SYMBOLOGY IMAGING AND READING APPARATUS AND METHOD

摘要

Diffuse "dark field" illumination (90) and "bright field" illumination (162, 164) are each provided for a hand-held encoded symbology imager/reader; to be projected therefrom upon symbology disposed on a target (component part, goods, package, etc.). The imager/reader (30) is encased in a housing ergonomically configured to be gripped in more than one manner and to thus facilitate holding the imager/reader steady. The symbology to be imaged (40, 42, 44) is targeted by a line that not only spots the symbology, but by extending a length commensurate with that of the symbology, indicates that the symbology is in the field of view of the imager/reader. A CCD (252), disposed to receive light reflected from the symbology, has its readout controlled so that only selected portions of the CCD need to be analyzed for illumination and focusing purposes. To optimize imaging and decoding time, and to optimize use of power, readout from some portions of the CCD is accomplished in relatively rapid time by speeding up the readout of the CCD in some of its active area; while reverting back to a slower readout for data to be analyzed for illumination and focusing control and decoding purposes. In addition, special application of entropy principles facilitate determining the optimum focus and illumination conditions for the imager/reader.