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Chapter 5. Input and Output. Learning Objectives. Identify several types of input and output devices and explain their functions. Describe the characteristics of the input equipment that most users encounter regularly — namely, keyboards and pointing devices. - PowerPoint PPT Presentation
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Understanding Computers, Ch.5 1
Chapter 5
Input and Output
Understanding Computers, Ch.5 2
Learning Objectives Identify several types of input and output devices and
explain their functions.
Describe the characteristics of the input equipment that most users encounter regularly—namely, keyboards and pointing devices.
Explain what source data automation is and discuss how scanners and other devices can be used to accomplish it.
Understand what the term “biometrics” means and the purpose of biometric input devices.
Understanding Computers, Ch.5 3
Learning Objectives, Cont’d.
List several types of multimedia input devices and discuss their purposes.
Describe the characteristics of the output equipment that most users encounter regularly—namely, display devices and printers.
Understand what hardware devices are used for multimedia output.
Understanding Computers, Ch.5 4
Overview
This chapter covers:
Keyboards and pointing devices Scanners and related devices Biometric and multimedia input devices Various types of display devices Various types of printers Multimedia output devices
Understanding Computers, Ch.5 5
Input and Output Input devices convert data from the user into a form
understood by the computer.
Output devices convert the processed 0s and 1s into a form that the user can understand.
Hard copy—permanently recorded, such as on paper.
Soft copy—temporarily recorded, such as on a computer screen.
Understanding Computers, Ch.5 6
Keyboards
Computers usually use a keyboard for text-based input.
Keyboards can differ in number of keys, key arrangement, types of special keys, and touch.
Function keys enable software packages to be customized to meet a user's applications needs.
The numeric keypad makes it easy to enter numbers quickly.
Understanding Computers, Ch.5 8
Keyboards, Cont’d.
Portable keyboards and thumb pads are increasingly being used with portable PCs and mobile devices.
Understanding Computers, Ch.5 9
Pointing Devices
Mice
The mouse is the most common type of pointing device.
Can be mechanical or optical.
Used to select onscreen objects, issue commands, move objects, scroll through documents, etc.
Understanding Computers, Ch.5 11
Pointing Devices, Cont’d.
Electronic pens (light pen, stylus)
An alternative to the mouse to select objects or to write or draw on the screen.
Commonly used with: Graphics tablets Digital portfolios and digital pens Signature capture devices Pen-based computers Handwriting recognition technology
Understanding Computers, Ch.5 13
Pointing Devices, Cont’d.
Touch screens Used when other input
devices are impractical.
Often used when consumer input is required, as in consumer kiosks.
Understanding Computers, Ch.5 14
Pointing Devices, Cont’d.
Other common pointing devices
Joysticks and other gaming devices
Trackballs
Pointing sticks
Touch pads
Understanding Computers, Ch.5 15
Scanners and Related Devices
Source data automation involves converting source documents to digital form or initially collecting data in digital form.
Often involves scanning or reading devices.
Understanding Computers, Ch.5 16
Scanners
Scanners (optical scanners) convert hard-copy images of text pages, photographs, and drawings into digital form.
Types of scanners: Flatbed Sheet-fed Handheld Drum Three-dimensional
Quality of scanned images are measured by resolution.
Understanding Computers, Ch.5 18
Optical Mark Readers (OMRs)
Read optical marks, such as on:
Exams Census forms Voting ballots Lottery forms
Understanding Computers, Ch.5 19
Bar-Code Readers
Bar code—an optical code consisting of several bars of varying widths that form a unique, identifiable code.
Read by fixed or portable bar-code readers.
Common types: Universal Product Code (UPC) POSTNET code Proprietary codes for shippers, hospitals, and
other businesses
Understanding Computers, Ch.5 20
Understanding Computers, Ch.5 21
Optical Character Recognition (OCR) Devices
Optical characters are designed to be identifiable by humans as well as OCR device.
Widely used in turnaround documents, such as monthly bills.
