Abstract: An image forming apparatus including a photoreceptor, wherein the photoreceptor includes an image forming portion having two ends substantially parallel to the rotating direction and a gap forming member located outside of each of the two ends of the image forming portion; a charging roller configured to charge the photoreceptor, wherein the charging roller contacts the gap forming members of the photoreceptor to form a gap g between the surface of the image forming portion and the peripheral surface thereof; an imagewise light irradiator; an image developer; and an image transfer device, wherein the relationship t≧2g is satisfied, where g represents the gap and t represents a distance between an inside edge of one of the gap forming members and nearer one of the two ends of the image forming portion of the photoreceptor.

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: An image formation apparatus including a photoreceptor, a charger having a charger member for charging the photoreceptor, a latent image write unit for writing an electrostatic latent image onto the photoreceptor charged by the charger, and a developing device having a developer support with a magnetic field production member, for rendering visible the electrostatic latent image written by the latent image write unit with a developer. Further, the charging member of the charger is disposed under effect of a magnetic field produced by the magnetic field production member of the developing device, and the charging member is made of a nonmagnetic material.

Abstract: An image forming apparatus includes a rotatable image bearing member; a charging rotatable member, contactable to the image bearing member at a contact position, for electrically charging the image bearing member, the charging rotatable member being rotatable for counterdirectional peripheral movement relative to rotation of the image bearing member at the contact position; developing means for developing an electrostatic image formed on the image bearing member with a developer, the developing means being capable of collecting a residual developer from the image bearing member; and wherein start of rotation of the charging rotatable member is simultaneous with or prior to start of rotation of the image bearing member.

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: 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 device of the present invention includes a charging member and a body to be charged forming a nip therebetween. Charge-promoting conductive grains, frictionally charged to polarity opposite to the polarity of a voltage applied to the charging member, are held at the above nip. The charging device is operable in a cleaning mode for cleaning the body to be charged.

Abstract: A charging apparatus has a movable image bearing member, a first charging member for charging the image bearing member, and a second charging member provided upstream of the first charging member with respect to the direction of movement of the image bearing member, the second charging member having an elastic rotary member rubbing against the image bearing member.

Abstract: According to the present invention, in an image-forming apparatus having at least two chargers for charging a rotating image carrier, in accordance with change in bias applied to a second charger disposed on the downstream side in a rotational direction of the image carrier, the bias applied to a first charger disposed on the upstream side is changed. Thereby, the electric power required for the charging is reduced.

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 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: An image forming apparatus including a photoreceptor, wherein the photoreceptor includes an image forming portion having two ends substantially parallel to the rotating direction and a gap forming member located outside of each of the two ends of the image forming portion; a charging roller configured to charge the photoreceptor, wherein the charging roller contacts the gap forming members of the photoreceptor to form a gap g between the surface of the image forming portion and the peripheral surface thereof; an imagewise light irradiator; an image developer; and an image transfer device, wherein the relationship t≧2g is satisfied, where g represents the gap and t represents a distance between an inside edge of one of the gap forming members and nearer one of the two ends of the image forming portion of the photoreceptor.

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: 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: 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 flexible charging member, which forms a nip portion between itself and an image bearing member. The charging member charges the image bearing member and is applied with a voltage when the charging member at least charges the image bearing member for an image formation. The nip portion is provided with an electrically conductive particles developing device for developing an electrostatic image formed on the image bearing member with a developer. The developing device executes a developing operation and, at the same time, executes a collecting operation for collecting a residual developer on the image bearing member.

Abstract: In order not to expel toner excessively when bias is applied, a cleanerless image forming apparatus includes a first developer charge amount controlling device 7, provided on a downstream side of a transfer device 5 in a moving direction of an image bearing member 1, e.g. a photosensitive drum, for applying a DC bias for making uniform a charge amount of residual developer remaining on the image bearing member 1, and/or a second developer charge amount controlling device 8, provided on a downstream side of the first developer charge amount controlling device 7 in a rotating direction of the image bearing member 1, for applying a DC bias for charging the residual developer in a normal polarity. An absolute value of a slope of the DC voltage applied to the first developer charge amount controlling device 7 and/or an absolute value of a slope of the DC voltage applied to the second developer charge amount controlling device 8 are equal to 2000 V/sec or smaller.

