Screens and monitors
- Pc's connected - monitor that user can see what is happening as they work or view a finished product (document/animation)
- Have advantage of being able to display moving image rather than static (printer)
- Quality of monitor - depends on size and resolution
- Most computers - user set the resolution they want to work at
- Screens set - high resolution - display detailed images - images smaller in size - on a screen set to a lower resolution
- Graphic artists & architects - work on complex graphics - large good quality displays - buy large high resolution monitors.
- Resoloution - measured in pixels
- Most common are CRT or TFT types -
- CRT: based on cathode ray tubes - fire electrons at screen - make pixel glow correct colour - length of cathode ray - CRT monitors are deep and take up a lot of room - many users still use CRT monitors - clear, sharp displays, low cost - new systems sold with TFT monitors
- TFT: much flatter, take up less space than CRT monitors. Use liquid crystals to form image. Size makes them extremely popular, image on cheaper TFT screens may not be as clear as the equivalent size of a CRT.
- Image produced by a computer needs to be shown to a large number of people - several alternatives
- Digital projectors - project a large version of monitor output onto screen - viewed by a large audience (classroom or business presentations) - can be portable (often ceiling mounted) - don't need to be set up each time used. Vary brightness (measured in lumen's) & brighter projectors needed very large rooms or bright conditions
- Interactive Whiteboards - used to project images - Touch sensitive surface they can be written on using stylus or finger - Often used in classrooms (activities) - Handwriting recognition; convert handwritten text to computer text - Input and Output device
- Plasma screens - Often used as TV's - used instead of normal computer monitors - seen in public areas (shopping centres, reception areas or business) - Illuminate fluorescent lights to make image - available in large sizes - used together to make huge wall-mounted displays.
- Mobile phone screens - come with software pre-installed to enable internet access - check email, weather, travel instructions, football scores - Can also display live video, good quality image which refreshes quickly - 2 inch TFT mobile screen; display 16 million colours - practical to use - Challenge for web designers as need to design content useable in small display area - Tv companies - phone users to download content (viewed/listened) on mobile devices - watch news on the train when they travel to work.
- PDAs: larger screen than mobiles = run application (word processors/spreadsheets). User has to scroll around large documents - keep this to a minimum by designing screen layouts carefully. Touch screens overall size can be kept down - part of the screen devoted to a virtual keyboard - stylus used.