Patent ID: 6709084
Filing Date: 2004-03-23
Classification: B41J

Abstract:
A method comprising:ejecting a first ink drop onto a medium at a first ejection velocity by a first nozzle of a printhead in the printing mechanism when the printhead moves at a first moving velocity along a scanning axis and when it reaches a first position along the scanning axis, ejecting a second ink drop onto the medium at a second ejection velocity by a second nozzle of the printhead when the printhead moves at a second moving velocity along the scanning axis and when it reaches a second position along the scanning axis, wherein the spacing between the two nozzles along the scanning axis and the spacing between the two positions along the scanning axis are predetermined, measuring the spacing between the first and second ink drops on the medium along the scanning axis; and determining the pen-to-paper spacing from the first and second moving velocities, the first and second ejection velocities, the spacing between the first and second nozzles along the scanning axis, the spacing between the first and second positions along the scanning axis and the spacing between the first and second ink drops on the medium along the scanning axis.