Method and apparatus for compensation of arbitrary banding sources using inline sensing and control

A method for compensation of banding in a marking platform, comprising:

• a) initiating a cycle up stage in a phase learning mode to determine phase banding characteristics for each of one or more current dominant banding signatures in conjunction with processing a marking job on a marking platform, the marking platform comprising a plurality of marking modules at least a portion of which are select marking modules, each select marking module being a potential banding source such that a fundamental frequency for banding characteristics associated with each select marking module is known, each dominant banding signature reflecting amplitude and frequency banding characteristics over at least one sample period of the corresponding fundamental frequency for corresponding dominant banding sources;
• b) establishing a timing reference after the plurality of marking modules have achieved a relatively constant velocity in conjunction with the cycle up stage;
• c) marking a banding test pattern on an image receiving member over at least multiple intervals of a lowest fundamental frequency among the select marking modules;
• d) obtaining banding image data for the banding test pattern from a test pattern image sensor in conjunction with the marking in c);
• and
• e) processing the banding image data obtained in d) with each of the one or more current dominant banding signatures in relation to the timing reference to form a corresponding banding phase estimate for each of the one or more current dominant banding signatures in conjunction with processing the marking job.

A method for compensation of banding in a marking platform, comprising:

• a) initiating a banding signature validation mode to test if current dominant banding signatures for a marking platform need to be replaced with fresh dominant banding signatures, the marking platform comprising a plurality of marking modules at least a portion of which are select marking modules, each select marking module being a potential banding source such that a fundamental frequency for banding characteristics associated with each select marking module is known, each current dominant banding signature reflecting amplitude and frequency banding characteristics over at least one sample period of the corresponding fundamental frequency for corresponding dominant banding sources;
• b) periodically processing each of one or more current dominant banding signatures with corresponding banding phase estimates in relation to a timing reference to determine a current banding compensation value for the marking platform, each banding phase estimate formed from banding image data associated with a banding test pattern, each banding phase estimate processed using the corresponding current dominant banding signature in relation to the timing reference, the timing reference established after the plurality of marking modules achieve a relatively constant velocity in conjunction with the banding signature validation mode, wherein the timing reference is used to combine the dominant banding signatures in time relation to determine the current banding compensation value;
• c) correlating the current banding compensation value with the banding image data in relation to the timing reference to determine a corresponding current effectiveness metric;
• and
• d) determining at least one current effectiveness metric determined in c) exceeds a corresponding effectiveness threshold.

A method for compensation of banding in a marking platform, comprising:

• a) processing banding image data in relation to a timing reference to form a banding profile for each of one or more banding sources within a marking platform, the marking platform comprising a plurality of marking modules at least a portion of which are select marking modules, each select marking module being a potential banding source such that a fundamental frequency for banding characteristics associated with each select marking module is known, wherein the fundamental frequency for each banding source is used to determine banding characteristics attributed to the corresponding banding source and filter banding characteristics not attributed to the corresponding banding source for the corresponding banding profile, each banding profile reflecting a phase relation of amplitude and frequency banding characteristics to the timing reference for the corresponding banding source in relation to a banding test pattern;
• b) determining at least one amplitude value in one or more banding profiles exceed a corresponding amplitude threshold to identify dominant banding profiles and corresponding dominant banding sources;
• and
• c) processing each dominant banding profile to form a dominant banding signature for the corresponding dominant banding source, each dominant banding signature reflecting the phase relation of amplitude and frequency banding characteristics over at least one sample period of the corresponding fundamental frequency for the corresponding dominant banding source.

An apparatus for compensation of banding in a marking platform, comprising:

• means for initiating a signature learning mode to determine banding characteristics of a marking platform, the marking platform comprising a plurality of marking modules at least a portion of which are select marking modules, each select marking module being a potential banding source such that a fundamental frequency for banding characteristics associated with each select marking module is known;
• means for establishing a timing reference after the plurality of marking modules have achieved a relatively constant velocity in conjunction with the signature learning mode;
• means for marking a banding test pattern on an image receiving member over at least multiple intervals of a lowest fundamental frequency among the select marking modules;
• means for obtaining banding image data for the banding test pattern from a test pattern image sensor in conjunction with the marking of the banding test pattern;
• means for processing the banding image data in relation to the timing reference to form a banding profile for each of one or more banding sources within the marking platform, wherein the fundamental frequency for each banding source is used to determine banding characteristics attributed to the corresponding banding source and filter banding characteristics not attributed to the corresponding banding source for the corresponding banding profile, each banding profile reflecting a phase relation of amplitude and frequency banding characteristics to the timing reference for the corresponding banding source;
• means for determining at least one amplitude value in one or more banding profiles exceed a corresponding amplitude threshold to identify dominant banding profiles and corresponding dominant banding sources;
• and
• means for processing each dominant banding profile to form a dominant banding signature for the corresponding dominant banding source, each dominant banding signature reflecting the phase relation of amplitude and frequency banding characteristics over at least one sample period of the corresponding fundamental frequency for the corresponding dominant banding source.