Abstract: An image forming apparatus includes a development device for supplying a developer containing toner and carrier to an electrostatic latent image carrying member for carrying thereon an electrostatic latent image, or a process cartridge for integrally storing the development device and the electrostatic latent image carrying member. The development device includes a conveyance path for charging and conveying the developer, and a developer carrying member for developing the electrostatic latent image into a toner image with the use of the developer conveyed through the conveyance path. The conveyance path includes a first conveyance member for receiving replenished toner and generating conveyance force for conveying the replenished toner and the developer in one direction, and a second conveyance member for generating conveyance force for conveying a portion of the developer conveyed by the first conveyance member in the opposite direction to the conveyance direction of the first conveyance member.

Abstract: A wet type developing apparatus in which a liquid developer is fed onto a developing roller from a liquid developer supply roller immersed in the developing liquid within a liquid developer tank and an electrostatic latent image formed on a photoconductor drum is developed into a toner image by said developing roller is improved to enable the liquid developer to be kept fed at an appropriate amount of feed from the liquid developer supply roller onto the developing roller without air residual in the surface region of the liquid developer supply roller. The improvement comprises a partition plate disposed generally under the liquid developer supply roller within the liquid developer tank for partitioning the liquid developer tank into two in the direction of rotation of the liquid developer supply roller, the partition plate having its upper end juxtaposed with a peripheral surface of the liquid developer supply roller over its total axial length across a gap spacing between 0.05 and 0.5 mm.

Abstract: A developing device includes: a developer carrying body that carries liquid developer containing toner and carrier liquid; a developer supplying member adapted to rotate in a first sense of rotation to supply liquid developer to the developer carrying body; a contact member arranged at a first side relative to a virtual perpendicular plane passing through the axis of the developer supplying member so as to contact the developer supplying member; a supply section that stores liquid developer to be supplied by the developer supplying member to the developer carrying body; and an agitating member adapted to rotate in a second sense of rotation different from the first sense of rotation and arranged at a second side relative to the virtual perpendicular plane passing through the axis of the developer supplying member.

Abstract: A development apparatus includes an anilox roller for supplying liquid developer to a development roller and a supply roller arranged in a developer container and held in contact with the anilox roller to supply the liquid developer to the anilox roller. An AC voltage is applied to the supply roller, and a bias voltage is applied to the development roller. Liquid developer contained in grooves of undulations of an anilox pattern formed on a surface of the anilox roller is applied to the development roller.

Abstract: An image forming apparatus (100) includes a photoreceptor drum (1), a development unit (2), a pressing member (7), and a vibration absorption member (8). The development unit (2) is disposed adjacent to the photoreceptor drum (1), and supported movably toward and away from the photoreceptor drum (1). The pressing member (7) urges the development unit (2) toward the photoreceptor drum. The vibration absorption member (8) frictionally suppresses the movement of the development unit (2) toward and away from the photoreceptor drum (1). The vibration absorption member (8) attenuates a self-excited vibration of the development unit (2), by suppressing the movement of the development unit (2).

Abstract: An image forming apparatus includes: a latent image bearing drum that rotates and on which a latent image is formed; an exposure head having a first light-emitting element that exposes a first region of the latent image bearing drum and a second light-emitting element that exposes a second region of the latent image bearing drum; a storage unit that stores first speed-related information relating to the rotational speed of the first region of the latent image bearing drum and second speed-related information relating to the rotational speed of the second region of the latent image bearing drum; and a light-emission timing adjustment unit that adjusts the timing of the light emission of the first light-emitting element based on the first speed-related information and adjusts the timing of the light emission of the second light-emitting element based on the second speed-related information.

Abstract: The invention provides a developing device employing a liquid developer which is capable of effectively cleaning a development roller or the like having an elastic outer layer. The developing device of the invention is provided with an elastic roller such as a development roller for developing a latent image formed on an image carrier. In image forming process, toner particles uniformly dispersed in carrier are agglutinated to the elastic roller side by means of compaction. A cleaning blade is provided for cleaning the agglutinated toner particles.

Abstract: A developing device includes a developer storage portion that stores a liquid developer including toner and carrier liquid. A first coating member rotates and coats the liquid developer stored in the developer storage portion. A second coating member contacts the first coating member and rotates in a direction opposite to that of the first coating member. A developer supporting body contacts the second coating member and rotates in the same direction as that of the second coating member. A contact member contacts the liquid developer coated on the second coating member by the first coating member.

