Brother Kogyo Kabushiki-kaisha

Sadaharu Kato

Yusuke Mizuno

Tokifumi Tanaka

Hirotaka Imaeda

Tomonori Watanabe

Fumitake Tajiri

Shunsuke Ueki

Kazuna Taguchi

Shintaro Sakaguchi

Shuhei Fukue

Mingguang Zhang

Shuya Ichikawa

In an image-forming apparatus, a controller is configured to perform: in a case where the controller performs forming a multicolor image on a sheet: bringing, in response to a temperature of a fixing device reaching a first temperature lower than a fixing temperature, first and second developing rollers into contact with first and second photosensitive drums; and feeding, after a first period of time elapses from a time when the temperature of the fixing device reaches the first temperature, a sheet from a sheet tray toward the belt using a pickup roller. The controller is configured to further perform: in a case where the controller performs forming a single-color image on the sheet: bringing, after a second period of time elapses from the time when the temperature of the fixing device reaches the first temperature, the second developing roller into contact with the second photosensitive drum; and the feeding.

Image-forming apparatus provided with photosensitive drums, developing rollers and fixing device and forming both multicolor image and single-color image preliminary

An image forming apparatus includes a first fixing member, a second fixing member, a heater, a switching mechanism capable of switching a nip state of the first fixing member and the second fixing member between (i) a first nip state in which the belt is nipped between each of the first nip forming member and the second nip forming member, and the first fixing member, and (ii) a second nip state in which the belt is nipped between the first nip forming member and the first fixing member in a state in which the belt is not nipped between the second nip forming member and the first fixing member, and a controller configured to switch the nip state from the first nip state to the second nip state when a jam error occurs in the first nip state.

Image forming apparatus and method for controlling the same

In an image forming device, a first fixing member has a roller. A second fixing member has a belt to form a nip together with the first fixing member. A pressure modifying mechanism modifies a nip pressure at the nip to selected one of a first nip pressure and a second nip pressure smaller than the first nip pressure. A controller drives the first motor to drive the roller and fixes the developer image on a sheet in a state that the nip pressure is the first nip pressure. The controller modifies the nip pressure from the first nip pressure to the second nip pressure while driving the first motor in a case where a final sheet among one or more sheets fixed according to a print job has passed the nip, and halts the first motor after the nip pressure is modified to the second nip pressure.

Image forming device modifying nip pressure of nip formed in fixing device before motor is halted

In an image forming apparatus, a controller causes a first fixing member to heat up to a standby temperature Tr lower than a fixing temperature, through a control process executed from a state in which rotation of the first fixing member is stopped and a nip pressure is set at a second pressure smaller than a first pressure. The control process includes: a first process of activating and controlling a heater to cause the first fixing member to heat up toward a target temperature; a second process of starting the rotation of the first fixing member; a third process of changing the nip pressure from the second pressure to the first pressure; a fourth process of changing the nip pressure from the first pressure to the second pressure; and a fifth process of stopping the rotation of the first fixing member, executed in this sequence.

Image forming apparatus

An image forming apparatus includes a photoconductive drum, a developing roller, a sheet supplier, a fixing unit, and a controller. The fixing unit includes a heating roller, a first heater, a second heater, a first temperature sensor, and a second temperature sensor. The controller is configured to control the first heater so that a first detected-temperature becomes a target temperature at a central area, and control the second heater so that a second detected-temperature becomes a target temperature at an end area, and in accordance with a heat storage amount of the fixing unit stored by the heating of the second heater, change (i) a timing when supply of the sheet is started or (ii) the target temperature at the end area.

A second heater has such an output that a peak position in a particular direction is located within a largest sheet area. The largest sheet area is an area in which a heating member contacts a sheet having a largest size in the particular direction that is conveyable through a fixing device. A first sensor detects temperature of a center area. A second sensor detects temperature at an outside position in an end area. The outside position is outside the largest sheet area in the particular direction. A controller controls a first heater such that a first detection temperature detected by the first sensor becomes a first target temperature; controls the second heater such that a second detection temperature detected by the second sensor becomes a second target temperature; and determines the second target temperature based on an edge position of a sheet relative to the peak position.

Image forming apparatus configured to control target temperature of fixing device based on edge position of sheet, and method for controlling image forming apparatus

In an image forming device, a first fixing member has a roller. A second fixing member has a belt to form a nip together with the first fixing member. A first motor drives the roller. A pressure modifying mechanism modifies a nip pressure at the nip to selected one of a first nip pressure and a second nip pressure smaller than the first nip pressure. A controller starts driving the first motor to drive the roller in a case where a print command is received in a state that the nip pressure is the second nip pressure. The controller modifies the nip pressure from the second nip pressure to the first nip pressure after the driving is performed and fixes the developer image on the sheet in a state that the nip pressure is the first nip pressure.

Image forming device including pressure modifying mechanism modifying nip pressure of nip formed between first fixing member and second fixing member

An image forming apparatus includes: a heating member configured to heat a sheet; a heat source configured to heat the heating member; a temperature sensor configured to acquire a temperature of the heating member; a switching circuit configured to supply a current to the heat source by switching a voltage inputted from an alternating-current power source between an energization state and a non-energization state; and a controller. The controller executes: print processing of forming an image on the sheet; first energization processing of supplying the current to the heat source after a printing command is received and before the print processing is started; and second energization processing of setting a duty ratio of an output current of the switching circuit based on a detection result of the temperature sensor so that the heating member has a fixing temperature and supplying the current to the heat source, in the print processing.

Image forming apparatus and image forming method

An image forming apparatus has a process unit, a heating member that heats a sheet, a first heat source, a second heat source, a first temperature detector that detects a temperature of a first region including a central portion of the heating member in a width direction, a second temperature detector that detects a temperature of a second region including an end portion of the heating member, and a controller. The controller controls a supply of a current to the first heat source such that a temperature of the first region reaches a first target temperature, increases the first target temperature with a first gradient toward a first fixing temperature, controls a supply of a current to the second heat source such that a temperature of the second region reaches a second target temperature, and increases the second target temperature with a second gradient toward a second fixing temperature.

Image forming apparatus and control method thereof

In an image forming apparatus a controller starts a heater to heat up in response to a print command In a first case where temperature of the fixing device at a timing of reception of the print command is lower than a first threshold value, the controller starts rotating a first motor, and subsequently starts rotating a second motor before the conveying device conveys the sheet according to the received print command. The first threshold value is lower than the target temperature. In a second case where the temperature of the fixing device at the timing of reception of the print command is higher the first threshold value, the controller starts rotating the second motor, and subsequently starts rotating the first motor before the conveying device conveys the sheet according to the received print command.

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Kariya, Japan

Sadaharu Kato