Holographic laser scanning method and system employing visible scanning-zone indicators identifying a three-dimensional omni-directional laser scanning volume for package transport navigation

• US 6,629,640 B2
• Filed: 05/07/2001
• Issued: 10/07/2003
• 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: Smith, Nancy A., Dorris, R. Monroe, Dickson, LeRoy, Amundsen, Thomas
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US09/681,606
• Publication Number:
  US 20020000467A1
• Time in Patent Office: 883 Days
• Field of Search: 235/462.01, 235/462.65, 235/472.01, 235/472.03, 235/454, 235/470, 235/494, 250/566, 250/339, 250/201
• 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 26/106 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 2207/1013 Multi-focal
• 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: G07F 9/002 : Vending machines being part of a centrally controlled network of vending machines
• CPC Class Codes: G07G 1/0054 : with control of supplementary check-parameters, e.g. weight or number of articles
• CPC Class Codes: H01L 21/28575 : on semiconductor bodies comprising AIIIBV compounds
• CPC Class Codes: H01L 29/452 : on AIII-BV compounds

Abstract

A method of and system for automatically identifying packages during manual package sortation operations, wherein, a laser scanning system is supported above a workspace environment of 3-D spatial extent, which can be occupied by a human operator involved in the manual sortation of packages bearing bar code symbols. In the illustrative embodiment, the laser scanning system includes a housing having a light transmission aperture, and a laser scanning pattern generator disposed within the housing. During operation of the system, the laser scanning pattern generator employs a holographic scanning disc to project through the light transmission aperture, an omnidirectional laser scanning pattern which is substantially confined within the spatial extent of a predefined 3-D scanning volume that spatially encompasses a substantial portion of the workspace environment, through which packages are transported during sorting operations. Apparatus contained within the housing is used to automatically project a visible scanning-zone indication pattern onto the floor surface immediately beneath the omni-directional laser scanning pattern. As the human operator uses the visible scanning-zone pattern to guide the transport of a package bearing a bar code symbol through the workspace environment, the package is automatically identified by the laser scanning system supported above the workspace environment. Thereafter, the package can be manually sorted by the human operator working beneath the laser scanning system. By virtue of the present invention, bar coded packages can now be automatically identified as a human operator manually sorts the same within the allocated workspace environment, while improving package sortation accuracy and worker productivity.

Claims

1. A method of automatically identifying packages during manual package sortation operations, comprising the steps of:

(a) supporting a laser scanning system above a workspace environment of 3-D spatial extent occupied by a human operator involved in the manual sortation of packages bearing bar code symbols, said laser scanning system including a housing having a light transmission aperture, and a laser scanning pattern generator disposed within said housing;

(b) projecting from said laser scanning pattern generator, and through said light transmission aperture, an omnidirectional laser scanning pattern substantially confined within the spatial extent of a predefined 3-D scanning volume and spatially encompassing a substantial portion of said workspace environment;

(c) projecting from a visible scanning-zone indication pattern generator, a visible scanning-zone indication pattern onto a floor surface immediately beneath said workspace environment so as to provide a visible indication of points substantially corresponding to the boundary of the projection of said omni-directional laser scanning pattern onto said floor surface;

(d) said human operator using said visible scanning-zone indication pattern to help guide the transport of a package bearing a bar code symbol through said predefined 3-D scanning volume so that said omnidirectional laser scanning pattern automatically reads the bar code symbol on said package, and said laser scanning system automatically produces symbol character data representative of said read bar code symbol and the identity of said package; and

(e) manually sorting said package identified during step (d) within said workspace environment.

2. The method of claim 1, wherein step (b) further comprises:

projecting said omnidirectional laser scanning pattern from said laser scanning pattern generator, wherein said omnidirectional laser scanning pattern further comprises a plurality of focal planes definable relative to said housing, and said omnidirectional laser scanning pattern consists of a plurality of scanlines disposed within each said focal plane for repeatedly scanning the bar code symbol on said package as said package is transported through said predefined 3-D scanning volume.

3. The method of claim 1, wherein step (a) comprises supporting said laser scanning system above said workspace environment, wherein said laser scanning pattern generator includes:

a plurality of laser beam sources for producing a plurality of laser beams;

a holographic scanning disc, rotatable about an axis of rotation, and supporting a plurality of holographic optical elements for scanning and focusing said plurality of laser beams so as to produce a plurality of scanning planes;

a plurality of beam folding mirrors disposed about said holographic scanning disc, for folding said plurality of scanning planes so as to project said omnidirectional laser scanning pattern through said light transmission aperture and within the spatial extent of said predefined 3-D scanning volume;

a plurality of light focusing elements disposed beneath said holographic scanning disc, each said light focusing element focusing towards a focal point above said holographic scanning disc, light rays reflected off said scanned bar code symbol and collected by said holographic optical elements; and

a plurality of photodetectors, each said photodetector being proximately disposed at one said focal point above said holographic scanning disc, and being radially aligned with the optical axis of one of said light focusing elements, for directly detecting the intensity of focused light rays retransmitted through said holographic optical elements as said holographic scanning disc rotates, and generating a scan data signal for subsequent processing and conversion into said symbol character data.

