|
Barcode Scanner World Glossary Terms
Barcode ScannerA barcode reader (or barcode scanner) is an electronic device for reading printed barcodes. Like a flatbed scanner,
it consists of a light source, a lens and a light sensor translating
optical impulses into electrical ones. Additionally, nearly all barcode
readers contain decoder circuitry analyzing the barcode's image
data provided by the sensor and sending the barcode's content to the
scanner's output port.
Goal for this page:
This page was designed to not only inform, but also to allow one to quickly go to the scanner that the information is talking about. So if you feel like the description represents the type of barcode scanner you need, then just click on the black bold/underlined heading and it will take you to the category that has the scanners with that feature.
Barcode Scanner Type:- 2D Barcode Scanner-are the fourth and newest type of bar code reader currently available.
They use a small video camera to capture an image of a bar code. The
reader then uses sophisticated digital image processing techniques to
decode the bar code. Video cameras use the same CCD technology as in a
CCD bar code reader except that instead of having a single row of
sensors, a video camera has hundreds of rows of sensors arranged in a
two dimensional array so that they can generate an image.
They also come in patterns of squares, dots, hexagons and other
geometric patterns within images termed 2D (2 dimensional) matrix codes
or symbologies. Although 2D systems use symbols other than bars, they
are generally referred to as barcodes as well.
Sample 2D barcode (PDF417):  - CCD Barcode Scanner- CCD readers (also referred to as LED scanner- excellent for indoor use, no moving parts, less expensive) use an array of hundreds of tiny light sensors lined up in a row in the head of the reader.[1]
Each sensor measures the intensity of the light immediately in front of
it. Each individual light sensor in the CCD reader is extremely small
and because there are hundreds of sensors lined up in a row, a voltage
pattern identical to the pattern in a bar code is generated in the
reader by sequentially measuring the voltages across each sensor in the
row. The important difference between a CCD reader and a pen or laser
scanner is that the CCD reader is measuring emitted ambient light from
the bar code whereas pen or laser scanners are measuring reflected
light of a specific frequency originating from the scanner itself.
- Laser Barcode Scanner- Laser scanners (excellent for outdoor use, multiple moving parts, more expensive) work the same way as pen type readers except that they use a laser
beam as the light source and typically employ either a reciprocating
mirror or a rotating prism to scan the laser beam back and forth across
the bar code.[1]
As with the pen type reader, a photodiode is used to measure the
intensity of the light reflected back from the bar code. In both pen
readers and laser scanners, the light emitted by the reader is tuned to
a specific frequency and the photodiode is designed to detect only this
modulated light of the same frequency.
- Linear Imager Barcode Scanner- Scanners designed to scan bar codes represented data in the widths (lines) and the
spacings of parallel lines, and may be referred to as linear or 1D (1
dimensional) barcodes or symbologies.
Sample 1D or Linear Barcode: - Long Range Barcode Scanner- scanners designed to scan from a few feet away from the barcode, instead of being restricted to having to be within a few inches of the barcode to scan accurately. A Long Range Scanners can scan anywhere from 2-30 (1-13 meters) depending on the specs specific to the scanner, and the size of the barcode. Some scanners have been recognized as Extra Long Range Scanners to denote those that can scan up to the 30 feet range without compromising data integrity. These scanners are commonly employed in warehouse, rugged outdoors, or any environment in which getting only a few inches from a barcode can prove difficult.
- No Reader Barcode Scanner- are mobile handheld computers that do not have scanner hardware incorporated to scan 1D (linear) or 2D barcodes. These are commonly used for the purpose of collecting data by data entry from the user into the handheld. The information is either or both collected/stored on the handheld and/or transmitted live to a data collection terminal. An sample application for which a handheld computer is used for, is when an officer checks meters and creates tickets for violations.
- Omni Directional Barcode Scanner- uses "series of straight or curved scanning lines of varying directions
in the form of a starburst (which is why this type of scanning is preferred for POS-busy retail locations with many products to scan quickly), a lissajous pattern, or other multiangle
arrangement are projected at the symbol and one or more of them will be
able to cross all of the symbol's bars and spaces, no matter what the
orientation."[2]
Omni-directional scanners almost all use a laser. Unlike the simpler
single-line laser scanners, they produce a pattern of beams in varying
orientations allowing them to read barcodes presented to it at
different angles. Most of them use a single rotating polygonal mirror
and an arrangement of several fixed mirrors to generate their complex
scan patterns.
Omni-directional scanners are most familiar through the horizontal
scanners in supermarkets, where packages are slid across a glass or
sapphire window. There are a range of different omni-directional units
available which can be used for differing scanning applications,
ranging from retail type applications with the barcodes read only a few
centimetres away from the scanner to industrial conveyor scanning where
the unit can be a couple of meters away or more from the code.
Omni-directional scanners are also better at reading poorly printed, wrinkled, or even torn barcodes.
- RFID Scanner- Radio-frequency identification (RFID) is the use of an
object (typically referred to as an RFID tag) applied to or
incorporated into a product, animal, or person for the purpose of
identification and tracking using radio waves. Some tags can be read
from several meters away and beyond the line of sight of the reader.
