NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Competencies Competencies  Input  Input devices including keyboard, pointing devices and scanning devices  Image capturing devices including digital cameras, digital video cameras and audio input devices  Output  Output devices including monitors, printers and audio output devices  Combination input and output devices, including fax machines, multifunctional devices, internet telephones and terminals Chapter 7 Input and Output Device

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY What’s input? What’s input?  Input is any data or instructions that are used by a computer  Input devices: hardware used to translate the data that people understand into a form that the computer can process Keyboard entry: basic input device for a computer Keyboard entry: basic input device for a computer Common used types Common used types Traditional keyboards: full-size, rigid, rectangular keyboards that include function, navigational, and numeric keys. Traditional keyboards: full-size, rigid, rectangular keyboards that include function, navigational, and numeric keys. Flexible Keyboards: fold and roll up for easy packing and storage, designed for mobile users Flexible Keyboards: fold and roll up for easy packing and storage, designed for mobile users Ergonomic keyboards: similar to traditional keyboards. The arrangement is not rectangular and a palm rest is provided. Used to alleviate wrist strain Ergonomic keyboards: similar to traditional keyboards. The arrangement is not rectangular and a palm rest is provided. Used to alleviate wrist strain

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Wireless Keyboards: transmit input through air. More flexible and convenient Wireless Keyboards: transmit input through air. More flexible and convenient PDA Keyboard: used for PDA and other small electronic devices PDA Keyboard: used for PDA and other small electronic devices Special numeric keypad Special numeric keypad Famous manufacturers: Logitech, Microsoft, BenQ, Philips, A4tech Famous manufacturers: Logitech, Microsoft, BenQ, Philips, A4tech Features: Features: numeric keypad: NUM Lock numeric keypad: NUM Lock Toggle key: CAPS Lock Toggle key: CAPS Lock Combination keys: Ctrl key, ALT key, Tab key, Shift Key Combination keys: Ctrl key, ALT key, Tab key, Shift Key Navigational Key Navigational Key Functional Key Functional Key Escape Key Escape Key

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Pointing Devices Pointing Devices  One of the most natural devices that provide a comfortable gestures and interface for users  Common pointing devices: mouse, joystick, touch screen, light pen and stylus  mouse Control pointer displayed on the monitor Control pointer displayed on the monitor Mouse pointer usually appears in an arrow shape, also changes depending on different applications. Mouse pointer usually appears in an arrow shape, also changes depending on different applications. Have two or more buttons to select command options and control pointer Have two or more buttons to select command options and control pointer Usually have a wheel button that can be rotated to scroll through information displayed on the screen. Usually have a wheel button that can be rotated to scroll through information displayed on the screen.  Three basic types of mice: Mechanical mouse: traditional types, has a ball on the button, attached with cord to the system unit Mechanical mouse: traditional types, has a ball on the button, attached with cord to the system unit

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Optical mouse: Optical mouse: having no moving parts, emit and sense light to detect mouse movement. having no moving parts, emit and sense light to detect mouse movement. used on any surface. More precise and don’t require periodic cleaning used on any surface. More precise and don’t require periodic cleaning Cordless or wireless mouse: Cordless or wireless mouse: battery-powered device battery-powered device use infrared light to communicate with the system use infrared light to communicate with the system should be used together with a receiver on the system unit should be used together with a receiver on the system unit  other devices similar to a mouse Trackball: roller ball Trackball: roller ball Touch pad: moving and tapping the finger Touch pad: moving and tapping the finger Pointing stick: located in the middle of the surface, such as IBM Pointing stick: located in the middle of the surface, such as IBM  Joystick: popular used input device for computer games. popular used input device for computer games. varying pressure, speed, direction, buttons and triggers to control games varying pressure, speed, direction, buttons and triggers to control games

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY  Touch Screen: A particular monitor with a clear plastic outer layer. A particular monitor with a clear plastic outer layer. Behind the layer are crisscrossed invisible beams of infrared light Behind the layer are crisscrossed invisible beams of infrared light Select actions and commands by touching the screen with a finger Select actions and commands by touching the screen with a finger Used to use, especially when people need information quickly. Used to use, especially when people need information quickly. Popular used at restaurants, information center, bus/train/airport stations Popular used at restaurants, information center, bus/train/airport stations  Light Pen A light-sensitive penlike input device A light-sensitive penlike input device Placed against the monitor Placed against the monitor Close a photoelectric circuit and identifies the spot for entering and modifying data Close a photoelectric circuit and identifies the spot for entering and modifying data Used for handheld electronic devices, such as Smart mobile phone. Used for handheld electronic devices, such as Smart mobile phone.

