Method and apparatus for forming droplets
US6260741A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Feb 19, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2101/42
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An apparatus for dispensing a fluid includes a dispensing chamber coupled to a dispensing orifice and a fluid reservoir. The dispensing chamber is coupled to a transducer which is adapted to change the volume of the dispensing chamber in response to a signal applied to the transducer. The signal is characterized by 1) an initial rise time RT1 during which an increasing amplitude signal is applied to the transducer to gradually expand the dispensing chamber from a first volume at a first amplitude to a second volume at a second amplitude; 2) a fall time FT during which a decreasing amplitude signal is applied to the transducer to contract or compress the dispensing chamber rapidly (relative to the initial rise time RT1) to a third volume at third amplitude; 3) a final rise time RT2 during which an increasing amplitude signal is applied to the transducer to gradually expand the dispensing chamber to a fourth volume at a fourth amplitude. Preferably, the first volume is less than the second volume, the second volume is substantially greater than the third volume, the third volume is less than the fourth volume, and the first volume is same as the fourth volume and both are equal to th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.