Automatic hand-supportable laser projection scanner for omni-directional reading of bar code symbols within a narrowly confined scanning volume

• US 6,286,760 B1
• Filed: 03/12/1996
• Issued: 09/11/2001
• 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: Wilz, David M. Sr., Rockstein, George B., Schmidt, Mark C., Knowles, Carl H.
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): St. Cyr, Daniel
• Application Number:
  US08/615,054
• Time in Patent Office: 2,009 Days
• Field of Search: 235/462.01, 235/462.14, 235/462.17, 235/462.32, 235/462.35, 235/463.33, 235/462.36, 235/462.37, 235/462.38
• US Class Current: 235/462.32
• 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: G06K 7/1443 : locating of the code in an image
• 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

Abstract

A fully automatic bar code symbol reading system comprising an automatic (i.e., triggerless) portable bar code symbol reading device with an omni-directional laser scanning engine mounted within the head portion of its hand-supportable housing, and an associated base unit positioned within the data transmission range thereof without a physical wiring connection thereto.

Claims

1. A projection laser scanner for producing a narrowly confined scanning volume for scanning code symbols presented therein, while preventing unintentional scanning of code symbols on nearby objects located outside thereof, said projection laser scanner comprising:

(a) a hand-supportable housing having a light transmission window with a substantially planar extent through which laser light can exit said hand-supportable housing and travel towards an object bearing a code symbol, reflects therefrom, travel back through said light transmission window, and enter said hand-supportable housing;

(b) an optical bench fixedly mounted in said hand-supportable housing and having a central reference axis extending along the longitudinal extent of said optical bench;

(c) laser beam producing means disposed within said hand-supportable housing and fixedly mounted with respect to said optical bench for producing a laser beam;

(d) a laser beam sweeping means disposed within said hand-supportable housing and mounted with respect to said optical bench for rotation abut a rotational axis intersecting said central reference axis,

said laser beam sweeping means having at least first, second and third rotating light reflective surfaces each being disposed at a different acute angle with respect to said rotational axis, for sweeping the laser beam about said rotational axis along a plurality of different paths, and

said intersection of said rotational axis and said central reference axis defining a central reference plane extending along the longitudinal extent of said optical bench;

(e) a stationary array of at least first, second, third, fourth and fifth stationary light reflective surfaces disposed within said hand-supportable housing substantially under said light transmission window and fixedly mounted with respect to said optical bench,

said first stationary light reflective surface having a transverse axis extending substantially perpendicularly with respect to said central reference plane,

said second and third stationary light reflective surfaces being symmetrically disposed on opposite sides of said central reference plane, respectively, and immediately adjacent said first stationary light reflective surface, and

said fourth and first stationary light reflective surfaces being symmetrically disposed on opposite sides of said central reference plane, and immediately adjacent said second and third light reflective surfaces, respectively, and adjacent said laser beam sweeping means;

(f) a light collection subsystem within said compact housing and fixedly mounted with respect to said optical bench, said light collection subsystem including

(1) a light collection mirror fixedly mounted along said central reference plane, at a height above and immediately adjacent said first stationary light reflective surface and allowing the laser beam produced from said laser beam producing means to pass from said light collection mirror, substantially along said central reference plane, directly to said laser beam sweeping means, for sweeping about said rotational axis thereof along said plurality of different paths, and

(2) light receiving means for receiving light from said light collection mirror at a height above said laser beam sweeping means and at a point substantially within said central reference plane, said detecting the intensity of said received light and producing an electrical signal indicative of said detected intensity;

(g) signal processing means within said hand-supportable compact housing, for processing said electrical signal;

(h) control means within said hand-supportable housing for controlling the operation of said laser beam producing means and said laser beam sweeping means so that, during scanner operation, the laser beam produced from said laser beam producing means passes from said light collection mirror, substantially along said central reference plane, directly to said first, second and third rotating light reflective surfaces of said laser beam sweeping means, and as the laser beam reflects off said first, second and third rotating light reflective surfaces the laser beam is repeatedly swept across said first, second, third, fourth and fifth stationary reflective surfaces thereby producing first, second, third, fourth and fifth groups of plural scan lines, respectively, which are projected out through said light transmission window and intersect about a projection axis extending from said light transmission window, and within a narrowly confined scanning volume extending from adjacent said light transmission window to at least about six inches therefrom so as to produce a highly collimated projected scanning pattern within said narrowly confined scanning pattern, by which a code symbol can be scanned omni-directionally while preventing unintentional scanning of code symbols on objects located outside of said narrowly confined scanning volume,

each scan line in said first group of scan lines being substantially parallel to each other scan line in said first group of scan lines,

each scan line in said second group of scan lines being substantially parallel to each other scan line in said second group of scan lines,

each scan line in said third group of scan lines being substantially parallel to each other scan line in said third group of scan lines,

each scan line in said fourth group of scan lines being substantially parallel to each other scan line in said fourth group of scan lines,

each scan line in said fifth group of scan lines being substantially parallel to each other scan line in said fifth group of scan lines,

whereby when the code symbol is presented to the highly collimated projected scanning pattern within said narrowly confined scanning volume, the code symbol is scanned within said highly collimated projected scanning pattern and at least a portion of the laser light reflected from said scanned code symbol is directed through said light transmission window, reflected off said first, second, third, fourth and fifth stationary light reflective surfaces, reflected off said first, second and third rotating light reflective surfaces of said laser beam sweeping means, collected by said light collection mirror, and received by said light receiving means for detection, whereupon said electrical signal is produced for use in decode signal processing; and

(i) said hand-supportable housing including a base means for supporting said optical bench with respect to a counter surface so that said highly collimated projected scanning pattern is projected above said counter surface for scanning the code symbol presented to said highly collimated projected scanning pattern.

