Abstract: In a color laser printer, the amount of reversely transferred developing agent on the surface of a developing roller is estimated based on the operating time of the color laser printer, the surface area of an image, and the charging amount of developing agent. When the estimated amount of reversely transferred developing agent reaches a predetermined value, a solid image is formed on a photoconductor drum. By transferring the solid image onto recording paper, a conveyer belt, or an intermediate transfer belt, the reversely transferred developing agent is removed. Alternatively, by rotating the developing roller in a state in which the developing roller is separated from the photoconductor drum, the reversely transferred developing agent on the surface of the developing roller is collected into a developing agent hopper.

Abstract: In an image forming apparatus of the present invention capable of forming a full-color image by superposing a black toner image formed by a black image forming unit using a developing and simultaneous cleaning type developing unit over color toner images obtained by color image forming units using developing and simultaneous cleaning developing units arranged in tandem, adhered toners generated from the black image forming unit or the color image forming units to be recovered are all recovered by a same single cleaner.

Abstract: An apparatus having image forming units to form respective toner images of different colors on a toner-image receiving medium, each unit including an image carrier, a static-latent-image forming portion to form a static latent image on the image carrier, a developing portion to apply a toner of the corresponding color to the image carrier, for forming the toner image on the image carrier, and a toner transferring portion to transfer the toner image from the image carrier to the medium, wherein the image forming units are disposed so as to be opposed to the medium and operable to sequentially transfer the toner images from the image carriers to the medium, and the developing portion of each unit is operable to adsorb the toner remaining on the image carrier after the toner image is transferred to the medium, and wherein at least the image forming unit located at the most upstream position of the apparatus is provided with a dust removing portion to remove, from the image carrier, a dust which has been transfer

Abstract: An apparatus for forming a multi-color image is disclosed which includes a controller that performs an anti reverse-transfer control such that a surface potential of a previously-formed separated-developer-image subset of a plurality of single-color separated-developer-images which has been previously transferred onto an image transferred medium is reduced, prior to a subsequent transfer in which a remainder of the plurality of separated-developer-images is transferred onto the image transferred medium after a previous transfer of the previously-formed separated developer-image subset onto the image transferred medium, to thereby prevent a reverse transfer of a part of a developer material on the image transferred medium from the image transferred medium onto a photoconductor at the subsequent transfer.

Abstract: A cleanerless cartridge in which a photoconductor body and a charger are integrated, and a cleaner-equipped cartridge in which a photoconductor body, a charger and a cleaner are integrated are prepared. An image forming apparatus body is configured such that the cartridges are attachable to first- to fourth-stage image forming sections. When the cleanerless cartridge is attached to the first- to fourth-stage image forming sections, an image forming operation is controlled under an image formation condition for a cleanerless process. When the cleaner-equipped cartridge is attached to the first- to fourth-stage image forming sections, an image forming operation is controlled under an image formation condition for a cleaner-equipped process.

Abstract: It is intended to provide an image forming apparatus capable of conducting charge adjustment of post-transfer residual toner appropriately by securing a contact area of a temporarily-collecting member and an electrode, without applying excessive deformation load to the temporarily-collecting member. There are arranged a brush roller for temporarily collecting post-transfer residual toner, and an electrode of which inwardly-curved face being in contact with the brush roller in a toner charge apparatus. Thereby, charged-in-opposite-polarity toner, out of post-transfer residual toner, is collected by the brush roller, polarity of the toner is reversed to original polarity, and then, returned to a photosensitive drum. The inner face of the electrode, i.e., a contact face of the electrode and the brush roller is formed in an inwardly-curved face. Thereby, a large contact area and light pushing force of the electrode to the brush roller can go together.

Abstract: The invention provides an image forming apparatus provided with an image bearing body, and developer charge providing device for providing a charge thereby charging residual developer, remaining on the image bearing body after image transfer, to a normal polarity. The developer charge providing device charges an area of the image bearing body, and such area is further charged by the charging device. When the voltage applied to the developer charge providing device for charging such area is, varied, the voltage applied to the charging means for charging such area is also varied. Thus the image forming apparatus can execute uniform charging in stable manner over a prolonged period.

