1. INTRODUCTION

In 1932 a small group of students from Harvard University, London first developed the concept

of Automatic Product Identification By passing a high intensity light through some Morse Code.

Which gradually developed to Bar-coding system from the year, 1948. Soon the bar-coding

technology opened for public use from, 1967.

In 1974, the first the first bar coding was introduced to the retail world on a packet of Wrigley’s

Gum. Thirty eight years later the number of applications for bar code technology has exploded,

going far beyond grocery stores and retail. Read between the lines and you will see bar code

technology popping up in new and unusual places such as hospitals, law firms, retail stores,

security, and Department of Defense, corporate offices, libraries, and rental cars.

Figure 1.1 :- Barcode & Barcode Reader

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2. BARCODING TECHNOLOGY

A barcode is an optical machine-readable representation of data relating to the object to which it

is attached. Originally barcodes systematically represented data by varying the widths and

spacing's of parallel lines, and may be referred to as linear or one-dimensional (1D). Later they

evolved into rectangles, dots, hexagons and other geometric patterns in two dimensions (2D).

Although 2D systems use a variety of symbols, they are generally referred to as barcodes as well.

Barcodes originally were scanned by special optical scanners called barcode readers. Later,

scanners and interpretive software became available on devices including desktop printers and

smart phones.

The Laser Light Scans the barcode & generates wave-form from the light reflected back from the

white areas of the barcode.There are Two Quiet Zones at the two ends of the barcode, then it has

a start checkpoint & end checkpoint at it's two sides, after the start point it contains the actual

data then a check symbol validates the existence of the scanned code.

Figure 2.1 - Barcode Design Construction

Figure 2.2 - Barcode Construction Rules

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3. BAR CODE SYMBOL CHARACTERISTICS

1. Magnification

The magnification (size) of the bar code symbol is determined by the X-dimension (one narrow module

width) in relation to a nominal size.

The allowable magnification range depends on the symbol type and the intended scanning environment.

Reliability of scanning is always enhanced by selecting a magnification higher than the minimum.

To print an accurate and high quality bar code symbol a number of factors, such as the printing process,

ink quality, and substrate, must be taken into consideration.

2. Bar Height

Once the magnification of the bar code symbol has been determined, for EAN/UPC Bar Code

symbols it is important to ensure that the height remains in proportion to the magnification, and

does not drop below the minimum specified.

3. Quiet Zones (Light Margins)

The Quiet Zones (Light Margin) of the bar code symbol are the solid, light areas before the first

bar and after the last bar. These areas are extremely important as they allow the scanner to

recognise the beginning and end of the bar code symbol.

Any obstruction or reduction in the Quiet Zones will most likely result in scanning difficulties. 

The minimum size required for the Quiet Zones depends on the magnification of the bar code

symbol.

It is recommended to allow slightly more than the minimum required Quiet Zones to allow for

any possible ink spread or plate registration issues.

4. Colours

The colours and type of ink you choose for your bar code symbols is very important. As a scanner reads a

bar code symbol using an infrared light source it sees the symbol differently to the human eye.

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As a result, some colour combinations and ink types are unsuitable for scanning because they do

not provide sufficient contrast between the dark bars and the light background, or they provide a

much too high reflectance value.

The most suitable and reliable colour combination is black bars on a white background. 

However, as a general rule, the background of the bar code symbol can be a light, warm colour

that does not contain any black (such as yellow or light orange), and the bar colour can be a dark,

cool colour that has no, or low, red content (such as dark blue or dark green).

5. Substrate

The substrate (the material the bar code symbol is printed on) is very important. If unsuitable this can

cause scanning difficulties. Different packaging materials reflect light differently, which can have an

effect on the scanning ability of the bar code symbol.

This is especially evident on transparent and translucent packages where the background is not printed.

For printing bar code symbols it is recommended that you avoid the following:

• High gloss substrates

• Transparent or semi-transparent backgrounds

• Transparent wrappers over the printed bar code symbol if necessary to print onto a highly reflective

(flexible) substrate, we recommend the following:

• Increase the magnification of the bar code symbol to between 105% and 120% (X-dimension 0.35mm -

0.40mm)

• Increase the amount of Bar Width Reduction

• Make the background of the symbol as dense and less reflective as possible. To do this you may try the

following:

• If you are not using wet inks, print two background layers. This may be two layers of the one colour, or

you may use all light colours in the print run (e.g. white and yellow)

• Use a less viscous ink that will provide maximum coverage and density

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6. Bar Widths and Print Quality

Always ensure that the print quality of the bar code symbol is of a high standard. Ensure that the

bars in the symbol are clearly defined, watch for voids or smudging, and avoid flecks in the

background colour.

