INPUT DEVICESINPUT DEVICES

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WHAT IS INPUT DEVICE?WHAT IS INPUT DEVICE?• Entering data or instructions into

a computer is called INPUT.• Therefore, an input device is a

device which enters data or instructions into a computer.

• Input devices are necessary to convert data into a form which can be understood by computers.

INPUT DEVICES CAN BE INPUT DEVICES CAN BE CLASSIFIED INTO FOLLOWING CLASSIFIED INTO FOLLOWING

CATEGORIES:CATEGORIES:

• KEYBOARD DEVICES• POINT AND DRAW DEVICES• DATA SCANING DEVICES• DIGITIZER• ELECTRONIC CARDS BASED

DEVICES• VOICE RECOGNITION DEVICES• VISION BASED DEVICES

KEYBOARD DEVICESKEYBOARD DEVICES• The keyboard is a way to input letters

or numbers into different applications or programs.

•   A keyboard also has special keys that help operate the computer.

• Keyboards come in different shapes and sizes depending on the type of brand. They are similar to typewriters.

• Most popular keyboard used today is the 101- keys QWERTY keyboard.

KeyboardKeyboard• Numeric Keys:- (1 to 9).• Alphanumeric Keys:- (A To Z).• Function Keys:- (F1 To F12).• Arrow Keys:- ( go to left ,right ,up and down).• Tab:- It is used for fixed spacing.• Long Space key:- It is used for single space.• Shift:- performs various function like Shift + any

alphanumeric key display capital letter . It is also used for inserting symbols (numeric keys).

• Caps Lock:- It is used for inserting Capital letters.• Enter:- To go to next line.• Backspace:- It is used for deleting text from ending side of

cursor.• Delete:- It is used for deleting text from Starting side of

cursor.• Alt:- The combination of Alt+Shift is used for Hindi &

English Font.

KEYBOARD DEVICESKEYBOARD DEVICES

POINT AND DRAW POINT AND DRAW DEVICESDEVICES

• GUI is used to interact with Computer.

• A GUI provides a screen full of graphic icons to user and allow the user to make the rapid selection from displayed icons to give the instruction to the computer.

• With such interface ,basic requirement to have a Input Device.

POINT AND DRAW POINT AND DRAW DEVICESDEVICES

• POINT AND DRAW DEVICES used to rapidly point to and select a particular graphic icon from the multiple options displayed on the screen.

• These are also used to create the graphic elements on the screen such as Lines ,Curves, spheres etc.

POINT AND DRAW POINT AND DRAW DEVICESDEVICES

• Mouse• Trackball• Joystick• Electronic Pen• Touch Screen

MOUSEMOUSE• The mouse is the most popular POINT AND

DRAW DEVICE.• A mouse is a small hand-held Device, which

can comfortably fit in a user's palm.• It rolls on a small bearing.• It has one or more buttons on the top.• When a user rolls the mouse across a flat

surface, the graphic cursor moves on the screen of monitor in the direction of mouse ‘s movement.

• Graphic cursor is used to point and to draw.

MouseMouse• This input device controls the cursor

on the computer screen.• It is quite easy to operate a mouse.• The mouse is used to open and close files.

C:\Documents and Settings\sandeep\Desktop\media\image5.jpeg

Optical mouseOptical mouse• A mouse that uses light to detect

movement. It emits a light and senses its reflection as it is moved. Early optical mice required a special mouse pad, but today's

• devices can be rolled over traditional pads like a mechanical mouse as well as over almost any surface other than glass or mirror.

TrackballTrackball• A trackball is a pointing device.• It is similar to Mouse.• The ball is placed on the top with the

buttons.• To move the graphic cursor around

the screen, ball is rolled with the hand.

• A trackball requires less space than a mouse for operation.

TrackballTrackball• Trackball is commonly used in the

Laptop computers.• A trackball comes in various shape

and forms with same functionality.• Three commonly used shapes are a

Ball, a Button and a Square.• In case of ball, ball is rolled with the

help of finger to move the graphic cursor .

TrackballTrackball• In case of button, button is pushed

with a finger in the desire direction of the graphic cursor movement .

• In case of a square plastic, finger is placed on top of it, and moved in the desired direction of the graphic cursor movement .

TrackballTrackball

JoystickJoystick

• A Joystick is a pointing device, which works on the same principle as a trackball.

• To make the movement of the spherical ball easier, the spherical ball, which moves in a socket ,has a stick mounted on it.

• The stick can be moved forward or backward, left or right to move and position the graphic cursor at the desire position.

• Potentiometers are used to sense the movements.

• On the most joysticks, a button on the top is provided to select the option, which is currently pointed to by cursor.

JoystickJoystick

• Typical uses of a joystick include video games, flight simulators, training simulators and controlling industrial robots.

JoystickJoystick

Electronic PenElectronic Pen• Another point and draw device is an

electronic pen.• You can hold the pen in your hand.• It is used to directly point with it on

the screen to select icons.• It is used to directly draw the

graphics on the screen.

Electronic PenElectronic Pen• With this pen, you can write with it on a

special pad for direct input of the written information to the system.

