The low-light night vision equipment with image intensifier as the core component is called low-light night vision device. Due to its function of light enhancement process, people can effectively obtain scene image information under extremely low illumination (10^-5lx) conditions.

 

Low-light night vision device includes four main components: strong light force objective lens, image intensifier, eyepiece, and power supply. In terms of optical principles, low-light night vision devices are special telescopes with image intensifiers. The weak natural light is reflected by the target surface and enters the night vision device; under the action of the strong light force objective lens, it is focused on the photocathode surface of the image intensifier (coinciding with the back focal plane of the objective lens), and photoelectrons are excited; the photoelectrons are electronically optical inside the image intensifier Under the action of the system, it is accelerated, focused, and imaged, bombarding the phosphor screen of the image intensifier at a very high speed, and excites enough visible light to turn a distant target illuminated by weak natural light into a visible light image suitable for human observation. After further magnification of the eyepiece, more effective target observation can be achieved. The above process includes two conversions from an optical image to an electronic image and then to an optical image.