Abstract: In a developing device, a developing roller has: a first rotational shaft extending in a first direction; and a first roller body covering the first rotational shaft and configured to carry developer. A supply roller has: a second rotational shaft extending in the first direction; and a second roller body covering the second rotational shaft and configured to supply the developer to the developing roller. A housing accommodates the developing roller, the supply roller, and the developer. The housing includes a first wall and a second wall opposed with each other in the first direction. The first wall is formed with a first cutout. The second wall being formed with a second cutout. The first rotational shaft and the second rotational shaft are positioned in both the first cutout and the second cutout when projected in the first direction.

Abstract: A developing device includes: a developer carrying member, rotatable while carrying a developer, for supplying the developer to an image bearing member; a developer supplying member, which is provided with a foam layer at its surface and is rotatable in contact to the developer carrying member, for supplying the developer to the developer carrying member; a first gear for transmitting a driving force to the developer supplying member; and a pressing member for pressing the first gear so that the first gear is, during initial drive of the developer carrying member, moved from a first position where the driving force is not transmitted to the developer supplying member to a second position where the driving force is transmitted to the developer supplying member.

Abstract: Provided is a developing device which can prevent the occurrence of a phenomenon of an excessive increase of a developer quantity in a developer standby space, thereby acquiring a stable image. The developing device comprises a developer agitation-transfer unit, a developer roller, a developer feeding roller, a developer guide member and a space forming member. The developing device is characterized in that the developer feeding roller rotates to transfer the developer transferred by the agitation-transfer means, upward from the clearance between the developer feeding roller and the developer guide member, and in that, when the developer standby space formed in the device is filled with the developer transferred by the developer feeding roller, the developer feeding roller is rotated to carry the developer, which overflows from the developer standby space, and to move the same in the direction away from the developer roller, so that the developer is once discharged from the developer standby space.

Abstract: A development system (10) for an electrophotographic printer with multiple augers containing a development roller (11) and a first channel contains a feed auger (13) and developer, with a plurality of paddles (12) attached to the feed auger, at least some the paddles increase in size with respect to a previous paddle along a direction of developer flow (18). This arrangement of paddles ensures that a uniform layer of developer is formed on the development roller despite the volume of developer in the first channel decreasing along the length of the first channel in the direction of developer flow.

Abstract: A developing device of an image forming apparatus to convey a developing agent, the developing device including a housing having a developing agent accommodating compartment disposed therein, a first rotation member and a second rotation member that are disposed inside the developing agent accommodating compartment, a plurality of developing agent convey members that rotate around the first rotation member and the second rotation member being arranged along a shaft direction of the first rotation member, and at least one torque limiter coupled to between the first rotation member and at least one of the plurality of developing agent convey members, the at least one torque limiter to allow at least one of the plurality of developing agent convey members to perform a relative rotation with respect to the first rotation member when a load is applied to the plurality of developing agent convey members is varied.

Abstract: A developing device for use with an image forming apparatus, includes a developing roller for carrying a developer and for forming a developer image on an image bearing member; a supplying roller for supplying the developer to the developing roller, wherein the supplying roller has a foam layer at its surface and forms a nip between itself and the developing roller; an accommodating portion, provided below the supplying roller, for accommodating the developer; and a feeding member for feeding the developer from the accommodating portion onto the nip by being rotated in a direction opposite to a rotational direction of the supplying roller. The supplying roller is rotated in a direction which is from a lower end of the nip to an upper end of the nip. The supplying roller is provided so that its top is higher than a top of the developing roller.

Abstract: An image forming apparatus provided with an image carrying member to carry an electrostatic latent image, a toner carrying member to develop the electrostatic latent image on the image carrying member with toner; a first developer carrying member to carry developer containing toner, carrier, reverse polarity particles and to supply toner to the toner carrying member; and a second developer carrying member to carry developer and to recover toner on the toner carrying member, wherein an ability to move the reverse polarity particles from the toner carrying member to the first developer carrying member is larger than an ability to move the reverse polarity particles from the second developer carrying member to the toner carrying member.

Abstract: A developer supplying member includes a foamed member formed of continuous foams for supplying developer to a developer supporting member. The foamed member has a high resistivity in terms of electrical conductivity through ion conductivity, and has a low resistivity in terms of electrical conductivity after carbon black is attached to foam cell walls thereof.