Abstract: A toner suitable for use in an image forming method including a contact charging step is provided. The toner includes: toner particles comprising at least a binder resin and a colorant, and fine particles. The fine particles comprise: (i) a tungsten-containing tin oxide, or (ii) base particles, and a tungsten-containing tin compound coating the base particles, the fine particles contain tin (Sn) in a weight ratio (Sn/b) of 0.01 to 2.0 with respect to the base particles (B). In the fine particles, tungsten (W) is contained in a mol ratio (W/Sn) of 0.001 to 0.3 with respect to the tin (Sn).

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 formation method which remarkably extends developer life while providing size reduction and high speed coloring. Also, a replenishing toner and a method of producing the same, and a toner cartridge. In the image formation method, conducting image formation by an image formation apparatus having a plurality of xerography units, the developer apparatus of at least one xerography unit has a developer recovering mechanism appropriately replenishing a replenishing toner composed of a toner and a carrier into the developer apparatus and recovering an excess portion of a developer from the equipment. The above-mentioned replenishing toner has a carrier content in the range of 5 to 40% by weight, the above-mentioned carrier is a carrier coated with a resin having a specific composition, and/or the above-mentioned toner is in a specific shape. The replenishing toner may be produced using the above-mentioned recovered developer.

Abstract: A method including: (a) dispensing an electrically conductive liquid into a contact member permeable to the liquid; (b) rubbing the contact member and a surface against each other, at a contact length greater than a tangential contact length, to release the liquid from the contact member to wet the surface with the electrically conductive liquid in a layer ranging in thickness from about 1 to about 100 micrometers; and (c) electrifying the liquid at any time effective for imparting an electrical charge to the surface.

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 charger has a cylindrical rotation tube coming in contact with an image receptor on which a toner image is formed, the rotation tube to which a predetermined charge bias is applied, and drive means for driving the rotation tube at a predetermined peripheral speed, the charger for uniformly charging the surface of the image receptor. When the peripheral speed of the image receptor is V1 and the peripheral speed of the rotation tube is V2, the following relation is satisfied: 1.01<(V2/V1)≦1.10.

Abstract: An image forming apparatus includes an image bearing member; a charger for electrically charging the image bearing member; an electrostatic image forming device for forming an electrostatic image by selectively discharging a surface of the charged image bearing member; a developer for developing the electrostatic image formed on the image bearing member into a toner image; a transfer device for transferring the toner image from the image bearing member onto a transfer material; wherein the charger is capable of collecting residual toner from the image bearing member after an image transfer operation; an electric field forming device forms an electric field between the charger and the image bearing member to transfer the toner in the charger to the image bearing member; and a controller controls a length of time during which the electric field forming device forms the electric field, wherein the controller controls the length of time substantially in accordance with wear of a surface of the image bearing membe

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.

Abstract: A charging device charging a photosensitive medium of an electronograph type image formation apparatus while being in contact with the photosensitive medium, supports both ends of a charging member having a plate-shaped elastic member by a support member, so that the charging member has a semicircular section. A curved surface of the charging member contacts a surface of the photosensitive medium to maintain a predetermined contact nip and a contact linear pressure. The charging device controls a total resistance by adjusting a material, a thickness, a contact area, and a radius of the charging member, and maintains the contact linear pressure and the contact nip from the photosensitive medium. As a result, the charging device can easily adjust an electric resistance, minimizing variations of the contact linear pressure and the contact nip, material and processing expenses can be cut down, and productivity of the charging device is improved.

Abstract: An image forming apparatus includes an image bearing member and an electrostatic image forming device, which is adapted to form an electrostatic image on the image bearing member, and which includes an electrifying member contacted with the image bearing member to electrify the image bearing member. The electrifying member includes a first conductive member to which voltage is applied, and a developer carrying member cooperating with the image bearing member to form a nip therebetween and is adapted to carry developer to the nip and to develop the electrostatic image with the developer. The electrifying member also includes a second conductive member to which a voltage is applied. A resistance value between the second conductive member and a developer layer of the developer carried on the developer carrying member is greater than a resistance value between the first conductive member and a surface of the image bearing member.

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 method including: (a) dispensing an electrically conductive liquid into a contact member permeable to the liquid; (b) rubbing the contact member and a surface against each other, at a contact length greater than a tangential contact length, to release the liquid from the contact member to wet the surface with the electrically conductive liquid in a layer ranging in thickness from about 1 to about 100 micrometers; and (c) electrifying the liquid at any time effective for imparting an electrical charge to the surface.

