HAND-SUPPORTABLE PLANAR LASER ILLUMINATION AND IMAGING (PLIIM) DEVICE EMPLOYING A PAIR OF LINEAR LASER DIODE ARRAYS MOUNTED ABOUT AN AREA IMAGE DETECTION ARRAY, FOR ILLUMINATING AN OBJECT TO BE IMAGED WITH A PLURALITY OF OPTICALLY-COMBINED SPATIALLY-INCOHERENT PLANAR LASER ILLUMINATION BEAMS (PLIBS) SCANNED THROUGH THE FIELD OF VIEW (FOV) OF SAID AREA IMAGE DETECTION ARRAY, AND REDUCING THE SPECKLE-PATTERN NOISE POWER IN DETECTED 2-D IMAGES BY TEMPORALLY-AVERAGING DETECTED SPECKLE-NOISE PATTERNS

• US 6,971,575 B2
• Filed: 04/08/2002
• Issued: 12/06/2005
• 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, Good, Timothy A., Knowles, C. Harry, Schnee, Michael D., Tsikos, Constantine J., Wirth, Allan
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US10/118,850
• Publication Number:
  US 20030042314A1
• Time in Patent Office: 1,338 Days
• Field of Search: 23546201-46245, 235/472.01, 235/472.02, 235/472.03, 235/454, 235/455, 235/436, 235/375, 235/494, 235/470, 235/462.47
• US Class Current: 235/462.01
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0052 the light source comprising a laser diode coupling into light guides using intermediate optical elements G02B6/4204; semiconductor lasers having optical devices external to the laser cavity H01S5/005
• CPC Class Codes: G02B 19/0085 for use with both a detector and a source , e.g. in a transceiver, G02B19/009, G02B19/0095 take precedence
• CPC Class Codes: G02B 19/009 for use with infrared radiation
• CPC Class Codes: G02B 19/0095 for use with ultraviolet radiation
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 27/095 Refractive optical elements
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/146 the method including quality enhancement steps
• CPC Class Codes: G06Q 10/00 Administration; Management
• CPC Class Codes: G06Q 30/00 Commerce
• CPC Class Codes: G06V 20/62 Text, e.g. of license plates, overlay texts or captions on TV images
• CPC Class Codes: G06V 30/144 using a slot moved over the image; using discrete sensing elements at predetermined points; using automatic curve following means
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence

Abstract

A hand-supportable area-type planar laser illumination and imaging (PLIIM) based device comprising an area-type image formation and detection (IFD) module having a 2-D array of image detection elements. The IFD module also includes image formation optics having a 3-D field of view (FOV). The 3-D FOV focuses a 2-D image of said object onto the 2-D array of image detection elements. A pair of planar laser illumination arrays (PLIAs) are arranged on opposite sides of the linear image formation and detection module, and produce a plurality of spatially-incoherent planar laser illumination beam (PLIB) components that are optically combined with respect to other PLIB components so as to produce a composite PLIB. The composite PLIB is automatically swept through the 3-D field of view so that the composite PLIB is arranged in a coplanar relationship with at least a portion of the 3-D FOV.

Claims

1. A hand-supportable area-type planar laser illumination and imaging (PLIIM) based device, comprising:

a hand-supportable housing having a light transmission aperture;

a support platform mounted within said hand-supportable housing;

an area-type image formation and detection module mounted on said support platform, and having a 2-D array of image detection elements and also image formation optics having a 3-D field of view (FOV) projectable through said light transmission aperture and into a space definable external to said hand-supportable housing, and in which an object can be presented for illumination and imaging, and a 2-D image of said object within said 3-D FOV is formed onto said 2-D array of image detection elements;

a pair of planar laser illumination arrays (PLIAs) arranged on opposite sides of said area-type image formation and detection module and mounted within said hand-supportable housing, each said planar laser array (PLIA) producing a plurality of spatially-incoherent planar laser illumination beam (PLIB) components that are optically combined with respect to other said PLIB components so as to produce a composite planar laser illumination beam (PLIB);

each said PLIA including a plurality of planar laser illumination modules (PLIMs) arranged together in a linear manner, and each said PLIM including a laser diode and beam focusing and diverging optics for producing one of said plurality of spatially-incoherent PLIB components;

a planar laser beam folding/sweeping mirror arrangement, mounted within said hand-supportable housing for folding and sweeping said composite PLIB so that the optical path of said composite PLIB is oriented in said predetermined imaging direction that is coplanar with a section of said 3-D FOV as said composite PLIB is swept through said 3-D FOV during object illumination and imaging operations,

whereby the object is illuminated by said composite PLIB and imaged within said 3-D FOV, and a series of linear digital 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 detect a two-dimensional digital image of said object and also a number of substantially different individual speckle noise patterns at said 2-D array of image detection elements during the photo-integration time period thereof; and

wherein the level of speckle noise power observed at said 2-D array of image detection elements is reduced through temporal averaging of said substantially different individual speckle noise patterns at said 2-D array of image detection elements during said photo-integration time period.

