Introduction The Computers in our world now are very good and faster. Users are very fast to learn how to use the computer. In modern world computer is a part of our life because computer is our need to do our work. Computer has a part like, the brain or CPU, mouse, keyboard, speaker, printer, AVR and monitor. Monitors in this year are modern it upgrade like computer.
Brief history of a monitor
The video display terminal, or VDT, marked the early days of computer monitors. These VDTs included a screen and attached keyboard linked to a larger computer by a serial connection. Because VDTs required a connection to a larger computer, they were often referred to as "dumb terminals." Dumb terminals displayed text only in two colors, usually black and green. The Apple II and first game machines began using a television CRT.
IBM's CRT
The ssssst of its new PS/2 computer system. The display technology allowed for 256 different colors and 640 x 480 resolutions. Despite the appearance of newer display techniques, VGA has become a computer monitor standard. Indeed, the VGA may have become the impetus for the modern computer gaming industry as the increased color palette made graphics possible. Up to this point, computer displays were limited to text.

RESEARCH
Types of Monitors

A cathode ray tube or CRT
CRT technology, computer monitors continue to be referred to as "The Tube". 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 screenful of images.
A Liquid crystal display (LCD) is a thin, flat display device made up of any number of color or monochrome pixels arrayed in front of a light source or reflector. It uses very small amounts of electric power, and is therefore suitable for use in battery-powered electronic devices.
A plasma display is an emissive flat panel display where light is created by phosphors excited by a plasma discharge between two flat panels of glass. The gas discharge contains no mercury a mixture of noble gases (neon and xenon) is used instead. This gas mixture is inert and entirely harmless.
The glass panels seem to be vacuum sealed, because when they are broken the plasma breaks up, seemingly from the addition of air to the space.
Surface-conduction electron-emitter display (SED) is a flat-panel, high-resolution display. Some SEDs have a diagonal measurement exceeding one meter (approximately 40 inches).
The SED consists of an array of electron emitters and a layer of phosphor, separated by a small space from which all the air has been evacuated. Each electron emitter represents one pixel. The SED requires no electron-beam focusing, and operates at a much lower voltage than a CRT. The brightness and contrast compare favorably with high-end CRTs. Prototype electron emitters have been developed with diameters of a few nanometers. SED technology can offer unprecedented image resolution.
Digital Light Processing (DLP) is a technology used in projectors and video projectors. In DLP projectors, the image is created by microscopically small mirrors laid out in a matrix on a semiconductor chip, known as a Digital Micro mirror Device (DMD). Each mirror represents one pixel in the projected image. The number of mirrors corresponds to the resolution of the projected image: 800x600, 1024x768, 1280x720, and 1920x1080 (HDTV) matrices are some common DMD sizes. These mirrors can be repositioned rapidly to reflect light either through the lens or on to a heat sink.
An organic light-emitting diode (OLED) is a thin-film light-emitting diode(LED) in which the emissive layer is an organic compound OLED technology is intended primarily as picture elements in practical display devices. These devices promise to be much less costly to fabricate than traditional LCD displays. When the emissive electroluminescent layer is polymeric, varying amounts of OLEDs can be deposited in rows and columns on a screen using simple "printing" methods to create a graphical color display, for use as computer displays, portable system screens, and in advertising and information board applications. OLED may also be used in lighting devices. OLEDs are available as distributed sources while the inorganic LEDs are point sources of light.

