LED-based planar light illumination and imaging (PLIIM) engine

• US 6,991,166 B2
• Filed: 06/28/2002
• Issued: 01/31/2006
• 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, Amundsen, Thomas, Schnee, Michael D., Tsikos, Constantine J., Giordano, Patrick A., Schmidt, Mark C.
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US10/187,473
• Publication Number:
  US 20030102379A1
• Time in Patent Office: 1,313 Days
• Field of Search: 23546201-46248, 235/472.01, 235/472.02, 235/472.03, 235/454, 235/455, 235/494, 235/470
• 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 LED-based planar light illumination and imaging (PLIIM) engine for use in a hand-supportable linear imager adapted for manual movement relative to an object to be illuminated and imaged. The LED-based PLIIM engine comprises an engine housing having a light transmission aperture, and a linear image formation and detection (IFD) module having a linear image detection array with image detection elements and image formation optics having a field of view (FOV) projected through the light transmission aperture into an illumination and imaging field, in which an object is presented for illumination and imaging. A pair of planar light illumination arrays (PLIAs) are arranged on opposite sides of the linear IFD module. Each PLIA includes a plurality of planar light illumination modules (PLIMs) for producing a plurality of spatially-incoherent planar light illumination beam (PLIB) components which are spatially aligned to produce a planar light illumination beam (PLIB) arranged in a coplanar relationship with a portion of the FOV. Each PLIM includes a light emitting diode (LED) and beam focusing and diverging optics for producing one PLIB component. An image frame grabber is provided for grabbing images formed and detected by the linear IFD module. An image data buffer is provided for buffering the grabbed linear images. A controller is provided for controlling the linear IFD module, and the pair of planar light illumination arrays. As the engine housing moves past the object, a series of linear images of the object are sequentially detected by the linear IFD module, grabbed by the image frame grabber, and buffered in the image data buffer for subsequent processing by an image processing computer, so to decode a 1-D or 2-D bar code symbol structure represented within the structure of said two-dimensional image, or recognize character strings or other forms of graphical intelligence represented therewithin.

Claims

1. A planar light illumination and imaging (PLIIM) engine for use in a hand-supportable linear imager adapted for manual movement relative to an object to be illuminated and imaged, said PLIIM engine comprising:

an engine housing having a light transmission aperture;

a linear image formation and detection (IFD) module mounted within said engine housing, and having a linear image detection array with image detection elements and image forming optics having a field of view (FOV) projected through said light transmission aperture into an illumination and imaging field external to said engine housing and in which an object is presented for illumination by a planar light illumination beam (PLIB), and a linear image of the object is formed and detected by said linear IFD module;

a pair of planar light illumination arrays (PLIAs) mounted within said engine housing and arranged on opposite sides of said linear IFD module, each said PLIA including a plurality of planar light illumination modules (PLIMs) for producing a plurality of spatially-incoherent planar light illumination beam (PLIB) components which are spatially aligned to produce a planar light illumination beam (PLIB) arranged in a coplanar relationship with a portion of said FOV, and each said PLIM including a light emitting diode (LED) and beam focusing and diverging optics for producing one said PLIB component;

an image frame grabber mounted within said engine housing, for grabbing linear images formed and detected by said linear IFD module;

an image data buffer mounted in said engine housing, for buffering said grabbed linear images; and

a controller mounted in said engine housing, for controlling said linear IFD module, and said pair of planar light illumination arrays;

whereby a series of linear images of said object are sequentially formed and detected by said linear IFD module as said engine housing moves past said object, so that said series of linear images are grabbed by said image frame grabber, and buffered in said image data buffer for subsequent processing.

2. The PLIIM engine of claim 1, which further comprises an image processing computer in operable communication with said image data buffer, for receiving and processing said linear images.

3. The PLIIM engine of claim 2, wherein said image processing computer receives and processes a series of buffered linear images to compose a two-dimensional image, and then processes said two-dimensional image so as to decode a 1-D or 2-D bar code symbol structure represented within the structure of said two-dimensional image.

4. The PLIIM engine of claim 2, wherein said image processing computer receives and processes a series of buffered linear images so as to compose a two-dimensional image, and then processes said two-dimensional image so as to recognize character strings or other forms of graphical intelligence represented within the structure of said two-dimensional image.

