Dear friend, today we will know about the input devices of the computer, what is the input device in the computer and what are the types of inputs in the computer. We will understand with full explanation about List of Input Devices of Computer. And you will understand in very easy language with image example, so stay with me till the end. So first of all we know what are input devices?
What are Input Devices? Input Devices of Computer
INPUT DEVICES : A computer is only useful when it is able to communicate with the external environment. When you work with the computer you feed your data and instructions through some devices to the computer. These devices are called Input devices.
For a particular application one from of device is more desirable compared to others. We will discuss various types of Input Devices that are used for different types of applications. They are also known as peripheral devices because they surround the CPU and make a communication between computer and the outer world.
Input Devices are necessary to convert our information or data in to a form which can be understood by the computer. A good input device should provide timely, accurate and useful data to the main memory of the computer for processing followings are the most useful input devices. Now we go ahead and know that,
List of Input Devices of Computer
- Keyboard
- Mouse
- Scanner
- Bar Code Readers
- Digital Camera
- Magnetic Ink Character Recognition (MICR)
- Optical Mark Reader (OMR)
- Optical Character Recognition (OCR)
- Light Pen
- Joysticks
- Touch Screen
- Trackball
- Voice Recognition
- Digital Tablet
Now by defining all of these, I will tell you what they are and what are their uses.
1. What is Keyboard ?
Keyboard is the standard input device attached to all computers. e should provide timely, accurate and useful data to the main memory of the computer for processing followings are the most useful input devices. The layout of keyboard is just like the traditional typewriter of the type QWERTY. It also contains some extra command keys and function keys. It contains a total of 101 to 104 keys. A typical keyboard used in a computer is shown in Figure above. You have to press correct combination of keys to input data. The computer can recognize the electrical signals corresponding to the correct key combination and processing is done accordingly.
2. What is Mouse ?
Mouse is an input device that is used with your personal computer. It rolls on a small ball and has two or three buttons on the top. When you roll the mouse across a flat surface the screen censors the mouse in the direction of mouse movement. The cursor moves very fast with mouse giving you more freedom to work in any direction. It is easier and faster to move through a mouse.
3. What is Scanner ?
The keyboard can input only text through keys are provided in it. If we want to input a picture the keyboard cannot do that. Scanner is an optical device that can input any graphical matter and display it back. The common optical scanner devices are Magnetic Ink Character Recognition (MICR), Optical Mark Reader (OMR) and Optical Character Reader (OCR).
4. What is Bar Code Readers ?
A bar code is a specialized code represented by sets of parallel bars of varying thickness and separation. This is used for fast identification of items with an optimal scanner. The optical scanner is called a bar code reader. The bar code reader is a photoelectric scanner that read the bar code.
5. What is Digital Camera ?
A digital camera is a camera that takes video or still photographs, or both, digitally by recording images on a light-sensitive sensor. Many compact digital still cameras can record sound and moving video as well as still photographs. In the Western market, digital cameras outsell their 35 mm film counterparts.
Digital cameras can include features that are not found in film cameras, such as displaying an image on the camera’s screen immediately after it is recorded, the capacity to take thousands of images on a single small memory device, the ability to record video with sound, the ability to edit images, and deletion of images allowing re-use of the storage they occupied. Digital cameras are incorporated into many devices ranging from PDAs and mobile phones (called camera phones) to vehicles. The Hubble Space Telescope and other astronomical devices are essentially specialised digital cameras.
6. What is Magnetic Ink Character Recognition (MICR) ?
This is widely used by banks to process large volumes of cheques and drafts. Cheques are put inside the MICR. As they enter the reading unit the cheques pass through the magnetic field which causes the read head to recognise the character of the cheques.
7. What is Optical Mark Reader (OMR) ?
This technique is used when students have appeared in objective type tests and they had to mark their answer by darkening a square or circular space by pencil. These answer sheets are directly fed to a computer for grading where OMR is used.
8. What is Optical Character Recognition (OCR) ?
This technique unites the direct reading of any printed character. Suppose you have a set of hand written characters on a piece of paper. You put it inside the scanner of the computer. This pattern is compared with a site of patterns stored inside the computer. Whichever pattern is matched is called a character read. Patterns that cannot be identified are rejected. OCRs are expensive though better the MICR.
9. What is Light Pen ?
An input device that utilizes a light-sensitive detector to select objects on a display screen. A light pen is similar to a mouse, except that with a light pen you can move the pointer and select objects on the display screen by directly pointing to the objects with the pen.
10. What is Joysticks ?
A lever that moves in all directions and controls the movement of a pointer or some other display symbol. A joystick is similar to a mouse, except that with a mouse the cursor stops moving as soon as you stop moving the mouse. With a joystick, the pointer continues moving in the direction the joystick is pointing. To stop the pointer, you must return the joystick to its upright position. Most joysticks include two button are called triggers.
Joysticks are used mostly for computer games, but they are also used occasionally for CAD/CAM (Computer-Aided Design and CAM stands for Computer-Aided Manufacturing) systems and other applications.
11. What is Touch Screen ?
A type of display screen that has a touch-sensitive transparent panel covering the screen. Instead of using a pointing device such as a mouse or light pen, you can use your finger to point directly to objects on the screen.
Although touch screens provide a natural interface for computer novices, they are unsatisfactory for most applications because the finger is such as a relatively large object. It is impossible to point accurately to small areas of the screen. In addition, most users find touch screens tiring to the arms after long use.
12. What is Trackball ?
A pointing device. Essentially, a trackball is a mouse lying on its back. To move the pointer, you rotate the ball with your thumb, your fingers, or the palm of your hand. There are usually one to three buttons next to the ball, which you use just like mouse buttons.
The advantage of trackballs over mice is that the trackball is stationary so it does not require much space to use it. In addition, you can place a trackball on any type of surface, including your lap. For both these reasons, trackballs are popular pointing devices for portable computers.
13. What is Voice Recognition ?
Voice recognition is “the technology by which sounds, words or phrases are spoken by humans and are converted into electrical signals, and these signals are transformed into coding patterns to which meaning has been assigned”. Spoken words are first digitized and then matched against a dictionary of patterns previously stored in the computer. The advantage of the voice input systems is that they enable users to keep their hands free for other tasks.
14. What is Tablet/Digitizer Tablet ?
A digitizer tablet is also called a graphics tablet or just a digitizer.
The digitizer is a drawing tablet used to sketch new images or trace old drawing or photograph. The user uses a pen-like which is device called a cursor to draw images. Designers and architects usually use digitizer. Light pen and digitizer technologies are used for pen-based computing.
