Abstract: When image formation is performed by an apparatus comprising: a magnetic roll for generating a magnetic brush by carrier having toner adhering triboelectrically thereto, a developer roll on the surface of which a thin layer of the toner supplied by the magnetic brush is formed, and a photoreceptor onto which the toner of thin layer jumps selectively in accordance with the latent image thereon; positively chargeable toner of which charge amount is controlled in 5˜20 &mgr;C/g is used, the surface potential of the photoreceptor is set to a range above 0 to 250 V, and the after exposure potential which is the potential right after the photoreceptor is exposed is in a range of 0˜ to 100 V.

Abstract: Electrostatic latent images are developed with a toner in such a configuration that an electrostatic-latent-image-bearing member is disposed to face a developer-bearing member which bears thereon a developer consisting of a magnetic carrier and a toner by relatively moving the developer-bearing member and the electrostatic-latent-image-bearing member at different velocities, with the development being carried out under conditions represented by formula (1): 0.

Abstract: A developing device includes a rotatable developer carrying member for carring a developer; a magnet roller provided in the developer carrying member; a first electrode portion connected electrically with the developer carrying member, the first electrode portion being rotatable with the developer carrying member; a second electrode portion provided with a contact portion in sliding contact with the first electrode portion, the contact portion being disposed outside a longitudinal end portion of the magnet roller substantially at a center of rotation of the developer carrying member.

Abstract: A two-component developer consists of a toner, which contains at least a resin and a colorant and to which an external additive is added, and a carrier. This two-component developer has the toner that has a number average molecular weight (Mn) of 3,000 or less and contains particles having a molecular weight of 1,000 or less at 40 number % or more, and also has the carrier that satisfies general formula (1) as follows: 3,000,000≦&sgr;1000×Dc3≦20,000,000  (1) where &sgr;1000 represents a magnetization (emu/g) of a carrier at 1,000 oersted, and Dc represents volume average particle diameter (&mgr;m) of the carrier.

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

Abstract: A two-component developer including at least a magnetic toner and a magnetic carrier having magnetic particles coated with carbon black. The magnetic toner adheres to the magnetic carrier due to the magnetic interaction.

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: A two-component developer consists of a toner, which contains at least a resin and a colorant and to which an external additive is added, and a carrier.

Abstract: A multicolor imaging apparatus utilizes a recording medium adapted to having a plurality of latent electrostatographic images defined by image charge potential areas and background charge potential areas. The recording medium moves in a process direction such that an image is recorded on the recording medium and then developed at a plurality of development stations. At least one of the development stations includes not less than two development housings, with each such housing including at least one donor roll, which is electrically biased.

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

Abstract: The invention concerns a pressing portion of a layer thickness-regulating blade for pressing toner on a developing roller and forming a thin layer of toner is formed from a silicone rubber. The pressing force of the pressing portion is set to 15-30 gf/cm. Since toner is pressed against the developing roller by the portion made of the silicone rubber having a high electrical charging characteristic, toner is sufficiently electrically charged. Furthermore, since the pressing force or pressure of the pressing portion is very weak, the abrasion of the silicone rubber-made portion is reduced.

Abstract: A developer roll sleeve and method for making the same is disclosed. In a preferred embodiment, a core substrate roll is spray coated with a conductive composition including a host resin composition and a wear-resistance imparting additive. Preferably, the host resin composition includes a phenolic thermosetting resin and a conductivity additive such as carbon black, graphite and the like. Further, the wear resistance imparting additive is preferably selected from the group consisting of a polytetrafluoroethylene resin (e.g., Teflon), graphite, ultra-high molecular weight polyethylene having a molecular weight from about 3,000 to about 4,500 grams, molybdenum, molybdenum disulfide, silicone and mixtures thereof. The wear resistance imparting additive is preferably provided in an amount sufficient to obtain a thickness wear rate of less than about 0.00047 percent per printing cycle.

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

Abstract: An apparatus for developing a latent image recorded on an imaging surface, including a housing defining a chamber for storing a supply of developer material including toner; a dispensing system for dispensing toner of a first color and toner of a second color into said housing; an air system for fuildizing and mixing toner of said first color and toner of said second color; a donor member, spaced from the imaging surface, for transporting toner on the surface thereof to a region opposed from the imaging surface, said donor member includes an electrode array on the outer surface thereof, said array including a plurality of spaced apart electrodes extending substantial across width of the surface of the donor member; and a multi-phase voltage source operatively coupled to said electrode array, the phase being shifted with respect to each other such as to create an electrodynamic wave pattern for moving toner particles to and from a development zone.

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: A developer cylinder and drive gear arrangement includes a drive gear having a coupling hole at one end of its gear shaft, and a developer cylinder having a coupling block at its one end coupled to the coupling hole at the gear shaft of the drive gear, wherein the coupling block of the developer cylinder has a plurality of teeth spirally disposed around the periphery thereof.