Abstract: A development device includes a developer container internally divided by a partition into a supply path and a recovery path, a developer bearing member, a supply conveyance member to apply force to convey developer to a developer retaining space through the supply path, the developer retaining space retaining the developer to be conveyed by the developer bearing member, a recovery conveyance member, a communication pathway provided between the supply path and the developer retaining space, the communication pathway passing the developer from the supply path to the developer retaining space, and a developer softening member to soften the developer that is present above the partition, provided at least one of at a position in the communication pathway and at a position close to the communication pathway.

Abstract: A developing device includes a developer supporting member for supplying developer to an image supporting member; a developer supplying member for supplying developer to the developer supporting member; and a stirring member disposed to be freely rotatable. The stirring member includes a free end portion arranged to contact with the developer supplying member and a stirring section for stirring developer when the stirring member rotates.

Abstract: A developer supply device, comprising a casing having an opening facing a supply target and a developer reservoir portion provided on an opposite side; a roller-like developer holding body placed around the opening to face the supply target; a main carrying substrate that is located to face the developer holding body at a downstream end portion thereof in a developer transport direction and is configured to carry the developer through a traveling electric field to the developer holding body; and a sub carrying substrate that has a facing part to face the main carrying substrate, the sub carrying substrate being configured to carry the developer from the developer reservoir portion to the facing part through a traveling electric field, and wherein the sub carrying substrate carries the developer in the facing part in a direction opposite to a direction in which the main carrying substrate carries the developer.

Abstract: A developing device includes a developing container for accommodating a developer; a developer carrying member, provided rotatably in the developing container, for carrying and feeding the developer to develop an electrostatic image; a developer feeding member, including an elastic feeding portion and being rotatably provided in the developing container, for feeding the developer in the developing container toward the developer carrying member; and a circulation changing member for changing circulation of the developer in the neighborhood of the developer carrying member. In a plane perpendicular to a rotational axis of the developer carrying member, the circulation changing member is provided in a maximum rotation area of the developer feeding member so as to create a gap between itself and an entire inner surface of the developing container and a gap between itself and the developer carrying member.

Abstract: Background development in a multi-color electrophotographic printer is reduced. A print job including a plurality of separations is received. Each separation has an image area and a non-image area. A printer is provided, including a development member for supplying toner to a photoreceptor for each separation. A developing and a non-developing zone are determined for each separation, corresponding to the image area and non-image area, respectively. Developer is automatically supplied to the development members, and automatically removed developer from the respective non-developing zone of each development member.

Abstract: A developing unit including a retainer receiving portion for receiving a developer retainer, a first agitation portion adjacent to the retainer receiving portion, a second agitation portion adjacent to the first agitation portion, a first conveyance member received in the first agitation portion, a second conveyance member received in the second agitation portion, a layer thickness limiting member made of a magnetic material and disposed between the second conveyance member and the developer retainer to limit the layer thickness of a developer retained on the surface of a retaining member, and a blocking portion disposed on the upstream side of the layer thickness limiting member in the rotation direction of the retaining member and in a space located between the layer thickness limiting member and the second agitation portion to block a developer on the upstream side of the layer thickness limiting member from entering the space.

Abstract: A developer supply device, comprising: a developer holding body having a circumferential surface and a rotation axis extending in a main scanning direction and being placed to face a supply target at a developer supply position; a carrying substrate that has a plurality of electrodes arranged along a direction intersecting with the main scanning direction and that carries a developer in a developer transport direction through a traveling electric field generated by application of a multiphase alternating voltage to the plurality of electrodes, the carrying substrate being located such that an end of the carrying substrate in the developer transport direction is positioned to face the developer holding body; and a voltage application unit configured to apply, to the plurality of electrodes and the developer holding body, the multiphase alternating voltage having alternating components synchronizing with each other.

