Abstract: The invention seeks to provide an electrophotographic apparatus, which can have a simplified and safe construction in an image forming apparatus using an a-Si photo-sensitive drum and form clear images free from the flow of image or "fog". The image forming apparatus that is sought uses image development a non-magnetic uni-component toner prepared by a polymerization process as a preamble, and is characterized in that a developing roller is rotated in contact with an a-Si photo-sensitive drum via a layer of non-magnetic uni-component toner. The volume resistivity of the developing roller is set to 3.times.10.sup.7..OMEGA. cm or below. The photo-sensitive drum has a surface layer with an element ratio composition represented as (a-Si.sub.1-x C.sub.x :H), x being 0.95.ltoreq.x<1, the dynamic push hardness of the outer surface of the surface layer being 300 kgf/mm.sup.

Abstract: A magnet roller capable of adjusting the height and position of a magnetic force peak after formation of a roller, and easily meeting a requirement to attain a complex magnetic force pattern without significantly increasing the cost. In the magnet roller, at least two kinds of first magnet pieces and second magnet pieces different from each other in orientation characteristic of magnetic powders are fixedly disposed around the outer periphery of a shaft. The first magnet pieces is a magnet piece in which anisotropic magnetic powders are oriented in such a manner to converge from both the side surfaces and the back surface to a specific position on the front surface side.

Abstract: An apparatus unit includes a detachably mounted unit having a developing sleeve, a toner and a toner applicator, all of which are enclosed by an outer casing. The toner has a shape factor SF-1 of 100-150 and is formed of 100 parts binder, 1-20 parts of a non-magnetic color and 5-40 parts wax and has a specific storage modulus ratio (a) at 60.degree. C. and 80.degree. C. and (b) at 155.degree. C. and 190.degree. C., of at least 80 for (a) and of 0.95-5 for (b). Toner images are visualized by forming an electrostatic image, developing the electrostatic image with the toner, transferring the toner image to a transfer material and fixing the toner image by heat and pressure.

Abstract: A developing roller for use in an image forming apparatus using an electrophotographic process. The image forming apparatus includes a photosensitive drum having a transcribing roller cleaning device; the developing roller disposed between a transcribing device and an exposing device adjacent to the photosensitive drum, for frictionally charging toner at a place where the developing roller contacts with a supply roller and transferring the charged toner to a developing region so as to attach the charged toner to a latent image formed on the photosensitive drum; a regulating blade disposed between the developing region and the supply roller, for regulating a toner layer on the developing layer into a thin toner layer, being in contact with the developing roller; the supply roller in contact with the developing roller, for frictionally charging the toner transferred into a contact nip by a relative motion therebetween; and an agitator for transferring the toner in a toner cartridge to the supply roller.

Abstract: An electrophotographic image forming apparatus includes a cylindrical member having a thin portion at a longitudinal end thereof and an engaging member being mounted as fitted to an internal surface of the longitudinal end of the cylinder and having a depressed portion corresponding to the thin portion of the cylinder. The engaging member is attached to the cylinder by bending the thin portion of the cylinder toward the depressed portion.

Abstract: A developing device including a developing roller and applicable to an electrophotographic image forming apparatus is disclosed. The developing roller is made up of a flexible member and a shaft and feeds toner to a latent image formed on a photoconductive element. A supply roller supplies the toner to the developing roller. A gap is formed between the flexible member and the shaft at at least one end portion of a printing region assigned to the developing roller. The gap sets up a uniform pressure between the supply roller and the developing roller and between the developing roller and the photoconductive element.

Abstract: A cylindrical structural body for use in an image forming apparatus and a method of producing the same are disclosed. The structural includes a cylindrical sleeve and flanges or similar end members respectively affixed to opposite ends of the sleeve. The flanges can be firmly and easily affixed to the sleeve without causing the sleeve to deform. The structural body is therefore low cost and highly accurate.

