INPUT DEVICESINPUT DEVICESTYPES OF INPUT DEVICETYPES OF INPUT DEVICE

INPUTINPUT DEVICESDEVICESAn input device is used to convert the input to a form An input device is used to convert the input to a form

that the C.P.U can understand and process. that the C.P.U can understand and process.

The computer is digital and understands machine The computer is digital and understands machine language. language.

Words in machine language consists 0’s and 1’s. Words in machine language consists 0’s and 1’s.

For example 10010 represent the number 18 For example 10010 represent the number 18

CATEGORIESCATEGORIES OFOF INPUTINPUT DEVICESDEVICES..

Keyboard entry devices Keyboard entry devices Terminal entry devicesTerminal entry devices Pointing devicesPointing devices Source data entry (SDE) devices Source data entry (SDE) devices Multimedia inputMultimedia input

KEYBOARDKEYBOARD INPUTINPUT

The keyboard is the most commonly use input The keyboard is the most commonly use input device. device.

It is used to enter numerical values, alphabetical It is used to enter numerical values, alphabetical values and special character.values and special character.

There are two main type of keyboards:There are two main type of keyboards:

1.1. Alphanumeric keyboardAlphanumeric keyboard

2.2. Specialized keyboardSpecialized keyboard

ALPHANUMERICALPHANUMERIC KEYBOARDKEYBOARD

Looks like a type writer Looks like a type writer

Types of keys Types of keys 1.1. Alphanumeric - ABC, 123Alphanumeric - ABC, 1232.2. Numeric -123Numeric -1233.3. Function keys - F1-F12Function keys - F1-F124.4. Toggle keys - CAPS LOCK, NUM LOCKToggle keys - CAPS LOCK, NUM LOCK

5.5. Modifying keys - SHIFT, CTRL, ALTModifying keys - SHIFT, CTRL, ALT6.6. Directional Arrow keysDirectional Arrow keys

SPECIALIZED KEYBOARDSPECIALIZED KEYBOARD

These are designed for special applications. These are designed for special applications.

For example: For example:

The retail keyboard – used by fast food The retail keyboard – used by fast food restaurants and other retail stores.restaurants and other retail stores.

TERMINAL ENTRY DEVICESTERMINAL ENTRY DEVICES

A terminal is an input/output device. A terminal is an input/output device. Includes a keyboard, a video display unit, Includes a keyboard, a video display unit, and a communication link to send or and a communication link to send or receive information from a centralized receive information from a centralized computer system.computer system.

The centralized system is usually a The centralized system is usually a minicomputer or mainframe.minicomputer or mainframe.

1. 1. Dumb TerminalsDumb TerminalsThis terminal doesn’t have a C.P.U This terminal doesn’t have a C.P.U (brain). It can’t operate on its own. It (brain). It can’t operate on its own. It can only send and receive data from a can only send and receive data from a central computer system. These can be central computer system. These can be found in airports, banks etc.found in airports, banks etc.

TYPES OF TERMINAL ENTRY TYPES OF TERMINAL ENTRY DEVICESDEVICES

2. 2. Smart terminalsSmart terminals: these have a C.P.U. : these have a C.P.U. and therefore can do some work on their and therefore can do some work on their own. However they rely on a central own. However they rely on a central computer for storage and most of the computer for storage and most of the processing.processing.

3. 3. Intelligent terminalsIntelligent terminals:: It accepts data It accepts data and processes it before sending the and processes it before sending the information to a main computer. It information to a main computer. It therefore has its own C.P.U, storage therefore has its own C.P.U, storage unit and memory.unit and memory.

4. 4. Point of sale (POS)Point of sale (POS)

These are used in stores and super markets These are used in stores and super markets to calculate bills and generate receipt. A to calculate bills and generate receipt. A device is passed over a special tag that is device is passed over a special tag that is attached to the item to read the relevant attached to the item to read the relevant information, or it is typed in by the clerk. The information, or it is typed in by the clerk. The terminal will show the description of the terminal will show the description of the product as well as the cost.product as well as the cost.

5. 5. Automated teller machines (ATM)Automated teller machines (ATM)

ATM’s accepts requests for different ATM’s accepts requests for different transactions such as withdrawal, transactions such as withdrawal, deposits or bill payments. The request is deposits or bill payments. The request is sent to a main computer for processing sent to a main computer for processing and the result sent back to the userand the result sent back to the user. .

