Optical system for reformatting a line image

• US 5,789,735 A
• Filed: 10/16/1995
• Issued: 08/04/1998
• Est. Priority Date: 10/16/1995
• Status: Expired due to Fees

• Current Assignee: Goodrich Corporation (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Gigioli, George W. Jr.
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US08/543,446
• Time in Patent Office: 1,023 Days
• Field of Search: 250/208.1, 250/201.8, 250/216, 250/201.3, 250/226, 348/143, 382/316, 359/363-364, 359/372
• US Class Current: 250/208.1
• CPC Class Codes: G02B 27/4227 in image scanning systems
• CPC Class Codes: G02B 27/4294 in multispectral systems, e.g. UV and visible

Abstract

An optical system is coupled between a one-dimensional line image and a two-dimensional detector array. The line image is segmented and reimaged onto respective image cells of the detector array, each image cell being a row of detector cells. The optical system positionally segments the line image into lengths of a predetermined length. The predetermined length of the segments optically fit within the width of image cells within the array. The optical system reimages the line segments to image cell positions on the detector array. The optical system preferably employs diffractive (binary) optic elements.

Claims

1. An optical system for reformatting an image, comprising:

at least one optical subsystem having a plurality of planar optical elements optically coupled to a line image, the at least one optical subsystem (i) segmenting the line image into a plurality of image segments, each image segment being of a predetermined segment length and located at a respective original position in the line image, and (ii) reimaging each of the image segments onto at least one image cell in accordance with the original position of the image segments in the line image.

2. The optical system of claim 1 wherein the image cells are arranged into an array of image cells.

3. The optical system of claim 2 wherein each image cell contains a plurality of detector cells in a detector array.

4. The optical system of claim 1 wherein the image cells form an imaging spectrometer, each image segment being reimaged to a plurality of imaging cells in accordance with the wavelengths of light in the image segments.

5. The optical system of claim 1 wherein there are a plurality of sequential line images, further comprising a data processor coupled to the image cells to perform Time Delay and Integration on the line images.

6. The optical system of claim 1 wherein the planar optical elements include a binary optic element.

7. The optical system of claim 1 wherein the planar optical elements include a prism.

8. The optical system of claim 1 further comprising an image source subsystem for imaging light from a view to form the line image.

9. The optical system of claim 1 further comprising an optical combiner to direct the reimaged line segments through a common exit pupil of the system.

10. The optical system of claim 1 further comprising at least one image corrector optically coupled to the planar optical elements to correct for image degradation introduced by the planar optical elements.

11. An optical system for reformatting an image, comprising:

a first optical subsystem optically coupled to a line image for segmenting the line image into a plurality of image segments, each image segment located at an original position in the line image, the image segments being of a first length;

an array of detector cells arranged into rows; and

a second optical subsystem having a plurality of planar optical reimaging elements optically coupled to the first optical subsystem for reimaging each of the image segments through a select reimaging element onto at least one row of detector cells in accordance with the original position of the image segments in the line image, each detector cell being of a second length.

12. The optical system of claim 11 wherein the reimaging elements include a binary optic element.

13. The optical system of claim 11 wherein the reimaging elements include a prism.

14. The optical system of claim 11 wherein the array of detector cells forms an imaging spectrometer, each image segment being reimaged to a plurality of rows of detector cells in accordance with the wavelengths of light in the image segments.

15. The optical system of claim 11 wherein there are a plurality of sequential line images, further comprising a data processor coupled to the array of detector cells to perform Time Delay and Integration on the line images.

16. The optical system of claim 11 wherein the line image contains more than about one thousand pixels.

17. The optical system of claim 16 wherein the line image contains about six thousand pixels.

18. The optical system of claim 11 wherein the first optical subsystem comprises a plurality of planar optical segmenting elements which separate the light from the line image into image segments.

19. The optical system of claim 18 wherein the segmenting elements include a binary optic element.

20. The optical system of claim 18 wherein the segmenting elements include a prism.

21. The optical system of claim 11 further comprising an image source subsystem for imaging light from a view to form the line image.

22. The optical system of claim 11 further comprising a image combiner to direct the reimaged line segments through a common exit pupil of the system.

23. A method of optically reformatting a line image comprising the steps of:

optically coupling at least one optical subsystem having a plurality of planar optical elements to the line image;

in the optical subsystem, segmenting a line image into a plurality of image segments located at an original position in the line image, the segments being of a predetermined segment length;

and

in the optical subsystem, reimaging each of the image segments from the line image onto at least one image cell in accordance with the original position of the image segments in the line image.

24. The method of claim 23 wherein the step of reimaging comprises reimaging the image segments onto an array of image cells, each imaging cell having a plurality of detector cells.

25. The method of claim 23 further comprising the step of spectral analyzing the reimaged image segments.

26. The method of claim 23 further comprising the step of time delaying and integrating image data from a plurality of sequential line images.

