Method of reading code symbols using a hand-supportable digital image capturing and processing device employing a micro-computing platform supporting an event-driven multi-tier modular software architecture

• US 7,490,778 B2
• Filed: 11/30/2006
• Issued: 02/17/2009
• Est. Priority Date: 11/13/2003
• Status: Expired due to Term

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Ghosh, Sankar, Spatafore, Pasqual, Zhu, Xiaoxun, Knowles, C. Harry, Au, Ka Man, Liu, Yong, Liu, Liang, Schmidt, Mark, Kotlarsky, Anatoly, Tao, Xi, Zhang, Wenhua, Amundsen, Thomas, Hou, Rui, Russell, Garrett, Byun, Sung, Yu, Hongpeng, Bonanno, John, Schnee, Michael
• Primary Examiner(s): Kim; Ahshik
• Application Number:
  US11/607,112
• Publication Number:
  US 20070138294A1
• Time in Patent Office: 810 Days
• Field of Search: 235/472.01, 235/462.01, 235/462.09, 235/472.02, 235/462.15
• US Class Current: 235/472.01
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners

Abstract

A portable digital image capturing and processing system comprising: an image formation and detection subsystem; a narrow-band illumination subsystem; a narrow-band transmission-type optical filter subsystem; an automatic light exposure measurement subsystem; and an automatic illumination control subsystem. The image formation and detection subsystem has an area-type image sensing array for detecting digital images of objects formed thereon by image formation optics providing a field of view (FOV) for the system. Within the FOV of the image formation and detection subsystem, the narrow-band illumination subsystem produces a field of narrow-band illumination consisting essentially of a narrow band of wavelengths of visible illumination. The narrow-band transmission-type optical filter subsystem transmits substantially only the narrow band of wavelengths of visible illumination produced from the narrow-band illumination subsystem, and rejects all other optical wavelengths outside the narrow band however generated by ambient illumination sources. The automatic light exposure measurement subsystem employs a photo-detector operated independently from the area-type image sensing array, for automatically measuring the light exposure incident upon a selected portion of the FOV, and producing an electrical signal representative of the light exposure measurement. Only when all sensor elements in the image-sensing sensing array are activated and in state of integration, then narrow-band illumination is produced for illuminating objects in FOV of the system and simultaneously detected by a photo-detector for measuring light exposure within the FOV, and also by an area-type image sensing array for detecting a digital image of said illuminated object.

Claims

1. A method of reading code symbols using a hand-supportable digital image capturing and processing device, said method comprising the steps of:

(a) providing an imaging-based bar code symbol reader having a hand-supportable housing containing a micro-computing platform having a microprocessor, a memory architecture, and a three-tier modular software architecture characterized by an Operating System (OS) layer, a System CORE (SCORE) layer, and an application layer,

wherein said OS layer includes one or more software modules selected from the group consisting of an OS kernel module, an OS file system module, and device driver modules;

wherein said SCORE layer includes one or more of software modules selected from the group consisting of a tasks manager module, an events dispatcher module, an input/output manager module, a user commands Manager module, the Timer Subsystem module, an Input/Output Subsystem module and an Memory Control Subsystem module;

and wherein said application layer includes one or more software modules selected from the group consisting of a code symbol decoding module, a function programming module, an application events manager module, a user commands table module, and a command handler module,

(b) prior to reading one or more code symbols on an object, said microprocessor rapidly initializing said micro-computing platform by

(1) accessing one or more software modules in said OS layer and executing code contained in the software modules in said OS layer,

(2) accessing one or more software modules in said SCORE layer and executing code contained in the software modules in said SCORE layer; and

(3) accessing one or more software modules in said application layer and executing contained in the software modules in said application layer;

(c) positioning said imaging-based bar code symbol reader in proximity to the object so that the object is within a field of view (FOV) of image formation optics associated with an image formation and detection subsystem disposed in said hand-supportable housing and having an area-type image sensing array for detecting imaged light reflected off the object during illumination operations when rows of sensor elements in said area-type image sensing array are enabled so as to detect a 2D digital image of the object formed on said area-type image sensing array;

(d) after said micro-computing platform has been initiated, generating a triggering event so as to cause rows of sensor elements in said area-type image sensing array to become ready for integration of light imaged on said area-type image sensing array;

(e) when rows of sensor elements in said area-type image sensing array are ready for integration of light imaged on said area-type image sensing array,

(1) automatically producing a field of illumination within said FOV, from an illumination subsystem having an illumination array disposed in said hand-supportable housing, and illuminating the object within said FOV, and

(2) automatically detecting a 2D digital image of the illuminated object formed on said area-type image sensing array while said object is being illuminated by said field of illumination;

(g) automatically capturing and buffering the detected 2D digital image of the object using an image capturing and buffering subsystem disposed in said hand-supportable housing;

(h) processing the captured and buffered 2D digital image using an image-processing subsystem disposed in said hand-supportable housing, and producing processed image data;

(i) outputting processed image data to an external host system or other information receiving or responding device, using an input/output subsystem disposed in said hand-supportable housing; and

(j) using a system control subsystem disposed in said hand-supportable housing, for controlling and/or coordinating the operation of the subsystem components described during steps (a) through (i).

2. The method of claim 1, wherein step (d) comprises generating said triggering event by manually actuating a trigger switch integrated with said hand-supportable housing.

3. The method of claim 2, wherein during step (d), said manual actuation of said trigger switch is caused by an operator manually pulling the trigger switch with his or her finger.

4. The method of claim 2, wherein during step (d), said manual actuation of said trigger switch is caused by the placement of said hand-supportable housing within a stand supported on a work surface.

5. The method of claim 1, wherein step (d) comprises generating said triggering event by automatically detecting the presence of the object in said FOV using an automatic object presence detection subsystem disposed in said hand-supportable housing.

6. The method of claim 1, wherein step (e) comprises automatically producing a field of visible illumination within said FOV using said illumination array, and said field of visible illumination forming said 2D digital image of the illuminated object on said area-type image sensing array while said object is being illuminated by said field of visible illumination.

7. The method of claim 1, wherein said field of illumination comprises narrow-band illumination produced from an array of light emitting diodes (LEDs).

8. The method of claim 1, wherein step (e) further comprises:

(1A) while illuminating the object within said field of illumination, automatically measuring the light exposure incident upon a selected portion of said FOV, using a photo-detector associated with an automatic light exposure measurement subsystem disposed in said hand-supportable housing, and operated independently from said area-type image sensing array, for producing an electrical signal representative of said light exposure measurement; and

(1B) automatically controlling the operation of said illumination subsystem using an automatic illumination control subsystem disposed in said hand-supportable housing, whereby said automatic illumination control subsystem responds to said electrical signal and controls the duration of illumination produced from said illumination subsystem.

9. The method of claim 8, wherein said selected portion of said FOV is a central portion of said FOV.

10. The method of claim 8, wherein a light collecting optical component is used to measure the light exposure incident upon said selected portion of said FOV.

11. The method of claim 10, wherein said light collecting optical component comprises a light collecting mirror for focusing illumination in the selected portion of said FOV, onto said photo-detector.

12. The method of claim 11, wherein said light collecting mirror comprises a parabolic mirror.

13. The method of claim 1, wherein said area-type image sensing array comprises a CMOS image sensing array.

14. The method of claim 1, wherein said object bears a code symbol, and said image-processing subsystem processes said 2D digital image so as to read the code symbol and producing symbol character data representative of said read code symbol.

15. The method of claim 14, wherein said code symbol is a bar code symbol selected from the group consisting of a 1D bar code symbol, a 2D bar code symbol and a data matrix type code symbol structure.