Sharp Kabushiki Kaisha Corporation

Atsushi Ide

Yoshinobu Tateishi

Toshiya Mikita

Yasunori Minakuchi

Kazuhiro Matsuyama

Hiroaki Hori

Toshio Yamanaka

Takashi Yamanaka

Toyoaki Nanba

Kimihide Tsukamoto

Hiroshi Nakatani

Osamu Fujimoto

Toshiaki Kagawa

Susumu Murakami

Yasuhiro Takai

Takashi Mukai

Masashi Hirai

Yoritaka Tsubaki

Hideo Matsuda

Kohji Aoki

Noriko Inoue

Koji Aoki

Takashi Kubo

Yuji Okamoto

Norio Tomita

Masaru Tsuji

Kazuyuki Ohnishi

Yoichi Yamamoto

Hiroshi Tachiki

Katsuyoshi Fujiwara

Fumikazu Shimanuki

Tetsunori Mitsuoka

Shinichi Takeda

Kenzo Yoshida

Kazushi Yamamoto

Tatsuya Shinkawa

Hidekazu Sakagami

Hideo Yamasa

Tadaaki Kawano

Masao Yamamoto

Kazuo Maeyama

Osamu Tashiro

Koichi Nakamura

Kazumi Irie

Fukusaburo Ito

Koichi Yamauchi

A fixing device is provided with a fixing roller, a peeling claw that peels a recording paper from the fixing roller, a peeling claw holder that rotatably supports the peeling claw, and a support member that movably supports the peeling claw holder to enable the peeling claw to retract by moving apart from the fixing roller, wherein not less than two directions are set as retracting directions of the peeling claw holder to be moved when the peeling claw is caused to retract by moving apart from the fixing roller.

Fixing device and image forming apparatus provided with same

A fixing device of the present invention includes: an external heating belt which is to contact with a surface of a fixing roller so as to heat up the fixing roller; and a cleaning member (a scraper and/or cleaning pad) which is to contact with the external heating belt. The cleaning pad which is impregnated with silicone oil is to contact with a surface of the external heating belt, thereby applying the silicone oil (release agent) to the surface of the external heating belt. This makes it possible to prevent generation of an offset.

Fixing device and image forming apparatus having same

In a fixing device including (i) an external heat belt which abuts against a surface of a fixing roller so as to heat the fixing roller and (ii) a cleaning member which abuts against the external heat belt, a fixing temperature, which is a surface temperature of the fixing roller during a fixing process, is set per group into which recording media to be subjected to the fixing process are divided according to their widths in a direction of a rotary axis of the fixing roller, in such a way that the fixing temperature is set to a lower temperature for a group of narrower widths. This makes it possible to prevent a reduction in releasability of the fixing roller caused by a material, which is scraped off from the external heat belt by the cleaning member and then adhered to the fixing roller, thereby preventing the high-temperature offset.

Fixing device, image forming apparatus, and method for controlling fixing device

In a fixing apparatus provided with a plurality of fixing heaters having heat distribution characteristics that are different from each other inside a fixing roller, and an image forming apparatus provided with the fixing apparatus, an auxiliary heater is provided, the auxiliary heater being provided inside the fixing roller and to which power is distributed only during the warm-up period until the fixing roller in a lower temperature state reaches a predetermined fixing temperature. The plurality of fixing heaters includes a first fixing heater having first heat distribution characteristics that mainly heats a center portion of the fixing roller, and a second fixing heater having second heat distribution characteristics that mainly heats both end portion regions of the fixing roller.

Fixing apparatus and image forming apparatus

In one embodiment of the present invention, a fixing apparatus that causes a recording material to pass through a nip portion formed by a rotating heat roller and a rotating pressure roller being in contact so as to perform a fixing operation is configured including a pressing mechanism that can switch between a pressure applied state in which the pressure roller presses against the heat roller using a bias and a pressure cancelled state in which the pressure is cancelled, a pressure state detection unit, and a control unit that performs a pressure cancelation operation and a pressure application operation. If the pressure state detection unit does not detect the pressure cancelled state even when the control unit has performed pressure cancellation control for a certain time period with respect to the pressing mechanism in the pressure applied state, the control unit permits a fixing operation in only the pressure applied state after performing pressure application control for a certain time period with respect to the pressing mechanism.

Fixing device having control unit for detecting pressure cancellation failure of pressure roller against heating roller

In one embodiment, a fixing apparatus is configured of a pressing portion for causing the pressure roller to enter a pressure applied state by applying bias, a switching portion for causing the pressing portion in the pressure applied state to enter a pressure released state by causing a cam to rotate forward, a pressure state detection portion for detecting the pressure released state, and a control portion for, when shifting from the pressure applied state to the pressure released state, turning forward the cam of the switching portion in the pressure applied state and stopping the cam after the pressure state detection portion detects the pressure released state. If the cam is turned forward with respect to the switching portion for a certain time period, but the pressure state detection portion does not detect the pressure released state, the control portion performs forward rotational direction retry control.

Fixing apparatus with pressure state detection and control

The present invention carries out temperature detection and temperature control accurately in a temperature control device using a noncontact-type temperature detecting section. The temperature control device obtains the surface temperature of a fixing roller by using a temperature correspondence table in which correspondences between output voltage values of a main NTC thermistor which detects heat generated by infrared radiation from the fixing roller and the surface temperatures of the fixing roller are shown for respective output voltage values of a compensation NTC thermistor. Here, the output voltage values of the main NTC thermistor and the output voltage values of the compensation NTC thermistor are set in the temperature correspondence table so that an interval between adjacent values of the compensation temperatures corresponding to the output voltage values of the compensation NTC thermistor is smaller than an interval between adjacent values of the surface temperatures of the fixing roller which temperatures correspond to the output values of the main NTC thermistor.

