Ink-jet print head having improved thermal uniformity
US5635964A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1995 |
| Grant date | Jun 3, 1997 |
| Priority date | — |
| Expiry date | Jan 18, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J29/38
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An improved media-width phase-change ink-jet print had (102) maintains a uniform temperature across its width to produce consistent drop mass and uniform print quality. The print head uses a heater (120) including two separately controlled, overlapping heating zones (154). The heating zones produce heat gradients (170, 172) that have maximum outputs toward opposing edges (168a, 168b) of the print head and are controlled in response to thermistors (138s, 168b) positioned at the corresponding edges. The two heating zones together produce a linear heat gradient (180) across the print heat to compensate for uneven head-to-drum spacing (166) and other unsymmetrical thermal loads on the print head. The improved print head also includes baffles (192) that reduce air flow between the head and the attached reservoir (118), and thermal breaks (218) that insulate the section (220) of the head that includes the jets from the thermal gradients at the edges of the print head.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.