Corona discharge device

Claim 2

A charging apparatus for use in such apparatus as electrophotographic mechanisms for depositing increments of charge on a charge-bearing surface, said apparatus comprising a corona discharge wire held in spaced relationship to said surface; a pair of bias rods each positioned in substantially the same spaced relationship to said surface as said corona discharge wire; means for holding one of said bias rods in fixed position on each side of said wire; and means to impress an electrical voltage potential on said wire and rods whereby said rods effect a virtual ground plane extending to the surface to enhance the charge flow from said wire to said surface.

Claim 3

The charging apparatus according to claim 1 wherein said bias rods are positioned parallel to said corona discharge wire.

Claim 4

The charging apparatus according to claim 2 wherein said bias rods and said corona discharge wire are included in a plane substantially parallel to said charge-bearing surface.

Claim 5

The charging apparatus according to claim 1 wherein said electrical voltage potential on said corona discharge wire comprises a potential in the range of 6 to 8 kilovolts and the electric voltage potential on said bias rods comprises a range from substantially ground potential to one quarter of the corona wire potential.

Claim 6

The charging apparatus according to claim 1 wherein said electrical voltage potential on said corona wire comprises a potential of 7 kilovolts and the electrical voltage potential on said bias rods comprises substantially ground potential.

Claim 7

A charging apparatus for use in such apparatus as electrophotographic mechanisms for depositing increments of charge on a charge-bearing surface, said apparatus comprising: a corona discharge wire held in spaced relationship to said surface; a pair of bias rods positioned in substantially the same spaced relationship to said surface as said corona discharge wire; means for holding one of said bias rods in fixed position on each side of said wire; a suppressor screen positioned in spaced relationship intermediate said wire and said charge-bearing surface; and means to impress a first relatively high electrical voltage potential on said wire, a second relatively lower electrical voltage potential on said rods and a third electric voltage potential relatively lower than said second potential on said suppressor screen, whereby the charge flow from said wire to said surface is enhanced.

Claim 8

A charging apparatus for use in such apparatus as electrophotographic mechanisms for depositing increments of charge on a charge-bearing surface, said apparatus comprising: a corona discharge wire held in spaced relationship to said surface; a pair of bias rods positioned in substantially the same spaced relationship to said surface as said corona discharge wire; means for holding one of said bias rods in fixed position on each side of said wire; a suppressor screen positioned in spaced relationship intermediate said wire and said charge-bearing surface; and means to impress a first relatively high electrical voltage potential on said wire, a second relatively lower electrical voltage potential on said rods and a third electric voltage potential relatively lower than said second potential on said suppressor screen, whereby the charge flow from said wire to said surface is enhanced.

Claim 9

The charging apparatus according to claim 6 wherein said bias rods are positioned parallel to said corona discharge wire.

Claim 10

The charging apparatus according to claim 7 wherein said bias rods and said corona discharge wire are included in a first plane substantially parallel to said charge-bearing surface and spaced a first distance therefrom; and said suppressor screen is included in a second plane parallel to said first plane and said charge-bearing surface, said second plane being located a closer distance to said charge-bearing surface than said first distance.

Claim 11

A charging apparatus for use in such apparatus as electrophotographic mechanisms for depositing increments of charge on a charge-bearing surface, said apparatus comprising: a plurality of corona discharge wires held in spaced relationship to said surface; a plurality of bias rods each positioned in substantially the same spaced relationship to said surface as said corona diScharge wires; means for holding one of said bias rods in flanking relation on each side of each of said wires; and means to impress an electrical voltage potential on said wires and rods whereby said rods effect a virtual ground plane extending to the surface to enhance the charge flow from said wires to said surface.

Claim 12

A charging apparatus for use in such apparatus as electrophotographic mechanisms for depositing increments of charge on a charge-bearing surface, said apparatus comprising: a plurality of corona discharge wires held in spaced relationship to said surface; a plurality of bias rods each positioned in substantially the same spaced relationship to said surface as said corona diScharge wires; means for holding one of said bias rods in flanking relation on each side of each of said wires; and means to impress an electrical voltage potential on said wires and rods whereby said rods effect a virtual ground plane extending to the surface to enhance the charge flow from said wires to said surface.