Patent ID: 6167228
Filing Date: 2000-12-26
Classification: G03G

Abstract:
In a development system for developing a latent image being composed of solid areas and fine line areas on an imageable surface with developer material comprising:a housing containing developer material;a first magnetic roll, spaced a first predefined distance from said image, for transporting said developer material from said housing to develop primarily solid areas of said image, said magnetic roll including a magnetic assembly and a cylindrical sleeve enclosing and rotating about said magnetic assembly;a second magnetic roll, spaced a second predefined distance from said image, said second predefined distance being substantially less than said first predefined distance, for transporting said developer material from said housing to develop primarily fine line areas of said image, said magnetic roll including a magnetic assembly and a cylindrical sleeve enclosing and rotating about said magnetic assembly; andmeans for biasing said first magnetic roll with a DC and AC bias and means for biasing said second magnetic roll with an AC and DC bias, said DC applied to said first magnetic roll to insure background regions of the latent electrostatic image are not developed.