Electrostatic developing system with cylindrical drum liquid contact unit

Claim 2

The liquid developing system of claim 1 including means for advancing the image-bearing surface tangentially to the foraminous suRface.

Claim 3

The liquid developer system of claim 3 wherein the cylindrical drum comprises a foraminous surface supported on an inner support having a helical groove for receiving liquid developer from the foraminous surface.

Claim 4

The liquid developer system of claim 1 including means for varying the spacing between the support means and drum.

Claim 5

The liquid developer system of claim 1 including means for distributing liquid developer onto an upper surface of the drum.

Claim 6

The liquid developer system of claim 1 wherein the foraminous surface consists essentially of an electrically-conductive material thereby providing an integral field shaping means.

Claim 7

The liquid developer system of claim 7 wherein the foraminous surface consists essentially of a metal structure having electrically interconnected land areas with discrete openings to provide liquid reservoirs in the interstitial areas between the metal land areas.

Claim 8

The liquid developer system of claim 8 wherein the superficial ratio of land area to open area is about 1:9 to 9:1.

Claim 9

The liquid developer system of claim 7 wherein the foraminous surface consists essentially of a woven metal-containing cloth fabric screen of about 40 to 400 mesh.

Claim 10

In a liquid developing system wherein a flexible web or sheet carrying a latent electrostatic image on one surface is contacted with a liquid developer having developer particles suspended in a liquid carrier, the improvement which comprises: a rotary cylindrical drum intensifier having a substantially uniform electrically-conductive surface with openings sufficiently large to pass developer particles and a foraminous surface forming reservoirs for carrying liquid developer; means for advancing the sheet or web downwardly toward the drum in a tangential direction with the surface carrying the latent image in facing contact with the drum; means for distributing liquid developer onto an upper surface of the drum to provide liquid developer between the drum and the web or sheet and to fill the reservoirs on the foraminous surface with liquid developer; support means spaced apart from the drum for guiding the flexible web or sheet around the drum, thereby forming a trough with the web or sheet for containing excess liquid developer and maintaining contact of developer with the surface carrying the latent image only; a developer tank positioned under the drum for receiving liquid developer; and means for removing excess liquid developer through the openings of the drum intensifier and flowing the excess liquid developer outwardly from the web or sheet surface into the developer tank; and means for separating the web or sheet bearing a developed image from the drum.

Claim 11

The liquid developing system of claim 11 wherein the support means comprises a plurality of curved ribs spaced apart from the drum providing a contact angle for the web or sheet under the drum of about 90* to 190*.

Claim 12

The liquid developing system of claim 11 including means for distributing liquid developer from the developer tank above the drum between the foraminous surface and the web or sheet.

Claim 13

The liquid developing system of claim 13 wherein the drum has a surface liquid carrying capacity of at least about 0.04 ml/cm2.

Claim 14

The liquid developing system of claim 11 wherein the openings on the drum intensifier are about 35 to 450 microns in size.

Claim 15

The liquid developing system of claim 15 wherein the foraminous surface consists essentially of a metal structure having electrically interconnected land areas with discrete openings to provide liquid reservoirs in the interstitial areas between the metal land areas, and wherein the superficial ratio of land area to open area is about 1:9 to 9:1.