Abstract: A process cartridge includes an image bearer, a developer bearer, and a positioning member. The image bearer is rotatable. The developer bearer is rotatable and opposite to the image bearer. The positioning member determines an opposing distance between the image bearer and the developer bearer, and includes a fitting portion and a groove. A fitted portion of the image bearer rotatably fits to the fitting portion. The groove extends from a ceiling portion to a bottom portion. A shaft portion of the developer bearer is slidingly movable in the groove. The groove is formed such that the shaft portion of the developer bearer contacts the bottom portion and is supported by the bottom portion. The ceiling portion of the groove is open upward so that the shaft portion of the developer bearer is insertable to and removable from the groove.

Abstract: An image formation apparatus includes an image-bearing member, an exposure device, an electro-conductive member, a bias application unit and a development device having a development roller and a toner supply roller. The bias application unit configured to apply biases to the toner supply roller, the development roller, and the electro-conductive member during image formation so that a first potential difference between the toner supply roller and the development roller and a second potential difference between the electro-conductive member and the development roller cause normally charged toner to travel respectively from the toner supply roller and the electro-conductive member to the development roller, and a third potential difference between the electro-conductive member and the toner supply roller causes normally charged toner to travel from the electro-conductive member to the toner supply roller.

Abstract: A developing unit includes a conveying member which rotates to convey the developer to the developer bearing member. The conveying member includes a sheet portion with one end fixed to a rotation shaft and a free end which enters the developing chamber through an opening when the conveying member rotates around a rotation center, wherein relations C>A and B>A are satisfied, where A is a distance from the rotation center to an upstream end of the opening in a rotational direction, B is a distance from the rotation center to a downstream end of the opening in the rotational direction, and C is a length from the rotation center to the free end of the sheet portion in an unbent state. The upstream end of the opening is lower in a direction of gravitational force than the downstream end at an orientation in use.

Abstract: A developing device includes a developing rotator configured to rotate through a developing region while carrying a magnetic developer, a supply transport member configured to rotate to transport the developer to be supplied to the developing rotator, a non-magnetic movement assist member arranged between the developing rotator and the supply transport member, and having a slope that receives the developer from the supply transport member and moves the developer to the developing rotator, a first adjusting member having a facing surface that faces, with distances, the slope of the movement assist member and a surface of the developing rotator at a part passing over the movement assist member, and configured to adjust a movement amount of the developer from the movement assist member to the developing rotator and a carrying amount of the developer on the surface of the developing rotator, and a second adjusting member having a distance from the surface of the developing rotator at a part passing over the first

Abstract: A toner conveying device that conveys toner. The toner conveying device includes a housing, a toner guide portion, and at least two vibration motors. The housing has, in its inside, a toner conveyance path. The toner guide portion is provided in the housing and includes an opening through which toner flows in or out, and a guide passage communicating between the opening and the toner conveyance path. The at least two vibration motors apply vibrations to the toner guide portion. The vibration motors are started at different timings, and driven and controlled by drive signals in which a first pulse and a second pulse of different pulse widths alternately continue.

Abstract: In an example, a method comprises fabricating a first validation device for association with a first replaceable print apparatus component. The device may be to form part of circuitry arranged on the first replaceable print apparatus component, and may provide an associated electrically detectable characteristic which varies with the position of at least part of the first validation device. The electrically detectable characteristic may be measured and data indicative of the characteristic may be stored in a first memory. The first replaceable print apparatus component comprising the first device and the first memory may be assembled.

Abstract: A target value for a gap between a developer bearing member supported by a developing frame member and a regulating blade that is fixed to the developing frame member is determined based on input information about a local maximum peak value of magnetic flux density of a predetermined magnetic pole which is located closest to the regulating blade when the regulating blade is fixed to the developing frame member among a plurality of magnetic poles included in a magnet fixedly located inside the developer bearing member and configured to generate a magnetic field for causing a developer to be borne by the developer bearing member.

