| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable magnification lens which can maintain favorable performance even if it is used at a photographing magnification in an extensive variable magnification region beyond unmagnification. SOLUTION: This variable magnification lens HL1 is provided with, from an object side in order, a 1st lens group G1 having a positive refracting power, a 2nd lens group G2 having a negative refracting power, an aperture diaphragm F, and a 3rd lens group G3 having a positive refracting power, and the 1st lens group G1 is constituted including at least one combined lens group of a positive lens with the convex surface faced to the object side so as to be located nearest to the object side and a negative lens; the 2nd lens group is constituted of a combined lens of three negative power lenses, and the 3rd lens group G3 is constituted including a combined lens of three negative power lenses with the concave surface faced to the object side so as to be located nearest to the object side. Then, when focusing from a high magnification side toward a low magnification side, the variable magnification lens is configured so that an air space between the 1st lens group G1 and the 2nd lens group G2 (for example, d6 in Table 1) and an air space between the 2nd lens group and the 3rd lens group (for example, d11 in Table 1) vary. COPYRIGHT: (C)2005,JPO&NCIPI
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