Image-reading device performing a white-shading correction by obtaining a peak value of average values of image data and read from a reference-white member in blocks as white-shading data
First Claim
1. An image-reading device comprising:
- a photoelectric converting element reading a first image from a subject copy;
a reference-white member functioning as a reference white used in a white-shading correction;
reading means for reading a second image from a constant range on a surface of said reference-white member by using said photoelectric converting element;
averaging means for dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
peak-value determining means for obtaining a peak value of said average values; and
white-shading correcting means for performing the white-shading correction to image data of said first image by using said peak value as white-shading data.
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Accused Products
Abstract
An image-reading device is provided. The image-reading device comprises a photoelectric converting element reading a first image from a subject copy, a reference-white member functioning as a reference white used in a white-shading correction, reading means for reading a second image from a constant range on a surface of the reference-white member by using the photoelectric converting element, averaging means for dividing image data of the second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines and obtaining average values of image data of the lines in the blocks respectively, peak-value determining means for obtaining a peak value of the average values, and white-shading correcting means for performing the white-shading correction to image data of the first image by using the peak value as white-shading data.
79 Citations
33 Claims
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1. An image-reading device comprising:
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a photoelectric converting element reading a first image from a subject copy;
a reference-white member functioning as a reference white used in a white-shading correction;
reading means for reading a second image from a constant range on a surface of said reference-white member by using said photoelectric converting element;
averaging means for dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
peak-value determining means for obtaining a peak value of said average values; and
white-shading correcting means for performing the white-shading correction to image data of said first image by using said peak value as white-shading data. - View Dependent Claims (8, 9, 10)
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2. An image-reading device comprising:
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a photoelectric converting element reading a first image from a subject copy;
a scanning optical system scanning said subject copy by exposing said subject copy to light so as to form said first image on said photoelectric converting element;
a reference-white plate functioning as a reference white used in a white-shading correction;
reading means for reading a second image from a constant range on a surface of said reference-white plate by using said photoelectric converting element;
averaging means for dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
peak-value determining means for obtaining a peak value of said average values; and
white-shading correcting means for performing the white-shading correction to image data of said first image by using said peak value as white-shading data.
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3. An image-reading device comprising:
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a subject-copy-conveying path conveying a subject copy;
a photoelectric converting element placed on said subject-copy-conveying path so as to read a first image from a surface of said subject copy;
a read roller placed opposite said photoelectric converting element with said subject-copy-conveying path therebetween so as to keep a distance constant between said surface of said subject copy and said photoelectric converting element by revolving, a surface of the read roller functioning as a reference white used in a white-shading correction;
reading means for reading a second image from a constant range on said surface of said read roller by using said photoelectric converting element;
averaging means for dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
peak-value determining means for obtaining a peak value of said average values; and
white-shading correcting means for performing the white-shading correction to image data of said first image by using said peak value as white-shading data. - View Dependent Claims (4, 5, 6, 7)
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11. An image-forming device comprising:
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an image-reading device including;
a photoelectric converting element reading a first image from a subject copy;
a reference-white member functioning as a reference white used in a white-shading correction;
reading means for reading a second image from a constant range on a surface of said reference-white member by using said photoelectric converting element;
averaging means for dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
peak-value determining means for obtaining a peak value of said average values; and
white-shading correcting means for performing the white-shading correction to image data of said first image by using said peak value as white-shading data, wherein an image is formed on a sheet according to the image data of said first image. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 28, 29, 30, 31, 32, 33)
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12. An image-forming device comprising:
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an image-reading device including;
a photoelectric converting element reading a first image from a subject copy;
a scanning optical system scanning said subject copy by exposing said subject copy to light so as to form said first image on said photoelectric converting element;
a reference-white plate functioning as a reference white used in a white-shading correction;
reading means for reading a second image from a constant range on a surface of said reference-white plate by using said photoelectric converting element;
averaging means for dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
peak-value determining means for obtaining a peak value of said average values; and
white-shading correcting means for performing the white-shading correction to image data of said first image by using said peak value as white-shading data, wherein an image is formed on a sheet according to the image data of said first image.
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13. An image-forming device comprising:
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an image-reading device including;
a subject-copy-conveying path conveying a subject copy;
a photoelectric converting element placed on said subject-copy-conveying path so as to read a first image from a surface of said subject copy;
a read roller placed opposite said photoelectric converting element with said subject-copy-conveying path therebetween so as to keep a distance constant between said surface of said subject copy and said photoelectric converting element by revolving, a surface of the read roller functioning as a reference white used in a white-shading correction;
reading means for reading a second image from a constant range on said surface of said read roller by using said photoelectric converting element;
averaging means for dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
peak-value determining means for obtaining a peak value of said average values; and
white-shading correcting means for performing the white-shading correction to image data of said first image by using said peak value as white-shading data, wherein an image is formed on a sheet according to the image data of said first image.