Abstract: An electroconductive elastic member including an electroconductive material prepared from a polyurethane foam or polyurethane elastomer using a polyester polyol and a quaternary ammonium salt to impart electroconductivity. The polyurethane foam or polyurethane elastomer can be produced using, as a polyisocyanate component, a hydrogenated product from diphenyl-methane diisocyanate, hexamethylene diisocyanate, or any of various modified diphenylmethane/hexamethylene diisocyanate The elastic member may be used in an electrophotographic apparatus. Thus the member is well suited for producing an elastic roller with intermediate electric resistance in an electrophotographic process.

Abstract: There are disclosed a foamed rotary member having a surface of a foam, and a large number of cells provided in the foam and each having a prolate spheroid shape, wherein the major axis direction of the cell is along the rotation axis direction, and also a developing device using the foamed rotary member as a toner supplying rotary member.

Abstract: An oil holding cylinder for an oil coating roller is provided. The cylinder includes at least a cylindrical non-sintered molded body, which is formulated from a mixture of at least ceramic fiber and an organic binder. In addition, the mixture can further include clay, an inorganic binder, or a combination thereof. The molded body preferably has a porosity in a range of about 30% to about 70%. In operation, the oil holding cylinder disclosed herein can stably and uniformly supply oil to the fixing rollers and the like for an extended period of time, while preventing offset.

Abstract: A developer carrier comprising a cylindrical support having provided on the outer surface thereof a coating layer for retaining a developer, wherein the coating layer comprises electrically conductive fine particles and a binder resin comprising a phenolic resin having a weight-average molecular weight of from 3,000 to 5,000 as determined before being crosslinked. Also disclosed is a developing apparatus which comprises a developer carrier for retaining a developer on the surface thereof and for conveying the developer onto the position at which an electrostatic latent image formed on a latent image carrier is developed, wherein the developer carrier comprises a cylindrical support having provided on the outer surface thereof a coating layer for retaining a developer, wherein the coating layer comprises electrically conductive fine particles and a binder resin comprising a phenolic resin having a weight-average molecular weight of from 3,000 to 5,000 as determined before being crosslinked.

Abstract: In a developing device according to the present invention, a developer carrying member in which a dielectric layer is formed on the surface of a conductive base substrate is used. In conveying a monocomponent developer containing no carrier to a developing area opposite to the image carrying member with the developer held on the surface of the developer carrying member, to develop a latent image formed on the image carrying member by the developer, the dielectric layer in the developer carrying member satisfies the following conditions:t.gtoreq.50, .di-elect cons..ltoreq.10, and 15.ltoreq.t/.di-elect cons..ltoreq.35where t (.mu.m) is the thickness of the dielectric layer, and .di-elect cons. is the relative dielectric constant of the dielectric layer.

Abstract: A developing roller (1) includes a highly conductive shaft (2) and a conductive elastic layer (3). When the developing roller carring a one-component developer thereon comes in contact with or in proximity to an image forming body, the developer is supplied from the roller to a surface of the image forming body, thereby forming a visible image on the image forming body surface. The elastic layer (3) has applied to its surface a resin component having an elongation at rupture of less than 10% as measured according to JIS K7113. The developing roller ensures that images of high quality are reproduced without a drop of image density over a long period of time.

Abstract: A developing device according to the present invention has a developer carrying member for conveying a developer to a developing area opposite to an image carrying member with the developer held on its surface and a controlling member for controlling the amount of the developer conveyed to the developing area upon being pressed against the surface of the developer carrying member, the surface of the developer carrying member and/or the surface of the controlling member pressed against the surface of the developer carrying member being composed of an elastic material having a rubber hardness of 20.degree. to 70.degree. and having elongation of 400 to 1200%.

Abstract: An image-forming machine having a photosensitive drum disposed in the machine housing, a movable mounting plate disposed in the machine housing so as to be moved toward, and away from, the photosensitive material drum, a developing device detachably mounted on the movable mounting plate from the front side of the machine housing, and a push-operation mechanism for moving the developing device and the movable mounting plate between a push position close to the photosensitive material drum and a push-release position moved away from the push position.

