An output device is an important peripheral to facilitate the communication between user and the computer system because unless we obtain resulting information from the computer we are unable to do anything with it. By means of these output devices, we are able to receive the data from the computer which is converted into human readable form. Output information can be displayed as screen information, printed or paper, or outputted as sound.
Also Read: Computer Input Devices
List of Output Devices
Today, with the advancement of technology, there is a variety of output devices available in the market.
A monitor is the screen on which words, numbers, and graphics can be seen. The monitor is the most common output device. It is also referred to as screen or VDU (Visual Display Unit). Screen sizes are measured diagonally and are still quoted in inches. Most popular sizes are 15 inches (38 cm) and 17 inches (43 cm).
Types of Monitors
Advantages of Monitors:-
- Display text and graphics in a wide range of colors.
Disadvantages of Monitors:-
- There is no provision to maintain a permanent copy.
- Problematic for those who have visual problems.
Technology used in Monitors
a) Cathode Ray Tubes (CRTs)
It is an interesting fact that most of the computer monitors are similar in many ways to a television. They use cathode ray tubes (CRTs) containing an electron gun at the back of the tube which fires electrons at a collection of phosphor dots coating the inside of the screen.
When the electrons strike the phosphor dots they glow to give the colors. On a color monitor, each group of phosphor dots is made up of one green, one blue and one red dot (known as RGB color pattern). By varying the brightness of each of these primary colors, the whole group will appear to the human eye as any color possible. One group of dots is called a pixel (known as picture element). The spacing of the pixels determines the clarity, or resolution, of the screen image.
- VGA (Video Graphics Array) 640*480 pixels
- SVGA (Super Video Graphics Array) 800*600 pixels
- VGA (Extended Graphics Array) 640*480 pixels
b) Liquid Crystal Displays (LCDs)
These use tiny crystals which, when a charge is applied across them, polarize the light passing through them. Used in combination with special filters, this means that light will not pass through when an electrical charge is applied. LCDs are also used in watches and calculators. They use much less power than a normal monitor and are also used in watches and calculators.
List of Top Selling Monitors:-
- Lenovo 23.8″ QHD Near Edgeless Monitor
- Zebronics 27 inch (68.5 cm) LED Monitor with Full HD Display
- Samsung 24 inch (60.4 cm) IPS
- BenQ GW2475H 24 Inch (60.45 cm) IPS Eye-Care Full HD 1080P Monitor
- LG UltraWide 34 Inch WFHD (2560 x 1080) IPS Display – HDR 10
- BenQ 31.5 inch(80.01 cm) Gaming Monitor
- LG Ultragear 69 cm (27-inch) IPS FHD, G-Sync Compatible, HDR 10, Gaming Monitor with Display Port
- BenQ 54.6 (21.5-inch) LED Backlit Computer Monitor
- LG 24-inch (60.96 cm), Full HD IPS (1920 x 1080) Monitor
- LG 22 inch (55cm) IPS Monitor
- Acer 21.5 Inch Full HD IPS Ultra Slim (6.6mm Thick) Monitor
Printer is one of the most commonly used output device which produces output in the form of a hard copy i.e. on the paper.
Some of the important types of printers are explained below:
a) Dot-Matrix Printer
It has a print head that travels across the paper.The head has a set of pins which are pushed out to form the shape of each character. The pins hit an ink ribbon against the paper as the print head moves along.
Advantages of Dot-Matrix Printer:-
- The purchase as well as running costs are very low.
- They are robust and can operate even in harsh environments.
- Multiple copies can be produced if several sheets of self-carbonating paper are placed into the printer.
Disadvantages of Dot-Matrix Printer:-
- The printing quality is low.
- These printers generate a low to medium quality black and white printing and can only print low resolution graphics.
- These printers can be quite noisy because of the impact of the pins against the paper.
- Limited to situations where carbon copies are needed.
- Used more often where the quality is not an important issue.
b) Ink-Jet Printers
inkjet printers constitute the print head which contains tiny nozzles through which different colored inks can be sprayed onto the paper to form the characters or the graphic images. The ink is enforced by heat or by tiny piezoelectric crystals which alter the shape when an electric current is applied across them.
Advantages of Ink-Jet Printers:-
- These printers are comparatively inexpensive.
- They can produce high quality black and white or color printing.
Disadvantages of Ink-Jet Printers:-
- The ink cartridges can be expensive so we can conclude that running costs can be high.
- The printing speed is slow compared to a laser printer.
- Institutes and organizations where small amounts of printing are done, these printers are best choice.
c) Laser Printers
Laser printers solve the printing purpose in the same way as photocopy machines generally do. The powdered ink (toner) is transferred to the paper and then fixed by heat and pressure.
Advantages of Laser Printers:-
- They fast and produce high quality printouts.
- They do not produce much of the noise while working.
- Running cost is comparatively low.
- Long lasting cartridges are used that increases the life of printer also.
Disadvantages of Laser Printers:-
- Color laser printers are significantly more expensive.
- It is a common practice to use these printers where fast, high quality printing is required.
List of Top Selling Printers:-
- Brother DCP-L2520D Multi-Function Monochrome Laser Printer with Auto-Duplex Printing
- HP Deskjet 2332 Colour Printer, Scanner and Copier
- HP Deskjet 2331 Colour Printer, Scanner and Copier
- HP Deskjet 1212 Colour Printer
- Epson EcoTank L3150 Wi-Fi All-in-One Ink Tank Printer
- HP Deskjet Ink Advantage 4178 WiFi Colour Printer, Scanner and Copier
- Canon Pixma G2012 All-in-One Ink Tank Colour Printer
- Canon E4270 All-in-One Ink Efficient WiFi Printer with FAX/ADF/Duplex Printing
Plotter is used to produce hard copies mainly of graphical pictures, images or design patterns. Plotter uses high precision motors to describe on paper with colored ink pens. The motors move an arm across the paper in the x-direction and a pen unit up and down the arm in the y-direction. An electromagnet lifts and drops the pen onto the paper.
Plotters are often used in science and engineering applications for drawing building plans, printed circuit boards and machine parts. They are fast and accurate but relatively expensive compared to printers. They can produce far larger printouts than standard printers. Flat-bed and drum plotters are the two most commonly used plotters.
Speakers are used to receive the information in the form the voice.
Speakers can play music by the computer from programs or from CD-ROMs as well as spoken output. Speech synthesis is used by for directory enquiries service.