Transcript Bar Codes.pdf

BAR CODE SCANNER
A.ANUSHA
(06N61A0402)
What is bar code?

A barcode is a machine readable
representation of information.
 Barcode stores data in widths and spacing
of printed parallel lines.
 They also come in patterns of dots,
concentric circles.
BAR CODE TECHNOLOGY

It is an automatic identification technology

Bar code is a predefined format of dark bars and white
spaces

Structured to contain a specific piece of information

It allows real-time data to be collected accurately and
rapidly

Combination of barcode technology with computer and
application software improves performance,
productivity and profitability
Representation of bar code:
Barcode Terminology:

Quiet zone: represents the right and left end
of the bar code symbol.
 Start/stop character: indicates start or end of
the data.
 Data (message): bar patterns of character
representing data.
 Check digit: a numeric value calculated for
read error.
Types of barcode:

1-D: contains 16 alphanumeric characters
 2-D (QR,data matrix): stores up to 700
characters
Discrete Symbology
Continuous Symbology
Information stored on a barcode

Product identification
 Size/weight of a product
 Where the product has come from
 Who manufactured the product
Information not stored on a
barcode

Product name

Price of the product
What is Bar code scanner?
– Computers cannot read bar codes. For a
computer to make use of the information
contained in the barcode data must be captured
and decoded into a data format that the
computer can process. the device that reads the
bar code data and sends it to the decoder is
known as bar code reader
Types of barcode scanner

Pen based scanner:

CCD(charge coupling
device) barcode
scanner

Laser scanners

Camera based
scanners
Parts of barcode scanner

A bar code reader consists of a scanner
 decoder (either built in or externally )
 Cable (used to connect reader with a pc)
BAR CODE SCANNERS

A device used to extract information
optically from a Bar Code

Bar Code symbol consists of series of
vertical dark bars separated by light spaces

When illuminated reflected light is detected
by electro optical sensor

The intensity of reflected light from the
dark bars is less than that of spaces
SCANNERS …

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 (READERS)

CONTACT READERS
– Must touch or come in close proximity of symbol
– Good where the label cannot be placed in an easy-
to-view position
– Normally hand-held/stationary units
– Common type is pen/wand reader
– A high-density resolution wand used to read a low-
density symbol might see an ink spot as bar or an
ink void as a space
CONTACT READERS

…
A low-resolution wand may not be able to
recognize a narrow bar of high-density
symbol

Positioned angle of wand to the surface and
movement speed across the symbol are key
parameters
Contact Readers
NON-CONTACT READERS

Reader need not come in contact with
symbol
 Scan distance may be from 6” to several
feet depending upon symbol size and
scanner design
 Hand-held, fixed beam readers
Bar-code system
Types of output interfaces

Keyboard wedge: when one scan a barcode with a
keyboard wedge scanner the data that is encoded
in a barcode goes into the pc through the keyboard
port.
 RS-232:this means that you would connect the bar
code scanner directly to an available RS232 serial
port on the back of your pc.
 USB output: they can work either as keyboard
wedge or as RS232 serial output scanner
APPLICATIONS

…
RETAIL APPLICATIONS
–
–
–
–
Super markets
Counter-mounted Bar Code scanners
Universal Product Code (UPC)
Price and description information

WARE HOUSING
 HEALTH CARE APPLICATIONS
– Drugs, devices, instruments
– Identification of expiry date
– Blood banking
Blood group
 Expiry date
 Donor traceability

APPLICATIONS …
BENEFITS OF BAR CODING

REPRESENT UNIQUE IDENTITY OF A PRODUCT

ACCURACY OF DATA INPUT (ERROR FREE)

AID EFFECTIVE MANAGEMENT OF RESOURCES
AND INVENTORIES

LABOUR SAVINGS BY AVOIDING MANUAL
SYSTEM
Future

Barcode future seems to be advancing
technology towards a new technology called
bokodes.
 They can transmit information directly to
cell phones about products,expiry date,
quantity .
Thank You