Patent ID: 9707785
Date: 2017-07-18
CPC Classifications: B41J

Claim:
1. A method of identifying an inoperable ejector in a printhead comprising: operating with a controller a plurality of ejectors in a printhead to eject drops of a marking agent onto an image receiving surface to form a plurality of marks in a printed test pattern, the printhead and image receiving surface being held in a stationary position with reference to each other during operation of the plurality of ejectors; operating with the controller an optical sensor to generate image data of the plurality of marks in the printed test pattern on the image receiving surface; identifying with the controller a plurality of candidate mark locations in the image data; identifying with the controller a row of printed marks in the image data with reference to a linear arrangement of a portion of the plurality of candidate mark locations, the linear arrangement corresponding to a single row of ejectors in the plurality of ejectors in the printhead; identifying with the controller an inoperable ejector in the row of ejectors in the printhead in response to an expected location of a mark from the inoperable ejector located along the linear arrangement in the image data not corresponding to any of the identified printed marks; and operating with the controller a printhead maintenance unit in response to identification of the inoperable ejector.