Detection device and detection method for optical back focal length of thermal imaging lens

Abstract

The invention discloses a detection device and detection method for the optical back focal length of a thermal imaging lens, and belongs to the technical field of optical lenses. The detection device comprises an infrared light source, a target, a collimating and beam expanding lens, a spectroscope, a total-reflection lens, a standard lens, an infrared detector and a control device which are sequentially arranged, and the detection device has an adjustable working state. The detection method comprises the steps that the positions of all the parts in the detection devices are regulated to the state that the centers are at the same height and are coaxial; the spectroscope is regulated to the position where a 45-degree included angle is formed between the spectroscope and the system optical axis; the standard lens and the infrared detector are regulated to the position where the infrared detector is located at the back focal plane of the standard lens; the standard lens and the infrared detector are regulated to the positions where a 45-degree included angle is formed between the standard lens and the infrared detector and the system optical axis; the infrared detector is regulated to generate a clear image for the target; the distance between the thermal imaging lens and the total-reflection lens is measured to serve as the optical back focal length value. According to the technical scheme, the detection device has the advantages of achieving optical back focal length detection and being simple in structure and high in detection precision.

Description

technical field [0001] The invention relates to the technical field of optical lenses, in particular to a detection device and a detection method for the optical back focus of a thermal imaging lens. Background technique [0002] The optical back focus of the lens is usually one of the important parameters of the lens, and its numerical difference directly affects the imaging quality of the lens. The difference in the optical back focus value is usually caused by various factors such as the processing error of the optical workpiece, the processing error of the structural part, and the group length error of the lens. Therefore, it is usually necessary to monitor the optical back focus after the lens is completed. [0003] Compared with visible light lenses, thermal imaging lenses have a wider operating temperature range, and infrared materials are relatively more sensitive to temperature changes than glass materials used in visible bands, so higher temperature refractive inde...

AI Technical Summary

Problems solved by technology

It can be seen that the optical back focus detection of thermal imaging lenses is more complicated than that of visible light lenses

[0004] However, in the prior art, the method, device and detection standard for thermal imaging lens parameter detection, especially optical back focus detection, are lacking compared with visible light lenses, and there is no relatively standard detection method and device for thermal imaging lenses in the prior art. It makes it difficult to detect the relevant parameters of the thermal imaging lens

Images