Abstract: A developing device includes a developing container, a first stirring and conveying member, a second stirring and conveying member, a developer replenishing port, a developer discharging portion, a developing roller, a toner supply roller, a regulating blade, a toner receiver member, and a vibration generating device. The developing device is capable of executing a toner collecting mode in which the vibration generating device vibrates the toner receiver member so that toner deposited on the toner receiver member is shaken off by vibration and is collected into the second conveying chamber, in the non-image formation period. The developing device is capable of executing a forced discharge mode in which developer containing the collected toner collected from the toner receiver member into the second conveying chamber is forcibly discharged from the developer discharging portion to outside of the developing container, after the toner collecting mode is executed.

Abstract: A developing device includes a developing roller, a toner supply roller, a regulating blade, a casing, a toner-reception supporting member, a toner reception member, and a vibration generating unit. The toner-reception supporting member is opposed to the developing roller or the toner supply roller between the regulating blade and the image carrier. The toner reception member is located so as to make a downward slope toward the toner supply roller side from the image carrier side along a longitudinal direction of the toner-reception supporting member. The toner reception member has a toner receiving surface that receives the toner dropping from the developing roller. The vibration generating unit vibrates the toner reception member. The toner reception member includes a sheet-shaped toner crushing member attached to overlap approximately a whole region of the toner receiving surface in a longitudinal direction. The toner crushing member is swingably supported with respect to the toner receiving surface.

Abstract: An image forming apparatus includes: an image forming portion that includes a developing portion configured to supply toner to an image bearing member bearing an electrostatic latent image formed thereon to develop the electrostatic latent image as a toner image, and is configured to form a toner image on a long paper sheet; a notification portion configured to notify a user about information; and a control portion configured to calculate, in accordance with coverage of a toner image that is a target of image formation, a toner image formation distance with which successive image formation is possible without forcibly discharging degraded toner from the developing portion, and to control the notification portion to notify the calculated toner image formation distance as a first toner image formation distance.

Abstract: To provide a composition for a cleaning blade for an electrophotographic apparatus, and a cleaning blade for an electrophotographic apparatus that are capable of suppressing wear, chipping, curling, and contamination. A urethane composition contains (a) a polyester polyol, (b) a polyisocyanate, and (c) a modified silicone oil, wherein the (c) modified silicone oil contains a polysiloxane block and an alkylene oxide block, the alkylene oxide block having a hydroxyl group protected by a protecting group, and the (c) modified silicone oil has no hydroxyl group. A cleaning blade is made of a molding of the urethane composition and contains a polyurethane elastomer and the (c) modified silicone oil.

Abstract: Disclosed is a toner for developing an electrostatic latent image, the toner comprising a plurality of toner particles, each toner particle includes: a core particle that contains a binding resin, a coloring agent, and a releasing agent; and an external additive attached to the surface of the core particle, wherein the toner has two endothermic peaks in a heat curve, which is obtained at the time of the secondary temperature rise in differential scanning calorimetry of the toner, and a stepped endothermic curve; and first and second melting temperatures, which are determined to be the locations of vertices of the two endothermic peaks, a glass transition temperature, which is determined to be the midpoint of a linear portion of the stepped endothermic curve, and first and second heat of melting, which are determined to be the areas of the two endothermic peaks, satisfy the condition set forth herein.

Abstract: Provided is a technique for manufacturing a toner supply roller in which the toner conveying performance and the scraping performance of unneeded toner are excellent as well as the above-mentioned problems in molding can be resolved.

Abstract: A developing device of the present disclosure includes a developing roller, a toner supplying roller, a regulation blade, a casing, a toner receiver support member, a toner receiver member, and a vibration generator. The toner receiver support member is disposed inside the casing so as to face the developing roller or the toner supplying roller between the regulation blade and an image carrier. The toner receiver member is disposed along a longitudinal direction of the toner receiver support member, and has a toner receiving surface that receives toner falling from the developing roller. The vibration generator vibrates the toner receiver member. At each end part of the toner receiving surface in its longitudinal direction, there is formed a thin-walled portion that is thinner in thickness than other parts of the toner receiving surface.

Abstract: A developing device 43 includes a first rotation control portion and a second rotation control portion. When a developing process is performed, the first rotation control portion causes a developer carrying member to rotate in a first rotation direction at a first rotation speed previously determined. When the developing process is not performed, the second rotation control portion causes the developer carrying member to rotate at a second rotation speed V2 faster than a rotation speed V1 during the developing process in a direction X2 reverse to a development rotation direction X1, and then, causes the developer carrying member to rotate at a third rotation speed V3 slower than the second rotation speed V2 in the direction X2.

