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

 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

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

How To Read a Barcode
Professor Koon ISE 370

 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

 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

 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
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 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
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 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
4/10/2020
 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
4/10/2020 Professor Koon ISE 312 28

Questions?
Professor Koon ISE 370