As to expanding the application areas, monitoring and control system in the environment of the light or the light is very weak, hd low illumination cameras has been difficult to meet the application requirements. In this case, the infrared camera to meet the specific requirements of the monitor. The text/guangzhou beauty electric bell electric power technology co., LTD

With the growing popularity of the monitoring system, video camera is widely used in various fields, the security escort for the society. Each different application field, needs to have different types of cameras, such as road surveillance cameras, ir waterproof camera, star level low illumination camera, night vision integration series, smoke type camera, pinhole camera, the flying saucer camera series, gun type cameras, integrated cameras, hemisphere cameras, high-speed ball, video cameras and riot video cameras, and other categories.

With expanding the application of the monitoring system, new problems have emerged: if the camera is in the light or the light is very weak environment, such as "safe city" monitoring project, some monitoring points in street lamp or light is very poor, how to deal with? Obviously, the traditional hd low illumination cameras already difficult to meet the application requirements, in this case, using infrared camera can better meet the needs of monitoring.

The principle of infrared overview

In nature, anything as long as it's temperature above absolute zero (273 ℃), there is a molecular and atomic movement without rules, it will continually infrared radiation.

Infrared radiation and follow the law of blackbody. Black body simply is in any case for all wavelengths of light incident radiation, the object, its absorption rate is equal to 1, that is fully absorbed. Obviously exist in the nature of any object incident radiation with different wavelengths of light, there is a certain reflection (absorption rate is not equal to 1), black people just abstracting the object model of an idealized, but the basic rule of blackbody radiation is the foundation of the ir research and application.

Infrared camera technology principle

Infrared camera technology is divided into passive infrared imaging technology and active infrared imaging technology.

Passive infrared camera technology is the use of any material above absolute zero (- 273 ℃) is launching the principle of infrared light, infrared light from the human body and the engine is stronger, infrared light from other objects are relatively weak, using special thermal infrared night-vision goggles can realize monitoring at night. But this kind of special thermal infrared night-vision goggles is expensive, and not intuitive and clearly reflect the status of the environment, less so in night vision system usually used.

Active infrared imaging technology, it is using infrared lamp to generate the infrared radiation, infrared light to illuminate a person see not object and the environment, can use normal low illumination CCD or black and white camera automatically turn black and white "" color during the day night cameras or" infrared low illumination color video camera "reflected infrared light to feel the surrounding scenery, so as to realize the night vision function. (as shown in figure 1)

At this stage of the infrared camera system basic configuration is: camera, camera, infrared lamp, lamp power supply, etc. Here refers to the camera requirement is low illumination cameras, and the launch of the infrared lamp can be received the camera, camera can also require infrared sensor, the main index F value (light) is smaller, the better night vision effect. The stand or fall of camera effect, the reasonable choice and related components to the camera has a direct relationship.

Camera is when your subject scenery brightness low sensitivity to a certain extent and make the camera output video signal level is low to a specified value of scenery brightness value, the higher the sensitivity of the camera, the faint light induction ability is stronger. Of course, the better the sensitivity camera price is more expensive. Some camera manufacturer, optional increase output signal strength, sensitivity is good, but the signal-to-noise ratio is very poor, "snow point" a lot of images, image quality.

The different specifications of the CCD camera significantly affect the infrared camera image effect. The specification of the CCD cameras have 1/2 ", 1/3, 1/4 ". "l / 3" CCD light flux is 1/2 "44% of the CCD, 1/4" CCD light flux is 1/3 "CCD 50%, visible 1/2" late camera image effect is best, so you can choose according to different environment and monitoring requirements of different specifications of the camera.

