Canon Kabushiki Kaisha

Hiroshi Tomii

Sumito Tanaka

Toshihisa Yago

Hidekazu Nakashio

An image forming apparatus includes an image forming unit including a photosensitive member, a light source, and a developing roller, and a controller configured to control the image forming unit to form a detection image, obtain density data regarding density levels in a plurality of areas in the detection image at a plurality of positions in a scanning direction in which the photosensitive member is scanned with the light from the light source, generate, based on the density data, a first image forming condition for forming a first test image and a second image forming condition for forming a second test image, the second image forming condition being different from the first image forming condition, and control the image forming unit to form the first test image and the second test image, respectively based on the first image forming condition and the second image forming condition.

Image forming apparatus for performing calibration to control a density unevenness

An information processing apparatus is configured to communicate with an image forming apparatus. The image forming apparatus includes a document feeder configured to convey, in order to read an original on an original tray, the original on the tray. The image forming apparatus is configured to form an image on a sheet based on a result of reading the original. The information processing apparatus includes an acquisition unit configured to acquire user instruction information about types of calibration selected from among a plurality of types of calibration for adjusting a quality of an image to be formed by the image forming apparatus; and a controller configured to determine test charts to be created by the image forming apparatus based on the user instruction information; receive an execution instruction that instructs to create the test charts in succession.

Image processing apparatus configured to instruct execution of calibration using test chart, and image forming apparatus configured to execute calibration using test chart

Image forming apparatus for correcting density unevenness in a scanning direction

In an image forming apparatus a controller receives user instruction information for printing a test chart, controls a printer to print the test chart on a sheet regardless of a result of reading mode selection, controls a display to display a screen for selecting a reading mode for reading the test chart among a plurality of reading modes, and controls a conveyance roller and a reading sensor to read the test chart on the sheet while conveying a stacked sheet in a case where a first reading mode is selected on the screen. The controller also controls the reading sensor to read the test chart on the sheet on a platen in a case where a second reading mode is selected on the screen, and controls density of the image to be printed by the printer based on a reading result of the test chart by the reading sensor.

Image forming apparatus having test chart printing control

An image forming apparatus includes a sensor configured to detect a length of a sheet, which is placed on a platen, in a predetermined direction and a controller. The controller is configured to convert an image signal based on a conversion condition, control the image forming unit to form an image based on the converted image signal, and execute calibration in which the conversion condition is generated. The controller is configured, in a case in which the calibration is to be executed, to acquire information related to a size of a sheet on which a test chart is to be formed, select a sheet based on the information, form the test chart on the selected sheet acquire reading data output from the reader, and generate the conversion condition based on the reading data.

Image forming apparatus

An image forming apparatus includes an image forming unit configured to form an image, a conveying unit configured to convey a sheet on which the image is formed, a reader configured to read the sheet conveyed by the conveying unit and a controller. The controller is configured to execute first calibration in which a density of an image to be formed by the image forming unit is controlled based on a result of reading by the reader, and execute second calibration in which a geometric characteristic of an image to be formed by the image forming unit is controlled based on a result of reading by the reader. The controller allows usage of a sheet of a first type in the first type of calibration, wherein the controller prevents usage of a sheet of a second type in the first type of calibration.

Image forming apparatus which accepts multiple types of test sheets for calibration of image density and geometric characteristics

An image forming apparatus includes a sensor configured to detect a length of a sheet, which is placed on a platen, in a predetermined direction and a controller. The controller is configured to convert an image signal based on a conversion condition, control the image forming unit to form an image based on the converted image signal, and execute calibration in which the conversion condition is generated. The controller is configured, in a case in which the calibration is to be executed, to acquire information related to a size of a sheet on which a test chart is to be formed, select a sheet based on the information, form the test chart on the selected sheet, acquire reading data output from the reader, and generate the conversion condition based on the reading data.

