Array jet velocity normalization
US5212497A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1991 |
| Grant date | May 18, 1993 |
| Priority date | — |
| Expiry date | Jun 17, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/04581
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A multi-orifice ink jet print head array (32) includes multiple drive circuits that drive respective PZTs (16) to cause ink drops to be ejected from respective orifices (28). Each drive circuit includes a voltage divider (36) having a resistor R.sub.S. The ink drop ejection velocity is controlled by selecting an appropriate value of R.sub.S for each voltage divider, thereby compensating for imperfections in manufacturing of the print head array. The value of a particular R.sub.S is selected by temporarily connecting the corresponding voltage divider (36A), in which the value of R.sub.S is R.sub.I, to assessment circuit (56). The assessment circuit includes a potentiometer (66) with resistance value R.sub.POT. Ink drops are ejected at a rapid periodic rate as a camera (102) records the position of the ink drops with respect to a graticule (94) at the time a strobe (100) flashes. The value of R.sub.POT is adjusted until the ink drops are on the graticule as viewed on a monitor (108), at which time R.sub.POT =R.sub.T. R.sub.S is then laser trimmed by an amount R.sub.T, so that R.sub.S =R.sub.F, where R.sub.F =R.sub.I +R.sub.T.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.