Electrophotographic copying arrangement

Claim 2

Electrophotographic copying arrangement comprising, in combination, transporting means having a movable surface; means for forming on said surface a latent image; developing means for applying a powder to said latent image to form a powder image on said surface; means for feeding a chargeable copy carrier to said surface in the region of said powder image; a transfer charging device emitting a first ion stream toward said copy carrier for charging said copy carrier with a first charge having a first polarity so that said powder image is transferred to said charged copy carrier and an electrostatic force attracts said charged copy carrier to said surface; and a compensating charging device emitting a second ion stream toward said copy carrier for charging said charged copy carrier during passage of said compensating charging device by said copy carrier with a second charge having a second polarity opposite to said first polarity and being substantially equal to said first charge produced by said first ion stream during passage of said transfer charging device by said copy carrier for at least substantially neutralizing said first charge so that said copy carrier does not adhere to said surface of said transporting means.

Claim 3

Copying arrangement as claimed in claim 1 wherein said transfer charging device includes first throttling means for throttling said first ion stream; wherein said compensating charging device includes second throttling means for throttling said second ion stream to a greater degree than said first ion stream is throttled by said first throttling means.

Claim 4

Copying arrangement as claimed in claim 2 wherein said means for forming a latent image include a third charging device emitting a third ion stream directed at said surface for producing a charged area thereon, and including third throttling means for throttling said third ion stream to a lesser degree than said second throttling means throttles said second ion stream, and means for projecting an image onto said charged area.

Claim 5

Copying arrangement as claimed in claim 1 wherein said transfer charging device includes a first throttling slot for throttling said first ion stream; wherein said compensating charging device includes a second throttling slot narrower than said first throttling slot for throttling said second ion stream to a greater degree than said first ion stream is throttled by said first throttling slot.

Claim 6

Copying arrangement as claimed in claim 1 wherein said transfer charging device includes first throttling means for throttling said first ion stream; wherein said compensating charging device includes second throtTling means for throttling said second ion stream to a greater degree than said first ion stream is throttled by said first throttling means; and comprising means for applying equal voltages of opposite polarity to said transfer charging device and said compensating charging device, respectively.

Claim 7

Electrophotographic copying arrangement comprising, in combination, transporting means having a movable surface; means for forming on said surface a latent image; developing means for applying a powder to said latent image to form a powder image on said surface; means for feeding a chargeable copy carrier to said surface in the region of said powder image; a transfer charging device disposed at a first distance from said copy carrier for charging said copy carrier with a first charge having a first polarity so that said powder image is transferred to said charged copy carrier and an electrostatic force attracts said charged copy carrier to said surface; and a compensating charging device disposed at a second distance from said copy carrier for charging said charged copy carrier with a second charge having a second polarity opposite to said first polarity for at least substantially neutralizing said first charge so that said copy carrier does not adhere to said surface of said transporting means. Said second distance being greater than said first distance whereby the same voltage applied to said charging devices produces a lesser second charge.

Claim 8

Electrophotographic copying arrangement comprising, in combination, transporting means having a movable surface; means for forming on said surface a latent image; developing means for applying a powder to said latent image to form a powder image on said surface; means for feeding a chargeable copy carrier to said surface in the region of said powder image; a transfer charging device disposed at a first distance from said copy carrier for charging said copy carrier with a first charge having a first polarity so that said powder image is transferred to said charged copy carrier and an electrostatic force attracts said charged copy carrier to said surface; and a compensating charging device disposed at a second distance from said copy carrier for charging said charged copy carrier with a second charge having a second polarity opposite to said first polarity for at least substantially neutralizing said first charge so that said copy carrier does not adhere to said surface of said transporting means. Said second distance being greater than said first distance whereby the same voltage applied to said charging devices produces a lesser second charge.

Claim 9

Copying arrangement as claimed in claim 6 comprising a transformer adapted to be connected to a source of alternating voltage; first and second rectifiers connected with said transformer to block negative pulses and positive pulses, respectively, said first and second rectifiers being, respectively, connected with said transfer charging device and with said compensating charging device so that said transfer charging device produces a positive first charge and said compensating charging device produces a negative second charge of said copy carrier.

Claim 10

Electrophotographic copying arrangement comprising, in combination, transporting means including a rotary cylinder having a peripheral surface moving in one direction; means for forming on said surface a latent image; developing means for applying a powder to said latent image to form a powder image on said surface; means for feeding chargeable copy carrier to said surface; a transfer charging device for charging said copy carrier with a first charge having a first polarity, said feeding means feeding said copy carrier to said surface in the region of said transfer charging device so that said powder image is transferred to said charged copy carrier and an electrostatic force attracts said charged copy carrier to said surface; a compensating charging device disposed following said transfer charging device in said one direction for charging said charged copy carrier with a second charge having a second polarity opposite to said first polarity for at least substantially neutralizing said first charge so that said copy carrier does not adhere to said surface of said transporting means; and blower means for blowing a low pressure stream of air toward the leading edge of said copy carrier and past said compensating charging device.

