MEASURING DEVELOPER DENSITY IN AN ELECTROPHOTOGRAHIC SYSTEM

摘要

An apparatus for measuring developer density in an electrophotographic system (100). A first electrode (415) and a second electrode (410) are disposed to define a working volume (420) between them through which developer (514) moves without contacting the first electrode (415), wherein the electrodes are electrically insulated from each other by the working volume. A voltage source (430) selectively applies an AC bias across the electrodes. A measuring device (A) measures the current across the electrodes while the bias is applied. A processor (450) is adapted to automatically determine the density of the developer in the working volume based on the measured current and the applied bias.