Patent ID: 7225988
Filing Date: 2007-06-05
Classification: G06K

Abstract:
1. A hand-supportable digital imaging-based bar code symbol reading device having a working range, and 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-type 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; an automatic object presence and range detection subsystem for producing an object detection field spatially encompassing said FOV, detecting the presence of an object within a near-field or far-field portion of said FOV, generating a first control signal upon detection of an object to be imaged within the near-field portion of said FOV, and generating a second control signal upon detection of an object to be imaged within the far-field portion of said FOV; a multi-mode LED-based illumination subsystem for producing fields of narrow-band illumination from LED-based illumination arrays, wherein said multi-mode LED-based illumination subsystem produces a field of narrow-area narrow-band illumination within said FOV when said multi-mode image formation and detection subsystem is operated in said narrow-area image capture mode, and said automatic object presence and range detection subsystem detects an object within said FOV; wherein said multi-mode LED-based illumination subsystem produces a field of wide-area narrow-band illumination within the near-field portion of said FOV when said multi-mode image formation and detection subsystem is operated in said wide-area image capture mode, and said automatic object presence and range detection subsystem detects an object within said near-field portion of said FOV; wherein said multi-mode LED-based illumination subsystem produces a field of wide-area narrow-band illumination within the far-field portion of said FOV when said multi-mode image formation and detection subsystem is operated in said wide-area image capture mode, and said automatic object presence and range detection subsystem detects an object within said far-field portion of said FOV; an automatic light exposure measurement and illumination control subsystem for automatically measuring the light exposure incident upon a central portion of said FOV, and controlling the operation of said multi-mode LED-based illumination subsystem; an image capturing and buffering subsystem for capturing and buffering 2-D digital images detected by said multi-mode image formation and detection subsystem; an 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 reading 1D and 2D bar code symbols represented in said 2-D digital mages; an input/output subsystem for outputting processed image data to an external host system or other information receiving or responding device; and a system control subsystem for controlling the operation of said subsystems during system operation.