Abstract: An image forming apparatus having: an image forming body for forming a latent image and a toner image; a developing device for developing with a toner the latent image formed on the image forming body to form the toner image; a primary transfer device for transferring the toner image on the image forming body onto an intermediate transfer body; and a secondary transfer device for transferring the toner image on the intermediate transfer body onto an image support. The primary transfer device has conductive body or semi-conductive body, and is provided with a power supply unit for applying a bias voltage. It is characterized in that the variation coefficient of the shape factor of the toner is 16% or less, and the number variation coefficient of the number particle size distribution of the toner is 27% or less.

Abstract: An image forming apparatus includes: an endless belt; a plurality of image carriers; a plurality of charging units; an exposing unit; and a plurality of developing units configured to develop an electrostatic latent image on each of the image carrier with a developer of different color to form a developer image and to retrieve a residual developer on the image carrier, wherein the endless belt is configured to be transferred the developer images formed on each of the plurality of image carriers thereon to form a color image, and transfers the color image onto a recording medium, and wherein the developing unit provided at a most upstream position with respect to the moving direction of the endless belt forms the developer image with a developer of black color, and is configured to retrieve a residual developer on the endless belt.

Abstract: The present removing system has a feature to remove a left-over toner that is accumulated on a brush that touches a left-over toner on a photoreceptor. More specifically, the present removing system is so arranged that an alternating voltage (superimposing voltage) on which a positive direct current voltage is superimposed is applied onto a conductive brush in accordance with a user's instruction. With this arrangement, even if a positively electrified left-over toner is accumulated on the conductive brush, it is possible to remove the positively electrified left-over toner accumulated on the conductive brush, because a voltage value (positive) applied on the conductive brush in a moment is large. Moreover, because a voltage of the conductive brush becomes negative in a moment, it is possible to remove a negatively electrified left-over toner attached on the conductive brush.

Abstract: An image forming apparatus includes an image bearing member configured to form an electrostatic latent image on a surface thereof, and a separating mechanism configured to separate an irregular charge toner from a residual toner remaining on the surface of the image bearing member after a completion of an image forming process, to provide an extra travel passage to give a time delay to the irregular charge toner, and to return the irregular charge toner with the time delay to the surface of the image bearing member.

Abstract: An image forming apparatus, including toner image agitating units installed between transfer locations and charging locations of a plurality of image forming portions disposed on a transfer carrier belt, reducing adhesion of residual toner to photosensitive conductors. Toner agitating intensities by the toner image agitating units increase in a direction in which the transfer carrier belt transfers paper. Accordingly, a degradation of the quality of an image due to the residual toner is substantially prevented, leading to an improvement in the printing quality. Also, due to adequate distribution of loads upon the photosensitive conductors, the manufacturing costs and life spans of the photosensitive conductors may be reasonably controlled while keeping a high quality image.

Abstract: An image forming apparatus of the present invention includes a sheet affixed at one edge portion and including a flat surface in the other edge portion. The flat surface is formed with a plurality of grooves each extending over the image forming range of a photoconductive drum perpendicularly to the direction in which the surface of the drum moves. The sheet is deformed such that the flat portion contacts the surface of the drum. In this condition, the downstream edges of the grooves in the above direction shave off the surface of the drum a plurality of times during one rotation of the drum, thereby obviating filming on the drum.

Abstract: An image forming apparatus includes a photosensitive drum, a charging roller, a transfer roller, and a toner charging brush, wherein the toner charging brush reciprocates in a longitudinal direction of the photosensitive drum. In the image forming apparatus, when a number of rotations per a unit time of the image bearing member is assumed to be “a” and a number of times of reciprocation per unit time of the toner charging brush is assumed to be “b” assuming that R=b/a, R is set to be in a range of 1/25?R?3. However, R=m/n (m and n are integers of 5 or less) is excluded. Consequently, generation of a periodic attachment pattern appearing on the photosensitive drum is eliminated.

