Abstract: Gear (52) and resin body (2) supported on shaft (1) and between frame members (14a) and (14b) are protected from contacting a frame member. Frame (14a) has a partial hole (22) with an opening (24) and a cavity (26), which is open at the hole (22) and on the side toward the opening (24). A bearing (18) has a inner body (30) which internally is partially circular with diameter substantially the same as opening (22). The outer portion of body (30) forms an outwardly extending nub (34). Wall (36) extends across body (30). The part (38) of bearing 18 opposite body 30 has an extended part (38a) to serve as an electrical contact. A shaft end (Sa) past a circular ledge (3a) is supported by bearing (18). The nub (34) fits in the cavity (26) and the wall (36) defines the proper position of rotation of the bearing. This protects gear (52) from being dislodged from its position on shaft (1).

Abstract: An imaging apparatus that is capable of realizing good cleaning characteristics and transfer characteristics, and obtaining a high quality image using toner having a high average roundness is provided. The imaging apparatus includes an image carrier, a charge unit, a developing unit, a transfer unit, and a cleaning unit. The transfer unit may directly transfer a toner image onto a recording medium that is carried by a transfer belt, or transfer the toner image onto the transfer belt first to then transfer the toner image onto the recording medium from the transfer belt. The cleaning unit includes a cleaning blade and a brush roller. The toner used in the imaging apparatus has an average roundness &PSgr; within a range of 0.93˜0.99, and a friction coefficient &mgr;s of the image carrier satisfies a condition, friction coefficient &mgr;s≦3.6−3.3×average roundness &PSgr;.

Abstract: A image forming apparatus includes a photosensitive body as an image bearing member having a surface layer. The surface layer includes a charge transport layer having the thickness from 10 &mgr;m to 20 &mgr;m. An exposing unit exposes the surface layer to the light to form latent image, and has a resolution greater than 600 dpi. A developing unit develops the latent image with toner so that a toner layer is formed on the photosensitive body. The toner layer formed on the photosensitive body includes two or three layers of toner particles.

Abstract: A developing cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the developing cartridge includes a developing roller, for developing an electrostatic latent image formed on an electrophotographic photosensitive member, having an elastic roller portion and a shaft portion supporting the elastic roller portion, a developer regulating member contactable to the elastic roller portion to regulate an amount of the developer deposited on the elastic roller portion; a protecting member including a contact portion provided at a side for contact with the elastic roller portion when the protecting member is demountably mounted between the developing roller and the developer regulating member; and a supporting portion for supporting the contact portion, the supporting portion being provided at a side for contact with the elastic roller portion when the protecting member is demountably mounted between the developing roller and the developer regulating member, wherein the

Abstract: A toner separation apparatus includes a target, an inlet through which toner laden carrier enters to strike the target, an exit for carrier particles below the target, and an exit for toner particles downstream of the target. A filter can be positioned between the target and the toner exit, and a mesh to which the target is attached can be located between the inlet and the filter. The toner-laden carrier can be entrained by air driven by one or more impellers, which can be located within or without the apparatus, upstream or downstream of the target.

Abstract: The increasing ratio of development density to increase in potential difference between a photoreceptor and a development roller differs between the region where the potential difference is small and the region where the potential difference is large. The increasing ratio of development density at the region where the potential difference is small is smaller than the increasing ratio of development density at the region where the potential difference is large. Development is conducted under the developing characteristics in which the upper limit of the development density at the region where the increasing ratio of development density is small is at least 0.3.

Abstract: Elastic members are fixed at one end to the housing of an image forming apparatus while their distal ends extend into the framework of the developing unit. When a toner cartridge is fitted to the framework of a developing unit, the distal ends of the elastic members abut the top surface of the toner cartridge, so that the elastic members are compressed to produce repulsive force, which in turn causes the developing unit to rotate clockwise about a support so as to bring the developer roller into pressing contact with a photoconductor.

Abstract: A developing unit of an electrophotographic image forming apparatus includes at least one developing apparatus installed to be capable of accessing and being separated with respect to a photoreceptive drum and including a developing roller developing an electrostatic latent image formed on the photoreceptive drum and a gap maintenance member closely contacting the photoreceptive drum such that the developing roller accesses the photoreceptive drum in a non-contact state while maintaining a predetermined gap with the photoreceptive drum, and a guide portion formed on a frame to guide a movement of the developing apparatus. An inclined portion facing a center shaft of the photoreceptive drum is provided at a leading end of the guide portion so that the gap maintenance member closely contacts the photoreceptive drum while pressing the photoreceptive drum in a radial direction of the photoreceptive drum.

