BAR CODE SYMBOL SCANNING SYSTEM FOR AUTOMATICALLY LASER SCANNING BAR CODE SYMBOLS WITHIN A 3-D SCANNING VOLUME AND PRODUCING INFORMATION SPECIFYING THE POSITION OF EACH BAR CODE SYMBOL DETECTED WITHIN SAID 3-D SCANNING VOLUME

• US 6,464,141 B2
• Filed: 02/18/1999
• Issued: 10/15/2002
• Est. Priority Date: 08/17/1994
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Dickson, LeRoy, Amundsen, Thomas, Knowles, Carl Harry, Groot, John
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US09/252,254
• Publication Number:
  US 20020050525A1
• Time in Patent Office: 1,335 Days
• Field of Search: 235/462.01, 235/472.01, 235/462--46, 235/472.02, 359/3, 359/4, 359/24, 359/29
• US Class Current: 235/462.34
• 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 26/106 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 provisions 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: G07F 9/002 : Vending machines being part of a centrally controlled network of vending machines
• 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 bar code symbol scanning system for laser scanning bar code symbols within a 3-D scanning volume and automatically producing bar code symbol position information specifying the position of each bar code symbol detected within said 3-D scanning volume. The system comprises a laser scanning mechanism and a scan data signal processor. The laser scanning mechanism generates and scans a laser beam so as produce a laser scanning pattern which is substantially confined within a 3-D scanning volume having a plurality of focal planes. During system operation, the laser scanning pattern, consisting of a plurality of scanlines disposed within each focal plane, scans the bar code symbol on each object transported through the 3-D scanning volume. In response thereto, the laser scanning mechanism automatically produces scan data indicative of the scanned bar code symbol. Therewhile, the scan data processor processes the produced scan data so as to detect each scanned bar code symbol within the 3-D scanning volume, and produce bar code symbol position data specifying the position of the detected bar code symbol therewithin. By virtue of the present invention, information specifying the position of detected bar code symbols can now be accurately generated on a real-time basis, and used for various purposes including focusing a laser scanning beam to a particular focal plane within the 3-D scanning volume, steering a laser scanning beam to a particular location therein, as well as other control functions known in the bar code symbol reading art.

Claims

1. A bar code symbol scanning system for laser scanning bar code symbols within a 3-D scanning volume and automatically producing bar code symbol position information specifying the position of each bar code symbol detected within said 3-D scanning volume, said bar code symbol scanning system comprising:

a housing having a light transmission aperture, and supportable within a work environment through which objects bearing bar code symbols are transported;

a laser scanning mechanism, disposed within said housing, for generating a laser beam and scanning said laser beam so as to project through said light transmission aperture, a laser scanning pattern substantially confined within a 3-D scanning volume having a plurality of focal planes definable relative to said housing, said laser scanning pattern consisting of a plurality of scanlines disposed within each said focal plane and repeatedly scanning the bar code symbol on each said object when said object is transported through said 3-D scanning volume, and in response to scanning the bar code symbol on said transported object, said laser scanning mechanism automatically producing scan data indicative of said scanned bar code symbol; and

a data processor for automatically processing said scan data produced from said laser scanning mechanism so as to detect each said scanned bar code symbol within said 3-D scanning volume, and produce bar code symbol position data specifying the position of said detected bar code symbol within said 3-D scanning volume.

2. The bar code symbol reading system of claim 1, wherein said 3-D scanning volume has at least four focal zones and a depth of field of at least 24 inches.

3. The bar code symbol reading system of claim 1, wherein said laser scanning pattern is an omnidirectional laser scanning pattern.

4. The bar code symbol reading system of claim 1, wherein said objects are transported along a conveyor belt, above which said housing is supported.

5. The bar code symbol reading system of claim 1, wherein said laser scanning mechanism comprises a holographic laser scanning system 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 said laser scanning pattern within said 3-D scanning volume.

6. The bar code symbol reading system of claim 5, wherein said laser scanning pattern is an omnidirectional laser scanning pattern.

7. The bar code symbol reading system of claim 1, which further comprises a computing device having access to a translation table so that said bar code symbol position data can be used to produce information specifying a volumetrically-quantized region of space within which said bar code symbol is detected.

8. A method of laser scanning bar code symbols within a 3-D scanning volume and automatically producing bar code symbol position information specifying the position of each bar code symbol detected within said 3-D scanning volume, said method comprising the steps of:

(a) supporting within a work environment, a housing having a light transmission aperture, and a laser scanning mechanism disposed therein;

(b) generating a laser beam from said laser scanning mechanism, and scanning said laser beam so as to project through said light transmission aperture, a laser scanning pattern substantially confined within a 3-D scanning volume having a plurality of focal planes definable relative to said housing, said laser scanning pattern consisting of a plurality of scanlines disposed within each said focal plane and repeatedly scanning a bar code symbol on each said object when said object is transported through said 3-D scanning volume, and in response to scanning the bar code symbol on said transported object, said laser scanning mechanism automatically producing scan data indicative of said scanned bar code symbol; and

(c) processing said scan data produced from said laser scanning mechanism so as to detect each said scanned bar code symbol within said 3-D scanning volume, and produce bar code symbol position data specifying the position of said detected bar code symbol within said 3-D scanning volume.

9. The method of claim 8, wherein during step (b) said 3-D scanning volume has at least four focal zones and a depth of field of at least 24 inches.

10. The method of claim 8, wherein during step (b) said laser scanning pattern comprises an omnidirectional laser scanning pattern.

11. The method of claim 8, wherein during step (b) said objects are transported along a conveyor belt, above which said housing is supported.

12. The method of claim 8, wherein during step (b) said laser scanning mechanism comprises a holographic laser scanning system 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 said laser scanning pattern within said 3-D scanning volume.

13. The method of claim 12, wherein during step (b) said laser scanning pattern comprises an omnidirectional laser scanning pattern.

14. The bar code symbol reading system of claim 8, which further comprises a computing device having access to a translation table so that said bar code symbol position data can be used to produce information specifying a volumetrically-quantized region of space within which said bar code symbol is detected.