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

Abstract: Rolls include a core and a glass outer coating on the core. The glass can be electrically charged and discharged. The outer coatings have smooth finishes and controlled electrical properties. The outer coatings can also provide selected mechanical, chemical and thermal properties. The rolls can be used in various applications in which controlled electrical properties are desired. For example, the rolls can be used as charge donor rolls in electrostatographic imaging apparatus.

Abstract: A used developer-carrying member having a resin coating layer on a substrate is regenerated through a step of scraping the resin coating layer of the used developer-carrying member to form a developer-carrying member surface having unevenness showing a central line-average roughness Ra of at most 0.8 &mgr;m, and a step of coating the developer-carrying member surface having the unevenness with a coating layer of a resinous composition comprising at least a binder resin and electroconductive fine powder. The regenerated developer-carrying member can be reinstalled in a developing apparatus and subjected to repetitive electrophotographic image forming cycles.

Abstract: A roller spacing device roller mechanisms having rollers in close contact under a given pressure to separate first and second rollers by a constant distance to keep the rollers from touching when roller mechanisms are not used for a long period of time. The roller spacing device comprises a spacing member shiftably mounted between first and second positions on a shaft having a partial D-cut portion and associated with one of the roller members to be separated. The spacing member has a spacing nose overlapped in the second position with an outer circumferential surface of a driving gear connected to the other roller member to separate the first roller member from the second roller member by the constant distance; and a shifting unit shifting the spacing member between first and second positions on the shaft.

Abstract: A developing device for developing a latent image formed on an image carrier includes a developer carrier having a developer carrying surface. The developer carrying surface includes a plurality of grooves to carry the developer. Dispersion D (%) in depth of the plurality of grooves is calculated according to an equation, D (%)={(A−B)/2}/C, where A is a maximum depth of the plurality of grooves, B is a minimum depth of the plurality of grooves, and C is an average depth of the plurality of grooves. The dispersion D (%) is at most approximately 30%.

Abstract: A developing apparatus includes sealing members which are installed on both inside walls of a housing and closely contact the housing, a developer roller, and a blade to prevent the toner contained in the housing from leaking out. Each sealing member includes a first sealing member and a second sealing member. The first sealing member has a side part that elastically and closely contacts one inside wall of the housing and a short side part of the blade, and a front part that elastically and closely contacts the outer circumference of the developer roller. The second sealing member overlaps with the first sealing member and has a front part that elastically and closely contacts an inside surface of the blade and the outer circumference of the developer roller. Therefore, deterioration of a close contact of the sealing members due to compression and deformation of the sealing members may be prevented. Accordingly, a developing apparatus is configured to prevent leakage of toner.

Abstract: An image-forming apparatus includes a toner-supplying roller and a developing roller assembled into a developing unit. The toner-supplying roller supplies toner to the developing roller. The developing roller applies the toner to an electrostatic latent image on a photoconductor to form a toner image. The toner image is transferred onto a print medium at a transfer unit, and finally fused into a permanent image at a fixing unit. The toner includes a wax that remains solid at room temperature and melts at a fixing temperature. At least one of the toner-supplying roller and the developing roller is a silicone roller on which oligomer in the form of siloxane is deposited. The silicone roller contains non-cured siloxane in the range of 10 to 8000 PPM.

Abstract: A developer bearing member for bearing toner is disclosed. The developer bearing member has a multitude of depressions on its surface, and each of the depressions has a multitude of protrusions on its surface.

Abstract: In a developing assembly comprising a developer-carrying member and a developer quantity control blade kept in pressure contact with the developer-carrying member, the developer-carrying member has a deformation percentage D of 0.5% or less in the direction of pressure contact, and the developer quantity control blade has a ten-point average roughness Rz of from 0.3 &mgr;m to 20 &mgr;m at its surface on the side kept in contact with the developer-carrying member (a charge control face). The developing assembly can prevent faulty images such as lines and uneven images due to the deformation of developer-carrying member even though any deformation due to the pressure contact of the developer quantity control blade has taken place in the developer-carrying member while the developing assembly is stopped.

