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Output devices

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... forth on the page and prints by impact, striking an ink-soaked ... low cost, high quality of output, capability of printing in vivid color, and ease of use. ... – PowerPoint PPT presentation

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Title: Output devices


1
Output devices
  • Szabó Norbert

2
Types of output devices
  • Monitor
  • Printer
  • Speaker
  • Plotter

3
Monitors
  • Its the most important output device
  • 2 common types
  • CRT
  • LCD
  • Featured by
  • Refresh rate
  • Resolution
  • Visible screen size
  • Response time

4
CRT monitors
  • This acronym stands for Cathode Ray Tube
  • Very widespread
  • Cheap
  • Good performance

5
Working method of CRT monitor
  • The back of the tube has a negatively charged
    cathode, so called electron gun. The electron gun
    shoots electrons down the tube and onto a
    positively charged screen. The screen is coated
    with a pattern of red, green and blue phosphor
    dots that will glow when struck by the electron
    stream. The three dots together make up a pixel.

6
LCD screens
  • LCD means Liquid Crystal display
  • Good quality
  • Environment friendly
  • (no lead in the glass)

7
How it works?
  • There is a thin liquid cristal layer between a
    horizontal and a vertical filter. Thanks to an
    appropriate voltage liquid cristals get arranged
    and light can pass the filters. This light will
    appear on the screen.
  • In color LCDs each individual pixel is divided
    into three cells, or subpixels, which are colored
    red, green, and blue. Each subpixel can be
    controlled independently to yield thousands or
    millions of possible colors for each pixel.

8
Printers
  • A computer printer, or more commonly just a
    printer, is a device that produces a hard copy of
    documents stored in electronic form, usually on
    physical print media such as paper.
  • In addition, many modern printers can directly
    interface to electronic media such as memory
    sticks or memory cards, or to image capture
    devices such as digital cameras, scanners some
    printers are combined with a scanners and/or fax
    machines in a single unit.

9
Main types of printers
  • Dot matrix
  • Inkjet
  • Laser
  • Thermal

10
Dot matrix printer
  • A dot matrix printer or impact matrix printer
    refers to a type of computer printer with a print
    head that runs back and forth on the page and
    prints by impact, striking an ink-soaked cloth
    ribbon against the paper, much like a typewriter.
    Unlike a typewriter, graphics can be produced.

11
Inkjet printers
  • Inkjet printers are a type of computer printer
    that operates by propelling tiny droplets of
    liquid ink onto paper. They are the most common
    type of computer printer for the general consumer
    due to their low cost, high quality of output,
    capability of printing in vivid color, and ease
    of use.

12
Laser Printers
  • Laser printers are printer that uses laser
    technology to print images on the paper. These
    work in a manner similar to a photocopier. The
    laser recreates the image on a negatively drum. A
    roller is charged with electricity, then a laser
    is used to remove the charge from portions of the
    roller. Powdered ink (toner) sticks to the parts
    of the roller that were hit by the laser, and
    this toner is transferred from the roller to the
    paper. Then the ink is baked into the paper using
    a heater.

13
Speaker
  • Speakers allows the computer to display sound.
  • There are built-in ones, but you can choose
    external types too. Its better, because it
    provides a better quality even can perform
    surround sounding which is the best choice for
    games and videos.

14
Plotter
  • A plotter is a vector graphics printing device
    that connects to a computer.
  • Plotters print their output by moving a pen
    across the surface of a piece of paper. This
    means that plotters are restricted to line art,
    including text, but do so very slowly because of
    the mechanical movement of the pens. Plotters are
    used primarily in technical drawing where they
    have the advantage of working on very large paper
    sizes while maintaining high resolution.

15
Happy end
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