TWO-PLANE OPTICAL CODE READER FOR ACQUISITION OF MULTIPLE VIEWS AN OBJECT

• US 20100163628A1
• Filed: 12/23/2009
• Published: 07/01/2010
• Est. Priority Date: 02/12/2008
• Status: Active Grant

• Current Assignee: Datalogic Adc, Inc. (Datalogic S.p.A.)
• Original Assignee: Datalogic Scanning Incorporated (Datalogic S.p.A.)
• Inventors: Olmstead, Bryan L.
• Granted Patent: US 8,678,287 B2
• Time in Patent Office: Days
• US Class Current: 235/470
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence
• CPC Class Codes: G06K 7/10831 Arrangement of optical elements, e.g. lenses, mirrors, prisms optical elements per se G02B
• 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

Abstract

An optical code reader forms images of an optical code on an object. The reader comprises first and second viewing surfaces generally transverse to one another. The surfaces bound a viewing volume in which the object may be imaged. The reader also comprises a set of one or more imagers positioned on an opposite side of one or more of the first and second viewing surfaces relative to the viewing volume, and oriented and configured to capture images of the object from at least three different views. Each of the views passes through one of said first and second viewing surfaces. At least one of said views passes through the first viewing surface, and at least one of said views passes through the second viewing surface. The reader also comprises at least one mirror, off which is reflected at least one of the views.

Claims

1. A method for reading an optical code on an object in a viewing volume bounded on two generally transverse sides by respective first and second viewing surfaces, by use of a number of imagers, the method comprising:

directing a plurality of views from the viewing volume onto different imager portions of the set of imagers, wherein each of the plurality of views passes through one of said first and second viewing surfaces, at least one of said views passes through the first viewing surface, at least one of said views passes through the second viewing surface, wherein the number of views is at least three, wherein at least one of the views is reflected off at least one mirror, and wherein the number of views is greater than the number of imagers;

forming at least one image with said number of imagers; and

processing the optical code based on said at least one image.

2. A method according to claim 1, wherein the number of imagers is greater than one.

3. A method according to claim 1, wherein said at least one of said number of imagers forms images from multiple views.

4. A method according to claim 3, wherein the number of imagers is two, wherein a first imager has three distinct views, each passing through the first viewing surface, and wherein a second imager has one view, which passes through the second viewing surface.

5. A method according to claim 3, wherein the number of imagers is two, wherein a first imager has three distinct fields of view, each passing through the first viewing surface, and wherein a second imager has three distinct fields of view, each field of view passing through the second viewing surface.

6. A method according to claim 3, wherein the directing step comprises:

directing a first view from the viewing volume onto a first portion of a split-view imager via reflection off a first surface on a compound mirror structure; and

directing a second view from the viewing volume onto a second portion of a split-view imager via reflection off a second surface on the compound mirror structure.

7. A method according to claim 6, wherein the compound mirror structure is a monolithic piece.

8. A method according to claim 1, wherein the number of imagers is one.

9. A method according to claim 8, wherein the imager has three distinct views, two of which pass through the first viewing surface and one of which passes through the second viewing surface.

10. A method according to claim 8, wherein the imagers has four distinct views, three of which pass through the first viewing surface and one of which passes through the second viewing surface.

11. A method according to claim 1, wherein the directing step comprises:

directing at least one of said plurality of views from the viewing volume along a perspective through a viewing surface onto an imager via a tortuous path reflecting off at least one mirror, thereby causing the imager to be closer to the viewing surface than if a straight path having the same perspective were utilized.

12. A method according to claim 1, wherein the processing step is performed by equipment located entirely behind one of said viewing surfaces.

13. A method according to claim 1, wherein the optical code is a one-dimensional optical code.

14. A method according to claim 13, wherein the processing step comprises:

stitching together a first portion of the optical code in an image formed by a first imager portion and a second portion of the optical code in an image formed by a second imager portion.

15. A method according to claim 1, wherein the decoding step comprises:

processing pixels of an image along a virtual scan line across the image.

16. A method according to claim 15, wherein the virtual scan line is a member of a set of omnidirectional virtual scan lines.

17. A method according to claim 16, further comprising:

switching from use of the set of omnidirectional virtual scan lines to a set of more closely spaced unidirectional virtual scan lines.

18. A method according to claim 1, further comprising:

illuminating the object in the viewing volume.

