FIELD ASSISTED TRANSFER ROLL
Original Publication Date: 1995-Oct-31
Included in the Prior Art Database: 2004-Apr-07
Xerox Disclosure Journal
The difficulties of successful image transfer are well known. In the pre-transfer (pre-nip) region, before the copy paper contacts the image, if the transfer fields are high, the image is susceptible to premature transfer across the air gap, leading to decreased resolution or fuzzy images. Further, if there is ionization in the pre-nip air gap from high fields, it may lead to strobing or other image defects, loss of transfer efficiency, and a lower latitude of system operating parameters. Yet, in the directly adjacent nip region itself, the transfer field should be large as possible (greater than approximately 20 volts per micron) to achieve high transfer efficiency and stable transfer. In the next adjacent post-nip region, at the photoconductorkopy sheet separation area, if the transfer fields are too low, hollow characters may be generated. On the other hand, improper ionization in the post-nip region may cause image instability or copy sheet detacking problems. Variations in ambient conditions, copy paper, contaminants, etc. can all affect the necessary transfer parameters for simplex copying and especially for duplex copying.