Abstract: An image forming apparatus of the present invention includes a charging device including a charge roller formed with annular grooves at opposite end portions thereof and configured to charge an image carrier. Annular gap forming members each are fitted in the annular grooves for forming a gap between the charge roller and the image carrier. The gap forming members each have an area of 1.0×10?6 m2 to 3.0×10?6 m2 in a section containing the axis of the charge roller.

Abstract: The present invention provides an electrically conductive member including a core and a resin layer provided on an outer peripheral surface of the core, wherein the resin layer is made of a resin composition in which an electrically conductive agent is dispersed, and the abrasion amount of the resin composition, measured by JIS K6902, is 20 mg or less. Moreover, the present invention provides a unit for cleaning an image holding member, a process cartridge, and an image forming apparatus each using the electrically conductive member.

Abstract: An electro-conductive roll is provided that makes contact with a body to be charged in a state in which a voltage is applied thereto, and charges the body to be charged, a surface of the electro-conductive roll satisfying the following conditions (a) and (b): (a) the surface of the electro-conductive roll has a 10-point average roughness of 5 ?m or less; and (b) the surface of the electro-conductive roll has a dynamic ultra-microhardness in the range of 0.04 to 0.5.

Abstract: In a charging member having a support and one or more cover layer(s), the ten-point average surface roughness of the surface of the charging member, the height of a hill of the surface of the charging member, the area at the part of the hill, and the area of a region surrounded by hills each having the height H (?m) and other hills each having a height of not less than the height H (?m), and not including any hills having a height of more than 0.5H (?m) satisfy a specific relationship. Also, a surface layer of the charging member contains high-molecular compound particles whose average particle diameter is between 2 and 50 ?m and whose range of particle size distribution of average particle diameter is above 0?m and not greater than 7 ?m.

Abstract: A charging device includes a charge roller adjoining or contacting the surface of a photoconductive element. A DC and an AC voltage source output a DC and an AC voltage, which are applied to the charge roller. The AC voltage has a waveform pattern of at least one of white noise and pink noise.

Abstract: In an image forming system, an image-bearing member having a photoconductor layer comprising an Si-based non-single crystal material is charged at a relatively low potential of 250 to 600 volts by a contact charging member in the presence of electroconductive fine powder. An electrostatic latent image formed on the image-bearing member is developed with a magnetic toner which includes magnetic toner particles comprising at least a binder resin and a magnetic iron oxide, and inorganic fine powder and electroconductive fine powder present at the surface of the magnetic toner particles. The magnetic toner has a weight-average particle size of 3-10 ?m and an average circularity of 0.950 to 0.995, and contains 0.05 to 3.00% of isolated iron-containing particles.

Abstract: A charging member for being contactably disposed to an image bearing member and being supplied with a bias voltage includes a resistance layer having an ionic electrical conductivity. The resistance layer comprises a foamed elastic member and satisfies the following relationships: B?(5/3)×A?0.3, and B?0.6, wherein A represents a surface bubble-containing density measured, in a state that air bubbles are attached to the surface of said resistance layer, by immersion method according to JIS Z 8807; and B represents a surface bubble-deaerated density measured, in a state that said air bubbles are removed from the surface of said resistance layer, by immersion method according to JIS Z 8807.

Abstract: Aspects of the invention relate to hard imaging device charging systems, liquid electrophotography charging systems, hard imaging apparatuses, and hard imaging device electrophotography charging methods. In one embodiment, a hard imaging device charging system is described. The charging system may include a first charging device configured to charge a respective first region of a cylindrical image bearing member used to form latent images during hard imaging operations of the hard imaging device. The charging system may also include a second charging device configured to charge a respective second region of the cylindrical image bearing member used to form latent images during hard imaging operations of the hard imaging device. The first and second regions may have different radii from a central axis of the cylindrical image bearing member.

