Image reader comprising CMOS based image sensor array

• US 9,465,970 B2
• Filed: 03/21/2014
• Issued: 10/11/2016
• Est. Priority Date: 03/11/2005
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Wang, Ynjiun P., Havens, William H.
• Primary Examiner(s): Haupt, Kristy A
• Application Number:
  US14/221,903
• Publication Number:
  US 20140204257A1
• Time in Patent Office: 935 Days
• US Class Current: 1/1
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/1439 including a method step for retrieval of the optical code
• CPC Class Codes: H04N 23/54 Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/63 by using electronic viewfinders
• CPC Class Codes: H04N 23/631 Graphical user interfaces [GUI] specially adapted for controlling image capture or setting capture parameters
• CPC Class Codes: H04N 23/667 Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 25/70 SSIS architectures; Circuits associated therewith
• CPC Class Codes: H04N 25/745 Circuitry for generating timing or clock signals
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 25/7795 Circuitry for generating timing or clock signals
• CPC Class Codes: H04N 25/78 Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters

Abstract

The invention features an image reader and a corresponding method for capturing a sharp distortion free image of a target, such as a one or two-dimensional bar code. In one embodiment, the image reader comprises a two-dimensional CMOS based image sensor array, a timing module, an illumination module, and a control module. The time during which the target is illuminated is referred to as the illumination period. The capture of the image by the image sensor array is driven by the timing module that, in one embodiment, is able to simultaneously expose substantially all of the pixels in the array. The time during which the pixels are collectively activated to photo-convert incident light into charge defines the exposure period for the sensor array. In one embodiment, at least a portion of the exposure period occurs during the illumination period.

Claims

1. An apparatus comprising:

a bar code decoding module that is configured to decode representations of at least a two dimensional bar code in image data captured by an image reader, the image reader further comprising;

a CMOS image sensor array comprising a plurality of pixels in a two-dimensional array, wherein the CMOS image sensor array is operable, in a global shutter mode, and wherein in the global shutter mode all or substantially all of the pixels in the image sensor array are exposed in the image sensor array in response to an exposure control timing pulse so as to enable the collection of image data in the form of at least a two dimensional bar code; and

at least one illumination light source configured to illuminate at least a portion of the bar code in response to an illumination control timing pulse, wherein the exposure control timing pulse and the illumination control timing pulse are interdependent.

2. The apparatus of claim 1, wherein the bar code decoding module is further configured to select a decoding algorithm for decoding the representation of the bar code from a plurality of decoding algorithms each configured to decode a different one dimensional bar code or a two dimensional bar code.

3. The apparatus of claim 1, wherein the at least one illumination light source is configured to project a two-dimensional observable illumination pattern over the target.

4. The apparatus of claim 1, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse.

5. The apparatus of claim 1, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse and is configured to be deactivated during another portion of the exposure control timing pulse.

6. The apparatus of claim 1, wherein the bar code decoding module further comprises:

a classifier module that is configured to determine whether the image data comprises a one dimensional bar code or a two dimensional bar code.

7. The apparatus of claim 1, wherein the bar code decoding module is further configured to at least decode two or more of a one dimensional universal product code bar code, a two dimensional PDF417 bar code or a bar code having abutting bar code symbols.

8. The apparatus of claim 1, wherein the at least one illumination light source is configured to be substantially bright and the exposure control timing pulse is configured to be substantially short so as to enable the image data to be substantially non-distorted.

9. The apparatus of claim 1, wherein the barcode decoding module further comprises:

a read out module configured to read out a set of digital values corresponding to incident light on a plurality of pixels of the CMOS image sensor array simultaneously exposed to capture the image data, a frame of image data comprises a plurality of pixel values, wherein the read out module is controlled by a read out timing control pulse.

10. The apparatus of claim 1, further comprising:

a lens driver module, wherein the lens sensor driver module has a plurality of discrete settings, each discrete setting being configured to cause the image data to be collected by the CMOS image sensor for objects located at a particular distance from the image reader.

11. The apparatus of claim 1, further comprising:

an auto-focusing module configured to read the image data from one or more exposed rows such that the image data is analyzed by a focusing algorithm operable to determine an auto-focus setting, the auto-focusing module configured to move a lens according to the auto-focus setting.

12. The apparatus of claim 1, wherein the apparatus comprises one or more of a magnetic stripe reader, a biometric reader, a printer, a radio-frequency identification tag reader, a radio-frequency payment reader, or a smart card reader.

