IMAGING DEVICE WITH SHUTTERLESS NON-UNIFORMITY CORRECTION

• US 20150226613A1
• Filed: 02/07/2014
• Published: 08/13/2015
• Est. Priority Date: 02/07/2014
• Status: Abandoned Application

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Bauer, Marc C., Williams, Ross E.
• Application Number:
  US14/175,023
• Publication Number:
  US 20150226613A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01J 2005/0077 Imaging
• CPC Class Codes: G01J 2005/202 Arrays
• CPC Class Codes: G01J 5/06 Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity for adjusting of solid angle of collected radiation G01J5/07; means for wavelength selection G01J5/0801
• CPC Class Codes: G01J 5/061 by controlling the temperature of the apparatus or parts thereof, e.g. using cooling means or thermostats
• CPC Class Codes: G01J 5/10 using electric radiation detectors
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: G01J 5/22 Electrical features thereof
• CPC Class Codes: G01J 5/52 using comparison with reference sources, e.g. disappearing-filament pyrometer
• CPC Class Codes: H04N 25/67 applied to fixed-pattern noise, e.g. non-uniformity of response
• 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

Abstract

An imaging device including a focal plane array and capable of providing non-uniformity correction (NUC) without using a shutter outside the focal plane array. In one example, the imaging device includes a focal plane array that comprises an array of pixels arranged in rows and columns, the array of pixels corresponding to an imaging area of the focal plane array, the plurality of pixels including a first plurality of imaging pixels and a second plurality of reference pixels. The first plurality of imaging pixels are configured to receive incident electromagnetic radiation from a viewed scene and provide image signals, and the second plurality of reference pixels are shielded from receiving the incident electromagnetic radiation and are configured to produce non-uniformity correction signals.

Claims

1. An imaging device comprising:

a focal plane array comprising an array of pixels arranged in rows and columns, the array of pixels corresponding to an imaging area of the focal plane array, the plurality of pixels including a first plurality of imaging pixels and a second plurality of reference pixels;

wherein the first plurality of imaging pixels are configured to receive incident electromagnetic radiation from a viewed scene and provide image signals; and

wherein the second plurality of reference pixels are shielded from receiving the incident electromagnetic radiation and are configured to produce non-uniformity correction signals.

2. The imaging device of claim 1, further comprising optics configured to focus the incident electromagnetic radiation onto the imaging area of the focal plane array.

3. The imaging device of claim 2, wherein the optics includes a lens having an f/#=1.

4. The imaging device of claim 1, further comprising a substrate, wherein the focal plane array is disposed over the substrate.

5. The imaging device of claim 4, wherein the substrate is a ceramic substrate.

6. The imaging device of claim 4, further comprising a thermocooler positioned between the substrate and the focal plane array.

7. The imaging device of claim 1, further comprising a reflective coating disposed over the second plurality of reference pixels, the reflective coating shielding the second plurality of reference pixels from receiving the incident electromagnetic radiation.

8. The imaging device of claim 7, wherein the reflective coating includes a layer of gold.

9. The imaging device of claim 8, wherein the layer of gold has a thickness in a range of approximately 2-300 nanometers.

10. The imaging device of claim 7, wherein the reflective coating includes a layer of aluminum.

11. The imaging device of claim 1, wherein the second plurality of reference pixels are arranged in a regular pattern over the array of pixels.

12. The imaging device of claim 11, wherein the second plurality of reference pixels comprises between approximately 0.39% and 50% of the array of pixels.

13. The imaging device of claim 12, wherein the second plurality of reference pixels comprises approximately 12.5% of the array of pixels.

14. The imaging device of claim 11, wherein the second plurality of reference pixels includes at least one reference pixel in each row and column of the array of pixels.

15. The imaging device of claim 1, wherein the focal plane array is a microbolometer array, and wherein the incident electromagnetic radiation is infrared radiation.