Abstract: An image forming apparatus including a cylindrical image carrier configured to carry an electrostatic latent image while rotating, and a cylindrical developer carrier configured to bear a developer and supply the developer to the image carrier by contacting the image carrier at a nip while rotating, wherein the surface of the image carrier has a friction coefficient of from about 0.1 to about 0.4. The image carrier may be an endless belt.

Abstract: An apparatus for developing a latent image recorded on an imaging surface, including: a housing defining a chamber for storing a supply of developer material comprising toner; a donor member, spaced from the imaging surface, for transporting toner on the surface thereof to a region opposed from the imaging surface, the donor member includes an electrode array on the outer surface thereof, the array including a plurality of spaced apart electrodes extending substantial across width of the surface of the donor member; and a multi-phase voltage source operatively coupled to the electrode array, for generating a first electrodynamic wave pattern for moving toner particles along the surface of the electrode array to and from a development zone and generating a second electrodynamic wave to provide a fast oscillating-like toner motion along and perpendicular to the surface of the electrode array.

Abstract: A motor pulley for driving a photosensitive drum and a motor gear for driving a developing roller are fixed to a rotating shaft of a motor. The developing roller is provided with a developing roller driving gear which engages with the motor gear, and the photosensitive roller is provided with a photoreceptor driving pulley, to which a driving force from the motor pulley is transmitted.

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 pneumatically coupled sonic toner release development apparatus is provided for reliably and uniformly developing latent electrostatic images in a toner image reproduction machine using charged toner particles. The pneumatically coupled sonic toner release development apparatus includes a development housing defining a sump for holding developer material containing the charged toner particles; a developer material moving device mounted within the sump for transporting developer material within the sump; and a pneumatically coupled sonic toner release assembly including an acoustic transducer, a pneumatic coupling device connected to the acoustic transducer, and a pneumatic donor assembly connected to the pneumatic coupling device.

Abstract: A developing device has a developing container containing a toner therein, and a toner carrying member provided in the opening portion of the developing container and rotatable with the toner carried thereon. The difference between the work function of the surface of the toner carrying member and the work function of the toner is greater than 0.1 and smaller than 1.0.

Abstract: An image forming apparatus has a photoreceptor drum and a developing roller supported in the developing unit for retaining and conveying the developer, and further has a sealed viscous fluid damper having a viscous fluid sealed therein, arranged coaxially with the rotary shaft of the photoreceptor drum.

Abstract: A developer cylinder and drive gear arrangement, includes a drive gear having a coupling hole at one end of its gear shaft, and a developer cylinder having a coupling block at its one end coupled to the coupling hole at the gear shaft of the drive gear, wherein the coupling block of the developer cylinder has six peripheral sides and six peripheral angles.

Abstract: The present invention relates to a toner for developing an electrostatic latent image, comprising a calix arene compound expressed by the following general formula ?I!: ##STR1## wherein R.sub.1 and R.sub.2 each represent a hydrogen atom, an alkyl group having a carbon number of 1 to 5, or --(CH.sub.2).sub.m COOR.sub.3 (in which R.sub.3 represents a hydrogen atom or a lower alkyl group; and m represents an integer of 1 to 3); n represents an integer of 0 to 7.The present invention further relates to a charge-giving member comprising a calix arene compound expressed by the foregoing general formula ?I!.

Abstract: In a developing device for an image forming device, such as a laser printer, a supply roller is in rolling contact with and supplies toner particles to a developing roller which in turn is in rolling contact with a photosensitive drum and supplies toner particles to an electrostatic latent image formed thereon. The developing roller and the supply roller press against each other with a slight pressure. The supply roller has a resilient outer form layer formed from a silicone foam or urethane foam and fluororesin particles are dispersed within the foam. With the dispersion of the fluororesin particles throughout the resilient outer form layer of the supply roller, toner particles can be better charged by contact between the resilient outer foam layers of the supply roller and the developing roller. As a result, improper image development is less likely to occur and the developing roller will not scratched or otherwise damaged.

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: A developing device using one component developer for developing an electrostatic latent image on a photoconductive drum. The one component developer includes particles of parents of toner, resin beads and silica. The silica adhere to a surface of each resin bead. The resin beads and the silica further adhere to a surface of the parents of toner. A volume average diameter of the resin beads is more than that of the silica and is less than that of the parents of toner.

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: A developer carrying member includes a substrate, the surface of which is covered with a conducting layer. The conducting layer contains a binder resin and conducting spherical particles dispersed therein having a number average particle diameter of from 0.3 .mu.m to 30 .mu.m and a true density of 3 g/cm.sup.3 or below.

