Developer unit utilizing a non-magnetic single component developer

Claim 2

A developer unit receiving a non-magnetic single-component developer, the developer unit comprising: a developer carrier having at least an electrically conductive core; an electrically conductive constraining member in the shape of a sheet, abutting the developer carrier and serving for forming a substantially uniform thin layer of the developer on the developer carrier, an electrical developing bias being applied to the developer carrier to cause developer to fly across a gap to an image area of an electrostatic latent image formed on a latent image carrier opposed to the developer carrier; and further comprising: an electrically conductive yieldable charging member rotatably disposed in physical contact with the developer carrier, a high voltage being applied to the charging member, the constraining member and the developer carrier, whereby the constraining member charges the developer on the developer holder to a predetermined potential.

Claim 3

A developer unit according to claim 1, wherein the yieldable charging member comprises a porous electrically conductive resilient member.

Claim 4

A developer unit according to claim 1, wherein the yieldable changing member comprises a fibrous electrically conductive member.

Claim 5

A developer unit according to claim 1 in which the developer holder carries a dielectric layer on its surface.

Claim 6

A developer unit according to claim 1 in which the constraining member comprises a composite of a conductive material and resilient material.

Claim 7

A developer unit according to claim 1, wherein the developer holder has a layer of conductive resin thereon.

Claim 8

A developer unit according to claim 5, wherein the constraining member includes a non-conductive portion disposed for abutment against the developer holder and also including a conductive portion on the opposite side, the constraining member controlling the thickness of a thin layer of developer formed on the developer holder and charging the developer to a given level; a high voltage being applied to each of the developer holder; the porous conductive resilient member and the conductive portion of the constraining member.

Claim 9

A developer unit as claimed in claim 6, in which the conductive resin layer has a thickness from 1.5 to 5.0 mm and a resistivity from 10 4 to 10 12 ohm-cm.

Claim 10

A developer unit according to claim 1, wherein the developer carrier conductive core is metallic.

Claim 11

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core; a porous conductive resilient member disposed to be rotatable while maintaining a contact with the developer holder; and a conductive constraining member in the shape of a sheet, abutting the developer holder and serving for controlling the thickness of a thin layer of developer formed on the developer holder and for charging the developer to a given level; a high voltage being applied to each of the developer holder, the porous conductive resilient member and the constraining member.

Claim 12

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core; a porous conductive resilient member disposed to be rotatable while maintaining a contact with the developer holder; and a conductive constraining member in the shape of a sheet, abutting the developer holder and serving for controlling the thickness of a thin layer of developer formed on the developer holder and for charging the developer to a given level; a high voltage being applied to each of the developer holder, the porous conductive resilient member and the constraining member.

Claim 13

A developer unit according to claim 10 in which the developer holder carries a dielectric layer on its surface.

Claim 14

A developer unit according to claim 10 in which the constraining member comprises a composite of a conductive material and a resilient material.

Claim 15

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core; a fibrous conductive member disposed to be rotatable while maintaining a contact with the developer holder; and a conductive constraining member in the shape of a sheet, abutting the developer holder and serving for controlling the thickness of a thin layer of developer formed on the developer holder and for charging the developer to a given level; a high voltage being applied to each of the developer holder, the fibrous conductive member and the constraining member.

Claim 16

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core; a fibrous conductive member disposed to be rotatable while maintaining a contact with the developer holder; and a conductive constraining member in the shape of a sheet, abutting the developer holder and serving for controlling the thickness of a thin layer of developer formed on the developer holder and for charging the developer to a given level; a high voltage being applied to each of the developer holder, the fibrous conductive member and the constraining member.

Claim 17

A developer unit according to claim 13 in which the developer holder carries a dielectric layer on its surface.

Claim 18

A developer unit according to claim 13 in which the constraining member comprises a composite of a conductive material and a resilient material.

Claim 19

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core with a coating of conductive resin layer thereon; a porous conductive resilient member disposed to be rotatable while maintaining a contact with the developer holder; and a conductive constraining member in the shape of a sheet, abutting the developer holder and serving for controlling the thickness of a thin layer of developer formed on the developer holder and for charging the developer to a given level; a high voltage being applied to each of the metal core of the developer holder, the porous conductive resilient member and the constraining member.

Claim 20

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core with a coating of conductive resin layer thereon; a porous conductive resilient member disposed to be rotatable while maintaining a contact with the developer holder; and a conductive constraining member in the shape of a sheet, abutting the developer holder and serving for controlling the thickness of a thin layer of developer formed on the developer holder and for charging the developer to a given level; a high voltage being applied to each of the metal core of the developer holder, the porous conductive resilient member and the constraining member.

Claim 21

A developer unit according to claim 16 in which the constraining member comprises a composite of a conductive material and a resilient material.