Abstract: A cleaner-less image former that can prevent cleaning efficiency from reducing and maintain high print quality. After a printing process is started, one lookup table LUT is selected from a group of LUTs based on a temperature detected by a temperature sensor and the number of sheets of paper which have been printed. A pre-transfer bias is determined by applying a current value memorized in a feedback current value memorizing part to the selected LUT, the determined pre-transfer bias is applied to a transfer roller, and then a transfer bias is determined based on the above current value and the temperature. The determined transfer bias is applied to the transfer roller. The residual toner remaining on the transfer roller, a charge brush and a memory removal brush is removed by applying the pre-transfer bias.

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

Abstract: An image forming apparatus includes an image bearing member; a charging member for electrically charging the image bearing member; developing means for developing with a developer an electrostatic latent image formed on the image bearing member, the developing means having a developer carrying member for carrying the developer, wherein a gap is formed between the developer carrying member and the image bearing member; bias voltage applying means for applying a bias voltage to the developer carrying member, wherein the bias applying means applies an AC bias when the electrostatic latent image is developed, wherein the developing means is capable of collecting the developer fro the image bearing member, and an amplitude of an AC bias voltage applied to the developer carrying member by the bias applying means when the the developer is collected, is larger than that when the the electrostatic latent image is developed.

Abstract: An image formation apparatus has developing agent charging device situated downstream in the direction of motion of a photosensitive drum from a transfer roller and upstream from a charging roller, for charging residual developing agent remaining on the photosensitive drum. Applying AC voltage to the charging roller is started before a portion on the face of the photosensitive drum where application of voltage to the developing agent charging device has started reaches a position of coming into contact with the charging roller, and applying AC voltage to the charging device is ended after the portion on the face of the photosensitive drum where application of voltage to the developing agent charging device has ended reaches a position of coming into contact with the charging roller. This configuration prevents adhesion of developing agent to the photosensitive drum and charging roller, avoids resultant substandard images, and provides high-quality images for prolonged periods.

Abstract: An image forming device includes an image forming unit that includes a photoconductive drum which carries an electrostatic latent image, a developing roller which forms a developing nip by contacting the photoconductive drum and develops the latent image by using toner, and a transfer roller that forms a transferring nip by contacting the photoconductive drum and transfers a toner image onto a recording paper. A transferring voltage impressing circuit impresses to the transfer roller, a voltage of an opposite polarity to a polarity of a transfer process, for a prescribed period of time during a period when the recording paper is absent in the transferring nip. A developing voltage impressing circuit impresses to the developing roller, a voltage of a same polarity as a developing process and lower than the developing process when a field impressed with the voltage of the opposite polarity by the transferring voltage impressing circuit passes the developing nip.

Abstract: There is provided a simply structured, cleanerless image forming apparatus capable of suppressing occurrence of filming without significant remodeling. An image forming apparatus 100 according to the present invention comprises a plurality of image forming units 100a, 100b, 100c, and 100d for forming toner images of corresponding colors on photoconductor drums 3a, 3b, 3c, and 3d according to a cleanerless system. These image forming units respectively have adhered toner film cleaners 1a, 1b, 1c, and 1d each of which touches a surface of the photoconductor and mechanically cleans the surface at every cleaning timing for cleaning the surface of the photoconductor. The adhered toner film cleaner does nothing during image formation, but cleans the photoconductor surface only at cleaning timing when the image formation is complete for the specified number of sheets. Accordingly, it is possible to decrease filming without affecting the photoconductor's life.

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 process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes a photosensitive drum; a developing roller rotatable in the drum-rotating direction when the cartridge is mounted to the apparatus; first and second separation members disposed at one and the other end of the roller so as to provide a gap between the roller and the drum and contacting the drum surface adjacent one and the other end thereof; a charging roller, contacting and charging the drum, which is rotatable with a peripheral speed difference relative to the drum; and a cleaning member contacting the drum adjacent one end thereof, the cleaning member having an effective area outside a developing-roller developing zone and inside a charging-roller-and drum contact region and which is in a region where the first separation member contacts the drum.

