Display units


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Display units

  1. 1.  The cathode rayed tube can easily increase the monitor’s brightness byreflecting the light. They produce more colours The Cathode RayTube monitors have lower price rate than the LCDdisplay or Plasma display. The quality of the image displayed on a Cathode RayTube is superior tothe LCD and Plasma monitors. The contrast features of the cathode ray tube monitor are consideredhighly excellent.
  2. 2.  They have a big back and take up space on desk. The electromagnetic fields emitted by CRT monitors constitute a healthhazard to the functioning of living cells. CRTs emit a small amount of X-ray band radiation which can result in ahealth hazard. Constant refreshing of CRT monitors can result in headache. CRTs operate at very high voltage which can overheat system or result inan implosion Within a CRT a strong vacuum exists in it and can also result in aimplosion They are heavy to pick up and carry around
  3. 3. A CRT monitor contains millions of tiny red, green, and blue phosphor dotsthat glow when struck by an electron beam that travels across the screento create a visible image. In a CRT monitor tube, the cathode is a heatedfilament.The heated filament is in a vacuum created inside a glass tube.The electrons are negative and the screen gives a positive charge so thescreen glows.
  4. 4.  Larger viewing angle, 160º compared to LCD 40º & rear projection 120º.(Allows a larger audience to be able to view the image reproduction) No projection throw distance limitations. All plasma display units are considerably thinner in width than thecathode ray tube monitors. Most plasma display units are either free standing or can be mounted ona ceiling or wall. The plasma display units has a clearer image, brighter viewing angle,better colour quality and higher contrast ratio than the CRT and LCDdisplay units.
  5. 5.  Compared to other display units the plasma display unit has a very shortlife span, the manufactures estimate the life span to be around 20,000hours to 30,000 hours (at a rate of 4 hours ofTV a day that gives only13.7 years). As your plasma display unit gets older its brightness gets dimmer. Plasma display units are considerably more expensive than cathode raytube monitors. Plasma display units must be handled carefully because they are a veryfragile display unit.
  6. 6.  the television lights up thousands of tiny dots with a high-energy beamof electrons. In most systems, there are three pixel colours -- red, greenand blue which are evenly distributed on the screen. By combining thesecolours in different proportions, the television can produce the entirecolour spectrum.The phosphors on the screen of the plasma enhancesthe viewing pleasure
  7. 7.  The sharpness of a LCD display is at maximum tweakness. Zero geometric distortion at the native resolution of the panel. High peak intensity produces very bright images. Best for brightly litenvironments. Screens are perfectly flat. Thin, with a small footprint. Consume little electricity and produce little heat The LCD display unit is very light and can be put anywhere or movedanywhere in the house. Lack of flicker and low glare reduce eyestrain.
  8. 8.  After a while the LCD display the some of the pixels will die you will see adiscoloured spot on a black spot on the display. The cost of a LCD is considerably at a high price. The LCD display will have slow response times. The LCD display has a fixed resolution display and cannot be changed. LCDs use analog interface making careful adjustment of pixeltracking/phase in order to reduce or eliminate digital noise in the image. The viewing angle of a LCD display is very limited due to the Automaticpixel tracking/phase controls.
  9. 9. Liquid crystal displays work by the tiny pixels on the screen showing morethan 20,000,000 colours an LCD screen is a multilayered, sidewayssandwich. A fluorescent light source, known as the backlight.This lightpasses through the first of two polarizing filters.The polarized light thenpasses through a layer that contains thousands of liquid crystal pixelsarrayed in tiny containers called cells.The cells are, in turn, arrayed inrows across the screen; one or more cells make up one pixel. Electricleads around the edge of the LCD create an electric field that twists thecrystal molecule, which lines the light up with the second polarizing filterand allows it to pass through it.