Canon Kabushiki Kaisha

Other

Yasuhito Shirafuji

Nobuhiko Zaima

Tomohisa Itagaki

Takahiro Ishihara

Yasushi Takeuchi

Jun Mochizuki

Kazukiyo Akashi

Ryuichi Araki

Naoka Omura

Provided is an image forming apparatus, which is capable of detecting a color misregistration amount with high accuracy even when a density characteristic thereof is changed. The image forming apparatus includes a plurality of image forming units configured to form toner images of different colors on a predetermined intermediate transfer belt, and a density sensor configured to measure densities of the toner images formed on the intermediate transfer belt. The image forming apparatus determines a density target depending on a measurement result of a density correction image, which is formed by the plurality of image forming units, from the density sensor. The image forming apparatus causes the plurality of image forming units to form position detection images so that the position detection images have densities corresponding to the density target.

Image forming apparatus

An image forming apparatus includes a conversion unit that converts image data based on a conversion condition, an image forming unit that forms an image based on the converted image data, a measurement unit that measures a measuring image, and a generation unit that controls the image forming unit to form a first measuring image while the image forming unit is continuously forming images, and generates the conversion condition based on first measurement data of the first measuring image and a first feedback condition. The generation unit controls the image forming unit to form a second measuring image during a period from when toner discharge processing has been performed until the image forming unit forms a subsequent image, and generates the conversion condition based on second measurement data of the second measuring image, and a second feedback condition with a larger correction amount than the first feedback condition.

An image forming apparatus includes a conversion unit configured to convert image data based on a conversion condition, an image forming unit configured to be controlled based on an image forming condition, and to form an image based on the converted image data, a measurement unit configured to measure a plurality of measurement images, a first determination unit configured to determine the image forming condition based on a first measurement result of a first measurement image, a generation unit configured to generate the conversion condition based on second measurement results of second measurement images and a feedback condition, and a second determination unit configured to determine the feedback condition based on the first measurement result. The image forming unit sets the determined image forming condition in next timing. The conversion unit updates the conversion condition after the generation unit generates the conversion condition and before the next timing.

Image forming apparatus that suppresses fluctuations in density of successively formed images even if charge amount of developer changes

An image forming apparatus includes: a measuring unit configured to measure a plurality of measurement images, the plurality of measurement images including a first measurement image and second measurement images; a generation unit configured to generate a conversion condition based on second measurement data corresponding to the second measurement images; a first determination unit configured to determine an execution condition based on first measurement data corresponding to the first measurement image; and a second determination unit configured to determine a light intensity based on the first measurement data. A subsequent timing when the plurality of measurement images are to be formed is determined based on the execution condition, and an exposure unit updates the set light intensity to the light intensity determined by the second determination unit when the plurality of measurement images are formed at the subsequent timing.

Image forming apparatus that corrects image forming condition based on measurement result of measurement image

An image forming apparatus includes: a forming unit configured to form an image on an image carrier; a holding unit configured to hold a reference table and a tone correction table that convert a plurality of input image data values into corresponding output image data values; and a correcting unit configured to control the forming unit to form a first test pattern including a plurality of images having different densities on the image carrier using the tone correction table, and correct the tone correction table by detecting densities of the plurality of images. The correcting unit is further configured to correct the tone correction table by updating the tone correction table using the detected densities of the plurality of images and then interpolating the updated tone correction table using the reference table.

Image forming apparatus including correction unit that corrects tone correction table

An image forming apparatus includes: a correction unit configured to correct image data based on a correction condition; an image forming unit configured to form an image based on the image data corrected by the correction unit; a measurement unit configured to measure a measurement image formed by the image forming unit; an update unit configured to control the correction unit to correct measurement image data based on the correction condition, control the image forming unit to form the measurement image based on the corrected measurement image data, and update the correction condition based on a measurement result and reference data corresponding to the measurement image; and a control unit configured to control whether or not to convert a measuring result of a target measurement image by the measurement unit to target reference data corresponding to the target measurement image.

Image forming apparatus holding tone correction table

An image forming apparatus includes: an update unit configured to cause an image forming unit to form a first measurement image, to cause a measurement unit to measure the first measurement image, and to update a process condition based on a measurement result; a first determination unit configured to cause the image forming unit to form a plurality of second measurement images, to cause the measurement unit to measure the plurality of second measurement images, and to determine the process condition based on a measurement result, the plurality of second measurement images being formed according to a plurality of test process conditions; and a second determination unit configured to determine the plurality of test process conditions, based on environment information obtained by an obtainment unit and the process condition updated by the update unit.

