Light-Emitting-Diode (LED) Display!

An LED display is a video display which uses light-emitting diodes. An LED panel is a small display, or a component of a larger display. They are typically used outdoors in store signs and billboards. LED panels are sometimes used as form of lighting, for the purpose of general illumination, task lighting, or even stage lighting rather than display.

A light-emitting diode (LED) is an electronic light source. The LED was first invented in Russia in the 1920s, and introduced in America as a practical electronic component in 1962. Oleg Vladimirovich Losev was a radio technician who noticed that diodes used in radio receivers emitted light when current was passed through them. In 1927, he published details in a Russian journal of the first ever LED.

All early devices emitted low-intensity red light, but modern LEDs are available across the visible, ultraviolet and infra red wavelengths, with very high brightness.

LEDs are based on the semiconductor diode. When the diode is forward biased (switched on), electrons are able to recombine with holes and energy is released in the form of light. This effect is called electroluminescence and the color of the light is determined by the energy gap of the semiconductor. The LED is usually small in area (less than 1 mm2) with integrated optical components to shape its radiation pattern and assist in reflection.

LEDs present many advantages over traditional light sources including lower energy consumption, longer lifetime, improved robustness, smaller size and faster switching. However, they are relatively expensive and require more precise current and heat management than traditional light sources.

Applications of LEDs are diverse. They are used as low-energy indicators but also for replacements for traditional light sources in general lighting and automotive lighting. The compact size of LEDs has allowed new text and video displays and sensors to be developed, while their high switching rates are useful in communications technology.

The first recorded flat panel LED television screen developed was by J. P. Mitchell in 1977 [1]. The modular, scalable display array was initially enabled by hundreds of MV50 LEDs and a newly available TTL (transistor transistor logic) memory addressing circuit from National Semiconductor[2]. The 1/4 inch thin flat panel prototype and the scientific paper were each displayed.[3] at the 29th Engineering Exposition in Anaheim May 1978, organized by the Science Service in Washington D.C. The LED TV display received awards and recognition from NASA[4], General Motors Corporation[5], and faculty from area Universities[6]. The event was open to technology and business representatives from the U.S. and overseas. The monochromatic prototype remains operational. A LCD (liquid crystal display) matrix design was also cited as a future flat panel TV possibility in the accompanying scientific paper as a future alternate television display method using a similar array scanning design.

Additionally, Mitchell presented his paper at the 90th Session of The Iowa Academy of Science April 21-22, 1978, at the University of Northern Iowa, Cedar Falls, Iowa

In order to develop a color display, a triad of red, green and blue LEDs are needed. Efficient blue LEDs did not emerge until the early 1990s. High-brightness colors gradually emerged in the 1990s enabling new designs for outdoor signage and huge video displays for billboards and stadiums.