Abstract: An image forming apparatus includes a controller and multiple image forming units each of which includes an image bearer, a toner image forming device to form a toner image on the image bearer, a transfer device to transfer the toner image from the image bearer onto a transfer medium, a cleaning device to remove toner from a surface of the image bearer, a waste-toner tube through which toner removed by the cleaning device is transported, and a toner conveying member to transport toner by rotation and disposed inside the waste-toner tube. The controller changes a rotation speed of the toner conveying member for each of the multiple image forming units according to toner type including a first toner and a second toner having poorer flow properties than the first toner, and at least one image forming units uses the second toner and the rest use the first toner.

Abstract: A developing device includes a contact member and a developing adhesion member. The contact member is provided to an air releasing part communicating an inside and an outside of a developer case storing a developer containing a toner, in a condition being contactable with an agitating member agitating and conveying the developer in the developing case. The developing adhesion member is supported by the contact member and is configured to collect the developer within air flowing from the inside to the outside of the developing case and to receive vibration caused by agitating and conveying operations of the agitating member through the contact member.

Abstract: An object of the present invention is to provide a toner-conveying roller that has high toner-conveying property and in which a roller-shape thereof is less likely to be transferred to the image, a mold capable of manufacturing said roller, and a method of manufacturing said mold. The toner-conveying roller according to the present invention has a shaft body and a urethane foam layer formed around the shaft body, and recesses and protrusions are irregularly formed on a circumference surface of the urethane foam layer. The mold for manufacturing the roller according to the present invention has recesses and protrusions irregularly formed on the inner surface of a mold for manufacturing the roller.

Abstract: The present invention relates to a developing unit including a developer bearing member configured to bear a developer, the axis of the developer bearing member being inclined with respect to the axis of an image bearing member. The developing unit includes a developer accommodating chamber that accommodates the developer; and a conveying member provided in the developer accommodating chamber and supplying the developer from the developer accommodating chamber to the developer bearing member by rotation. The axis of the conveying member is inclined with respect to the axis of the developer bearing member. The developer conveying force of the conveying member differs depending on the position in the axial direction thereof and increases as the distance from the axis of the conveying member to the surface of the developer bearing member increases.

Abstract: A developing device includes: a developer container having first and second transport passages, for containing developer; a developer carrier for carrying, on its surface, developer inside the second transport passage; a first stirring/transporting member having a rotary shaft and a transport blade formed on its circumferential surface, for stirring/transporting developer inside the first transport passage; a second stirring/transporting member for stirring/transporting developer inside the second transport passage in a direction opposite to the first stirring/transporting member; a first developer passing portion for delivering developer from the first to the second transport passage; and a second developer passing portion for delivering developer from the second to the first transport passage.

Abstract: A developing apparatus includes a developing sleeve, a regulating member configured to regulate a developer, and first and second chambers forming a circulation route of the developer. A magnet is fixed in the developing sleeve and includes a first magnetic pole, a second magnetic pole having the same polarity as the first magnetic pole, and a third magnetic pole having a different polarity from the second magnetic pole. The second magnetic pole is arranged upstream of an intersection at which a vertical line passing through a rotation center of a first conveying member in the first chamber arranged below the rotation center of the developing sleeve intersects with a lower surface of the developing sleeve.

Abstract: An improved printer cartridge is provided with a barrier for reducing pressure on printing assembly components in an extended yield cartridge. A printing assembly, including cartridge casing, magnetic developer roller, and hopper, is provided for use with laser printers. A barrier formed by a base and a wall is positioned within the cartridge casing, between the magnetic developer roller and a feed section of the hopper. The wall of the barrier is tangent to the magnetic developer roller, minimizing the area of the magnetic developer roller which is exposed to a medium stored within the hopper and feed section, such as toner. Since exposed surface area is reduce, the amount of pressure on the magnetic developer roller is correspondingly reduced, allowing for an increase in lifespan for the magnetic roller and interactive components, primarily a doctor blade and sealing blade.

Abstract: A developing apparatus includes a developing unit configured to transfer a developer to an image carrying unit on which an electrostatic image is formed, a supplying unit configured to supply the developer to the developing unit, a regulating unit configured to regulate a thickness of the developer on the developing unit, and a repelling unit disposed between the supplying unit and the regulating unit and configured to repel the developer.