Abstract: An image forming apparatus including a latent image carrier and a developing means for charging a toner into a negative polarity by triboelectric charging, wherein the work function of the toner is set to be larger than the work function of the surface of the latent image carrier. When the apparatus includes an intermediate transfer medium, the work function of the toner is set to be larger than the work function of the surface of the intermediate transfer medium. In another embodiment, the work function ?OPC of the surface of the latent image carrier, the work function ?t of the toner, and the work function ?TM of the surface of the intermediate transfer medium are set to satisfy a relationship ?t>?OPC>?TM. These relationships help to reduce fog, and improve transfer efficiency which reduces the consumption of the toner.

Abstract: An image forming apparatus includes an image bearing member capable of being rotated, a first charging unit, an electrostatic image forming unit, a developing unit, and a second charging unit. The first charging unit is capable of being rotated in the same direction as a rotational direction of the image bearing member with being in contact with the image bearing member, and is capable of charging the image bearing member and toner on the image bearing member. The electrostatic image forming unit is capable of forming an electrostatic image on the image bearing member charged by the first charging unit. The developing unit is capable of collecting the toner on the image bearing member and visualizing the electrostatic image.

Abstract: An image forming apparatus of the present invention includes a charging device including a charge roller formed with annular grooves at opposite end portions thereof and configured to charge an image carrier. Annular gap forming members each are fitted in the annular grooves for forming a gap between the charge roller and the image carrier. The gap forming members each have an area of 1.0×10?6 m2 to 3.0×10?6 m2 in a section containing the axis of the charge roller.

Abstract: A charge roller that includes a metal core, an elastic member configured wrapped around the metal core, and film members is disclosed. Each of the film members is wrapped around each end of the elastic member in a circumferential direction of the metal core such that at least a part of each of the film members exists at every position around the ends of the elastic member in an axial direction of the metal core. Portions of the film members do not overlap each other in an radial direction of the metal core.

Abstract: In a conductive member having a support and provided thereon at least one cover layer, the cover layer has a surface layer, and the surface layer contains fine particles. In the surface layer, fine particles present at the surface-layer lower part corresponding to a range within 30% of the total layer thickness from the lowermost plane have an average particle diameter which is larger than the average particle diameter of fine particles present at the surface-layer upper part corresponding to a range within 30% of the total layer thickness from the uppermost plane. A process cartridge and an electrophotographic apparatus have such a conductive member.

Abstract: An image forming apparatus of the present invention includes a charging device including a charge roller formed with annular grooves at opposite end portions thereof and configured to charge an image carrier. Annular gap forming members each are fitted in the annular grooves for forming a gap between the charge roller and the image carrier. The gap forming members each have an area of 1.0×10?6 m2 to 3.0×10?6 m2 in a section containing the axis of the charge roller.

Abstract: A charging device of the present invention includes a charge roller adjoining or contacting the surface of a photoconductive element. A DC and an AC voltage source output a DC and an AC voltage, respectively. A voltage applying device superposes the DC and AC voltage and applies the resulting superposed voltage to the charge roller. A waveform controller causes the AC voltage source to generate an AC voltage having the waveform pattern of particular noise and frequency lying in a preselected range.

Abstract: A charging voltage controller of an image forming apparatus includes a charging roller charging a photoconductive drum with a predetermined charging voltage, a high voltage supply unit supplying the predetermined charging voltage to the charging roller, an electric current detecting unit detecting an electrical current flowing the charging roller, and a control unit supplying first and second test voltages of different degrees to the charging roller, determining a first reference voltage to be applied to the charging roller based on data from the electric]current detecting unit outputted in response to the first test voltage, calculating slope data based on the electrical current data detected from the electric current detecting unit in response to the first and second test voltages, and determining the charging voltage to be applied to the charging roller as a sum of the first reference voltage and a preset offset voltage that corresponds to the slope data.

Abstract: A charging apparatus includes plural charging devices including a first charging device and a second charging device, in which an absolute value of a current flowing from the second charging device to a member to be charged is 25% or less of an absolute value of a sum of currents respectively flowing from the plural charging devices to the member to be charged, thereby achieving uniform charging of the member to be charged.

