comparison of crt and lcd monitors factory

CRT stands for Cathode Ray Tube and LCD stands for Liquid Crystal Display area unit the kinds of display devices wherever CRT is employed as standard display devices whereas LCD is more modern technology. These area unit primarily differentiated supported the fabric they’re made from and dealing mechanism, however, each area unit alleged to perform identical perform of providing a visible variety of electronic media. Here, the crucial operational distinction is that the CRT integrates the 2 processes lightweight generation and lightweight modulation and it’s additionally managed by one set of elements. Conversely, the LCD isolates the 2 processes kind one another that’s lightweight generation and modulation.

Responsible for performing installations and repairs (motors, starters, fuses, electrical power to machine etc.) for industrial equipment and machines in order to support the achievement of Nelson-Miller’s business goals and objectives:

• Perform highly diversified duties to install and maintain electrical apparatus on production machines and any other facility equipment (Screen Print, Punch Press, Steel Rule Die, Automated Machines, Turret, Laser Cutting Machines, etc.).

• Provide electrical emergency/unscheduled diagnostics, repairs of production equipment during production and performs scheduled electrical maintenance repairs of production equipment during machine service.

Almost all of us have watched television at some point in our lives. And, most of us have a general understanding of how television works – images and videos are displayed on a screen by shooting electrons at it, which makes the pixels light up and create the image. However, there is a lot more to the process than just that. In order to create an image, television screens need to be able to control the number of pixels that are lit up and the intensity of the light. There are two main ways that this is done – using cathode ray tube (CRT) screens or liquid crystal display (LCD) screens.

CRT is an analog type display that was popular two decades ago, while LCD is a digital type display and is considered as the successor of CRT monitors. But LCDs are not superior in every aspect with CRT monitors.

A decade ago, CRT, or Cathode Ray Tube, was a commonly used analog display technology. It works by projecting electrons onto a phosphor screen. When an electron beam hits the screen, the phosphor lights up, creating a colorful image.

CRT technology was used in a variety of devices, from televisions to computer monitors. It was also used in early video game consoles, like the Atari 2600. While CRT technology is no longer used in today’s devices, it was an important stepping stone in the development of modern display technology.

A CRT display has a vacuumed tube (a tube with no air in it). Plus, it also has an electrode in the back of the vacuum tube that releases electrons. Because it emits positively charged particles, it is referred to as the cathode gun (Because electrons are negatively charged, we know that they’re negatively charged particles). And the electron gun is made up of an array of components which include the heater filament (heater) and the cathode.

Screens are coated in phosphor that glows according to the strength of the beam. When the cathode gun is activated and electrons are fired into the screen, the beam of electrons goes towards various areas of the screen. Then, line by line, the deflection takes place by covering the whole screen.

The brightness of the beam is responsible for the brightness of the image. If your image is much brighter, the electron gun fires a strong electron beam. And if your image is a dark one, the electron gun fires a weak electron beam.

There are both black and white CRT displays and Color CRT displays. Moreover, black and white CRT displays use a phosphor to emit light, while color CRT displays use three phosphors to emit red, green, and blue light. The human eye perceives these three colors when the brain combines the light from the three phosphors.

LCD, Liquid Crystal Display is a digital display technology made of liquid crystals that function by blocking the light. If you have an LCD screen, then you may have noticed that the image on the screen is made up of tiny dots of color. These dots are called pixels, and each pixel is made up of three smaller dots of color. One dot is red, one dot is green, and one dot is blue. Together, these three colors make up the colors that you see on the screen.

An LCD display is composed of two pieces made of polarized glasses that have the liquid crystal substance between the two. And there is a backlight which is important because, without the backlight, we can’t see the image.

The two main types of display technologies used in monitors today are CRT and LCD. CRT uses analog technology while LCD uses digital technology to display the image. Both have their pros and cons, but LCD is the more popular technology today.

When we think of older technology, we often think of big, bulky CRT monitors with a 4:3 display ratio. So, this was the most popular ratio two decades ago, and because of that, most CRT displays were made with a 4:3 aspect ratio. However, it’s not only CRT monitors that had this ratio. Back in the day, even LCD monitors came in a 4:3 ratio. Now, most LCD displays come in a 16:9 ratio, which is known as widescreen displays.

Why did the 4:3 display ratio become so popular? Well, back in the day, most computer users were using their computers for work-related tasks. Word processing, spreadsheet work, and other business applications were the norm. Therefore, the 4:3 ratio was well-suited for these types of applications.

However, as time went on and computer usage became more diversified, the need for a wider display became more apparent. This is especially true for media-related tasks such as watching movies and playing video games. The 16:9 widescreen ratio is much better suited for these types of activities.

The costs of manufacturing CRT and LCD displays used to be quite similar. However, the cost of manufacturing LCD displays has fallen significantly in recent years, making them more affordable than ever before. Thanks to advancements in technology, LCD panels can now be produced more cheaply than CRTs, making them the preferred choice for many consumers.

CRT monitors are typically much larger and heavier than their LCD counterparts. This is due to the fact that CRT monitors use a cathode ray tube to produce the image on the screen. This tube takes up a lot of space, which results in a larger overall footprint for the monitor. Additionally, the heavy glass casing of a CRT monitor can add a lot of weight.

LCDs, on the other hand, are much thinner and lighter, and even there are many display size selections. Moreover, LCD display-to-body ratio is increasing every year.

When it comes to power consumption, CRT displays consume more power compared to LCD monitors. In CRT monitors, there has to be a heated filament so electrons can flow off of the cathode. In order to maintain the heated filament, the CRT monitor requires a high voltage power supply. In addition, the CRT monitor has a yoke coil that needs the power to move the electron beam back and forth on the screen. When the CRT is turned on, it uses a small amount of power to keep the cathode warm.

One of the benefits of LCD monitors is that they are more energy efficient than CRT monitors. LCD monitors do not have a heated filament or yoke coil, so they do not require a high voltage power supply.

LCD displays offer many advantages over CRTs, including lower power consumption, thinner form factors, and sharper images. Thanks to their lower manufacturing cost, LCDs are now the preferred choice for many manufacturers.

As of July 2021, CRT monitors are no longer in production. Even if you managed to get a used CRT monitor, there is a issue of connecting it to your system as newer PCs/notebooks come equipped only with HDMI and/or DisplayPort display ports. However, this can be worked around using HDMI to VGA adapters.