Abstract: A developer supply device configured to supply charged development agent to an intended device is provided, the developer supply device including a developer storage section storing the development agent, an electric-field transfer board that includes transfer electrodes arranged along a developer transfer path in parallel with each other, and transfers the development agent stored in the developer storage section along the developer transfer path when the transfer electrodes are supplied with a multi-phase alternating-current voltage, and a brush roller that is disposed to face the intended device in a predetermined developer supply position and face the electric-field transfer board in a predetermined developer carrying position, and configured to receive the development agent from the electric-field transfer board in the predetermined developer carrying position and carry the received development agent to the predetermined developer supply position where the development agent is supplied to the intended de

Abstract: A developer supply device is provided, which includes a casing including a developer storage section at a bottom portion therein and an opening formed at an end thereof away from the developer storage section, development agent chargeable with a predetermined polarity, stored in the developer storage section, and a transfer board that is disposed in the casing and configured to transfer the development agent stored in the developer storage section when a multi-phase alternating-current voltage is applied to transfer electrodes of the transfer board. The development agent includes a mother particle having, around an outer surface thereof, an electrically insulating layer without a polar group having a charge polarity identical to the predetermined polarity, and an external additive, absorbed to around the mother particle in an easily desorbable manner, which is an electrically insulating fine particle having a charge polarity identical to the predetermined polarity.

Abstract: A developing unit includes a developer receiving vessel and a developer conveyance member as defined herein, the developer conveyance member includes a rotary shaft, a first conveyance member and a second conveyance member as defined herein, the second conveyance member is supported on the rotary shaft and bent in contact with the wall surface of the developer receiving chamber with rotation of the rotary shaft while conveying the developer toward the developer retainer, and the second conveyance member includes a second conveyance member body supported on the rotary shaft and located out of the overlapping range, and a second overlapping portion extending from the second conveyance member body to the other axial end of the overlapping range, designed to be movable relatively to the rotary shaft and disposed adjacently to an upstream side of the first overlapping portion in a rotation direction.

Abstract: A developer unit according to one aspect of the invention includes: a developer accommodation member configured to accommodate a developer having charging polarity to a first polarity opposite to a second polarity; a developing roller arranged at the developer accommodation member, the developing roller being configured to carry the developer; a supply roller arranged at the developer accommodation member and configured to supply the developer to the developing roller, an image formation width being defined on a surface of the supply roller along an axis direction of the supply roller; and a charging member brought into sliding contact with an outside of the image formation width of the supply roller. The charging member at a portion brought into sliding contact with the supply roller is formed of a material which is positioned on a side of the second polarity on a triboelectric series relative to the supply roller.

Abstract: A developing apparatus includes a frame supporting the developing roller; a sealing member provided at each of one and the other ends of the developing device frame and contacted to the developing roller to prevent leakage of the developer; and a developing blade contacted to the developing roller to regulate an amount of the developer carried on the developing roller, the developing blade having a free end in a downstream side with respect to a rotational moving direction of the developing roller, wherein each of one and the other ends of the developing blade is provided with a projected portion projecting in the rotational axis direction between the developing roller and the sealing member.

Abstract: A developing unit includes a brush member that includes a base member and a plurality of raisings that are erected on a surface of the base. The brush member traps toner within the raisings and causes a flicker movement in the raisings of the brush so that the toner trapped within the raisings is shaken and flown due to the flicker movement to the surface of a toner carrying member.

Abstract: An image forming apparatus includes a toner supply member which is in contact with the toner carrier and is provided within the container, has a foam layer on its surface, rotates in a predetermined direction for image formation and supplies the toner to the toner carrier and has a contact area with the toner carrier with an uppermost stream position in the predetermined direction of the contact area being higher than a lowermost stream position and has a period when the toner supply member rotates in the opposite direction of the predetermined direction to increase the toner amount contained in the foam layer.

Abstract: A developing unit includes a toner storage portion containing toner and a toner supply member, and a development portion disposed above the toner storage portion. A partition wall divides the toner storage portion from the development portion. The partition wall includes a supply opening that defines a toner supply path from the toner storage portion to the development portion, and a discharge opening that defines a toner discharge path from the development portion to the toner storage portion.

Abstract: A method for detecting, in-situ, a cross-process linearity error in an image printing system that prints on an image bearing surface movable in the process direction is provided. The method includes placing marking material to form of a row of registration marks on the image bearing surface, detecting a position in a cross-process direction of each registration mark in the row using a linear array sensor that extends in the cross-process direction, and determining a correction function with a processor using the positions of the registration marks as detected by the linear array sensor to compensate for an error in the positions in the cross-process direction of the registration marks. The row of registration marks extends in a cross-process direction transverse to the process direction.

