Patent ID: 7676169

Claim:
A toner patch sensor for use in an image forming device, the toner patch sensor comprising: a detector oriented at a first reflection angle relative to a measurement surface; and a source adapted to reflect specular light toward the detector along a second incident angle relative to the measurement surface, the second angle being equal to but opposite the first angle, the source further adapted to reflect diffuse light along a third incident angle relative to the measurement surface, the third angle being different than either the first angle or the second angle, wherein the toner patch sensor further comprises a controller operative to change the amount of one or both of the specular and diffuse light received by the detector, wherein the source comprises a first emitter oriented at the second incident angle relative to the measurement surface and a second emitter oriented at the third incident angle relative to the measurement surface, and wherein the controller selectably adjusts a ratio of illumination power between the first and second emitters.