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY  Stylus Similar to light pen Similar to light pen A penlike devices commonly used by PDA and Tablet PC A penlike devices commonly used by PDA and Tablet PC Use pressure to draw images and input data on a screen Use pressure to draw images and input data on a screen Used together with handwriting recognition software that can translate handwritten notes into a form that computer can process Used together with handwriting recognition software that can translate handwritten notes into a form that computer can process

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Scanning Device Scanning Device  Convert scanned text and images into a form that computer can process  Three types: optical scanners, bar code readers, and character and mark recognition devices  Optical Scanners(Also known as scanners) Do not recognize individual letters or images Do not recognize individual letters or images Recognize light, ark and colored area that make up text or image Recognize light, ark and colored area that make up text or image Save scanned document in files(usually image files, such as JPEG file) that can be further processed by computer. Save scanned document in files(usually image files, such as JPEG file) that can be further processed by computer.  Two types of optical scanners: Flatbed scanner: Flatbed scanner: much like a copy machine much like a copy machine Place the text or image on the glass surface and the scanner scans and records it from below Place the text or image on the glass surface and the scanner scans and records it from below

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Portable scanner: Portable scanner: A handheld device A handheld device Directly contact the text or image and then slide across it Directly contact the text or image and then slide across it  Card Readers: Cards: Cards: Credit card, debit card, access card(parking card or building card), identification card, telephone card Credit card, debit card, access card(parking card or building card), identification card, telephone card Card Readers: Card Readers: Used to read information from and write information into the card, such as user’s name, identification number and signature embossed on the card Used to read information from and write information into the card, such as user’s name, identification number and signature embossed on the card Two types: Two types: Magnetic card reader: read information stored on a thin strip on the back of the card Magnetic card reader: read information stored on a thin strip on the back of the card

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Radio Frequency Card reader: Radio Frequency Card reader: RFC: has a small embedded RFID microchip RFC: has a small embedded RFID microchip RFCR: RFCR:  do not require the card make contact with the reader  can read the information from a RFC which is several inches away from the card.

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY  Bar Code Readers: Bar Code Readers or Scanners Bar Code Readers or Scanners Handheld wand readers Handheld wand readers Platform scanners Platform scanners Contain photoelectric cells that can read bar codes or vertical zebra- striped marks on the product container Contain photoelectric cells that can read bar codes or vertical zebra- striped marks on the product container Universal Product Code(UPC) Universal Product Code(UPC) Bar Code Reader System used by supermarkets Bar Code Reader System used by supermarkets Scan the UPC code on the product container. Scan the UPC code on the product container. Each code corresponds to a product’s description in the database, such as the price, inventory level. Each code corresponds to a product’s description in the database, such as the price, inventory level. Self-checkout stations Self-checkout stations

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY  Character and Mark Recognition Devices: Scanners used to recognize special characters and marks Scanners used to recognize special characters and marks Used for special applications, such as examinations. Used for special applications, such as examinations. Three types: Three types: Magnetic-ink character recognition(MiCR): Magnetic-ink character recognition(MiCR): used by banks to automatically read the numbers or signals on the bottom of checks or deposit slips, which are recorded by the special magnetic ink. used by banks to automatically read the numbers or signals on the bottom of checks or deposit slips, which are recorded by the special magnetic ink. Optical-character recognition(OCR) Optical-character recognition(OCR) Actually is a handheld wand reader which can read the special preprinted characters, such as retail price tags on the product container. Actually is a handheld wand reader which can read the special preprinted characters, such as retail price tags on the product container. Some applications: handwriting recognition, license plate recognition Some applications: handwriting recognition, license plate recognition

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Optical-mark recognition(OMR) Optical-mark recognition(OMR) Sense the presence of absence of a mark, such as a pencil mark Sense the presence of absence of a mark, such as a pencil mark Often used to score multiple-choice tests, such as GRE, SAT Often used to score multiple-choice tests, such as GRE, SAT

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Image Capturing Devices Image Capturing Devices  Optical scanners make copy from an original image, while image capturing devices create or capture original images.  Digital Cameras Similar to traditional cameras except that record the digital images on a disk or memory rather than a film. Similar to traditional cameras except that record the digital images on a disk or memory rather than a film.  Digital Video Cameras Record motion digitally on a disk or memory Record motion digitally on a disk or memory WebCams: WebCams: specialized digital video cameras used by a computer to record motion images and send them to the Internet specialized digital video cameras used by a computer to record motion images and send them to the Internet

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Audio Input Devices Audio Input Devices  Convert sounds, such as human voice and music into a form that can be processed by computers  Most widely used audio-input device: microphone  Voice recognition system Use a microphone, sound card and special software to record the human voice and recognize them to create a document. Use a microphone, sound card and special software to record the human voice and recognize them to create a document.