19. A method according to claim 18, wherein illuminating the object in the viewing volume comprises:

illuminating a portion of the viewing volume seen in the first view at approximately the same time when an imager is exposed to form an image from the first view; and

illuminating a portion of the viewing volume seen in the second view at approximately the same time when an imager is exposed to form an image from the second view.

20. A method according to claim 1, further comprising:

focusing a total field of view for each imager in the set of one or more imagers through a respective lens for each such imager.

21. A method according to claim 1, wherein said at least one mirror is fixed in position.

22. A method according to claim 1, wherein the plurality of views are capable of cumulatively viewing at least four sides of a six-sided polyhedron positioned within the viewing volume.

23. A method according to claim 22, wherein the plurality of views are capable of cumulatively viewing at least five sides of the six-sided polyhedron.

24. A method according to claim 1, wherein the number of imagers is two and the number of views is four.

25. A method according to claim 1, wherein the number of imagers is two and the number of views is six.

26. A method according to claim 1, wherein the number of imagers is one and the number of views is three.

27. A method according to claim 1, wherein the number of imagers is one and the number of views is four.

28. A method for reading an optical code on an object in a viewing volume bounded on two generally transverse sides by respective first and second viewing surfaces, by use of a plurality of imagers, the method comprising:

directing a plurality of views from the viewing volume onto different imager portions of the set of imagers, wherein each of the plurality of views passes through one of said first and second viewing surfaces, at least one of said views passes through the first viewing surface, at least one of said views passes through the second viewing surface, wherein the number of views is at least three, and wherein at least one of the views is reflected off at least one mirror;

forming at least one image with said plurality of imagers, wherein at least a first and second of said plurality of imagers are mounted on opposing surfaces of a common circuit board; and

processing the optical code based on said at least one image.

29. A method according to claim 28, wherein the first imager has a first receiving surface with a first orientation at a first angle with respect to the common circuit board and the second imager has a second receiving surface with a second orientation at a second angle with respect to the common circuit board, the first angle being different from the second angle.

30. A method according to claim 28, wherein the number of imagers equals the number of views.

31. A method according to claim 28, wherein the number of imagers is six, wherein three imagers have three respective distinct fields of view, each passing through the first viewing surface, and wherein three imagers have three respective distinct fields of view, each passing through the second viewing surface.

32. A method according to claim 31, wherein the three imagers having fields of view passing through the first viewing surface are mounted on one side of the common circuit board, and the three imagers having fields of view passing through the second viewing surface are mounted on the opposite side of the common circuit board.

33. An optical code reader for forming images of an optical code on an object, the optical code reader comprising:

a first viewing surface;

a second viewing surface generally transverse to the first viewing surface, the first and second surfaces bounding a viewing volume in which the object may be imaged;

a set of one or more imagers positioned on an opposite side of one or more of the first and second viewing surfaces relative to the viewing volume, and oriented and configured to capture images of the object, when the object is in the viewing volume, from at least three different views, wherein each of the views passes through one of said first and second viewing surfaces, at least one of said views passes through the first viewing surface, at least one of said views passes through the second viewing surface, and the number of views is greater than the number of imagers; and

at least one mirror positioned on an opposite side of one or more of the first and second viewing surfaces relative to the viewing volume, wherein at least one of the views is reflected off one or more of said at least one mirror.

34. An optical code reader according to claim 33, wherein the number of imagers is two, wherein a first imager has three distinct views, each passing through the first viewing surface, and wherein a second imager has one view, which passes through the second viewing surface.

35. An optical code reader according to claim 33, wherein the number of imagers is two, wherein a first imager has three distinct fields of view, each passing through the first viewing surface, and wherein a second imager has three distinct fields of view, each passing through the second viewing surface.

36. An optical code reader according to claim 33, wherein one of said imagers is a split-view imager, and a first view from the viewing volume onto a first portion of the split-view imager is via reflection off a first surface on a compound mirror structure, and a second view from the viewing volume onto a second portion of the split-view imager is via reflection off a second surface on the compound mirror structure.

37. An optical code reader according to claim 36, wherein the compound mirror structure is a monolithic piece.

38. An optical code reader according to claim 33, wherein the number of imagers is one.

39. An optical code reader according to claim 38, wherein the imager has three distinct views, two of which pass through the first viewing surface and one of which passes through the second viewing surface.

