1. ‘OUTPUT DEVICES ’ 1

2. OUTPUT DEVICES These devices are used to produce the results either as :- – soft copy – hard copy 2

3. Soft copy – Monitors – Projectors Hard copy – Printers – Plotters 3

4. VIDEO DISPLAY UNIT Monitor is available in two types:- – CRT – LCD 4

5. PRINTER Produces a hard copy of documents stored in electronic form. Uses print media like paper or transparencies. Printers are of 2 types : – Impact printers – Non-impact printers 5

6. IMPACT & NON-IMPACT PRINTER IMPACT PRINTER DOT MATRIX DAISY WHEEL NON-IMPACT PRINTER INKJET PRINTER LASER PRINTER 6

7. IMPACT PRINTERS 7

8. DOT MATRIX Head runs back and forth, up and down. Strike an ink-soaked cloth ribbon. Produces output on paper. 8

9. DAISY WHEEL Contains raised character set Motor position the character on ribbon Hammer strikes to print character. 9

10. Drum printer 10

11. NON IMPACT PRINTER 11

12. THERMAL Prints by heating thermal paper. Coating turns black where heated It creates the image. 12

13. INKJET PRINTER Propel drops of ink on page. Most common type. Low cost. High quality output 13

14. LASER PRINTER Uses static electricity as temporary glue. Toner clinges to –ve charged area of drum Drum rolls over the paper to give output 14

15. PLOTTER Used to produce graphs or diagrams. It is used to give perfectly proportioned, high quality graphic output on large sheets. Two type of plotters are there : – Flatbed plotter – Drum plotter 15

16. FLATBED PLOTTER Paper is fixed on flat surface. Pens are moved to draw the image. Can use different colour pen to draw. 16

17. DRUM PLOTTER The pen is moved on single axis. Paper itself moves on drum. It gives different axis or dimension. 17

18. ELECTROSTATIC PLOTTER Produces a raster image by charging the paper with a high voltage. This voltage attracts toner which is then melted into the paper with heat. This type of plotter is fast, but the quality is generally considered to be poor. 18

19. PROJECTOR Takes a video signal. Project the image on screen. Uses a high quality bright light and lens system. Used for conference, class room training. 19

20. VOICE RESPONSE Allows a user to talk to computer. It has an audio response device that make audio output. 20

21. VOICE REPRODUCTION Selection of audio output from pre defined audio responses. It is then converted into digital data. It is then again converted into analog form. 21

22. SPEECH SYNTHESIS Raw text is converted into equivalent witten out words. Phonetic transcription is assigned to each word It is then converted into sound or speech 22