Instant portable bar code reader

• US 4,766,300 A
• Filed: 02/07/1986
• Issued: 08/23/1988
• Est. Priority Date: 08/06/1984
• Status: Expired due to Term

• Current Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Original Assignee: Norand Corporation (Baker Hughes Company)
• Inventors: Laser, Vadim, Chadima, George E. Jr.
• Primary Examiner(s): PITTS, HAROLD I
• Application Number:
  US06/827,286
• Time in Patent Office: 928 Days
• Field of Search: 235/472, 235/462, 235/455
• US Class Current: 235/462.21
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10772 Moved readers, e.g. pen, wand
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners

Abstract

A lens and elliptical-effect reflector respond to the bar code image.

Claims

1. A portable instant bar code reader comprising:

a hand-held unit having illumination and light receiving window means;

a flash illuminating device positioned behind said window means;

said flash illuminating device and window means being configured to distribute light across the surface of a bar code being read by said reader, said window means being configured to receive light reflected from the surface of said bar code;

a photodetector disposed within the reader;

lens means for casting an image of light received through said window means onto said photodetector;

said flash illuminating device comprising elliptical-effect reflector means having a light source at a near focal point thereof, and having a second focal point disposed in front of said window means, such that the elliptical axis for said elliptical-effect reflector means extends obliquely relative to said window means.

2. A portable instant bar code reader according to claim 1 with said elliptical-effect reflector means having its second focal point lying generally in a bar code sensing field region aligned with said lens means.

3. A portable instant bar code reader according to claim 1 with said lens means having an optical axis extending through said window means and through a bar code sensing field region in front of said window means and intersecting said elliptical axis at a substantial distance from said window means.

4. In a portable bar code reader

a hand-held bar code reader unit having an elongated relatively narrow hand grip portion for grasping in the hand of a user and having an enlarged reader head portion of greater width than said hand grip portion,

said elongated hand grip portion having a length and cross sectional configuration so as to be grasped by the hand with all fingers in gripping relation thereto, and said enlarged reader head portion having a length less than the length of said elongated hand grip portion,

said reader head portion having extended window means with a width dimension greater than the width of said hand grip portion which is to be gripped by the fingers of a hand,

extended light source means in said reader head portion for producing a sheet of light energy directed outwardly from the reader head portion through said window means over substantially the entire width of said window means so as to flood a bar code sensing region in front of said window means having a width dimension approximately equal to the width of said window means, having a depth dimension equal to at least about ten millimeters and a height dimension equal to at least about one millimeter, such that a bar code pattern in the sensing region with reflect light from said extended light source means along an optical axis directed generally normal to said window means, and

lens means for focusing bar code patterns in said sensing region onto an image plane in said reader unit with a resolution of at least forty line pairs per millimeter.

10. In a portable bar code reader according to claim 4, said lens means focusing bar code patterns with said resolution of at least forty line pairs per millimeter over a depth range of at least ten millimeters in said sensing region, and means comprising said reader unit for reading bar code patterns with marked curvature with said resolution of at least forty line pairs per millimeter over said depth range of at least ten millimeters.

11. In a portable bar code reader according to claim 4, said reader head portion having a first mirror means spaced from said window means along said optical axis for receiving reflected light from a bar code pattern in the sensing region and for re-reflecting such light along a second optical axis directed generally toward said window means, and having a second mirror means nearer to said window means than said first mirror means, said second mirror means being disposed relative to said second optical axis so as to direct light from the first mirror means along a third optical axis toward said lens means, and said lens means being located more remote from said window means than said second mirror means.

12. In a portable bar code reader according to claim 11, said lens means having stop aperture means providing an aperture for light directed parallel to the third axis with a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in the sensing region, said width dimension of said aperture being not more than about two millimeters.

13. In a portable bar code reader according to claim 10, said lens means having stop aperture means with an aperture of a width dimension of about two millimeters in a lateral direction corresponding to the high resolution direction of the bar code pattern.

14. In a portable bar code reader according to claim 12, the lens means causing lateral marginal rays of the light energy from the second mirror means which lie in a lateral plane corresponding to the high resolution direction of the bar code pattern to converge in the vicinity of said aperture and thereafter to diverge so as to occupy a laterally extended region at the image plane of the reader unit, said second mirror means having an operative width between the lateral marginal rays generally corresponding to the lateral extent of the image of the bar code pattern at said image plane of the reader unit.

