CODE SYMBOL READING SYSTEM EMPLOYING DYNAMICALLY-ELONGATED LASER SCANNING BEAMS FOR IMPROVED LEVELS OF PERFORMANCE

摘要

A laser scanning bar code symbol reading system for scanning and reading poor quality and damaged bar code symbols in flexible operating conditions. The system includes a housing having a light transmission window; a dynamically-elongated laser beam production module, including a multi-cavity visible laser diode (VLD), for producing a dynamically-elongated laser beam having (i) a direction of propagation extending along a z reference direction, (ii) a height dimension being indicated by the y reference direction, and (iii) a width dimension being indicated by the x reference direction, where x, y and z directions are orthogonal to each other. Each dynamically-elongated laser beam is characterized by an elongation ratio (ER) that is defined as Y/X where, for any point within the working range of the laser scanning bar code symbol reading system, extending along the z direction, (i) Y indicates the beam height of the dynamically-elongated laser beam measured in the Y reference direction, (ii) X indicates the beam width of the dynamically-elongated laser beam measured in the X reference direction, and (iii) the beam height (Y) and the laser beam width (X) are measured at 1/e² intensity clip level. A laser scanning mechanism is provided for scanning the dynamically-elongated laser beam out the light transmission window and across a scanning field defined external to the housing, in which a bar code symbol is present for scanning by the dynamically-elongated laser scanning beam.