Abstract: A development unit for a printing device is described. An equalizing element is provided to minimize residual charges which cause ghosting. The equalizing element can, for example, be a roller or a blade positioned downstream of a cleaning nip between the cleaning roller and the development roller and charged to an electric potential which is substantially the same as an electric potential of the development roller. The equalizing element can alternatively, or in addition to being charged to perform equalization, operate to aid in charge residual charge dissipation on the development roller by blocking developer from reaching the development roller downstream of the cleaning roller.

Abstract: The present invention discloses a developing unit that can block unnecessary supply of liquid developer to an image support member and can prevent waste of liquid developer, and an image forming device comprising the same. The developing unit includes a developing member that is in contact with an image support member and supplies the image support member with liquid developer, a developer supply member that supplies the developing member with liquid developer, and an unattached region forming member that forms at least an unattached region that is free of liquid developer on the developing member, the unattached region extending from the contact point between the developing member and the image support member and the contact point between the developing member and the developer supply member.

Abstract: A wire bar is formed by winding a wire, which comprises a first flat portion formed along an overall longitudinal length, around a peripheral surface of a metal core such that the peripheral surface of the metal core and the first flat portion tightly contact with each other. Since this increases the area size of a contact portion where the wire and the metal core contact each other, it is possible to increase the force of static friction which fixes the wire to the metal core. Fixing of the wound wire to the metal core by the strong force of static friction effectively prevents the wound wire from getting deviated.

Abstract: The invention relates to an abhesive layer and to a method for producing an abhesive coating from cross-linked inorganic nanosols. It is an object of the invention to develop an abhesive layer, which has a strong abhesive effect especially with respect to adhesive liquids or pastes, such as printing inks and, while adhering well to the coated materials, has an improved, wear resistance. This objective is accomplished by an abhesive layer or abhesive coating of cross-linked inorganic nanosols with additions of polyorganosiloxanes, which form a three-dimensional network in the layer.

Abstract: A developer carrying member is disclosed which can prevent a toner from being excessively charged in a developing assembly while keeping the charge quantity of the toner at a somewhat higher level, and seldomly causes toner melt adhesion to the developer carrying member.

Abstract: An object of the present invention is to provide a liquid developing electrographic device roller suppressed in volumetric variation caused by a carrier. As a means for solving the problems, the present invention provides a liquid developing electrophotographic device roller including a shaft and an elastic material layer provided around the outer peripheral side of the shaft, wherein the elastic material layer is formed by using a polyurethane obtained by reacting a polyester polyol with a difunctional isocyanate.

Abstract: An image forming device contains: a latent image holding member; a latent image forming unit; a developer storage unit that stores a liquid developer including a toner and an aqueous medium; a developer supply member that supplies the liquid developer to a latent image holding member; and a transfer unit that transfers a toner image to a recording medium. The developer supply member has a surface formed of a liquid absorbent member and is disposed such that a part of the liquid absorbent member is immersed in the liquid developer stored in the liquid developer storage unit and that another part of the liquid absorbent member is in contact with and compressed by the latent image holding member. The water repellency of the surface of the latent image holding member is higher than the water repellency of the surface of the developer supply member.

Abstract: A development device includes a developer carrier 20Y that carries liquid developer containing toner liquid and carrier liquid, a developer supply member 32Y that supplies liquid developer to the developer carrier 20Y, a developer carrier cleaning member 21Y that collects liquid developer from the developer carrier 20Y, a collection reservoir 31aY that stores the liquid developer collected by the developer carrier cleaning member 21Y, a supply section 31bY that makes liquid developer flow to the collection reservoir 31aY, a conveyance member 34Y that conveys the liquid developer collected in the collection reservoir 31aY in a first direction X and a conveyance capacity regulation section 39bY that regulates the conveyance capacity of the conveyance member 34Y.

Abstract: A developing device includes: a developer carrying body that carries liquid developer containing toner and carrier liquid; a developer supplying member adapted to rotate in a first sense of rotation to supply liquid developer to the developer carrying body; a contact member arranged at a first side relative to a virtual perpendicular plane passing through the axis of the developer supplying member so as to contact the developer supplying member; a supply section that stores liquid developer to be supplied by the developer supplying member to the developer carrying body; and an agitating member adapted to rotate in a second sense of rotation different from the first sense of rotation and arranged at a second side relative to the virtual perpendicular plane passing through the axis of the developer supplying member.

