19-11-2012, 03:24 PM
LED and LCD
LED
LED TVs are simply LCD TVs that use a different type of lamp made from light emitting diodes, in place of a fluorescent lamp (typically called CCFLs) for illuminating the picture. LED lamps are placed on around the panel beneath the screen bezelor like CCFLs(Cold cathode fluorescent lamp), behind the LCD panel.
LCD
LCDs are screens of colored pixels. They do not create light, and as such, they require a light source. (Plasmas and the old style CRTs don't need lamps, because the phosphors that make up their screens emit light and color when zapped with electricity.)
With LCDs, the CCFL lamps are always placed directly behind the panel, which adds to the thickness.Power consumption is lower in LED TVs compared to CCFL bulb equipped LCDs, making LED sets more energy efficient.
OLED
Meanwhile, OLED really is a whole new large-screen technology. The flat panel is made up of millions of tiny LEDs. The “O” in OLED stands for “organic” which means there is carbon within the molecules of the emissive (light producing) layer of the panel. Large-screen OLED panels need no lamps -- they are self illuminating. OLED HDTVs can be thinner and lighter than the skinniest LED LCDs, and have several other advantages over LCD TVs, regardless of whether the LCD is lit by LED or CCFL.
For instance, they provide very wide and consistent color no matter where you are seated in the room. LED LCDs tend to get significantly dimmer as you move away from the center, and many exhibit color shift
CCFL
Conventional light source technology, CCFL (Cold cathode fluorescent lamp), does a good job, but has its drawbacks. It’s bulky, because it houses both lamps and a reflector. It also has a limited lifespan, and because CCFLs span the entire width of the screen, control over contrast ratio is difficult, so you’re not getting the best picture possible
LED backlighting
LED backlighting is a newer technology that delivers many benefits while conserving energy and space. Samsung’s advanced LED-lit monitors are brilliant examples of this advanced technology’s many advantages.Because LED lights are locally dimmed, you can dim certain areas of the screen while keeping other areas bright. The result is a higher contrast ratio, which creates a better picture, along with energy savings.
LED Monitors are More Environmentally Friendly
unlike CCFLs, LED-lit monitors contain no mercury, halogen or lead. That makes them safe for the environment when the time comes to recycle them.