Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of a member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a variable voltage waveform onto which a DC bias is superimposed. The amount of DC bias is selected to set the signal voltage such that a minimally acceptable amount of AC corona is created sufficient for uniform photoreceptor charging while avoiding unnecessary excessive positive corona that causes excessive photoreceptor wear.

Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a rectified AC waveform onto which a DC bias is superimposed after the waveform has been rectified. The result is the ability to raise the voltage potential of the photoreceptor with less pulse voltage and, more particularly, to increase the voltage potential of the photoreceptor along as if only DC voltage were applied far above what is possible in the prior art. Among the advantages of the invention is the ability to minimize photoreceptor wear at higher levels of photoreceptor charge since the DC-offset bias enables the second Paschen threshold to be avoided for higher levels of the photoreceptor charge.

Abstract: A toner includes a resin and a colorant; wherein the toner is obtained by carrying out a step of salting-out/fusing resin particles and colorant particles in a water-base medium, the toner satisfying the following relationship: 0.88≦F25/F50≦1.0, where F25 represents an adhesive stress at a toner temperature of 25° C., and F50 represents an adhesive stress at a toner temperature of 50° C.

Abstract: An apparatus for applying an electrical charge to a charge retentive surface, wherein a bias charge roll member is situated proximately to a surface to be charged such as, a photoreceptor. The bias contact roll member is supplied with an electrical bias including an oscillating voltage signal having, in one mode of operation, a clipped AC input voltage and in a second mode, an unclipped AC input voltage.

Abstract: A charger of the present invention includes a charging member contacting or adjoining an image carrier for charging the image carrier. A conductive facing member faces a portion of the charging member other than a portion of the same that faces the image carrier. Discharge occurs between the charging member and the facing member to thereby remove impurities deposited on the charging member. An image forming apparatus including the charger is also disclosed.

Abstract: An image forming apparatus has an image bearing member; and a charging member forming a nip with the image bearing member to charge the image bearing member. Conductive particles are provided in the nip and a time factor &agr; represented by a following equation satisfies a condition &agr;>15: &agr;=2&pgr;·k·Nc·(W/Vc)/(&rgr;·Cd·Z) Z=−0.5·1n(&pgr;·k·Nc)−1n({square root over (&bgr;)}·D/2) (&bgr;=1.

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: An electroconductive member contains an electroconductive composition using a thermoplastic elastomer material having advantages such as reduction in energy of production process thereof and capability of being recycled, and which makes it possible to prevent a change in resistance by sending an electric current, improve uniformity of electric resistance, and reduce dependency on an electric field and a resistance-change by environment. The electroconductive resin composition contains an epoxidized diene block copolymer; a thermoplastic elastomer other than the epoxidized diene block copolymer, a conductive agent and one of a thermoplastic resin and a compound having an amino group.

Abstract: An improved donor member for applying a toner release agent to a toned receiver comprises a support an intermediate layer disposed on the support, and an outermost layer formed from a cured composition comprising a fluorocarbon thermoplastic random copolymer, a curing agent, a particulate filler containing zinc oxide, and a curable aminosiloxane, wherein the fluorocarbon thermoplastic random copolymer has subunits of: —(CH2CF2)x—, —(CF2CF(CF3)y—, and —(CF2CF2)z—, and x is from 1 to 40 or 60 to 80 mole percent, y is from 10 to 90 mole percent, z is from 10 to 90 mole percent, and x+y+z equals 100 mole percent.

Abstract: A charging device is provided. The charging device comprises a charging member having two spacers made of tape, and the charging member is pressed to contact with the non-image forming region of an image supporter. The surface of the charging member between the spacers is opposite to the surface of the image supporter by a tiny gap. A charging voltage is then applied to the charging member to charge the image supporter. As the image supporter rotates, a large variation of the tiny gap can be avoided. The pressing force of the spacers against the image supporter is set at 4 N to 25 N (Newton), and in a moving direction of the surface of the supporter, a contact width of a contact portion where the spacer is pressed to contact with the image supporter is set below 0.5 mm.

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 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: An electrophotographic drum-shaped photoconductor has an electroconductive support and a photoconductive layer formed thereon, with a lubricating material being applied to the surface thereof in the shape of a plurality of bands spaced therebetween, constituting band-shaped lubricating material applied areas, extending along a circumference of the drum-shaped photoconductor in the direction perpendicular or substantially perpendicular to an axis of rotation of the drum-shaped photoconductor. An electrophotographic image formation method and an image forming apparatus employing the above-mentioned drum-shaped photoconductor are also disclosed.