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14. An image-reading device comprising:
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a photoelectric converting element reading a first image from a subject copy;
a reference-white member functioning as a reference white used in a white-shading correction;
an image-reading unit reading a second image from a constant range on a surface of said reference-white member by using said photoelectric converting element;
an average-value circuit dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
a peak-value circuit obtaining a peak value of said average values; and
a white-shading calculating circuit performing the white-shading correction to image data of said first image by using said peak value as white-shading data.
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15. An image-reading device comprising:
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a photoelectric converting element reading a first image from a subject copy;
a scanning optical system scanning said subject copy by exposing said subject copy to light so as to form said first image on said photoelectric converting element;
a reference-white plate functioning as a reference white used in a white-shading correction;
an image-reading unit reading a second image from a constant range on a surface of said reference-white plate by using said photoelectric converting element;
an average-value circuit dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
a peak-value circuit obtaining a peak value of said average values; and
a white-shading calculating circuit performing the white-shading correction to image data of said first image by using said peak value as white-shading data.
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16. An image-reading device comprising:
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a subject-copy-conveying path conveying a subject copy;
a photoelectric converting element placed on said subject-copy-conveying path so as to read a first image from a surface of said subject copy;
a read roller placed opposite said photoelectric converting element with said subject-copy-conveying path therebetween so as to keep a distance constant between said surface of said subject copy and said photoelectric converting element by revolving, a surface of the read roller functioning as a reference white used in a white-shading correction;
an image-reading unit reading a second image from a constant range on said surface of said read roller by using said photoelectric converting element;
an average-value circuit dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
a peak-value circuit obtaining a peak value of said average values; and
a white-shading calculating circuit performing the white-shading correction to image data of said first image by using said peak value as white-shading data.
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24. An image-forming device comprising:
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an image-reading device including;
a photoelectric converting element reading a first image from a subject copy;
a reference-white member functioning as a reference white used in a white-shading correction;
an image-reading unit reading a second image from a constant range on a surface of said reference-white member by using said photoelectric converting element;
an average-value circuit dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
a peak-value circuit obtaining a peak value of said average values; and
a white-shading calculating circuit performing the white-shading correction to image data of said first image by using said peak value as white-shading data, wherein an image is formed on a sheet according to the image data of said first image.
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25. An image-forming device comprising:
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an image-reading device including;
a photoelectric converting element reading a first image from a subject copy;
a scanning optical system scanning said subject copy by exposing said subject copy to light so as to form said first image on said photoelectric converting element;
a reference-white plate functioning as a reference white used in a white-shading correction;
an image-reading unit reading a second image from a constant range on a surface of said reference-white plate by using said photoelectric converting element;
an average-value circuit dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
a peak-value circuit obtaining a peak value of said average values; and
a white-shading calculating circuit performing the white-shading correction to image data of said first image by using said peak value as white-shading data, wherein an image is formed on a sheet according to the image data of said first image.
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26. An image-forming device comprising:
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an image-reading device including;
a subject-copy-conveying path conveying a subject copy;
a photoelectric converting element placed on said subject-copy-conveying path so as to read a first image from a surface of said subject copy;
a read roller placed opposite said photoelectric converting element with said subject-copy-conveying path therebetween so as to keep a distance constant between said surface of said subject copy and said photoelectric converting element by revolving, a surface of the read roller functioning as a reference white used in a white-shading correction;
an image-reading unit reading a second image from a constant range on said surface of said read roller by using said photoelectric converting element;
an average-value circuit dividing image data of said second image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively;
a peak-value circuit obtaining a peak value of said average values; and
a white-shading calculating circuit performing the white-shading correction to image data of said first image by using said peak value as white-shading data, wherein an image is formed on a sheet according to the image data of said first image.
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27. A method of creating reference-white data comprising:
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the reading step of reading an image from a constant range on a surface of a reference-white member by using a photoelectric converting element, the reference-white member functioning as a reference white used in a white-shading correction;
the averaging step of dividing image data of said image into a plurality of blocks in a sub-scanning direction so that each of the blocks includes a plurality of lines, and obtaining average values of image data of said lines in said blocks respectively; and
the peak-value determining step of obtaining a peak value of said average values so as to create white-shading data.
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Specification