Head or face mounted image display apparatus

• US 5,701,202 A
• Filed: 07/21/1995
• Issued: 12/23/1997
• Est. Priority Date: 05/18/1995
• 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): Nelms, David C.
• Assistant Examiner(s): SCHWARTZ, JORDAN MARC
• Application Number:
  US08/505,516
• Time in Patent Office: 886 Days
• Field of Search: 359/631-632, 359/636, 359/630, 359/633, 359/720, 359/384
• US Class Current: 359/631
• CPC Class Codes: G02B 17/0816 off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements
• 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 2027/0116 comprising devices for correcting chromatic aberration
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features

Abstract

The present invention is an optical apparatus, e.g. 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 light in weight and hence unlikely to cause the observer to be fatigued. The optical apparatus has an image display device (6), and an ocular optical system (7) for leading an image of the image display device (6) to an observer'"'"'s eyeball (1). The ocular optical system (7) includes, in order from the image side, a third surface (5) which forms an entrance surface, a first surface (3) which forms both a reflecting surface and an exit surface, and a second surface (4) which forms a reflecting surface. The first to third surfaces (3 to 5) are integrally formed with a medium put therebetween which has a refractive index larger than 1. A bundle of light rays emitted from the image display device (6) enters the ocular optical system (7) while being refracted by the third surface (5) and is internally reflected by the first surface (3) and reflected by the second surface (4). Then, the ray bundle is incident on the first surface (3) again and refracted thereby so as to be projected into the observer'"'"'s eyeball with the observer'"'"'s iris position or eyeball rolling center as the exit pupil (1).

Claims

1. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading the image to an observer'"'"'s eyeball,

said ocular optical system comprising first, second and third surfaces, in which a space defined by said first, second and third surfaces is filled with a medium having a refractive index larger than 1,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, a first surface serving as both a refracting surface and an internally reflecting surface, a second surface serving as a reflecting surface of positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and a third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least three surfaces having a finite curvature radius;

wherein any one of said first, second and third surfaces is a decentered aspherical surface;

wherein any one of said first, second and third surfaces is an anamorphic surface;

wherein said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer'"'"'s visual axis is defined as a YZ-plane, and a horizontal plane containing said observer'"'"'s visual axis is defined as an XZ-plane;

2. 5<

R_y2 /R_x2 <

5

where R_y2 is a curvature radius of said second surface in the YZ-plane, and R_x2 is a curvature radius of said second surface in the XZ-plane.

3. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading the image to an observers eyeball,

said ocular optical system comprising first, second and third surfaces, in which a space defined by said at least first, second and third surfaces is filled with a medium having a refractive index larger than 1,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, a first surface serving as both a refracting surface and an internally reflecting surface, a second surface serving as a reflecting surface of positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and a third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius;

wherein any one of said first, second and third surfaces is a decentered aspherical surface;

wherein any one of said first, second and third surfaces is an anamorphic surface;

wherein said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer'"'"'s visual axis is defined as a YZ-plane, and a horizontal plane containing said observer'"'"'s visual axis is defined as an XZ-plane;

4. 5<

R_y2 /R_x2 <

5

where R_y2 is a curvature radius of said second surface in the YZ-plane, and R_x2 is a curvature radius of said second surface in the XZ-plane,

wherein internal reflection that is performed by said first surface is total reflection.

9. An optical apparatus according to claim 4 or 5, wherein either one of said first and third surfaces of said ocular optical system is tilted or decentered with respect to said observer'"'"'s visual axis.

5. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading the image to an observer'"'"'s eyeball,

said ocular optical system comprising first, second and third surfaces, in which a space defined by said at least first, second and third surfaces is filled with a medium having a refractive index larger than 1,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, a first surface serving as both a refracting surface and an internally reflecting surface, a second surface serving as a reflecting surface of positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and a third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least three surfaces having a finite curvature radius;

wherein any one of said first, second and third surfaces is a decentered aspherical surface;

wherein any one of said first, second and third surfaces is an anamorphic surface;

wherein said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer'"'"'s visual axis is defined as a YZ-plane, and a horizontal plane containing said observer'"'"'s visual axis is defined as an XZ-plane;

6. 5<

R_y2 /R_x2 <

5

where R_y2 is a curvature radius of said second surface in the YZ-plane, and R_x2 is a curvature radius of said second surface in the XZ-plane,

wherein internal reflection that is performed by said first surface is total reflection,

wherein said first surface has an internally reflecting region which has been mirror-coated.

