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 reader employing an event-driven system control subsystem, automatic IR-based object detection, and a trigger-switch activated image capture and processing subsystem.
1. A hand-supportable digital imaging-based bar code symbol reading device supporting narrow-area and wide-area modes of illumination and image capture, said hand-supportable digital imaging-based bar code symbol reading device comprising:
a hand-supportable housing;
a multi-mode area-type 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 area-type image sensing array are enabled, or (ii) a wide-area image capture mode in which numerous or substantially all rows of the area-type image sensing array are enabled;
a multi-mode LED-based illumination subsystem for producing narrow-area and wide-area fields of narrow-band illumination within the FOV of said image formation and detection subsystem during narrow and wide area modes of image capture, respectively;
an image capturing and buffering subsystem for capturing and buffering 2-D images detected by said multi-mode area-type image formation and detection subsystem;
an image-processing based bar code symbol reading subsystem for automatically processing images captured and buffered by said image capturing and buffering subsystem and reading one or more 1D and/or 2D bar code symbols represented in said images;
an IR-based object presence detection subsystem for producing an IR-based object detection field within the FOV of said multi-mode area-type image formation and detection subsystem; and
a manually-actuatable trigger switch for generating a trigger event within said hand-supportable digital imaging-based bar code reading device; and
a system control subsystem for controlling and/or coordinating said subsystem components in accordance with a method of controlled subsystem operation;
wherein upon automatic detection of an object within said IR-based object detection field, said IR-based object presence detection subsystem automatically generates an object detection event and in response thereto, said multi-mode LED-based illumination subsystem automatically produces a narrow-area field of narrow-band illumination within the FOV of said multi-mode area-type image formation and detection subsystem; and
(A) upon the generation of said trigger event by the user depressing said manually-actuatable trigger switch, the following operations are automatically carried out:
(i) said image capturing and buffering subsystem automatically captures and buffers a narrow-area digital image of the object using said narrow-area field of narrow-band illumination within the FOV, during said narrow-area image capture mode of said multi-mode area-type image formation and detection subsystem, and
(ii) said image-processing based bar code symbol reading subsystem automatically processes said narrow-area digital image in effort to read a 1D bar code symbol represented in said narrow-area digital image, and upon successfully decoding a 1D bar code symbol in said narrow-area digital image, automatically produces symbol character data representative of said 1D bar code symbol; and
(B) upon said multi-mode image-processing based bar code symbol reading subsystem failing to successfully read said 1D bar code symbol represented in said narrow-area digital image, the following operations are automatically carried out:
(i) said multi-mode LED-based illumination subsystem automatically produces a wide-area field of narrow-band illumination within the FOV of said multi-mode area-type image formation and detection subsystem,
(ii) said image capturing and buffering subsystem captures and buffers a wide-area digital image during said wide-area image capture mode of said multi-mode area-type image formation and detection subsystem, and
(iii) said image-processing based bar code symbol reading subsystem processes said wide-area digital image in effort to read at least one 1D and/or 2D bar code symbols represented in said wide-area digital image, and upon successfully decoding at least one 1D and/or 2D bar code symbols in said wide-area digital image, automatically produces symbol character data representative of said at least one 1D and/or 2D bar code symbols.
2. The hand-supportable digital imaging-based bar code symbol reading device of claim 1 , which further comprises:
an automatic light exposure measurement and illumination control subsystem for measuring the light exposure incident upon a central portion of said FOV, and for controlling the operation of said multi-mode LED-based illumination subsystem.
3. The hand-supportable digital imaging-based bar code symbol reading device of claim 2 , which further comprises:
an input/output subsystem for outputting symbol character data to an external host system or other information receiving or responding device.
4. A hand-supportable digital imaging-based bar code symbol reading device supporting narrow-area and wide-area modes of illumination and image capture, said hand-supportable digital imaging-based bar code symbol reading device comprising:
a hand-supportable housing having a light transmission aperture;
a multi-mode area-type 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 area-type image sensing array are enabled, or (ii) a wide-area image capture mode in which many or substantially all rows of the image sensing array are enabled;
a multi-mode LED-based illumination subsystem for producing narrow and wide area fields of LED illumination within the FOV of said multi-mode area-type image formation and detection subsystem during said narrow-area and wide-area modes of image capture, respectively;
an image capturing and buffering subsystem for capturing and buffering 2-D images detected by said multi-mode area-type image formation and detection subsystem;
an image-processing based bar code symbol reading subsystem for processing images captured and buffered by said image capturing and buffering subsystem and reading one or more 1-D and/or 2-D bar code symbols represented in said images;
an input/output subsystem for outputting processed image data to an external host system or other information receiving or responding device;
an IR-based object presence and range detection subsystem for automatically producing an IR-based object detection field within the FOV of said image formation and detection subsystem, and upon detecting the presence of an object within said IR-based object detection field, generating an object detection event;
a manually-actuatable trigger switch for generating a trigger event upon a user manually actuating said manually-actuatable trigger switch; and
an event-driven system control subsystem for responding to events generated within said hand-supportable digital imaging-based bar code symbol reading device, including said object detection event and said trigger event, and controlling and coordinating a plurality of said subsystems;
wherein upon detecting said object detection event, said event-driven system control subsystem automatically controls said subsystems so that said multi-mode LED-based illumination subsystem produces a narrow-area field of LED-based illumination within the FOV of said multi-mode area-type image formation and detection subsystem; and
wherein upon detecting said trigger event, said event-driven system control subsystem controlling said subsystems so that following operations are automatically carried out:
(a) said image capturing and buffering subsystem automatically captures and buffers a narrow-area digital image of the object using the narrow-area field of LED-based illumination within the FOV, during the narrow-area image capture mode of said multi-mode area-type image formation and detection subsystem; and
(b) said image-processing based bar code symbol reading subsystem automatically processes said narrow-area digital image in effort to read a 1D bar code symbol represented in said narrow-area digital image, and upon successfully decoding a 1D bar code symbol in said narrow-area digital image, automatically produces symbol character data representative of said 1D bar code symbol; and
wherein upon said image-processing based bar code symbol reading subsystem failing to successfully read the 1D bar code symbol represented in the narrow-area digital image, the following operations are automatically carried out:
(c) said multi-mode LED-based illumination subsystem automatically produces a wide-area field of LED illumination within the FOV of said multi-mode area-type image formation and detection subsystem,
(d) said image capturing and buffering subsystem captures and buffers a wide-area digital image during the wide-area image capture mode of said multi-mode area-type image formation and detection subsystem, and
(e) said image-processing based bar code symbol reading subsystem processes the wide-area digital image in effort to read one or more 1D and/or 2D bar code symbols represented therein, and upon successfully decoding one or more 1D of and/or 2D bar code symbols therein, automatically produces symbol character data representative thereof.
