Imaging lens, projection light path system and projection equipment

Abstract

The invention belongs to the technical field of projection equipment, and provides an imaging lens, a projection light path system and projection equipment. The imaging lens comprises a first lens and a second lens which are oppositely arranged, the first lens comprises a first convex surface S1 and a first concave surface S2, and the second lens comprises a second convex surface S3 and a second concave surface S4; the first convex surface S1 of the first lens and the second concave surface S4 of the second lens are incident surfaces, and the first concave surface S2 of the first lens and the second convex surface S3 of the second lens are emergent surfaces. On the basis of meeting normal projection of short-focus projection equipment, only the two lenses are adopted as the projection lenses of the imaging lens, so that the structure of the imaging lens can be simplified, and the manufacturing cost of the imaging lens is reduced; meanwhile, with the imaging lens adopted, the rear working distance of the imaging lens in a projection light path system can be shortened, so that a smaller projection ratio is obtained, a picture with a larger size is projected within a shorter projection distance, and the projection effect is improved.

Description

technical field [0001] The present invention relates to the technical field of projection equipment, in particular to an imaging lens, a projection optical path system and projection equipment. Background technique [0002] A short-throw projector is a projection device with a very short throw ratio. With the help of a short-throw projector, it is possible to watch bright and colorful large-screen images in any room, classroom, and conference room. [0003] There are two types of short-focus projectors currently on the market. One is a reflective projector. The working principle is to add an aspheric mirror in front of the short-focus projection lens, and project it onto the screen after reflection. The other is an ordinary short-focus projector. However, there are some problems in the above two short-focus projectors in the actual application process: one is that a large number of lenses will be set in the imaging lens to ensure the projection quality, which makes the stru...

AI Technical Summary

Problems solved by technology

However, there are some problems in the above two short-focus projectors in the actual application process: one is that a large number of lenses will be set in the imaging lens to ensure the projection quality, which makes the structure of the imaging lens complex and the manufacturing cost is high; the other is that The use of an aspheric mirror will increase the size of the projector, and the cost of the aspheric mirror itself is relatively high, and the use of an aspheric mirror will cause a large imaging error, which not only increases the cost of the projector but also reduces shadow effect

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