Types of Barcode Readers

Scanning methods are differentiated by the amount of operator manipulation needed:

  • Pen or wand type readers: needs the operator to filch the pen over codeBarcode scanners
  • Semi-automatic handheld readers: the operator doesn’t need to filch but it need to position the reader close to the label.
  • Fix-mount readers for the purpose of automatic reading: this reading is done by passing the label over the reader.
  • Reader gates for doing automatic scanning: placement of code should be under the gate for short time, letting the scanner sweep to get the code target effectively.

Here is some of the type of readers:

  • Pen type readers

This type of readers has a light source and a photodiode which are placed next to each other on the tip of a wand or a pen. For reading the barcode, the tip of pen swings across the bar in a stable proposition. Photodiode measures the intensity of light which is reflected back from the source of light and get to generate a waveform which is used to measure the width of bars and space in the bar code. Dark bars which is placed in the bar code is used to absorb light and the white spaces is used to reflect light so that the voltage which is created by the generation of waveform by the photodiode is an representation and pattern of space in the bar code.

  • Laser Scanners

The working of laser scanners is same as the working of pen type readers except the fact that they use a laser beam as the source of light and engage a reciprocating mirror or a rotating prism for scanning the laser beam back and forth across the bar code. In case of pen type readers, photodiode is used for measuring the light intensity. While in laser scanners, laser beam is used.

  • CCD readers

CCD readers take into account use of plenty of tiny light sensors which are lined up in a row in front of the reader. Every sensor measures the light intensity instantly in front of it. Every individual light sensor in the CCD reader is very minute and as there are plenty of sensors lined up in a row, a pattern of voltage which is similar to the pattern in bar code is created. The main difference between CCD reader and the pen readers and laser scanner is that CCD measures the emitted light from the bar code and pen and laser measures the reflected light frequency.

  • Camera based readers

The newest and the most unique type of bar code reader which is available are camera based readers. It takes into use a small video camera to take an image of a bar code.  The reader then makes the use of high qualitative digital image processing techniques for decoding the bar code. This video camera uses the same technique as in the CCD bar code reader but instead of having single sensor row here it has plenty of rows of sensors for the generation of image.



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