Automatic optical projection scanner for omni-directional reading of bar code symbols within a confined scanning volume

• US 6,604,684 B1
• Filed: 05/18/2001
• Issued: 08/12/2003
• Est. Priority Date: 11/24/1993
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Schmidt, Mark C., Wilz, David M. Sr., Rockstein, George B., Knowles, Carl H.
• Primary Examiner(s): Frech, Karl D.
• Assistant Examiner(s): St. Cyr, Daniel
• Application Number:
  US09/861,150
• Time in Patent Office: 816 Days
• Field of Search: 235/462.01, 235/462.14, 235/462.17, 235/462.32, 235/462.35, 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

An automatic bar code symbol reading system having an automatic laser scanning device which can be used at a point-of-sale (POS) station as either a portable hand-supported laser scanner when operated in its automatic hands-on mode of operation, or as a stationary laser projection scanner when operated in its automatic hands-free mode of operation. The bar code symbol reading system provides a collimated scanning pattern projected from the hand-supportable device about a projection axis. The collimated scanning pattern intersects the projection axis within a narrowly confined scanning volume so that bar code symbols disposed within this scanning volume can be read omnidirectionally, while inadvertent scanning of bar code symbols outside of the scanning volume is prevented.

Claims

1. An optical projection scanner for producing a confined scanning volume for scanning code symbols presented therein, while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume, the optical projection scanner comprising:

(a) a housing having an optically admissive window through which optical energy can exit said housing and travel towards an object bearing a code symbol;

at least a portion of the optical energy reflecting from the object, traveling back through the window, and entering the housing;

whereby a central reference axis extends in a substantially longitudinal direction through the housing;

(b) an optical energy generation mechanism disposed within the housing for producing a beam of optical energy;

(c) a beam sweeping mechanism disposed within the housing for rotation about a rotational axis;

the beam sweeping mechanism having at least first, second and third rotating optically reflective surfaces each being disposed at a different acute angle with respect to the rotational axis, for sweeping the beam about the rotational axis along a plurality of different paths, the rotational axis intersecting the central reference axis to thereby define a central reference plane;

(d) a stationary array of at least first, second, third, fourth, and fifth stationary optically reflective surfaces disposed within the housing and fixedly mounted with respect to the central reference axis;

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

the second and third stationary optically reflective surfaces being substantially symmetrically disposed on opposite sides of the central reference plane, respectively, and adjacent the first optically reflective surface, and

the fourth and fifth stationary optically reflective surfaces being substantially symmetrically disposed on opposite sides of the central reference plane, and substantially adjacent to the second and third stationary optically reflective surfaces, respectively, and substantially adjacent to the beam sweeping mechanism;

(e) an optical energy collection mechanism disposed within the housing and fixedly mounted with respect to the central reference axis, the collection mechanism including

(1) a collection mirror fixedly mounted along the central reference plane, so as to permit the beam produced by the optical energy generation mechanism to pass from the collection mirror, substantially along the central reference plane, to the beam sweeping mechanism, for sweeping the beam about the rotational axis thereof along the plurality of different paths, and

(2) an optical energy receiving mechanism for receiving optical energy from the collection mirror at a point substantially within the central reference plane, and detecting the received optical energy and producing an electrical signal indicative of the detected optical energy;

(f) a processing and control mechanism within the housing, for processing the electrical signal, and for controlling the operation of at least one of;

(i) the optical energy generation mechanism, and (ii) the beam sweeping mechanism, so that, during scanner operation, optical energy produced by the optical energy generation mechanism passes from the collection mirror, substantially along the central reference plane, directly to the first, second and third rotating optically reflective surfaces of the beam sweeping mechanism, and as the beam reflects off said first, second and third rotating optically reflective surfaces, the beam is swept across the first, second, third, fourth and fifth stationary optically reflective surfaces, so as to produce first, second, third, fourth and fifth groups of plural scan lines, respectively, which are projected out through the window and intersect about a projection axis extending from the window, and within a confined scanning volume extending from subsantially adjacent the window to at least about six inches from the window so as to produce a substantially collimated projected scanning pattern within the confined scanning volume, by which a code symbol can be scanned omni-directionally while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume,

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

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

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

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

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

whereby, when a code symbol is presented to the collimated projected scanning pattern within the confined scanning volume, the code symbol is scanned within the collimated projected scanning pattern and at least a portion of the optical energy reflected from the scanned code symbol is directed through the window, reflected off the first, second, third, fourth and fifth stationary optically reflective surfaces, reflected off the first, second and third rotating optically reflective surfaces of the beam sweeping mechanism, collected by the collection mirror, and received by the receiving mechanism for detection, whereupon the electrical signal is produced.

