Answering about IR
Published：2014/11/6 Views：1401
The visible radiation ordered as the wave length of light from long to short: red, orange, yellow, green, cyan, blue, purple, by turns. Thereinto the wave length of red light 0.62～0.76μm, the wave length of purple light 0.38～0.46μm. The shorter than purple light call as ultraviolet ray, The longer than red light call as infrared ray, it unviewable of infrared ray. We all know the digital camera induct all the light(visible light、infrared ray and ultraviolet ray) through CCD , It get to different image between camera and naked-eye. To solve this problem , it is favor to install a IR filter lens between lens and CCD. The function is prevent IR come into CCD, and CCD can just induct visible light. Then to get the same image from camera and naked-eye.
IR nightvision that is digital camera send out the unviewable IR light up the object under the darkness, and shut off IR filter lens, never preventing the IR irradiation. IR through the object reflect into lens, so we can see the image reflect through IR not visible light. That is we can see the unviewable image through naked-eye under darkness.
At present time ,most of IR camera adopt LED as primary material of IR camera.
Principle of IR camera and recommendation for usage and selection.
At the video surveillance system project, it is few use of IR in the past , but with the incessant increase of crime rate ,IR act as an more important role at the nighttime surveillance system. Not only adopt as treasury、oil depot、armory、library、
culture relics department、prison ,as this severity institution adopted, but also wide use of common surveillance system, even adopted by residential area surveillance system. It means people has more normative、 higher standard demands for surveillance system. Make good incessant supervisory for primary venue.
Radiation “lighting” scenery and ambient ,using the common low illumition CCD B/W camera or the camera“day as clour and night turn to B/W” and the other “IR low illumination camera” to induct IR reflect from ambient, thereto implemented lightvision
we can implement the nightvision by use of visible light but it will expose the supervisory goal. At present time it all adopt IR technology to concealed nightvision surveillance.IR technology sort of passive IR camera technology and initiative IR camera technology. Passive IR camera technology is use the theory of all of object are all IR gamma ray source when the temperature above the absolute zero point.
Because of human being and heating element is stronger IR emission and other unheating element are weak IR emission. So through the professional IR camera we can implement supervisory at nighttime. Because of expensive manufacturing cost and it can not imaging the ambient so the passive IR camera technology is unusual applicated. Initiative IR camera technology take advantage of “IR light”to product the IR by artificial way. The IR could be inducted by the camera but can not be saw by the naked-eye. Radiation “lighting” scenery and ambient ,using the common low illumination CCD B/W camera or the camera “day as color and night turn to B/W” and the other “IR low illumination camera” to induct IR reflect from ambient, thereto implemented nightvision.
