What else should I look for when buying a television?
In addition to energy performance, there are many other important operating and convenience features to consider when shopping for televisions
Plasma, LCD, and Flat-Screen Displays
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?
- Plasma TVs
are known as “emissive” displays because the panel is actually self-lighting. Basically, the gas (plasma) causes the pixels to glow, which creates the TV image.
are known as “transmissive” displays because the light isn’t created by the liquid crystals themselves. Instead, a light source (bulb) behind the panel shines light through the display.
- Flat Screen Display
strictly refers to the flat surface of the TV screen. It does not necessarily refer to plasma TVs or thin, flat-paneled LCDs. Flat-screen CRT sets are available and are usually less expensive than other flat-screens such as plasma and LCDs, but tend to be more expensive than conventional CRT models. Flat-screen CRT TVs have reduced glare, but not necessarily the enhanced picture of a plasma or LCD display.
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.”
Purchase an appropriately sized refrigerator.
Generally, the larger the refrigerator, the greater the energy consumption. The most energy-efficient models are typically 16–20 cubic feet.
What is progressive scan?
- Standard Digital TV (SDTV)
- has 480 horizontal and 640 vertical lines, and will offer better picture quality and sound quality than a standard analog TV.
- High-Definition TV (HDTV)
- has at least 720p or 1080i horizontal scan lines (p for progressive scan and i for interlaced scan) and 1280p or 1920i vertical scan lines. HDTV sets have approximately six times the number of pixels as a standard CRT set. The pixels used for HDTV are also smaller than those of CRTs. The combination of more and smaller pixels means a TV capable of a much sharper picture.
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.
What’s a pixel?
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.
Other Television Features
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.
Picture In Picture (PIP)
The PIP feature allows you to simultaneously watch two TV programs on the same screen.
- A single-tuner PIP
-requires an alternate device with a tuner (e.g., a VCR or cable box) to display two programs.
- Dual-tuner PIP
includes a second tuner so that no outside source is needed to generate the second picture.
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.