Abstract: In a hybrid development method using a plurality of toner carriers, a development device and image forming apparatus are provided, wherein high image quality in which toner density is not reduced even in the case of high speed printing and the occurrence of development hysteresis (ghost) is controlled is ensured by accelerating the collection of the post-development residual toner on the toner carrier. The counter-charge having occurred in the developer remains in the developer without decreasing to disappear until the developer moves to the second toner carrier on the downstream-side, wherein this counter-charge is caused by supplying toner to the first toner carrier upstream in the rotating direction of the developer carrier.

Abstract: A method and apparatus transfer a material from first roller within a container to at least one second roller, and transfer the material from the second roller to at least one third roller. The second roller and the third roller form a loading nip at a location where the second roller is closest to the third roller. The method and apparatus transfer the material from the third roller to at least one recipient device, and measure current flow between the second roller and the third roller using a measurement device. Then, the method alters the relative rotation rate difference between the first roller and the second roller based on the current flow to maintain a predetermined density of the material at the loading nip using a controller.

Abstract: A development device includes an image carrier configured to develop an electrostatic latent image by using a developer, a development member configured to supply the developer to the image carrier, a developer supply member configured to supply the developer onto a surface of the development member, and a developer restriction member including a contact portion configured to form a developer layer on the surface of the development member while being in contact with the surface. A curvature radius R [mm] of the contact portion of the developer restriction member is 0.17 [mm] to 0.28 [mm], both inclusive, and an ASKER F hardness [°] of the developer supply member is 181.82×R+9.09?F??250×R+130.

Abstract: A developer container for an image forming apparatus includes a developer accommodating chamber, provided with an opening, for accommodating a developer to be supplied to the opening; a feeding member, provided in the developer accommodating chamber and having an elasticity, for feeding the developer by rotation thereof; a deforming portion, provided in the developer accommodating chamber and contactable to the feeding member, for deforming the feeding member against the elasticity with the rotation of the feeding member; and a restoration portion for permitting the feeding member deformed by the deformed portion to restore elastically, thereby to throw the developer toward the opening, wherein a boundary portion between the deformed portion the restoration portion is disposed below a lower end of the opening.

Abstract: A donor roll assembly for a developer unit including a donor roll for delivering toner onto a moving photoconductive member. The donor roll is supported for rotation and has an input shaft, a gear slideably received on the input shaft, and a torsion damper for rotationally coupling the gear to the input shaft of the donor roll for torsion damping. The torsion damper includes a resilient member adapted to deform under torsion to damp speed error (jitter) of a driving component, such as a motor.

Abstract: A developing apparatus is incorporated in an image forming apparatus. An electrostatic latent image is formed on an image bearing body. A developing member supplies a developer material to the electrostatic latent image. A supplying member supplies the developer material to the developing member. A developer material chamber holds the developer material therein. A layer forming member is provide in the proximity to the supplying member, and forms a layer of the developer material. The layer forming member is positioned such that a gap ?g is defined between the layer forming member and the supplying member. When the supplying member rotates, the surface of the layer forming member applies pressure to the toner on the supplying member to form the layer having a smooth surface not more than 0.5 mm.

Abstract: An image forming unit and an image forming apparatus comprising the image forming unit are supplied capable of preventing toner in bottom part of toner accommodating room from accumulating so as to obtain toner image with good quality. In the image forming unit, a developer accommodating section that accommodates developer; a developing member that supplies developer to an electrostatic latent image on an image carrying body; a supplying member that faces to the developing member and supplies developer to the developing member; and a conveying mechanism that conveys developer in bottom part of the developer accommodating section to the upper part of the developer accommodating section.

Abstract: A developing device is provided with a developing roller arranged to face a photoconductor for forming an electrostatic latent image and adapted to supply a toner to the photoconductor, an agitating member for agitating a developer, a supply roller that holds the developer agitated by the agitating member, and supplies the toner to an area facing the developing roller; a restricting member for blocking the developer supplied onto the supply roller and restricting the amount of the developer conveyed by the supply roller, and an intermediate roller including a first magnetic pole facing in a direction toward the staying developer by being restricted by the restricting member for attracting the staying developer and arranged at such a position as to face the developer blocked by the restricting member. Thus, the developing device can avoid image quality deterioration even when a developing process continues over a long period of time.

Abstract: A developing unit includes: a developing roller; a first conveying member provided in a first container, having a first shaft and a spiral blade, that agitates and conveys developer; a second conveying member provided in a second container connected to the first container via a hole, having a second shaft and a spiral blade, that agitates and conveys the developer; and a supplying member having a third shaft and a paddle blade, that supplies the developer conveyed by the first or the second conveying member to a developing roller, wherein: at least one of the first and second shafts includes a first portion that faces the hole and a second portion that does not face the hole; and a diameter of the at least one of the first and second shafts in at least a part of the first portion is smaller than a diameter in the second portion.

