Apparatus for developing electrostatic latent image

Claim 2

Apparatus for developing an electrostatic latent image on an electrophotographic sheet of material optionally having an electroconductive backing layer, said apparatus comprising: a developing electrode disposed adjacent to and spaced from said electrophotographic sheet of material; means for providing a developing liquid between said developing electrode and said electrophotographic sheet of material to develop said electrostatic latent image; resistive means for connecting either or both of said developing electrode and said electroconductive backing layer to a reference potential, the resistance of said resistance means being in the range of 106 to 1012 ohms, to prevent excessive background fogging and image streaking during development of said latent image.

Claim 3

Apparatus as in claim 1 wherein said reference potential is 0 volts.

Claim 4

Apparatus as in claim 1 including means for effecting relative movement between said electrophotographic sheet of material and said developing electrode.

Claim 5

Apparatus as in claim 3 including a container for storing said developing liquid and where said means for effecting relative movement between said electrophotographic sheet of material and said developing electrode includes an endless belt driven around a pair of rollers, said electrophotographic sheet being disposed on said belt for movement with respect to said developing electrode and said endless belt being inclined by an angle of about 5* to 20* with respect to the horizontal plane and where said means for providing said developing liquid between said electrophotographic sheet and said developing electrode is disposed adjacent the upper end of said endless belt to introduce said developing liquid between said electrophotographic sheet and said developing electrode so that it flows therebetween and then to said container for said developing liquid which is disposed beneath the lower end of said endless belt.

Claim 6

Apparatus as in claim 3 including a container for said developing liquid, said developing electrode being disposed in said developing liquid and where said means for effecting said relative movement between said electrophotographic sheet and said developing electrode includes a rotatably driven Drum having disposed around a portion thereof said electrophotographic sheet, said portion being partially disposed in said developing liquid and adjacent said developing electrode.

Claim 7

Apparatus as in claim 3 including a first plurality of drive rollers disposed at one side of said electrophotographic sheet and where said developing electrode includes a second plurality of drive rollers respectively disposed adjacent said first plurality of drive rollers at the other side of said electrophotographic sheet, said first and second plurality of drive rollers moving said electrophotographic sheet therebetween.

Claim 8

Apparatus as in claim 6 including a shaft for each of said second plurality of rollers and a bearing for each of said shafts.

Claim 9

Apparatus as in claim 7 where said resistive means is disposed on the sides of said bearing and in electrical connection with said shaft and said bearing being connected to said reference potential.

Claim 10

Apparatus as in claim 7 where at least the outer portion of said shaft comprises said resistance means, said shaft being in electric contact with said bearing and said bearing being maintained at said reference potential.

Claim 11

Apparatus as in claim 3 including a container for said developing liquid and for a second liquid having a larger specific gravity than and immiscible with said developing liquid and where said developing electrode is disposed in said second liquid and where said means for effecting relative movement between said electrophotographic sheet and said developing electrode comprises a rotatably driven drum having disposed around a portion thereof said electrophotographic sheet, said portion being disposed completely in said developing liquid and partially in said second liquid whereby said developing liquid is dragged between said drum and said developing electrode due to the rotation of said drum to thereby effect said developing.

Claim 12

Apparatus as in claim 3 including a container for said developing liquid and an electrically conductive liquid having a larger specific gravity than and immiscible with said developing liquid, said electrically conductive liquid acting as said developing electrode and where means for effecting said relative movement between said electrophotographic sheet and said developing electrode comprises a rotatably driven drum having disposed around a portion thereof said electrophotographic sheet, said portion being completely disposed in said developing liquid and partially disposed in said electrically conductive liquid.