Happy 50 years, LED
The LED is a technology that has changed our gadgets in many ways, so that sometimes we do not realize. From traffic lights to pocket calculators, shoes with little lights and optical mouse, this technology is present in our daily lives.
The origin of the LED is a bit fuzzy and goes back over 50 years. It is said that the Russian Oleg Vladimirovich Losev created the first in 1927, appearing in magazines published in Europe, however, was not made practical use of this technology until the 1960s.
In 1961, researchers at Texas Instruments Robert Biard and Gary Pittman found that gallium arsenide (GaAs) infrared radiation emitted when an electrical current. This phenomenon was exploited in 1962 to create the first LED in practice, made by Nick Holonyak in General Electric.
The setting LED layers are fabricated on a semiconductor crystal film. As you add layers, add a substance that determines the color of the LED. In its early versions, the substance used produced a red color, so this was his first color. With new processes have been achieved LEDs varied tones, but in its first 10 years the color was red.
Despite the limitations of color, the LED was relatively inexpensive, low-power, so that was first used in calculators and watches as a replacement for incandescent bulbs.
In 1993 he invented the bright blue LED, which painted yellow coverage delivered white light, opening the door to new options for this technology, and later as flashlights, bulbs.
The mouse also benefited from the LED, eliminating the wheel that had a light down, which allows image sensors track the movements of the mouse on any surface. On the other hand, took advantage of the LED TVs also for backlighting, giving better contrast and colors, in addition to reducing electricity usage of the device.
In general, the LED has been gaining in brightness and lowering energy consumption through the years, so we’ll probably see still many applications that we have not yet imagined.
Link: 50 years of LED technology (Wired)Tags: 50 years, Invention, LED, light, Lighting, vial