2. The hand-supportable area-type PLIIM based device of claim 1, which further comprises:

an image frame grabber for grabbing two-dimensional digital images formed and detected by said area-type image formation and detection module;

an image data buffer for buffering said grabbed two-dimensional digital images;

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

a camera control computer for controlling said area-type image formation and said detection module, and said pair of PLIAs.

3. The hand-supportable area-type PLIIM based device of claim 2, wherein:

said image processing computer performs one or more image processing algorithms (e.g. bar code symbol decoding algorithms) and operators on said two-dimensional digital images.

4. The hand-supportable area-type PLIIM based device of claim 1, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed 3-D field of view (FOV).

5. The hand-supportable area-type PLIIM based device of claim 1, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed 3-D field of view (FOV).

6. The hand-supportable area-type PLIIM based device of claim 1, wherein said image forming optics have a variable focal distance and a variable focal length providing a variable 3-D field of view (FOV).

7. The hand-supportable area-type PLIIM based device of claim 1, wherein said 2-D array of image detection elements comprise a 2-D array of photo-electronic detectors.

8. The hand-supportable area-type PLIIM based device of claim 1, wherein said pair of PLIAs are mounted on said support platform.

9. A hand-supportable area-type planar laser illumination and imaging (PLIIM) based device comprising:

a hand-supportable housing having a light transmission aperture;

a support platform mounted within said hand-supportable housing;

an area-type image formation and detection module mounted on said support platform, and having a 2-D array of image detection elements and also image formation optics having a 3-D field of view (FOV) projectable through said light transmission aperture and into a space definable external to said hand-supportable housing, and in which an object can be presented for illumination and imaging, and a 2-D image of said object within said 3-D FOV is focused onto said 2-D array of image detection elements;

a stationary field of view folding mirror, disposed in said hand-supportable housing, for folding said 3-D FOV in a predetermined imaging direction with respect to said light transmission aperture;

a pair of planar laser illumination arrays (PLIAs) arranged on opposite sides of said area-type image formation and detection module and mounted within said hand-supportable housing, each said planar laser array (PLIA) producing a plurality of spatially-incoherent planar laser illumination beam (PLIB) components that are optically combined with respect to other said PLIB components so as to produce a composite planar laser illumination beam (PLIB);

each said PLIA including a plurality of planar laser illumination modules (PLIMs) arranged together in a linear manner, and each said PLIM including a laser diode and beam focusing and diverging optics for producing one of said plurality of spatially-incoherent PLIB components;

a planar laser beam folding/sweeping mirror arrangement, mounted within said hand-supportable housing for folding and sweeping said composite PLIB so that the optical path of said composite PLIB is oriented in said predetermined imaging direction that is coplanar with a section of said 3-D FOV as said composite PLIB is swept through said 3-D FOV during object illumination and imaging operations,

whereby the object is illuminated by said composite PLIB and imaged within said 3-D FOV, and a series of linear digital 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 detect a two-dimensional digital image of said object and also a number of substantially different individual speckle noise patterns at said 2-D array of image detection elements during the photo-integration time period thereof; and

wherein the level of speckle noise power observed at said 2-D array of image detection elements is reduced through temporal averaging of said substantially different individual speckle noise patterns at said 2-D array of image detection elements during said photo-integration time period.

10. The hand-supportable area-type PLIIM based device of claim 9, which further comprises:

an image frame grabber for grabbing two-dimensional digital images formed and detected by said area-type image formation and detection module;

an image data buffer for buffering said grabbed two-dimensional digital images;

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

a camera control computer for controlling said area-type image formation and said detection module, and said pair of PLIAs.

11. The band-supportable area-type PLIIM based device of claim 10, wherein said image processing computer performs one or more image processing algorithms (e.g. bar code symbol decoding algorithms) and operators on said two-dimensional digital images.

12. The hand-supportable area-type PLIIM based device of claim 9, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed 3-D field of view (FOV).

13. The hand-supportable area-type PLIIM based device of claim 9, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed 3-D field of view (FOV).

14. The hand-supportable area-type PLIIM based device of claim 9, wherein said image forming optics have a variable focal distance and a variable focal length providing a variable 3-D field of view (FOV).

15. The hand-supportable area-type PLIIM based device of claim 9, wherein said pair of PLIAs are mounted on said support platform.

16. An area-type planar laser illumination and imaging (PLIIM) based engine for use in a host system, said area-type PLIIM based engine comprising:

an engine housing having a light transmission aperture;

a support platform mounted within said engine housing;

an area-type image formation and detection module mounted on said support platform, and having a 2-D array of image detection elements and also image formation optics having a 3-D field of view (FOV) projectable through said light transmission aperture and into a space definable external to said band-supportable housing, and in which an object can be presented for illumination and imaging, and a 2-D image of said object within said 3-D FOV is focused onto said 2-D array of image detection elements;

a pair of planar laser illumination arrays (PLIAs) arranged on opposite sides of said area-type image formation and detection module and mounted within said hand-supportable housing, each said planar laser array (PLIA) producing a plurality of spatially-incoherent planar laser illumination beam (PLIB) components that are optically combined with respect to other said PLIB components so as to produce a composite planar laser illumination beam (PLIB) during object illumination and imaging operations;

