Abstract: An image fixing apparatus is formed by a fixing roller which contacts an image surface of a recording mediums and performs fixing, a pressure roller which is urged against the fixing roller to thereby apply a necessary pressure needed for fixing of a toner image upon the recording medium, and an external heating roller which has an internal heat surface and when urged against the fixing roller, keeps a surface layer of the fixing roller at a predetermined temperature which is necessary for fixing. A heat transfer coefficient of the fixing roller is 20 W/m2·K to 100 W/m2·K. This guarantees a necessary fixing nip width which is needed for fixing of images without increasing the size of the apparatus or remarkably increasing a holding pressure at the fixing nip portion. Further, it is possible to stably maintain an appropriate fixing temperature without increasing the temperature gradient of the surface layer portion for adding a filler material to the surface layer.

Abstract: A fixing device includes a hollow cylindrical sleeve provided to surround a hollow glass roller containing a halogen heater therein, and a pressure roller that contacts and presses the glass roller and the sleeve. The glass roller is made of an infrared-transparent material. The sleeve has an inner diameter larger than the outer diameter of the glass roller and it is heated by absorbing infrared rays from the halogen heater. The pressure roller nips and holds the sheet carrying the toner between itself and the glass roller and as the sleeve.

Abstract: 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).S1+S2.gtoreq.0.3.times.S3 (1)0.2.ltoreq.S2/(S1+S2).ltoreq.0.8 (2)1 mm.ltoreq.Dmax.ltoreq.5 mm (3)wherein S1 stands for the cross sectional area of the core 18, S2 for the cross sectional area of the coil 20, S3 for the cross sectional area of the sleeve 12, and Dmax for the maximum distance formed between the outer periphery of the holder 14 and the inner periphery of the sleeve 12.

Abstract: A cleaning device which has a flexible cleaning blade held by a holder with one end portion thereof so that another end portion contacts with a surface of a photosensitive member. The holder is rotatably connected with a frame about an axis positioned between the one end portion and the another end portion of the cleaning blade so that the pressure contact angle does not change even when the amount of flexion of the cleaning blade changes.

Abstract: A cleaning device for removing substances remaining on a rotatable image holding member in an image forming apparatus, which includes:a cleaning roller rotatably supported in a state contacting the image holding member so as to remove the substances remaining on a surface of the image holding member, and a drive change-over device arranged to change-over driving so as to rotate the cleaning roller following rotation of the image holding member during a period in which image formation is effected by the image holding member, and to impart a speed difference to the cleaning roller with respect to the image holding member during other periods in which the image formation is not effected.

Abstract: An image recording apparatus including a plurality of electrode elements arranged in a line and a supporting member for supporting the plurality of electrode elements, the improvement comprising means for magnetically transporting a developer to the plurality of electrode elements, wherein a pointed end of each electrode element sinking in the supporting member so that a wall portion is defined between the neighboring electrode elements.

Abstract: A cleaning apparatus for cleaning the surface of a photosensitive member having a cleaning blade, and a cleaning roller which is disposed on the upstream side of the cleaning blade with respect to the rotational direction of the photosensitive member, and is moved laterally as to the rotational axis thereof by the driving power that rotates the same.

Abstract: A residual toner cleaning device for removing the residual toner on a photosensitive drum of an image forming apparatus of the invention is provided with an elastic roller in contact with said photosensitive drum and rotatable to remove said residual toner from said photosensitive drum, regulating means encompassing at least a portion of said elastic roller and having a compressing portion which compresses said elastic roller and a releasing portion for releasing said elastic roller from the compression to release the residual toner carried by said elastic roller, and toner collecting means for collecting the toner released by said elastic roller. The elastic roller ejects the toner toward the toner collecting means by the restoring force of the elastic roller released from the compression by the compressing portion of the regulating means, and the toner collecting means collects the toner.

Abstract: A developing unit which accommodates black toner is operated for developing process by black toner only at a proper time when color image forming operation is not performed by other developing units which accommodate other colored toners. Then, a cleaning blade is actuated without conducting transfer process of the developed image onto a transfer material, and residual toner is removed from the photoconductor.

Abstract: An automatic image density control apparatus, wherein an original placed on a document table and a reference image pattern provided on one edge of the document table and having a image portion or half-tone portion and a non-image portion are scanned, and by way of an exposure, their electrostatic latent images are formed on a photosensitive member on which the non-developing portion with no developer is also formed, and by means of a density sensor for detecting the image density, the initial image density of the non-developing portion and the image density which varies as the time elapses are detected and by the ratio of them, the image density of the image portion or half-tone portion and the non-image portion of the reference image pattern are corrected, and according to the respective preset reference values of the image portion or half-tone portion and non-image portion and their corrected image density, the image portion or half-tone portion density and the non-image portion density of an image are unif