Abstract: A charging member for charging a member to be charged, includes an elastic foam member provided at a surface of the charging member. The elastic foam member includes a plurality of cell portions with wall portion defining the cell portions. The gaps connecting the cell portions have areas which are not less than 5% and not more than 50%, for respective cells.

Abstract: A charging system includes a rotatable member to be charged, and a rotatable charging member provided with electroconductive particles thereon and forming a nip part with the member to be charged and disposed in the nip part to charge the member to be charged. When the diameter of the member to be charged is defined as LD (mm) and the diameter of the charging member is defined as LC (mm), LD?25 and LD×LC?350. As a result,, in the charging system, and a process cartridge and an image-forming apparatus including such a charging system, an image-bearing member can be made small in diameter.

Abstract: A charging unit, used for an image forming device, is provided, which comprises a conductive base, and a single-layered resistant layer, covering on a surface of the conductive base. The charging unit is in contact with an electrified body, and by applying a voltage to the conductive base, a charging process is performed in a contact charging manner. Furthermore, the single-layered resistant layer has a thickness equal to or below 0.7 mm, and has a surface resistance between 1×103 (?/?) and 1×1015 (?/?). Therefore, a charging roller can be made with a very simple structure of the single-layered resistant layer surrounding the core metal, so that a cheap conductive roller can be provided. In addition, the charging unit can be spaced from the electrified body by a small gap and the resistant layer can include nylon.

Abstract: A charging member electrically charges a member to be charged in a state that said charging member forms a nip with the member to be charged and electroconductive particles are present at the nip. The charging member includes an elastic foam member provided at a surface of said charging member. The elastic foam member includes cell portions and cell wall portions defining the cell portions. The cell wall portions have a thickness proportion to the cell portions of not less than 2% and not more than 40%.

Abstract: A charging apparatus includes a charging member, contactably provided to a member to be charged, for charging the member to be charged; a voltage application device for applying alternating voltages having different peak-to-peak voltages to the charging member; and a determination device for determining a peak-to-peak voltage to be applied to the charging member with respect to a second area of the member to be charged, on the basis of a peak-to-peak voltage corresponding to a minimum current which is not less than a predetermined current of alternating currents through the member to be charged when the alternating voltages having the different peak-to-peak voltages are applied to the charging member with respect to a first area of the member to be charged.

Abstract: A roller spacing device roller mechanisms having rollers in close contact under a given pressure to separate first and second rollers by a constant distance to keep the rollers from touching when roller mechanisms are not used for a long period of time. The roller spacing device comprises a spacing member shiftably mounted between first and second positions on a shaft having a partial D-cut portion and associated with one of the roller members to be separated. The spacing member has a spacing nose overlapped in the second position with an outer circumferential surface of a driving gear connected to the other roller member to separate the first roller member from the second roller member by the constant distance; and a shifting unit shifting the spacing member between first and second positions on the shaft.

Abstract: An image forming system that can prevent the image carrier from wearing because of excessive discharge, even under property fluctuations in the charging unit and surrounding conditions, and can maintain stable, excellent image quality for a long time. The system lowers fluctuations in current detection by making the characteristic of the AC charge current detection circuit variable and switching the AC charge current detecting characteristics between the voltages lower than discharge threshold voltage and the voltages higher than that.

Abstract: A method for regenerating a charging member for an electrophotographic system that is pressed against a surface of a body to charge the body, a charging member and a device for regenerating a charging member are provided. The method includes a step of applying heat treatment to the charging member. A used charging member, whose resistance is not decreased enough to recover a required chargeability by cleaning the surface thereof, can easily be regenerated and reused.

Abstract: A charging member for charging a member to be charged and an image forming apparatus provided with the same have electrically conductive particles and an electrically conductive particle bearing member having elasticity and bearing the electrically conductive particles thereon, and the degree of cohesion of the electrically conductive particles is 0.1 to 85%. Thereby, the non-uniformity of a halftone image peculiar to particle charging can be improved.

