Large zoom ratio continuous zooming projection lens

Abstract

The invention relates to a large zoom ratio continuous zooming projection lens. Optical system lenses comprise a focusing unit, a zoom unit, a first compensation unit, a second compensation unit, and a rear fixing unit. The units are arranged from a screen side to an image plane side along an optical axis. A diaphragm is disposed on the second compensation unit. Focusing is realized by back and forth movement of the focusing unit, and zooming is realized by moving the zoom unit, the first compensation unit and the second compensation unit in the same direction from the wide angle end to the telephotograph end along the optical axis, wherein in the zooming process, projection images are kept clear, the total distance from the first surface of the lens to the image plane is fixed, and all the lenses are made of glass which is frequently used in domestic, and are spherical lenses. The large zoom ratio continuous zooming projection lens is low in the cost and good in technology, is suitable for batch production, and can be widely applied to the field of mini projection.

Description

technical field [0001] The invention belongs to the technical field of digital projectors, and is a large zoom ratio continuous zoom projection lens used in conjunction with a telecentric lighting optical path, which is applied to a digital projector with an LED light source. Background technique [0002] With the development and deepening of semiconductor technology, LED light source digital projection display technology has been developed in the spring, and the projection display industry based on LED and light source technologies such as DLP, LCOS, and LCD has developed rapidly. In recent years, LED light source projection display technology has developed rapidly with its rich colors, high-definition pictures, high-brightness images and high-contrast displays. It can achieve product characteristics of smaller size, lighter weight and long life , especially in the field of micro-projection projection technology, its advantages are unparalleled. [0003] The prominent prob...

AI Technical Summary

Problems solved by technology

In the existing disclosed continuous zoom projection lens technology, part of the application of aspheric technology, that is, by adding an aspheric lens to the optical system of the zoom projection lens to improve the imaging quality of the system or simplify the system structure, but the application of the aspheric lens Strict requirements on its processing and assembly are not conducive to the improvement of production efficiency and the reduction of cost; and in the technology that does not use aspheric lenses, in order to achieve better optical performance, the technical measures are generally to increase the number of lenses, or Using high-grade optical materials with high refractive index or high dispersion coefficient, such as FCD1, which has significantly improved aberration, is expensive, poor in manufacturability, low in processing efficiency and yield

Chinese patent 100345188C provides a continuous zoom projection lens with a zoom ratio of only 1.2 times, adopts 13 spherical lenses, and uses heavy lanthanum flint glass or heavy flint glass such as ZLAF4 and ZF14 with a refractive index greater than 1.9; US patent 7177090 technology disclosure In a continuous zoom projection lens, the number of lenses used reaches 15, including a double-sided aspheric lens, so there are also problems such as high cost and low work efficiency.

At the same time, since the projection lens mostly adopts a fixed aperture, the aperture value will decrease with the increase of the focal length during the zooming process, and energy loss will occur during the zooming process.

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