Abstract: A development device includes a development casing, a developer bearer, a first developer conveyance member to supply developer to the developer bearer, a second developer conveyance member to transport developer axially, and a partition dividing an interior of the development casing into a supply channel and a collecting channel via which developer received from a downstream end portion of the supply channel is forwarded to an upstream end portion of the supply channel. The supply channel includes a conveyance area and a buffer area disposed adjacent to the conveyance area in a direction perpendicular to an axial direction to temporarily retain developer and midway in the developer conveyance direction inside the supply channel, and an upstream end face defining an upstream end of the buffer area is inclined relative to the axial direction to draw away from the conveyance area downstream in the developer conveyance direction.

Abstract: A developing device includes a developer-carrying member and a developer control member, a supply member, and a rotating member that are disposed opposite the developer-carrying member. The developer-carrying member accommodates a magnetic source that generates a magnetic force for carrying a developer containing magnetic particles on an outer surface thereof. The developer control member controls the thickness of a layer of the developer carried on the outer surface of the developer-carrying member. The supply member rotates to transport the developer in a rotation axis direction thereof and to supply the developer to the developer-carrying member. The rotating member is disposed at a position where the rotating member is submerged in the developer between the developer control member and the supply member and rotates to supply the developer from between the developer control member and the supply member to the supply member.

Abstract: A drawing-up magnetic pole and a control magnetic pole of a magnetic field generator that is disposed in a developer carrier are adjacent to each other and a prevention member is provided that secures, between the prevention member and an upper end of a side wall of a developer supply conveyance path, a supply path through which a developer in the developer supply conveyance path passes toward the developer carrier at least over the entire width of a developing area and that prevents a control retained developer, which is prevented by a developer control member from passing through a control gap, from moving toward the surface of the developer carrier along lines of the control magnetic force. The peak of the magnetic flux density of the drawing-up magnetic pole in the normal direction is disposed below the lower end of the supply path.

Abstract: An image forming apparatus has a first voltage application section for applying a first bias to a magnetic roller, a second voltage application section for applying a second bias to a developing roller, and a controller for controlling the voltages of the first and second voltage application sections and the driving/rotating of the magnetic roller and the developing roller. When no image formation is taking place, the controller can execute a toner collection mode in which, with the first and second biases set at the same potential and the second bias set lower than the voltage applied to an image carrying member, the magnetic roller is rotated in the direction reverse to that in which it is rotated during image formation.

Abstract: A developing device includes a developer carrier which carries a developer containing a toner and a carrier, and a developing chamber which feeds the developer to the developer carrier. In addition, a conveying member conveys the developer of the developing chamber, and a regulating member regulates an amount of the developer coated on the developer carrier. A guide portion guides the developer to the developer carrier and forms a buffer portion that temporarily contains the developer fed from the developing chamber between the regulating member and the guide portion. The guide portion has a facing surface opposing the developer carrier along a front surface of the developer carrier and a guiding surface which guides the developer from an upper edge of the guide portion to a downstream side of the facing surface in a rotational direction of the developer carrier.

Abstract: A longitudinal end portion of an opposing magnetic member of a developer supporting rotator is positioned more longitudinally outside than a longitudinal end portion of a toner supporting side magnetic member. With respect to the opposing magnetic member facing the toner supporting side magnetic member and a downstream magnetic member disposed more downstream than the opposing magnetic member in a rotational direction, a magnetic force generated in a vicinity of both longitudinally end portions thereof is greater than a magnetic force generated longitudinally inside thereof. A housing includes a sealing portion that projects from a position facing a face at a longitudinal end portion of the developer supporting rotator toward the face, such that the sealing portion prevents the toner in a space between the face and an inner face of the housing from scattering outside.

Abstract: A developing device including a developer bearing member containing a magnetic field generator having multiple magnetic poles and a developer containing chamber is provided. The developer containing chamber contains a two-component developer comprising magnetic carrier particles having a saturated magnetization of 58 to 70 emu/g in a magnetic field of 1KOe and toner particles, and has a divider to define an upper supply chamber and a lower collection chamber. The supply chamber includes a supply conveyer to supply the two-component developer to the developer bearing member at an upstream side from the developing area. The collection chamber includes a collection conveyer to collect the two-component developer from the developer bearing member at a downstream side from the developing area. The multiple magnetic poles includes three developer bearing poles capable of bearing the developer on its surface.