Abstract: A method of controlling a charging potential of an organic photoconductive cell (OPC) includes a first operation of applying two charging voltages Vc1 and Vc2 having respective duties D1 and D2 established in an engine controller unit (ECU) to a conductive roller via a high voltage power supply (HVPS) to charge the OPC, a second operation of measuring sensing voltages Vs1 and Vs2 through a sensing resistor Rs coupled to the conductive roller so that the ECU establishes a target charging current it and calculates a new charging voltage Vc3 and a new duty D3, a third operation of applying the new charging voltage Vc3 and the new duty D3 to the conductive roller via the HVPS to charge the OPC and measuring a charging current Ic3 of the conductive roller, and a fourth operation of comparing a difference between the charging current Ic3 of the conductive roller and the target charging current It with a tolerance value TOL to control the charging potential by using the target charging current when the difference is

Abstract: An image forming apparatus includes an image bearing member; a charging roller cooperable with the image bearing member to form a nip therebetween, for charging the charging roller is rotatable for counterdirectional peripheral movement relative to the image bearing member at the nip; a developing unit for developing with a developer an electrostatic image formed on the image bearing member; wherein the potential of a potential changing portion of the image bearing member changes with respect to the peripheral moving direction of the image bearing member; and wherein at tA (sec) after arrival at an upstream end of the nip, of the potential changing portion, the developing unit is supplied with a voltage for collecting particles from the image bearing member to the developing unit, where tA (sec) is a sum of a time duration required for a surface of the charging roller to move from the upstream end of the nip to a downstream end of the nip and a time duration required for a surface of the image bearing member

Abstract: In a charging member having a support and provided thereon one or more cover layer(s), where the ten-point average surface roughness of the surface of the charging member is represented by Rz (&mgr;m), the height of a hill of the surface of the charging member is represented by H (&mgr;m), the area at the part of the hill is represented by Sa (&mgr;m2), and the area of a region surrounded by hills each having the height H (&mgr;m) and other hills each having a height of not less than the height H (&mgr;m), and not including any hills having a height of more than 0.5H (&mgr;m) is represented by Sb (&mgr;m2), these Ra, H, Sa and Sb satisfy a specific relationship.

Abstract: The present invention provides an electrically conductive member comprising a core and a resin layer provided on an outer peripheral surface of the core, wherein the resin layer is made of a resin composition in which an electrically conductive agent is dispersed, and the abrasion amount of the resin composition, measured by JIS K6902, is 20 mg or less. Moreover, the present invention provides a unit for cleaning an image holding member, a process cartridge, and an image forming apparatus each using the electrically conductive member.

Abstract: An electrophotographic photosensitive member is disclosed in which a photosensitive layer and a protective layer are formed on a conductive substrate in that order. In this photosensitive member, when its surface is charged to −700 V under a 23° C./5% RH environment and irradiated with white light in a light quantity of 10 lux·sec, if the surface potential at the time 0.2 seconds have passed from the irradiation and the surface potential at the time 0.5 seconds have passed from the irradiation are defined as Vsl(0.2) and Vsl(0.5), respectively, the absolute value of Vsl(0.2) and the absolute value of Vsl(0.2)−Vsl(0.5) satisfy specific conditions.

Abstract: An electro-conductive roll is provided that makes contact with a body to be charged in a state in which a voltage is applied thereto, and charges the body to be charged, a surface of the electro-conductive roll satisfying the following conditions (a) and (b):

Abstract: An electrophotographic apparatus and a process cartridge have a charge unit for charging the surface of a photosensitive member by direct injection of electrical charge from a contact charging member to the photosensitive member. The charging unit also functions as a unit for supporting residual toner on the surface of the photosensitive member after transfer, for normalizing the electrical charge of the residual toner, and for returning the normalized residual toner to the surface of the photosensitive member. A developing unit also functions as a unit for recovering the normalized residual toner returned to the surface of the photosensitive member. The absolute value of the difference in charged potential between a first rotation and a second rotation of the photosensitive member is higher than 5 V and lower than 70 V. The photosensitive member has a charge injection layer having a specific composition and the charging member supports charged particles having specific characteristics.

