Page 32 - DCAP504_Computer Graphics

Unit 3: Overview of Graphics I/O Devices

Figure 3.2 displays a soft copy from a soft copy display device (monitor), and hard copy from a hard
copy display device (printer).

Figure 3.2: Types of Outputs

Source: Computer Graphics, Bhatia, K, I.K. International, Second Edition, Chapter 2-Interactive Devices, Page 10.
Printer and plotters are the most widely used hard copy display devices. The graphics stored on a
computer’s disk drive are printed using printers.
Monitors and flat panel display devices are the most commonly used soft copy display devices.
Monitors are used commonly as output device for computer graphics. Any monitor performs the basic
function, which is to allow the users to interact with the computer through sight and the use of a
Graphical User Interface (GUI).
3.2.2 Random Scan Display

Random scan displays refers to direct view storage tube display and calligraphic display. Random scan
displays are also known as line drawing displays.
Cathode Ray Tube (CRT) Model Technique

The most commonly used display device is the Cathode Ray Tube (CRT). In this display device, when
an electronic beam falls on phosphorescent surface then it produces a beam of light. The electronic or
magnetic fields can be used to focus the beam of light to a single point on the screen.

LOVELY PROFESSIONAL UNIVERSITY 25