Planar laser illumination and imaging (PLIIM) system employing an area-type image detection array

• US 6,764,008 B2
• Filed: 02/05/2002
• Issued: 07/20/2004
• Est. Priority Date: 06/07/1999
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Zhu, Xiaoxun, Amundsen, Thomas, Naylor, Charles A., Knowles, Carl Harry, Schnee, Michael D., Tsikos, Constantine J., Dobbs, Russell Joseph
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US10/067,509
• Publication Number:
  US 20030010823A1
• Time in Patent Office: 896 Days
• Field of Search: 235/472-1-4, 235/462-1-4, 235/454, 235/470, 235/494
• US Class Current: 235/462.01
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G06K 7/10554 Moving beam scanning
• CPC Class Codes: G06K 7/10574 Multiple sources
• CPC Class Codes: G06K 7/10633 by oscillation
• CPC Class Codes: G06K 7/10683 Arrangement of fixed elements
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches

Abstract

In a planar light illumination and imaging (PLIIM) system, a planar light illumination module (PLIM) of compact construction produces a planar laser illumination beam (PLIB) which emanates substantially within a single plane along the direction of beam propagation towards an object to be optically illuminated and imaged. The PLIM comprises a module housing which has an axial extent, first and second end portions, a central bore formed along the axial extent, and a recess integrally formed in the second end portion. A visible laser diode (VLD) is mounted along the bore at the first end portion of the module housing, for producing a laser beam generally along the axial extent. A focusing lens is mounted along the bore between the first and second end portions, for focusing the laser beam to a predetermined focal point. A laser beam expansion element is mounted within the recess at the second end portion of the module housing, and expanding the laser beam along a predetermined direction and producing a substantially planar laser illumination beam from the beam expansion component.

Claims

1. A planar laser illumination and imaging (PLIIM) based system comprising:

a system housing having first, second and third light transmission apertures linearly aligned with and optically isolated from each other, and said third light transmission aperture being disposed between said first and second light transmission apertures;

an area-type image formation and detection module disposed in system housing, and having image formation optics with a field of view projectable through said third light transmission aperture and within a 3-D scanning region in which an object is present during object illumination and imaging operations;

a pair of planar laser illumination arrays (PLIAs) disposed in said system housing, each said planar laser array (PLIA) including a plurality of laser diodes arranged together in a linear manner and said planar laser illumination arrays being arranged in relation to said area-type image formation and detection module, and for producing a pair of planar laser illumination beams (PLIBs); and

a pair of planar laser beam folding/sweeping mirrors for folding and sweeping said pair of planar laser illumination beams so that the optical paths of said planar laser illumination beams are oriented in an imaging direction that is coplanar with a section of said field of view of said area-type image formation and detection module as said planar laser illumination beams are swept through the 3-D scanning region during object illumination and imaging operations so that the object can be simultaneously illuminated by said planar laser illumination beams and imaged within said field of view of said area-type image formation and detection module,

whereby a series of linear images of said object are sequentially detected by said area-type image formation and detection module over the photo-integration time period thereof so as to construct a two-dimensional image of said object.

2. The PLIIM based system of claim 1, which further comprises:

an image frame grabber for grabbing images formed and detected by said area-type image formation and detection module,

an image data buffer for buffering said grabbed images;

an image processing computer operably associated with said image data buffer, for processing said buffered images; and

a camera control computer for controlling said area-type image formation and said detection module, and said pair of planar laser illumination arrays.

3. The PLIIM-based system of claim 2, which further comprises:

an image processing computer, operably connected to said image data buffer, for receiving and buffering said 2-D image, and for carrying out image processing algorithms (e.g. bar code symbol decoding algorithms) and operators on said two-dimensional digital images.

4. The PLIIM-based system of claim 1, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed field of view.

5. The PLIIM-based system of claim 1, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed field of view.

6. The PLIIM-based system of claim 1, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed field of view.

7. The PLIIM-based system of claim 1, wherein said image forming optics have a variable focal distance and a variable focal length providing a variable field of view.

8. The PLIIM-based system of claim 1, wherein said area-type image formation and detection module further comprises a 2-D array of photo-electronic detectors realized,

wherein each said planar laser illumination array comprises an array of planar laser illumination modules (PLIMs), and

wherein each said PLIM comprises a laser diode source and optic for producing an planar laser illumination beam component.

