Four Types of Barcode Scanners
Barcodes
are machine-readable data codes that serve a broad range of
organizational and financial applications. Barcodes are used to keep
track of shipments, price retail items, manage financial documents, and
to perform many other logistical and organizational services because a
large number of coded information can be translated into barcode
symbology, and then scanned and read by different types of barcode
readers. There are four primary types of barcode readers that are each
designed to fulfill specific information needs.
Barcodes,
such as UPC codes, use thin and thick bar patterns to represent data
while more complex coding systems, known as 2D matrix codes, use
intricate patterns of blocks and arrangements to store masses of
information. Both types of barcode are able to store information for
later use if read by a barcode scanner,
which reads the barcode and then uses software to convert the optical
code information into a digital signal. The digital signal is then sent
on to perform another function, such as representing information on a
digital read out or logging stock in an inventory database.
Four Types of Barcode Readers
- Pen
Pen
barcode readers resemble small wand-type sticks that resemble a small
pen. The pen-style barcode reader consists of an LED light and a
photodiode in its tip. The user passes this tip over a barcode and the
LED light illuminates the black and white bars. The photodiode measures
the reflection of light and is able to determine width and color (white
or black) of each bar. This information allows for a digital reading of
the barcode, and information is transmitted to another unit for
processing.
Pen
or wand barcode readers are designed for durable, inexpensive use by a
single user who can quickly scan packages or other items. However,
because of the shakiness and imprecision of human use, the user may need
some practice to perfect the scan.
- Laser
Slightly
more advanced than a pen scanner, a laser barcode scanner is capable of
more exact light readings which prevent false positives or scanner
errors. In a laser scanner, a laser beam is shot at a mirror inside the
actual unit. This mirror makes a movement so that the laser sweeps
across the barcode in a straight line. This light then reflects back to a
diode, which measures the level of reflection. This reflection is
translated into a digital signal readout of the barcode. Laser scanners
can either be mounted in a scanning unit or be part of a handheld unit.
- CCD
A
charge coupled device (CCD), also known as an LED scanner, features
hundreds of tiny LED lights arranged in one long row. These lights are
shot directly onto a barcode, and a sensor then measures not the
reflection, but voltage of the ambient light directly in front of each
lightbulb. This voltage measurement provides a digital snapshot of the
barcode. CCD units can be very expensive, but are highly accurate and
versatile pieces of equipment.
- 2D Camera
Some
barcodes do not consist of white and black bars, but white and black
spaces in a two-dimensional (2D) target. These 2D barcodes cannot be
read by standard machinery, but they do allow for versatility of
information coding as they can hold and provide much more data than a
standard barcode. To read these barcodes, a 2D camera image scanner is
necessary. This camera consists of hundreds of tiny lights like the CCD
scanner, but these are arranged in multiple rows. The lights flash onto
the barcode and take a digital picture of the barcode, which is then
sent to software as a digital signal. The software then decodes the
information.
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