In addition to energy performance, there are other important operating and convenience features to consider when shopping for TVs.
ENERGY STAR does not endorse any of the features, but provides this information to help you select the best product for your individual needs.
Both plasma and LCD (Liquid Crystal Display) use different picture-generating technologies than the standard CRT, making them lightweight and super-thin in comparison. However, the term “flat screen” can be confusing because CRTs can also have flat screens.
Comparing TV pictures? Compare contrast ratios. Contrast ratio is a measure of color representation (how the color information appears against a dark background). The higher the number, the better the color representation.
Digital signals can transmit more information than analog signals. They can then be translated into more scan lines on your TV screen, which, in turn, create a higher-resolution picture. Digital televisions display a higher-resolution picture than most analog TVs and can take advantage of the picture improvements offered by progressive scan DVD players.
Digital televisions come in two subgroups, which are differentiated by sharpness of picture, usually described as “lines of resolution.”
There are two ways that a TV picture can update itself to display moving images. One way is by using an interlaced signal and the second is by using a progressive scan signal. An interlaced signal, which is the method used by the standard analog screen, updates half of the scan lines (i.e. every other scan line) every 60th of a second. A progressive scan signal updates all of the scan lines every 60th of a second. So progressive scan technology creates a picture having a noticeably sharper image and less flicker.
The term “pixel” is shorthand for “picture element”. A pixel is the smallest item of information displayed on a television screen. Think of pixels as the tiniest dots that the picture is made of.
Older model projection TVs use three small CRTs (one each for red, green and blue) that project an image onto the back of the screen. CRT models produce pictures that look best when viewed straight on, from a seated position, but the picture looks dimmer if you’re viewing from the side or standing up. However, models are now available in HDTV and LCD, which are thinner and have improved picture visibility.
Widescreen TVs have a larger aspect ratio than the standard TV. The aspect ratio refers to the relationship between the width of the picture and its height. The television industry uses 4:3 for most programming. In the 1950s, the film industry moved to a larger aspect ratio-16:9 (they wanted to offer something more than TV to get people out of their homes and into theaters). Widescreen TVs reflect the larger aspect ratio of the film industry. Some TV programs are now being broadcast in 16:9.
If you’re a movie buff, you might consider a widescreen TV. It allows for better DVD viewing because it displays the picture in its original format.
The PIP feature allows you to simultaneously watch two TV programs on the same screen.
ENERGY STAR has just added energy-efficiency guidelines for digital cable ready (DCR) televisions with a point of deployment (POD) slot. Basically, these TVs add the functions of a cable box to your television set by using a card that you can get from your local cable operator. ENERGY STAR qualified versions of these TVs are not yet available, but look for them in the future.
The biggest benefit these TVs offer is that you’ll be able to get rid of your cable box. And, you’ll be able to take your cable capabilities with you when you move — all you’ll need is a new card from your new local cable operator.