OUTPUT DEVICES: DISPLAY SCREENS PROFESSIONAL ENGLISH IN USE FOR COMPUTER

 

PROFESSIONAL ENGLISH IN USE FOR COMPUTER 7. OUTPUT DEVICES: DISPLAY SCREENS

 

A CRTs and LCDs The screen of a computer is often known as the monitor, or VDU (visual display unit). Inside the computer, there is a video card which processes images and sends signals to the monitor. When choosing a monitor, you have to take into account a few basics. ·         Type of display – the choice is between a CRT or an LCD screen. The Cathode Ray Tube of a monitor is similar to a traditional TV set. It has three electron guns (one for each primary colour: read, green, and blue) that strike the inside of the screen, which is coated with substances called phosphors, which glow and create colours. CRTs are cheap, but they are heavy, can flicker and emit radiation. A Liquid Crystal Display is made from flat plates with a liquid crystal solution between them. The crystals block the light in different quantities to create the image. Active-matrix LCDs use TFT (thin film transistor) technology, in which each pixel has its own transistor switch. They offer better quality and take up less space, so they are replacing CRTs. B Big screens: plasma and projection TVs EXERCISES 7.1 Read A opposite and then correct these false statements. 1 The images sh.own on a monitor are not generated by the video card. 2 All visible colours can be made from mixing the three primary colours of red, yellow and blue 7.2 Match each term with the correct definition. 1 phosphors a the frequency at which a monitor renews its image, measured in Hz 2 LCD screen b a flat-panel display which works by emitting light through a special liquid 7.3 Complete the technical specifications of this monitor with words from A opposite. 7.4 Complete these sentences with words from B opposite. 1 If you intend to set up a _____________ _____________, consider getting a very big screen, a DVD recorder and a good set of speakers. 2 A _____________-_____________ _____________ takes digital images and displays them on a screen or wall.

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