5. The hand-supportable digital imaging-based bar code symbol reading device of claim 4 , which further comprises:
an automatic light exposure measurement and illumination control subsystem for measuring the light exposure incident upon a central portion of said FOV, and for automatically controlling the operation of said multi-mode LED-based illumination subsystem.
6. The hand-supportable digital imaging-based bar code symbol reading device of claim 5 , wherein said multi-mode LED-based illumination subsystem and said automatic light exposure measurement and illumination control subsystem are realized on an illumination board carrying components realizing electronic functions supported by said subsystems.
7. The hand-supportable digital imaging-based bar code symbol reading device of claim 4 , wherein said multi-mode area-type image formation and detection subsystem is realized on a camera board carrying a high resolution CMOS-type image sensing array with randomly accessible region of interest (ROI) window capabilities.
8. The hand-supportable digital imaging-based bar code symbol reading device of claim 4 , wherein said image-processing based bar code reading subsystem is realized on a computing platform including (i) a microprocessor, (ii) an expandable memory, (iii) SDRAM, and (iv) an FPGA FIFO configured to control camera timings and drive an image acquisition process.
9. The hand-supportable digital imaging-based bar code symbol reading device of claim 4 , wherein said I/O subsystem is realized on an interface board.
10. The hand-supportable digital imaging-based bar code symbol reading device of claim 4 , wherein said IR-based object presence and range detection subsystem is realized using an IR-based object presence and range detection circuit.
11. The hand-supportable digital imaging-based bar code symbol reading device of claim 4 , wherein said imaging-processing based bar code symbol reading subsystem processes digital images that have been captured and buffered by said image capturing and buffering subsystem, during both narrow-area and wide-area illumination modes of system operation.
12. A method of controlling the operation of a hand-supportable image-processing bar code symbol reader having an IR-based object presence detection subsystem, a multi-mode LED-based illumination subsystem, a multi-mode image formation and detection subsystem having a field of view (FOV), an image capturing and buffering subsystem, an image processing bar code symbol reading subsystem, an event-driven system control subsystem, and a manually-actuatable trigger switch, said method comprising the steps:
(a) upon generating an IR-based object detection field from said IR-based object presence detection subsystem, and upon detection of an object within said FOV, automatically generating an object detection event;
(b) in response detecting said object detection event, said multi-mode LED-based illumination subsystem automatically producing a narrow-area field of narrow-band illumination within said FOV;
(c) a user manually-actuating said trigger switch, and said event-driven system control subsystem controlling the following operations:
(d) said image capturing and buffering subsystem automatically capturing and buffering a narrow-area digital image of the object using the narrow-area field of narrow-band illumination within the FOV; and
(e) said image processing bar code symbol reading subsystem automatically processing said narrow-area digital image in effort to read a 1D bar code symbol represented in said narrow-area digital image, and upon successfully decoding a 1D bar code symbol in said narrow-area digital image, automatically producing symbol character data representative of said 1D bar code symbol;
(f) upon said image processing bar code symbol reading subsystem failing to successfully read a 1D bar code symbol represented in the narrow-area digital image, said event-driven system control subsystem controlling the following operations:
(g) said multi-mode LED-based illumination subsystem automatically producing a wide-area field of narrow-band illumination within the FOV of said multi-mode image formation and detection subsystem for illuminating said detected object,
(h) said multi-mode image formation and detection subsystem forming and detecting a wide-area digital image of the object during a wide-area image capture mode of said multi-mode image formation and detection subsystem,
(i) said image capturing and buffering subsystem capturing and buffering said wide-area digital image during said wide-area image capture mode of said multi-mode image formation and detection subsystem, and
(j) said image processing bar code symbol reading subsystem processing the wide-area digital image in effort to read one or more 1D and/or 2D bar code symbols represented in, said wide-area digital image, and upon successfully decoding one or more 1D and/or 2D bar code symbols, automatically produces symbol character data representative of said one or more 1D and/or 2D bar code symbols.