Flat-Panel vs. CRT Monitors


This article was published by ComputorEdge, issue #2228, 2004-07-09, as the cover article, in both their print edition (on pages 14 and 16) and their website.

Ever since the inception of personal computing, display monitors based upon cathode rate tube (CRT) technology have been the primary choice for displaying a computer's output. There have been some exceptions — such as Braille devices, and synthesized speech, for the visually challenged — but for most computer users, CRT monitors have been the only choice available.

This is not to say that CRTs have been a favorite for most users. Rather, these large, heavy, desk-consuming, and electricity-slurping "tubes" are the only effective alternative. In a sense, this is similar to the voting ballots previously used in the former communist countries, which allowed people to "choose" between voting for the single candidate on the ballot, invariably the incumbent, or not voting at all, and facing the consequences. Choice is good; but in the world of computer monitors, choice has been but a distant dream to those of us comprising the PC proletariat.

Yet all of that has been changing during the past few years, as flat-panel monitors have become widely available, and in little time, have also become the favorite of the millions of computer users who can afford them. But before we examine the reasons as to why flat-panel monitors have so rapidly overtaken their heftier competitors, we will briefly explore the underlying science that makes it all possible.

Colorful Crystals

Flat-panel monitors utilize an elegant and remarkable technology, liquid crystal display (LCD). Even though LCD products are only recently becoming widespread in use, their origins date back to the late 19th century. In 1888, the Austrian botanist Friedrich Reinitzer discovered substances that were later named "liquid crystals" by a German physicist, Otto Lehmann. These substances are neither solid nor liquid, but exhibit the properties of both forms. In particular, light passing through the almost transparent material follows the alignment of the molecules (a property of solids).

It was not until the mid-1960s that researchers were able to demonstrate that electrically charging the liquid crystals changes their molecular alignment (a property of liquids), and thus the way light passes through them, namely, the light's color. In the late 1960s, LCD display prototypes were tested, but the materials used for the liquid crystals were not stable enough for mass production. All of that changed when a British research team, led by Professor Cyril Hilsum, proposed the use of biphenyl, a stable, liquid crystal material. It has since become the world standard for creating LCDs.

Pros and Cons

Back when CRTs were the only display "choice" available for personal computer users, anyone lugging one of those 50-pound, 19-inch behemoths up a flight of stairs may have paused and, while gasping for breath, wondered why a better alternative had not yet been invented. Though flat-panel monitors certainly have some downsides, CRT monitors have far more disadvantages, and none of them trivial.

Some of the most critical problems with CRT monitors are noticeable even before powering up the units. Like a conventional television, a CRT monitor is primarily composed of a vacuum tube, which requires a minimum amount of metal and glass, neither of which are light. In fact, a CRT can be much heavier than the computer system itself, especially for the 19- and 21-inch models preferred by graphics designers and serious gamers.

Secondly, a CRT requires a minimum depth (from the display glass in front to the electron "gun" in back), which in turn can require a tremendous amount of desk space. The larger the monitor's display dimensions, the larger the tube, and the more "real estate" consumed. For home PC users with small desks, this can be a serious disadvantage, as the desk must be pulled away from the wall just to allow the keyboard to be located in front of the monitor.

Once a CRT monitor has been powered up, it can eventually make its presence known in an unexpected way — your electric bill. Even a small 15-inch CRT can consume 180 watts, while a flat-panel monitor will use about one-quarter to one-third of that amount, depending upon whether it is a passive matrix LCD (PMLCD) or an active matrix LCD (AMLCD).

But even before that higher electric bill arrives, you will see that a CRT monitor can be prone to annoying color variations across the screen, as well as incorrect focusing of the image. While flat-panel monitors — especially the earlier models — can be prone to "ghosting", their displays tend to be more crisp and their colors more consistent. Many users have found that flat-panel displays are easier on the eyes, particularly as a result of the image stability, as opposed to the "wavering" seen on some CRTs.

Another disadvantage of CRT monitors is that their high-voltage electrical circuits and strong magnetic fields, create electromagnetic radiation, whose long-term dangers are not fully known. For many people — especially for those who spend the bulk of their time working on computers — the uncertainty as to the potential health problems, is reason enough to minimize time on the computer, or find an alternative display, regardless of increased financial cost.

Pre-Shopping Research

In only a few years, flat-panel monitors have decisively and permanently replaced CRT monitors as the display of choice. Not only is this a logical result of their advantages greatly outweighing those of CRTs, but also a consequence of flat-panel monitor prices dropping as manufacturers improve the production processes and costs of materials. As with any replacing technology, there was a tipping point at which flat-panel monitors, despite still costing more than CRTs, had fallen in price to make the difference worthwhile. When 15-inch flat panels dropped to a few hundred dollars (after starting at double that), many consumers took the plunge.

As you begin researching available flat-panel monitors, be sure to read at least several current reviews of available models. These product reviews can be found in computer magazines (such as PC World and PC Magazine), and the websites of those magazines, as well as hardware-specific sites, such as Tom's Hardware Guide and HardwareCentral. Also talk with computer-savvy friends, and technicians at trusted local computer shops, to get their input.

Consider Recycling, not Trashing (CRT)

If you have an unneeded CRT monitor, possibly as a result of upgrading to flat-panel technology, then it would be wise to sell it or donate it to a charitable organization or a local school. Or you could bring the monitor to a recycling center, so the CRT's environmentally unfriendly components do not end up in a landfill. Whatever you do, do not toss that metal and glass dinosaur into the trash, for doing so is not only wasteful, but can be illegal. Even though you may be able to happily trade up to a flat-panel monitor, not everyone has that option — and somewhere, someone could put that old monitor to new use.

Copyright © 2004 Michael J. Ross. All rights reserved.

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