Lecture on Input Devices AssignmentPoint

1. Lecture on Input Deviceswww.AssignmentPoint.com

2. Topics • Keyboard • Mouse • Touch screen • Light pen • Joysticks • Trackball • Bar code reader • OMR • OCR • Scanner or digitizer • Video digitizer • MICR • Digital camera • Voice or Speech input system

16. Uses for which OCR is Suitable • OCR is used in billing (e.g. gas and electricity bills, insurance premium renewals) and giro-forms. • Billing often involves a turn-around document. For example, electricity bills are prepared in OC by the computer, sent out to customers who return them with payment checques. The documents are then re-entered via the OC reader into the computer system as evidence of payment. Note that no transcription is needed.

17. Advantages of OCR • Key-entry is eliminated and data is captured in machine-readable form at the earliest opportunity. This should increase throughput and reduce costs and input errors. • Characters can be read by people. • Document design is less complicated and cumbersome than for OMR forms. • Printing for OCR must meet high standards, and this is expensive. • OCR is economical only when a large number of documents are to be processed. • Only certain types of printed or handwritten characters are recognized. • Document readers are relatively expensive. • Only certain fonts are acceptable. • The reject rate depends on the quality of the document, e.g. smudges, damaged forms, torn forms, etc. • A high standard of printing is needed. • Hand-printed characters can cause high rejection rates. • Document design must still follow a rigid format.

19. Situations where OMR is used • The data to be input is simple; • The volume of data is large enough to justify designing documents; • Turn around documents are used; • Preparation equipment would be expensive or impractical.

20. Some examples of uses for where OMR are suitable • Multiple-choice examinations, aptitude tests; • Insurance premium collection; • Market research questionnaires - consumer research; • In supermarkets for stock reordering; • Traffic surveys; • Payroll data entry.

21. Advantages of OMR • Sensitivity can be altered to allow for different surfaces and pencils and inks. • Has a better recognition rate than OCR. • Can be prepared where data originates, without machines. • Errors are easily corrected.

22. Disadvantages of OMR • Mark readers are relatively slow. • Verification of marked data is difficult. • Document may be difficult to understand and fill in or impractical to design. • The document reader will have to be reprogrammed for each new document design.

24. Uses of bar codes • On labels on shelves - used for stocktaking, e.g. in factory stores. • Printed on shop goods - see supermarket example. • In libraries - for book and borrower identification.

26. Advantages • The characters are easily recognizable to the human being. • There is high accuracy in reading the characters by the input device. • The input devices are reasonable in cost. • MICR coding is flexible since documents of varying sizes, thickness and widths can be used without hampering the processing capability of the reading or sorting equipment.

29. Digital Camera • A digital camera (or digicam) is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. • Many compact digital still cameras can record sound and moving video as well as still photographs.