Pyroelectric sensor and method for determining a temperature of a portion of a scene utilizing the pyroelectric sensor

• US 20060163482A1
• Filed: 12/27/2005
• Published: 07/27/2006
• Est. Priority Date: 12/28/2004
• Status: Abandoned Application

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Mantese, Joseph V.
• Application Number:
  US11/319,033
• Publication Number:
  US 20060163482A1
• Time in Patent Office: Days
• US Class Current: 250/338.200
• CPC Class Codes: G01J 5/34 using capacitors, e.g. pyroelectric capacitors
• CPC Class Codes: H10N 15/10 Thermoelectric devices using thermal change of the dielectric constant, e.g. working above and below the Curie point
• CPC Class Codes: H10N 19/00 Integrated devices, or assemblies of multiple devices, comprising at least one thermoelectric or thermomagnetic element covered by groups H10N10/00 - H10N15/00

Abstract

A pyroelectric sensor and a method for determining a scene temperature are provided. The pyroelectric sensor includes a ferroelectric layer having first and second sides. The pyroelectric sensor further includes a first metal electrode disposed on the first side of the ferroelectric layer. The pyroelectric sensor further includes a second metal electrode disposed on the first side of the ferroelectric layer a predetermined distance from the first metal electrode. When a switching voltage is applied to between the first and second metal electrodes so as to switch a polarization state of the ferroelectric layer, an amount of current flowing between the first and second metal electrodes is indicative of a temperature level of the ferroelectric layer.

Claims

1. A pyroelectric sensor, comprising:

a ferroelectric layer having first and second sides;

a first metal electrode disposed on the first side of the ferroelectric layer; and

a second metal electrode disposed on the first side of the ferroelectric layer a predetermined distance from the first metal electrode, wherein when a switching voltage is applied between the first and second metal electrodes so as to switch a polarization state of the ferroelectric layer, an amount of switching current flowing between the first and second metal electrodes is indicative of a temperature level of the ferroelectric layer.

2. The pyroelectric sensor of claim 1, further comprising a voltage source electrically coupled to the first and second metal electrodes, the voltage source configured to generate the switching voltage applied between the first and second metal electrodes.

3. The pyroelectric sensor of claim 1, wherein the first metal electrode has a first base portion and at least first and second extension portions extending generally in a first direction from the first base portion, and the second metal electrode having a second base portion and at least third and fourth extension portions extending generally in a second direction from the second base portion toward the first base portion, the second direction being opposite the first direction, the first base portion being disposed substantially parallel to the second base portion.

4. The pyroelectric sensor of claim 1, wherein the first metal electrode has a generally spiral configuration, and the second metal electrode has a generally spiral configuration and is disposed a predetermined distance from the first metal electrode along substantially an entire length of the second metal electrode.

7. The pyroelectric sensor of claim 1, wherein the first and second electrical terminals extend from the first and second metal electrodes, respectively, substantially parallel to one another.

8. The pyroelectric sensor of claim 1, wherein the first metal electrode is comprises at least one of a copper electrode, an aluminum electrode, a platinum electrode, and a titanium electrode.

9. The pyroelectric sensor of claim 1, further comprising an insulation layer disposed on the second side of the ferroelectric layer.

10. The pyroelectric sensor of claim 9, wherein the insulation layer comprises a silicon dioxide layer.

11. The pyroelectric sensor of claim 1, further comprising a heat absorbing layer disposed over the first and second metal electrodes and at least a portion of the first side of the ferroelectric layer, wherein the heat absorbing layer is tuned to a particular waveband of light.

12. The pyroelectric sensor of claim 1, wherein the ferroelectric layer is a planar member and the first and second electrodes are printed onto the first side of the ferroelectric layer.

13. The pyroelectric sensor of claim 1, wherein the first metal electrode comprises a first plurality of extension portions extending generally in a first direction, and the second metal electrode comprises a plurality of second extension portions extending generally in a second direction, the second direction being opposite the first direction, wherein the first plurality of extension portions and the second plurality of extension portions are arranged in a spaced inter-leaving manner on the first side of the ferroelectric layer.

14. The pyroelectric sensor of claim 13, further comprising a heat absorbing layer disposed over the first and second metal electrodes and at least a portion of the first side of the ferroelectric layer, wherein the heat absorbing layer is tuned to a particular waveband of light.

15. The pyroelectric sensor of claim 14, further comprising an insulation layer disposed on the second side of the ferroelectric layer.

5. The pyroelectric sensor of claim 5, further comprising first and second electrical terminals electrically coupled to the first and second metal electrodes, respectively.

6. The pyroelectric sensor of claim 5, wherein the first and second electrical terminals extend from the first and second metal electrodes, respectively, substantially perpendicular to one another.

16. A focal plane array, comprising:

a plurality of pyroelectric sensors, each pyroelectric sensor comprising;

a ferroelectric layer having first and second sides;

a first metal electrode disposed on the first side of the ferroelectric layer; and

a second metal electrode disposed on the first side of the ferroelectric layer a predetermined distance from the first metal electrode, wherein when a switching voltage is applied between the first and second metal electrodes so as to switch a polarization state of the ferroelectric layer, an amount of switching current flowing between the first and second metal electrodes is indicative of a temperature level of the ferroelectric layer.

17. The focal plane array as in claim 16, wherein the array is configured to generate a signal indicative of a temperature of a portion of an image scene that is detected by the plurality of pyroelectric sensors.

18. The focal plane array as in claim 16, wherein the first metal electrode of each of the plurality of pyroelectric sensors comprises a first plurality of extension portions extending generally in a first direction, and the second metal electrode of each of the plurality of pyroelectric sensors comprises a plurality of second extension portions extending generally in a second direction, the second direction being opposite the first direction, wherein the first plurality of extension portions and the second plurality of extension portions are arranged in a spaced inter-leaving manner on the first side of the ferroelectric layer;

and each of the plurality of pyroelectric sensors, further comprises a heat absorbing layer disposed over the first and second metal electrodes and at least a portion of the first side of the ferroelectric layer and an insulation layer disposed on the second side of the ferroelectric layer.

19. A method for determining a temperature of a portion of a scene utilizing a pyroelectric sensor, the pyroelectric sensor having a ferroelectric layer, and first and second metal electrodes, the ferroelectric layer having first and second sides, the first metal electrode disposed on the first side of the ferroelectric layer, the second metal electrode disposed on the first side of the ferroelectric layer a predetermined distance from the first metal electrode, the method comprising:

applying a switching voltage between the first and second metal electrodes disposed on the first side of the ferroelectric layer; and

measuring an amount of switching current flowing between the first and second metal electrodes that is indicative of a temperature level of the ferroelectric layer.

20. The method of claim 19, further comprising receiving light reflected from a portion of a scene of an environment onto a heat absorbing layer disposed over at least a portion of the first and second metal electrodes and the ferroelectric layer, wherein the heat absorbing layer is tuned to a particular waveband of light.

21. The method of claim 20, wherein the amount of switching current is further indicative of a temperature level of the portion of the scene.