Developing device with microfields formed on developer carrier

A developing device incorporated in image forming equipment for developing a latent image electrostatically formed on an image carrier by a developer to produce a visible image, said device comprising:

• a developer carrier driven to move a surface thereof and having both conductive portions connected to ground and dielectric portions distributed on said surface, wherein said surface of said developer carrier including said conductive portions and said dielectric portions is substantially smooth such that said developer carrier has a continuous smooth surface;
• a developer supply member driven to move a surface thereof while contacting the surface of said developer carrier for supplying the developer to said developer carrier;
• wherein a plurality of microfields are formed in the vicinity of the surface of said developer carrier due to friction between said developer supply member and said developer carrier, and the developer charged by friction at said contact position is deposited in a layer on said developer carrier by said microfields;
• and
• wherein the surface of said developer supply member is moved toward said developer carrier on an inner periphery of a lower wall of a casing included in said device.

A developing device incorporated in image forming equipment for developing a latent image electrostatically formed on an image carrier by a developer to produce a visible image, said device comprising:

• a developer carrier driven to move a surface thereof and having conductive portions connected to ground and dielectric portions distributed on said surface together with said conductive portions;
• a developer supply member driven to move a surface thereof while contacting the surface of said developer carrier for supplying the developer to said developer carrier;
• wherein a plurality of microfields are formed in the vicinity of the surface of said developer carrier due to friction between said developer supply member and said developer carrier, and the developer charged by friction at said contact position is deposited in a layer on said developer carrier by said microfields;
• wherein the surface of said developer supply member is moved toward said developer carrier on an inner periphery of a lower wall of a casing included in said device;
• and
• wherein the inner periphery of said lower wall of said casing is configured to contact the surface of said developer supply member over a range extending from a position adjoining a supply position where the developer is supplied to said developer supply member to a position adjoining said contact position.

A developing device incorporated in image forming equipment for developing a latent image electrostatically formed on an image carrier by a developer to produce a visible image, said device comprising:

• a developer carrier driven to move a surface thereof and having conductive portions connected to ground and dielectric portions distributed on said surface together with said conductive portions;
• a developer supply member driven to move a surface thereof while contacting the surface of said developer carrier for supplying the developer to said developer carrier;
• wherein a plurality of microfields are formed in the vicinity of the surface of said developer carrier due to friction between said developer supply member and said developer carrier, and the developer charged by friction at said contact position is deposited in a layer on said developer carrier by said microfields;
• wherein the surface of said developer supply member is moved toward said developer carrier on an inner periphery of a lower wall of a casing included in said device;
• and
• the developing device further comprising a regulating member having a lower edge contacting the surface of said developer supply member to prevent the developer from directly advancing toward part of the surface of said developer carrier downstream of said contact position with respect to the direction in which said surface of said developer carrier is moved.

A developing device incorporated in image forming equipment for developing a latent image electrostatically formed on an image carrier by a developer to produce a visible image, said device comprising:

• a developer carrier driven to move a surface thereof and having conductive portions connected to ground and dielectric portions distributed on said surface together with said conductive portions;
• a developer supply member driven to move a surface thereof while contacting the surface of said developer carrier for supplying the developer to said developer carrier, wherein the developer supply member and the developer carrier are rotated in opposite directions such that said surface of said developer supply member is moved in the same direction as said surface of said developer carrier at a contact position where said surfaces contact each other;
• wherein a plurality of microfields are formed in the vicinity of the surface of said developer carrier due to friction between said developer supply member and said developer carrier, and the developer charged by friction at said contact position is deposited in a layer on said developer carrier by said microfields;
• a levelling member contacting part of the surface of said developer carrier downstream of said contact position with respect to the direction in which said surface of said developer carrier is moved, wherein the levelling member contacts the surface of said developer carrier at a pressure between 10 g/cm and 20 g/cm.

A developing device incorporated in image forming equipment for developing a latent image electrostatically formed on an image carrier by a developer to produce a visible image, said device comprising:

• a developer carrier driven to move a surface thereof and having conductive portions connected to ground and dielectric portions distributed on said surface together with said conductive portions;
• a developer supply member driven to move a surface thereof while contacting the surface of said developer carrier for supplying the developer to said developer carrier;
• wherein a plurality of microfields are formed in the vicinity of the surface of said developer carrier due to friction between said developer supply member and said developer carrier, and the developer charged by friction at said contact position is deposited in a layer on said developer carrier by said microfields;
• wherein the surface of said developer supply member is moved toward said developer carrier on an inner periphery of a lower wall of a casing included in said device;
• and
• further comprising a levelling member contacting part of the surface of said developer carrier downstream of said contact position with respect to the direction in which said surface of said developer carrier is moved, wherein said levelling member is made of a material having a low resistance.

A developing device incorporated in image forming equipment for developing a latent image electrostatically formed on an image carrier by a developer to produce a visible image., said device comprising:

• a developer carrier driven to move a surface thereof and having both conductive portions connected to ground and dielectric portions distributed on said surface, wherein said surface of said developer carrier including said conductive portions and said dielectric portions is substantially smooth such that said developer carrier has a continuous smooth surface;
• a developer supply member driven to move a surface thereof while contacting the surface of said developer carrier for supplying the developer to said developer carrier;
• wherein a plurality of microfields are formed in the vicinity of the surface of said developer carrier due to friction between said developer supply member and said developer carrier, and the developer charged by friction at said contact position is deposited in a layer on said developer carrier by said microfields;
• and
• wherein said developer supply member is made of a material having a low resistance.

A developing device for an image forming apparatus for developing a latent image electrostatically formed on an image carrier by a developer to thereby produce a visible image, said device comprising:

• a driven developer carrier having a surface which moves as said developer carrier is driven;
• a driven developer supply member having a surface which contacts the surface of said driven developer carrier, wherein said developer carrier carries developer to a developing location downstream from said contact position, such that developer is transferred to an image carrier at said developing location;
• and
• means for forming a plurality of microfields on the surface of said developer carrier by friction between the developer supply member and the developer carrier such that developer charged by friction at said contact position is deposited in a layer on said developer carrier by said microfields, said means for providing a plurality of microfields by friction including conductive portions provided in the surface of said developer carrier, said conductive portions connected to ground, and dielectric portions distribution on said surface of said developer carrier;
• said developing device further including means for preventing developer which has not passed through said contact position from being carried by said developer carrier toward said developing location.

A developing device incorporated in image forming equipment for developing a latent image electrostatically formed on an image carrier by a developer to produce a visible image, said device comprising:

• a developer carrier driven to move a surface thereof and having both conductive portions connected to ground and dielectric portions distributed on said surface, wherein said surface of said developer carrier including said conductive portions and said dielectric portions is substantially smooth such that said developer carrier has a continuous smooth surface;
• a developer supply member driven to move a surface thereof while contacting the surface of said developer carrier for supplying the developer to said developer carrier;
• and
• means for preventing developer which has not passed through said contact position from being carried by said developer carrier toward an image carrier;
• wherein a plurality of microfields are formed in the vicinity of the surface of said developer carrier due to friction between said developer supply member and said developer carrier, and the developer charged by friction at said contact position is deposited in a layer on said developer carrier by said microfields.