IMAGE READING APPARATUS

• US 20030132384A1
• Filed: 05/11/2000
• Published: 07/17/2003
• Est. Priority Date: 05/12/1999
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Sugiyama, Miho, Wada, Hiroyuki
• Granted Patent: US 6,765,206 B2
• Time in Patent Office: Days
• US Class Current: 250/330
• CPC Class Codes: H04N 1/4097 Removing errors due external factors, e.g. dust, scratches

Abstract

An image reading method for forming an image on a transmission original irradiated with visible light and infrared light by an image forming optical system and reading the image by reading means, comprising an image forming magnification correction step of correcting a difference between the image forming magnification of a visible-light image and the image forming magnification of an infrared-light image by the image forming optical system, so that the image reading apparatus can be miniaturized and simplified and defects such as foreign matters and flaws on the original can adequately be corrected.

Claims

1. An image reading method for forming an image on a transmission original illuminated with visible light and infrared light by an image forming optical system and reading the image by reading means, comprising:

an image forming magnification correction step of correcting a difference between the image forming magnification of a visible-light image and the image forming magnification of an infrared-light image of said image forming optical system.

2. The image reading method according to claim 1 wherein said transmission original is a developed photograph film.

3. The image reading method according to claim 1, further comprising:

an optical path length change step of changing an optical path length from said transmission original to said reading means between when said visible-light image is read and when said infrared-light image is read.

4. The image reading method according to claim 1, further comprising:

a correction area determination step of determining a correction requiring area based on said infrared-light image .

5. The image reading method according to claim 1 wherein a reading resolution in the case in which said visible-light image is read is higher than the reading resolution in the case in which said infrared-light image is read.

6. The image reading method according to claim 1 wherein said image forming optical system enlarges and projects said transmission original with respect to said reading means.

7. The image reading method according to claim 1, further comprising:

a storing step of storing the image read by said reading means;

a calculation step of comparing and calculating contents stored in said storing step;

a judgment step of judging from the image read by said reading means whether an area requires correction; and

a correction step of correcting image data in said correction requiring area.

8. An image reading apparatus for forming an image on a transmission original illuminated with visible light and infrared light by an image forming optical system and reading the image by reading means, comprising:

image forming magnification correction means for correcting a difference between an image forming magnification of a visible-light image and the image forming magnification of an infrared-light image of said image forming optical system.

9. The image reading apparatus according to claim 8 wherein said transmission original is a developed photograph film.

10. The image reading apparatus according to claim 8, further comprising:

optical path length change means for changing an optical path length from said transmission original to said reading means between when said visible-light image is read and when said infrared-light image is read.

11. The image reading apparatus according to claim 8, further comprising:

correction area determination means for determining a correction requiring area based on said infrared-light image.

12. The image reading apparatus according to claim 8 wherein a reading resolution in the case in which said visible-light image is read is higher than the reading resolution in the case in which said infrared-light image is read.

13. The image reading apparatus according to claim 8 wherein said image forming optical system enlarges and projects said transmission original with respect to said reading means.

14. The image reading apparatus according to claim 8, further comprising:

storing means for storing the image read by said reading means;

calculation means for comparing and calculating contents stored by said storing means;

judgment means for judging from the image read by said reading means whether an area requires correction; and

correction means for correcting image data in said correction requiring area.

15. A memory medium which stores a control program to control an image reading apparatus for forming an image on a transmission original irradiated with visible light and infrared light by an image forming optical system and reading the image by reading means and which is readable by information reading means, said control program comprising:

an image forming magnification correction module for correcting a difference between an image forming magnification of a visible-light image and the image forming magnification of an infrared-light image of said image forming optical system.

16. An image reading method for illuminating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means, comprising:

an infrared-light image extraction step of focusing by a visible-light image and subsequently changing an optical path length to extract an infrared-light image; and

an area determination step of correcting an image magnification change caused during the extraction of said infrared-light image and determining a correction requiring area.

17. The image reading method according to claim 16, further comprising:

a selection step of selecting whether or not to change said optical path length in accordance with a reading resolution of said reading means.

18. The image reading method according to 16 wherein said transmission original is a developed photograph film.

19. An image reading apparatus for illuminating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means, comprising:

infrared-light image extraction means for focusing by a visible-light image and subsequently changing an optical path length to extract an infrared-light image; and

area determination means for correcting an image magnification change caused during the extraction of said infrared-light image and determining a correction requiring area.

20. The image reading apparatus according to claim 19, further comprising:

selection means for selecting whether or not to change said optical path length in accordance with a reading resolution of said reading means.