Abstract: An image forming device is provided that is capable of easily preventing occurrence of stripe-like image noise that may be caused by intimate contact between a contact electrifying member and an image carrier even when an image forming operation is stopped for a while. In the image forming device having an electrifying roller in contact with a photoconductor, AC voltage is applied to the electrifying roller before the image carrier and the electrifying roller start rotating.

Abstract: An image forming apparatus includes a movable member; a roller contacted to the movable member, the roller having an elastic layer contacted to the movable member, the elastic layer having an ion electroconductivity and having a hardness of not less than 20° and not more than 50°, wherein the hardness and a density of the elastic layer satisfy (hardness/density)≧65, wherein the hardness is an Asker-C hardness of a material of the elastic layer cut out into a thickness of 4.0 mm under a weight of 500 g applied to the material.

Abstract: An electrophotographic photosensitive member includes a charge generating material and a charge transfer material. The charge transfer material contains a triarylamine compound synthesized from an amine compound and an aryl halide in the presence of a catalyst comprising a phosphine compound represented by formula (1) and a palladium compound: wherein Ar1 to Ar3 are each independently an alkyl or aryl group which may have a substituent group, and at least one of Ar1 to Ar3 is an aryl group. A process cartridge includes the electrophotographic photosensitive member.

Abstract: After an application of a first AC voltage for selecting a peak-to-peak voltage of a charging AC voltage for charging an image forming area of an image bearing member and before an application of a charging AC voltage, there is applied a second AC voltage having a peak-to-peak voltage larger than a peak-to-peak voltage of the first AC voltage.

Abstract: A conductive isolation member for electrophotography components is disclosed. In one embodiment, a cartridge for use in an image forming device includes a photosensitive drum, an electrophotography component, and a conductive isolation member electrically connected to the electrophotography component to permit discharge of static charge on the electrophotography component upon removal of the conductive isolation member.

Abstract: A charging device including: a charging roller having a metal cylinder and an elastic layer located on the metal cylinder; a cleaner configured to clean the charging roller, which includes an electroconductive brush roller including a roller having a shaft; and hair located overlying the roller, wherein the hair includes a fiber which has a width of from 0.1 to 20 denier, and a length of from 0.3 to 2.5 mm and which is planted at a density of from 7,000 to 46,000 lines/cm2, and a member configured to impart substantially the same potential as that of the charging roller to the electroconductive brush roller when a bias voltage is applied to the charging roller. A process cartridge and an image forming apparatus including the charging device are also provided.

Abstract: A conductive isolation member for electrophotography components is disclosed. In one embodiment, a cartridge for use in an image forming device includes a photosensitive drum, an electrophotography component, and a conductive isolation member electrically connected to the electrophotography component to permit discharge of static charge on the electrophotography component upon removal of the conductive isolation member.

Abstract: The present invention provides a conductive member used for a charging unit a development unit, a transfer unit, and a cleaning unit, which are used for electrophotographic apparatus or an electrostatic recording process. The conductive member includes an elastic layer and a resin layer, wherein the resin layer is formed on the outer side of the elastic layer directly or indirectly via another layer. When the surface of the resin layer being in a state not containing any conductive agent is charged due to corona discharge generated by applying a voltage of 8 kV to a corona discharger disposed with a gap of 1 mm put between the surface of the resin layer and the corona discharger, a surface potential of the resin layer after an elapse of 0.3 sec is in a range of 50 V or less and a surface potential of the resin layer after an elapse of 10 sec is in a range of 5 V or less.

Abstract: A charging roller for a contact charging assembly is provided including a conductive substrate, an elastic layer which covers the periphery of the conductive substrate, and a seamless tube externally so fitted as to cover the periphery of the elastic layer. The seamless tube constitutes a surface layer of the charging roller, and the charging roller has a surface of 3.0 &mgr;m or less in ten-point average roughness (Rz jis 94) and 0.10 mm or less in roughness curve average length (RSm).

