Toner measurement and darkness control using printer systems
US6718147B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 2002 |
| Grant date | Apr 6, 2004 |
| Priority date | — |
| Expiry date | Nov 4, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/556
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Toner usage is measured with good accuracy. Printing tends to darken with the depletion of toner from a source. A toner cartridge employed in a printer (70) has the capability at the cartridge of determining the amount toner used. In an embodiment this is by a torsion spring (60) drive to a toner paddle (3). At turn-on and cover open, the amount of toner is measured at the cartridge (80). That is stored in NVRAM (78) when it is very different from the current amount stored in NVRAM. At certain amount levels observed at the cartridge the amount in NVRAM is revised to the new amount. Between those levels the amount of toner used is tracked by counting pels (94). Use amounts are converted to operating factors in a table (100), and the operating factors are applied to the printer to keep the darkness of printing more constant. Writing to NVRAM is minimized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.