Alternative forms for commands

(1)

Chapter 5 Input Devices

• What Is Input? • The Keyboard • The Keyboard • Pointing Devices • Voice Input

• PDAs, Tablet PCs, and Smart Phones

• Digital Cameras

1

• Video Input • Scanners • Terminals • Biometric Input

Information Technology Kontemporer, FMIPA UGM

What Is Input?

The two basic types of input:

 Unprocessed text,

 Data

numbers, images, audio, and video

 Instructions

 Programs

 Commands

 User responses

2

 User responses

 AnInput deviceis

(2)

The Computer Keyboard

Thekeyboardareas  Typing area  Numeric keypad  Numeric keypad  Function keys, special

keys that issue commands

 Often used with other keys for shortcuts

3

Types of keyboards:  Standard USB or PS1

 Wireless (communicates via a receiver)  Built-in keyboards (notebooks)

The Keyboard

Alternative forms for commands

Key Menu |

 Many programs allow you to use

Command Combination Command Button

Copy Shift+F2 or Edit | Copy

Ctrl+C

Open Ctrl+F12 File | Open

P t Ct l+V Edit | P t

ow you o use key combination, menu, or button to obtain same result

4

Paste Ctrl+V Edit | Paste

Theinsertion point

 Blinking vertical bar that indicates where next character you type will display

(3)

Pointing Devices

Amouseis:

 Pointing device that fits under palm of hand

 Pointing devicecontrols movement of pointer, also called mouse pointer

 Mechanical mouse

 has rubber or metal ball on underside

Also

 Optical mouse (light)

mouse buttons

wheel button

ball

5  Optical mouse (light)

 Laser mouse

 Wireless mouse

mouse pad

Pointing Devices

The optical mouse:

Inside each optical mouse is a small camera that takes more than a thousand snapshot pictures every second. A small LED (light-emitting diode) provides light underneath the mouse, helping to highlight slight differences in the surface underneath the mouse.  No moving mechanical

parts inside

 Senses light to detect mouse’s movement  More precise than mechanical mouse

6

mechanical mouse  Connects using a

(4)

Other Pointing Devices

Atrackballis:

 A stationary pointing device with a ball on its top

 To move pointer rotate ball  To move pointer, rotate ball

with thumb, fingers, or palm of hand

Atouch screen:

 Touch areas of screen with finger or other device  Often used with kiosks

7  Often used with kiosks

 Latest Developments: micro-touch privacy glass for liquid crystal displays

 Actual touch registers up to 1mm (0.04”)

before the physical touch on the Touch Surface.

 Surface acoustic wave touchscreens

http://www.neuro-logic.com/saw.htm

Other Pointing Devices

Touchpadand apointing stick:

 Touchpadis small, flat, rectang lar pointing de ice rectangular pointing device sensitive to pressure and motion

 Pointing stickis pointing device shaped like pencil eraser

positioned between keys on keyboard

8

(5)

Other Pointing Devices

Joystickand Wheel  Joystickis vertical

lever mounted lever mounted on a base  Wheelis

steering-wheel-type input device

 Pedal simulates car brakes and

9 car brakes and

accelerator

Other Pointing Devices

Light pen:

 Handheld input device that can detect light

can detect light

 The tip of the light pen contains a light-sensitive element which, when placed against the screen, detects the light from the screen enabling the computer to identify the location of the pen on the screen.

Stylus:

A li h k i h

10

 Looks like a ballpoint pen, but uses pressure to write text and draw lines

 Used withgraphics tablets,

flat electronic boards

A light pen can work with any CRT-based monitor, but cannot work with LCD screens,

(6)

Voice Input

How does voice recognitionwork?

Step 2. An analog-to-digital converter (ADC) translates sound waves into digital measurements computer can process Measurements include pitch volume silences and

Step 1. A user dictates text into a microphone.

process. Measurements include pitch, volume, silences, and phonemes. Phonemes are sound units such as awand guh.

10010111010110101100001101

Step 3. Software compares spoken measurements with those in its database to find a match or li t f ibl t h

Step 4. To narrow a list down, software presents user with a list of choices or uses a natural language component to predict most likely match. User may correct any selection

d b ft

11

list of possible matches.

Matches

made by software.

Natural Language Engine

Other Input

MIDI (musical instrument digital interface):

 E t l d i h

 External device, such as electronic piano keyboard, to input music and sound effects

 General MIDI's most recognized

feature is the defined list of sounds or "patches" However

12

(7)

PDAs, Tablet PCs, and Smart Phones

Entering data into a PDA:

13

PDAs, Tablet PCs, and Smart Phones

A docking station is:  An external device that

holds mobile computer holds mobile computer  It provides connections to

peripherals

(8)

PDAs, Tablet PCs, and Smart Phones

What is a smart phone?  Users can input and send

text messages, graphics, text messages, graphics, pictures, video clips, and sound files

 Many have a built-in or attachable camera

15

Digital Cameras

What is adigital camera?  Allows you to take

digital pictures  Images viewable

immediately on

camera if LCD screen is provided

 Download image files to computer

16 p

 Post pictures to Web  Print (sometimes with

purpose built printer)  Edit image files using

(9)

Digital Cameras

How does a digital camera work?

