3D interaction-type projection lens

Abstract

The invention provides a projection lens. The projection lens comprises a first lens set, a second lens set, a third lens set and a fourth lens set from an imaging side to an image source side in sequence, wherein the first lens set comprises a first lens with negative focal power and a reflection optical face enabling a light path to bend; the second lens set comprises a second lens with positive focal power, and the faces, facing the imaging side, of the second lens and the image source side, of the second lens are convex faces; the third lens set comprises a third lens with negative focal power; the fourth lens set has positive focal power and comprises one or more lenses with focal power, and the face, closest to the imaging side, of the fourth lens set is a convex face. The lens meets the following relation of ImgH / D>0.55, wherein ImgH is one half the diameter of an image source, and D is the vertical distance between the face, facing the imaging side, of the first lens and the center position of the reflection optical face. According to the projection lens, because the four lens sets are adopted, the size of a lens system can be effectively reduced, it can be guaranteed that the lens has a large resolution ratio under the large-view-angle condition, and the large-view-field-angle, small-distortion and high-resolution-ratio technical effects are achieved.

Description

technical field [0001] The invention relates to an optical projection system composed of four lens groups, in particular to a projection lens applicable to a 3D interactive system. Background technique [0002] In recent years, with the continuous advancement of technology and the gradual rise of 3D interactive devices, the application range of projection lenses has become wider and wider. In order to be suitable for miniaturized electronic equipment, the projection lens needs to have a sufficient field of view while ensuring miniaturization, so as to obtain a larger picture in a narrower place. [0003] Traditional projection lenses are generally used for imaging. By using more lenses to eliminate various aberrations to improve resolution, but the overall length of the projection lens will be lengthened, which is not conducive to miniaturization; and the general large field of view projection The lens and the distortion will be large, which cannot meet the requirements of ...

AI Technical Summary

Problems solved by technology

[0003] Traditional projection lenses are generally used for imaging. By using more lenses to eliminate various aberrations to improve resolution, but the overall length of the projection lens will be lengthened, which is not conducive to miniaturization; and the general large field of view projection Lens, distortion will be large, can not meet the requirements of high resolution

For example, the patent number is "CN102879888A" and the publication date is "2013.1.16". The lens has seven lenses and a total reflection prism in sequence. The number of lenses and the position of the prism determine that the lens size cannot be further improved. Shrunken, can not meet the requirements of miniaturization

Another example is that in a general zoom lens, a prism is placed between the lens groups to reduce the lens volume, but this structure cannot guarantee the telecentric characteristics of the lens system, so that the edge illumination of the lens is low, which cannot meet the requirements of high resolution. Require

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