The Common Size of a Computer Monitor
The table below shows the usual monitor sizes, their typical viewable size and surface area (see here for more on these) and a "typical price" to get a good quality monitor of that size specification. Monitor prices vary widely but those prices give a general indication; better brands will be more expensive and lesser brands cheaper, but they will usually be so across the product line and I am interested in relative cost here. Then, the value is calculated as the number of square inches of surface area per dollar spent on the monitor): Nominal Size | Typical Viewable Size | Viewable Surface Area (in^2) | Typical Price | Value (Square Inches per Dollar) | 14" | 13.2" | 83.6 | $250 | 0.33 | 15" | 13.8" | 91.4 | $350 | 0.26 | 17" | 15.9" | 121.3 | $650 | 0.19 | 20" | 18.8" | 169.7 | $1400 | 0.12 | 21" | 19.8" | 188.2 | $1600 | 0.12 |
As you can see, you pay a definite premium to go to monitor sizes above 15", and especially to go to 20" or 21". This is why most people use either 15" or 17" monitors; 20" and 21" monitors are used mainly by graphics designers (and serious gamers with a lot of money :^). 14" monitors provide a good solution for economy PCs but their abilities are often too limited for many people.
Features of Computer Monitor
Resolution
A monitor's resolution refers to the number of picture elements, or pixels, that make up an image. More pixels means finer detail. Most monitors can display at several resolutions, generally from 640x480 to 1920x1200, depending on the monitor and the computer's graphics card. An LCD usually displays its sharpest image when set to its "native" resolution--typically 1440x900 for a 19-inch display, 1680x1050 for a 22-inch, and 1920x1200 for a 24-inch. Typical resolutions for wide-screen monitors are 1600x900 for a 20-inch, 1920x1080 for a 22-inch, and 1920x1200 for a 24-inch. The Apple display we tested has resolution of 2560x2440.
The higher the resolution, the smaller the text and images, meaning more content can fit on the screen. Higher resolution is better for working with photos and graphics.
Response time
A flat-panel display's response time indicates how quickly the screen can respond to video image transitions.
Contrast
Expressed as a ratio, this is a measure of the difference between the brightest white and the deepest black. A higher contrast ratio can produce images that are more vivid and punchy. But because the way manufacturers measure contrast ratio is not uniform, advertised figures are not reliable.
Brightness
A bright screen is important if you're working in a brightly lit room. The spec is expressed as candelas per square meter, or cd/m2. The higher the number, the better. You can also control an LCD's brightness with buttons or on-screen controls. Most monitors also have controls for color balance (usually called color temperature), adjusting the screen geometry, and similar functions.
Connectors
Virtually all new monitors have the DVI (digital visual interface) ports you need to take advantage of higher-end video cards for a sharper image. Not all include the necessary DVI cable, however (you can buy one for about $10). HDMI (high-definition multimedia interface) ports are becoming more prevalent. You'll also find them on some newer computers and electronics equipment such as Blu-ray/DVD players. One of the advantages of the HDMI interface is it allows for video and audio to be sent over the same cable (useful only if the monitor has built-in speakers). If you choose a monitor without one, you can buy an adapter for $25 or less that turns a DVI port into an HDMI connector, but you won't get audio through it.
DisplayPort is another connector beginning to show up on monitors. It can provide the same functionality as HDMI, but because it is royalty-free, it costs less for manufacturers to use it. Last year, several computer and display makers said they would eventually replace DVI and VGA connectors with DisplayPort and HDMI ports.
Touch screen
Another feature you'll be seeing on more monitors is touch-screen technology. The touch-screen monitors we've tested already work with the touch capabilities built into Windows 7. What's more important to consider is what's coming with Windows 8, which is being developed with tablets and computers in mind. That new operating system will incorporate a lot of touch-screen features into its new interface, which will include a series of tiles that represent your applications, documents, and so on. Windows 8 is due out this fall.
3D
You'll find this feature on a few new monitors. All of the 3D monitors in our Ratings use active 3D technology, which generally does a much better job maintaining the 3D effect at various viewing angles than displays that use passive 3D technology. In our tests, all produced great-looking 3D images. The picture on an active 3D monitor isn't quite as bright in 3D mode as it is on a passive display. You'll need special glasses to view 3D. Compared with glasses for passive 3D, active-3D glasses tend to be heavier, cost more, and might need batteries. Of the monitors in our Ratings, only the Acer HN274H ($680) came with glasses.
Extras
Some monitors include a microphone, one or more USB ports, integrated or separate speakers, and HDMI inputs for viewing the output of a Blu-ray player or camcorder. You may also see LCD monitors with memory-card readers, so you can display photos on-screen directly from a camera, and iPod docks for viewing images or playing music through the monitor. A built-in TV tuner is another feature to look for if you want your monitor to double as a TV. MULTIPLE MONITOR COMPUTING Multiple monitor computing (utilizing more than one monitor) is just in the very early stage of its adoption curve and is about to take off as a major trend that increases productivity and enhances capability for mainstream computer users. According to a recent Jon Peddie Associates Multi-Display Study, Multiple monitor computing increased 5,622% from 1992 to 1999 among a new category of users, those who do not fall into the traditional financial and graphics categories. In 1999 multiple monitor computing accounted for 1.6 Million computer users in the United States alone. And between 1992 and 1999 the annual growth of multiple monitor video card sales increased 450%, rising from 200,000 seats in 1992 to over 900,000 in 1999.
MASS ADOPTION OF MULTIPLE MONITOR COMPUTING There are five critical factors, which will drive the explosion of the multiple monitor industry to the point where it will reach critical mass.