Abstract: A method for producing a liquid developer comprising an insulation liquid and toner particles dispersed in the insulation liquid is provided. The method comprising the steps of: a wet grinding step for grinding a toner material mainly composed of a resin material in a first liquid which contains as its main component a fatty acid monoester to obtain a ground material dispersed liquid; and a mixing step for mixing the ground material dispersed liquid and a second liquid which contains as its main component a fatty acid triglyceride, wherein the first and second liquids constitute the insulation liquid, and the ground resin material dispersed in the insulation liquid constitutes the toner particles. According to the producing method, it is possible to produce a liquid developer in which toner particles having a sufficiently small size are stably dispersed with high production efficiency. Further, a liquid developer produced by the method and an image forming apparatus are also provided.

Abstract: A wire bar is formed by winding a wire, which comprises a first flat portion formed along an overall longitudinal length, around a peripheral surface of a metal core such that the peripheral surface of the metal core and the first flat portion tightly contact with each other. Since this increases the area size of a contact portion where the wire and the metal core contact each other, it is possible to increase the force of static friction which fixes the wire to the metal core. Fixing of the wound wire to the metal core by the strong force of static friction effectively prevents the wound wire from getting deviated.

Abstract: The invention provides a developing device employing a liquid developer which is capable of effectively cleaning a development roller or the like having an elastic outer layer. The developing device of the invention is provided with an elastic roller such as a development roller for developing a latent image formed on an image carrier. In image forming process, toner particles uniformly dispersed in carrier are agglutinated to the elastic roller side by means of compaction. A cleaning blade is provided for cleaning the agglutinated toner particles.

Abstract: Provided are a liquid developing apparatus and an image forming apparatus, wherein a high-viscosity liquid developer layer is transferred sequentially from a developer supply member to a developer coating member and to the developer carrying member among rollers, and the developer supply width of the developer supply member is made smaller than the width of the developer coating member and greater than the width of the developer carrying member, whereby an occurrence of the area, at the end portions of the developer carrying member, where the volume of developer is uneven is reduced, and the liquid developer is prevented from wrapping around the end faces of the developer coating member, without making the apparatus complicated.

Abstract: A liquid application apparatus includes: a roller member which is driven so as to rotate in a rotational direction; an application liquid supply device which supplies an application liquid onto a portion of the roller member while the roller member is rotating; a blade member which is arranged so as to abut against a circumferential surface of the roller member at an abutment position that is on a downstream side of the application liquid supply device in terms of the rotational direction of the roller member, the blade member wiping away an excess of the supplied application liquid on the roller member; a substitute fluid spray device which is arranged on a downstream side of the abutment position of the blade member in terms of the rotational direction of the roller member, the substitute fluid spray device spraying a substitute fluid onto a region of the circumferential surface of the roller member so as to remove the application liquid on the region of the circumferential surface of the roller member afte

Abstract: A high speed electrostatic printing machine has a toner supply to supply to a supply roller (13) a high viscosity highly concentrated toner; a pick-up roller (16) which is spaced from the supply roller by a first feed gap; a metering roller (21) which receives a thin layer of the toner from the pick-up roller; a doctor blade (23) bearing against the metering roller which bears against a development member (31) with an interference fit (32) to transfer a thin layer of the toner onto the development member; an image forming stage (40), the image forming stage comprising an image carrying member (41) having a surface adapted to retain an electrostatic latent image thereon with the development member engaging against the image carrying member with an interference fit (46) to give a selected contact time therebetween; a development stage in which toner particles in the thin layer on the development member are transferred to the image carrying member under the influence of the electrostatic latent image on the imag

Abstract: A wire bar is formed by winding a wire, which comprises a first flat portion formed along an overall longitudinal length, around a peripheral surface of a metal core such that the peripheral surface of the metal core and the first flat portion tightly contact with each other. Since this increases the area size of a contact portion where the wire and the metal core contact each other, it is possible to increase the force of static friction which fixes the wire to the metal core. Fixing of the wound wire to the metal core by the strong force of static friction effectively prevents the wound wire from getting deviated.

Abstract: The invention provides a developing device employing a liquid developer which is capable of effectively cleaning a development roller or the like having an elastic outer layer. The developing device of the invention is provided with an elastic roller such as a development roller for developing a latent image formed on an image carrier. In image forming process, toner particles uniformly dispersed in carrier are agglutinated to the elastic roller side by means of compaction. A cleaning blade is provided for cleaning the agglutinated toner particles.

