Zoom projection fish-eye lens generally used for digital projector

Abstract

The invention discloses a zoom projection fish-eye lens generally used for a digital projector, which comprises a front main tube of a lens, a zoom tube of the lens, a compensation tube of the lens, a rear main tube of the lens, a front fixed mirror group, a zoom mirror group, a compensation mirror group, a rear fixed mirror group and an aperture diaphragm, wherein the front fixed mirror group, the zoom mirror group, the compensation mirror group, the rear fixed mirror group and the aperture diaphragm are coaxially arranged on the positions of the front main tube of the lens, the zoom tube of the lens, the compensation tube of the lens and the rear main tube of the lens. The zoom structure mode of the zoom projection fish-eye lens disclosed by the invention is a mechanical compensation method positive-group zoom and negative-group compensation mode designed by a ''non-object-image exchange principle''. Two cam curves followed by the zoom mirror group and the compensation mirror group are both constructed into standard spiral lines. According to the zoom projection fish-eye lens generally used for the digital projector, which is disclosed by the invention, two standard spiral lines with a regular lead are used as the cam curves of the zoom mirror group and the compensation mirror group, so that the production difficulty and the assembling and adjusting difficulty are lowered, and the stability of a lens structure and the regulation smoothness are improved. The zoom projection fish-eye lens generally used for the digital projector is favorable for mass production and can be used for common 1LCD (liquid crystal display), 3LCD or 1DMD (digital micro-mirror device)-type digital projectors with chips of different sizes and different chip length-width ratios.

Description

technical field [0001] The invention relates to a zoom projection fisheye lens commonly used in digital projectors. Within a certain range, it can meet the projection requirements of 1LCD, 3LCD or 1DMD common mainstream digital engineering projectors with different chip sizes and different chip aspect ratios for full spherical screens and hemispherical screens. Background technique [0002] Fisheye lens is a very special kind among all optical lens categories. The functional relationship between its image height and field angle can be set according to needs. It is generally used for shooting and projection in 120o to 180o field of view environment. The imaging principle is " Non-similar imaging", that is, by introducing quantitative "distortion", it produces a large anti-telephoto ratio and increases the field of view of the lens. In different application fields, the structural parameters and application environment parameters of fisheye lenses are different. In the 1970s,...

AI Technical Summary

Problems solved by technology

At the same time, with the continuous major breakthroughs in optical design theory and design software, the ability to control and optimize the optical aberration of the fisheye lens structure has been greatly enhanced, so various types of fisheye lenses have emerged one after another. The structure of the projection fisheye lens is a fixed-focus structure, and the structure is relatively complicated, generally 10-12 elements

In recent years, a large number of digital projectors of new brands and specifications have emerged continuously. The chip types, sizes and chip aspect ratios used by them are different. In the mainstream engineering machine range, the chip size ranges from 0.63 to 0.98 inches (diagonal ), the aspect ratio is 4:3 and 16:9, and the image height of the fisheye lens is generally equal to the length of the short side of the chip. Projection is a special form of projection, and its demand and application are far less than conventional forms. As a result, fisheye lenses cannot be produced on a large scale, and production costs cannot be reduced, which in turn affects the development of dome projection technology.

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