Abstract: A developing method of the present invention develops a latent image formed on an image carrier with a two-ingredient type developer, which consists of toner grains and magnetic carrier grains for supporting the toner grains. A developer carrier faces the image carrier and accommodates magnetic field forming device therein for causing the developer to deposit on the developer carrier. The developer is conveyed to a developing zone formed between the image carrier and the developer carrier. The latent image is developed by a magnet brush including free toner grains, which part from brush chains formed by the carrier grains when the brush chains start rising on the developer carrier in the developing zone. The method insures a high-density, smooth solid image. A device for practicing the method is also disclosed.

Abstract: A developing method of the present invention develops a latent image formed on an image carrier with a two-ingredient type developer, which consists of toner grains and carrier grains retaining the toner grains thereon, deposited on a developer carrier in the form of brush chains. Assume that the brush chains on the developer carrier has a height of h as measured at a zero field point where the magnetic field formed by a main magnet is zero, and that a gap for development that is the shortest distance between the developer carrier and the image carrier is a, then a and h are equal to each other. Image quality is estimated by varying the combination of an angle &thgr; between the gap and the zero field point, the outside diameter of the image carrier and the outside diameter of the developer carrier and the height h. A desirable or an optimum range of the results of estimation are selected to set various conditions.

Abstract: An image forming apparatus of the present invention includes an image carrier. A rotary developing device adjoins the image carrier and includes a plurality of developing sections for developing a latent image formed on the image carrier with a magnetic developer. A toner cartridge unit includes a plurality of toner cartridges and is rotatable integrally with the developing device. A plurality of toner conveying device each connect one toner cartridge to the associated developing section and each include a toner passage and a toner conveying member disposed in the toner passage. A magnet adjoins a toner outlet, which is formed in the toner passage and communicated to the developing section, for forming a magnetic field that traverses the toner passage over the entire diameter of the toner passage. Toner stored in each toner cartridge is prevented from unexpectedly flowing into the associated developing section when replenishment is not effected.

Abstract: A developing method of the present invention develops a latent image formed on an image carrier with a two-ingredient type developer, which consists of toner grains and magnetic carrier grains for supporting the toner grains. A developer carrier faces the image carrier and accommodates magnetic field forming means therein for causing the developer to deposit on the developer carrier. The developer is conveyed to a developing zone formed between the image carrier and the developer carrier. The latent image is developed by a magnet brush including free toner grains, which part from brush chains formed by the carrier grains when the brush chains start rising on the developer carrier in the developing zone. The method insures a high-density, smooth solid image. A device for practicing the method is also disclosed.

Abstract: An image forming apparatus of the present invention includes an image carrier. A rotary developing device adjoins the image carrier and includes a plurality of developing sections for developing a latent image formed on the image carrier with a magnetic developer. A toner cartridge unit includes a plurality of toner cartridges and is rotatable integrally with the developing device. A plurality of toner conveying device each connect one toner cartridge to the associated developing section and each include a toner passage and a toner conveying member disposed in the toner passage. A magnet adjoins a toner outlet, which is formed in the toner passage and communicated to the developing section, for forming a magnetic field that traverses the toner passage over the entire diameter of the toner passage. Toner stored in each toner cartridge is prevented from unexpectedly flowing into the associated developing section when replenishment is not effected.

Abstract: An image forming device which allows reducing a linear velocity ratio of a developing roller against a sensitive body, which enables a pole pitch of a magnetic field generating layer to be miniaturized, and which generates a uniform and adequately thick toner layer on the developing roller. A toner regulating element formed by a sheet metal material having elasticity and non-magnetic characteristics elastically contacts a surface of the developing roller. The developing roller has an elastic body layer and a magnetic field generating layer having a minute pole pitch. The toner regulating elements serves to regulate a thickness of the toner layer without vibration induced from the pole pitch of the magnetic field generating layer. Thus, the toner layer can be uniform and of an adequate thickness, and reducing the linear velocity ratio of the developing roller against the sensitive body does not generate any drawbacks.

Abstract: A method of developing latent electrostatic images and a developer-bearing member for use in the method are disclosed, which method includes the steps of (a) forming numerous micro closed electric fields near the surface of a rotatable developer-bearing member which comprises an electroconductive support and a surface layer formed thereon comprising an electroconductive organic polymeric matrix and numerous minute charge-retainable insulating segments distributed at least one the surface of the surface layer, by electrically charging the surface of the charge-retainable insulating segments; (b) supplying a one-component type developer comprising toner particles to the rotatable developer-bearing member to hold the developer on the rotatable developer-bearing member to hold the developer on the rotatable developer-bearing member by the numerous micro closed electric fields; and (c) bringing the rotatable developer-bearing member near or into contact with a latent-electrostatic-image-bearing member which bears

Abstract: A developer carrier capable of forming microfields on the surface thereof and a method of producing such a developer carrier. A great amount of sufficiently charged one-component developer is carried on the surface of the developer carrier by the microfields and transported to a developing station for developing an electrostatic latent image. The developer carrier has a simple structure and is easy and economical to produce.

Abstract: A developing apparatus includes a toner supporting member for attaching toner to an image supporting member on which an electrostatic latent image is formed so as to develop the electrostatic latent image with the toner supporting member and the image supporting member contacting each other. A toner restricting member forms a toner layer on the toner supporting member uniformly. Further, the toner supporting member has an elastic inner layer and a surface layer on which a magnetic portion is formed, and non-magnetic portions are formed on both end portions of said surface layer. Moreover, a length of the surface layer may be equal to or larger than a length of the inner layer in a longitudinal direction.