The viewable area is about 0.9 - 1.1 inch smaller than the size specified on paper. This is due to the frame around the glass screen. So a 15" CRT would have only about 14" of viewable area.

17 inch LCD has 17 inch viewable. 24 inch LCD has about 23.8" viewable depending on model. Slightly less viewable as sizes go bigger, but not as severe as CRT.

Many manufacturers tout true flatness for their CRT monitors, but the sad truth is that most are fake. In reality it is only the outer glass that is flat, and not the actual screen. The true 100% perfect flat monitors are the aperture grille tubes made by Mitsubishi and Sony. Even then, these tubes have a disadvantage - a faint thin line or two (depending on size) running through the screen to stabilize the grill. Some people find this distracting, especially if you work on a white background (eg. documents) most of the time.

CRTs emit electromagnetic radiation. Much of it is filtered by the lead heavy glass front and the rest that reaches your eyes are mostly harmless. Even then, radiation still passes through the screen and some people regard them as hazardous.

CRTs weigh heavier, especially in the front (the display area) 17 inch CRT weighs around 16kg. 19 inch CRT weighs around 20kg.

Higher power usage, more than 400% compared to an LED backlight LCD of equivalent size. 17 inch CRT requires around 90 watts 19 inch CRT requires around 110 watts

LCDs are free from the burn-in issue that plagues CRTs and Plasma displays. However, they do occasionally have Image Persistence problems which can be fixed by switching off the LCD for an extended period of time.

LCDs do not "paint" their image. They provide a flicker free image every time. However, games and fast moving videos benefit from a higher refresh rate monitor by appearing smoother

LCD panels are prone to dead or stuck pixels (or dots) on the screen due to their manufacturing process. However, stiff competition has made many manufacturers adopt zero dead pixel / stuck pixel warranties for their products.

Must be used at its native resolution (maximum resolution) for best quality. Using the display at a lower resolution will result interpolation (scaling of the image), causing image quality loss. For this reason, gamers should avoid buying a monitor too high a resolution (e.g. 4K) as you will need more processing power (and more fan noise) to run the game in native resolution. As of 2021, we recommend 1920 x 1080 monitors when paired with recent GPUs/processors.

As CRT monitors are no longer manufactured, LCD monitors are the only way to go. Our recommendation is to go for a LED backlight LCD monitor that has a native resolution of 1920 x 1080.

Currently I am using a curved 31.5 inch 1920 x 1080 G-Sync 144hz monitor - the Acer Predator Z321 Qbmiphzx. It was bought from Amazon UK but it is no longer available as of July 2021. My reason was that it was the biggest G-Sync monitor I could get for 1080p resolution as I did not want Windows to scale font sizes (but I still had to anyway). Before this I was using a 26" Sony LCD TV as a monitor for its 1360 x 768 resolution.

Always preferred tube TV"s, I always had one plus the way they work interests me. I sill got my 36 inch Sony hd tube good tv I won"t make the mistake of buying a cheap liquid crap display again I wasted $150 for 1 year of tv then it burned out meanwhile my old tube doesnt even show signs of wear. So don"t waste time buying liquid crap. Lol

I don"t really like LCD"s, I prefer Old CRT TV"s because it works better with my VCR, and old video gaming systems, with LCD it has the VHS tapes have black bars at the sides and same with the video games. Ssame with my grandson (who is currently 12), so we switched back to our 25 inch CRT zenith Televison and everything went smooth, my grandson enjoys it too.

I have a CRT TV and used to have a LCD HDTV and I think I liked both but I had huge problems with an LCD TV because the screen broke easily and I called up to repair it but my warranty has expired and unable to repair my TV. So I bought another TV and its a Samsuck LED LCD TV and same sh*t happens again. So I give up and used my Old CRT TV left in the storage and I have no problems with this thing. So in conclusion I think CRT TVs are bit better then LCD but I liked LCD because it has HD 1080p and I can save up some space on my table to put stuff on it.

I have both CRT and LCD, but prefer CRT because ic an play at lower resolution (but with AA) this requires less powerfull videocard. Also i like to play old games that have low resolution. LCD displays look crappy whenusing low resolution

Seriously looks like a Windows bashing Linux, or visa-versa. Most of the facts where so outdated, at the time this comparison was written, that it isn"t even funny. LCD only had 8bit color, in 2008? More like 16. But don"t take my word for it, Google is your friend!

You should really make sure the comparisons at the bottom always list CRT on the same side, currently you"re switching between left and right, which makes for a very confusing read. Fix that and it"ll be much better.

actually most LED/LCD tvs are 8 bit panels and then some use 8bit+Frc (pseudo 10bit) then the best we have out in 2019 ATM is a true 10bit panel no 12 bit panels out yet not even the best dolby pulsar is 12 bit....but all that being said the only 10 bit color space format is HDR or HGL and Dolby vision even bluray are only 8bit so it"s pointless before

I made my little research. What I found out is that brainwash marketing confuse people more than the technology itself!. CRT TVs are good with Freeview digital box work fine. But now marketing encourages to buy LED over LCD, the same marketing told us LCD far better than CRT. The difference between LED and LCD: one uses bulbs one uses fluorescent light But huge price gap!. The same applies to smart phones people brainwashed into consumerism, most people don"t need sophisticated smart phones just need reasonable mobile phone can call/text maybe a bit of extras like camera, bluetooth, etc

Brainwash is right. LEDs have been here how long now, and the market has to pretend that LCDs and fluorescents are better than CRTs just to get the consumers to buy them so we have to buy them all over again in a LED solution? It"s all part of a planned progression scheme. The fact is this: CRTs were the green solution, because unlike the LCDs, they only had to be manufactured ONCE to work for at least 30 years verses LCDs which I had to replace every three years. So typical for the baby-boomers to believe every bit of nonsense that"s out there. By the way, I dropped my lap top 3" off the ground and the LCD broke! Meanwhile, I"ve hit my CRT television several times and it still works, it also was in a flood and still works, my house was broken into and it"s still there: they couldn"t carry it on their tweaker bike.

Great article. You just forgot about a very big advantage in CRT screens which is their durability and robustness. like if I accidentally hit my CRT TV, I will hurt myself. I I accidentally hit my LCD TV I will brake it...

