Compensating for drift and sensor proximity in a scanning sensor, in color calibrating incremental printers
US7023581B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2001 |
| Grant date | Apr 4, 2006 |
| Priority date | — |
| Expiry date | Sep 22, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6033
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
To compensate for color-calibration sensor drift, a measurement of bare-print-medium tonal value is taken in immediate time juxtaposition to each color test pattern; measured bare-medium tone is then used to correct color-patch readings. A line sensor or the like, on the scanning printhead carriage, is used for the reading. Preferably two such readings are taken, one at each end of each test pattern; ideally separate scans of the bare medium are taken without any test-pattern patch to develop longterm and short-term drift profiles, for refining the corrections. To compensate for calibration error due to runout in the carriage track—particularly for wide-bed printers—sensor response to bare medium is used to represent variations in carriage-to-medium spacing along the track; these variations are corrected in later sensor use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.