27. The method of claim 23 wherein the step of segmenting comprises separating the image segments from the line image using a plurality of planar optical segmenting elements.

28. The method of claim 23 further comprising, before the step of segmenting, the step of imaging light from a view through an image source subsystem to form the line image.

29. The method of claim 23 further comprising the step of directing each of the reimaged line segments through a common exit pupil of the system.

30. The method of claim 23 further comprising the steps of:

optically coupling an image corrector to the planar optical elements; and

in the image corrector, correcting image degradation introduced by the planar optical element.

31. A method of optically reformatting a line image comprising the steps of:

optically coupling a first optical subsystem to the line image;

in the first optical subsystem, segmenting a line image into a plurality of image segments located at an original position in the line image, the segments being of a first length;

providing an array of detector cells having rows of detector cells;

optically coupling a second optical subsystem having a plurality of planar optical reimaging elements to the first optical subsystem; and

in the second optical subsystem, reimaging each of the image segments from the line image through a select reimaging element onto at least one row of detector cells in accordance with the original position of the image segments in the line image.

32. The method of claim 31 further comprising the step of spectral analyzing the reimaged image segments.

33. The method of claim 31 further comprising the step of time delaying and integrating image data from a plurality of sequential line images.

34. The method of claim 31 wherein the step of segmenting comprises separating the image segments from the line image using a plurality of planar optical segmenting elements.

35. The method of claim 31 further comprising, before the step of segmenting, the step of imaging light from a view through an image source subsystem to form the line image.

36. The method of claim 31 further comprising the step of directing each of the reimaged line segments through a common exit pupil of the system.

37. An optical system for reformatting an image, comprising:

an image source subsystem having a lens for imaging light from a view to form a line image of light bundles; and

an optical subsystem optically coupled to the image source subsystem for (i) segmenting the light bundles of the line image into a plurality of image segments, each image segment being of a predetermined length and located at a respective original position in the line image, and (ii) reimaging each of the image segments onto at least one image cell in accordance with the original position of the image segments in the line image.

38. The optical system of claim 37 wherein the optical subsystem comprises:

a first optical subsystem optically coupled to the image source subsystem to segment light bundles of the line image; and

a second optical subsystem optically coupled to the first optical subsystem to reimage the image segments.

39. The optical system of claim 38 wherein the first optical subsystem includes a plurality of planar optical segmenting elements optically coupled to the line image for separating the light bundles of the line image into a plurality of image segments, each segmenting element dedicated to a respective image segment.

40. The optical system of claim 38 wherein the second optical subsystem includes a plurality of planar optical reimaging elements, each of the image segments being reimaged through a respective reimaging element.

41. The optical system of claim 37 wherein there are a plurality of sequential line images, further comprising a data processor coupled to the image cells to perform Time Delay and Integration on the line images.

42. The optical system of claim 37 wherein the image cells form an imaging spectrometer, each image segment being reimaged to a plurality of image cells in accordance with the wavelengths of light in the light bundles.

43. The optical system of claim 37 further comprising an image combiner to direct each reimaged line segment through a common exit pupil of the system.

44. The optical system of claim 43 further comprising a cold stop disposed at the common exit pupil to inhibit spurious thermal energy.

45. A method for reformatting an image, comprising the steps of:

imaging light from a view through a lens of an image source subsystem to form a line image of light bundles;

optically coupling an optical subsystem to the image source subsystem;

in the optical subsystem, segmenting the light bundles of the line image into a plurality of image segments, each image segment being of a predetermined length and located at a respective original position in the line image; and

in the optical subsystem, reimaging each of the image segments onto at least one image cell in accordance with the original position of the image segments in the line image.

46. The method of claim 45 wherein the step of optically coupling the optical subsystem comprises:

optically coupling a first optical subsystem to the image source subsystem to segment the light bundles of the line image; and

optically coupling a second optical subsystem to the first optical subsystem to reimage the image segments.

47. The method of claim 46 wherein the step of optically coupling the first optical subsystem includes:

providing a plurality of planar optical segmenting elements for separating the light bundles of the line image into a plurality of image segments; and

optically coupling the segmenting elements to the line image such that each segmenting element is dedicated to a respective image segment.

48. The method of claim 46 wherein the step of optically coupling the second optical subsystem includes:

providing a plurality of planar optical reimaging elements; and

reimaging each of the image segments through a respective reimaging element.

49. The method of claim 45 further comprising the steps of:

providing a plurality of sequential line images;

coupling a data processor to the image cells;

and

in the data processor, performing Time Delay and Integration on the line images.

50. The method of claim 45 further comprising the steps of:

forming an imaging spectrometer from a plurality of image cells; and

reimaging each image segment to the imaging cells in accordance with the wavelengths of light in the light bundles.

51. The method of claim 45 further comprising the step of directing the reimaged line segments through a common exit pupil of the system.

52. The method of claim 51 further comprising the step of disposing a cold stop at the common exit pupil.