Abstract: A development device includes a development casing, a developer bearer, a first developer conveyance member to supply developer to the developer bearer, a second developer conveyance member to transport developer axially, and a partition dividing an interior of the development casing into a supply channel and a collecting channel via which developer received from a downstream end portion of the supply channel is forwarded to an upstream end portion of the supply channel. The supply channel includes a conveyance area and a buffer area disposed adjacent to the conveyance area in a direction perpendicular to an axial direction to temporarily retain developer and midway in the developer conveyance direction inside the supply channel, and an upstream end face defining an upstream end of the buffer area is inclined relative to the axial direction to draw away from the conveyance area downstream in the developer conveyance direction.

Abstract: A developing device includes a case for housing a developer, a magnetic roller, an agitating member, a layer thickness restricting member, an auxiliary developer storing portion and a plate-like flexible member. The magnetic roller includes a rotary shaft and magnetically carries the developer on a circumferential surface. The agitating member includes a shaft center and a screw forming portion arranged around the shaft center and agitates and conveys the developer while rotating. The layer thickness restricting member restricts the layer thickness of the developer to a predetermined thickness. The auxiliary developer storing portion faces the circumferential surface of the magnetic roller at a side upstream of the layer thickness restricting member in a rotating direction of the magnetic roller. The plate-like flexible member extends toward the circumferential surface of the magnetic roller and forms a wall surface on an upstream side of the auxiliary developer storing portion.

Abstract: A developing device includes: a developing member including a magnetism-generating member having plural magnetic poles polarized in a circumferential-direction thereof, and a rotating member that is rotated about the magnetism-generating member; a developer-pumping pole provided in the magnetism-generating member, and that pumps up the developer, which is supplied from a developer accommodating portion, to the rotating member surface; a developer-peeling-off pole provided in the magnetism-generating member below a rotation axis of the rotating member in a vertical direction on an upstream side of the developer-pumping pole in a rotational-direction of the rotating member, that peels off the developer from the rotating member surface; and a magnetic body provided in at least a portion between a facing position facing the developer-peeling-off pole in a circumferential-direction of the rotating member and an intermediate position between the developer-peeling-off pole and the developer-pumping pole in the circu

Abstract: A development unit including: a developer carrier configured to carry a developer, and capable of supplying the carried developer to an electrostatic latent image; and a developer supplying member configured to supply the developer to the developer carrier and having a surface thereof made of a foamed body. Relationships expressed by v<S/10 and S/Dv?125 are satisfied, where a cell opening size of the foamed body is S [?m], a volume mean particle diameter of the developer is Dv [?m], and a volume ratio of particles having a particle diameter of 5 [?m] or less to the total developer is v [%].

Abstract: The developing device includes: a developing container that stores a developer including a non-magnetic toner and a magnetic carrier; a toner bearing member that bears the toner and conveys the toner to a developing portion; and a separating portion wherein a surface of the toner bearing member includes a plurality of recess structures in which a smallest opening width R is equal to or larger than rt10 and equal to or smaller than rc10, and a depth D is equal to or larger than rt10/2, where rt10 is a particle diameter in which an accumulated number distribution in a toner granularity distribution is 10%, and rc10 is a particle diameter in which an accumulated number distribution in a carrier granularity distribution is 10%; and a percentage of the recess structures per unit area in a toner bearing region of the toner bearing member is equal to or larger than 55%.

Abstract: A developing device includes a developing member including a scooping pole generating the magnetic lines of force to scoop up a developer, rotating while holding the developer scooped up by the scooping pole on a surface thereof, and supplying the developer to an image holding body to develop the electrostatic latent image, and an agitation transport unit that is disposed at a position where a developer used for development and separated and falling from the developing member is received, rotates about a rotating shaft extending along a rotating shaft of the developing member, agitates the developer, and transports the agitated developer to a scoop position, wherein the scooping pole is disposed on the downstream side of a line, which connects the rotating shaft of the developing member with the rotating shaft of the agitation transport unit, in a rotation direction of the developing member.