Abstract: An electrophotographic type image forming device having a developing roller and a photosensitive drum. A nip portion is provided therebetween for supplying developing agents from the developing roller to the photosensitive drum. The developing roller and the photosensitive drum are rotated in the same rotational direction, i.e, a peripheral moving direction of the developing roller is opposite to peripheral moving direction of the photosensitive drum at the nip portion, so that toners provide vivid mobility at or adjacent the nip portion so as to cancel Van der Waals attraction force, and so that the toners can be attracted to the photosensitive drum only by applied electrical field. Developing is performed immediately upstream of the nip portion in rotational direction of the developing roller, and residual toners are collected by the developing roller immediately downstream of the nip portion for collecting and reusing the residual toners.

Abstract: An image-forming machine comprises a movable mounting plate disposed in said machine housing in a manner to be moved toward, and away from, a photosensitive material drum, and a push-operation mechanism for moving the developing device mounted on the movable mounting plate between a push position close to said photosensitive material drum and a push-release position. The push-operation mechanism is equipped with a push lever disposed on the front side of the machine housing. When the push lever is brought to the first position on the upper side of the mounting surface of the movable mounting plate, the push-operation mechanism brings the developing device to the push position and when the push lever is brought to the second position of nearly the same height as the mounting surface of the movable mounting plate, the push-operation mechanism brings the developing device to the push-release position.

Abstract: It is an object of this invention to provide a cylindrical body manufacturing method capable of setting a high coaxiality and a high run-out accuracy between a cylindrical member and a flange member. To achieve this object, in a cylindrical body manufacturing method according to this invention, the diameter of an end portion of a sleeve is increased by heating the end portion. A flange held at the end of a robot hand is clearance-fitted in an inner-diameter processed hole in the end portion of the sleeve while the central axis of the flange is aligned with that of the sleeve. The flange is then pushed to make the outer periphery of the flange abut against the end face of the sleeve.

Abstract: A donor roll for transporting marking particles to an electrostatic latent image recorded on a surface is provided. The donor roll is adaptable for use with an electric field to assist in transporting the marking particles from the donor roll to a development zone adjacent the surface. The donor roll includes a rotatably mounted body and a first electrode member mounted on the body. The donor roll further includes a second electrode member mounted on the body and spaced from the first electrode member and a resistive member electrically interconnecting the first electrode member and the second electrode member so that when an activation potential for creating an electric field is applied to the first electrode member a portion of the potential will be transferred to the second electrode member creating an attenuated field.

Abstract: An image forming machine including a single layer dispersion type photoconductor drum, a charging device for charging the surface of the photoconductor drum to a specific polarity, and a developing roller for conveying a developer to the surface of the photoconductor drum having a latent electrostatic image formed thereon. The photoconductor drum and the developing roller are adapted to contact each other at their surfaces and to be rotationally driven in reverse directions. The photoconductor drum has a diameter set at 10 to 20 mm, while the developing roller has a diameter set at 90 to 110% of the diameter of the photoconductor drum.

Abstract: A device for developing an electrostatic latent image includes a developing roller disposed in a developing housing and a developing agent-limiting device for limiting the amount of the developing agent held on the peripheral surface of the developing roller. The developing agent-limiting device includes a flexible blade brought into pressed contact with the peripheral surface of the developing roller, a flexible support plate that is mounted on the blade and supports the blade in a predetermined positional relationship with respect to the developing roller, and a resilient urging device that is constituted by a plurality of spring members arranged on the back surface of the support plate at a distance in the direction of width thereof and pushes the blade in a direction in which it comes into pressed contact with the peripheral surface of the developing roller via the support plate.

Abstract: A developing device of the type developing a latent image formed on an image carrier with a two-ingredient type developer, i.e., a mixture of toner and magnetic carrier particles is disclosed. The device is operable without a sophisticated toner content control mechanism or a sophisticated developer agitating and conveying mechanism, and is capable of obviating various problems ascribable to the increase in the toner content of the developer at the opposite end portions of a developer carrier. For this purpose, the device restricts the movement of a developer present on the developer carrier in the direction substantially perpendicular to the direction in which the developer carrier conveys the developer.

Abstract: A developing apparatus which is equipped with a developer control member for controlling the developer on a developer supporter to a prescribed thickness, and which uses a one-component developer, characterized in that recessed sections are formed at the surface of the developer supporter to receive the developer, and the density .alpha. of particles of the developer which enter the recessed sections and the nip width L1 between the developer control member and the developer supporter satisfy the relationship: 3<.alpha..multidot.L1<10.

