Patent ID: 8431313

Claim:
A printing method comprising the steps of forming at least one first toner image by charging a primary imaging member to have an image modulated difference of potential of a first polarity between a higher difference of potential and a lower difference of potential relative to a ground at locations on the primary imaging member where toner is to be developed and to have an image modulated difference of potential below a lower difference of potential at locations on the primary imaging member where no toner is to be developed; establishing a first development difference of potential of the first polarity between the higher difference of potential and the lower difference of potential at a first development station to form a net first development difference of potential between the first development station and individual engine pixel locations on the primary imaging member with the net first development difference of potential less any image modulated difference of potential at the individual engine pixel locations and positioning a first toner charged at a second polarity at the first development station such that the first toner is electrostatically urged to deposit in the individual engine pixel locations according to the net first development difference of potential for the individual engine pixel locations; transferring each first toner images in registration to form a composite toner image on a receiver; creating a second net development difference of potential of the first polarity between a second development station, a bias member and the first toner at each location on the receiver used for printing, with the net second development difference of potential being a second development difference of potential between the second development station and the bias member less any difference of potential relative to ground of any first toner at each location; and, providing a second toner of the second polarity at the second development station such that the second toner is electrostatically urged to deposit at individual locations on the receiver in amounts according to the net second development difference of potential at the individual locations; wherein the second development difference of potential is set at a level such that the second toner is deposited on the receiver to cause a total amount of first toner and any second toner deposited at each location on the receiver to be maintained within a range that is less than a range of first toner amounts on the receiver.