Wide field personal display

• US 10,649,210 B2
• Filed: 01/20/2017
• Issued: 05/12/2020
• Est. Priority Date: 01/22/2016
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Cobb, Joshua Monroe, Magierski, Kevin J
• Primary Examiner(s): Choi, William
• Application Number:
  US15/411,179
• Publication Number:
  US 20170212352A1
• Time in Patent Office: 1,208 Days
• Field of Search: 359629, 359630, 359631, 359633
• CPC Class Codes: G02B 1/041 Lenses
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 1/18 Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films G02B1/16 takes precedence
• CPC Class Codes: G02B 17/0856 comprising a refractive element with a reflective surface, the reflection taking place inside the element, e.g. Mangin mirrors
• CPC Class Codes: G02B 17/086 wherein the system is made of a single block of optical material, e.g. solid catadioptric systems
• 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 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/0154 with movable elements
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G02B 27/0179 Display position adjusting means not related to the information to be displayed
• CPC Class Codes: G02B 27/1066 for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001

Abstract

A display apparatus has an image generator that generates image-bearing light from a f surface and a lens spaced apart from the image generator and having an aspheric incident refractive surface concave to the image generator and having an aspheric reflective surface concave to the image generator, wherein a principal axis of the reflective surface is normal to the image generator. A beam splitter plate disposed in free space between the image generator and the lens has first and second parallel surfaces that are oblique to a line of sight of a viewer. The lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer.

Claims

1. A display apparatus comprising:

at least one image generator that generates image-bearing light and is configured to provide electronic correction for distortion;

a lens spaced apart from the image generator, the lens having an aspheric incident refractive surface concave to the image generator and having an aspheric reflective surface concave to the image generator, wherein the lens is configured to correct field curvature and to provide focus of the image-bearing light and wherein the lens has a principal axis that is orthogonal to the at least one image generator; and

a beam splitter plate disposed in free space between the image generator and the lens, the beam splitter plate having first and second surfaces that are oblique to a line of sight of a viewer and oblique to the principal axis, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer.

2. The display apparatus of claim 1 wherein the first and second surfaces of the beam splitter plate are parallel to within 50 arc seconds.

3. The display apparatus of claim 2 wherein the first and second surfaces of the beam splitter plate are parallel to within 40 arc seconds.

4. The display apparatus of claim 1 wherein the first and second surfaces of the beam splitter plate are parallel to within 20 arc seconds.

5. The display apparatus of claim 1 further comprising a field lens in the path of the image-bearing light.

6. The display apparatus of claim 1 wherein the beam splitter plate is a polarization beam splitter and further comprising a quarter wave plate disposed between the beam splitter plate and the lens.

7. The display apparatus of claim 1, further comprising a curved protective shield that includes an anti-reflective coating on a side facing the viewer.

8. The display apparatus of claim 1, wherein the lens is a plastic lens.

9. The display apparatus of claim 1, wherein the lens is an acrylic lens.

10. The display apparatus of claim 1 which further includes adjustment components structured to adjust rotation of the image generator about an axis parallel to the principal axis of the reflective surface.

11. The display apparatus of claim 10 wherein the adjustment components comprise at least one screw engaging the image generator at one side and at least one spring plunger engaging the image generator at another side.

12. The display apparatus of claim 10 wherein the adjustment components comprise a plurality of screws engaging the image generator at one side and a plurality of spring plungers engaging the image generator at another side.

13. The display apparatus of claim 1, wherein

the image generator generates a flat field of image-bearing light from a flat display surface;

the first and second surface of the beam splitter plate are substantially parallel surfaces that are oblique to a line of sight of a viewer; and

wherein measured distance, along that portion of the principal axis that extends between the at least one image generator and the beam splitter plate, equals the optical path length.

14. The display apparatus of claim 13, wherein the beam splitter is a polarization beam splitter.

15. The display apparatus of claim 14, further comprising a polarizing plate adjacent to the image generator and a ¼

wave plate situated between the lens and the beam splitter.

16. The display apparatus of claim 13 wherein the display apparatus is wearable by the viewer.

17. The display apparatus of claim 13 wherein the beam splitter plate is formed using a fusion draw process.

18. The display apparatus of claim 13 wherein the first and second surfaces of the beam splitter plate are parallel to within 30 arc seconds.

