Light weight head mounted image display device

• US 6,697,200 B2
• Filed: 07/27/2001
• Issued: 02/24/2004
• Est. Priority Date: 08/01/2000
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Nagaoka, Toshiyuki
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): Harrington, Alicia M
• Application Number:
  US09/916,196
• Publication Number:
  US 20020041446A1
• Time in Patent Office: 942 Days
• Field of Search: 359/631, 359/633, 359/634, 359/636, 359/637, 359/638, 359/640
• US Class Current: 359/630
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features

Abstract

An image display element 1 and an observation optical system 2 which forms an exit pupil 4 for observation of an image displayed on the image display element are included, wherein the observation optical system 2 has at least one surface 2₁ that has a lens function, and the following condition (1) is satisfied:

0.1<P·PD·ZD<5  (1)

where P is a pixel pitch (in μm) of the image display element, PD is a diameter (in mm) of the exit pupil, and ZD is a distance (in mm) from the display surface of the image display element to the first surface having a lens function. Whereby, weight reduction is achieved while good image quality is maintained regarding an image display apparatus that is used for magnifying observation of an image on a display element.

Claims

1. An image display apparatus comprising:

an image display element; and

an observation optical system which forms an exit pupil for observation of an image displayed on said image display element,

wherein said observation optical system has at least one surface that has a lens function, and the following condition is satisfied;

2. An image display apparatus according to claim 1, wherein said observation optical system comprises:

a first optical member comprising a first surface that has an action of reflecting bundles of rays from said image display element; and

a second optical member having an action of further reflecting the bundles of rays reflected from said first surface, and

wherein a space between said first optical member and said second optical member is filled with gas.

3. An image display apparatus according to claim 1, wherein at least one surface of said observation optical system is constructed of a diffraction element which is given a lens function by diffraction effect.

4. An image display apparatus according to claim 1, wherein the following condition is satisfied:

5. An image display apparatus according to claim 1, wherein at least one surface of said observation optical system has a curved surface shape to exert a power on bundles of rays, and said curved surface shape is configured as a rotationally asymmetric surface shape to compensate aberrations generated by decentering.

6. An image display apparatus comprising:

an image display element; and

an observation optical system which forms an exit pupil for observation of an image displayed on said display element,

wherein said observation optical system comprises at least one diffraction element that is given a lens function by diffraction effect and an optical member that satisfies the following condition;

7. An image display apparatus according to claim 6, wherein said observation optical system comprises at least one prism member, and said prism member has an entrance surface via which bundles of rays emergent from said image display element enter said prism member, at least one reflecting surface which reflects the bundles of rays inside said prism member, and an exit surface via which the bundles of rays exit out of said prism member, and

wherein said at least one reflecting surface has a curved surface shape to exert a power on bundles of rays, and said curved surface shape is configured as a rotationally asymmetric surface shape to compensate aberrations generated by decentering.

8. An image display apparatus according to claim 6, wherein said optical member satisfies the condition:

9. An image display apparatus comprising:

an image display element; and

an observation optical system which forms an exit pupil for observation of an image displayed on said image display element,

wherein said observation optical system comprises;

a first unit that comprises at least one prism member with a positive refracting power; and

a second unit, and

said first unit is constructed to be movable for alignment of optical axes.

10. An image display apparatus according to claim 9, wherein at least one surface in said observation optical system is configured as an optical element that is given a lens function by diffraction effect.

11. An image display apparatus according to claim 9, wherein said at least one prism member in said observation optical system has an entrance surface via which bundles of rays emergent from said image display element enter said prism member, at least one reflecting surface which reflects the bundles of rays inside said prism member, and an exit surface via which the bundles of rays exit out of said prism member, and

wherein said at least one reflecting surface has a curved surface shape to exert a power on the bundles of rays, and the curved surface shape is configured as a rotationally asymmetric surface shape to compensate aberrations generated by decentering.

12. An image display apparatus according to claim 9, wherein said second unit has a positive refracting power.

13. An image display apparatus according to claim 9, wherein, for alignment of an optical axis of said image display element, an optical axis of said first unit and an optical axis of said second unit, said first unit is adjusted so that, upon a first pinhole being arranged on an exit surface side of said first unit and aligned with the optical axis of said first unit and a second pinhole being arranged on an exit surface side of said second unit and aligned with the optical axis of said second unit, and then upon a central portion of said image display element being made to flash as a point light source, said point light source is observable through said first pinhole and said second pinhole.

14. An image display apparatus according to claim 9, wherein a photographing optical system is disposed on an exit pupil side so as to photograph an image displayed on said LCD.

15. An image display apparatus according to claim 9, wherein said first unit is fixed with adhesive after alignment of the optical axes.

16. An image display apparatus comprising:

an image display element; and

an observation optical system which forms an exit pupil for observation of an image displayed on said image display element,

wherein said observation optical system comprises;

a first unit that comprises at least one prism member with a positive refracting power; and

a second unit with a positive refracting power, a primary image surface is formed between said first unit and said second unit, and

the following condition is satisfied;

17. An image display apparatus according to claim 16, wherein a member that has an action of interrupting stray light from said image display element is disposed between said image display element and said exit pupil.

18. An image display apparatus according to claim 16, wherein at least one flare stop is disposed between said first unit and said second unit.

19. An image display apparatus according to claim 16, wherein at least one prism member of said observation optical system has an entrance surface via which bundles of rays emergent from said image display element enter said prism member, at least one reflecting surface which reflects the bundles of rays inside said prism member, and an exit surface via which the bundles of rays exit out of said prism member, and wherein said at least one reflecting surface has a curved surface shape to exert a power on bundles of rays, and said curved surface shape is configured as a rotationally asymmetric surface shape to compensate aberrations generated by decentering.

20. An image display apparatus according to claim 16, whrein the following condition is satisfied:

21. An image display apparatus comprising:

an image display element; and

an observation optical system which forms an exit pupil for observation of an image displayed on said image display element,

wherein said observation optical system has a positive refracting power, and the following condition is satisfied;

22. An image display apparatus according to claim 21, wherein said observation optical system comprises a first unit with a positive refracting power and a second unit.

23. An image display apparatus according to claim 22, wherein said first unit comprises at least one prism member having a positive refracting power, and said prism member has an entrance surface via which bundles of rays emergent from said image display element enter said prism member, at least one reflecting surface which reflects the bundles of rays inside said prism member, and an exit surface via which the bundles of rays exit out of said prism member, and

wherein said at least one reflecting surface has a curved surface shape to exert a power on bundles of rays, and said curved surface shape is configured as a rotationally asymmetric surface shape to compensate aberrations generated by decentering.

24. An image display apparatus according to claim 22, wherein said second unit has a positive refracting power.

25. An image display apparatus according to claim 21, wherein at least one surface in said observation optical system is an optical element that is given a lens function by diffraction effect.

26. An image display apparatus according to claim 21, wherein the following condition is satisfied:

27. An image display apparatus according to claim 21, wherein the following condition is satisfied:

28. An image display apparatus according to claim 21, wherein the following condition is satisfied: