Image display apparatus comprising an internally reflecting ocular optical system

• US RE37,579 E1
• Filed: 08/26/1999
• Issued: 03/12/2002
• Est. Priority Date: 02/13/1996
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Takahashi, Koichi
• Primary Examiner(s): Mack, Ricky
• Application Number:
  US09/383,382
• Time in Patent Office: 929 Days
• Field of Search: 359/630, 359/631, 359/633, 359/636, 359/637, 359/639, 359/640, 345/7, 345/8
• US Class Current: 359/633
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0172 characterised by optical features

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

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.

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.

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.

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.

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.

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:

14. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

15. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

16. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

17. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

18. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

19. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

20. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

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:

23. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

24. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

25. An image display apparatus according to claim 3 or 4, which satisfies the following condition:

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.

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.

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:

37. A finder optical system comprising:

38. A camera apparatus comprising:

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:

48. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

49. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

50. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

51. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

52. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

53. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

54. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

55. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

56. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

57. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

58. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

59. An imaging optical system according to claim 35 or 36, which satisfies the following condition:

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.

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:

64. A viewing optical system comprising:

image-forming means for forming an observation image on an image plane, and

66. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

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:

80. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

81. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

82. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

83. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

84. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

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:

87. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

88. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

89. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

90. A viewing optical system according to claim 64 or 65, which satisfies the following condition:

65. A viewing optical system comprising:

image-forming means for forming an observation image on an image plane, and