13. The apparatus of claim 1, wherein the barcode decoding module is further configured to perform feature extraction such that a quiet zone is identifiable in the image data.

14. The apparatus of claim 1, wherein the barcode decoding is further configured to perform feature extraction such that a finder pattern is identifiable in the image data.

15. The apparatus of claim 1, wherein the illumination control timing pulse occurs in response to the exposure control timing pulse.

16. The apparatus of claim 1, wherein the exposure control timing pulse occurs in response to the illumination control timing pulse.

17. The apparatus of claim 1, wherein a read out control timing pulse begins at the conclusion of the illumination control timing pulse.

18. The apparatus of claim 1, wherein a read out control timing pulse begins at the conclusion of the exposure control timing pulse.

19. The apparatus of claim 1, wherein the at least one illumination light source is configured to operate at a peak power level during at least a portion of the exposure control timing pulse in accordance with a power budget.

20. The apparatus of claim 1, wherein the CMOS image sensor array comprises at least 640×

480 active pixels.

21. The apparatus of claim 1, wherein the CMOS image sensor array comprises an infrared filter.

22. An apparatus comprising:

a bar code decoding module that is configured to decode representations of at least a two dimensional bar code in grey level image data captured by an image reader, the image reader further comprising;

a CMOS image sensor array comprising a plurality of pixels in a two-dimensional array, wherein the CMOS image sensor array is operable in a global shutter mode, and wherein in the global shutter mode all or substantially all of the pixels in the image sensor array are exposed in the image sensor array in response to an exposure control timing pulse so as to enable the collection of image data in the form of at least the two dimensional bar code; and

at least one illumination light source configured to illuminate at least a portion of the bar code in response to an illumination control timing pulse, wherein the exposure control timing pulse and the illumination control timing pulse are interdependent.

23. The apparatus of claim 22, wherein the bar code decoding module is further configured to select a decoding algorithm for decoding the representation of the bar code from a plurality of decoding algorithms each configured to decode a different one dimensional bar code or a two dimensional bar code.

24. The apparatus of claim 22, wherein the at least one illumination light source is configured to project a two-dimensional observable illumination pattern over the target.

25. The apparatus of claim 22, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse.

26. The apparatus of claim 22, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse and is configured to be deactivated during another portion of the exposure control timing pulse.

27. The apparatus of claim 22, wherein the bar code decoding module further comprises:

a classifier module that is configured to determine whether the grey level image data comprises a one dimensional bar code or a two dimensional bar code.

28. The apparatus of claim 22, wherein the bar code decoding module is further configured to at least decode two or more of a one dimensional universal product code bar code, a two dimensional PDF417 bar code or a bar code having abutting bar code symbols.

29. The apparatus of claim 22, wherein the at least one illumination light source is configured to be substantially bright and the exposure control timing pulse is configured to be substantially short so as to enable the grey level image data to be substantially non-distorted.

30. The apparatus of claim 22, wherein the barcode decoding module further comprises:

a read out module configured to read out a set of digital values corresponding to incident light on a plurality of pixels of the CMOS image sensor array simultaneously exposed to capture the grey level image data, a frame of grey level image data comprises a plurality of pixel values, wherein the read out module is controlled by a read out timing control pulse.

31. The apparatus of claim 22, further comprising:

a lens driver module, wherein the lens sensor driver module has a plurality of discrete settings, each discrete setting being configured to cause the grey level image data to be collected by the CMOS image sensor for objects located at a particular distance from the image reader.

32. The apparatus of claim 22, further comprising:

an auto-focusing module configured to read the grey level image data from one or more exposed rows such that the grey level image data is analyzed by a focusing algorithm operable to determine an auto-focus setting, the auto-focusing module configured to move a lens according to the auto-focus setting.

33. The apparatus of claim 22, wherein the apparatus comprises one or more of a magnetic stripe reader, a biometric reader, a printer, a radio-frequency identification tag reader, a radio-frequency payment reader, or a smart card reader.

34. The apparatus of claim 22, wherein the barcode decoding module is further configured to perform feature extraction such that a quiet zone is identifiable in the grey level image data.

35. The apparatus of claim 22, wherein the barcode decoding is further configured to perform feature extraction such that a finder pattern is identifiable in the grey level image data.

36. The apparatus of claim 22, wherein the illumination control timing pulse occurs in response to the exposure control timing pulse.

37. The apparatus of claim 22, wherein the exposure control timing pulse occurs in response to the illumination control timing pulse.