Abstract: A positively chargeable single-component developer for visualizing electrostatic latent images comprises a binding resin having an acid value of 1.5 to 10 (KOH mg/g), a colorant, and an additive such as polyfluoroethylene fine powder having an electron attractive group. The additive is added in an amount of 0.05 part by weight to 2 parts by weight with respect to 100 parts by weight of the positively chargeable single-component developer. The acid value of the binding resin may be adjusted by mixing two or more resins having different acid values. The developer prevents a surface of a photosensitive member from decrease in electric potential which would be otherwise caused by electrons released when toner particles and the photosensitive member are frictionally charged. Accordingly, the developer makes it possible to provide good image quality with less fog and with a dense density.

Abstract: A roller including a cylindrical member and an engagement member, wherein the engagement member has plural fitting portions pairs each having two opposed fitting portions. The cylindrical member and the engagement member will be connected, while leaving at least one of the plural fitting portion pairs unused, by fitting end portions of the cylindrical member to at least one of the fitting portion pairs by cutting and bending the end portions. The roller may be a photoconductive drum or a developing roller for use in an image forming apparatus.

Abstract: A process for producing an aluminum pipe is disclosed which has the steps of cutting the aluminum pipe on its periphery, and thereafter carrying out rotary pressure rolling. Also, an electrophotographic photosensitive member, a device unit, an electrophotographic apparatus and a developing roll having the aluminum pipe are disclosed.

Abstract: A developing sleeve including a cylindrical portion having a circular cross-sectional shape, and a non-cylindrical portion having a non-circular cross-sectional shape integral with the cylindrical portion, is disclosed, for use in a developing device.

Abstract: A developing roller includes a magnet roller and a rotatable sleeve thereon. The sleeve is covered with a surface coating of a metal, alloy, metal nitride, metal oxide, metal carbide or metal sulfide by dry plating. The coating has a resistivity of up to 0.01 .OMEGA.cm. The sleeve is fully wear resistant at its surface. Formation of the coating by dry plating minimizes the variation of coating thickness to improve the dimensional precision of the sleeve surface. The developing roller and a developing apparatus equipped therewith can produce images of quality for a long time.

Abstract: An image forming apparatus including a developing device having various components with specific relationships between their lengths. There is an image bearing member such as a photoconductive drum or belt having a photosensitive layer. The photosensitive layer has a length A. A first toner transporting roller has two ends, the length between the two ends being defined as B. Additionally, there is a second toner transporting roller, disposed between and contacting both the image bearing member and the first toner transporting roller. The length of the second toner transporting roller being defined as C. The components of the image forming apparatus are constructed such the length of the second toner transporting roller is less than or equal to the lengths of both the first toner transporting roller and the photosensitive layer of the image bearing member. This means that the relationships A>C and B>C may exist. As an alternative, B is approximately equal to C with A being greater than both B and C.

Abstract: A developing roller (1) having a highly conductive shaft (2), an elastic layer (3) having conductivity around the shaft, and a conductive layer (4) on the elastic layer containing carbon black having an oil absorption of 30-80 ml/100 g and a specific surface area of 30-150 m.sup.2 /g. The developing roller carries a developer on its surface and comes in contact with or close to a photoconductor drum having an electrostatic latent image borne on its surface whereby the developer is supplied to the photoconductor drum to visualize the latent image. The developing roller has a low hardness, ensures intimate contact with the photoconductor drum, and is improved in electric conduction stability and anti-staining so that acceptable images can be consistently produced over a long term.

Abstract: A copying apparatus including a photosensitive drum having an image carrying surface and a developing unit. The developing unit includes a developer storage device, a developing roller having a developing surface for conveying a developer from the developer storage device to the image carrying surface, and a matching roller near each end of the developing roller for contacting the photosensitive drum to provide a predetermined gap between the image carrying surface and the developing surface. The developing unit is slidably supported in both a first direction parallel to the axis of rotation of the photosensitive drum and in a second direction transverse to the axis of rotation of the photosensitive drum.