15. In a portable bar code reader according to claim 4, said lens means having stop aperture means with an aperture having a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in the sensing region, and having a height dimension in a direction at right angles to said lateral direction, and corresponding to a direction parallel to the bars of a bar code pattern in the sensing region, the ratio of the height dimension of said aperture to said width dimension being at least about two to one.

5. The method of reading bar code patterns which comprises:

(a) receiving a light image from a sensing region having a width dimension greater than the length of the total bar code pattern and of a substantial height dimension greater than one millimeter,

(b) converging the rays of said light image to pass through an aperture having a width dimension of about two millimeters and a height dimension of about four millimeters which is substantially less than the width dimension of the sensing region,

(c) focusing the light image onto a light receiving region of a photodetector having a resolution sufficient to sense a predetermined bar code, and

(d) reading out the individual elements of the light image focused on the photodetector for processing into bar code data.

6. The method of claim 5, where the photodetector has a predetermined operative length dimension in a direction of high resolution along which the focussed light image is to impinge,

the converging of the rays of said light image being such as to pass through an aperture having a width dimension substantially less than the predetermined operative length dimension of the light receiving region of the photodetector,

said method further comprising causing the rays of the light image passing through said aperture to diverge as they are focused so as to impinge over substantially the entire operative length dimension of the light receiving region of the photodetector, while blocking from the photodetector all light rays not passing through said aperture.

7. The method of claim 5, said method further comprising directing light rays reflected from a sensing region having a depth of at least about ten millimeters through said aperture, and onto said photodetector with a depth of focus of at least ten millimeters and a resolution of about forty line pairs per millimeter.

8. The method of claim 5, said method further comprising filtering out a long wavelength region of the spectrum of light energy from the sensing region prior to passage of the light energy through said aperture.

9. The method of claim 7, said method further comprising filtering out a long wavelength region of the spectrum of light energy from the sensing region prior to passage of the light energy through said aperture.

16. A portable instant bar code reader comprising:

(a) a hand-held bar code reader unit, said hand-held bar code reader unit having a portion thereof defining illumination window means, and flashable illuminator means disposed near said illumination window means for producing a flash of light therethrough;

(b) said hand-held bar code reader unit having a portion thereof defining light receiving window means for receiving reflections of light emitted through said illumination window means;

(c) photodetector means positioned within said hand-held bar code reader in the path of light rays reflected into and through said light receiving window means;

(d) light directing means positioned between said light receiving window means and said photodetector means for receiving a light pattern from said light receiving window means and focusing the same onto said photodetector means;

(e) said light directing means comprising lens means and providing a bar code sensing region in front of said window means having a width of at least about fifty millimeters, said photodetector means having an image plane for receiving an image of a bar code pattern in said sensing region, and said light directing means providing a resolution at the image plane of at least forty line pairs per millimeter, with a depth of focus of at least ten millimeters in front of said window means.

17. In a portable instant bar code reader according to claim 16, said lens means focusing bar code patterns with said resolution of at least forty line pairs per millimeter over a depth range of substantially twenty-five millimeters in said sensing region.

18. In a portable instant bar code reader according to claim 16, said light directing means having a first mirror means spaced from said light receiving window means along an optical axis for receiving reflections of light from a bar code pattern in the sensing region and for re-reflecting such light along a second optical axis directed generally toward said light receiving window means and having a second mirror means nearer to said light receiving window means than said first mirror means, said second mirror means being disposed relative to said second optical axis so as to direct light from the first mirror means along a third optical axis towards aid lens means, and said lens means being located more remote from said window means than said second mirror means.

19. In a portable instant bar code reader according to claim 18, said lens means having stop aperture means providing an aperture for light directed parallel to the third axis with a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in the sensing region, said width dimension of said aperture being not more than about two millimeters.

20. In a portable instant bar code reader according to claim 17, said lens means having stop aperture means with an aperture of a width dimension of about two millimeters in a lateral direction corresponding to the high resolution direction of the bar code pattern.

21. In a portable instant bar code reader according to claim 19, the lens means causing lateral marginal rays of the light energy from the second mirror means which lie in a lateral plane corresponding to the high resolution direction of the bar code pattern to converge in the vicinity of said aperture and thereafter to diverge so as to occupy a laterally extended region at the image plane of the reader unit, said second mirror means having an operative width between the lateral marginal rays generally corresponding to the lateral extent of the image of the bar code pattern at said image plane of the reader unit.

