Brother Kogyo Kabushiki-Kaisha

Yasuhiro Maruyama

Tomoaki Hazeyama

Akihiro Kobayashi

Naoyuki Iwata

Yuji Nishigaki

Yusuke Murodate

Makoto Souda

Yuichi Ikeno

Masataka Maeda

Kei Ishida

Tomoaki Hattori

Kenjiro Nishiwaki

Takanori Uno

Mitsukiyo Okamura

Yuta Uchiyama

Selecting one conveyance mode from a plurality of conveyance modes includes a first selection process of selecting the one conveyance mode based on a detection temperature of a temperature sensor from a first time point at which rotation of a fixing rotator is started to a second time point at which a particular period elapses from the first time point. The first selection process includes: determining whether an initial temperature is higher than or equal to a first temperature, the initial temperature being a detection temperature of the temperature sensor when a print instruction is received; in response to determining that the initial temperature is lower than the first temperature, setting the particular period to a first period; and in response to determining that the initial temperature is higher than or equal to the first temperature, setting the particular period to a second period longer than the first period.

Image forming apparatus

A fixing device includes a heater, an endless belt, a holder, a temperature detector, and a partition sheet. The heater includes a substrate, and a resistance heating element provided on the substrate, and has a frontside surface and a backside surface opposite to the frontside surface. The endless belt is configured to rotate around the heater and has an inner peripheral surface in contact with the frontside surface of the heater. The holder holds the heater. The temperature detector is configured to detect a temperature of the heater and has a detection surface that detects a temperature. The partition sheet is located between the backside surface of the heater and the holder, and is in contact with the detection surface. A length of the partition sheet in a direction of conveyance of a recording material is longer than a length of the heater in the direction of conveyance.

Fixing device

A heating unit includes a heater including a substrate and a resistance heating element, a temperature sensor, an endless belt, a holder, a first heat conductive sheet located between the heater and the holder, and a second heat conductive sheet which is smaller than the first heat conductive heat member. The first heat conductive sheet includes a first heater-side surface which is in contact with a back surface of the heater and a first opposite surface. The first heat conductive sheet has a heat conductivity higher than that of the substrate. The second heat conductive sheet includes a second heater-side surface which is in contact with the first opposite surface and a second opposite surface. The temperature sensor is in contact with the second opposite surface of the second heat conductive sheet.

Heating unit for an image forming apparatus

A heating unit includes a heater including a substrate and a resistance heating element provided on the substrate, an endless belt configured to rotate around the heater, a thermostat configured to interrupt energization to the resistance heating element when the heater is abnormally increased in temperature, the thermostat having a heat sensitive surface and a heat-insulating member disposed between the thermostat and the heater. The heat-insulating member has a heat conductivity less than that of a material constituting the heat sensitive surface. The heat sensitive surface of the thermostat is in contact with the heat-insulating member.

Heating unit

An image forming apparatus includes a controller configured to identify a selected sheet size setting as defined by a dimension in the width direction and a dimension in the conveyance direction, set a cooling threshold at a first threshold if the selected sheet size setting is a first size having a dimension in the width direction larger than a predetermined dimension, and a dimension in the conveyance direction larger than the dimension in the width direction, and set the cooling threshold at a second threshold lower than the first threshold if the selected sheet size setting is a second size having a dimension in the width direction that is the same as the dimension in the width direction of the first size, and a dimension in the conveyance direction smaller than the dimension in the width direction.

Image forming apparatus having controller for setting cooling threshold according to sheet size

A heating unit includes a heater, a temperature sensor, an endless belt, a holder, a first heat conductive member, and a second heat conductive member. The first heat conductive member includes a first heater-side surface facing the heater, a first opposite surface, and an opening. The first heat conductive member has a heat conductivity higher than that of the substrate. The second heat conductive member includes a second heater-side surface facing the heater and a second opposite surface. The second heat conductive member is positioned at a position corresponding to the opening when viewed in an orthogonal direction orthogonal to the first opposite surface. The temperature sensor is in contact with the second opposite surface of the second heat conductive member.

A fixing device includes: an endless fusing belt; a heater; a nip member; and a backup member. The endless fusing belt has a width in a widthwise direction. The nip member is disposed spaced apart from the heater. The nip member has a contact surface. The contact surface has widthwise end portions in the widthwise direction. The backup member is configured to nip the fusing belt in cooperation with the nip member. The fusing belt is configured to move in a moving direction at a position where the fusing belt is nipped between the nip member and the backup member. The contact surface has at least two grooves one formed in corresponding one of the widthwise end portions and another formed in the other of the widthwise end portions and extending at an angle equal to or smaller than 10 degrees with respect to the moving direction.

