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2. LCD vs. CRT
3. LCD basics
4. CRT basics
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7. Warranties
8. Monitor glossary
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In a marketplace full of so many types of displays, in so many sizes, finding the right monitor can be a challenge. CNET provides some basic information to help you get your bearings.
Sizing up your screen:
What is an LCD? |
What is a CRT monitor?
What is an LCD?| LCDs, or liquid-crystal displays (also called flat panels or flat screens), are thin sandwiches of glass containing a liquid-crystal material. When exposed to electric current, the molecules of liquid-crystal material change their alignment to either transmit or block light, which ultimately creates an image. Each pixel is composed (in most cases) of red, green, and blue subpixels.
LCD monitors cost more than same-size, old-school CRTs, but they offer a few significant advantages. Here's how LCDs stack up, for better or worse. |
 |
Pros |
Cons |
| Thin and stylish | Relatively expensive |
| Energy efficient | Fragile |
| Relatively lightweight, especially in larger sizes | Limited viewing angle |
| Crisp image | Colour rendition may be limited or inconsistent |
| More display area (a 15-inch LCD is equivalent to a 17-inch CRT) | Moving images may smear |
| No refresh-rate flicker | May flicker from inability to synchronise with signal correctly |
| Little or no low-frequency electromagnetic emissions compared with a CRT | Image quality is greatly reduced when running in nonnative resolution, because the image must be scaled to match the pattern of physical pixels |
| Perfect screen geometry | |
| No convergence problems |
What is a CRT monitor?| The original CRT (cathode ray tube) technology was invented more than 100 years ago and has been greatly refined since. Inside a colour CRT, three electron guns shoot streams of electrons at the screen. A mask blocks the electrons so that the beam from one gun hits only red phosphor dots on the screen, just as the beams from the other guns only hit green or blue phosphors. By controlling the position of the beams and how fast they turn on and off, a CRT can create pixels of varying sizes, so it can produce different-resolution images with little loss of image quality.
Although they're big and boxy, CRTs are inexpensive--and indispensable for some computing tasks such as video-editing and gaming. Here's a look at the good and the bad in CRTs. |
 |
Pros |
Cons |
| Relatively inexpensive | Large and bulky |
| Rugged | Energy inefficient |
| Unlimited viewing angle | Relatively heavy, especially in larger sizes |
| Generally good colour rendition | Pixels are not clearly defined at any resolution |
| Moving images do not smear | Less display area (a 15-inch LCD is equivalent to a 17-inch CRT) |
| No flicker from problems with synchronising with a signal | Refresh-rate flicker is below 75Hz; flicker is more severe with larger monitors |
| Can display different-resolution images with relatively little loss of quality | More low-frequency electromagnetic emissions than LCDs |
| Nearly impossible to get perfect screen geometry, especially with flat-faced CRT designs | |
| Almost impossible to get perfect convergence of red, green, and blue beams on all parts of the screen |
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| Apple iPhone 3GS 32GB | 33 plans |  6% |
| Apple iPhone 3GS 16GB | 33 plans |  2% |
| Nokia N97 | 37 plans | 1% |
| Apple iPhone 8GB | 33 plans | 1% |
| Nokia E63 | 33 plans | 1% |
| Apple mobile phones | 3% |
| Nokia mobile phones | 1% |
| Samsung mobile phones | 1% |
| Sony Ericsson mobile phones | 1% |
| LG mobile phones | 1% |
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