Security Monitoring: Infrared Camera Features Development Analysis
Infrared technology was discovered in 1800 after the British astronomer Herschel, it was more and more scientists study how to apply in a variety of occasions, including active infrared technology in the security surveillance camera Applications after nearly 20 years of rapid development of technically mature. Infrared cameras with lightning speed to grow, while also constantly diversifying product types, applications are further expanded.
Infrared Camera Product Features
Infrared cameras are generally divided into two categories, one is Analog infrared camerasOne is an infrared network camera. But no matter the kind of infrared cameras all have the same characteristics of its main features: (1) the different characteristics of the infrared light source; (2) low-light camera choice. Only this 2:00 with a good infrared camera can become an excellent product.
For different occasions, to choose a different distance from the infrared light source and, an infrared light source whose main features are as follows: infrared light having a wavelength greater than 780nm is not visible. General current infrared camera There are two types of infrared light.
1 using an infrared light emitting diode LED or LED array to generate infrared light. This device is to generate infrared light through the gallium arsenide (GaAs) semiconductor electrons recombine with holes;
2, using infrared laser diode LD, but also for infrared light. However, it should be in a lower energy state to a higher energy excited state or pump up, the laser radiation is maintained by the infrared light through a large particle distribution inverted resonance.
The first is the use of semiconductor gallium arsenide light-emitting diode array consisting of infrared light, especially now that the use of new technology development and production of light-emitting array integrated chip LEDArray. Its an LED-Array of The optical output reached 800mw-1000mw, and become an ordinary LED replacement, LED-Array light-emitting half-power angle of 10-120 ° (variable angle). Since the LED- Array is a highly integrated LED, while the volume is only one penny coin size, its life of 50,000 hours.
The second is to use an infrared laser diode LD. For more than 1km long distance monitoring the scene, or to select an infrared light source LD. Because semiconductor laser with high brightness than LED, directional, and other characteristics.
Features surveillance infrared light at different distances: Because infrared light emitting diode LED can be mounted on the camera, equipped with infrared cameras and a sense of, or directly mounted on the casing around the camera and the lens mount. Clearly, both the assembly Infrared LED less, and its certainly not as separate from the irradiated infrared LED light irradiation far. General 50m or more, the best selection of individual infrared light as well, another LD used for monitoring more than 1km from the scene of the night Depending on the illumination, the thin and strong LD beam, the infrared beam to illuminate a range of scenarios, also be required by a beam expander lens beam expander down.
Infrared camera sensor chip features: Head Before the cameras CMOS and CCD photosensitive devices have two kinds. Same as CCD, CMOS image sensor chip is also the reaction of the infrared light, but it is within the sensitivity range of 890-980nm than CCD image Sensor chip to be much higher, and increases with wavelength attenuation gradient is also slower. General infrared camera sensor chip technical indicators are in control of the requirements generally ≤ 0.02Lux, both day and night using automatic conversion function Energy. Infrared camera image sensor sizes bigger the better. Can not be used due to 1/4CCD IR effective distance of 15m or more, because 1/4CCD flux of only 50% 1/3CCD. And CCD size large, luminous flux received large;CCDSmall size, less acceptable flux. So, night vision cameras multiple choice CCD 1/2, to test the 1/3 can be viable, but we can not choose 1/4 The.
Infrared camera lens features: using infrared lens. For ordinary optical lens, the object lens infrared light reflected back is not effective to focus CCD target surface, infrared night vision is compromised at this time, so the best selection of infrared lens. Especially the color to black camera, infrared camera does not make the choice of day and night surveillance consistent focal plane, resulting in an image can not be maintained day and night Clear.