Barcode Readers

Question 1

What is a barcode

Answer 1

A printed diagram that consists of light and dark portions. Contain info that can be read by a computer
White portions reflect light
Dark portions absorb light

Question 2

2D Barcode VS 1D Barcode

Answer 2

2D contains more information in the same amount of space.
2D requires more processing power to extract information

Question 3

What does a Barcode Reader consist of?

Answer 3

Laser Light source
Lens
Photodiodes
Mirror

Question 4

How does a barcode reader work?

Answer 4

1) A mirror directs light from a laser onto the barcode.
2) The reflected light passes through the lens and is incident on a photodiode - light changed to electrical charge
3) electrical charge can be measured and processed to form a digital signature.

Question 5

What error detection and prevention methods do barcodes use?

Answer 5

1) Parity Bits and check digits
2) If a barcode does not scan correctly, the reader will continue to scan until the barcode is read successfully
- barcode readers can scan barcodes 1000s of times per second