19. The display apparatus of claim 13 wherein the beam splitter plate is a polarization beam splitter and further comprising a quarter wave plate disposed between the beam splitter plate and the lens.

20. The display apparatus of claim 13 further comprising a field lens situated directly adjacent to the image generator and in the path of the image-bearing light.

21. The display apparatus of claim 20 wherein the field lens comprises an aspheric surface.

22. The display apparatus of claim 13 wherein the image generator comprises an organic light-emitting diode.

23. The display apparatus of claim 13 wherein the image generator comprises a personal communications device.

24. The display apparatus of claim 13 wherein the first and second surfaces of the beam splitter plate are parallel to within 30 arc seconds.

25. The display apparatus of claim 13 wherein the lens is molded from acrylic.

26. The display apparatus of claim 13 wherein light from a physical scene is transmitted through the beam splitter plate to viewer'"'"'s eyes and combined with the light provided by the image generator.

27. The display apparatus of claim 26, further comprising a curved protective shield made from polycarbonate that transmits the light from a physical scene before being combined by the beam splitter plate.

28. The display apparatus of claim 27, wherein curved protective shield comprises an oleo-phobic and/or an anti-fog coating.

29. The display apparatus of claim 13 which further includes adjustment components structured to adjust rotation of the image generator about an axis parallel to the principal axis.

30. The display apparatus of claim 29 wherein the adjustment components comprise screws pushing the image generator against spring plungers.

31. The display apparatus of claim 13 which further includes a power activator for activating the display source.

32. The display apparatus of claim 13 wherein said lens has a center thickness of 5 to 10 mm and two aspheric surfaces of the design that have a sag, z, described by:

33. The display apparatus of claim 13, wherein the display apparatus is collapsible about a first hinge that couples one edge of the beam splitter plate to the at least one image generator and a second hinge that couples another edge of the beam splitter plate to the lens.

34. The display apparatus of claim 1, wherein the beam splitter comprises an antireflection coating on the side facing the image generator.

35. The display apparatus of claim 1, wherein dimensions and orientation of the beam splitter, image generator, and lens are selected to result in a field of view of the viewer for the object scene that is larger than the field of view within which the virtual image is formed.

36. The display system according to claim 1 further comprising at least one of:

a GPS sensor, at least one eye tracking sensor, an accelerometer, or a camera that is structured to look at either the viewer'"'"'s eye or at a scene viewed by the viewer.

37. A display apparatus comprising:

a) a flat image generator configured to apply electronic distortion correction to image bearing light;

b) a lens spaced apart from the image generator and having an aspheric incident refractive surface concave to the image generator, wherein the lens is configured for field curvature correction and to provide focus of the image-bearing light and having an aspheric reflective surface concave to the image generator, wherein a principal axis of the reflective surface is normal to the image generator; and

c) a beam splitter plate disposed in free space between the image generator and the lens and along a line of sight of an object scene for a viewer, the beam splitter plate having a viewing position with first and second substantially parallel surfaces oblique to the line of sight,

wherein the beam splitter plate is further disposed to transmit image-bearing light from the image generator to the lens and wherein the beam splitter plate and lens define an optical path that conveys the image-bearing light for a first refraction through the aspheric incident refractive surface, reflects the refracted light from the aspheric reflective surface, and refracts the reflected light from the aspheric incident refractive surface back to the beam splitter plate that reflects the light from the lens toward a viewer eye box along the line of sight of the viewer,

wherein the beam splitter plate has a first flexible coupling to the image generator on one side of the line of sight and has a second flexible coupling to the lens on the opposite side of the line of sight and is movable via the first and second couplings between the viewing position and a folded position that orients the first and second substantially parallel surfaces of the beam splitter to be substantially normal to the principal axis of the reflective surface, and wherein the angle of the beam splitter plate determines a distance between the image generator and the lens.

38. The display apparatus of claim 37 wherein the beam splitter plate weighs less than 25 grams and provides a horizontal full field of view that exceeds 40 degrees.

