Barcodes

Professor Koon ISE 370

Code Reading Technology

 Original Barcode Readers  Contact Wand Professor Koon ISE 370

Code Reading Technology

 Non-Contact Scanner  How a checkout scanner works  Optoelectronics:  Optical Image to electrical Signals Professor Koon ISE 370

Code Reading Technology



Non-Contact Scanner

Professor Koon ISE 370

Code Reading Technology

Professor Koon ISE 370

BarCode History



Grocery stores need for a system to automatically read items at checkout



Increase Productivity



Reduce Human Error



Silver, Woodland and Johanson

  1948 Drexel Institute of Technology Students 1949 First patent for “Classifying Apparatus and Method”  Linear  “Bulls-eye” Image: http://www.ournewhaven.org.uk/images/uploaded/scaled/Shop_s.jpg

Professor Koon ISE 370

Standardization



“Without the advancements involving lasers and microchips, the development of the Universal Product Code and the dream of an automated checkout would not have been possible.” – Marvin L. Mann

Professor Koon ISE 370

UCC >> First BarCode (1974) Professor Koon ISE 370

UPC – Universal Product Code 12 Digits (6 ID, 5 item, 1 check) Symbology is a standard that defines the printed symbol.

How scanners should read and decode the symbol.

Professor Koon ISE 370

Decode Barcode

 Black Bars with White Bars Between  Thinnest Bar = 1 unit wide  All Bars 1 to 4 units wide  Start (L) is 1-1-1 (B-W-B)  Final ( R) is 1-1-1 (B-W-B)  All Digits add to 7 widths Professor Koon ISE 370

UPC Barcode

 How to read a standard 12 decimal digit code Digit Pattern Digit Pattern 0 0001101 5 0110001 1 2 3 4 0011001 0010011 0111101 0100011 6 7 8 9 0101111 0111011 0110111 0001011 Professor Koon ISE 370

How To Read a Barcode Professor Koon ISE 370

Check Digit (UPC Code)

 Add all digits in Odd positions  Multiply sum results by 3  Add all digits in Even positions  Add 3x Odd sum to Even sum  This sum plus check digit must be a multiple of 10. (e.g. 110) 

Try 63938200039

Professor Koon ISE 370

Different Types of Barcodes  Other most commonly used codes: 

UPC-A, UPC-E, and UPC Supplemental



EAN-13

(13 Digits: One for Flag) 

Code 39 (US Military 1981)



Interleaved 2 of 5



Code 128 (Alphanumeric)



Two-Dimensional (Stacked, Multi-row)

Professor Koon ISE 370

Interleaved 2 of 5

 Numbers Only  Long as Necessary  Check Digit is optional  Digit is encoded in the bars  Next digit is encoded in the spaces  Start >> NB-NS-NB-NS  Data = five bars each  Stop >> WB-NS-NB Professor Koon ISE 370

Number Pattern 2 of 5



0 >> NNWWN



1 >> WNNNW



2 >> NWNNW



3 >> WWNNN



4 >> NNWNW



5 >> WNWNN



6 >> NWWNN



7 >> NNNWW



8 >> WNNWN



9 >> NWNWN

Professor Koon ISE 370

Different Types of Barcodes 

American Standard Code for Information Interchange

(

ASCII

)  Coding Standard Professor Koon ISE 370

Different Types of Barcodes >> Linear or Matrix (2D)  Code 39  A symbology that can encode uppercase letters (A through Z), digits (0 through 9) and a handful of special characters like the $ sign. 

Military Usage

 Drawbacks  Low Data Density  Requires More Space Professor Koon ISE 370

Different Types of Barcodes

 Code 128  A very high-density barcode symbology  Used extensively world wide in shipping and packaging industries  Can encode all 128 characters of ASCII Professor Koon ISE 370

CODE 49 Professor Koon ISE 370

Code 49



2 to 8 rows stacked



Cross between UPC & Code 39



Developed in 1987 Intermec Corp.



Modified Scanner Needed

Professor Koon ISE 370

Different Types of Barcodes  Data Matrix  A 2D matrix barcode consisting of black and white “cells” or “modules” arranged in either a square or rectangular pattern.

 Most common in marking small items (as small as 2-3mm 2 )  Pack a lot of information in a very small space. Stores between 1 to 500 characters. Can scale down to 1 mil square. (500 million characters per inch).

Professor Koon ISE 370

Aztec Code  Design for ease of printing & ease of decoding  Square central bullseye finder.

 Smallest 15 x 15 modules.

 Largest 151 x 151 modules.

 1995 by Welch Allyn Inc.

Professor Koon ISE 370

3D Barcode (Bumpy)  Small circular symbols  Shiny, curved metal surfaces Professor Koon ISE 370

SuperCode

 In public domain.

 Invented in 1994.

 Packet structure (multi-row).

 Greater freedom in placing packets.

 32 error correction levels.

Professor Koon ISE 370

Radio Frequency Identification (RFID)  No contact of line of sight  Active or Passive Tags (See note sheet)  Electromagnetic Waves Active tags contain a battery and can transmit signals autonomously.

Passive have no battery and require an external source to provoke signal Transmission.

Cost under ¢10 Implementation into cell phones Professor Koon ISE 370

Standardization 5/2/2020  Problems with standardizing new technology  Will Barcodes Prove to be Economic?

 IBM proposed designed by George J. Laurer  12 Decimal Digit code -

S

LLLLLL

M

RRRRRR

E

     (S) Start – Bit pattern of 101 (L) Left – 7 Bit pattern (M) Middle – Bit pattern of 01010 known as guard bars (R) Right – 7 Bit pattern (E) End – Bit pattern of 101 Professor Koon ISE 312 27

What is a Barcode?

1  A

bar code

(also

barcode

) is an optical machine readable representation of data.  Originally, bar codes represented data in the widths (lines) and the spacings of parallel lines and may be referred to as linear or 1D barcodes or symbologies.  Now they also come in patterns of squares, dots, hexagons and other geometric patterns within images termed 2D matrix codes or symbologies. 1 Image and Definition: http://en.wikipedia.org/wiki/Barcode 5/2/2020 Professor Koon ISE 312 28

Questions?

Professor Koon ISE 370