22. In a portable instant bar code reader according to claim 16, said lens means having stop aperture means with an aperture having a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in the sensing region, and having a height dimension in a direction at right angles to said lateral direction, and corresponding to a direction parallel to the bars of a bar code pattern in the sensing region, the ratio of the height dimension of said aperture to said width dimension being at least about two to one.

23. A portable instant bar code reader in accordance with claim 16, with electronic means for reading a light pattern received by the photodetector means, for assessing the validity of the bar code represented thereby, and for automatically repeating the actuation of the flashable illuminator means in the absence of a valid code reading.

24. A portable instant bar code reader according to claim 16, with said hand-held bar code reader unit having a reading capability at a distance in front of said window means of from about zero millimeters to about twenty-five millimeters.

25. A portable instant bar code reader comprising:

(a) a hand-held unit having illumination transmitting and light receiving window means;

(b) flash illuminating means positioned behind said window means;

(c) said flash illuminating means and window means being configured to distribute light across the surface of a bar code being read by said reader, said window means being configured to receive light reflected from the surface of a bar code;

(d) photodetector means disposed within the reader;

(e) lens means for casting an image of light received through said window means onto said photodetector means; and

(f) said hand-held unit having first mirror means spaced from said window means along a first optical axis for receiving reflected light from a bar code pattern in front of the window means, and for re-reflecting such light along a second optical axis directed generally toward said window means, and having second mirror means nearer to said window means than said first mirror means, said second mirror means being disposed relative to said second optical axis so as to direct light from the first mirror means along a third optical axis toward said lens means, and said lens means being located more remote from said window means than said second mirror means.

26. In a portable instant bar code reader according to claim 25, elliptical-effect reflector means having the flash illuminating means at a near focal point thereof, and having a second focal point disposed in front of said window means, such that the elliptical axis for said elliptical-effect reflector means extends obliquely relative to said window means.

27. A portable instant bar code reader according to claim 26, with said elliptical-effect reflector means having its second focal point lying generally in a bar code sensing region aligned with the first optical axis and in front of said window means.

28. A portable instant bar code reader according to claim 25, with said lens means having a lens means optical axis extending through said window means and through a bar code sensing region in front of said window means.

29. A portable instant bar code reader according to claim 28, with said lens means optical axis extending through the elliptical-effect reflector means centrally of a long dimension of the reflector means.

30. In a portable instant bar code reader according to claim 25, said lens means focusing bar code patterns with a resolution of at least forty line pairs per millimeter over a depth range of at least ten millimeters in front of said window means, and means comprising said hand-held unit for reading bar code patterns with marked curvature with said resolution of at least forty line pairs per millimeter over said depth range of at least ten millimeters.

31. A portable instant bar code reader according to claim 25, with said hand-held unit having a reading capability for bar code patterns from adjacent the window means out to a distance in front of said window means of at least about twenty-five millimeters.

32. In a portable instant bar code reader according to claim 25, said lens means having stop aperture means with an aperture having a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in front of the window means, and having a height dimension in a direction at right angles to said lateral direction, and corresponding to a direction parallel to the bars of a bar code pattern in front of the window means, the ratio of the height dimension of said aperture to said width dimension being at least about two to one.

33. In a portable instant bar code reader according to claim 32, said stop aperture means having an aperture of a width dimension of about two millimeters in the lateral direction corresponding to the high resolution direction of the bar code pattern.

34. In a portable instant bar code reader according to claim 25, the lens means having a stop aperture, and causing lateral marginal rays of the light energy from the second mirror means which lie in a lateral plane corresponding to the high resolution direction of the bar code pattern to converge in the vicinity of said aperture and thereafter to diverge so as to occupy a laterally extended region at the photodetector means, said second mirror means having an operative width between the lateral marginal rays generally corresponding to the lateral extent of the image of the bar code pattern at said photodetector means.

35. In a portable instant bar code reader according to claim 25, said lens means having stop aperture means providing an aperture for light directed parallel to the third axis with a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in front of the window means, said width dimension of said aperture being not more than about two millimeters.