1) Operating Software support -Windows 98, Windows ME, Windows XP, Windows 2000, Windows NT, MAC, UNIX, and Linux all offer multiple monitor support as standard features. Between 70-90% of the total multiple monitor users in 1999 were using Windows NT 4.0

2) RAM price erosion - multiple channel video cards require between 32 and 128 MB of video RAM. The sharp decline in RAM prices has enabled the video card manufacturers to significantly lower multiple output video card prices by over 70% over the last 5 years.

3) Monitor price decline - since 1997 large monitor prices have fallen by over 60%. The has contributed significantly to the reduction in multiple monitor system costs.

4) LCD technology - One of the primary problems with multiple monitor systems has been the mass of two or more CRT monitors. LCD monitors required a fraction of the space and are about 80% lighter that a CRT monitor of equal size.

5) LCD price decline - As of 2000 prices for 18.1 and larger have been in a steady and significant price decline. Analysts project that this trend will continue over the coming years.

MULTIPLE MONITOR COMPUTING SAVES TIME AND MONEY BY INCREASING PRODUCTIVITY AND ENABLING COMPUTING CAPABILITIES

multiple monitor computing is quickly becoming a necessary solution to efficiently manage and productively interact with today’s increasingly demanding computing scenarios. Utilizing simply one monitor to deal with the abundance of information and software the average person contends with on a daily basis is like trying to do your taxes while seated at a TV tray.

Multi-tasking It is commonplace and almost a necessity to run several applications at once during computing sessions. Windows are maximized and minimized, resized and rearranged so that users can access and interact with all of the information they need. This is a time consuming and non-intuitive situation that wastes valuable time while it hinders seamless integration of information and tasks. If several applications were easily visible on several screens the user could easily and intuitively move between applications and better synthesize the information available.

Software interoperability and interface As we utilize an ever increasing amount of software with ever more robust interface, our visual workspace continues to be reduced. Though most computer users have upgraded screens to an average of 17 inches from 15 inches, the amount of visual ‘workspace’ has effectively been reduced by the software interface as well as the fact that we continue to use more software packages and move between them more often due to their increasing compatibility. Multiple monitor users have the advantage of allocating screens to toolbars, freeing up valuable visual workspace and eliminating the need to constantly scroll and zoom in/out of images to work.

Internet & Email The Internet is an essential tool and resource in many computing activities including research as well as entertainment. Users move around the Internet and oftentimes utilize more than one window to view multiple web sites and pages. Users also move between software applications and Internet sites while gathering and processing information. To constantly minimize and maximize between the two or to have less than a full-screen view available hinders the user’s ability to most effectively and efficiently process the information. Additionally, throughout the day users access email accounts, taking time away from other tasks while they minimize and maximize work and windows to access, check for and send email messages. In implementing a multiple screen approach to interaction with the Internet and Email users have the ability to keep those windows open and accessible, enabling them to monitor them throughout the computing session without taking time and attention away from primary tasks.

