Optical scanner and image reader for reading images and decoding optical information including one and two dimensional symbologies at variable depth of field

• US 6,123,261 A
• Filed: 05/05/1998
• Issued: 09/26/2000
• Est. Priority Date: 05/05/1997
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symagery Microsystems, Inc. (Motorola Solutions, Inc.)
• Inventors: Roustaei, Alexander R.
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US09/073,501
• Time in Patent Office: 875 Days
• Field of Search: 235/472.01, 235/462.01, 235/462.25, 235/462.26, 235/462.1, 235/462.24, 235/462.41
• US Class Current: 235/462.01
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: G06K 7/10544 by scanning of the records by radiation in the optical part of the electromagnetic spectrum
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• 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 7/1098 the scanning arrangement having a modular construction

Abstract

An integrated system and method for reading image data. An optical scanner/image reader is provided for reading images and decoding optical information or code, including one and two dimensional symbologies at variable depth of field, including memory and image processing for high speed applications.

Claims

1. An optical reading apparatus for reading image information selected from a group consisting of optical codes, one-dimensional symbologies, two-dimensional symbologies and three-dimensional symbologies, said image information being contained within a target image field, said optical reading apparatus comprising:

a light source projecting light onto said target image field;

an optical assembly comprising at least one lens, said optical assembly focusing said light reflected from said target field;

a sensor, said sensor including a plurality of pixel elements for sensing an illumination level of said focused reflected light;

an optical processor generating an electrical signal proportional to said illumination level received from said sensor and converting said electrical signal into output data, said output data describing at least one value for each pixel element;

a memory receiving and storing the output data, the stored output data indicative of the target image field;

an image processor receiving a portion of the output data and generating distinguishing data from an identified area of interest; and

a data processing unit coupled with said memory and responsive to the distinguishing data, the data processing unit including processing circuits processing the stored data to produce decoded data representing said image information.

2. The apparatus of claim 1 wherein said sensor, and said optical processor are integrated onto a single chip.

3. The apparatus of claim 1 wherein said sensor, said optical processor and said image processor are integrated onto a single chip.

4. The combination of claim 1 wherein said sensor, said optical processor and said image processor are integrated onto a single chip.

5. The apparatus of claim 1 wherein said sensor, said optical processor, said image processor and said data processing unit are integrated onto a single chip.

6. The apparatus of claim 1 further comprising a frame locator means for directing said sensor to an area of interest in said target image field.

7. The apparatus of claim 1 further comprising a camera and a digital imaging means.

8. The apparatus of claim 1 further comprising a view finder including an image display.

9. The apparatus of claim 1 wherein said optical assembly includes a fixed focused lens assembly.

10. The apparatus of claim 1 wherein said optical assembly includes digital zoom function means.

11. The apparatus of claim 1 wherein said data processing unit further comprises an integrated function means for high speed and low power digital imaging.

12. The apparatus of claim 1 wherein said optical assembly further comprises an image processing means having auto-zoom and auto-focus means controlled by said data processing unit for determining an area of interest at any distance, using high frequency transition between black and white.

13. The apparatus of claim 1 wherein said data processing unit further comprises a pattern recognition means for global feature determination.

14. The apparatus of claim 1 further comprising an image processing means using gray scale and color processing, said processing associated with a form factor.

15. The apparatus of claim 1 further comprising means for auto-discriminating between a camera function and an optical code recognition function and means for implementing a decoding function to read encoded data within the optical image.

16. The apparatus of claim 1 further comprising an aperture and means for reading optical codes bigger than the physical size of the aperture.

17. The apparatus of claim 1 wherein said sensor is selected from a group consisting of a CCD, CMOS sensor or CMD.

18. The apparatus of claim 1 wherein said light source is selected from a group consisting of a light emitting diode, strobe, laser diode or halogen light.

19. The apparatus of claim 1 wherein the optical processor includes a sample and hold circuit.

20. The apparatus of claim 1 wherein the optical processor includes an analog to digital converter circuit.

21. The apparatus of claim 1 wherein the optical processor includes a sample and hold circuit and an analog to digital converter circuit.

22. The apparatus of claim 1 wherein said image processor includes an ASIC.

23. The apparatus of claim 1 wherein said image processor includes an FPGA.

24. The apparatus of claim 1 wherein said image processor includes a binary processor and a gray scale processor.

25. The apparatus of claim 1 wherein said image processor includes a binary processor in series with a run length code processor.

