Canon Kabushiki Kaisha

Other

Nobuhiko Zaima

Tomohisa Itagaki

Yasuhito Shirafuji

Takahiro Ishihara

Kazuo Suzuki

Nobuatsu Sasanuma

Yuichi Ikeda

Takao Ogata

Jiro Ishizuka

Makoto Kanbayashi

Kenichi Nakagawa

An image forming apparatus configured to form an image on a sheet includes an image bearing member configured to rotate in a predetermined direction, and an image forming unit configured to form an image on the image bearing member based on image data converted based on a conversion condition. A controller of the image forming apparatus controls the image forming unit to form a plurality of measurement images different in density along the predetermined direction of the image bearing member, detects the plurality of measurement images, and generates the conversion condition based on detection results of the plurality of measurement images. The controller controls the image forming unit to form the plurality of measurement images in a dispersed manner in terms of positions of the plurality of measurement images on the image bearing member in accordance with periodic unevenness that occurs in the measurement images.

Image forming apparatus with tone correction

An image forming apparatus that is capable of finding density of an output image with high accuracy even if reflectance of an image bearing member varies. A conversion unit converts image data based on a conversion condition. An image forming unit forms an image based on the converted image data. A measurement unit measures irregular reflection light from a measurement image on the image bearing member. A controller controls the image forming unit to form measurement images, controls the measurement unit to measure irregular reflection light from an area on the image bearing member where the measurement images are not formed, controls the measurement unit to measure the irregular reflection light from the measurement images, selects a measurement result from among measurement results of the measurement images based on the measurement result of the area, and generates the conversion condition based on the selected measurement result.

Image forming apparatus that uses a predetermined measurement image and controls image density

An image forming apparatus includes a converting unit, a plurality of image forming units, a scanning unit, a first generating unit, a second generating unit, an intermediate transfer member, a measuring unit, and a controller configured to, after the first generating unit generates an image forming condition, control the plurality of image forming units to form a measurement image, control the measuring unit to measure the measurement image, and control whether to control the second generating unit to generate a conversion condition or not on the basis of a result of the measurement performed on a previous measurement image and a result of the measurement performed on a current measurement image.

Image forming apparatus capable of performing calibration

An image forming apparatus includes a correction unit configure to correct image data based on a correction condition; an image bearing member; an image forming unit configured to form an image on the image bearing member, based on the corrected image data; a transfer unit configured to transfer the image onto a recording material; a measurement unit configured to measure a measurement image formed on the image bearing member; and a converting unit configured to convert, based on a conversion condition, a measurement result of the measurement image measured by the measurement unit. A printer controller controls the image forming unit to form the measurement image, control the measurement unit to measure the measurement image, control the converting unit to convert the measurement result of the measurement image, and generate the correction condition based on the measurement result converted by the converting unit.

Image forming apparatus with image correction using measurement image and image forming method

Image formation is properly performed by suppressing an influence on a transfer property in the image formation due to variation in a toner particle charge amount. An image forming apparatus comprises a developing device for performing development using developer including a charged toner particle, a toner supply container for supplying the toner particle to a development unit, and a CPU for controlling a toner particle amount supplied to the developing device. The CPU calculates a toner consumption amount consumed by the development. Then, from the result, the CPU calculates a toner supply amount which makes the toner charge amount in the developing device constant. Then, the CPU supplies the toner of the calculated amount to the developing device.

Image forming apparatus

To add an arbitrary recording medium as a recording medium that can be used for calibration to maintain the quality of an image to be formed, an image forming unit forms a pattern image on each of a specific recording medium that can be used for the calibration and the arbitrary recording medium. A creating unit creates second conversion setting information applied to the arbitrary recording medium to convert luminance information into density information, using first luminance information obtained from the pattern image formed on the specific recording medium, second luminance information obtained from the pattern image formed on the arbitrary recording medium, and first conversion setting information applied to the specific recording medium for converting luminance information into density information. A determining unit determines a common image formation condition applied to the specific recording medium and the arbitrary recording medium based on the second conversion setting information.

Apparatus that performs calibration for maintaining image quality

An image forming apparatus corrects image data using a correction condition. An image forming unit forms an image on a recording medium, based on the corrected image data. Read data is obtained by a reading unit reading a measurement image formed on the recording medium. A determination unit determines a process condition used when the image forming unit forms the image based on the image data, based on the read data. A conversion unit converts the read data to density data, using a conversion condition corresponding to the recording medium. A first generation unit generates the correction condition, based on the density data. A storage unit stores a first conversion condition corresponding to a specific recording medium. A second generation unit controls the image forming unit to form a first image pattern on the specific recording medium and forms a second image pattern on another recording medium.

Image forming apparatus that performs calibration for maintaining image quality

An image forming apparatus includes a correcting unit that corrects image data using a tone correction condition. An image forming unit forms an image on a printing medium based on the corrected image data. An obtaining unit obtains read data by a reading unit reading a pattern image formed on the medium by the image forming unit. A converting unit converts the read data into density data using a converting condition corresponding to the printing medium. A first creating unit creates the tone correction condition based on the density data converted by the converting unit. A second creating unit controls the correcting unit to correct the patch data using the tone correction condition created by the first creating unit, controls the image forming unit to form a patch image on another printing medium based on the corrected patch data, and creates the converting condition corresponding to the other printing medium.

Image forming apparatus which performs calibration for maintaining image quality

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 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 forms a pattern image on a first printing medium and creates a first image processing condition for adjusting a tone characteristic based on a first luminance value. When performing the calibration using a second printing medium different from the first printing medium, the apparatus corrects, based on a luminance value of a background region of the second printing medium, a second luminance value output in accordance with light reflected by the second printing medium, and creates the first image processing condition based on the corrected second luminance value.

A luminance value for a second printing medium that has been obtained by reading a pattern image formed on the second printing medium different from a first printing medium is converted into a corresponding density value on the first printing medium. Calibration for the first printing medium can then be performed using the second printing medium.

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.

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Kashiwa, Japan

Nobuhiko Zaima