Michael L Levin

US Patent:

50513290, Sep 24, 1991

Filed:

Dec 19, 1989

Appl. No.:

7/452994

Inventors:

Edward B. Caruthers - West Chester PA
Michael L. Levin - Downingtown PA
Catharine E. Looney - Centerville DE
Steven P. Schmidt - Chester Springs PA
Dana S. Smith - Wilmington DE

Assignee:

DXImaging - Lionville PA

International Classification:

G03G 1310

US Classification:

430100

Abstract:

Process for reversal development of a latent electrostatic image in a layer on a conductive support by developing with an electrostatic developer having electrostatically charged toner particles by (a) generating imagewise areas in the layer having different rates of charge decay and/or charge acceptance, (b) charging the layer, (c) allowing formation of an electrostatic image corresponding to the imagewise generated areas by differential charge decay and/or charge acceptance, (d) creating an electrical field to attract toner particles preferentially to the areas of lesser charge, and (e) developing the areas of lesser charge with electrostatically charged toner particles having the same polarity as that of the charged layer. The developed image can be transferred to a receptor surface, e. g. , paper. The process is useful with many type photosensitive masters in preparing reversal images with the use of only one master, toner and film original.