LCD vs. CRT

Which Monitor is the Best to Buy?

Introduction

PC computer displays have reached a turning point. Over the last two years, LCD monitors have begun to replace the traditional CRT monitors. LCDs are priced much higher than comparable CRT monitors, but this is changing as production of LCDs increase and the costs to producing them goes down. So which type of monitor should one get? This article will discuss the pros and cons of each type of monitor in the hopes of clarifying which type is best suited for you.

Cathode Ray Tube or CRT

Most people are familiar with the general functioning of a television set. A television tube consists of a large vacuum tube with an electron beam inside of it. This beam is constantly scanning across the front of the tube containing phosphorus, exciting the particles and producing the light.

The first and foremost advantage is cost. Dollar for dollar, it is possible to get a larger and better display buying a CRT monitor when compared to an LCD screen. This primarily comes from the fact that CRT monitors have been developed over the last 20 years of computing and as such the manufacturers have already paid for most of the development and manufacturing costs.

CRTs also have multisync capability. This allows the electron gun inside the tube to adjust itself to various resolutions and refresh rates. This is very desirable if you have any need to display multiple resolutions. Games are a common area where multiple resolutions are useful. New games that may tax your computer at higher resolutions can be scaled down to lower resolutions.

The high refresh rates and response times of CRT monitors also makes them ideal for video purposes. Since the tubes are based on the same technology that is used in television sets, it makes sense that the video display of a monitor is better able to reproduce the fluid motion of video playback on the CRT.

Finally, the color clarity of CRT monitors cannot be matched by an LCD screen. With the myriad of adjustments that can be made to the contrast, brightness and hues, CRT monitors are better able to represent actual document colors. This is extremely important for individuals who work in either print or graphics industries. Having an accurate reproduction of the color of a document on the screen when it is printed can save a huge amount of hassle when it comes time to have documents published.

Of course, all these advantages do have their drawbacks as well. The biggest drawback to CRT monitors is their bulkiness. The tubes within the CRT monitors are extremely heavy. This is primarily necessary for safety reasons. The tube is a vacuum and if it were to crack, the monitor tube would implode. The tubes also draw a large amount of power. Some larger CRT monitors now can actually draw more current than the computer they are attached to. The visible area of the tube is also smaller than the actual tube size. When a company markets a 19" CRT monitor, the actual visible area of the screen will be about 1 inch less than the tube's full size due to the cabinet surrounding the tube.

Pros:

• Inexpensive
• Multisync Capable
• High Refresh Rates
• Color Clarity and Depth

Cons:

• Large Footprint on Desktop
• Very Heavy
• Use Large Amounts of Energy
• Generate Excess Heat

Liquid Crystal Display

LCDs have been around for many years in the portable computing market but they are fairly new to desktops. A liquid crystal display functions based upon the characteristics of crystals when electricity is applied to them. A matrix of these crystals forms up the film of the display which can have the colors turned on or off by the application of a current. A backlight behind the film them illuminates the film so that it is visible in any lighting condition.

The biggest advantage to LCD monitors is their size and weight. Most LCDs sold on the market range from about 1 to 3 inches in thickness compare to CRT monitors that can be as much as 24 inches.

LCD screens also tend to produce less eye fatigue to the user. The constant light barrage and scan lines of a CRT Tube tend to cause strain on heavy computer users. The lower intensity of the LCD monitors coupled with their constant screen display of pixels either being on or off produces less fatigue for the user.

Finally, LCD monitors are much more energy efficient compared to a CRT monitor. Most of the energy used by LCD displays is for the backlighting of the LCD screen. The amount of voltage required to maintain the state of the various pixels as on or off is negligible when compared to that of the backlighting. CRT displays on the other hand use vast amounts of power to keep the electron beam constantly streaming across the screen.

Since LCD technology is much newer compared to CRT technology, it is much more expensive to produce LCD monitors. This is a big drawback when a 19" CRT monitor can be purchased for roughly half the cost of a 17" LCD monitor even though they have the same rough visible screen area. Over time as the manufacturers improve their techniques of manufacturing LCDs and the demand for them grows, the costs will begin to come down.

The second disadvantage to LCD screens is their fixed or native resolution. An LCD screen can only display the number of pixels in its matrix and no more. It can display a lower resolution in one of two ways. Using only a fraction of the total pixels on the display or through interpolation. Interpolation is a method whereby the monitor blends multiple pixels together to simulate a single smaller pixel. This can often lead to a blurry or fuzzy image particularly with text when running the screen below is native resolution.

Finally, the technology behind the LCD screens can cause a ghosting of moving images on a screen against a dark background. This is caused from the fact that while changing the state of the crystals from off to on is fast, the speed at which it can be turned off is about four times slower or more. This tends to leave slight after images on the display while the pixel is being turned from on to off. This can be noticed most in video playback or games where bright objects are moving against a dark background.

Pros:

• Takes up Little Space on Desktop
• Light Weight
• Energy Efficient
• Causing Less Eye Fatigue

Cons:

• Expensive
• Blurry Images Outside Native Resolution
• Motion Blur on Fast Moving Images
• Washed Out Colors

Conclusions

So which is the better type of monitor to buy? It all comes down to how one will be using the monitor with their computer systems. CRTs are best suited for individuals who use it for desktop publishing, graphics development, gaming (and don't need portability) or are on a tight budget for buying a computer. LCDs are best suited for those individuals who use the computer heavily for word processing, programming or have limited desk space for the computer. As the technology improves with LCDs and the cost comes down more, LCDs will dominate the market and CRTs will remain for those who require them for specific professions. Just remember that monitors tend to outlive the functional lifetime of a computer system and can easily be used between systems, so it is best not to skimp too much when buying a display.