Dark decay control system utilizing two electrostatic voltmeters

US5157441A · kind A · utility

Assignee

• Xerox Corporation · US

Inventors

• Mark A. Scheuer · Williamson, US
• Patricia J. Donaldson · Pittsford, US
• Daniel W. MacDonald · Macedon, US
• Anthony J. Paolini · Henrietta, US
• Kenneth S. Palumbo · Irondequoit, US
• Robin E. Berman · Rochester, US
• Carl B. Hurwitch · Rochester, US

Key dates

• Filing date: Sep 5, 1991
• Grant date: Oct 20, 1992
• Expiry date: Sep 5, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G03G15/5041
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A single pass tri-level imaging apparatus and method. Compensation for the effects of dark decay on the background voltage, V.sub.Mod, and the color toner patch, V.sub.tc readings is provided using two ESVs (ESV.sub.1 and ESV.sub.2), the former located prior to the color or DAD housing and the latter after it. Since the CAD and black toner patch voltages are measured (using ESV.sub.2) after dark decay and CAD voltage loss have occurred, no compensation for these readings is required. The DAD image voltage suffers little dark decay change over the life of the P/R so the average dark decay can be built into the voltage target.