An image forming unit forms a toner image on an image carrier using toner. A transfer unit transfers the toner image to a sheet. A cleaner removes, from the image carrier, residual toner that was not transferred to the sheet by the transfer unit. In a detection mode for detecting a part of the image forming apparatus causing a streak, a controller may control the image forming unit to form a pattern on the image carrier, control the transfer unit so that the pattern passes through a transfer position without transferring the pattern to the sheet, control the cleaner to remove the pattern on the image carrier, and control the transfer unit to transfer a residual streak from the image carrier to the sheet. The residual streak occurs from the pattern image by causing an error of the cleaner.

Method for detecting fault location of image forming apparatus

A controller controls a charging unit to charge a photosensitive member so that a surface potential of the photosensitive member is controlled to a first potential, controls an exposure unit to expose the photosensitive member so that a potential of an exposure region on the photosensitive member is controlled to a second potential, controls a surface potential of a developing sleeve of a developing unit to a third potential, and forms a test image on a sheet by controlling the photosensitive member, the charging unit, the exposure unit, and the developing unit. An absolute value of the first potential is higher than an absolute value of the second potential. An absolute value of the third potential is higher than the absolute value of the first potential.

Image forming apparatus for detecting fault location

In an image forming apparatus including a reader that can read an original and a printer that can form an image on a sheet based on a read result of the reader, a controller can control the printer to form a test chart on the sheet and control the reader to read the test chart. The test chart is used for detecting a causal part of a streak that occurs when an image is formed by the printer. The test chart has a pattern for obscuring an image defect occurring when the test chart is formed by the printer.

Image forming apparatus for detecting causal part of streak occurring at time of image forming

A controller controls a first image forming unit and a second image forming unit to form a test image having a pattern. The test image is formed by the first image forming unit based on a first image forming condition in which an absolute value of a developing potential of a first developing sleeve is greater than an absolute value of a charging potential of a first photosensitive member. The pattern is formed by a second image forming unit based on a second image forming condition in which an absolute value of a developing potential of a second developing sleeve is smaller than an absolute value of a charging potential of a second photosensitive member. A controller controls a sensor to read the test image having the pattern.

In a case where a first mode, in which a reader reads test patterns while sheets are fed to the reader by a document feeder, is executed, an image forming apparatus forms a first test pattern on a first sheet and a second test pattern on a second sheet before the first test pattern on the first sheet placed on an original tray of the document feeder is read by the reader. In a case where a second mode, in which the reader reads the test patterns on the sheets without feeding the sheets by the document feeder is executed, the apparatus forms the second test pattern after a reading of the first test pattern on the first sheet is started by the reader.

Apparatus for reading image formed on sheet either fed from sheet feeder or placed on platen

An image forming apparatus includes a photosensitive member, a charging unit, an exposure unit, a developing unit, a transfer unit, and a controller configured to control the photosensitive member, the charging unit, the exposure unit, the developing unit, and the transfer unit to form a measurement image on the sheet, and acquire read data on the measurement image output from a reading device. The measurement image includes a first measurement image and a second measurement image. The controller forms the first measurement image based on a first image signal value and forms the second measurement image based on a second image signal value different from the first image signal value. The controller detects a streak included in the first measurement image or the second measurement image and determines an error based on a detection result.

Image forming apparatus and method for controlling image forming apparatus

An image forming apparatus includes an image forming portion configured to form an image on an intermediate transfer belt, a density sensor configured to measure a density of the image formed on the intermediate transfer belt, and a printer controller. On the intermediate transfer belt, a first test image and a third test image having different densities are alternately formed at different positions in a main scanning direction. At a position adjacent to the first test image in a sub-scanning direction, a second test image having a different density from that of the first test image is formed. At a position adjacent to the third test image in the sub-scanning direction, a fourth test image having a different density from that of the third test image is formed. The printer controller generates a gradation correction table based on a result of measurement of each test image by the density sensor.

Growing community of inventors

Kashiwa, Japan

Hiroshi Tomii