Lots of these are untrue: 1st- Power consumed- Yes CRT can take more current at startup but it consumes as much or even less power than LCD when in darker scenes. LCD"s lamps are always on and therefore consume the same current all the time, while CRT fluctuates.

2- "Image sharpness is less than LCD" This is untrue. A CRT monitor can be much more sharp than a LCD monitor, and that at all resolutions supported. This all depends on CRT quality... and these days CRT quality is poorer and poorer with low tube quality control.

3- Radiation- You"d be surprised at how much real radiation is being output. Using a detector.. you have to be at 1 inch of the screen to detect radiation.. just by comparison the detector detects a microwave running at 20 feet.

No one adopted a 0 dead pixel policy. A summary of inquiries for most manufacturers can be viewed on intend dot ro, bottom RMA, then TFT somewhere on that page. Only a select few have a 1 pixel tolerance, the rest no RMA unless it"s over 3 dead pixels.

Without the lcd, we would have no laptops. My father was working on a computer in a suitcase back in 1981 and I said what will you use for a monitor, he said "These will be for businessmen and they will plug into a pay monitor at airports or wherever they will be installed". I said to him that It"ll never fly. What his idea was, is the modern laptop computer, if it weren"t for the monitor issue he could have died a billionaire.

Since the production of cathode ray tubes has essentially halted due to the cost and environmental concerns, CRT-based monitors are considered an outdated technology. All laptops and most desktop computer systems sold today come with LCD monitors. However, there are a few reasons why you might still prefer CRT over LCD displays.

While CRT monitors provide better color clarity and depth, the fact that manufacturers rarely make them anymore makes CRTs an unwise choice. LCD monitors are the current standard with several options. LCD monitors are smaller in size and easier to handle. Plus, you can buy LCD monitors in a variety of sizes, so customizing your desktop without all the clutter is easy.

The primary advantage that CRT monitors hold over LCDs is color rendering. The contrast ratios and depths of colors displayed on CRT monitors are better than what an LCD can render. For this reason, some graphic designers use expensive and large CRT monitors for their work. On the downside, the color quality degrades over time as the phosphors in the tube break down.

Another advantage that CRT monitors hold over LCD screens is the ability to easily scale to various resolutions. By adjusting the electron beam in the tube, the screen can be adjusted downward to lower resolutions while keeping the picture clarity intact. This capability is known as multisync.

The biggest disadvantage of CRT monitors is the size and weight of the tubes. An equivalently sized LCD monitor can be 80% smaller in total mass. The larger the screen, the bigger the size difference. CRT monitors also consume more energy and generate more heat than LCD monitors.

For the most vibrant and rich colors, CRTs are hard to beat if you have the desk space and don"t mind the excessive weight. However, with CRTs becoming a thing of the past, you may have to revisit the LCD monitor.

The biggest advantage of LCD monitors is the size and weight. LCD screens also tend to produce less eye fatigue. The constant light barrage and scan lines of a CRT tube can cause strain on heavy computer users. The lower intensity of the LCD monitors coupled with the constant screen display of pixels being on or off is easier on the eyes. That said, some people have issues with the fluorescent backlights used in some LCD displays.

The most notable disadvantage to LCD screens is the fixed resolution. An LCD screen can only display the number of pixels in its matrix. Therefore, it can display a lower resolution in one of two ways: using only a fraction of the total pixels on the display, or through extrapolation. Extrapolation blends multiple pixels together to simulate a single smaller pixel, which often leads to a blurry or fuzzy picture.

For those who are on a computer for hours, an LCD can be an enemy. With the tendency to cause eye fatigue, computer users must be aware of how long they stare at an LCD monitor. While LCD technology is continually improving, using techniques to limit the amount of time you look at a screen alleviates some of that fatigue.

Significant improvements have been made to LCD monitors over the years. Still, CRT monitors provide greater color clarity, faster response times, and wider flexibility for video playback in various resolutions. Nonetheless, LCDs will remain the standard since these monitors are easier to manufacture and transport. Most users find LCD displays to be perfectly suitable, so CRT monitors are only necessary for those interested in digital art and graphic design.

Are LED monitors better than their LCD predecessors? How are the two technologies differ in terms of functionality and performance? All these questions will be answered by the LED vs. LCD comparison presented in here.

The age of CRT (cathode ray tube) displays is over and LCD displays are already being replaced with LED screens. Technology is evolving at an exponential pace, pushing existing technologies into obsolescence. Just when we thought LCD screens will be the default choice for some time to come, they were supplanted by LED monitors, with their superior power efficiency and rich picture quality.

Considering that we spend a major amount of our lifetime in front of screens these days and eyes are not a replaceable commodity, a discerning consumer must opt for technology that is soft on the eyes, while providing a rich visual experience.

There seems to be a lot of confusion about the differences between LED (Light Emitting Diode) and LCD (Liquid Crystal Display) monitors that need clarification. Here"s a succinct analysis of the similarities and differences between the two models.

LED and LCD monitors are based on the same basic technology for image display but differ in the kind of backlighting used. While LCD monitors use CCFL (cold cathode fluorescent lamps) for backlighting, the latter use light-emitting diodes. This is the prime difference between the two display technologies. So LED monitors are in actuality, a type of LCD monitors or an improvement over them.

Unlike CRT monitors that generate their own light through cathode ray incidence on fluorescent materials, LCD displays have to rely on external lighting, as their display is created through manipulation of light, passing through polarized liquid crystals. Backlighting affects picture quality substantially and light shed by LEDs offers superior picture quality compared to LCDs.

This is because LEDs offer much more gradation in intensity and a larger light wavelength spectrum, providing a truer color quality. These types of monitors offer a better dynamic contrast ratio as well. So if you compare LED and LCD monitors from a gaming perspective and for use in intensive graphic applications, LED monitors are surely better choices. They provide vivid and more lifelike colors, with better gradation.

In this type of monitor, the white LEDs are placed along the edge of the screen, taking up less space overall, making the entire monitor slimmer, as well as cheaper. This is the most common type of LED screen available in the market.

LED monitors cure one of the basic problems with LCD TVs, which is the inability to display true black colors. They can produce true black hues, by switching off LEDs entirely, increasing the blackness quotient of the screen, and providing better contrast in the process.

