Ultra-short-focus projection lens system

Abstract

The invention discloses an ultra-short-focus projection lens system which is applicable to a DLP digital projector and is capable of realizing the effect that a large frame is projected in a short distance. The lens system is composed of a display chip, a refraction lens set and an aspheric reflector. Light is emitted out from the display chip, passes through the refraction lens set and is imaged on the screen through the aspheric reflector. The display chip is a digital micro-mirror device DMD. The refraction lens set includes twelve glass spherical lenses and one PMMA resin aspheric lens which are arranged from left to right and from small to big. The aspheric reflector is formed by free curved surface calculating and fitting, and field curvature and distortion are corrected. All optical surfaces are of a rotary symmetrical structure, optical centers of the refraction lens set are coaxial, no gummed lens is used, and the aspheric reflector is eccentric. The ultra-short-focus projection lens system has the advantages that the view field is large, the distortion is distortion, a high-definition large frame is projected in a very short distance, the structure is simple, the tolerance is good, the total used glass is normal and environmental-friendly, and scale production is facilitated.

Description

Technical field [0001] The present invention relates to projection technology in the optoelectronic display industry, in particular to an ultra-short throw projection lens system for imaging display. Background technique [0002] In recent years, projection display technology has achieved considerable development, thanks to the increasing maturity of high-brightness light sources, optical processing, and ultra-high resolution image sources. Among them, short-focus projection technology has always been a hot spot in the projector market because of its outstanding advantages, short-distance projection of large images, and has quickly been favored by users during the development process. [0003] The current technology used in short-focus projection is mainly a wide-angle fisheye lens, which is a refraction design. The projection lens is entirely composed of lenses. Due to the limitation of the structure, this kind of refraction projection lens increases with the field of view and F-n...

AI Technical Summary

Problems solved by technology

[0008] The above-mentioned representative patents all adopt telecentric optical system design, so they need to be equipped with a bulky and bulky prism system, which will also lead to low contrast of the projected picture of the projector, and doublet lenses and more than 2 lenses are used in the refracting lens group. Advanced aspheric lenses will bring problems such as complex processing and assembly processes, high manufacturing costs, difficult to guarantee accuracy, and low yield

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