Characterization of toner patch sensor
AssigneeLexmark International, Inc.
InventorsMark A. Omelchenko, John Parker Richey
Life of this patent
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Abstract
Methods and devices for operating a toner patch sensor in an electrophotographic image forming device. A characterization procedure for a light detector in the toner patch sensor may use one or multiple reflectance standards. A gain setting is determined that produces a predetermined target output from the toner patch sensing circuit for each of the standards. The characterization procedure may be carried out at a test bench or with the toner patch sensor installed in the corresponding device.
Claims16
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.
A method of operating a toner patch sensor circuit for an image forming device, comprising:
- exposing a light sensor of the toner patch sensor circuit to a first light level and achieving a first predetermined output from a toner patch sensor circuit by adjusting a gain thereof to a first gain setting;
- exposing the light sensor to a second light level and achieving a second predetermined output from the toner patch sensor circuit by adjusting the gain to a second gain setting;
- storing the first and second settings;
- retrieving one of the first and second gain settings from the memory and operating the toner patch sensor circuit based on the one of the first and second gain settings;
- and
- determining at least one offset value that compensates for sensor output without a reflectance standard in view of the light sensor.
A method of operating a toner patch sensor circuit for an image forming device, comprising:
- exposing a light sensor of the toner patch sensor circuit to a first light level and achieving a first predetermined output from a toner patch sensor circuit by adjusting a gain thereof to a first gain setting;
- exposing the light sensor to a second light level and achieving a second predetermined output from the toner patch sensor circuit by adjusting the gain to a second gain setting;
- storing the first and second settings;
- retrieving one of the first and second gain settings from the memory and operating the toner patch sensor circuit based on the one of the first and second gain settings;
- wherein the toner patch sensor circuit comprises a first amplifier and a second amplifier.
Dependencies are inferred from the claim text.