Digital imaging-based bar code reading system wherein the time duration that an CMOS image sensing array is exposed to narrow-band illumination from an LED-based illumination array is managed by controlling the time that said LED-based illumination array generates narrow-band illumination in response to control activation signals generated by the CMOS image sensing array and an automatic object presence detection subsystem aboard said system

摘要

A hand-supportable digital imaging-based bar code symbol reading system comprises: an automatic object presence detection subsystem; an image formation and detection subsystem employing a CMOS area-type image detection array; an LED-based illumination subsystem employing a LED illumination array for generating a field of narrow-band LED illumination; an automatic light exposure measurement and illumination control subsystem employing LED illumination driver circuitry; an image capturing and buffering subsystem; an image-processing bar code symbol reading subsystem; an input/output subsystem; a narrow-band transmission-type optical filter subsystem; and a system control subsystem for controlling the subsystems. The time duration that the CMOS area-type image sensing array is exposed to narrow-band illumination, from the LED-based illumination array, is managed by controlling the time that the LED-based illumination array generates narrow-band illumination in response to first and second control activation signals generated by the CMOS image sensing array and the automatic object presence detection subsystem, respectively, aboard the system