USRE37579EExpiredUtilityPatentIndex 93
Image display apparatus comprising an internally reflecting ocular optical system
Est. expiryFeb 13, 2016(expired)· nominal 20-yr term from priority
Inventors:TAKAHASHI KOICHI
G02B 2027/0125G02B 2027/0132G02B 27/0172G02B 27/0101G02B 2027/0118G02B 2027/0178G02B 2027/011
93
PatentIndex Score
28
Cited by
29
References
90
Claims
Abstract
An image display apparatus which enables observation of a clear image at a wide field angle with substantially no reduction in the brightness of the observation image, and which is extremely small in size and fight in weight and hence unlikely to cause the observer to be fatigued. The image display apparatus includes an image display device and an ocular optical system for projecting an image formed by the image display device and for leading the projected image to an observer's eyeball. The ocular optical system (3) has three surfaces, and a space formed by the three surfaces is filled with a medium having a refractive index larger than 1. The three surfaces include, in the order in which light rays pass in backward ray tracing from the observer's eyeball (1) to the image display device (4), a first surface (5) which functions as both a refracting surface and an internally reflecting surface, a second surface (6) which is a reflecting surface facing the first surface (5) and decentered or tilted with respect to an observer's visual axis (2), and a third surface (7) which is a refracting surface closest to the image display device (4), so that reflection takes place three times in the path from the observer's eyeball (1) to the image display device (4).
Claims
exact text as granted — not AI-modifiedWhat we claim is:
1. An image display apparatus comprising an image display device for displaying an image, and an ocular optical system for projecting the image formed by said image display device and for leading the projected image to an observer's eyeball,
said ocular optical system being arranged such that light rays emitted from said image display device are reflected three or higher odd-numbered times before reaching said observer's eyeball, and that a surface of said ocular optical system that is disposed immediately in front of said observer's eyeball is a refracting surface which internally reflects the light rays, and through which the light rays exit from said ocular optical system.
2. An image display apparatus comprising an image display device for displaying an image, and an ocular optical system for projecting the image formed by said image display device and for leading the projected image to an observer's eyeball,
said ocular optical system being arranged such that light rays emitted from said image display device are reflected three times before reaching said observer's eyeball, and that a surface of said ocular optical system that is disposed immediately in front of said observer's eyeball is a refracting surface which internally reflects the light rays, and through which the light rays exit from said ocular optical system.
3. An image display apparatus comprising an image display device for displaying an image, and an ocular optical system for projecting the image formed by said image display device and for leading the projected image to an observer's eyeball,
said ocular optical system having at least three surfaces, wherein a space formed by said at least three surfaces is filled with a medium having a refractive index larger than 1,
said at least three surfaces including, in an order in which light rays pass in backward ray tracing from said observer's eyeball to said image display device, a first surface which functions as both a refracting surface and an internally reflecting surface, a second surface which is a reflecting surface facing said first surface and decentered or tilted with respect to an observer's visual axis, and a third surface which is a refracting surface closest to said image display device, so that reflection takes place three times in a path from said observer's eyeball to said image display device.
4. An image display apparatus comprising an image display device for displaying an image, and an ocular optical system for projecting the image formed by said image display device and for leading the projected image to an observer's eyeball,
said ocular optical system having at least four surfaces, wherein a space formed by said at least four surfaces is filled with a medium having a refractive index larger than 1,
said at least four surfaces including, in an order in which light rays pass in backward ray tracing from said observer's eyeball to said image display device, a first surface which functions as both a refracting surface and an internally reflecting surface, a second surface which is a reflecting surface facing said first surface and decentered or tilted with respect to an observer's visual axis, a third surface which is a reflecting surface facing said first surface and adjacent to said second surface, and a fourth surface which is a refracting surface closest to said image display device, so that reflection takes place three times in a path from said observer's eyeball to said image display device.
5. An image display apparatus according to any one of claims 1 to claim 3 or 4 , wherein at least one of the surfaces constituting said ocular optical system is a flat surface.
