Helmet/head mounted projector system

• US 5,726,671 A
• Filed: 10/07/1996
• Issued: 03/10/1998
• Est. Priority Date: 10/07/1996
• Status: Expired due to Term

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Inventors: Chen, Chungte Bill, Ansley, David A.
• Primary Examiner(s): Bayerl, Raymond J.
• Assistant Examiner(s): Vail, Seth D.
• Application Number:
  US08/729,738
• Time in Patent Office: 519 Days
• Field of Search: 345/8, 345/7, 348/39, 348/115, 385/116, 385/115, 359/630, 359/631, 359/633, 434/44
• US Class Current: 320/119
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 2027/0198 System for aligning or maintaining alignment of an image in a predetermined direction
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/12 Reflex reflectors
• CPC Class Codes: H04N 5/7491 of head mounted projectors

Abstract

A head mounted projector system with extremely high resolution. The system includes a retro-reflecting gain screen. The on-helmet apparatus of the system includes a truncated spherical mirror, a redirecting multi-faceted mirror and a small rotating polygon scanner. The system includes off-helmet apparatus including a background image source and an area-of-interest (AOI) image source. The background and AOI images are scanned into a linear ribbon array of fibers. To provide 20/20 visual acuity, one fiber per each 0.7 arc-minute field-of-view is used.

Claims

1. A helmet/head mounted projector system, comprising:

a set of off-helmet mounted elements, including a background image generator, an area-of-interest (AOI) image generator, apparatus for combining the background image and the AOI image to form a combined image, said apparatus for combining said background image and said AOI image comprising a beam combiner, and apparatus for scanning the combined image into an input end of a fiber optic ribbon apparatus;

a set of on-helmet/head mounted elements, said set including a rotating polygon scanner and an optical apparatus for redirecting image light from an output end of said fiber optic ribbon apparatus onto said polygon scanner; and

a screen, said polygon scanner for redirecting said image light onto said screen for viewing by an observer.

2. The system of claim 1 wherein said screen comprises a retro-reflecting screen.

3. The system of claim 1 wherein said optical apparatus for redirecting image light from said output end includes a flat mirror and a spherical mirror for redirecting and collimating said image light.

4. The system of claim 1 wherein said fiber optic ribbon apparatus comprises a plurality of fiber optic ribbons, and said optical apparatus for redirecting light from said output end includes a flat mirror apparatus comprising a plurality of flat mirror segments, one each for said fiber optic ribbons, and a collimating mirror.

5. The system of claim 4 further characterized by a system field of view (FOV), and wherein said plurality of fibers comprises a number of fibers sufficient for one fiber for each 0.7 arc-minute of the system FOV.

6. The system of claim 1 wherein said apparatus for scanning said combined image into an input end of said fiber optic ribbon apparatus comprises a galvo scanner device for scanning said combined image.

7. The system of claim 6 wherein said AOI image generator comprises a first reflective liquid crystal display (LCD), said background image generator comprises a second LCD, and said apparatus for scanning further comprises a line illumination source for illuminating corresponding lines of said first and second LCDs being scanned by said galvo scanner.

8. The system of claim 7 wherein said apparatus for scanning further comprises a beam combiner for redirecting light from said line illumination source onto said first and second LCDs while passing said combined image.

9. The system of claim 1 wherein said polygon scanner rotates at a relatively slow rotation rate which does not exceed 20 revolutions per second.

10. The system of claim 9 wherein said polygon scanner has four facets.

11. The system of claim 1 wherein said AOI image generator has an AOI image resolution in AOI image pixels per line, said background image generator has a background image resolution in background image pixels per line, wherein said background image resolution is lower than said AOI resolution, and wherein said system further includes apparatus for cloning pixels defining said background image so as to produce fill-in pixels in said background image.

12. The system of claim 1 wherein said AOI image generator has an AOI image resolution in AOI image pixels per line, said background image generator has a background image resolution in background image pixels per line, wherein said background image resolution is lower than said AOI resolution, and wherein said system further includes apparatus for producing interpolated pixels defining said background image so as to produce fill-in pixels in said background image, wherein intensity values of said interpolated pixels are interpolated from intensity values of neighboring background pixels.

13. The system of claim 1 wherein said AOI image generator has an AOI image resolution in AOI image pixels per line, said background image generator has a background image resolution in background image pixels per line, wherein said background image resolution is lower than said AOI resolution, and wherein said system further includes:

cloning apparatus for cloning pixels defining said background image so as to produce a first set of fill-in pixels in said background image;

interpolating apparatus for producing interpolated pixels defining said background image so as to produce a second set of fill-in pixels in said background image, wherein intensity values of said interpolated pixels are interpolated from intensity values of neighboring background pixels; and

controller apparatus for controlling said cloning apparatus and said interpolating apparatus so as to produce cloned and/or interpolated pixels between neighboring background pixels in dependence on proximity of said neighboring background pixels to said AOI.

