Canon Kabushiki Kaisha

Yoichiro Maebashi

Hiroshi Kita

Tomoaki Nakai

Tatsuya Kobayashi

Hiroshi Sasame

Hiroki Tezuka

Tetsuya Kobayashi

Akihiko Uchiyama

Yoshiro Saito

Naoki Enomoto

Haruo Fujii

Kazushi Suzuki

Takeshi Sugita

Tamotsu Kaneko

Hisahiro Saito

Shinji Katagiri

Toshiaki Miyashiro

Takaaki Tsuruya

Yuki Nishizawa

Takao Aoki

Satoshi Shimizu

Kenichi Iida

Takehiko Suzuki

Masaki Ojima

Takashi Kawana

Hiroyuki Yamazaki

Toshihiko Ochiai

Hideki Anayama

Koichi Hiroshima

Seiji Uchiyama

Shinichi Tsukida

Jun Suzuki

Tatsunori Ishiyama

Kimitaka Ichinose

Toshiki Nakayama

Takashi Shibuya

Yasuo Yoda

Hiroshi Kawaguchi

Motoi Kato

Tatsuhiko Hayakawa

An image forming apparatus is capable of being attached with a toner supply container. The toner supply container stores a toner that is to be supplied to a developing portion. An attachment location of the toner supply container is below a light scanning portion in a vertical direction.

Image forming apparatus

A structure for a transport path for a recording material within a transfer portion varies between a margin-less print mode and a normal print mode. A necessity of cleaning of a transfer member also varies between both modes. Thus, provided is an image forming apparatus in which the structure of the transfer portion is switched between the normal print and the margin-less print, and the margin-less print cannot be carried out with a structure of the transfer portion for the normal print. This is because, when the so-called margin-less print is carried out with the structure of the transfer portion for the normal print, there is a possibility that an image defect of a print image to be outputted is caused, or a stain of toner on a rear surface of the recording material is caused.

An image forming apparatus of this invention includes an image forming position correction unit which corrects an inclination or curve of an image in the main scanning direction by converting coordinates designating pixel positions of a bitmap image in the sub-scanning direction. It is discriminated whether image formation is normal image formation or formation of the toner image for detection by an image forming condition correction unit. Based on the discrimination result, the image forming apparatus is controlled so as to correct the image forming position by using the image forming position correction unit in a case in which the image formation is discriminated as the normal image formation, but so as not to correct the image forming position by using the image forming position correction unit in a case in which the image formation is discriminated as formation of the toner image for detection.

Image forming apparatus and method of controlling the same to correct image forming position in an amount smaller than one pixel

A color image forming apparatus includes a density sensor which detects the light reflecting characteristics of an unfixed toner image formed on an image carrier or a transfer material carrier, and a color sensor which detects the light reflecting characteristics of the fixed toner image formed on a transfer material. A test image is formed on the transfer material in accordance with the detection result of the density sensor, and a density control process of controlling image forming conditions is controlled to be executed in accordance with a detection result of detecting the test image by the color sensor.

Color image forming apparatus and control method therefor

An image forming apparatus includes a coordinate converter that corrects an image position in one pixel unit by converting a coordinate, a gradation value converter that corrects the image position in less-than-one pixel unit by converting a gradation value, an image outputting unit that forms a detection toner image including an intermediate gradation pixel onto an image bearing member that can bear a toner image, and a light reflection characteristic detector that detects a light reflection characteristic of the detection toner image. The gradation value converter is adjusted in accordance with a detection output of the light reflection characteristic detector.

An image forming apparatus includes an image forming unit adapted to form images of a plurality of colors in a manner in which a predetermined pattern of a predetermined color is registered thereon and superimpose those images to form a color image, a controller configured to control the image forming unit so as to form a patch image of each color for density detection, and a detector configured to detect the density of each of the patch images. The controller controls the image forming unit so as to superimpose the predetermined pattern of the predetermined color upon the patch image of a predetermined color and not to superimpose the predetermined pattern of the predetermined color upon the patch images of the other colors.

Image forming apparatus employing a forgery discrimination pattern

In an image forming apparatus using an optical sensor for detecting light reflection characteristics of a toner image fixed on a transfer material, occurrence of gloss unevenness in a printed image can be prevented. The image forming apparatus includes a first transfer material conveying path for normal printing, a second transfer material conveying path for image density control, a sensor contact member integral with the optical sensor and a transfer material supporting member contacting a transfer material rear surface in a position opposing the sensor contact member. At the time of normal printing, the sensor contact member and the transfer material supporting member are disposed in a spaced position against the transfer material, and at the time of image density control, the sensor contact member or the transfer material supporting member moves so that the sensor contact member and the transfer material supporting member contact the transfer material.

Image forming apparatus with transfer material regulating members

Provided are a method of making correction for color sensor output values in color image forming apparatus, which succeeds in improving color reproducibility of the color image forming apparatus, and the color image forming apparatus provided with the method. For this purpose, the apparatus and method according to the present invention make correction for deviation due to a color detecting device, of a color sensor output value Sin detection of a fixed patch; set a boundary turning point D between an ignorable region of toner bearing amounts where the influence of a color of a transferring material is ignorable on chromaticity of the patch and an unignorable region of toner bearing amounts where the influence is unignorable; make further correction for a corrected value S'after the correction for the deviation due to the color detecting device, using different methods for the unignorable region and the ignorable region, thereby to eliminate the influence of the color of the transferring material on the chromaticity of the patch.

Method of making correction for color sensor output values in color image forming apparatus, and color image forming apparatus

A color image forming apparatus and related method forms a color image on a transfer material. The apparatus is provided with a first optical sensor capable of detecting optical reflection characteristics of an unfixed toner image and a second optical sensor capable of detecting optical reflection characteristics of a toner image after fixation. A first forming step forms a mixed-color toner image including plural toners. A calculation step calculates, based on optical reflection characteristics of the mixed-color toner image detected by the second optical sensor, a condition that the mixed-color toner image becomes achromatic. A second forming step forms a toner image corresponding to the calculated toner mixing ratio. A processing step processes an output of the first optical sensor based on the optical reflection characteristics of the monochromatic toner image detected by the first optical sensor.

An image forming apparatus includes a movable image bearing member, a movable intermediary transfer member, wherein an image on the image bearing member is transferred onto the intermediary transfer member by primary transfer and the image transferred onto the intermediary transfer member is transferred onto a transfer material by secondary transfer, a discriminator for discriminating a kind of the transfer material, and a controller for controlling a moving speed ratio between the image bearing member and the intermediary transfer member on the basis of an output of the discriminator.

Image forming apparatus with control feature based on transfer material discrimination

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

A color image forming apparatus includes a first density detecting unit for detecting a density of a first detection toner image formed on an image bearing member or a transferring material carrying member, and a second density detecting unit for detecting a density of a second detection toner image fixed onto a transferring material, and executes image density control based on a detection result of the first density detecting unit and a detection result of the second density detecting unit. A detecting light application position of the first density detecting unit and a detection light application position of the second density detecting unit are almost equal relative to a perpendicular direction to a transferring material conveying direction. It is thereby possible to shorten time required for density control and to prevent deterioration of density control accuracy caused by a temporal change and a positional change in the density of a detection toner patch.

Color image forming apparatus and method for controlling the same

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Tokyo, Japan

Yoichiro Maebashi