Input Device of Computer | Keyboard, Mouse, Scanner & Barcode Reader: Know about the different types of most commonly used Input Devices with the help of which you can give input to the computer.
Keyboard device is the most commonly used input device today. The Computer keyboard is a typewriter style device which uses an arrangement or keys to act mechanical levers or electronic switches.
It is an input device that allows a person to enter letters, numbers and other symbols (these are called characters in a Keyboard) into a computer.
Using a keyboard to enter lots of data is called typing. A keyboard contains many mechanical switches or push buttons called “keys”.
The most popular keyboard used today is the 101 keys QWERTY keyboard.
Check out these:
- Logitech MK270r Wireless Keyboard and Mouse Combo for Windows, 2.4 GHz Wireless, Spill-resistant Design, 8 Multimedia & Shortcut Keys, 2-Year Battery Life, PC/Laptop- Black
- Zebronics ZEB-KM2100 Multimedia USB Keyboard Comes with 114 Keys Including 12 Dedicated Multimedia Keys & with Rupee Key
Input Device Mouse:
A mouse is an input device that controls the movement of the cursor or pointer on a display screen. It is the most popular point and draw device.
It is must have device on modern personal computers and workstations because they support GUI as their primary user interface.
A mouse is a small object that can be comfortably held in a user’s palm which can be rolled along a hard, flat surface.
Its name is derived from its shape which looks a bit like a mouse, its connecting wire that one can imagine to be mouse’s tail, and the fact that one must make it scurry along a surface. As you move the mouse, the pointer on the display screen moves in the same direction.
It contains at least one button and sometimes as many as three which have different functions depending on what program is running.
Some new mouse also include a scroll wheel for scrolling through long documents. Different applications display the graphics cursor or different symbol such arrow, a wrist with the pointing finger etc.
Commonly used are mechanical mouse and optical mouse. A mechanical mouse has a ball inside it that partially projects out through an opening in its base.
The ball rolls due to surface friction when a user moves the mouse on a flat surface. On two sides of the ball are two small wheels that spin to match the speed of the ball.
Check out these:
- Logitech Pebble M350 Wireless Mouse with Bluetooth or USB – Silent, Slim Computer Mouse with Quiet Click for Laptop, Notebook, PC and Mac – Graphite
- Logitech M221 Wireless Mouse, Silent Buttons, 2.4 GHz with USB Mini Receiver, 1000 DPI Optical Tracking, 18-Month Battery Life, Ambidextrous PC/Mac/Laptop – Charcoal Grey
Each wheel of the mouse connects to a sensor. As the mouse ball rolls when a user moves the mouse, the sensors deduct how much each wheel spins and send this information to the computer in the form of changes to the current position of the graphics cursor on the screen.
An optical mouse has no mechanical parts like the ball and wheels. Instead, it has a built in photo detector. It comes with a special pad with gridlines printed on it.
When a user moves the mouse on the pad, the photo detector senses each horizontal and vertical line on the pad and sends this information to the computer in the form of changes to the current position of the graphics cursor on the screen.
A scanner is an input device that captures images from photographic prints, posters , magazine pages and similar sources for computer editing and display, scanners come in hand held, Iced in and flatbed types and for scanning black and white or color.
Very high resolution scanners are used for scanning for high resolution printing but lower resolution scanners arc adequate for capturing images for computer display.
Scanners usually come with software such as adobe’s photoshop product, that lets you resize and modify a captured image.
So we can say that a scanner is a hardware that optically scans an image or even a document and creates a digital copy of it which in turn can be stored in a computer and viewed or modified using software applications.
The basic principle of scanner is to analyze an image and reproduce it to a digital one using the optical character recognition techniques.
Check out these:
- Canon P-215II Document Scanner
- HP Deskjet 2331 Colour Printer, Scanner and Copier for Home/Small Office, Compact Size
Input Device Barcode Reader:
A barcode reader (or barcode scanner) is an optical scanner that can read printed barcodes, decode the data contained in the barcode and send the data to a computer.
Like a flatbed scanner, a lens and light sensor translating for optical impulses into electricals signals. So it is an electronic scanning machine that reads and sends barcode information.
It allows real time data to be collected accurately and rapidly with the help of barcode reader and it also enables fast data entry.
Barcodes have now become an essential part of almost every Company. You will rarely find a product without a barcode tag.
Different types of barcodes are used for different purposes in business sectors.
There are several advantages of using barcodes as compared to manual data entry.
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