Compact electro-optical sensor assembly having single aperture for multiple detectors

• US 6,174,061 B1
• Filed: 03/31/1998
• Issued: 01/16/2001
• Est. Priority Date: 03/31/1998
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Cooper, Erwin E.
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): Treas, Jared
• Application Number:
  US09/052,911
• Time in Patent Office: 1,022 Days
• Field of Search: 359/355, 359/357, 359/353, 359/366, 359/364, 359/362, 359/351, 359/354, 356/856, 356/857, 356/858, 356/859, 356/860, 356/861, 356/364, 356/366
• US Class Current: 359/857
• CPC Class Codes: G02B 13/14 for use with infrared or ultraviolet radiation G02B13/008, G02B13/16 take precedence
• CPC Class Codes: G02B 23/12 with means for image conversion or intensification

Abstract

A sensor assembly (10) includes first and second focusing mirrors (21, 22) which direct converging radiation to a tilted beam splitter (31) through an opening (23) provided in the first mirror. The beam splitter passes selected infrared radiation, which then passes through a lens system (33, 34, 41) to an infrared detector (16). The beam splitter reflects other radiation, which then passes through a different lens system (46, 56, 58, 61, 62, 67, 68, 69) to a second beam splitter (73). The second beam splitter passes laser light, which travels through a lens (77) to a laser light detector (18). The second beam splitter reflects near-infrared radiation, so that it travels to a further detector (17).

Claims

1. An apparatus, comprising:

a focusing mirror arrangement which is operative to receive radiation traveling along a first optical path, and to focus the received radiation to travel along a second optical path;

a part defining an aperture, wherein the first optical path extends through said aperture;

a beam splitter disposed along the second optical path and operative to cause a first portion of the radiation which has a first wavelength to be directed along a third optical path and to cause a second portion of the radiation which has a second wavelength different from the first wavelength to be directed along a fourth optical path different from the third optical path;

a first detector disposed along the third optical path and operative to detect radiation at the first wavelength;

a second detector disposed along the fourth optical path and operative to detect radiation at the second wavelength;

a first lens arrangement disposed along the third optical path between said beam splitter and said first detector; and

a second lens arrangement disposed along the fourth optical path between said beam splitter and said second detectors;

wherein a region is bounded by a length dimension less than 1.5 times a transverse dimension of said aperture and by transverse dimensions less than the transverse dimension of said aperture, the region having therein said focusing mirror arrangement, said beam splitter, said first and second detectors, and said first and second lens arrangements.

2. An apparatus according to claim 1, wherein said focusing mirror arrangement includes facing first and second mirrors, said first mirror focusing the radiation traveling along the first optical path onto said second mirror, and said second mirror focusing the radiation from said first mirror to travel along the second optical path, said first and second optical paths being colinear, said first mirror having an opening therethrough, and said second optical path extending through said opening in said first mirror.

3. An apparatus according to claim 2, wherein said first mirror is a concave parabolic mirror and said second mirror is a convex conic mirror.

4. An apparatus according to claim 2, wherein said second mirror is moveably supported, and including a mechanism which is operative to control movement of said second mirror so as to effect image motion stabilization.

5. An apparatus according to claim 2, wherein said part is a housing which encloses said region.

6. An apparatus according to claim 1, including first and second reflecting mirrors which are respectively provided along said third and fourth optical paths and which are each movably supported, and including first and second mechanisms each operative to control movement of a respective one of said first and second reflecting mirrors so as to effect image motion stabilization.

7. An apparatus according to claim 1, wherein the radiation traveling along the first optical path is collimated radiation;

and wherein said beam splitter is located in converging radiation.

8. An apparatus according to claim 7, wherein said focusing mirror arrangement produces an image at a location along the second optical path prior to said beam splitter.

9. An apparatus according to claim 1, wherein said first and second lens arrangements each have only refractive lenses therein.

10. An apparatus according to claim 1, wherein said first lens arrangement includes a diffractive element.

11. An apparatus according to claim 1, wherein said first detector includes a two-dimensional infrared staring array.

12. An apparatus according to claim 1, wherein said first and second detectors each detect radiation in a respective different one of a range of 0.7 to 0.9 micron wavelengths, a range of approximately 1.06 to 1.54 micron wavelengths, a range of approximately 3 to 5 micron wavelengths, and a range of approximately 8 to 10 micron wavelengths.

13. An apparatus according to claim 1, wherein said first detector senses infrared radiation, and wherein said first lens arrangement includes only three lenses between said beam splitter and said first detector.

14. An apparatus according to claim 1, wherein said first detector senses infrared radiation, and wherein said first lens arrangement includes only two lenses between said beam splitter and said first detector.

15. An apparatus according to claim 1, including a mirror movable between first and second positions in which said mirror is respectively disposed in and spaced from the third optical path, wherein when said mirror is in said first position said mirror is operative to redirect radiation traveling along a fifth optical path to travel along the third optical path toward said first detector, the fifth optical path being different from the first and second optical paths;

and including a third lens arrangement disposed along said fifth optical path.

16. An apparatus according to claim 15, including a part which defines a further aperture, wherein the fifth optical path extends through said further aperture.

17. An apparatus according to claim 16, wherein a portion of said third lens arrangement is movable between first and second positions in which said portion of said third lens arrangement is respectively disposed in and spaced from the fifth optical path, and wherein when said portion of said third lens arrangement is in said first position said third lens arrangement is operative to provide a wide field of view, and when said portion of said third lens arrangement is in said second position said third lens arrangement is operable to provide a middle field of view.

18. An apparatus according to claim 1, wherein the first and second optical paths are free of refractive and diffractive optical elements.