Abstract: An image forming apparatus includes an image bearing member; a rotatable charging member, forming a nip with the image bearing member, for electrically charging the image bearing member; developing structure for developing an electrostatic image formed on the image bearing member to form a toner image, the developing structure supplying electroconductive particles to the image bearing member, wherein the electroconductive particles are fed to the nip by the image bearing member; and transferring structure for transferring the toner image onto a recording material at a transfer position.

Abstract: A first control member is disposed in a drum shaft away from a photoconductive drum, and a second control member is disposed in a roller shaft away from a transfer roller. The first and second control members abut on each other at their circumferential surfaces. This helps reduce an amount of displacement resulting from an impact caused by insertion of a recording paper sheet in between the photoconductive drum and the transfer roller, and thereby reduce vibrations in the photoconductive drum. Consequently, a toner image formed on the photoconductive drum and an unfixed toner image transferred onto the recording paper sheet are not affected by vibrations, so that a high-quality image is obtained that is free from blurriness or irregularities.

Abstract: A charging device, an image forming apparatus including the charging device, an image carrier unit including the charging device and a charging roller, which faces a body to be charged and is applied with a voltage, are disclosed. The charging roller includes a metallic core and an elastic member covering the core. Films are respectively wrapped around and adhered to the opposite end portions of the elastic member. Springs press the charging roller toward a body to be charged, causing the elastic member to deform due to compression. The maximum deformation of the films, which deform along the outer periphery of the elastic member, is selected to be smaller than the thickness of each film in the radial direction of the charge roller. A gap is therefore formed between the elastic member and the body to be charged. This prevents the portion of the elastic member, which corresponds to an image forming region, other than opposite end portions from contacting the surface of the body to be charged.

Abstract: A bracket to mount a charge roller and a blade against a photoconductive drum within an image forming apparatus. Bracket may include a pair of guides that extend outward to receive the ends of the charge roller. A biasing device may be positioned to bias the charge roller against the photoconductive drum. The guides may include an opening sized to allow the charge roller to move and maintain contact with the photoconductive drum. A mounting surface may be positioned on the bracket for receiving adhesive to mount the blade. In one embodiment, the bracket is constructed of an electrically conductive material such that a charge introduced to the bracket is delivered to the charge roller.

Abstract: In a charging roller having a support member and a conductive cover layer, the conductive cover layer is formed of a seamless tube. The seamless tube contains at least (A) a thermoplastic styrene elastomer, (B) a polystyrene resin and (C) a carbon black, and the proportion of the component (A) to the component (B) is (A)/(B)=60/40 to 20/80 in weight ratio. A process cartridge and an electrophotographic apparatus have such a charging roller.

Abstract: The present invention relates to a charging member for charging a surface of a member to be charged in an image-forming apparatus, and one aspect of the present invention provides a charging member having an outermost surface layer containing a conductive elastic material.

Abstract: The spacing member comprises: a spacing portion for spacing an electrophotographic photosensitive drum and a charging roller when the spacing member is attached to the process cartridge; a stopper portion for preventing a shutter member from retracting from a protection position for covering an exposure portion, when the spacing member is attached to the process cartridge; and a protective portion for covering a positioning portion, which positions the process cartridge in an apparatus body when the process cartridge is mounted in the apparatus body, when the spacing member is attached to the process cartridge. Thus, it is possible to reliably keep the spaced state between the photosensitive drum and the charging roller.

Abstract: A developing device according to the present invention includes a developer carrying member, a storage portion for storing a toner to be supplied to the developer carrying member, and a regulating member disposed in contacting relation with a surface of the developer carrying member for regulating the amount of toner carried on the developer carrying member, the surface of the developer carrying member having a rubber hardness of 20 to 70 degrees, an elongation of 400 to 1200% and a volume electrical resistance of 1×104 to 1×109 &OHgr;.cm, the toner containing an organic aromatic solvent and a vinyl monomer in combined concentrations of not more than 500 ppm.