POINTING DEVICESPOINTING DEVICESTHE MOUSETHE MOUSE

– This is the most popular pointing device.This is the most popular pointing device.– It is a handheld device that fits comfortably It is a handheld device that fits comfortably

under the palm of your hand. under the palm of your hand. – The mouse is used to control the The mouse is used to control the graphicsgraphics

cursorcursor or the mouse pointer. This cursor or the mouse pointer. This cursor normally takes the shape of an arrow, a hand or normally takes the shape of an arrow, a hand or an I beam.an I beam.

– Whenever the mouse is moved on the surface of Whenever the mouse is moved on the surface of a desk or on a mouse pad, the graphics cursor a desk or on a mouse pad, the graphics cursor on screen will move in a similar direction.on screen will move in a similar direction.

– The mouse is often used in selecting items, The mouse is often used in selecting items, highlighting text and icons (icons are pictures of highlighting text and icons (icons are pictures of functions).functions).

THE MOUSETHE MOUSE (cont’d)(cont’d)

A mouse can connect to your computer in several A mouse can connect to your computer in several ways. Most have a cable that attaches to a ways. Most have a cable that attaches to a mouse port or a Universal Serial Bus (USB) mouse port or a Universal Serial Bus (USB) port on the system unit. port on the system unit.

A later invention that is becoming popular is the A later invention that is becoming popular is the CORDLESS or WIRELESS mouse. These are CORDLESS or WIRELESS mouse. These are battery powered and transmits data using battery powered and transmits data using wireless technology such as radio waves or wireless technology such as radio waves or infrared light waves. infrared light waves.

MOUSEMOUSE

CORDLESS MOUSECORDLESS MOUSE

TYPES OF MOUSETYPES OF MOUSE There a two popular types or mouseThere a two popular types or mouse

– The The MECHANICALMECHANICAL mouse – has a rubber or mouse – has a rubber or metal ball on its underside and usually has metal ball on its underside and usually has two or more buttons (and maybe a wheel two or more buttons (and maybe a wheel that is used for scrolling) on the top. that is used for scrolling) on the top.

– Whenever the mouse is moved, the ball Whenever the mouse is moved, the ball underneath rolls thus causing the graphics underneath rolls thus causing the graphics cursor on the computer screen to move.cursor on the computer screen to move.

– A mechanical mouse should always be A mechanical mouse should always be placed on a mouse pad, as it better protects placed on a mouse pad, as it better protects the ball from getting dirty. A dirty ball will the ball from getting dirty. A dirty ball will cause the mouse to malfunction. cause the mouse to malfunction.

TYPES OF MOUSE (cont’d)TYPES OF MOUSE (cont’d) The other type of mouse is the The other type of mouse is the OPTICALOPTICAL

mouse.mouse.– This type of mouse has no moving This type of mouse has no moving

mechanical parts inside. Instead it uses a mechanical parts inside. Instead it uses a device to produce and sense light that device to produce and sense light that detect the mouse’s movement.detect the mouse’s movement.

– You can place an optical mouse on almost You can place an optical mouse on almost any surface, thus eliminating the need for a any surface, thus eliminating the need for a mouse pad. mouse pad.

– It is more accurate than a mechanical mouse It is more accurate than a mechanical mouse and does not require any cleaning.and does not require any cleaning.

TRACKBALLTRACKBALL This resembles an upside down mechanical This resembles an upside down mechanical

mouse. The ball is on top and is moved by the mouse. The ball is on top and is moved by the users palm or finger, thus eliminating the need users palm or finger, thus eliminating the need to move the device.to move the device.

The ball in most trackballs is about the size of The ball in most trackballs is about the size of a Ping-Pong balla Ping-Pong ball

A trackball usually has one or more buttons A trackball usually has one or more buttons that work similar to those of a mousethat work similar to those of a mouse

Trackballs must be frequently cleaned because Trackballs must be frequently cleaned because it picks up oils from fingers and dust from the it picks up oils from fingers and dust from the environment.environment.

TRACKBALLTRACKBALL

GLIDEPADGLIDEPAD//TOUCHPADTOUCHPAD//TRACKPADTRACKPAD This is a small, flat, rectangular touch sensitive This is a small, flat, rectangular touch sensitive

pad that is used in controlling the graphics pad that is used in controlling the graphics cursor. cursor.

The user slides the finger across the pad and The user slides the finger across the pad and the cursor follows the finger movements.the cursor follows the finger movements.

To make a selection the user may either click To make a selection the user may either click buttons that are around the edge of the pad or buttons that are around the edge of the pad or tap the pad with a finger.tap the pad with a finger.

