Abstract: A developing apparatus including a magnetic conveying means 4 comprising a non-magnetic metal sleeve 7, onto which a developer containing a magnetic toner and a magnetic carrier is attracted, a permanent magnet member 8 having a plurality of magnetic poles and stationary inside the sleeve 7; a casing 1a having a developer-containing portion 5 for receiving the magnetic conveying means 4 and a toner-containing portion 3 disposed adjacent to the developer-containing portion 5 for storing the magnetic toner; and a doctor blade 10 for regulating a thickness of the developer 11 on the sleeve 7, the sleeve 7 being rotated such that the magnetic toner is attracted onto a surface of an electrostatic image-bearing member 12, further comprising a downward partition 3a and an upward partition 3b between the developer-containing portion 5 and the toner-containing portion 3 in such a positional relation that the downward partition 3a is closer to the sleeve 7 than the upward partition 3b, a developer which has not passed

Abstract: The toner supply roller 20 is so constructed that the outer diameter L of the toner supply roller 20 is set in a range of 10-13 mm, the outer diameter M of the roller shaft 20B is set in a range of 5-6 mm, and a difference between the distance between the rotating center E1 of the toner supply roller 20 and the rotating center E2 of the developing roller 19 and the sum of the radius R1 of the toner supply roller 20 and the radius R2 of the developing roller 19, i.e., the compression amount is set in a range of 0.5-0.8 mm so that there is a good balance between the rigidity of the roller shaft 20B and the rigidity of the roller member 20C. Accordingly, this makes it possible to use the toner supply roller 20 having a small roller diameter L and to supply just sufficiently toner to the developing roller 19. As a result, a resultant image excellent in image quality can be formed for a long period.

Abstract: A developing apparatus uses a dual-component developer containing a magnetic carrier and toner electrically attracted to the magnetic carrier for selectively transferring the toner to an electrostatic latent image formed on an image support for visualizing the latent image. The developing apparatus includes a developer transport member facing the image support and having a peripheral surface for supporting and transporting the developer. A toner excess supplying member supplies excess toner to the developer supported on the developer transport member. An excess toner separator separates toner having a small adhesion force to the carrier from the developer to which excessive toner is applied.

Abstract: A method and apparatus for delivering a uniform supply of toner to a development zone in an electrostatographic system is disclosed. Additional toner control in the form of magnets located near the donor member attract toner to the toner pick-up area and insure that a constant supply of toner reaches the development zone. The additional control of toner is especially useful when the supply of toner to the toner pick-up area is limited or the toner does not naturally flow to the toner pick-up area.. The toner supply is enhanced by a stationary magnet located adjacent the donor member and a magnet located on the charge metering blade. Both of the additional toner supply magnets form magnetic brushes of toner particles on the donor member surface, these magnetic brushes insuring a constant supply of toner to the development zone despite problematic development conditions.

Abstract: A developing device for an image forming apparatus and of the type using a developer consisting of toner and magnetic particles is disclosed. While a developing sleeve conveys the developer deposited thereon, toner is automatically replenished to the developer from a toner hopper via an opening formed in the hopper due to the movement of the developer. At the same time, the toner introduced into the developer is charged by friction. A developer storing member includes a penthouse portion. A projection protrudes from the surface of the penthouse portion facing the developing sleeve toward the sleeve and extends in the direction perpendicular to the direction in which the sleeve conveys the developer. The developer forms on the sleeve a layer having stable toner content and stable toner charge without resorting to a sophisticated toner content control mechanism.

Abstract: A development apparatus having a development sleeve for carrying and transporting a magnetic developer, a regulating roll for controlling the thickness of a layer of the developer on the development sleeve, a first magnetic pole provided in the development sleeve in the vicinity of a position of layer thickness control by the regulating roll, a second magnetic pole provided in the regulating roll to form a magnetic field for restraining the developer in cooperation with the first magnetic pole. The first and second magnetic poles are provided on the upstream side of a straight line connecting a center of the development sleeve and a center of the regulating roll in the direction of transport of the developer by the development sleeve so that the following inequalities are satisfied:0<.theta..ltoreq..alpha./2, , 0.ltoreq.r.multidot.sin .phi.<R.multidot.sin .theta.where .alpha. is an angle of a half-value width of a magnetic flux density distribution of the first magnetic pole; .theta.

Abstract: An apparatus for developing an image by using spherical non-magnetic toner particles has a latent image carrier on which a latent image is formed by a potential contrast, a toner transporter having a surface for transporting the spherical non-magnetic toner particles to the latent image carrier, and an elastic blade having a surface for passing the spherical non-magnetic toner particles transported by the toner transporter through a gap between the surfaces of the toner transporter and elastic blade, thereby forming a thin toner layer which is charged. The toner transporter develops an electrostatic latent image on the latent image carrier with the thin toner layer which is charged. Surface roughnesses of the elastic blade and of the toner transporter are different from each other, and the spherical non-magnetic toner particles are rotated between the elastic blade and the toner transporter and charged electrostacially.