Abstract: A developer recycling system is provided for replenishing a fresh developer to a developing device of an image forming apparatus and collecting it after use. A developer cartridge applicable to the system is also provided. When the fresh developer is replenished from the cartridge to the developing device, a developer existing in the developing device overflows in an amount corresponding to the replenished developer. The developer overflown the developing device is recirculated to the cartridge and reused.

Abstract: A toner comprising a binder resin and a coloring agent, with an aggregation degree of 5 to 60%, and an absolute value of Q/M measured by the suction method of 2 to 30 .mu.

Abstract: A developing device develops a latent image electrostatically formed on an image carrier in a developing region to produce a corresponding visible image. The developing device includes a rotatable developer carrier for carrying a developer to the developing region and a charging device for forming small closed electric fields in the vicinity of the surface of the developer carrier. The developer is deposited on the surface of the developer carrier by the small closed electric fields. The developer carrier comprises a conductive base and dielectric bodies fixedly buried in recesses formed in the conductive base with each of the dielectric bodies having a predetermined cross-section which extends in a direction of a line normal to the surface of the developer carrier.

Abstract: A developing device which is particularly advantageous from the standpoint of avoiding leakage or scattering of toner. The developing device is additionally advantageous in allowing for a compact design while reliably supplying toner to the complete area of a photosensitive member upon which a latent image is formed. The developing device includes a toner container having an opening in a lower part thereof, through which toner falls. A magnet bar is provided below the opening, with a developing grid covering a portion of the magnet bar. The magnet bar forms a magnetic toner brush which penetrates through holes in the developing grid, with the magnetic toner brush and grid cooperating to prevent excessive toner from falling through the opening and thus preventing excessive toner from scattering outside the developing device.

Abstract: A developing apparatus using a developer carrier which is capable of forming microfields on the surface of the carrier. A great amount of sufficiently charged one-component developer is deposited on the surface of the developer carrier by the microfields and transported to a developing region to be supplied to an electrostatic latent image. The developer carrier has a plurality of surface portions, each having a particular characteristic, such that at least one surface portion holds a first charge while at least another surface portion holds a second charge that is equal to and of an opposite polarity to the first charge.

Abstract: A developing apparatus for image forming equipment capable of insuring images with high resolution while preserving tonality. A developing sleeve is provided with conductive portions and insulative portions on its surface by knurling. A magnetic roller is accommodated in the sleeve to constitute a developing roller. A toner supply roller is held in contact with the developing sleeve. A doctor blade is disposed above and spaced apart by a predetermined distance from the developing sleeve and made of a magnetic material. Bias applying means applies an alternating voltage to the sleeve to effect reversal development.

Abstract: A developing apparatus having a rotatable toner carrier for transporting a toner to a developing region where it faces an image carrier on which a latent image has been electrostatically formed. The surface of the toner carrier is constituted by a mixture of conductive surface portions and dielectric surface portions and selectively holds a charge to form microfields. The toner having been charged is electrostatically deposited on the toner carrier by the microfields and transported to the developing region as the toner carrier moves. In the developing region where the toner carrier and the image carrier face each other while defining a developing gap therebetween, the toner electrostatically flies from the toner carrier to the latent image formed on the image carrier to thereby develop it.

Abstract: A developing device incorporated in an image forming apparatus and having a developing roller or similar image carrier for transporting a developer to a photoconductive element or similar image carrier to develop an electrostatic latent image formed on the image carrier. The developing roller is configured to form microfields on the surface thereof. An alternating voltage is applied to the developing roller as a bias voltage for development to thereby deposit a non-magnetic toner on the surface of the roller. Silica particles are admixed with the toner. The developing device is operable with an adequate developing bias at all times.

Abstract: A method and apparatus for developing a latent image electrostatically formed on an image carrier by a developer carried on a developer carrier in a developing region where the image carrier and the developer carrier are located face-to-face. A great number of electric fields are produced on the surface of the developer carrier. An electric field is produced by a voltage applying device in the developing region. The movement of the developer is controlled by an electric field determined by the relationship between a potential deposited on the image carrier, a potential deposited on the developer carrier, and the electric field produced by the voltage applying device.

Abstract: A developing device incorporated in an image forming apparatus and including a developing roller or similar developer carrier for transporting a developer to a developing region where it faces an image carrier, so as to develop a latent image electrostatically formed on the image carrier. The developer carrier has a first and a second substance different in charging characteristic from each other and exposed to the outside on the surface of the developer carrier in a regular or irregular pattern. At least one of the first and second substances is charged to predetermined polarity on the surface of the developer carrier to form a great number of microfields. Alternatively, the developer carrier may have a conductive base and a surface layer provided on the base and constituted by a conductive substance in which insulating particles are dispersed. At least the insulating particles are charged on the surface of the developer carrier to form a number of microfields.

Abstract: A developer carrier constituting a developing roller which carries a developer on the surface thereof where numerous microfields are developed. The developing roller has a conductive base and a plurality of different kinds of substances each having a particular charging characteristic. The different kinds of substances show themselves on the surface of the base in a regular or irregular pattern, and each is charged to a particular polarity.