Image reading apparatus
AssigneeNisca Corporation
InventorsSatoshi Tanaka, Yoshihiko Minagawa, Hideaki Inoue, Junya Ozawa, Yoshihiro Hanagata, Hotaka Ishimaru
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Abstract
An image reading apparatus that reads images of document images having different gloss levels with a reproducibility suitable for uses includes a data processor to irradiate a document image with light from a regular reflection light source and a diffuse reflection light source, and to generate image data based on a regular reflection output value and a diffuse reflection output value obtained from a photoelectric converter.
Claims18
An image reading apparatus for reading document images having different gloss levels, comprising:
- a platen setting a document image;
- a regular reflection light source for photoelectric conversion of substantially regular reflection light from the document image;
- a diffuse light source for photoelectric conversion of substantially diffuse reflection light from the document image;
- a photoelectric conversion means photoelectrically converting reflection light from the document image on the platen;
- a control means executing regular reflection reading of the document image irradiated with light from the regular reflection light source, and diffuse reflection reading of the document image irradiated with light from the diffuse light source;
- and
- a data processing means generating image data based on each output value of regular reflection and diffuse reflection from the photoelectric conversion means;
- wherein
- the data processing means obtains, based on:
- a regular reflection correction value for correcting a regular reflection output value from the photoelectric conversion means;
- a diffuse correction value for correcting a diffuse reflection output value from the photoelectric conversion means;
- and
- a determining threshold for determining whether or not the regular reflection output value is a gloss pixel;
- gloss pixel data based on the regular reflection correction value after comparing the regular reflection output value from the document image with the determining threshold;
- and
- non-gloss pixel data based on the diffuse correction value for the diffuse reflection output value of the document image.
An image reading apparatus for reading document images having different gloss levels or a document image having different gloss level regions in the same document, comprising:
- a platen setting a document image;
- a regular reflection light source for photoelectric conversion of substantially regular reflection light from an the document image;
- a diffuse light source for photoelectric conversion of substantially diffuse reflection light from the document image;
- a photoelectric conversion means photoelectrically converting the reflection light from the document image on the platen;
- a control means executing regular reflection reading of the document image irradiated with light from the regular reflection light source, and diffuse reflection reading of the document image irradiated with light from the diffuse light source;
- and
- an output value correcting means correcting each output value of a regular reflection and a diffuse reflection from the photoelectric conversion means to be values suitable for reading;
- the output value correcting means is provided with a correction value generating means generating:
- a maximum output reference value set from the output value of the photoelectric conversion means irradiated with light from the regular reflection light source to a high gloss level reference surface;
- a first minimum output reference value set from the output value of the photoelectric conversion means irradiated with light from the regular reflection light source to a low gloss level reference surface;
- a second minimum output reference value set from a dark output value of the photoelectric conversion means;
- and
- a first correction data based on the first minimum output reference value and the maximum output reference value, and a second correction data based on the second minimum output reference value and the maximum output reference value:
- the control means being configured in such a way that, during executing the regular reflection reading of the document image, it is possible to select to correct by the first correction data or to correct by the second correction data.
Dependencies are inferred from the claim text.