Developing systems

An apparatus for developing an electrostatic latent image comprising:

• 1. means for creating and moving a latent electrostatic image on an imaging surface;
• 2. a developer module in actual or potential registration with a latent electrostatic image on the imaging surface and comprising
• a. a movable path-defining applicator surface having a pattern of lands and valleys to a depth of from about 1.5 mils to about 6 mils;
• b. an aperture in said developer module for selectively effecting transfer by electrostatic attraction of developer material between said applicator surface and a latent electrostatic image on said imaging surface when in register;
• c. developer feeding means within said developer module for applying developer material to the applicator surface;
• d. doctoring means mounted in doctoring arrangement with respect to said applicator surface for maintaining a metering amount of developer on the applicator surface;
• e. means for sequentially moving each part of said applicator surface past the feeding means and doctoring means and into developing configuration through said aperture with said imaging surface;
• and
• 3. means for developing engagement and disengagement of the developer module in register with movement of said imaging surface.