ESV readings of toner test patches for adjusting IRD readings of developed test patches
US5227270A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 1991 |
| Grant date | Jul 13, 1993 |
| Priority date | — |
| Expiry date | Sep 5, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00042
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a single pass tri-level imaging apparatus, a pair of Electrostatic Voltmeters (ESV) are utilized to monitor various control patch voltages to allow for feedback control of Infra-Red Densitometer (IRD) readings. The ESV readings are used to adjust the IRD readings of each toner patch. For the black toner patch, readings of an ESV positioned between two developer housing structures are used to monitor the patch voltage. If the voltage is above target (high development field) the IRD reading is increased by an amount proportional to the voltage error. For the color toner patch, readings using an ESV positioned upstream of the developer housing structures and the dark decay projection to the color housing are used to make a similar correction to the color toner patch IRD readings (but opposite in sign because, for color, a lower voltage results in a higher development field).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.