Scanning device calibration system and method
AssigneeHewlett-Packard Development Company, L.P.
InventorsPatrick J. Chase, Craig T. Johnson
Life of this patent
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Abstract
In one embodiment, a scanning device includes a light source configured to selectively illuminate an area of interest and a light sensitive receiver configured to receive light from the light source and generate signals based on the received light. Control logic is configured to power the light source at a power, generating mid-tone-scan signals at the light sensitive receiver. Calibration logic is configured to determine a calibration factor for a selected pixel based data including the mid-tone-scan signals.
Claims20
A scanning device comprising:
- a light source configured to selectively illuminate an area of interest;
- a light sensitive receiver configured to receive light from the area of interest and generate signals based on the received light;
- control logic configured to power the light source at at least one power level to generate a measured signal at the light sensitive receiver corresponding to at least one known target value, and to power the light source at at least one approximate power level to generate a second calibration signal at the light sensitive receiver corresponding to at least one approximate target value;
- and
- calibration logic configured to determine a calibration factor for a selected pixel based on at least the known target value and the approximate target value.
A computer readable medium comprising:
- control logic configured to cause measurements to be obtained under at least two different illuminations, where one of the measurements relates to a response of the scanning device in a mid-tone;
- and
- calibration logic configured to derive a calibration factor from data including the measurements relating to the mid-tone response.
A calibration system comprising:
- control logic configured to power a light source at a non-zero power level which is less than an operational scan power;
- an optical path configured to direct light from the light source to a light sensitive receiver;
- and
- calibration logic configured to receive signals from a light sensitive receiver responsive to the light source being powered at the plurality of power levels, the calibration logic configured to derive a mid-tone value.
A method of calibrating a scanning device comprising:
- obtaining measurements under at least two different illuminations, where one of the measurements relates to a response of the scanning device in a mid-tone;
- and
- deriving a calibration factor from data including the measurements relating to the mid-tone response.
The method as set forth in claim 18, where the obtaining comprises:
- receiving signals across a scan line responsive to a first illumination of a light source;
- and
- receiving signals across the scan line responsive to a second illumination of the light source, where the second illumination is less than the first illumination.
Dependencies are inferred from the claim text.