26. The apparatus of claim 25 wherein said run length code processor outputs indicator data.

27. The apparatus of claim 1 wherein said image processor includes a gray scale processor.

28. The optical reading apparatus according to claim 1 wherein at least a portion of the output data is compressed and stored, and the image processor processes compressed data.

29. The optical reading apparatus according to claim 28 wherein a least a portion of the compressed data is received and stored before the memory receives and stores the sensed illumination level for all pixel elements.

30. The optical reading apparatus according to claim 28 wherein the compression includes binarization.

31. The optical reading apparatus according to claim 28 wherein the compression includes run-length coding.

32. The optical reading apparatus according to claim 1 wherein the distinguishing data is generated before the memory receives and stores the output data indicative of all pixel elements.

33. The optical reading apparatus according to claim 1 wherein the image processor includes means for processing the portion of the output data to identify an area of interest as indicative of a type of optical code.

34. The optical reading apparatus according to claim 1 wherein the image processor includes means for performing sub-pixel interpolation.

35. The optical reading apparatus according to claim 1 wherein the image processor includes means for determining an angle that the symbologies make with the orientation of the sensor.

36. The apparatus of claim 1 wherein said sensor, said optical processing means and said image processor are each implemented on discrete chips.

37. The apparatus of claim 1 wherein the values represent gray scale values.

38. The apparatus of claim 1 wherein the values represent color values.

39. An optical reading apparatus for reading image information selected from a group consisting of optical codes, one-dimensional symbologies, two-dimensional symbologies and three-dimensional symbologies, said image information being contained within a target image field, said optical reading apparatus comprising:

a light source means for projecting an incident beam of light onto said target image field;

an optical assembly means for focusing said light reflected from said target field;

a sensor means for sensing an illumination level of said focused reflected light;

an optical processing means for generating an electrical signal proportional to said illumination levels received from said sensor and for converting said electrical signal into output data, said output data describing at least one value for each pixel element;

a memory means for receiving and storing the output data;

an image processor means for receiving a portion of the output data and generating distinguishing data from an identified area of interest; and

a data processing unit means coupled with said memory for processing the output data to produce decoded data representing said image information, the data processing unit being responsive to the distinguishing data.

40. A method for reading image information selected from a group consisting of optical codes, one-dimensional symbologies, two-dimensional symbologies and three-dimensional symbologies, said image information being contained within a target image field, said method comprising:

projecting light onto said target image field;

focusing said light reflected from said target field;

sensing an illumination level of said focused reflected light;

generating an electrical signal proportional to said illumination levels received from said sensor and converting said electrical signal into output data, said output data describing at least one value for each pixel element;

storing the output data the stored output data indicative of the target image field;

locating an area of interest in a portion of the output data;

processing data indicative of the area of interest to generate distinguishing data;

selecting responsive to the distinguishing data, a decoding process; and

processing using the selected decoding process the stored output data to produce decoded data representing said image information.

41. A method for processing image data corresponding to a physical image selected from a group consisting of optical codes, one-dimensional symbologies, two-dimensional symbologies and three-dimensional symbologies, said method using an optical reading apparatus having a focal plane, said method comprising:

searching for a series of coherent bars and spaces in said image data;

identifying textual data;

determining a subset of said data containing meaningful data;

determining an angle of said physical image with respect to said focal plane; and

performing sub-pixel interpolation to generate output data corresponding to said physical image.

42. The method of claim 41 wherein said step of determining an angle uses a checker pattern technique for determining said angle.

43. The method of claim 41 wherein said step of determining an angle uses a chain code technique for determining said angle.

66. The apparatus of claim 42 wherein the first processing means includes a binary processor in series with a run length code processor.

67. The apparatus of claim 66 wherein the run length code processor outputs indicator data.

44. An optical reading apparatus for reading image information contained within a target image field, the optical reading apparatus comprising:

a light source for projecting light onto the target image field;

an optical assembly directing the light reflected from the target image field to an optical path;

a sensor within the optical path, the sensor including a plurality of pixel elements for sensing the focused reflected light;

an optical processing means for processing the sensed target image into output data, the output data indicative of the sensed light for each of the pixel elements;

a first processing means for processing at least a portion of the output data to generate a first representation of the target image;

a second processing means for processing the output data to generate a second representation of the target image; and

wherein the second processing means uses the first representation to decode the target image.

45. The apparatus of claim 44 wherein the sensor and the optical processing means are integrated onto a single chip.

46. The apparatus of claim 44 wherein the sensor, the optical processing means and the first and second processing means are integrated onto a single chip.

47. The apparatus of claim 44 further comprising a frame locator means for directing the sensor to an area of interest in the target image field.

