Surprisingly LED lights, or light emitting diodes, were first recognized over 100 years ago. A History of Electroluminescent Displays states that in 1907 Captain Henry Joseph Round, a Marconi lab employee, “Reported that a yellow light was produced when a current was passed through a silicon carbide detector.” This phenomenon is called electroluminescence. The forerunner to today’s LED lighting, the semiconductor radiant diode, was patented by Texas Instruments in 1962.
How does it Work?
Energy Star defines an LED as “Light–emitting diodes, are semiconductor devices that produce visible light when an electrical current is passed through them.” It’s a semiconducting chip with electrons of differing energy levels flowing from the anode to the cathode. Electrons meet holes along the path lowering energy and releasing photons, which are the light source.
Britannica.com offers this comparison of an LED to a flashlight. “The term diode refers to the twin-terminal structure of the light-emitting device. In a flashlight, for example, a wire filament is connected to a battery through two terminals, one (the anode) bearing the negative electric charge and the other (the cathode) bearing the positive charge. In LEDs, as in other semiconductor devices such as transistors, the “terminals” are actually two semiconductor materials of different composition and electronic properties brought together to form a junction.”
Why use LED’s?
Among the reasons to use LED lighting, not the least of which are the many environmental advantages, these four top the list.
• Lower energy consumption
• Zero heat emission
• Long life
• Compact size
TKO Signs uses high quality LED lighting in the signs we design, produce, and install. We also maintain and replace signs using LED technology. If you’d like to learn more about LED lighting, signs, or sign maintenance—let us know.