Infrared camera research and development background

Pinyin: hong wai she xiang ji

English: Infrared camera

The visible light that the human eye can see is arranged in order from long to short wavelength, in order: Red, orange, yellow, green, cyan, blue, purple. The wavelength range of red light is 0.62~0.76μm; the wavelength range of purple light is 0.38~0.46μm. (Visible light, infrared and ultraviolet, etc.)

Infrared night vision means that in the night vision state, the digital camera will emit infrared light that is invisible to the naked eye to illuminate the object being photographed. Turn off the infrared filter. Light mirror, what we see at this time is the image formed by the reflection of infrared rays, rather than the image formed by the reflection of visible light, that is, at this time, we can capture images that are invisible to the naked eye in a dark environment.

In TV surveillance system engineering, infrared lights were rarely used in the past. However, due to the increasing crime rate in today's society, infrared rays play a more prominent role in night surveillance, not only in vaults, oil depots, armories, and books It is used in important departments such as document libraries, cultural relics departments, and prisons, and is also used in general monitoring systems. Even residential area TV monitoring projects also use infrared cameras. This shows that people's requirements for TV monitoring system engineering are becoming more and more standardized and higher. Important places are increasingly required to be monitored 24 hours a day.

To achieve night vision, conventional visible light illumination can be used, but this method not only cannot conceal, but also exposes the monitoring target. Covert night vision surveillance uses infrared camera technology. Infrared camera technology is divided into passive infrared camera technology and active infrared camera technology. Passive infrared camera technology uses the principle that any object emits infrared light above absolute zero (-273°C). Since the human body and heating objects emit strong infrared light, and other non-heating objects emit very weak red light, night monitoring can be achieved using special infrared cameras. Passive infrared camera technology is not used in night vision systems because of its high equipment cost and inability to reflect the surrounding environment. Active infrared camera technology uses a special infrared lamp to artificially generate infrared radiation, which produces infrared light that is invisible to the human eye but can be captured by ordinary cameras. The radiation illuminates the scenery and environment. It uses ordinary low-light CCD black and white cameras or uses daytime color to automatically change to black and white at night. A camera or an infrared low-illumination color camera is used to sense the infrared light reflected back from the surrounding environment, thereby realizing the night vision function.