Abstract: A fixing device includes an endless fixing belt that is rotatable, a heating device that heats the endless fixing belt, a fixing roller that internally touches the endless fixing belt and a pressure member that abuts against the fixing roller through the endless fixing belt under a given pressure. The endless fixing belt and the pressure member form a fixing nip portion through which a recording medium passes to fix an unfixed toner image on the recording medium. The fixing roller includes a roller body made of metal, and an elastic layer bonded to an outer peripheral surface of the roller body, the elastic layer is formed of a foam having open cells, and both ends of the elastic layer are tapered.

Abstract: A fixing device is disclosed that includes a fixing roller, a pressure roller that is in pressure contact with the fixing roller, a plurality of belt support rollers that are mutually spaced apart from each other, and an endless belt that is wrapped around the belt support rollers. A portion of the outer peripheral surface of the endless belt is in pressure contact with a portion of the outer peripheral surface of the fixing roller, and the endless belt is heated by at least one heat generating element arranged in at least one of the belt support rollers. The fixing roller is rotatively driven by the electric motor M.

Abstract: A fixing device is provided with a fixing roller, a pressure roller that is in pressure contact with the fixing roller, first and second belt support rollers that are mutually spaced apart from each other, and an endless belt that is wrapped around both the first and the second belt support rollers. A portion of the outer peripheral surface of the endless belt is in pressure contact with a portion of the outer peripheral surface of the fixing roller, and the endless belt is heated by a heating device. The fixing roller is rotatively driven by the electric motor M.

Abstract: A fixing device is disclosed that includes a fixing roller, a pressure roller that is in pressure contact with the fixing roller, first and second belt support rollers that are mutually spaced apart from each other, and an endless belt that is wrapped around both the first and the second belt support rollers. A portion of the outer peripheral surface of the endless belt is in pressure contact with a portion of the outer peripheral surface of the fixing roller, and the endless belt is heated by means of a heating means. The fixing roller is rotatively driven by the electric motor M.

Abstract: A fixing device is disclosed that includes a fixing roller, a pressure roller that is in pressure contact with the fixing roller, first and second belt support rollers that are mutually spaced apart from each other, and an endless belt that is wrapped around both the first and the second belt support rollers. A portion of the outer peripheral surface of the endless belt is in pressure contact with a portion of the outer peripheral surface of the fixing roller, and the endless belt is heated by means of a heating means. The fixing roller is rotatively driven by the electric motor M.

Abstract: An image forming apparatus includes a fusing device comprising of a fuser roller, which fuses toner on a sheet of paper, and a pressure roller getting into contact with the fuser roller to form a nip between them where the sheet of paper passes through. A fuser-side external heat roller having an internal heater comes into contact with the fuser roller. A pressure-side heat roller having an internal heater comes into contact with the pressure roller. The fuser roller and the pressure roller have approximately same outer diameter and are both composed of an elastic material. An approximate radius of the nip formed between the two rollers is set to be equal to or larger than a radius of the fuser roller or the pressure roller. In another construction, the rollers are different in outer diameter, but each composed of an elastic material and a nip between them is set to be equal to or larger than 1.25 times as large as the radius of either the fuser roller or the pressure roller with smaller outer diameter.

Abstract: A destaticizer which is adapted to remove electric charges from the surface of a photoreceptor by exposing the photoreceptor surface to light. The destaticizer includes a light source, and a light guide member for generally uniformly guiding light from the light source to a light exposure area on the photoreceptor. In accordance with one embodiment, the light guide member is an elongated member, which has an end face serving as a light receiving face for receiving the light emitted from the light source, a light transmitting path for transmitting the light received by the light receiving face, and a plurality of reflecting portions arranged along the length of the light guide member for reflecting the light transmitted through the light transmitting path in a direction intersecting the length of the light guide member.

Abstract: The present invention relates to an image forming apparatus such as a copying machine. In the image forming apparatus according to the present invention, a sealing member is interposed between a transparent platen on which an original is put and a frame member on which the transparent platen is mounted. Therefore, the sealing properties between the transparent platen and the frame member on which the transparent platen is mounted are improved, thereby to make it possible to prevent external air from entering the apparatus from a portion between the frame member and the transparent platen. As a result, it is possible to prevent image degradation and an increase in toner consumption.

Abstract: Disclosed is a toner having an excellent transparency for full color development, which comprises a binder resin and a magenta coloring dispersed therein wherein (i) said magenta coloring agent is a quinacridone pigment, (ii) said pigment is dispersed in the binder resin in the form of fine particles and that when the toner is formed into a layer having a thickness of 0.9 .mu.m, the area occupied by the dispersed pigment in 780,000 .mu.m.sup.2 of the area of the formed surface is such that the number of dispersed pigment particles having a size of 10 to 12.5 .mu.m.sup.2 is smaller than 40 and the number of dispersed pigment particles having a size of 12.5 to 15.0 .mu.m.sup.2 is smaller than 20, and (iii) the binder resin has an electroconductivity of 1.0.times.10.sup.-9 to 5.0.times.10.sup.-9 (s/cm). The critical quantities of these dispersed particles having the above sizes differ among magenta, cyan and yellow toners.

Abstract: The present invention provides a magnetic brush developing method using a two-component developer, characterized in that the development is carried out under such conditions that at the position where the sliding contact of the magnetic brush with the surface of the photosensitive material drum terminates, the following requirement is satisfied:P.sub.x .gtoreq.430, orP.sub.x <430 and P.sub.y .gtoreq.-P.sub.x +800,wherein P.sub.x represents the magnetic force (Gauss) acting in the tangential direction on the surface of the developing sleeve, and P.sub.y represents the magnetic force (Gauss) acting in the normal line direction on the surface of the developing sleeve.

Abstract: Disclosed is a developing process using a two-component type magnetic developer, where the main pole of developing magnetic poles in the developing sleeve is arranged upstream of the position, where a photosensitive drum becomes closest to the developing sleeve, in the rotation direction of the developing sleeve, this closest position between the drum and the developing sleeve is included in a region where the flux density in the magnetic force distribution of the main pole decreases toward the downstream side in the rotation direction of the sleeve, an alternating current voltage is applied between the developing sleeve and the drum to form an alternating electric field between the highest voltage and lowest voltage of the electrostatic latent image and in this state the development is carried out. According to this process, the conditions required for the supply of the developer are considerably moderated and an image having a high quality can be advantageously obtained.

Abstract: Disclosed is a developing process using a two-component type developer comprising a magnetic carrier and a toner, in which the developing conditions of the two-component type developer, that is, the composition and density of the developer in a distance between a photosensitive material drum and a developing sleeve (or a distance of a developing zone), are specified based on relations of these conditions to this distance. According to this developing process, the flowability of the developer in the developing zone is improved, and furthermore, the transferability of the toner to the photosensitive material drum is improved.