Description
An LED (from the English word for light-emitting diode) is an electronic semiconductor device constructed as a diode that emits light when a current passes through it. This can be visible light in various colors, but also infrared or ultraviolet radiation. After their invention in 1962, LEDs were initially used only as indicator lights and for signal transmission. Due to technological improvements, their light output increased, and by the late 1990s, LEDs suitable for everyday use could be produced. Typically, an LED is housed in a small, transparent housing, a few millimeters in diameter, which also functions as a lens.
