What are optical input devices?

Optical inout devices that uses light as a source of input. They eliminate the need for manual entry of data, thus accuracy increases. Three examples of optical input devices are:

1. barcode reader

2. image scanner

3. light pen

Barcode readers convert a barcode (pattern of bars on products) to a code that computers can understand. Image scanners are of two types,flat bed and hand-held. Light pens use a light sensitive detector.