Hybrid infrared sensor array having heterogeneous infrared sensors

• US 10,110,833 B2
• Filed: 07/10/2017
• Issued: 10/23/2018
• Est. Priority Date: 04/23/2010
• Status: Active Grant

• Current Assignee: Teledyne FLIR LLC (Teledyne Technologies Incorporated)
• Original Assignee: FLIR Systems, Inc. (Teledyne Technologies Incorporated)
• Inventors: Teich, Andrew C., Terre, William A., Boulanger, Pierre, Frank, Jeffrey D., Distelzweig, John H.
• Primary Examiner(s): Gunberg, Edwin
• Application Number:
  US15/645,988
• Publication Number:
  US 20170374298A1
• Time in Patent Office: 470 Days
• Field of Search: None
• CPC Class Codes: G01J 2005/0077 Imaging
• CPC Class Codes: G01J 5/025 Interfacing a pyrometer to an external device or network; User interface
• CPC Class Codes: G01J 5/026 Control of working procedures of a pyrometer, other than calibration; Bandwidth calculation; Gain control
• CPC Class Codes: G01J 5/04 Casings
• CPC Class Codes: G01J 5/0846 having multiple detectors for performing different types of detection, e.g. using radiometry and reflectometry channels
• CPC Class Codes: G01J 5/12 using thermoelectric elements, e.g. thermocouples
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: G01J 5/80 Calibration using comparison with reference sources G01J5/52
• CPC Class Codes: H04N 25/702 SSIS architectures characterised by non-identical, non-equidistant or non-planar pixel layout
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

Various techniques are provided for an infrared sensor assembly having a hybrid infrared sensor array. In one example, such a hybrid infrared sensor array may include a plurality of microbolometers and a non-bolometric infrared sensor. The non-bolometric infrared sensor may be a thermopile or other type of infrared sensor different from a bolometer-based sensor. The non-bolometric infrared sensor may be utilized to provide a more accurate and stable temperature reading of an object or area of a scene captured by the array. In some embodiments, the non-bolometric infrared sensor may also be utilized to perform a shutter-less radiometric calibration of the microbolometers of the array. An infrared sensor assembly may include, for example, the hybrid infrared sensor array, as well as a substrate including bond pads and/or appropriate circuits to obtain and/or transmit output signals from the non-bolometric infrared sensor.

Claims

1. An infrared sensor assembly comprising:

an array of infrared sensors, the array comprising;

a plurality of microbolometers configured to image a scene, and

at least one non-bolometric sensor configured to detect infrared radiation from at least a portion of the scene; and

a substrate coupled to the array, the substrate comprising;

a readout integrated circuit (ROIC) configured to provide first signals from the microbolometers corresponding to a captured infrared image of the scene,

an output circuit configured to provide second signals from the at least one non-bolometric sensor corresponding to the infrared radiation, and

a processor configured to radiometrically calibrate the microbolometers based on the second signals provided by the output circuit.

2. The infrared sensor assembly of claim 1, wherein the processor is further configured to radiometrically calibrate the microbolometers further based on the first signals provided by the ROIC.

3. The infrared sensor assembly of claim 1, wherein the captured infrared image contains at least one blind spot corresponding to the location of the at least one non-bolometric sensor among the array, and wherein the processor is configured to generate a blended infrared image that has the at least one blind spot filled based at least on the captured infrared image.

4. The infrared sensor assembly of claim 3, wherein the processor is configured to generate the blended infrared image by converting the second signals from the at least one non-bolometric sensor into pixel data and combining the pixel data with the captured infrared image.

5. The infrared sensor assembly of claim 3, wherein the processor is configured to generate the blended infrared image by extrapolating pixel data for the at least one blind spot from an average of neighboring pixels to the at least one blind spot in the captured infrared image without using the second signals from the at least one non-bolometric sensor.

6. The infrared sensor assembly of claim 1, wherein the at least one non-bolometric sensor comprises one of a thermopile infrared sensor or a pyroelectric detector.

7. The infrared sensor assembly of claim 1, wherein the at least one non-bolometric sensor comprises a plurality of non-bolometric sensors, and wherein the plurality of non-bolometric sensors and configured to:

determine an average temperature of the scene using the plurality of non-bolometric sensors; and

obtain multiple spot temperature readings of the scene using the plurality of non-bolometric sensors without moving the infrared sensor assembly.

8. The infrared sensor assembly of claim 1, wherein the processor is configured to radiometrically calibrate the microbolometers without using a shutter or black body device for the infrared sensor assembly.

9. The infrared sensor assembly of claim 8, wherein the scene is of substantially uniform temperature during radiometrically calibrating the microbolometers by the processor.

10. The infrared sensor assembly of claim 1, wherein the at least one non-bolometric sensor is provided in place of one or more of the microbolometers.

11. A method comprising:

receiving, at an array of infrared sensors, infrared radiation from a scene, wherein the array comprises a plurality of microbolometers and at least one non-bolometric sensor;

providing, by a readout integrated circuit (ROIC) communicatively coupled to the plurality of microbolometers, infrared image data representing an infrared image of the scene;

providing, by an output circuit communicatively coupled to the at least one non-bolometric sensor, temperature information associated with the scene, wherein the ROIC and the output circuit are provided on a substrate; and

radiometrically calibrating the plurality of microbolometers based on the temperature information provided by the output circuit.

12. The method of claim 11, wherein the radiometrically calibrating the plurality of microbolometers is further based on the infrared image data provided by the ROIC.

13. The method of claim 11, wherein the infrared image contains at least one blind spot corresponding to a location of the at least one non-bolometric sensor on the array, and wherein the method further comprises:

generating a blended infrared image data representing a blended infrared image that has the at least one blind spot filled based at least on the infrared image data.

14. The method of claim 13, wherein the generating the blended infrared image comprises:

converting the temperature information from the at least one non-bolometric sensor into pixel data; and

combining the pixel data with the infrared image data.

15. The method of claim 13, herein the generating the blended infrared image comprises:

extrapolating pixel data for the at least one blind spot from an average of neighboring pixels to the at least one blind spot in the infrared image data without using the temperature information from the at least one non-bolometric sensor.

16. The method of claim 11, wherein the at least one non-bolometric sensor comprises a plurality of non-bolometric sensors, and wherein the method further comprises:

determining an average temperature of the scene using the plurality of non-bolometric sensors; and

obtaining multiple spot temperature readings of the scene using the plurality of non-bolometric sensors without moving the infrared sensor assembly.

17. The method of claim 11, radiometrically calibrate the microbolometers without using a shutter or black body device for the infrared sensor assembly

and wherein the scene is of substantially uniform temperature during radiometrically calibrating the microbolometers by the processor.

18. The method of claim 11, wherein the at least one non-bolometric sensor is provided in place of one or more of the plurality of microbolometers.

19. A method of providing a hybrid infrared sensor assembly, the method comprising:

fabricating microbolometers to form a focal plane array (FPA);

fabricating at least one non-bolometric sensor on the FPA;

providing a readout integrated circuit (ROIC) electrically coupled to the microbolometers to generate output signals corresponding to an image of infrared radiation incident on the microbolometers; and

providing bond pads electrically connected to the at least one non-bolometric sensor and configured to form an electrical connection with an external device to generate temperature information associated with the infrared radiation using the at least one non-bolometric sensor, wherein the external device radiometrically calibrates the microbolometers based on the temperature information.

20. The method of providing a hybrid infrared sensor assembly of claim 19, wherein the external device further radiometrically calibrates the microbolometers based on the output signals corresponding to the image of the infrared radiation provided by the ROIC.