Hyperspectral notch filter imaging

Patent metadata

Field	Value
Publication number	US-10136077-B1
Application number	US-201615380484-A
Country	US
Kind code	B1
Filing date	Dec 15, 2016
Priority date	Dec 15, 2015
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

An imaging device includes a detector array and an aperture disposed along an optical path, with an array of filter elements positioned within the aperture in the optical path. Each filter element is configured to filter out energy that is within a unique wavelength band of interest within a wavelength spectrum of interest, to form filtered energy within the wavelength spectrum of interest that is outside the unique wavelength band of interest. The filtered energy is passed from each filter element to a plurality subsets of non-contiguous detector elements in the detector array, which in turn each generate one or more detector values based on the received energy. The detector values may be processed to determine an intensity value for the wavelength band of interest.

First claim

What is claimed is:

1. An imaging device comprising:
a detector array comprising a plurality of detector elements sensitive to a wavelength spectrum of interest, the wavelength spectrum of interest comprising a plurality of wavelength bands of interest;
a microlens array positioned between the detector array and an aperture of the imaging device, the microlens array comprising a plurality of microlens elements;
a diaphragm forming the aperture at an aperture plane, the aperture and the detector array forming an optical path; and
a filter array comprising a plurality of filter elements positioned adjacent one another within the aperture at the aperture plane in the optical path, each filter element comprising a notch filter element and being configured to:
filter out energy within a unique wavelength band of interest of the plurality of wavelength bands of interest to form filtered energy within the wavelength spectrum of interest outside the unique wavelength band of interest;

wherein each microlens element is configured to receive the filtered energy from each of the filter elements and send the filtered energy from each filter element to a different detector element of the plurality of detector elements;
a processor device in communication with the detector array, the processor device configured to:
receive a detector value from each detector element that quantifies the filtered energy received by the detector element; and
determine, based on the detector value and filter elements that are mapped to the detector elements that generated the detector values, data that quantifies the energy filtered out by the plurality of filter elements.

2. The imaging device of claim 1 , wherein each detector element of the plurality of detector elements is configured to:
receive energy within the wavelength spectrum of interest; and
generate a detector value based on the received energy within the wavelength spectrum of interest, and
wherein the imaging device further comprises:
the processor device in communication with the detector array, the processor device configured to, for each detector element:
receive the detector value generated by the detector element; and
determine an intensity value for the corresponding unique wavelength band of interest based on the detector value generated by the detector element and at least one other detector value generated by another detector element of the plurality of detector elements.

3. The imaging device of claim 1 , the microlens array comprising the plurality of microlens elements, each microlens element configured to pass the filtered energy from the filter array to a contiguous subset of detector elements of the plurality of detector elements,
wherein, for each filter element of a plural subset of filter elements of the plurality of filter elements, each microlens element is configured to pass the filtered energy from the respective filter element to at least one unique detector element of the contiguous subset of detector elements.

4. The imaging device of claim 3 , wherein each detector element of the plurality of detector elements is configured to:
receive energy within the wavelength spectrum of interest; and
generate a detector value based on the received energy within the wavelength spectrum of interest, and
wherein the imaging device further comprises:
the processor device in communication with the detector array, the processor device configured to, for each contiguous subset of detector elements:
receive the detector value generated by each detector element of the contiguous subset of detector elements; and
for each detector element of the contiguous subset of detector elements, determine an intensity value for the corresponding wavelength band of interest based on the detector value generated by the detector element and at least one other detector value generated by another detector element of the contiguous subset of detector elements.

5. The imaging device of claim 3 , wherein each filter element of the plurality of filter elements is configured to pass the filtered energy to a single corresponding detector element of each contiguous subset of detector elements.

6. The imaging device of claim 3 , wherein each filter element is configured to pass the filtered energy to a plurality of corresponding detector elements of each contiguous subset of detector elements.

7. The imaging device of claim 1 , the filter array containing a number of filter elements in a range of 4 to 256.

8. The imaging device of claim 1 , wherein the filter array is an N×N array of filter elements, wherein N is in a range of 2 to 16.

9. The imaging device of claim 1 , wherein the filter array is transversely movable with respect to the optical path, and
wherein each detector element is configured to:
receive the filtered energy from a first filter element when the filter array is in a first filter array position; and
receive the filtered energy from a second filter element when the filter array is in a second filter array position.

10. The imaging device of claim 1 , each unique wavelength band of interest comprising a plurality of non-contiguous wavelength bands within the wavelength spectrum of interest.

11. The imaging device of claim 1 , each notch filter element comprising a multivariate notch filter element.

12. The imaging device of claim 1 , the wavelength spectrum of interest comprising at least a portion of a visible light spectrum.

13. The imaging device of claim 1 , the wavelength spectrum of interest comprising at least a portion of an infrared spectrum.

14. An imaging device comprising:
a detector array comprising a plurality of detector elements sensitive to a wavelength spectrum of interest, the wavelength spectrum of interest comprising a plurality of wavelength bands of interest;
a diaphragm forming an aperture, the aperture and the detector array forming an optical path, the aperture configured to pass energy within the wavelength spectrum of interest to the plurality of detector elements of the detector array along the optical path; and
a filter array comprising a plurality of multivariate notch filter elements positioned within the aperture in the optical path, each multivariate notch filter element configured to:
filter out energy within a plurality of unique wavelength bands of interest of the plurality of wavelength bands of interest to form filtered energy within the wavelength spectrum of interest outside the unique wavelength bands of interest; and
pass the filtered energy to a plurality of non-contiguous subsets of detector elements of the plurality of detector elements.

Assignees

• Lockheed Corp

Inventors

• Twede David R
• Veras Johann M

Classifications

• G01J1/0488 Primary

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• H04N23/54

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• H04N23/71

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• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• G02B3/0056

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