The Cathode Ray Tube (CRT) computer monitor is now a dinosaur. As a device it has been around for almost 100 years and suddenly it is passé. Of course, we have been expecting this to happen for a long time and now, almost suddenly, it has happened. Only a few years ago a very good 19" CRT cost about $1000.00. I know because I paid that for one. Now, you can get a good 19" Liquid Crystal Display (LCD) for less than that, in fact quite a bit less. I saw one at Sam's the other day for about $600.00. Of course, you cannot directly compare the two devices. It is somewhat like comparing apples and oranges and it is likely to stay that way. The two have characteristics of their own and you will have to accept this.

One very nice thing about the LCD is that it is smaller, lighter and requires less than one-half the power of a CRT to operate. Future models will require even less power. When you add up all the CRT's in the world, and compare the power they require as opposed to that of the LCD's, you are looking at lots of oil, coal or atomic power depending on the energy source in your part of the world. Here in Pensacola it is coal. This characteristic alone makes the LCD a very valuable peripheral to have in your home.

Like the present CRT's, the currently manufactured LCD's have both imperfections and paragons. Let us examine some of the things about the LCD's that are currently available and see how one can best fit into your future. The first thing you will notice about an LCD is the brightness and clarity. The word "crisp" has been suggested as best describing the way an LCD display appears. It is much brighter than a CRT and the difference is quite noticeable. The LCD brightness comes from backlighting in the form of incandescent light. Some LCD's come in several stages of brightness which you can control. For example, you will want the textual material to be bright while colored photographs can be less so. The next thing you will notice is referred to as the viewing angle. If you look directly at the LCD, with your eyes focused at its center, you will see the display at its best. If you move to either side, or move up or down, the brightness, and even the colors, will change slightly. If you watch carefully at a moving object you will probably notice that rapid movement causes fuzziness. This relates to the response time of the transistors (pixels) which make up the LCD matrix. These things, brightness, viewing angle and response time, are important to understand before committing yourself to an LCD purchase.

To better understand how an LCD functions, let us examine how they are constructed. The actual construction is very complicated. I will give just the bare details. First, the LCD is composed of many thousands of transistors which are mounted on a thin transparent surface. Some models use glass. This is referred to as "Thin Film Technology" (TFT). Each LCD has what is known as a native resolution, a number that indicates the actual number of transistors in that particular LCD display. An LCD with a native resolution of say 1280 x 1024 will have 1280 transistors on the horizontal plane, and 1024 transistors on the vertical plane. If you multiply 1280 by 1024 you get 1,310,720.00 which is the number of transistors embedded on the thin sheet of the display. There is a light behind the display which shines through the transistors in varying amounts depending on the color selected. Each of these transistors is capable of displaying the colors red, green and blue which make up the colored displays you see. You should use the LCD at its native resolution otherwise you will cause the display to be distorted. LCD's can be driven by either analog or digital signals depending on the model. The type of driver signal relates to the graphics board in your computer. The best LCD display occurs when it is presented with a digital signal from the graphics board. In some cases, you may need to purchase another graphics board for your computer to provide the digital signal however keep in mind that not all LCD's can accept a digital signal.

Here are a few numbers and additional information that might help in the selection of your LCD. Please understand that these numbers will change in the next few years, or even months, because the LCD's are rapidly being improved. You must realize, however, that you should view the manufacturer's claims with a jaundiced eye because they may not be realistic.

Native resolution: for a 15" LCD, 1024 x 768; for a 17" LCD, 1080 x 1024; for a 19" LCD, 1280 x 1024. The refresh rate is also important. This refers to the number of times per second the face of the monitor is redrawn. Don't accept less than 75 Hz at the native resolution and try for more.

Response time: This refers to the number of milliseconds required for individual transistors (pixels) to reverse their state. The smaller time is best. Less expensive LCD's have times of about 25 ms, but try for 10 ms.

Viewing angle: Try for 170 degrees in either direction.

Color reproduction: The manufacturers claim support for 32 bit color however the display is not capable of reproducing all 16.7 million colors. This is probably not an issue with the casual observer however a graphics designer will be offended by some of the color displays.

Contrast ratio: This refers to the difference in brightness between white and black on the screen. Numbers of 350:1 are acceptable however a ratio of 500:1 or even 600:1 is desirable. The screen is usually incapable of displaying true black. This is a technical problem which you may encounter and which cannot be improved on your particular LCD. It is related to the transistors (pixels) being turned "off" thus preventing the backlighting from showing through. However, not all of the light is blocked thus producing a dark grey rather than true black.

Dead pixels: With all those transistors (usually referred to as pixels) on the face of the LCD, it is inevitable that some of them will be defective. Once a transistor (pixel) is gone it cannot be resurrected. Each manufacturer has a different scheme for returning an LCD that has a number of defective transistors (pixels). In any case, if you must return the LCD to the manufacturer for replacement you will be without a monitor for a period of time. It might be a good idea to examine the LCD manual before purchase. The various information mentioned above is likely to be available there and no where else. Also, the guarantee is important and should be investigated. Those dead pixels can become annoying. Caveat Emptor!

Speakers: Some models come equipped with loud speakers mounted just below the display. If your computer already has speakers you will be paying extra for something you will possibly never use. Also, most of the speakers are of poor quality and produce inferior sound.

PCWorld Magazine recently tested a number of 19" LCD's and recommended the Samsung SyncMaster 191T and the ViewSonic VX900 as being best buys. Let me suggest you read their story in the February 2003, issue, page 109. It includes a number of good suggestions as well as additional information about LCD's.

If you purchase a new computer in 2003 you are likely to opt for an LCD as the monitor. If you plan to replace your present CRT, by all means replace it with an LCD if you can afford to do so. The LCD's time has arrived. Expect to see them universally used during the present and upcoming years. I repeat, the CRT is a dinosaur.