All induction infrared camera, infrared under the condition of visible light for the camera is a kind of complex light, lowers the camera's resolution and color reproduction, color video camera filter is to prevent infrared imaging. To make color video camera infrared sensor, now have two, first, switching filter, under the condition of visible light blocking infrared to enter; The second is when there is no visible under the condition of filter, let the infrared into, the good image quality. (as shown in figure 2)

The selection of the infrared camera lens

The amount of the optical lens or relative aperture, decided the lens optical capability, relative aperture F1.0 lens light is relative aperture F2.0 shot four times the amount of light. The same camera, infrared lamp, the above two kinds of lens, infrared range can vary. Large aperture lens is better than conventional normal lens through light four to ten times, and by rights should be infrared night vision surveillance must form a complete set of products, but because of the high cost of production technical difficulty is big, the vast majority of infrared products manufacturers don't have the ability to supply.

Infrared lamp selection

Light is an electromagnetic wave, with wavelength ranging from a few nanometers (1 nm = 10? 9 m) to 1 millimeter (mm). Visible to the human eye is just one part of a, referred to as visible light, the wavelength of visible light is 380 nm to 780 nm range, the visible wavelength from long to short respectively red, orange, yellow, green, green, blue, and purple light, called ultraviolet wavelength shorter than purple light, the wavelength than red light, long known as infrared light. Night vision system in the selection of infrared lamp, will directly affect the camera imaging effect.

Infrared halogen lamp is a more traditional technology, the high energy consumption, calorific value, short service life, low efficiency, so gradually become less. LED lamp because of its low cost, has become the most used infrared light emitting devices, its shortcomings for nearly irradiation (single LED optical output for 5 mw - 15 mw), small Angle (7 to 12 degrees Celsius) light distribution is not equal.

Multichip LED and LED array), LED lamp irradiation distance is insufficient because the energy, the chip set more together, of course the energy is big, further irradiation. But may due to the defects in structure, making multiple chip LED light-emitting focus, no light system is unreasonable, use efficiency is low. LED lamp calorific value is big, multichip LED calorific value is bigger, so the heat dissipation problem very important, will seriously affect the life.

Single chip LED production process is simple, easy to guarantee quality, low calorific value, light emitting optical system is reasonable, the lamp is an ideal device, the service life of the theory of up to 100000 hours.

Infrared lamp maximum irradiation distance depends on the weather conditions, the object of reflective rate and the surrounding illumination level, infrared spotlight furthest distance as follows, the values for the ideal value, not absolute.

　　W = 150, 500 to 150 meters;

　　W = 80, 300 to 80 meters;

　  50 w = 15 to 30 meters;

　　30 w = 5 to 15 meters.

Infrared lamp perspective is not the bigger the better, so some people think that the infrared lamp launch Angle, the greater the room to choose lens is, the greater the choice wide-angle lens won't appear "flashlight" phenomenon. Using large Angle infrared lamp with small Angle lens, exist waste phenomenon of light. In general, the Angle of the lamp are consistent with the Angle of the camera, the effect is best.

Install the matters needing attention

Infrared camera, try to avoid direct light source, because the lamp power supply control part is on the infrared lamp board according to the installation of photosensitive resistance to control the work of infrared lamp power or not.

Infrared camera view should try to avoid have full black objects, empty place objects, such as water absorption of infrared light, infrared lamp form a complete set of CCD camera is to rely on launch infrared light reflect on the objects the CCD camera into images, if the infrared light is absorbed or reduced, will greatly weaken the infrared lamp irradiation effect.

Red abuse

More than 700 nm wavelength of light called infrared light, more than the wavelength of 900 nm infrared lamp basically no red storm, the shorter the wavelength, the stronger the red storm, but infrared induction degree is higher.

Now in the market there are two kinds of main infrared lamp, one kind is slightly red storm, at about 850 nm wavelength; A is a red storm, wavelength at about 940 nm. The same camera, in the 850 - nm wavelength of sensing, is better than in the 940 - nm wavelength of sensing degrees to 10 times. So 850 nm this slight red infrared lamp has a higher efficiency.

conclusion

With the development of the society, social safety problems gradually appear, so as to promote the development of each security domain, especially the application of security products in special environment increasingly mature, pertinence, for the development of security, and the application of infrared development to have the meaning of product level.