| 摘要 |
PURPOSE:To satisfactorily compensate the aberration, by satisfying the prescribed conditions for a Gaussian lens system of 5 groups and 6 lenses and accordingly using no glass of a large refractive index to 4 sheets of positive lenses. CONSTITUTION:The lens system comprises 5 groups and 6 lenses. That is, the 1st and 2nd groups include positive meniscus lenses with their convex faces turned to the subject side, the 3rd group is a negative meniscus lens with its convex face turned to the subject side, the 4th group is a composite lens of a biconcave lens and a biconvex lens stuck to each other with its concave face turned to the object side, and the 5th group is a positive lens lespectively in that order from the object side. Then the conditions (1)-(9) are satisfied when the synthetic focal distance of the whole system is referred to as (f), the sum of the spaces between lenses is SIGMAd, the refractive index of the i-th material counted from the subject side is ni, the Abbe's number is nui, the glass exponent is Gi, the radius carvature of the surface of the i-th lens from the subject side, and the space of the surface of the i-th lens from the subject side respectively. |
