Night vision device is not to amplify the light proportionally, there are certain limitations, once there is a strong light night vision device burned out. The working principle of the night vision device
People's understanding of the things around them, about 85% of the light as a medium, through the visual response, which shows that the light for people to observe, understand and analyze the importance of things. But because of the limitations of human vision, in order to expand people's field of vision, it is necessary to use some equipment, for example, observation of distant views with the help of binoculars, observation of fine need microscope, then observe the scene in the dark, we need to use night vision.
The human eye can directly observe the scene of the necessary condition is light, but this is not sufficient. A sufficient condition is the need for a certain amount of ambient illumination and visible light. Night vision technology is centered around solving these problems.
Light is also a kind of electromagnetic wave, it is a kind of electromagnetic wave with high frequency and small wavelength. Its wavelength is generally between 10 and 10E+6 nanometers (1 nanometer is equivalent to 10E-9 meters), and visible light accounts for only a small part of it, about 390 to 776 nanometers. 390 nanometers below the ultraviolet, 776 nanometers above the infrared.
How can people turn invisible light into visible light, and increase low light levels? This begins with a property of light. Nineteenth-century Irishman Smith discovered a photoelectric effect, which makes light and electricity to convert each other possible. In today's highly developed science and technology, the electrical signal for frequency conversion, phase change and amplification, is not a difficult task. As long as the scene of the different parts of the brightness into different sizes of electrical signals (current and voltage), and then through the scanning technology, the optical image into an electrical image, this process is called camera. Finally, the use of imaging technology to restore the electrical image to the optical image, in order to achieve the purpose of observation. Infrared night vision devices, for example, the use of infrared light on the target, because infrared light is invisible light, you can not expose themselves, and then through the infrared tube will not be able to see the electrical image into an adult eye visible optical image, to achieve the purpose of observation. Thermal imaging utilizes the thermal contrast between a target and its surroundings due to differences in temperature or emissivity. Because of the difference in thermal contrast and the infrared radiation energy density distribution map is displayed as a thermal image, and then through the thermal image of the infrared image into a visible light image.
USA AN/PVS-5A Night Vision Goggles
USA AN/TVS-5 Crewserved Weapon Sight
British Eagle Long Range Handheld Night Vision Goggles
British Eagle Long Range Handheld Night Vision Goggles
British Eagle Long Range Handheld Night Vision Goggles
British Eagle Long Range Handheld Night Vision Goggles
British OTIS Observer's Thermal Imaging System
China's self-developed night vision
China's GW89-200 Low-Light Night Vision
China's GW89-200 Low-Light Night Vision
China's GW89-200 Low-Light Night Vision
China's second-generation helmet-mounted low-light night-vision device is a kind of high-vision spectacles with batteries, which is widely used for driving vehicles at night, observing, patrolling at night, firing and aiming of man-portable weapons, as well as reading and repairing on the battlefield. The field of view is 38 degrees, the weight is 800 grams, and the recognition distance of a person in the moonlight is 150 meters.