21. The image reading apparatus according to claim 20 wherein said transmission original is a developed photograph film.

22. An image reading method comprising:

a light emission step of emitting visible light and infrared light to illuminate a transmission original;

an optical path length change step of changing the optical path length of an optical system for forming the light transmitted through said transmission original into an image;

a focusing step of using said optical path length change step to perform a focusing operation;

a light detection step of detecting the light transmitted through said optical system;

a storing step of storing a light detection result in said light detection step;

a calculation step of comparing and calculating contents stored in said storing step;

a judgment step of judging whether an area requires correction or not from the light detection result in said light detection step; and

a correction step of correcting image data in said correction requiring area, wherein when said transmission original is illuminated with said visible light, a focused state is obtained by said focusing step, and when said transmission original is illuminated with said infrared light, the optical path length is changed only by a predetermined amount predetermined in said optical length change step, from said focused state.

23. The image reading method according to claim 22, further comprising:

an area determination step of correcting an image magnification change by said optical path length change to determine said correction requiring area.

24. The image reading method according to claim 23 wherein said area determination step multiplies the light detection result by said infrared light by a factor attributed to said image magnification change to change image information, and determines said correction requiring area.

25. The image reading method according to claim 23 wherein said area determination step converts said correction requiring area determined by the light detection result by said infrared light into position information, multiplies the position information by a factor attributed to said image magnification change to correct said correction requiring area, and determines said correction requiring area.

26. The image reading method according to claim 22, further comprising:

a selection step of selecting whether or not to change said optical path length in accordance with a reading resolution of said reading means.

27. The image reading method according to claim 22 wherein said transmission original is a developed photograph film.

28. An image reading apparatus comprising:

light emission means for emitting visible light and infrared light to illuminate a transmission original;

an optical system for forming the light transmitted through said transmission original into an image;

optical path length change means for changing the optical path length of said optical system;

focusing means for using said optical path length change means to perform a focusing operation;

light detection means for detecting the light transmitted through said optical system;

storing means for storing a light detection result by said light detection means;

calculation means for comparing and calculating contents stored by said storing means;

judgment means for judging from the light detection result by said light detection means whether an area requires correction or not; and

correction means for correcting image data in said correction requiring area, wherein when the transmission original is illuminated with said visible light, a focused state is obtained by said focusing means, and when the transmission original is illuminated with said infrared light, the optical path length is changed only by a predetermined amount predetermined by said optical length change means, from said focused state.

29. The image reading apparatus according to claim 28, further comprising:

area determination means for correcting an image magnification change by said optical path length change to determine said correction requiring area.

30. The image reading apparatus according to claim 29 wherein said area determination means multiplies the light detection result by said infrared light by a factor attributed to said image magnification change to change image information, and determines said correction requiring area.

31. The image reading apparatus according to claim 29 wherein said area determination means converts said correction requiring area determined by the light detection result by said infrared light into position information, multiplies the position information by a factor attributed to said image magnification change to correct said correction requiring area, and determines said correction requiring area.

32. The image reading apparatus according to claim 28, further comprising:

selection means for selecting whether or not to change said optical path length in accordance with a reading resolution of said reading means.

33. The image reading apparatus according to claim 28 wherein said transmission original is a developed photograph film.

34. An image reading method for illuminating a transmission original with visible light and infrared light and reading a transmission original image by reading means, comprising:

a reading resolution setting step of allowing a reading resolution by the visible light to differ from the reading resolution by the infrared light.

35. The image reading method according to claim 34 wherein said reading resolution setting step sets the resolution of image data read by said infrared light to be smaller than the resolution of the image data read by said visible light.

36. The image reading method according to claim 34 wherein said reading resolution setting step sets a set value of the resolution of image data read by said infrared light to be variable in accordance with the resolution of the image data read by said visible light.

37. The image reading method according to claim 34 wherein said transmission original is a developed photograph film.

38. An image reading apparatus for irradiating a transmission original with visible light and infrared light and reading a transmission original image by reading means, comprising:

reading resolution setting means for allowing a reading resolution by the visible light to differ from the reading resolution by the infrared light.

39. The image reading apparatus according to claim 38 wherein said reading resolution setting means sets the resolution of image data read by said infrared light to be smaller than the resolution of the image data read by said visible light.

40. The image reading apparatus according to claim 38 wherein said reading resolution setting means sets a set value of the resolution of image data read by said infrared light to be variable in accordance with the resolution of the image data read by said visible light.

