With the continuous development of security monitoring, users have more and more intense monitoring requirements for 24 hours a day and night, which brings higher requirements to the camera, and ensures that the image is clear under any light in any time period. Since most of the scenes at night are poorly lit, it is difficult to get good image effects from the camera by natural light alone. In this context, infrared cameras have emerged, and cameras with infrared light sources have become more prominent in the field of video surveillance. At present, the infrared camera market is dominated by guns and hemispheres. In the past two years, infrared ball machines have emerged and become the star products of infrared cameras; laser infrared generally appears in the cloud-type cameras; infrared guns are installed more. Outdoor, so it is generally required to be waterproof; hemisphere products have been mostly conch-type in recent years, and have begun to cooperate with explosion-proof tamper-proof structures in recent years; the built-in movement of the ball machine products, the infrared lamp group should be multiplied with the movement, and the infrared distance is more Far, generally can reach more than 80 meters; laser pan/tilt is mostly used for remote monitoring scenes, and the laser line can be up to three or four hundred meters or more. Principle of infrared camera Generally, the wavelength of visible light is 0.4 to 0.7 microns, which is the light that our eyes can see. The section from 0.7 to 400 microns is infrared, and the infrared light is invisible, beyond the range that our human eyes can see. In addition, any object emits thermal radiation infrared rays above its absolute zero level, and a heat-generating object such as a human body emits a larger amount than objects such as houses, trees, and stones. The camera's sensor CCD or CMOS, also commonly referred to as "sensor", is equivalent to the eye of the camera and is a semiconductor device that converts optical images into digital signals. But what is more powerful than our eyes is that it can sense some invisible light, such as infrared light. The sensor has an indicator sensitivity, also called the minimum illumination value, which is a reflection of weak light. The higher the sensitivity, the stronger the ability to sense light, and the stronger the ability to sense infrared. Since the sensor can sense infrared rays, infrared rays in the light also enter the image during the day, which causes the overall image to be reddish. Therefore, ordinary cameras have filters on the surface of the sensor to filter out the infrared rays in the light. If the infrared camera is also attached with such a filter, the infrared light that is actively emitted by the night camera infrared light will also be filtered out, causing the infrared light to fail. In order to avoid this situation, high-end infrared cameras are generally equipped with dual filters, that is, open the infrared filter during the day, filter out the infrared rays in the light, turn off the infrared filter at night, and let the fill infrared light enter the image through the lens. This is why the infrared camera can be clearly imaged at night when our eyes are not visible. Depending on the characteristics of the camera sensor, the infrared sensor can be used to achieve night vision by using infrared fill light or the object's own infrared heat radiation. In the meantime, double filters are used to ensure that the daytime images are not color cast. Ningbo Kyson Cool Electronic Technology Co., Ltd. , https://www.kysonrefrigeration.com
How infrared cameras work
[ Huaqiang Security Network News ]