EP 0429309 B1 19941214 - Biasing scheme for improving latitudes in the tri-level xerographic process.
Title (en)
Biasing scheme for improving latitudes in the tri-level xerographic process.
Title (de)
Polarisierungsweise zur Verbesserung der Eigenschaften der Drei-Niveau-Xerographie.
Title (fr)
Méthode de polarisation pour améliorer les caractéristiques du procédé xérographique à trois niveaux.
Publication
Application
Priority
- US 44091389 A 19891122
- US 44091489 A 19891122
Abstract (en)
[origin: EP0429309A2] The operating latitude of the tri-level xerographic process is improved by replacing the standard DC bias that is applied to one or both of the developer housings (32, 34) in conventional tri-level imaging with a chopped DC (CDC) developer bias (41, 43). Chopped DC biasing is the alternate application of two discrete bias voltages to a developer strucrute in a periodic fashion at a given frequency, with the period of each cycle divided up between the two bias levels at a duty cycle of from 5-10% or 90-95% depending upon which of the two developer structures is being biased. In the case of the DAD developer structure (32) the duty cycle of the higher of the two biases is 5-10% and in the case of a CAD developer structure (34) the duty cycle of the higher of the two biases is 90-95%. The apparatus can be switched to operate in a black monochrome mode, in which only the black developer structure (34) is biased using a standard momchrome bias (4-5).
IPC 1-7
IPC 8 full level
G03G 13/01 (2006.01); G03G 15/01 (2006.01)
CPC (source: EP US)
G03G 13/013 (2013.01 - EP US); G03G 15/0121 (2013.01 - EP)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0429309 A2 19910529; EP 0429309 A3 19911106; EP 0429309 B1 19941214; DE 69015131 D1 19950126; DE 69015131 T2 19950727
DOCDB simple family (application)
EP 90312719 A 19901122; DE 69015131 T 19901122