US 6,747,766 B1Granted

Color image reader for use in image forming apparatus

AssigneesKabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha

InventorsYoshikatsu Kamisuwa, Koji Tanimoto, Rintaro Nakane

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Abstract

A color image reader according to the present invention has a reading object holder which is plate shape and which can transmit light and holds the subject to be read, a lighting device for illuminating the subject to be read on the reading object holder a reducing lens for providing convergence to the image light from the reading object, a 3-line CCD sensor for receiving the image light with convergence given by the reducing lens and outputting three electrical signals corresponding to the image light, and a lateral chromatic aberration correction circuit for designating one output signal of the three output signals outputted from the 3-line CCD sensor to the reference, comparing the two remaining output signals with the output signal used for the reference, and providing a predetermined correction to the two remaining output signals, and can suppress generation of image color deviation which depends on the distance between the 3-line CCD sensor and the optical axis of the reducing lens.

Claims11

Dependent claims

A color image reader comprising:

a reading object holder, having plate shape and which can transmit light, for holding a subject to be read;
a lighting device for illuminating the subject to be read on the reading object holder;
a reducing lens for providing convergence to the image light from the reading object;
a 3-line CCD sensor for receiving the image light with convergence given by the reducing lens and outputting three electrical signals corresponding to the image light;
and
a lateral chromatic aberration correction circuit for storing only parameters representing an approximate expression or linear expression for correcting color deviation in all pixel positions in a main scanning direction, for designating one output signal of the three output signals outputted from the 3-line CCD sensor to the reference, for comparing the two remaining output signals with the output signal used for the reference, and for providing a predetermined correction to the two remaining output signals,
wherein the 3-line CCD sensor contains three sets of line sensors arranged on the same plane in parallel to one another, and are positioned in such a manner that the image light passing through the center of the reducing lens impinges on the line sensor located at the center of the three sets of the line sensors, and
wherein the lateral chromatic aberration correction circuit finds the difference of the outputs corresponding to the optional pixel in each of the two remaining outputs with respect to the output of the center line sensor to the optional pixel for the three outputs outputted by the 3-line CCD sensor.

5 more elements

A color image forming apparatus comprising:

a color image reader including:
a reading object holder, having plate shape and which can transmit light, for holding a reading object;
a lighting device for illuminating the reading object on the reading object holder;
a reducing lens for giving convergence to the image light from the reading object;
a 3-line CCD sensor for receiving the image light with convergence given by the reducing lens and outputting three electrical signals corresponding to the image light;
and
a lateral chromatic aberration correction circuit for storing only parameters representing an approximate expression or linear expression for correcting color deviation in all pixel positions in a main scanning direction, for designating one output signal of the three output signals outputted from the 3-line CCD sensor to the reference, for comparing the two remaining output signals with the output signal used for the reference, and for providing a predetermined correction to the two remaining output signals;
an exposure device for irradiating the exposed light with the light intensity varied in correspondence with the output image signal generated by the color image reader to a predetermined position;
the first and the second image forming apparatus in which each of the image forming apparatuses comprises a photosensitive material which is a light receptor, a developing apparatus for selectively supplying the visualized material to the photosensitive material, a transcription apparatus for transcribing the visualized material from the photosensitive material to the transferred material, wherein individual image forming apparatus which supply the visualized material by the developing apparatus to the latent image formed on the photosensitive material by the exposed light irradiated from the exposure apparatus to visualize the image and form the visualized image are disposed in a predetermined arrangement, and form a plurality of toner images for each color component in correspondence with the output image signals for each color component supplied from the color image reader in conformity to time series;
a transferred material conveying mechanism located at a predetermined position with respect to each of the transcription apparatus of the first and the second image forming apparatus and conveying the visualized image formed by the first and the second image forming apparatus transcribably onto the transferred material while the transferred material fed from the storage section is being conveyed;
and
a fixing apparatus including a heating mechanism and pressurizing mechanism, for fixing the visualized image transferred on the transferred material to the transferred material being conveyed by the transferred material conveying mechanism.

9 more elements

Dependencies are inferred from the claim text.