What is Input Devices ? With full Details.

Input is the data or instructions that are given to a computer. We use input devices to enter data and information into a computer. An input device converts data and instructions entered using the device into binary codes and electrical signals.These signals can be processed easily by a digital computer. A user inputs data and instructions (Example: using a keyboard, initiates a task (Example using a mouse), transfers images (example using a web camera), using the input devices.

What is keyboard ?

Keyboard is most important input device. We use a keyboard to input data and instructions into a computer.

The keys on a keyboard are broadly divided into 5 types -

Typing keys (a-z), Numeric keys (0-9), Function keys (F1-F12), Control keys (Arrow keys, Home, End etc.) and Special purpose keys (Enter, Shift, Caps Lock, etc .

Types of keys

Alphabet Keys

These keys are used to type the letters of the English alphabet. Pressing an alphabet key alone types a lowercase letter and pressing it together with Shift types a capital letter.

Number Keys

There are number keys in the row above the alphabet keys. Digits from 0 to 9 are typed with these keys. The keyboard also has a separate set of keys for typing numbers, which is called the Numeric Key Pad.

Escape Key

This key is used to exit some programs.

Function Keys

The keys from F1 to 12 are called function keys. They are used for specific tasks defined in the computer. Their work also depends on the running program.

Cursor Control Keys

These keys have left arrowheads. With these keys, the cursor can be moved anywhere on the desktop. On pressing an arrow key, the cursor moves forward one place in the direction of the arrow touched on it, eg. Pressing the key will move the cursor one line down and pressing the key will move the cursor one place to the right.

Numeric Key

This is a special set of keys on the right side of the keyboard, from which only numeric data is created. The format of this key-pat is like a simple electronic calculator. About 90% of the data we fill in the computer is numeric. This key pad has been installed to facilitate the preparation of numeric data. On this we can type numeric data with only one hand. Num Lock button to activate it. Must be ON.

Control Key

This key is used in conjunction with other keys to give certain commands. For example, in the Windows environment, pressing the key with the Control key ( Ctrl ) or Ctrl + c on a selected key. The object or material is copied to the clip board. The control keys are similarly used to give various shortcut commands.

Alt Key

This key is also used in some shortcut commands like the Control key.

Enter Key

It is also called Return key. It works to send any order prepared by us to the computer. In MS-DOS environment, the command is sent to the computer on pressing Enter. In the Windows environment, it serves to activate a selected command or icon. It is also used to start a new 'paragraph' while preparing a document.

Shift Keys

These keys are used to capitalize letters while typing. If a key has two symbols printed on it, then pressing it with shift will type the symbol above. There are two shift keys on the keyboard.

Back Space Key

By pressing it, the text to the left of the cursor is erased.

Caps Lock Key

When this key is activated, uppercase is typed in lowercase and lowercase in uppercase. So this key affects only alphabet keys.

Other Keys

In addition to the ones mentioned above, there are many other keys on the keyboard; Like- Pause, Break, Print, Screen, Scroll etc. They are used for special tasks.

Tab Key

When this 'key' is pressed alone it moves the cursor to the right side and when it is pressed together with the shift 'key' it moves the cursor to the left side.

PrtScr (print screen)

It is used to print the things seen on the screen.

Scroll Lock

When it is pressed with the control ' key', it interferes with the program being run.

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WHAT IS MOUSE

Mouse is the most popular pointing device. It is a famous cursor-control device which is a small box with a round ball at its base. This ball senses the movement of the mouse and sends corresponding signals to the CPU when the mouse buttons are pressed. Usually, a mouse has two buttons called the left and the right button and a wheel in between the buttons. A mouse can be used to control the position of the cursor on the screen, but it cannot be used to enter text into the computer.

TYPES OF MOUSE

Mechanical Mouse :

A mechanical mouse is a mouse made of a metal or rubber ball in its underside. Moving the mouse causes the ball to roll, and the sensors inside the mouse detect the movement of the ball and send signals to the cursor on the screen. The mechanical mouse has now been replaced by the optical mouse. A mechanical mouse is also known as a ball mouse.

Optomechanical Mouse :

This type of computer mouse is similar to the mechanical mouse except that it uses optical sensors to sense the motion of the ball. It is important to keep a mouse pad under the mouse so that it doesn't collect any dust.

Optical Mouse :

This type of mouse uses a for detecting the mouse's movement. You don't need a mouse pad but you can use one made for optical mice. Optical mice do not have any mechanical moving parts. This type responds more quickly and precisely than the mechanical and optomechanical mice.

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WHAT IS JOYSTICK ?

Joystick is also a pointing device, which is used to move the cursor position on monitor screen, It is a stick having a spherical ball at its both lower and upper .

The lower spherical ball moves in a socket. The joystick can be moved in all fou directions.

The function of the joystick is similar to that of a mouse. It is man used in Computer Aided Designing (CAD) and playing computer games.

It has a long handle in which four microswitches are mounted in four directions. When the joystick is rotated in any of the four directions (East, West, North and South), it transmits all the signals in that direction to the cursor which appears to be moving on the screen i.e. the direction in which the joystick is moved. The cursor also moves in the same direction it is rotated.