Abstract: A developing device to develop with two-component developer an electrostatic latent image includes a developer bearer to carry thereon developer supplied to the latent image bearer, a first conveyance channel disposed adjacent to the developer bearer, a second conveyance channel disposed adjacent to the first conveyance channel and farther from the developer bearer than the first conveyance channel, a first conveying member disposed in the first conveyance channel to agitate and transport developer supplied to the developer bearer, a second conveying member including a spiral blade winding around a shaft to transport developer in the second conveyance channel in a predetermined developer conveyance direction, and a collected-developer guide to guide a part of developer that leaves the developer bearer to the second conveyance channel beyond the first conveyance channel.

Abstract: A developing device includes a developing roller, toner supplying roller, regulation blade, and casing. The developing roller faces an image carrier on which an electrostatic latent image is to be formed, and supplies toner to the image carrier. The toner supplying roller faces the developing roller, and supplies the toner to the developing roller. The regulation blade faces the toner supplying roller at predetermined distance. The casing houses the developing roller, toner supplying roller, and regulation blade. The casing includes a toner catching support member facing the developing roller or the toner supplying roller between the regulation blade and the image carrier. The developing device further includes a toner catching member, which is arranged along a longitudinal direction of the toner catching support member and catches toner that drops from the developing roller, and a vibration generating portion, which vibrates the toner catching member.

Abstract: A developing device includes a first developing member rotating such that a moving direction of a portion opposing the image carrier is opposite a moving direction of the image carrier. A second developing member is provided on a downstream side of the first developing member in a rotating direction of the image carrier rotating such that a moving direction of a portion opposing the image carrier is the same as the moving direction of the image carries. A distributing member is supported movably relative to a proximal portion where the first developing member is closest to the second developing member so as to distribute developer to the first and second developing members by contact with the developer, and a biasing member biases the distributing member upstream in the rotating direction of the first developing member.

Abstract: A developing device includes a developer carrier that holds a developer on a surface thereof, rotates around a rotation axis, and supplies the developer to an image carrier at a facing portion at which the developer carrier faces the image carrier; a transport member that transports the developer in a transport direction along the rotation axis while supplying the developer to the surface of the developer carrier; and a guide member that includes a guide portion that guides, toward downstream in the transport direction, the developer that has passed the facing portion without being supplied to the image carrier, the guide member making an amount of the developer that reaches the transport member on an upstream side of the guide portion in the transport direction be smaller than an amount of the developer that reaches the transport member in on a downstream side of the guide portion.

Abstract: A developing device in the embodiment includes: a developer carrier that carries a two-component developer, moves the surface, and supplies the toner to a latent image on a surface of a latent image carrier; a first conveying member that conveys the developer in a first conveying path; a second conveying member that conveys the developer in a second conveying path; and a developer passing unit that conveys upward the developer which has reached at a conveying-direction posterior end of the second conveying path and passes the developer to the first conveying path. The developer passing unit includes a plurality of pushing members that push up the developer. The developer can pass through from upper surfaces of the pushing members to lower surfaces of the pushing members.

Abstract: A development device includes a developer bearer to carry the developer to a development range, a magnetic field generator disposed inside the developer bearer for generating magnetic force, a developer regulator for adjusting an amount of the developer, a developer supply compartment disposed adjacent to the developer bearer, separated by a side wall from a portion where the developer bearer is provided, a developer agitator provided in the supply compartment, and a blocker disposed above the side wall of the supply compartment across a supply gap through which the developer moves from the supply compartment. The magnetic field generator has an attraction magnetic pole and a regulation magnetic pole. The blocker prevents the developer blocked by the developer regulator from moving along a magnetic force line of the regulation magnetic force toward the circumferential surface of the developer bearer.

Abstract: A developing unit according to an embodiment of the present disclosure includes a developer container, a stirring member, a magnetic roller, a developing roller, a developer supply port, and a developer discharge portion. The developer discharge portion includes a discharge blade having a spiral blade and conveying an excess developer, a developer discharge port through which the excess developer conveyed by the discharge blade is discharged outside of the developer container, and an air outlet through which an airflow in the developer container passes toward the outside of the developer container. The developer discharge port is located at a position lower than the upper surface of the developer present in the developer discharge portion; and the air outlet is located at a position higher than the upper surface of the developer present in the developer discharge portion.

