In this post we learn output devices in detail
Output devices are called peripherals that receive or display the output generated by the computer. Peripheral Devices means those computer hardware whose function is to provide input and output for the computer. For example, when we input data from an input device such as a keyboard, the processing related to it runs in the CPU, whatever result is received after data processing, an output device performs the task of displaying it to the user, e.g. - Monitor.
1. Monitor : Monitor is a display unit that displays video and graphics generated by a computer. Its design is very similar to that of a television, but it usually displays information in high resolution. These devices are most common in output devices, also known as computer screens or visual display units (VDU's).
Monitor
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| Monitor |
Older computer monitors were larger and heavier because they used Cathode Ray Tubes (CRTs). However, today flat-screen LCD monitors and LED monitors are used in devices such as laptops and desktop computers, as they are more lightweight and energy efficient devices.
Following are some of the different types of computer monitors:
Cathode ray tube(CRT) Monitor
CRT is an older type o Crystal Display in short LCD Monitor is utilized in the majority of the PCs today. A layer of pixels is utilized to show the picture. They are very slender in size and light in weight. Aside from this, it utilizes less force than CRT. Despite the fact that it is more costly as far as cost. One of its impediments is that in the event that you check out a LCD screen from an alternate point, it has little impact on the nature of the picture showed.f display device, which is heavier in weight and bigger in size . In these, the electron beam is struck on the phosphorescent surface to create the picture. Basically, a CRT is a vacuum tube, with an electron gun toward one side and a fluorescent screen at the opposite end.. However, now a days manufacturing and uses of CRT Monitors has largely stopped.
LCD Monitor or Liquid Crystal Display
Liquid Crystal Display is used in most of the PCs today. A line of pixels is used to display the image. They are quite thin in size and light in weight. Apart from this, it uses less power than CRT. Although it is more expensive in terms of price. One of its disadvantages is that if you look at an LCD monitor from a different angle, it has little effect on the quality of the image displayed.
LED Monitor or Light-Emitting Diodes
Now a days these are considered to be the most modern monitors . It comes with flat-panel and slightly curved display. Instead of back-lighting, they use Light-Emitting Diodes, which help in giving it better picture quality. Advantage of these types of monitor is that they display high contrast images. Compared to LCD, they consume less power, and they are considered more environment friendly. The only downside of LED monitors is that they tend to be more expensive.
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| Printer |
Impact Printer:
In Impact Printer, an ink ribbon is pressed against the paper with a metal or pin to print the image on the paper. Through which all the images or characters are printed on that paper sheet. Impact printer was mainly applied for commercial data processing, and word processing but can also be used for personal desktop printing. Its disadvantage was that it was relatively slow and noisy. This is the oldest printing technology ever.Due to the low cost of printing, its demand was high in small industries.
There are three main types of Impact Printer, which include Dot-matrix, Daisy Wheel and Line Printer.
Dot-Matrix Printer : In this type of printers , characters are printed with the help of tiny dots. In this, a carbon is attached between the pin and the paper. When these pins are pressed against the carbon, the characters are printed on the paper placed below. The pins through which the ribbon or carbon are struck are called print-wires. The compartment which contains the print-wires is called the print-head. The quality of the image in a Dot Matrix printer depends on the number of dots per-inch.
Daisy-Wheel Printer: Their design is very similar to that of a typewriter. Print-heads of these printers are made of metal and plastic wheels, which are cut into petals. Each palette represents a Character, Number and Punctuation Mark. When you press that palette, it hits the printer ribbon, resulting in the word being printed on the paper. Daisy-wheel printers are very loud and slow, graphics cannot be printed through them.
Line Printer: A mechanism is used in this, which can print the entire line at a time. To do this, Spinning Drum or Looped Chain is used. Hammers push the paper against the surface of the drum or chain as it starts to spin. Due to which those characters are printed on the paper. Because it can print a whole line at a time, it is also called Line-at-a-time Printer. It prints faster than Dot-Matrix and Display-Wheel printers due to its technology.