LIGHT PEN

Light pen is a pointing device similar to a pen. It is used to select a displayed menu item or draw pictures on the screen. A light pen is made up of a photocell and an optical system that is placed in a small tube. When the tip of a light pen is moved over the monitor screen and the pen button is pressed, its photocell sensing element detects the screen location and sends the corresponding signal to the CPU.

TRACK BALL

Track ball is an input device that is mostly used in notebook or laptop computer, instead of a mouse. This is a bail which is half inserted and by moving fingers on the ball, the pointer can be moved. Since the whole device is not moved, a track ball requires less space than a mouse. A track ball comes in various shapes like a ball, a button, or square.

SCANNER

Scanner is an input device, which works more like a photocopy machine. It is used when some information is available on paper and it is to be transferred to the hard disk of the computer for further manipulation, Scanner captures images from the source which are then converted into a digital form that can be stored on the disk. These images can be edited before they are printed.

There are three types of scanners:

Drum Scanner
Flatbed Scanner
Handheld Scanner

DIGITIZER

Digitizer is an input device which converts analog information into digital form. Digitizer can convert a signal from the television or camera into a series of numbers that can be stored in a computer. They can be used by the computer to create picture of whatever the camera had been pointed at Digitizer is also known as Tablet or Graphics Tablet as it converts graphics and pictorial data into binary inputs. A graphic tablet as digitizer is used for fine works of drawing and image applications.
Microphone is an input device to input sound that is then stored in a digital form. The microphone is used for various applications such as adding sound to a multimedia presentation or for mixing music .

MAGNETIC INK CARD READER ( MICR )

MICR input device is generally used in banks as there are large number of checks to be processed every day. The bank's code number and check number are printed on the checks with a special type of ink that contains particles of magnetic material that are machine readable. This reading process is called Magnetic Ink Character Recognition ( MICR). The main advantages of MICR is that it is faster and less error prone.

There are two types of fonts used in MiCR

one of which is known as E23B. It consists of numbers from 0 to 9 and four special types of signs. They are mainly used in Bank Cheques.

The second font is CMCS, which contains numbers from 6 to 9, alphabets and five symbols. These signs are made up of seven lines, which are magnetized. There are 6 spaces between these seven lines, whose width is different. A wider space represents a 1 and a smaller space represents a 0. The check is passed through a magnetic field before being read, due to which these seven lines, which are written with charged ink, become magnetized. Now by the Magnetize Sensor a code is received in the form of 0,1 based on the width of the spaces present between these lines, from which the necessary information is obtained. The reading speed of MICR is about 1,200 Documents Per Minute.

OPTICAL CHARACTER READER ( OCR )

OCR is an input device used to read a printed text OCR scans the text optically character by character , converts them into a machine readable code , and stores the text on the system memory.

OCR is a technique in which preprinted characters are identified by OCR standard characters by looking at the difference. The OCR tool reads characters printed from a typewriter, cash register characters, and credit card characters. OCR fonts (types or currency characters of the same type) are stored in the computer, which is called OCR standard. Of these, OCR-A and OCR-B are more popular. An optical reader scans the characters using a photo-electric device and converts the reflected light data into binary data (1 and 0) and inputs it into the computer. They are identified in the computer by the standard OCR font.

The normal speed of OCR is 1500 to 3000 characters per second, in offices where bills or slips are torn, OCR technology is more used .Printed by computer The other half page of the bill can again be used for data entry while the consumer re-presents it to deposit the bill amount.

There are mainly two types of fonts used in OCR

OCR - A (American Standard)

OCR B (European Standard). Their reading speed is about 2,400 characters per second.

BARCODE READERS

Bar Code Reader is a device used for reading barcoded data ( data in the form of light and dark lines ). Bar coded data is generally used in labeling goods , numbering the books etc. It may be a handheld scanner or may be embedded in a stationary Code Reader scanner , Bar Code Reader scans a bar code image , converts it into an alphanumeric value , which is then fed to the computer that the bar code reader is connected to .

OPTICAL MARK READER ( OMR )

OMR is a special type of opticalscanner used to recognize the type of mark made by a pen or pencil . It is used where one out of a few alternatives is to be selected and marked. It is specially used for checking the answer sheets of examinations having multiple choice questions .

DIGITAL CAMERA

A digital camera uses an electronic image sensor to create still photographs and record video . The optical system of a digital camera works like a film camera in which a typical lens is used to adjust electronic image sensor lighting. Digital cameras equip photographers with multiple automated control functions. Advanced digital cameras facilitate manual control of most functions. A digital camera is also known as a digicam . The key advantage of digital FLAT photography is the videos and images can be vie ed immediately .

MIKE

Mike Mike is such an input device that is used for various tasks in the computer; For example, it can be done in sound recording, presentation, etc. Low intensity sound can be heard with more intensity by the use of mic and speaker. The mic receives analog signals in the form of sound and the sound card (to which the mic is attached) converts these analog signals into digital signals. In this way we can use the input received in the form of this sound with the computer.

Read More :

What is Computer ?

What is ROM (Read Only Memory) ? & Types of ROM.

Output device and his types define and

pictures.

Keyboard Keys

Mouse & There Types.

Printer & its Types.

What is DVD(Digital Versatile Disc) ? Types of DVD .

What is Blu-Ray Disk

What is Primary Memory?

What is Secondary Memory?