2. The optical projection scanner of claim 1 wherein the housing is adapted for use with a base mechanism for supporting the housing with respect to a counter surface so that at least a portion of the collimated projected scanning pattern is projected above the counter surface so as to permit scanning a code symbol presented to the collimated projected scanning pattern.

3. The optical projection scanner of claim 2 wherein the base mechanism is attached to the housing.

4. The optical projection scanner of claim 3 wherein the base mechanism is detachable from the housing.

5. The optical projection scanner of claim 2 wherein the collimated scanning pattern is oriented laterally outward above the counter surface at a point of sale station.

6. The optical projection scanner of claim 2, wherein the base mechanism further includes a mechanism for selectively supporting the housing in any one of a plurality of positions above the counter surface so that the collimated scanning pattern can be projected about the projection axis above the counter surface in any one of a plurality of orientations corresponding to the plurality of positions.

7. The optical projection scanner of claim 1 wherein the processing and control mechanism is adapted to decode the electrical signal and produce data representative of the scanned code symbol.

8. The optical projection scanner of claim 1, wherein the different acute angles are selected so that the scan lines within each group of scan lines are substantially equidistant from each other at a distance from the window.

9. The optical projection scanner of claim 1, wherein the optical energy generation mechanism includes a laser diode fixedly mounted with respect to the central reference axis, and wherein the first, second, third, fourth and fifth stationary reflective surfaces include first, second, third, fourth and fifth planar mirrors, respectively, each fixedly mounted with respect to the central reference axis.

10. The optical projection scanner of claim 1, wherein the first, second, third, fourth and fifth stationary reflective surfaces include first, second, third, fourth and fifth planar mirrors, respectively.

11. The optical projection scanner of claim 1 wherein the housing has a head portion and a handle portion.

12. The optical projection scanner of claim 1 further including a planar support structure upon which said first, second, third, fourth and fifth stationary reflective surfaces are mounted.

13. The optical projection scanner of claim 1, wherein the receiving mechanism comprises a photodetector.

14. The optical projection scanner of claim 13, wherein the photodetector is positioned so as to permit receipt of optical energy from the beam sweeping mechanism, and also positioned substantially within the central reference plane.

15. The optical projection scanner of claim 1, wherein the code symbol is a bar code symbol.

16. An optical projection scanner for producing a confined scanning volume for scanning code symbols presented therein, while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume, the optical projection scanner comprising:

(a) a housing having an optically admissive window through which optical energy can exit said housing and travel towards an object bearing a code symbol;

at least a portion of the optical energy reflecting from the object, traveling back through the window, and entering the housing;

whereby a central reference axis extends, in a substantially longitudinal direction, through the housing;

(b) an optical energy generation mechanism disposed within the housing for producing a beam of optical energy;

(c) a beam sweeping mechanism disposed within the housing for rotation about a rotational axis;

the beam sweeping mechanism having a plurality of rotating optically reflective surfaces each being disposed at a different acute angle with respect to the rotational axis, for sweeping the beam about the rotational axis along a plurality of different paths, the rotational axis intersecting the central reference axis to thereby define a central reference plane;

(d) a stationary array of at least first, second, third, fourth, and fifth stationary optically reflective surfaces disposed within the housing and fixedly mounted with respect to the central reference axis;

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

the second and third stationary optically reflective surfaces being substantially symmetrically disposed on opposite sides of the central reference plane, respectively, and adjacent the first optically reflective surface, and

the fourth and fifth stationary optically reflective surfaces being substantially symmetrically disposed on opposite sides of the central reference plane, and substantially adjacent to the second and third stationary optically reflective surfaces, respectively, and substantially adjacent to the beam sweeping mechanism;

(e) an optical energy collection mechanism disposed within the housing and fixedly mounted with respect to the central reference axis, the collection mechanism including

(1) a collection mirror fixedly mounted along the central reference plane, so as to permit the beam produced by the optical energy generation mechanism to pass from the collection mirror, substantially along the central reference plane, to the beam sweeping mechanism, for sweeping the beam about the rotational axis thereof along the plurality of different paths, and

(2) an optical energy receiving mechanism for receiving optical energy from the collection mirror at a point substantially within the central reference plane, and detecting the received optical energy and producing an electrical signal indicative of the detected optical energy;

(f) a processing and control mechanism within the housing, for processing the electrical signal, and for controlling the operation of at least one of;

