Canon Kabushiki Kaisha

Tohru Saito

Shinji Hashiguchi

Masahiro Suzuki

Masashi Tanaka

Akihiko Uchiyama

Eiji Uekawa

Atsutoshi Ando

Osamu Nagasaki

Koichi Suzuki

Hideo Nanataki

Takehiko Suzuki

Tomoo Akizuki

Kenta Kamikura

Tomoaki Nakai

Yoshiro Saito

Atsuyoshi Abe

Keisuke Mochizuki

Tetsuya Sano

Hisashi Nakahara

Jun Asami

Masato Sako

Shoichiro Ikegami

Yuzo Seino

Hideaki Yonekubo

Go Shindo

Takahiro Endo

Jun Haruna

Hirokazu Okugawa

Shinobu Akama

In an image forming apparatus, a fixing member has a surface layer having conductivity. A developer is a toner having a toner particle including a binder resin, a reactant of a polyhydric acid and a compound containing a group 4 element is present on a surface of the toner particle, and Tv/Fv&#x3e;100 is satisfied where Tv represents a volume resistivity upon being unfixed, and Fv represents a volume resistivity after fixing. A bias applying unit can selectively apply a bias of a positive polarity and a bias of a negative polarity, and applies a bias of the same polarity as the charged polarity of a filler included in a recording material when the recording material passes through a fixing nip portion, and when the recording material does not pass through the fixing nip portion, respectively.

Image forming apparatus

An image heating apparatus includes an endless film, a pressing member forming a nip portion together with the film, and a film holding member provided at a longitudinal end portion of the film. The film holding member includes a movable member including a restriction surface configured to restrict a longitudinal movement of the film and a guide surface configured to guide a rotation of the film, the guide surface including a lubricant application unit. The film holding member further includes a biased member supporting the movable member and including a force reception portion, and is configured to cause the movable member to move upstream in a conveyance direction of the recording material at the nip portion relative to the biased member and cause the lubricant application unit to abut against an inner peripheral surface of the fixing film, when the movable member moves longitudinally.

Image heating apparatus

An image forming apparatus includes an image forming portion, a first fixing member, and a second fixing member that forms a nip with the first fixing member. An air blowing device blows air for cooling an end portion region of at least one of the first and second fixing members with respect to a longitudinal direction, perpendicular to a recording material feeding direction, in the nip. In addition, a controller capable of selecting one of an operation in a first mode, in which cooling of the end portion region by the air blowing device is carried out depending on a recording material size, with respect to a widthwise direction of the recording material, and an operation in a second mode, in which the cooling is carried out depending on a size of a print region of the image, with respect to a direction perpendicular to the recording material feeding direction.

Image forming apparatus and fixing device that control an air blowing device based on one of a recording material size and a size of a print region of an image

A control portion has a conversion portion that converts image data to be used for forming a recorded image by using either a first conversion condition which has been set such as to obtain a first gradation characteristic in the image to be formed on the recording material when a first image forming operation is executed or a second conversion condition which has been set such as to obtain a second gradation characteristic, which is different from the first gradation characteristic, in the image when a second image forming operation is executed, a peripheral velocity ratio between an image bearing member and a developer bearing member being larger during the second image forming operation than during the first image forming operation, and enables the first image forming operation or the second image forming operation to be performed on the basis of converted image data.

Image forming apparatus with controllable velocity ratio between image and developer bearing members

The image heating apparatus includes an endless belt, a roller which contacts an outer face of the belt, and a nip portion forming unit which contacts an inner face of the belt, and forms a nip portion with the roller, for nipping and conveying a recording material. The nip portion forming unit includes a component which is longer than the belt in a generatrix direction of the belt. The apparatus also includes a regulation portion provided to oppose an end face of the belt, for regulating a shift movement of the belt to the generatrix direction of the belt. The regulation portion is integrally-molded with the component. As a result, damage of the end of the endless belt can be reduced.

Image heating apparatus regulating a shift movement of an endless belt the inner face of which contacts a nip portion forming unit forming a nip portion with a roller contacting an outer face of the belt

An image heating device includes an endless belt including a base layer and an elastic layer formed around the base layer, a contact member contacting an inner surface of the endless belt, a pressure rotating member forming a nip portion configured to convey a recording material while nipping the recording material along with the contact member via the endless belt, wherein an image formed on the recording material is heated at the nip portion using heat from the endless belt, and wherein one end of the endless belt is coated with the elastic layer and the other end of the endless belt is not coated with the elastic layer, and a belt lateral shifting direction regulating mechanism configured to regulate a direction in which the endless belt shifts when the endless belt is rotated, toward the end coated with the elastic layer.

