Infrared light emitting diode infrared radiation from the high efficiency of material (with gallium arsenide-GaAs to made of PN junction), to draw the infrared light when forward voltage injection current to the PN junction。The spectral power distribution of the central wavelength of 830 ~ 950nm, half peak bandwidth is about 40nm. Its biggest advantage is completely without red storm,(with 940 ~ 950nm wavelength infrared tube) or only faint red storm (red storm for visible light) and extend the service life time. Light is an electromagnetic wave, its wavelength range from several nanometers (1nm=10-9m) to 1 mm (about mm). Visible only a part of them, which we call visible light, visible light wavelength range is 380nm ~ 780nm, visible from long to short wavelength is divided into red, orange, yellow, green, cyan, blue, purple, short than violet wavelength we called the ultraviolet light, longer than infrared light is called infrared light.Usually used the infrared emission tube wavelength: 850nm, 870Nnm, 880nm, 840nm, 980nm
The relationship between the power and the infrared emission tube wavelength: 850nm>880nm>940nm
The peak wavelength :lambda λP (energy distribution of NM luminous body or the measured object in the spectrometer, and the peak corresponding to the wavelength.)
Radiation intensity (POWER):unit as nm / Sr, said infrared tube (IR LED) radiation infrared energy size.
Radiation intensity (POWER) and the input current is proportional (If), radiation intensity and the emission distance is inversely proportional. The unit as nm / sr: infrared radiation intensity unit, for transmitting tube infrared light emitting unit solid angle (SR) size of the optical power emitted. Artificially increased the power of the infrared emitting tube, can only temporarily boost irradiation distance, and to draw the wafer attenuation speed, resulting in infrared light more and more dark, night vision more and more not clear. The external light source irradiation environment is complex, the infrared camera leaf can not play its due effect. Transmitting distance, the emission angle (15 degrees, 30 degrees, 45 degrees, 60 degrees, 90 degrees, 120 degrees, 180 degrees), light intensity, wavelength emission. Above is the physical parameters.
Electric performance parameters
The diameter as 3mm, 5mm for low power infrared LED tube. And 8mm, 10mm for power and high-power transmitting tubes. Small power transmitting tube forward voltage: 1.1-1.5V, current 20mA. In power transmitting tube forward voltage: 1.4-1.65V, current 50-100mA. High power transmitting tube forward voltage: 1.5-1.9V, current 200-350mA.
Directional characteristics of IR LED
The emission intensity of the infrared light-emitting diode for emitting direction varies. When the steering angle is zero, the definition of the radiation intensity of 100%, when the steering angle is large, relatively reduce the radiation intensity, emission intensity by optical axis such as take the direction angle of the half, its value is the half of the peak, the angle is called the direction of the half angle, the angle that the smaller the representative element directivity of more sensitive. The general use of infrared light emitting diodes are attached to the lens, the directivity of more sensitive.