Reflective wide-angle lens

Abstract

The invention provides a reflective wide-angle lens. The reflective wide-angle lens is used for projecting light from a display assembly, and belongs to the field of semiconductors. The reflective wide-angle lens comprises a first lens group, a second lens group and a curved surface reflector, wherein the first lens group is used for receiving the light from the display assembly and comprises at least one group of triplet lenses, at least one first aspheric lens and at least one group of first doublet lenses; the second lens group is used for receiving light from the first lens group and comprises at least two second aspheric lenses and a group of second doublet lenses; the focal lengths of the first lens group, the second lens group and the concave reflector are f1, f2 and f3 respectively; and the relation among the three focal lengths meets the requirements that the absolute value of f2 / f1 is more than 3.4 and less than 4.25 and the absolute value of f3 / f1 is more than 1.1 and less than 1.45. The reflective wide-angle lens has a large aperture and a small projection ratio, uses few optical lenses, does not need to independently adjust some lenses during production, and is simple in process and beneficial to mass production.

Description

technical field [0001] The invention relates to a reflective wide-angle lens. Background technique [0002] With the advancement of key components of projection, the resolution of display components has reached 4K / 2K, and the light source matched with it, whether it is LED or laser, has an increasingly brighter light source, making projection products more mature for entering the home market. [0003] Short-throw projection can greatly shorten the distance between the projector and the screen. Usually, only a few tens of centimeters of projection distance can project a picture of hundreds of inches. The short-throw projector can be placed on the TV cabinet, which is different from ordinary TVs The position is the same, compared with the general telephoto projector, it has the advantages of saving space and easy installation, so the short-focus projection is more practical in use than the general projector. [0004] In recent years, short-throw projection technology has grad...

AI Technical Summary

Problems solved by technology

[0004] In recent years, short-throw projection technology has gradually become the focus of the market, and the current short-throw projection has a throw ratio between 0.24-0.65, but it is still technically difficult to achieve an ultra-short-throw lens with a throw ratio below 0.2

In addition, in the case of using a large-aperture projection lens to increase brightness, in order to achieve a smaller projection ratio, the light output from the lens must have a larger incident angle on the screen. The projection distance is extremely short and it is easy to cause distortion of the projected image. To eliminate these adverse phenomena, more lenses are needed to solve the problem, but more lenses will cause assembly errors, and the accumulated assembly errors will affect the projection image quality. In addition, when assembling and producing ultra-short-focus lenses, it is still necessary to fine-tune the position of some lenses in the lens to obtain a clearer image, resulting in a more complicated manufacturing process, which is not conducive to the demand for mass production

Images