Hand-supportable imaging-based bar code symbol reader employing a CMOS-type image sensing array with a band-pass optical filter subsystem integrated within the hand-supportable housing thereof

摘要

A hand-supportable digital imaging-based bar code symbol reading device comprises: an automatic object presence and range detection subsystem; an area-type image formation and detection subsystem; a LED-based illumination subsystem having narrow-area and wide area illumination modes of operation; an automatic light exposure measurement and illumination control subsystem; an image capturing and buffering subsystem; a image-processing bar code symbol reading subsystem; an input/output subsystem; and a system control subsystem for controlling each of the above-described subsystems. A narrow-band transmission-type optical filter subsystem is integrated within the hand-supportable, so that only light transmitted from the LED-based illumination subsystem and reflected from the illuminated object is transmitted through the narrow-band transmission-type optical filter subsystem and detected by the CMOS area-type image sensing array, while all other components of ambient light are substantially rejected.