US 6,507,713 B2Granted

Image-formation apparatus, controlling method thereof and image-formation method

AssigneeRicoh Company, Ltd.

InventorHiroshi Koide

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Abstract

An image formation apparatus is provided with a photosensitive drum, an optical writing device which writes an image on the outer surface of the photosensitive drum, a developing device which develops the image using toner an intermediate transfer belt onto which the toner image on the photosensitive drum is transferred, a rotation angle detection unit which detects the rotation angle of the photosensitive drum, an eccentric detection unit which detects the amount eccentricity of the photosensitive drum from the rotary axis of the photosensitive drum, and a correction unit which, obtains eccentricity of the photosensitive drum based on the amount eccentricity, the rotation angle and the radius of the photosensitive drum, and corrects a distortion and a color offset in the toner image based on the obtained eccentricity.

Claims16

Dependent claims

An image formation apparatus comprising:

at least one photosensitive drum;
an optical writing device which carries out an optical writing process in a main-scanning direction on the outer surface of the at least one photosensitive drum at least line by line;
a developing device which develops an electrostatic latent image optically written on the at least one photosensitive drum into a toner image by using toner;
an intermediate transfer belt which transfers the toner image located on the at least one photosensitive drum, that is shifted in synchronism with the at least one photosensitive drum while being pressed onto the at least one photosensitive drum;
a rotation angle detection unit which detects a rotation angle of the at least one photosensitive drum directly or indirectly;
an eccentricity detection unit which detects an eccentric position from the rotary axis of the at least one photosensitive drum located in the center of a circle cross-section of the at least one photosensitive drum;
and
a correction unit which, based upon results of detection by the rotation angle detection unit and the eccentricity detection unit, finds an amount of eccentricity of the at least one photosensitive drum, an eccentric rotation angle and a radius of the at least one photosensitive drum, and based upon resulting values, compensates for a distortion and a color offset of a toner image before the transfer to a sheet.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/816,456Filed 26 Mar 2001
Priority: JP 2000-08601427 Mar 2000
Published: US 2001/0046391 A129 Nov 2001
Granted: 14 Jan 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

G03G 15/0131
Details of unit: for transferring a pattern to a second base
G03G 15/0194
Using more than one reusable electrographic recording member, e.g. one for every monocolour image: primary transfer to the final recording medium
G03G 15/757
Details relating to xerographic drum, band or plate, e.g. replacing, testing: drive mechanisms for photosensitive medium, e.g. gears
H04N 1/0473
Detection, control or error compensation of scanning velocity or position: in subscanning direction, e.g. picture start or line-to-line…