Belt transfer system

Claim 2

In an electrostatographic copying system in which an image is formed on an imaging surface and transferred at a transfer station to a copy sheet by electrical transfer fields generated by electrical transfer means, the improvement comprising: copy sheet transport means including a copy sheet supporting belt, said supporting belt having a multiplicity of integral electrically discrete closely spaced adjacent conductors forming an extensive pattern over said belt; support means for moving said supporting belt intimately past said imaging surface at said transfer station; and biased electrode means for differentially electrically charging adjacent said conductors of said supporting belt for generating over said supporting belt a fine charge pattern of alternating closely adjacent differentially charged areas providing copy sheet retaining electrical fringe fields; the spacing of said conductors being sufficiently close so that said image transfer at said transfer station is unaffected by said charge pattern of electrical fringe fields.

Claim 3

The copying system of claim 1 wherein said spacing between said adjacent conductors is not substantially greater than the thickness of said copy sheet.

Claim 4

The copying system of claim 1 wherein said spacing between said adjacent conductors is less than approximately 0.13 millimeters.

Claim 5

The copying system of claim 1 wherein said electrical transfer means comprises a plurality of electrically biased transfer electrodes at said transfer station, all of which are mounted in fixed spaced positions relative to said imaging surface independently of the position of said belt or said copy sheet, and wherein said transfer electrodes are electrically isolated from said conductors in said belt, so as to provide a constant transfer field gap with said imaging surface.

Claim 6

The copying system of claim 4 wherein there are three of said transfer electrodes, spaced apart and differently biased and positioned at a prenip, nip, and postnip areas of said transfer station respectively, and wherein said supporting belt passes freely between said transfer electrodes and said imaging surface.

Claim 7

The copying system of claim 1 wherein said electrical transfer means comprises a set of differently biased contactor means electrically connecting different electrical biases sequentially to selected said conductors of said belt with movement of said belt at said transfer station to provide tailored transfer fields between said selected conductors and said imaging surface.

Claim 8

In an electrostatographic copying system in which an image is formed on an imaging surface and transferred at a transfer station to a copy sheet by electrical transfer fields generated by electrical transfer means, the improvement comprising: copy sheet transport means including a copy sheet supporting belt; said supporting belt having a multiplicity of integral electrically discrete closely spaced adjacent conductors forming an extensive pattern over said belt; support means for moving said supporting belt intimately past said imaging surface at said transfer station; and biased electrode means for differentially electrically charging adjacent said conductors of said supporting belt for generating over said supporting belt a fine charge pattern of alternating closely adjacent differentially charged areas providing copy sheet retaining electrical fringe fields; wherein said electrical transfer means comprises a set of differently biased contactor means electrically connecting different electrical biases sequentially to selected conductors of said belt with movement of said belt at said transfer station to provide tailored transfer fields between said selected conductors and said imaging surface.

Claim 9

In an electrostatographic copying system in which an image is formed on an imaging surface and transferred at a transfer station to a copy sheet by electrical transfer fields generated by electrical transfer means, the improvement comprising: copy sheet transport means including a copy sheet supporting belt; said supporting belt having a multiplicity of integral electrically discrete closely spaced adjacent conductors forming an extensive pattern over said belt; support means for moving said supporting belt intimately past said imaging surface at said transfer station; and biased electrode means for differentially electrically charging adjacent said conductors of said supporting belt for generating over said supporting belt a fine charge pattern of alternating closely adjacent differentially charged areas providing copy sheet retaining electrical fringe fields; wherein said electrical transfer means comprises a set of differently biased contactor means electrically connecting different electrical biases sequentially to selected conductors of said belt with movement of said belt at said transfer station to provide tailored transfer fields between said selected conductors and said imaging surface.

Claim 10

The copying system of claim 7 wherein said transfer electrode means comprises at least three fixed and spaced apart electrical contact members making said electrical connections sequentially with said conductors as said conductors move with said belt through said transfer station.

Claim 11

The copying system of claim 7 wherein said conductors are interconnected by electrical resistance material on said belt which smoothly distributes said electrical bias applied by said electrical contact members to said conductors.

Claim 12

The copying system of claim 7 wherein said electrical contact members are in commonly biased pairs at opposite sides of said belt.

Claim 13

The copying system of claim 8 wherein said contact members are spaced apart along said belt by a multiplicity of said conductors.

Claim 14

The copying system of claim 9 wherein said resistive material extends along at least one edge of the belt, and said electrical contact members contact said resistive material whereby said resistive material provides a series resistance between said electrical contact members and said conductors.