40. An optical code reader according to claim 38, wherein the imagers has four distinct views, three of which pass through the first viewing surface and one of which passes through the second viewing surface.

41. An optical code reader according to claim 33, further comprising:

a housing positioned on an opposite side of one or more of the first and second viewing surfaces relative to the viewing volume, the housing containing the set of one or more imagers.

42. An optical code reader according to claim 41, wherein the housing comprises first and second intersecting housing portions, wherein the first housing portion borders the first viewing surface and the second housing portion borders the second viewing surface, and wherein the set of one or more imagers is both contained within either the first housing portion or the second housing portion or in an intersection thereof.

43. An optical code reader according to claim 42, wherein one of the first and second housing portions is an upper side housing portion and the other is a lower housing portion, and the first and second housing portions form a generally L-shaped structure.

44. An optical code reader according to claim 40, wherein an optical path from of at least one of said views onto an imager is via a tortuous path reflecting off at least one mirror, thereby causing the imager to be closer to the viewing surface than if a straight path having the same perspective were utilized.

45. An optical code reader according to claim 33, further comprising:

electronic circuitry connected to the set of one or more imagers operable to decode the optical code by processing the images of the object.

46. An optical code reader according to claim 45, wherein the electronic circuitry is positioned entirely on an opposite side of one of the first and second viewing surfaces relative to the viewing volume.

47. An optical code reader according to claim 46, wherein the first viewing surface is a horizontal surface, and the second surface is a vertical surface, and the electronic circuitry is positioned entirely below the first viewing surface.

48. An optical code reader according to claim 33, further comprising:

a focusing lens positioned in an optical path for each imager in the set of one or more imagers, wherein there is one separate focusing lens for each such imager.

49. An optical code reader according to claim 33, wherein said at least one mirror is fixed in position.

50. An optical code reader according to claim 33, wherein the plurality of views are capable of cumulatively viewing at least four sides of a six-sided polyhedron positioned within the viewing volume.

51. An optical code reader according to claim 50, wherein the plurality of views are capable of cumulatively viewing at least five sides of the six-sided polyhedron.

52. An optical code reader according to claim 33, wherein the first and second viewing surfaces are orthogonal to one another.

53. An optical code reader according to claim 33, wherein the optical code reader is bioptic.

54. An optical code reader according to claim 33, wherein each of the views reflects off the same mirror no more than once.

55. An optical code reader according to claim 33, wherein the number of imagers is two and the number of views is four.

56. An optical code reader according to claim 33, wherein the number of imagers is two and the number of views is six.

57. An optical code reader according to claim 33, wherein the number of imagers is one and the number of views is three.

58. An optical code reader according to claim 33, wherein the number of imagers is one and the number of views is four.

59. An optical code reader for forming images of an optical code on an object, the optical code reader comprising:

a first viewing surface;

a second viewing surface generally transverse to the first viewing surface, the first and second surfaces bounding a viewing volume in which the object may be imaged;

a set of two or more imagers positioned on an opposite side of one or more of the first and second viewing surfaces relative to the viewing volume, and oriented and configured to capture images of the object, when the object is in the viewing volume, from at least three different views, wherein each of the views passes through one of said first and second viewing surfaces, at least one of said views passes through the first viewing surface, and at least one of said views passes through the second viewing surface;

a common circuit board having opposing first and second sides, wherein at least some of said imagers are mounted on the first side of the common circuit board and at least some of said imagers are mounted on the second side of the common circuit board; and

at least one mirror positioned on an opposite side of one or more of the first and second viewing surfaces relative to the viewing volume, wherein at least one of the views is reflected off one or more of said at least one mirror.

60. An optical code reader according to claim 59, wherein a first imager has a first receiving surface with a first orientation at a first angle with respect to the common circuit board and a second imager has a second receiving surface with a second orientation at a second angle with respect to the common circuit board, the first angle being different from the second angle.

61. An optical code reader according to claim 59, wherein the number of imagers is six, wherein three imagers have three respective distinct fields of view, each passing through the first viewing surface, and wherein three imagers have three respective distinct fields of view, each passing through the second viewing surface.

62. An optical code reader according to claim 61, wherein the three imagers having fields of view passing through the first viewing surface are mounted on one side of the common circuit board, and the three imagers having fields of view passing through the second viewing surface are mounted on the opposite side of the common circuit board.

63. An optical code reader according to claim 59, wherein the number of imagers equals the number of views