US 8,543,020 B2Granted

Image forming apparatus and method of correcting image misalignment

AssigneeRicoh Company, Ltd.

InventorsTatsuya Miyadera, Tomohiro Ohshima

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Abstract

An image forming apparatus includes a transport member, image forming units (used as pattern forming unit), a pattern detector, and an image misalignment detector. The image forming units form correction-use patterns for each color on the transport member. The pattern detector directs a light beam onto the transport member having the correction-use patterns and detect reflected light reflecting from the transport member. The image misalignment detector detects image misalignment of the correction-use patterns. The pattern forming unit forms a reference color pattern and a first color pattern. The pattern detector uses an irradiation light having a first wavelength matched to a spectral sensitivity peak of the first color pattern to detect an intensity of reflected light reflected from the transport member. The image misalignment detector computes an image misalignment value between the reference and first color patterns based on the intensity of reflected light reflected from the transport member.

Claims13

Dependent claims

An image forming apparatus, comprising:

an endless transport member;
a plurality of image forming units including a plurality of image bearing members arranged along a moving direction of the endless transport member, each of the image bearing members forming images of one of multiple colors using electrophotography, the images transferable to the endless transport member, each of the image forming units useable as a pattern forming unit to form a plurality of correction-use patterns for each color on the endless transport member;
a pattern detector, disposed near the endless transport member, to detect the correction-use patterns formed on the endless transport member by directing a light beam onto the correction-use patterns formed on the endless transport member, the pattern detector capable of detecting regular reflected light and diffuse reflected light reflecting from the endless transport member and the correction-use patterns formed on the endless transport member;
an image misalignment detector to detect image misalignment of the correction-use patterns formed on the endless transport member based on a detection result of the correction-use patterns obtained by the pattern detector;
and
a rotatable multi-faced mirror to optically scan the image bearing member,
wherein the pattern forming unit forms at least a reference color pattern and a first color pattern as correction-use patterns, each of the reference color pattern and the first color pattern being formed as a developed image,
the pattern detector uses an irradiation light having a first wavelength matched to a spectral sensitivity peak of the first color pattern to detect an intensity of light reflected from the endless transport member having the reference color pattern and the first color pattern formed thereon,
the image misalignment detector computes an image misalignment value between two color images of the reference color pattern and the first color pattern, based on the intensity of reflected light reflected from the reference color pattern and the first color pattern as detected by the pattern detector, and
the rotatable multi-faced mirror uses a first reflection face for exposing the reference color pattern and a second reflection face opposing the first reflection face for exposing other color patterns,
wherein one of:
the first wavelength corresponds to red light and the first color pattern includes a cyan pattern,
the first wavelength corresponds to green light and the first color pattern includes a magenta pattern, and
the first wavelength corresponds to blue light and the first color pattern includes a yellow pattern.

11 more elements

A method of correcting image misalignment of images formed by an image forming apparatus, the image forming apparatus including:

an endless transport member;
a plurality of image forming units including a plurality of image bearing members arranged along a moving direction of the endless transport member, each of the image bearing members forming images of one of multiple colors using electrophotography, the images transferable to the endless transport member, each of the image forming units useable as a pattern forming unit to form a plurality of correction-use patterns for each color on the endless transport member;
a pattern detector, disposed near the endless transport member, to detect the correction-use patterns formed on the endless transport member by directing a light beam onto the correction-use patterns formed on the endless transport member, the pattern detector capable of detecting regular reflected light and diffuse reflected light reflected from the endless transport member and the correction-use patterns formed on the endless transport member;
an image misalignment detector to detect image misalignment of the correction-use patterns formed on the endless transport member based on a detection result of the correction-use patterns obtained by the pattern detector;
and
a rotatable multi-faced mirror to optically scan the image bearing member,
the method comprising the steps of:
forming at least a reference color pattern and a first color pattern using the pattern forming unit as correction-use patterns, each of the reference color pattern and the first color pattern being formed as a developed image;
detecting, using the pattern detector, an intensity of light reflected from the endless transport member and the correction-use patterns formed on the endless transport member by irradiating the reference color pattern and the first color pattern with an irradiation light having a first wavelength matched to a spectral sensitivity peak of the first color pattern;
and
computing, using the image misalignment detector, an image misalignment value between two color images of the reference color pattern and the first color pattern, based on the intensity of reflected light reflected from the reference color pattern and the first color pattern as detected by the pattern detector,
wherein the rotatable multi-faced mirror uses a first reflection face for exposing the reference color pattern and a second reflection face opposing the first reflection face for exposing other color patterns,
wherein one of:
the first wavelength corresponds to red light and the first color pattern includes a cyan pattern,
the first wavelength corresponds to green light and the first color pattern includes a magenta pattern, and
the first wavelength corresponds to blue light and the first color pattern includes a yellow pattern.

13 more elements

A non-transitory computer-readable medium storing a program for correcting image misalignment of images formed by an image forming apparatus, the program comprising instructions that when executed by a computer cause the computer to execute a method of correcting image misalignment of images formed by an image forming apparatus, the image forming apparatus including

an endless transport member;
a plurality of image forming units including a plurality of image bearing members arranged along a moving direction of the endless transport member, each of the image bearing members forming images of one of multiple colors using electrophotography, the images transferable to the endless transport member, each of the image forming units useable as a pattern forming unit to form a plurality of correction-use patterns for each color on the endless transport member;
a pattern detector, disposed near the endless transport member, to detect the correction-use patterns formed on the endless transport member by directing a light beam onto the correction-use patterns formed on the endless transport member, the pattern detector capable of detecting regular reflected light and diffuse reflected light reflected from the endless transport member and the correction-use patterns formed on the endless transport member;
an image misalignment detector to detect image misalignment of the correction-use patterns formed on the endless transport member based on a detection result of the correction-use patterns obtained by the pattern detector;
and
a rotatable multi-faced mirror to optically scan the image bearing member,
the method comprising the steps of:
forming at least a reference color pattern and a first color pattern using the pattern forming unit as correction-use patterns, each of the reference color pattern and the first color pattern being formed as a developed image;
detecting, using the pattern detector, an intensity of light reflected from the endless transport member and the correction-use patterns formed on the endless transport member by irradiating the reference color pattern and the first color pattern with an irradiation light having a first wavelength matched to a spectral sensitivity peak of the first color pattern;
and
computing, using the image misalignment detector, an image misalignment value between two color images of the reference color pattern and the first color pattern, based on the intensity of reflected light reflected from the reference color pattern and the first color pattern as detected by the pattern detector,
wherein the rotatable multi-faced mirror uses a first reflection face for exposing the reference color pattern and a second reflection face opposing the first reflection face for exposing other color patterns,
wherein one of:
the first wavelength corresponds to red light and the first color pattern includes a cyan pattern,
the first wavelength corresponds to green light and the first color pattern includes a magenta pattern, and
the first wavelength corresponds to blue light and the first color pattern includes a yellow pattern.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/723,813Filed 15 Mar 2010
Priority: JP 2009-06169813 Mar 2009
Published: US 2010/0232817 A116 Sep 2010
Granted: 24 Sep 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G03G 15/161
Using at least one intermediate support: with means for handling the intermediate support, e.g. heating, cleaning, coating with a transfer agent
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 15/1605
Of a toner pattern, e.g. a powder pattern , e.g. magnetic transfer: using at least one intermediate support
G03G 2215/0161
Colour registration: generation of registration marks

Family

US 2010/0232817 A1Pre-grant publication · published 16 Sep 2010
US 8,543,020 B2This patent

From the US filing history. Foreign family members aren’t listed.

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