Non-contacting temperature sensing device
US6222454A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1999 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | Jul 1, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J5/80
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The device according to the invention provides a non-contacting temperature sensing device incorporating micro-bolometric detectors as the suitable infrared sensors for automotive applications. A first and second infrared sensors each include an active infrared sensing element and a temperature drift compensating element. A current bias is applied to the active infrared sensing element as well as to the temperature drift compensating element, which is identical in structure with the active infrared sensing element, and the voltage outputs of these two elements pass through a differential amplifier. The fluctuation in the substrate temperature or the ambient temperature affects the active sensing element and the compensating element in the same way, thus it is cancelled out. Instead of using one spectral band of the infrared radiation, as in the prior art, two spectral bands are used resulting in a first and second signal generated by the first and second infrared sensors. A ratio of the first and second signals is obtained. The ratio of the signals is emissivity independent, so that the device of the present invention provides a more accurate measurement of temperature. The need to…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.