1.3.4 Other Output Devices
Output device receives information from the CPU and presents it to the user in the desired from.The output is usually produced in one of the two ways – on the display device, or on paper (hard copy).
Liquid Crystal Displays (LCD)
First introduced in watches and clocks in 1970s, LCD is now applied to display devices of a computer. The major advantage of LCD is the low energy consumption. The CRT is replaced by liquid crystal to produce the image. These also have colour capability but the image quality is relatively poor. First introduced in watched and clocks in1970s, LCD is now applied to display devices of a computer. The major advantage of LCD is the low energy consumption. The CRT is replaced by liquid crystal to produce the image. These also have colour capability but the image quality is relatively poor.
Printers are used to produce paper (commonly known as hard copy) output. Based on the technology used, they can be classified as Impact or Non-impact printers.
Impact printers use the typewriting printing mechanism wherein a hammer strikes the paper through a ribbon in order to produce output. Dot-matrix and Character printers fall under this category.
Non-impact printers do not touch the paper while printing. They use chemical, heat or electrical signals to etch the symbols on paper. Inkjet, Deskjet, Laser, Thermal printers fall under this category of printers.
Plotters are used to print graphical output on paper. It interprets computer commands and makes line drawings on paper using multi colored automated pens. It is capable of producing graphs, drawings, charts, maps etc.
Sound cards and Speaker(s)
An expansion board that enables a computer to manipulate and output sounds. Sound cards are necessary for nearly all CD-ROMs and have become commonplace on modern personal computers. Sound cards enable the computer to output sound through speakers connected to the board, to record sound input from a microphone connected to the computer, and manipulate sound stored on a disk.