Piezo-resistive thermal detection apparatus
US6565172B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2002 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Mar 15, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/14153
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A piezo-resistive thermal detection apparatus for detecting the temperature of fluid inside a cavity device, such as the temperature of ink inside an inkjet print head. The apparatus includes a detection region and a plurality of piezo-resistive devices. The detection region is disposed on the inkjet print head in the form of a rectangle and made of a semiconductor material. The piezo-resistive devices are disposed on centers of each side of the detection region, wherein stresses produced by deformation of the piezo-resistive devices are exerted on the piezo-resistive devices. When the temperature of the ink rises, the surface of the inkjet print head is heated and expands, resulting in the deformation of the thermal detection apparatus. The piezo-resistive devices experience large amounts of stress due to the deformation of the thermal detection apparatus and thus the resistances of the piezo-resistive devices change. The piezo-resistive devices are connected together in the form of a circuit bridge so that a voltage signal indicative of the changes in their resistances can be outputted. According to the voltage signal outputted, the temperature of the ink is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.