Abstract: A development device includes a developer bearer, a developer regulator to adjust an amount of developer on the developer bearer, a supply compartment adjacent to the developer bearer across a side wall formed monolithic with the development casing using an identical material, a developer supply member to transport developer in the supply compartment in an axial direction, and a channel forming member having higher rigidity than that of the side wall. The channel forming member defines, with the side wall, a supply route extending over an entire development range, through which developer moves from the supply compartment to the developer bearer, and defines, with an inner wall of the development casing, a collecting route through which developer blocked by the developer regulator is collected in the supply compartment. Both axial end portions of the channel forming member are supported by the development casing.

Abstract: A developing device includes a developing sleeve, a magnet roller mounted in the developing sleeve, a first conveying screw feeding a developer to the developing sleeve, and a regulating blade regulating a layer thickness of the developer. The developing device further includes a guide member that backs up the developer from the first conveying screw at an upstream side of the regulating blade based on a rotational direction of the developing sleeve and that forms a buffer portion temporarily containing the developer between the regulating blade and the guide member. The guide member is installed so that a direction of a resultant force of a magnetic force and a gravitational force acting on a carrier particle becomes a direction away from a surface of the guide member on a facing surface of the guide member which is opposite to the regulating blade.

Abstract: A development device includes a developer bearer to carry the developer to a development range, a magnetic field generator disposed inside the developer bearer for generating magnetic force, a developer regulator for adjusting an amount of the developer, a developer supply compartment disposed adjacent to the developer bearer, separated by a side wall from a portion where the developer bearer is provided, a developer agitator provided in the supply compartment, and a blocker disposed above the side wall of the supply compartment across a supply gap through which the developer moves from the supply compartment. The magnetic field generator has an attraction magnetic pole and a regulation magnetic pole. The blocker prevents the developer blocked by the developer regulator from moving along a magnetic force line of the regulation magnetic force toward the circumferential surface of the developer bearer.

Abstract: A developing system includes a first developer carrier to carry and supply two-component developer including toner and carrier to a latent image formed on an image bearer. A first magnetic field generator having plural first magnetic poles is rotatably installed in the first developer carrier and causes the two-component developer to put forth ears and conveys the two-component developer on the developer carrier. A cross-sectional center of the first magnetic field generator is deviated from that of the first developer carrier toward the image bearer by a prescribed length. A developer peel-off device including a second magnetic field generator is provided in the vicinity of the surface of the first developer carrier to peel off the developer not supplied to the image bearer and remaining on the surface of the first developer carrier.

Abstract: A developing device includes a developing roller, a magnetic roller, a capacitor, a transformer, and a control signal generating unit. The developing roller carries toner. The magnetic roller performs supply of toner to the developing roller and removal of toner from the developing roller. The transformer includes a primary side to which a capacitor is connected and a secondary side from which an AC voltage is output and applied to the developing roller. The control signal generating unit inputs a control signal to the capacitor and adjusts a DC bias value of the control signal so that a DC component of the control signal is the same before and after the change of the duty ratio of the control signal.

Abstract: A developing device includes a developer accommodating chamber containing a developer; a developer carrying member for carrying the developer to develop an electrostatic image; a feeding belt for feeding the developer toward the developer carrying member by rotation of the driving roller in a stretched state in which the feeding belt is stretched by a driving roller and a follower roller; and a switching mechanism for switching the feeding belt from a loosened state in which the feeding belt is looser than in the stretched state to the stretched state.

Abstract: A developing device includes a developer supporting rotator, toner supporting rotator and voltage application unit. The toner supporting rotator is arranged opposite to a developer supporting rotator, supports toner supplied from the developer supporting rotator, and forms a toner layer by a magnetic brush. The voltage application unit causes the toner supported by the toner supporting rotator to an electrostatic latent image on a surface of an image carrier to develop it into a toner image. A longitudinal end portion of the toner supporting side magnetic member is positioned longitudinally more outside than a longitudinal end portion of the developer supporting side magnetic member. A surface of the second rotating sleeve positioned more outside than the end of the developer supporting side magnetic member is composed of a surface of low adherence with lower toner adherence and a higher dielectric constant than those of a surface positioned inside thereof.