Abstract: The pressure between a developing roller and a photosensitive drum is set to 0.24 MPa. Because the pressure is smaller than 0.31 MPa, if the potential difference &Dgr;V between the non-image forming part on the photosensitive drum and the electrically-charged polymer toner on the surface of the developing roller is at the preset proper voltage (300 volts), pressure fogging will be prevented. Because the pressure is 0.24 MPa or less, even if the potential difference varies within the range of 200 volts to 400 volts that occurs in practice, pressure fogging will be prevented. By resetting the pressure to 0.22 MPa, even if the potential difference &Dgr;V varies in a wider voltage range of 100 to 400 volts, pressure fogging will be prevented. In this way, by setting the pressure between the developing roller and the photosensitive drum appropriately, pressure fogging can be prevented even when using the opposite-direction developing method and polymer toner.

Abstract: An image forming apparatus of the type which develops a latent image on an image carrier with toner stored in a developing unit and transferring the resulting toner image to a recording medium. The developing unit includes a developer carrier which contacts the image carrier at least at two spaced apart points with a gap being formed between the at least two points of contact. A moving mechanism will move opposite ends of the developer carrier independent distances relative to one another so as to eliminate the gap and establish full contact between the image carrier surface and developer carrier surface.

Abstract: An image forming apparatus or toner cartridge component thereof uses a bias voltage contact device that fits into an electrobushing which transmits the electrical contact has been invented. Thus, now a bushing can also act as an electrical contact and thereby a spring is not a requirement. The cylindrical bias voltage contact fits into a developer roller and has a smaller portion that is also cylindrical and fits into an electrobushing. The electrobushing is contacted electrically to the power supply of the image forming apparatus. The cylindrical bias voltage contact may have a cylindrical portion that fits into the developer roller by press fit with the new feature where the cylindrical portion has more than one diameter for obtaining a better press fit.

Abstract: A shaft is disclosed, having good electroconductivity and an electroconductive elastic layer which is formed on the outside periphery of the shaft, and which has a thermal conductivity of at least 0.15 W /m·K; and an image formation apparatus equipped with the developing roller. The above developing roller is capable of suppressing temperature rise of the roller surface, thereby preventing a developer from being adhesively fixed to the roller surface, suppressing wear on the roller surface, suppressing the generation of cracking, crazing and the like on the roller end, and thus affording favorable images for a long period of time.

Abstract: A developing roller installed in an image forming apparatus to transfer a toner to a photosensitive member and a manufacturing method of the developing roller include a roller member having an outer cylindrical vessel, an inner vessel installed within the outer cylindrical vessel in concentric with the outer cylindrical vessel, a hollow portion formed at a center of the inner vessel, and a plurality of ribs connecting and supporting the outer cylindrical vessel and the inner vessel so as to connect and support the outer cylindrical vessel and the inner vessel, and a rotating shaft compressively fitted into the hollow portion of the inner vessel.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus includes an electrophotographic photosensitive drum, a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum with a developer, a frame for rotatably supporting the electrophotographic photosensitive drum, a developing blade, provided in the frame, for regulating the amount of the developer applied on a peripheral surface of the developing roller, a supporting member, journaled in the frame for rotation about a center of rotation, for rotatably supporting the developing roller at a position away from the center of rotation thereof, and an urging member for elastically urging the supporting member to urge the developing roller toward the electrophotographic photosensitive drum.

Abstract: An electroconductive roller is capable of exhibiting stable conductivity regardless of environmental change and is accompanied by small bleed-out of additives. The conductive roller includes an electroconductive support, an electroconductive elastic layer coating the support and a resistance layer coating the elastic layer; wherein the elastic layer comprises at least one species of rubber selected from the group consisting of acrylonitrile-butadiene rubber, epichlorohydrin rubber and chloroprene rubber, an ether oxygen containing alkyl phthalate derivative, a quaternary ammonium perchlorate compound and a fatty oil, and the ether oxygen-containing alkyl phthalate derivative, quaternary ammonium perchlorate compound and fatty oil are contained in a total amount of 0.1-20 wt. parts per 100 wt. parts of the rubber. The conductive roller is suitably used as a contact charging member in an electrophotographic apparatus.

Abstract: A function separated laminated electrophotography photosensitive body is equipped with at least a charge generating layer and a charge transport layer on top of a conductive substrate. A contact angle &thgr; of pure water on the charge transport layer satisfies the equation &thgr;>=94°. The resulting organic electrophotography photosensitive body prevents contamination of the photosensitive body surface resulting from component migration from the developing roller and achieves a stable image quality.

