Abstract: 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 1×1016 &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.

Abstract: A fixing device has a fixing roller which heat-fixes an unfixed toner image on a recording member transported between the fixing roller and another rotating member. The fixing roller is provided with a base member, a surface coat layer provided on the surface of the base member and which comes into contact with the recording member during the fixing process, and a silica protective layer provided over the part of the surface not provided with the surface coat layer.

Abstract: 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.

Abstract: 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 1×1016 &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.

Abstract: 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.

Abstract: A fixing belt is applied to a fixing apparatus of an electronic photography type printer. The fixing belt consists of a belt base and an elastic layer having a thickness of 200 .mu.m or more formed on the belt base. The elastic layer consists of first, second and third elastic layers arranged in that order from the base side, and is deformable to conform to the surface shape of a recording paper so that all unfixed toner held on the recording paper can be pressed. The second elastic layer is a barrier layer for preventing releasing agent from permeating and the belt from swelling to suppress the thickening of the elastic layer as a whole and maintain the belt thickness within a range that does not cause any image noises.

Abstract: A fixing apparatus for controlling an oil transfer apparatus to maintain a releasing agent holding layer such that it is not always saturated with the releasing agent. This makes it a compact, cost-effective unit with a long service life and provides a uniform, stable oil coating that eliminates image noise problems. In order to use a constant and minimum necessary amount of releasing agent, a releasing agent supply nozzle is incorporated with multiple protrusive or retrusive droplet growth assisting members at or near multiple releasing agent discharge ports. The supply nozzle used for supplying the oil has multiple discharge holes having approximately equal opening cross-sectional areas and an equalizing member which equalizes the amount of oil discharged from each discharge hole. The outer diameter D1 of the oil supply roller, the outer diameter D2 of the metal core and the distance P of adjacent through-holes formed on the periphery of the metal core satisfy a relation, 0.6<D1.multidot.(D1-D2)/(D2.

Abstract: 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.

Abstract: A fixing device of the belt system is provided in which slippage of a heating belt is prevented from occurring so that a recording member is stably transported, and the inner face of an end portion of the heating belt is prevented from being damaged. In a fixing device, an endless heating belt 34 is supported by a driving roller 31 and a heating roller 33, a pressure roller is pressingly contacted with an outer peripheral portion of the belt so as to form a nip portion, and an unfixed image on a recording medium transported to the nip portion is fixed to the recording medium. The axial lengths L2 of the driving roller 31 and the heating roller 33 are set to be shorter than the width L1 of the belt 34, and the axial length L3 of an oil applying roller 51 which abuts against the outer peripheral portion of the belt 34 to apply oil thereto is set to be shorter than the axial lengths L2 of the driving roller 31 and the heating roller 33.

Abstract: 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.

Abstract: A fusing device has a pair of fusing rollers of which at least one is covered by an elastically deformable layer of heat resistant material with the fusing rollers being brought into contact with each other; a recording material guide member and a pre-heating member having a plane-shaped heating surface opposite to the recording material guide member on an upstream side recording material which maintains a toner image away of a nip portion where the fusing roller make contact. While the recording material which maintains the toner image is guided on said recording material guide member, the toner image is heated by means of the pre-heating member and passed through the nip portion. The fusing device is set to satisfy the relationship of 0<F<0.5.theta..sup.2 +0.05.theta. for an angle .theta.(.degree.

Abstract: A fusing belt type heat fusing device has a rotating fusing roller, a driven heating roller, an endless fusing belt wrapped and stretched around the two rollers, a pressure roller that applies pressure to the fusing roller through the fusing belt, and a separation agent application and tension transmission element that applies an offset suppression separation agent to the fusing belt in addition to transmitting tension to the fusing belt. The separation agent application and tension transmission element is installed so as to make contact with the fusing belt at an upstream side of the heating roller in the rotation direction of the fusing belt between the fusing roller and the heating roller and at a position closer to the heating roller than a center position between the fusing roller and the heating roller.

Abstract: A transparent film used as recording media in an electrophotographic apparatus and having different expansion and shrinkage characteristics during heating in length and width directions. At the end portion of the film in the direction in which the film has slighter shrinkage is provided a non-transparent member so that the passage of the film can be detected by means of photosensors without the non-transparent member being peeled away from the film due to the differences in the shrinkage factors of the film and the non-transparent member upon fixing.An image forming method for forming an image on the transparent film. In the above method, the transparent film is set at a supply portion of the electrophotographic apparatus so as to be fed along the direction in which the film has greater shrinkage during heating, so that the film does not jam and roll up on a fixing rollers and is allowed stable image formation.

Abstract: Control circuit is arranged to move a mold releasing agent coating roller in contact with end toward and away from a fixing roller in a timing a sheet passing through a pair of fixing rollers is detected whether it is a film or not. In the case when the sheet is a film, the mold releasing agent coating roller is brought in contact with the fixing roller in the timing the leading end of the mold releasing agent reaches a nip section of the fixing roller after the leading end of the sheet has run into the nip section, while it is moved away from the fixing roller when the rear end of the sheet leaves the fixing roller simultaneously with the timing the rear end of the mold releasing agent passes through the nip section.

Abstract: A thermal fixing device having a heating roller and a pressing member for thermally fixing a toner image held on the front side of the recording sheet. The heating roller is provided to confront the toner image of the recording sheet and the pressing member is provided to confront the back side of the sheet for making pressure contact with said heating roller through the sheet when the recording sheet is transported between the heating roller and the pressing member. The heating roller and the pressing member respectively include heat-resistant elastic layers the surface of which have the triboelectricity to the recording sheet. The heat-resistant elastic layer of the pressing member has higher triboelectricity to the recording sheet than the heat-resistant elastic layer of the heating roller.

Abstract: A press cam is driven when fixing rollers are rotated for a warm-up operation at the time the power is applied simultaneously with the timing a recording material is fed to a fixing roller whereby an oil coating roller is controlled to be brought in contact with and moved away from the fixing rollers. Oil is coated on the fixing rollers for only a predetermined period of time during the fixing rollers are rotated at the warm-up operation which correspond to the time until the recording material reaches the fixing rollers.