Basis of night vision

1. Basic concept and classification of night vision equipment The so-called night vision technology is the photoelectric technology that uses photoelectric imaging equipment to realize observation under weak light conditions, and night vision equipment is the photoelectric conversion equipment

An instrument that converts infrared light into visible light. Night vision devices can be divided into two categories: active and passive. Active infrared night vision devices have low cost, clear imaging, good contrast, and are less affected by ambient lighting conditions during use. Militarily, it has the disadvantage of being easily detected by enemy detection equipment. Passive night vision devices use the radiation emitted by the target itself to take thermal images of the target using infrared detectors, also known as thermal imagers. Compared with active infrared night vision equipment, low light night vision equipment is small in size, light in weight, and because of the passive working mode, safety is greatly improved, not easy to expose, but the shortcomings of low light night vision equipment is also very obvious, its working distance and observation effect is greatly affected by environmental conditions. It doesn't work properly on rainy and foggy days, and completely fails in total darkness.

2. Imaging principle of night vision apparatus

1. The objective lens focuses and collects infrared light from all objects in the line of sight.

2. Send the collected light to the image enhancement tube. In most night vision goggles, the image enhancement tube is powered by two or more batteries.

3. Photons of light energy are converted into electrons through an image enhancement tube.

4.At the end of the image enhancement tube, electrons hit a phosphorus-coated screen to produce an image. The phosphorus coating creates a green icon on the screen that reflects night vision.

5. The green fluorescent image is viewed through another lens eyepiece, which magnifies and focuses the image.

3. Night vision

It is suitable for night patrol, investigation and collection of evidence by military, customs, border guards and public security guards. Banks, Treasury, cultural relics, important material warehouses for night monitoring. Exploration of seabed resources at night, monitoring of underwater parts of offshore oil platforms, deep-sea fishing. Satellite remote sensing telemetry, the night observation of weak stars in astronomical galaxies. Record night plant growth law research, nocturnal animal living habits research.

4. Common Problems of choosing a night vision device Use a night vision device for a long time

Does the back eye feel uncomfortable?

Night vision is a kind of image brightening device, so if not properly designed, it can be very unpleasant to the eyes. Some brands blindly increase image contrast with no investment cost in design, which will result in many low-end night vision devices. There will be tears.

What are the differences between different generations of night vision equipment?

The main difference is advances in booster technology. The first generation used an enhancer tube to enhance the brightness of the surrounding environment, thereby accelerating the flow of electrons hitting the phosphor surface, and the second and third generations modified the enhancer to increase the number of electrons hitting the phosphor surface, thereby increasing the brightness. As the first generation of night vision technology is backward, it is necessary to use infrared auxiliary light source to find the target, the distance of infrared auxiliary light source is generally only 50 meters, infrared auxiliary light source will appear red burst, easy to be found. Therefore, in theory, the second generation of night vision should be chosen, with an observation distance of up to 200 meters.

What is the best range for night vision?

Depending on the environment, such as cloudy or rainy days, the scope of the night vision will be shortened. In addition, even for same-generation night vision devices, the quality of the image tube, internal optics, and data processing are closely related.