Image heating device with a belt lateral shifting direction regulating mechanism

An image forming system includes an image forming apparatus including a heating fixing portion and a host computer capable of instructing printing. In the image forming apparatus, throughput can be changed and discriminated in accordance with a printing number. For printing on small size sheets, the system is operable in a normal small size sheet mode and in a high speed small size sheet output mode, in which the printing is effected at a throughput which is higher than that in the normal small size sheet mode and, after completion of the printing, the image forming apparatus rests for a predetermined rest period. The host computer includes a mode selector for selecting a mode from the high speed small size sheet output mode and the normal small size sheet mode, and a controller for transmitting the mode selected by the mode selector to the image forming apparatus.

Image forming system and apparatus with different printing modes for different numbers of printing sheets

The heat fixing apparatus includes a fixing heater and a pressure roller. The fixing heater has a plurality of resistance-type heat generation layers which are different in heat distribution in the longitudinal direction perpendicular to the direction of conveying a recording material. The recording material P is heated when passed through a fixing nip portion formed between the fixing heater and the pressure roller. The pressurization conditions between the fixing heater and the pressure roller can be changed. The heat fixing apparatus includes a fixing member which adjusts the lengthwise heat distribution of the fixing heater by changing the applied current proportion of the plurality of resistance-type heat generation layers according to the pressurization conditions between the fixing heater and the pressure roller.

Heat fixing apparatus

An image forming apparatus includes a high-voltage power supply having a piezoelectric transformer. The power supply includes a positive output voltage generation circuit and a negative output voltage generation circuit. Each of the positive output voltage generation circuit and the negative output voltage generation circuit includes a piezoelectric transformer, a piezoelectric transformer driving circuit, an output voltage detection circuit, and a drive control circuit for outputting a control signal for controlling the piezoelectric transformer driving circuit using a signal from the output voltage detection circuit and an output voltage setting signal for setting an output voltage. The positive output voltage generation circuit and the negative output voltage generation circuit are simultaneously turned on when the output polarity of the high-voltage power supply with a piezoelectric transformer is switched.

Image forming apparatus and power supply

A piezoelectric-transformer high-voltage power supply in combination with an image-forming apparatus including a latent-image forming section configured to form an electrostatic latent image on an image carrier, a developing section configured to form a toner image on the electrostatic latent image, and a transfer section configured to transfer the toner image onto a transfer material includes a piezoelectric transformer; a piezoelectric-transformer drive circuit; an output-voltage setting-signal output circuit configured to output an output-voltage setting-signal; an output-voltage detector circuit, and a drive control circuit configured to output a control signal on the basis of a signal from the output-voltage detector circuit and the output-voltage setting-signal, for controlling the piezoelectric-transformer drive circuit. The output-voltage setting-signal output circuit outputs an output-voltage setting-signal corresponding to a voltage lower than a target voltage and, then, another output-voltage setting-signal corresponding to the target voltage.

Image forming apparatus utilizing a piezoelectric-transformer high-voltage power supply and method for controlling the same

An update value for updating a count value is changed in accordance with the time interval of activations of a fixing unit. Every time the fixing unit is activated, the count value is updated in accordance with the update value. The target temperature of the heater of the first rotary body is set in accordance with the updated count value to control the temperature of the fixing unit.

Image forming apparatus with time interval control of fixing unit and control method therefor

An image heating apparatus has a heat generating element with an electroconductive portion; a magnetic flux generating unit for generating a magnetic flux, wherein the magnetic flux generated by the magnetic flux generating unit produces eddy current in the heat generating element to heat the heat generating element; a back-up member cooperating with the heat generating element to form a nip therebetween, wherein the nip feeds a recording material carrying an image; a pressing member for applying pressure to the nip; a holding member of metal for holding a pressure by the pressing member; and a shield member provided between the magnetic flux generating unit and the holding member, for shielding magnetic.

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Mishima, Japan

Tohru Saito