Reproduction machine having image deletions reducing control system and

Abstract

An electrostatographic reproduction machine that includes an image bearing member means for forming a latent image having image areas and background areas; at least a development housing containing charged carrier beads, charged fragments of the charged carrier beads which undesirably cause image deletions, and charged toner particles for developing image areas to form a toner image; means for transferring the toner image to a sheet of paper, and means for fusing the toner image to the sheet of paper. Importantly the reproduction machine includes a method and control system for reducing halftone image deletions in future halftone images. The method and control system include means for distinguishing latent solid image patterns from latent halftone image patterns; means for counting a number of solid image patterns developed with toner on the image bearing surface; means for providing an electrostatic halftone stress image pattern for electrostatically forming and developing on the image bearing surface; and means for forming and developing a number of the halftone stress image patterns on the image bearing surface, under certain machine operating conditions, so as to attract charged fragments of the charged carrier beads out of the development housing, thereby reducing deletions that would otherwise be undesirably caused by the carrier bead fragments in future halftone toner images