DENSITOMETER FOR MEASURING DEVELOPABILITY

摘要

An infrared densitometer which measures the reflectivity of a selected region on a moving photoconductive belt (10) covered at least partially with marking particles. Collimated light rays are projected onto the selected region of the moving photoconductive member with or without marking particles thereon. The light rays reflected from the selected region of the moving photoconductive member are collected and directed onto a photodiode array (106). The photodiode array generates electrical signals proportional to the diffuse component of the total reflectivity of the selected region of the photoconductive member with and without marking particles thereon. Circuitry determines a control signal as a function of the difference in electrical signals.