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LED Technology

A light-emitting diode (LCD) is a semiconductor component that emits light when an electric current passes through it. LED backlights are rapidly replacing incandescent lighting (CCFL) in LCD panels. LED systems have rapidly become 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 capacities coupled with their small size and system flexibility make them ideal for any industry. LED backlighting technology also provides an LCD with an advanced level of high brightness while requiring lower power consumption.

Integrating an LED backlight typically requires heat management. It is necessary to dissipate operating heat as efficiently as possible, keeping sensitive LED components safe from thermal damage created by dissipation of current. Inefficient heat management can damage or shorten the life of an LED backlight. AGDisplays continually inspects the value and quality of our products. With each integration of our latest generation LED technology, we also integrate high efficient heat management technology to preserve the lifespan of your LED.

LED backlighting is typically designed as edge-lit or in a direct backlighting arrangement. Both types have the LEDs concentrated into a diffuser source (light guide of the display) distributing the light uniformly throughout the viewing area. With an edge-lit backlight design, LEDs are aligned along edge of the internal light guide of the LCD. The backlight array may be mounted on one, two, or all four edges, depending on the size of the display and the amount of luminance required. With this design, light from the LEDs is captured and spread across the viewing display by way of the light guide. Benefits of this design include a slimmer profile of the product, lower cost of LEDs.


FIGURE 1. EDGELIT LED CONFIGURATION.

In a direct backlighting arrangement, LEDs are placed in a flat array behind the light guide and the diffuser plate. Direct backlighting works as a uniform source of backlighting, like most CCFL LCDs. One of the pros of integrating a direct backlight arrangement allows for local-dimming aspect, which means the display is able to dim zones behind the dark areas of the screen in fairly specific areas to make the image really pop, drastically increasing the apparent contrast ratio providing a more accurate color adjustment and enhancing overall viewing quality. Blacks are true black and grays are more defined.

FIGURE 2. DIRECT BACKLIGHTING.

AGDisplays continues to upgrade our LED technology to keep up with the active marketplace. The following is a breakdown of some of the big changes we have made as LED technology advances.

1st Generation LWW
From CCFL, this white LED has a smaller footprint and provides a longer lifespan.

2nd Generation LW
From our Gen1, our white Gen2 LED has an increased output (brightness) and altered electrical characteristics.

3rd Generation PLCC2
Our white Gen3 LED provides a high bright output, with a small amount of power consumption. It also has a smaller footprint from Gen2.

4th Generation PLCC4
Gen4, our current white LED model, provides an even higher output than Gen3, and with the same small footprint.


Advantages of LEDs

LEDs are now being used in a variety of the latest and largest display applications as well as in TVs, not to mention some of the smallest handheld units as a result of their superior efficiency. Because of the increased efficiency of LEDs, they continue to grow in popularity and only become more advanced. Integrating LED backlighting in your LCD panel increases your panel's reliability by protecting it against environmental factors such as shock & vibration, extreme humidity, and frigid temperatures.

  • Improved ruggedization - the compact and rugged packaging of the LED is extraordinarily resistant to shock and vibration; LEDs are free of glass and other small, breakable parts.
  • Environmentally safe: LEDs are ROHS-compliant; they are mercury- and lead- FREE.
  • LEDs are driven at a low voltage current with a constant current LED driver, therefore reduce power consumption.
  • The overall lifespan of an LED is 10,000 to 100,000 hours.
  • Reduced EMI emissions.
  • Given the nature of the LED, there is almost no limit to shape and size in which they can be manufactured.
  • LEDs are much more durable in Harsh temperatures (-40 to 85°C)


POWER CONSUMPTION
LCD SIZE AND COMPONENT STOCK LUMINANCE (NITS) REQUIRED WATTAGE
10.4" CCFL LIT LCD 450 5.8w
10.4" LED-ENHANCED LCD 450 1.2w