Thin type large screen back projection TV objection lens for projection

Abstract

This invention discloses a kind of projection object lens, concretely relates to a kind of projection object lens that projects the object which is composed of image element to the screen to image, it is applicable for the thin large screen back projection TV such as DMD,LCOS image element plate. Its object front group [U1] is negative power; it is composed of a meniscus negative PMMA single-side non-spherical surface lens [L1] and the glass lens [L2,L3] whose focal power are positive and negative; its object back group [U2] is positive power; it is composed of a group of lens [L4-L9]whose focal power are positive, positive, negative, negative, positive, positive; the first positive lens [L4] is double convex thick lens; the last positive lens [L9] is PMMA material single-side non-spherical surface lens, the other are all glass lens. This object lens make TV realize that the machine is light and thin, large screen, high definition, and more close structure, and the material of the lens are common optical materials; it can reduce the produce cost, and has wide market foreground.

Description

technical field [0001] The present invention relates to a projection objective lens, in particular to a projection objective lens for projecting an object composed of pixels onto a screen for imaging, where the object is a pixelated flat panel such as DMD and LCOS. Background technique [0002] In recent years, the development of TV technology mainly reflects three major trends: large-screen, high-definition, and digital. Rear-projection digital TV is one of the important means of realizing large-screen, especially ultra-large-screen high-definition digital TV. [0003] The projection objective lens is one of the core components of rear-projection digital TV. It takes a pixelated flat panel as its object and images it on the Fresnel projection screen. In order to make the objective lens have a higher imaging quality, some of its optical performance indicators, such as Focal length, back intercept, magnification, resolution, image plane illuminance, distortion, number of len...

AI Technical Summary

Problems solved by technology

This objective lens has the following two deficiencies: First, although the 90-degree angle structure is adopted, the distance from the front surface of the objective lens to the center of the reflective surface of the mirror and the distance from the pixelated plane to the center of the reflective surface of the mirror Both are relatively large, and the structure is still not compact enough; second, the objective lens uses two pieces of ultra-low dispersion optical glass, which increases the production cost

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