Monitor

It is an output device. It shows result of processing as well as the input being provided. So that it is called an input/output device. It is also called a VDU (Visual Display Unit). It looks like a television screen. The output is formed in monitor by Cathode Ray Tube (CRT). The internal layer of monitor is coated by phosphorus. When electrons are sent to the layer of phosphorus they start glowing. Monitor produces characters using a set of dots on the screen. Those dots are called pixels (picture element). The maximum number of pixels which can be displayed by monitor is called Resolution of monitor. As many pixels are formed then the production quality of a monitor will be better. Monitor shows output with the help of only three colors beam. These are Red, Green and Blue; the characters are generally redisplayed up to 75 times and more in a second in monitor. It is termed as its Refresh Rate.

The electronic circuit which control formation of characters on the screen is called display adaptor.

Following types of display adaptors being used for monitors: 
MGA – Monochrome Graphics Adaptor (supports two colors Black and white)

CGA –  Color Graphics Adaptor (supports up to 16 colors)

VGA – Video Graphics Array (supports up to 256 colors)

SVGA – Super Video Graphics Array (supports up to 2¹⁶ to 2³² colors)

 A general monitor consumes 60 to 90 watts electrical power.

Liquid Crystal Display (LCD)/ Light Emitting Diode (LED):- It is a special type of display device which is used for laptop computer and TFT (Thin Film Transistor) monitor. It consumes only 25 to 40 watts electrical power. It shows color as well as black and white output. But the output quality of LCD is poor than CRT monitors.

A monitor may refer to any of the following:

1. Alternatively referred to as a VDT (video display terminal) and VDU (video display unit), a monitor is an output device that displays video images and text. A monitor is made up of circuitry, a screen, a power supply, buttons to adjust screen settings, and casing that holds all of these components.

Like most early TVs, the first computer monitors were comprised of a CRT (cathode ray tube) and a fluorescent screen. Today, all monitors are created using flat panel display technology, usually backlit with LEDs. The image to the right shows an ASUS LCD 
When was the first computer monitor invented?
The first computer monitor was part of the Xerox Alto computer system, which was released on March 1, 1973.
What are the different types of monitors?
There are essentially two types of monitors, with the second having two variations based on backlighting (CCFL vs. LED). The first (and oldest) is the CRT (cathode-ray tube) monitor, which was based on the same technology as early televisions. The second is the LCD (liquid-crystal display) monitor.
Why is a monitor an output device?
A traditional monitor is only used to display (output) information from a computer and provides no source of input. For this reason, a computer monitor is considered an output device.

Note

Newer PCs, smartphones, and tablets have touch screens, which allow the user to interact with their computer by touching what is shown on the screen with their finger. If the monitor has touch screen capabilities, it is considered an Input/Output devices. However, if it has no source of input it is only considered an output device.

Types of monitor connections

Computer monitors have at least one of the following types of monitor connectors to connect to a computer.

Tip

Video adapters are available to convert from one type of connector to another, such as DVI to VGA or HDMI to VGA, and vice versa.

2. Monitor is a term used to describe the act of watching over someone or something.

3. A resident monitor was system software used with machines utilizing punch card input. Resident monitors came before, but was very similar to, an operating system.