Patent ID: 7890006

Claim:
A method of operating a toner patch sensor for an image forming device, comprising: positioning a first reflectance standard in view of a light sensor; generating a first output proportional to an amount of light directed to the light sensor from said first reflectance standard; adjusting a gain associated with said first output to a first gain value to achieve a first predetermined target output; replacing the first reflectance standard with a second reflectance standard, the second reflectance standard including a different reflectance than the first reflectance standard; generating a second output proportional to an amount of light directed to the light sensor from said second reflectance standard; adjusting a gain associated with said second output to a second gain value to achieve a second predetermined target output; storing the first and second gain values in a memory; retrieving at least one of the first and second gain values from said memory and operating the toner patch sensor based thereon; and removing the second reflectance standard from in view of the light sensor and determining a first offset corresponding to the first gain value and a second offset corresponding to the second gain value.