Glide pads are mostly found in laptop Glide pads are mostly found in laptop computerscomputers

TOUCHPADTOUCHPAD

POINTING STICKPOINTING STICK This is another device that is popular with This is another device that is popular with

laptop computers.laptop computers. It is a pressure sensitive pointing device that is It is a pressure sensitive pointing device that is

shaped like a pencil erasershaped like a pencil eraser It is positioned between the keys on the It is positioned between the keys on the

keyboard.keyboard. To move the graphics cursor on screen the To move the graphics cursor on screen the

user pushes the pointing stick with the finger.user pushes the pointing stick with the finger.

POINTING STICKPOINTING STICK

JOYSTICKJOYSTICK

This is a vertical lever that is mounted on a This is a vertical lever that is mounted on a base. base.

The joystick is mostly used in playing The joystick is mostly used in playing games.games.

The lever is moved in different directions to The lever is moved in different directions to control the actions of the usercontrol the actions of the user

The lever usually includes buttons (called The lever usually includes buttons (called triggers) that can be pressed to activate triggers) that can be pressed to activate certain events in the game.certain events in the game.

JOYSTICKJOYSTICK

LIGHT PENLIGHT PEN This is a hand-held, pen shaped device that is This is a hand-held, pen shaped device that is

connected to the computer using a cable.connected to the computer using a cable. Using a special software or a special monitor Using a special software or a special monitor

the light pen detects the presence or absence the light pen detects the presence or absence of light on the computer’s screen.of light on the computer’s screen.

To select objects, the pen can be pressed To select objects, the pen can be pressed against the surface of the screen or you can against the surface of the screen or you can point the pen at the screen and press a button point the pen at the screen and press a button on the pen.on the pen.

Light pens are often used by doctors and Light pens are often used by doctors and dentists, as they can slide a protective sleeve dentists, as they can slide a protective sleeve over the pen thus keeping their fingers free of over the pen thus keeping their fingers free of contaminantscontaminants

LIGHT PENLIGHT PEN

TOUCH SCREENTOUCH SCREEN This is a touch sensitive display. You This is a touch sensitive display. You

interact with this device by touching interact with this device by touching sensitive areas on the screen with your sensitive areas on the screen with your finger.finger.

Touch screens are normally used in Touch screens are normally used in situations that only require you to touch situations that only require you to touch words, pictures, numbers or locations that words, pictures, numbers or locations that are identified on the screen. are identified on the screen.

TOUCH SCREENTOUCH SCREEN

GRAPHICS TABLETGRAPHICS TABLET/ / DIGITIZERDIGITIZER//DIGITIZING TABLETDIGITIZING TABLET

This is a flat, rectangular, electronic plastic board. This is a flat, rectangular, electronic plastic board. Each location on the graphics tablet corresponds Each location on the graphics tablet corresponds

to a specific location on the screen.to a specific location on the screen. A pen-like device called a A pen-like device called a stylusstylus is used to write is used to write

on the tablet.on the tablet. Writings or drawings on the tablet are converted Writings or drawings on the tablet are converted

to digital signals and are sent into the computer.to digital signals and are sent into the computer. Graphics tablets are often used by architects, Graphics tablets are often used by architects,

mapmakers, artists etc.mapmakers, artists etc.

GRAPHICS TABLETGRAPHICS TABLET

SOURCE DATA ENTRY (SDE) or SOURCE DATA ENTRY (SDE) or AUTOMATED INPUT DEVICESAUTOMATED INPUT DEVICES

These input devices are used to get data These input devices are used to get data into the computer without typing it in. into the computer without typing it in.

Using these devices increases the speed Using these devices increases the speed of data input and reduces the errors of data input and reduces the errors associated with manual input.associated with manual input.

Examples of SDE devices

Magnetic Ink Character Reader (MICR) Optical Mark Reader (OMR) Optical Character Reader (OCR) Bar Code Reader Scanner Sensor

MAGNETIC INK CHARACTER READER (MICR)MAGNETIC INK CHARACTER READER (MICR)

This device is used in banks to read the magnetised This device is used in banks to read the magnetised numbers found at the bottom of cheques and deposit numbers found at the bottom of cheques and deposit slips. slips.

The numbers encode the The numbers encode the – cheque numbercheque number– branch number of the bankbranch number of the bank– customer’s account numbercustomer’s account number

MICR cheques serve as a deterrent to fraud because MICR cheques serve as a deterrent to fraud because those photocopied will not have magnetic ink.those photocopied will not have magnetic ink.

