Long-wave infrared objective lens

Abstract

The invention relates to a long-wave infrared objective lens which comprises a lens group. The long-wave infrared objective lens is characterized in that the lens group comprises a first lens, a second lens and a third lens, which are coaxially arranged in sequence from object space to image space, wherein the first lens is a concave lens, the second lens and the third lens form a positive lens group, and the concave lens and the positive lens group are separated from each other at certain distances; the convex surfaces of the first lens, the second lens and the third lens are even aspheric surfaces and face towards the object space, and the concave surfaces of the first lens, the second lens and the third lens face towards the image space. The design inherits the advantages of a retrofocus structure, and the long-wave infrared objective lens has the characteristics of simple structure, small size, light weight and uniform illumination of an image surface and has an oversized field of view, so that the long-wave infrared objective lens has wide application prospects.

Description

technical field [0001] The design relates to a long-wave infrared objective lens and belongs to the field of optical technology. Background technique [0002] The uncooled infrared focal plane array detector can work well at room temperature, and has the advantages of light weight, small size, long life, low cost, low power consumption, fast startup and good stability, etc., which meets the needs of civilian infrared systems and some Military infrared systems urgently need long-wave infrared detectors and have been widely used. However, compared with the cooled infrared detector, the sensitivity of the uncooled infrared detector is obviously not high, so the relative aperture of the optical system is required to be about 1 (larger than 1 as much as possible) to make up for this deficiency. With the development of scanning technology, electronic scanning will completely replace traditional mechanical scanning to achieve staring imaging. Acquiring infrared images of large sc...

AI Technical Summary

Problems solved by technology

[0003] Reflective and catadioptric structures are not suitable for large field of view and short focal length optical systems, because: the focal length is too short to meet the space requirements of reflective elements in reflective and catadioptric structures, and with the increase of field of view , the central obscuration ratio will also increase accordingly, resulting in a decrease in the utilization rate of radiation energy of the system

Images