Abstract: An image forming apparatus includes an image carrier that rotates and carries an image on a surface of the image carrier, a latent image forming device that forms an electrostatic latent image on the image carrier, a developing device that develops the electrostatic latent image with a developer including a lubricant, and a transfer device that transfers the developed image to a transfer material. The image forming apparatus further includes a control device including a lubricant application executing device and controlling the lubricant application executing device to execute an application of the lubricant to the image carrier by actuating the developing device to apply the developer to the surface of the image carrier during one job of an image forming operation from a start of rotation of the image carrier to a stopping of the rotation of the image carrier.

Abstract: The increasing ratio of development density to increase in potential difference between a photoreceptor and a development roller differs between the region where the potential difference is small and the region where the potential difference is large. The increasing ratio of development density at the region where the potential difference is small is smaller than the increasing ratio of development density at the region where the potential difference is large. Development is conducted under the developing characteristics in which the upper limit of the development density at the region where the increasing ratio of development density is small is at least 0.3.

Abstract: An image forming apparatus includes a developing device assembly, an inertia acceptor and a setting mechanism. The developing device assembly has a plurality of developing devices to develop a latent image formed on a photosensitive member. The assembly can rotate to switch from one of the developing devices to another. The energy of rotational inertia is shifted from the developing device assembly to the inertia acceptor when the inertia acceptor stops the rotation of the developing device assembly. The setting mechanism controls the movement of the inertia acceptor driven by the energy of rotational inertia shifted from the developing device assembly.

Abstract: A developer driving apparatus which drives a plurality of developing rollers via a gear chain including pivotable gears and one way gears. A reversible driving motor is coupled to a deceleration gear which directly drives a first swing drive gear and drives a second swing drive gear via an odd number of idler gears. Each swing drive gear is rotationally coupled with a respective swing gear having a center of rotation which is pivotable about a center of rotation of the respective swing drive gear. In a first position each swing gear drives one of the plurality of rollers via a respective one way gear and in a second position, each swing gear drives another of the plurality of rollers via a respective one way gear. A solenoid activated lever moves each swing gear between respective first and second positions.

Abstract: Disclosed are a developing device, a developing cartridge, a process cartridge, and an image forming apparatus in which image deficiency is prevented by absorbing the tolerance of each component and making the position of the developing roller in the thrust direction constant and which are easy to assemble. A frame member is equipped with an urging unit that axially urges the developing roller, the urging unit urging the developing roller in the direction of movement of the developing roller by the thrust force of a helical gear when driving force is transmitted to the developing roller to thereby make the position of the developing roller in the thrust direction constant.

Abstract: A spacing device for image processing systems to maintain a development gap between an image-receiving member and a developer roller thereby facilitating efficient development and consistently maintaining high image quality and methods for manufacturing and using the same. The spacing device comprises one or more spacing members that have preselected lengths and that are configured to be coupled with, and extend from, an imaging-receiving module and/or a developer cartridge of an image processing system. When the image processing system is properly assembled, a predetermined development gap is formed between an image-receiving member of the imaging-receiving module and a developer roller of the developer cartridge, and the spacing members are disposed substantially between, and in contact with, the imaging-receiving module and the developer cartridge. The spacing members, being formed from a substantially rigid material, are configured to maintain the predetermined development gap.

Abstract: An image forming apparatus includes a developing cartridge having a developing roller driven by developing roller drive gear, a supply roller driven by a supply roller drive gear, an input gear, a gear holder formed with a developing roller support member, supply roller support member and input gear support member, a gear holder integrally formed with the support members and a shaft receiving member formed at a location opposite the gear holder.

Abstract: A developing device is detachably mountable to the main body of an electrophotographic image forming apparatus. The device is for developing an electrostatic latent image on an electrophotographic photosensitive member and includes a developing member for developing the electrostatic latent image formed on the electrophotographic photosensitive member, a developer container containing therein a developer to be used to effect the development of the electrostatic latent image by the developing member, a developing frame for supporting the developing member, a welding rib provided along the lengthwise direction of the developing frame to connect the developer container and the developing frame together by-ultrasonic welding, and a plurality of reinforcing members provided on the back of that surface of the developing frame on which the welding rib is provided, along the lengthwise direction of the welding rib, to increase the strength of the developing frame.