MICRMICR

OPTICAL MARK READER (OMR)OPTICAL MARK READER (OMR) These devices collect data as hand drawn These devices collect data as hand drawn

marks made on pre-printed forms like those marks made on pre-printed forms like those used for multiple choice answer sheets or used for multiple choice answer sheets or questionnaires.questionnaires.

The master document (such as the answer The master document (such as the answer sheet for the test) is first passed through the sheet for the test) is first passed through the OMR so that the correct answers can be OMR so that the correct answers can be recorded. recorded.

The remaining documents are then passed The remaining documents are then passed through the device and their pattern of light through the device and their pattern of light matched against the master document’s matched against the master document’s pattern.pattern.

OMROMR

OPTICAL CHARACTER READER (OCR)OPTICAL CHARACTER READER (OCR) This device is used to read typewritten, computer-This device is used to read typewritten, computer-

printed, or handwritten characters from ordinary printed, or handwritten characters from ordinary documents and translating the images into a form documents and translating the images into a form that the computer can understand.that the computer can understand.

Most OCR devices include a small optical scanner Most OCR devices include a small optical scanner for reading characters and sophisticated software for reading characters and sophisticated software for analyzing what is read.for analyzing what is read.

OCR is often used on turn around documents. A OCR is often used on turn around documents. A turn around documentturn around document is computer produced is computer produced output that is ultimately returned to the computer output that is ultimately returned to the computer as machine readable input. These documents are as machine readable input. These documents are normally used by utility companies. normally used by utility companies.

OCROCR

SCANNERSSCANNERS A scanner is a light sensing input device that A scanner is a light sensing input device that

reads printed text and graphics from paper and reads printed text and graphics from paper and then changes result into a form that the computer then changes result into a form that the computer can use. can use.

Once an object has been scanned it can be Once an object has been scanned it can be displayed on the screen, stored on storage displayed on the screen, stored on storage medium, printed, faxed and e-mailed. The medium, printed, faxed and e-mailed. The resolutionresolution (clearness of an image) is measured in (clearness of an image) is measured in ddots ots pper er iinch (dpi).nch (dpi).

SCANNERS are used in desktop publishing SCANNERS are used in desktop publishing (creating newsletters or similar documents). (creating newsletters or similar documents).

TYPES OF SCANNERSTYPES OF SCANNERS FlatbedFlatbed – works similar to a photo copy – works similar to a photo copy

machine except that the results are sent to machine except that the results are sent to the computer instead of paper. A paper is the computer instead of paper. A paper is placed on a flat scanning surface and a placed on a flat scanning surface and a light shines along the length of the light shines along the length of the document.document.

Hand held or wandHand held or wand - - usually has a usually has a scanning width of approximately four scanning width of approximately four inches. It is normally used for copying inches. It is normally used for copying small images such as signatures, logos, small images such as signatures, logos, and small photographs.and small photographs.

FLATBED SCANNERSFLATBED SCANNERS

HAND HELD SCANNERSHAND HELD SCANNERS

BAR CODE READERSBAR CODE READERS This device uses laser beams to read bar codes. This device uses laser beams to read bar codes.

A A bar codebar code is an identification code that consists of is an identification code that consists of a series of vertical lines and spaces that vary in a series of vertical lines and spaces that vary in width and have numbers and letters printed at the width and have numbers and letters printed at the bottom. bottom.

They are found on a variety of products example They are found on a variety of products example books, clothes and food items and are used to books, clothes and food items and are used to encode information such as price, the name of the encode information such as price, the name of the product and manufacturer.product and manufacturer.

BARCODE READERBARCODE READER

SENSORSSENSORS

Sensors are used to measure mechanical, Sensors are used to measure mechanical, thermal, electrical and chemical quantities. thermal, electrical and chemical quantities. The measurement is recorded by the sensor The measurement is recorded by the sensor and is sent to the CPU where it is analysed and is sent to the CPU where it is analysed and the relevant output given. and the relevant output given.

USES OF A SENSORUSES OF A SENSOR regulates temperatureregulates temperature measures and regulates radiation in a measures and regulates radiation in a

nuclear plantnuclear plant measures and regulate the temperature measures and regulate the temperature

in a furnacein a furnace control traffic light signalscontrol traffic light signals Create characteristics in robots (such as Create characteristics in robots (such as

seeing, hearing, feeling etc.seeing, hearing, feeling etc. add security to a buildingadd security to a building (motion (motion

sensors)sensors)

SENSORSSENSORS

Temperature sensor

Traffic sensorTemperature sensor

MULTIMEDIA INPUTMULTIMEDIA INPUT Multimedia is the presentation of Multimedia is the presentation of

information on a computer using text, information on a computer using text, graphics, audio and video.graphics, audio and video.

