The monitor is connected to the video/graphics card through a cable that attaches to a connector on its back.

The video/graphics card converts PC/digital signals to analog signals

On laptops, the data remains digital because laptop displays are digital

15 Pin VGA Standard):

Widely know as VGA

Used by newer monitors

SVGA monitors uses it

 

 

 

 

9 Pin (Older VGA,EGA, CGA):

Used in older displays

9 Pin to 15 Pin converters for older systems on newer video cards

 

 

 

 

BNC Connectors:

Used in high performance / newer & larger monitors

Uses special coaxial cable with a standard 15-pin connector

Some monitors that have BNC connectors on them also have a

Standard 15-pin VGA, and either can be used.

The BNC cable can be expensive, but provides better shielding from noise and interference than the standard VGA cable.

1. Cathode ray tube (CRT)

2. Liquid Crystal Display (LCD)

Major and most expensive component

Used by almost every desktop computer

Monitors are mostly referred to as CRT’s

2. Liquid Crystal Display

Used in laptop computers, digital clocks and watches, microwave ovens, CD players and many other electronic devices

They are thinner and lighter and draw much less power than cathode ray tubes, also much

Clearer than CRT’s

4. Enhanced Graphics Adapter (EGA)

Introduced in 1984 by IBM

Renders 16 different colors

Maximum resolution of 640 pixels horizontally by 350 pixels vertically.

5. Video Graphics Array (VGA)

Introduced in 1987 by IBM

First to use analog technology

Renders 256 different colors on

resolution of 320 x 200 pixels

Maximum resolution is 640 x 480 with 262, 144 colours

Backward compatible with EGA and CGA

6. Extended Graphics Array (XGA)

Introduced in 1990 by IBM

800x600 pixel resolution in true color (16.8 million colors)

1,024x768 resolution in 65,536 colors Widely used today

 

7. Ultra Extended Graphics Array (UXGA)

Up to 16.8 million colors

Resolutions of up to 1600x1200 pixels, depending on the video memory of the graphics card

The CRT is lined with a phosphorous material that glows when it is struck by a stream of electrons. This material is arranged into an array of millions of tiny cells, usually called dots or pixels

At the back of the monitor is a set of electron guns (3 in modern monitors), which produce a controlled stream of electrons

The electron guns are controlled by the video data stream coming into the monitor from the video card

To produce a picture on the screen (Coated with phosphor), these guns start at the top of the screen and scan very rapidly from left to right.

Then, they return to the left-most position one line down and scan again, and repeat this to cover the entire screen

This happens extremely fast, and the entire screen is drawn in a small fraction of a second.

 

 

 

 

 

 

 

 

 

The size of the display is measurered in the aspect ratio and the screen size

Most computer displays have an aspect ratio of 4:3 (4 = width and 3 = height)

Typical Screen sizes: "15, "17, "19 and "21

CRT Uses 110 watts of power

LCD uses 30 – 40 watts of power

Monitor uses 80% of the PC’s power