(i) the optical energy generation mechanism, and (ii) the beam sweeping mechanism, so that, during scanner operation, optical energy produced by the optical energy generation mechanism passes from the collection mirror, substantially along the central reference plane, and in a sequential manner to each of a plurality of the rotating optically reflective surfaces of the beam sweeping mechanism, and as the beam sequentially reflects off each of the plurality of rotating optically reflective surfaces, the beam is swept across the first, second, third, fourth and fifth stationary optically reflective surfaces, so as to produce first, second, third, fourth and fifth groups of plural scan lines, respectively, which are projected out through the window and intersect about a projection axis extending from the window, and within a confined scanning volume extending from substantially adjacent the window to at least about six inches from the window so as to produce a substantially collimated projected scanning pattern within the confined scanning volume, by which a code symbol can be scanned omni-directionally while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume,

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

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

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

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

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

whereby, when a code symbol is presented to the collimated projected scanning pattern within the confined scanning volume, the code symbol is scanned within the collimated projected scanning pattern and at least a portion of the optical energy reflected from the scanned code symbol is directed through the window, reflected off the first, second, third, fourth and fifth stationary optically reflective surfaces, sequentially reflected off the rotating optically reflective surfaces of the beam sweeping mechanism, collected by the collection mirror, and received by the receiving mechanism for detection, whereupon the electrical signal is produced.

17. The optical projection scanner of claim 16 wherein the housing is adapted for use with a base mechanism for supporting the housing with respect to a counter surface so that at least a portion of the collimated projected scanning pattern is projected above the counter surface so as to permit scanning a code symbol presented to the collimated projected scanning pattern.

18. The optical projection scanner of claim 17 wherein the base mechanism is attached to the housing.

19. The optical projection scanner of claim 18 wherein the base mechanism is detachable from the housing.

20. The optical projection scanner of claim 16 wherein the processing and control mechanism is adapted to decode the electrical signal and produce data representative of the scanned code symbol.

21. The optical projection scanner of claim 16, wherein the different acute angles are selected so that the scan lines within each group of scan lines are substantially equidistant from each other at a distance from the window.

22. The optical projection scanner of claim 16, wherein the optical energy generation mechanism includes a laser diode fixedly mounted with respect to the central reference axis, and wherein the first, second, third, fourth and fifth stationary reflective surfaces include first, second, third, fourth and fifth planar mirrors, respectively, each fixedly mounted with respect to the central reference axis.

23. The optical projection scanner of claim 16, wherein the first, second, third, fourth and fifth stationary reflective surfaces include first, second, third, fourth and fifth planar mirrors, respectively.

24. The optical projection scanner of claim 16 wherein the housing has a head portion and a handle portion.

25. The optical projection scanner of claim 17 wherein the collimated scanning pattern is oriented laterally outward above the counter surface at a point of sale station.

26. The optical projection scanner of claim 17, wherein the base mechanism further includes a mechanism for selectively supporting the housing in any one of a plurality of positions above the counter surface so that the collimated scanning pattern can be projected about the projection axis above the counter surface in any one of a plurality of orientations corresponding to the plurality of positions.

27. The optical projection scanner of claim 16 further including a planar support structure upon which said first, second, third, fourth and fifth stationary reflective surfaces are mounted.

28. The optical projection scanner of claim 16, wherein the receiving mechanism comprises a photodetector.

29. The optical projection scanner of claim 28, wherein the photodetector is positioned so as to permit receipt of optical energy from the beam sweeping mechanism, and also positioned substantially within the central reference plane.

30. The optical projection scanner of claim 16, wherein the code symbol is a bar code symbol.

31. An optical projection scanner for producing a confined scanning volume for scanning code symbols presented therein, while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume, the optical projection scanner comprising:

(a) a housing having an optically admissive window through which optical energy can exit said housing and travel towards an object bearing a code symbol;

at least a portion of the optical energy reflecting from the object, traveling back through the window, and entering the housing;

whereby a central reference axis extends, in a substantially longitudinal direction, through the housing;

(b) an optical energy generation mechanism disposed within the housing for producing a beam of optical energy;

(c) a beam sweeping mechanism disposed within the housing for rotation about a rotational axis;

the beam sweeping mechanism having a plurality of rotating optically reflective surfaces each being disposed at a different acute angle with respect to the rotational axis, for sweeping the beam about the rotational axis along a plurality of different paths, the rotational axis intersecting the central reference axis to thereby define a central reference plane;

(d) a stationary reflection mechanism including a plurality of stationary optically reflective surfaces disposed within the housing and fixedly mounted with respect to the central reference axis;

wherein the plurality of stationary optically reflective surfaces includes at least a first stationary optically reflective surface having a transverse axis extending substantially perpendicularly with respect to the central reference plane;