4. The method of claim 3, wherein each said light focusing element is realized as a parabolic mirror element.

5. The method of claim 3, wherein said plurality of laser beam sources comprises a plurality of visible laser diodes.

6. The method of claim 3, wherein step (c) comprises projecting said visible scanning-zone indication pattern from said visible scanning-zone indication pattern generator which comprises apparatus for producing a visible light pattern that characterizes the spatial location of the boundary of the projection of said omni-directional laser scanning pattern onto said floor surface.

7. The method of claim 6, wherein during step (c) said visible light pattern comprises light emitted from one of at least one white light source, at least one light-emitting diode, and at least one visible laser diode.

8. The method of claim 6, wherein during step (c) said visible light pattern is pulsed.

9. The method of claim 8, wherein said visible light pattern is pulsed at a frequency less than the critical flicker frequency.

15. The system of claim 3, wherein said visible scanning-zone indication pattern generator comprises apparatus for producing a visible light pattern that characterizes the spatial location of the boundary of the projection of said omni-directional laser scanning pattern onto said floor surface.

16. The system of claim 15, wherein said visible light pattern comprises light emitted from one of at least one white light source, at least one light-emitting diode, and at least one visible laser diode.

17. The system of claim 15, wherein said visible light pattern is pulsed.

18. The system of claim 17, wherein said visible light pattern is pulsed at a frequency less than the critical flicker frequency.

10. A system for automatically identifying packages during manual package sortation operations, comprising:

a laser scanning system supported above a workspace environment of 3-D spatial extent occupied by a human operator involved in the manual sortation of packages bearing bar code symbols,

said laser scanning system including

a housing having a light transmission aperture,

a laser scanning pattern generator disposed within said housing, for projecting through said light transmission aperture an omnidirectional laser scanning pattern substantially confined within the spatial extent of a predefined 3-D scanning volume that spatially encompasses a substantial portion of said workspace environment occupied by said human operator, and

a visible scanning-zone indication pattern generator for projecting a visible scanning-zone indication pattern onto a floor surface immediately beneath said workspace environment so as to provide a visible indication of points substantially corresponding to the boundary of the projection of said omni-directional laser scanning pattern onto said floor surface,

wherein said human operator can use said visible scanning-zone indication pattern to visually guide the transport of a package bearing a bar code symbol through said predefined 3-D scanning volume, so that said omnidirectional laser scanning pattern automatically reads the bar code symbol on said package, and said laser scanning system automatically produces symbol character data representative of said read bar code symbol and the identity of said package, and thereafter, said package can be manually sorted by said human operator within said workspace environment.

11. The system of claim 10, wherein said omnidirectional laser scanning pattern further comprises a plurality of focal planes definable relative to said housing, and said omnidirectional laser scanning pattern consists of a plurality of scanlines disposed within each said focal plane for repeatedly scanning the bar code symbol on said package as said package is transported through said predefined 3-D scanning volume.

12. The system of claim 10, wherein said laser scanning pattern generator comprises:

a plurality of lasers beam sources for producing a plurality of laser beams;

a holographic scanning disc, rotatable about an axis of rotation, and supporting a plurality of holographic optical elements for scanning and focusing said plurality of laser beams so as to produce a plurality of scanning planes;

a plurality of beam folding mirrors disposed about said holographic scanning disc, for folding said plurality of scanning planes so as to project said omnidirectional laser scanning pattern through said light transmission aperture and within the spatial extent of said predefined 3-D scanning volume;

a plurality of light focusing elements disposed beneath said holographic scanning disc, each said light focusing element focusing towards a focal point above said holographic scanning disc, light rays reflected off said scanned bar code symbol and collected by said holographic optical elements; and

a plurality of photodetectors, each said photodetector being proximately disposed at one said focal point above said holographic scanning disc, and being radially aligned with the optical axis of one of said light focusing elements, for directly detecting the intensity of focused light rays retransmitted through said holographic optical elements as said holographic scanning disc rotates, and generating a scan data signal for subsequent processing conversion into said symbol character data.

13. The system of claim 12, wherein each said light focusing element is realized as a parabolic mirror element.

14. The system of claim 12, wherein said plurality of laser beam sources comprises a plurality of visible laser diodes.