6. An image display apparatus according to claim 3 or 4 , wherein the internal reflection at said first surface is total reflection.
7. An image display apparatus according to any one of claims 3 or 4 , wherein said second surface is a reflecting surface which is concave toward said first surface.
8. An image display apparatus according to any one of claims 3 or 4 , wherein said first surface is a surface which functions as both a transmitting surface and a reflecting surface, said first surface being convex toward said second surface.
9. An image display apparatus according to any one of claims 3 or 4 , wherein said first surface is a flat surface which functions as both a transmitting surface and a reflecting surface.
10. An image display apparatus according to claim 3 or 4 , wherein an internally reflecting region of said first surface has a reflective coating.
11. An image display apparatus according to claim 3 or 4 wherein said first surface is a surface which functions as both a transmitting surface and a reflecting surface, said first surface being concave toward said second surface.
12. An image display apparatus according to claim 3 or 4 , wherein said second surface is a reflecting surface which is convex toward said first surface.
13. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
0°<θ 2 <50° (1)
wherein θ 2 is an incident angle of an axial principal ray at a first reflection by said second surface in the backward ray tracing.
14. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
10°<θ 2 <40° (2)
wherein θ 2 is an incident angle of an axial principal ray at a first reflection by said second surface in the backward ray tracing.
15. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
−20°<θ 1 <40° (3)
wherein θ 1 is an incident angle of an axial principal ray at said first surface.
16. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
−10°<θ 1 <25° (4)
wherein θ 1 is an incident angle of an axial principal ray at said first surface.
17. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
20°<θ 3 <70° (5)
wherein θ 3 is an incident angle of an axial principal ray at internal reflection by said first surface.
18. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
30°<θ 3 <55° (6)
wherein θ 3 is an incident angle of an axial principal ray at internal reflection by said first surface.
19. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
20°<θ 4 <80° (7)
wherein θ 4 is an incident angle of an axial principal ray when reflected for a second time in the backward ray tracing by said second surface of said ocular optical system comprising three surfaces, or θ 4 is an incident angle of an axial principal ray at said third surface of said ocular optical system comprising four surfaces.
20. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
30°<θ 4 <65° (8)
wherein θ 4 is an incident angle of an axial principal ray when reflected for a second time in the backward ray tracing by said second surface of said ocular optical system comprising three surfaces, or θ 4 is an incident angle of an axial principal ray at said third surface of said ocular optical system comprising four surfaces.
21. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
−30°<θ 5 <40° (9)
wherein θ 5 is an incident angle of an axial principal ray at said third surface in said ocular optical system comprising three surfaces, or θ 5 is an incident angle of an axial principal ray at said fourth surface in said ocular optical system comprising four surfaces.
22. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
−40°<θ i <40° (10)
wherein θ i is an incident angle of an axial principal ray at a display surface of said image display device.
23. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
−25°<θ i <25° (11)
wherein θ i is an incident angle of an axial principal ray at a display surface of said image display device.
24. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
1.45<N d <2.0 (12)
where N d is a refractive index for the spectral d-line of said medium having a refractive index larger than 1.
25. An image display apparatus according to claim 3 or 4 , which satisfies the following condition:
1.5<N d <2.0 (13)
where N d is a refractive index for the spectral d-line of said medium having a refractive index larger than 1.
26. An image display apparatus according to any one of claims 1 to claim 3 or 4 , wherein at least one of the surfaces constituting said ocular optical system is an aspherical surface.
27. An image display apparatus according to claim 26 , wherein at least one of the surfaces constituting said ocular optical system is an anamorphic surface.
28. An image display apparatus according to claim 26 , wherein at least one of the surfaces constituting said ocular optical system is a free curved surface.
29. An image display apparatus according to claim 3 or 4 , wherein a display surface of said image display device is tilted with respect to an axial principal ray.
30. An image display apparatus according to claim 29 , wherein said image display device is disposed in such a manner that a side thereof which is reverse to said display surface faces said observer.
31. An image display apparatus according to any one of claims 1 to claim 3 or 4 , further comprising means for positioning both said image display device and said ocular optical system with respect to the observer's head.
