Canon Kabushiki Kaisha

Naoto Tsuchihashi

Eiji Uekawa

Hiroshi Kataoka

Keisuke Mochizuki

Atsushi Iwasaki

Shuji Saito

Noriaki Sato

Hiroshi Hagiwara

Yohei Suzuki

Masafumi Monde

Yoshitaka Zaitsu

Takahiro Uchiyama

Hiromitsu Kumada

Yasutaka Yagi

Seiji Hara

Takayuki Mizuta

Yasuo Yoda

Yoshiki Kudo

Hiroshi Mano

Atsushi Ogata

Toshiaki Miyashiro

Tatsuaki Orihara

Hideki Ohta

Hideaki Yonekubo

Takeshi Kawamura

Hidetoshi Hanamoto

Toshikazu Tsuchiya

Yasunari Kobaru

Tadashi Okanishi

Jiro Moriya

Yoshisuke Kasuya

Daisuke Usami

An image forming apparatus includes a stack portion having recording materials, an image forming unit, a basis weight detection unit, an operating sound detection unit, and a mode selection unit. The basis weight detection unit detects a recording material basis weight based on an ultrasonic wave. The operating sound detection unit detect an abnormality of a generated operating sound. The mode selection unit selects, for each recording material fed to the image forming unit, between transmitting to the basis weight detection unit a first instruction for detecting the recording material basis weight and transmitting to the operating sound detection unit a second instruction for detecting the operating sound abnormality. In determining an interval at which each second instruction is transmitted, the mode selection unit determines the interval so that the interval and a cycle, in which properties of recording materials on the stack portion are repeated, do not continuously coincide.

Image forming apparatus

In an image heating device including a heater including a substrate, a first conductor provided on the substrate, a second conductor provided at a position different from the first conductor on the substrate in a direction orthogonal to a longitudinal direction of the substrate, and a plurality of heat-generating resistors, each having the same shape and electrically connected in parallel between the first conductor and the second conductor on the substrate and a plurality of temperature detection elements for detecting a temperature of the heater and heating an image formed on a recording material by the heater, the plurality of temperature detection elements includes at least two temperature detection elements whose relative positions with respect to the closest heat-generating resistor in the plurality of heat-generating resistors are the same, respectively, the closest heat-generating resistors corresponding to the at least two temperature detection elements are independently controlled.

Image heating device, image forming apparatus, and heater

A fixing unit includes a changing portion configured to change a state of a first rotary member and a second rotary member between a first pressurization state and a second pressurization state. A control portion is configured to control the driving source and the changing unit and capable of performing first control that causes the driving source to rotate the first rotary member and then stop the first rotary member, while continuing the first pressurization state from a last image forming operation, and second control that causes the changing portion to change the state of the first rotary member and the second rotary member from the first pressurization state to the second pressurization state.

An apparatus includes a control portion. When a toner image formed on a first recording material is fixed onto the first recording material by the fixing portion, and then an image is formed on a second recording material of which width is larger than that of the first recording material, the control portion can execute a cooling sequence to cool a non-passing region of the fixing portion through which the second recording material passes but the first recording material does not pass, before the toner image formed on the second recording material is fixed by the fixing portion. The control portion sets an execution condition to execute the cooling sequence in accordance with information on the toner image in the region of the second recording material corresponding to the non-passing region.

In a case where an image formed on a recording material includes a contiguous image portion formed across a plurality of heating regions at a given density, power supplied to a plurality of heating elements that heat the plurality of heating regions is controlled by correcting respective control heating amounts of the plurality of heating regions set in accordance with respective maximum densities of image regions resulting from dividing the image into the plurality of heating regions, so that a difference between a maximum value and a minimum value of the control heating amounts among the plurality of heating regions in which the image portion is heated from among the plurality of heating regions, lies within a predetermined range.

Image heating device and image forming apparatus

In an image heating apparatus for heating an image formed on a recording material, a target temperature of heat generating elements corresponding to regions without an image when a recording material passes a nip portion is set in accordance with a length of the regions without an image in a longitudinal direction of a heater.

Image heating apparatus

A fixing apparatus fixes a toner image on a recording material by conveying and heating the recording material at a nip portion, and includes a first rotating member, a second rotating member configured to form the nip portion with the first rotating member, the first and second rotating members being arranged such that rotation of the second rotating member causes rotation of the first rotating member, a frame configured to support the second rotating member, so as to be rotatable and an opening and closing part arranged to open and close relative to the frame on the downstream side of the nip portion in the conveyance direction of the recoding material, the opening and closing part having a duct through which air flows.

Fixing apparatus

A fixing device includes first and second members, a frame supporting the second member, and two pressure mechanisms provided on either end of the first member. The mechanism includes a lever having one end supported by the frame in a rotatable manner in a pressure direction, and a helical compression spring disposed between a first spring support provided on the other end of the lever and a second spring support on the frame. At least one of the first and second spring supports includes a first area and a second area closer to the spring in the axial direction than the first area, the first area is in contact with an area of the spring close to a winding end of the spring, and the second area is in contact with an area of the spring farther away from the winding end in a winding direction than the first area.

Fixing device

An image forming apparatus includes: a fixing portion for heat-fixing the image on a recording material; a duct including a suction port for sucking air from outside of the image forming apparatus and an exhaust port for delivering the air to the outside of the image forming apparatus; and a fan for forming a flow of the air from the suction port toward the exhaust port in the duct. The duct includes a merging portion, between the suction port and the exhaust port, for merging the air from the neighborhood of the fixing portion with the flow of the air by taking the air from the neighborhood of the fixing portion inside the duct. The recording material on which the image is fixed at the fixing portion is cooled by the air delivering through the exhaust port.

An image forming apparatus for forming a toner image on a recording material has an image forming unit configured to form the toner image on the recording material; a fixing unit configured to fix the toner image on the recording material while heating and conveying the recording material bearing the toner image at a nip portion, the fixing unit including a heating rotation member and a roller forming the nip portion with the heating rotation member; and a voltage applying unit configured to apply a potential difference between a surface of the heating rotation member and a surface of the roller, wherein a plurality of print modes different in conveyance speed of the recording material at the nip portion are carried out, and wherein the voltage applying unit applies the potential difference smaller in a first print mode than the potential difference in a second print mode.

A fixing device includes: a cylindrical film; a nip forming member; and a back-up member for forming a nip. The nip forming member includes a projected portion. The projection amount of the projected portion is smaller in an end portion region positioned at an end portion of the projected portion with respect to a generatrix direction of the film than in a central region positioned at a central portion of the projected portion with respect to the generatrix direction, at least a part of the end portion region being inside a feeding region of a maximum-sized recording material usable in the fixing device. With respect to the recording material feeding direction, the width of the part of the projected portion inside the nip is broader in the end portion region than in the central region.

Fixing device with back-up member and nip forming member including a projecting portion projecting toward the back-up member

A roller used for a fixing apparatus has: a core; a first elastic layer that is formed outside the core and includes a first tapered portion on an edge of the roller in an axis direction; and a second elastic layer that is formed outside the first elastic layer and includes a second tapered portion on the edge in the axis direction on the same side as the first elastic layer. The second elastic layer has a hardness that is higher than the hardness of the first elastic layer. A second start point, which is a start point of the second tapered portion, is set in a position closer to the center of the roller in the axis direction than a first start point, which is a start point of the first tapered portion.

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Yokohama, Japan

Naoto Tsuchihashi