Engineer Manager Name: Jacky
WhatsApp/ Wechat: 0086-187 9245 6795
Email: mh_elec@126.com or jacky@mh-elec.com
1.The core component of night vision Binocular-image intensifier tube
According to the generation of the image intensifier tube, night vision binocular can be divided into 1st generation, 2nd generation, 3rd generation, etc. What can really be called low-light night vision binocular are night vision binocular of the 2nd generation or above. The 1st generation night vision binocular must rely on infrared auxiliary lights to achieve night observation.The low-light night vision binocular we usually call does not require an active light source.
As the core component of night vision binocular, the image intensifier tube plays a vital role. The image intensifier tube is mainly composed of three parts, namely the cathode surface, the microchannel plate, and the fluorescent screen. The three parts are closely arranged inside the image intensifier, which is completely vacuum. The purpose of the vacuum is first to prevent air from interfering with the electrons, and also to prevent components from being oxidized by air.
The main difference between the 2nd generation night vision binocular and the 3rd generation night vision binocular is the type of cathode side of the image intensifier. Usually the cathode surface of the 2nd generation night vision binocular is S25, and the cathode surface of the 3rd generation night vision device is (GaAs) gallium arsenide. The two cathode surfaces have different photosensitive abilities, and the third-generation night vision device is better.
2.How low-light night vision binocular work
When ambient light at night enters the night vision binocular through the objective lens, the first thing it encounters is something called a photocathode. Photons shine up, electrons fly out, and light is converted into electricity. Under the influence of the electric field, the electrons continue to move forward. The second layer is called a microchannel plate. There are many small channels evenly distributed on it. Each channel is more than ten micrometers long. The channels are more than ten micrometers apart and the channels are inclined at 8 degrees. This is a magical place. After electrons enter, they will collide with the channel. Each collision will knock out more electrons. New electrons will continue to collide forward. The effect is that one electron goes in and tens of thousands of electrons rush out. so the signal is greatly enhanced. The electrons continue to rush to the third layer under the action of the electric field, and the third layer is the fluorescent screen. As long as the electrons are hit, they will emit fluorescence, and the electricity will turn back into light, and we can see the enhanced image.
3."The image is green" determining factor-fluorescent screen
At night, light of different colors will enter the night vision binocular, but the color is not distinguished, only the intensity of the light is distinguished. Most of the coating materials on the fluorescent screen use zinc sulfide phosphor, which emits green light under the action of this phosphor, so the images seen by most low-light night vision binocular are green. However, some spot are bright green, and some spots are dark green.
4.Low light night binocular effect image other colors - white and color
The fluorescent screen is a glass plate coated with fluorescent agent (phosphor powder), located in the image intensifier tube. The fluorescent agent emits light after being hit by electrons. It is a device that converts electric current amplified tens of millions of times into visible light. The fluorescent screens have different colors, green, white (so-called white phosphor, but in fact white phosphorus tubes are bluish). It should be noted that the disadvantage of the white phosphor is that it will reduce the brightness of the image. The advantage is that it is not so easy to cause eye fatigue.
Engineer Manager Name: Jacky
WhatsApp/ Wechat: 0086-187 9245 6795
Email: mh_elec@126.com or jacky@mh-elec.com