39. The display apparatus of claim 38, wherein the beam splitter plate weighs 3-15 grams.

40. A display apparatus comprising:

a first beam splitter plate having first and second parallel surfaces and disposed to define a first viewer eye box along a line of sight of a viewer;

a curved protective shield that transmits the light from a physical scene after being combined by the first beam splitter; and

a first virtual image forming apparatus for forming a first virtual image at the first viewer eye box, the first virtual image forming apparatus comprising;

(i) a first image generator spaced apart from the first beam splitter plate that directs a first flat field of image-bearing light toward the first surface of the first beam splitter plate wherein the first image generator is configured to apply electronic distortion correction to the image bearing light;

(ii) a first lens having a first aspheric incident refractive surface concave to the first image generator and having a first aspheric reflective surface concave to the first image generator, wherein the first lens is configured for field curvature correction and to provide focus of the image-bearing light, wherein a first principal axis of the first reflective surface is normal to the first image generator.

41. The display apparatus according to claim 40 further comprising:

a second beam splitter plate having third and fourth parallel surfaces and disposed to define a second viewer eye box along the line of sight of a viewer; and

a second virtual image forming apparatus for forming a second virtual image at the second viewer eye box, the second virtual image forming apparatus comprising;

(i) a second image generator spaced apart from the second beam splitter plate that directs a second flat field of image-bearing light toward the third surface of the second beam splitter plate wherein the second image generator is configured to apply electronic distortion correction to the image bearing light;

(ii) a second lens having a second aspheric incident refractive surface concave to the second image generator and having a second aspheric reflective surface concave to the second image generator, wherein the second lens is configured for field curvature correction and to provide focus of the image-bearing light, wherein a second principal axis of the second reflective surface is normal to the second image generator.

42. The display apparatus of claim 41 wherein the first and second image generators direct image-bearing light in opposite directions.

43. A display apparatus comprising:

a beam splitter plate disposed to define a left-eye and right-eye viewer eye box along a corresponding line of sight of a viewer, the beam splitter plate having first and second parallel surfaces oblique to the line of sight; and

a left-eye virtual image forming apparatus and a right-eye virtual image forming apparatus, each virtual image forming apparatus disposed to form a corresponding left- or right-eye virtual image to be viewed at the corresponding viewer eye box and comprising;

(i) an image generator spaced apart from the beam splitter plate wherein the image generator is configured to apply electronic correction for distortion and to direct a flat field of image-bearing light toward the first surface of the beam splitter plate; and

(ii) a monolithic lens spaced apart from the second surface of the beam splitter plate and having an aspheric incident refractive surface concave to the image generator wherein the lens is configured to correct field curvature and to provide focus of the image-bearing light and wherein the lens has a principal axis that is orthogonal to the at least one image generator and having an aspheric reflective surface concave to the image generator, wherein a principal axis of the reflective surface is normal to the image generator.

44. The display apparatus of claim 43 wherein a first edge of the beam splitter plate is hinged to the monolithic lens.

45. The display apparatus of claim 43 wherein a second edge of the beam splitter plate is coupled to a housing and wherein the housing accepts a personal communications device as the image generator.

46. The display apparatus of claim 43 wherein the apparatus is foldable with respect to the vertical direction.

47. The display apparatus of claim 43 wherein the monolithic lens for at least one of the virtual image forming apparatus blocks a portion of the horizontal field of view.

48. A display apparatus comprising:

at least one image generator out of the direct line of sight of the viewer, the image generator capable of generating an image-bearing light and electronically correcting the generated image-bearing light for distortion;

a lens spaced apart from the image generator, the lens having an aspheric incident refractive surface concave to the image generator and having an aspheric reflective surface concave to the image generator, wherein the lens curvature is configured for field curvature correction and for focus of the image-bearing light and wherein the lens has a principal axis that is orthogonal to the at least one image generator; and

a flat beam splitter plate disposed in free space between the image generator and the lens, wherein the beam splitter plate has a first flexible coupling to the image generator and a second flexible coupling to the aspheric reflective surface, and wherein the beam splitter plate is configured for orientation in either;

(i) an oblique position, having first and second surfaces that are oblique to a line of sight of a viewer and oblique to the principal axis, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer;

or

(ii) a folded position, wherein the free space between the image generator and the lens is reduced along the principal axis.

49. The display apparatus of claim 48, wherein the image generator is a telecommunications device.

50. The display apparatus of claim 49, wherein the image generator is a cell phone.

51. The display apparatus of claim 48, wherein measured distance, along that portion of the principal axis that extends between the at least one image generator and the beam splitter plate, equals the optical path length.

