| 摘要 |
PURPOSE:To obtain a zoom lens which has a compact and simple body frame structure, and a large zoom ratio, by satisfying the prescribed conditions, in a lens system consisting of lens components of positive, negative, positive, negative and positive in order from the side of an object. CONSTITUTION:In a lens system consisting of 5 lens components having power of positive, negative, positive, negative and positive, in order from the side of an object, it is constituted so that the partial system of the first and second lens components has a negative composite focus, the partial system of the third through fifth lens components has a positive composite focal distance, and when the first, third and fifth lens components move in one body and zoom to the telephoto end from the wide angle end, the space between the first and second lens components and the space between the third and fourth lens components are increased, and the space between the second and third lens components and the space between the fourth and fifth lens components are decreased. In this way, it is possible to obtain a zoom lens which has a compact and simple body frame structure, and a large zoom ratio. |