48. The apparatus of claim 44 further comprising a camera or a digital imaging means.

49. The apparatus of claim 44 further comprising a view finder including an image display.

50. The apparatus of claim 44 wherein the optical assembly includes a fixed focus lens assembly.

51. The apparatus of claim 50 wherein the lens assembly is part of the sensor packaging.

52. The apparatus of claim 44 wherein the optical assembly includes digital zoom function means.

53. The apparatus of claim 44 wherein the first processing means further comprises an integrated function means for high speed and low power digital imaging.

54. The apparatus of claim 44 wherein the optical assembly further comprises an image processing means having auto-zoom and auto-focus means controlled by the first processing means for determining an area of interest at any distance, using high frequency transition between black and white.

55. The apparatus of claim 44 wherein the first processing means further comprises pattern recognition means for global feature determination.

56. The apparatus of claim 44 further comprising an image processing means using gray scale, color, and/or shade processing, said image processing associated with a form factor.

57. The apparatus of claim 44 further comprising means for auto-discriminating between a camera function and an optical code recognition function and means for implementing a decoding function to read encoded data within an optical image.

58. The apparatus of claim 44 further comprising an aperture and means for reading optical codes bigger than the physical size of the aperture.

59. The apparatus of claim 44 wherein the sensor is selected from a group consisting of a CCD, CMOS sensor, or CMD.

60. The apparatus of claim 44 wherein the light source is selected from a group consisting of a light emitting diode, strobe, laser diode, or halogen light.

61. The apparatus of claim 44 wherein the optical processing means includes a sample and hold circuit.

62. The apparatus of claim 44 wherein the optical processing means includes a sample and hold circuit and an analog to digital converter circuit.

63. The apparatus of claim 44 wherein the first processing means includes an ASIC.

64. The apparatus of claim 44 wherein the first processing means includes an FPGA.

65. The apparatus of claim 44 wherein the first processing means includes a binary processor and a gray scale processor.

68. The apparatus of claim 44 wherein the first processing means includes a gray scale processor.

69. The apparatus of claim 44 wherein the first processing means provides the first representation of the target image prior to all the pixel elements being processed into output data by the optical processing means.

70. The apparatus of claim 44 wherein the first representation of the target image data is a binary representation.

71. The apparatus of claim 44 wherein the first representation of target image data is a run length coded representation.

72. The apparatus of claim 44 wherein the first representation of target image data is used to identify areas of interest in the target image.

73. The apparatus of claim 44 wherein the first processing means further includes means for determining an angle that the symbologies make with the orientation of the sensor.

74. The apparatus of claim 44 wherein the first processing means further includes means for identifying the type of optical code used for said symbologies.

75. The apparatus of claim 44 wherein the first processing means further includes means for performing sub-pixel interpolation.

76. The apparatus of claim 75 wherein the processing means uses the result of the sub-pixel interpolation to extract coded information from the symbologies.

77. The apparatus of claim 44 wherein the second processing means uses the first representation of the target image to extract coded information from said symbologies.

78. The apparatus of claim 44 wherein the second processing means uses gray scale data to extract coded information from the symbologies.

79. The apparatus of claim 44 wherein the sensor and the optical processing means are each implemented on discrete chips.

80. The apparatus of claim 44 wherein the sensor, the optical processing means and the first and second processing means are each implemented on discrete chips.

81. A method for reading image information contained within a target image field, said method comprising:

projecting light onto the target image field;

directing the light reflected from the target image field to an optical path;

sensing the reflected light in the optical path;

processing the sensed light into output data, the output data indicative of the sensed light for each pixel element corresponding to discrete points within the target image field;

processing at least a portion of the output data to generate a first representation of at least a portion of the target image field;

selecting, responsive to the first representation, a decoding process; and

decoding the output data, using the selected decoding process, to generate data indicative of the image information.

82. A method for processing image data corresponding to a physical image selected from a group consisting of optical codes, one-dimensional symbologies, two-dimensional symbologies, and three-dimensional symbologies, the method using an optical reading apparatus having a focal plane, the method comprising:

searching for a series of coherent bars and spaces in the image data;

identifying textual data;

determining a subset of the data containing meaningful data;

determining an angle of the physical image with respect to the orientation of the optical reading apparatus; and

performing sub-pixel interpolation to generate output data corresponding to the physical image.

83. The method of claim 82 wherein the step of determining an angle uses a checker pattern technique for determining the angle.

84. The method of claim 82 wherein the step of determining an angle uses a chain code technique for determining the angle.