Imaging system

• US 8,511,823 B2
• Filed: 02/14/2011
• Issued: 08/20/2013
• Est. Priority Date: 02/18/2010
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Black, Stephen H., Portnoy, Andrew D., Silver, Alan G.
• Primary Examiner(s): Dinh, Jack
• Application Number:
  US13/026,854
• Publication Number:
  US 20110199578A1
• Time in Patent Office: 918 Days
• Field of Search: 351/206, 351/205, 351/246
• US Class Current: 351/206
• CPC Class Codes: A61B 3/12 for looking at the eye fundus, e.g. ophthalmoscopes A61B3/13 takes precedence
• CPC Class Codes: H04N 25/40 Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled
• CPC Class Codes: H04N 25/443 by reading pixels from selected 2D regions of the array, e.g. for windowing or digital zooming
• CPC Class Codes: H04N 25/445 by skipping some contiguous pixels within the read portion of the array
• CPC Class Codes: H04N 25/702 SSIS architectures characterised by non-identical, non-equidistant or non-planar pixel layout

Abstract

According to certain embodiments, foveal array elements of a foveal region of a focal plane array are sampled at a faster sampling rate to yield foveal array data. Peripheral array elements of a peripheral region of the focal plane array are sampled at a slower sampling rate or sparser sampling density to yield peripheral array data. The foveal array data is processed to yield foveal image data for a foveal region of a display. The peripheral array data is processed to yield peripheral image data for a peripheral region of the display.

Claims

1. A method of producing infrared imagery comprising:

for each of a plurality of frames, sampling a plurality of foveal array elements of a detector foveal region of a microbolometer array at a faster sampling rate to yield foveal array data;

sampling a plurality of peripheral array elements of a detector peripheral region of the microbolometer array at a slower sampling rate to yield peripheral array data, the plurality of peripheral array elements including a plurality of sub-regions, each sub-region including two or more peripheral array elements, and wherein sampling the plurality of peripheral array elements comprises for each sub-region;

sampling a first subset of the each sub-region for a first frame of the plurality of frames; and

sampling a second subset of the each sub-region for a second frame of the plurality of frames, the second subset not equal to the first subset;

processing the foveal array data to yield foveal image data for a display foveal region of a display; and

processing the peripheral array data to yield peripheral image data for a display peripheral region of the display.

2. The method of claim 1, wherein the first and second subsets are of each sub-region.

3. The method of claim 1, the processing the peripheral array data further comprising:

generating first image data generated from the first subset of the peripheral array elements for the first frame and the second frame; and

generating second image data generated from the second subset of the peripheral array elements for the second frame and a third frame.

4. The method of claim 1, the processing the peripheral array data further comprising:

generating first image data generated from the first subset of the peripheral array elements for the first frame; and

holding the first image data for the second frame.

5. The method of claim 1, the processing the peripheral array data further comprising:

generating first image data generated from the first subset of the peripheral array elements for the first frame; and

averaging the first image data with second image data generated from the second subset of the peripheral array elements for the second frame.

6. The method of claim 1, further comprising:

designating a plurality of array elements as the foveal array elements to set the foveal region.

7. The method of claim 1, further comprising setting the foveal region by:

sending one or more fovea start addresses and one or more fovea stop addresses to the microbolometer plane array.

8. The method of claim 1:

further comprising maintaining a constant bias duty cycle to compensate for an impact of one or more changes in Joule heating in one or more peripheral array elements as a sampling duty cycle changes.

9. The method of claim 1:

further comprising electronically adjusting one or more bias conditions of the microbolometer array to compensate for an impact of one or more changes in Joule heating in one or more peripheral array elements as a sampling duty cycle changes.

10. The method of claim 1:

further comprising electronically adjusting an operating bias of supporting circuitry of the microbolometer array to compensate for an impact of one or more changes in Joule heating in one or more peripheral array elements as a sampling duty cycle changes.

11. A system comprising:

a microbolometer array; and

one or more processors operable to;

for each frame of a plurality of frames, sample a plurality of foveal array elements of a detector foveal region of the microbolometer array at a faster sampling rate to yield foveal array data;

sample a plurality of peripheral array elements of a detector peripheral region of the microbolometer array at a slower sampling rate to yield peripheral array data, wherein the plurality of peripheral array elements includes a plurality of sub-regions, each sub-region including two or more peripheral array elements, and sampling the peripheral array elements includes for each sub-region;

sampling a first subset of the each sub-region for a first frame; and

sampling a second subset of the each sub-region for a second frame, the second subset not equal to the first subset;

process the foveal array data to yield foveal image data for a display foveal region of a display; and

process the peripheral array data to yield peripheral image data for a display peripheral region of the display.

12. The system of claim 11, wherein the first and second subsets are

proper subsets of each sub-region.

13. The system of claim 11, the processing the peripheral array data further comprising:

generating first image data generated from the first subset of the peripheral array elements for the first frame and the second frame; and

generating second image data generated from the second subset of the peripheral array elements for the second frame and a third frame.

14. The system of claim 11, the processing the peripheral array data further comprising:

generating first image data generated from the first subset of the peripheral array elements for the first frame; and

holding the first image data for the second frame.

15. The system of claim 11, the processing the peripheral array data further comprising:

generating first image data generated from the first subset of the peripheral array elements for the first frame; and

averaging the first image data with second image data generated from the second subset of the peripheral array elements for the second frame.

16. The system of claim 11, the one or more processors further operable to set the foveal region by:

sending one or more fovea start addresses and one or more fovea stop addresses to the microbolometer array.

17. The system of claim 11:

the one or more processors further operable to maintain a constant bias duty cycle to compensate for an impact of one or more changes in Joule heating in one or more peripheral array elements as a sampling duty cycle changes.

18. The system of claim 11:

the one or more processors further operable to electronically adjust one or more bias conditions of the microbolometer array to compensate for an impact of one or more changes in Joule heating in one or more peripheral array elements as a sampling duty cycle changes.