Big screen TVs provide great options for home entertainment.
Although the overall size and weight of big screen sets has changed dramatically since about 2003, when thinner sets began to supplant tube-based rear projection televisions, screen sizes are in approximately the same range. Defined loosely as any TV with a screen larger than 50 diagonal inches, big screen sets are offered in plasma, LCD, DLP, and other iterations.
Plasma TV
Plasma sets operate by allowing electrical current to excite internal inert gases, such as neon and xenon, illuminating the individual phosphors. These phosphor chemicals create a bright, colorful, and engaging experience, simulating a thin version of a tube TV in terms of detail in the shadows and dark areas. Although it is possible to "burn in" (create a temporary retention of an image on the screen), this is caused primarily by lack of attention paid to the display. In most cases, it's not a permanent problem. It can be alleviated by continuing to play moving images until the issue resolves itself.
LCD TV
Liquid crystal TVs are a little more energy-efficient than plasma sets and are virtually immune to burn-in. Images are created by a back light that shines through the individual LCD cells. These color cells open and close at various intervals, blocking light to create black and other shades of gray. The processor tells each picture element (or "pixel") what color to display, and at what intensity. Most LCD TVs are a little poorer in performance if the viewer is dramatically to one side or the other. He or she will experience reduced black levels. However, LCD sets tend to have less reflection on the screen and brighter overall light output.
DLP TV
Digital light processing (DLP) televisions have effectively replaced bulky CRT (cathode ray tube) big screens in the rear-projection category of televisions. DLP technology processes images through a prism and off of a chip the size of a slide. The chip is comprised of millions of micro-mirrors that move, and each mirror represents one picture element, or pixel. Although off-axis response suffers a little due to reduced brightness, this happens only when viewing at extreme angles, and DLP still offers a bright overall image. All DLP sets currently share technology from Texas Instruments, allowing them to be sold at lower average prices than technological competitors. Because DLP sets are available in some of the largest screen sizes and offer the lowest weight per screen-inch, these big screen TVs can offer an amazing value. In fact, despite their larger overall size, DLP sets can be as much as 30 percent lighter than comparable LCD or plasma sets.
OLED Displays
Organic light emitting diodes (OLEDs) offer the potential for even slimmer displays and less power consumption than other flat panel sets. Flexible enough to create curved screens and resistant to temperature extremes, OLED sets are slimmer and brighter than their competitors. Picture elements are coated with an organic compound that reacts to electrical current. These materials are placed between layers of conductors and energized to create the image, replacing the phosphor or liquid crystal found in other flat panel technologies. Like LCD TVs, OLED sets feature individual pixels that are told what colors to display (and at what intensity) by the set's processor. OLED sets offer displays whose thickness is measured in millimeters rather than inches.
Tube or CRT Sets
CRT big screen televisions have been around since the 1970s. Mostly supplanted by DLP and other technologies by 2004, CRT sets offer great black level detail. This is beneficial because it allows the sets to more easily display accurate color--as all colors are affected by black, white, and associated shades of gray. This advantage is offset by heavy cabinets, inefficiency, and the ever-present issue of burn-in. CRT technologies in television sets require convergence (the process of aligning three guns to form one image), and the individual CRT guns must be in near-perfect alignment to generate an accurate picture. Each gun represents a primary color (red, blue, and green). These drift over time, due mainly to vibration. The CRT chassis also requires a high potential charge, needed to energize the guns. This ever-present charge creates a static field, attracting dust and other airborne contaminants, so the chassis must be cleaned periodically.
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