Monitors

When shopping for a new computer system, we tend to fret over such things as the CPU speed or hard disk size, but what about the one component of your system that is used just as much? Of course we're talking about the monitor. Often referred to as a display screen, a video display terminal (VDT) or visual display unit (VDU), the monitor is the component of your computer system that displays the messages and data being processed and utilized by the computer's CPU.

The two types of monitor technologies available to consumers are available in CRT monitors and LCD monitors. There are big differences between LCD and CRT, and while LCD technology has advanced to the point where its viewing quality is comparable to CRTs, many people today still choose to purchase a CRT monitor. CRTs are bigger and bulkier than an LCD, they consume more power and are prone to screen flicker. LCD monitors, however, are more expensive when compared to CRTs, they introduce the problem of viewing angles, and generally have less accurate color replication.

Each type of monitor, as you can see, has its advantages and disadvantage. In this article we will provide a comparison of CRT and LCD monitors, along with defining some of the many specifications and terminology you should be aware as you decide between an LCD and CRT monitor.

CRT Monitors

Short for cathode-ray tubes, CRT monitors were the only choice consumers had for monitor technology for many years. Cathode ray tube (CRT) technology has been in use for more than 100 years, and is found in most televisions and computer monitors. A CRT works by moving an electron beam back and forth across the back of the screen. Each time the beam makes a pass across the screen, it lights up phosphor dots on the inside of the glass tube, thereby illuminating the active portions of the screen. By drawing many such lines from the top to the bottom of the screen, it creates an entire screen of images.

LCD/Flat panel Monitors

Short for liquid crystal display, LCD technology can be found in digital watches and computer monitors. LCD displays use two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light. Color LCD displays use two basic techniques for producing color: Passive matrix is the less expensive of the two technologies. The other technology, called thin film transistor (TFT) or active-matrix, produces color images that are as sharp as traditional CRT displays, but the technology is expensive.

CRT vs. LCD - The Pros and Cons of Each

A CRT monitor can be viewed from almost any angle, but with an LCD this is often a problem. When you use an LCD, your view changes as you move different angles and distances away from the monitor. At some odd angles, you may notice the picture fade, and possibly look as if it will disappear from view.

Refresh Rate

Some users of a CRT may notice a bit of an annoying flicker, which is an inherent trait based on a CRTs physical components. Today's graphics cards, however, can provide a high refresh rate signal to the CRT to get rid of this otherwise annoying problem. LCDs are flicker-free and as such the refresh rate isn't an important issue with LCDs.

Dot Pitch

Dot pitch refers to the space between the pixels that make up the images on your screen, and is measured in millimeters. The less space between pixels, the better the image quality. On either type of monitor, smaller dot pitch is better and you're going to want to look at something in the 0.26 mm dot pitch or smaller range.

Screen (viewable) Size

Most people today tend to look at a 17-inch CRT or bigger monitor. When you purchase a 17-inch CRT monitor, you usually get 16.1 inches or a bit more of actual viewing area, depending on the brand and manufacturer of a specific CRT. The difference between the "monitor size" and the "view area" is due to the large bulky frame of a CRT. If you purchase a 17" LCD monitor, you actually get a full 17" viewable area, or very close to a 17".

Physical Size

There is no denying that an LCD wins in terms of its physical size and the space it needs. CRT monitors are big, bulky and heavy. They are not a good choice if you're working with limited desk space, or need to move the monitor around between computers. An LCD on the other hand is small, compact and lightweight. LCDs are thin, take up far less space and are easy to move around. An average 17-inch CRT monitor could be upwards of 40 pounds, while a 17-inch LCD would weigh in at around 15 pounds (or less).

Price

LCD monitors have come down a lot in price. Throughout a lifetime, LCDs are cheaper as they are known to have a longer lifespan and also a lower power consumption. The cost of both technologies have come down over the past few years, and LCDs are reaching a point where smaller monitors are within many consumers' price range. You will pay more for a 17" LCD compared to a 17" CRT, but since the CRT's actual viewing size is smaller, it does bring the question of price back into proportion.

Resolution

Coupled with the computer's graphics card, a CRT monitor can produce a sharp image in more than one resolution. For example, a CRT monitor may be capable of a maximum resolution of 1,280 x 1,024 pixels, but to enlarge the type and images on the screen, the user can change the resolution to 800 x 600 pixels without losing sharpness. An LCD monitor is preset at a maximum native resolution, say 1,280 x 1,024, but when the user switches to 800 x 600 pixels or any other lower resolution, the images are no longer sharp.

How to Make the Best Choice

Choose the smallest monitor that will meet your needs

The bigger the CRT monitor, the more energy it uses. For example, a 17-inch monitor consumes 35 percent more electricity than a 14-inch monitor.

LCD and CRT monitors are available in the same sizes, but buyers should be aware that monitor measurements are different between the two types. For example, a 13.5-inch LCD monitor has the same size viewing area as a 15-inch CRT monitor. See Table 3 for more comparisons.

Once you've made your choice, you can save even more energy with the following strategies:

Practice wise power management. Did you know that when your screen-saver is running, the monitor is not "sleeping" but using the same amount of electricity as if you were working away on a spreadsheet or your resume? To save energy while your computer is idle, make sure that your monitor's power-management settings are enabled.

Turn monitors off at night, on weekends, and anytime they are not being used for extended periods of time.

Shorten the delay time before your monitor automatically powers-down into sleep mode.

For older monitors without built-in power management systems, install external control devices that can shut a monitor off after a preset delay.