Abstract: An apparatus for digitally generating an image comprises a photoconductor assembly, a corona assembly, and a light source assembly to generate a latent image on the photoconductor. The apparatus also includes a developer assembly that includes a developer, such as powder paint, to generate an image. The apparatus may include a fuser for generating a film image. The apparatus of the present invention may include a cartridge for storing and digitally applying adhesive to the image. Furthermore, the apparatus of the present invention includes a controller for selectively controlling voltages to control thickness of the image. Additionally, apparatus may include a consumable sheet to remove excess adhesive from the substrate.

Abstract: A developing device for developing a static latent image is disclosed. The relation between an average of the circle corresponding diameter of the toner aggregates in the toner image on the image carrier surface formed by developing the static latent image and a value obtained by dividing the standard deviation of a circle corresponding diameter of the toner aggregate by the average circle corresponding diameter of the toner aggregates satisfies following Formula 1. 0<Y<179.01×X−1.9031 wherein X is a diameter of the circle corresponding to toner aggregate in &mgr;m (X>20 &mgr;m), and Y is CV1, CV1=Standard deviation of the circle corresponding diameter of the toner aggregate/Average of the circle corresponding diameter of the toner aggregates X.

Abstract: An image-forming machine has a development station with a dusting control system that generates a flow barrier adjacent to a development region.

Abstract: An image forming apparatus of the present invention includes a toner scatter preventing device for a developing device configured to develop a latent image formed on an image carrier with toner. The toner scatter preventing device includes an exhausting section for exhausting air inside the developing device via an exhaust passage extending from the top of developing device. Air is sucked out of the developing device to thereby generate a stream of air that sucks air around an opening for development formed in the developing device. A suction port is formed in the developing device and communicated to the exhaust passage. The suction port is positioned outside of an image forming width assigned to the developing device.

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 means for developing an electrostatic image formed on the image bearing member to form a toner image, the developing means supplying electroconductive particles to the image bearing member, wherein the electroconductive particles are fed to the nip by the image bearing member; transferring means for transferring the toner image onto a recording material at a transfer position; wherein the developing means is capable of feeding the electroconductive particles of a region of the image bearing member which corresponds to a region between a first recording material and a second recording material immediately subsequent to the first recording material, and a time period from passage of a trailing end of the first recording material through the transfer position to arrival of a leading end of the second recording materia

Abstract: A toner deliver system, such as a development roller, in an electrophotographic printer is conditioned with clear toner particles. The clear toner particles are made of similar resins and contains all of the flow and charge agents of color toner particles, but does not contain any pigment.

Abstract: An image forming apparatus includes an image carrier on which a latent image is formed; and a developing roller provided in the vicinity of a surface of the image carrier for conveying a two-component developer to develop the latent image, wherein the following conditional inequality (1) is satisfied, 1<(Vs/Vp)≦(Dsd/Dws)×0.129 . . . (1) where Vs/Vp represents a relative velocity of the developing roller to the image carrier, Dsd (&mgr;m) represents a distance between the surface of the image carrier and a surface of the developing roller, and Dws (mg/cm2) represents an amount of the developer which has been held and conveyed by the developing roller.

Abstract: A toner delivery system, such as a development roller, in an electrophotographic printer is conditioned with a clear toner. The clear toner is made of similar resins and contains all of the flow and charge agents of color toners, but does not contain any pigment.

Abstract: The increasing ratio of development density to increase in potential difference between a photoreceptor and a development roller differs between the region where the potential difference is small and the region where the potential difference is large. The increasing ratio of development density at the region where the potential difference is small is smaller than the increasing ratio of development density at the region where the potential difference is large. Development is conducted under the developing characteristics in which the upper limit of the development density at the region where the increasing ratio of development density is small is at least 0.3.

Abstract: A developing device for developing a static latent image is disclosed. The relation between an average of the circle corresponding diameter of the toner aggregates in the toner image on the image carrier surface formed by developing the static latent image and a value obtained by dividing the standard deviation of a circle corresponding diameter of the toner aggregate by the average circle corresponding diameter of the toner aggregates satisfies following Formula 1.

