Canon Kabushiki Kaisha

Shizuma Nishimura

Tomoaki Nakai

Masaki Shimomura

Tomonori Sato

Michio Uchida

Shinji Hashiguchi

Hideaki Yonekubo

Tomoyuki Makihira

Akira Kuroda

Mahito Yoshioka

Yuki Nishizawa

Munehito Kurata

Koji Nihonyanagi

Hiroyuki Sakakibara

Masahide Hirai

Seiji Obata

Seiji Inada

Takashi Honke

Koji Uchiyama

Yoji Oya

Hisahiro Saito

Osamu Sotome

A flange member is adapted such that a first distance between a first position at which a part thereof on an upstream side in a recording material conveyance direction comes into contact with a film inner surface and a nip center that is an intersection of a first virtual line and a second virtual line is longer than a second distance between a second position at which a region of an outer surface of the flange member facing the film inner surface intersects the first virtual line and the nip center, and a film guide is adapted such that a third distance between a third position that faces the film inner surface on the upstream side and the nip center is longer than a fourth distance between a fourth position that faces the film inner surface on the downstream side and the nip center on the first virtual line.

Image heating device and image forming apparatus

An image heating device heats up an image formed on a recording material, the device having: a heating member provided with a heater having a plurality of heating elements juxtaposed in a direction perpendicular to a conveyance direction of the recording material; a roller, such that the circumference of the roller increases from a central portion towards ends portions, in a direction perpendicular to the conveyance direction; and a control portion that controls individually the power supplied to the plurality of heating elements. The control portion sets a control target temperature, being set in order to supply power to a heating element corresponding to a non-sheet passing area, from among the plurality of heating elements, to be higher than a lowest control target temperature from among control target temperatures that are set in order to supply power to a heating element corresponding to a sheet passing area.

A controller is configured to execute a larger gamut technology mode in which the controller performs image formation by controlling a ratio of a rotation speed of a development roller to a rotation speed of a photosensitive drum such that the ratio becomes a second speed ratio higher than a first speed ratio in a normal mode. The controller is configured to, when the controller executes the larger gamut technology mode, control transfer voltage based on a humidity around an image forming apparatus.

Image forming apparatus

An image forming apparatus includes: an image forming unit configured to form an image on a sheet based on original image data; a selection unit configured to determine a non-image region of the sheet to which toner does not attach in a formation of the image by the image forming unit based on the original image data, and select, from the non-image region, a determination region depending on an image defect to be detected; a reading unit configured to read a surface of the sheet; and a control unit configured to obtain read image data by causing the reading unit to read the determination region after the image forming unit has formed the image, and perform detection processing for detecting whether the image defect has occurred based on the read image data.

Image forming apparatus that detects occurrence of image defect

Image forming apparatus to reduce deterioration of transferability

An image forming apparatus for forming a toner image on a sheet includes a main assembly, an image forming station provided in the main assembly and configured to form a toner image on the sheet, and a fixing portion provided in the main assembly and configured to fix the toner image formed on the sheet, on the sheet, the fixing portion including a fixing rotatable member and a covering member covering the rotatable member. The image forming apparatus also includes a suction mechanism including a duct connected with an opening provided in the covering member, and a fan configured to suck air inside the covering member through the duct. The air sucked by the suction mechanism is discharged into a space in the main assembly other than a space through which the sheet passes.

Image forming apparatus that discharges air to a space in a main assembly

An image heating apparatus for heating an image formed on a recording material includes a tubular rotary member including a conductive layer, a magnetic core inserted into a hollow portion of the rotary member, a coil helically wound around an outer side of the magnetic core in the hollow portion, and a control unit configured to control a frequency of an alternating current flowing through the coil, in which the conductive layer generates heat by an electromagnetic induction in an alternating magnetic field formed when the alternating current flows through the coil, and the control unit controls the frequency in accordance with a size of the recording material.

Image heating apparatus

A fixing apparatus for fixing a toner image on a recording material while conveying and heating, at a nip portion, the recoding material on which the toner image has been formed, the fixing apparatus including a rotary member including a conductive layer, a helical coil provided inside the rotary member, a helical axis of the helical coil extending in a generatrix direction of the rotary member, a magnetic core provided inside the helical coil, the magnetic core having a shape that does not form a loop outside the conductive layer, and a back-up member forming a nip portion together with the rotary member. In the generatrix direction, when winding pitches of the helical coil in a middle area, in end-portion areas, and in intermediate areas that are areas between the middle area and the end-portion areas are X, Y, and Z, respectively, then Y&#x3c;X&#x3c;Z is satisfied.

Fixing apparatus

A fixing device includes: a rotatable member including an electroconductive layer; a helical coil having a helical axis direction along a generatrix direction of the rotatable member; a magnetic member not forming a loop outside the electroconductive layer; a frequency setting portion for setting a frequency of an AC current caused to flow through the coil; and a temperature detecting portion for detecting a temperature of the rotatable member, including a first temperature detecting member and a second temperature detecting member. The electroconductive layer generates heat through electromagnetic induction heating by magnetic flux resulting from the AC current, and an image is fixed on a recording material by heat of the rotatable member. The frequency setting portion sets the frequency depending on a value of a difference between a detection temperature of the first temperature detecting member and a detection temperature of the second temperature detecting member.

Heat-fixing device

An image heating apparatus, to heat an image formed on a recording material includes a cylindrical rotatable member having a conductive layer, a coil having a helically shaped portion which is helically wound in a generatrix direction of the rotatable member inside the rotatable member, and a magnetic core disposed inside the helically shaped portion. The coil, which includes a number of turns, produces an alternating magnetic field to cause the conductive layer to generate heat by electromagnetic induction. The magnetic core includes a plurality of divided cores into which the magnetic core is divided in the generatrix direction. The number of turns of the coil per unit length, at a region that corresponds to a boundary between the plurality of divided cores, is larger than the number of turns of the coil at a region that corresponds to the plurality of divided cores.

An image heating apparatus, which is configured to heat an image formed on a recording material, includes a cylindrical rotatable member including a conductive layer, and a coil including a helically shaped portion helically wound along a generatrix direction of the rotatable member inside the rotatable member. The coil is configured to produce an alternating magnetic field for causing the conductive layer to generate heat by electromagnetic induction. The image heating apparatus further includes a magnetic core disposed in the helically shaped portion. The magnetic core includes a plurality of divided cores into which the magnetic core is divided in the generatrix direction. The number of turns of the coil per unit length at a region that corresponds to a boundary between the divided cores is larger than the number of turns of the coil at a region that does not correspond to the boundary.

An image heating apparatus for heating an image formed on a recording material includes a heating device which heats the image formed on the recording material, and a pressure roller which forms a nip portion in cooperation with the heating device, with the recording material being conveyed in the nip portion. The pressure roller has a heat resistive rubber in which acicular fillers with a thermal conductivity of more than 300 W/mK are dispersed in a rate of 12 to 26 volume percentage. An image heating apparatus is achieved which prevents increasing the temperature at the area through which a recording material does not pass.

Growing community of inventors

Suntou-gun, Japan

Shizuma Nishimura