BARCODES

Technology and Implementation

OUTLINE:

INTRODUCTION

SYMBOLOGY

POPULAR SYMBOLOGIES

BARCODE PRINTING

TYPES OF SCANNERS

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INTRODUCTION

• In ancient times, when there were small scale business firms ,records were manually maintained.

• In today’s highly competitive business world, the market has spread and the distance between the producer and the consumer has increased.

• Collecting data through manual entry has many drawbacks. Studies show that averagely 1 error for every 300 characters is obvious.

• To overcome the disadvantages of manual data entry, several automatic data entry technologies have been developed.

• The most popular techniques are OCR (Optical Character Recognition), Magnetic Stripe, Smart Card, Biometric ID, EDI (Electronic Data Interchange) and also BARCODES.

• The use of automatic data entry technology ranges from the familiar retail outlets, to manufacturing industry, banking sectors, health care, security, time and attendance.

• We can get the accurate capture of detailed sales information and the ability to process the data by the computer system, resulting in saving time not only of customer but also the management.

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Barcodes

▹Barcodes are simple machine readable codes that the computer can reproduce directly into the bit streams of zeroes and ones which is the machine language of all computers and is known as digital language.

▹The information or data is encoded using the width of printed bars, the white spaces between the bars.

▹The data is read by scanning the Barcode label by a scanner. The differences in the amount of light reflected from the dark bars and spaces are measured and the decoder translates its information to the data that it represents.

▹Barcode system is the most cost-effective and least expensive way of coding information, since they can be printed on plain paper, which the machine can easily read and encode the data or information.

SYMBOLGIES

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•The bars and spaces of the barcode are arranged as per a set of rules that relate those patterns to their encoded message. These rules are called “Symbologies”.

•About a dozen barcode symbologies are internationally standardized having widespread use, though over 260 have been invented.

UPC

• UPC is primarily used in retail industry as a POS (Point of Sale) barcode symbology.

• UPC is used in the United States and Canada in the retail industry.

• The two types of UPC codes are

UPC-A and UPC-E.

UPC-A

• UPC-A is a twelve digit numeric barcode and the structure of the code is as follows:

1= System digit

2-6= The manufacturers ID given by the registering body.

7-11= Represents the product code.

12= A check digit based on the preceding 11 digits calculated using modulo 10 algorithm.

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EAN

• EAN (European Article Numbering) is based on the UPC-A standard.

• Primarily used in retail industry as a POS (Point of Sale) barcode symbology.

• There are two types of EAN codes :

EAN-8 and EAN-13.

EAN-13

It is a 13 digit barcode and has 4 parts.

A=2 or 3 digits= identifying the country or the authority who assigned the code.

B=5 or more digits= To identify the manager.

C=12-{A+B} digits= Code to identify the product.

D=1= Check digit calculated by using modulo-10 algorithm.

Different Symbologies

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Linear- Linear symbologies have single row of bars and spaces and are read by single linear scanner such as wand, moving beam laser or linear CCD.

Stacked (multiple scan) symbologies have several rows of bars and spaces typically read by multiple 1-D scans with a moving beam laser or linear CCD.

Matrix- Matrix symbologies are regular polygon arrays of data cells, plus ‘finder’ and orientation structures that are typically read from 2D images from a CCD array.

«Code 39

«EAN-8

«EAN-13

«UPC-A

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«UPC-E

BARCODE PRINTING

• A number of technologies are used to prevent barcodes. There are four basic types of printers:

• Dot Matrix Printer

• Inkjet Printer

• Laser Printer

• Thermal Printer

DOT MATRIX PRINTER

• The barcode image is produced by hundreds of dots printed in a matrix to make series of lines and spaces commonly referred to as a barcode.

ADVANTAGES

▹Easily accessible and less expensive option of printing.

▹ Various surfaces can be used to print on.

▹Multi-pass ribbons can reduce costs for ribbons and label materials.

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•LIMITATIONS

o Barcodes are low to medium density and may not match a user’s standard.

o Ink saturation can lead to bleeding on the paper resulting in image distortion.

o These labels are often not durable, nor chemical or water resistant.

o No graphics capability.