Abstract: A housing 10 of a development apparatus is vertically divided into two segments; a lower housing 20 and an upper housing 30. The housings 20, 30 are fixedly joined together without use of fixing means such as screwing or welding means but by means of causing a plurality of engaging projection pieces 26 formed on a joining surface section 25 to engage with engage holes 36 formed on a joining surface section 35, and causing resiliently-deformable snap-fit engaging sections 27 to engage with engaged sections 37. Side brackets 40, 50 are fitted to respective sides of the thus-joined housings 20, 30, thereby reinforcing the joined state of the housings 20, 30. No damage arises at the time of assembly or disassembly of the housing, and the housing can be reused.

Abstract: An image forming apparatus using a toner containing toner particles having a coefficient of shape falling within a range of 1.0 to 1.6 of an amount of at least 65% by number, and having no protrusion of an amount of at least 50% by number, the image forming apparatus including a charging device for uniformly charging a photoreceptor, a developing device for developing an image obtained by imagewise exposure with the toner, a transfer device for transferring a toner image onto a transfer material, a fixing device for fixing, and a cleaning device for cleaning the photoreceptor after the transfer of a toner image, wherein when a toner image which is not to be transferred is formed on the photoreceptor, image formation is performed after cleaning is done a plurality of times for an area on which the toner image has been formed in the previous process.

Abstract: A seamed flexible belt having a substrate and a seam having interlocking seam members, wherein the interlocking seam members are held together by an adhesive having polyamide and an optional electrically conductive filler, for use in electrostatographic, contact electrostatic, digital and other like printing machines.

Abstract: An apparatus for developing a latent image recorded on an imaging surface, including: a first developer unit for developing a portion of the latent image with a toner of custom color, the first developer unit including a housing defining a reservoir for storing a supply of developer material including conductive toner; a dispenser for dispensing toner of a first color and toner of a second color into the housing, the dispenser including device for mixing toner of the first color and toner of the second color together to form toner of the custom color; a donor member for transporting toner of the custom color on an outer surface of the donor member to a development zone; device for loading a toner layer of the custom color onto the outer surface of the donor member; and device for inductive charging the toner layer onto the outer surface of the donor member prior to the development zone to a predefine charge level; and a second developer unit for developing a remaining portion of the latent image with toner be

Abstract: An electrophotographic image forming apparatus of the present invention frees images from various defects including the thinning of horizontal lines, the omission of the trailing edge an image, background contamination, granularity particular to a halftone image, carrier scattering, and image noise. Further, the apparatus of the present invention solves problems ascribable to patches used to sense image density. Moreover, the apparatus of the present invention faithfully reproduces tonality and has a high developing ability.

Abstract: An image forming apparatus is disclosed in which an electrophotographic photosensitive member is rotated at a peripheral speed of 150 mm/second or more and a specific toner is used. The toner has a weight-average particle diameter from 5 to 12 &mgr;m, and of the toner having a circle-equivalent diameter of 3 &mgr;m or more, particles with a circularity of 0.900 or more are present at a rate of 90% or more in a number-based cumulative valve. The toner also satisfies one of two sets of conditions which are defined by the relationship between a cut rate and a weight-average particle diameter and the relationship between a number-based cumulative valve and a wight-average particle diameter.

Abstract: A toner scatter preventing device of the present invention is applicable to an image forming apparatus of the type developing a latent image formed on an image carrier with toner stored in a developing device. The device includes an exhausting device for discharging air present in the developing device via an exhaust passage. A toner collecting device collects the toner entrained by air discharged by the exhausting device. A toner storing device is positioned upstream of the toner collecting device in the direction of air flow for storing the toner collected by the toner collecting device without causing it to drop into the toner present in the developing device. The developer is a toner and carrier mixture in which carrier grains have a weight mean grain size of 65 &mgr;m or below.

Abstract: A rotating force transmitting apparatus includes: a first and a second transmitting devices for transmitting rotating forces to a first and a second rotary members, wherein the first and the second transmitting devices include a first and a second clutches for intermittently transmitting the rotating forces; a common driving device for imparting the rotating forces to the first and the second transmitting devices, wherein the second clutch can be switched from the turned-off state thereof to the turned-on state thereof for rotating the second rotary member when the first rotary member is rotating with the first clutch being turned on; and a permitting device for permitting the transmission of a rotating force only in a normal rotational direction of the driving device to the first transmitting device.

