Principle of low-light night vision device

The low-light night vision device uses the low-brightness night sky light, star moonlight, atmospheric glow and other natural light reflected by the night target to enhance and amplify it to hundreds of thousands of times. It is suitable for reconnaissance, observation, aiming, vehicle driving and other battlefield operations at night with the naked eye.

Low-light night vision devices are made based on the physical principles of the photoelectric effect. Photons enter the night vision device and hit the metal plate, producing photoelectrons. These electrons pass through a thin disk placed in front of the light screen. There are millions of microchannels (millions of pixels) on the disk, The electrons enter the microchannels.The electrons are then multiplied and finally projected onto a fluorescent screen for imaging.

Because the low-light night vision device uses night skylight to work, it works in a passive way, so it can better hide itself. It is the most suitable for departments engaged in special work, such as military, criminal investigation, suppress smuggling, drug control, night surveillance, and security applications.

Development Trend of Low-Light Night Vision Devices

Three generations have been developed. The first generation is a three-stage cascade low-light night vision device (composed of three 0-generation photoelectric tubes connected in series). The second generation is a micro-channelplate type low-light night vision device, and the third generation is a |||-V family negative electron affinity photocathode image intensifier low-light night vision device. Developed as the second generation transitioned to the third generation,a super second-generation photoelectric tube is called second-generation plus, and its technical performance is second only to third-generation products. If low-light night vision devices are subdivided, they are gen 0, gen 1, and gen 2, gen2+, gen3, total five grades. With the development of low-light night vision devices today, the technology is relatively mature, the image quality is good, and the cost is low, so they will remain a major part of the world's night vision equipment for quite some time to come. The gen2 and gen3 products have the characteristics of small size, light weight,clear image, full functions and practicality. It is the military, public security, armed police, customs, oil industry, news gathering, tourism, aquaculture, nature lovers and other industries working equipment at night.

However, because its core component, the low-light image intensifier, is a high-tech product, the process is particularly complex, the cost is high, and the price is relatively high. But in terms of performance-price ratio, it's still pretty good.

The main parameters of low-light night vision equipment

Night vision equipment indicators are actually not very important, especially the manufacturer’s nominal maximum viewing distance, which is generally have huge error and has no reference value. The indicator part just need to pay attention to the magnification and diameter.

Many of the data given by manufacturers are theoretical values. The observation distance of night vision devices is seriously affected by the degree of darkness and weather quality (such as fog, rain, etc.). At the same time, the observation distance of the night vision device includes low light observation distance and total darkness observation distance. The total black observation distance requires the assistance of an infrared transmitter, so it will be affected by the distance of the infrared transmitter.

The observation distance of a night vision device is mainly affected by the generation of image intensifier tubes of the night vision device.

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