Light Emitting Diode (LED) technology is the future and AGDisplays is and has been fully committed and focused on developing this technology with products necessary to create LED solutions for the current panel market.
LED systems are rapidly becoming the light source of choice for a variety of applications due to their ruggedness, dependability, long life, energy efficiency and low maintenance requirements. Innovative LED technology has opened up new opportunities with dynamic color mixing and color sequencing capabilities. These new capacities coupled with their small size and system flexibility make them ideal for any industry.
Advancements in semiconductor technology paired with original theories in packaging design, a drastic increase in LED brightness is anticipated making the importance of Light Emitting Diodes used in backlighting applications vital. LED's are now being used in a variety of the latest and largest display applications as well as in TV's, not to mention some of the smallest handheld units as a result of their superior efficiency. Because of the increased efficiency of LED's, they continue to grow in popularity over what was once the leading choice in all backlighting applications being CCFL or cold cathode fluorescent lamps. LED's have an array of advantages over CCFL on account of casing technology and the basic physical attributes of the semiconductor.
LEDs differ radically from traditional light sources in that there are no glass bulbs or filaments to break, or electrodes to decay. Instead, LEDs are solid state light sourcesbasically, a chemical chip embedded in a plastic capsule. When the chip is energized by applying a voltage, it emits visible light, the color depending on the chip's chemical composition. The light can then be focused, routed, or scattered using lenses, waveguides or diffusers. Because LED's run on direct current, they must be operated with a transformer- type power supply. With LED's solid state construction comes durability and exceptionally long life. For example, a properly operated red or yellow LED can maintain up to 50% of its initial brightness after 100,000 hours.
Due to the tremendous pace of technical developments, LED efficacy now rivals or surpasses that of standard incandescent lamps. For example, white LED's are now producing more than 20 lumens per watt, compared to 815 lumens per watt for incandescent lamps. White LEDs are actually blue LED's with a phosphor coating, which converts a portion of the blue light to yellowthe combination resulting in white light. First available in cool white, white LED's will be available in neutral and warm white. LED's are even more efficient at producing pure colored light, as their entire light output is channeled into single wavelengths. With traditional light sources, colored filters must be used to create colored light, absorbing and wasting much of the lamp's light output.
Here is a list of some advantages of LED's over CCFL:
- LED's can be driven at a much lower voltage current than CCFL therefore consuming less power and extending battery life.
- The overall lifespan of the LED is also much longer than that of CCFL.
- The compact and rugged packaging of the LED is extraordinarily resistant to shock and vibration, where as CCFL can be damaged easily when exposed in these types of harsh environments.
- Given the nature of the LED, there is almost no limit to shape and size in which they can be manufactured.
- LED's are ROHS compliant and are Mercury and Lead FREE.
- LED's are much more durable in Harsh temperatures (-40 to 85 °C)
The configurations of the LED backlight are simple; Direct LED Backlighting and Edge lit LED backlighting. Both types have the LED's concentrated into a diffuser source (Light guide of the display) distributing the light uniformly throughout the viewing area. In the instance of "Direct" Backlighting, a large quantity of LED's are evenly spaced and mounted behind the light guide.
Conversely, in the Edge lit configuration, LED's are mounted on the side (top or bottom in most cases and sometimes both) limiting the number of LED's needed to be used, therefore consuming less power and contributing a much more compact display.
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