Understanding Computers, Ch.5 22
Magnetic Ink Character Recognition (MICR) Readers
MICR readers can read the special magnetic characters and sort and processdocuments accordingly.
Used primarily for processing checks.
Understanding Computers, Ch.5 23
Biometric Input Devices
Used to input biometric data about a person.
Biometric data is based on unique physical characteristics (e.g. fingerprint) or personal traits (e.g. voice).
Used for access and to verify transactions.
Biometric readers can be stand-alone or built into keyboards or other hardware devices.
Understanding Computers, Ch.5 24
Multimedia Input Devices
Digital cameras record data onto digital media instead of conventional film or tape.
Images can be transferred to a PC via a cable or the storage media (such as a flash memory card with a digital still camera).
Can be digital still cameras or digital video cameras.
Understanding Computers, Ch.5 25
Multimedia Input Devices, Cont’d. Digital still cameras
Images are usually stored on flash memory cards.
Photos can usually be immediately previewed and deleted, if needed.
Photos are easily transferred to a PC to be stored and/or printed.
Camera quality is measured in mexapixels.
Digital photos can be printed at home or at a photo lab.
Understanding Computers, Ch.5 27
Multimedia Input Devices, Cont’d.
Digital video cameras
Store images on digital media (typically digital tape or optical discs).
Video can be easily transferred to a PC for editing and/or burning onto a DVD.
Can be used for videoconferencing and Web cams.
Understanding Computers, Ch.5 29
Multimedia Input Devices, Cont’d.
Audio input devices
Voice-input systems convert spoken words to digital data.
Voice input can be used to input data or commands into a PC as well as for telephony.
Music-input systems can input and record music (either original compositions or via a CD or DVD player).
Understanding Computers, Ch.5 30
Display Devices
Display device characteristics
Color vs. monochrome displays
Size (measured diagonally)
Screen resolution
Graphic standards
Understanding Computers, Ch.5 31
Display Devices, Cont’d.
CRT (cathode-ray tube) monitors—display images similar to conventional televisions.
Quality is measured in dot pitch.
Understanding Computers, Ch.5 32
Display Devices, Cont’d.
Flat-panel displays—form images by manipulating electronically-charged chemicals or gases between thin panes or glass or plastic.
Common types: Liquid crystal displays (LCD) Gas plasma
Used for monitors, televisions, handheld devices, and other consumer products.
Understanding Computers, Ch.5 33
Understanding Computers, Ch.5 34
Display Devices, Cont’d.
Smart displays
HDTV monitors
Data projectors
Emerging display technologies and applications (e.g. flexible displays, e-paper, integrated displays, etc.)
Understanding Computers, Ch.5 35
Printers Printer characteristics
Printer resolution—measured in dots per inch (dpi)
Impact vs. non-impact printing
Color vs. black and white
Personal vs. network printers
Speed
Understanding Computers, Ch.5 36
Laser Printers
The standard for business documents.
Work similarly to photocopy machines; print with toner powder.
Are usually black and white, though color laser printers are available.
Fast print speed; print one page at a time.
Understanding Computers, Ch.5 37
Understanding Computers, Ch.5 38
Ink-Jet Printers
Print with tiny drops of liquid ink.
Typically print in color.
Often the choice for home use.
Print fairly slowly, one line at a time.
Quality not quite as good as a laser printer.
Understanding Computers, Ch.5 39
Understanding Computers, Ch.5 40
Special Purpose Printers
Photo printers
Bar-code printers
Label printers
Portable printers
Plotters and wide-format ink-jet printers
Fax machines
Multifunction devices
Understanding Computers, Ch.5 42
Multimedia Output Devices
Speakers
Voice-output systems
Understanding Computers, Ch.5 43
Summary
Input and output
Keyboards
Pointing devices
Scanners and related devices
Biometric input devices
Understanding Computers, Ch.5 44
Summary, Cont’d.
Multimedia input devices
Display devices
Printers
Multimedia output devices