A heating device includes a substrate, one or more heating elements arranged along the substrate, a heat conductor contacting the substrate, a plurality of thermometers each configured to measure a temperature of the heat conductor, and a plurality of thermostats each configured to measure a temperature of the heat conductor and interrupt electrical power supplied to the heating elements. The thermometers and the thermostats are alternately arranged in a longitudinal direction of the substrate.

An image heating apparatus includes a first rotary member, a second rotary member, a frame member, a guide portion, and a cover. The first rotary member is configured to heat a toner image formed on a recording material. The second rotary member is configured to contact the first rotary member and form a fixing nip portion with the first rotary member. The frame member is configured to support the first rotary member and the second rotary member. The guide portion is configured to guide the first rotary member to be moved upstream in a conveyance direction of the recording material when the first rotary member is being removed. The cover is attached to the frame member and configured to turn around a rotation shaft to open and close the guide portion. The cover is configured to turn in a direction toward the conveyance direction to open the guide portion.

Provided is an image heating apparatus comprising: a first rotating member; a second rotating member that forms a nip with the first rotating member so as to nip the recording material therebetween; a heater that heats the nip; a conductive sheet member that is disposed so as to overlap with a part of the heater; and a restricting member that restricts relative positions between the sheet member and the heater. The restricting member is configured so as to restrict a relative movement between the sheet member and the heater in a first direction, which is a direction where the sheet member overlaps with a part of the heater, and to allow the relative movement in a second direction which is perpendicular to the first direction. A reinforcing land, that joins the heater and the sheet member, is disposed in a position that is electrically isolated.

A fixing unit includes a first heater, a first switch, a second heater, and a second switch. In an image forming mode, a controller controls the first switch and the second switch to keep a temperature of the fixing unit at a fixing temperature serving as a target temperature for fixing the image on the sheet. In a standby mode, the controller controls the first and second switches to keep the temperature of the fixing unit at a standby temperature, and controls the first and second switches such that a period in which a first current is supplied to the first heater and a period in which a second current is supplied to the second heater do not overlap.

A controller obtains a first duty cycle of a first current to be supplied to a first heater and a second duty cycle of a second current to be supplied to a second heater and controls the first switch and the second switch after the reduction control period, such that the temperature of a fixing unit maintains a target temperature for fixing the image by the fixing unit.

In a caser where a first current is supplied to a first heater, a controller gradually increases the first current in a first period, supplies the first current based on a first duty cycle in a second period, and gradually reduces the first current to stop supplying the first current in a third period. In a case where a second current is supplied to a second heater, the controller gradually increases the second current in a fourth period, supply the second current based on a second duty cycle in a fifth period, and gradually reduces the second current to stop supplying the second current in a sixth period. The controller controls the supply of the second current such that part of the fourth period overlaps with the third period.

A fixing unit includes a tubular film, a pressure roller, a heater including a first heating element and a second heating element, a detector configured to detect a temperature of the heater, a switcher configured to switch which of the first heating element and the second heating element is supplied power from a power supply, and a controller configured to control the switcher. The controller is configured to execute a first control of determining a first electric energy and a second electric energy based on the temperature of the heater detected by the detector and a target temperature of the heater, and a second control of causing the switcher to switch between a state in which power is supplied to the first heating element by the first electric energy and a state in which power is supplied to the second heating element by the second electric energy.

An image heating device includes a conveyance belt having a heat generation layer, and a first electrode portion, a second electrode portion and a third electrode portion that are in contact with the heat generation layer. The conveyance belt conveys a recording medium that includes an image. A first heat generation region formed on the conveyance belt between the first electrode portion and the second electrode portion generates heat to a first temperature that is equal to or greater than a deformation temperature at which a material forming the image is deformable. A second heat generation region formed between the second electrode portion and the third electrode portion generates heat to a second temperature that is different from the first temperature. The first heat generation region and the second heat generation region are located in a region of the conveyance belt to contact the recording medium.

A fixing apparatus includes a fixing belt that is rotatable and endless, a pad, a pressing rotary member, and a scraping member. The pad contacts an inner circumferential surface of the fixing belt. The pressing rotary member contacts the pad via the fixing belt to form a nip portion. In cooperation with the fixing belt, the pressing rotary member fixes a toner image to a recording material by applying heat and pressure to the recording material at the nip portion. A lubricant is applied to the inner circumferential surface of the fixing belt. The scraping member includes an inclined portion inclined downward toward an outer side of the fixing belt and contacting an edge portion of the fixing belt to scrape the lubricant. The inclined portion is in contact with the edge portion of the fixing belt in an area where an outer surface of the fixing belt faces upward.

A fixing device includes a fixing rotator, a pressure rotator, a heater inside the fixing rotator, a reflector, and a sliding member. The pressure rotator is in contact with the fixing rotator to form a nip and presses a recording medium passing through the nip. The reflector includes a reflecting portion that reflects radiant heat radiated by the heater toward an inner circumferential surface of the fixing rotator and a pressure receiving portion that receives a pressing force of the pressure rotator via the fixing rotator. The pressure receiving portion is thermally coupled to the reflecting portion. The sliding member is between the pressure receiving portion and the fixing rotator and in contact with the pressure receiving portion and the fixing rotator. With respect to the inner circumferential surface of the fixing rotator, the sliding member has a smaller friction coefficient than a surface of the pressure receiving portion.