Method of driving a plurality of visible and invisible LEDs so as to produce an illumination beam having a dynamically managed ratio of visible to invisible (IR) spectral energy/power during object illumination and imaging operations

摘要

A method of driving a plurality of visible and invisible laser diodes so as to produce an illumination beam having a dynamically managed ratio of visible to invisible (IR) spectral energy/power during object illumination and imaging operations. The method involves supplying a plurality of visible laser and invisible laser diodes with a predetermined/default values of diode drive currents so as to illuminate the object with a spectral mixture of illumination during object illumination and imaging operations. One or more digital images of the illuminated object are captured and the image contrast quality thereof is measured, in real-time, so as to generate feedback or control data. This feedback or control data is used to dynamically generate the necessary values for the adjusted diode drive currents that are used to drive the visible and invisible laser diodes and produce an illumination beam having a dynamically managed ratio of visible to invisible (IR) spectral energy/power required to produce images of sufficient image contrast to ensure satisfactory image processing, while minimizing visual brightness to humans, at a POS station during object illumination and imaging operations.