Input Devices

Question 1

What are barcodes used for today?

Answer 1

The identification of thousands of applications including tracking parcels, shipping cartons, passenger luggage, blood, tissue and organ products around the world

Question 2

What are the two types of barcodes?

Answer 2

Linear (1D barcodes) and 2D barcodes (such as quick response, QR, code)

Question 3

What barcodes can hold more information?

Answer 3

2D barcodes

Question 4

What are the four types of barcode readers?

Answer 4

Pen-type scanners, laser scanners, CCD readers and camera-based readers

Question 5

How does a pen-type reader, read a barcode?

Answer 5

The tip of the pen is dragged across all the bars at even speed, the photo diode measure the intensity of the light source and generates a waveform that is used to measure the width of the bars and spaces in the barcode

Question 6

Describe a pen-type readers attributes?

Answer 6

In a pen-type reader, a light source and a photo diode are placed next to each other in the tip of the pen

Question 7

What is an advantages of pen-type scanners?

Answer 7

Their simple design, pen-type scanners are the most durable type of barcode scanner, and can be tightly sealed against dust, dirt and other environmental hazards, their small size and low weight makes it suitable with portable computers or very low volume scanning applications

Question 8

What is an disadvantage of pen-type scanners?

Answer 8

Their applications are limited because they must come into direct contact with a barcode to read it

Question 9

How does laser scanners work?

Answer 9

It measure he intensity of light reflected back from the light source and generates a waveform that is used to measure the widths of the bars and spaces in the barcode, the same way as a pen scanner, but with laser beams as the light source

Question 10

What is an advantage of laser scanners?

Answer 10

They are reliable and economical for low-volume applications

Question 11

How does a camera-based reader work?

Answer 11

it uses a camera and image processing techniques to decode a 1D or 2D barcode by using an imaging scanner

Question 12

What is an advantage of Camera-based scanners?

Answer 12

it can read a barcode on any surface, printed or onscreen, and can also read a code that is damaged or poorly printed

Question 13

What are some of the uses of Camera-based scanners?

Answer 13

Scanning drivers licences, couponing, event ticketing, can be used by a cell phone

Question 14

How does a digital camera work?

Answer 14

Uses CCD or CMOS (Complementary Metal Oxide Semiconductor) sensor comprising millions of tiny light sensors arranged in a grid, the binary data from each sensor is recorded onto the camera’s memory card so that the image can be reproduced using suitable software at a computer

Question 15

What is an advantage of CCD?

Answer 15

It tends to produce higher quality images and are used in higher end cameras, they are more reliable since the technology has been around for much longer

Question 16

What is an disadvantage of CCD?

Answer 16

They have higher power consumption, using up to 100 time that of a CMOS sensor

Question 17

What is an example of a digital camera at work?

Answer 17

Mastercard app allows customers to make a purchase by taking a selfie rather than a password, there photograph of the user is converted into binary code using facial recognition technology, which is then compared with a stored code

Question 18

What is the input device and output used by a Radio Frequency Identification (RFID)?

Answer 18

An input device to read the signal from an RFID chip, and output to transmit a signal from an active tag

Question 19

What are RFID used for?

Answer 19

They are being used to identify and track things like household product and cards to bank cards and animals

Question 20

What is an advantage of RFID?

Answer 20

They can read without a line of sight from up to 300 metres

Question 21

Why are active tags larger than passive tags?

Answer 21

They include a battery to power the tag so that it actively transmits a signal for a reader to pick up

Question 22

What is an advantage of a active tag?

Answer 22

They are used to track things likely to be read from further away

Question 23

What is an advantage of a passive tag?

Answer 23

These are much cheaper to produce as they do not have a batter, relying on radio waves

Question 24

How does a passive tag work?

Answer 24

The radio waves emitted from a reader up to a metre away provide sufficient electromagnetic power to the card using its coiled antenna, once energised, the transponder inside the RFID tag can send its data to the reader nearby

Question 25

When are passive tags most common?

Answer 25

In tagging items, such as some grouches, music CDs and for smart cards such as Transport for London’s Oyster card or a contactless bank card