Patent ID: 7237722
Filing Date: 2007-07-03
Classification: G06K

Abstract:
1. A hand-supportable digital imaging-based bar code symbol reading device, comprising: a hand-supportable housing; a multi-mode image formation and detection subsystem having image formation optics for producing a field of view (FOV) upon an object to be imaged and an area image sensing array for detecting imaged light reflected off the object during illumination operations in either (i) a narrow-area image capture mode in which a few central rows of pixels on the image sensing array are enabled, or (ii) a wide-area image capture mode in which substantially all rows of the image sensing array are enabled; a multi-mode illumination subsystem for producing narrow and wide area fields of narrow-band illumination within said FOV during narrow-area and wide-area image capture modes, respectively; an image capturing and buffering subsystem for capturing and buffering 2-D digital images detected by said multi-mode image formation and detection subsystem; a multi-mode image-processing based bar code symbol reading subsystem, for processing 2-D digital images captured and buffered by said image capturing and buffering subsystem and automatically reading 1D and 2D bar code symbols represented in said buffered 2-D digital images; an input/output subsystem for outputting processed digital image data to an external host system or other information receiving or responding device; and a system control subsystem for controlling or managing the operation of each said subsystem employed in said device; wherein said multi-mode image-processing based bar code symbol reading subsystem has at least two modes of operation which are selected from the group consisting of: a first mode of operation, wherein said multi-mode image-processing based bar code symbol reading subsystem is configured to automatically process a captured wide-area frame of digital image data so as to search for one or more bar codes represented in said captured wide-area frame of digital image data in an incremental manner, and to continue searching until the entire wide-area frame of digital image data is processed; a second mode of operation, wherein said multi-mode image-processing based bar code symbol reading subsystem is configured to automatically process a captured wide-area frame of digital image data, starting from the center or sweep spot of the digital image of the object at which the user would have aimed said bar code reading device, so as to search for one or more bar code symbols represented in said captured wide-area frame of digital image data, by searching in a helical manner through frames or blocks of extracted image feature data and marking the extracted image feature data and processing the corresponding digital image data until a bar code symbol is recognized/read within the captured frame of digital image data; a third mode of operation, wherein said multi-mode image-processing based bar code symbol reading subsystem is configured to automatically process a specified region of interest (ROI) in a captured wide-area frame of digital image data so as to search for one or more bar codes represented in said captured wide-area frame of digital image data, in response to coordinate data specifying the location of the bar code symbol within said FOV; a fourth mode of operation, wherein said multi-mode image-processing based bar code symbol reading subsystem is configured to automatically process a captured narrow-area frame of digital image data, without feature extraction and marking operations used in said first, second and third modes, so as read one or more bar code symbols represented in said digital image data; and a fifth mode of operation, wherein said multi-mode image-processing based bar code symbol reading subsystem is configured to automatically process a captured wide-area frame of digital image data along any one or more predetermined virtual scan line orientations, without feature extraction and marking operations used in said first, second and third modes, so as to read one or more bar code symbols represented in said digital image data; and wherein said multi-mode image-processing based bar code symbol reading subsystem has four processing modules, namely a Tracker Module, a Finder Module, a Marker Module, and a Decoder Module, for use in carrying out the modes of operation of said multi-mode image-processing based bar code symbol reading subsystem.