Monitors

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• Most commonly used output device.
• Monitor size is indicated by the diagonal length of viewing area.
• Common sizes are 15,17,19,21 inches.
• Larger size monitors have advantage to display more information at one time.
• Clarity is based upon the resolution, which is measured in pixels.
• Pixels are individual dots that forms image on the screen.

Basic standards of monitors resolutions

1) SVGA (Super Video Graphics Array):

• Offers resolution 800 by 660.
• Used in 15 inches monitors.

2) XGA (Extended Graphics Array):

• Offers resolution 640 by 480 pixels with 65535 and 1024 by 768 pixel with 256 colors.
• Used in 17 and 19 inches monitors.

3) SXGA (Super Extended Graphics Array):

• Offers resolutions 1280 by 1024 pixels.
• Popularly used in 19 and 21 inches monitors.

4) UXGA (Ultra Extended Graphics Array):

• Offers resolution 1600 by 1200 pixels.
• Newest standard and its popular to increase dramatically.
• Used in high engineering design and graphics arts.

Types

Cathode-Ray Tubes:

Working:

• Contains a cathode consisting of thick heated wire that is covered with a glass tube, which is vacuum sealed to eliminate resistance.
• Cathode emits stream of electrons into the tube and travels down its length.
• These electrons are attracted and accelerated by anode (positive terminal).
• After getting high speed they are strucked to phosphorescent screen at the end of tube.
• This causes to glow that part.
• String coils consists of copper wire wrapped around the picture tube itself, to create magnetic fields that steer the electron beam to distinct pixel on the screen.
• This group of distinct pixels form an image on the screen.
• Color television uses three electron beams at once.

Liquid Crystal Display (LCD) or Flat-Panel monitors :

• There are two types of LCD monitors.
• Passive matrix:
• • Creates images by scanning entire screen.
  • Requires less power but clarity is not sharp.
• Active matrix:
• • Also called as TFT (Thin Film Transistor).
  • Each pixel is independently activated.
  • More colors with clarity can be achieved.
  • Requires more power and are expensive.

Other types of monitors:

Ebook readers, data projectors, high definiton television. Specially used for reading books, making presentation, and watching television.

Ebook reader:

• Handheld, booksized devices that display text and graphics.
• Used to read books, magazines and entire books.

Data Projectors:

• Commonly used for presentation in classrooms and seminar halls.
• There are two types of projectors LCD projectors and DLP projectors.

High definition Television (HDTV):

• Set of digital television that offers good resolution and sharpness.
• Horizontal resolution is 1080 pixels and veritcal resolution is 1920 pixels.
• Allows motion Tracking.
• Allows full featured editing (view real time video and effects without rendering).
• Helpful for artists, designers, engineers etc.

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