36. In a portable instant bar code reader according to claim 25, said hand-held unit having a reading capability for a position of a bar code pattern with minimum spacing from the window means out to a distance in front of the window means of about twenty-five millimeters.

37. In a portable instant bar code reader according to claim 36, said hand-held unit having an optimum focal plane about six millimeters in front of said window means.

38. A portable instant bar code reader in accordance with claim 25, with means for reading a light pattern received by the photodetector means, for assessing the validity of the bar code represented thereby, and for automatically repeating the actuation of the flash illuminating means in the absence of a valid bar code reading.

39. An electroptical pattern reader comprising:

(a) a hand-held reader unit with momentary illuminator means;

(b) means for triggering the momentary illuminator means;

(c) means positioning the momentary illuminator means in the reader unit for illuminating a pattern external to the reader unit and for accommodating a path for reflected light therefrom upon the triggering of said momentary illuminator means which path is directed into the hand-held reader unit;

(d) optoelectronic spatial sensor means; and

(e) lens means for producing an image of said pattern from said reflected light and focusing the same onto said optoelectronic spatial sensor means;

(f) said hand-held reader unit providing a resolution of at least about forty line pairs per millimeter for patterns at a distance of about ten millimeters along the optical axis of the lens means as measured from a point external to the reader and adjacent thereto.

40. A reader according to claim 39, with said lens means having effective marginal rays, directed at angles of about plus and minus fifteen degrees to an optical axis of the lens means.

41. A reader according to claim 39, with said hand-held reader unit having a reading capability at a distance in front of said reader unit of at least about twenty-five millimeters.

42. A reader according to claim 41, with an optimum focal plane about six millimeters in front of said hand-held reader unit.

43. A reader in accordance with claim 39, with means for reading a light pattern received by the sensor means, for assessing the validity of the pattern represented thereby, and for automatically repeating the triggering of the momentary illuminator means in the absence of a valid pattern reading.

44. In a reader according to claim 39, said hand-held reader unit having a frontal face with a pattern sensing region exterior to the reader unit at the frontal face, and having first mirror means spaced from the frontal face along a first optical axis for receiving reflected light from a pattern in the sensing region and for re-reflecting such light along a second optical axis directed generally toward said frontal face, and having second mirror means nearer to said frontal face than said first mirror means, said second mirror means being disposed relative to said second optical axis so as to direct light from the first mirror means along a third optical axis toward said lens means, and said lens means being located more remote from said frontal face than said second mirror means.

45. In a reader according to claim 44, said lens means focusing bar code patterns with said resolution of at least forty line pairs per millimeter over a depth range of at least ten millimeters in said sensing region, and means comprising said hand-held reader unit for reading patterns with marked curvature with said resolution of at least forty line pairs per millimeter over said depth range of at least ten millimeters.

46. A reader according to claim 39, with said hand-held reader unit having a reading capability for patterns at a distance in front of said reader unit of about twenty-five millimeters.

47. A reader according to claim 46, with said hand-held reader unit having an optimum focal plane about six millimeters in front of said reader unit long said optical axis.

48. In a reader according to claim 44, said lens means having stop aperture means providing an aperture for light directed parallel to the third axis with a width dimension in a lateral direction of about two millimeters.

49. In a reader according to claim 44, said lens means having stop aperture means with an aperture having a width dimension in a lateral direction which corresponds with a high resolution direction of a pattern in the sensing region, and having a height dimension in a direction at right angles to said lateral direction, and corresponding to a direction of lesser resolution of a pattern in the sensing region, the ratio of the height dimension of said aperture to said width dimension being at least about two to one.

50. In a reader according to claim 49, the lens means causing lateral marginal rays of the light energy from the second mirror means which lie in a lateral plane corresponding to a high resolution direction of a pattern to converge in the vicinity of said aperture and thereafter to diverge so as to occupy a laterally extended region at the image plane of the reader unit, said second mirror means having an operative width between the lateral marginal rays generally corresponding to the lateral extent of the image of the pattern at said sensor means of said hand-held reader unit.