Abstract: A liquid developer includes an insulation liquid containing a fatty acid monoester and toner particles comprised of a resin material, the resin material containing a first resin component and a second resin component of which weight-average molecular weight Mw2 is larger than a weight-average molecular weight Mw1 of the first resin component. The first resin component and the second resin component are characterized in that the weight-average molecular weight Mw1 of the first resin component is in the range of 3,000 to 12,000, the weight-average molecular weight Mw2 of the second resin component is in the range of 20,000 to 400,000, and when an amount of the first resin component contained in the resin material is defined as A (wt %) and an amount of the second resin component contained in the resin material is defined as B (wt %), A and B satisfy a relation: 1.0?A/B?9.0. The liquid developer described above is harmless to the environment.

Abstract: In a method or device for transport of liquid developer to an image carrier element for electrophoretic digital printing, a developer unit is arranged adjacent to the image carrier element, the developer unit directing a liquid developer having toner particles to the image carrier element, the toner particles crossing over to the image carrier element corresponding to previously-generated potential images. A raster unit is arranged adjacent to the developer unit. The raster unit transports the liquid developer to the developer unit by use of a raster. An electrical voltage is applied between the raster unit and the developer unit in order to exert a targeted field effect on the toner particles in a direction towards the developer unit. A chamber scraper having a dosing scraper is arranged adjacent to the raster unit and having liquid developer having the toner particles which are already charged. From the chamber scraper the raster unit accepts the liquid developer via the dosing scraper.

Abstract: A developer system component includes at least one surface configured to be driven so as to create fluid flow providing a shear force adjacent a cleaner.

Abstract: An image forming apparatus includes a development device for supplying a developer containing toner and carrier to an electrostatic latent image carrying member for carrying thereon an electrostatic latent image, or a process cartridge for integrally storing the development device and the electrostatic latent image carrying member. The development device includes a conveyance path for charging and conveying the developer, and a developer carrying member for developing the electrostatic latent image into a toner image with the use of the developer conveyed through the conveyance path. The conveyance path includes a first conveyance member for receiving replenished toner and generating conveyance force for conveying the replenished toner and the developer in one direction, and a second conveyance member for generating conveyance force for conveying a portion of the developer conveyed by the first conveyance member in the opposite direction to the conveyance direction of the first conveyance member.

Abstract: A liquid developer includes: an insulating liquid having dispersed therein toner particles, the insulating liquid containing a fatty acid monoester that is an ester of a fatty acid and a monohydric alcohol, and the insulating liquid having an aniline point of from 5 to 80° C.

Abstract: Disclosed is a developing unit 6 including a tank containing a liquid toner, a pick-up roller 10 for drawing the liquid toner from the tank, an application roller 11 whose circumferential surface 11a is supplied with the liquid toner by the pick-up roller 10, and a developing roller 12 whose circumferential surface 12a is applied with the liquid toner by the application roller 11. The pick-up roller 10 and the application roller 11 are arranged in parallel to each other and circumferential surfaces 10a, 11a thereof are in contact with each other. The circumferential surfaces 10a, 11a of the pick-up roller 10 and the application roller 11 are formed with a plurality of grooves 13, 14, respectively, which extend continuously in the axial direction X1.

Abstract: A liquid developer includes: an insulating liquid having dispersed therein toner particles, silica fine particles subjected to hydrophobic treatment and a polymer dispersant, the silica fine particles having an average particle diameter of from 5 to 100 nm, and a content of the silica fine particles being from 0.1 to 5.0 parts by weight per 100 parts by weight of the toner particles, the insulating liquid containing an unsaturated fatty acid triglyceride and a fatty acid monoester.

Abstract: A wet type image forming apparatus forms an image in accordance with an electrophotographic imaging process using a developing solution containing a toner in a carrier solution. The image forming apparatus includes a developing roller that holds the developing solution thereon, the developing roller being electrically charged to attract a toner contained in the developing solution toward its surface, a photoconductive drum on which a latent image to be developed is formed, the photoconductive roller being arranged to contact the developing roller, a scraping blade disposed in contact with the developing roller, the scraping blade scraping off the developing solution that has not been consumed for developing from the surface of the developing roller, and a toner separator that separates the toner that has not been consumed for developing from the surface of the developing solution carrier before the developing solution is scraped off by the scraping blade.

