Otherwise known as video display monitor, this is one of the Input/Output devices of the computer. This is where the presentation of the user is first viewed upon before he can make a hard copy of his presentation. It is an ordinary TV screen (cathode ray tube); the only difference is that it is connected to the CPU. It shows what the user “key’s-in” in the computer through the keyboard. In other words, it is where a “soft copy” of alphanumeric or/and graphical output of a presentation is displayed.
TYPES OF CATHODE RAY TUBES:
Raster-scan CRTs, this is the more common of the CRTs. An electron beam sweeps the screen horizontally many times per second, creating two dimensional grid of dots; each of this dots, or pixels, maybe manipulated in color and intensity.
Vector CRTs, in this kind of CRT, the electron beam sweeps back and forth between two or more points on the screen, creating an image composed of lines. Vector CRTs are commonly employed in drafting, for which line drawings are adequate.
A monitor like other video display unit has an element
of resolution. But there is a different way of measuring the resolution
of the computer’s display monitor. It is measured by pixels.
A pixel, short for picture element, is a single memory location on a computer display screen, or monitor, and is represented by a small dot of light. Any image on the screen is composed of a collection of pixels. The greater the number of pixels per unit of display area, the sharper the image--that is, the higher its resolution.
Monitor resolution usually is expressed by the number of pixels horizontally times the number vertically. For example, a VGA (Video Graphics Array) display has a resolution of 640 x 480, which means that there are 640 pixels in each horizontal row and a total of 480 horizontal rows on the screen.
The number of bits per pixel determines how many colors can be represented in an image. VGA, a graphics standard widely used in personal computers, typically has 8 bits per pixel and can display as many as 256 colors simultaneously from a palette of 256,000 colors.