Abstract: A developing device, a process cartridge and an image forming apparatus are provided which can suppress and prevent the slipping-through of a developer to the end portions of a developing sleeve and can suppress and prevent the leakage of the developer by a shock or the like. A developer sleeve 31 having a magnet roller 32 therein is disposed in the opening portion of a developing container 30, and magnet seal members 34 for regulating the movement of the toner are disposed in non-contact with the developing sleeve 31 on the outer peripheral surface of the opposite ends of the developing sleeve 31, which is adjacent to the developing container 30. The magnet roller 32 has a plurality of magnetic poles, and N and S poles are magnetized to multiple magnetic poles on the inner peripheral surfaces of the magnet seal members 34.

Abstract: The present invention provides a developing apparatus comprising a developing container for containing magnetic developing agent, a developing agent bearing member provided at an opening portion of the developing container and adapted to bear and convey the magnetic developing agent, an internal magnet provided within the developing agent bearing member, and a magnetic seal member provided along a circumferential direction of the developing agent bearing member and adapted to prevent leakage of the developing agent at ends of the developing agent bearing member, and wherein the internal magnet and the magnetic seal member have magnetic poles of same polarities in the vicinity of a collecting inlet of the opening portion.

Abstract: In a developing method, a layer of electrically charged toner particles is formed on a surface of a developer carrying member, and magnetic particles which retain on their surfaces electrically charged toner particles are dispersed on the surface of the developing carrying member. The toner particles and magnetic particles are carried on the developing carrying member to a developing position where a surface of an electrostatic latent image bearing member for bearing an electrostatic latent image is opposed with a clearance to the surface of the developer carrying member. An alternating electric field is formed at the developing position against the electrostatic image and chains of magnetic particles are formed by stationary magnetic field generating apparatus disposed behind the developer carrying member.

Abstract: An image forming apparatus includes a movable image bearing drum; a device for forming a dot distribution electrostatic latent image on the drum in accordance with an image signal; a developing device for developing the dot distribution electrostatic latent image with a developer containing magnetic carrier particles and toner particles, the developing device including a rotatable developer carrying sleeve for carrying the developer to a developing zone, voltage source for applying an oscillating bias voltage to the sleeve, and a magnet stationarily disposed in the sleeve; wherein the magnet has first and second magnetic poles opposite polarities first magnetic pole being positioned upstream of a position where the drum and the sleeve are closest to each other and in an upstream part of the developing zone, the second magnetic pole is positioned downstream of the developing zone, wherein a downstream part of the developing zone include a region where an angle of magnetic line of force relative to a surface of

Abstract: A developing apparatus for developing an electrostatic latent image formed on an image bearing member includes a developer carrying member for carrying a developer containing toner particles and magnetic carrier particles. The developer carrying member moves through a developing zone for applying the developer to the electrostatic latent image. A stationary magnet assembly is disposed in the developer carrying member. The magnet assembly comprises a rare earth magnet having a first magnetic pole for forming a magnetic field in the developing zone and a resin magnet having a second magnetic pole disposed adjacent to the first magnetic pole downstream of the first magnetic pole with respect to a movement direction of the developer carrying member, wherein a maximum magnetic flux density on a developer carrying member provided by the first magnetic pole is larger than a maximum magnetic flux density on the developer carrying member by the resin magnet.

Abstract: A magnet is disposed stationarily in a rotatable developing sleeve. The magnet at least has a developing magnetic pole and a conveying magnetic pole disposed adjacent to it and downstream of it. In the magnetic flux density distribution of the conveying pole, an inflection point is provided upstream of the maximum magnetic flux density position in the magnetic flux density distribution.The point of inflection is defined as the point where the secondary differentiation of the magnetic flux density Br (gauss), which is .delta..sup.2 Br/.delta..sup.2 .THETA., equals zero. The result of setting the inflection point to such a position is an improvement of developer conveying power.

Abstract: A developing apparatus for developing an electrostatic latent image formed on an image bearing member includes a developer chamber containing a developer comprising non-magnetic toner particles and magnetic carrier particles; a rotatable cylindrical developer carrying member, faced to the image bearing member, for carrying the developer supplied thereto in the developer chamber to supply it to the image bearing member; a magnet stationarily disposed in the developer carrying member to form a magnetic brush of the developer contactable to the image bearing member, wherein a position of maximum magnetic flux density in a direction normal to a surface of the developer carrying member provided by a developing magnetic pole of the magnet is not less than 3 degrees away from a position where the developer carrying member is closest to the image bearing member, and wherein a position of a peak of magnetic force in a direction normal to the surface of the developer carrying member provided by the developing magnetic

Abstract: A developing apparatus for developing an electrostatic latent image formed on an image bearing member includes a rotatable developer carrying member for being supplied with developer in a developer container and for carrying the developer through a developing zone. A magnet is stationarily disposed in the developer carrying member. The magnet has a first magnetic pole for forming a magnetic field in the developing zone, a second magnetic pole disposed downstream thereof with respect to a rotational direction of the developer carrying member and having a magnetic polarity opposite thereto, and a third magnetic pole disposed downstream of the second magnetic pole with respect to the direction and disposed adjacent to the second magnetic pole. The second magnetic pole has a magnetic flux density satisfying(X50/X0)>(Y50/Y0)where X0 is a distance from a position B.sub.

Abstract: A developing method including forming a layer of electrically charged toner particles on a surface of the developer carrying member and dispersing magnetic particles retaining on their surfaces electrically charged toner particles on the surface of the developer carrying member, carrying the particles on the developer carrying member to a developing position where a surface of an electrostatic latent image bearing member for bearing an electrostatic latent image is opposed with a clearance to the surface of the developer carrying member, applying an alternating electric field across the clearance and forming the magnetic particles into chains of the magnetic particles by magnetic field generating means disposed behind the developer carrying member, and developing the electrostatic latent image by the charged toner particles on the surface of the developer carrying member and on the surfaces of the magnetic particles.

Abstract: A developing method utilizing a developer including a mixture of magnetic carrier particles and toner particles wherein a stationary layer containing magnetic particles is formed on a developer carrying member in a developer container. The stationary layer is allowed to expand and contract in order to control an area of the developer supplying opening upstream of the stationary layer with respect to movement of the developer carrying member thus stabilizing the toner content in the developer supplied to the developing station.

Abstract: A camshaft in which the outer peripheral surface of a shaft (13) is provided with an axial groove (14), and a fitting member (10) is connected to the shaft (13) by liquid-phase sintering under the state in which a projection (12) on the surface of a bore (11) in the fitting member (10) is fitted into the groove (14). The projection (12) in the bore (11) of the fitting member (10) is formed so that its cross-sectional configuration is smaller than that of the groove (14) in the shaft (13). Therefore there is no possibility that the fitting member (10) made of a green compact can be damaged during the fitting or sintering.