2. Excellence Publication Co. Ltd. Volume 1 2.41 Volume 1

3. Excellence Publication Co. Ltd. Volume 1 2.42 A. Monitors  used to display text, graphics, animation and video  There are two types of monitors: 1. Cathode Ray Tube (CRT) Monitors

4. Excellence Publication Co. Ltd. Volume 1 2.43 Monitor Monochrome CRT Gray-scale CRT Colour CRT Colour Capability One background colour and one foreground colour, e.g. Black and White Different shades of gray 16 to more than one million different colours. A comparison of different CRT monitors

5. Excellence Publication Co. Ltd. Volume 1 2.44 2. Liquid Crystal Displays (LCDs)  LCD is much thinner than the CRT monitor.  Consumes much less power because it works on the principle of blocking light rather than emitting it.

6. Excellence Publication Co. Ltd. Volume 1 2.45 Tips on buying Monitors Screen size is measured in diagonal inches 1. Identify your resolution needs. 2. Know the size of monitors. 3. Check the refresh rate. 4. Match your graphics card.

7. Excellence Publication Co. Ltd. Volume 1 2.46 B. Loudspeakers  used to reproduce sounds How loudspeakers work Voice coil Vibrates the diaphragm Vibrates the air Produce a sound wave

8. Excellence Publication Co. Ltd. Volume 1 2.47 C. Printers  used to print characters or images on paper 1. Daisy-wheel Printer  There are different types of printers:  use hammers to press plastic or metal wheels against ribbons  Noisy  Slow speed  cannot print graphics

9. Excellence Publication Co. Ltd. Volume 1 2.48 3. Thermal Printer  push heated pins against heat-sensitive paper  print receipts 2. Line Printer  make character chains or pins and print an entire line at one time  produce low quality text

10. Excellence Publication Co. Ltd. Volume 1 2.49 4. Dot-matrix Printer  Strike pins against ink ribbons  print invoices in carbon paper and continuous form 5. Ink-jet Printer  Spray ink at paper  Fast speed  Non-impact  Better print quality

11. Excellence Publication Co. Ltd. Volume 1 2.410 6. Laser Printer  Use lasers to produce images on drums and then print the images  Quiet  Support an almost unlimited variety of fonts  Can print both characters and images in high quality

12. Excellence Publication Co. Ltd. Volume 1 2.411 D. Plotters  used to draw images on paper with ink pens There are two types of potters: Drum Plotter Flatbed Plotter  paper is wrapped around drums with pins feeds  paper is placed on flat surface  paper is moved back and forth for one direction of plot  the size of the surface determines the maximum drawing size

13. Excellence Publication Co. Ltd. Volume 1 2.412 A Comparison between a Plotter and a Printer Plotter Printer  draw real continuous lines to provide infinite resolution  only simulate lines by printing closely spaced dots  usually used to produce drawings of large sizes  usually used to produce drawings of small sizes  suitable for engineering and architectural drawings  suitable for home and general office users

14. Excellence Publication Co. Ltd. Volume 1 2.413 State the reasons why many customers prefer LCD to CRT monitor nowadays. And discuss whether LCD would replace LRT monitors in the coming five years.

15. Excellence Publication Co. Ltd. Volume 1 2.414 Back