Principle characteristic of IR lamp
Light is an IR Illuminator electromagnetic wave, its wavelength range from several nano (1nm10-9m) to 1 mm (mm) around. The human eye is visible only part of it, we call it visible, visible light wavelength range for 380nm--780nm, visible light wavelength from long to short divided into red, orange, yellow, green, blue, blue, violet, the wavelength than the violet short known as ultraviolet light, IR Illuminator the wavelength than the infrared light is called infrared light.
Ordinary CCD black-and-white camera can feel the spectral characteristics of light, it can not only feel the visible light, but also can feel the infrared light. IR Illuminator This is the use of ordinary CCD black-and-white cameras, with the infrared lamp can be more economical to achieve the principle of night vision. The spectral characteristics of ordinary color cameras cannot be used for night vision.
Infrared light According to its infrared radiation mechanism is divided into semiconductor solid-state luminescence (infrared emitting two-level tubes) infrared lamp and thermal radiation infrared lamp Two. Its principle and characteristics are described as follows:
1. Infrared emission diode (LED) infrared lamp principle and characteristics
A luminescent body is composed of a two-level infrared luminous tube matrix. IR emission two-level tubes are manufactured by the high Infrared radiation efficiency IR Illuminator materials (commonly used gallium arsenide GaAs), plus the positive bias pressure to inject current to PN junction excitation IR light. Spectral power distribution is the center wavelength 830--950nm, half-peak bandwidth about 40nm, it is narrow-band distribution, for ordinary CCD black-and-white cameras can feel the range. Its biggest advantage is that IR Illuminator it can be totally free of red storms, (using 940--950nm wavelength infrared tubes) or only faint red storms (red bursts with visible red light) and long life.
The emission power of IR LEDs is expressed by irradiance μ W/m2. In general, the infrared radiation power is proportional to the positive current, but when the IR Illuminator maximum rated value is close to the positive current, the temperature of the device rises due to the heat consumption of the current, which decreases the light emission power. The infrared diode current is too small, IR Illuminator will affect its radiant power to play, but the working current will affect its longevity, even the infrared diode burned.
When the voltage crosses the forward threshold voltage (about 0.8V) The current is flowing, and it is a very steep curve indicating that its working current is very sensitive to the operating voltage. IR Illuminator Therefore, the working voltage is accurate and stable, otherwise the radiation power is affected and its reliability is required. The radiation power decreases with the increase of ambient temperature (including the increasing ambient temperature of its own fever). Infrared lamps, IR Illuminator especially long-distance infrared lamps, heat consumption is the design and selection of the problems should be noticed.
The maximum radiation intensity of IR diodes is generally in front of the optical axis, and decreases with the increase of the angle of the radiation direction and the optical axis. The radiation intensity is the maximum of 50 angles called half-intensity radiant angle. IR Illuminator The radiation angles of IR LEDs differ from the different packaging process models.