Abstract: A new charging member which is durable enough to exhibit stable performance over a long period of time without deterioration by the sticking of toner particles. It is characterized by its surface having a universal hardness no higher than 10 N/mm2 at a depth equivalent to the diameter of toner particles.

Abstract: A charging device, suitable for use in an electrophotographic image forming apparatus, is formed of an object to be charged, and a roller-shaped charging member disposed in contact with the object via electroconductive particles and supplied with a voltage to charge the objects. The charging member has a surface layer including an elastic foam and is moved with a surface speed difference relative to the object. The charging member has surface cavities having an average diameter of 5 to 150 &mgr;m and occupying an area percentage of 50 to 90%. An image forming apparatus and a process cartridge therefor including the charging device are also provided.

Abstract: A charging device for electrically charging a member to be charged includes charging particles including electroconductive particles having particles diameters in the range of 10 nm-10 &mgr;m; and a charging particles carrying member, which has a nip with the member to be charged forming a nip with said member to be charged, for carrying the charging particle to the nip; wherein said charging particles have resistances in the range of 10−1-1012 &OHgr;cm; wherein (an amount, per unit area, of said charging particles carried by said charging particles carrying member)/(an average roughness Ra of a surface of said charging particles carrying member) is in the range of 0.005-1 mg/cm2/&mgr;m.

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: The present invention provides an electrophotographic photosensitive member wherein a maximum height (RmaxD) of a surface roughness of a support portion is 1.2 &mgr;m RmaxD≦5.0 &mgr;m, an average roughness (Rz) of 10 points is 1.2 &mgr;m≦Rz≦3.0 m, an arithmetic average roughness (Ra) is 0.15 &mgr;m≦Ra≦0.5 &mgr;m, and an irregularity average interval (Sm) is 30 &mgr;m≦Sm≦80 &mgr;m. The photosensitive member's charge generation layer contains a phthalocyanine compound, its charge transport layer has a thickness which is at least 9 &mgr;m but not larger than 18 &mgr;m, the electrophotographic photosensitive member in every 1 cm2 area has an electrostatic capacity (C) of 130 pF or more. This invention also provides a process cartridge and an electrophotographic apparatus containing the electrophotographic photosensitive member.

Abstract: An OPC 2, a charger 9, a cleaner 10 for cleaning the charger 9, a holder 11 for holding the charger 9, a support frame 12 for supporting the holder 11, a pair of springs 13 and 14 and a driver 15 for driving the holder are accommodated in a single process cartridge 8. The cleaner 10 can be brought into contact with the charger 9 and separated from the same. The driver 15 moves the cleaner 10 between a position of contact at which the cleaner 10 is brought into contact with the charger 9 and a position of separation at which the cleaner 10 is separated from the charger 9. The charger 9 has a wettability that is lower than that of a photosensitive member on which an electrostatic latent image is formed.

Abstract: An image forming apparatus includes a movable image bearing member, a charger means including a charge member for electrically charging the image bearing member with electroconductive particles between the charge member and the image bearing member and a developing member for developing a latent image with toner mixed with electroconductive particles. The latent image is formed on the image bearing member having been charged by the charging means, and a toner image provided by development of the latent image by the developing member is transferred onto a recording material. The electroconductive particles mixed in the toner is carried by the image bearing member and are fed to between the charge member and the image bearing member.

Abstract: A conductive blade includes a blade member formed of an electrically conductive rubber, and an electrically conductive holder. The blade member has one widthwise end portion serving as a free end portion and the other widthwise end portion serving as a bonding end portion. One end of the free end portion is brought into contact with a subject member. The holder is bonded to the bonding end portion of the blade member over the length of the blade member. A conductive layer formed of a conducting filler and an elastomer is provided for connecting the end face of the bonding end portion of the blade member and a portion of the holder which is adjacent to the end face of the bonding end portion.

Abstract: An image forming apparatus includes an image bearing member; charging means for electrically charging the image bearing member, the charging means carrying electroconductive particles and having a charging member elastially press-contacted to the image bearing member; image forming means for forming an electrostatic image by selectively dissipating electric charge on the image bearing member charged by the charging means; developing means for developing the electrostatic image on the image bearing member with toner and for supplying the electroconductive particles to the image bearing member, wherein the electroconductive particles supplied by the developing means is carried to a press-contact portion of the charging member to contribution for electric charging of the image bearing member; and changing means for changing a relation between the charging member and a supply position of the electroconductive particles of the developing means.

