Infrared night vision device working principle and purchase
Infrared night vision is a military night vision instrument using photoelectric conversion technology. It is divided into active and passive two kinds: the former with infrared searchlight irradiation target, receive the reflected infrared radiation to form an image; the latter does not emit infrared, relying on the target's own infrared radiation to form a "thermal image", so it is also known as the "thermal imaging camera". Currently on the market to sell infrared night vision device, are active. Passive infrared night vision devices are generally not called night vision devices, are renamed thermal imaging cameras.
Active infrared night vision device imaging principle
Simply put: the principle of active infrared night vision device is the target from the human eye can not see the light (micro or infrared light) signals converted into electrical signals, and then amplify the electrical signals, and electrical signals into the human eye visible light signals.
Professional: active infrared night vision device principle is through the eyepiece will focus the light on the image enhancer to collect and enhance the existing light, in the enhancer, a photocathode will be light "activated", and photon energy into electrons, these electrons are located in the enhancement of the internal static area is accelerated, impact on the phosphorus Surface screen (like a green TV screen), the formation of the human eye visible image; after the acceleration of the electrons, enhanced brightness and clarity of the image, as shown in the figure below.
Shimmering night vision, in order to see objects at night, through the incremental processing of weak light to achieve the naked eye visible instrument, in order to achieve better results, now the shimmering night vision basically with infrared emitters, when the light is too dark can be assisted in the illumination. But because it is easy to be found, that is, domestic enthusiasts often say "red exposure", so now basically used in the civilian market.
Purchase night vision devices, according to the following order to choose. 1:
1. Booster tube: is a few generations. When you buy, be sure to confirm with the business. Because the night vision device packaging and instructions are generally not marked on how many generations of booster tube. Of course, if you want to buy 2 or 3 generations of night vision devices, it is best to buy a clearly marked is a few generations of booster tube night vision devices, so as to avoid infringement of your rights and interests. Currently on the market, such as the Russian RHO night vision devices in the product packaging and machines are marked on the use of the first generation of the tube.
2. Lens: look at the lens calibre and magnification. In the case of not considering the volume, of course, the bigger the better. The same tube situation, in principle, the larger the calibre, the greater the observation distance, the clearer the image.
3. Image enhancement technology: generally with this technology night vision device, under the same conditions the image brightness will be better and clearer.
4. Infrared emitter: this performance is good or bad, but also directly affects the image quality.
5. Resolution: the resolution of the lens is very important, the higher the resolution, the clearer the image displayed.
