Single camera multi-spectral imager

• US 20070159541A1
• Filed: 01/09/2006
• Published: 07/12/2007
• Est. Priority Date: 01/09/2006
• Status: Active Grant

• Current Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Original Assignee: BAE Systems Spectral Solutions LLC (BAE Systems Plc)
• Inventors: Sparks, Andrew, DeWeert, Michael
• Granted Patent: US 7,855,786 B2
• Time in Patent Office: Days
• US Class Current: 348/272
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths

Abstract

An imaging system has a single focal plane array that does not require the precise alignment of multiple cameras relative to one another. It incorporates a multi-band, band pass filter that includes filter elements corresponding to pixel regions of a detector within a camera. The imaging system may further incorporate a detector that vertically discriminates among radiation in different spectral bands incident on an image plane of the detector. In this manner, spectral content may be determined in each spatial region without the need for beam splitting or multiple cameras. The filter itself may further comprise different filter elements, for example, filter elements A and B arranged in a checkerboard pattern, where filter element A passes different spectral bands than filter element B. In this manner, multi-spectral, high resolution images may be generated using a single camera that significantly improves upon image discrimination as compared to, for example, the Bayer color filter array pattern. The single camera implementation is well suited for incorporation into marine, land and air vehicles.

Claims

1. An imaging system, comprising:

a camera comprising a detector having an image plane and photosensing layers beneath the image plane corresponding to different bands;

a multi-band, band pass filter for filtering radiation received from a target and optically conveying it to the image plane, the filter including at least some filter elements having more than two bands, wherein the filter elements convey radiation to a pixel region of the image plane.

2. The imaging system according to claim 1, wherein the filter elements comprise at least two different types of filter elements, each transmitting different bands to the image plane.

3. The imaging system according to claim 2, wherein the filter elements of different types are arranged in a checkerboard pattern to comprise the filter.

4. The imaging system according to claim 1, wherein the filter comprises more than four substantially non-overlapping bands.

5. The imaging system according to claim 1, wherein the filter comprises six substantially non-overlapping bands.

6. The imaging system according to claim 1, wherein the filter comprises twelve substantially non-overlapping bands.

7. The imaging system according to claim 3, wherein each of the different types of filter elements comprises a three band filter.

8. The imaging system according to claim 3, wherein the filter comprises four different types of filter elements and each filter element comprises a three band filter.

9. The imaging system according to claim 1, further comprising a lens between the filter and the camera that conveys the image from the filter to the image plane.

10. The imaging system according to claim 9, wherein the lens comprises a lens array.

11. The multi-band, band pass filter according to claim 1, wherein the filter elements comprise multi-layer dielectric filters.

12. The imaging system according to claim 1, further comprising a processing unit for processing signals output from the camera.

13. The imaging system according to claim 1, wherein the imaging system is mounted in a vehicle.

15. The multi-band, band pass filter according to claim 12, wherein the filter elements each corresponding to one pixel region on an image plane of a detector.

16. The multi-band, band pass filter according to claim 12, wherein the filter elements comprise multi-layer dielectric filters.

14. A multi-band, band pass filter comprising a plurality of filter elements, each corresponding to at least one pixel region on an image plane of a detector.