System And Method For Process Direction Registration Of Inkjets In A Printer Operating With A High Speed Image Receiving Surface

An inkjet printer comprising:

• a media transport configured to move a print medium in a process direction past a printhead having a plurality of inkjets and an optical sensor;
• a controller operatively connected to the media transport, the printhead, the optical sensor, and a memory, the controller being configured to:
• operate the media transport to move the print medium past the printhead and the optical sensor at a predetermined rate;
• generate firing signals to eject a plurality of drops from a first inkjet in the printhead at a first predetermined rate onto the print medium, the first rate of ejecting the ink drops from the first inkjet being less than a maximum ejection rate of the first inkjet;
• generate with the optical sensor a plurality of image data samples of the print medium including a plurality of portions of the print medium that received the plurality of drops ejected from the first inkjet, the plurality of image data samples being generated at a second predetermined rate, the second predetermined rate being less than the maximum ejection rate of the first inkjet to enable at least one image data sample between two image data samples depicting an ink drop to depict a portion of the image receiving surface that does not have an ink drop;
• identify a center of the plurality of ink drops on the print medium in the process direction with reference to the plurality of image data samples;
• identify a process direction offset between the identified center of the plurality of drops ejected from the first inkjet and a center identified with reference to another plurality of image data samples generated for another portion of the image receiving surface having another plurality of ink drops ejected by a second inkjet;
• and
• store a timing adjustment value corresponding to the identified offset in the memory in association with the first inkjet.