LED monitors are a very recently introduced technology and they are preferred over LCD monitors because of the amazingly rich picture quality and viewing comfort. One more advantage that LED monitors to have over LCD ones is the power consumption factor. LED monitors require a lot less power to operate than cold cathode fluorescent lamps. This property can be attributed to the inherently low energy required by an LED to function. Their power consumption is as much as 40% lesser than conventional LCD monitors.

LED monitors are also a lot softer on the eyes than LCD monitors, making them popular choices for people who work for long hours on their desktop computers. They are also a lot more eco-friendly because mercury is not used in their production. LEDs last longer than cold cathode fluorescent lamps, with little reduction in their power output over time, which makes these monitors long-lasting.

To conclude this LCD vs. LED monitor comparison, let us compare the price ranges. One major factor that has been holding back LED technology from reaching the masses is the high price factor. The manufacturing of these devices is a bit costlier currently, compared to LCD displays which have raised their overall price. However, the cost gap is slowly lowering with time, as the demand for superior LED back-lit displays is on the rise all over the world. Even laptop computers and now smartphones come equipped with LED displays. While some of the best LCD monitors are available for a price of around $100, the best LED monitors fall in the $150 to $200+ range.

Also, setup and key adjustments are more complicated with LCDs—and much more necessary—than they are with CRTs. To be sure, all displays can benefit from proper tuning and adjustment. But LCDs are more likely to experience clarity or viewability issues if they"re not tuned and tweaked to optimum conditions.

In this Recipe, we"ll tackle the system-building differences between LCDs and CRTs. We"ll also describe the kinds of usage situations best suited to one kind of display over the other. Finally, we"ll describe some important tools you can use to make sure your customers get the most from their LCD choices.

We"ll start with the pros and cons of CRT displays, and then do likewise for LCDs. After that, we"ll make some comparisons and explain which type of display is best-suited for specific, identifiable usage scenarios.

Our comparison of the pros, cons, and differences between CRT and LCD displays hinges on the differences between analog and digital technologies. CRTs are analog; therefore, they support continuous values, smooth scaling, and arbitrarily high resolutions (within reason or the limits of technology). LCDs are digital and therefore work like an array of individual, discrete pixels with individual, discrete color and gray-scale values, and a fixed, native resolution. In mathematical terms, it"s the difference between a continuous integral versus a stair-step function. Here"s how they line up:

Color/gray-scale accuracy: Best color and gray scale accuracy; used as reference standard for professional calibration. Perfectly smooth gray-scale with infinite number of intensity levels.

Motion artifacts: The faster images move on a display, the more past display values can affect current display contents; these leftovers are called motion artifacts. CRTs offer fast response times with no motion artifacts. For this reason, CRTs are the best choice for fast-moving or ever-changing images.

Resolution: CRTs operate at any resolution, geometry, and aspect ratio with no need to rescale images shown. CRTs also run at the highest resolutions graphics cards support.

Emissions: CRTs emit electrical, magnetic, and electromagnetic fields, where magnetic fields are often believed to pose health hazards (although no available scientific evidence supports this belief).

Geometric distortion: CRTs are subject to geometric distortion and generally include adjustments to counter same. But they may also be affected by magnetic fields from other devices.

Interference: CRTs produce visual distortions known as Moire patterns. While many monitors offer Moire reduction, this doesn"t entirely eliminate this problem.

Sharpness: CRTs use electron beams to activate pixels on their screens. This results in softer images than an LCD operating at its native resolution. (But a CRT is usually sharper than an LCD not operating at its native resolutions.)

Size, weight, and power consumption: CRTs are big and bulky. They consume more power—and give off more heat—than most other display technologies.

Size, weight, and power consumption:LCDs are thin-profile devices that are generally lighter than CRTs. LCDs also consume less electricity—and give off less heat—than CRTs.

Aspect ratio: Any LCD has a fixed resolution and aspect ratio. For panels with a resolution of 1280 x 1024 (common for 17- and 19-inch models), the aspect ratio is 5:4 or 1.25, smaller than the 4:3 or 1.33 ratio common for other displays. This may require letterboxing to a 1280 x 960 resolution to get a standard 4:3 ratio.

Bad pixels and screen uniformity: LCDs may include malfunctioning pixels that are weak, or stuck in on or off modes. They are also subject to variations in backlighting, owing to the use of light sources at the top or bottom edges of the display.

Black-level, contract, color saturation: LCDs are poor at producing deep blacks and dark grays. This results in lower contrast and reduced color saturation for low intensity colors, which makes LCDs a poor choice for dimly lit or dark environments.

Color and gray scale accuracy: Internal gamma and gray-scale on an LCD varies by location on the display surface. LCDs normally produce only a limited number—fewer than 256—of discrete intensity levels. This leads to image-accuracy issues with black level, gray-scale, and gamma, and it isn"t suitable for professional color balancing.

Interference: LCDs using analog input require painstaking adjustment of pixel tracking and phase to minimize digital noise in image display. Automatic controls seldom produce optimum outputs, and it may be impossible to eliminate all digital noise completely.

Motion artifacts: The slower an LCD"s pixel refresh rate—often called response time, though this term is more appropriate for CRTs—the more likely it is that motion artifacts will appear. For continuous or very fast motion, some artifacts are inevitable on an LCD.

Resolution: Native resolution is set by the manufacturer and cannot be altered. All other resolutions require re-scaling and leads to image degradation, especially where fine text and graphics are concerned.

White saturation: White levels on LCDs are easily overloaded, and maximum brightness occurs before gray-scale values peak. This phenomenon is best managed by careful contrast-setting adjustments.

When it comes to picking one kind of display over the other, here"s what you should advise your customers on a number of criteria, including needs, pocketbooks, and working environments:

Color or gray-scale accuracy: Users who need or want higher color or gray-scale accuracy, and more viewable deep blacks or dark grays, will be better served by CRTs. Professional color balancing demands a high-quality CRT.

Contrast: CRTs produce the brightest contrast levels available, LCDs fare somewhat more poorly, especially with black and dark colors. Contrast ratio numbers published for LCD displays cannot always be taken literally.

Environmental concerns:CRTs, especially the picture tube itself, are chock-full of heavy metals of several varieties and pose more challenges for recycling than do LCDs. Also, smaller size and weight means less waste to manage. Also, LCDs emit less heat and other forms of energy—electrical, electromagnetic and magnetic—than do CRTs.

