What Is Difference Between LCD & LED TV?
The HDTV market is becoming ever saturated, with HD projectors, plasma, LCD and LED TVs lining the shelves of electronics stores. This helps consumers, because more products on the shelves means more competition and, ultimately, lower prices, but the terms surrounding TVs can get a bit confusing. There's a few things you need to know about LCD and an LED TVs before making your choice.
LCD and LED
LCD TV gets its name from the liquid-crystal diodes that create the picture. Traditionally, LCD TVs used cathode fluorescent lamps behind the screen to light the image. This light is called the backlight, and its brightness controls the brightness of the LCD screen. LED stands for "light emitting diode," and LED is a replacement for CFL -- not LCD. In fact, LED TVs are LCD TVs with a different kind of backlight. The distinction is important for two reasons: LED TVs are, as of May 2011, more expensive than standard LCD TVs; and LED picture quality is usually better than standard LCD TVs with a CFL backlight.
In the early days of HDTV, LCD TVs competed with plasma-screen TVs. This latter group was hailed for its true black levels, something that was impossible on an early LCD screens because of the backlighting technology. LED technology corrects this by controlling which parts of the screen are lit up at certain times, leaving the black parts of images black by simply not shining as much light through the screen. One advantage of LED LCD TVs over standard LCD TVs is this true black display, which results in better viewing.
Local Dimming vs Edge Lit
Even within the LED TV subset, slight technological differences exist that affect picture quality. Some LCD TVs use LED edge lighting (a series of LED lights around the outside of the picture) while other LED sets use local dimming (LED lights spread evenly behind the picture). According to LCD TV Buying Guide, local dimming LED TVs have superior contrast and color, but edge-lit LED TVs are much thinner.
The Price Gap
Prices vary across the HDTV market, but LCD TVs that use LED lighting tend to be more expensive than their CFL-lit counterparts. As with most HDTVs, you can expect to pay more for a larger screen than a smaller one. Prices jump once you start looking at sets above 42 inches, but -- again -- this depends on the brand and retailer. CNET Asia expects the prices of LED-lit LCD TVs to level out as the TVs become more mainstream, but for LED TVs to always command a slight premium over CFL-lit LCDs.