9. The PLIIM-based system of claim 1, wherein said system housing has a unitary construction.

10. A hand-supportable bar code symbol reading system embodying the PLIIM-based system of claim 1.

11. A planar laser illumination and imaging (PLIIM) based system comprising:

a system housing having first, second and third light transmission apertures linearly aligned with and optically isolated from each other, and said third light transmission aperture being disposed between said first and second light transmission apertures;

an area-type image formation and detection module disposed in system housing, and having image formation optics with a field of view projectable through said third light transmission aperture and within a 3-D scanning region in which an object is present during object illumination and imaging operations;

a stationary field of view folding mirror, disposed in said system housing, for folding the field of view of said area-type image formation and detection module in a predetermined direction with respect to said third light transmission aperture;

a pair of planar laser illumination arrays (PLIAs) disposed in said system housing, each said planar laser array (PLIA) including a plurality of laser diodes arranged together in a linear manner and said planar laser illumination arrays being arranged in relation to said area-type image formation and detection module, and for producing a pair of planar laser illumination beams (PLIBs); and

a pair of planar laser beam folding/sweeping mirrors for folding and sweeping said pair of planar laser illumination beams so that the optical paths of said planar laser illumination beams are oriented in an imaging direction that is coplanar with a section of said field of view of said area-type image formation and detection module as said planar laser illumination beams are swept through the 3-D scanning region during object illumination and imaging operations so that the object can be simultaneously illuminated by said planar laser illumination beams and imaged within said field of view of said area-type image formation and detection module,

whereby a series of linear images of said object are sequentially detected by said area-type image formation and detection module over the photo-integration time period thereof so as to construct a two-dimensional image of said object.

12. The PLIIM based system of claim 11 which further comprises:

an image frame grabber for grabbing images formed and detected by said area-type image formation and detection module,

an image data buffer for buffering said grabbed images;

an image processing computer operably associated with said image data buffer, for processing said buffered images; and

a camera control computer for controlling said area-type image formation and said detection module, and said pair of planar laser illumination arrays.

13. The PLIIM-based system of claim 12 which further comprises:

an image processing computer, operably connected to said image data buffer, for receiving and buffering said 2-D image, and for carrying out image processing algorithms (e.g. bar code symbol decoding algorithms) and operators on said two-dimensional digital images.

14. The PLIIM-based system of claim 11, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed field of view.

15. The PLIIM-based system of claim 11, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed field of view.

16. The PLIIM-based system of claim 11, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed field of view.

17. The PLIIM-based system of claim 11, wherein said image forming optics have a variable focal distance and a variable focal length providing a variable field of view.

18. The PLIIM-based system of claim 11, wherein said system housing has a unitary construction.

19. A hand-supportable bar code symbol reading system embodying the PLIIM-based system of claim 11.

20. A planar laser illumination and imaging (PLIIM) based system comprising:

a system housing having first, second and third light transmission apertures linearly aligned with and optically isolated from each other, and said third light transmission aperture being disposed between said first and second light transmission apertures;

an area-type image formation and detection module disposed in system housing, and having image formation optics with a field of view projectable through said third light transmission aperture and within a 3-D scanning region in which an object is present during object illumination and imaging operations;

a planar laser illumination array (PLIA) disposed in said system housing, each said planar laser array (PLIA) including a plurality of laser diodes arranged together in a linear manner and said planar laser illumination arrays being arranged in relation to said area-type image formation and detection module, and for producing a planar laser illumination beam (PLIB); and

a planar laser beam folding/sweeping mirror for folding and sweeping said planar laser illumination beam so that the optical path of said planar laser illumination beam is oriented in an imaging direction that is coplanar with a section of said field of view of said area-type image formation and detection module as said planar laser illumination beam is swept through the 3-D scanning region during object illumination and imaging operations so that the object is simultaneously illuminated by said planar laser illumination beam and imaged within said field of view of said area-type image formation and detection module,

whereby a series of linear images of said object are sequentially detected by said area-type image formation and detection module over the photo-integration time period thereof so as to construct a two-dimensional image of said object.

21. The PLIIM based system of claim 20, which further comprises:

an image frame grabber for grabbing images formed and detected by said area-type image formation and detection module,

an image data buffer for buffering said grabbed images;

an image processing computer operably associated with said image data buffer, for processing said buffered images; and

a camera control computer for controlling said area-type image formation and said detection module, and said pair of planar laser illumination arrays.

22. The PLIIM-based system of claim 20, which further comprises:

an image processing computer, operably connected to said image data buffer, for receiving and buffering said 2-D image, and for carrying out image processing algorithms (e.g. bar code symbol decoding algorithms) and operators on said two-dimensional digital images.

23. The PLIIM-based system of claim 20, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed field of view.

24. The PLIIM-based system of claim 20, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed field of view.

25. The PLIIM-based system of claim 20, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed field of view.

26. The PLIIM-based system of claim 20, wherein said image forming optics have a variable focal distance and a variable focal length providing a variable field of view.

27. The PLIIM-based system of claim 20, wherein said system housing has a unitary construction.

28. A hand-supportable bar code symbol reading system embodying the PLIIM-based system of claim 20.

29. The PLIIM-based system of claim 20, wherein said area-type image formation and detection module further comprises a 2-D array of photo-electronic detectors realized,

wherein each said planar laser illumination array comprises an array of planar laser illumination modules (PLIMs), and

wherein each said PLIM comprises a laser diode source and optic for producing an planar laser illumination beam component.