51. In a portable bar code reader,

(a) a hand-held bar code reader unit having an elongated reduced cross section hand grip portion for grasping in the hand of a user and having an enlarged cross section reader head portion frontally of said hand grip portion,

(b) said elongated hand grip portion having a length and cross sectional configuration so as to be grasped by the hand, and said reader head portion having a length less than the length of said elongated hand grip portion,

(c) said reader head portion having extended window means with a width dimension of at least fifty millimeters,

(d) extended light source means in said hand-held bar code reader unit for producing a sheet of light energy directed outwardly through said window means over substantially the entire width of said window means so as to flood a bar code sensing region in front of said window means having a width dimension of at least about fifty millimeters, having a depth dimension equal to at least about ten millimeters and a height dimension equal to at least about one millimeter, such that a bar code pattern in the sensing region will reflect light from said extended light source means along an optical axis directed through said window means, and

(e) lens means for focusing bar code patterns in said sensing region onto an image plane in said reader unit with a resolution of at least forty line pairs per millimeter, and with a depth of focus at said bar code sensing region of at least ten millimeters.

52. In a portable bar code reader according to claim 51, said hand-held bar code reader unit having a reading capability at a distance in front of the reader head portion of at least about twenty millimeters.

53. In a portble bar code reader according to claim 51, said hand-held bar code reader unit having a resolution of at least forty line pairs per millimeter over a depth range in front of said reader head portion of substantially twenty-five millimeters.

54. In a portable bar code reader according to claim 51, means comprising said reader unit for reading bar code patterns with marked curvature with said resolution of at least forty line pairs per millimeter over said depth range of at least ten millimeters, with remote portions of a curved bar code pattern anywhere within about twenty-five millimeters of the front of the reader head portion.

55. In a portable bar code reader according to claim 51, said lens means focusing bar code patterns with said resolution of at least forty line pairs per millimeter over a depth range of at least twenty-five millimeters in said sensing region.

56. In a portable bar code reader according to claim 51, said hand-held bar code reader unit having a reading capability at a distance in front of said window means of at least about twenty millimeters, and with an optimum focal plane about six millimeters in front of said window means.

57. In a portable bar code reader according to claim 51, said light source means producing a momentary sheet of light energy therefrom upon pulsing thereof, and means for reading a light pattern received at the image plane, for assessing the validity of the bar code represented thereby, and for automatically repeating the pulsing of the light source means in the absence of a valid bar code reading.

58. In a portable bar code reader according to claim 51, said lens means having stop aperture means with an aperture having a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in the sensing region, and having a height dimension in a direction at right angles to said lateral direction, and corresponding to a direction parallel to the bars of a bar code pattern in the sensing region, the ratio of the height dimension of said aperture to said width dimension being at least about two to one.

59. In a portable bar code reader according to claim 51, said lens means having stop aperture means with an aperture of a width dimension of about two millimeters in a lateral direction corresponding to the high resolution direction of the bar code pattern.

61. In a portable bar code reader according to claim 51, said hand-held bar code reader unit having a first mirror means spaced from said window means along said optical axis for receiving reflected light from a bar code pattern in the sensing region and for re-reflecting such light along a second optical axis directed generally toward said window means, and having a second mirror means nearer to said window means than said first mirror means, said second mirror means being disposed relative to said second optical axis so as to direct light from the first mirror means along a third optical axis toward said lens means, and said lens means being located more remote from said window means than said second mirror means.

63. In a portable bar code reader according to claim 61, the lens means causing lateral marginal rays of the light energy from the second mirror means which lie in a lateral plane corresponding to the high resolution direction of the bar code pattern to converge in the vicinity of said aperture and thereafter to diverge so as to occupy a laterally extended region at the image plane of the reader unit, said second mirror means having an operative width between the lateral marginal rays generally corresponding to the lateral extent of the image of the bar code pattern at said image plane of the reader unit.

60.

62. In a portable bar code reader according to claim 60, said lens means having stop aperture means providing an aperture for light directed parallel to the third axis with a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in the sensing region, said width dimension of said aperture being not more than about two millimeters.

64. In a portable bar code reader according to claim 62, said window means receiving effective marginal rays from the sensing region which impinge at the lateral margins of the first mirror means and which are directed at angles of about plus and minus fifteen degrees to the optical axis.

65. In a portable bar code reader according to claim 60, said extended light source means being disposed in said hand-held bar code reader unit between said second mirror means and said extended window means.

66. In a portable bar code reader according to claim 60, said extended light source means comprising a flashable illuminator for supplying pulses of light energy to the entire bar code sensing region.