Abstract: An image forming apparatus includes a rotary for changing an attitude of a developing device to a first attitude in which developer in a developer accommodating chamber is feedable to a developer feeding member and to a second attitude in which the developer having been located above a nip between the developer feeding member and a developing roller drops from the nip. In the image attitude of the developing device, an electrostatic latent image is developed. In the second attitude of the developing device, detection of a remaining amount of the developer is carried out.

Abstract: A developing apparatus includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with a developer, and a developer feeding member, for supplying the developer to the carrying member. The developing apparatus also includes a regulating member for regulating an amount of the developer carried on the carrying member, the regulating member having a free end portion contacted to the carrying member. The developer feeding member is supplied with a voltage which is different from a potential of the developer member toward a regular charging polarity of the developer. The carrying member is provided with a surface facing substantially downward, in a range from a downstream-most edge of the developer member in the contact portion with respect to a rotational direction of the carrying member to a contact portion between the carrying member and the regulating member.

Abstract: A developer supply device configured to supply charged development agent to an intended device, includes a carrying assist member disposed, apart from a developer transfer path, to face a developer carrying surface of a developer carrying member at an upstream side relative to a developer carrying position, in which a transfer board is opposite and in closest proximity to the developer carrying surface, in a direction in which the developer carrying surface moves when the developer carrying member is driven to rotate. The carrying assist member is configured to, when a predetermined voltage is applied thereto, generate an electric field, under which the charged development agent heads for the developer carrying surface, between the carrying assist member and the developer carrying member.

Abstract: A developing device which includes a developing roller which supplies a toner to a photoreceptor and a supply roller which performs supply of a toner to the developing roller and peeling of a toner from the developing roller, and applies a bias voltage to the developing roller so as to develop an electrostatic latent image formed on the photoreceptor with a toner. The developing device includes a first current measuring portion which measures a value of a current flowing in the developing roller, a second current measuring portion which measures a value of a current flowing in the supply roller, and a control portion which calculates a toner charging amount on the developing roller and a toner peeled amount by the supply roller based on measured results by the first current measuring portion and the second current measuring portion.

Abstract: A developing device including a housing, toner a developing roller, and a feed roller in pressure contact with the developing roller so as to form a nip portion and which feeds toner to the developing roller. The developing device including a feed stabilizing member contacting a lower portion of the feed roller so as to form a second nip portion and restricting toner feed quantity. The feed stabilizing member extending from a generally triangular-shaped first region below the first nip portion up to one side of the nip portion opposite to the first region side. The developing device further including a toner circulation path for pushing back toner from the first region through below the feed stabilizing member to a second region on the one side opposite to the first region side with an aid of pressure of toner that tends to accumulate in the first region.

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: An image forming apparatus includes a developer tank which houses two-component developer containing toner and carrier, and a supply unit which supplies the developer tank with supply developer containing toner and carrier, wherein, when the ratio of mass of inorganic fine particles attached to the carrier contained in the two-component developer to mass of the carrier contained in the two-component developer is A, and when the ratio of mass of inorganic fine particles attached to the carrier contained in the supply developer to mass of the carrier contained in the supply developer is B, the following Formula (1) is satisfied: 0.7<B/A<0.96??(1).

Abstract: Provided are an image forming apparatus equipped with a hybrid developing apparatus including a toner-collecting developer-carrying member and a method for developing an electrostatic latent image, which apparatus is capable of stably forming high definition images without occurrence of a leakage current even under a high-humidity environment. In the apparatus, each of a toner-supplying developer-carrying member and the toner-collecting developer-carrying member has a conductive substrate to which a bias voltage is applied, and at least one of the surfaces of the conductive substrates of the toner-supplying developer-carrying member and the toner-collecting developer-carrying member has a resistive layer formed thereon.

Abstract: An image forming apparatus is provided. The image forming apparatus includes an accommodating member configured to accommodate developer; a supply member configured to supply the developer of the accommodating member; a developer holding member configured to supply the developer from the supply member to an image holding member; and a voltage controller configured to apply a first predetermined voltage to the supply member and apply a second predetermined voltage to the developer holding member so as to supply the developer from the accommodating member to the electrostatic latent image formed on the image holding member through the supply member and the developer holding member. The voltage controller, when starting to apply a voltage to the supply member, applies an excessive voltage to the supply member, the excessive voltage having a polarity same as the first predetermined voltage and being larger in an absolute value than the first predetermined voltage.

