Large-field angle low-projection ratio digital projector lens

Abstract

The invention discloses a large-field angle low-projection ratio digital projector lens, comprising ten lenses of seven lens groups which are arrayed in sequence, wherein the first lens group is a negative crescent spherical lens; the second lens group is a negative crescent single-face even-order aspherical lens; the third lens group is a double bonding lens consisting of a crescent lens and a double concave lens; the fourth lens group is a double convex lens; the fifth lens group is a double bonding lens consisting of two crescent lenses; the sixth lens group is a plano-convex lens ; and the seventh lens group is a double bonding lens consisting of a double convex lens and a crescent lens. The large-field angle low-projection ratio digital projector lens has the advantages that the structure is simple, the price is low, the manufacturability is good and the tolerance performance is stronger. The lens has ultra-low projection ratio, can project an oversized picture of 94 inches within one-meter distance, and can satisfy the use of a single-target surface or three-target surface digital projector with different light sources and the target surface size of 0.55-1.3 inch based on three core technologies including DLP (Digital Light Processing), LCD (Liquid Crystal Display) and D-ILA (Direct Drive-Image Light Amplification).

Description

technical field [0001] The invention relates to a lens structure of a digital projector, in particular to a lens of a digital projector with a large viewing angle and a low projection ratio, which is applied to splicing large screens or special-shaped screens. Background technique [0002] The throw ratio of ordinary digital projectors is usually between 1.5-1.9. And when the throw ratio reaches below 0.6, we usually call it an ultra-short-focus lens. Because for a room that does not change in size, the shorter the focal length, the larger the picture you will see. When the space restriction is small, the throw ratio is not necessary, but when the space restriction is large, the throw ratio needs to be calculated. For example, in a small space, the projection distance is only 1.2 meters, but a 100-inch screen needs to be projected for display. The screen width is 2 meters, and the throw ratio is 1.2 / 2=0.6. Short-focus lenses are more complicated than ordinary lenses, and ...

AI Technical Summary

Problems solved by technology

[0004] In the process of projection lens design, relevant parameters such as image height, field of view, focal length, and relative aperture are mutually restricted, which have a great impact on the final imaging quality. In particular, the amount of distortion is difficult to control, so it is difficult to design a lens with a transmittance less than 0.5, a lens with high transmittance and distortion that meets the requirements of use

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