Reflective wide-angle lens

Abstract

The invention provides a reflective wide-angle lens, which is used for projecting light from a display component and comprises a first lens group, a second lens group and a curved surface reflector, the first lens group is used for receiving the light from the display component, and the second lens group is used for receiving the light from the display component. Comprising 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, and the focal lengths of the first lens group, the second lens group and the concave reflector are f1, f2 and f3 respectively, the relationship among the three focal lengths satisfies the following conditions: 3.4 < f2 / f1 < 4.25 and 1.1 < f3 / f1 < 1.45. The lens has a large aperture and a small projection ratio, uses fewer 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. Whether the light source is LED or laser, the brightness of the light source is also increasing, making the projection products more mature for the home market. [0003] Short-throw projection can greatly shorten the distance between the projector and the screen, often only a few tens of centimeters of projection distance can project a picture of hundreds of inches. Compared with the general telephoto projector, it saves space and has the advantages of installation, so the short throw projection is more practical than the general projector. [0004] In recent years, short-throw projection technology has gradually become the focus of the market. The current short-throw projection has a throw ratio of about 0.24-0.65, but it is still technically difficult to ach...

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 quality of the projection image. 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

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