Abstract: An image forming apparatus includes a developing device including plural developer supporters provided opposite to a photoconductor, a development bias applying unit for applying a development bias voltage generated by superimposing an AC voltage on a DC voltage to each of the developer supporters, and a phase shifter for shifting a phase of the AC voltage in the development bias voltage in each of the developer supporters.

Abstract: A developing device including: a developing container for containing a developer, the developing container being provided so as to oppose an image bearing member; first and second developer bearing members for bearing and carrying the developer in the developing container to the image bearing member; and a pressurizing member for pressurizing the vicinity of an end of the second developer bearing member toward the image bearing member side, in which the developing container has a first supporting portion for rotatably supporting the vicinity of an end of the first developer bearing member and a second supporting portion for supporting the vicinity of the end of the second developer bearing member rotatably and swingably with the first supporting portion as a swinging center such that a distance between the first developer bearing member and the second developer bearing member does not substantially vary.

Abstract: In an image forming method, when viewed from the moving direction of a photosensitive body 1, there is disposed, on the upstream side, a first developing roller 61 opposed to and adjacent to the photosensitive body 1 and rotatable in the opposite direction to the photosensitive body 1, while the peripheral speed ratio of the roller 61 to the photosensitive body 1 ranges from 0.8 to 2.0; on the downstream side of the roller 61, there is disposed a second developing roller 62 rotatable in the same direction to the photosensitive body 1, while the peripheral speed ratio of the roller 62 to the photosensitive body 1 ranges from 1.05 to 2.0; and the shape coefficient SF1 of the toners of two-component developing agent ranges from 120 to 170, while the shape coefficient SF2 ranges from 110 to 130.

Abstract: A development apparatus includes a first developer carrying member for carrying developer and is adapted to develop a latent image formed on an image bearing member with the developer at a first developing area. A second developer carrying member carries the developer and is adapted to develop the latent image formed on the image bearing member with the developer at a second developing area. A regulating member is borne on the second developer carrying member and is adapted to regulate a thickness of a layer of the developer. The second developer carrying member regulates a thickness of a layer of the developer carried on the first developer carrying member.

Abstract: A developing device including: a first developer carrying member for carrying a developer to develop a latent image formed on an image bearing member; a first regulating member, disposed on one end of a longitudinal direction of the image bearing member, for regulating a gap between the image bearing member and the first developer carrying member; a second developer carrying member for carrying a developer to develop the same latent image formed on the image bearing member; and a second regulating member, disposed on the one end of the longitudinal direction of the image bearing member, for regulating a gap between the image bearing member and the second developer carrying member, wherein the first and second regulating members are disposed without being superposed upon each other in the longitudinal direction.

Abstract: A developing device includes rotatable first and second developer carrying members carrying developer thereon to develop an electrostatic image formed on an image bearing member with the developer, the first and second developer carrying members being provided with a plurality of non-rotary magnetic pols therein, respectively, the second developer carrying member being provided upstream of the first developer carrying member in the direction of movement of the image bearing member to regulate the amount of the developer carried on the first developer carrying member, the direction of rotation of the second developer carrying member being the same direction as the direction of rotation of the first developer carrying member, and a developer regulating member for regulating the amount of the developer carried on the second developer carrying member.

Abstract: An image forming apparatus includes a developing device including plural developer supporters provided opposite to a photoconductor, a development bias applying unit for applying a development bias voltage generated by superimposing an AC voltage on a DC voltage to each the developer supporter, and a phase shifter for shifting a phase of the AC voltage in the development bias voltage in each the developer supporter.

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: An image forming apparatus of the present invention includes a developing device including two developing rollers arranged in parallel in a direction in which an image carrier moves each for forming a magnet brush thereon. The magnetic poles of the developing rollers for effecting hand-over of a developer between the rollers are provided with the same polarity. An optical writing device optically writes an image on the image carrier in accordance with tonality data of four levels or less for a single dot. The developing device prevents the developer from moving through a gap between the developing rollers and bringing about irregular image density and background contamination. In addition, the optical writing device successfully obviates ghosts, which are likely to appear when a uniform halftone image including solid portions or bold characters is reproduced.

Abstract: An apparatus for non-interactive, dry powder development of electrostatic Images composed of solid areas and fine lines areas on an imageable surface including a housing containing developer material; a first magnetic roll, spaced a first predefined distance from the image, for transporting the developer material from the housing to develop solid areas of the image, the magnetic roll including an magnetic core and a cylindrical sleeve enclosing and rotating about the magnetic core; and a second magnetic roll, spaced a second predefined distance from the image, for transporting the developer material from the housing to develop fine line areas of the image, the magnetic roll including an magnetic core and a cylindrical sleeve enclosing and rotating about the magnetic core.

