G03G15/20

Image forming apparatus and method for controlling same

Disclosed is an image forming apparatus including: a fixation unit configured to heat a toner image formed corresponding to image data and fix the heated toner image onto a recording material; and a control unit configured to determine a fixation target temperature used by the fixation unit to heat the toner image on the basis of the image data, wherein the control unit performs a first determination to calculate a first target temperature on the basis of image density information in each of a plurality of regions in which the image data is divided in a main-scanning direction and a sub-scanning direction and a second determination to determine whether the image data is a text image, and determines the fixation target temperature on the basis of results of the first determination and the second determination.

Fixing unit and image forming apparatus
11709446 · 2023-07-25 · ·

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.

IMAGE FORMING APPARATUS
20230022651 · 2023-01-26 ·

An image forming apparatus includes first and second image forming portions provided with first and second image bearing member, respectively. A controller controls a first operation in which the image to be transferred to the recording material is formed only in the first image forming portion, a second operation in which the image to be transferred is formed in the first and second image forming portions, and a supplying operation in which a lubricant is attached to the second image bearing member and supplied to a contacting portion of the second image bearing member. In a case that stopping time exceeds a predetermined threshold when a start instruction of the first operation is input in a stopping state of the first and second image bearing members, the controller controls to execute the supplying operation during from a current start instruction of the first operation is input until a next start instruction of the first or second operation is input.

IMAGE HEATER
20230229100 · 2023-07-20 ·

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.

IMAGE FORMING APPARATUS
20230229102 · 2023-07-20 ·

An image forming apparatus is disclosed. A fixing device includes a heating rotary member and a pressing rotary member. The fixing device further includes an acquisition means that acquires information about a printing medium for a predetermined number of sheets beforehand, and a temperature control means that controls a temperature of the heating rotary member based on the information about a basis weight acquired by the acquisition means. A job in which different basis weights are mixed is a mixed job. In a case where the mixed job is executed and the temperature of the heating rotary member is changed while the mixed job is executed, a change amount of the temperature of the heating rotary member is reduced based on the information about the basis weight of the printing medium acquired by the acquisition means.

FIXING APPARATUS

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.

HEATER CONTROL DEVICE AND IMAGE FORMING APPARATUS
20230229101 · 2023-07-20 · ·

A heater control device includes a triac connected in series between an alternating-current power supply and a heater, the triac including a first main electrode, a second main electrode, and a gate electrode; a phototriac coupler configured to transmit a heater trigger signal to the gate electrode of the triac; a first resistor and a second resistor each of which is connected in series to the phototriac coupler and configured to limit current in accordance with a phase control enable signal indicative of a period of phase control; and a resistor selection circuit configured to select one of the first resistor and the second resistor and connect the selected resistor to the second main electrode of the triac. The first resistor and the second resistor have different rated powers and different breakabilities from each other.

FIXING DEVICE AND IMAGE FORMING APPARATUS INCORPORATING SAME
20230229104 · 2023-07-20 ·

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.

CONNECTOR MEMBER
20230229103 · 2023-07-20 ·

A connector member connectable to a heating unit inside a heating roller of a fixing device includes a cover having a recess into which an end of a substrate of the heating unit in a first direction parallel to a rotation axis of the heating roller can be inserted, and an energizing terminal stored in the cover and including a contact portion on one side of the recess and to be in contact with a contact point on the substrate, and a connecting portion to which a conducting wire for receiving electric power is connected and located on the other side of the recess.

FIXING DEVICE AND IMAGE FORMING APPARATUS
20230229099 · 2023-07-20 ·

A fixing device includes a fixing film, a heater for heating the fixing film, a heater holder including a heater holding portion holding the heater, and a pressing roller forming a nip between itself and the fixing film to be heated by the heater. In the nip, a toner image carried on a recording material is fixed. The heater holder includes an opposing surface which is provided on a side upstream of the heater holding portion with respect to a recording material feeding direction and which opposes the pressing roller, a lubricant holding portion provided on the opposing surface, for supplying a lubricant to between the fixing film and the heater, and a projected portion provided on the side upstream of the heater holding portion with respect to the recording material feeding direction and projecting toward the pressing roller from the opposing surface.