Input Flashcards
input device
a piece of hardware used to enter data into a computer or similar device for processing
input devices can be
manual- requiring a person to interact with it in some way
automatic- once set up, handles the whole process of inputting data itself. it can handle inputs much quicker, efficiently and accurately than manual devices
barcodes used for
keeping track of items accurately e.g. grocery items, tracking parcels, blood/tissue/organ products, luggage, shipping cartons and people attending events
types of barcodes
linear 1D and QR quick response 2D (holds more information than 1D)
uses for QR 2D barcodes
ticketless entry to concerts and scanning on mobiles for more information and URLs and boarding airline/eurostar train
barcodes can hold information on
product ID number which can be used to access database and details on the product, country of origin and manufacturer
types of barcode readers
pen type readers
laser scanners
camera based readers
CCD readers
pen readers
consists of a light source and a photo diode next to each other at the tip of the pen
advantages of pen type readers
small lightweight
simple design- durable: sealed against dust, dirt and env hazards
disadvantages of pen type readers
must come in direct contact with barcode
to read barcodes for pen type
tip of pen dragged along bars at an even speed and the photo diode measures intensity of light reflected back from light source and generates a waveform used to measure the width of the bars and spaces
uses of pen type readers
portable laptop computers and low volume scanning applications
laser scanners consist of
a photo diode and laser beam
how laser scanners read
the photo diode measures the intensity of the light reflected back from the laser beam and generates a waveform to measure the width of bars and spaces in the barcode
uses of laser scanners
in counter units in supermarkets
low volume applications: economical and reliable