Lighting: Users who work in bright light are bound to prefer an LCD. Users who work in lower-light conditions will increasingly prefer a CRT as ambient light decreases.

Motion and artifacts: Users who need or want to work with fast or constantly moving images are best served by CRTs. But this also limits diagonal sizes to no more than 24 inches.

Operating costs: Those concerned about energy consumption will favor LCDs, as these monitors consume at least 40 percent less electricity than CRTs with the same rated diagonal measurements. (And standby mode savings are about 40 percent.) In theory, users can also get away with less office space by using LCDs, translating into lower rent.

Purchase cost: Those with smaller budgets should consider CRTs, as they cost 50 percent or less than LCDs with the same reported diagonal measurements.

Resolution: If a user doesn"t like an LCD at its native resolution, this spells trouble. Native resolution for an LCD is equivalent to maximum resolution on a CRT; it represents the upper limit of picture quality for a given model. So if a user needs a monitor to run at multiple resolutions, especially if they also need fine text and graphics for all resolutions, this virtually mandates a CRT.

With more customers switching to LCDs, system builders should understand how to set up these monitors and configure them properly once they"re in place. A system builder should also know how to get the best-looking text on the screen. To help, we"ll now describe some great tools for system builders working with LCD displays.

ClearType is a Microsoft technology specifically designed to improve text readability on LCD screens, including laptop screens, mobile device displays, and flat-panel monitors. ClearType technology can access individual color elements in each pixel on an LCD display. Prior to its introduction, the level of detail operated at the pixel level. But with ClearType running on an LCD monitor, features of text as small as a fraction of a pixel in width can be displayed, according to Microsoft. This leads to a visible improvement in the sharpness of tiny text details. It not only improves readability, but also is easier on the eyes, especially over extended periods of time.

ClearType is included with Windows XP. But to tweak text settings on individual LCD displays, you must download a Windows PowerToy called ClearType Tuner.

Once downloaded and installed, ClearType Tuner appears as a control panel widget named ClearType Tuning. Its users work with a wizard that asks them to select among multiple on-screen displays that look the best, in much the same way an optometrist works with patients to help determine a new prescription for corrective lenses.

Using the ClearType Tuning widget is fast and easy, and a bit of practice makes working with it a snap. You"ll also see noticeable improvements to text on LCD screens as a consequence of its use, as toggling the check box for "Turn on ClearType" in the widget itself will show.

DisplayMate Technologies is a small and highly-regarded company that offers a family of powerful tools of great interest to system builders and consultants. The company offers a $89 (download only) or $99 (CD and manual shipped to buyer) product called DisplayMate for Windows Video Edition, which we highly recommend. It not only supports both CRT and LCD displays, but also other display types, including liquid crystal on silicon (LCoS), digital light processing (DLP), TV, HDTV, Plasma, and multi-media displays. Though this product aims primarily at end-users and consumers, system builders and consultants on a tight budget can get plenty of value from this product.

System builders who work with lots of displays and really want to get the most out of them will probably prefer the higher end DisplayMate Multimedia Edition, which sells for $495. It not only handles the same kinds of displays as the aforementioned Windows Video Edition, but also includes many more test patterns and command scripts to perform customized display testing and tuning.

This scaffolding around the consumer-level DisplayMate for Windows program provides users with a set of detailed descriptive text screens that precede each of the monitor test sequences under two general headings: Set-Up Program and Tune-Up Program.

The Set-Up program helps familiarize users with graphics and display capabilities on the systems under test, and to establish initial configuration. The Tune-Up Program provides quick checks on specific display capabilities, with opportunities to tweak and tune them for optimal display output.

Introduction: A lead-in screen for the program that briefly describes its capabilities and (more important) provides the option to toggle the Novice Option on or off. Beginners will appreciate its information and instructions, while experienced users can ignore this.

Set-Up Display: A stepwise procedure that leads users through all available user controls on their display and graphics card, each of which is associated with a test pattern and an explanation of how to use its appearance on screen to achieve settings that are visually optimal. First, an initial explanation appears on screen. Then, users click through a sequence of 22 test-pattern screens that include checks on brightness and contrast, intensity range, black-level, and gray scale checks, numerous standard test patterns and color gauges, and numerous geometry checks. The whole sequence takes at least 30 minutes to traverse the first few times through, especially if you read all the preliminary text that precedes each individual test (and if our experience is any guide, you definitely should).

Video Obstacle Course: A set of demanding and difficult images designed to stress test displays and show settings in need of adjustment or improvement. The software also provides information about what users will see during these 24 tests, and how to remedy any potential problems or issues they may expose. About a third of the tests repeat from the previous Set-Up Display sequence, but others deal with important checks related to Moire patterns, color registration, screen and local display regulation, and more. Expect to spend at least 30 minutes working through this series of test patterns and checks.

Master Test Pattern: As the name suggests, this one has a little bit of everything: Geometry, focus and resolution checks, gray-scale and color levels and saturation, and more. You"ll learn to use this to take a quick look at a display and see if it needs some (or more) work.

Video System Information: Shows what information from your display and graphics card DisplayMate can read, including native resolution, screen colors, gray levels, screen and pixel aspect ratios, pixel shape (square or not), color depth, palette, and planes, as well as system font and display driver information. Useful to make sure everything is as it should be.

The DisplayMate Tune-Up Program includes the following elements, whose organization indicates that this tool takes a functional view of the various activities involved in display tuning and tweaking:

Sharpness and Resolution: Deals with sharpness, focus, and resolution with numerous horizontal and vertical bars, as well as the battery of Moire pattern tests (18 in all).

Screen Pixel Resolution: Shows a series of 15 visually interesting test patterns to check screen resolution, fineness of detail, and accuracy in a series of complex line and pattern traces. This is some of the coolest looking stuff in the program.

Miscellaneous Effects: A series of 14 tests and checks that let you fool around with colors and gray scales on the display. Be sure to toggle through color selections where you can; click the right mouse button to toggle through such options where available.

In our test lab, we have a number of LCD screens ranging in size from 17 inches (diagonal) to 30 inches. We found the DisplayMate program"s ability to help us properly set brightness, contrast, and pixel timing to be of greatest use. Those are the aspects of our LCDs that suffer the most when left at factory-default settings. System builders and consultants will find these tools useful in making sure that their customers and users have the best possible experiences when they upgrade or switch to LCD displays.