Ink Jet Printers

• Inkjet printers is usually used in high production settings where production of barcodes and human readable fonts need to be reproduced at high rates of speed.

ADVANTAGES

Requires only one step to finish the carton or readable material.

A favorite on high speed production lines due to its ability to mark “on the fly”.

LIMITATIONS

o System installation is very costly as this method is designed for high volume barcode printing-not for individual or batch printing.

o Materials use is restricted due to constant bleeding on certain materials.

o Requires constant supervision to prevent inkjet clogging and maintain proper print quality.

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LASER PRINTERS

• A laser printer works much like a photo-copier. Charging particles of the paper then attract the ions from the ink.

• These two particles are then bonded together due to the heat and pressure of the drum.

ADVANTAGES

Prints high quality text and graphics on paper documents

Can double as a document printer when not being used to print barcodes.

Density and resolution are very high, allowing the production of scan able barcodes at any wavelength when read with an infrared scanner.

LIMITATIONS

o Not well suited for industrial environments.

o Wasteful in small operations.

o Limited durability- cannot produce water resistant nor chemical resistant label.

o Toner costs are generally huge with laser printers as they require five times more toner than normal text.

THERMAL PRINTERS

• Thermal printing includes thermal transfers.

• A durable, polyester ribbon film coated with dry thermal transfer ink is placed between thermal print head and label.

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• The thermal print head transfers the ink onto the label surface, where it cools and anchors to the media surface.

• The polyester ribbon is then peeled away, leaving behind a stable, passive image.

ADVANTAGES

Crisp, high-definition text, graphics, and barcodes for maximum readability and scannability.

Produces long life scannability.

Produce batch or single print labels with minimum waste.

Long-term maintenance is low compared to dot matrix, inkjet and laser.

High durability.

LIMITATIONS

o Ribbon can be wasteful if little is printed from it.

o Poor candidate for recycling.

o Ribbon and media must be compatible.

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TYPES OF BARCODE SCANNERS

1. WAND SCANNER

A wand scanner is a hand held device used to read barcodes. The pen tip is tightly touched the label and moved across all the bars to the other side of the barcode in one continuous motion.

There is virtually no depth of field in a wand scanner.

ADVANTAGES

Allows the operator to read Barcodes of virtually any length.

Relative cost is low when compared with other scanning technologies.

Light weight.

Less power consumption.

DISADVANTAGES

o Several attempts to scan may be necessary before a good decode result.

o In any application when many barcodes have to be scanned continuously, this becomes extremely inefficient.

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NON CONTACT CCD Scanners

Introduced as a means of overcoming the near contact limitations of wand scanners.

These devices have range scan from contact to about 6 inches away, also some that can read from more than 20 inches are available.

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A trigger mechanism is used to activate the scanner. They use one or more LED’s to flood the barcode area with light, and an image of the code is transferred to an array of photo detectors.

The characteristics of the barcode are determined by electronically sampling each individual photo detector, which interprets each bar and space by the number of adjacent detector scanning black or white.

ADVANTAGES

Less expensive than lasers.

Easy to use.

Requires less training.

Well suited for most retail, banking, and manufacturing applications.

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LASER SCANNERS

Hand held scanners use a laser diode to create a scan line by projecting a beam of energy by oscillating mirror.

The beam is reflected out of the scanner onto the barcode, where light energy from the bars and spaces is reflected back to the scanner, collected on the mirror, focused and read by a photo detector.

The resulting signal may then be read using decoding software within the scanner or at the terminal host.

DISADVANTAGES

o Low durability.

o High costs as they have moving parts as mirrors.

o They are not as rugged as CCD’s or Wands.

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CONCLUSION

▹Thus, according to the technology of barcodes we can conclude that the barcodes is having great potential in today’s world because with the advancement of technology in android platform the size of increase in scanner which contains barcode a consumer can search for shopping in super market by using the built in barcodes in mobile.

Barcodes are used for many applications for different purposes with different usages.

References

Barcodes Technology- A .S .Bhaskar Raj

http://www.google.com

www.wikipedia.org

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