Abstract: An apparatus for developing a latent image recorded in a surface of a flexible photoconductive member. The apparatus includes a developer unit having a developer roll and a backing member. The roll is positioned opposed from the surface of the flexible photoconductive member and is used for developing the latent image with developer material. The backing member has an arcuate surface in engagement with a surface of the flexible photoconductive member opposed from the surface having the latent image recorded thereon. The flexible photoconductive member is wrapped about at least a portion of the arcuate surface of the backing member to form a negative wrap angle opposed from the developer unit. The centerpoint of the developer roll, the centerpoint of the backing member and the centerpoint of the arcuate surface are colinear.

Abstract: A developer cartridge for image forming apparatuses which performs development to form images with non-magnetic, one-component type developer. The cartridge includes a developing roller for supplying developer to a photoconductor drum, a developer feed roller in non-contact with the developing roller for supply developer to the developing roller, and a developer-layer thickness control member for controlling the thickness of the developer layer on the developing roller. The developer feed roller is shaped as a regular polygonal prism. Since no recesses are formed in the surface of the regular polygonal prism, driving torque does not increase when developer is scrubbed from the prism, thus ensuring consistent operation and improved image quality. Non-magnetic, one-component type developer is compressed onto the developing roller by supplying the developer via the developer feed roller into a bottleneck between the developing roller and a developer applying member.

Abstract: A developer roller contact device that provides a more reliable and longer lasting electrical connection between a bias voltage source and a developer roller of a toner cartridge assembly used in printers, copiers and facsimile machines. In the first embodiment, an improved contact device has been developed that has a conductive cylindrical member with a rim on one end. The cylindrical member is sized to fit snugly within the developer roller to contact the inner wall of the roller. The rim abuts against the end of the developer roller to hold the contact device in position. A contact surface provided inside the cylindrical member presses against the electrical contact mounted on the cartridge assembly. A second embodiment of the contact device is for a different type of cartridge assembly. The cylindrical member is divided into a large diameter portion for snugly fitting within the developer roller and a small diameter portion for fitting within an alignment piece on the cartridge assembly.

Abstract: An electrophotographic apparatus includes an electrophotographic photosensitive member, a charging member, an imagewise exposure system, a developing system having a toner feed member, a transfer system, and a cleaning system wherein the electrophotographic photosensitive member includes a surface layer containing a lubricative, fluorine-containing resin powder and the toner feed member includes a spacer member coming into contact with the surface layer of the electrophotographic photosensitive member; and also a process cartridge than can be detachably mounted on the electrophotographic apparatus.

Abstract: A developing unit having a pair of semicircular first sealing members longitudinally formed on a cylindrical portion of both ends of a toner conveying roller along an outer peripheral surface of a toner conveying roller such that a gap is set between the sealing members and a toner layer thickness determining plate in a frictional state. A pair of second sealing members are provided close to a position where the toner layer thickness determining plate faces the roller and at a position, opposite to a side facing the toner conveying roller. Each of the first and second sealing members applies predetermined pressure to the toner conveying roller, and each of the sealing members includes lubricating fine grains.

Abstract: In a developing device for developing an electrostatic latent image formed on a photosensitive member in an electrophotographic apparatus, a developing roller and a developing blade are formed such that the hardness of the surface of the developing blade is higher than the hardness of the surface of the developing roller by 30 degrees or more in JIS-A hardness. The developing blade deforms and bites into the developing roller. Accordingly, the developing roller can be brought into tight contact with the developing blade, and a great frictional force is applied to the toner passing between the developing roller and blade to fully charge the toner.

Abstract: Deteriorating developer including toner and carrier in a developer container is replaced by supplying carrier developer including carrier from a developer supply unit and discharging an amount of the deteriorated developer corresponding to the amount of the supplied carrier developer through a discharge opening formed in the developer container by opening a cover. The cover is driven by a solenoid for discharging. With this structure, even when the amount of developer in the developer container is changed and the surface level of the developer is changed, a predetermined amount of deteriorated developer is accurately discharged according to the driving of the cover. It is thus possible to control in a desired manner the replacement ratio of deteriorated developer in the developer container to new developer to be supplied. With this configuration, it is possible to maintain the charge of developer substantially uniform and good image quality of copies.