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 developing apparatus of an electrophotographic apparatus includes a housing for accommodating a developer, first, second and third developing rollers are rotatably disposed in the housing and arranged opposite to a photoconductor drum for conveying a developer carried on respective surfaces of the developing rollers, and a conveyor roller rotatably disposed in the housing for conveying the developer carried on a surface thereof to one of the developing rollers. First and second screw conveyors are disposed in the housing for conveying the developer in an axial direction opposite to each other. Each of these conveyors has an axial length larger than an axial length of the developing rollers. A partition wall is disposed between the first and second screw conveyors. A toner container for accommodating a toner is mounted on the housing. The toner in the toner container is supplied into the housing and agitators agitate the toner in the housing.

Abstract: A developing apparatus is provided for incorporation into an image forming machine. The developing apparatus includes a developer accommodating space for containing a developer composition, a series of developing rollers disposed in the developer accommodating space adjacent to each other and in facing relationship to an electrostatic latent image carrier for supplying the developer composition to the image carrier while transferring the developer composition from one developing roller to another, and a developer feed regulator for regulating the transfer of the developer composition between adjacent two of the developing rollers.

Abstract: An apparatus for developing an electrostatic latent image includes a first developing agent application device and a second developing agent application device disposed facing the peripheral surface of a photosensitive material drum, a developing agent stirring/conveying mechanism for conveying the developing agent to the first developing agent application device, a magnetic conveyer disposed at the back of the second developing agent application device, and a developing agent return guide plate for sending the developing agent conveyed by the magnetic conveyer to the side of the developing agent stirring/conveying mechanism. The second developing agent application device is provided with a developing agent-peeling zone where magnetic poles of the same polarity are magnetized neighboring each other on the upstream side of the position which is closest to the sleeve member of the magnetic conveyer in the direction of rotation.

Abstract: An image development system for developing a latent image on an imaging surface, such as a xerographic photoreceptor, with plural development rollers having internal axially extending developer magnets with relatively offset axial end positions, and wherein at least one development roller has a smooth surface area at that same end, to reduce edge banding image defects from the interaction of the axial ends of the magnets of adjacent development rollers, especially for large size copy sheets being printed, such as B4 size. The image developer unit may have three development rollers with three different lengths of developer magnets to provide three different magnetic end positions staggered on opposite sides of the end position of the large sheet (relative to the imaging surface).

Abstract: A uniform image is obtained by matching the sliding friction force, the moving speed and the developing agent in a developing region of two developing rollers and an electric characteristic of a photosensitive body used for image development. Two developing rollers rotating in directions opposite to each other are used, the moving direction of the first developing roller being opposite to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the first developing roller to a circumferential speed of the photosensitive body is within a rage of 0.5 to 2.5; and the moving direction of the second developing roller is equal to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the second developing roller to a circumferential speed of the photosensitive body is within a range of 1.5 to 3.5.

Abstract: A development apparatus according to the invention comprises at least two developer carrier members in juxtaposition for transporting a developer material to a development region between the developer carrier members and an image bearing member in opposed relation. An AC voltage applying device is adapted to apply AC voltages to the respective developer carrier members thereby applying AC electric fields to the respective gaps between the developer carrier members and the image bearing member based on an active period to apply the AC electric field and an inactive period to apply no AC electric field. When one of the adjacent developer carrier members is subject to the active period, the other developer carrier member is subject to the inactive period.

Abstract: A predetermined mathematical formula, which defines an occurrence degree of an image defect where the toner layer is thinned or no toner image is formed, is set up, which is valid for a developing device including a reverse turn developer carrier and a forward turn developer carrier. A difference between the total sum A of the values by the above formula showing the occurrence degree of the image defect on the forward turn developing roller and the total sum B of the values by the above formula showing the occurrence degree on the reverse turn developing roller, i.e., (A-B), is selected within a range of -0.56 to +0.5.

Abstract: The present invention provides a development apparatus capable of improving the development pole of a plurality of development rolls and the rotation speed thereof, thus obtaining stable printing quality. A first development roll rotatable in the opposite direction to the moving direction of photosensitive body is disposed in the upstream of it, whereas a group of second development rolls are disposed in the down stream, which development rolls are rotatable in the same direction as the moving direction of photoconductive body and have magnets of the same polarity. The first development roll and the photoconductive body define a peripheral speed ratio ranging from 0.5 to 1.5, while allowing the second development roll and the photoconductive body to define a peripheral speed ratio ranging from 0.6 to 1.5. A development control member is provided between the first development roll and the group of second development rolls.

Abstract: A developer station for an electrophotographic printing or copying machine has a developer chamber (12), a mixing chamber (13) and a developer-station sump (14) connected to the two chambers. Two developer-mixture circuits are produced in the developer station, namely a developer-mixture circuit for receiving fresh toner and a developer-mixture circuit for the actual development in a developer gap (18). A paddle roller (37) arranged in the developer-station sump (14) generates, in the outlet region of the mixing chamber (13), a mixture vortex which is enriched with fresh toner and from which developer mixture is extracted continuously for the development process. The mixture vortex serves essentially as a buffer store for compensating a high toner requirement during development and, in conjunction with the mixing chamber (13), for the triboelectric activation of the developer mixture.