| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized zoom lens which is made suitable for a video camera and an electronic still camera or the like, using a solid-state imaging element or the like, has high optical performance and to provide the lens with a variable power ratio of about 5 or larger. SOLUTION: The zoom lens is provided with a first lens group G1 having positive power, a second lens group G2 having negative power, a third lens group G3 having positive power, a fourth lens group G4 having positive power and a fifth lens group G5 having positive power, in this order starting from an object side. When zooming is conducted from a wide-angle end condition to a telophoto end condition, the space between the first group G1 and the second group G2 is increased, the space between the second group G2 and the third group G3 is decreased, the space between the third group G3 and the fourth group G4 is decreased and the space between the fourth group G4 and the fifth group G5 is increased so that the first group G1 is moved relative with respect to an image surface I, the second group G2 is temporarily moved to the image surface I side and then, moved to the object side, the third group G3 moves to the object side, the fourth group G4 moves to the object side and the fifth group G5 is relatively moved to the image surface I side and a prescribed conditional equation is satisfied. COPYRIGHT: (C)2006,JPO&NCIPI |