Abstract: An image forming apparatus is provided which is capable of inhibiting filing on photoreceptor and color toner mixing, while prolonging the life of the photoreceptor. The image forming apparatus includes a photoreceptor having a photosensitive surface carrying thereon an electrostatic latent image, a developing device for forming a toner image on the photosensitive surface and electrically recovering toner remaining on the photosensitive surface after image forming operation at the photosensitive surface, a transfer belt 101 having a belt surface which is in contact engagement with the photosensitive surface, and a cleaner S for removing toner attached on the belt surface, wherein the contact angle of the photosensitive surface for water is greater than that of the belt surface for water.

Abstract: A image forming apparatus includes an image bearing member to be moved rotationally, charging means for electrically charging the image bearing member and toner remaining on the image bearing member, electrostatic latent image forming means for forming an electrostatic latent image on the image bearing member charged by the charging means, developing means for visualizing the electrostatic latent image while recovering the toner remaining on the image bearing member, toner charging means which is disposed upstream from the charging means in a rotational direction of the image bearing member and is to be supplied with a voltage of a polarity identical to that of a voltage to be applied to the charging means to electrically charge the toner remaining on the image bearing member, recording means for recording an operation history of the image forming apparatus, and control means for controlling the voltage to be supplied to the toner charging means on the basis of the operation history of the image forming appar

Abstract: A cleaner-less image forming apparatus serves to prevent excessive expellation of toner from a photosensitive drum at the time of application of a bias voltage. A developer charging member for charging residual toner on the photosensitive drum is disposed in contact with the photosensitive drum at a location downstream of a transfer device and upstream of a charging device in a direction in which the photosensitive drum is rotating. A DC voltage of a polarity opposite to a normal charging polarity of the developer is applied to the developer charging member and has a slope whose absolute value at the start of voltage application is selectable from a first value and a second value which is greater than the first value.

Abstract: An image forming apparatus having an image carrier, a charging unit for charging the image carrier and residual toner on the image carrier, a charging bias applying unit, an electrostatic image forming unit, a developing unit for collecting the residual toner on the image carrier and visualizing the electrostatic image, and a developing bias regulating unit. The apparatus further comprises an image ratio calculating unit for calculating an image ratio on the basis of the electrostatic image, and a regulating unit for regulating a contrast potential between the developing unit collecting the residual toner and the image carrier on the basis of a calculated image ratio. In the apparatus, an occurrence of the problem of adhesion of toner to a non-image area is prevented by fully collecting transfer residual toner also in forming an image having a high image ratio.

Abstract: A process cartridge includes an image bearing member, a developing device developing an electrostatic image on the member using developer to form a developer image on the member and a developer charger charging residual developer on the member disposed downstream of a transferring position at which the developer image is transferred onto a transfer destination member and upstream of a position at which the electrostatic image is formed on the member with respect to the moving direction of the member. The developer charger is in contact with the member and is movable in the longitudinal direction of the member upon charging the residual developer. L1+d?L2 when L1 is the developing width of the developing device, L2 is the contact width of the developer charger with the member, and d is the width of movement of the developer charger in the longitudinal direction of the member.

Abstract: An image forming apparatus is provided which is capable of inhibiting filing on photoreceptor and color toner mixing, while prolonging the life of the photoreceptor. The image forming apparatus includes a photoreceptor having a photosensitive surface carrying thereon an electrostatic latent image, a developing device for forming a toner image on the photosensitive surface and electrically recovering toner remaining on the photosensitive surface after image forming operation at the photosensitive surface, a transfer belt 101 having a belt surface which is in contact engagement with the photosensitive surface, and a cleaner S for removing toner attached on the belt surface, wherein the contact angle of the photosensitive surface for water is greater than that of the belt surface for water.

Abstract: An image forming apparatus is provided, which includes: an image bearing member, a charging member for charging the image bearing member, the charging member bearing electrically conductive particles that contact the image bearing member, and a developer carrying member for carrying a developer provided with toner and electrically conductive particles, the developer carrying member being applied a voltage to develop an electrostatic image formed on the image bearing member with the developer and being capable of collecting a residual developer on the image bearing member, wherein the developer carrying member is provided in such a manner that the developer carrying member opposes the image bearing member via a gap of 150 ?m or more and 250 ?m or less.

