Canon Kabushiki Kaisha

Toshiki Nakayama

Mamoru Miyawaki

Kenji Suzuki

Akira Akashi

Isamu Ueno

Tatsuo Furukawa

Tomoaki Nakai

Yoichiro Maebashi

Seiji Uchiyama

Tomoyuki Okada

Hiroki Tezuka

Shiro Arikawa

An image of stabilized tint is output even if a supplied transfer medium is changed to a transfer medium of a different surface gloss or type of paper. If the supplied transfer medium has changed, the tint of a corrective image formed on the transfer medium is sensed, a tint correction of an image forming portion is performed based upon result of sensing, and corrective data of the tint correction and information relating to the transfer medium is stored. If a change of the transfer medium is sensed subsequently, a determination is made as to whether the transfer medium is substantially the same transfer medium, based upon the stored information relating to the transfer medium. If the transfer medium is substantially the same, then image processing is executed based upon the stored corrective data.

Color image forming apparatus and method of controlling same

A color image forming apparatus, when a white LED is made to emit light onto a color image so that the reflected light can be detected, changes a color measuring condition in adaptation to a reflectance predicted for the image from the forming condition of the color image to be detected. The amount of reflected light is detected by photodiodes, and the image forming condition is adjusted, based on the detected amount of reflected light of each color image. Thereby, irrespective of the reflectance of each color image, the color measurement of each color image is effected with good accuracy, and the hue and density of the color image to be detected are accurately detected, thereby to form a color image with excellent color reproduction.

Color image forming apparatus and color measurement controlling method therefor

An image forming apparatus has an image forming unit for forming an image on a recording medium; a conveying unit having a conveying part for conveying the recording medium while contacting the recording medium; a detection unit for detecting the chromaticity or the density of the image formed on the recording medium; and a control unit for controlling the image forming unit based on the chromaticity or the density of the image detected by the detection unit. The image forming unit forms an image for which the chromaticity or the density is to be detected at a predetermined position on the recording medium whereat the recording medium does not contact the conveying parts of the conveying unit. With this configuration, an image having a stable quality can be formed.

Image forming apparatus

An image forming apparatus is provided in which, by detecting an image formed on a recording medium, at least one of the density and chromaticity of the image can be properly controlled. The image forming apparatus includes an image forming unit for forming a toner image on an image carrier, a transfer unit for transferring the toner image formed by the image forming unit onto a transfer material in a transfer position, a fusing unit for fusing the toner image transferred by the transfer unit on the transfer material, a feed-direction changing unit for changing over a feed direction of the transfer material so that the transfer material having the toner image fused by the fusing unit is reversed and fed to the transfer position, a detecting unit for detecting, in a predetermined detecting position, the toner image fused on the transfer material by the fusing unit, and a control unit for controlling the image forming unit based on result detected by the detecting unit.

Image forming apparatus which performs image formation control based on the image after fixing

Disclosed are a shading correction method for a sensor capable of accurately detecting color tint of a toner patch without using any white-color reference to execute shading correction in the sensor, a shading correction apparatus for a sensor, and a color image forming apparatus. In the shading correction, light reflected by a rich K toner patch formed on a transferring material is detected, a shading correction value for the sensor is calculated based on detected data, and correction is executed using the shading correction value during operation for detecting a toner patch for color stabilization.

Shading correction method for a sensor, and color image forming apparatus

There is provided an image forming apparatus having good color reproductivity as well as a toner patch detection method, in which reflected light from a toner patch can be detected with a good S/N ratio based on a small quantity of light, and the color tint and density of the toner patch can be detected under limited time and a limited length of an intermediate transfer member or transfer material, without wasting the toner. A detecting operation of an accumulation type sensor for detecting a toner patch to be used for controlling at least one of density, tone reproduction and color tint of a toner image formed on a transfer material is controlled in accordance with a timing of detection by a synchronization circuit, of a toner patch for position detection formed on the transfer material.

Image forming apparatus and patch detection method

Image forming apparatus, communication controlling method and storage medium

In order to prevent variations in a power-supply voltage caused by a parasitic inductance, a series circuit including at least one resistance and at least one capacitance is provided adjacent to a switching circuit, between a high-voltage-side interconnection and a low-voltage-side interconnection of the power-supply voltage for the switching circuit.

Integrated semiconductor circuit with improved power supply control

A light emitting element drive apparatus includes a differential signal processing circuit for performing logic processing of input complementary image signals that are 180.degree. out of phase and at least one control signal using a differential circuit while maintaining the complementarity of signals to generate complementary output signals, and a switching circuit which is driven by the complementary output signals to supply a drive current to a light emitting element.

Light emitting element drive apparatus

This invention relates to a focus detecting apparatus using an area sensor as an AF sensor, and particularly provides a focus detecting apparatus in which when any area in a scene is designated and the focus state in that area is to be detected, the output from an area on the sensor corresponding to the designated area of the scene is read and processed on the basis of the information of an area on the area sensor corresponding to the designated area of the scene pre-memorized in a memory circuit.

Focus detecting apparatus having photoelectric area sensors

A photoelectric converter has photodetectors having plural arrays wherein plural photoreceiving elements are arranged for detecting incident light. The converter has a reading circuit for reading an output signal from the photodetector, the reading circuit having a detection circuit for detecting maximum and minimum signals from the plural photoreceiving elements of the photodetector. The photoelectric converter has at least three arrays arranged parallel to each other or substantially parallel to each other, and at least one array is arranged in a direction perpendicular to the at least three arrays. The reading circuit is arranged adjacent to the plural arrays, and the photodetectors and the reading circuit are provided on a common substrate.

Photoelectric converter with signal processing

A photoelectric sensor device has a two-dimensional arrangement of a multiplicity of unit structures each including a pixel. The sensor device includes a circuit for simultaneously designating a plurality of pixel blocks of any desired sizes at any desired positions on the two dimensional arrangement of unit structures, each pixel block being composed of pixels which are to be actually used. The sensor device also includes a monitor output circuit for outputting, for each of the pixel blocks, at least one monitor output as the representative of the amounts of charges accumulated in the pixels in each of the pixel blocks. The sensor device further includes a circuit which executes the control of accumulation of charges and the control of outputting of the image signals on each of the pixel blocks independently of other pixel blocks. Disclosed also is a focus detection system using the sensor device.

Photosensor device including means for designating a plurality of pixel

This invention relates to a focus detecting apparatus using an area sensor as an AF sensor, and particularly provides a focus detecting apparatus in which when any area in a scene is designated and the focus state in that area is to be detected, the output from an area on the sensor corresponding to the designated area of the scene is read and processed on the basis of the information of an area on the area sensor corresponding to the designated area of the scene pre-memorized In a memory circuit.

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Atsugi, Japan

Toshiki Nakayama