Abstract: A jump monocomponent development arrangement includes a dielectric photoreceptor belt having an image-bearing surface for receiving an electrostatic charge image and a development station having a supply of toner particles with a mean diameter in a range from 8 microns to 14 microns and including large and small additive particles having mean diameters in size ranges of 6 to 12 nm and 20 to 50 nm, respectively, and in amounts sufficient to provide surface coverage of the toner particles in ranges from about 5 percent to about 50 percent and about 50 percent to about 150 percent, respectively.

Abstract: The present invention provides a developing apparatus for developing a latent electrostatic image to a developed image with a developer, comprising a developer bearing member capable of carrying developer on a surface thereof, and a layer thickness regulating member for regulating developer carried on the developer bearing member to a uniform thickness, wherein at least the surface of the layer thickness regulating member comprises a material which comprises at least one component selected from the group consisting of a cross-linked alkylalkoxyl-group-containing nylon resin and a cyclic polyolefin.

Abstract: An image-forming apparatus includes a toner-supplying roller and a developing roller assembled into a developing unit. The toner-supplying roller supplies toner to the developing roller. The developing roller applies the toner to an electrostatic latent image on a photoconductor to form a toner image. The toner image is transferred onto a print medium at a transfer unit, and finally fused into a permanent image at a fixing unit. The toner includes a wax that remains solid at room temperature and melts at a fixing temperature. At least one of the toner-supplying roller and the developing roller is a silicone roller on which oligomer in the form of siloxan is deposited. The silicone roller contains non-cured siloxan in the range of 10 to 8000 PPM.

Abstract: A development roller has a core shaft and an external composite layer provided around the core shaft, the external composite layer including an elastic layer and a surface layer which are successively overlaid on the core shaft in that order, the development roller having a volume resistivity of 1.5×104 &OHgr;·cm or less and an electrostatic capacity of 1.5×10−4 F/m2 or more. A developer unit is provided with the above-mentioned development roller which is disposed so as to have a toner deposited on an image portion formed on a surface of a photoconductor, a toner supply roller which is disposed opposite to the development roller and is capable of forming therearound a magnetic brush of the toner and a carrier, and brings the magnetic brush into contact with the development roller to supply the toner to the development roller, and a doctor blade disposed in contact with the surface of the toner supply roller to regulate the thickness of a layer of the toner.

Abstract: A mold used to form a magnetic member includes a mold body having a mold opening, a mold support that supports the mold cavity, and a mold insert. The mold insert is disposed in the mold opening of the mold body to form a mold cavity. The mold insert is coated with a coating to protect the mold body from chemical attack and abrasive wear of the mold material. The coating comprises an electroless nickel layer formed on or over the mold insert, and a chromium nitride layer formed on or over the electroless nickel layer. The mold insert can be formed of beryllium-copper (Be—Cu).

Abstract: It is an exemplified object of the present invention to provide a developer, a development device and its elements, and an image-forming device that can more stably form a high-quality image by a relatively inexpensive and easy means. A noncontact-type development method according to the present invention utilizes a nonmagnetic and single component toner having a volume average particle diameter D (&mgr;m) and an average specific charge q/m (&mgr;C/g), a development roller having a ten-point average surface roughness Rz (&mgr;m), and a blade keeping in contact with the development roller at a blade line pressure Pb (gf/cm). In order to stably form a uniform toner layer dt (&mgr;m) on the development roller, the following relationship is to be met: dt=1.8×{q/m×Rz/(Pb−1)}½×D±0.25 D, and 1.5 D≦dt≦3.5 D.

Abstract: A developing device includes a developing roller and a toner charging roller. The toner charging roller has (a) a metallic layer which induces its electrons by receiving light irradiation, and (b) an ultraviolet irradiater which irradiates ultraviolet to the metallic layer. The toner charging roller gives the electrons to toner, so that the toner on the developing roller is charged. There is a space between the toner charging roller and the developing roller, and a grid electrode which controls a flow of the electrons is provided in the space. Thus, mechanical/thermal load given to the toner or the toner charging roller can be reduced, so that it is possible to prevent deterioration of toner and the device.

Abstract: The invention relates to a low tacky, conductive, soft urethane roller for use in a printer. The roller includes a metal salt evenly or homogeneously distributed in a copolymer formed of a diisocyanate, a reactive silicone containing an amine group; and a polyol or a polyamine. The roller can also have a volume resistivity of between about 1E5 ohm-cm and about 5E10 ohm-cm, and includes a metal salt solution in a copolymer formed of a diisocyanate, a reactive silicone containing a hydroxyl group and/or an amine group; and a polyol and/or a polyamine.

