You might all wonder what is a peripheral device or what does this word means? Well, it’s very simple to know everything about peripheral devices. These are the devices related to computers and are used by almost everyone who is operating on these machines. So let’s get started with our topic.
What are Peripheral Devices?
A computer device that is not a part of the main computer (like main memory, motherboard, etc.) is known as Peripheral Device. We can also say that it is an auxiliary device that is used to put information into the computer or to get the information out from the computer. These are the hardware devices ( physical devices that can be touched) that are connected to the computer for various functions. They are can be easily connected and removed from the main computer.
Peripheral Devices can be external such as a mouse, keyboard, printer, monitor, scanner, etc., and also they can be internal like CD-ROM drive, Disk Drive, or modem. Internal peripheral devices are often referred to as Integrated Peripherals.
Types of Peripheral Devices
Now let’s discuss the types of Peripheral Devices that came across our use on daily basis. There are mainly 3 types of Peripheral Devices.
- Input Devices
- Output Devices
The term “Input” means taken the instructions in or giving instructions to the computer.Devices that are used to enter data and instructions into the computer system are called Input devices. There are several types of input peripheral devices, let’s move forward to the types one by one.
Keyboard is the most widely used input device. It is used to enter data and instructions into the computer. But today we operate on screens that have inbuilt keypad/keyboard. so we don’t need extra keyboard for our device.
Now-a-days, keyboard has more than 100 keys. Some types of keys are:-
Alphabets– A-Z or a-z keys
Numeric-0-9 keys. These are present at two places on keyboard.
Mathematical Symbols– +,-, =, >,<, &, %, #, etc.
Punctuation Characters– . , : ; ‘ ” etc.
Function Keys-F1-F12 keys are used to perform different functions.
Special Function Keys-Home, End, Delete, Down, Insert, etc.
Arrow Keys– Four arrow keys are used to move the cursor on the screen.
Editing Function keys– ENTER, ESC, CTRL, ALT, etc are used in combinations with other keys of keyboard to perform different functions.
Mouse is an important input peripheral device. It is used for controlling screen cursor. (arrow we see on the screen)
It has two or three buttons on its top as you can see in the picture and a rubber or a metal ball inside its body.
Mouse is generally used in graphic applications, also used to play games on the computer. I remember as a kid, I used to play a lot more games on computer.
Digital scanner is an input device. It is also called optical reader or simply scanner. It scans or reads text and pictures printed on a paper and enter them directly into the computer memory.
The scanner takes electronic images of text or pictures from the paper. It breaks each image into light and dark dots and stores them into the computer memory in machine codes.
The advantage of a scanner is that the input data need not be typed in by the user. This is fast and accurate method for entering data into the computer.
4. DIGITAL CAMERA
Digital camera is also used as an input perpheral device. It is used to input pictures directly into the computer.
Like traditional cameras, digital cameras have a lens, a shutter and an optical view-finder.
In digital cameras, image falls on a chargecoupled device (CCD). A photosensitive computer chip transforms light patterns into dots.
A high quality digital camera divides a picture into millions of dots. After the image has been captured, it is saved into a camera’s memory card then to the computer memory.
The big advantage of digital cameras is that making photos is inexpensive and fast because there is no film processing.
A small, touch-sensitive pad used as a pointing device on some portable computers. By moving a finger or other object along the pad, you can move the pointer on the display screen. And you can click by tapping the pad or buttons available close to touch pad.
This is also an important input peripheral device. It is a pen-shaped input device that is held in hand and can detect the presence or absence of light with help of a photo-electric cell mounted at its front end. Its other end is connected to a computer terminal by means of a cable.
It is used to enter voice into the computer system. The sound waves are converted into digital form and then enter into the computer system for further processing. It is used to communicate with people also.
The information or results, we receive from the computer system are called output. The devices that are used to receive information from computer and give it to user are called output devices. Let’s discuss the types one by one.
The monitor or Visual Display Unit (VDU) is the most commonly used output peripheral device. It is like a TV screen. It can display alphanumeric characters, special characters and graphics. The output provided by monitor is called ‘soft copy’.
Types of monitors-
It is like a TV screen. The monitor contains a large Vacuum tube called Cathode Ray Tube (CRT). Due to CRT, they are also called CRT monitor. A CRT consists of three ‘Electron Guns’ of three colors Red, Green, Blue. Every picture is formed with combination of these three colors.
LCD stands for Liquid Crystal Display. A monitor that uses LCD technologies rather than the conventional CRT technologies is called an LCD monitor.
The main advantage of LCD monitors is that they take up less desk space and are lighter in weight.
Printers are used to produce output in the form of text and graphics on paper. The output on a paper is called ‘hardcopy’.
Impact printer is a type of printer i.e an output peripheral device. They print on the paper with the strikes of a hammer or pins on a ribbon. These printers work like a typewriter. They are mostly used with personal computers. E.g. Dot Matrix Printers.
A Dot-matrix printer is an impact printer. It makes a hard copy by printing one character at a time. It uses 100 to 300 dots per inch (DPI) to print output on the paper. Dot-matrix printers are also used to create character shapes of alphabets of other languages such as Urdu, Arabic, Chinese and Hindi, etc. They are less expensive printers.
The output from the CPU in digital signals makes the pins pressed forward by a magnetic device and the required character is printed.
The printing speed of the dot matrix varies from 200 to 1000 or more characters per minute.
Non-Impact printers use thermal, electrostatic, laser, and inkjet technologies for printing. These printers are faster and produce high-quality output as compared to the impact printers. E.g. Laser Printers, Inkjet Printers, etc
Laser stands for Light Amplification by Stimulated Emission of Radiation. Laser printer is a non-impact printer. It uses 300 to 2000 dots per inch (DPI). Laser printer print one page at a time that’s why these are also called page printers. Laser printer produces a very high quality text and graphics.
In these printers, a full page is assembled in the printer buffer, and a laser beam prints images of characters and pictures on the paper.
They have a very printing speed. The printing speed of these printers ranges from 5 to 300 pages per minute.
2. Inkjet Printer
Inkjet printer is a non-impact printer. It is a character printer its print quality is higher than that of the dot matrix printer.
It creates output on paper by a spray of ink from a fine jet. An electric field controls the spraying jet that forms characters or graphs on the paper.
It is a character printer and produces one character at a time. The printing speed of these printers vary from 1 page to 8 pages per minute.
To hear a voice from the computer we can attach speaker with the computer as an output peripheral device.
So, this was all about the peripheral devices. Hope this helps.