Variofocusing monitoring shot and monitoring device

Abstract

A zoom lens assembly for monitor and a monitoring device are provided. The lens assembly comprises a first to a thirteenth lenses (L-L) arranged successively coaxially along the transmission direction of an incident light beam. The first, the eighth, the tenth and the twelfth lenses (L, L, Land L) are biconvex positive lenses; the second, the ninth and the eleventh lenses (L, Land L) are falcate negative lenses; the third, the fourth, the sixth and the thirteenth lenses (L, L, Land L) are falcate positive lenses; the fifth lens (L) is a biconcave negative lens; and the seventh lens (L) is a plano-concave negative lens. The second and the third lenses (Land L) are closely adhered to each other, and the sixth and the seventh lenses (Land L) are closely adhered to each other. The intermediate parts of the second, the third, the fourth and the thirteenth lenses (L, L, Land L) are all convex toward a direction reverse to the transmission direction an incident light beam; the intermediate parts of the sixth, the ninth and the eleventh lenses (L, Land L) are all convex toward the transmission direction of the incident light beam; and the fifth, the sixth and the seventh lenses (L, Land L) can move synchronously along a light axis direction. The shot can realize all-weather, wide-range and variofocusing monitoring. The shot has a high imaging sharpness and a simple structure; and the cost of the material is low, thus controlling the manufacturing cost effectively.