5. The PLIIM engine of claim 1, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed field of view (FOV).

6. The PLIIM engine 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 engine 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. A planar light illumination and imaging (PLIIM) engine for use in a hand-supportable linear imager adapted for manual movement relative to an object to be illuminated and imaged, said PLIIM engine comprising:

a linear image formation and detection (IFD) module mounted on a support platform, and having a linear image detection array with image detection elements and image forming optics having a field of view (FOV) projectable into an illumination and imaging field in which an object is presented for illumination by a planar light illumination beam (PLIB), and a linear image of the object is formed and detected by said linear IFD module;

a pair of planar light illumination arrays (PLIAs) mounted on said support platform and arranged on opposite sides of said linear IFD module, each said PLIA including a plurality of planar light illumination modules (PLIMs) for producing a plurality of spatially-incoherent planar light illumination beam (PLIB) components which are spatially aligned to produce a planar light illumination beam (PLIB) arranged in a coplanar relationship with a portion of said FOV, and each said PLIM including a light emitting diode (LED) and beam focusing and diverging optics for producing one said PLIB component;

an image frame grabber for grabbing images formed and detected by said linear IFD module;

an image data buffer for buffering said grabbed linear images; and

a controller for controlling said linear IFD module, and said pair of planar light illumination arrays;

whereby a series of linear images of said object are sequentially formed and detected by said linear IFD module as said engine housing moves past said object, so that said series of linear images are grabbed by said image frame grabber, and buffered in said image data buffer for subsequent processing.

9. The PLIIM engine of claim 8, which further comprises an image processing computer in operable communication with said image data buffer, for receiving and processing said linear images.

10. The PLIIM engine of claim 9, wherein said image processing computer receives and processes a series of buffered linear images to compose a two-dimensional image, and then processes said two-dimensional image so as to decode a 1-D or 2-D bar code symbol structure represented within the structure of said two-dimensional image.

11. The PLIIM engine of claim 9, wherein said image processing computer receives and processes a series of buffered linear images so as to compose a two-dimensional image, and then processes said two-dimensional image so as to recognize character strings or other forms of graphical intelligence represented within the structure of said two-dimensional image.

12. The PLIIM engine of claim 8, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed field of view (FOV).

13. The PLIIM engine of claim 8, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed field of view.

14. The PLIIM engine of claim 8, wherein said image forming optics have a variable focal distance and a variable focal length providing a variable field of view.

15. A planar light illumination and imaging (PLIIM) engine for use in a hand-supportable linear imager adapted for manual movement relative to an object to be illuminated and imaged, said PLIIM engine comprising:

an engine housing having a light transmission aperture;

a linear image formation and detection (IFD) module mounted within said engine housing, and having a linear image detection array with image detection elements and image forming optics having a field of view (FOV) projected through said light transmission aperture into an illumination and imaging field external to said engine housing and in which an object is presented for illumination by a planar light illumination beam (PLIB) and a linear image of the object is formed and detected by said linear IFD module;

a pair of planar light illumination arrays (PLIAs) mounted within said engine housing and arranged on opposite sides of said linear (IFD) module, each said PLIA including a plurality of planar light illumination modules (PLIMs) for producing a plurality of spatially-incoherent planar light illumination beam (PLIB) components which are spatially aligned to produce a planar light illumination beam (PLIB) arranged in a coplanar relationship with a portion of said FOV, and each said PLIM including a light emitting diode (LED) and beam focusing and diverging optics for producing one said PLIB component;

an image frame grabber mounted within said engine housing, for grabbing images formed and detected by said linear IFD module;

an image data buffer mounted in said engine housing, for buffering said grabbed linear images; and

a controller mounted in said engine housing, for controlling said linear TED module, and said pair of planar light illumination arrays;

whereby a series of linear images of said object are sequentially formed and detected by said linear IFD module as said engine housing moves past said object, so that said series of linear images are grabbed by said image frame grabber, and buffered in said image data buffer for subsequent processing; and

an image processing computer mounted within said engine housing, and in operable communication with said image data buffer, for receiving and processing said linear images.

16. The PLIIM engine of claim 15, wherein said image processing computer receives and processes a series of buffered linear images to compose two-dimensional image, and then processes said two-dimensional image so as to decode a 1-D or 2-D bar code symbol structure represented within the structure of said two-dimensional image.

17. The PLIIM engine of claim 15, wherein said image processing computer receives and processes a series of buffered linear images so as to compose a two-dimensional image, and then processes said two-dimensional image so as to recognize character strings or other forms of graphical intelligence represented within the structure of said two-dimensional image.

18. The PLIIM engine of claim 15, wherein said image forming optics have a fixed focal distance and a fixed focal length providing a fixed field of view (FOV).

19. The PLIIM engine of claim 15, wherein said image forming optics have a variable focal distance and a fixed focal length providing a fixed field of view.

20. PLIIM engine of claim 15, wherein said image forming optics have a variable focal distance and a variable focal length providing a variable field of view.