Canon Kabushiki Kaisha

Kazuaki Ono

Akihiko Takeuchi

Koichi Tanigawa

Toshio Miyamoto

Hiroto Hasegawa

Hideo Nanataki

Hiroshi Sasame

Hideyuki Yano

Kimio Nakahata

Daigo Matsuura

Takayasu Yuminamochi

Minoru Matsuguma

Yasumasa Otsuka

Masayoshi Kachi

Hideo Nanatani

Masaharu Ohkubo

Yasumasa Ohtsuka

Hiroaki Sakai

Masanobu Tanaka

Hajime Motoyama

Katsuhiko Nishimura

Norio Hashimoto

Yasunari Kobaru

Shuji Moriya

An image forming apparatus includes a controller to execute a first mode for forming a toner image on a recording medium, in which a maximum toner carrying amount per unit area is a first maximum toner carrying amount, and a second mode for forming a toner image on the recording medium, in which the maximum toner carrying amount per unit is a second maximum toner carrying amount larger than the first maximum toner carrying amount. In the first mode, the controller sets a circumferential speed ratio of the toner bearing member against an image bearing member at a first circumferential speed ratio, and in the second mode the controller sets the circumferential speed ratio at a second circumferential speed ratio higher than the first circumferential speed ratio. The controller executes the second mode upon an order of the second mode by an operator.

Image forming apparatus with second mode rotating toner bearing member faster and larger second maximum toner carrying amount

Provided is an image forming apparatus including an image bearing member, a developing device, a bias applying portion, a driving portion, a transfer device, and a controller. In a case where the length of the recording material is a second length larger than a first length, the controller controls the speed ratio of the driving speed of the developer bearing member to the image bearing member to be a second speed ratio larger than a first speed ratio and controls the residual developer amount born per unit area of the developer bearing member after the developing of the electrostatic image becomes a second developer amount larger than a first developer amount.

Image forming apparatus

The present invention includes a compressor for generating compressed air for separating a sheet from a fixing portion. By using the compressed air generated by the compressor, an image forming portion, more specifically, for example, a charger, is cleaned.

A fixing apparatus that fixes a toner image on a sheet includes each of fans configured to respectively cool areas adjacent to a longitudinal center and longitudinal both ends of a pressure roller, and in a case where fixing processing is performed on thin paper of a maximum width size, includes a first mode in which the fixing processing is started after the fan configured to cool the area adjacent to the longitudinal center of the pressure roller is actuated for a predetermined time and a second mode in which the fixing processing is started after the fan configured to cool the area adjacent to the longitudinal both ends of the pressure roller is actuated for a predetermined time.

Fixing apparatus having cooling device for pressure roller

An image forming apparatuscapable of performingcan performan image forming operation together withtemperature rise by heating ofaheatfixingapparatusoperationto ensure a good fixability and ashortestshortfirst print out timeand to prevent loss ofwhile minimizingpower consumptionwithoutand not over-burdening a constitutional member of the image forming apparatus (e.g.,life-shorteningshortening the lifeof the constitutional member)is provided. The image forming apparatus includesan image forming unit anda fixingapparatusunitfor heat-fixing a toner image on a recording materialand a detection member for detecting a toner of a fixing apparatus member and performs simultaneously temperature rise by heating of the fixing apparatus and an image forming operation including a pre-process and an image forming sequence.In the image forming apparatus, a startA fixingtemperature ofthe pre-process and a start temperature of the image forming sequence with respect tothe fixingapparatus member areunit ismade variable depending on whether full-color image formationis performedor mono-color image formation is performed.

Image forming apparatus with change unit for changing temperature of fixing unit at time of actuating image forming unit

An image forming apparatus is provided which realizes an adequate operation of a paper dust removing device. The image forming apparatus has a storing portion which stores the likelihood that paper dust is produced upon previous image formation as previous paper dust production information according to the type of sheet. Further, the image forming apparatus has a CPU which adjusts paper dust removing performance upon current image formation to increase based on previous paper dust production information when the likelihood that paper dust is produced upon previous image formation is higher. Consequently, it is possible to realize an adequate paper dust removing operation of the paper dust removing device and prevent problems of images from occurring due to paper dust.

Image forming apparatus having paper dust removal device

An image heating apparatus includes an image heating rotational member configured to heat an image on a recording material, a pressure member configured to form a nip portion with the image heating rotational member and pinch the heated recording material in the nip portion, a first external heater including a first heat generation member and configured to contact an outer surface of the image heating rotational member and heat an area of the image heating rotational member that has passed the nip portion, and a second external heater including a second heat generation member and configured to contact an outer surface of the image heating rotational member and heat an area of the image heating rotational member heated by the first external heater. In the image heating apparatus, maximum power applied to the second heat generation member is smaller than maximum power applied to the first heat generation member.