Abstract: A toner contains a coloring agent and a binder including a wax and an ethyl polysaccharide, which has D-glucose units linked together by a linkage of 1,2-, 1,3-, 1,4-, or 1,6-glycosidic bond with an &agr; configuration, or by a linkage of 1,2-, 1,3-, 1,4- or 1,6-glycosidic bond with a &bgr; configuration, with at least one alcohol hydroxyl group in each D-glucose unit being ethyl-etherified. A one-component developer for electrophotography is prepared using the toner, and a two-component developer is prepared by the combination of the toner and a carrier.

Abstract: An electrophotographic printer having an improved flexible drive chain cover located to protect the toning shell drive chain from contamination with toner dust. The electrophotographic printer may include a rigid drive chain cover located adjacent the flexible drive chain guard and locate so that the flexible drive chain guard and the rigid drive chain overlap.

Abstract: A developing device detachably mountable to the main body of an electrophotographic image forming apparatus and for developing an electrostatic latent image on an electrophotographic photosensitive member includes a developing member for developing the electrostatic latent image formed on the electrophotographic photosensitive member, a developer container containing therein a developer to be used to effect the development of the electrostatic latent image by the developing member, a developing frame for supporting the developing member, a welding rib provided along the lengthwise direction of the developing frame to connect the developer container and the developing frame together by ultrasonic welding, and a plurality of reinforcing members provided on the back of that surface of the developing frame on which the welding rib is provided, along the lengthwise direction of the welding rib, to increase the strength of the developing frame.

Abstract: An apparatus for forming an image on a recording sheet having low toner pile height. A photoconductive member is provided, said photoconductive member includes a charge generation pattern for directing developed toner; means for recording a latent image of one color separation on said photoconductive member; means for developing said latent image on said photoconductive member; and means for transferring said developed said latent image on said photoconductive member to the recording sheet.

Abstract: An image forming apparatus includes a process unit detachably mountable to a main assembly of the apparatus, the process unit including an image bearing member for bearing an electrostatic image and process means actable on the image bearing member, the process means having a rotational shaft; a driving shaft, substantially co-axial with the rotational shaft, for rotating the rotational shaft; and a drive transmitting member, engaged with the driving shaft and with the rotational shaft, for transmitting a driving force to the rotational shaft from the driving shaft; wherein the drive transmitting member is engaged with the driving shaft with a play and is engaged with the rotational shaft with a play.

Abstract: The present invention provides an image forming apparatus comprising an image bearing member, an electrostatic image forming device adapted to form an electrostatic image on the image bearing member and including an electrifying member contacted with the image bearing member to electrify the image bearing member, the electrifying member having 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 adapted to carry developer to the nip and to develop the electrostatic image with the developer and having a second conductive member to which voltage is applied, and wherein 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 image forming machine comprising image bearing means, charging means, exposure means, reversal development means, transfer means, and cleaning means. The transfer means includes a rotationally driven transfer belt, and transfer voltage applicator means for applying a transfer voltage to the back side of the transfer belt. The transfer voltage applicator means applies the transfer voltage to the transfer belt over a predetermined effective transfer width. The face side of the transfer belt is brought into contact with the image bearing means via an image receiving member and directly over a predetermined effective contact width. The effective contact width is larger than an effective charging width and larger than the effective transfer width.

Abstract: An image forming apparatus including a plurality of process stations vertically arranged each of which includes an image bearing member on which a latent image is to be formed and a developing device for developing the latent image, image bearing member driving devices, for driving the image bearing members, development driving devices, for driving the developing devices, and a transfer material bearing and conveying device for bearing and conveying the transfer material, wherein, while the transfer member is vertically conveyed through transfer nips that are formed by the transfer material bearing and conveying device and the image bearing members of all of the plurality of process stations, images formed by the plurality of pocess stations are sequentially transferred to the transfer material to form an image, and wherein process stations to be used for image forming can be selected, and the image bearing member driving devices and the development driving devices are controlled, so that, during an image for

Abstract: To provide an image forming apparatus which can realize stable charging and development characteristics, with a high resistance provided on the photoreceptor side. A photoreceptor drum is laminated with a high-resistance layer, and with a photoreceptor layer. A charging roller is provided with a metal shaft on a photoreceptor support and it is laminated with a low-resistance layer. In the image forming apparatus, a condition, T/(Rp×&egr;p/dp)>2.3, is satisfied, where Rp (&OHgr;m2) is the resistance per unit area of the resistance layer in the perpendicular direction, T (sec) is a passage time of the charging nip at each point on a surface of the photoreceptor drum, &egr;p (F/m) is a dielectric constant of the photoreceptor layer, and dp (m) is a film thickness of the photoreceptor layer.

