Abstract Methods and apparatus for electrostatic printing including a multilayer screen having a conductive layer and an insulative layer and having apertures therein, means for deploying opposite electrostatic charges across the insulative layer, an imageprojecting system for discharging the insulative layer in accordance with light received thereby, a Corotron or other like means for projecting ions through unblocked apertures in the screen and through partially blocked apertures in the screen in fewer numbers to the insulative layer of a second multilayer screen, and either a Corotron or other like means for projecting ions through the second screen to a substrate for subsequent developing and fixing, or means for projecting charged marking material through the second screen to a substrate for fixing thereon to provide positive reproductions.
The apparatus of claim 1 wherein the means for directing charged particles and the means for projecting charged particles comprise ion sources.
Claim 2
Dependent Claim
29 words
The apparatus of claim 1 wherein the means for directing charged particles comprises an ion source and the means for projecting charged particles comprises a source of marking material.
Claim 3
Dependent Claim
78 words
The apparatus of claim 1 wherein the means for modifying the charges of the first screen means in accordance with an image comprises image light projection means which permit the dissipation of the charges in the areas of light impingement; and the means for directing charged particles toward the first screen means are oriented relative to the screen means to project charged particles of opposite sign to the charges on the side of the screen means adjacent thereto.
Claim 4
Dependent Claim
73 words
The apparatus of claim 1 wherein the means for modifying the charges of the first screen means in accordance with an image comprises image light projection means which permit the dissipation of the charges in the areas of light imPingement; and the means for directing charged particles from a further source are polarized to project charged particles of opposite sign to the charges on the side of the second screen means adjacent thereto.
Claim 5
Dependent Claim
70 words
The apparatus of claim 1 wherein the means for charging comprises a source of negative ions disposed adjacent to the insulative screen layer; the means for directing charged particles comprises a source of negative ions disposed adjacent to the conductive screen layer; and the means for projecting charged particles from a further source comprises a source of negative ions disposed adjacent to the conductive layer of the second screen means.
Claim 6
Dependent Claim
73 words
The apparatus of claim 1 wherein the means for charging comprises a source of negative ions disposed adjacent to the insulative screen layer; the means for directing charged particles comprises a source of negative ions disposed adjacent to the conductive screen layer; and the means for projecting charged particles from a further source comprises a source of inking material charged negatively and disposed adjacent to the conductive layer of the second screen means.
Claim 7
Dependent Claim
32 words
The apparatus of claim 1 wherein the first and second screen means are oriented to dispose their respective insulative layers to define the air gap between said first and second screen means.
Claim 8
Dependent Claim
123 words
Apparatus for electrostatic reproducing comprising in combination composite screen means supported for movement along predetermined paths, said screen means each comprising an insulative screen layer and a conductive screen layer; means for electrically charging the insulative layer of the first conveyor with substantially equal and opposite charges; means for modifying the charges of the first screen means in accordance with an image to be reproduced; means for directing ions toward the first screen means in the regions of modified charges to permit selective passage of ions to a second screen means across an air gap; means for projecting particles from a further source through the second screen means onto print-receiving means across a further air gap; and means for developing the print-receving means.