Applications In addition to increasing productivity with many computing tasks such as those outlined above, multiple monitors computing is ideal for as host of real-estate hungry applications enhancing: Productivity, 2D Graphics, 3D Graphics and Multimedia.
Specific applications include: spreadsheet analysis, desktop publishing, CAD, CAM, CAID, Web Site Design, timeline tracking, web design, gene sequencing, presentations, E-Mail, gaming, game development, model design, trade show presentations, presentation systems, financial analysis, day trading, stock trading, software development, simulation, videoconferencing, production, schedule maintenance, illustration, animation, video /audio editing, technical research and photo editing.
Multiple Monitor Adoption: Not if, but when and how
In closing, the reasons for the eventual adoption of multiple monitor computing by mainstream computer users is several fold, in summary, it is based on the rapid fall-in-cost and simultaneous rise-in-capability of today’s powerful image-based computing.

GLOSSARY Apple II - first game machines began using a television CRT Cathode Ray Tubes (CRT) - first monitor of computer Color Graphics Adapter - display four colors with a resolution of 320 by 200 pixels Digital Light Processing (DLP) - a technology used in projectors and video projectors. Digital Micro mirror Device (DMD) – the image created by microscopically small mirrors lay out in a matrix on a semiconductor chip.
Enhanced Graphics Adapter - capable of producing 16 colors and had a resolution of 640 by 350. Liquid crystal display (LCD) - a thin, flat display device Organic Light-Emitting Diode (OLED) - a thin-film light-emitting diode Plasma display - an emissive flat panel display Surface-conduction electron-emitter display (SED) - a flat-panel, high-resolution display Video Display Terminal (VDT) - a screen and attached keyboard Video Graphics Array (VGA) - part of its new PS/2 computer system. It allowed for 256 different colors and 640 x 480 resolutions.

REFERRENCES http://ezinearticles.com/?Types-of-Monitors&id=175963 http://www.consumerreports.org/cro/computer-monitors/buying-guide.htm

Monitor has a different sizes and features but user use a common sizes of monitor. The common sizes of monitor are 14, 15, 17, 20, and 21 inches, user don’t like to use a big and wide screen because