52. The display apparatus of claim 48, wherein the first flexible coupling is a hinge.

53. The display apparatus of claim 52, wherein the second flexible coupling is a hinge.

54. The display apparatus of clam 48, wherein the aspheric reflective surface has a dichroic coating.

55. The display apparatus of claim 54, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer.

56. A method of delivering an image-bearing light to a viewer comprising:

emitting the image bearing light from an image generator that electronically corrects for distortion, wherein the image generator is positioned in proximity to but outside of the direct line of sight of a viewer;

directing the image bearing light traveling directly through a beam splitter plate and to a lens that has first and second surfaces formed to focus and to correct field curvature of the image bearing light;

refracting the image bearing light a first time at the first surface of the lens;

reflecting the image bearing light back towards the beam splitter from the second surface of the lens;

prior to traveling back to the beam splitter, refracting the image bearing light at the first surface of the lens a second time; and

after said second refracting step, reflecting the image bearing light off of the beam splitter and into the line of sight of the viewer.

57. The method of claim 56, wherein the first and second refracting steps and the reflecting steps are achieved using a single lens having a reflective concave surface as the second surface which reflects the image.

58. A display apparatus comprising:

(i) an image generator that generates an image-bearing light from an image generator display surface with electronic correction for distortion and extends a first hinge coupling to a beam splitter plate;

(ii) a lens spaced apart from the image generator , the lens having an incident refractive surface concave to the image generator and having a reflective surface concave to the image generator, at least one of the lens surfaces being an aspheric surface, wherein the lens extends a second hinge coupling to the beam splitter plate;

(iii) the beam splitter plate disposed in free space between the image generator and the lens and having first and second surfaces that are oblique to a line of sight of a viewer, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer; and

(iv) a field lens situated against the image generator in the path of the image-bearing light, said field lens comprising at least one aspheric surface.

59. A display apparatus comprising:

an image generator that that electronically corrects for distortion and generates an image-bearing light from an image generator display surface;

two lenses spaced apart from the image generator, each of the lenses comprising an optical axis, an incident refractive surface concave to the image generator and a reflective surface concave to the image generator, wherein at least one of said surfaces is aspheric;

said surfaces structured such that said optical axes of each of said lenses are parallel to each other within 1 minute of arc and spaced apart from each other by a distance between 50 mm and 80 mm and wherein each of the two lenses is configured to correct field curvature and to provide focus of the image-bearing light;

a beam splitter plate disposed in free space between the image generator and the lenses and having a first hinged coupling to the image generator and a second and a third hinged coupling to each of the respective lenses and, with the beam splitter plate at a viewing angular position within the hinged couplings, having first and second surfaces that are oblique to a line of sight of a viewer, wherein the lenses and the beam splitter, in combination provide image-bearing light along the lines of sight of the viewer and, with the beam splitter plate at a storage angular position within the hinged couplings, having reduced free space between the image generator and the lenses and eliminating the lines of sight.

60. The display apparatus of claim 59 wherein each lens has a center thickness of 3-12 mm.

61. The display apparatus of claim 59 wherein each lens has a thickness of 3-10 mm.

62. The display apparatus of claim 59 wherein each lens has a thickness of 4-8 mm.

63. The display apparatus of claim 59 wherein the two lenses weigh a total of 5-80 grams.

64. The display apparatus of claim 63 wherein said beam splitter weighs less than 5 grams.

65. The display apparatus of claim 64 wherein said beam splitter weighs 2-10 grams.

66. The display system according to claim 65, wherein the image generator comprises two OLED devices.

67. The display system according to claim 59, wherein the image generator is a “

smart phone”

.

68. The display system according to claim 59, wherein the image generator comprises an OLED device.

69. The display system according to claim 59, wherein the image generator comprises a device with a liquid crystal display.

70. The display system according to claim 59, wherein the image generator is a screen with an image projected on it by another device.

71. The display system according to claim 59, further comprising at least one of:

a GPS sensor, a head tracking sensor, an eye tracking sensor(s), an accelerometer, a camera situated between the two lenses that looks through the beam splitter at viewer'"'"'s eyes.

72. The display system according to claim 59, further comprising at least one camera that is structured to look at either the viewer'"'"'s eye or at a scene viewed by the viewer.