Abstract: A charging member includes a conductive mandrel, a semiconductive foamed elastic layer provided on the periphery of the mandrel, and a functional double-layer film provided on the periphery of the semiconductive foamed elastic layer. The semiconductive foamed elastic layer is a layer formed by making the mandrel and a semiconductive rubber composition standing uncured and unfoamed pass through a crosshead die of an extruder to set the composition on the periphery of the mandrel, followed by curing and foaming. The semiconductive rubber composition has a Mooney viscosity of from 15 to 30 and has a curing percentage of 40% or less when the foaming pressure reaches 50%. The functional double-layer film is a double-layer tube having a thin layer such that a tube formed out of only the layer is hard to use for covering. Also disclosed are a process cartridge and an electrophotographic apparatus which have such a charging member.

Abstract: A charging device includes a rotatable elastic charging roller, contactable to a member to be charged, for electrically charging the member to be charged. The charging device also includes a DC voltage source for applying a DC voltage to the charging roller. The voltage source is capable of controlling the width of a variation of the DC voltage, the variation being caused by passage of a deformed portion of the charging roller, resulting from contact between the member to be charged and the charging roller, by a charging region of the charging roller for the member to be charged, to be not more than 1%.

Abstract: Apparatus for charging a substrate, comprising: an elongated charging member having a crowned surface; an elongated pressure member having, the pressure member being supported for pressure engagement with the charging member to form a nip therebetween adapted to receive the substrate. There is also disclose a method for making the apparatus.

Abstract: In order to solve the problem, there is provided a charging device having: a roll-like charging member disposed in contact with a surface of a member to be charged and for charging the surface of the member to be charged; wherein: the charging member includes a conductive substrate, and at least an elastic layer and a surface layer applied sequentially onto a surface of the conductive substrate; and opposite end portions of the surface layer axially project beyond opposite end portions of the elastic layer respectively, while the opposite end portions of the surface layer are made to cover the elastic layer and made open.

Abstract: An image forming method and apparatus, wherein a surface of a photoconductor is charged with a contact-type charging roller having a surface roughness of 2-40 &mgr;m, and exposed imagewise to form an electrostatic latent image thereon, the latent image being developed with a toner, transferred to a transfer member and fixed, and wherein the toner comprises a colorant, and a binder resin containing a tetrahydrofuran-soluble component having such a molecular weight distribution that at least one peak having a half width not greater than 15,000 is present between 1,000 and 10,000 when measured by gel permeation chromatography.

Abstract: The 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 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: A charging apparatus includes a charging member, contactably provided to a member to be charged, for charging the member to be charged; voltage application means for applying alternating voltages having different peak-to-peak voltages to the charging member; and determination means 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 bracket to mount a charge roller and a blade against a photoconductive drum within an image forming apparatus. Bracket may comprise 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: The present invention discloses: (1) an electrically conductive member including: a cylindrical base body; and electrically conductive powder sealed inside of the cylindrical base body in a substantially flowable state, or (2) an electrically conductive member including: a cylindrical base body; and electrically conductive powder sealed inside of the cylindrical base body so as not to completely fill the inner volume thereof, or (3) an electrically conductive member including: a cylindrical base body; and electrically conductive powder sealed inside of the cylindrical base body so as to fill only from 20 to 95% of the inner volume thereof. Moreover, the present invention discloses an image forming apparatus equipped with any of the electrically conductive members.

Abstract: A charging device includes a charging rotary member provided in contact with an image bearing member capable of bearing a toner for charging the image bearing member, in which a peripheral speed of the charging rotary member is different from a peripheral speed of the image bearing member, and the charging rotary member includes a surface layer frictionally charging the toner to a normal charging polarity.

Abstract: An object of the present invention is to provide an image forming apparatus that has an image bearing body, a flexible charging member constituting a nip portion together with the image bearing body, the nip portion being provided with conductive particles, and a developing member for developing an electrostatic image formed on the image bearing body, with use of a developing agent, wherein the developing agent has substantially spherical toner.

Abstract: An image forming apparatus includes an image bearing member and a charging member in proximity or in contact with the image bearing member. A frequency of an oscillating voltage is a first frequency when a peripheral speed of the image bearing member is a first peripheral speed, and the frequency of the oscillating voltage is a second frequency when the peripheral speed of the image bearing member is a second peripheral speed. A determining device determines a first peak-to-peak voltage of the oscillating voltage corresponding to the first peripheral speed and the first frequency and a second peak-to-peak voltage of the oscillating voltage corresponding to the second peripheral speed and the second frequency, based on first, second and third alternating currents flowing in the charging member in use of the first peripheral speed and the first frequency. The determined peak-to-peak voltages are applied to the charging member.