Abstract: An object of the present invention is to provide an image forming apparatus and a process cartridge in which an optimum range of toner charging amount is wide and excellent gradient can be obtained, and which has an image bearing body and a developer carrying body, wherein an electrostatic capacity of the image bearing body per cm2 is not less than 150 pF and not greater than 600 pF.

Abstract: A toner has toner particles and an external additive. The toner particles have a weight-average particle diameter of from 4 &mgr;m to 9 &mgr;m. The external additive has (i) first, small-particle-diameter hydrophobic fine silica particles (A) having a BET specific surface area of from 100 m2/g to 350 m2/g, having been treated with a silane, (ii) second, large-particle-diameter hydrophobic fine silica particles (B) having a BET specific surface area of from 15 m2/g to 80 m2/g, having been treated with a silicone oil, and (iii) fine alumina particles (C) having a BET specific surface area of from 50 m2/g to 150 m2/g.

Abstract: A mechanism for adjusting the location of a rotatable mixer and rotatable transport mechanism within the development station housing of an electrographic reproduction apparatus development station. The development station includes a housing, a rotatable mixer assembly located in a developer material reservoir within the housing, a developer device for applying developer material to an electrostatic image to be developed, a rotatable transport mechanism for moving developer material from the reservoir to the developer device, and a drive mechanism for rotating the rotatable mixer, the rotatable transport mechanism, and the developer device. The adjustment mechanism describes a first locating device for adjustably positioning the drive mechanism relative to the reservoir of the development station housing, and a second locating device for adjustably positioning the rotatable mixer and the rotatable transport mechanism relative to the development station housing.

Abstract: The present invention provides an image forming apparatus that has an image bearing member a charger for charging the image bearing member image forming means for selectively erasing charge on the image bearing member to thereby form an electrostatic image a developing device for developing the electrostatic image, the developing device including a developing roll contacting with the image bearing member and having a developing bias applied thereto and contacting and spacing means for contacting and spacing the developing roll with respect to the image bearing member the contacting and spacing means contacting the developing roll having the developing bias applied to the area thereof charged by the charger with the image bearing member at a start of image formation.

Abstract: A gap retaining member featuring high durability and high resistance to frictional charging is provided as a means for retaining a gap between an image bearing member and a developer bearing member in an image forming apparatus. The gap retaining member for maintaining a gap between the image bearing member and a cylindrical portion of the developer bearing member in the image forming apparatus, which has at least the image bearing member and the cylindrical developer bearing member that is rotatably held, is formed of a material that is composed of at least a polybutylene terephthalate resin and a reinforcing material.

Abstract: A positively chargeable toner suitable to be carried on a cylindrical developer-carrying member having a resinous surface for developing an electrostatic latent image is formed from a composition including a binder resin, an imidazole compound and a colorant. The binder resin comprises at least one member selected from the group consisting of (i) a mixture of vinyl resin having a carboxyl group and a vinyl resin having a glycidyl group, (ii) a vinyl resin having both a carboxyl group and a glycidyl group, and (iii) a vinyl resin having a carboxyl group and a glycidyl group in a form reacted with each other. The imidazole compound is a compound having an imidazo unit represented by formula (1) below: wherein R1-R4 independently denote hydrogen or a substituent as specified. In some cases, two or more such imidazole units can be included in a combined form to provide the imidazole compound.

Abstract: An image forming apparatus for injection charging which uses charging accelerating particles in a charging nip portion to rotate an image bearing body and a charging roller at different velocities and applies a bias in image forming which is different from a bias applied in non-image forming to feed substantially only the charging accelerating particles in non-image forming, thereby it is possible to enhance a charging property and to provide a favorable image.