Maintaining acceptable print quality and consistent print gain (ink spread) requires regular

ongoing checks.

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4. ANATOMY OF BARCODES

Fig 4.1: Anatomy Of Barcodes

This number is a UPC system number that characterizes specific types of barcodes. In a UPC

barcode it is normally on the left of the barcode. The actual "barcode" (the "bars" and "spaces")

is the first "barcode" after the first "guard bar". The Number System Character is the blue box on

the "Anatomy of a Barcode".

Codes of the Number System Character:

• 0 - Standard UPC number. • 1 - Reserved. • 2 - Random weight items like fruits, vegetables, and meats, etc. • 3 - Pharmaceuticals • 4 - In-store code for retailers. • 5 - Coupons • 6 - Standard UPC number. • 7 - Standard UPC number. • 8 - Reserved. • 9 - Reserved

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5 .TYPES OF BARCODES

Numeric-only barcodes

Codabar :  Older code often used in library systems, sometimes in blood banks

Code 11:  Used primarily for labeling telecommunications equipment

EAN-13:  European Article Numbering international retail product code

EAN-8:  Compressed version of EAN code for use on small products

Industrial 2 of 5:  Older code not in common use

Interleaved 2 of 5:  Compact numeric code, widely used in industry, air cargo

MSI:  Variation of the Plessey code commonly used in USA

Plessey:  Older code commonly used for retail shelf marking

PostNet:  Used by U.S. Postal Service for automated mail sorting

UPC-A:  Universal product code seen on almost all retail products in the USA and

Canada

Standard 2 of 5 :  Older code not in common use

UPC-E :  Compressed version of UPC code for use on small products

Alpha-numeric barcodes

Code 128:  Very capable code, excellent density, high reliability; in very wide use world-wide

Code 39:  General-purpose code in very wide use world-wide Code 93:  Compact code similar to Code 39 LOGMARS:  Same as Code 39, this is the U.S. Government specification

2-Dimensional barcodes

PDF417:  Excellent for encoding large amounts of data DataMatrix:  Can hold large amounts of data, especially suited for making very

small codes Maxicode:  Fixed length, used by United Parcel Service for automated package

sorting QR Code:  Used for material control and order confirmation Data Code Code 49 16K

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Industry Standards for Barcodes and Labels

Bookland EAN encodes ISBN numbers, used internationally to mark books ISSN and the SISAC Barcode:   International Standard Serial Numbering OPC:  Optical Industry Association barcode for marking retail optical products UCC/EAN-128:  Widely used data formatting model for Code 128

Fig5.1.Types of barcodes

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6. STRUCTURE OF BARCODE

bar code correctly. It is typically stripped from the data and not transmitted to the host. Quiet

Zone: The minimum required space for bar code scan-ability, preceding the Start Character of a

bar code symbol. The quiet zone should be free from any printing and be the same color and

reflectance as the background of bar code symbol. The Quiet Zone should be ten times the width

of the narrowest element in the bar code, or 0.25 inch minimum, also known as Clear Area.

Start Code: Indicates the start of the barcode. These are special bar code characters & they

signify the start of data to the scanner/reader. Start characters are usually strippedoff and not

transmitted to the host.

Check Digit: Check digit (not always present) is a mathematical sum that is used to verify the

accuracy of the other elements of the barcode. It is the extra digit added at the end of a bar code

to allow the scanner to confirm that it read the

Stop Code: Indicates the stopping point of the barcode. These characters signify the end of data

to the scanner/reader. They are also stripped-off and not transmitted to the host.

Fig6.1: Barcode structure

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7. WORKING OF BARCODE

Laser beam is incident on a mirror/prism which is then directed on the barcode from left to right.

The dark bars of barcode absorb the incident light but the light is reflected by light spaces.

