output information http://www.computersight.com/tags/output information New posts about output information Computer Output http://www.computersight.com/Hardware/Computer-Output.39867 What is output?

  • Data that has been processed into a useful form,
    called information.
  • Output device is any hardware component that can convey
    information to user.

What is a display device?

  • Output device that visually conveys information on display device sometimes
    called soft copy.
  • Monitor houses display device as separate peripheral

What is a CRT monitor?

  • Contains cathode-ray tube (CRT)
  • Screen coated with tiny dots of phosphor material
  • Each dot consists of a red, blue, and green phosphor
  • Common sizes are 15, 17, 19, 21, and 22 inches
  • Viewable size is diagonal measurement of actual viewing area

What is resolution?

  • Sharpness and clarity of image
  • Higher resolution makes image sharper, displays more text on screen, makes some elements smaller
  • Refresh rate is speed at which monitor redraws images on screen

How does video travel from the processor to a CRT monitor?

    Video card (also called a graphics card) converts digital output from computer into analog video signal

    • Step 1: The processor sends digital video data to the video card.
    • Step 2: The video card's digital-to-analog converter (DAC) converts the digital video data to an analog signal.
    • Step 3: The analog signal is sent through a cable to the CRT monitor.
    • Step 4: The CRT monitor separates the analog signal into red, green, and blue signals.
    • Step 5: Electron guns fire the three color signals to the front of the CRT.
    • Step 6: An image is displayed on the screen when the electrons hit phosphor dots on the
    • back of the screen.

    What are various video card configurations?

    What is a flat panel display?

    • Uses liquid crystal display
    • Also called LCD monitor
    • Takes up less desk space than CRT monitor
    • Consumes less than one-third the power

    How does LCD work?

    • Step 1. Panel of fluorescent tubes emits light waves through polarizing glass filter, which guides light toward layer of liquid crystal cells.
    • Step 2. As light passes through liquid crystal, electrical charge causes some of the cells to twist, making light waves bend as they pass through color filter.
    • Step 3. When light reaches second polarizing glass filter, light is allowed to pass through any cells that line up at the first polarizing glass filter. Absence and presence of colored light cause image to display on the screen.

    What is a printer?

    • Output device that produces text and graphics on paper
    • Result is hard copy, or printout
    • Two orientations: portrait and landscape

    What is a dot-matrix printer?

    • Impact printer that produces printed images when tiny wire pins strike ribbon
    • Impact printer forms characters by striking mechanism against inked ribbon that contacts paper

    What is a line printer?

    • High-speed impact printer that prints entire line at a time
    • Speed measured in lines per minute (lpm)
    • Band printer prints fully formed characters using a hammer mechanism
    • Shuttle-matrix printer is high-speed printer that works like dot-matrix printer

    What is an ink-jet printer?

    • A type of nonimpact printer that sprays tiny drops of liquid ink onto paper
    • Nonimpact printer forms characters and graphics without striking paper
    • Prints in black-and-white or color on a variety of paper types

    What is a laser printer?

    • High-speed, high-quality nonimpact printer
    • Prints text and graphics in very high-quality resolution, ranging from 600 to 2,400 dpi
    • Typically costs more than ink-jet printer, but is much faster

    How does a laser printer work?

    • Step 1. After user sends an instruction to print a document, drum rotates as gears and rollers feed sheet of paper into printer.
    • Step 2. Rotating mirror deflects low-powered laser beam across surface of drum.
    • Step 3. Laser beam creates a charge that causes toner to stick to drum.
    • Step 4. As drum continues to rotate and press against paper, toner transfers from drum to paper.
      • Step 5. Set of rollers uses heat and pressure to permanently fuse toner to paper.

    What is the resolution of a printer?

    • Sharpness and clarity
    • Measured by number of dots per inch (dpi) printer can output

    What is a thermal printer?

    • Generates images by pushing electrically heated pins against heat-sensitive paper
    • Dye-sublimation printer, (also called a digital photo printer) uses heat to transfer dye to specially coated paper


    What is an audio output device?

    Computer component that produces music, speech, or other sounds Speakers and headsets are common devices.

    What is a facsimile (fax) machine?

    Device that transmits and receives documents over telephone lines

    What is a multifunction peripheral?

    Provides functionality of printer, scanner, copy machine, and fax machine

    What is a data projector?

    Device that takes image from computer screen and projects it onto larger screen

    What is force feedback?

    • Sends resistance to joystick or wheel in response to actions of user
    • Fluorescent tube panel
    • Polarizing glass filter
    • Alignment layer
    • Transparent electrodes
    • Color filter
    • Liquid crystal cells
    • landscape
    • portrait

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