Claim 11

Electrophotographic copying arrangement comprising, in combination, transporting means including a rotary cylinder having a peripheral surface moving in one direction; means for forming on said surface a latent image; developing means for applying a powder to said latent image to form a powder image on said surface; means for feeding chargeable copy carrier to said surface; a transfer charging device for charging said copy carrier with a first charge having a first polarity, said feeding means feeding said copy carrier to said surface in the region of said transfer charging device so that said powder image is transferred to said charged copy carrier and an electrostatic force attracts said charged copy carrier to said surface; a compensating charging device disposed following said transfer charging device in said one direction for charging said charged copy carrier with a second charge having a second polarity opposite to said first polarity for at least substantially neutralizing said first charge so that said copy carrier does not adhere to said surface of said transporting means; and blower means for blowing a low pressure stream of air toward the leading edge of said copy carrier and past said compensating charging device.

Claim 12

Electrophotographic copying arrangement comprising, in combination, transporting means having a movable surface; means for forming on said surface a latent image; developing means for applying a powder to said latent image to form a powder image on said surface; means for feeding a chargeable copy carrier to said surface; a transfer charging device for charging said copy carrier with a first charge having a first polarity, said feeding means feeding said copy carrier to said surface in the region of said transfer charging device so that said powder image is transferred to said charged copy carrier and an electrostatic force attracts said charged copy carrier to said surface; and a compensating charging device for charging said charged copy carrier with a second charge having a second polarity opposite to said first polarity for at least substantially neutralizing said first charge so that said copy carrier does not adhere to said surface of said transporting means; and blower means for blowing a low pressure stream of air toward the copy carrier on said surface for separating the same from said surface.

Claim 13

Electrophotographic copying arrangement comprising, in combination, transporting means having a movable surface; means for forming on said surface a latent image; developing means for applying a powder to said latent image to form a powder image on said surface; means for feeding a chargeable copy carrier to said surface; a transfer charging device for charging said copy carrier with a first charge having a first polarity, said feeding means feeding said copy carrier to said surface in the region of said transfer charging device so that said powder image is transferred to said charged copy carrier and an electrostatic force attracts said charged copy carrier to said surface; and a compensating charging device for charging said charged copy carrier with a second charge having a second polarity opposite to said first polarity for at least substantially neutralizing said first charge so that said copy carrier does not adhere to said surface of said transporting means; and blower means for blowing a low pressure stream of air toward the copy carrier on said surface for separating the same from said surface.

Claim 14

Electrophotographic copy arrangement comprising, in combination, transporting means having a movable surface; means for forming on said surface a latent image; developing means for applying a powder to said latent image to form a powder image on said surface; means for feeding a chargeable copy carrier to said surface in the region of said powder image; a transfer charging device for charging said copy carrier with a first charge having a first polarity so that said powder image is transferred to said charged copy carrier and an electrostatic force attracts said charged copy carrier to said surface; a compensating charging device emitting an ion stream toward said copy carrier for charging said charged copy carrier with a second charge having a second polarity opposite to said first polarity for at least substantially neutralizing said first charge so that said copy carrier does not adhere to said surface of said transporting means; and blower means for blowing a low pressure stream of air past said compensating charging device toward said fed copy carrier and into said ion stream so as to displace said ion stream for separating said copy carrier from said surface, the pressure of said stream of air being insufficient to produce mechanical separation of said copy carrier from said surface.

Claim 15

Electrophotographic copy arrangement comprising, in combination, transporting means having a movable surface; means for forming on said surface a latent image; developing means for applying a powder to said latent image to form a powder image on said surface; means for feeding a chargeable copy carrier to said surface in the region of said powder image; a transfer charging device for charging said copy carrier with a first charge having a first polarity so that said powder image is transferred to said charged copy carrier and an electrostatic force attracts said charged copy carrier to said surface; a compensating charging device emitting an ion stream toward said copy carrier for charging said charged copy carrier with a second charge having a second polarity opposite to said first polarity for at least substantially neutralizing said first charge so that said copy carrier does not adhere to said surface of said transporting means; and blower means for blowing a low pressure stream of air past said compensating charging device toward said fed copy carrier and into said ion stream so as to displace said ion stream for separating said copy carrier from said surface, the pressure of said stream of air being insufficient to produce mechanical separation of said copy carrier from said surface.