Image heating apparatus

An image heating device includes: a rotatable heater for heating an image on a recording material; a pressor for pressing the heater to form a nip in which the recording material is to be nip-conveyed; a belt for heating and contacting the heater; a first member for heating the belt while pressing the belt against the heater; a second member, provided downstream of the first member with respect to a rotational direction of the heater, for heating the belt while pressing the belt against the heater; a first portion for heating the first member by energization; and a second portion for heating the second member by energization. Each of the first and second portions is supplied with power so that a maximum of the power supplied to the first means is smaller than that of the power supplied to the second portion.

Image heating device and image forming apparatus

An image forming apparatus includes: a device for forming a toner image on a sheet; a heater contacting and heating the toner image on the sheet; a detector for detecting a temperature of the heater a controller for controlling the heater to maintain the temperature of the heater at a target temperature based on an output of the detector; a selector for selecting a first mode continuously forming images on thin sheets, a second mode continuously forming images on thick sheets, and a third mode continuously forming images on the thin sheet and the thick sheet; and a setter for setting the target temperature based on the selected mode, wherein the target temperature in the second mode is higher than the target temperature in the first mode, and the target temperature in the third mode is higher than the target temperature in the second mode.

Image forming apparatus setting different target temperatures of an image heating device depending on the image forming modes

An image forming apparatus is constituted by a dark color image forming station for forming an image with such a toner of recording materials having the same hue and different lightness as has a lower lightness; a light color image forming station for forming an image with such a toner of the recording materials having the same hue and different lightness as has a higher lightness; and a control portion for effecting control so that an image to be emphasized by partly disappearing or by relatively and partly decreasing in density is formable substantially only with the toner having the higher lightness.

Image forming apparatus and image processing apparatus

An image forming apparatus capable of performing an image forming operation together with temperature rise by heating of a fixing apparatus to ensure a good fixability and a shortest first print out time and to prevent loss of power consumption without burdening a constitutional member of the image forming apparatus (e.g., life-shortening of the constitutional member) is provided. The image forming apparatus includes a fixing apparatus for heat-fixing a toner image on a recording material and a detection member for detecting a toner of a fixing apparatus member and performs simultaneously temperature rise by heating of the fixing apparatus and an image forming operation including a pre-process and an image forming sequence. In the image forming apparatus, a start temperature of the pre-process and a start temperature of the image forming sequence with respect to the fixing apparatus member are made variable depending on whether full-color image formation is performed or mono-color image formation is performed.

The image forming apparatus having a plurality of developing devices corresponding to a plurality of colors includes at least a predetermined color for developing an electrostatic image as toner images, an image bearing member bearing thereon the toner images developed by the plurality of developing devices, and a collecting device for collecting residual toners on the image bearing member after the toner images of the respective colors formed on the image bearing member have been respectively transferred onto a recording material. The collected toners with plural colors mixed together provide a pseudo-predetermined color, and a changing device capable of supplying the collected toners and the toner for the predetermined color to the developing device for the predetermined color, and changing the mixing ratio of the collected toners and the fresh toner for the predetermined color supplied to the developing device for the predetermined color, in conformity with the ratio of the toners of the respective colors constituting the toner of the pseudo predetermined color occupied in the collected toners.

Color image forming apparatus having toner recycling

An image heating device includes a movable belt for heating an image on a recording material; a supporting member, having an elastic layer, for supporting the belt, the supporting member having an outer diameter which is larger in a central portion than at opposite end portions; a pressing rotatable member, pressed toward the supporting member with the belt interposed therebetween, for forming the nip for nipping and feeding the recording material; and pressing means for supporting opposite end portions of the supporting member and for pressing the supporting member and the pressing rotatable member toward each other; wherein a surface hardness of the supporting member through the belt is smaller than a surface hardness of the pressing rotatable member, and the pressing roller has a straight configuration in a longitudinal cross-section.

Image heating apparatus and image forming apparatus

An image forming apparatus has a both-side image forming unit for forming images on both sides of a recording material; a rotatable belt for heating a toner image on a recording material through a belt; a rotatable supporting member, having an elastic layer, for supporting the belt; a rotatable pressing member, pressed toward the supporting member with the belt interposed therebetween, for forming the nip for nipping and feeding the recording material; the pressing member has a surface hardness which is larger than a surface hardness of the rotatable supporting member, wherein a surface hardness of the rotatable supporting member through the belt is different from a surface hardness of the pressing rotatable member by +4 degrees to &#x2212;8 degrees.

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Kashiwa, Japan

Kazuaki Ono