Abstract: A developing device of monocomponent development system for developing a latent image formed on an image bearing member according to the present invention includes a toner carrying member disposed opposite the image bearing member via a gap of 50 to 250 &mgr;m therebetween, and including a conductive substrate and an elastic layer having a rubber hardness of not more than 70 degrees and a thickness in the range of 7 to 50 &mgr;m, and a regulating member pressed against a surface of the toner carrying member for regulating the amount of toner on the toner carrying member.

Abstract: A developing roller according to the invention has an outer circumferential surface, which can be set in frictional contact with a photosensitive belt that is stretched to be driven in a prescribed direction. The outer surface is divided into two mirror surfaces and a rough surface. The mirror surfaces are provided on the end portions of the roller, they do not retain developer. The rough surface extends between the mirror surfaces, for retaining developer. Spacer means prevents the photosensitive belt from coming into frictional contact with the mirror surfaces. The mirror surfaces are therefore prevented from scraping the photosensitive belt. This prolongs the lifetime of the photosensitive belt.

Abstract: A developing roller having a superior setting ability and having a uniform and high conductivity is provided by improving dispersion and stability of carbon black mixed in a solution of a coating resin, and then forming a resin layer that has a low modulus of elasticity and a high conductivity when coated. The developing roller includes a core shaft, an elastic body layer formed around the core shaft and made of rubber as a main ingredient, and a resin layer coated at least on an outer surface of the elastic body layer. The resin layer contains carbon black having a DBP absorption amount of 80 to 110 ml/100 g, a ratio of a DBP absorption amount to a nitrogen specific surface area being not more than 0.012 ml/m2, and a ratio of a volatile component to a nitrogen specific surface area being not more than 2.0×10−4 g/m2.

Abstract: Disclosed is a toner comprising particles of a polyester resin, an optional colorant, and poly(3,4-ethylenedioxypyrrole), wherein said toner particles are prepared by an emulsion aggregation process. Another embodiment of the present invention is directed to a process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member with charged toner particles comprising a polyester resin, an optional colorant, and poly(3,4-ethylenedioxypyrrole), wherein said toner particles are prepared by an emulsion aggregation process.

Abstract: A space securing member defines a predetermined space between the first rotary member and the second rotary member which is arranged apart from the first rotary member with the predetermined space. The space securing member is provided with a circular hole that is rotatably supported by one of the first and second rotary members, and an arc-shaped portion that is in area contact with an outer peripheral surface of the other rotary member. The space securing member is used to provide a predetermined space between a charging roller and a photosensitive drum and/or a developing roller and the photosensitive drum.

Abstract: It is proposed to provide a developing agent carrier, developing unit, and image forming apparatus which can stably obtain a high-quality image. There is provided a developing agent carrier comprising an elastic portion which comes into contact with an image carrier, wherein an Asker C hardness of the elastic portion is not less than 20 and not more than 40, and a dynamic friction coefficient of a surface of the elastic portion is not less than 0.01 and not more than 0.2.

Abstract: A method for developing an electrostatic latent image including the step of developing an electrostatic latent image with a two component developer including a particulate carrier and a negatively charged toner and held on the surface of a developing roller to form a toner image, wherein the developing roller surface includes a material including one or more carbon atoms and one or more nitrogen atoms, and wherein a ratio of the number of carbon atoms to the number of nitrogen atoms is not greater than 100/1.

Abstract: An image forming apparatus or toner cartridge component thereof uses a bias voltage contact device that fits into an electrobushing which transmits the electrical contact has been invented. Thus, now a bushing can also act as an electrical contact and thereby a spring is not a requirement. The cylindrical bias voltage contact fits into a developer roller and has a smaller portion that is also cylindrical and fits into an electrobushing. The electrobushing is contacted electrically to the power supply of the image forming apparatus. The cylindrical bias voltage contact may have a cylindrical portion that fits into the developer roller by press fit with the new feature where the cylindrical portion has more than one diameter for obtaining a better press fit.

Abstract: An electrically conductive member comprising an electrically conductive elastic layer and a coating layer formed thereon, characterized in that said coating layer is formed from a polyurea resin as a cured product resulting from reaction between a polyamine compound and a polyisocyanate compound. It has a coating layer which readily conforms to elastic deformation of rubber or the likes, has long durability, and has good properties in protection of the photosensitive body from staining and prevention of toner sticking, control of the toner charging and a low coefficient of friction.