14. The system of claim 13 wherein said controller apparatus control said cloning apparatus and said interpolating apparatus so as to produce 100% interpolated pixels between neighboring background pixels located adjacent said AOI, and to produce 100% cloned pixels between neighboring background pixels located well away from said AOI.

15. A helmet/head mounted projector system, comprising:

a set of off-helmet mounted elements, including a background image generator, an area-of-interest (AOI) image generator, apparatus for combining the background image and the AOI image to form a combined image, and apparatus for scanning the combined image into an input end of a fiber optic ribbon apparatus;

a set of on-helmet/head mounted elements, said set including a first optical scanner and a second optical scanner, a first optical apparatus for redirecting image light from an output end of said fiber optic ribbon apparatus onto said first scanner, a second optical apparatus for redirecting light reflected from said first scanner onto said second scanner; and

a screen, said second scanner for redirecting said image light onto said screen for viewing by an observer.

16. The system of claim 15, wherein said first scanner is a first rotating polygon scanner, said second scanner is a second rotating polygon scanner, and wherein said first scanner rotates at a first rotation rate, said second scanner rotates at a second rotation rate, and said first rate is faster than said second rate.

17. The system of claim 16 wherein said second polygon scanner rotates at a relatively slow rotation rate which does not exceed 70 revolutions per second.

18. The system of claim 16 wherein said screen comprises a retro-reflecting screen.

19. The system of claim 16 wherein said second optical apparatus includes a spherical mirror having a center of curvature and a field mirror located at said center of curvature.

20. The system of claim 16 further characterized by a system field of view (FOV), and wherein said fiber optic ribbon apparatus is a single fiber optic ribbon comprising a plurality of optical fibers sufficient in number and of appropriate size such that said ribbon has one fiber for each 0.7 arc-minute of the system FOV.

21. The system of claim 16 wherein said apparatus for scanning said combined image into an input end of said fiber optic ribbon apparatus comprises a galvo scanner device for scanning said combined image.

22. The system of claim 21 wherein said AOI image generator comprises a first reflective liquid crystal display (LCD), said background image generator comprises a second LCD, and said apparatus for scanning further comprises a line illumination source for illuminating corresponding lines of said first and second LCDs being scanned by said galvo scanner.

23. The system of claim 22 wherein said apparatus for scanning further comprises a beam combiner for redirecting light from said line illumination source onto said first and second LCDs while passing said combined image.

24. The system of claim 16 wherein said AOI image generator has an AOI image resolution in AOI image pixels per line, said background image generator has a background image resolution in background image pixels per line, wherein said background image resolution is lower than said AOI resolution, and wherein said system further includes apparatus for cloning pixels defining said background image so as to produce fill-in pixels in said background image.

25. The system of claim 16 wherein said AOI image generator has an AOI image resolution in AOI image pixels per line, said background image generator has a background image resolution in background image pixels per line, wherein said background image resolution is lower than said AOI resolution, and wherein said system further includes apparatus for producing interpolated pixels defining said background image so as to produce fill-in pixels in said background image, wherein intensity values of said interpolated pixels are interpolated from intensity values of neighboring background pixels.

26. The system of claim 16 wherein said AOI image generator has an AOI image resolution in AOI image pixels per line, said background image generator has a background image resolution in background image pixels per line, wherein said background image resolution is lower than said AOI resolution, and wherein said system further includes:

cloning apparatus for cloning pixels defining said background image so as to produce a first set of fill-in pixels in said background image;

interpolating apparatus for producing interpolated pixels defining said background image so as to produce a second set of fill-in pixels in said background image, wherein intensity values of said interpolated pixels are interpolated from intensity values of neighboring background pixels; and

controller apparatus for controlling said cloning apparatus and said interpolating apparatus so as to produce cloned and/or interpolated pixels between neighboring background pixels in dependence on proximity of said neighboring background pixels to said AOI.

27. The system of claim 26 wherein said controller apparatus control said cloning apparatus and said interpolating apparatus so as to produce 100% interpolated pixels between neighboring background pixels located adjacent said AOI, and to produce 100% cloned pixels between neighboring background pixels located well away from said AOI.

28. The system of claim 16 wherein said apparatus for combining said background image and said AOI image is an electronic image combining means.

