Minolta Company, Ltd.

Tetsuro Ito

Yuusuke Morigami

Taizou Oonishi

Takeshi Kato

Mitsuru Isogai

Eiji Okabayashi

Noboru Yonekawa

Satoru Yoneda

Tetsuya Yamada

Keigo Tange

Koji Takahashi

Takashi Yamada

Shigeo Honma

The heat fixing device includes a heating roller and a pressure roller disposed in contact with the heating roller, the heating roller includes a base member and a surface layer, and the surface layer has a surface resistivity of 1&times;10 &OHgr; or lower, and a residual elongation percentage of 3% or lower. By this arrangement, charging of the heating roller can be prevented so that the recording medium can be prevented from being curled around the heating roller.

Fixing rotatable member for heat fixing device and fixing device using the same

A fixing device is provided with first and second fixing members each having an elastic member, a heater for heating at least one of the first and second fixing members and a controller. The first and second fixing members are abutted against each other so that the elastic members contact with each other. A sheet carrying an image of a developer is passed between the first and second fixing members, whereby the developer is fixed onto the sheet. The controller corrects fixing conditions including a fixing speed and a fixing temperature in accordance with an integrated energizing time that is an integrated value of an energizing time of the heater.

Fixing device capable of correcting fixing conditions in accordance with an integrated energizing time

Fixing device

A fixing device has first and second rollers respectively formed of a metallic cylindrical body provided with an elastic member. The rollers are abutted against each other so that the elastic members contact each other. The fixing device further has a heater for heating at least one of the rollers and a driver for rotating at least one of the rollers so that a transfer sheet passes through contact portion of the rollers. Roller hardness of the first roller is smaller than that of the second roller, and density of cross-link of the elastic member of the first roller is lower than that of the elastic member of the second roller.

A fixing device having a rotatable heating member heated by a heat source, a rotatable pressure member for pressing against the rotatable heating member, a heat-moving member formed of material having excellent thermal conductivity characteristics and constructed so as to freely make contact with at least one rotatable member among the rotatable heating member and the rotatable pressure member, and a drive unit to move the heat-moving member between a contact position and retracted position relative to at least one of the heating member and the rotatable pressure member. The heat-moving member changes either heat capacity or thermal conductivity or both heat capacity and thermal conductivity relative to the axial direction of the rotatable heating member or the rotatable pressure member.

Fixing device having a heat moving member

An induction heating fixing device is disclosed which is provided with a conducting sleeve, a coil for causing the sleeve to generate an induced current, and a high-frequency power source for feeding a high-frequency wave to the coil. This fixing device detects the switching cycle of the high-frequency power source and the electric power injected into the sleeve and, based on the detected switching cycle and the detected electric power, controls the amount of electric current to be fed from the high-frequency power source to the coil.

Apparatus and method for detecting a condition in an inductive heating

In a fixing apparatus having a flexible metal fixing sleeve provided around a holder, which holds a coil inside, and heated by induction current of the coil, and a pressure roller that pinches the fixing sleeve between it and the holder by pressing on the holder, the following relation is satisfied:

Apparatus for controlling the rotational motion of a fixing apparatus

In a fixing device with a fixing roller that fixes the toner held on a sheet, a pressuring roller that contacts with the fixing roller, and a supply roller that applies the oil to the fixing roller, image noises and offset phenomenon are prevented by replenishing the consumed oil immediately to the supply roller only when the fixing roller is rotating, based on the oil replenishing speed determined by the rotational speed of the fixing roller and the oil replenishing amount determined by the total rotation time of the fixing roller.

Fixing device, and releasing agent replenishing device and method for

A heating device for use in an induction heating type fixing system is composed of a sleeve 12 made of an electrical conductive material and an electromagnet 13 with a coil 20 and a core 18. It is constructed so as to fulfill the following formulas (1), (2), and (3).

Heating device

An image forming apparatus and a fixing device used therein capable of discriminating transport condition of a sheet in the fixing device without sheet sensors. The fixing device is provided with a fixing roller for heating unfixed toner borne on a sheet and fixing the toner onto the sheet. A temperature sensor is arranged for detecting the temperature of the fixing roller, which temperature sensor communicating with a controller of the image forming apparatus or the fixing device. The controller discriminates the transport condition of the sheet based on the temperature change of the fixing roller detected by the temperature sensor so as to execute varied control.

Apparatus discriminating the transport condition of a recording medium

The induction-heating apparatus of this invention contains a conductive member, a power source, and a first and a second induction coil connected to the power source and adapted for causing the conductive member to generate an induced current, the first and the second induction coil being parallelly connected. The induction coil is formed by winding a copper wire round a core in such a manner that the numbers of turns of the copper wire gradually decrease from the lowermost layer approximating most closely to the core to the upper layers. This heating apparatus has the thickness of the induction coil in the range of 0.2-0.8 mm. The gap between the induction coil and the conductive member is in the range of 0.5-4.0 mm. This heating apparatus has the induction coil thrust out of the conductive member. The induction coil is formed of a Litz wire.

Heating apparatus

A fixing device for an image forming apparatus having low heat losses. The fixing device consists of a fixing roller and a compression roller for abutting upon it under pressure. The fixing roller and compression roller have a release layer each formed on the surface of a core metal formed of an aluminum hollow cylinder. The release layer on the surface of the fixing roller is formed of a composite material of metallic powder of good thermal conductive material such as nickel, and fluorine resin such as polytetrafluoroethylene (PTFE) and polyphenylene alkoxyether (PFA), and has spectral emissivity at a wavelength of 5 to 10 .mu.m being within a range of 0.1 to 0.65. The compression roller is provided with a release layer formed of fluorine resin like the conventional one, or the same material as the release layer on the surface of the aforesaid fixing roller, having lower spectral emissivity.

Fixing device for image forming apparatus

A fixing device for heating and fixing an unfixed image to a record member bearing the unfixed image, including a heating roller, a backup member, and a current transmitting units. The heating roller includes a core roller, and a resistance heating member which is formed on the core roller and generates heat when a current is transmitted thereto through the current transmitting units, and is rotatably carried at opposite ends of the core roller by bearing units. The current transmitting units are arranged at positions opposed to the bearing units. The current transmitting unit includes a current receiver member and a current supply member. At mutual contact surfaces of them, the current receiver member has a concave section, and the current supply member has a convex section. The outer periphery circle of at least one side surface of said current receiver member has a radial difference of 6 mm or more with respect to an outer periphery circle of the heating roller at a sheet passing region. The heating roller has dust mevement restricting grooves.

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Anjo, Japan

Tetsuro Ito