Zooming short-range projection lens and zooming method thereof

Abstract

The invention relates to a zooming short-range projection lens. An optical system of the lens is sequentially provided with a positive focal power front fixing set A, a negative focal power zoom set B, a negative focal power compensation set C, a variable diaphragm D and a positive focal power back fixing set E along a left-to-right light incident direction, wherein the positive focal power front fixing set A comprises a flat convex lens A-1, a crescent negative lens A-2, a crescent positive lens A-3 which are sequentially arranged from left to right, the negative focal power zoom set B comprises a double concave negative lens B-1 and a crescent positive lens B-2 which are sequentially arranged from left to right, the negative focal power compensation set C comprises a crescent negative lens C-1, the position of the variable diaphragm D is not changed relative to the positive focal power back fixing set E, and the positive focal power back fixing set E comprises a crescent positive lens E-1, a double convex lens E-2, a crescent negative lens E-3 and a double convex positive lens E-4 which are sequentially arranged from left to right. According to the zooming short-range projection lens, the structure of the optical system is simple, intelligible projection of a 190mm object distance can be realized, and length of the lens structure is short.

Description

technical field [0001] The invention relates to a zoom short-distance projection lens and a zoom method thereof. Background technique [0002] Various zoom projection lenses are emerging in an endless stream today, but the projection object distance of the current zoom projection lens is greater than one meter. When these projection lenses project images with an object distance within 200mm, due to the influence of the projection object distance, the coma effect of the projection lens is caused, and a clear image cannot be projected, and the number of lenses of these projection lenses is large, and the assembly structure of the lenses is complicated. , The uncompact structure of the lens results in a large volume, which is very inconvenient to carry. Contents of the invention [0003] The object of the present invention is to provide a zoom short-distance projection lens with a simple structure and a compact lens assembly structure and a zoom method thereof for the above ...

AI Technical Summary

Problems solved by technology

[0002] Various zoom projection lenses are emerging in an endless stream today, but the projection object distance of the current zoom projection lens is greater than one meter

When these projection lenses project images with an object distance within 200mm, due to the influence of the projection object distance, the coma effect of the projection lens is caused, and a clear image cannot be projected, and the number of lenses of these projection lenses is large, and the assembly structure of the lenses is complicated. , the uncompact structure of the lens results in a large volume, which is very inconvenient to carry

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