Distortion Corrected display

• US 5,748,264 A
• Filed: 01/10/1995
• Issued: 05/05/1998
• Est. Priority Date: 01/10/1995
• Status: Expired due to Term

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Inventors: Hegg, Ronald G.
• Primary Examiner(s): LEE, MICHAEL
• Application Number:
  US08/370,719
• Time in Patent Office: 1,211 Days
• Field of Search: 348/115, 348/806, 348/745-747, 348/804, 348/781, 348/784, 348/832
• US Class Current: 348/746
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0143 the two eyes not being equipped with identical nor symmetrical optical devices
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G09B 9/165 Condition of cabin, cockpit or pilot's accessories
• CPC Class Codes: G09B 9/326 the image being transformed by optical means

Abstract

An image-projection display (10) includes a combiner (12) which is transparent to allow a view therethrough, and which is also at least partially reflective so that an image projected onto a surface of the combiner is reflected to a viewer. The display apparatus includes off-axis projection factors so that a rectilinear projected image would be perceived by the viewer as being distorted. A projector portion (20) of the display (10) includes an image source (36, 38) and a corrector element (46), as well as means (38, 46) for physically dislocating pixel elements of a rectilinear image so that the image as projected is de-linearized with compensatory distortion causing the image viewed by the viewer to be perceived with restored rectilinearity.

Claims

1. An image-projection display which includes an image projector projecting light to form an image, and means defining an imaging surface from which at least a portion of said light is reflected to be viewed as an image by a user of the display, said display including off-axis projection factors distorting a rectilinear projected image so that the user of the display would perceive an image with distorted rectilinearity, and the projector portion providing a projected image with compensatory image distortion so that the user of the display sees an image with substantially restored rectilinearity, said image-projection display comprising:

an image source for receiving a rectilinear image signal and providing a first image in response thereto;

a projector optical portion for receiving said first image from said image source and for providing a second image with said compensatory image distortion, said projector portion projecting said compensatorily-distorted second image to said imaging surface;

means for physically dislocating selected image elements (pixels) of one of said first image or said second image to compensatorily distort said second image, wherein said means for physically dislocating selected image pixels includes said image source having a fiber optic corrector element with a multitude of optical fibers extending therethrough and cooperatively defining opposite faces of said corrector element.

2. The image-projection display of claim 1 wherein said means for physically dislocating selected image pixels includes said image source having a physical configuration which is at least partially non-linear so that said rectilinear image signal provides a non-rectilinear first image on said image source.

3. The image-projection display of claim 2 wherein said image source includes a solid state image screen having a fixed number and location of pixel elements.

4. The image-projection display of claim 3 wherein said solid state image screen has said pixel elements arranged in rows and columns.

5. The image-projection display of claim 4 wherein said solid state image screen has a physical configuration which is at least partially non-linear and having an arcuate shape for one of the rows or columns of pixels of said image source.

6. The image-projection display of claim 1 wherein said fiber optic corrector element includes a face which is rectilinear with respect to the arrangement of the multiple optical fibers defining said face, and an opposite face which is non-rectilinear with respect to the arrangement of the multiple optical fibers defining said opposite face.

7. The image-projection display of claim 1 wherein said fiber optic corrector element includes a pair of opposite faces each receiving respective ends of the multitude of optical fibers, one face of said pair of opposite faces having a selected arrangement of said multitude of optical fibers, and the other face of said pair of opposite faces having a selectively different pattern of said multitude of optical fibers so that pixel image elements are selectively dislocated between said pair of opposite faces.

8. The image-projection display of claim 6 wherein said fiber optic corrector element includes said opposite face having an arcuate arrangement along a selected axis of said multitude of optical fibers.

9. The image-projection display of claim 6 wherein said fiber optic corrector element includes said opposite face having a trapezoidal arrangement of said multitude of optical fibers.

10. The image-projection display of claim 6 wherein said fiber optic corrector element includes said opposite face having an arcuate arrangement of said multitude of optical fibers along two perpendicularly arranged axis.

11. The image-projection display of claim 10 wherein said fiber optic corrector element includes said opposite face having two pairs of opposite side edges, at least one pair of which is arcuate, and said side edges intersecting to define cusps for said opposite face of said corrector element.

12. The image-projection display of claim 11 wherein said fiber optic corrector element includes both pairs of said opposite face having a pair of arcuate opposite side edges, and the side edges of said pairs of opposite faces intersecting to define cusps for said opposite face.

13. The image-projection display of claim 1 wherein said projector optical portion includes a set of projection lenses.

14. The image-projection display of claim 1 wherein said projector optical portion includes a folding prism set.

15. The image-projection display of claim 1 wherein said imaging surface is defined by a transparent and at least partially reflective combiner member.