Abstract: A liquid development device has a developer retaining roller having recesses, which are for retaining liquid developer, provided in the surface of the developer retaining roller; and a supplying roller for supplying the liquid developer to the developer retaining roller. The upper edge of the supplying roller is located above the lower edge of the developer retaining roller in the vertical direction, and the supplying roller supplies the liquid developer to the developer retaining roller downwards from above.

Abstract: A liquid developer imaging system comprising a developing container for receiving a quantity of developing solution, a sensing system for maintaining a predetermined processing level of developing solution within the container, a developer roller connected to a first power supply source that biases the developer roller to a development voltage, and a skiving element for plating the developing solution onto the developer roller and scraping excess developing solution from the developer roller to a predetermined thickness, wherein the skiving element is connected to a second power supply source for biasing the skiving element to a skiving voltage, wherein the skiving voltage is greater than the development voltage.

Abstract: An application roller comprises inclined sections which monotonously extend from central parts of peaks to the bottom of grooves. Hence, a liquid developer (a carrier liquid and toner particles) remaining on wall surfaces of the grooves of the application roller and the like without moving to a developer roller from the application roller, due to its own gravity, moves to the bottom of the grooves while applied upon the developer roller, and stays at inner bottom parts of the grooves. This effectively prevents air from getting trapped in the grooves during carrying of the liquid developer to the grooves, and hence, permits carrying of an appropriate amount of the liquid developer.

Abstract: A developing device includes: a developer bearing body for bearing liquid developer, the liquid developer bore by the developer bearing body being used by the developing device to develop a latent image bore by an image bearing body; a developer supplying member that has depressions in its surface and whose surface is pressed in contact with the developer bearing body for supplying the liquid developer retained in the depressions to the developer bearing body; and a restricting section for restricting the amount of the liquid developer on the developer supplying member, wherein the amount of the liquid developer, which is retained in the depressions and whose amount has been restricted by the restricting section, before being supplied to the developer bearing body is smaller than the volumetric capacity of the depressions that retain the liquid developer.

Abstract: An apparatus prevents developer wraparound in a wet electrophotographic printer using wraparound preventing units. Each of the wraparound preventing units has varied diameter parts formed at both ends of a developing roller, and matching parts formed at both ends of a metering roller to correspond to the varied diameter parts of the developing roller. Since the varied diameter parts and the matching parts are respectively installed at both ends of the developing roller and the metering roller, developer wraparound is not generated in the developing roller and a photosensitive roller during development.

Abstract: Disclosed is a developing unit of a wet electrophotographic printer, which has a photoconductive drum, a developing roller for transferring a developer onto the photoconductive drum, a cartridge for storing a developer therein, a developer guide disposed at a predetermined distance away from an inner wall of the cartridge, and having a developer supplying path defined therein to guide the developer in the cartridge to the developing roller, and a developer pumping means disposed in the cartridge to pump up the developer in the cartridge toward the developing roller.

Abstract: An electrostatic transfer type liquid electrophotographic printer which has a photoreceptor web having a charged surface and opposing back surface, at least one exposing unit for forming a latent electrostatic image onto the charged surface of the photoreceptor web, and at least one development unit for developing the latent electrostatic image on the photoreceptor web into a toner image, wherein each development unit has a developer roller, a toner removal roller, and a squeeze roller, and a backup roller corresponding to at least one of the developer roller, toner removal roller, and squeeze roller, and wherein the photoreceptor web is arranged to provide at least 1 degree of contact wrap around at least one of the backup rollers. The printer further includes an electrostatic transfer unit for transferring the toner images formed in each development unit from the photoreceptor web to a print medium by electrostatic force.

Abstract: In a device and method for electrographic printing or copying, a latent image carrier is provided having a potential pattern corresponding to an image pattern. An applicator pattern is provided that carries a liquid layer of ink spaced from a surface of the latent image carrier by an air gap. A surface of the applicator element is provided with a structure with which detachment of droplets from the liquid layer is facilitated, the structure having a plurality of first areas having an increased electrical conductivity, a plurality of second areas that differ from a remaining surface based on a portion of surface energy, and a plurality of third areas formed as microscopic elevations. A force field is applied in the air gap to act on the liquid layer. By overcoming the air gap, droplets are transferred from the liquid layer on the surface of the latent image carrier by overcoming the air gap for inking a latent image to create an inked image.