73. A display apparatus comprising:

an image generator with electronic correction for distortion that generates an image-bearing light from an image generator display surface and wherein the image generator has a first hinged coupling;

a lens spaced apart from the image generator over a variable distance, the lens having an incident refractive surface concave to the image generator and a reflective surface concave to the image generator wherein the lens is configured to correct field curvature and to provide focus of the image-bearing light and wherein the lens has a principal axis that is orthogonal to the at least one image generator and wherein the lens has a second hinged coupling; and

a beam splitter plate disposed in free space extending between the first hinged coupling at the image generator and the second hinged coupling at the lens and having first and second surfaces that are oblique to a line of sight of a viewer when the lens spacing from the image generator is at a first distance, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer;

wherein the distance between the image generator and the lens is 20-60 mm and wherein the surfaces of the beam splitter plate are parallel to the image generator when the lens spacing from the image generator is at a second distance.

74. The display apparatus of claim 73 wherein the first distance between the image generator and the lens is 30-50 mm.

75. The display system of claim 74 wherein said lens includes at least one aspheric surface.

76. The display system of claim 75 wherein said lens includes at two aspheric surfaces.

77. The display apparatus of claim 73 wherein said lens has an Abbe V number >

40.

78. The display apparatus of claim 77 wherein said lens has an Abbe V number >

50.

79. The display apparatus of claim 78 wherein said lens has an Abbe V number >

55.

80. The display apparatus of claim 79 wherein said lens has an Abbe V number between 50 and 70.

81. A display apparatus comprising:

an optical system comprising;

(i) an image generator that generates image-bearing light from a display surface and wherein the image generator is configured to electronically correct for distortion and has a first hinged coupling;

(ii) a lens spaced apart from the image generator over a variable distance, the lens having an incident refractive surface concave to the image generator and having a reflective surface concave to the image generator wherein the lens is configured to correct field curvature, and at least one of said surfaces is aspheric and wherein the lens has a second hinged coupling; and

(iii) a beam splitter plate disposed in free space extending between the first hinged coupling at the image generator and the second hinged coupling at the lens and having first and second surfaces that are oblique to a line of sight of a viewer when the lens spacing from the image generator is at a first distance, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer, said optical system further comprising an exit pupil, the exit pupil having an exit pupil diameter Dp≥

7 mm and wherein the surfaces of the beam splitter plate are parallel to the line of sight of the viewer when the lens spacing from the image generator is at a second distance that is less than the first distance.

82. The display apparatus of claim 81 wherein Dp is between 7 and 20 mm.

83. The display apparatus of claim 81 wherein Dp is >

10 mm.

84. A display apparatus comprising:

an optical system comprising;

(i) an image generator that generates image-bearing light from a display surface and wherein the image generator has a first hinged coupling and is configured to provide electronic correction for distortion;

(ii) a lens spaced apart from the image generator by a first distance along a principal axis of the lens that is normal to the image generator, wherein the lens is configured to correct field curvature, the lens having an incident refractive surface concave to the image generator and having a reflective surface concave to the image generator , and at least one of said surfaces is aspheric and wherein the lens has a second hinged coupling, wherein each of the hinged couplings has a view angle and a collapsed angle;

(iii) a beam splitter plate disposed in free space between the first hinged coupling at the image generator and the second hinged coupling at the lens and, with both couplings at the view angle, having first and second surfaces that are oblique to a line of sight of a viewer, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer, said beam splitter structured and positioned such that the image bearing light generated by the image generator traverses the beam splitter as it propagates toward the lens and is reflected from the beam splitter after it is reflected by the lens, and, with both couplings at the collapsed angle, the beam splitter plate lying between the image generator and the lens, with the image generator and the lens spaced apart along the principal axis by a second distance, smaller than the first distance.

85. The display apparatus of claim 84 wherein the beam splitter has a partially reflecting surface, the partially reflecting surface is positioned to face the lens.

86. A display apparatus comprising:

an optical system comprising;

(i) an image generator that generates an image-bearing light from a display surface and is configured to electronically correct distortion;

(ii) a lens spaced apart from the image generator along a principal axis of the lens that is normal to the image generator, the lens having an incident refractive surface concave to the image generator and having an aspheric reflective surface concave to the image generator, and at least one of said surfaces is aspheric wherein the lens is configured to correct field curvature of the image-bearing light; and

(iii) a beam splitter plate disposed in free space between the image generator and the lens and coupled to the image generator by a first hinge and coupled to the lens by a second hinge, wherein, at a first angular position of the first and second hinges, first and second surfaces of the beam splitter plate are oblique to a line of sight of a viewer, said beam splitter being structured and positioned such that the image bearing light generated by the image generator traverses the beam splitter as it propagates toward the lens , and is reflected from the beam splitter after it is reflected by the lens and at a second angular position of the first and second hinges, the first surface of the beam splitter plate extends parallel to the image generator display surface and the second surface of the beam splitter plate extends parallel to the lens ; and

said optical system further comprising an exit pupil, the exit pupil having an exit pupil diameter Dp≥

7 mm and has a vertical full field of view FOVv and a horizontal full field of view FOVh such that FOVh/FOVv>

1.5.