Abstract: A developing apparatus is capable of providing stable charging ability for a developer and stable transfer ability for transferring the developer to a photoreceptor for electronic photography to prevent residual positive images and stain of texture which appear on a toner image. A first toner transfer roller 23 has a core supported to be rotatable and a sheet type insulation layer wound around the outer periphery of the core. The insulation layer is made of elastic rubber in which magnetic material having a specified particle size is uniformly dispersed and the magnetic material is formed with ferromagnetic substance such as magnet and magnetized in advance. The first toner transfer roller 23 attracts toner T by actuating magnetism on the insulation layer since the magnetic material added to the insulation layer is magnetized.

Abstract: A method of developing an electrostatic latent image on a rotating image-bearing member with a magnetic developer in which a developing roll consist of only a permanent magnet member and the peripheral speed of the developing roll is regulated to be nearly equal to the moving speed of an image-bearing member. With such a construction, an electrophotographic recording apparatus can be miniaturized while producing an image of high quality.

Abstract: In an image forming apparatus, a developing device operable with toner or single component type developer has a hard first developing roller and a soft second developing roller. Fine magnetic N-S poles are formed on the periphery of the first roller. The second roller conveys the toner, electrostatically transferred thereto from the first roller, to an image carrier. The device frees a toner image from deterioration due to toner particles charged to a polarity opposite to an expected polarity. The toner forms a uniform thin layer on the first roller and is uniformly charged. Toner for use with this type of developing device is also disclosed.

Abstract: In an image forming apparatus, a developing device operable with toner or single component type developer has a hard first developing roller and a soft second developing roller. Fine magnetic N-S poles are formed on the periphery of the first roller. The second roller conveys the toner, electrostatically transferred thereto from the first roller, to an image carrier. The device frees a toner image from deterioration due to toner particles charged to a polarity opposite to an expected polarity. The toner forms a uniform thin layer on the first roller and is uniformly charged. Toner for use with this type of developing device is also disclosed.

Abstract: A developing device which includes a first toner transporting roller, a second toner transporting roller to which toner is transported from the first toner transporting roller and an image bearing member such as a photoconductive drum or belt. Seals are located between the circumferential ends of one of the toner transporting rollers and a bottom portion of a toner hopper. When the seals are between the bottom of toner hopper and the first toner transporting roller, the first toner transporting roller is longer than the second toner transporting roller and the circumferential portions of the first toner transporting roller which contact the seals do not contact the second toner transporting roller.

Abstract: An electrophotographic recording apparatus includes an image supporting member for supporting an electrostatic latent image on its surface, and a developing unit for supplying one-component toner to the image supporting member. The developing unit has a toner delivering member for directly delivering toner to the image supporting member. The included wetting angle to water of the surface of the toner delivering member is more than 20 degrees.

Abstract: In an image forming apparatus, a developing device of the type developing an electrostatic latent image formed on an image carrier by using single-component type toner has a regulating member for regulating the amount of the toner fed thereto, a first conveying member for conveying the toner regulated by the regulating member and deposited thereon, and a second conveying member for conveying the toner transferred from the first conveying member thereto to the image carrier. The first and second conveying members are each movable at a particular speed in a particular direction. The device is free from problems attributable to oppositely charged toner particles despite the use of the single-component type toner and, in addition, insures attractive images.

Abstract: A developing apparatus for developing an electrostatic latent image on an image retainer with two-component developer has a rotatable sleeve having a closest position on which the sleeve comes closest to the image retainer, a first magnet fixed in the sleeve in close proximity to the closest position, a second magnet disposed upstream of the first magnet in relation to a rotation direction of the sleeve and a control electrode member. The control electrode member includes an insulating plate member arranged either to be brought into contact with or to be positioned adjacent to the sleeve and a line-shaped electrode member fixed to the plate member.

Abstract: An apparatus for controlling the concentration of toner within a developer material of carrier and toner. The apparatus having a magnetic roll for transporting a combination of carrier material and toner particles, a donor roll for transporting toner particles from said magnetic roll to a photoreceptor transfer zone, the magnetic roll and the donor roll each having a voltage applied thereto. A sensor measures the dynamic current between the magnetic roll and the donor roll and generates a signal as a function thereof. The dynamic current between the magnetic roll and the donor roll is a function of the concentration of the toner particles and the carrier material. As a result of the sensor output signal toner particles are added to the developer sump to maintain proper triboelectric properties within the developer unit.