Photodiode measures the reflected light and gives out electrical signal. The analog electrical

signal is then converted into digital one. And corresponding barcode is read.

Fig7.1: Working of Barcode

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8. USE OF BARCODES

Barcodes such as the UPC have become a ubiquitous ele-ment of modern civilization, as

evidenced by their enthu-siastic adoption by stores around the world; most items other than fresh

produce from a grocery store now have UPC barcodes. This helps track items and also reduces

instances of shoplifting involving price tag swapping, al-though shoplifters can now print their

own barcodes.[15] In addition, retail chain membership cards (issued mostly by grocery stores

and specialty “big box” retail stores such as sporting equipment, o ce supply, or pet stores) useffi

barcodes to uniquely identify consumers, allowing for customized marketing and greater

understanding of indi-vidual consumer shopping patterns. At the point of sale, shoppers can get

product discounts or special marketing o ers through the address or e-mail address provided atff

registration.

Fig8.1.Example of barcode on a patient identification wristband

They are widely used in the healthcare and hospital set-tings, ranging from patient

identification (to access pa-tient data, including medical history, drug allergies, etc.) to creating

SOAP Notes[16] with barcodes to medication management. They are also used to facilitate the

sep-aration and indexing of documents that have been im-aged in batch scanning applications,

track the organiza-tion of species in biology,[17] and integrate with in-motion checkweighers to

identify the item being weighed in a conveyor line for data collection.

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They can also be used to keep track of objects and people; they are used to keep track of rental

cars, airline luggage, nuclear waste, registered mail, express mail and parcels. Barcoded tickets

allow the holder to enter sports arenas, cinemas, theatres, fairgrounds, and transportation, and are

used to record the arrival and departure of vehicles from rental facilities etc. This can allow

proprietors to identify duplicate or fraudulent tickets more easily. Bar-codes are widely used in

shop floor control applications software where employees can scan work orders and track the

time spent on a job.

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9. ADVANTAGES & DISADVANTAGES

Represent unique identity of a product

Accuracy of data input (error free)

Labour savings by avoiding manual system

More accurate despatch

Cost efficient

Real time data collection

Measurement of work in progress throughout the factory

Rapid access to total production costs

Scratched or crumpled barcodes may cause problems

System Failure may cost more delays.

Data must be coded in the barcode

In laser scanning, durability and cost are the two disadvantages

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CONCLUSION AND FUTURE SCOPE

Barcodes especially the UPC have slowly become an essential part of modern civilization. Their

use is widespread, and the technology behind barcodes is constantly improving. Some modern

applications of barcodes include:

Almost every item purchased from a grocery store, department store, and mass merchandiser has

a UPC barcode on it. This greatly helps in keeping track of a large number of items in a store and

also reduces instances of shoplifting involving price tag swapping, although shoplifters can now

print their own barcodes.

The tracking of item movement, including rental cars, airline luggage, nuclear waste, mail and

parcels.

Entertainment event tickets can have barcodes that need to be validated before allowing the

holder to enter sports arenas, cinemas, theatres, fairgrounds, transportation etc. This can allow

the proprietor to identify duplicate or fraudulent tickets more easily

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REFERENCES

[1] Barcode scanners. (2007). Wasp Technologies. Retrieved 5th March 2007 from

http://www.waspbarcode.com/scanners/

[2] www.flick2know.com/QRCodes

[3] http://smallbiztrends.com/2011/02/qr-codesbarcodes-rfid-difference.html

[4] http://marksprague.wordpress.com/qr-codestechnology/understanding-qr-codes/

[5] http://www.inlogic.com/rfid/passive_vs_active.aspx

[6] M.R. Rieback, B. Crispo, and A.S. Tanenbaum, ―The Evolution of RFID Security,‖ IEEE

Pervasive Computing, vol. 5, no. 1, 2006, pp. 62-69.

[7] Clarke, D., Gosain, S., &Thillairajah, V. (2005). Realizing the promise of RFID. Retrieved

21st October 2007 from http://www.ebizq.net/topics/rfid/features/6165.html

[8] O‘Donnell, P. (2007). RFID – One bit at a time! Manufacturing and Logistics IT Unlimited.

Retrieved 7th March 2007 from www.logisticsit.com /

[9] http://qrcodetracking.com/qr-code-capacity/

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