Image forming apparatus that updates process condition of image formation

An image forming apparatus configures a normal transfer potential in a yellow primary transfer unit, and configures a transfer potential which does not cause any retransfer phenomenon of a yellow measurement image in image carriers located on the downstream side of the yellow primary transfer unit. When a color difference obtained from a reference density and a density of a measurement image on an intermediate transfer belt becomes equal to or larger than a prescribed value, the image forming apparatus determines that multinary-color density adjustment is required.

Adjustment of image density, using a density adjustment condition, in image forming apparatus

An image forming apparatus includes; an exposure unit configured to perform, based on the image data, first exposure for a photosensitive member and second exposure for the photosensitive member exposed by the first exposure; a determination unit configured to determine a type of the image to be formed based on image data; and a control unit configured to control the exposure unit such that a difference in an exposure amount between the first exposure and the second exposure performed based on the image data when the type of the image is a character is larger than the difference in the exposure amount between the first exposure and the second exposure performed based on the image data when the type of the image is a picture.

Image forming apparatus for performing exposure a plurality of times

An image forming apparatus includes an image carrying member for carrying a toner image; an intermediary member for carrying the toner image transferred from the image carrying member; a first transfer member for transferring the toner image from the intermediary member onto a sheet, the first transfer member having a first resistance and being contacted to the intermediary member; a second transfer member for transferring the toner image from the intermediary member onto the sheet, the second transfer member having a second resistance higher than the first resistance and being contacted to the intermediary member at a position downstream of the first transfer member; and a voltage applying source, connected to both of said first and second transfer members, for applying the same voltage to the first and second transfer members to transfer the toner image onto the sheet.

An image forming apparatus capable of suppressing density unevenness of a toner image formed on a photosensitive member. A light amount of a light beam that exposes an end portion of the photosensitive member is made different from a light amount of a light beam that exposes a central portion thereof in order to suppress a density difference between a toner image density at the central portion of the photosensitive member and that at the end portion thereof in a scanning direction of the light beams.

Image forming apparatus having photosensitive member exposed to plural beams, and control apparatus for light source of image forming apparatus

An image forming apparatus includes an image forming unit having an exposure unit and a developing unit; a detection unit configured to detect a thickness and an area ratio of a toner layer of a pattern image formed by the image forming unit; a storage unit configured to store data indicating permissible ranges for the thickness and the area ratio of the toner layer; and a correction unit configured to change, when the thickness or the area ratio of the toner layer detected by the detection unit falls outside the corresponding permissible range indicated by the data stored in the storage unit, a spot diameter of the laser beam so that the thickness and the area ratio of the toner layer respectively fall within the permissible ranges.

Image forming apparatus for detecting and correcting thickness and area ratio of toner layer

An apparatus includes a forming unit; a reading unit; a conversion unit converting a signal corresponding to the image read by the reading unit into a signal indicating a density value; a correction unit performing tone correction on the density value of the signal output by the conversion unit; and a control unit controlling a tone correction setting in the tone correction unit by controlling the reading unit to read a tone correction image that was formed on a recording material by the forming unit. When controlling the tone correction setting, the control unit further changes a setting for image formation in the forming unit and a setting for conversion into a density value in the conversion unit according to the recording material used in the control of the tone correction setting.

Image forming apparatus in which tone correction setting is controlled

An image forming apparatus includes an image forming unit, a decision unit, an output unit, a control unit, and a setting unit. The image forming unit forms an image on an image bearing member. The decision unit decides a first image forming condition of the image forming unit for forming the image at a width that is wider than a predetermined width. The output unit outputs a signal in accordance with the thickness of the image. The control unit causes the image forming unit to form a measurement image having a width that is narrower than or equal to the predetermined width. The setting unit sets a second image forming condition of the image forming unit so that the thickness of the image that is narrower than or equal to the predetermined width becomes thinner than or equal to the predetermined thickness.

Image forming apparatus responsive to image forming conditions

A first transfer inner roller and a first transfer outer roller are arranged such that the leading edge of a recording material is pressed against an intermediate transfer member on the downstream side of an upstream side transfer portion to change a traveling direction of the recording material.

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Kashiwa, Japan

Yasuhito Shirafuji