Temperature control device, temperature control method, fixing device, image forming apparatus, temperature control program, computer-readable recording medium, and computer data signal

In one embodiment, an operation state, standby state or installation environment of an image forming apparatus is detected or determined, and details of heating control of the surface temperature of rollers of a fixing apparatus are changed in accordance with the detected or determined state or environment. For example, when the operation state is a state in which printing on a last sheet of recording paper in a print job is complete, or when the operation state is a state in which printing on recording paper is interrupted, and, in addition, when the installation environment is a low-temperature and low-humidity environment and the image forming apparatus enters the standby state, heating of the rollers is respectively controlled to prevent unexpected and inappropriate changes in the surface temperature of the rollers.

Roller temperature control method of image forming apparatus and image forming apparatus

A cleaning device according to the present invention comprises which includes a cleaning belt, an unwinder, a winder, and a detector. The unwinder is wound with the cleaning belt. The winder winds up the cleaning belt intermittently from the unwinder along a path leading past a cleaning position where the belt is brought into contact with a body to be cleaned. The detector is fitted in a detecting position on the path between the unwinder and the cleaning position. The cleaning belt has an end point set on it near its trailing end and associated with the detecting position. When detecting the end point, the detector outputs a detection signal.

Cleaning device, fixing device, and image forming apparatus

A fuser apparatus including: a fuser member having an endless contact surface to be brought into contact with each of successively transported recording media and a non-contact surface and being arranged to apply heat to the recording medium from the contact surface to fix a toner on the recording medium; a heating member energized to supply heat to the contact surface; a contact surface temperature detecting member for detecting a temperature of the contact surface; a non-contact surface temperature detecting member for detecting a temperature of the non-contact surface; and an energization controlling member for controling energization power of the heating member; wherein the energization controlling member controls the heating member energization power so that the heating member energization power is reduced as a difference between the non-contact surface temperature and the contact surface temperature decreases.

Fuser apparatus, image forming apparatus including the fuser apparatus, and fuser controlling method

A fixing apparatus for fusing and fixing an unfixed developer by heating/pressurizing a recording medium on which an image of the unfixed developer is formed, includes a fixing roller cleaning unit for cleaning surfaces of fixing rollers, and a propinquity/separation mechanism for moving the fixing roller cleaning unit close to and away from the fixing roller. The fixing apparatus operates the propinquity/separation mechanism so as to make the fixing roller cleaning unit contact the fixing roller when a temperature of the fixing roller becomes equal to or higher than a softening temperature of a developer. The fixing apparatus operates the propinquity/separation mechanism so as to move the fixing roller cleaning unit away from the fixing roller when a temperature of the fixing roller becomes lower than the softening temperature of the developer.

Fixing apparatus and image forming apparatus having the same, including a propinquity/separation mechanism for moving a fixing roller cleaner in relation to fixing rollers

In a fixing apparatus of the present invention, an end section fixing control temperature changing section selects an end section fixing control temperature in accordance with the number of paper sheets that have been processed in one continuous printing process. A sub-heater on/off determining section turns on or off a sub-heater in accordance with a temperature detected by an end section temperature sensor and the end section fixing control temperature selected by the end section fixing control temperature changing section. This prevents the occurrence of fixing failure even in continuous printing with respect to large-size paper sheets in an arrangement in which a temperature sensor is disposed outside a maximum-size sheet passing region at an end section of a fixing roller and controls energization of a heater which is disposed corresponding to the end section of the fixing roller in accordance with a temperature detected by the temperature sensor.

Fixing apparatus and image forming apparatus including the same

In one embodiment, the invention provides a paper separation claw disposed near the surface of at least one of fixing rollers that fix toner on recording paper transported in a sandwiched manner, the paper separation claw being disposed in order to separate the recording paper, and a cavity portion that is open facing the surface of the fixing roller is formed in the paper separation claw.

Paper separation claw having cavity and through-hole

A fixing control section of a fixing apparatus according to the present invention includes an end section priority temperature control mode. In the end section priority temperature control mode, the fixing control section temporarily turns off a main heater heating a center section of a fixing roller among a plurarity of heaters disposed inside the fixing roller in a case where a surface temperature of the end section of the fixing roller has reached a preset upper-limit fixing temperature, even if the surface temperature of the center section of the fixing roller is lower than a preset fixing temperature. As a result, destruction of the fixing roller can be prevented by a simple arrangement in the fixing apparatus which includes a plurarity of the heaters disposed inside the fixing roller.

Fixing apparatus and image forming apparatus including priority temperature control

In a fixing apparatus that an unfixed developer is fused and fixed by heating/pressurizing a recording medium on which an image of the unfixed developer is formed, a belt-shaped cleaning member is fed from a feeding roller, and the cleaning member is made to respectively contact a heating roller and a pressure roller by a pressure-contact roller, thereby cleaning that the heating roller and the pressure roller, respectively. When a winding roller takes up the cleaning member which has cleaned a roller surface, guide rollers are respectively provided between the pressure-contact roller and the winding roller, and between the feeding roller and the pressure-contact roller so as to contact the cleaning member.

Fixing apparatus having a cleaning member and image forming apparatus having the same

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Nara, Japan

Atsushi Ide