Holographic laser scanning system for producing an omni-directional scanning pattern within a 3-D scanning volume

• US 6,085,980 A
• Filed: 09/30/1997
• Issued: 07/11/2000
• 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:
  US08/941,782
• Time in Patent Office: 1,015 Days
• Field of Search: 235/462, 235/463, 235/467, 235/469, 235/470, 235/454, 235/472, 235/472.02, 359/200, 359/203, 359/201, 359/211, 359/216, 250/236
• US Class Current: 235/462.24
• 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 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: 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

Holographic laser scanning system employing a holographic scanning disc which generates a laser scanning pattern having overlapping astigmatic scanning planes for omni-directional code symbol scanning within a 3-d scanning volume.

Claims

1. A holographic laser scanning system for omnidirectionally scanning bar code symbols within a 3-D scanning volume, said holographic laser scanning system comprising:

a housing having a scanning window, and being supportable relative to a three-dimensional region of space through which objects bearing bar code symbols are to be passed;

a plurality of laser sources, disposed within said housing, for producing a plurality of laser beams; and

a holographic scanning disc, disposed within said housing, rotatably mounted about an axis of rotation and supporting a plurality of holographic optical elements,

wherein, each said holographic optical element diffracts and focuses each said laser beam and imparts scan-beam astigmatism to said diffracted laser beam so as to produce a plurality of diffracted laser beams as said holographic scanning disc rotates about said axis of rotation,

wherein each said diffracted laser beam is projected through said scanning window and focused over a focal region to a focal plane within a 3-D scanning so that said plurality of diffracted laser beams produce a plurality of overlapping focal regions within said 3-D scanning volume,

wherein each said overlapping focal region is defined between an adjacent pair of said focal planes within said 3-D scanning volume,

wherein the beam cross-section if each said diffracted laser beam is controlled by the scan-beam astigmatism imparted to said diffracted laser beam by said holographic optical element producing said diffracted laser beam;

an

wherein, over each said overlapping focal region, the beam cross-sections of each adjacent pair of said diffracted laser beams have orientations and directions of rotation which cooperate within said overlapping focal region so that, collectively, said plurality of diffracted laser beams produce an omnidirectional scanning pattern over said plurality of overlapping focal regions within said 3-D scanning volume.

2. The holographic laser scanning system of claim 1, wherein over each said overlapping focal region, the beam cross-sections of each said adjacent pair of diffracted laser beams therein are orientated in opposite directions.

3. The holographic laser scanning system of claim 1, wherein over each said overlapping focal region, the beam cross-sections of each said adjacent pair of diffracted laser beams therein rotate in opposite directions.

4. The holographic laser scanning system of claim 1, wherein said plurality of laser sources comprise a plurality of visible laser diodes.

5. The holographic laser scanning system of claim 1, wherein each said holographic optical element is a volume transmission hologram.

6. The holographic laser scanning system of claim 1, wherein said housing further comprises means for supporting said housing over work surface containing one or more objects bearing bar code symbols.