Abstract: A developing apparatus has a developer carrying body carrying a developer thereon, and a layer thickness regulating member for regulating the layer thickness of the developer carried on the developer carrying body. The developer carried on the developer carrying body contacting with an image bearing body after the layer thickness thereof has been regulated by the layer thickness regulating member. In the developing apparatus, when the charge amount per 1 g of the developer after the layer thickness has been regulated by the layer thickness regulating member and before the developer contacts with the image bearing body is defined as Q (&mgr;C/g) and the electrical resistance per axial length 1 mm of the developer carrying body is defined as R (&OHgr;/mm), R≧0.9×(−7.83×104|Q|+7.05×106) and R≦1.1×(−7.83×104|Q|+7.05×106) are satisfied.

Abstract: A is moved, the heating members heat treatment apparatus 18 for subjecting a sheet A, which must be subjected to heat treatment, to heat treatment by transferring the sheet along the surface of a heating member, the heat treatment apparatus incorporating: at least two heating members 120, 320 fixedly aligned in a direction in which the sheet A, which are arranged to subject the sheet A to heat treatment which is performed at a predetermined temperature; transferring mechanism for sliding and transferring the sheet A along the surface of each heating member; and a pressing mechanism 122, 322 for pressing at least a portion of the sheet A which is being transferred, against the surfaces of the heating members.

Abstract: An image recording apparatus comprises a heat-developing section for heat-developing a latent image formed on a photo/heat-sensitive material sheet in which antistatic agent is added, and conveying rollers made of resin for conveying the photo/heat-sensitive material sheet along a sheet feeding path including at least the heat-developing section.

Abstract: An article including a cylindrical roller core; and a titanium dioxide ceramic layer bonded to the exterior of the cylindrical core.

Abstract: Toner charging and/or delivery systems and methods charge and deliver charged toner particles to an image development zone without using carrier particles. Toner particles for imaging process are charged by filling the grooves or cups of a gravure member with uncharged toner particles and charging the toner particles in the grooves or cups using a corona discharge device. The charged toner particles are then transported directly or indirectly to an imaged photoreceptor, where the charged toner particles are used to develop a latent electrostatic image on the imaged photoreceptor. The developed image is then transferred to a copy sheet and permanently fused to the copy sheet.

Abstract: A developing apparatus includes: a first rotary member; a second rotary member having an elastic surface and adapted to be rotated in contact with the first rotary member. A contact depth controlling roller is kept in rotative free engagement with each end of a shaft of the second rotary member and having an outer circumferential surface abutting against the first rotary member and an inner circumferential surface abutting against the shaft of the second rotary member for keeping a contact depth of the second rotary member abutting against the first rotary member at a predetermined level. A controller is provided so as to rotate the second rotary. This structure, for example, eliminates the need for bearings.

Abstract: Disclosed is a toner support for preventing occurrence of an image failure such as stain, uneven image density, and fogging on a white image as much as possible, thereby certainly forming a high quality image enough to keep up with formation of a color image. The toner support is characterized in that the maximum value of a surface potential of the toner support, which is measured after an elapse of 0.35 sec since the surface of the toner support is charged by generating a corona discharge by means of applying a voltage of 8 kV to a corona discharger disposed apart from the surface of the toner support by 1 mm, is in a range of 90 V or less, and that the absolute value of a surface potential decay rate of the toner support, which is measured at an elapse of 0.2 sec after charges are imparted on the surface of the toner support by generating a corona discharge by means of applying a voltage of 8 kV to a corona discharger disposed apart from the surface of the toner support by 1 mm, is in a range of 0.

Abstract: A developing apparatus includes a developer bearing body, a drive transmission gear, a support member, and a developing frame body, and the support member has an engaging portion for engaging with the developing frame body in a position opposite to a position where the drive force is transmitted to the drive transmission gear with respect to a rotating center of the developer bearing body.

Abstract: In order to provide a developing apparatus in which the toner thin layer regulating capability and the toner charging capability can be enhanced by a developer regulating member of a simple structure, a development roller can be rotated with a small driving force, toner is prevented from adhering and development can be performed with high accuracy, the developer regulating member of the developing apparatus is provided with a surface constituting a step in a direction vertical to the direction of the rotation axis of the development roller, a pressed surface that is pressed against the development roller in the downstream side of the step and an opposed surface formed so as to be opposed to the development roller with a predetermined space therebetween in the upstream side of the step.

