Printhead with low viscous drag droplet ejection
US7637593B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 2007 |
| Grant date | Dec 29, 2009 |
| Priority date | — |
| Expiry date | Feb 10, 2028 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2202/20
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A inkjet printhead with heater elements adjacent an array of respective nozzles for heating a water-based printing fluid to form a gas bubble for ejecting a drop of the printing fluid from the nozzle. The heater is separated from the nozzle by less than 5 μm at their closest points and the nozzle length is less than 5 μm. The volume of liquid between the heater and the nozzle determines the inertia of the liquid and its acceleration in response to bubble formation. Moving the heater closer to the nozzle reduces the inertia of the liquid and increases its acceleration, so a lower bubble impulse is needed to eject a drop. This allows the printhead to use smaller heater elements with lower power requirements. Viscous drag in the nozzle reduces the momentum of fluid flowing through the nozzle. The viscous drag increases as the nozzle length (in the direction of fluid flow) increases. By reducing the nozzle length, a lower bubble impulse is needed to eject a drop. This also allows the printhead to use smaller heater elements with lower power requirements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.