Apparatus for non-interactive electrophotographic development

Apparatus for non-interactive, dry powder development of electrostatic images composed of solid areas and fine line areas on an imageable surface with developer material comprising:

• a housing containing developer material;
• a magnetic member, spaced a predefined distance from said images, for transporting said developer material from said housing to develop solid areas of said images, said magnetic member including a magnetic core and a cylindrical sleeve enclosing and rotating about said magnetic core;
• a donor member, adjacent to said magnetic member and spaced from the imageable surface and adapted to transport developer material to a development zone adjacent the imageable surface said magnetic member loads said donor member with developer material;
• an electrode positioned in the development zone between the imageable surface and the donor member;
• and
• a voltage supply for electrically biasing said electrode during a developing operation with an alternating current to detach developer material from said donor member, forming a cloud of developer material in the development zone, and developing fine line areas of said images from the cloud.