2. The projection laser scanner of claim 1, which further comprises signal processing means disposed within said hand-supportable housing, for decode processing said electrical signal and producing data representative of said scanned code symbol.

3. The projection laser scanner of claim 1, wherein said different acute angles are selected so that the scan lines in each said group of scan lines are substantially equidistant from each other at any distance from said light transmission window.

4. The projection laser scanner of claim 1, wherein said laser beam producing means comprises a laser diode fixedly mounted with respect to said optical bench, and wherein said first, second, third, fourth and fifth stationary reflective surfaces comprise first, second, third, fourth and fifth planar mirrors, respectively, each fixedly mounted with respect to said optical bench.

5. The projection laser scanners of claim 1, wherein said first, second, third, fourth and fifth stationary reflective surfaces comprise first, second, third, fourth and fifth planar mirrors, respectively.

6. The projection laser scanner of claim 1 wherein said hand-supportable has a head portion and a handle portion.

7. The projection laser scanner of claim 1, wherein said highly collimated laser scanning pattern is oriented laterally outward above said counter surface at a point of sale station.

8. The projection laser scanner of claim 1, said base means further comprises means for selectively supporting said optical bench in any one of a plurality of positions above said counter surface so that said highly collimated scanning pattern can be projected about said projection axis above said counter surface in any one of a plurality of orientations corresponding to said plurality of positions.

9. The projection laser scanner of claim 1, wherein said optical bench comprises a planar support structure upon which said first, second, third, fourth and fifth stationary reflective surfaces are fixed mounted.

10. The projection laser scanner of claim 1, wherein said light receiving means comprises a photodetector.

11. The projection laser scanner of claim 10, wherein said photodetector is disposed at a height above said laser beam sweeping means, substantially within said central reference plane.

12. The projection laser scanner of claim 1, wherein said code symbol is a bar code symbol.

13. A hand-supportable omnidirectional laser scanner comprising:

(a) a hand-supportable housing having a head portion, a handle portion extending from said head portion and supportable in the hand of an operator, and a light transmission window in said head portion through which laser light can exit said hand-supportable housing and travel towards an object bearing a code symbol, reflect therefrom, travel back through said light transmission window, and reenter said hand-supportable housing;

(b) an optical bench mounted in said head portion;

(c) laser beam producing means disposed within said head portion and mounted with respect to said optical bench, for producing a visible laser beam;

(d) laser beam sweeping means disposed within said head portion and mounted with respect to said optical bench, for sweeping and visible laser beam through said light transmission window and along an omnidirectional scanning pattern confined within a narrowly-confined 3-D scanning volume definable external to said head portion;

(e) a light collection subsystem disposed within said head portion and mounted with respect to said optical bench, for collecting laser light reentering said hand-supportable housing, said light collection subsystem including

(1) a light collection mirror mounted on said optical bench, and

(2) light detecting means for receiving light from said light collection mirror, detecting the intensity of said received light and producing an electrical signal indicative of said detected intensity;

(f) signal processing means within said hand-supportable compact housing, for processing said electrical signal;

(g) control means within said hand-supportable housing for controlling the operation of said laser beam producing means and said laser beam sweeping means so that, during scanner operation, the laser beam produced from said laser beam producing means passes to said laser beam sweeping means, and is projected out through said light transmission window and intersects about a projection axis extending from said light transmission window and through said 3-D scanning volume, so as to produce said omnidirectional scanning pattern within said highly-confined 3-D scanning volume,

whereby when the code symbol is presented to said omnidirectional scanning pattern within said narrowly-confined 3-D scanning volume, the code symbol is omnidirectionally scanned and at least a portion of the laser light reflected from said scanned code symbol is directed through said light transmission window, collected by said light collection mirror, and detected by said light detection means, whereupon said electrical signal is produced for use in decode signal processing; and

wherein said hand-supportable housing allows the operator to control the direction of said projection axis and said narrowly-confined scanning volume while the operator is holding the handle portion of said hand-supportable housing, thereby enabling easy alignment of said narrowly-confined scanning 3-D scanning volume with the code symbol on the object to be omnidirectionally scanned and identified.

14. The hand-supportable omnidirectional projection laser scanner of claim 13, which further comprises

signal processing means disposed within said hand-supportable housing, for decode processing said electrical signal and producing data representative of said scanned code symbol.

15. The projection laser scanner of claim 13, wherein said laser beam producing means comprises a laser diode.

16. The projection laser scanner of claim 13, wherein said code symbol is a bar code symbol.