Cycle up convergence of electrostatics in a tri-level imaging apparatus

In a method of printing tri-level images on a charge retentive surface during operation of a tri-level imaging apparatus, the steps of:

• uniformly charging said charge retentive surface;
• using a raster output scanner, forming voltage patches on said charge retentive surface;
• using a plurality of voltage measuring devices, measuring electrostatic values of said patches,
• comparing said values to predetermined target values, said predetermined target values representing values necessary for forming optimum tri-level images;
• and
• inhibiting formation of tri-level images until all of said electrostatic values meet said predetermined target values.

Apparatus for printing tri-level images on a charge retentive surface during operation of a tri-level imaging apparatus, said apparatus comprising:

• means for uniformly charging said charge retentive surface;
• a raster output scanner for forming voltage patches on said charge retentive surface;
• a plurality of voltage measuring devices for measuring electrostatic values of said patches;
• means for comparing said values to predetermined target values, said predetermined target values representing values necessary for forming optimum tri-level images;
• and
• means for inhibiting formation of tri-level images until all of said electrostatic values meet predetermined targets.