Indicia reading terminal processing plurality of frames of image data responsively to trigger signal activation

摘要

There is described a decodable indicia reading terminal which in one embodiment can capture and process a certain (e.g., a first) and a subsequent (e.g., a second) frame of image data, wherein the certain and the subsequent frames have different imaging attributes. In one embodiment the attributes between certain and subsequent frames are differentiated in that the certain frame represents light incident on pixels of a first image sensor and the subsequent frame of image data represents light incident on pixels of a second image sensor spaced apart from the first image sensor. Additionally, or in the alternative, the attributes between certain and subsequent frames can be differentiated in that the first frame represents light incident on an image sensor under a first illumination profile and the subsequent frame represents light incident on pixels of an image sensor under a second illumination profile. In one embodiment imaging attributes of a frame subject to decoding are maintained constant for each frame subject to processing during a time that a trigger signal remains active. In one embodiment the certain and subsequent frames can be processed to yield partial decoding results and the partial decoding results can be combined to form a complete decoding result.

主权项

1. A hand held indicia reading terminal for reading a decodable indicia disposed on a substrate, said hand held indicia reading terminal comprising:
an imaging assembly comprising an image sensor generating image signals and an imaging lens focusing an image onto an active surface of said image sensor, the imaging assembly having a field of view defined on said substrate when an imaging axis of said imaging assembly is directed toward said substrate; a working memory receiving image data corresponding to said image signals; a first illumination assembly having a first light source bank directing light toward said field of view; a second illumination assembly having a second light source bank directing light toward said field of view; a trigger button; wherein said terminal is adapted so that when a trigger signal is active said terminal operates in a first mode until a timeout period has expired and then switches to a second mode; wherein said terminal in said first mode receives into said working memory for decoding processing a plurality of frames, each frame subject to decoding processing in said first mode having a common illumination profile, wherein said terminal is adapted so that said timeout period is satisfied conditionally on the condition that subjecting multiple frames of said plurality of frames received in said first mode having a common illumination profile to decoding processing is not successful in determining a decoded message corresponding to said decoded indicia prior to said timeout period; wherein said terminal in said second mode varies an illumination profile of received frames received for decoding processing in such manner that in said second mode said terminal receives into a said working memory a certain and a subsequent frame of image data, wherein each of the certain and subsequent frames has a corresponding exposure period, wherein said certain frame of image data has a first illumination profile and said subsequent frame of image data has a second illumination profile, the first illumination profile being different than said second illumination profile, the first illumination profile being characterized by said first light source bank being ON and said second light source bank being OFF during said exposure period corresponding to said certain frame, said second illumination profile being characterized by said first light source bank being OFF and said second light source bank being ON during said exposure period corresponding to said subsequent frame of image data; wherein said terminal is adapted to subject to decoding processing each of said certain and subsequent frames of image data received in said second mode.