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY What’s Output? What’s Output?  Output is processed data or information, such as text, images, photos, videos.  Output devices: hardware used to provide or create output. hardware used to provide or create output. Translate information processed by computers into a form that human can understand. Translate information processed by computers into a form that human can understand.  Widely Used Output devices: monitors, printers, audio-output devices  Monitors(Display Screen): Used to present visual images of text and graphics Used to present visual images of text and graphics Soft Copy (corresponds to hard copy): output to the monitor Soft Copy (corresponds to hard copy): output to the monitor Features: Features: Clarity: quality and sharpness of the images displayed on the monitor, which include resolution, dot pitch, refresh rate and size Clarity: quality and sharpness of the images displayed on the monitor, which include resolution, dot pitch, refresh rate and size

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Resolution: Resolution:  One of the most important features of monitors  Pixels(Picture Elements): the smallest unit to form an image  Resolution is expressed as a matrix of the pixels  Example: 1280*1024 The monitor is scanned by row and column scanning lines. The monitor is scanned by row and column scanning lines. 1280: the number of column scanning lines 1280: the number of column scanning lines 1024: the number of row scanning lines 1024: the number of row scanning lines pixels: the intersection of the row and column scanning lines. pixels: the intersection of the row and column scanning lines. the number of pixels: 1280*1024= the number of pixels: 1280*1024=  The higher a monitor’s resolution, the clearer the image produced  The common monitor standard and resolution

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Dot(Pixel ) Pitch: Dot(Pixel ) Pitch:  The distance between each pixel.  The higher resolution of a certain size monitor, the lower the dot pitch  The lower the dot pitch, the clearer the images produced  Commonly dot pitch of the newer monitor:.31mm

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Refresh Rate: Refresh Rate:  Indicates how often the monitor is scanned(updated) or redrawn by the row and column scanning lines.  75hz means that the monitor is redrawn 75 times each second.  Monitors with refresh rate lower than 75hz appears to flicker and cause eye strain.  The faster the refresh rate, the better the quality of the images displayed Size Size  Measure by the diagonal length of a monitor’s viewing area  Common size: 15,17,19,21inches. Actually the features of the monitor are restricted each other, the 14’inch monitor usually has the resolution 800*600 and.22mm dot pitch

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Cathode-Ray Tubes monitor(CRT): Cathode-Ray Tubes monitor(CRT):  Ever popular used monitors for desktop computers  Similar to televisions in size and technology  Primary advantages: low cost, excellent resolution, brightness, color and contrast  Primary disadvantages: bulky, occupy large space and high radiation Flat-panel monitors Flat-panel monitors  Rapidly replacing CRT monitors due to that it is much thinner and require less power than CRTs

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY  LCD monitors(Liquid Crystal Display) Passive-matrix monitors(dual-scan monitors): Passive-matrix monitors(dual-scan monitors): scanning the entire screen and require very little power, however the clarity is not very sharp scanning the entire screen and require very little power, however the clarity is not very sharp Active-matrix monitors (thin film transistor monitors: TFT) Active-matrix monitors (thin film transistor monitors: TFT) Each pixel is independently activated instead scanning the entire screen. Each pixel is independently activated instead scanning the entire screen. Can display more colors with better clarity. Can display more colors with better clarity. More expensive and require more power More expensive and require more power

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Other monitors for specialized applications Other monitors for specialized applications  E-books: handheld, book-sized devices that displays text and graphics. handheld, book-sized devices that displays text and graphics. newspapers, magazines and books can be downloaded form web and read on E-books newspapers, magazines and books can be downloaded form web and read on E-books  Data-projectors: Similar to slide projectors and used for presentations Similar to slide projectors and used for presentations  High-definition television (HDTV) a digital television that can be used to readily freeze video sequences to create high-quality still images. a digital television that can be used to readily freeze video sequences to create high-quality still images. much clearer than regular television much clearer than regular television

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY  Printers Be used to present information on paper, which is often called hard copy Be used to present information on paper, which is often called hard copy Features: Features: resolution: resolution: similar to monitor resolution and is a measure of the clarity of produced images similar to monitor resolution and is a measure of the clarity of produced images Measure in dpi(dots per inch), such as 1200dpi. Measure in dpi(dots per inch), such as 1200dpi. The higher the dpi, the better the quality of produced images The higher the dpi, the better the quality of produced images Color capability(black and color) Color capability(black and color) have the option to print either black image or color image have the option to print either black image or color image Speed: measured in the number of pages printed per minute Speed: measured in the number of pages printed per minute Memory: Used to store printing instructions and documents waiting to be printed, which support offline printing. Memory: Used to store printing instructions and documents waiting to be printed, which support offline printing.