41. The image reading apparatus according to claim 38 wherein said transmission original is a developed photograph film.

42. An image reading method comprising:

a light emission step of emitting visible light and infrared light to illuminate a transmission original;

a light detection step of detecting the light transmitted through said transmission original;

a storing step of storing a light detection result in said light detection step;

a calculation step of comparing and calculating contents stored in said storing step;

a judgment step of judging from the light detection result by said light detection step whether an area requires correction or not;

a correction step of correcting image data in said correction requiring area; and

a reading resolution setting step of allowing a reading resolution by said visible light to differ from the reading resolution by said infrared light.

43. The image reading method according to claim 42 wherein said reading resolution setting step sets the resolution of image data read by said infrared light to be smaller than the resolution of the image data read by said visible light.

44. The image reading method according to claim 42 wherein said reading resolution setting step sets a set value of the resolution of image data read by said infrared light to be variable in accordance with the resolution of the image data read by said visible light.

45. The image reading method according to claim 42 wherein said transmission original is a developed photograph film.

46. An image reading apparatus comprising:

light emission means for emitting visible light and infrared light to illuminate a transmission original;

light detection means for detecting the light transmitted through said transmission original;

storing means for storing a light detection result by said light detection means;

calculation means for comparing and calculating contents stored by said storing means;

judgment means for judging from the light detection result by said light detection means whether an area requires correction or not;

correction means for correcting image data in said correction requiring area; and

reading resolution setting means for allowing a reading resolution by said visible light to differ from the reading resolution by said infrared light.

47. The image reading apparatus according to claim 46 wherein said reading resolution setting means sets the resolution of image data read by said infrared light to be smaller than the resolution of the image data read by said visible light.

48. The image reading apparatus according to claim 46 wherein said reading resolution setting means sets a set value of the resolution of image data read by said infrared light to be variable in accordance with the resolution of the image data read by said visible light.

49. The image reading apparatus according to claim 46 wherein said transmission original is a developed photograph film.

50. An image reading method of illuminating a transmission original with visible light and infrared light, reading a transmission original image by reading means, detecting an area of a correction object from image data by said infrared light, and correcting said detected correction object, comprising a display step of displaying images obtained before and after said correction.

51. The image reading method according to claim 50 wherein said display step includes a plurality of display modes.

52. The image reading method according to claim 51 wherein said plurality of display modes include a successive display mode, a simultaneous display mode, a division display mode, and a switch display mode.

53. The image reading method according to claim 50 wherein said transmission original is a developed photograph film.

54. The image reading method according to claim 50 wherein said correction object is a foreign matter.

55. The image reading method according to claim 50 wherein said correction object is a flaw.

56. An image reading apparatus for illuminating a transmission original with visible light and infrared light, reading a transmission original image by reading means, detecting an area of a correction object from image data by said infrared light, and correcting the detected correction object, comprising display means for displaying images obtained before and after said correction.

57. The image reading apparatus according to claim 56 wherein said display means includes a plurality of display modes.

58. The image reading apparatus according to claim 57 wherein said plurality of display modes include a successive display mode, a simultaneous display mode, a division display mode, and a switch display mode.

59. The image reading apparatus according to claim 56 wherein said transmission original is a developed photograph film.

60. The image reading apparatus according to claim 56 wherein said correction object is a foreign matter.

61. The image reading apparatus according to claim 56 wherein said correction object is a flaw.

62. An image reading method comprising:

a light emission step of emitting visible light and infrared light to illuminate a transmission original;

a light detection step of detecting the light transmitted through said transmission original;

a storing step of storing a light detection result in said light detection step;

a calculation step of comparing and calculating contents stored in said storing step;

a judgment step of judging from the light detection result by said light detection step whether an area requires correction or not;

a correction step of correcting image data in said correction requiring area; and

a display step of displaying a first image obtained before the correction is performed by said correction step and a second image obtained after the correction is performed by said correction step.

63. The image reading method according to claim 62 wherein said display step first displays said first image and then displays said second image.

64. The image reading method according to claim 62 wherein said display step displays the first image immediately after extracting said first image, and displays said second image immediately after the image is corrected by said correction step.

65. The image reading method according to claim 62 wherein said display step simultaneously displays said first image and said second image.

66. The image reading method according to claim 62 wherein said display step displays said first image and said second image so that the images can be switched therebetween.

67. The image reading method according to claim 62 wherein said storing step divides and stores said first image and said second image.

68. The image reading method according to claim 62 wherein said display step synthesizes the image data divided and stored by said storing step, and displays said first image and said second image.

