With so many options available for your viewing pleasure, selecting and comparing TVs can be a difficult and demanding process. Do you go with Plasma or LCD? Standard picture or HD? Keep this quick overview in your back pocket when comparing types of televisions at the store.
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 by comparison. However, the term “flat screen” can be confusing as CRTs can also have flat monitor screens.
- Plasma TVs are known as “emissive” displays because the panel is actually self-lighting. Basically, the gas (plasma) causes the pixels to glow, creating the television image.
- LCDs are known as “transmissive” displays since the light isn’t created by the liquid crystals themselves. Instead, a light source behind the panel shines through the display.
- Flat Screen Display strictly refers to the flat surface of a TV screen. It does not necessarily refer to plasma TVs or flat-paneled LCDs. Flat-screen CRT sets are available and usually less expensive than other flat-screen models. They are, however, usually more expensive than conventional CRT models – an important distinction to make when comparing types of televisions. Flat-screen CRT TVs have reduced glare but lack the enhanced picture of a plasma or LCD display.
- Compare contrast ratios are the gold standard in comparing TV pictures. Contrast ratio measures the representation of color information appears against a dark background on a monitor. The higher the number, the better the color representation.
Digital Televisions
Digital signals can transmit more information than analog signals and have become the standard method of television transmission. 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 higher quality DVD players. Digital televisions come in two subgroups differentiated by sharpness of picture, or “lines of resolution.” The hardest decision you may face in selecting and comparing TVs is whether or not to spring for High-Definition or stick with Standard Digital:
- 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.
Source: ENERGY STAR
