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US 6,145,745 AGranted
Method and apparatus for the reading of a bar code
AssigneeSick AG
InventorsPeter Hauser, Jurgen Reichenbach, Hubert Uhl
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AssigneeSick AG
InventorsPeter Hauser, Jurgen Reichenbach, Hubert Uhl
Estimating the term…
A method is described for the reading of a bar code consisting of a predetermined number of code elements for the production of a binary signal with sequential high and low phases the length of which correspond to the width of the sequential code elements. In the method the code elements are scanned by the scanning beam or by a plurality of scanning beams of a bar code reader along scanning lines extending substantial parallel to one another. During this the sweeping of the scanning beam over the bar code defines a scan and a scanning plane is defined by each scanning beam when sweeping over the bar code. The angle of tilt between the respective scanning plane and A predetermined reference plane is determined for essentially each scan. During the decoding of the bar code the angles of tilt thus found are evaluated to compensate for grid errors, i.e. for irregular spacings between adjacent scanning lines. Furthermore, a method for the compensation of fluctuations in the scanning speed and also an apparatus for carrying out the method are described.
A method of reading a bar code comprising a predetermined number of code elements for the generation of a binary signal with sequential high-low phases, the lengths of which correspond to the widths of the sequential code elements, the method comprising:
A method of reading a bar code consisting of a predetermined number of code elements for generation of a binary signal with sequential high-low phases, the length of which corresponds to the width of the sequential code elements, the method comprising:
An apparatus for the reading of a bar code consisting of a predetermined number of code elements for the production of a binary signal with sequential high-low phases, the lengths of which correspond to the widths of the sequential code elements, the apparatus comprising a bar code reader that transmits at least one scanning beam for the scanning of code elements along scanning lines extending substantially parallel to one another, wherein a scanning beam that sweeps over the bar code defines a scan and each scanning beam on sweeping over the bar code defines a scanning plane, means for determining the angle of tilt between the respective scanning plane and a predetermined reference plane for substantially each scan, and grid error compensation means for the compensation of grid errors that take account of the angle of tilt that has been found.
An apparatus for reading a bar code comprising a predetermined number of code elements for the generating of a binary signal with sequential high-low phases, the lengths of which correspond to the widths of sequential code elements, the apparatus comprising a bar code reader transmitting at least one scanning beam along at least one scanning line, wherein a scanning beam sweeping over the bar code defines a scan, normalizing means for the normalizing of detected code elements with respect to their position within the scanning line and also their width in the scanning direction, and decoding means for decoding of the bar codes with respect to the normalized positions and widths of detected code elements.
Dependencies are inferred from the claim text.