Abstract: A developing unit includes a toner storage portion for containing toner and a development portion for containing the toner supplied from the toner storage portion. The development portion includes a developing roller for supplying the toner to a photosensitive body, a supply roller and an auxiliary supply roller. The supply roller and the auxiliary supply roller rotate while facing each other to supply the toner to the developing roller. In the developing unit, an inequality that |D?(R1+R2)|?1.0 mm is satisfied, where a distance between the centers of the auxiliary supply roller and the supply roller in a region where the auxiliary supply roller and the supply roller face each other is D, a radius of the supply roller is R1, and a radius of the auxiliary supply roller is R2.

Abstract: An image-forming device can include an image acquiring unit that acquires image data, an image forming unit that forms an image based on the image data, a determining unit that determines whether the image data includes a part having density greater than or equal to a prescribed density, and a controller. The image forming unit can include a developing roller, a supply roller for supplying developer to the developing roller, and a bias applying unit that applies first and second voltages between the developing roller and the supply roller in first and second modes, respectively. The controller can control the bias applying unit to apply one of the first and second voltages when the determining unit determines whether the image data includes the part having density greater than or equal to a prescribed density.

Abstract: A developing unit includes a toner storage portion containing toner and including a toner supply member, a development portion disposed above the toner storage portion and containing the toner supplied from the toner storage portion by the toner supply member, and including a developing roller and a supply roller to supply the toner to the developing roller, and a partition wall to divide the toner storage portion and the development portion, and including an opening portion disposed under the lowest portion of the supply roller and forming a path of the toner supplied from the toner storage portion to the development portion.

Abstract: The image forming apparatus includes a developing cartridge mounted perpendicular to a horizontal printing medium delivery path. The developing cartridge contains a developer storage region, a supply roller, and a developing roller, which are successively arranged from the top to the bottom at one side of an optical path through which a vertically irradiated beam from a light scanning unit reaches a photoconductive medium, thereby ensuring the minimum body size.

Abstract: A toner supplying roller which is used in a developing apparatus and has the following characteristics: (1) an average diameter of a foam cell opening portion on a surface of a foam elastic member is 100 to 800 ?m, (2) an unopened cell closed by a skin layer of a film thickness of 50 ?m or less is present in the surface of the foam elastic member, and (3) assuming that a surface area of the foam elastic member is A, a total area of the foam cell opening portions is B, and a surface area of the unopened cell is C, the following relationship is satisfied: B A + 0.2 ? B + C A ? 0.95 .

Abstract: A development device includes: a developer carrier that is positioned to oppose an electrostatic latent image carrier and that supplies a developer to the electrostatic latent image carrier; a developer supply member that is positioned to oppose the developer carrier and that supplies the developer to the developer carrier; a developer charging member that is positioned to oppose the developer supply member and that charges the developer.

Abstract: A developer supply device, comprising: a carrying substrate having electrodes arranged along a developer transport path at predetermined intervals to carry a developer through a traveling electric field, wherein the carrying substrate comprises: a rigid upper carrying substrate formed to stand to carry the developer upward; and a flexible bottom carrying substrate curved to be a semispherical shape and is configured to charge the developer by friction with the developer and to be connected with a lower end portion of the upper carrying substrate so as to form a bottom surface of a developer reservoir portion, and wherein a joint portion of the bottom carrying substrate connected to the lower end portion is overlapped with the lower end portion such that the joint portion carries the developer in a same direction as a direction in which the developer is carried by the lower end portion.

Abstract: A developer supply device is provided, which includes a transfer board including an activating section and an always-transferring section. The activating section is disposed in a position close to a developer holding member and lower than a position where development agent is transferred onto the developer holding member. The activating section is supplied with an activating voltage for making the development agent leave a developer transfer path and drop into the developer storage section during an activating process performed at an initial stage of a developer transferring operation while supplied with the transfer bias voltage after the activating process. The always-transferring section is disposed across a position facing the developer storage section to a position lower than and adjacent to the activating section, and always supplied with a transfer bias voltage during the developer transferring operation.