Digital-imaging based code symbol reading system employing a plurality of coplanar illumination and imaging subsystems, global object motion detection subsystem for automatically detecting objects within its 3D imaging volume, and global control subsystem for managing the state of operation of said coplanar illumination and imaging substems

• US 7,571,859 B2
• Filed: 02/27/2007
• Issued: 08/11/2009
• Est. Priority Date: 11/24/2000
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Zhu, Xiaoxun, Knowles, C. Harry, Xian, Tao, Good, Timothy
• Primary Examiner(s): Kim; Ahshik
• Application Number:
  US11/711,857
• Publication Number:
  US 20070210170A1
• Time in Patent Office: 896 Days
• Field of Search: 235/462.25, 235/462.01, 235/462.09, 235/462.24, 235/462.42
• US Class Current: 235/462.25
• CPC Class Codes: G06K 2207/1012 Special detection of object
• CPC Class Codes: G06K 7/10693 for omnidirectional scanning
• 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 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06Q 20/20 Point-of-sale [POS] network systems
• CPC Class Codes: G06Q 20/202 Interconnection or interaction of plural electronic cash registers [ECR] or to host computer, e.g. network details, transfer of information from host to ECR or from ECR to ECR
• CPC Class Codes: G06Q 20/203 Inventory monitoring
• CPC Class Codes: G06Q 20/208 Input by product or record sensing, e.g. weighing or scanner processing
• CPC Class Codes: G06Q 20/209 Specified transaction journal output feature, e.g. printed receipt or voice output
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions
• CPC Class Codes: G06V 10/141 Control of illumination

Abstract

A digital image capturing and processing system comprising a plurality of coplanar illumination and imaging subsystem for producing a plurality of coplanar linear illumination and imaging planes which intersect within a 3D imaging volume defined relative to an imaging window. The system further includes a global object motion detection subsystem for detecting the motion of objects moving through the 3D imaging volume, and a global control subsystem for controlling the state of operations within each coplanar illumination and imaging station during system operation. Each coplanar illumination and imaging subsystem has an object detection state and a code symbol reading state of operation, and includes an array of planar illumination modules (PLIMs) for producing at least one substantially planar illumination beam (PLIB), and a linear image detection array having a field of view (FOV) on the linear image detection array and extending in substantially the same plane as the PLIB, to provide a coplanar illumination and imaging plane (PLIB/FOV) that is projected through the 3D imaging volume, for capturing linear (1D) digital images of an object passing therethrough, for subsequent processing and recognition of information graphically represented in the linear digital images. When the global object motion detection subsystem automatically detects the motion of an object passing through at least a portion of the 3D imaging volume, the global control subsystem manages the state of operation of each coplanar illumination and imaging station, e.g. by driving ore or more of coplanar illumination and imaging subsystems into the code symbol reading state of operation.

Claims

1. A digital-imaging based code symbol reading system comprising:

a system housing having an imaging window;

a plurality of coplanar illumination and imaging subsystems disposed in said system housing, wherein each said coplanar illumination and imaging subsystem has an object detection state of operation and a code symbol reading state of operation;

a global control subsystem for managing the state of operation of each said coplanar illumination and imaging subsystem; and

a global object motion detection subsystem for automatically detecting the motion of an object passing through at least a portion of a 3D imaging volume defined relative to said imaging window, and generating object detection data in response to said detected object motion;

wherein each said coplanar illumination and imaging subsystem includes

(i) one or more planar illumination modules (PLIMs) for producing a substantially planar illumination beam (PLIB), wherein each said PLIM includes at least one illumination source and optics for producing said PLIB,

(ii) a linear imaging array having a field of view (FOV) on said linear imaging array and extending in substantially the same plane as said PLIB so as to produce a coplanar illumination and imaging plane (PLIB/FOV) that is projected through said 3D imaging volume, for capturing linear (1D) digital images of said object passing through said 3D imaging volume, and subsequent processing so as to read one or more code symbols graphically represented in said linear digital images, and

(iii) a local control subsystem for locally controlling the operation of subcomponents in said coplanar illumination and imaging subsystem; and

wherein upon said global object motion detection subsystem automatically detecting the motion of said object passing through at least a portion of said 3D imaging volume, and generating object detection data in response to said detected object motion, said object detection data is transmitted to said global control subsystem, and said global control subsystem manages the state of operation of each said coplanar illumination and imaging subsystem by driving one or more of said coplanar illumination and imaging subsystems into said code symbol reading state of operation; and

wherein a plurality of said coplanar illumination and imaging planes are projected through said 3D imaging volume, and intersect within said 3D imaging volume to produce a complex of coplanar illumination and imaging planes, for illuminating and imaging the detected object moving through said 3D imaging volume and reading one or more code symbols graphically represented in captured linear digital images of said detected object.

2. The digital-imaging based code symbol reading system of claim 1, wherein said global object motion detection subsystem comprises a plurality of area-type image sensing arrays, wherein each said area type image sensing array has a field of view that spatially overlaps at least a portion of said PLIB/FOV, for detecting the motion of objects passing through the field of view during system operation.

3. The digital-imaging based code symbol reading system of claim 1, wherein said global object motion detection subsystem comprises a plurality of IR-based object motion detection subsystems, and wherein each said IR-based object motion detection subsystem projects an JR-based light beam through at least a portion of said PLIB/FOV, for detecting the motion of objects passing through the IR-based light beam during system operation.

4. The digital-imaging based code symbol reading system of claim 1, wherein when said global object motion detection subsystem detects said object passing through said 3D imaging volume and produces object detection data which is transmitted to said global control subsystem, then said global control subsystem automatically over-rides control operations in the local control subsystems, and drives said coplanar illumination and imaging subsystems into said code symbol reading state of operation, for capturing digital images of said detected object.

5. The digital-imaging based code symbol reading system of claim 1, wherein each said illumination source comprises an incoherent light source.

6. The digital-imaging based code symbol reading system of claim 5, wherein said incoherent light source is a light emitting diode (LED).

7. The digital-imaging based code symbol reading system of claim 1, wherein each said illumination source comprises a coherent light source.

8. The digital-imaging based code symbol reading system of claim 7, wherein said coherent light source is a visible laser diode (VLD).

9. The digital-imaging based code symbol reading system of claim 1, wherein said linear image imaging array is selected from the group consisting of a CMOS image sensing array and a CCD image sensing array.

10. The digital-imaging based code symbol reading system of claim 1, wherein said subsequent processing of one or more code symbols graphically represented in said linear digital images comprises buffering a series of said linear digital images and composing area-type (2D) digital images of said object, and subsequently processing said area-type digital images so as to recognize said one or more code symbols graphically represented in said area-type digital images.

11. The digital-imaging based code symbol reading system of claim 10, wherein said subsequent processing and recognition of said one or more code symbols graphically represented in said area-type digital images comprises decode processing said area-type digital images so as to read said one or more code symbols graphically represented in said area-type digital images.

12. The digital-imaging based code symbol reading system of claim 11, wherein said one or more code symbols comprise one or more bar code symbols selected from the group consisting of 1 D bar code symbols, 2D bar code symbols and data matrix type bar code symbols.