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US 5,495,340 AGranted
Image reading apparatus having color correction according to tempeature change improved
AssigneeMinolta Camera Kabushiki Kaisha
InventorsYoshikazu Naito, Shigeru Moriya, Takayoshi Hayashi
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Abstract
A chromatic color pattern and a monochromatic color pattern are read by an image sensor. A masking coefficient in a color masking portion or a gamma conversion characteristic of a gamma correction portion are selected in accordance with the ratio V1/V0 of a read value V1 of the chromatic color pattern and a read value V0 of the monochromatic color pattern. An output of an image data is corrected by masking processing with the selected masking coefficient and the like.
Claims18
An image reading apparatus, comprising:
- image reading means for reading a color original image and for color-separating light from said color original image to provide an output for each separated color;
- a chromatic color pattern separate from said color original image and provided at a position to be also readable by said image reading means to provide an output value corresponding to said chromatic color pattern;
- a monochromatic color pattern separate from said color original image and provided at a position to be also readable by said image reading means to provide an output value corresponding to said monochromatic color pattern;
- and
- correcting means for correcting an output value for the color original image from said image reading means based on both said output value corresponding to said chromatic color pattern from said image reading means and said output value corresponding to said monochromatic color pattern from said image reading means.
2 more elements
An image reading apparatus, comprising:
- a platen glass for placing an original thereon;
- a scanning optical system for scanning with exposure a color original placed on said platen glass;
- an image sensor for color-separating light reflected from the color original to provide an output for each separated color;
- an interference film filter provided on a light path of said reflected light for cutting a near infrared light component of said reflected light;
- a chromatic color pattern separate from said color original provided at a position to be also exposable by said scanning optical system to provide an output value corresponding to said chromatic color pattern;
- a monochromatic color pattern separate from said color original provided at a position to be also exposable by said scanning optical system to provide an output value corresponding to said monochromatic color pattern;
- comparing means for comparing said output value corresponding to said chromatic color pattern with said output value corresponding to said monochromatic color pattern from said image sensor;
- and
- correcting means for correcting an output value for the color original from said image sensor based on a comparison result by said comparing means.
6 more elements
Dependencies are inferred from the claim text.