10. An optical apparatus according to claim 6, further comprising means for positioning both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head.

11. An optical apparatus according to claim 6, further comprising means for supporting both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head so that said optical apparatus can be fitted to said observer'"'"'s head.

12. An optical apparatus according to claim 6, further comprising means for supporting at least a pair of said optical apparatuses at a predetermined spacing.

13. An optical apparatus according to claim 6, wherein said ocular optical system is used as an imaging optical system.

14. An optical apparatus according to claim 6, which satisfies the following condition:

space="preserve" listing-type="equation">10°

≦

α

≦

40°

(3)

where α

is an angle between said visual axis and a line normal to said second surface of said ocular optical system in the vicinity of an intersection between said observer'"'"'s visual axis and said second surface.

15. An optical apparatus according to claim 11, further comprising means for positioning both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head.

16. An optical apparatus according to claim 11, further comprising means for supporting both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head so that said optical apparatus can be fitted to said observer'"'"'s head.

17. An optical apparatus according to claim 11, further comprising means for supporting at least a pair of said optical apparatuses at a predetermined spacing.

18. An optical apparatus according to claim 11, wherein said ocular optical system is used as an imaging optical system.

19. An optical apparatus according to claim 11, wherein said device for displaying an image has a display surface which is tilted with respect to said observer'"'"'s visual axis.

20. An optical apparatus according to claim 16, further comprising means for positioning both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head.

21. An optical apparatus according to claim 16, further comprising means for supporting both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head so that said optical apparatus can be fitted to said observer'"'"'s head.

22. An optical apparatus according to claim 16, further comprising means for supporting at least a pair of said optical apparatuses at a predetermined spacing.

23. An optical apparatus according to claim 16, wherein said ocular optical system is used as an imaging optical system.

29. An optical apparatus according to claim 21, 22 or 23, further comprising means for positioning both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head.

30. An optical apparatus according to claim 21, 22 or 23, further comprising means for supporting both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head so that said optical apparatus can be fitted to said observer'"'"'s head.

31. An optical apparatus according to claim 21, 22 or 23, further comprising means for supporting at least a pair of said optical apparatuses at a predetermined spacing.

32. An optical apparatus according to claim 21, 22 or 23, wherein said ocular optical system is used as an imaging optical system.

7. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading the image to an observer'"'"'s eyeball,

said ocular optical system comprising first, second and third surfaces, in which a space defined by said at least first, second and third surfaces is filled with a medium having a refractive index larger than 1,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, a first surface serving as both a refracting surface and an internally reflecting surface, a second surface serving as a reflecting surface of positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and a third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius; and

wherein said first surface is a reflecting surface having a convex surface directed toward said second surface.

8. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading the image to an observer'"'"'s eyeball,

said ocular optical system comprising first, second and third surfaces, in which a space defined by said at least first, second and third surfaces is filled with a medium having a refractive index larger than 1,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, a first surface serving as both a refracting surface and an internally reflecting surface, a second surface serving as a reflecting surface of positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and a third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius;

wherein internal reflection that is performed by said first surface is total reflection, and

wherein said first surface is a reflecting surface having a convex surface directed toward said second surface.

24. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading said image to an observer'"'"'s eyeball,

said ocular optical system comprising at least first, second and third surfaces, in which a space defined by said surfaces is filled with a medium having a refractive index larger than 1,

said device for displaying an image being disposed at a position facing said third surface,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, said first surface serving as both a refracting surface and an internally reflecting surface, said second surface serving as a reflecting surface of a positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and said third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius,

wherein any one of said first, second and third surfaces is a decentered aspherical surface,

wherein any one of said first, second and third surfaces is an anamorphic surface, and

said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer'"'"'s visual axis is defined as a YZ-plane, and a horizontal plane containing said observer'"'"'s visual axis is defined as an XZ-plane;

space="preserve" listing-type="equation">0.5<

R.sub.y2 /R.sub.x2 <

5

where R_y2 is a curvature radius of said second surface in said YZ-plane, and R_x2 is a curvature radius of said second surface in said XZ-plane.

25. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading said image to an observer'"'"'s eyeball,

said ocular optical system comprising at least first, second and third surfaces, in which a space defined by said surfaces is filled with a medium having a refractive index larger than 1,

said device for displaying an image being disposed at a position facing said third surface,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, said first surface serving as both a refracting surface and an internally reflecting surface, said second surface serving as a reflecting surface of a positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and said third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius,

wherein internal reflection that is performed by said first surface is total reflection, wherein any one of said first, second and third surfaces is a decentered aspherical surface,

wherein any one of said first, second and third surfaces is an anamorphic surface, and

said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer'"'"'s visual axis is defined as a YZ-plane, and a horizontal plane containing said observer'"'"'s visual axis is defined as an XZ-plane;

26. 5<

R_y2 /R_x2 <

5

where R_y2 is a curvature radius of said second surface in said YZ-plane, and R_x2 is a curvature radius of said second surface in said XZ-plane.

27. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading said image to an observer'"'"'s eyeball,

said ocular optical system comprising at least first, second and third surfaces, in which a space defined by said surfaces is filled with a medium having a refractive index larger than 1,

said device for displaying an image being disposed at a position facing said third surface,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, said first surface serving as both a refracting surface and an internally reflecting surface, said second surface serving as a reflecting surface of a positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and said third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius,

wherein said first surface has an internally reflecting region which has been mirror-coated, wherein any one of said first, second and third surfaces is a decentered aspherical surface,

wherein any one of said first, second and third surfaces is an anamorphic surface, and

said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer'"'"'s visual axis is defined as a YZ-plane, and a horizontal plane containing said observer'"'"'s visual axis is defined as an XZ-plane;

28. 5<

R_y2 /R_x2 <

5

where R_y2 is a curvature radius of said second surface in said YZ-plane, and R_x2 is a curvature radius of said second surface in said XZ-plane.

35. An optical apparatus according to claim 28 or 29, further comprising means for positioning both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head.

36. An optical apparatus according to claim 28 or 29, further comprising means for supporting both said device for displaying an image and said ocular optical system with respect to an observer'"'"'s head so that said optical apparatus can be fitted to said observer'"'"'s head.

37. An optical apparatus according to claim 28 or 29, further comprising means for supporting at least a pair of said optical apparatuses at a predetermined spacing.

38. An optical apparatus according to claim 28 or 29, wherein said ocular optical system is used as an imaging optical system.

33. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading said image to an observer'"'"'s eyeball,

said ocular optical system comprising at least first, second and third surfaces, in which a space defined by said surfaces is filled with a medium having a refractive index larger than 1,

said device for displaying an image being disposed at a position facing said third surface,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, said first surface serving as both a refracting surface and an internally reflecting surface, said second surface serving as a reflecting surface of a positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and said third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius,

wherein said first surface is a reflecting surface having a convex surface directed toward said second surface.

34. An optical apparatus comprising:

a device for displaying an image; and

an ocular optical system for projecting an image formed by said device for displaying an image and for leading said image to an observer'"'"'s eyeball,

said ocular optical system comprising at least first, second and third surfaces, in which a space defined by said surfaces is filled with a medium having a refractive index larger than 1,

said device for displaying an image being disposed at a position facing said third surface,

said first, second and third surfaces including, in order from an observer'"'"'s eyeball side toward said device for displaying an image, said first surface serving as both a refracting surface and an internally reflecting surface, said second surface serving as a reflecting surface of a positive power which faces said first surface and is decentered or tilted with respect to an observer'"'"'s visual axis, and said third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius,

wherein internal reflection that is performed by said first surface is total reflection, and

wherein said first surface is a reflecting surface having a convex surface directed toward said second surface.