Abstract: A material is molded in the shape of a roller and then the molded material is vulcanized to manufacture an elastic roller. The material consists of 100 parts by weight of EPDM polymer (E505 (trade name) manufactured by Sumitomo Kagaku Co., Ltd.), 10 parts by weight of silica which is used as filler (NipsilVN3 (trade name) manufactured by Nippon Silica Co., Ltd.), 30 parts by weight of paraffin oil (PW-909 (trade name) manufactured by Idemitsu Kosan Co., Ltd.), one part by weight of stearic acid, five parts by weight of zinc oxide, two parts by weight of sulfur (manufactured by Tsurumi Kagaku Co., Ltd.), one part by weight of vulcanizing accelerator (mercaptobenzothiazole and Noxceller-M (trade name) manufactured by Ouchishinko Kagaku Co., Ltd.), 0.5 parts by weight of vulcanizing accelerator (tetraethylthiuram disulfide and Noxceller-TET (trade name) manufactured by Ouchishinko Kagaku Co., Ltd.

Abstract: A developer carrying member for carrying a developer is includes a substrate and a resin coat layer which is formed on the surface of the substrate and contains a binder resin and a conductive fine powder. The binder resin is composed of a copolymer having a monomeric unit of a methyl methacrylate monomer (M) and a monomeric unit of a nitrogen-containing vinyl monomer (N). A copolymerization molar ratio of the methyl methacrylate monomer (M) to the nitrogen-containing vinyl monomer (N) in the copolymer fulfills the following condition: M:N=4:1 to 999:1. The binder resin has a weight-average molecular weight (Mw) of from 3,000 to 50,000.

Abstract: A developing unit of the present invention includes a case which accommodates toner containing pigment, a developing roller, a supply roller having chamfered ends and formed of an elastic member arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller. The side surfaces of the developing roller have a surface roughness of 0.5 .mu.m or smaller in Rmax.

Abstract: An image support apparatus including a pair of rotatable disk shaped members, a cylindrical member supported and fixed at both ends by the pair of disk shaped members, a flexible image supporter shaped like a thin cylinder and formed with a photosensitive layer at the outer peripheral surface, support members being disposed on an outer peripheral surface of the cylindrical member for supporting the image supporter, a charge roller abutting the outer peripheral surface of the image supporter for uniformly charging the outer peripheral surface, and a frame. A distance between a portion of the image supporter supported by the support member and an end of the charge roller is set to a length to prevent the image supporter, which is bent as the charge roller abuts the image supporter, from becoming permanently deformed.

Abstract: A cylinder (2) for a printing machine, particularly a developing cylinder in an electrographic printing machine, having a rigid, elongated shaft body (10) and a rigid hollow body (11) whose exterior forms the covering and the top and bottom surfaces of the cylinder. In order that, during operation under constant conditions, the cylinder can roll properly against another rigid cylinder of the printing machine, flat sides (12,13) of the hollow body (11) which form the top and bottom surfaces of the cylinder, have centrical bore holes that are larger than the diameter of the shaft body (10) in the area of the flat sides. Located in the space between the shaft body and the flat sides of the hollow body is an elastic material (14,15) which joins the flat sides of the hollow body to the shaft body.

Abstract: A development device according to the invention has an arrangement wherein a developer carrying member holding a toner thereon and an image bearing member with an electrostatic latent image formed thereon oppose each other across a predetermined gap therebetween, and a power unit applies an alternating voltage to the gap for supplying the toner from the developer carrying member to the image bearing member, the development device satisfying any one the following conditions: ##EQU1## where a (.OMEGA.) denotes a resistance component of an impedance (a+b.multidot.i) of the developer carrying member, -b (.OMEGA.) denotes a capacitative reactance component of the impedance thereof, and f (Hz) denotes a frequency of the alternating voltage.

Abstract: A device and a method for developing an electrostatic latent image, which is located on a movable image carrier (1), using a non-conductive single-component toner. The device includes a toner feed device (3), in order to transport toner particles (5) from a toner reservoir (4) and charge them electrically, a rotationally mounted developing roller (2) to receive the charged toner particles from the toner feed device and to transport the toner particles which it holds into a gap between the developing roller and the image carrier, and a rotationally mounted doctor roller (6), which is arranged in the path of the toner particles from the toner feed device to the developing roller, to produce a uniform toner layer with a defined thickness on the developing roller. The surface of the developing roller (2) and the surface of the doctor roller (6) are separated from one another by a gap which is wider than the average diameter of the toner particles (5).