Control develop mass in a color system

摘要

An infrared densitometer which measures the diffuse component of reflectivity as marking particles are progressively deposited on a moving photoconductive belt. Collimated light rays are projected onto a test patch including the marking particles. The light rays reflected from the test patch are collected and directed onto a photodiode array. The photodiode array generates electrical signals proportional to the total flux and a diffuse component of the total flux of the reflected light rays. Circuitry compares the electrical signals and determines the difference to generate an electrical signal proportional to the specular component of the total flux of the reflected light rays. Additional circuitry adds the electrical signals proportional to the total flux and the diffuse component of the total flux of the reflected light rays and compares the result of the summed signal to the specular component to provide a total diffuse signal for controlling developed mass.