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Stylus Printer(Needle Printer): Stylus Printer(Needle Printer): hitting the ribbon with the needles on the print head to produce outputs on the paper hitting the ribbon with the needles on the print head to produce outputs on the paper Less expensive and mainly used for print bills or notes by banks Less expensive and mainly used for print bills or notes by banks Less clarity, slow and much noisy Less clarity, slow and much noisy Ink-jet printer Ink-jet printer Spray ink at high speed onto the paper surface. Spray ink at high speed onto the paper surface. Produces high-quality images, relatively inexpensive, and more quiet than stylus printer Produces high-quality images, relatively inexpensive, and more quiet than stylus printer Mainly used as photo printers Mainly used as photo printers The mainly disadvantage is that the ink cartridges are vey expensive, even than a ink-jet printer. The mainly disadvantage is that the ink cartridges are vey expensive, even than a ink-jet printer.

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Laser Printers Laser Printers Use the laser technology similar to that used by photocopy machine Use the laser technology similar to that used by photocopy machine Use laser beams and drums to produce high-quality outputs Use laser beams and drums to produce high-quality outputs More faster than ink-jet printers and stylus printers More faster than ink-jet printers and stylus printers The drums are very expensive, especially the color drums for color laser printers The drums are very expensive, especially the color drums for color laser printers Personal laser printers: Personal laser printers: typically do not support color and are less expensive and used by single users typically do not support color and are less expensive and used by single users Shared laser printers: Shared laser printers: support color and more expensive and used by group users in company. support color and more expensive and used by group users in company. much faster than personal laser printers. much faster than personal laser printers.

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Thermal printers Thermal printers Use heat elements to produce output on heat-sensitive paper Use heat elements to produce output on heat-sensitive paper Only used for scientific labs or by artists to produce high-quality images Only used for scientific labs or by artists to produce high-quality images Primary used in professional art and design work Primary used in professional art and design work Other printers Other printers Dot-matrix printers(stylus printers) Dot-matrix printers(stylus printers) Plotters Plotters Special-purpose printers used to create maps, images, architectural and engineering drawings. Special-purpose printers used to create maps, images, architectural and engineering drawings. Widely used by graphic artists, engineers and architects Widely used by graphic artists, engineers and architects Photo printers: Photo printers: Normally color ink-jet printers to print images on photo-quality paper. Normally color ink-jet printers to print images on photo-quality paper. Portable printers: small and lightweight printers for laptop computers Portable printers: small and lightweight printers for laptop computers

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY  Audio output devices Translate digital audio into sounds that people can understand Translate digital audio into sounds that people can understand Widely used devices: Widely used devices: Speakers and headphones Speakers and headphones Connect to audio card and play music Connect to audio card and play music Digital music players(digital media players) Digital music players(digital media players)

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY  Combination input and output devices The devices combine input and output capabilities The devices combine input and output capabilities Fax machine: Fax machine: Used by office to send and receive fax through telephone lines Used by office to send and receive fax through telephone lines Sending fax(similar to a scanner): Sending fax(similar to a scanner): scan the image of a document and convert it into the digital format that can be sent over standard telephone lines. scan the image of a document and convert it into the digital format that can be sent over standard telephone lines. Receiving fax(Similar to a printer): Receiving fax(Similar to a printer): print the document received from the telephone lines on the paper. print the document received from the telephone lines on the paper. Multifunctional devices (MFD): Multifunctional devices (MFD): Combine the capabilities of a scanner, printer, fax, and copy machine. Combine the capabilities of a scanner, printer, fax, and copy machine. Advantages: The cost are much slower and require much less space than a single-function devices. Advantages: The cost are much slower and require much less space than a single-function devices. Disadvantages: the quality and functionality are not as good as the separate one Disadvantages: the quality and functionality are not as good as the separate one

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Internet Telephones Internet Telephones Also known as: telephony, Internet telephony, IP telephony and Voice over IP(VoIP) Also known as: telephony, Internet telephony, IP telephony and Voice over IP(VoIP) Transmit telephone calls over computer networks though special hardware, software and Internet Transmit telephone calls over computer networks though special hardware, software and Internet Three approaches: Three approaches: Computer to computer Computer to computer Computer to traditional telephone Computer to traditional telephone Traditional telephone to traditional telephone Traditional telephone to traditional telephone

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY Terminals Terminals an input and output device that connect you to a mainframe computer an input and output device that connect you to a mainframe computer Three types of terminals Three types of terminals Dumb terminals: Dumb terminals: can be used to input and receive data, but cannot process data independently. can be used to input and receive data, but cannot process data independently. used to gain access and to send information to a mainframe computer used to gain access and to send information to a mainframe computer Usually used for airline reservations, book information check Usually used for airline reservations, book information check Intelligent terminals: a microcomputer Intelligent terminals: a microcomputer Network terminals, also known as thin client Network terminals, also known as thin client without a hard disk and must rely on a server for application and system software. without a hard disk and must rely on a server for application and system software. Ever used by large organizations. Ever used by large organizations.