(e) an optical energy collection mechanism disposed within the housing and fixedly mounted with respect to the central reference axis, the collection mechanism including

(1) a collection mirror fixedly mounted along the central reference plane, so as to permit the beam produced by the optical energy generation mechanism to pass from the collection mirror, substantially along the central reference plane, to the beam sweeping mechanism, for sweeping the beam about the rotational axis thereof along the plurality of different paths, and

(2) an optical energy receiving mechanism for receiving optical energy from the collection mirror at a point substantially within the central reference plane, and detecting the received optical energy and producing an electrical signal indicative of the detected optical energy;

(f) a processing and control mechanism within the housing, for processing the electrical signal, and for controlling the operation of at least one of;

(i) the optical energy generation mechanism, and (ii) the beam sweeping mechanism, so that, during scanner operation, optical energy produced by the optical energy generation mechanism passes from the collection mirror, substantially along the central reference plane, and in a sequential manner to each of a plurality of the rotating optically reflective surfaces of the beam sweeping mechanism, and as the beam sequentially reflects off each of the plurality of rotating optically reflective surfaces, the beam is sequentially swept across each of the plurality of stationary optically reflective surfaces of the stationary reflection mechanism, so as to produce a corresponding plurality of plural scan line groups which are projected out through the window and intersect about a projection axis extending from the window, and within a confined scanning volume extending from substantially adjacent the window to at least about six inches from the window so as to produce a substantially collimated projected scanning pattern within the confined scanning volume, by which a code symbol can be scanned omni-directionally while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume,

the plural scan line groups including at least a first group of scan lines wherein each scan line in the first group is substantially parallel to each other scan line in the first group;

whereby, when a code symbol is presented to the collimated projected scanning pattern within the confined scanning volume, the code symbol is scanned within the collimated projected scanning pattern and at least a portion of the optical energy reflected from the scanned code symbol is directed through the window, sequentially reflected off each of the plurality of stationary optically reflective surfaces of the stationary reflection mechanism and sequentially reflected off the rotating optically reflective surfaces of the beam sweeping mechanism, collected by the collection mirror, and received by the receiving mechanism for detection, whereupon the electrical signal is produced.

32. The optical projection scanner of claim 31 wherein the housing is adapted for use with a base mechanism for supporting the housing with respect to a counter surface so that at least a protion of the collimated projected scanning pattern is projected above the counter surface so as to permit scanning a code symbol presented to the collimated projected scanning pattern.

33. The optical projection scanner of claim 32 wherein the base mechanism is attached to the housing.

34. The optical projection scanner of claim 33 wherein the base mechanism is detachable from the housing.

35. The optical projection scanner of claim 31 wherein the processing and control mechanism is adapted to decode the electrical signal and produce data representative of the scanned code symbol.

36. The optical projection scanner of claim 31, wherein the different acute angles are selected so that the plural scan lines within each scan line group are substantially equidistant from each other at a distance from the window.

37. The optical projection scanner of claim 31, wherein the optical energy generation mechanism includes a laser diode fixedly mounted with respect to the central reference axis, and wherein the stationary reflection mechanism includes a plurality of planar mirrors, each fixedly mounted with respect to the central reference axis.

38. The optical projection scanner of claim 31, wherein the optical energy generation mechanism includes a laser diode fixedly mounted with respect to the central reference axis, and wherein the stationary reflection mechanism includes an integrated mechanical member comprising plurality of planar reflective surfaces.

39. The optical projection scanner of claim 31, wherein the stationary reflection mechanism includes first, second, third, fourth and fifth planar mirrors.

40. The optical projection scanner of claim 31 wherein the housing has a head portion and a handle portion.

41. The optical projection scanner of claim 32 wherein the collimated scanning pattern is oriented laterally outward above the counter surface at a point of sale station.

42. The optical projection scanner of claim 32, wherein the base mechanism further includes a mechanism for selectively supporting the housing in any one of a plurality of positions above the counter surface so that the collimated scanning pattern can be projected about the projection axis above the counter surface in any one of a plurality of orientations corresponding to the plurality of positions.

43. The optical projection scanner of claim 31 further including a planar support structure upon which the stationary reflection mechanism is mounted.

44. The optical projection scanner of claim 31, wherein the receiving mechanism comprises a photodetector.

45. The optical projection scanner of claim 44, wherein the photodetector is positioned so as to permit receipt of optical energy from the beam sweeping mechanism, and also positioned substantially within the central reference plane.

46. The optical projection scanner of claim 31, wherein the code symbol is a bar code symbol.