1.2) Input Devices- Touch Screens, OCR & OMR
Students should be able to: evaluate a range of input and output devices: keyboards, pointing devices, smart cards, bar codes, OMR, MICR, ATM, touch screen, printers, plotters, monitors, scanner, sensors, interactive white board, data projectors, OCR, speech input, speech output and actuators;
Touch Screen:
Touch Sensitive Screen
User touches icon,
Infrared light detects finger position.
Advantages:
Don’t need a mouse/ keyboard.
Easy to use.
No training needed.
Cannot steal components.
Easy to reprogram if changes need to be made.
Graphics Tablet
Consists of a flat surface containig a touch-sensitive membrane which detects the location of a specially designed stylus.
As stylus is moved across thew pad, movement is interpreted by software such as drawing, which appears on the computer screen.
Each point on tablet represents the same fixed point on the screen, in contrast to the position of the mouse.
OCR
Optical Character Recognition
A printed document is scanned on a flatbed scanner.
The image is captured using light/ a laser beam.
Special software can interpret or convert letters as ASCII (American Standard Code for Information Interchange) text which can then be processed as standard word processed text.
Most document formatting is not recognised.
OMR
Optical Mark Recognition
A special document/ form is used to collect the data.
This has specific areas/ boxes representing the users choices/ answers/ selections which the user shades in/ fills in perhaps using a specific grade of pencil/ using a HB pencil.
The document is scanned using light.
The reflected light is analysed and the positions of the users answer/ choices determined against a template.
Benefits- Human error is eliminated and the answers can be read at electronic speeds reducing the processing time.