Basic structure consisting of five groups of six fisheye lenses for digital projector

Abstract

The invention discloses a basic structure consisting of five groups of six fisheye lenses for a digital projector, which comprises five lens groups consisting of six lenses with standard spherical surfaces. The five lens groups consist of four single lens groups and a double-glued lens group; an aperture diaphragm is arranged between the double-glued lens group and the single lens group in front of the double-glued lens group; the absolute values of the focal power of the lenses are in a ratio of 1:1.51:0.485:0.14:1.51 from front to back in turn; the sum of the focal power of the lenses in front of an aperture diaphragm A is a negative value; the sum of the focal power of the lenses behind the aperture diaphragm A is a positive value; and the ratio of the absolute value of the negative value to the absolute value of the positive value is 1:1.539. The basic structure is simple, lowers the production cost and assembling difficulty and enhances the stability of a lens structure. Moreover, the fisheye lens structure can zoom out the focal length in proportion to adjust full-field image height so as to adapt to different sizes of digital projectors with three liquid crystal displays (LCDs) or one digital mirror device (DMD).

Description

technical field [0001] The invention relates to a basic structure of a five-group six-piece projection fisheye lens for a digital projector, which can be used in common digital projectors of the 3LCD or 1DMD type with chip sizes ranging from 0.5 inches to 1.8 inches. Background technique [0002] Fisheye lens is a very special kind of 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 120° to 180° field of view environment. The principle of imaging It 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, fisheye lenses first appeared in the film industry, and were used to shoot and project 35mm an...

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 fisheye lens is relatively complex, generally 9 to 12 elements, with poor structural manufacturability, low yield, and high cost, resulting in expensive lenses that cannot be widely promoted

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