Thermal emitted radiation detecting device
Assignee1138037 Ontario Ltd.
InventorJohn W. Patchell
Life of this patent
Estimating the term…
Abstract
A thermal emitted radiation detecting device is configured to detect objects in visual blind spots of a vehicle. A low cost differential detector is used which is sensitive to temperature change. Optics train two different fields of view on the detector and switch between the two fields of view to provide a blind spot field of view and a reference field of view. The presence of a vehicle in the blind spot field of view results in a temperature difference between the two fields of view. The resulting detector output signal is compared to predetermined threshold levels and then used to provide an indication, either visual or audible. Several embodiments of optics and switching fields of view are provided.
Claims28
A thermal emitted radiation detecting device for detecting objects in a blind spot comprising:
- detector means for generating an output signal responsive to thermal emitted radiation;
- means for defining first and second fields of view relative to the detector means;
- means for switching the field of view detected to generate a combined output signal;
- and
- means for deriving an indication of a proximate object from the combined output signal, whereby the first field of view comprises the blind spot and the second field of view comprises a reference field and switching between the first and second fields generates a difference in thermal emitted radiation at the detector means when the proximate object is in the first field of view.
A device as claimed in 23 wherein the means for deriving includes and annunciator.
A thermal emitted radiation detecting device for detecting objects in a blind spot comprising:
- a detector responsive to changes in thermal emitted radiation received to generate an output signal;
- optics for defining first and second fields of view relative to the detector;
- a shutter for switching the field of view detected to generate a combined output signal;
- a signal generator for providing a square wave of predetermined frequency for operating the shutter;
- a high-pass filter connected to the detector for filtering the combined output signal;
- a demodulator connected to the high-pass filter and the signal generator for deriving an object event signal;
- and
- an annunciator for comparing the object event signal to predetermined thresholds and providing an indication of the presence of an object in the blind spot, whereby the first field of view comprises the blind spot and the second field of view comprises a reference field and switching between the first and second fields generates a difference in thermal emitted radiation at the detector means when the proximate object is in the first field of view.
Dependencies are inferred from the claim text.