Automatic digital-imaging based bar code symbol reading system supporting pass-through and presentation modes of system operation using automatic object direction detection and illumination control, and video image capture and processing techniques

• US 7,484,666 B2
• Filed: 01/30/2007
• Issued: 02/03/2009
• 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: Zhu, Xiaoxun, Veksland, Michael, Au, Ka Man, Good, Timothy, Kotlarsky, Anatoly, Hou, Richard, Meagher, Mark, Hu, Daniel
• Primary Examiner(s): Kim; Ahshik
• Application Number:
  US11/699,760
• Publication Number:
  US 20070187509A1
• Time in Patent Office: 735 Days
• Field of Search: 235/462.45, 235/462.01, 235/462.09, 235/462.11, 235/462.41, 235/462.42
• US Class Current: 235/462.45
• CPC Class Codes: G06K 7/10683 Arrangement of fixed elements
• CPC Class Codes: G06K 7/10712 Fixed beam scanning
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10801 Multidistance reading
• 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

Abstract

An automatic digital-imaging based code symbol reading system supporting pass-through and presentation modes of system operation, automatic object direction detection and illumination control, and video image capture and processing techniques. By virtue of the present invention, the automatic digital-imaging based code symbol reading system ensures the reliable reading of code symbols graphically represented in digital images, in high-throughput point-of-sale and other environments.

Claims

1. An automatic digital-imaging based code symbol reading system supporting a pass-through and presentation modes of system operation, comprising:

a housing supportable on a countertop surface at a point-of-sale (POS) station or other work environment, and including an imaging window;

a digital image formation and detection subsystem, disposed within said housing, and having (i) image formation optics for projecting a field of view (FOV) from an area-type image detection array, through said imaging window, and upon an object to be imaged during object illumination and imaging operations, and (ii) said area-type image detection array for detecting frames of digital video data of the object during said object illumination and imaging operations carried out while said automatic digital-imaging based code symbol reading system is configured in either said pass-through or presentation modes of operation;

an automatic object direction detection subsystem, disposed in said housing, for automatically detecting the presence and direction of movement of the object in said FOV, and in response thereto, generating a first signal indicating a triggering event and a second signal indicating the direction of movement of said object with respect to said imaging window and/or said countertop surface;

an illumination subsystem, disposed within said housing, and having an illumination array for producing and projecting a field of illumination within said FOV during said object illumination and imaging operations;

an automatic illumination control subsystem, disposed within said housing, for controlling said illumination array during said object illumination and imaging operations;

a digital image capturing and buffering subsystem, disposed within said housing, for capturing and buffering said frames of digital video data in memory, during said object illumination and imaging operations;

a digital image processing subsystem, disposed in said housing, for processing said frames of digital video data and reading one or more 1D and/or 2D code symbols graphically represented in said frames of digital video data, and producing symbol character data representative of said read one or more 1D and/or 2D code symbols;

an input/output subsystem, disposed in said housing, for transmitting said symbol character data to an external host system or other information receiving or responding device; and

a system control subsystem, disposed in said housing, and responsive to said first signal, for controlling and/or coordinating the operation of said subsystems above.

2. The automatic digital-imaging based code symbol reading system of claim 1, wherein said automatic object direction detection subsystem comprises:

a plurality of IR-based object presence and direction detection fields projected through said FOV, for (i) automatically detecting an object moving through the object presence and direction detection fields, (ii) generating one or more detection signals in response to detecting an object moving through the object presence and direction detection fields, and (iii) processing said one or more detection signals so as to generate said second signal indicative that the detected object is being moved in a plurality of directions referenced with respect to said imaging window and/or countertop surface.

3. The automatic digital-imaging based code symbol reading system of claim 2, wherein said plurality of directions includes a pass-though direction and a presentation direction.

4. The automatic digital-imaging based code symbol reading system of claim 3, wherein said pass-though direction includes directions selected from the group consisting of left-to-right direction, right-to-left direction, up-to-down direction, and down-to-up direction;

and wherein said presentation direction includes towards said imaging window.

5. The automatic digital-imaging based code symbol reading system of claim 2, wherein said automatic object direction detection subsystem comprises a plurality of independent IR-based transmitters and receivers, and wherein each said IR-based transmitter and receiver comprises an IR-based light emitting diode (LED) and an IR-based photo-receiving diode, for supporting one of said plurality of IR-based object presence and direction detection fields and generating one said detection signal in response to the detection of an object in said object presence and direction detection fields.