38. The apparatus of claim 22, wherein a read out control timing pulse begins at the conclusion of the illumination control timing pulse.

39. The apparatus of claim 22, wherein a read out control timing pulse begins at the conclusion of the exposure control timing pulse.

40. The apparatus of claim 22, wherein the at least one illumination light source is configured to operate at a peak power level during at least a portion of the exposure control timing pulse in accordance with a power budget.

41. The apparatus of claim 22, wherein the CMOS image sensor array comprises at least 640×

480 active pixels.

42. The apparatus of claim 22, wherein the CMOS image sensor array comprises an infrared filter.

43. An apparatus comprising:

a bar code decoding module that is configured to decode representations of at least a two dimensional bar code in grey level image data captured by an image reader, the image reader further comprising;

a CMOS image sensor array comprising a plurality of pixels in a two-dimensional array, wherein the CMOS image sensor array is configured such that all or substantially all of the pixels in the image sensor array are exposed in the image sensor array during the duration of the exposure control timing pulse so as to enable the collection of image data in the form of at least the two dimensional bar code, wherein the exposure control timing pulse has a duration of less than 3.7 milliseconds; and

at least one illumination light source configured to illuminate at least a portion of the bar code in response to an illumination control timing pulse, wherein the exposure control timing pulse and the illumination control timing pulse are interdependent.

44. The apparatus of claim 43, wherein the bar code decoding module is further configured to select a decoding algorithm for decoding the representation of the bar code from a plurality of decoding algorithms each configured to decode a different one dimensional bar code or a two dimensional bar code.

45. The apparatus of claim 43, wherein the at least one illumination light source is configured to project a two-dimensional observable illumination pattern over the target.

46. The apparatus of claim 43, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse.

47. The apparatus of claim 43, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse and is configured to be deactivated during another portion of the exposure control timing pulse.

48. The apparatus of claim 43, wherein the bar code decoding module further comprises:

a classifier module that is configured to determine whether the grey level image data comprises a one dimensional bar code or a two dimensional bar code.

49. The apparatus of claim 43, wherein the bar code decoding module is further configured to at least decode two or more of a one dimensional universal product code bar code, a two dimensional PDF417 bar code or a bar code having abutting bar code symbols.

50. The apparatus of claim 43, wherein the at least one illumination light source is configured to be substantially bright and the exposure control timing pulse is configured to be substantially short so as to enable the grey level image data to be substantially non-distorted.

51. The apparatus of claim 43, wherein the barcode decoding module further comprises:

a read out module configured to read out a set of digital values corresponding to incident light on a plurality of pixels of the CMOS image sensor array simultaneously exposed to capture the grey level image data, a frame of grey level image data comprises a plurality of pixel values, wherein the read out module is controlled by a read out timing control pulse.

52. The apparatus of claim 43, further comprising:

a lens driver module, wherein the lens sensor driver module has a plurality of discrete settings, each discrete setting being configured to cause the grey level image data to be collected by the CMOS image sensor for objects located at a particular distance from the image reader.

53. The apparatus of claim 43, further comprising:

an auto-focusing module configured to read the grey level image data from one or more exposed rows such that the grey level image data is analyzed by a focusing algorithm operable to determine an auto-focus setting, the auto-focusing module configured to move a lens according to the auto-focus setting.

54. The apparatus of claim 43, wherein the apparatus comprises one or more of a magnetic stripe reader, a biometric reader, a printer, a radio-frequency identification tag reader, a radio-frequency payment reader, or a smart card reader.

55. The apparatus of claim 43, wherein the barcode decoding module is further configured to perform feature extraction such that a quiet zone is identifiable in the grey level image data.

56. The apparatus of claim 43, wherein the barcode decoding is further configured to perform feature extraction such that a finder pattern is identifiable in the grey level image data.

57. The apparatus of claim 43, wherein the illumination control timing pulse occurs in response to the exposure control timing pulse.

58. The apparatus of claim 43, wherein the exposure control timing pulse occurs in response to the illumination control timing pulse.

59. The apparatus of claim 43, wherein a read out control timing pulse begins at the conclusion of the illumination control timing pulse.

60. The apparatus of claim 43, wherein a read out control timing pulse begins at the conclusion of the exposure control timing pulse.

61. The apparatus of claim 43, wherein the at least one illumination light source is configured to operate at a peak power level during at least a portion of the exposure control timing pulse in accordance with a power budget.

62. The apparatus of claim 43, wherein the CMOS image sensor array comprises at least 640×

480 active pixels.

