Method and apparatus for compensating for a darkness shift during the life of an electrophotographic printer cartridge
US6175375A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 2000 |
| Grant date | Jan 16, 2001 |
| Priority date | — |
| Expiry date | Jan 25, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2221/183
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved EP printer will automatically compensate for printer output darkness shift over the usage life of one or more components of the print engine. In many EP print engines, the printer output darkness without correction will gradually change as the components are used, and typically, the darkness will increase to an extent that is perceptible. The printer output darkness can be controlled using a EP operating point that changes certain operating parameters, such as the laser diode current, the duty cycle of the video data signals driving the laser diode, and other voltage parameters including the charge roller voltage, or the developer bias voltage. It is desirable to make adjustments over the usage life of these components, so as to maintain the initial printer output darkness throughout the life of the major system components. The adjustments can occur at periodic intervals based upon a metric that includes one or more of the following parameters: number of pels produced, number of pages printed, number of cycles of one or more components of the print engine, and/or the consumption of toner in grams. The adjustment information can be provided as look-up tables, or in the f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.