• This pen consists of a photocell placed in a small tube. as user moves the tip of pen over screen, it is able to detect the light coming from the limited field of view. light from screen causes the photocell to respond when pen is pointed directly at a lighted area.

Electronic PenElectronic Pen

Touch ScreenTouch Screen• A touch screen is a computer display

screen that is sensitive to human touch, allowing a user to interact with the computer by touching pictures or words on the screen.

Touch ScreenTouch Screen• Touch screen are the most preferred

human-computer interface devices used in information kiosks( unattended information system like ATM).

• These are located at an Airport or a railway stations to provide the information to passenger about hotels, tourist spot in the city and in large museum or zoo to guide the visitors..

Touch ScreenTouch Screen

DATA SCANNING DEVICESDATA SCANNING DEVICES• Data scanning devices are input

devices.• These are used for direct data entry

into computer system from source documents.

• Some devices are also capable of recognizing marks or characters.

DATA SCANNING DEVICESDATA SCANNING DEVICES• These devices are direct data entry

devices ,they demand high quality of input document. documents that are poorly typed are normally rejected.

• These devices improves the data accuracy because there is no user participation in data entry.

• They eliminate the need for manual data entry by user.

DATA SCANNING DEVICESDATA SCANNING DEVICES• Image Scanner• OCR (Optical Character Recognition)• OMR (Optical Mark Reader)• Bar-Code Reader• MICR (Magnetic Ink Character

Recognition)

Image ScannerImage Scanner• An image scanner is a device which scans

pictures, text or objects and converts them to digital images.

• It is very useful in preserving the paper documents in electronic form.

• Electronic format of a scanned image is its bit map representation.

• Stored images can be altered and manipulated with image processing software.

Image ScannerImage Scanner• Image scanner come in various

shapes and sizes.• Flatbed Scanner• Handheld Scanner

Flatbed ScannerFlatbed Scanner• Flatbed scanners, also called desktop scanners,

are the most versatile and commonly used scanners.

• It is like a copy machine.• It consists of a box having a glass plate on its top

and a lid that covers the glass plate.• Light source is situated below the glass plate and

moves horizontally from left to right when activated.

• It takes 20 seconds to scan a document of size 21cm*28cm.

Flatbed ScannerFlatbed Scanner

Handheld ScannerHandheld Scanner• Handheld Scanner has a set of light

emitting diodes encased in a small case.

• Handheld Scanner can be held in hand during operation.

• To scan a document, scanner is slowly dragged from one end of the document to its other end with its light on.

Handheld ScannerHandheld Scanner• Handheld Scanner has to dragged very

steadily and carefully over the document, otherwise conversion of document into its equivalent bitmap will not be correct.

• They are much cheaper as compared to flatbed scanners.

• It is used where high accuracy is not required and volume of documents to be scanned is low.

Handheld ScannerHandheld Scanner

OCR (Optical Character OCR (Optical Character Recognition)Recognition)

OCR is an input device which interprets

handwritten marks, characters and any

printed text.

Scanner is equipped with a character

recognition software(OCR software),

which converts the bitmap images of

character to equivalent ASCII codes.

OCR (Optical Character OCR (Optical Character Recognition)Recognition)

OCR software is extremely complex, because it is

difficult to recognize unlimited number of fonts

and typefaces.

Standard fonts are OCR-A (American Standard)

and OCR-B (European Standard)

OCRs read at a rate of 2400 characters per

minute.

OCR devices are expensive.

OMR (Optical Mark Reader)OMR (Optical Mark Reader)

This device can recognize mark made by a

pencil on a specially designed form (OMR

Sheet).

These forms are divided into necessary

boxes, where the answer has to be marked by

a pencil.

Such forms are used in selection tests,

market survey questionnaires etc.

OMR (Optical Mark Reader)OMR (Optical Mark Reader)

• These answer sheet are fed to a computer for grading with the use of an OMR .

OMROMR

Bar-Code ReaderBar-Code Reader Bar-code reader is a device used for reading

bar-coded data.

Data coded in the form of light and dark lines

or bars are known as bar codes.

It is a series of black stripes of various

thicknesses on a white background.

Bar code reader are used in supermarkets

and departmental stores.

Bar-Code ReaderBar-Code Reader• Most widely known bar-coding

system is the universal product code (UPC).

• UPC bar code pattern are decoded as 10 digits. first 5 digits identify the manufacturer of the product, and next five digit identify the specific product of the manufacturer.

Bar-Code ReaderBar-Code Reader

Bar-Code ReaderBar-Code Reader

Magnetic Ink Character Magnetic Ink Character recognitionrecognition

MICR is used exclusively by the banking

industry for faster processing cheques.

Banks employ MICR technology, use a special

type of cheque.

in these cheque slip ,a special magnetic ink is

used to print characters , account number

and banks identification number.

An MICR device can read at the rate of 2500 cheques

per minute.

The MICR technology ensures accuracy of data entry.

Cheques are processed by using MICR reader-sorter .

MICR reader-sorter reads the data on the cheque and

sorts the cheques for distribution to other banks or for

processing.

Magnetic Ink Character recognitionMagnetic Ink Character recognition

Magnetic Ink Character Magnetic Ink Character recognitionrecognition

DigitizerDigitizer