87. The display system of claim 86, wherein FOVh/FOVv>

1.7.

88. The display system of claim 86, wherein 3≥

FOVh/FOVv>

1.7.

89. A display apparatus comprising:

an optical system comprising;

(i) an image generator that generates an image-bearing light from an image generator display surface and is configured to electronically correct distortion;

said image generator further comprising a camera and an optical element folding the viewing direction of the camera situated adjacent thereto;

(ii) a lens spaced apart from the image generator along a principal axis, wherein the principal axis of the lens is normal to the image generator, the lens having an incident refractive surface concave to the image generator and having an aspheric reflective surface concave to the image generator;

wherein the lens is configured to correct field curvature of the image-bearing light; and

(iii) a beam splitter plate disposed in free space between the image generator and the lens and coupled to the image generator by a first hinge and coupled to the lens by a second hinge, wherein, at a viewing angular position of the first and second hinges, first and second surfaces of the beam splitter plate are oblique to a line of sight of a viewer, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer and at a storage angular position of the first and second hinges, the first surface of the beam splitter plate lies closer to the image generator display surface than at the viewing angular position and the second surface of the beam splitter plate lies closer to the lens than at the viewing angular position.

90. The display apparatus of claim 89, wherein said optical element comprises a reflective surface such that the camera can view at least a portion of the view viewed by the viewer through the beam splitter.

91. The display apparatus of claim 89, wherein said optical element comprises a reflective surface such that the field of view of the camera includes the line of sight of the viewer through the beam splitter.

92. The display apparatus of claim 89, wherein said optical element comprises a prism structured such that such that the camera can view at least a portion of the view viewed by the viewer through the beam splitter.

93. The display apparatus of claim 89, wherein said optical element comprises a prism structured such that such that such that the field of view of the camera includes the line of sight of the viewer.

94. A display apparatus comprising:

an optical system comprising;

(i) an image generator that generates an image-bearing light and automatically corrects for distortion,

(ii) a polarizing plate situated adjacent to the image generator,

(iii) a lens spaced apart from the display source and from the polarizing pate, the lens having an incident refractive surface concave to the display source and having a reflective surface concave to the display source, wherein the lens is configured to correct field curvature of the image-bearing light and at least one of said surfaces is aspheric,

(iv) a beam splitter plate disposed in free space between the polarizing plate and the lens and having first and second surfaces that are oblique to a line of sight of a viewer; and

(v) a quarter wave retarder situated between the lens and the beam splitter, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer.

95. The display apparatus of claim 94, wherein the ¼

wave plate is achromatic across the visible spectrum.

96. A display apparatus comprising:

an image generator that generates an image-bearing light from an image generator display surface and that is configured to electronically correct distortion;

a lens having a principal axis, wherein the lens is spaced apart from the image generator, the lens having an incident refractive surface concave to the image generator and having a reflective surface concave to the image generator, wherein the lens is configured to correct field curvature of the image-bearing light and at least one of said surfaces is aspheric;

a beam splitter plate disposed in free space between the image generator and the lens and coupled to the image generator by a first hinge on one side of the principal axis and coupled to the lens by a second hinge on the other side of the principal axis, wherein, at a first angular orientation of the first and second hinges, first and second surfaces of the beam splitter plate are oblique to a line of sight of a viewer, wherein the lens and the beam splitter plate define a viewer eye box for the image-bearing light along the line of sight of the viewer, and wherein, said display apparatus exhibits at least one of;

(a) horizontal field of view between 30 and 70 degrees, an eye relief distance between 5 mm and 50 mm, focal length of the lens between 30 mm and 70 mm;

an exit pupil diameter between 7 mm and 20 mm, and a distance between the lens and the display of 30 mm to 70 mm;

(b) an eye relief distance between 5 mm and 40 mm, a horizontal FOV between 30 and 70 degrees and resolution between 1 min/pixel and 4 min/pixel,

and wherein, at a second angular orientation of the first and second hinges, the first surface of the beam splitter plate lies adjacent and parallel to the image generator plate and the second surface of the beam splitter plate faces toward the lens and is substantially at a normal to the principal axis.

