Thermal inkjet printhead having driver circuitry thereon and method for making the same
US5122812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1991 |
| Grant date | Jun 16, 1992 |
| Priority date | — |
| Expiry date | Jan 3, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2202/13
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An improved thermal inkjet printhead and manufacturing method in which driver circuitry (e.g. MOSFET transistors), heating resistors, and a specialized arrangement of conductive elements are used. A substrate is provided having a plurality of drive transistors thereon. A layer of resistive material (e.g. a tantalum-aluminum mixture) is deposited on the substrate and directly connected to the source, gate, and drain of at least one transistor. A layer of conductive metal (e.g. aluminum) is deposited on a portion of the resistive layer, forming both covered and uncovered regions thereof. The uncovered region functions as a heating resistor, and the covered regions function as direct electrical contacts to the transistor, thereby minimizing the number of conductive elements in the printhead. The resistor is positioned beneath an ink-retaining cavity, and is designed to heat ink therein for expulsion through an orifice plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.