Electrostatic imaging system

An apparatus for electrostatically reproducing a selected image comprising:

• a rotatable photoconducting drum;
• endless interposer means belted about said drum and adapted to movably contact portions thereof;
• first charge means for applying a first charge of a selected polarity to an area of said drum;
• optical means for applying a light and shadow representation of said selected image to said area to said drum;
• second charge means for applying a second charge of opposite polarity from said first charge, to a portion of said interposer means in contact with said area of said drum, the second charge being retained on the interposer according to the light and shadow representation and the first charge effectively transferring from the photoconducting drum to the interposer when the interposer moves out of contact with the drum;
• development fluid dispensing means adapted to pass a quantity of development fluid corresponding to said light and shadow representation applied by said optical means to said portion of said interposer means when moved out of contact with said drum;
• a pressure roller, adapted to urge said interposer means into contact with a copy medium for transferring said development fluids thereto;
• discharge means adapted to remove residual charges of said first charge from said drum prior to the application of another light and shadow representation on said area of said drum;
• and
• means for removing excess development fluid from said interposer means after said image is reproduced on a copy medium.

A method for electrostatically reproducing a selected image comprising the steps of:

• a. applying a first charge having a selected polarity to an area on a photoconducting drum;
• b. applying a light and shadow representation of said image to said area on said drum;
• c. applying a second charge, of opposite polarity from that of said first charge, to a portion of an interposer movably superimposed over said area on said drum, the second charge being retained on the interposer according to the light and shadow representation and the first charge effectively transferring from the photoconducting drum to the interposer when the interposer moves out of contact with the drum and leaving residual charges on the drum;
• d. moving said portion of said interposer out of superimposition with said drum;
• e. applying a quantity of development fluid, corresponding to said light and shadow representation, to said interposer;
• and
• f. transferring said development fluid from said interposer to a copying medium.