each said PLIA including a plurality of planar laser illumination modules (PLIMs) arranged together in a linear manner, and each said PLIM including a laser diode and beam focusing and diverging optics for producing one of said plurality of spatially-incoherent PLIB components;

a planar laser beam folding/sweeping mirror arrangement, mounted within said hand-supportable housing for folding and sweeping said composite PLIB so that the optical path of said composite PLIB is oriented in a direction that is coplanar with a section of said 3-D FOV as said composite PLIB is swept through said 3-D FOV during object illumination and imaging operations;

whereby the object is illuminated by said composite PLIB and imaged within said 3-D FOV, and a series of linear digital 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 detect a two-dimensional digital image of said object, and also a number of substantially different individual speckle noise patterns are detected at said 2-D array of image detection elements during the photo-integration time period thereof; and

wherein the level of speckle noise power observed at said 2-D array of image detection elements is reduced through temporal averaging of said substantially different individual speckle noise patterns at said 2-D array of image detection elements during said photo-integration time period.

17. The area-type PLIIM based engine of claim 16, which further comprises:

an image frame grabber for grabbing two-dimensional digital images formed and detected by said area-type image formation and detection module;

an image data buffer for buffering said grabbed two-dimensional digital images;

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

a camera control computer for controlling said area-type image formation and said detection module, and said pair of PLIAs.

18. The area-type PLIIM based engine of claim 16, wherein said processing computer performs one or more image processing algorithms (e.g. bar code symbol decoding algorithms) and operators on said two-dimensional digital images.

19. The area-type PLIIM based engine of claim 16, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed 3-D field of view (FOV).

20. The area-type PLIIM based engine of claim 16, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed 3-D field of view (FOV).

21. The area-type PLIIM based engine of claim 16, wherein said image forming optics have a variable focal distance and a variable focal length providing a variable 3-D field of view (FOV).

22. The area-type PLIIM based engine of claim 16, wherein said image detection elements comprise a 2-D array of photo-electronic detectors.

23. The area-type PLIIM based engine of claim 16, wherein said pair of PLIAs are mounted on said support platform.

24. An area-type planar laser illumination and imaging (PLIIM) based engine for use in a host system, said area-type PLIIM based engine comprising:

an engine housing having a light transmission aperture;

a support platform mounted within said engine housing;

an area-type image formation and detection module mounted on said support platform, and having a 2-D array of image detection elements and also image formation optics having a 3-D field of view (FOV) projectable through said light transmission aperture and into a space definable external to said hand-supportable housing, and in which an object can be presented for illumination and imaging, and a 2-D image of said object within said 3-D FOV is focused onto said 2-D array of image detection elements;

a stationary field of view folding mirror, disposed in said hand-supportable housing, for folding said 3-D FOV of said area-type image formation and detection module in a predetermined imaging direction with respect to said light transmission aperture;

a pair of planar laser illumination arrays (PLIAs) arranged on opposite sides of said area-type image formation and detection module and mounted within said hand-supportable housing, each said planar laser array (PLIA) producing a plurality of spatially-incoherent planar laser illumination beam (PLIB) components that are optically combined with respect to other said PLIB components so as to produce a composite planar laser illumination beam (PLIB);

each said PLIA including a plurality of planar laser illumination modules (PLIMs) arranged in a linear manner, and each said PLIM including a laser diode and beam focusing and diverging optics for producing one of said plurality of spatially-incoherent PLIB components;

a planar laser beam folding/sweeping mirror arrangement, mounted within said hand-supportable housing for folding and sweeping said composite PLIB so that the optical path of said composite PLIB is oriented in a predetermined imaging direction that is coplanar with a section of said 3-D FOV of said area-type image formation and detection module as said composite PLIB is swept through said 3-D FOV during object illumination and imaging operations,

whereby the object is illuminated by said composite PLIB and imaged within said 3-D FOV, and a series of linear digital 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 detect a two-dimensional digital image of said object, and also a number of substantially different individual speckle noise patterns at said 2-D array of image detection elements during the photo-integration time period thereof; and

wherein the level of speckle noise power observed at said 2-D array of image detection elements is reduced through temporal averaging of said substantially different individual speckle noise patterns at said 2-D array of image detection elements during said photo-integration time period.

25. The area-type PLIIM based engine of claim 24, which further comprises:

an image frame grabber for grabbing two-dimensional digital images formed and detected by said area-type image formation and detection module;

an image data buffer for buffering said grabbed two-dimensional digital images;

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

a camera control computer for controlling said area-type image formation and said detection module, and said pair of PLIAs.

26. The area-type PLIIM based engine of claim 24, wherein said image processing computer performs one or more image processing algorithms (e.g. bar code symbol decoding algorithms) and operators on said two-dimensional digital images.

27. The area-type PLIIM based engine of claim 24, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed 3-D field of view (FOV).

28. The area-type PLIIM based engine of claim 24, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed 3-D field of view (FOV).

29. The area-type PLIIM based engine of claim 24, wherein said image forming optics have a variable focal distance and a variable focal length providing a variable 3-D field of view (FOV).

30. The area-type PLIIM based engine of claim 24, wherein said pair of PLIAs area mounted on said support platform.