Abstract: An image forming apparatus including a photoreceptor having an image forming portion; a charging roller having a gap forming member on both ends thereof to form a gap between the photoreceptor and the charging roller and configured to charge the photoreceptor, wherein the gap forming members do not contact the image forming portion, and wherein the relationship t≧2g is satisfied; a light irradiator configured to form a latent image in the image forming portion; an image developer configured to form a toner image on the photoreceptor; and an image transferer configured to transfer the toner image onto a receiving material, wherein g is the gap and t represents a distance between an inside edge of one of the gap forming members and one of the two ends of the image forming portion closer to the inside edge of the gap forming member.

Abstract: A charging member 2a of a charger 2 is disposed under the effect of a magnetic field produced by a magnetic field production member 4b of a developing device 4 and is made of a nonmagnetic material. The charger 2 comprises the charging member 2a and a removal member 2b disposed in contact with an photoreceptor 1 in the upstream of the charging member 2a, the removal member 2b for removing a deposit on the photoreceptor 1 and the charging member 2a is disposed under the effect of a magnetic field produced by the magnetic field production member 4b of the developing device 4 and is made of a nonmagnetic material. On the other hand, the removal member 2b is disposed under the effect of a magnetic field produced by the magnetic field production member 4b of the developing device 4 and is made of a magnetic material.

Abstract: An image forming apparatus includes an image bearing member which is movable; an electrifying device which makes contact with the image bearing member and electrifies the image bearing member; a developing device for developing a latent image on the image bearing member by toner; and an abutting member which is provided on a downstream side in a moving direction of the image bearing member with respect to the electrifying device and the contacting portion of the image bearing member and abuts against the image bearing member. The image bearing member, electrified by the electrifying device, is exposed to have the latent image formed thereon, a toner image formed on the image bearing member by the developing device is transferred to a recording material, and the developing device recovers residual toner on the image bearing member after transfer.

Abstract: An apparatus and method are described for extending the life of a photoreceptor in xerographic printing. At a predetermined point in the life span of a photoreceptor, a correction circuit is interposed between the power supply and the charging device of the printer. Correction circuits of different designs can be selected to compensate for the photoreceptor properties at different stages of its useful life. The different correction circuits can be automatically activated over time, or can be retrofitted into a replaceable module when the replaceable module is remanufactured.

Abstract: A xerographic component including an intermediate transfer, fusing and/or biasing component, wherein one or more of each component may have a substrate and thereover a polymer coating with a thiophene filler dispersed or contained therein, and also an image forming apparatus for forming images on a recording medium having a charge-retentive surface to receive an electrostatic latent image thereon; a biasable component capable of receiving an electrical bias for charging one of a xerographic component or copy substrate surface; a development component to apply toner to the charge-retentive surface to develop the electrostatic latent image to form a developed image on the charge retentive surface; a transfer component to transfer the developed image from the charge retentive surface to a copy substrate; and a fuser component for fusing the developed image to a surface of the copy substrate, wherein at least one of the biasable component, transfer component and the fuser component have a) a substrate; and thereo

Abstract: An image forming apparatus includes a rotatable image bearing member; a charging rotatable member, contactable to the image bearing member at a contact position, for electrically charging the image bearing member, the charging rotatable member being rotatable for counterdirectional peripheral movement relative to rotation of the image bearing member at the contact position; developing means for developing an electrostatic image formed on the image bearing member with a developer, the developing means being capable of collecting a residual developer from the image bearing member; and wherein start of rotation of the charging rotatable member is simultaneous with or prior to start of rotation of the image bearing member.

Abstract: An image forming apparatus includes an image bearing member; a charging member, contactable to the image bearing member, for electrically charging the image bearing member at a charging position; developing means for developing an electrostatic image formed on the image bearing member with a developer; wherein when a first area on the image bearing member which is going to be an image formation area is at the charging position, the charging member moves with a peripheral speed difference relative to the image bearing member, and when a second area on the image bearing member which is a part of an area which is going to be a non-image formation area is at the charging position, the charging member moves substantially without a peripheral speed difference relative to the image bearing member, and wherein a collecting electric field is formed for collecting the developer from the second area to the developing means.

Abstract: A charger has a cylindrical rotation tube coming in contact with an image receptor on which a toner image is formed, the rotation tube to which a predetermined charge bias is applied, and drive means for driving the rotation tube at a predetermined peripheral speed, the charger for uniformly charging the surface of the image receptor.

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.