1. Standard Grade Computing COMPUTER STUDIES Standard Grade OUTPUT DEVICES Chapter 17

2. Standard Grade Computing FOUNDATION Laser Printer High quality printouts - can be in colour or B&W. Many pages can be printed very quickly. Toner is used to display the image on paper. Inkjet Printer Colour printouts Excellent photograph quality Slower to print but less expensive Uses ink cartridges PRINTERSPRINTERS Plotter Colour pens move up & down Used with CAD packages Flatbed Drum

3. Standard Grade Computing Monitors / VDUs Ergonomic monitor FOUNDATION CRT A computer video signal is received then the image is displayed on a screen More pixels per inch means a higher resolution A high resolution monitor displays high quality images

4. Standard Grade Computing MONITOR / VDU CRT: C ATHODE RAY TUBE Inside the flat end is coated with substances which glow when hit by electrons The coating has red, green & blue dots which glow to produce the colours needed LCD: LIQUID CRYSTAL DISPLAY Transistors charge liquid crystals between two glass plates. Fluorescent tubes provide the light source, which passes through a layer of crystals. Varying the electrical charge to the crystals creates images. GENERAL

5. Standard Grade Computing MONITOR / VDU continued TFT : THIN FILM TRANSISTOR LCD TFT monitors emit less radiations than a Standard LCD. AND emit MUCH less radiation than a CRT monitor! TFT also gives a picture up to an 80 degree angle. where as a LCD only goes to about a 45 degree. TFT also gives a sharper picture. GENERAL

6. Standard Grade Computing Comparing Printers Capital Costs Determined by the quality of hardware bought e.g. laser or inkjet printer? CRT or LCD monitor Running costs Determined by what is used to operate the hardware e.g. printer paper amount & quality, ink or toner? Speed How many pages are printed per minute (ppm) Resolution Determined by how many pixels or dots are present in each inch (dots per inch - dpi) GENERAL

7. Standard Grade Computing CREDIT Specialised Output devices for Disabled users Virtual Reality output SPEECH SYNTHESISER VR Headset / VR Visor Headphones for sound Goggles for video Press a key to hear the word spoken for the picture

8. Standard Grade Computing MULTIMEDIA White Board Headphones Multimedia Projector CREDIT Speakers HIGH QUALITY SOUND OUTPUT HIGH QUALITY SCREEN DISPLAY HIGH QUALITY VDU NEEDED FOR ANIMATION & MOVIE OUTPUT

9. Standard Grade Computing Multimedia continued CREDIT Sound Card IMPROVES SOUND QUALITY OF GAMES & MULTIMEDIA APPLICATIONS Graphics Card CONTROLS THE QUALITY OF OUTPUT ON A MONITOR VGA (CRT) output ViVo (video in/video out) DVI (Digital Output)

10. Standard Grade Computing And there are more…. Exciting chapters to follow So tune in again next time