A rear projection television (RPTV) refers to one in which the images are projected from within the unit, specifically behind the display screen, as opposed to front-projection systems, which entail a projector in front of and separate from the screen.
In the 1980s, rear projection televisions were the
biggest screens you could find in homes. Flat liquid crystal display (LCD) and plasma panels have since surpassed RPTVs in the thinness stakes, but they are stillthe more cost-effective and energy-efficient alternative. Moreover, rear projection TVsare known for the smoothness of their images. Meanwhile, flatLCD and plasma panels tend to show a latticework of pixilation, especially if the broadcast signal and the set’s native resolution is a mismatch.
Types of RPTVsRPTV is an umbrella term that encompasses four kinds of technology: LCD and Digital Light Processing (DLP), the same machinery behind today’s high-definition TVs; Cathode Ray Tube (CRT); and Liquid Crystal on Silicon (LCoS).
CRT has been around the longest, and it stands to reason that RPTVs employing this technology are characteristically colossal. An RPTV has a troika of CRTs—red, green and blue—that guns a ray of electrons in various intensities, reproducing colours in the visible spectrum.
A better image can be had with LCD RPTVs,or the kind in which a white lamp backlights a panel of liquid crystals sandwiched by electric currents. DLP RPTVs also rely on a white lamp, except that it uses a
Digital Micromirror Device (DMD chip), encased in minute mirrors, rather than a translucent LCD chip.
A newer variety of RPTVs use both liquid crystals and DMD chips: LCoS sets. The results are a superlative contrast ratio; minimalrainbow effect; and 1080p clarity. Unfortunately, manufacturers have discontinued this line of RPTVs.
Replacing lampsAt some point, the
lamp in a rear projection TV would have to burn out. This ‘life expectancy’ varies from one kind of TV to another.Some lamp manufacturers claim long lives of up to 8,000 hours; others are more modest at 1,000 hours. The average lamp is replaced every one to two years, but generally, there really is no telling when a lamp would exhaust itself, despite the best guidelinesof manufacturers.
To be sure, watch out for dimming; decline in picture quality; and areas of darkness on the screen. These do not mean you should immediately switch lamps, but you wouldn’t want to wait until the compromised brightness strains your eyesight either.
Lamp replacement prices differ among manufacturers. Be assured, however, that rear projection TV lamps are more affordable than the light sources of flat panel LCDs.
You can do the replacement or reinstallation yourself, but the services of a professional are recommended in most cases. He or she will determine the right type of bulb or lamp assembly for your rear projection TV.
Also, it makes good sense to invest in extra bulbs to reduce downtime from a burnt out lamp. This is especially true if the set has passed into obsolescence.
ConclusionOwnership of an RPTV requires a basic knowledge of how the set operates and its components: It requires forethought and sensibility to lamp life. This way, you can anticipate what kind of lamp goes into your RPTV should it call for a replacement.
If you plan to buy an RPTV, compare manufacturers’ offerings fiendishly. Also, remind yourself that this kind of TV is receding into history, as manufacturers are favouring flat screens and LED-based models. However, don’t let constant watchfulness suck the fun out of owning an RPTV. Just sit back, relax, and enjoy the smoothness and clarity of moving pictures as only an RPTV can give.