Fixing device provided with nip member capable of preventing outflow of lubricant

A fixing device configured to thermally fix a developing agent image to a recording sheet includes a fixing belt having a tubular shape defining an inner space, a heat generating member and a nip plate which are disposed in the inner space, and a rotating member disposed outside the inner space. The nip plate includes a plate-shaped portion holding the fixing belt against the rotating member, and a bent portion located downstream of the plate-shaped portion in a conveying direction of the recording sheet and bent to define a recess facing away from the rotating member. The bent portion protrudes farther away from the heat generating member than the plate-shaped portion. A temperature sensor for sensing a temperature of the nip plate is fitted in the recess of the bent portion so as not to be displaced in the conveying direction.

Fixing device with temperature sensor fitted in a recess of a nip plate

An image forming apparatus includes a heat unit, a pressure roller, a temperature sensor, and a controller. The heat unit includes a heater and a heated member configured to be heated by the heater. The pressure roller is configured to rotate at a rotational speed while being in contact with the heated member upon receiving a driving force. The temperature sensor is configured to detect a temperature of the heat unit. The controller is configured to control the rotational speed of the pressure roller on a basis of: the temperature detected by the temperature sensor; and a parameter that causes temperature of the pressure roller to change.

Image forming apparatus configured to control rotational speed of pressure roller using temperature of heat unit and parameter

A fixing device may include an endless belt and a nip member in contact with an inner peripheral surface of the endless belt. The fixing device may further include a backup member that nips the endless belt together with the nip member. The fixing device may include a contact member disposed opposite the backup member with the nip member therebetween. The contact member may be in contact with the nip member. The contact member may include a first portion that extends across a width of a maximum image forming area and a second portion positioned outside the width of the maximum image forming area and inside a width of the nip in an axial direction of the endless belt. A heat transfer coefficient per unit dimension between the nip member and the second portion may be smaller than that between the nip member and the first portion.

A fixing device includes an endless belt, a backup roller, and a nip member having a first slide contact surface, a second slide contact surface, and a connecting surface connecting the first and second slide contact surfaces. A curvature radius of the second slide contact surface is greater than that of the backup roller in cross section perpendicular to an axis of the backup roller. The connecting surface is disposed between a first imaginary plane and a second imaginary plane, the first imaginary plane including an edge of the endless belt and extending perpendicularly to the axis of the backup roller, the second imaginary plane including an end of a maximum image area proximate to the edge of the endless belt and extending perpendicularly to the axis of the backup roller.

A fixing device includes an endless belt extending in a first direction and configured to rotate, a nip member extending in the first direction and disposed in contact with an inner surface of the endless belt, a backup member extending in the first direction and disposed in contact with an outer surface of the endless belt such that that the backup roller and the nip member sandwich the endless belt therebetween and the backup member and the endless belt form a nip therebetween, a first heating element extending along the endless belt in the first direction and configured to generate heat, and an inner surface guide disposed in contact with an end portion of the inner surface of the endless belt in the first direction and spaced apart from the nip in a second direction. The inner surface guide includes a second heating element configured to generate heat.

Heating elements for maintaining temperature of a fixing film in a fixing device and image forming apparatus

An image forming apparatus may include a main body having a surface. The main body may accommodate a photosensitive member disposed away from the surface and along a conveying path and a fuser. The fuser may be disposed downstream from the photosensitive member along the conveying path and have a portion disposed further away from the surface than the photosensitive member. The fuser may include an endless belt and a nip plate. The nip plate may include a first surface with lubricant thereon that faces an inner surface of the endless belt, and a second surface that extends from an end of the first surface. The second surface may be spaced apart from the inner surface of the endless belt and include a furthest downstream portion of the nip plate.

A fixing device includes an endless belt, a nip member having a contact surface that is in contact with the inner surface of the endless belt, a backup member configured to pinch the endless belt in conjunction with the nip member, an upstream guide disposed upstream of the nip portion in the rotating direction, and a regulating portion. The upstream guide and the nip member are disposed while a first gap is provided, in a conveying direction of the recording sheet, between a middle portion of the upstream guide and a middle portion of the nip member. The regulating portion and one of the upstream guide and the nip member are disposed while a second gap is provided therebetween in the conveying direction of the recording sheet. The second gap is smaller than the first gap in the conveying direction of the recording sheet.

A fixing device configured to thermally fix a developing agent image to a recording sheet includes a fixing belt having a tubular shape defining an inner space, a heat generating member, a nip member, and a stay which are disposed in the inner space of the fixing belt, and a rotating member disposed outside the inner space of the fixing belt. The fixing belt is nipped between the nip plate and the rotating member. The stay comprises a first receiving portion and a second receiving portion which are positioned upstream and downstream of the heat generating member, respectively, in a conveying direction of the recording sheet and are configured to receive a force exerted from the rotating member to the nip member. The heat insulator is disposed between the nip member and one of the first receiving portion and the second receiving portion of the stay.

Growing community of inventors

Kasugai, Japan

Yasuhiro Maruyama