Non-Impact Printers :
These are today's printers, which use laser or inkjet technology to print the image. Their printing speed is much better than Impact printers, and they do not make any noise at all. Along with this, they are known for producing very good quality prints. These printers are very cheap, if we compare them with other types of printers. This category includes some of the main Non-Impact Printers — Inkjet Printers, Laser Printers and Thermal Printers.Let us discuss each in details.
Inkjet Printer: In this type of printer, ink is sprayed onto the paper with a nozzle (a kind of pipe) to print characters and pictures. Ink comes out as steam through the tiny holes in those nozzles, and forms an image on the paper. These printers are generally used in offices and educational purposes , for both black and white and for colored printing .Now a days these are the most commonly used printers .
Laser Printer: This types of printers use a laser or electrical based system instead of the traditional printing model of ink on paper. They have the capability that they can print the computer output page by page continuously. Prints much faster than inkjet printers. They are often used in business where better print quality and speed are required. Whenever the user sends a command to printout, the entire page is first stored in the printer's memory, after which it goes on to print.
Thermal Printers: These are used to make bar-codes and shipping labels. They use heat for printing. These are also called electro-thermal printers. This being a cheaper printer, they are also more economical as their only use is paper. You will often find this printing technology in calculators and fax machines.
Speaker: Speaker is an output device, which takes electronic signals as a input and convert it into sound . To create sound by the speaker, the amplifier is used in it, which vibrates at different frequencies according to the data received from the computer, from which sound is produced. The signals through which sound is produced are created with the help of sound card installed in the computer.
Although there are many types of speakers, but all of them are used to play the audio output received from the computer. Speakers are differentiate according to size and frequencies j. volumes. The sound produced by the different types of speakers having different frequency and amplitude. Frequency determines how high and low the pitch of the sound is. Speakers are broadly classify into two parts - Passive and Powered Speaker.
Passive speakers are connected to the amplifier using a speaker wire because they do not have an internal amplifier, Whereas Powered Speakers have an internal amplifier, which allows us to increase the sound volume. Speakers often come in pairs, which helps them produce stereo sound from two separate audio channels.
Plotter:
Plotter is a graphic printer that prints graphical output on paper. It is similar to a printer, but it is capable of making graphs, drawings, charts, banners, posters and maps etc. The plotter uses a multi-colour automatic pen to draw sketches on paper. Unlike a typical printer, a plotter draws a point-to-point line to form an image.
Plotter can only draw data in vector graphic format. They are mostly used in the field of engineering projects, such as mechanical drawings, building plans and circuit diagrams, etc. They are larger in size than traditional printers, and also more expensive. There are many types of plotters, the main ones being:
Drum Plotter: This is a pan plotter in which paper is wrapped around a drum with a pin feed attachment. As the drum starts to spin, the pan moves in the other direction, printing the image on the paper.
Flat-bad Plotter : This is a mechanical drafting device that creates an image by placing paper on a flat surface.
Electrostatic Plotter : It uses electrostatic method of printing. They draw pictures on the paper which has a positive charge along with a negative charge.
Projector:
It is also an output device, which displays the image generated by the computer on a surface such as a white screen or screen. Projector is usually used to showing presentations includes videos and images to a large group of people. In most projectors, light is focused through a small transparent lens, onto the projector screen or wall, to produce the image. While some new projectors project the image directly through the laser.
Projectors are used in many big places such as theaters, conference halls and classrooms, etc for presentations .Now a days, video projectors are mostly used. It is a digital form of projectors which replaces previous projectors such as slide projectors and overhead projectors. However, new types of handheld projectors use lasers or LEDs to project graphics.
It is also an output device, which displays the image generated by the computer on a surface such as a white screen or screen. Projector is usually used to showing presentations includes videos and images to a large group of people. In most projectors, light is focused through a small transparent lens, onto the projector screen or wall, to produce the image. While some new projectors project the image directly through the laser.
Projectors are used in many big places such as theaters, conference halls and classrooms, etc for presentations .Now a days, video projectors are mostly used. It is a digital form of projectors which replaces previous projectors such as slide projectors and overhead projectors. However, new types of handheld projectors use lasers or LEDs to project graphics.
