Patent ID: 7995939

Claim:
A method for calibrating an image forming device using a toner patch sensor which emits and detects light at a given wavelength in the infrared spectrum comprising: depositing a plurality of toner patches onto a control surface, wherein said toner patches include a first toner patch including a black toner, a second toner patch including said black toner deposited over a non-black toner, and a third toner patch including said non-black toner; measuring signals indicative of the reflectivity of said plurality of toner patches and the reflectivity of said control surface by emitting light of a given wavelength in the infrared spectrum and detecting the amount of incident light reflected from said plurality of toner patches and said control surface, wherein said first toner patch exhibits a first reflectivity R 1 at said given wavelength, said second toner patch exhibits a second reflectivity R 2 at said given wavelength, said third toner patch exhibits a third reflectivity R 3 at said given wavelength, said control surface exhibits a fourth reflectivity R control at said given wavelength, wherein R control ≠R 3 ; and adjusting an operating parameter based upon said measurements.