20. An apparatus according to claim 15, wherein said focusing mirror arrangement includes first and second focusing mirrors which face each other, said first and second optical paths being colinear, said first mirror having an opening therethrough, said first mirror focusing onto the second mirror the radiation traveling along the first optical path, and said second mirror focusing radiation from said first mirror along the second optical path, the second optical path extending through said opening in said first mirror.

21. An apparatus according to claim 20, wherein said second focusing mirror is moveably supported, and including a mechanism which is operative to control movement of said second mirror so as to effect image motion stabilization.

22. An apparatus according to claim 20, wherein said part is a housing which encloses said region.

19. An apparatus comprising:

a focusing mirror arrangement which is operative to receive radiation traveling along a first optical path and to focus the received radiation to travel along a second optical path;

a part defining an aperture, wherein the first optical path extends through said aperture;

a first beam splitter disposed along the second optical path and operative to cause a first portion of the radiation to be directed along a third optical path and a second portion of the radiation to be directed along a fourth optical path different from the third optical path;

a first detector disposed along the third optical path and operative to detect radiation at a first wavelength;

a first lens arrangement disposed along the third optical path between said first beam splitter and said first detector;

a second beam splitter disposed along the fourth optical path and operative to cause respective portions of the radiation traveling along the fourth optical path to be respectively directed along fifth and sixth optical paths which are different;

a second detector disposed along the fifth optical path and operative to detect radiation at a second wavelength different from the first wavelength;

a third detector disposed along the sixth optical path and operative to detect radiation at a third wavelength different from each of the first and second wavelengths;

a second lens arrangement disposed along the fourth optical path; and

a third lens arrangement disposed along the fifth optical path;

wherein a region is bounded by a length dimension less than 1.5 times a transverse dimension of said aperture and by transverse dimensions less than the transverse dimension of said aperture, the region having therein said focusing mirror arrangement, said first and second beam splitters, said first, second and third detectors, and said first, second and third lens arrangements.

23. An apparatus according to claim 19, wherein the first and second optical paths are free of refractive and diffractive optical elements.

24. An apparatus according to claim 19, including first and second reflecting mirrors which are respectively provided along the third and fourth optical paths and which are each movably supported, and including first and second mechanisms which are each operative to control movement of a respective one of said first and second reflecting mirrors so as to effect image motion stabilization.

25. An apparatus according to claim 19, wherein the radiation traveling along the first optical path is collimated radiation;

and wherein said first beam splitter is located in converging radiation.

26. An apparatus according to claim 25, wherein said focusing, mirror arrangement produces an image at a location along the second optical path prior to said first beam splitter.

27. An apparatus according to claim 19, wherein said first detector includes a two-dimensional infrared staring array.

28. An apparatus according to claim 19, including a mirror movable between first and second positions in which said mirror is respectively disposed in and spaced from the third optical path, wherein when said mirror is in said first position said mirror is operative to redirect radiation traveling along a seventh optical path to travel along the third optical path toward said first detector, the seventh optical path being different from the first and second optical paths;

and including a fourth lens arrangement disposed along the seventh optical path.

29. An apparatus according to claim 28, including a part which defines a further aperture, wherein the seventh optical path extends through said further aperture, said fourth lens arrangement being disposed along the seventh optical path between said further aperture and said mirror.

30. An apparatus according to claim 29, wherein a portion of said fourth lens arrangement is movable between first and second positions in which said portion of said fourth lens arrangement is respectively disposed in and spaced from the seventh optical path, and wherein when said portion of said fourth lens arrangement is in said first position said fourth lens arrangement is operative to provide a wide field of view, and when said portion of said fourth lens arrangement is in said second position said fourth lens arrangement is operable to provide a middle field of view.

31. An apparatus comprising:

a part defining an aperture, wherein a first optical path extends through said aperture and wherein the first optical path is free of refractive and diffractive optical elements;

a focusing mirror arrangement which is operative to receive radiation traveling alone a first portion of the first optical path prior to said focusing mirror arrangement, and to focus the received radiation to travel along a second portion of the first optical path subsequent to said focusing mirror arrangement;

a beam splitter responsive to radiation traveling along the second portion of the first optical path and operative to cause a first portion of the radiation which has a first wavelength to be directed along a second optical path and to cause a second portion of the radiation which has a second wavelength different from the first wavelength to be directed along a third optical path different from the second optical path;

a first detector disposed along the second optical path and operative to detect radiation at the first wavelength;

a second detector disposed along the third optical path and operative to detect radiation at the second wavelength;

a first lens arrangement disposed along the second optical path between said beam splitter and said first detector; and

a second lens arrangement disposed along the third optical path between said beam splitter and said second detector;

wherein a region is bounded by a length dimension less than 1.5 times a transverse dimension of said aperture and by transverse dimensions less than the transverse dimension of said aperture, the region having therein said apertures, said focusing mirror arrangement, said beam splitter, said first and second detectors, and said first and second lens arrangements.

32. An apparatus according to claim 31, further including:

a further beam splitter disposed along the third optical path between said second detector and said second lens arrangement and operative to cause the second portion of the radiation having the second wavelength to continue traveling along the third optical path and to cause a third portion of the radiation having a third wavelength different from each of the first and second wavelengths to be directed along a fourth optical path which is different from the third optical path;

a third detector disposed along the fourth optical path and operative to detect radiation at the third wavelength; and

a third lens arrangement disposed along the fourth optical path.

33. An apparatus according to claim 32, wherein the radiation traveling along the first portion of the first optical path is collimated radiation;

and wherein the region has therein said further beam splitter, said third detector, and said third lens arrangement.