Abstract: To provide an amorphous Si photosensitive member and an image forming apparatus which form favorable images by preventing toner adhesion at a cleaning time. A photoconductive layer 102 containing amorphous Si is formed on an electrically conductive substrate 101 so that a surface of a photosensitive member has an average inclination &Dgr;a within a range of 0.12 to 1.0, more preferably 0.15 to 0.8 within a range of 10 &mgr;m×10 &mgr;m, and an electrically conductive substrate has surface roughness Ra within the range of 10 &mgr;m×10 &mgr;m is lower than 9 nm, preferably lower than 6 nm.

Abstract: A method of forming a toner image employing a photoreceptor is described.

Abstract: A charge roller of the present invention includes a shaft, an elastic member affixed to the circumference of the shaft, and a plurality of spacers affixed to the elastic member. Assume that rising portions formed, when the circumference of the elastic member is ground during production, at axially opposite end portions of the elastic member each have a width of W mm in the axial direction. Then, the spacers each are positioned at a distance of at least W/9 mm from the end of the elastic member toward the center in the axial direction.

Abstract: An image formation apparatus having a charge unit that charges a photosensitive member without contact, capable of accurately maintaining the gap between the charge member and the photosensitive member is provided. A gap keeping member is formed on the both ends outside the image area of a charge roller (1) as the charge unit by coating a diamond-like carbon film (3). The charge roller can be rotated, accompanied by rotation of the photosensitive member (6) via the diamond-like carbon film (3) contacted with the rotation of the photosensitive member (6). Thereby, the uniform charge can be applied by accurately maintaining the gap G with respect to the photosensitive member (6). The gap between the charge roller (1) and the photosensitive member (6) formed by the diamond-like carbon film (3) at the time is 100 &mgr;m or less, and both the direct current voltage and the alternative current voltage are superimposed between the charge roller (1) and the photosensitive member (6).

Abstract: A charging member for charging a member to be charged includes: an electrically conductive member to which a voltage is applicable; and a coating layer that coats the electrically conductive member, in which when a d.c. voltage of |10| to |300| (V) is applied to the electrically conductive member, the following relationship is satisfied: Z/Ra is 0.7 or less, where Z is the standard deviation of a resistance of the charging member, and Ra is an average value of the resistance of the charging member.

Abstract: A charging device is described, including a charging member 40BK disposed opposite to a surface of an image carrier 60BK. The image carrier 60BK is charged by applying a voltage to the charging member 40BK, and the charging member 40BK comprises a substrate 101BK and a resistor layer 104BK thereon. The resistor layer 104BK is disposed with two spacers 105BK contacting with the image carrier 60BK, so that a gap is created between the image carrier 60BK and the resistor layer 104BK between the two spacers 105BK, wherein width variation of the gap with time is prevented. The end portions of the resistor layer 104BK of the charging member 60BK protrude above the resistor layer 104BK between them, and the spacers 105BK are constituted by protrudent fractions of the end portions of the resistor layer 104BK.

Abstract: An electroconductive member contains an electroconductive composition using a thermoplastic elastomer material having advantages such as reduction in energy of production process thereof and capability of being recycled, and which makes it possible to prevent a change in resistance by sending an electric current, improve uniformity of electric resistance, and reduce dependency on an electric field and a resistance-change by environment. The electroconductive resin composition contains an epoxidized diene block copolymer; a thermoplastic elastomer other than the epoxidized diene block copolymer, a conductive agent and one of a thermoplastic resin and a compound having an amino group.

Abstract: Conductive article, for example a roller, a doctor blade or a flat or curved plate, at least comprising a conductive sleeve and a covering layer, the covering layer containing a conductive polymer and a film-forming polymer, and method for fabricating such an article, at least comprising the application of a covering layer to a conductive sleeve, wherein the covering layer is formed by the application, to the sleeve, of a mixture of a conductive polymer and a film-forming polymer.

Abstract: A nonbleeding bias charging member having an outer layer on a supporting substrate with fluorinated carbon and zinc oxide dispersed in the outer layer material, where bleeding of contaminants to imaging members is decreased or eliminated.

Abstract: An electrophotographic drum-shaped photoconductor has an electroconductive support and a photoconductive layer formed thereon, with a lubricating material being applied to the surface thereof in the shape of a plurality of bands spaced therebetween, constituting band-shaped lubricating material applied areas, extending along a circumference of the drum-shaped photoconductor in the direction perpendicular or substantially perpendicular to an axis of rotation of the drum-shaped photoconductor. An electrophotographic image formation method and an image forming apparatus employing the above-mentioned drum-shaped photoconductor are also disclosed.

Abstract: An electrifier for electrifying a member to be charged includes a charge rotary member that forms a first nip with the member to be charged, to charge the member to be charged, and that holds and carries charge particles to the first nip, and a nip forming member that forms a second nip with the charge rotary member, the nip forming member having a bias charge having the same polarity as the developer.