29. A helmet/head mounted projector system, comprising:

a set of off-helmet mounted elements, including a background image generator, an area-of-interest (AOI) image generator, apparatus for combining the background image and the AOI image to form a combined image, and apparatus for scanning the combined image into an input end of a fiber optic ribbon apparatus, said apparatus for scanning said combined beam into an input end of said fiber optic ribbon apparatus comprising a galvo scanner device for scanning said combined image;

a set of on-helmet/head mounted elements, said set including a rotating polygon scanner and an optical apparatus for redirecting image light from an output end of said fiber optic ribbon apparatus onto said polygon scanner; and

a screen, said polygon scanner for redirecting said image light onto said screen for viewing by an observer.

30. The system of claim 29 wherein said AOI image generator comprises a first reflective liquid crystal display (LCD), said background image generator comprises a second LCD, and said apparatus for scanning further comprises a line illumination source for illuminating corresponding lines of said first and second LCDs being scanned by said galvo scanner.

31. The system of claim 30 wherein said apparatus for scanning further comprises a beam combiner for redirecting light from said line illumination source onto said first and second LCDs while passing said combined image.

32. A helmet/head mounted projector system, comprising:

a set of off-helmet mounted elements, including a background image generator, an area-of-interest (AOI) image generator, apparatus for combining the background image and the AOI image to form a combined image, said apparatus for combining including an electronic image combining circuit, and apparatus for scanning the combined image into an input end of a fiber optic ribbon apparatus;

a set of on-helmet/head mounted elements, said set including a rotating polygon scanner and an optical apparatus for redirecting image light from an output end of said fiber optic ribbon apparatus onto said polygon scanner; and

a screen, said polygon scanner for redirecting said image light onto said screen for viewing by an observer.

33. The system of claim 32 wherein said screen comprises a retro-reflecting screen.

34. The system of claim 33 wherein said optical apparatus for redirecting image light from said output end includes a flat mirror and a spherical mirror for redirecting and collimating said image light.

35. The system of claim 33 wherein said fiber optic ribbon apparatus comprises a plurality of fiber optic ribbons, and said optical apparatus for redirecting light from said output end includes a flat mirror apparatus comprising a plurality of flat mirror segments, one each for said fiber optic ribbons, and a collimating mirror.

36. The system of claim 35 further characterized by a system field of view (FOV), and wherein said plurality of fibers comprises a number of fibers sufficient for one fiber for each 0.7 arc-minute of the system FOV.

37. The system of claim 33 wherein said apparatus for scanning said combined image into an input end of said fiber optic ribbon apparatus comprising a galvo scanner device for scanning said combined image.

38. The system of claim 37 wherein said AOI image generator comprises a first reflective liquid crystal display (LCD), said background image generator comprises a second LCD, and said apparatus for scanning further comprises a line illumination source for illuminating corresponding lines of said first and second LCDs being scanned by said galvo scanner.

39. The system of claim 38 wherein said apparatus for scanning further comprises a beam combiner for redirecting light from said line illumination source onto said first and second LCDs while passing said combined image.

40. The system of claim 33 wherein said polygon scanner rotates at a relatively slow rotation rate which does not exceed 20 revolutions per second.

41. The system of claim 40 wherein said polygon scanner has four facets.

42. The system of claim 33 wherein said AOI image generator has an AOI image resolution in AOI image pixels per line, said background image generator has a background image resolution in background image pixels per line, wherein said background image resolution is lower than said AOI resolution, and wherein said system further includes apparatus for cloning pixels defining said background image so as to produce fill-in pixels in said background image.

43. The system of claim 33 wherein said AOI image generator has an AOI image resolution in AOI image pixels per line, said background image generator has a background image resolution in background image pixels per fine, wherein said background image resolution is lower than said AOI resolution, and wherein said system further includes apparatus for producing interpolated pixels defining said background image so as to produce fill-in pixels in said background image, wherein intensity values of said interpolated pixels are interpolated from intensity values of neighboring background pixels.

44. The system of claim 33 wherein said AOI image generator has an AOI image resolution in AOI image pixels per line, said background image generator has a background image resolution in background image pixels per line, wherein said background image resolution is lower than said AOI resolution, and wherein said system further includes:

cloning apparatus for cloning pixels defining said background image so as to produce a first set of fill-in pixels in said background image;

interpolating apparatus for producing interpolated pixels defining said background image so as to produce a second set of fill-in pixels in said background image, wherein intensity values of said interpolated pixels are interpolated from intensity values of neighboring background pixels; and

controller apparatus for controlling said cloning apparatus and said interpolating apparatus so as to produce cloned and/or interpolated pixels between neighboring background pixels in dependence on proximity of said neighboring background pixels to said AOI.

45. The system of claim 44 wherein said controller apparatus control said cloning apparatus and said interpolating apparatus so as to produce 100% interpolated pixels between neighboring background pixels located adjacent said AOI, and to produce 100% cloned pixels between neighboring background pixels located well away from said AOI.