refractive power, a fourth lens group GR4 having positive refractive power, a fifth lens group GR5 having negative refractive power and a sixth lens group GR6 having positive refractive power in order along an optical axis from an object side to an image side. The first lens group GR1 includes a reflection member L2 for bending the optical axis by about 90 degrees. The first and the third lens groups GR1 and GR3 are positionally fixed on the optical axis when varying power and when focusing. By moving the second, the fourth and the fifth lens groups GR2, GR4 and GR5 on the optical axis, the power is varied, and by moving the fourth lens group GR4 and/or the fifth lens group GR5 on the optical axis, focusing is performed. By moving the sixth lens group GR6 in a direction nearly orthogonal to the optical axis, image shift is performed, and the fourth lens group GR4 includes only a positive lens and a negative lens. COPYRIGHT: (C)2009,JPO&INPIT
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