ED TITTEL is a freelance writer and trainer in Austin, TX, who specializes in Windows topics and tools, especially networking and security related matters. JUSTIN KORELC is a long-time Linux hacker and Windows maven who concentrates on hardware and software security topics. Ed and Justin are also co-authors of Build the Ultimate Home Theater PC (John Wiley, 2005).

The US Environmental Protection Agency"s Design for the Environment Program is conducting an industry-wide environmental life-cycle assessment of cathode ray tube (CRT) and liquid crystal display (LCD) computer monitors. Preliminary results are presented for 16 environmental impact categories that show the relative difference in life-cycle impacts for the CRT and LCD. Considering the entire life cycle of each monitor, global warming and water eutrophication impacts were greater for the LCD while all other impact categories (e.g., resource use, energy, ozone depletion, landfill space use, etc.) were greater for the CRT. Energy inputs for CRT glass manufacturing data, for which there was relatively low confidence in the data, drive many of the CRT impacts. When comparing the manufacturing stages of each monitor type, the LCD has more relative burdens on the environment than does the CRT. Using these study results can allow industry to begin focusing on where environmental improvements can be made.

CRT and LCD are both display devices. CRT is an old technology whereas LCD is modern one. One major difference between CRT and LCD is in the technology used for image formation. The CRT display produces an image by using an electron beam, while LCD display produces an image on the screen using liquid crystal display.

CRT stands for Cathode Ray Tube. CRT displays produce an image on the screen by using a sharp beam of electrons that is highly focused to hit a phosphor screen present in front of the tube. The important components of a CRT are electron gun, focusing mechanism, and phosphor screen.

CRT was used in earlier TVs and computer monitors. CRT produces poor quality images on the screen and also consumes large electricity. The lifespan of CRT displays is very short. Because of all reasons, CRTs are being replaced by other display technologies these days.

LCD stands for Liquid Crystal Display. In LCD, liquid crystals are used to produce images on the screen. LCD displays are thin and more energy efficient, thus they are used in several small sized devices like mobiles, laptops, TVs, desktop computer monitors, calculators, etc.

In LCDs, light is obtained from external sources, and then it is converted into a definite graphics pattern using optical effects. LCDs have several advantages over CRT such as less power consumption, faster response, smaller size, low cost, etc.

Both CRT and LCD have their own advantages and disadvantages. However, these days, CRTs have almost become extinct. No one seems to be using them anymore. LCDs and other display technologies have replaced them because the new devices are highly efficient in terms of cost, power, and performance.

CRT displays use the same picture tube technology with many enhancements as the first color televisions did more than half a century ago. But old doesn"t necessarily mean obsolete. A good CRT display, such as the Samsung 997DF 19" model shown in Figure 11-1, provides excellent image quality at a reasonable price. CRT displays are an excellent choice for many people, and will remain so for years.

In autumn 2005, Robert finally replaced his beloved Hitachi SuperScan Elite 751 19" CRT display which he had been using as his primary display for six years with a 19" Samsung 930BF LCD display. The Hitachi is a top-notch display, and Robert would have sworn that its image quality was as good then as the day it was first installed. Until, that is, he connected the Samsung 930BF. The difference was startling. The Samsung provided much better brightness, contrast, and color saturation.

Does that mean that a good LCD display always beats a good CRT display, or that current display technology is worlds better than that of six years ago? Nope. It just means that every CRT display even the best models decreases in brightness, contrast, and saturation as it ages. From day to day, the difference is imperceptible, but as the months and years pass the accumulated difference becomes large.

There is a happy ending to this story, though. Robert had been running the Hitachi CRT at 50% brightness and 85% contrast for years. Boosting brightness to 75% and contrast to 100% greatly improved the display quality, so there"s life in it yet. Barbara promptly grabbed the Hitachi for her own office, where it will probably live for another few years.

The CRT is essentially a large glass bottle, flat or nearly so on one end (the screen), tapering to a thin neck at the back, and with nearly all air exhausted. The inside of the screen end is covered with a matrix of millions of tiny phosphor dots (or stripes). A phosphor is a chemical compound that, when struck by electrons, emits visible light of a particular color. Phosphors are organized by groups of three, collectively called a pixel. Each pixel contains one phosphor dot that emits each of the additive primary colors, red, green, and blue. By choosing which dots to illuminate and how brightly to illuminate each, any pixel can be made to emit any one of thousands or millions of discrete colors. The distance between nearest neighbors of the same phosphor color on adjacent rows is called the dot pitch or stripe pitch. A smaller pitch results in a sharper image and the ability to resolve finer detail.

The phosphor dots are excited by one or more electron emitters, called electron guns, located in the neck at the back of the monitor. A gun comprises a heated cathode, which emits electrons, and circuitry that focuses the free electrons into a thin beam.

The deflection yoke is located around the tapered portion of the CRT, between the guns and the screen. This yoke is actually a large electromagnet, which, under the control of the monitor circuitry, is used to steer the electron beam(s) to impinge on the correct phosphor dot at the correct time and with the correct intensity.

The mask sits between the electron guns and the phosphor layer, very close to the latter. This mask may be a sheet of metal with a matrix of fine perforations that correspond to the phosphor dot triads on the screen, called a shadow mask, or a series of fine vertical wires that correspond to phosphors laid down in uninterrupted vertical stripes, called an aperture grill. In practice, and despite the marketing efforts of manufacturers to convince us otherwise, we find that the mask type makes little real difference. Good (read: more expensive) monitors produce good images, regardless of their mask type. Inexpensive monitors produce inferior images, regardless of their mask type.

Screen size is specified in two ways. The nominal size the size by which monitors are advertised and referred to is the diagonal measurement of the tube itself. However, the front bezel of the monitor conceals part of the tube, making the usable size of the monitor less than stated. Various consumer lawsuits have resulted in monitor manufacturers also specifying the Viewable Image Size (VIS), which is the portion of the tube that is actually visible. Typically, VIS is an inch or so less than nominal. For example, a nominal 17" monitor may have a 15.8" VIS. Small differences in VIS for example, 15.8" versus 16" make little practical difference. The smallest monitors still available are 15". While 17" remains the most popular size, 19" models are now so inexpensive that they have nearly overtaken 17" models in unit sales. Monitors 21" and larger are still relatively expensive, and are used primarily by graphics artists and others who require huge displays.

