Apparatus and method for MEMS resonant sensor arrays

Patent metadata

Field	Value
Publication number	US-10288487-B2
Application number	US-201715673553-A
Country	US
Kind code	B2
Filing date	Aug 10, 2017
Priority date	Aug 10, 2017
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

A method is provided. The method comprises: transmitting a periodic chirp to at least two pixels of a MEMS sensor array; determining a resonant frequency of each MEMS resonant sensor receiving the periodic chirp; determining the change in resonant frequency of each MEMS resonant sensor receiving the periodic chirp; determining a power level incident upon each pixel receiving the periodic chirp. In one embodiment, the method further comprises calibrating the MEMS sensor array. In another embodiment, calibrating comprises generating a reference resonant frequency for each MEMS resonant sensor. In a further embodiment, determining the power level comprises determining a difference between the determined resonant frequency and the reference resonant frequency.

First claim

What is claimed is:

1. An apparatus, comprising:
a signal generator configured to generate periodic chirps;
detector circuit;
a MEMS resonant sensor array comprising at least two pixels coupled to the signal generator system and the detector system;
a processing circuit coupled to the detector circuit;
a shutter coupled to the processing circuit, and configured, when activated, to isolate the MEMs resonant sensor array from incident radiation;
wherein the detector circuit is configured to determine a reference resonant frequency for each of at least two pixels when the shutter activated, and at least one non-reference resonant frequency of each of at least two pixels when the shutter is not activated; and
wherein the processing circuit is configured to determine at least one power level of the incident radiation upon each of at least two pixels using a corresponding reference resonant frequency and a corresponding non-reference reason frequency.

2. The apparatus et claim 1 , wherein the detector circuit comprises at least one detector.

3. The apparatus of claim 1 , wherein the processing circuit comprises:
a peak detector system configured to determine a resonant frequency of each pixel in in the MEMS resonant sensor array;
an image detection system configured to determine radiation power incident upon each pixel based upon a difference between the determined resonant frequency and a corresponding reference resonant frequency; and

wherein the image detection system comprises at least one of a reference database and a scale factor database.

4. The apparatus of claim 3 , wherein the apparatus further comprises a counter system coupled to the signal generator.

5. The apparatus of claim 1 , wherein the shutter comprises an electro-optical shutter.

6. The apparatus of claim 1 , wherein the periodic chirps linearly increase in frequency during each period.

7. The apparatus of claim 1 , wherein each pixel comprises:
a resonator; and
an absorber on the resonator.

8. The apparatus of claim 7 , wherein the absorber is an infrared absorber.

9. An apparatus, comprising:
a signal generator configured to generate periodic chirps; a detector system comprising at least one detector, wherein each of the at least one detectors comprises a detector circuit coupled to an analog to digital converter;
a MEMS infrared resonant sensor array comprising M rows and N columns of pixels coupled to the signal generator and the detector system; and
a processing circuit, coupled to the detector system, comprising:
a peak detector system configured to determine a resonant frequency of each pixel in the MEMS infrared resonant sensor array;
an image detection system configured to determine infrared radiation power incident upon each pixel based upon a difference between the determined resonant frequency and a corresponding reference resonant frequency; and
wherein the processing circuit comprises at least one of a reference database and a scale factor database.

10. The apparatus of claim 9 , wherein the apparatus further comprises a shutter system coupled to the processing circuit.

11. The apparatus of claim 10 , wherein the shutter system comprises an electro-optical shutter.

12. The apparatus of claim 9 , wherein the apparatus further comprises a counter coupled to the signal generator.

13. A method, comprising:
calibrating a MEMS resonant sensor array by isolating the MEMs resonant sensor array from incident radiation when a shutter is closed to permit determination of reference resonant frequencies of each pixel in the MEMS resonant sensor array:
transmitting a periodic chirp to at least two pixels of a MEMS resonant sensor array;
determining a resonant frequency of each pixel receiving the periodic chirp;
determining the change in resonant frequency of pixel receiving the periodic chirp; and
determining a power level incident upon each pixel receiving the periodic chirp.

14. The method of claim 13 , where in calibrating comprises generating a reference resonant frequency for each pixel.

15. The method of claim 13 , wherein determining the power level comprises determining a difference between the determined resonant frequency and a reference resonant frequency.

16. The method of claim 13 , wherein generating a periodic chirp comprises generating a periodic chirp having a linearly increasing frequency during a period.

17. The method of claim 13 , wherein determining the resonant frequency comprises:
identifying a count corresponding to a maximum measured amplitude detected from a pixel; and
converting the count to a resonant frequency of that pixel.

Assignees

• Honeywell Int Inc

Inventors

• Tin Steven

Classifications

• G01J2005/0077

  Imaging · CPC title

• G01J2005/106

  Arrays · CPC title

• G01J5/10 Primary

  using electric radiation detectors · CPC title

• G01J5/0215

  Compact construction · CPC title

• H04N5/33

  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 title