Barcode Vartika Agarwal Accurate institute of management and technology Computer science(3 rd year)

BARCODE EXAMPLE OF BARCODE BAR CODE TERMINOLOGY TYPES OF BARCODE BARCODE SCANNERS TYPES OF SCANNERS BENEFITS OF BARCODES LIMITATONS OF BARCODES

A Bar Code is just a different way of encoding numbers and letters by using a combination of bars and spaces of varying widths. A Bar Code is just another way of entering data into a computer. A bar code is a reference number that a computer uses to look up an associated record that contains descriptive data and other important information.

For example A barcode found on a soda can does not contain the product name, type of soda, or price, instead, it contains a 12-digit product number. When this number is scanned by the cashier at the check- out, it is transmitted to the computer which finds the record associated with that item number in the data base. The matching item record contains a description of the product, vendor name, price, quantity-on-hand, etc. The computer instantly does a "price lookup" and displays the price on the cash register. It also subtracts the quantity purchased from the quantity-on-hand. This entire transaction is done instantly.

In a nutshell, a bar code typically has ID data encoded in it, and that data is used by computer to look up all specific information associated with the data.

BAR The darker, non reflective element of a Bar Code. SPACE The lighter, reflective element of a Bar Code. CHECK DIGIT A calculated character included within the Bar Code for error detection.

Terminology... BI-DIRECTIONAL SYMBOL A Bar Code symbol format which permits reading in either direction across the bars and spaces. START CHARACTER A special pattern of bars and spaces used to identify the beginning of a Bar Code symbol. STOP CHARACTER A special pattern of bars and spaces used to identify the end of a Bar Code symbol.

Types Of Barcode 1. Alpha-numeric barcodes 2. Numeric-only barcodes 3. 2-D 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.

UPC-A : - Universal Product Code seen on almost all retail products in the USA and Canada. EAN-13 : - European Article Numbering international retail product code. Codabar : - Older code often used in library systems, sometimes in blood banks.

DataMatrix : Can hold large amounts of data, especially suited for making very small codes. PDF417 : Excellent for encoding large amounts of data. Maxicode : Fixed length, used by United Parcel Service for automated package sorting.

EAN-13 EAN-13 is used world-wide for marking retail items. EAN-13 is used where the country code is required. This code is composed of 2 numbers for country code. 10 numbers for data characters and one for checksum. The checksum calculation: Add the values of the digits in the even-numbered positions: 2, 4, 6, etc. Multiply this result by 3. Add the values of the digits in the odd-numbered positions: 1, 3, 5, etc. Sum the results of steps 2 and 3. The check character is the smallest number which, when added to the result in step 4, produces a multiple of 10.

Example: Assume the barcode data = = * 3 = = = X = 90 (nearest equal or higher multiple of 10), therefore X = 5 (checksum)

A device used to extract information optically from a Bar Code. Bar Code symbol consists of series of vertical dark bars separated by spaces. Illuminated reflected light is detected by electro optical sensor. The intensity of reflected light from the dark bars is less than that of spaces.

Reflected light is converted into electrical voltage signals. Analog voltages are digitized into raw data. The decoder converts this data into the character data representation of the symbol’s code.

TYPES OF SCANNERS 1. Pen type readers (bar code wands) 2. Laser bar code scanners 3. CCD(Charge Couple Devices) barcode readers 4. Camera based barcode readers

Pen Type Readers Pen-type readers consist of a light source and a photodiode that are placed next to each other in the tip of a pen. To read a bar code, drag the tip of the pen across the barcode at a steady, even pace.

Laser Barcode Scanners The laser barcode scanner sends a low energy laser beam to read between a pattern on the image space and the beam moves backwards and forwards by means of a mobile mirror which in turn causes a blinking effect and one can see the reading line moving over the barcode. This reflection returns and is then read by the fixed mirror in the scanner.

CCD(Charge Couple Devices) Barcode Readers CCD barcode scanners use an array of tiny light sensors lined up in a row in the head of the barcode reader.

Camera Based Barcode Readers The fourth and newest types of bar code reader currently available are camera based readers that use a small video camera to capture an image of a barcode.

Benefits Of Barcode

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Limitations Of Barcode