Reproduction and enlarging imaging system and method using a pulse-width modulated air stream
US4914522A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1989 |
| Grant date | Apr 3, 1990 |
| Priority date | — |
| Expiry date | Apr 26, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2002/031
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for copying images onto a long sheet of paper or vinyl while. A flow of constant-pressure air is pulse-width modulated in accordance with the control signals and passed over an ink meniscus maintained on the end of a small nozzle. The pulse-modulated air flowing across the meniscus causes the ink to be sprayed onto the recording medium. The dot size on the image remains constant and the pulse width within each pixel is varied to produce the desired density of color. Pressure surges in the ink supply system, produced for example by vibration or acceleration of the ink, are suppressed by a second meniscus in the ink-supply system, formed by a gas bubble or interface near the nozzle meniscus. The second meniscus should have a surface area at least as large as that of the jet meniscus. At the end of each pixel, the ink flow is interrupted for a period of about 100 microseconds to restore system equilibrium. A second and continuous air flow around the air nozzle supplies air to the turbulent flow across the ink jet and reduces recirculation of atomized ink and minimizes contamination of the nozzle and adjacent surfaces. The supply roll is mounted at each end on independently mo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.