16. The image-projection display of claim 15 wherein said combiner member is curved along at least one axis.

17. The image-projection display of claim 16 wherein said combiner member is curved along a pair of orthogonal axes.

18. The image-projection display of claim 15 wherein said combiner member is formed by a visor of a safety helmet, said display including a housing attaching to an exterior surface of said helmet and housing said projector portion, said projector portion projecting said image onto an inner surface of said visor for reflection to a wearer of the helmet.

19. The image-projection display of claim 18 wherein said projector portion projects said image inwardly through a transparent portion of said visor and onto said inner surface of said visor for reflection to said wearer of the helmet.

20. A helmet-mounted display apparatus comprising:

a transparent visor/combiner module for attachment to a helmet in front of the face of a wearer of the helmet, said visor/combiner module being configured to both shield the eyes of said wearer from wind blast, and to provide the wearer of the helmet with a view outwardly therethrough, said visor/combiner also defining an inner surface forward of the eyes of the wearer of the helmet which is at least partially reflective to reflect to the helmet wearer an image projected onto said inner surface;

a projector module of said display securing to said helmet, including an image source and projection optics, and projecting said image onto said inner surface of said visor/combiner module for reflection to said wearer, said projector module and said visor/combiner module in conjunction including off-axis projection and/or reflection factors which result in a rectilinear projected image being seen by said wearer of the helmet with distortions which destroy the rectilinearity of the image, said image source and projection module including means for compensatorily distorting the image as projected so that said off-axis factors result in the image as seen by the helmet wearer having substantially restored rectilinearity, the projection module physically compensatorily distorting the image.

21. The helmet-mounted display apparatus of claim 20 wherein said means for compensatorily distorting said image as projected includes said image source having a physical configuration at least partially non-linear so that said rectilinear image is rendered by said image source as a non-rectilinear image supplied to said projection optics.

22. The helmet-mounted display apparatus of claim 21 wherein said image source includes a solid state image screen having a fixed number and location of pixel elements.

23. The helmet-mounted display apparatus of claim 22 wherein said solid state image screen has said pixel elements arranged in rows and columns.

24. The helmet-mounted display apparatus of claim 22 wherein said solid state image screen has an arcuate shape for one of the rows or columns of pixels of said image source.

25. The helmet-mounted display apparatus of claim 20 wherein said means for compensatorily distorting said image as projected includes said image source including a fiber optic corrector element with a multitude of optical fibers extending therethrough and cooperatively defining opposite faces of said corrector element.

26. The helmet-mounted display apparatus of claim 25 wherein said fiber optic corrector element includes a face which is rectilinear with respect to the arrangement of the multiple optical fibers defining said face, and an opposite face which is non-rectilinear with respect to the arrangement of the multiple optical fibers defining said opposite face.

27. The helmet-mounted display apparatus of claim 26 wherein said fiber optic corrector element includes a pair of opposite faces each receiving respective ends of the multitude of optical fibers, one face of said pair of opposite faces having a selected pattern of said multitude of optical fibers, and the other face of said pair of opposite faces having a selectively different pattern of said multitude of optical fibers so that pixel image elements are selectively dislocated between said pair of opposite faces.

28. An image-projection display which includes an image projector projecting light to form an image, and means defining an imaging surface from which at least a portion of said light is reflected to be viewed as an image by a user of the display, said display including off-axis projection factors distorting a rectilinear projected image so that the user of the display would perceive an image with distorted rectilinearity, and the projector portion providing a projected image with compensatory image distortion so that the user of the display sees an image with substantially restored rectilinearity, said image-projection display comprising:

an image source for receiving a rectilinear image signal and providing a first image in response thereto;

a projector optical portion for receiving said first image from said image source and for providing a second image with said compensatory image distortion, said projector portion projecting said compensatorily-distorted second image to said imaging surface; and

means for physically dislocating selected image elements (pixels) of one of said first image or said second image to compensatorily distort said second image, wherein said projector optical portion includes a folding prism set.

29. The image-projection display of claim 28 wherein said imaging surface is defined by a transparent and at least partially reflective combiner member.

30. The image-projection display of claim 29 wherein said combiner member is curved along at least one axis.

31. The image-projection display of claim 30 wherein said combiner member is curved along a pair of orthogonal axes.

32. The image-projection display of claim 29 wherein said combiner member is formed by a visor of a safety helmet, said display including a housing attaching to an exterior surface of said helmet and housing said projector portion, said projector portion projecting said image onto an inner surface of said visor for reflection to a wearer of the helmet.

33. The image-projection display of claim 32 wherein said projector portion projects said image inwardly through a transparent portion of said visor and onto said inner surface of said visor for reflection to said wearer of the helmet.