CA-3299716-A1 - MOBILE GAS AND CHEMICAL IMAGING CAMERA

Abstract

In one embodiment, an infrared (IR) imaging system for determining a concentration of a target species in an object is disclosed. The imaging system can include an optical detector, a lens spaced from the optical detector along an axis which is positioned to transfer light to the optical detector, a first thermal element comprising a first material having a first coefficient of thermal expansion (CTE), and a second thermal element mechanically and thermally coupled to the first thermal element and the lens. The second thermal element comprises a second material having a second CTE, wherein the second CTE is different from the first CTE. In response to a temperature change, respective lengths of the first and second thermal elements change so as to adjust a position of the lens relative to the optical detector along the axis.

Inventors

• Robert Timothy Kester

Assignees

• REBELLION PHOTONICS, INC.

Dates

Publication Date

20260302

Application Date

20171020

Priority Date

20161021

Claims (1)

1. <pat:ClaimStatement>CLAIMS:</pat:ClaimStatement> <pat:Claims com:id="claims"> <pat:Claim com:id="CLM-00001"> <pat:ClaimNumber>1</pat:ClaimNumber> <pat:ClaimText>1. An optical system comprising: an optical detector; a lens spaced from the optical detector along an axis, the lens positioned to transfer light to the optical detector; a first thermal element comprising a first material having a first coefficient of thermal expansion (CTE); and a second thermal element mechanically and thermally coupled to the first thermal element and the lens, wherein the second thermal element comprises a second material having a second CTE, and wherein the second CTE is different from the first CTE; wherein, in response to a temperature change, respective lengths of the first and second thermal elements change so as to adjust a position of the lens relative to the optical detector along the axis. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00002"> <pat:ClaimNumber>2</pat:ClaimNumber> <pat:ClaimText>2. The optical system of claim 1, further comprising a base structure, wherein the optical detector is coupled with the base structure. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00003"> <pat:ClaimNumber>3</pat:ClaimNumber> <pat:ClaimText>3. The optical system of claim 2, wherein the first thermal element is mechanically and thermally coupled with the base structure. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00004"> <pat:ClaimNumber>4</pat:ClaimNumber> <pat:ClaimText>4. The optical system of claim 1, wherein a focal length of the lens changes in response to the temperature change, and wherein, in response to the temperature change, the respective lengths of the first and second thermal elements change to cause relative motion between the lens and the optical detector so as to maintain the transfer of light to the optical detector. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00005"> <pat:ClaimNumber>5</pat:ClaimNumber> <pat:ClaimText>5. The optical system of claim 4, wherein the temperature change comprises a temperature increase and wherein, in response to the temperature increase, the respective lengths of the first and second thermal elements change to cause the lens to move closer to the optical detector so as to maintain the transfer of light to the optical detector. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00006"> <pat:ClaimNumber>6</pat:ClaimNumber> <pat:ClaimText>6. The optical system of claim 4, wherein the temperature change comprises a temperature decrease and wherein, in response to the temperature decrease, the respective lengths of the first and second thermal elements change to cause the lens to move away from the optical detector so as to maintain the transfer of light to the optical detector. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00007"> <pat:ClaimNumber>7</pat:ClaimNumber> <pat:ClaimText>7. The optical system of claim 2, further comprising: a third thermal element comprising a third material having a third CTE, wherein the third thermal element is mechanically and thermally coupled with the first thermal element and the base structure, and wherein the third CTE is different from the first CTE. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00008"> <pat:ClaimNumber>8</pat:ClaimNumber> <pat:ClaimText>8. The optical system of claim 2, further comprising: a housing structure mechanically and thermally coupled with the base structure, wherein the optical detector is disposed within the housing structure; and an optical window mechanically and thermally coupled with the housing structure. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00009"> <pat:ClaimNumber>9</pat:ClaimNumber> <pat:ClaimText>9. The optical system of claim 1, wherein the first material comprises aluminum. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00010"> <pat:ClaimNumber>10</pat:ClaimNumber> <pat:ClaimText>10. The optical system of claim 1, wherein the second material comprises Delrin with a CTE of about 120 ppm/°C. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00011"> <pat:ClaimNumber>11</pat:ClaimNumber> <pat:ClaimText>11. The optical system of claim 7, wherein the third material is the same as the first material. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00012"> <pat:ClaimNumber>12</pat:ClaimNumber> <pat:ClaimText>12. The optical system of claim 1, wherein the optical detector comprises an infrared focal plane array (FPA). </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00013"> <pat:ClaimNumber>13</pat:ClaimNumber> <pat:ClaimText>13. The optical system of claim 8, wherein the housing structure comprises Kovar, and the optical window comprises Germanium. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00014"> <pat:ClaimNumber>14</pat:ClaimNumber> <pat:ClaimText>14. The optical system of claim 1, wherein the second CTE is greater than the first CTE. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00015"> <pat:ClaimNumber>15</pat:ClaimNumber> <pat:ClaimText>15. The optical system of claim 1, wherein, when the optical system is operated at any temperature within a range of -60 °C. to 100 °C., an effective focal length of the lens changes by an amount in a range of 1 micron to 50 microns. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00016"> <pat:ClaimNumber>16</pat:ClaimNumber> <pat:ClaimText>16. The optical system of claim 1, wherein the lens comprises a plurality of lens elements. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00017"> <pat:ClaimNumber>17</pat:ClaimNumber> <pat:ClaimText>17. The optical system of claim 1, further comprising one or more optical filters disposed along the axis. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00018"> <pat:ClaimNumber>18</pat:ClaimNumber> <pat:ClaimText>18. The optical system of claim 1, wherein the optical detector is configured to detect infrared radiation. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00019"> <pat:ClaimNumber>19</pat:ClaimNumber> <pat:ClaimText>19. The optical system of claim 1, wherein the lens comprises Germanium. </pat:ClaimText> </pat:Claim> <pat:Claim com:id="CLM-00020"> <pat:ClaimNumber>20</pat:ClaimNumber> <pat:ClaimText>20. The optical system of claim 1, wherein the optical system is configured to be worn by a person. </pat:ClaimText> </pat:Claim> </pat:Claims>

