Thin type large screen back projection TV objection lens for projection

Abstract

The invention discloses a projection objective lens, in particular to a projection objective lens for projecting an object composed of pixels onto a screen for imaging. Its objective lens front group [U1] is negative refractive power, which is composed of a meniscus-shaped negative film PMMA single-sided aspheric lens [L1] and glass lenses [L2, L3] with positive and negative refractive powers respectively; its objective lens The rear group [U2] is positive refractive power, which is composed of a group of lenses [L4~L9] with positive, positive, negative, negative, positive and positive respectively, among which, the first positive lens [L4] is double Convex thick lens; the last positive lens [L9] is a single-sided aspherical lens made of PMMA material, and the others are all glass lenses. The objective lens has a more compact structure while enabling the TV to achieve light and thin body, large screen, and high definition, and the materials used for the lens are all common optical materials, which can effectively reduce production costs and have broad market prospects .

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 the rear projection digital TV. It uses a pixelated flat panel as the 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 ...

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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