Abstract: An image forming apparatus includes a process cartridge detachably mountable with respect to the main body of the apparatus. The process cartridge is provided with an image bearing member, a charger for charging the image bearing member, a power supply for applying an alternating current voltage to the charger, and a controller for variably controlling the alternating current supplied from the power supply to the charger in conformity with information about the use situation of the process cartridge. The process cartridge can also include an image bearing member, a charger for charging the image bearing member, the charger permitting an alternating current voltage to be applied thereto by a power supply, and a memory for storing therein information about the use situation of the process cartridge, and information of a plurality of preset control values for an alternating current supplied from the power supply to the charger to be variably controlled in conformity with the information.

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 an image forming apparatus with a charging member which charges an image bearer with a photoconductive surface. Forming a layer containing ferroelectric as part on the charging member, and applying the electric field formed by dipoles of the ferroelectric, the photosensitive member surface is electrified, thereby downsizing a charger and reducing power consumption thereof are achieved for realizing low-cost and reducing the number of consumable parts sufficiently.

Abstract: An image forming apparatus includes an image bearing member, a flexible changing member and a developing device. When a first area to be an image forming area of the image bearing member, is present in a nip portion, a superimposed voltage resulting from a direct current voltage and an alternating voltage having a peak to peak voltage smaller than an alternating voltage applied when a charging potential of the image bearing member is converged is applied to the charging member. When a part of a second area to be a non-image area of the image bearing member exists in the nip portion, a direct current voltage without an alternating voltage is applied to the charging member.

Abstract: An image forming apparatus includes a rotatable member to be charged; a rotatable charge member for electrically charging the member to be charged, the charge member being contactable to the member to be charged; and a moving element for moving the member to be charged and the charge member in a longitudinal direction of the member to be charged.

Abstract: An image forming apparatus includes an image bearing member, a charging rotary member rotating while contacting with the image bearing member, and a slide friction sheet contacting with the charging rotary member along an axial direction of the charging rotary member for dispersing contamination adhered to the charging rotary member.

Abstract: A conductive 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 conductive 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 (&OHgr;/□) and 1×1015 (&OHgr;/□). Therefore, a conductive 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.

Abstract: An image forming device which is capable of preventing generation of toner filming and obtaining a stable image quality without defects over a long period and which is environmentally friendly. The image forming device, for forming an image with a spherical toner, includes image holding members, contact type charging member, exposing member, developing member, and transfer member. A toner shape change ratio (Tt) of deformed toner particles passed between the contacting portions of the image holding members and the charging member is in a range of 50 to 100 percent.

Abstract: The present invention provides a charging member for charging a body to be charged by bringing the charging member into contact with the body to be charged and applying a voltage between the body to be charged and the charging member. The charging member includes an elastic layer and a resin layer containing a conductive agent, 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 outermost resin layer after and elapse of 10 sec is in a range of 5 V or less. The present invention also provides a charging unit using the charging member.

Abstract: An electro-mechanical roll such as a bias transfer roll for use in a printing or copying apparatus comprising a conductive core having a segmented layer of compressible material positioned in a tandem relation to another thereon to form a generally cylindrical roll member.

Abstract: Disclosed is an image forming method comprising a charging step of carrying out charging by applying voltage from the outside to a charging member which is brought into contact with an electrophotographic photoreceptor; an electrostatic latent image-forming step of forming a latent image; and a toner image-forming step of visualizing the latent image by using a developer, wherein the charging member is produced using a charging roll obtained by laminating an ionic conductive elastic material layer and a surface layer, in which an electroconductive material is dispersed, on a conductive support in this order; and the developer contains a toner which satisfies specific requirements.

Abstract: An ethylene propylene rubber foam which comprises as the crude rubber, an ethylene propylene rubber having an iodine value of 35 to 45 and a Mooney viscosity ML1+4 at 100° C. of 20 to 50, and which has less compression set and is suitable as a material for a transfer member, a primary transfer member, a secondary transfer member, a cleaning member for image formation bodies, a bias member, a backup member, etc.; an electroconductive ethylene propylene rubber foam which comprises as the crude rubber, an ethylene propylene rubber having an iodine value of 35 to 45 and a Mooney viscosity ML1+4 at 100° C.

Abstract: A charging apparatus includes a charging member, to which a voltage is applicable, for charging a member to be charged; the charging member including: a flexible member for forming a nip with the member to be charged, wherein the flexible member is moved with a peripheral speed difference between surfaces of the flexible member and the member to be charged at the nip; and electroconductive particles in the nip.