Night Vision Goggle Techinical Guide (3)

21. Battery box

Battery box: parts used to load batteries and circuits on monocular night vision instrument, and parts separated from the body used for power supply of some binocular night vision instruments

22. Tipper

The part that fixes the night vision on the helmet. It is recommended to buy a high-quality l4g24 tipper, which will give you a much better experience than other models.

22. J arm

The j arm is used to link the monocular night vision instrument with the dumper. Some specially designed models do not need this part.

23. Photocathode

A device used to convert weak light into weak current. It is located in the image enhancement tube, and its sensitivity directly affects the brightness of the night vision instrument. The first- and second-generation night vision instruments adopt multi alkali photocathodes, and the third-generation night vision instrument adopts revolutionary gallium arsenide (GaAs) photocathode. The sensitivity is more than twice that of the second-generation night vision instrument and has a brighter picture. It should be noted that only the night vision instrument using GaAs photocathode can be called the third-generation night vision instrument. GaAs can also be used to make solar cells and digital imaging components (CMOS or CCD).

24. Microchannel plate (MCP):

Microchannel plate (MCP): a device used to amplify a weak current thousands of times. It is located in an image enhancement tube and is usually made of silicon. There are also microchannel plates made of glass fiber in the Russian technical system. It can be imagined as a long plate with many small holes. After entering the small holes, electrons collide with the hole wall and release thousands of electrons.

25. Ion feedback film

a layer of film located near the photocathode surface of the microchannel plate, which is used to increase the service life of the microchannel plate.

26. Fluorescent screen

A glass plate coated with a fluorescent agent is located in the image enhancement tube. The fluorescent agent will emit light after being impacted by electrons. It is a device that converts the amplified current into visible light. The fluorescent screen has different colors, including P22 and p43 in green and P45 in white. It should be noted that the performance of fluorescent screens has an impact on the performance of night vision instruments. P43 is undoubtedly the best fluorescent screen with excellent brightness and imaging sharpness. The imaging sharpness of white phosphorus tube P45 is much lower than that of p43, and the brightness is also low. The disadvantage of white phosphorus is that it will reduce the brightness of the night vision instrument, and the advantage is that it is not so easy to make glasses tired.

27. Optical fiber inverted image

it is a pile of optical fibers welded together and twisted 180 degrees. It is located in some types of image enhancement tubes. Its function is to twist the inverted image formed by the fluorescent screen into a positive image.

28. Automatic brightness control technology (ABC)

The brightness of the night vision device is controlled by detecting the current of the image intensifier tube and changing the voltage between the photocathode and MCP, which can make the night vision device automatically reduce the brightness under strong light conditions to avoid blinding users and damaging the night vision device. However, when the brightness decreases, the resolution will decrease and dark details will be lost, In most cases, it has been replaced by gating technology.

29. Gating technology

The brightness of the night vision instrument is controlled by constantly switching the image intensifier. Compared with ABC, gating technology can reduce the decline of resolution and the loss of dark details under strong light.Besides, it can respond faster to flash. Generally, ABC technology takes hundreds of milliseconds to restore brightness after flash, while gating technology only takes tens of milliseconds. The disadvantage is that the electric field between MCP, photocathode and fluorescent screen is constantly changing due to the continuous switching of image intensifier, and the MCP is constantly moving. The anti-seismic performance is poor. Only the reinforcing tube with particularly good quality is suitable for firearms to deal with the recoil force of firearms.