32. An image display apparatus according to any one of claims 1 to claim 3 or 4 , further comprising means for supporting both said image display device and said ocular optical system with respect to the observer's head.
33. An image display apparatus according to any one of claims 1 to claim 3 or 4 , further comprising means for supporting at least a pair of said image display apparatuses at a predetermined spacing.
34. An image display apparatus according to any one of claims 1 to claim 3 or 4 , wherein said ocular optical system is used as an imaging optical system.
35. An imaging optical system wherein a light beam from an object is passed through a pupil to form an object image on an image plane, said imaging optical system comprising:
at least an optical member for one of converging and diverging the light beam,
said optical member being provided between said pupil and said image plane,
said optical member having at least three surfaces, wherein a space formed by said at least three surfaces is filled with a medium having a refractive index larger than 1 ,
said at least three surfaces including, in an order in which light rays pass in ray tracing from said pupil to said image plane, a first surface which functions as both a refracting surface and an internally reflecting surface, a second surface which is a reflecting surface facing said first surface and decentered or tilted, and a third surface which is a refracting surface closest to said image plane, so that reflection takes place three times in a path from said pupil to said image plane.
36. An imaging optical system wherein a light beam from an object is passed through a pupil to form an object image on an image plane, said imaging optical system comprising:
at least an optical member for one of converging and diverging the light beam,
said optical member being provided between said pupil and said image plane,
said optical member having at least four surfaces, wherein a space formed by said at least four surfaces is filled with a medium having a refractive index larger than 1 ,
said at least four surfaces including, in an order in which light rays pass in ray tracing from said pupil to said image plane, a first surface which functions as both a refracting surface and an internally reflecting surface, a second surface which is a reflecting surface facing said first surface and decentered or tilted, a third surface which is a reflecting surface facing said first surface and adjacent to said second surface, and a fourth surface which is a refracting surface closest to said image plane, so that reflection takes place three times in a path from said pupil to said image plane.
37. A finder optical system comprising:
the imaging optical system of
claim 35
or
36
;
an imaging erecting optical system for erecting the object image formed on said image plane by said imaging optical system; and
an ocular optical system for viewing said object time.
38. A camera apparatus comprising:
the imaging optical system of
claim 35
or
36
, said imaging optical system being incorporated as an optical system for forming an object image.
39. An imaging optical system according to claim 35 or 36 , wherein at least one of the surfaces constituting said optical member is a flat surface.
40. An imaging optical system according to claim 35 or 36 , wherein the internal reflection at said first surface is total reflection.
41. An imaging optical system according to claim 35 or 36 , wherein said second surface is a reflecting surface which is concave toward said first surface.
42. An imaging optical system according to claim 35 or 36 , wherein said first surface is a surface which functions as both a transmitting surface and a reflecting surface, said first surface being convex toward said second surface.
43. An imaging optical system according to claim 35 or 36 , wherein said first surface is a flat surface which functions as both a transmitting surface and a reflecting surface.
44. An imaging optical system according to claim 35 or 36 , wherein an internally reflecting region of said first surface has a reflective coating.
45. An imaging optical system according to claim 35 or 36 , wherein said first surface is a surface which functions as both a transmitting surface and a reflecting surface, said first surface being concave toward said second surface.
46. An imaging optical system according to claim 35 or 36 , wherein said second surface is a reflecting surface which is convex toward said first surface.
47. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
0 °<θ 2 < 50 ° ( 1 )
where θ
2
is an incident angle of an axial principal ray at a first reflection by said second surface in the ray tracing.
48. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
10 °<θ 2 < 40 ° ( 2 )
where θ
2
is an incident angle of an axial principal ray at a first reflection by said second surface in the ray tracing.
49. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
− 20 °<θ 1 < 40 ° ( 3 )
where θ
1
is an incident angle of an axial principal ray at said first surface.
50. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
− 10 °<θ 1 < 25 ° ( 4 )
where θ
1
is an incident angle of an axial principal ray at said first surface.
51. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
20 °<θ 3 < 70 ° ( 5 )
where θ
3
is an incident angle of an axial principal ray at internal reflection by said first surface.
52. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
30 °<θ 3 < 55 ° ( 6 )
where θ
3
is an incident angle of an axial principal ray at internal reflection by said first surface.
53. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
20 °<θ 4 < 80 ° ( 7 )
where θ 4 is one of ( 1 ) an incident angle of an axial principal ray when reflected for a second time in the ray tracing by said second surface of said optical member comprising three surfaces, and ( 2 ) an incident angle of an axial principal ray at said third surface of said optical member comprising four surfaces.
54. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
30 °<θ 4 < 65 ° ( 8 )
where θ 4 is one of ( 1 ) an incident angle of an axial principal ray when reflected for a second time in the ray tracing by said second surface of said optical member comprising three surfaces, and ( 2 ) an incident angle of an axial principal ray at said third surface of said optical member comprising four surfaces.
55. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
− 30 °<θ 5 < 40 ° ( 9 )
where θ 5 is one of ( 1 ) an incident angle of an axial principal ray at said third surface in said optical member comprising three surfaces, and ( 2 ) an incident angle of an axial principal ray at said fourth surface in said optical member comprising four surfaces.
56. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
− 40 °<θ i < 40 ° ( 10 )
where θ
i
is an incident angle of an axial principal ray on said image plane.
57. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
− 25 °<θ i < 25 ° ( 11 )
where θ
i
incident angle of an axial principal ray on said image plane.
58. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
1 . 45 <N d < 2 . 0 ( 12 )
where N d is a refractive index for the spectral d - line of said medium having a refractive index larger than 1 .
59. An imaging optical system according to claim 35 or 36 , which satisfies the following condition:
1 . 5 <N d < 2 . 0 ( 13 )
where N d is a refractive index for the spectral d - line of said medium having a refractive index larger than 1 .
60. An imaging optical system according to claim 35 or 36 , wherein at least one of the surfaces constituting said optical member is an aspherical surface.
61. An imaging optical system according to claim 60 , wherein at least one of the surfaces constituting said optical member is an anamorphic surface.
62. An imaging optical system according to claim 35 or 36 , wherein a front optical system is placed on an object side of said pupil.
63. An imaging optical system according to claim 35 or 36 , wherein said image plane is tilted with respect to an axial principal ray.
64. A viewing optical system comprising:
image - forming means for forming an observation image on an image plane, and
an ocular optical system for projecting said observation image and for leading the projected image to an observer's eyeball,
said ocular optical system having at least three surfaces, wherein a space formed by said at least three surfaces is filled with a medium having a refractive index larger than 1 ,
said at least three surfaces including, in an order in which light rays pass in backward ray tracing from said observer's eyeball to said observation image, a first surface which functions as both a refracting surface and an internally reflecting surface, a second surface which is a reflecting surface facing said first surface and decentered or tilted with respect to an observer's visual axis, and a third surface which is a refracting surface closest to said observation image, so that reflection takes place three times in a path from said observer's eyeball to said observation image.
65. A viewing optical system comprising:
image - forming means for forming an observation image on an image plane, and
an ocular optical system for projecting said observation image and for leading the projected image to an observer's eyeball,
said ocular optical system having at least four surfaces, wherein a space formed by said at least four surfaces is filled with a medium having a refractive index larger than 1 ,
said at least four surfaces including, in an order in which light rays pass in backward ray tracing from said observer's eyeball to said observation image, a first surface which functions as both a refracting surface and an internally reflecting surface, a second surface which is a reflecting surface facing said first surface and decentered or tilted with respect to an observer's visual axis, a third surface which is a reflecting surface facing said first surface and adjacent to said second surface, and a fourth surface which is a refracting surface closest to said observation image, so that reflection takes place three times in a path from said observer's eyeball to said observation image.
66. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
1 . 5 <N d < 2 . 0 ( 13 )
where N d is a refractive index for the spectral d - line of said medium having a refractive index larger than 1 .
