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Barcodes

Barcodes. Code Reading Technology. Original Barcode Readers Contact Wand. Code Reading Technology. Non-Contact Scanner How a checkout scanner works Optoelectronics: Optical Image to electrical Signals. Code Reading Technology. Non-Contact Scanner. Code Reading Technology.

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Barcodes

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  1. Barcodes Professor Koon ISE 370

  2. Code Reading Technology • Original Barcode Readers • Contact Wand Professor Koon ISE 370

  3. Code Reading Technology • Non-Contact Scanner • How a checkout scanner works • Optoelectronics: • Optical Image to electrical Signals Professor Koon ISE 370

  4. Code Reading Technology • Non-Contact Scanner Professor Koon ISE 370

  5. Code Reading Technology Professor Koon ISE 370

  6. 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

  7. 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

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

  9. UPC – Universal Product Code12 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

  10. 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

  11. UPC Barcode • How to read a standard 12 decimal digit code Professor Koon ISE 370

  12. How To Read a Barcode Professor Koon ISE 370

  13. 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

  14. 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

  15. 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

  16. 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

  17. Different Types of Barcodes • American Standard Code for Information Interchange (ASCII) • Coding Standard Professor Koon ISE 370

  18. 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

  19. 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

  20. CODE 49 Professor Koon ISE 370

  21. Code 49 • 2 to 8 rows stacked • Cross between UPC & Code 39 • Developed in 1987 Intermec Corp. • Modified Scanner Needed Professor Koon ISE 370

  22. 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 2-3mm2) • 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

  23. 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

  24. 3D Barcode (Bumpy) • Small circular symbols • Shiny, curved metal surfaces Professor Koon ISE 370

  25. SuperCode • In public domain. • Invented in 1994. • Packet structure (multi-row). • Greater freedom in placing packets. • 32 error correction levels. Professor Koon ISE 370

  26. 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

  27. Standardization • Problems with standardizing new technology • Will Barcodes Prove to be Economic? •  IBM proposed designed by George J. Laurer • 12 Decimal Digit code -SLLLLLLMRRRRRRE • (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

  28. 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 Professor Koon ISE 312

  29. Questions? Professor Koon ISE 370

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