Method of reading code symbols using a digital image capturing and processing system employing a micro-computing platform with an event-driven multi-tier software architecture

• US 7,681,799 B2
• Filed: 06/25/2007
• Issued: 03/23/2010
• 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: Zhang, Wenhua, Hou, Rui, Yu, Hongpeng, Zhu, Xiaoxun, Au, Ka Man, Liu, Yong, Liu, Liang, Kotlarsky, Anatoly, Tao, Xi
• Primary Examiner(s): Kim; Ahshik
• Application Number:
  US11/821,739
• Publication Number:
  US 20080011858A1
• Time in Patent Office: 1,002 Days
• Field of Search: 235/462.42, 235/462.01, 235/162.09, 235/462.15, 235/462.24
• US Class Current: 235/462.42
• CPC Class Codes: G06F 9/44526 Plug-ins; Add-ons
• CPC Class Codes: G06K 2207/1012 Special detection of object
• CPC Class Codes: G06K 7/10712 Fixed beam scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10831 Arrangement of optical elements, e.g. lenses, mirrors, prisms optical elements per se G02B
• 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
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence

Abstract

A method of reading code symbols using a digital image capture and processing system which includes: an image formation and detection subsystem; an illumination subsystem; an illumination control subsystem; a digital image processing subsystem; and an input/output subsystem; and a system control subsystem. In the illustrative embodiment, a micro-computing platform implements the digital image processing subsystem, the input/output subsystem and the system control subsystem. The micro-computing platform includes a microprocessor, a memory architecture, and a multi-tier modular software architecture responsive to the generation of a triggering event within the system. Triggering events can be generated by an automatic object detector or by a manually actuated trigger switch.

Claims

1. A method of reading code symbols using a digital image capturing and processing system, said method comprising the sequence of steps:

(a) providing a digital image capturing and processing system contained within a housing having a light transmission window, and including the following subsystems and components;

(i) an image formation and detection subsystem having image formation optics providing a field of view (FOV) extending from an area-type image detecting array with rows of sensor elements, through said light transmission window, to an object positioned outside of said housing,

(ii) an illumination subsystem having at least one illumination array for producing a beam of illumination within said FOV for illuminating the object disposed within at least a portion of said FOV,

(iii) an image capturing and buffering subsystem for capturing and buffering area-type (2D) digital images of the object within said FOV, detected by said area-type image detecting array,

(iv) a digital image processing subsystem for processing said 2D digital images and producing processed image data,

(v) an input/output subsystem for receiving processed image data produced by said digital image processing subsystem,

(vi) a system control subsystem for controlling and/or managing one or more of said subsystems defined above, and

(vii) a micro-computing platform implementing at least portions of said digital image processing subsystem, said input/output subsystem, and said system control subsystem, and controlling and/or coordinating operations of said subsystems,

wherein said micro-computing platform includes a microprocessor, a memory architecture, and a multi-tier 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 the 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 a 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) initializing said micro-computing platform;

(c) positioning the object within said FOV;

(d) generating a triggering event within said multi-tier software architecture so as to cause rows of sensor elements in said area-type image detecting array to become ready for integration of light imaged on said area-type image detecting array;

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

(1) automatically producing a field of illumination from said illumination subsystem, and illuminating the object present within said FOV, and

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

(g) automatically capturing and buffering said one or more detected 2D digital images of the object using said image capturing and buffering subsystem;

(h) processing the one or more captured and buffered 2D digital images using said digital image processing subsystem, and producing symbol character data representative of one or more code symbols graphically represented in said one or more detected 2D digital images; and

(i) outputting processed image data to an external host system or other information receiving or responding device, using said input/output subsystem.

2. The method of claim 1, wherein said housing is a hand-supportable housing, and 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 housing.

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

7. The method of claim 1, wherein said at least one illumination array comprises an array of light emitting diodes (LEDs) for producing a field of narrow-band illumination.

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, and producing an electrical signal representative of said light exposure measurement; and

(1B) automatically controlling the operation of said illumination subsystem using said electrical signal.

9. 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 operating independently from said area-type image detecting array, and producing an electrical signal representative of said light exposure measurement; and

(1B) automatically controlling the operation of said illumination subsystem using said electrical signal.

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

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

12. The method of claim 1, wherein step (b) comprises

(1) accessing one or more software modules from said OS layer and executing code contained therein;

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

(3) accessing one or more software modules from said application layer and executing code contained therein.

13. The method of claim 1, wherein said memory architecture comprises a first memory device for storing at least one code symbol reading application, and a second memory device for storing said one or more 2D digital images captured and buffered by said image capturing and buffering subsystem.

14. The method of claim 1, wherein said FOV is projected through said light transmission window and upon the object to be imaged in said FOV.

15. The method of claim 1, wherein during step (a) said housing is hand-supportable.

16. The method of claim 1, wherein during step (a) said housing is supportable upon the countertop surface of a point of sale (POS) station.

17. A method of reading code symbols using a digital image capturing and processing system, said method comprising the sequence of steps:

(a) providing a digital image capturing and processing system contained within a housing having a light transmission window, and including the following subsystems and components;

(i) an image formation and detection subsystem having image formation optics providing a field of view (FOV) extending from an area-type image detecting array with rows of sensor elements, through said light transmission window, to an object positioned outside of said housing,

(ii) an illumination subsystem having at least one illumination array for producing a beam of illumination within said FOV,

(iii) an image capturing and buffering subsystem for capturing and buffering area-type (2D) digital images of the object within said FOV, detected by said area-type image detecting array,

(iv) a digital image processing subsystem for processing said 2D digital images and producing processed image data,

(v) an input/output subsystem for receiving processed image data produced by said digital image processing subsystem,

(vi) a system control subsystem for controlling and/or managing one or more of said subsystems defined above, and

(vii) a micro-computing platform implementing at least portions of said digital image processing subsystem, said input/output subsystem, and said system control subsystem, and controlling and/or coordinating operations of said subsystems,

wherein said micro-computing platform includes a microprocessor, a memory architecture, and a multi-tier software architecture characterized by a first layer and a second layer,

(b) initializing said micro-computing platform;

(c) positioning the object within said FOV;

(d) generating a triggering event within said multi-tier software architecture so as to cause rows of sensor elements in said area-type image detecting array to become ready for integration of light imaged on said area-type image detecting array;

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

(1) automatically producing a field of illumination from said illumination subsystem, and illuminating the object present within said FOV, and

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

(g) automatically capturing and buffering said one or more detected 2D digital images of the object using said image capturing and buffering subsystem;

(h) processing the one or more captured and buffered 2D digital images using said digital image processing subsystem, and producing symbol character data representative of one or more code symbols graphically represented in said one or more detected 2D digital images; and

(i) outputting processed image data to an external host system or other information receiving or responding device, using said input/output subsystem.

18. The method of claim 17, wherein said first 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, and wherein said second layer includes one or more of the 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, a timer subsystem module, an input/output subsystem module, and a memory control subsystem module.

19. The method of claim 17, wherein said housing is a hand-supportable housing, and wherein step (d) comprises generating said triggering event by manually actuating a trigger switch integrated with said hand-supportable housing.

20. The method of claim 17, 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 housing.