DISCCUSION
Monitor size on a CRT monitor is not measured like a TV. On a TV, a 32″ TV means that the actual picture is 32″, measured diagonally. On a computer monitor, a 17″ monitor might only have a 15.7″ viewable image, measured diagonally. The law requires that a monitor manufacturer disclose the actual viewable image size along with the monitor size, but the marketing used often leads one to think they are getting a bigger picture than they really are.
LCD monitors, on the other hand, are not measured using the tricky viewable area measurement. An LCD monitor is measured by the actual size of the screen. The measurement is taken diagonally, from corner to corner, just as with the CRT.
When searching for your next monitor you have the choice to choose between a regular CRT monitor or a more modern LCD display. Since the prices of LCD’s have dropped considerably in recent years, the choice between the two often comes down to application. Whereas some hard-core gamers and graphics developers may still stick to a larger, advanced CRT screen, the average computer user can now seek out an LCD screen at affordable price. LCD’s offer several advantages offer conventional CRT monitors including a sharper image and smaller footprint (size). There is also no more need to adjust the refresh rate with LCD’s as there was with CRT’s.
If you are still interested in CRT monitors, a size of 17″ or 19″ has pretty much become standard these days. One would be foolish to purchase anything smaller than this, and a CRT less than 17″ is pretty hard to find these days anyway. At the time of this writing, the same size standards happen to hold true for LCD’s due to continued advances in technology and continued decreases in price. Many owners of LCD displays have either a 17″ or 19″ model. 15″ or smaller LCD’s are starting becoming pretty rare these days, and often cost the same as a 17″ LCD, sometimes even more. If you are shopping for an LCD, you are best of buying a bigger, newer, model unless you are really pressed for space.
At the end, the choice of LCD vs. CRT is up to the individual user and the intended application, but there is a general trend in the technology industry of moving away from CRT technology towards newer and more advanced LCD displays. Going along with this trend, the next section is therefore dedicated solely to LCD displays.
LCD Size and Price
It is true that LCD monitors used to be more expensive than CRTs. The primary reason for this was because of complexity and quality control. TFT LCD monitors are rather complicated, incorporating million of transistors in the screen in order to control current to each individual pixel. This is very different than a CRT monitor, where each pixel is just a phosphor dot that is ignited using an electron gun. And, with the increased complexity of the LCD comes a higher emphasis on quality control. Producing glass sheets containing millions of transistors for an LCD screen is an involced process, and all of the transistors need to work. A bad transistor means that the corresponding LCD pixel will not work. Each transistor panel that is manufactured has to be tested for this. If the panel contains too many bad transistors, the unit is discarded. Out of any batch of LCD’s, some are discarded for this problem, while others are fine and move on to become full LCD monitors. But, the cost of the monitors also has to absorb the cost of this increased quality control. These factor led to LCD screens being more expensive.
Advancements in the LCD manufacturing process lead to cost cutting measures that can be taken. Hence, the prices of LCD’s are are continuing to come down. Whereas the smaller 15″ LCD’s used to be more expensive than a 17″ or 19″ CRT, prices have now come down to the point where a 19″ LCD can be had for under $200, which is quite affordable to the average computer user.. Because of this the, majority of computer builders purchase an LCD with their new build nowadays as opposed to an older CRT monitor (although some hard-core gamers might beg to differ here). Larger sizes of LCD’s exit, but currently the prices rise considerably for LCD’s greater than 21″. The largest LCD’s are quite expensive, often costing several thousand dollars. It turns out that at the time of this writing a 19″ LCD can be had for around $180, a 20″-21″ LCD between $200-300, and 24″ and greater LCD can cost to close to $400 and beyond.
Bundled Monitors
Often, if you buy a pre-built PC, you will receive a LCD/CRT monitor with it. Some assume that the manufacturer knows something they don’t and that the monitor is the perfect match for that particular computer and video card. This is not necessarily true. While this monitor will provide a basic set of features and adequate performance, the manufacturer has value in mind instead of quality and performance.
Many PC’s these days come bundled with a 17″ LCD monitor. Some come bundled with 19″ or larger LCD monitors, as well. Some vendors do not offer a bundled monitor at all, but instead offer it as an upgrade for an additional fee. Of course, the cheapest will be the smallest and most basic. It is worth it, though, to check out the upgraded, more expensive monitor. In some cases, you can get a great deal on a nice size monitor through a vendor when you are purchasing a PC.
Lastly, many vendors offer bundled CRT/LCD monitors that come with the vendor’s own label on it (e.g. Dell). Some may wonder if this monitor is as good as a name brand LCD/CRT monitor. This is not a problem, though. Chances are that these monitors are being assembled in the same place by the same people. The vendor is simply purchasing the monitor wholesale and slapping their own label on it. Some vendors simply have the manufacturer modify the monitors a tad to bring them to a certain standard. Nevertheless, the vendor is probably not making their own monitor.
Lastly, it is good to have an understanding of the term “flat screen”. Some vendors offer “flat screen displays” are seemingly very affordable prices with their computers. Many consumers automatically assume this means you are getting an LCD. But, this is not always the case. CRT monitors are also available in flat screen versions. These monitors operate using standard CRT technology, but use a flat screen rather than the normally concave screen seen on older CRTs. One needs to be sure they know which type of screen is being advertised. Do not be fooled.

CONCLUSION Now that you know what to look for in a monitor, you're ready to go out and get one. Be sure to consider each of these aspects – size, ratio, resolution, response time, contrast, interface choices, and audio – carefully when you look at the selection, and you'll be sure to find a computer monitor that you'll be happy with.

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