Step 1. Point to the image to photograph and take picture. Light passes into the lens of the

Step 2. Image is focused on a chip called a charge-coupled device (CCD).

Step 3. CCD generates an analog signal that represents the image.

l i l i d g p

camera.

( )

Step 4. Analog signal is converted to digital signal by analog-to-digital converter (ADC).

Step 5. Digital signal processor (DSP) adjusts quality of image and usually stores digital image on miniature mobile storage media in the camera.

Step 6. Images are transferred to a computer’s hard disk by plugging one

Step 7. Using software

17

computer s hard disk by plugging one end of the cable into a camera and the other end into a computer; or images are copied to hard disk from storage media used in the camera.

p g supplied with the camera, images are viewed on screen, incorporated into documents, edited, and printed.

Digital Cameras

Image resolution:

 Sharpness and clarity of image

image

 The higher the resolution, the better the image quality, but the more expensive the camera

 Pixel (picture element) is single point in

18

is single point in electronic image

(10)

Video Input

Video input:

 The process of entering full-motion images into computerg p

 AVideo capture cardis an adapter card that converts analog video signal into a digital signal that computer can use

Di it l id (DV)

19

 Digital video (DV) camerarecords video as digital signals

Video Input

PC video camera& Web cam  DV camera used to capture video

and still images and to make and still images, and to make video telephone callson Internet

 Also called PC camera

 Web camc—cvideo camera whose output displays on a Web page

20

Video conferencing:

(11)

Scanners and Reading Devices

What is ascanner?

Flatbed

 Light-sensing device that

reads printed text and _{Pen or}

Handheld

Sheet-fed

reads printed text and graphics

 Used for image processing, converting paper documents into electronic images

21

Drum

Scanners and Reading Devices

Flatbed scanner:

Step 1. Document to be scanned is placed face down on the glass window.

Step 2. Bright light moves underneath scanned document.

Step 3. Image of the document is reflected into a series of mirrors.

Step 6 Users can print image

Step 4. Light is converted to analog electrical current that is

22 Step 6. Users can print image, e-mail it, fax it, include it in a document, or place it on a Web page. current that is

converted to digital signal by an analog-to-digital converter (ADC).

(12)

Scanners and Reading Devices

Anoptical readeris:

 Device that uses light source to read characters, marks, and codes and then converts them into digital data  Optical character recognition

(OCR)reads characters in

OCR font

 Optical mark recognition

(OMR)reads hand-drawn pencil

marks such as small circles

and codes and then converts them into digital data

23 marks, such as small circles

 Bar code scanner

Scanners and Reading Devices

What is abar code reader?

 Uses laser beams to read bar codes

What is abar code?

 Identification code that consists of a set of vertical lines and spaces of different widths

 Universal Product Code (UPC)

24

(13)

A Magnetic-ink character recognition (MICR) reader:

Scanners and Reading Devices

 Can read text printed with magnetized ink  Can read text printed with magnetized ink  Banking industry almost exclusively uses MICR

for check processing

25

Scanners and Reading Devices

A data collection device:

 Obtains data directly at location where transaction or event takes place

 Transmits data over network

or Internet

 Often used to assist in stock

26

(14)

Terminals

Point of sale (POS) terminal (s):

 Records purchases, processes credit or debit cards, and updates inventory

 Swipe credit or debit card through card

readerc—creads customer’s personal data

from magnetic strip

Automated teller machine (ATM) (s):  Self-service banking machine

that connects to a host

27

computer through a network A smart displayis:

 A thin monitor that detaches from computer to function as

portable wireless touchscreen

Biometric Input

Biometrics are used when a system :

 Authenticates a person’s identity by verifying personal

by verifying personal characteristic

 Fingerprint scannercaptures

curves and indentations of fingerprint

 Hand geometry systemmeasures

(15)

Biometric Input

What are examples of biometric technology?  Voice verification system compares live

speech with stored voice pattern speech with stored voice pattern

 Signatureverification system recognizes shape of signature

 Retina & Irisrecognition systems

 Biometric data is sometimes stored

onsmart card which stores

29

on smart card, which stores

personal data on microprocessor embedded in card

Information Technology Kontemporer, FMIPA UGM Input Devices for Physically Challenged Users

What input devices are available for those with physical limitations?

 Keyguard allows users to rest  Keyguard allows users to rest

hands on keyboard without accidentally pressing keys

 Head-mounted pointer controls pointer on screen

 New developments include gesture

iti d t i d

30