Development system with electrical field generating means

Claim 3

An apparatus as recited in claim 1, wherein said depositing means includes: a magnetic member; and a non-magnetic tubular member interposed telescopically over said magnetic member and being spaced from the latent image to define a gap therebetween.

Claim 4

An apparatus as recited in claim 2, wherein said generating means includes a voltage source.

Claim 5

An apparatus as recited in claim 3, wherein said voltage source applies a peak voltage ranging from about 20 to about 100 volts per micron of gap.

Claim 6

An apparatus as recited in claim 4, wherein said voltage source applies an alternating voltage having a frequency ranging from about 500 hertz to about 5,000 hertz.

Claim 7

An apparatus as recited in claim 3, wherein said voltage source is electrically coupled to said tubular member.

Claim 8

An electrophotographic printing machine of the type having an electrostatic latent image recorded on a photoconductive member, wherein the improvement includes: means for depositing particles having the resistivity thereof varying as a function of the electrical field applied thereto on the latent image; and means for generating an electrical field between the photoconductive member and said depositing means, said generating means forming a constant electrical field with an alternating electrical field superimposed thereover with the alternating electrical field having a peak amplitude sufficient to render the particles substantially conductive.

Claim 9

An electrophotographic printing machine of the type having an electrostatic latent image recorded on a photoconductive member, wherein the improvement includes: means for depositing particles having the resistivity thereof varying as a function of the electrical field applied thereto on the latent image; and means for generating an electrical field between the photoconductive member and said depositing means, said generating means forming a constant electrical field with an alternating electrical field superimposed thereover with the alternating electrical field having a peak amplitude sufficient to render the particles substantially conductive.

Claim 10

A printing machine as recited in claim 7, wherein said depositing means includes: a magnetic member; and a non-magnetic tubular member interposed telescopically over said magnetic member and being spaced from the latent image recorded on the photoconductive member to define a gap therebetween.

Claim 11

A printing machine as recited in claim 8, wherein said generating means includes a voltage source.

Claim 12

A printing machine as recited in claim 8, wherein said voltage source applies a peak voltage ranging from about 20 to about 100 volts per micron of gap.

Claim 13

A printing machine as recited in claim 10, wherein said voltage source applies an alternating voltage having a frequency ranging from about 500 hertz to about 5,000 hertz.

Claim 14

A printing machine as recited in claim 9, wherein said voltage source is electrically coupled to said tubular member.

Claim 15

A printing machine as recited in claim 7, further including means, positioned remotely from said generating means, for transferring the particles from the latent image recorded on the photoconductive member to a sheet of support material, said transferring means being sufficiently remote from said generating means so that the particles are substantially resistive.

Claim 16

A printing machine as recited in claim 13, further including means for substantially permanently affixing the particles to the sheet of support material.