Abstract: The present invention provides an image fixing device including a heat fusing roller with heating means inside and an elastic material layer on a peripheral surface of the heat fusing roller, the heat fusing roller being rotatably mounted, an endless belt movable in contact with the heat fusing roller, and a pressure applying member fixed and contacting the endless belt on the heat fusing roller and applying pressure to form a belt nip portion between the endless belt and the heat fusing roller.

Abstract: A fixing apparatus for an image forming apparatus of the present invention includes: a rotatable heat roll; a heat-resistant elastic member fixedly disposed to form a nip section in contact with an outer circumferential surface of the heat roll, the heat-resistant elastic member being impregnated with a liquid release agent which is supplied to the nip section; and a porous fluororesin film formed by sintering a fluororesin powder for coating a surface of the heat-resistant elastic member coming in contact with the heat roll so that the release agent can be supplied by a predetermined amount while permeating through the film. The porous fluororesin film may include: a film formed by using metal fibers, glass fibers, or the like as a supporting member thereof, and a film formed by applying a gelled dimethyl silicone oil at least to a single surface of the film.

Abstract: A fixing apparatus comprising built-in heating means, a heat-fixing roll which is driven to rotate, and an endless pressure belt which is stretched along a plurality of rolls and made to be contact and wound around the heat-fixing roll, wherein the heat-fixing roll is provided with a resilient layer on the peripheral surface thereof; one of the plurality of rolls for stretching the pressure belt is a pressure roll which is located in a press contact portion where the pressure belt is forced to be contact with the heat-fixing roll on the downstream side in the direction of rotation of the heat-fixing roll and pressed against the heat-fixing roll so that the resilient layer of the heat-fixing roll undergoes compressional deformation; an auxiliary pressure roll is provided on the upstream side of the press contact portion and forced to be contact with the heat-fixing roll via the pressure belt; and a soft resilient layer formed of material not harder than what is used to form the resilient layer of the heat-fixi

Abstract: An image fixing device is provided that includes a heat roller disposed rotatably, and a fixed way to apply pressure for contacting and applying pressure to the heat roller to form a nip portion. A recording sheet on which an unfixed toner image is formed passes through the image fixing device for fixing the toner image. The heat roller has a releasing layer on its surface for stripping the recording sheet which has passed through the nip portion, and .mu..sub.2 and .mu..sub.2 having the following relation.mu..sub.1 /.mu..sub.2 .gtoreq.5,wherein .mu..sub.1 is a frictional coefficient between the releasing layer of the heat roller and the recording sheet and .mu..sub.2 is a frictional coefficient between the surface of the pressure applying means and the recording sheet.

Abstract: The present invention provides an image fixing device for fixing toner on a transfer member comprises a heat roller which is a hollow cylindrical member rotatably supported at both end portions and having heating means inside thereof, pressure means press-contacted to the heat roller for pressing the transfer member passing between the heat roller and the pressure means against to a peripheral surface of the heat roller, and the pressure means is a pressure roller disposed approximately parallel to the heat roller and supported rotatably, at least one of the heat roller and the pressure roller has a layer of elastic material on its peripheral surface, and a value A/B is set to be within a range from 0.7 to 0.8 wherein A represents a nip width at an approximate central portion of an area between the heat roller and the pressure roller where the transfer member passes through and B represents a nip width at end portions of the area.

Abstract: A fusing device for fusing a toner image by passing a recording sheet carrying an unfused toner image by means of the torque of a heating roll through a nip portion between the rotating heating roll and a heat-resistant solid elastic member which is forced to contact the outer peripheral surface of the heating roll to form the nip portion. In the fusing device, the heat-resistant solid elastic member includes an elastic body penetrated with a liquid release agent, and a lease-agent penetration control film whose region which is used for covering the surface of the elastic body and corresponds to at least the nip portion is formed of a porous film.

Abstract: A method for forming an image with a copying machine capable of both color copying and black-and-white copying is disclosed, in which a black toner contains at least a colorant and a resinous component having a weight average molecular weight (Mw) of from 25,000 to 80,000 and a number average molecular weight (Mn) of from 2,000 to 8,000, with a Mw/Mn ratio being not less than 10, and having an apparent melt viscosity of 1.times.10.sup.4 poise at a temperature between 115.degree. C. and 140.degree. C. as measured by a flow tester method, and the quantity of heat of fixing is varied between a B/W mode and a color mode.

Abstract: A fixing device includes a contact portion formed by making a part of an endless belt supported by a plurality of tension rollers contact a fixing roller having an elastic body applied thereon. The contact portion includes a contact point formed by making a pressure roller inside the endless belt bear against the fixing roller under pressure through the endless belt at an exit point of the contact portion. The fixing device also includes a braking device which brakes the transport of the endless belt at the contact point such that the endless belt at the point where the pressure roller bears against the fixing roller moves at a speed greater than the remaining portions of the endless belt.

Abstract: A fixing unit has a fixing roller and an endless belt. When a recording sheet bearing a toner image not yet fixed passes between the fixing roller and the endless belt, the fixing unit fixes the toner image onto the recording sheet in the nip area. The endless belt is a film-like belt consisting of a base film and a layer on the base film, the layer being made of a composite material containing porous material and elastomer. A fixing unit is thus provided which is free from the problems of image offset and lifetime shortening, and can realize the increase of fixing speed and/or size reduction.