Ink cartridge for an ink jet printer
US4571599A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 1984 |
| Grant date | Feb 18, 1986 |
| Priority date | — |
| Expiry date | Dec 3, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/17513
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A plurality of disposable, individually replaceable ink supply cartridges are mountable on the carriage of an ink jet printer. Each cartridge has a thermal printhead fixedly attached thereto. A constant slightly negative pressure is maintained at the nozzles of the printhead by means of a secondary reservoir with a level of ink maintained below the ink supply. The majority of the ink is stored in a hermetically sealed main reservoir in the cartridge which contains the ink supply at the negative pressure. A passageway provides ink from the main reservoir to the printhead nozzles. The secondary reservoir holds an air pocket at atmospheric pressure and releases air into the main reservoir as required to maintain the desired negative pressure constant therein as the ink supply is depleted. The passageway entrance is sized to maintain a meniscus when the cartridge is tilted to prevent loss of the desired nozzle pressure by air from the second reservoir. A membrane filter passes air to the secondary reservoir, but is impervious to ink. Means to reduce the effects of fluid inertia on the ink caused by sudden changes of printing duty cycles is optionally provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.