Abstract: A developing device for developing a latent image formed on an image carrier with a developing liquid includes a liquid storing section for storing the liquid including a developing substance and a carrier liquid. A developer carrier deposits the liquid fed from the liquid storing section thereon. A float type liquid level sensor senses a liquid level in the liquid storing section. The liquid level sensor includes a magnetic force generating member for generating a magnetic force, a magnetic force sensing device for sensing the magnetic force, and floats movable up and down in accordance with the liquid level in the liquid storing section. A distance between the magnetic force generating member and the magnetic force sensing device varies in accordance with the movement of the floats, allowing the liquid level to be determined on the basis of the output of the magnetic force sensing device.

Abstract: A removal nip having a predetermined width is formed by a sweep roller pressurizing mechanism, which adjusts the length of a tension spring by rotating an adjustment screw, and adjusting the size of an energizing force of a sweep roller with respect to a photosensitive drum. A pressurizing mechanism similar to the sweep roller pressurizing mechanism is also provided in a developing roller, to adjust the energizing force of the developing roller, to thereby form a developing nip having a predetermined width.

Abstract: A device for coating a developing liquid included in an developing device of the present invention includes a coating member rotatable with the developing liquid deposited thereon in a preselected amount. An intermediate member has a surface contacting the surface of the coating member and is movable at the same speed and in the same direction as the surface of the coating member. Also, the surface of the intermediate member contacts the surface of a developing roller to be coated with the developing liquid and is movable in the opposite direction to the surface of the developing roller.

Abstract: A developing unit includes a developing roller including a roller portion. The developing roller is rotatable while carrying a developing liquid on the roller portion. The developing unit also includes a voltage applying device that applies a voltage to the roller portion to form an electric field for development between the roller portion and an image carrier, whereby the developing liquid deposited on the roller portion is transferred to a latent image formed on the image carrier. The roller portion includes a volume resistivity ranging from 0 ?·cm to 107 ?·cm.

Abstract: A device for coating a developing liquid included in an developing device of the present invention includes a coating member rotatable with the developing liquid deposited thereon in a preselected amount. An intermediate member has a surface contacting the surface of the coating member and is movable at the same speed and in the same direction as the surface of the coating member. Also, the surface of the intermediate member contacts the surface of a developing roller to be coated with the developing liquid and is movable in the opposite direction to the surface of the developing roller.

Abstract: A developing unit using a high concentration ink includes a developing solution supply unit supplying the developing solution containing the high concentration ink, a developing roller, whose lower half is soaked in the developing solution of the developing solution supply unit, absorbing the developing solution by a surface tension, and a photosensitive drum contacting the developing roller, receiving the developing solution absorbed on a surface of the developing roller and developing a latent electrostatic image formed on a surface of the photosensitive drum. Accordingly, as much as about 100% of a binary ink development (BID) is achieved, thereby providing a high quality image.

Abstract: A developer unit for a wet-type color image forming apparatus. The developer unit includes a developer bath filled with a liquid developing agent to a predetermined depth, and a developing roller that develops an electrostatic latent image formed on a photoreceptor to correspond to an original image by supplying the liquid developing agent while being partially immersed in the liquid developing agent. The developer unit further includes a cleaning roller that cleans the surface of the developing roller, a depositing roller that deposits the liquid developing agent onto the cleaned surface of the developing roller, and a metering roller that adjusts the thickness and concentration of the liquid developing agent deposited onto the surface of the developing roller by the depositing roller to suitable levels to develop the electrostatic latent image. The developer unit also includes a developer cartridge that supplies the liquid developing agent into the developer bath.

Abstract: There is described an applicator element for providing a layer of a liquid ink, in particular for inking a latent image carrier of a device for electrographic printing or copying, the surface of the applicator element having a structure with a plurality of areas at which the detachment of droplets from the liquid layer is facilitated.

Abstract: A removal nip having a predetermined width is formed by a sweep roller pressurizing mechanism, which adjusts the length of a tension spring by rotating an adjustment screw, and adjusting the size of an energizing force of a sweep roller with respect to a photosensitive drum. A pressurizing mechanism similar to the sweep roller pressurizing mechanism is also provided in a developing roller, to adjust the energizing force of the developing roller, to thereby form a developing nip having a predetermined width.