6. The automatic digital-imaging based code symbol reading system of claim 2, wherein said automatic object direction detection subsystem further comprises a signal processor for processing said detection signals generated by said plurality of independent IR-based transmitters and receivers.

7. The automatic digital-imaging based code symbol reading system of claim 1, wherein said area-type image detection array for detects narrow-area frames of digital video data of the object during said object illumination and imaging operations carried out while said digital image formation and detection subsystem is configured in said pass-through mode of system operation.

8. The automatic digital-imaging based code symbol reading system of claim 7, wherein said frames of digital video data detected during said object illumination and imaging operations are narrow-area frames of digital video data, and wherein said field of view and said area-type image detection array are arranged so that said narrow-area frames are taken substantially perpendicular to the surface on which said housing is supported, as said object is moved through said FOV during said pass-through mode of system operation.

9. The automatic digital-imaging based code symbol reading system of claim 3, wherein each 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.

10. The automatic digital-imaging based code symbol reading system of claim 1, wherein said image formation optics comprises a lens barrel assembly for supporting a plurality of lenses.

11. The automatic digital-imaging based code symbol reading system of claim 1, which further comprises an automatic exposure measurement subsystem, disposed within said housing, for measuring the intensity of illumination reflected and/or scattered of the illuminated object, and producing an electrical signal representative of said measured intensity;

and wherein said automatic illumination control subsystem further comprises digital circuitry for controlling drive signals provided to said illumination array, in response to said electrical signal produced by said automatic exposure measurement subsystem.

12. The automatic digital-imaging based code symbol reading system of claim 1, wherein said illumination subsystem comprises:

(i) an illumination board supported within said housing and having a central aperture through which said FOV passes during object illumination and imaging operations, and on which said illumination array is mounted, and

(ii) an assembly of lenses for focusing and/or shaping illumination emanating from said illumination array so as to produce said field of illumination within said FOV.

13. The automatic digital-imaging based code symbol reading system of claim 10, wherein said automatic exposure measurement subsystem includes an optical component for collecting illumination scattered off an illuminated object present in said FOV, and directing the collected illumination onto a photo-detector, operating independently from said area-type image detection array, for measuring the intensity of said collected illumination and producing an electrical signal representative of said measured intensity.

14. The automatic digital-imaging based code symbol reading system of claim 1, wherein said field of illumination comprises narrow-band illumination produced from said illumination array.

15. The automatic digital-imaging based code symbol reading system of claim 14, wherein said narrow-band illumination is visible to the human vision system.

16. The automatic digital-imaging based code symbol reading system of claim 1, wherein said illumination array comprises a plurality of light emitting diodes (LEDs).

17. The automatic digital-imaging based code symbol reading system of claim 1, which further comprises a mechanism for automatically configuring said automatic digital-imaging based code symbol reading system in said presentation mode of system operation, upon said housing being placed on said countertop surface.

18. The automatic digital-imaging based code symbol reading system of claim 1, which further comprises a computing platform, disposed in said housing, for implementing said digital image processing subsystem, said input/output subsystem and said system control subsystem.

19. The automatic digital-imaging based code symbol reading system of claim 18, wherein said computing platform comprises:

(i) a multi-tier modular software architecture characterized by an Operating System (OS) layer, a System CORE (SCORE) layer, and an Application layer; and

(ii) a microprocessor for running one or more applications stored in one or more software libraries maintained in said Application layer, and

wherein said one or more software libraries contains code associated with a digital-imaging based code symbol reading application which is responsive to the generation of said triggering event while said automatic digital-imaging based code symbol reading system is operating in said presentation mode of system operation.

20. The automatic digital-imaging based code symbol reading system of claim 19, wherein said OS layer comprises one or more software modules selected from the group consisting of an OS kernal module, an OS file system module, and device driver modules.

21. The automatic digital-imaging based code symbol reading system of claim 20, 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.

22. The automatic digital-imaging based code symbol reading system of claim 21, 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.

23. The automatic digital-imaging based code symbol reading system of claim 1, wherein said housing is also hand-supportable.