LED
Abbr. for “light emitting diode”, light emitting diode, luminescent diode.
Is installed in LED lighting in industrial image processing. LEDs are virtually wear-free. Ageing (several 10,000 h) reduces their luminosity somewhat. Strong (local) heating causes LEDs to age more quickly. Sufficient cooling must therefore be ensured.
Typical LED spectra (source: Vision Doctor).
Depending on the semiconductor material, LEDs generate monochromatic (single-color) light. White light is produced either by combining different colored (RGB) LEDs or by converting short-wave light (blue or UV LEDs) into longer-wave light using a phosphor (photoluminescent dye). The color impression of white LEDs is quantified by the color temperature (in Kelvin).
The luminous flux is almost proportional to the operating current supplied by a constant current source (regulated power supply unit) or a lighting controller. In flash mode (typical switch-on time < 1 ms), the operating current can be briefly excessive (up to 10 times higher).
Further information can be found on Wikipedia.