Dot pitch or stripe pitch is measured in millimeters, and specifies the center-to-center distance between the nearest neighboring phosphor dots or stripes of the same color. Smaller pitch means a sharper image that resolves finer detail. Unfortunately, dot pitch, which is used to describe shadow mask monitors, cannot be compared directly to stripe pitch, which is used to describe aperture grill monitors. For equivalent resolution, stripe pitch must be about 90% of dot pitch. That is, a 0.28 mm dot pitch monitor has resolution similar to a 0.25 mm stripe pitch monitor.

Maximum resolution specifies the maximum number of pixels that the monitor can display, which is determined by the physical number of pixels present on the face of the tube. The maximum resolution of many low-end monitors is identical to the optimum resolution for that monitor size. For example, 1024x768 is optimum for 17" monitors, so many low-end 17" monitors provide 1024x768 maximum resolution. Conversely, midrange and high-end monitors may have maximum resolutions higher than practically usable. For example, a high-end 17" monitor may support up to 1600x1200. There is no real benefit to such extreme resolutions, although it can be useful to have one step higher than optimum (e.g., 1280x1024 on a 17" monitor or 1600x1200 on a 19" monitor) available for occasional use for special purposes.

The synchronization range specifies the bandwidth of the monitor, which determines which combinations of resolution, refresh rate, and color depth can be displayed. Synchronization range is specified as two values:

Vertical Scanning Frequency (VSF) is the inverse of the time the monitor requires to display one full screen. VSF (also called refresh rate) is measured in hertz (Hz) and specifies the number of times per second the screen can be redrawn. To avoid screen flicker, the monitor should support at least 70 Hz refresh at the selected resolution. Within reason, higher refresh rates provide a more stable image, but rates beyond 85 or 90 Hz are necessary only for specialized applications such as medical imaging. Most monitors support a wide range of refresh rates, from very low (e.g., 50 Hz) to very high (e.g., 120 to 160 Hz).

Horizontal Scanning Frequency (HSF) is the inverse of the time the monitor requires to display one full scan line. HSF is measured in kilohertz (KHz), and specifies the overall range of bandwidths supported by the monitor. For example, a monitor running 1280x1024 at 85 Hz must display 1024 lines 85 times per second, or 87,040 scan lines per second, or about 87 KHz. In fact, some overhead is involved, so the actual HSF for such a monitor might be 93.5 KHz.

Resolution and refresh rate are interrelated parts of synchronization range of an analog monitor. For a given resolution, increasing the refresh rate increases the number of screens (and accordingly the amount of data) that must be transferred each second. Similarly, for a given refresh rate, increasing the resolution increases the amount of data that must be transferred for each screen. If you increase resolution or refresh rate, you may have to decrease the other to stay within the HSF limit on total bandwidth.

Note that manufacturers often specify maximum resolution and maximum refresh rate independently, without consideration for their interrelatedness. For example, specifications for a 19" monitor may promise 1600x1200 resolution and 160 Hz refresh. Don"t assume that means you can run 1600x1200 at 160 Hz. 160 Hz refresh may be supported only at 640x480 resolution; at 1600x1200, the monitor may support only 70 Hz refresh.

Resolution and refresh rate alone determine the required bandwidth for an analog monitor. Color depth is immaterial, because the color displayed for a given pixel is determined by the analog voltages present on the red, green, and blue lines at the time that pixel is processed. Therefore, at a given resolution and refresh rate, an analog monitor uses exactly the same bandwidth whether the color depth is set to 4, 8, 16, 24, or 32 bits, because the video card converts the digital color data to analog signals before sending it to the monitor. For purely digital monitors, such as LCD displays, greater color depth requires greater bandwidth, because color information is conveyed to a digital monitor as a digital signal.

Monitors use one of three geometries for the front viewing surface. Older monitors used spherical tubes or cylindrical tubes, both of which have noticeably curved surfaces. Flat square tubes (FST) are nearly flat. Other than some "value" models, all current monitors use an FST. Don"t consider buying a monitor that is not FST.

CRTs cost less than LCDs. For the same price as an entry-level 17" LCD, you can buy a midrange 19" CRT or two good 17" CRTs. The pricing differential has somewhat narrowed recently, but LCDs are likely for the foreseeable future to cost more than CRTs with similar size, features, and quality.

LCDs are designed to operate at one resolution, typically 1024x768 for 15" models and 1280x1024 for 17", 18", and 19" models. Although you can run an LCD at lower resolution than it was designed to use, you don"t want to. At nonnative resolution, you must choose between having a sharp image that occupies only a portion of the screen or using pixel extrapolation, which results in a full-screen image with significantly degraded image quality. CRTs, conversely, can operate at various resolutions, which means that you can choose the resolution that suits your own preferences and vision.

A high-quality CRT normally lasts for many years. It"s common for a CRT to remain in use for five years or more, and even ten years is not unheard of. LCDs use an array of cold cathode ray tubes (CCRTs), which are similar to fluorescent tubes, to provide the backlight required to view the image. A failed CCRT is not economically repairable. When a CCRT burns out, the LCD display must be replaced.

CRTs use phosphor pixels, which can be turned on or off almost instantly. LCDs use transistorized pixels that respond more slowly. This slower response may be visible as a smearing or ghosting effect when an LCD displays fast-motion video, such as DVD video or graphics-intensive games. Although better LCDs don"t exhibit this problem, at least not as severely as cheaper models, it is common and intrusive with entry-level LCDs.

CRTs present essentially the same image quality regardless of viewing angle. Conversely, LCDs present their best image quality only within a relatively small viewing angle, although midrange and better LCD models typically have larger viewing angles than entry-level models.

Many graphic artists refuse to use LCDs because the appearance of colors and the relationship between them changes with viewing angle. This problem is particularly acute with inexpensive LCDs, although even premium units exhibit it at least to some extent. The best LCD models are good enough in this respect for routine use, but most who insist on accurate color reproduction still prefer high-quality CRT monitors.

A CRT never has defective pixels. An LCD panel is manufactured as a monolithic item that contains more than a million pixels, and on some LCD panels one or a few of those pixels are defective. Defective pixels may be always-on (white), always-off (black), or some color. People vary in their reaction to defective pixels. Many don"t even notice a defective pixel or two, while others, once they notice a defective pixel, seem to be drawn to that pixel to the exclusion of all else. Most manufacturer warranties specifically exclude some number of defective pixels, typically between five and ten, although the number may vary with display size and, sometimes, with the location of the defective pixels and how closely they are clustered. As long as the display meets those requirements, the manufacturer considers the display to be acceptable. You may or may not find it acceptable.

