Printer with multi-toner discharged area development

摘要

Printers are provided in which a charge pattern is formed with a first area having a surface potential that is at least 30 percent less than a surface potential of an adjacent second area that creates an inter-area field between the first area and second area that extends into a portion of the first area that is proximate to the second area. A development station applies a first development field and a first toner is partially developed in the first area based upon the influence of the inter-area and first development fields. The charge pattern and first toner are further developed with a different second toner. The surface charge, the first toner and second toner have the same polarity.

主权项

1. A printer comprising:
a print engine having a primary imaging member on which a charge pattern can be formed, primary imaging system generating the charge pattern of a first polarity on a primary imaging member including a first area having a first imagewise modulated surface potential relative to ground and a second area having an imagewise modulated surface potential relative to ground that is at least about 30% greater than the first image modulated surface potential so that an inter-area field forms having a component that extends from the second area into an edge proximate portion of the first area; a first development system partially developing the charge pattern with a first toner having a first polarity using a first development field to urge the first toner to develop in the first area in amounts that increase with increases in a first net development difference of potential between a first bias voltage at a first development station and a first imagewise modulated surface potential in the first area with the component of the inter-area field that extends into the first area further urging development of first toner in the edge proximate portion of the first area so that there is at least 15% more first toner per unit area in the edge proximate portion of the first area than in a remaining portion of the first area; and a second development system further developing the charge pattern and a first toner image with a second toner having the first polarity using a second development field that urges the second toner to develop in the first area in amounts that increase with increases in a difference of potential between a second bias voltage and the first surface potential which is modulated by the charge of the first toner developed in the first area to urge the second toner to develop predominately in the remaining portion of the first area wherein the first toner and the second toner are different.