Electric-field manipulation of ejected ink drops in printing

An ink jet printer for forming an image on a print substrate, comprising:

• a printhead comprising,
• a face nearest the print substrate,
• a plurality of apertures formed in the face, and
• drop expelling means for expelling a drop, the drop having a velocity directed toward the print substrate;
• drop accelerating means comprising a plurality of electrodes on a side of the print substrate opposite the printhead, each of the plurality of electrodes corresponding to a column of apertures on the printhead;
• a controller controlling the drop expelling means and the drop accelerating means;
• wherein the expelled drops are charged and accelerated in at least one of a direction perpendicular to the print substrate and a direction parallel to the print substrate based on charges on the plurality of electrodes.

An ink jet printer for forming an image on a print substrate, comprising:

• a printhead having a print resolution and comprising:
• a face nearest the print substrate,
• a plurality of apertures formed in the face, and
• drop expelling means for expelling a drop, the drop having an initial velocity directed toward the print substrate;
• drop charging means for charging expelled drops;
• drop steering means comprising a first steering electrode formed on the face of the printhead and located adjacent to at least one of the plurality of apertures;
• and
• a second steering electrode formed on the face of the printhead and located adjacent to the at least one of the plurality of apertures and on a side opposite the first electrode, wherein the first and second steering electrodes are interdigitated;
• and
• a controller controlling the drop expelling means, the drop charging means and the drop steering means;
• wherein charged drops are accelerated in directions parallel to the print substrate to increase the print resolution of the printhead.

A method for increasing a print resolution of a printer having an ink jet printhead and a print substrate, comprising the steps:

• producing an electric field extending between the ink jet printhead and the print substrate;
• expelling a charged ink drop from the ink jet printhead toward the print substrate, the expelled ink drop initially directed in a center trajectory defining a first print resolution;
• and
• controlling the electric field such that the charged drop is directed in at least one direction other than the center trajectory to increase the print resolution of the printhead.