69. The image reading method according to claim 62 wherein said transmission original is a developed photograph film.

70. An image reading apparatus comprising:

light emission means for emitting visible light and infrared light to illuminate a transmission original;

an optical system for forming the light transmitted through said transmission original into an image;

light detection means for detecting the light transmitted through said optical system;

storing means for storing a light detection result by said light detection means;

calculation means for comparing and calculating contents stored by said storing means;

judgment means for judging from the light detection result by said light detection means whether an area requires correction or not;

correction means for correcting image data in said correction requiring area; and

display means for displaying a first image obtained before the correction is performed by said correction means and a second image obtained after the correction is performed by said correction means.

71. The image reading apparatus according to claim 70 wherein said display means first displays said first image and then displays said second image.

72. The image reading apparatus according to claim 70 wherein said display means displays the first image immediately after extracting said first image, and displays said second image immediately after the image is corrected by said correction step.

73. The image reading apparatus according to claim 70 wherein said display means simultaneously displays said first image and said second image.

74. The image reading apparatus according to claim 70 wherein said display means displays said first image and said second image so that the images can be switched therebetween.

75. The image reading apparatus according to claim 70 wherein said storing means divides and stores said first image and said second image.

76. The image reading apparatus according to claim 70 wherein said display means synthesize s the image data divided and stored by said storing means, and displays said first image and said second image.

77. A memory medium which stores a control program to control an image reading apparatus for illuminating a transmission original with visible light and infrared light and reading an i mage on the transmission original by reading means and which is readable by information reading means, said control program comprising:

an infrared-light image extraction module for focusing by a visible-light image and subsequently changing an optical path length to extract an infrared-light image; and

an area determination module for correcting an image magnification change caused during the extraction of said infrared-light image and determining a correction requiring area.

78. The memory medium according to claim 77 wherein said control program comprises a selection module for selecting whether or not to change said optical path length in accordance with a reading resolution of said reading means.

79. The memory medium according to claim 77 wherein said transmission original is a developed photograph film.

94. The memory medium according to any one of claims 77 to 92 and 93 wherein said memory medium is a floppy disk.

95. The memory medium according to any one of claims 77 to 92 and 93 wherein said memory medium is a hard disk.

96. The memory medium according to any one of claims 77 to 92 and 93 wherein said memory medium is an optical disk.

97. The memory medium according to any one of claims 77 to 92 and 93 wherein said memory medium is an optical magnetic disk.

98. The memory medium according to any one of claims 77 to 92 and 93 wherein said memory medium is a compact disk read only memory (CD-ROM).

99. The memory medium according to any one of claims 77 to 92 and 93 wherein said memory medium is a compact disk recordable (CD-R).

100. The memory medium according to any one of claims 77 to 92 and 93 wherein said memory medium is a magnetic tape.

101. The memory medium according to any one of claims 77 to 92 and 93 wherein said memory medium is a nonvolatile memory card.

102. The memory medium according to any one of claims 77 to 92 and 93 wherein said memory medium is a read only memory (ROM) chip.

80. A memory medium which stores a control program to control an image reading apparatus for illuminating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means and which is readable by information reading means, said control program comprising:

a light emission module for emitting the visible light and the infrared light to illuminate the transmission original;

an optical path length change module for changing an optical path length of an optical system for forming the light transmitted through said transmission original into an image;

a focusing module for using said optical path length change module to perform a focusing operation;

a light detection module for detecting the light transmitted through said optical system;

a storing module for storing a light detection result by said light detection module;

a calculation module for comparing and calculating contents stored by said storing module;

a judgment module for judging from the light detection result by said light detection module whether an area requires correction or not; and

a correction module for correcting image data in said correction requiring area, wherein when said transmission original is illuminated with said visible light, a focused state is obtained by said focusing module, and when said transmission original is illuminated with said infrared light, the optical path length is changed only by a predetermined amount predetermined by said optical path length change module, from said focused state.

81. The memory medium according to claim 80 wherein said control program comprises an area determination module for correcting an image magnification change by said optical path length change to determine said correction requiring area.

82. The memory medium according to claim 81 wherein said area determination module multiplies the light detection result by said infrared light by a factor attributed to said image magnification change to change image information, and determines said correction requiring area.

83. The memory medium according to claim 81 wherein said area determination module converts said correction requiring area determined by the light detection result by said infrared light into position information, multiplies the position information by a factor attributed to said image magnification change to correct said correction requiring area, and determines said correction requiring area.

84. The memory medium according to claim 80 wherein said control program further comprises a selection module for selecting whether or not to change said optical path length in accordance with a reading resolution of said reading means.

