1.1 Input

1.1 Input

1. Input Devices - they input sound, numbers, text, pictures and movies.

   • Keyboards have letter keys and function keys (esc). Also ergonomic keyboards are designed to reduce RSI.
   • Mouse have two main types - optical uses light sensors, mechanical use ball to senses position
   • Concept Keyboards are used in checkout tills so the item name can be pressed instead of having to remember the price
   • Touch screens interprets signals caused by pressing the screen, they are easy to use, compact, limit input options and can have a virtual keyboard
   • PDAs use touch screens to write or draw on. This writing is interpreted by handwriting recognition software used for note taking
   • Graphics tablets are useful for drawing as the stylus is like a pencil or for Chinese characters. Interactive whiteboards used in schools
   • Speech recognition involves speaking into a microphone, sounds are compared to a sound-bank and converted into text. can be slow and unreliable
   • Card readers are.magnetic strip (easy to read but not much data held) and smart cards (large data chip, hard to reproduce, encryption, less fraud)
   • Optical mark recognition allows for marks on a paper (e.g multiple-choice exam papers) to be detected. It is quick and accurate
   • Optical character recognition is where a paper document is scanned, shapes are matched to its dictionary and converted into an electronic copy
   • Radio frequency ID scans a RFID tag using radio wave to retrieve data off the tag. used in products and animals
   • Scanners scan graphical images onto a computer where they can be edited. Can be used with with OCR to scan in text
   • Bar code Readers recognise a series of thick and thin lines to interpret the price quickly
   • Magnetic ink character recognition is used in a MICR reader to read the magnetic particles. This is good as hard to forge, durable and readable by us
   • Microphone
   • Webcams is a camera that is accessed and displayed by the www. 30 images per second for video
   • Digital Cameras store images digitally on a storage device. This picture can be downloaded onto a computer later
   • Game Controllers have fast response times to allow the user to drive a car, fly a plane etc.

2. Special Purpose Input Devices for people with disablities

3. Choosing an input device