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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.
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Chapter 5 Input and Output Understanding Computers, Ch.5
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
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
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
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
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
Keyboards, Cont’d. • Portablekeyboardsand thumb pads are increasingly being used with portable PCs and mobile devices. Understanding Computers, Ch.5
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
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
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
Pointing Devices, Cont’d. • Other common pointing devices • Joysticks and other gaming devices • Trackballs • Pointing sticks • Touch pads Understanding Computers, Ch.5
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 readingdevices. Understanding Computers, Ch.5
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
Optical Mark Readers (OMRs) • Read opticalmarks, such as on: • Exams • Census forms • Voting ballots • Lottery forms Understanding Computers, Ch.5
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
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
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
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
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
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
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
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
Display Devices • Display device characteristics • Color vs. monochrome displays • Size (measured diagonally) • Screen resolution • Graphic standards Understanding Computers, Ch.5
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
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
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
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
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
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
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
Multimedia Output Devices • Speakers • Voice-output systems Understanding Computers, Ch.5
Summary • Input and output • Keyboards • Pointing devices • Scanners and related devices • Biometric input devices Understanding Computers, Ch.5
Summary, Cont’d. • Multimedia input devices • Display devices • Printers • Multimedia output devices Understanding Computers, Ch.5