Method and apparatus for determining the velocity of a liquid stream of droplets
US4217594A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1977 |
| Grant date | Aug 12, 1980 |
| Priority date | — |
| Expiry date | Oct 17, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/125
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A pressurized ink jet stream is broken up into droplets spaced substantially uniform distances by application of a predetermined frequency to the stream. When the velocity of the stream is to be determined, a frequency perturbation is placed in the predetermined frequency to produce a gap in the stream of droplets at a selected distance from the perturbation application point. The presence of the gap is optically sensed at the selected distance by determining when the time period between adjacent droplets at the selected distance exceeds a predetermined period of time. The velocity of the stream is determined in accordance with the time that it takes from the perturbation of the gap until the gap is sensed at the selected distance because of the time period between adjacent droplets exceeding the predetermined period of time. After the velocity of the stream is determined, it is compared with a desired velocity, and corrections in the pressure of the stream are made in accordance with the difference between the determined velocity and the desired velocity and whether the determined velocity is larger or smaller than the desired velocity so that the velocity of the stream can be cor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.