Abstract: A process cartridge includes an image holding member that is capable of holding a developing agent image thereon, a shaft that supports the image holding member, a bearing portion that receives the shaft, a charging device that is capable of charging the image holding member, and a first frame that supports the bearing portion and the charging device.

Abstract: An improved detack corotron reduces the likelihood of a paper jam arising from a curled paper edge getting caught in the corotron. The detack corotron includes an electrically conductive coronode having a plurality of field emitters, each field emitter having a terminating end, the terminating ends of the field emitters being spatially separated from one another, and a paper edge guide having a plurality of generally planar members, the generally planar members being perpendicular to the conductive coronode and the generally planar members having a height that extends above the terminating ends of the field emitters.

Abstract: An image forming apparatus having an image reading unit for reading optically an image on an original document and an image forming unit for forming the image on a recording medium based on image information read with the image reading section includes a mounting member composed of a first mounting member mounting the image forming unit thereon and a second mounting member mounting the image reading unit thereon, formed above the first mounting member and configured as upward and downward movable with respect to the first mounting member, a pushing section for pushing upward the second mounting member, and a level setting section for setting the second member at a prescribed level.

Abstract: A developing device using a trickle system is realized which includes developer discharging means for (i) suppressing changes in discharge of developer due to inclinations of the developing device and (ii) maintaining the stability in amount of the developer in a developer tank. In the developing device, the developer tank includes agitating chambers parted by a partition, and each of the agitating chambers has an agitating screw. Further, discharging openings for discharging an excess of the developer in the developer tank are provided downstream in transport directions of the agitating screws, respectively.

Abstract: An amount of toner transfer on a reference pattern is calculated by using an optical detecting unit that detects both regular reflection light and diffuse reflection light from a detection target simultaneously, based on a relative ratio between a value obtained by subtracting a result of multiplying a “diffuse reflection output” by a “minimum value of a ratio between a regular reflection output and the diffuse reflection output” from the “regular reflection output” of the density detection reference pattern, and a value obtained by subtracting a result of multiplying the “diffuse reflection output” by a “minimum value of a ratio between the regular reflection output and the diffuse reflection output” from the “regular reflection output” in the background of a transfer belt or an intermediate transfer body.

Abstract: An image heating apparatus includes a heating rotatable member and a belt cooperative with the heating rotatable member to form the nip in which an image on a recording material is heated. The apparatus further includes swinging means for swing the belt in a widthwise direction and control means for controlling a rotational speed of the heating rotatable member. The control means rotates the heating rotatable member at a relatively low speed when the belt is brought into contact to the heating rotatable member while the swinging means is swing the belt, and the control means effects an increase of the rotational speed of the heating rotatable member before the heating operation is started.

Abstract: A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes an electrophotographic photosensitive drum, a process device actable on the drum, a cartridge positioning portion for engaging a main assembly positioning portion to position the cartridge with respect to a direction crossing the direction of the axis of the drum when the cartridge is mounted to the main assembly in a direction parallel with the axis of the photosensitive drum, and a movable member movable between a first position contacting the main assembly in the process of mounting of the cartridge to the main assembly, and a second position contacting a main assembly urging member and receiving a force in the crossing direction to contact the cartridge positioning portion to the main assembly positioning portion to position the cartridge in the crossing direction, when the cartridge is mounted to the main assembly.

Abstract: A developing unit in an image forming device is disclosed in which developer peeled off from a developing roller can be reliably retrieved to an agitation transport member and avoid being directly drawn thereto. A developing unit has a drawing magnetic pole and a peel-off magnetic pole. A first agitation transport member is arranged below a developing roller and agitates and transports the developer in the axial direction simultaneously and supplies it to the developing roller. A guide member has a sloping surface guiding the developer torn off from the developing roller to the first agitation transport member. The magnetic pole is arranged between horizontal positions of the sloping surface, and the magnetic pole is arranged horizontally outward of the lower end of the sloping surface.

Abstract: An image forming apparatus which allows an independent and easy replacement of replaceable image forming devices including an image forming unit detachably provided in the image forming apparatus. The image forming unit includes a housing, a plurality of replaceable devices, and a nonvolatile memory. The plurality of replaceable devices are replaceably mounted inside the housing. The nonvolatile memory is mounted on the housing and stores lifetime information of the image forming unit and each one of the plurality of replaceable devices.

Abstract: An image registration device for an image production system is disclosed which adjusts any axial image misregistration in situ and quasi instantaneously. This image registration device contains, in operation, a rotating image carrying element and a rotating image receiving element in rolling contact with each other and each having a flange co-axially mounted on their respective shafts. The image registration device includes a further rotating element in rolling contact with the flanges of the rotating elements to ensure that the image carrying element axially follows the image receiving element or vice versa to establish axial image registration.

Abstract: An image forming unit includes an image forming device that forms an image on a recording medium disposed at a lower portion thereof, a device frame that supports the image forming device at the lower portion, having a first attaching portion to which to attach a first storage frame and a second attaching portion to which to attach a second frame. Either a first storage unit or a second storage unit is attached to the image forming unit. The first storage unit includes a first storage tray having a first storage capacity, a first guide member and the first storage frame. The second storage unit includes a second storage tray having a second storage capacity larger than the first storage capacity, the second guide member and the second storage frame.

