Method for adjusting transfer voltage controls based on environmental conditions to improve print quality in a direct transfer image forming device

US8036547B2 · kind B2 · utility

Assignee

• Lexmark International, Inc. · US

Inventors

• Robert Reed Booth · Lexington, US
• Ryan David Brockman · Lexington, US
• Kerry Leland Embry · Midway, US
• Paul Wesley Etter · Lexington, US
• Claudia Alexandra Marin · Lexington, US
• Travis Alan Riggs · Shelbyville, US

Key dates

• Filing date: Sep 29, 2008
• Grant date: Oct 11, 2011
• Expiry date: Dec 27, 2029

Classification

• Technology area (CPC G): Physics
• CPC primary: G03G21/203
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The present application is directed to methods of controlling the transfer voltage in a transfer nip formed between the photoconductive member and the transfer member. The methods offset the effects of large transfer current spikes caused when a media sheet enters and exits the transfer nip and account for temperature and humidity operating parameters using wet-bulb temperature measurements to adjust the transfer voltage. The control may include either ramping up or ramping down the transfer voltage. The ramped transfer voltage may include a series of alternating positive and negative steps that generally trend to ramp up or down. The size of the steps may further be adjusted to provide a smooth transition.