97. A display apparatus comprising:

an optical system comprising;

(i) an image generator that generates an image-bearing light and that is configured to electronically correct distortion,

(ii) a polarizing plate situated adjacent to the image generator,

(iii) a lens having a principal axis that is normal to the image generator, wherein the lens is spaced apart from the image generator and from the polarizing plate along the principal axis, the lens having an incident refractive surface concave to the display source and having an aspheric reflective surface concave to the display source, wherein the lens is configured to correct field curvature of the image-bearing light; and

(iv) a beam splitter plate disposed in free space between the polarizing plate and the lens and coupled to the image generator by a first hinge on one side of the principal axis and coupled to the lens by a second hinge on the other side of the principal axis, wherein, at a first angular orientation of the first and second hinges, first and second surfaces of the beam splitter plate are oblique to a line of sight of a viewer and define a viewer eye box for the image bearing light along the line of sight of the viewer,

and wherein, in a transition from the first angular orientation to a second angular orientation of the first and second hinges, the image generator and polarizing plate are moved toward the lens along the principal axis.

98. A display apparatus comprising:

an image generator that generates an image-bearing light from an image generator display surface and that is configured to electronically correct distortion;

at least two lenses spaced apart from the image generator, each of the two lenses having an incident refractive surface concave to the image generator and having an aspheric reflective surface concave to the image generator wherein each lens is further configured to correct field curvature of the image-bearing light; and

a beam splitter plate disposed in free space and having a first hinged coupling to the image generator and a second hinged coupling to each of the at least two lenses wherein the beam splitter plate is configurable within the hinged couplings to a storage angle that disposes both the image generator and the at least two lenses against the beam splitter plate, and a viewing angle that further separates the image generator and the at least two lenses and orients first and second surfaces of the beam splitter plate to be oblique to a line of sight of a viewer, wherein each lens and the beam splitter plate define a corresponding viewer eye box for the image-bearing light along the line of sight of the viewer, and wherein, said display apparatus exhibits at least one of;

(a) horizontal field of view between 30 and 70 degrees, an eye relief distance between 5 mm and 50 mm, focal length of the lens between 30 mm and 70 mm;

an exit pupil diameter between 7 mm and 20 mm, and a distance between the lens and the display of 30 mm to 70 mm;

(b) an eye relief distance between 5 mm and 40 mm, a horizontal FOV between 30 and 70 degrees and resolution between 1 min/pixel and 4 min/pixel.

99. The display apparatus according to claim 98, wherein eye relief distance is at least 8 mm.

100. The display apparatus according to claim 98, wherein the two lenses are situated in contact with one another.

101. The display apparatus according to claim 98 wherein the two lenses are molded together as one monolithic component.

102. The display apparatus according to claim 98 wherein the two lenses are formed as a monolithic single component.

103. The display apparatus according to claim 98, wherein the two lenses are shaped to provide an insertion space for viewer'"'"'s nose.

104. The display apparatus according to claim 98 wherein each of the lenses comprises an optical axis, and the lenses are structured and positioned such that the optical axis of each of said lenses are parallel to each other within 1 minute of arc.

105. The display apparatus according to claim 104 wherein each of the lenses comprise an optical axis, and the lenses are structured and positioned such that the optical axis of each of said lenses are parallel to each other within 50 arc seconds.

106. The display apparatus according to claim 104 wherein the image generator display surface is a flat surface.

108. The display apparatus of claim 98 wherein the display apparatus exhibits lateral chromatic aberration that is less than the width of the pixel of the display device.

109. The display apparatus of claim 98 wherein the image generator is situated above the viewer'"'"'s eye and the lens is situated below viewer'"'"'s eyes.

107. The display apparatus of 98 wherein the display apparatus exhibits lateral chromatic aberration that is less than 44 micrometers.

110. The display apparatus of 98 wherein the image generator is situated below viewer'"'"'s eyes, and the lens is situated above viewer'"'"'s eyes.