System for Tailoring a Transfer NIP Electric Field for Enhanced Toner Transfer in Diverse Environments

A system for tailoring a second transfer nip electric field at a second transfer station for enhanced toner transfer in diverse environments, comprising:

• a plurality of image-forming first transfer stations;
• a second transfer station having a second transfer nip;
• and
• an endless transfer belt transported in an endless path passing, first, through a plurality of first transfer nips at said first transfer stations where toner forming an image is deposited on the transfer belt and, second, into and through said second transfer nip of said second transfer station where the toner is transferred from said transfer belt onto a media sheet;
• said second transfer station including
• a rotatable transfer roll having a first potential,
• a rotatable backup roll having a second potential and forming said second transfer nip between said rolls as said rolls counter-rotate relative to one another, and
• a rotatable pre-nip roll having a third potential and being positioned upstream from said transfer and backup rolls and said transfer nip such that said transfer belt moving past said pre-nip, transfer and backup rolls separately makes contact with, wraps partially around, and rotates each of said pre-nip, transfer and backup rolls as a media sheet is fed into said transfer nip after first passing through a gap defined between said pre-nip roll and said transfer roll such that by presetting the position, geometry and potential of said pre-nip roll relative to said transfer and backup rolls a voltage field at said second transfer nip can be tailored for enhanced toner transfer from the transfer belt to the media sheet in diverse environments.