Although the contrast and brightness of recent high-end LCDs are excellent, most LCDs provide subjectively less vibrant color than a good CRT. This is particularly evident in the darkest and lightest areas, where tones seem to be compressed, which limits subtle gradations between light tones or dark tones that are readily evident on a good CRT. Also, some LCDs add a color cast to what should be neutral light or dark tones. For example, dark neutral tones may appear shifted toward the blue (cooler) or red (warmer) ranges. This problem is less prevalent in high-quality LCDs than in entry-level units, and is also more likely to occur if you are using an analog interface rather than a digital interface.

If your budget is limited, a CRT offers far more bang for the buck than an LCD and, particularly for entry-level models, overall display quality will also be higher.

Remember that a CRT display is a long-term purchase. Even with heavy use, a high-quality CRT can be expected to last five years or more, so buy quality and choose a model that"s likely to keep you happy not just for your current system, but for one or even two systems after that.

Make sure the CRT is big enough, but not too big. We consider 17" models suitable only for casual use or those on the tightest of budgets. For not much more, you can buy a 19" model that you"ll be much happier with. Conversely, make sure your desk or workstation furniture can accommodate the new CRT. Many people have excitedly carried home a new 21" CRT only to find that it literally won"t fit where it needs to. Check physical dimensions and weight carefully before you buy. Large CRTs commonly weigh 50 lbs. or more, and some exceed 100 lbs. That said, if you find yourself debating 17" versus 19" or 19" versus 21", go with the larger model. But note that if your decision is between a cheap larger CRT and a high-quality smaller one for about the same price, you may well be happier with the smaller CRT. A $130 17" CRT beats a $130 19" CRT every time.

Stick with good name brands and buy a midrange or higher model from within that name brand. That doesn"t guarantee that you"ll get a good CRT, but it does greatly increase your chances. The CRT market is extremely competitive. If two similar models differ greatly in price, the cheaper one likely has significantly worse specs. If the specs appear similar, the maker of the cheaper model has cut corners somewhere, whether in component quality, construction quality, or warranty policies.

RECOMMENDED BRANDS Our opinion, which is shared by many, is that NEC-Mitsubishi, Samsung, and ViewSonic make the best CRTs available. Their CRTs, particularly midrange and better models, provide excellent image quality and are quite reliable. You"re likely to be happy with a CRT from any of these manufacturers.

If possible, test the exact CRT you plan to buy (not a floor sample) before you buy it. Ask the local store to endorse the manufacturer"s warranty that is, to agree that if the CRT fails you can bring it back to the store for a replacement rather than dealing with the hassles of returning it to the manufacturer. Mass merchandisers like Best Buy usually won"t do this they try to sell you a service contract instead, which you shouldn"t buy but small local computer stores may agree to endorse the manufacturer"s warranty. If the CRT has hidden damage from rough handling during shipping, that damage will ordinarily be apparent within a month or two of use, if not immediately.

BUY CRTS LOCALLY After shipping costs, it may actually cost less to buy locally, but that is not the main reason for doing so. Buying locally gives you the opportunity to examine the exact CRT you are buying. CRTs vary more between samples than other computer components. Also, CRTs are sometimes damaged in shipping, often without any external evidence on the CRT itself or even the box. Damaged CRTs may arrive DOA, but more often they have been jolted severely enough to cause display problems and perhaps reduced service life, but not complete failure. Buying locally allows you to eliminate a "dud" before you buy it, rather than having to deal with shipping it back to the vendor or manufacturer.

Most mainstream CRT manufacturers produce three Good, Better, and Best models in 17", 19", and 21". In general, the Good model from a first-tier maker corresponds roughly in features, specifications, and price to the Better or Best models from lower-tier makers. For casual use, choose a Good model from a first-tier maker, most of which are very good indeed. If you make heavier demands on your CRT such as sitting in front of it eight hours a day you may find that the Better model from a first-tier maker is the best choice. The Best models from first-tier makers are usually overkill, although they may be necessary if you use the CRT for CAD/CAM or other demanding tasks. Best models often have generally useless features like extremely high resolutions and unnecessarily high refresh rates at moderate resolutions. It"s nice that a Best 17" model can display 1600x1200 resolution, for example, but unless you can float on thermals and dive on rabbits from a mile in the air, that resolution is likely to be unusable. Similarly, a 17" CRT that supports 115 MHz refresh rates at 1024x768 is nice, but in practical terms offers no real advantage over one that supports an 85 or 90 MHz refresh.

Choose the specific CRT you buy based on how it looks to you. Comparing specifications helps narrow the list of candidates, but nothing substitutes for actually looking at the image displayed by the CRT. For example, CRTs with Sony Trinitron tubes have one or two fine horizontal internal wires whose shadows appear on screen. Most people don"t even notice the shadow, but some find it intolerable.

Make sure the CRT has sufficient reserve brightness. CRTs dim as they age, and one of the most common flaws in new CRTs, particularly those from second- and third-tier manufacturers, is inadequate brightness. A CRT that is barely bright enough when new may dim enough to become unusable after a year or two. A new CRT should provide a good image with the brightness set no higher than 50%.

Like all other component manufacturers, CRT makers have come under increasing margin pressures. A few years ago, we felt safe in recommending any CRT from a first-tier maker, because those companies refused to put their names on anything but top-notch products. Alas, first-tier makers have been forced to make manufacturing cost reductions and other compromises to compete with cheap Pacific Rim CRTs.

Accordingly, low-end models from first-tier makers may be of lower quality than they were in the past. The presence of a first-tier maker"s name plate still means that CRT is likely to be of higher quality than a similar no-name CRT, but is no longer a guarantee of top quality. Many first-tier CRTs are actually made in the same Pacific Rim plants that also produce no-name junk, but don"t read too much into that. First-tier CRTs are still differentiated by component quality and the level of quality control they undergo. There is no question in our minds that the first-tier CRTs are easily worth the 10% to 20% price premium they command relative to lesser brands. In fact, we think it is worth the extra cost to buy not just