Most RFID tags contain at least two parts. One is an integrated circuit for storing and processing information, modulating and demodulating a radio-frequency (RF) signal, and other specialized functions. The second is an antenna for receiving and transmitting the signal. There are generally three types of RFID tags: active RFID tags, which contain a battery
and can transmit signals autonomously, passive RFID tags, which have no
battery and require an external source to provoke signal transmission
and battery assisted passive (BAP) which require an external source to
wake up but have significant higher forward link capability providing
great read range. Today, RFID is used in enterprise supply chain management to improve the efficiency of inventory tracking and management. Sample EPC RFID tag used by Wal-Mart:  Barcode Scanner Connections:- Acoustical Barcode Scanner- barcode scanners capable of transmitting data via the phone. Commonly used acoustical barcode scanners are the telxon and msi units. But Cipherlab has come out with an acoustical barcode scanner that's superior performance and size is quickly becoming the preferred acoustical supplement to the telxon or msi.
- Batch Barcode Scanner- barcode scanners that can collect and store data on the unit. This proves useful in an environment where the user needs to scan data or barcodes beyond wireless range or where there is no wireless capability. The scanner stores the data and then transmitts the data once it's within wireless range or is placed in the designated cradle to transmitt data. With batch capability, the user is simply not limited on geographical range, but is limited on how much data the scanner can store (usually most scanners can be upgraded with data storage anywhere from 2MB-10MB).
- Cordless Barcode Scanner- Cordless Barcode Scanners can transmit wirelessly by use radio
frequencies (similar to cordless phones) to send scanned information
back to a computer-attached base station. Chief criteria for selecting
a cordless barcode scanner are range and battery life. RF Cordless
barcode scanners can heighten the functional flexibility of use by
being able to access and scan packages during shipping and receiving
applications, that otherwise might be difficult doing when the scanner
is corded.
- PS2 Keyboard Wedge Scanner- PS/2 cables are connected to the host computer in a Y formation, the PS/2 keyboard port with its first end, to the keyboard
with its second, and to the barcode reader with its third end. The
barcode characters are then received by the host computer as if they
came from its keyboard decoded and converted to keyboard input within
the scanner housing. This makes it easy to interface the bar code
reader to any application that is written to accept keyboard input.
 - Radio Frequency (RF) Barcode Scanner- Cordless Barcode Scanners can transmit wirelessly by use radio
frequencies (similar to cordless phones) to send scanned information
back to a computer-attached base station. Chief criteria for selecting
a cordless barcode scanner are range and battery life. RF Cordless
barcode scanners can heighten the functional flexibility of use by
being able to access and scan packages during shipping and receiving
applications, that otherwise might be difficult doing when the scanner
is corded.
- RS-232 (Serial) Barcode Scanner- Early barcode scanners, of all formats, almost universally used the then-common RS232
serial interface. This was an electrically simple means of connection
and the software to access it is also relatively simple, although
needing to be written for specific computers and their serial ports.
Barcode Scanner Form: - Hands Free Barcode Scanner- Hands Free barcode scanners are simply any scanner that does not
require to be operated directly by the user to scan barcodes. These
scanners are stationary scanners, which means they are wall- or
table-mounted scanners that the barcode is passed under or beside.
These are commonly found at the checkout counters of supermarkets and
other retailers.
Pen type readers consist of a light source and a photodiode that are placed next to each other in the tip of a pen or wand. [1]
To read a bar code, the tip of the pen moves across the bars in a
steady motion. The photodiode measures the intensity of the light
reflected back from the light source and generates a waveform that is
used to measure the widths of the bars and spaces in the bar code. Dark
bars in the bar code absorb light and white spaces reflect light so
that the voltage waveform generated by the photo diode is a
representation of the bar and space pattern in the bar code. This
waveform is decoded by the scanner in a manner similar to the way Morse code dots and dashes are decoded. Other Barcode Scanner Terms:- Barcode- (also bar code) 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 (1 dimensional) barcodes or symbologies. They also
come in patterns of squares, dots, hexagons and other geometric
patterns within images termed 2D (2 dimensional) matrix codes or
symbologies. Although 2D systems use symbols other than bars, they are
generally referred to as barcodes as well.
The first use of barcodes was to label railroad cars, but they were not
commercially successful until they were used to automate supermarket checkout
systems, a task in which they have become almost universal. Their use
has spread to many other roles as well, tasks that are generically
referred to as Auto ID Data Capture
(AIDC). Systems such as attempting to make inroads in the AIDC market,
but the simplicity, universality and low cost of barcodes has limited
the role of these other systems. It costs about US$0.005 to implement a
barcode compared to passive RFID which still costs about US$0.07 to US$0.30 per tag. [1]
Barcodes can be read by optical scanners called barcode readers, or scanned from an image by special software. - Handheld Computer- barcode scanners than have a sophisticated operating system (Windows, Toshiba Dos, etc) embedded in it, allowing for enhanced and customized use.
References:
http://en.wikipedia.org/wiki/Barcode_reader, 27 June 2009.
|
