Hand-supportable digital imaging-based bar code symbol reader employing an event-driven system control subsystem, automatic IR-based object detection, and trigger-switch activated image capture and processing subsystem

A hand-supportable digital imaging-based bar code symbol reading device comprising:

• a hand-supportable housing;
• an area-type image formation and detection subsystem, disposed in said hand-supportable housing, and 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 an image capture mode in which in which one or more rows of the image sensing array are enabled;
• an LED-based illumination subsystem, disposed in said hand-supportable housing, and including at least one LED array for producing a field of narrow-band illumination within said FOV during said image capture mode;
• an automatic light exposure measurement and illumination control subsystem, disposed in said hand-supportable housing, for automatically measuring the light exposure incident upon a central predetermined portion of said FOV, and controlling the operation of said LED-based illumination subsystem;
• an image capturing and buffering subsystem, disposed in said hand-supportable housing, for capturing and buffering 2-D images detected by the image formation and detection subsystem;
• and
• an image-processing based bar code symbol reading subsystem, disposed in said hand-supportable housing, for processing images captured and buffered by said image capturing and buffering subsystem and reading 1D and 2D bar code symbols represented in said processed images;
• wherein said automatic light exposure measurement and illumination control subsystem has a light collecting element and a photodiode arranged within said hand-supportable housing, wherein incident illumination is collected from a selected portion of said FOV using said light collecting element, and then focused upon said photodiode for detection of the intensity of incident illumination and subsequent processing by said automatic light exposure measurement and illumination control subsystem.