Multimedia input includes:Multimedia input includes:– Voice inputVoice input– Video inputVideo input– Sound or audio input Sound or audio input

VOICE INPUTVOICE INPUT This is the process of entering data by This is the process of entering data by

speaking into a computer’s microphone. The speaking into a computer’s microphone. The microphone is attached to the sound card port microphone is attached to the sound card port in the system unit. in the system unit.

A voice recognition system is used to A voice recognition system is used to distinguish between spoken words. It can only distinguish between spoken words. It can only recognize words pre-programmed in its recognize words pre-programmed in its vocabulary. vocabulary.

Voice recognition systems can either be Voice recognition systems can either be speaker dependent or speaker independent.speaker dependent or speaker independent.

SOUND/AUDIO INPUTSOUND/AUDIO INPUT This is the process of entering any This is the process of entering any

sound into the computer such as speech, sound into the computer such as speech, music, and sound effects. music, and sound effects.

Sound can be entered using a Sound can be entered using a microphone, tape player, Compact disk microphone, tape player, Compact disk (CD) player or radio. These devices are (CD) player or radio. These devices are attached to the sound card port in the attached to the sound card port in the system unit.system unit.

VIDEO INPUTVIDEO INPUT

Video input or video capture is the Video input or video capture is the process of entering a full-motion process of entering a full-motion recording into a computer and storing it recording into a computer and storing it on a storage medium.on a storage medium.

VIDEO INPUT DEVICESVIDEO INPUT DEVICES

WEB CAMWEB CAM

The output from this camera is displayed on The output from this camera is displayed on a Web page. It can be used to show a Web page. It can be used to show weather or traffic information, work in weather or traffic information, work in progress or any thing you want to be progress or any thing you want to be displayed on the internet.displayed on the internet.

VIDEO INPUT DEVICES VIDEO INPUT DEVICES (cont’d)(cont’d)

Personal Computer (PC) cameraPersonal Computer (PC) camera

This is used by home users to record and This is used by home users to record and edit motion or still images. It is also used to edit motion or still images. It is also used to make video telephone calls (you are able to make video telephone calls (you are able to see the person as you speak to them). It is see the person as you speak to them). It is plugged in the Universal Serial Bus (USB) plugged in the Universal Serial Bus (USB) port on the system unit and usually sits on port on the system unit and usually sits on top of the monitor.top of the monitor.

VIDEO INPUT DEVICES VIDEO INPUT DEVICES (cont’d)(cont’d)

DIGITAL CAMERADIGITAL CAMERA

This allows you to take pictures and store This allows you to take pictures and store them digitally instead of on traditional films. them digitally instead of on traditional films. Images can then be transferred to the Images can then be transferred to the computer or viewed on the television.computer or viewed on the television.

Most digital cameras come with a color Most digital cameras come with a color Liquid Crystal Display (LCD) screen (similar Liquid Crystal Display (LCD) screen (similar to those on a laptop computer). You can use to those on a laptop computer). You can use the LCD screen to view the photographs the LCD screen to view the photographs taken.taken.

VIDEO INPUT DEVICES VIDEO INPUT DEVICES (cont’d)(cont’d)

DIGITAL VIDEO CAMERADIGITAL VIDEO CAMERA

This allows you to record video in a format This allows you to record video in a format that you can save in the computer. Digital that you can save in the computer. Digital videos are more clear and crisp than the videos are more clear and crisp than the traditional videos (analog videos).traditional videos (analog videos).

VOICE RESPONSE UNITSVOICE RESPONSE UNITS

These units produce computer generated These units produce computer generated voice output. They provide pre-recorded voice output. They provide pre-recorded information for users either with or without information for users either with or without request. request. Interactive Voice Response UnitsInteractive Voice Response Units (IVRs)(IVRs) consist of an automated telephone consist of an automated telephone answering system that responds with a answering system that responds with a voice menu allowing the user to make voice menu allowing the user to make choices and enter information via the choices and enter information via the keypad. IVR systems are widely used in call keypad. IVR systems are widely used in call centers as well as a replacement for human centers as well as a replacement for human switchboard operators.switchboard operators.