Abstract: An electrostatic latent image developing device equipped with a developing housing, a developing roller rotatably disposed between the two side walls of the developing housing, and a feeding roller rotatably disposed between the two side walls of the developing housing neighboring the developing roller. A first bearing member is mounted on one side wall and has two bearings for supporting the ends of the rotary shafts of the developing roller and the feeding roller. A second bearing member is mounted on the other side wall and has a bearing for supporting the opposite end of either the rotary shaft of the developing roller or the feeding roller. A third bearing member is mounted on the other side wall and has a bearing for bearing support of the opposite end of the rotary shaft of the developing roller or the feeding roller not supported in bearing fashion by the second bearing member.

Abstract: A printing machine for creating an image through the use of toner particles. the printing machine having a development device for preparing the toner, and the development device having at least one filter for selecting toner particles.

Abstract: An image forming apparatus adopting a non-magnetic one component developing system is arranged such that a charge brush and a developing roller are aligned along the circumference of a photoreceptor drum, that is rotatably driven, in order from an upstream side in a rotating direction of the photoreceptor drum. A transfer roller is placed opposing the photoreceptor drum with a sheet transportation path in-between. The charge brush, the developing roller and the transfer roller are rotatably driven while contacting the photoreceptor drum respectively. A photoconductive layer of the photoreceptor drum is made of an organic photoconductive material, and a coefficient of friction of the photoreceptor drum and the developing roller is selected to be not more than 0.5. As this eliminates the irregularity in rotary movement of the photoreceptor, offers a quality image and reduces a driving force for the photoreceptor drum, an apparatus of a light weight and high cost can be achieved.

Abstract: A developing apparatus according to the present invention comprises a rotating developing sleeve, a developer supplying portion for supplying developer to the surface of the developing sleeve, a developer collecting portion for collecting the developer from the surface of the developing sleeve, the developer collecting portion and the developer supplying portion being vertically aligned, a pair of magnetic poles fixed in the developing sleeve, the pair of magnetic poles forming a triangle area which is surrounded by tangent lines at points where the magnetic poles have the maximum magnetic force, and a wall positioned between the developer supplying portion and the developer collecting portion, the edge of the wall being positioned in the triangle area formed by the pair of magnetic poles.

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 toner for developing an electrostatic image is formed as a mixture of toner particles containing at least a binder resin and a colorant, and inorganic fine powder. The inorganic fine powder includes: (A) inorganic fine powder (A) treated at least with silicone oil, and (B) inorganic fine powder (B) comprising a composite metal oxide including at least Si as a constituent element and having a weight-average particle size of 0.3-5 .mu.m. Because of the inclusion of the two types of inorganic fine powders (A) and (B), the toner is stably provided with a high flowability and a high triboelectric charge under various environmental conditions including low-humidity to high-humidity conditions. The toner is suitably used in an image forming system including a contact-charging means, a contact-transfer means and a film (or surf)-fixing system.

Abstract: An electrophotography developing apparatus of non-contacting type using a nonmagnetic one-component toner is provided. The developing apparatus adopts a soft roller as a developing roller and a developing gap of 50-200 .mu.m is formed between a developing drum and developing roller. A desirable image can be provided by adopting the soft roller as the developing roller and properly setting the developing gap between the developing roller and the developing drum. Generally, the electrophotography developing apparatus is used in the apparatus for printing and communicating, such as a duplicator, a printer and a facsimile.

Abstract: An electrophotographic printing machine, wherein an electrostatic latent image recorded on a photoconductive member is developed with toner to form a visible image thereof, wherein the improvement includes an apparatus for alleviating toner contamination of the electrophotographic printing machine while maintaining high quality visible images. The apparatus includes a first housing defining a chamber storing a supply of toner of a first color; the first housing including a first toner donor member spaced a first predetermined spacing from the surface and being adapted to transport toner of the first color to a region opposed from the surface, and a second toner donor member spaced a second predetermined spacing from the surface and being adapted to transport toner of the first color to the region opposed from the surface; and wherein the first predetermined spacing is substantially greater than the second predetermined spacing.

Abstract: A developing method using negative toner, constituted by a toner carrier 1 and toner so that triboelectric series of the toner carrier 1, a toner base particle 3 and a surface additives 2 have a relationship in which the toner carrier 1, the surface additives 2 and the toner base particle 3 are arranged in this order from the plus side.

Abstract: An ink applicator or donor is provided in which a belt tracks the surface of a prim member over a defined distance of the print member. A geometric conformance device is located inside the belt to ensure that the belt is equidistantly spaced apart from the print member surface.

Abstract: A multi-color printer using a stretch toner release development system to provide either partial or full color copies with minimal degradation of developed toner patterns by subsequent over-development with additional colors and minimal back contamination of developer materials. Multiple scanning beams, each modulated in accordance with distinct color image signals, are scanned across the printer's photoreceptor at relatively widely separated points, there being a buffer provided to control timing of the different color image signals to assure registration of the color images with one another. Each color image is developed prior to scanning of the photoreceptor by the next succeeding beam. After developing of the last color image, the composite color image is transferred to a copy sheet. Development is accomplished by stretching the surface of a toner carrying member and thereby reducing the net force of adhesion of toner to the surface of the toner carrying member.