Abstract: A cleaning apparatus 30 is provided with a cleaning roller 33 that is a rotating member, a scraper 35, a partition wall 36, opening/closing members 37, and a discharge screw 38 that is a discharging member. The scraper 35 supported by the partition wall 36 scrapes toner by bringing the tip thereof into contact with the cleaning roller 33. The partition wall 36 has a plurality of openings 36a, and partitions between a space S1 formed on an upstream side of the cleaning roller 33 in a rotation direction of a drum and a space S2 in which the discharge screw 38 is provided. The opening/closing members 37 are individually provided for the openings 36a so as to permit toner to move through the openings 36a only in a direction from the space S1 to the space S2. With this structure, it is possible to make toner present in the vicinity of the cleaning roller 33 smoothly move toward the discharge screw 38.

Abstract: A developing device is provided with a developer accommodating vessel accommodating developer having as primary components a nonmagnetic toner and magnetic particles referred to as a carrier. The carrier is composed of a magnetic material as a core material that is uniformly covered with an insulating synthetic resin. The toner is mixed with the carrier at a weight ratio to the overall weight of the developer of 3-10%. The carrier has an average particle size of 65 ?m or less and a saturation magnetization of at least 70 emu/g. The developing device includes a developing roller and a sleeve roller that rotates about the developing roller. The surface of the sleeve roller is processed with metal shot to achieve a surface roughness of 0.45-1.08 times the average particle size of the carrier, or more specifically a roughness Rz of about 30 ?m.

Abstract: An image forming apparatus includes a specific color image forming station for forming a black image and one or more non-specific color image forming stations for forming images of colors other than black, the photosensitive drum of the specific color image forming station is located vertically downward of the photosensitive drums of the non-specific color image forming stations, and the capacity of the black toner cartridge of the specific color image forming station is made larger than those of the toner cartridges of the non-specific color image forming stations. With this arrangement, the frequency of replacement of the black toner cartridge can be reduced without adversely affecting the size of an apparatus main body.

Abstract: A process cartridge is provided with a frame body made up of at least first and second frame bodies that are movable relative to each other to form a space, a frame body positioning member positioning the first and second frame bodies, a latent image bearing member supported by the frame body and replaceable via the space formed by the first and second frame bodies, a developing unit supplying a developing agent to the latent image bearing member, and a developing position determining member. The developing position determining member is disposed at a non-overlapping position relative to the frame body positioning member, and positions the developing unit with respect to the frame body.

Abstract: A fixing device (30) has a fixing member (30) adapted to be heated by induction heating based on a magnetic field from an induction coil (34). A pressing member (40) is disposed in contact with the fixing member (30) to define therebetween a nip zone (N) for passing a sheet (P) therethrough. The fixing member includes a heating layer (32). The heating layer (32) has a temperature-sensitive metal layer (321) and formed on the side of the induction coil (34), and a nonmagnetic metal layer (322) laminated onto the temperature-sensitive metal layer (321). The nonmagnetic metal layer is made of aluminum as a metal having a low specific resistance, and formed to have a thickness (50 ?m) allowing the nonmagnetic metal layer to be substantially free from a temperature rise due to the induction heating.

Abstract: A fixing device comprising a fixing roller, support rollers wrapped with a belt, bearings of the support rollers arranged at both ends thereof, pressing plates arranged between the bearings and each having a pair of tilted pressing surfaces that come in contact with the outer circumferential surfaces thereof, and pressing means for pressing the pressing plates toward the axis of the fixing roller. When pressed by the pressing means, the pressing plates press the support rollers toward the axis of the fixing roller via the tilted pressing surfaces and the outer circuferential surfaces of the bearings so that part of the region of the belt in the circumferential direction is press-contacted to part of the region on the outer circuferential surface of the fixing roller and, further, press the support rollers in a direction in which they separate away from each other to impart a tension to the belt.

Abstract: An image forming apparatus includes detecting means for detecting a toner image formed on an image carrier, and transport means for transporting a sheet. The detecting means is disposed on an inner side in a width of the image carrier, and on an outer side of a contact region with the transport means and the sheet, in a direction perpendicular to a transporting direction of the sheet.

Abstract: An electrophotographic photosensitive drum usable with an electrophotographic image forming apparatus, includes a non-circular twisted projection provided at one longitudinal end of the drum, and engageable with a non-circular twisted hole being disposed at a central portion of a driving rotatable member of a main assembly of the image forming apparatus, and an electroconductive member provided on the projection, electrically connected to the drum, and contactable with an electroconductive member electrically connected with a main assembly of the image forming apparatus and disposed in the hole to ground the drum. The contact position between the electroconductive members moves in interrelation with the projection being moved toward the hole by rotation of the driving rotatable member when the projection is engaged with the hole.

Abstract: An electrophotographic developing roller in which air tightness and electrical conductivity in a fit section between a cylindrical metal base body and a metal flange are satisfactory and outside diameter deflection accuracy is satisfactory; and an electrophotographic developing roller which is relatively inexpensive, excellent in mechanical rigidity, surface processability and plating film formation (corrosion resistance) and capable of being satisfied with a prescribed dimensional accuracy are provided. The electrophotographic developing roller is a developing roller having a cylindrical metal base body and a metal flange. The metal flange has a larger diameter section to be fitted in the opening end inner surface of the cylindrical metal base body and a smaller diameter section serving as a central shaft body coaxial with the cylindrical metal base body.