Omni-directional tunnel-type laser scanning system for scanning bar code symbols on object surfaces facing any direction within a three-dimensional scanning volume disposed above a conveyor belt

• US 6,588,665 B2
• Filed: 08/13/2001
• Issued: 07/08/2003
• Est. Priority Date: 12/18/1995
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Wilz, David Sr., Good, Timothy A., Knowles, C. Harry, Dickson, LeRoy, Amundsen, Thomas C., Carullo, Thomas, Naylor, Charles
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US09/928,920
• Publication Number:
  US 20020047048A1
• Time in Patent Office: 694 Days
• Field of Search: 235/462-1-4, 235/472-1-4, 235/375, 235/380, 235/383, 235/494
• US Class Current: 235/462.01
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 26/106 having diffraction gratings as scanning elements, e.g. holographic scanners holographic optical elements G02B5/32, holography G03H
• CPC Class Codes: G06K 17/0022 arrangements or provisious for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L
• CPC Class Codes: G06K 2207/1012 Special detection of object
• CPC Class Codes: G06K 2207/1013 Multi-focal
• CPC Class Codes: G06K 2207/1016 Motor control or optical moving unit control
• CPC Class Codes: G06K 2207/1017 Programmable
• CPC Class Codes: G06K 2207/1018 Source control
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G06K 7/10564 Light sources
• CPC Class Codes: G06K 7/10584 Source control
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10603 Basic scanning using moving elements
• CPC Class Codes: G06K 7/10663 using hologram
• CPC Class Codes: G06K 7/10673 Parallel lines
• CPC Class Codes: G06K 7/10693 for omnidirectional scanning
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned
• CPC Class Codes: G06K 7/10801 Multidistance reading
• CPC Class Codes: G06K 7/10811 Focalisation
• 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: 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: G06K 7/10871 : randomly oriented data-fields, code-marks therefore, e.g. concentric circles-code
• CPC Class Codes: G06K 7/10881 : constructional details of hand-held scanners
• CPC Class Codes: G06K 7/10891 : the scanner to be worn on a finger or on a wrist
• CPC Class Codes: G06K 7/109 : adaptations to make the hand-held scanner useable as a fixed scanner
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G07G 1/0045 : with a code reader for reading of an identifying code of the article to be registered, e.g. barcode reader or radio-frequency identity [RFID] reader
• CPC Class Codes: G07G 1/0054 : with control of supplementary check-parameters, e.g. weight or number of articles

Abstract

A fully automated package identification and measuring system, in which an omni-directional laser scanning systems are used to read bar codes on packages entering the tunnel, while a package dimensioning subsystem is used to capture information about the package prior to entry into the tunnel. Mathematical models are created on a real-time basis for the geometry of the package and the position of the laser scanning beam used to read the bar code symbol thereon. The mathematical models are analyzed to determine if collected and queued package identification data is spatially and/or temporally correlated with package measurement data using vector-based ray-tracing methods, homogeneous transformations, and object-oriented decision logic so as to enable simultaneous tracking of multiple packages being transported through the scanning tunnel.

Claims

1. An automated tunnel-type laser scanning system capable of scanning bar code symbols applied to the surfaces of packages facing along any direction or orientation within a three-dimensional scanning volume disposed above a conveyor belt structure, said automated tunnel-type laser scanning system comprising:

a conveyor belt structure for transporting packages along a predetermined direction of travel, said conveyor belt structure having a width dimension and first and second conveyor platforms arranged closely together in a predetermined direction, with a gap region disposed between said first and second conveyor platforms and extending across said width dimension of said conveyor belt structure, and each said package having a plurality of surfaces and a bar code symbol applied to at least one said surface and each said package being arrangeable on said conveyor belt structure in any arbitrary orientation for transport along said predetermined direction of travel;

a scanner support framework arranged above a first position of said conveyor belt structure for supporting a plurality of laser scanning subsystems above said conveyor belt structure so as to form a tunnel-type structure through which said conveyor belt structure extends and along which said packages are transported in an automated manner;

a bottom-located scanning subsystem disposed between said gap region in said conveyor belt structure, for producing an omni-directional scanning pattern along substantially the entire width dimension of said conveyor belt structure; and

a plurality of laser scanning subsystems mounted from said scanner support framework and arranged so that each said laser scanning subsystem projects an omni-directional laser scanning pattern confined substantially within a three-dimensional scanning volume disposed above said conveyor belt structure and having a large depth-of-field; and

wherein the omni-directional scanning pattern produced from said bottom-located scanning subsystem and the plurality of omni-directional laser scanning patterns produced from said plurality of laser scanning subsystems cooperate and collectively produce a composite three-dimensional scanning pattern contained within said three-dimensional scanning volume disposed above said conveyor belt structure, enabling the automated scanning of bar code symbols applied to the surfaces of said packages facing any direction or orientation within said three-dimensional scanning volume, and production of symbol character data representative of each said scanned bar code symbol.

2. The automated tunnel-type laser scanning system of claim 1, wherein the omnidirectional laser scanning pattern produced by each said laser scanning subsystem has multiple focal planes and a highly confined geometry extending about a projection axis extending from a scanning window provided within said laser scanning subsystem and above said conveyor belt structure.

3. The automated tunnel-type laser scanning system of claim 1, wherein said three-dimensional scanning volume has a widthwise dimension of at least about 1 meter extending along the width dimension of said conveyor belt structure, a lengthwise dimension of at least 1 meter extending along said predetermined direction of travel, and a heightwise dimension of at least 1 meter extending about said conveyor belt structure.

4. The automated tunnel-type laser scanning system of claim 1, wherein said composite three-dimensional laser scanning pattern fills said three-dimensional scanning volume with at least 100,000 scan lines per second.

5. The automated tunnel-type laser scanning system of claim 1, wherein said plurality of laser scanning subsystems are mounted within the corners of said scanner support framework, on the top and sides of said scanner support framework, and on the front and back of said scanner support framework.

6. The automated tunnel-type laser scanning system of claim 1, wherein said bottom-located scanning subsystem comprises a projection-type laser scanning subsystem.

7. The automated tunnel-type laser scanning system of claim 1, which further comprises a package dimensioning subsystem, installed along a second portion of said conveyor belt structure, for measuring the dimensions of each package being transported through said tunnel-like structure.

8. The automated tunnel-type laser scanning system of claim 1, which further comprises a computer system interfaced with said plurality of laser scanning subsystems and said bottom-located scanning subsystem through an input/output port multiplexer, said computer system supporting functions including scan data management and system configuration.

9. The automatic limited-type laser scanning system of claim 1, wherein each said laser scanning subsystem is a holographic laser scanning subsystem employing a plurality of laser beam sources for producing a plurality of laser beams, and a holographic scanning disc for scanning said plurality of laser beams and producing one said omni-directional laser scanning pattern confined substantially within said three-dimensional scanning volume.