Night vision equipment from the classification point of view, can be divided into night vision tube scanner (traditional night vision instrument) and infrared night vision thermal imager two types.
Ordinary infrared night vision instrument This active night vision instrument, the goal is to need to have light, so traditionally known as low-light night vision instrument, the principle is that the target weak light, through its internal core component tube, zoom into people The light that can be observed by the eye. In the case of full darkness, it is impossible to see any target, so this night vision device is equipped with an infrared transmitter to illuminate the target with an invisible infrared light in a dark condition and make the target visible.
According to the algebra of the tube, night-vision goggles can be divided into one generation to four generations. Due to a generation of night vision devices, the brightness and sharpness of images cannot meet people's needs. Therefore, it has rarely seen generations and generations of night vision devices abroad. If you want to achieve real use, you need to purchase a second-generation plus night vision goggles.
Basically, thermal imaging night vision devices are called passive night vision devices. Passive thermal imaging night vision devices use infrared detectors, optical imaging objectives, and optomechanical scanning systems (the current advanced focal plane technology eliminates the need for a light-machine scanning system). The infrared radiation energy distribution pattern of the measured target is reflected in the infrared light. On the photodetector of the detector, between the optical system and the infrared detector, there is an optical scanning mechanism (the focal plane thermal imager does not have this mechanism) to scan the infrared imager of the object to be measured and focus on the unit or On the spectroscopic detector, the detector converts the infrared radiant energy to an electrical signal, which is amplified and converted into a standard video signal to display an infrared thermal image through a television screen or a monitor. This thermal imaging night vision device is exactly the same in all black and daylight observations and is not affected by light.
At the end of the last century, with the development of thermal imaging technology, due to the thermal imaging technology's superiority to traditional night vision devices, the US military began to deploy infrared night vision thermal imaging devices. Infrared night vision thermal imager has made great progress in the past 10 years.
The difference between night vision and thermal imager
1, effect effect
If you use an ordinary night-vision goggles, you will find that night-vision goggles and general infrared thermal imaging cameras are completely different. This is because the general night vision device directly observes the object through the lens, so the field of vision seen is the same as that seen by the telescope lens. It is circular and the screen is green. If the clarity is enough, it is able to identify who the character's goal is and see the person's features.
The infrared night vision thermal imager sees the image on the internal LCD screen instead of directly seeing the target, so the field of view is square. Infrared night vision thermal imager imaging will be based on the temperature distribution, the higher the temperature the greater the brightness, while the low temperature is dim, the main purpose is to find the target, identify the target category, such as the target is human, animal and so on.
2, the influence of light factors
The second generation + night vision instrument is influenced by the environment due to the principle of imaging. In particular, with light effects, the observation distance is shortened when the light is dimmed. In the case of full black, it is necessary to use an auxiliary infrared light source, and the distance of the auxiliary infrared light source is generally only up to 100 meters. At the same time, it is also afraid of glare, although many traditional night vision devices have strong light protection. However, if the ambient brightness changes greatly, it will have a great impact on the observation.
Infrared thermal imaging night vision equipment will not be affected by light. The target objects can be clearly observed whether it is day or night or in rain, snow or fog. It is for this reason that top-grade night vision devices such as Mercedes-Benz BMW use infrared thermal imagers.
1, detector resolution
The haike series is hand-held with detectors that use non-refrigerated sensors, so the detector does not require the installation of a cooling device in the system, so it is smaller, lighter, and consumes less power. In addition, they offer wider spectral response and longer operating time than the cooled photon detectors. Therefore, non-cooling technology can provide users with a lower cost, more highly sensitive high-sensitivity sensors.
Everyone knows that the level of resolution will directly affect the fineness of the picture or icon displayed on the screen. The higher the resolution of the image, the finer the screen, the clearer the image, and the better the viewing effect. So the level of resolution is an important parameter for choosing a thermal imager.
There are many kinds of resolution of the infrared thermal imager, the relatively high-end product pixel is 640x480, the middle infrared thermal imager's pixel is 384x288. When the same object is photographed at the same distance, the higher the pixels of the infrared camera, the clearer the infrared thermal images obtained. The higher the pixel, the higher the price of an infrared camera. The haike series has a high resolution of 384x288 and is also the mainstream high-end handheld thermal imager on the market.
2, objective lens diameter, magnification
The lens is a very important part of the thermal imager. The viewing effect and the extent of the visual field are all related to the size of the lens. Generally, the lens on the market is between 14mm and 75mm. The lens of the thermal imager is a professional lens, not the kind of lens used by traditional night vision or normal telescopes. When purchasing the lens factory of the thermal imager, it is based on the weight in grams to purchase. For example, the F44 lens costs about 5,000 yuan. Bigger lens costs will be more expensive.
3, LCD screen
The O LCD 800x600 ultra-clear LCD screen equipped with the G series has a large screen, super high resolution, and a clearer observation effect than an ordinary thermal imager. Even if it is used in rain, snow, fog, or dark weather, it will allow Your vision is clear, and darkness is like day.
The current professional imager has a built-in display with a high resolution and the price is about a few thousand dollars or even higher. The non-professional thermal imager uses a low-resolution, small screen and costs only a few hundred dollars. Therefore, thermal imaging cameras with the same resolution, professional large lenses, and high resolution built-in thermal imaging cameras cost more than 10,000 yuan more than non-professional thermal imaging cameras.
The G-series frame rate is 50Hz, and the thermal imager's frame rate is between 20Hz and 50Hz. The higher the frame rate, the faster the refresh rate and the more consistent the imaging frame. In addition to these features, the G-Series also supports video output so that everything is viewed clearly, fluently, easily, and without fatigue.
Note: 1, night vision device can see the details of the target, rather than a general outline, if it is night black state, the observation effect is greatly reduced, due to the need for external light source assistance, concealment and safety to be examined.
2. The thermal imager can be used normally in harsh environments such as daytime and nighttime, and has better safety and concealment. It can observe target objects at close range. More suitable for outdoor lovers night hunting.
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