67. A viewing optical system according to claim 64 or 65 , wherein at least one of the surfaces constituting said ocular optical system is an aspherical surface.
68. A viewing optical system according to claim 67 , wherein at least one of the surfaces constituting said ocular optical system is an anamorphic surface.
69. A viewing optical system according to claim 67 , wherein at least one of the surfaces constituting said ocular optical system is a free curved surface.
70. A viewing optical system according to claim 64 or 65 , wherein an image surface of said observation image formed by said image- forming means is tilted with respect to an axial principal ray.
71. A viewing optical system according to claim 64 or 65 , wherein at least one of the surfaces constituting said ocular optical system is a flat surface.
72. A viewing optical system according to claim 64 or 65 , wherein the internal reflection at said first surface is total reflection.
73. A viewing optical system according to claim 64 or 65 , wherein said second surface is a reflecting surface which is concave toward said first surface.
74. A viewing optical system according to claim 64 or 65 , wherein said first surface is a surface which functions as both a transmitting surface and a reflecting surface, said first surface being convex toward said second surface.
75. A viewing optical system according to claim 64 or 65 , wherein said first surface is a flat surface which functions as both a transmitting surface and a reflecting surface.
76. A viewing optical system according to claim 64 or 65 , wherein an internally reflecting region of said first surface has a reflective coating.
77. A viewing optical system according to claim 64 or 65 , wherein said first surface is a surface which functions as both a transmitting surface and a reflecting surface, said first surface being concave toward said second surface.
78. A viewing optical system according to claim 64 or 65 , wherein said second surface is a reflecting surface which is convex toward said first surface.
79. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
0 °<θ 2 < 50 ° ( 1 )
where θ
2
is an incident angle of an axial principal ray at a first reflection by said second surface in the backward ray tracing.
80. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
10 °<θ 2 < 40 ° ( 2 )
where θ
2
is an incident angle of an axial principal ray at a first reflection by said second surface in the backward ray tracing.
81. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
− 20 °<θ 1 < 40 ° ( 3 )
where θ
1
is an incident angle of an axial principal ray at said first surface.
82. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
− 10 °<θ 1 < 25 ° ( 4 )
where θ
1
is an incident angle of an axial principal ray at said first surface.
83. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
20 °<θ 3 < 70 ° ( 5 )
where θ
3
is an incident angle of an axial principal ray at internal reflection by said first surface.
84. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
30 °<θ 3 < 55 ° ( 6 )
where θ
3
is an incident angle of an axial principal ray at internal reflection by said first surface.
85. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
20 °<θ 4 < 80 ° ( 7 )
where θ 4 is one of ( 1 ) an incident angle of an axial principal ray when reflected for a second time in the backward ray tracing by said second surface of said ocular optical system comprising three surfaces, and ( 2 ) an incident angle of an axial principal ray at said third surface of said ocular optical system comprising four surfaces.
86. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
30 °<θ 4 < 65 ° ( 8 )
where θ 4 is one of ( 1 ) an incident angle of an axial principal ray when reflected for a second time in the backward ray tracing by said second surface of said ocular optical system comprising three surfaces, and ( 2 ) an incident angle of an axial principal ray at said third surface of said ocular optical system comprising four surfaces.
87. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
− 30 °<θ 5 < 40 ° ( 9 )
where θ 5 is one of an incident angle of an axial principal ray at said third surface in said ocular optical system comprising three surfaces, and ( 2 ) an incident angle of an axial principal ray at said fourth surface in said ocular optical system comprising four surfaces.
88. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
− 40 °<θ i < 40 ° ( 10 )
where θ
i
is an incident angle of an axial principal ray on a surface of said observation image.
89. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
− 25 °<θ i < 25 ° ( 11 )
where θ
i
is an incident angle of an axial principal ray on a surface of said observation image.
90. A viewing optical system according to claim 64 or 65 , which satisfies the following condition:
1 . 45 <N d < 2 . 0 ( 12 )
where N d is a refractive index for the spectral d - line of said medium having a refractive index larger than 1 .Cited by (0)
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