Image reading device and image forming apparatus
First Claim
1. An image reading device comprising:
- a photoelectric device provided with an empty transfer part;
an A-D converter performing A-D conversion on an output signal for each pixel of said photoelectric device;
a reference voltage varying part varying a reference voltage of said A-D converter;
a detecting part detecting a black correction reference data from output for each pixel of said photoelectric device;
a black shading correcting part subtracting the black correction reference data from digital image data obtained from the output signal for each pixel of said photoelectric device when an image is read, through said A-D converter having the reference voltage set therein; and
a correcting part correcting the black correction reference data by a ratio between an output level of said empty transfer part obtained through said A-D converter when the black correction reference data is detected and an output level of said empty transfer part obtained through said A-D converter when the image is read.
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Accused Products
Abstract
An image reading device includes a photoelectric device provided with an empty transfer part; an A-D converter performing A-D conversion on an output signal for each pixel of the photoelectric device; a reference voltage varying part varying a reference voltage of the A-D converter; a detecting part detecting a black correction reference data from output for each pixel of the photoelectric device; a black shading correcting part subtracting the black correction reference data from digital image data obtained from the output signal for each pixel of the photoelectric device when an image is read by the A-D converter having the reference voltage set therein; and a correcting part correcting the black correction reference data by a ratio of an output level of the empty transfer part obtained through the A-D converter when the black correction reference data is detected and an output level of the empty transfer part obtained through the A-D converter when the image is read.
26 Citations
20 Claims
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1. An image reading device comprising:
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a photoelectric device provided with an empty transfer part;
an A-D converter performing A-D conversion on an output signal for each pixel of said photoelectric device;
a reference voltage varying part varying a reference voltage of said A-D converter;
a detecting part detecting a black correction reference data from output for each pixel of said photoelectric device;
a black shading correcting part subtracting the black correction reference data from digital image data obtained from the output signal for each pixel of said photoelectric device when an image is read, through said A-D converter having the reference voltage set therein; and
a correcting part correcting the black correction reference data by a ratio between an output level of said empty transfer part obtained through said A-D converter when the black correction reference data is detected and an output level of said empty transfer part obtained through said A-D converter when the image is read. - View Dependent Claims (3, 5, 7, 9)
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2. An image reading device comprising:
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a photoelectric device;
an empty transfer part output generating part falsely generating an output of empty transfer part of said photoelectric device by outputting a predetermined voltage in predetermined timing;
an A-D converter performing A-D conversion on an output signal for each pixel of said photoelectric device;
a reference voltage varying part varying a reference voltage of said A-D converter;
a detecting part detecting a black correction reference data from output for each pixel of said photoelectric device;
a black shading correcting part subtracting the black correction reference data from digital image data obtained from the output signal for each pixel of said photoelectric device when an image is read, through said A-D converter having the reference voltage set therein; and
a correcting part correcting the black correction reference data by a ratio of an output level of said empty transfer part output generating part obtained through said A-D converter when the black correction reference data is detected and an output level of said empty transfer part output generating part obtained through said A-D converter when the image is read. - View Dependent Claims (4, 6, 8, 10)
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11. An image reading device comprising:
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photoelectric means provided with empty transfer part;
A-D converting means for performing A-D conversion on an output signal for each pixel of said photoelectric means;
reference voltage varying means for varying a reference voltage of said A-D converting means;
detecting means for detecting a black correction reference data from output for each pixel of said photoelectric means;
black shading correcting means for subtracting the black correction reference data from digital image data obtained from the output signal for each pixel of said photoelectric means when an image is read, through said A-D converting means having the reference voltage set therein; and
correcting means for correcting the black correction reference data by a ratio of an output level of said empty transfer part obtained through said A-D converting means when the black correction reference data is detected and an output level of said empty transfer part obtained through said A-D converting means when the image is read. - View Dependent Claims (13, 15, 17, 19)
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12. An image reading device comprising:
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photoelectric means;
empty transfer part output generating mean for falsely generating an output of empty transfer part of said photoelectric means by outputting a predetermined voltage in predetermined timing;
A-D converting means for performing A-D conversion on an output signal for each pixel of said photoelectric means;
reference voltage varying means for varying a reference voltage of said A-D converting means;
detecting means for detecting a black correction reference data from output for each pixel of said photoelectric means;
black shading correcting means for subtracting the black correction reference data from digital image data obtained from the output signal for each pixel of said photoelectric means when an image is read, through said A-D converting means having the reference voltage set therein; and
correcting means correcting the black correction reference data by a ratio of an output level of said empty transfer part output generating means obtained through said A-D converting means when the black correction reference data is detected and an output level of said empty transfer part output generating means obtained through said A-D converting means when the image is read. - View Dependent Claims (14, 16, 18, 20)
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Specification