| 摘要 |
PURPOSE:To make a zoom lens compact and high-power by constituting the zoom lens so that air gaps among a positive lens group G1, a negative lens group G2, a positive or negative lens group G3, a positive lens group G4, and a negative lens group G5 which are arranged in order from the object side satisfy specific conditions. CONSTITUTION:The zoom lens consists of the positive lens group G1, the negative lens group G2, the positive or negative lens group G3, the positive lens group G4, and the negative lens group G5 which are arranged in order from the object side; and when air gaps among individual lenses are changed for zooming, lens groups G1, G3, G4 and G5 are moved in the same direction to set air gaps between lens groups G1 and G2 and between lens groups G4 and G5 to D1W and D4W respectively in case of the wide angle end and to D1T and D4T respectively in case of the telephoto end, and conditions of formulas I and IIare satisfied when focal lengths of lens groups G1, G2, G4, and G5 are denoted as F1, F2, F4, and F5 respectively, thereby making the zoom lens compact and high-power with a relatively simple constitution as the whole. |