Description

MOBILE GAS AND CHEMICAL IMAGING CAMERA [0001] This is a division of Canadian Patent Application No. 3,041,105, filed October 20, 2017. [0002] Continue to [0003]. STATEMENT REGARDING FEDERALLY SPONSORED R&D [0003] Funding for some portions of the technology disclosed m this application was provided by the Advanced Research Projects Agency - Energy (ARPA- E) under Contract Number DE-AR0000541. The government may have certain rights in these portions of the technology. FIELD OF THE INVENTION [0004] The present invention generally relates to a system and method for gas cloud detection and, in particular, to a system and method of detecting spectral signatures of chemical compositions in infrared spectral regions. DESCRIPTION OF THE RELATED TECHNOLOGY [0005] Spectral imaging systems and methods have applications in a variety of fields. Spectral imaging systems and methods obtain a spectral image of a scene in one or more regions of the electromagnetic spectrum to detect phenomena, identify material compositions or characterize processes. The spectral image of the scene can be represented as a three-dimensional data cube where two axes of the cube represent two spatial dimensions of the scene and a third axis of the data cube represents spectral information of the scene in different wavelength regions. The data cube can be processed using mathematical methods to obtain information about the scene. Some of the existing spectral imaging systems generate the data cube by scanning the scene in the spatial domain (e.g., by moving a slit across the horizontal dimensions of the scene) and/or spectral domain (e.g., by scanning a wavelength dispersive element to obtain images of the scene in different spectral regions). Such scanning approaches acquire only a portion of the full data cube at a time. These portions of the full data cube are stored and then later processed to generate a full data cube. SUMMARY [0006] The systems, methods and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein. [0007] In one embodiment, an infrared (IR) imaging system for determining a concentration of a target species in an object is disclosed. The imaging system can include an optical system including an optical focal plane array (FPA) unit. The optical system can have components defining at least two optical channels thereof, said at least two optical channels being spatially and spectrally different from one another. Each of the at least two optical channels can be positioned to transfer IR radiation incident on the optical system towards the optical FPA. The system can include a processing unit containing a processor that can be configured to acquire multispectral optical data representing said target species from the IR radiation received at the optical FPA. Said optical system and said processing unit can be contained together in a data acquisition and processing module configured to be worn or carried by a person. [0008] In another embodiment, an infrared (IR) imaging system for determining a concentration of a target species in an object is disclosed. The imaging system can comprise an optical system including an optical focal plane array (FPA) unit. The optical system can have components defining at least two optical channels thereof, said at least two optical channels being spatially and spectrally different from one another. Each of the at least two optical channels can be positioned to transfer IR radiation incident on the optical system towards the optical FPA. The system can include a processing unit containing a processor that can be configured to acquire multispectral optical data representing said target species from the IR radiation received at the optical FPA. Said data acquisition and processing module can have dimensions less than 8 inches x 6 inches x 6 inches. [0009] In another embodiment, an infrared (IR) imaging system for determining a concentration of a target species in an object is disclosed. The imaging system can include an optical system including an optical focal plane array (FPA) unit. The optical system can have components defining at least two optical channels thereof, said at least two optical channels being spatially and spectrally different from one another. Each of the at least two optical channels can be positioned to transfer IR radiation incident on the optical system towards the optical FPA. The system can include a processing unit containing a processor that can be configured to acquire multispectral optical data representing said target species from the IR radiation received at the optical FPA. Said data acquisition and processing module can have a volume of less than 300 cubic inches. [0010] In yet another embodiment, a method of identifying a target species or quantifying or characterizing a parameter of the target species in an object is disclosed. The method can include wearing or carrying