63. The apparatus of claim 43, wherein the CMOS image sensor array comprises an infrared filter.

64. An apparatus comprising:

a bar code decoding module that is configured to decode representations of at least a two dimensional bar code in a grey level image captured by an image reader that is configured to operate a CMOS image sensor array operable in a global shutter mode to capture a substantially distortion free image, the image reader further comprising;

the CMOS image sensor array comprising a plurality of pixels in a two-dimensional array, wherein the CMOS image sensor array is operable in the global shutter mode such that all or substantially all of the pixels in the image sensor array are exposed in the image sensor array in response to an exposure control timing pulse so as to enable the collection of image data in the form of at least the two dimensional bar code;

at least one illumination light source configured to illuminate at least a portion of the bar code in response to an illumination control timing pulse, wherein the exposure control timing pulse and the illumination control timing pulse are interdependent; and

an autodiscrimination module configured to search the captured grey level image for one or more markers, wherein in an instance in which at least one marker of the one or more markers is detected, the bar code decoding module that is configured to decode the captured grey level image in accordance with a decoding algorithm associated with the at least one marker.

65. The apparatus of claim 64, wherein the bar code decoding module is further configured to select a decoding algorithm for decoding the representation of the bar code from a plurality of decoding algorithms each configured to decode a different one dimensional bar code or a two dimensional bar code.

66. The apparatus of claim 64, wherein the at least one illumination light source is configured to project a two-dimensional observable illumination pattern over the target.

67. The apparatus of claim 64, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse.

68. The apparatus of claim 64, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse and is configured to be deactivated during another portion of the exposure control timing pulse.

69. The apparatus of claim 64, wherein the bar code decoding module further comprises:

a classifier module that is configured to determine whether the grey level image data comprises a one dimensional bar code or a two dimensional bar code.

70. The apparatus of claim 64, wherein the bar code decoding module is further configured to at least decode two or more of a one dimensional universal product code bar code, a two dimensional PDF417 bar code or a bar code having abutting bar code symbols.

71. The apparatus of claim 64, wherein the at least one illumination light source is configured to be substantially bright and the exposure control timing pulse is configured to be substantially short so as to enable the grey level image data to be substantially non-distorted.

72. The apparatus of claim 64, wherein the barcode decoding module further comprises:

a read out module configured to read out a set of digital values corresponding to incident light on a plurality of pixels of the CMOS image sensor array simultaneously exposed to capture the grey level image data, a frame of grey level image data comprises a plurality of pixel values, wherein the read out module is controlled by a read out timing control pulse.

73. The apparatus of claim 64, further comprising:

a lens driver module, wherein the lens sensor driver module has a plurality of discrete settings, each discrete setting being configured to cause the grey level image data to be collected by the CMOS image sensor for objects located at a particular distance from the image reader.

74. The apparatus of claim 64, further comprising:

an auto-focusing module configured to read the grey level image data from one or more exposed rows such that the grey level image data is analyzed by a focusing algorithm operable to determine an auto-focus setting, the auto-focusing module configured to move a lens according to the auto-focus setting.

75. The apparatus of claim 64, wherein the apparatus comprises one or more of a magnetic stripe reader, a biometric reader, a printer, a radio-frequency identification tag reader, a radio-frequency payment reader, or a smart card reader.

76. The apparatus of claim 64, wherein the barcode decoding module is further configured to perform feature extraction such that a quiet zone is identifiable in the grey level image data.

77. The apparatus of claim 64, wherein the barcode decoding is further configured to perform feature extraction such that a finder pattern is identifiable in the grey level image data.

78. The apparatus of claim 64, wherein the illumination control timing pulse occurs in response to the exposure control timing pulse.

79. The apparatus of claim 64, wherein the exposure control timing pulse occurs in response to the illumination control timing pulse.

80. The apparatus of claim 64, wherein a read out control timing pulse begins at the conclusion of the illumination control timing pulse.

81. The apparatus of claim 64, wherein a read out control timing pulse begins at the conclusion of the exposure control timing pulse.

82. The apparatus of claim 64, wherein the at least one illumination light source is configured to operate at a peak power level during at least a portion of the exposure control timing pulse in accordance with a power budget.

83. The apparatus of claim 64, wherein the CMOS image sensor array comprises at least 640×

480 active pixels.