85. The memory medium according to claim 80 wherein said transmission original is a developed photograph film.

86. A memory medium which stores a control program to control an image reading apparatus for illuminating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means and which is readable by information reading means, said control program comprising a reading resolution setting module for allowing a reading resolution by the visible light to differ from the reading resolution by the infrared light.

87. The memory medium according to claim 86 wherein said reading resolution setting module sets the resolution of image data read with said infrared light to be smaller than the resolution of the image data read with said visible light.

88. The memory medium according to claim 86 wherein said reading resolution setting module sets a set value of the resolution of image data read with said infrared light to be variable in accordance with the resolution of the image data read with said visible light.

89. The memory medium according to claim 86 wherein said transmission original is a developed photograph film.

90. A memory medium which stores a control program to control an image reading apparatus for illuminating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means and which is readable by information reading means, said control program comprising:

a light emission module for emitting the visible light and the infrared light to illuminate the transmission original;

a light detection module for detecting the light transmitted through an optical system for forming the light transmitted through said transmission original into an image;

a storing module for storing a light detection result by said light detection module;

a calculation module for comparing and calculating contents stored by said storing module;

a judgment module for judging from the light detection result by said light detection module whether an area requires correction or not;

a correction module for correcting image data in said correction requiring area; and

a reading resolution setting module for allowing a reading resolution by said visible light to differ from the reading resolution by said infrared light.

91. The memory medium according to claim 90 wherein said reading resolution setting module sets the resolution of image data read with said infrared light to be smaller than the resolution of the image data read with said visible light.

92. The memory medium according to claim 90 wherein said reading resolution setting module sets a set value of the resolution of image data read with said infrared light to be variable in accordance with the resolution of the image data read with said visible light.

93. The memory medium according to claim 90 wherein said transmission original is a developed photograph film.

103. An image reading apparatus comprising:

a visible-light filter for forming a visible-light original image;

an infrared-light filter for forming an infrared-light original image; and

correction means for correcting a defect of said visible-light original image based on said infrared-light original image, wherein thickness values of said visible-light filter and said infrared-light filter are set so that an original image forming error caused by a difference in wavelength between visible light and infrared light is corrected.

107. The image reading apparatus according to any one of claims 103 to 106, further comprising:

lens moving mans for moving an original image forming lens to correct at least one of the original image forming error and the magnification error caused by the difference in wavelength between the visible light and the infrared light.

109. The image reading apparatus according to any one of claims 103 to 108 wherein said infrared-light filter has a high transmittance distribution with respect to light of the wavelength of 800 to 850 nm.

110. The image reading apparatus according to any one of claims 103 to 108 wherein said infrared-light filter has a high transmittance distribution with respect to light of the wavelength of 850 to 950 nm.

111. The image reading apparatus according to any one of claims 103 to 108 wherein said infrared-light filter has a high transmittance distribution with respect to light of the wavelength of 950 nm or more.

112. The image reading apparatus according to any one of claims 103 to 108 wherein a light source for radiating said visible light to the original and a light source for radiating said infrared light to the original are a common light source which includes a visible-light component and an infrared-light component.

113. The image reading apparatus according to any one of claims 103 to 108, further comprising image reading means for reading said visible-light original image and said infrared-light original image.

104. An image reading apparatus comprising:

a visible-light filter for forming a visible-light original image;

an infrared-light filter for forming an infrared-light original image;

signal processing means for correcting an original image magnification error caused by a difference in wavelength between visible light and infrared light; and

correction means for correcting a defect of said visible-light original image based on said infrared-light original image.

105. An image reading apparatus comprising:

a visible-light filter for forming a visible-light original image;

an infrared-light filter for forming an infrared-light original image; and

correction means for correcting a defect of said visible-light original image based on said infrared-light original image, wherein thickness values of said visible-light filter and said infrared-light filter are set so that an original image magnification error caused by a difference in wavelength between visible light and infrared light is corrected.

106. An image reading apparatus comprising:

a visible-light filter for forming a visible-light original image;

an infrared-light filter for forming an infrared-light original image; and

correction means for correcting a defect of said visible-light original image based on said infrared-light original image, wherein thickness values of said visible-light filter and said infrared-light filter are set so that an original image forming error and a magnification error caused by a difference in wavelength between visible light and infrared light are corrected.

108. An image reading apparatus comprising:

a visible-light filter for forming a visible-light original image;

an infrared-light filter for forming an infrared-light original image;

an original image forming lens which moves to correct at least one of an original image forming error and a magnification error caused by a difference in wavelength between visible light and infrared light; and

correction means for correcting a defect of said visible-light original image based on said infrared-light original image.