Ultra-compact type continuous zooming medium-wave infrared optical system

Abstract

The invention discloses an ultra-compact type continuous zooming medium-wave infrared optical system. A secondary imaging structural form is adopted; the secondary imaging assembly can compress the aperture of the front group lens; the 100% cold diaphragm efficiency is achieved; a silicon substrate diffraction element is used; structure is greatly simplified, the absolute length is only 110 mm, and good imaging quality can be achieved. The system comprises a front group and a rear group, wherein the front group comprises a front fixed group, a zoom lens, a compensation lens, a focusing lens and the like; the rear group comprises two lenses, the lenses are made of common materials of silicon and germanium for an infrared optical system, the zoom lens and the compensation lens move back andforth along an optical axis in the zooming process to achieve the purpose of continuous zooming, the focal length range of the optical lens is 70mm-240mm, and the F number is 4. The lens is suitable for a high-resolution 640 * 512 medium-wave refrigeration detector, has the advantages of being ultra-compact, small in size, light in weight, high in resolution and the like, and has good imaging quality in a full-focus section.

Description

technical field [0001] The invention relates to an infrared optical system, in particular to an ultra-compact continuous zoom mid-wave infrared optical system suitable for a high-resolution mid-wave cooling detector. Background technique [0002] Infrared thermal imaging cameras are not affected by adverse weather conditions such as fog and rain, can work around the clock, and adopt a passive working mode with strong anti-interference ability. In recent years, they have developed greatly in military and civilian fields. [0003] The infrared continuous zoom lens can take into account the capture, tracking, monitoring and calibration of the target very well, it can maintain the stability and continuity of the image, the target image will not be lost, and it can remain clear, while taking into account the large field of view search and small field of view Resolution has many applications in various photoelectric loads. [0004] With the development and demand of handheld and ...

AI Technical Summary

Problems solved by technology

[0004] With the development and demand of handheld and pod photoelectric equipment, as well as the continuous progress of optical cold processing, precision machining, and coating technology, infrared zoom lenses continue to develop towards small and compact sizes. The absolute length of the zoom optical system puts forward higher requirements. Since the Abbe number of silicon is larger than that of germanium, processing the diffractive surface on the silicon lens can better correct the chromatic aberration. During the process, the vibration between the tool and the material is often prone to problems such as chipping, and the surface finish and surface accuracy are also difficult to control. Often, diffractive surfaces are made on soft materials such as germanium and zinc selenide.

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