84. The apparatus of claim 64, wherein the CMOS image sensor array comprises an infrared filter.

85. An apparatus comprising:

a bar code decoding module that is configured to decode representations of at least a two dimensional bar code in image data captured by an image reader that is configured to operate in a global shutter mode to capture a substantially distortion free image, the image reader further comprising;

the CMOS image sensor array comprising a plurality of pixels in a two-dimensional array, wherein the CMOS image sensor array is operable in the global shutter mode such that all or substantially all of the pixels in the image sensor array are exposed in the image sensor array in response to an exposure control timing pulse so as to enable the collection of image data in the form of at least a two dimensional bar code;

at least one illumination light source configured to illuminate at least a portion of the bar code in response to an illumination control timing pulse, wherein the exposure control timing pulse and the illumination control timing pulse are interdependent;

a binarizer module that is configured to binarize the image data to create a binarized image according to at least one of local thresholding or target image size normalization; and

an autodiscrimination module configured to search the binarized image for one or more markers, wherein in an instance in which at least one marker of the one or more markers is detected, the bar code decoding module that is configured to decode the binarized image in accordance with a decoding algorithm associated with the at least one marker.

86. The apparatus of claim 85, wherein the bar code decoding module is further configured to select a decoding algorithm for decoding the representation of the bar code from a plurality of decoding algorithms each configured to decode a different one dimensional bar code or a two dimensional bar code.

87. The apparatus of claim 85, wherein the at least one illumination light source is configured to project a two-dimensional observable illumination pattern over the target.

88. The apparatus of claim 85, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse.

89. The apparatus of claim 85, wherein the at least one illumination light source is configured to operate at a substantially peak power level during at least a portion of the exposure control timing pulse and is configured to be deactivated during another portion of the exposure control timing pulse.

90. The apparatus of claim 85, wherein the bar code decoding module further comprises:

a classifier module that is configured to determine whether the image data comprises a one dimensional bar code or a two dimensional bar code.

91. The apparatus of claim 85, wherein the bar code decoding module is further configured to at least decode two or more of a one dimensional universal product code bar code, a two dimensional PDF417 bar code or a bar code having abutting bar code symbols.

92. The apparatus of claim 85, wherein the at least one illumination light source is configured to be substantially bright and the exposure control timing pulse is configured to be substantially short so as to enable the image data to be substantially non-distorted.

93. The apparatus of claim 85, wherein the barcode decoding module further comprises:

a read out module configured to read out a set of digital values corresponding to incident light on a plurality of pixels of the CMOS image sensor array simultaneously exposed to capture the image data, a frame of image data comprises a plurality of pixel values, wherein the read out module is controlled by a read out timing control pulse.

94. The apparatus of claim 85, further comprising:

a lens driver module, wherein the lens sensor driver module has a plurality of discrete settings, each discrete setting being configured to cause the image data to be collected by the CMOS image sensor for objects located at a particular distance from the image reader.

95. The apparatus of claim 85, further comprising:

an auto-focusing module configured to read the image data from one or more exposed rows such that the image data is analyzed by a focusing algorithm operable to determine an auto-focus setting, the auto-focusing module configured to move a lens according to the auto-focus setting.

96. The apparatus of claim 85, wherein the apparatus comprises one or more of a magnetic stripe reader, a biometric reader, a printer, a radio-frequency identification tag reader, a radio-frequency payment reader, or a smart card reader.

97. The apparatus of claim 85, wherein the barcode decoding module is further configured to perform feature extraction such that a quiet zone is identifiable in the image data.

98. The apparatus of claim 85, wherein the barcode decoding is further configured to perform feature extraction such that a finder pattern is identifiable in the image data.

99. The apparatus of claim 85, wherein the illumination control timing pulse occurs in response to the exposure control timing pulse.

100. The apparatus of claim 85, wherein the exposure control timing pulse occurs in response to the illumination control timing pulse.

101. The apparatus of claim 85, wherein a read out control timing pulse begins at the conclusion of the illumination control timing pulse.

102. The apparatus of claim 85, wherein a read out control timing pulse begins at the conclusion of the exposure control timing pulse.

103. The apparatus of claim 85, wherein the at least one illumination light source is configured to operate at a peak power level during at least a portion of the exposure control timing pulse in accordance with a power budget.

104. The apparatus of claim 85, wherein the CMOS image sensor array comprises at least 640×

480 active pixels.

105. The apparatus of claim 85, wherein the CMOS image sensor array comprises an infrared filter.

106. The apparatus of claim 85, wherein the binarizer module is further configured to reduce multi-pixel thick line segments in the image data into at least one single pixel thick line.

107. The apparatus of claim 85, wherein the image data is grey level image data.