Patent attributes
A system is provided that determines the amount of toner on a photo receptor in a xerographic operation. A photo receptor is charged in one or more locations to create an image. A developer places a patch of a predetermined amount of toner onto the one or more charge locations of the photo receptor. A light emitting diode projects light onto the photo receptor, wherein the intensity of the light varies based on the voltage provided to the LED. An optical reflective sensor measures the reflectance of the toner placed on the photo receptor, the amount of reflectance of the toner is related in a known way to the intensity of the LED. A direct relationship between LED intensity and the reflectance of the toner allow for accurate extrapolation at LED intensities greater than the point of saturation.