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TV Technology Decoded: Your Guide to TV Specs and Terminology

June 27, 2013 | Comments

TVs were pretty much the same for well over half a century: a bulky box with a picture tube in it. Then along came digital television and high-definition broadcasting, which led us into the millennial Age of Flat-Panel TV.

As screen sizes get bigger, the TVs themselves are getting thinner and come packed with more features than ever before. If a new TV is in your future, here are a few things to keep in mind.

Motorized TV lift in cabinet

Len Wallis Audio
, Lane Cove, NSW, Australia

The Technology

Today's HDTVs use LCD or plasma display technology to create an image made up of thousands of tiny pixels.

LCD and plasma TVs might look the same on the outside, but they are very different on the inside. An LCD TV employs electrically charged liquid crystals, polarizing glass, switching transistors, and a fluorescent or LED backlight to create an image. In a plasma TV, there is no backlight. Electric current applied to red, green and blue phosphors in each of the tiny gas-filled pixels causes the phosphors to glow, which collectively form the visual image.

While both technologies are capable of producing an excellent picture, there are differences.

LED

An "LED TV" is a type of LCD TV that uses LED (light emitting diode) backlighting instead of a fluorescent light source. LED-based TVs are brighter than regular LCD sets and differ in terms of how the LEDs are configured.

The best LED sets have "full-array" backlighting with "local dimming" instead of the more common "edge-lit" approach where LEDs are arranged along the edge of the LCD panel (instead of behind the entire panel). "Local dimming" means individual zones of LEDs can be dimmed or brightened independently.

LCD (Liquid Crystal Display)

LCD is by far the most common type of TV today. LCD TVs produce brighter picture than plasma TVs, making them an ideal choice for sun-drenched rooms. On the other hand, LCDs tend to have a narrower viewing angle, meaning the image fades somewhat as you move to the side. Finally, LCD TVs consume less energy than plasma sets, with LED-based LCD TVs being the most energy-efficient TV available.

Plasma

Plasma has long been a favorite of home theater enthusiasts and can still deliver a better picture than LCD, especially in terms of a set's ability to produce deep black. Plasmas also tend to have better contrast, which can make the picture seem more realistic. Still, a few high-end LCD TVs - those with "full-array" LED backlighting and "local dimming" - can match plasma performance in these areas.

Plasma has a reputation for being susceptible to "burn in," where stationary images like station IDs linger as faint ghosts after the TV is turned off. The effect is temporary and nothing to worry about - unless the TV is left on for days with bright, static images on its screen.

Specs that Matter

Manufacturers tend to bombard TV shoppers with a dizzying array of buzz words and specifications. The bottom line: Technical specs like "refresh rate," "contrast ratio" and "viewing angle" don't really tell you much about picture quality in and of themselves. You'll get a much better idea of how a particular TV model performs by reading reviews and using your own eyes.

Spec sheets do, however, provide useful information about inputs and outputs, dimensions, weight (important for wall mounting) and features such 3D capability and Internet connectivity.

Ultimately, you want a TV to provide an engaging experience, which is another way of saying bigger is better. Movies will be far more engrossing on a 55-inch TV than a 32-inch screen. Go as big as you can.

To learn more about TV and creative installation options, consult a CEDIA professional. Click here for a list of CEDIA-member home technology professionals in your area.