Abstract: The image forming apparatus includes: a plurality of image forming units each having an image bearing member and a developing unit; and a transfer member provided to be able to contact the plurality of image bearing members. The toner used in at least one of the plurality of developing units contains a toner particle group with a particle size of 12.7 ?m or more, a ratio of the toner particle group to the entire toner being 1.0% or less. Accordingly, incomplete transfer can be prevented.

Abstract: An image forming apparatus containing an image holding member, a contact-type charger for charging a surface of the image holding member, an exposure unit for forming an electrostatic latent image by exposing the charged surface of the image holding member, a developing unit for developing the electrostatic latent image with a spherical toner to obtain a toner image, and a transfer member for electrostatically transferring the toner image from the surface of the image holding member onto a transfer material. A number of toner particles remaining on the surface of the image holding member before passing through an abutting portion between the image holding member and the contact-type charger is in a range of 100 to 400 per unit area (mm2).

Abstract: To provide a method for forming images in which the image bearing member and the toner carrying member are arranged with a gap of 100 ?m to 250 ?m, and the equation (1) and equation (2) are satisfied. (1) 22?(the frequency of the alternating current component of the alternating electric field/the peripheral speed of the toner carrying member)×the maximum electric field intensity at the time of developing?1.20. (2) 8?(the frequency of the alternating current component of the alternating electric field/the peripheral speed of toner carrying member)×(the fluidity index of Carr/the floodability index of Carr)?50. According to the method for forming images of the present invention, it is possible to obtain a high quality image without generating fog and light shielding while attaining a uniform halftone with a high image density even over long-term.

Abstract: In a transfer unit of an image forming apparatus, an auxiliary transfer roller and a main transfer roller are provided relative to a photosensitive drum, with a transfer belt interposed. A low voltage for avoiding occurrence of a high electric field is applied to the auxiliary transfer roller, while a high transfer voltage for realizing sufficient transfer is applied to the main transfer roller.

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

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

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

Abstract: An image forming apparatus includes: an endless belt; a plurality of image carriers; a plurality of charging units; an exposing unit; and a plurality of developing units configured to develop an electrostatic latent image on each of the image carrier with a developer of different color to form a developer image and to retrieve a residual developer on the image carrier, wherein the endless belt is configured to be transferred the developer images formed on each of the plurality of image carriers thereon to form a color image, and transfers the color image onto a recording medium, and wherein the developing unit provided at a most upstream position with respect to the moving direction of the endless belt forms the developer image with a developer of black color, and is configured to retrieve a residual developer on the endless belt.

Abstract: There is provided a simply structured, cleanerless image forming apparatus capable of suppressing occurrence of filming without significant remodeling.

Abstract: Image deterioration due to contact of a cleaning roller and a photosensitive member when an image forming operation stops can be prevented. When the image forming operation stops, a photosensitive belt is stopped in a condition that a stop position of the photosensitive belt corresponds to a photosensitive belt cleaning roller. Even if a stain is caused in the stop position of the photosensitive belt by the contact with the photosensitive belt cleaning roller, an image is formed in an image region of the photosensitive belt, separate from the stop position, in the image forming operation and the image is not deteriorated by the stain.

Abstract: An image-forming apparatus includes a pre-charge exposure device which removes electric charge from a photoconductor drum to increase a potential contrast between the surface of the photoconductor drum and the surface of a charge roller in an upstream region of a nip region between the photoconductor drum and the charge roller in the rotating direction of the photoconductor drum, so that toner accumulating in an upstream region of the nip region in the rotating direction of the photoconductor drum is restrained and prevented from being discharged onto an image-forming region. When the toner accumulating in the upstream region of the nip region in the rotating direction of the photoconductor drum is to be discharged onto a non-image-forming region, the pre-charge exposure device is turned off so that the potential contrast decreases.

Abstract: An image forming apparatus of cleaner-less system using toner particles comprising resin mother particles coated with external additives, having an adhesive force between a primary transfer member and the toner particle that is larger than the adhesive force between an image carrier and the toner particle, and an adhesive force between the primary transfer member and the resin mother particle that is larger than the adhesive force between the image carrier and the resin mother particle. As a result, a stable transfer property is provided which prevents the generation of residual toner particles. Furthermore, when images with toner particles of different colors are superposed at the transfer portion, color-to-color separation of the toner particles can be prevented by setting the adhesive force between the resin mother particles of the different colors to be larger than the adhesive force between the image carrier and the resin mother particle.

