Method and apparatus electrostatically classifying toner particles

Claim 3

The method of claim 1 further comprising the step of collecting the particles attracted to said conductive surface.

Claim 4

The method of claim 1 wherein said step of exposing and said step of placing said second charge are performed simultaneously.

Claim 5

The method of claim 1 further comprising the step of placing a second bias potential of a different magnitude than said predetermined bias potential upon a second conductive surface located a predetermined distance from said first conductive surface whereas particles of a second or more range of sizes of particles are attracted to said second or more conductive surfaces from said first conductive surface for a further classification of said particles.

Claim 6

The method of claim 1 further comprising the step of varying the magnitude of one of said second charge or said bias potential to selectively vary the range of sizes of said particles attracted to said conductive surface.

Claim 7

The method of claim 1 further comprising the step of varying the distance between said photoconductive surface and said conductive surface to alter the range of sizes of said particles attracted to said conductive surface.

Claim 10

The method of claim 7 wherein the surface of the support member on which the particle layer is formed is electrically conductive.

Claim 11

The method of claim 7 wherein the surface of the support member on which the particle layer is formed includes a photoconductive insulating material and further including the step of exposing particle layer to light simultaneously with the depositing of electrostatic charge on the particle layer.

Claim 12

The method of claim 7 wherein the surface of the support member on which the particle layer is formed includes a photoconductive insulating material and further including the step of exposing the particle layer to light subsequent to depositing electrostatic charge on the particle layer.

Claim 13

The method of claim 7 further including classifying the particles separated from the particle layer to the separation member by steps including moving the separated particles on the seParation member from the vicinity of the support member, spacing a third electrically conductive member a predetermined distance from the separated particles on the separation member, and coupling an electrical bias of a third potential to the third member whereby the magnitude of the charge on the separate particles, the difference between the second and third potentials and the spacing between the separation and third members establish the size particle attracted to the third member for further classification of the particles.

Claim 14

The method of claim 11 further including depositing electrostatic charge onto the separated particles on the separation member prior to spacing the third member adjacent the separated particles.

Claim 15

Apparatus for classifying according to size electroscopic toner particles composed of the same material comprising a xerographic plate surface including a photoconductive surface said plate being coupled to an electrical bias of a first potential, first charging means for depositing electrostatic charge of a first polarity on a surface of said support member, development means for forming a particle layer of charged toner particles of a second polarity opposite the first on the charged surface of said support member, second charging mean for depositing electrostatic charge of the second polarity on said particle layer formed on the support member, exposure means for exposing said charged particle layer to light and an electrically conductive separation member coupled to an electrical bias of a second potential and adapted to be spaced a predetermined distance from a charged and exposed particle layer whereby the magnitude of the charge of second polarity, the difference between the first and second potentials and the spacing between the support and separation members establish the size particle separated from the particle layer on the support member.

Claim 16

Apparatus for classifying according to size electroscopic toner particles composed of the same material comprising a xerographic plate surface including a photoconductive surface said plate being coupled to an electrical bias of a first potential, first charging means for depositing electrostatic charge of a first polarity on a surface of said support member, development means for forming a particle layer of charged toner particles of a second polarity opposite the first on the charged surface of said support member, second charging mean for depositing electrostatic charge of the second polarity on said particle layer formed on the support member, exposure means for exposing said charged particle layer to light and an electrically conductive separation member coupled to an electrical bias of a second potential and adapted to be spaced a predetermined distance from a charged and exposed particle layer whereby the magnitude of the charge of second polarity, the difference between the first and second potentials and the spacing between the support and separation members establish the size particle separated from the particle layer on the support member.