Browse Prior Art Database

FIELD ASSISTED TRANSFER ROLL

IP.com Disclosure Number: IPCOM000027222D
Original Publication Date: 1995-Oct-31
Included in the Prior Art Database: 2004-Apr-07
Document File: 4 page(s) / 140K

Publishing Venue

Xerox Disclosure Journal

Abstract

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.

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Page 1 of 4

XEROX DISCLOSURE JOURNAL

ROLL

Proposed Classification
U.S. C1.355/271 Int. C1. G03g 15/16

FIELD ASSISTED TRANSFER

Richard F. Bergen

70 72 -

J

\- c

T

27

FIG. 1

XEROX DISCLOSURE JOURNAL Vol. 20 No. 5 September/Odober 1995 445

[This page contains 1 picture or other non-text object]

Page 2 of 4

FIELD ASSISTED TRANSFER ROLL (Cont'd)

I

63

60

-

FIG. 2

446 XEROX DISCLOSURE JOURNAL Vol. 20 No. 5 SeptembedOctober 1995

[This page contains 1 picture or other non-text object]

Page 3 of 4

FIELD ASSISTED TRANSFER ROLL (Cont'd)

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.

Field assisted transfer is one way of addressing the above-mentioned problems. For example, an apparatus 10 which transfers a developed toner image 30 from a charge retentive surface 20 mounted on a support 21 to a copy sheet 18 is shown in FIG. 1. The apparatus 10 includes a conductive transfer blade 12 that is overcoated with an insulati...