Abstract: To provide an image forming apparatus improving discharging of a developer from charge providing member for providing charge to the developer remaining on an image bearing member to the image bearing member, the developer is charged from the charge providing member to the image bearing member. When a developer discharging region of the image bearing member is disposed at a charging position, charging member is applied with a voltage having a direct current component of an absolute value equal to or smaller than an absolute value of voltage applied to the charge providing member without an alternating current component.

Abstract: An image forming apparatus is provided, which includes: an image bearing member, a charging member for charging the image bearing member, the charging member bearing electrically conductive particles that contact the image bearing member, and a developer carrying member for carrying a developer provided with toner and electrically conductive particles, the developer carrying member being applied a voltage to develop an electrostatic image formed on the image bearing member with the developer and being capable of collecting a residual developer on the image bearing member, wherein the developer carrying member is provided in such a manner that the developer carrying member opposes the image bearing member via a gap of 150 &mgr;m or more and 250 &mgr;m or less.

Abstract: When image forming is repeated with cleanerless image forming apparatus “positive ghost” which means that the preceding image is slightly left occurs because residual toner is not recovered by developing means. Even if an image forming apparatus with an electrically conductive brush or auxiliary means repeats image forming or continuously forms image with a high image ratio, resistance of the brush increases because residual toner is deposited on the electrically conductive brush. In the results, advantages of the electrically conductive brush which erases traces of the preceding image are lost. Therefore, they are provided, an image forming apparatus which does not let image traces leave and an image forming apparatus which prevents the resistance of auxiliary means and cleans auxiliary means.

Abstract: An image forming apparatus is provided which is capable of inhibiting filming on photoreceptor and color toner mixing, while prolonging the life of the photoreceptor.

Abstract: The image forming apparatus includes: a plurality of image forming units each having an image bearing member and a developing unit; and a transfer member provided to be able to contact the plurality of image bearing members. The toner used in at least one of the plurality of developing units contains a toner particle group with a particle size of 12.7 &mgr;m or more, a ratio of the toner particle group to the entire toner being 1.0% or less. Accordingly, incomplete transfer can be prevented.

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

Abstract: An image forming process and apparatus, the apparatus including a toner container, a transfer belt below the toner container, a process cartridge below the transfer belt, and an imaging device below the process cartridge. The process cartridge includes a rotating image carrier having an image carrier surface, a brush roller in contact with the image carrier surface, a charging member in contact with the image carrier surface and configured to transfer a charge to the image carrier surface, and a casing including a miler in contact with the image carrier surface and arranged to separate the brush roller from the charging member.

Abstract: A image forming apparatus includes an image bearing member to be moved rotationally, charging means for electrically charging the image bearing member and toner remaining on the image bearing member, electrostatic latent image forming means for forming an electrostatic latent image on the image bearing member charged by the charging means, developing means for visualizing the electrostatic latent image while recovering the toner remaining on the image bearing member, toner charging means which is disposed upstream from the charging means in a rotational direction of the image bearing member and is to be supplied with a voltage of a polarity identical to that of a voltage to be applied to the charging means to electrically charge the toner remaining on the image bearing member, recording means for recording an operation history of the image forming apparatus, and control means for controlling the voltage to be supplied to the toner charging means on the basis of the operation history of the image forming appar

Abstract: An image forming apparatus containing an image holding member, a contact-type charger for charging a surface of the image holding member, an exposure unit for forming an electrostatic latent image by exposing the charged surface of the image holding member, a developing unit for developing the electrostatic latent image with a spherical toner to obtain a toner image, and a transfer member for electrostatically transferring the toner image from the surface of the image holding member onto a transfer material. A number of toner particles remaining on the surface of the image holding member before passing through an abutting portion between the image holding member and the contact-type charger is in a range of 100 to 400 per unit area (mm2).