Claim 22

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core having a coating of a conductive resin layer thereon; a fibrous conductive member disposed to be rotatable while maintaining a contact with the developer holder; and a conductive constraining member in the shape of a sheet, abutting the developer holder and serving for controlling the thickness of a thin layer of developer formed on the developer holder and for charging the developer to a given level; a high voltage being applied to each of the metal core of the developer holder, the fibrous conductive member and the constraining member.

Claim 23

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core having a coating of a conductive resin layer thereon; a fibrous conductive member disposed to be rotatable while maintaining a contact with the developer holder; and a conductive constraining member in the shape of a sheet, abutting the developer holder and serving for controlling the thickness of a thin layer of developer formed on the developer holder and for charging the developer to a given level; a high voltage being applied to each of the metal core of the developer holder, the fibrous conductive member and the constraining member.

Claim 24

A developer unit according to claim 18 in which the constraining member comprises a composite of a conductive material and a resilient material.

Claim 25

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core; a porous conductive resilient member disposed to be rotatable while maintaining a contact with the developer holder; and a constraining member including a non-conductive portion disposed for abutment against the developer holder and also including a conductive portion on the opposite side, the constraining member controlling the thickness of a thin layer of developer formed on the developer holder and charging the developer to a given level; a high voltage being applied to each of the developer holder, the porous conductive resilient member and the conductive portion of the constraining member.

Claim 26

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core; a porous conductive resilient member disposed to be rotatable while maintaining a contact with the developer holder; and a constraining member including a non-conductive portion disposed for abutment against the developer holder and also including a conductive portion on the opposite side, the constraining member controlling the thickness of a thin layer of developer formed on the developer holder and charging the developer to a given level; a high voltage being applied to each of the developer holder, the porous conductive resilient member and the conductive portion of the constraining member.

Claim 27

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core; a fibrous conductive member disposed to be rotatable while maintaining a contact with the developer holder; and a constraining member including a non-conductive portion disposed for abutment against the developer holder and also including a conductive portion on the opposite side, the constraining member controlling the thickness of a thin layer of developer formed on the developer holder and charging the developer to a given level; a high voltage being applied to each of the developer holder, the fibrous conductive member and the conductive portion of the constraining member.

Claim 28

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core; a fibrous conductive member disposed to be rotatable while maintaining a contact with the developer holder; and a constraining member including a non-conductive portion disposed for abutment against the developer holder and also including a conductive portion on the opposite side, the constraining member controlling the thickness of a thin layer of developer formed on the developer holder and charging the developer to a given level; a high voltage being applied to each of the developer holder, the fibrous conductive member and the conductive portion of the constraining member.

Claim 29

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core having a coating of conductive resin layer thereon; a porous conductive resilient member disposed to be rotatable while maintaining a contact with the developer holder; and a constraining member including a non-conductive portion disposed for abutment against the developer holder and also including a conductive portion on the opposite side, the constraining member controlling the thickness of a thin layer of developer formed on the developer holder and charging the developer to a given level; a high voltage being applied to each of the metal core of the developer holder, the porous conductive resilient member and the conductive portion of the constraining member.

Claim 30

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core having a coating of conductive resin layer thereon; a porous conductive resilient member disposed to be rotatable while maintaining a contact with the developer holder; and a constraining member including a non-conductive portion disposed for abutment against the developer holder and also including a conductive portion on the opposite side, the constraining member controlling the thickness of a thin layer of developer formed on the developer holder and charging the developer to a given level; a high voltage being applied to each of the metal core of the developer holder, the porous conductive resilient member and the conductive portion of the constraining member.

Claim 31

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core having a coating of conductive resin layer thereon; a fibrous conductive member disposed to be rotatable while maintaining a contact with the developer holder; and a constraining member including a non-conductive portion disposed for abutment against the developer holder and also including a conductive portion on the opposite side, the constraining member controlling the thickness of a thin layer of developer formed on the developer holder and charging the developer to a given level; a high voltage being applied to each of the metal core of the developer holder, the fibrous conductive member and the conductive portion of the constraining member.

Claim 32

A developer unit in which a non-magnetic single component developer is supplied to the surface of a developer holder and is formed into a uniform thin layer thereon by means of a constraining member, and in which a developing bias is applied to the developer holder to cause the developer to fly to an image area of an electrostatic latent image formed on a latent image carrier which is disposed in opposing relationship with the developer holder with a gap therebetween, comprising a developer holder formed of a metal core having a coating of conductive resin layer thereon; a fibrous conductive member disposed to be rotatable while maintaining a contact with the developer holder; and a constraining member including a non-conductive portion disposed for abutment against the developer holder and also including a conductive portion on the opposite side, the constraining member controlling the thickness of a thin layer of developer formed on the developer holder and charging the developer to a given level; a high voltage being applied to each of the metal core of the developer holder, the fibrous conductive member and the conductive portion of the constraining member.