Output Devices with examples
An output devices is a piece of computer hardware that receives data from a computer and then translates that data into another form. That form may be audio, visual, textual or hard copy such as printed document.
The output produced by output devices. Some of common used output devices are :-
1) Monitor
it is also known as Visual Display Unit (VDU). Monitor is the most commonly used output device to display the information. It resembles the television screen. It also displays the programs or application output.
It forms images from tiny dots, called pixels that are arranged in a rectangular form. The sharpness of the image depends upon the number of pixels.
The types of monitors are given below.
a) CRT (Cathode Ray Tube) Monitor – CRT monitors are based on the cathode ray tubes. They are like vacuum tubes which produce images in the form of video signals
b) LCD (Liquid Crystal Display) Monitor – These types of monitor is a flat panel screen that is compact and light-weight as compared to CRT monitors. It is based on liquid crystal display technology which is used in the screens of laptops, tablets, smart phones, etc.
c) LED (Light/Liquid Emitted Diode) Monitor – The LED monitor is an improved version of an LCD monitor. It also has a flat panel display and uses liquid crystal display technology like the LCD monitors. The difference between them lies in the source of light to backlight the display. Modern electronic devices such as mobile phones, LED TVs, laptop and computer screens, etc., use a LED display.
d) Plasma Monitor – The plasma monitor is also a flat panel display that is based on plasma display technology.
2) Printer
Printer prints the data and information from computer onto a paper. It can print documents in color as well as in black &White. The clarity of printer is determined by the clarity of a print.
Based on the printing mechanism, the printers are of two types-: Impact Printers and Non-impact Printers.
i) Impact Printer – Impact printers print the characters by striking them on the ribbon, which is then pressed on the paper.
Impact printers are further divided into two types – Character Printers and Line printers.
a) Character Printer – Character printer prints a single character at a time or with a single stroke of the print head or hammer. It does not print one line at a time. Dot Matrix printer and Daisy Wheel printer are character printers. Today, these printers are not in much use due to their low speed and because only the text can be printed. The character printers are of two types – Dot Matrix Printer and Daisy Wheel Printer.
- Dot Matrix Printer – In this type of printer Each character printed is in the form of pattern of dots and head consists of a Matrix of Pins of size (5*7, 7*9, 9*7 or 9*9) which come out to form a character which is why it is called Dot Matrix Printer. The speed of Dot Matrix printers is around 200-500 characters per second.
- Daisy Wheel Printer – It consists of a wheel or disk that has spokes or extensions and looks like a daisy, so it is named Daisy Wheel printer. It cannot be used to print graphics and is often noisy and slow, i.e., the speed is very low around 25-50 characters per second.
b) Line Printer – Line printers are the printers which print one line at a time. It is a high-speed impact printer as it can print 500 to 3000 lines per minute. Drum printer and chain printer are examples of line printers.
- Drum Printer – This printer is like a drum in shape hence it is called drum printer. Drum printer is a line printer that is made of a rotating drum to print characters. The drum has circular bands of characters on its surface. It has a separate hammer for each band of characters. When you print, the drum rotates, and when the desired character comes under the hammer, the hammer strikes the ink ribbon against the paper to print characters. These printers are known to be very noisy due to the use of hammering techniques.
- Chain Printer – Chain printer is a line printer that uses a rotating chain to print characters .A standard character set may have 48, 64, or 96 characters. Chain Printer can type 500 to 3000 lines per minute. They are also noisy due to the hammering action.
ii) Non- impact printer – Non-impact printers print the characters without using the ribbon. These printers print a complete page at a time, thus they are also called as Page Printers.
These printers are of two types − Laser Printers and Inkjet Printers
- Laser Printer – A laser printer is a non-impact printer that uses a laser beam to print the characters. The laser printers use powdered toner for printing instead of liquid ink and produce quality print objects with a resolution of 600 dots per inch (dpi) or more.
- Inkjet Printers- Inkjet printers are non-impact character printers based on a relatively new technology. They print characters by spraying small drops of ink onto paper. Inkjet printers produce high quality output with presentable features. Modern inkjet printers are color printers that have four cartridges containing different colors: Cyan, Magenta, Yellow, and Black. It is capable of printing high-quality images with different colors. It can produce print objects with a resolution of at least 300 dots per inch (dpi).
3) Plotter
Plotter are used to print graphical output on paper. It interprets computer commands and makes line drawing line on paper using multicolor automated pens. It is capable of producing graphs, drawing, charts, maps etc. plotters usually come in two forms – Flatbed and Drum Plotter.
4) Speaker
it is an output devices that receives sound in the form of electric current. It needs a sound card connected to a CPU, that generates sound. These are attached internally or externally to a computer.
5) Projector
A projector is an output device that enables the user to project the output onto a large surface such as a big screen or wall. It can be connected to a computer and similar devices to project their output onto a screen. It uses light and lenses to produce magnified texts, images, and videos. So, it is an ideal output device to give presentations or to teach a large number of people.
