Infrared environment, in the absence of light or night and use camera configuration, can take better quality images, in order to achieve the monitoring effect of 24 hours a day and night.
What is infrared (Infra - Red)?
Although the infrared for the human eye is not visible, but in Black and white camera is visible light, commonly known as \"Black\" (Black light). Infrared wavelength between 700 nm to 1000 nm, while infrared lamp with camera use, the wavelength of the camera will curve from 400 nm to 700 nm to 940 nm. Applies infrared surveillance system, can prolong the curve of the CCD camera to wavelength, raise the sensitivity of the black and white camera, not only when there is no light source of the environment or night photography can complement illuminant, can also help improve the image quality.
Filter (Infra - Red Filters)
Filter is a kind of high temperature resistant, coating the surface of optical glass, the penetration rate of 98%, is the infrared shoot the lamp to the body of the main components. Will be visible by the filter (filter) through the \"full coverage (Covert)\" or \"half covers (Semi - Covert)\" the resistance filter way, casting different wavelengths (700 nm to 1000 nm) is not visible, which generate infrared light.
In general, the manufacture of infrared filter can be divided into 730 nM, 840 nM and 940 nM three wavelengths. When the choice can be from product detection effect, lifespan, power consumption and cost of high and low for consideration. The wavelength of 730 nM presents the general red light, such as the traffic red light; The 840 nM is faintly visible red, belongs to a half cover type. As for 940 - nm is full coverage is not visible, belong to the whole cover type. Although the wavelength of 730 nm filter in appearance than 840 nm and 940 nm bright, irradiation distance is longer, but because the work presents the dazzling bright red, so difficult to accepted by users. The 940 - nm filter has the highest cost, best wavelength of 880 nm and 840 nm due to close to the camera, so it is the most commonly used filter.
The collocation of the camera and infrared
The camera
CCD camera itself must have three conditions, tie-in infrared light source to shoot a good effect.
High sensitivity, low intensity of illumination;
High noise ratio;
High sensitivity, strong ability to receive infrared.
The lens
In general, the CCTV camera is used in visible light (400 nm to 700 nm), when used in the night, the lens of the fill light ability must achieve maximum minimum value (F), but in this way, will cause the image depth, out-of-focus images. Therefore, if choose fixed lens, the user must be in low light environment and focal depth for compromise; But if you use automatic aperture of the lens, there is no this problem, because the camera in low light environment is automatically turned on the aperture (the lowest F value).
In addition, because of visible light and infrared light have different wavelengths, therefore in the environment of the two kinds of light source, the focal length of the lens must be adjusted. And infrared under 840 ~ 940 nm wavelength, the focal length of the lens need larger adjustment. So have zero focal length adjustment function of the lens, on the unmanned or remote monitoring management is a breakthrough.
The infrared projector Lamp Lamp (IR)
On the design of the infrared body structure, waterproof processing and heat dissipation is very important. Without a complete waterproof function, the body easily conductive, even produce shock, construction personnel will have the risk of electric shock; And poor heat dissipation, can make the light bulb life cut short. Currently manufacturers often use the fan in order to achieve the cooling effect, but the effect is not good, the fan working under high temperature easy to malfunction, and the body of LiuFeng hole is not easy to achieve waterproof function. Recently have manufacturers have developed with the principle of heat sink, high hardness of aluminum, with beams, with cylinder jagged appearance, be 360 ° radial heat dissipation, and achieve the goal of cooling.
The type of infrared projector lamp
General component is the design of infrared projector lamp LED and halogen lamp type.
The LED type
LED type infrared projection provides about 6000 hours of life for a long time, have low current consumption, and long service life, low cost and easy in maintenance. But compared with halogen lamp type products, LED type effect is insufficient, therefore more suitable for indoor distance is shorter, with high sensitivity to use the camera.
Halogen lamp type
Although halogen lamp type current consumption, short service life, high cost, but can provide different distance, Angle and wavelength of infrared (730 nM, 840 nM, 940 nM). 730 nm appearance than the other two bright, but the cost is the highest at 940 nm. General halogen lamp type infrared projection beam, can be divided into narrow Angle (Spot) 10 ° and small wide Angle (N Flood) 30 ° (FIG. 3, 4). And because the brand is different, the Angle of the beam vary slightly.
Detection to achieve good results, proper deployment of lens with infrared projection Angle is necessary. For example: the view of the long distance open it is best to use a long telescopic lens 16 mm - 160 mm, configure the narrow Angle of 10 ° double light type infrared light; Or 10 mm - 100 mm lens with narrow Angle of 10 ° and small wide Angle 30 ° N Flood double lamp type infrared lamp use.
The use of infrared lamp
Not all at night or no light environment can be configured using infrared lamp, such as in open areas, water, grasslands, being low reflective coefficient is not as ideal environment, even if the configuration of infrared ray, the effect of monitoring will be discounted, even have no effect. So the actual effect after installing infrared camera, must regard reflection of detection distance, landscape, climate condition, the sensitivity and the function of the lens of the camera.
In addition, the infrared lamp also can be the remote control, in addition to the power source controller built-in remote control switch device, such as: infrared remote control remote manual control mode, there are CDS photoresistor light automatic control. CDS style design is when the luminosity to 35 lux, CDS began, with the decline of luminosity, gradually began to gradually fill light, when the luminosity to 10 lux, infrared completely open, to achieve the effect of completely fill light. CDS design can avoid the instantaneous switch makes image rendering flutter or reverse phenomenon.
The configuration and installation of the infrared lamp in the configuration infrared lamp, there are three basic steps:
* step 1: confirm the camera position and Angle;
* step 2: choose the ideal infrared lamp (distance and Angle), in the proper position fixed erect;
* step 3: confirm the power, voltage, insert the plug into the power supply, such as outside, must be the power connector waterproof measures.
Must pay attention to: when the configuration
Infrared lamp erect is best done in the night, in order to test. Test can shading, let CDS forced to boot.
Erect, to avoid glare of the area, such as street lamps and other lighting facilities. Because the illuminate of strong light can affect the function of the CDS automatic detection.
Infrared lamp erect position does not necessarily with the camera to the same place, such as tied for parallel must reside in the same position, Angle and the camera is the same person is beautiful, the best way is to infrared lamp overlapping with the camera up and down building.
The height of the infrared lamp installation shoulds not be too tall, 3-4 m is suitable for, Angle of depression to top-down from the Angle of 20 ° better elevation will make is according to reflective, effect is bad instead.
Some infrared lamp work will produce high temperature, do not touch with the hand, nor to the camera, so as to avoid burns my eyes.
In addition to large infrared lamp with wire mesh filter protection, the other in the process of handling device to be careful, in case of broken scrape.
Filter optical glass, the fragile easy dirty, when should look with alcohol to wipe the dirt on the surface, can wipe with a clean cotton cloth, do not use rough or scratch generating material or organic solvent to clean.
Infrared lamp bulb life have a fixed term, consumables, change easily, can change itself.
