Resistance-stable thermal print heads
US5745147A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1996 |
| Grant date | Apr 28, 1998 |
| Priority date | — |
| Expiry date | Mar 15, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/3357
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A thermal print head which includes an array of individually addressable resistors on a substrate is provided to substantially reduce undesirable drift in the resistance values of the resistors. The thermal print head includes a thermally stable glaze having a smooth surface formed on the substrate, and an electrically resistive doped-semiconductive layer formed on the smooth glaze surface. An array of first and second electrode pairs is formed on the resistive layer such that each of the electrodes forms a gap therebetween. A protective layer is formed over the electrode pairs and over the resistive layer at the gap. An electrically conductive layer is formed on the protective layer. The thermal print head includes a structure for applying first and second potentials respectively to the first and second electrodes of each of the pairs for selectably heating each of the resistors, and applying a third potential to the conductive layer. The thermal print head further includes a structure for switching the potential of the first electrode from a low terminal potential state to a state substantially equal to the potential of the second electrode, and for providing the absolute value o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.