Head mounted display and viewing system using a remote retro-reflector and method of displaying and viewing an image

• US 6,147,805 A
• Filed: 08/26/1998
• Issued: 11/14/2000
• Est. Priority Date: 08/24/1994
• Status: Expired due to Term

• Current Assignee: Fergason Patent Properties
• Original Assignee: Fergason Patent Properties
• Inventors: Fergason, James L.
• Primary Examiner(s): Mack, Ricky
• Application Number:
  US09/139,926
• Time in Patent Office: 811 Days
• Field of Search: 359/630, 359/633, 359/636, 359/631, 345/7, 345/8
• US Class Current: 359/630
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0136 with a single image source for both eyes
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/0143 the two eyes not being equipped with identical nor symmetrical optical devices
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G03B 15/12 using mirrors

Abstract

A head mounted display system includes focusing optics to focus light from an image source, retro-reflector and beamsplitter, the image source and beamsplitter directing light toward the retro-reflector to focus a real image, and the light reflected from the retro-reflector being directed via the beamsplitter for viewing, thereby to use conjugate optics effectively to place the viewing eye or detector in relation to the image source the same as the relation of the focusing optics to the image source. The retro-reflector may be mounted on a common housing or support with the beamsplitter and focusing optics or it may be remotely located. A method for forming an image using conjugate optics in which light from a source is focused to form a real image at a retro-reflector and is reflected for viewing.

Claims

1. In an apparatus for viewing visual information, including a beamsplitter for reflecting or transmitting light representing visual information, and a retro-reflector for reflecting light received in a first path from said beamsplitter for delivery via said beamsplitter for viewing of such visual information, the improvement comprising a lens cooperative with said retro-reflector to enhance the focusing of the visual information for viewing.

2. In the apparatus of claim 1, wherein said lens is in the optical path between said beamsplitter and said retro-reflector.

3. A method for improving the focusing of visual information for viewing, comprising retro-reflecting light from a beamsplitter along at least one conjugate path for viewing via reflection or transmission by the beamsplitter, and focusing light relative to the retro-reflector to enhance the focusing of the visual information for viewing.

4. The method of claim 3, comprising using a lens to increase positional accuracy of the light directed to and from said retro-reflector.

5. The method of claim 3, wherein said focusing comprises using a lens in the optical path between the beamsplitter and the retro-reflector.

6. An optical device for presenting for viewing at a viewing location images from an image source, comprising:

focusing means for focusing light from a source to form a real image,

retro-reflector means for receiving incident light from said focusing means and reflecting light along an at least partly conjugate optical path relative to the incident light thereon toward a viewing location, and

beamsplitter means for reflecting and transmitting light,

said beamsplitter means being in the optical path between said focusing means and said retro-reflector means and being operative at least one of (a) to reflect light toward said retro-reflector means and to transmit light from said retro-reflector means for viewing and (b) to transmit light to said retro-reflector means and to reflect light from said retro-reflector means for viewing,

said retro-reflector means and said beamsplitter means being cooperatively related in effect to cause the viewing location where the image is presented to appear, relative to the image source, at the location of said focusing means,

said retro-reflector means comprising two retro-reflectors, one being positioned to receive light reflected by said beamsplitter means and one being positioned to receive light transmitted by said beamsplitter means, and further comprising a lens in the light path between said beamsplitter means and one of the retro-reflectors to focus light from said one retro-reflector for viewing at the viewing location in overlapping coincidence with light from the other retro-reflector.

7. The device of claim 6, wherein said focusing means, retro-reflector means, and beamsplitter means provide different respective images to two respective human eyes.

8. The system of claim 6, said lens comprising a flat lens array.

9. The device of claim 6, said focusing means comprising a lens.

10. The device of claim 6, wherein said focusing means forms the real image at said retro-reflector means.

11. The device of claim 6, wherein said focusing means forms the real image behind said retro-reflector means.

12. The device of claim 6, further comprising an output lens to provide comfortable viewing of the image at approximately 20 inches or more from the viewing location.

13. The device of claim 12, said output lens being operative to provide a virtual image of the real image for viewing from the viewing location.

14. The device of claim 6, wherein said focusing means, retro-reflector means, and beamsplitter means provide images to two respective human eyes.

15. The device of claim 6, said beamsplitter means comprising a beamsplitter that is optical polarization responsive to transmit light having a polarization characteristic and reflecting light having a different polarization characteristic.

16. The device of claim 15, said beamsplitter being operative to reflect light having a plane of polarization in a first direction and to transmit light having a plane of polarization that is in a direction which is orthogonal to said first direction.

17. The device of claim 15, said beamsplitter being operative to reflect light having one direction of circular polarization and to transmit light having the opposite direction of circular polarization.

18. The device of claim 15, further comprising an image source for providing to said focusing means polarized light having image characteristics.

19. The device of claim 18, said image source providing plane polarized light.

20. The device of claim 19, further comprising means for converting said plane polarized light to circularly polarized light.

21. The device of claim 20, further comprising means for changing the polarization characteristics of light to distinguish between light incident on and light reflected by said retro-reflector means.

22. The device of claim 21, said means for changing comprising a wave plate.

23. The device of claim 22, said wave plate comprising a quarter wave plate.

24. An optical system, comprising

a retro-reflector for receiving incident light and reflecting light as reflected light,

wherein at least part of the paths of the incident light and the reflected light are a conjugate light path,

a beamsplitter in the conjugate light path for directing light to said retro-reflector as such incident light to form a real image,

said beamsplitter also directing reflected light from said retro-reflector to a viewing location, and

focusing means in the path of light to or from said beam splitter for causing the image viewed at the viewing location to appear at a comfortable viewing distance.

25. The system of claim 24, wherein said viewing distance is at least about 20 inches.

26. The system of claim 24, wherein said focusing means is between a source of the incident light and said beamsplitter.

27. The system of claim 26, wherein said focusing means comprises a negative lens.

28. The system of claim 24, further comprising focusing means to focus a real image in relation to said retro-reflector.

29. The system of claim 28, further comprising means for sensing information representing such focusing for adjusting the focus of said focusing means to focus the real image at said retro-reflector.

30. The system of claim 29, said means for sensing information comprising means for sensing a distance relation.

31. In an apparatus for viewing visual information, including a beamsplitter for reflecting or transmitting light representing visual information, and a retro-reflector for reflecting light received in a first path from said beamsplitter for delivery via said beamsplitter for viewing of such visual information, the improvement comprising a lens cooperative with said retro-reflector to enhance the focusing of the visual information for viewing and, wherein said lens is a flat lens array.

32. An optical system, comprising

a retro-reflector for receiving incident light and reflecting light as reflected light,

wherein at least part of the paths of the incident light and the reflected light are a conjugate light path,

a beamsplitter in the conjugate light path for directing light to said retro-reflector as such incident light to form a real image,

said beamsplitter also directing reflected light from said retro-reflector to a viewing location, and

a further retro-reflector for reflecting back to said beamsplitter light that is directed by said beamsplitter in a direction that is not toward said retro-reflector, and further comprising a lens to focus light from said further retro-reflector for coincidence at the viewing location with light reflected by said retro-reflector.

33. A system for adjusting image position in space, comprising

a retro-reflector to receive incident light and to reflect light to a viewing location,

a beamsplitter in the light path between the source of incident light and the retro-reflector and between the retro-reflector and the viewing location, and

a lens in the light path between the beamsplitter and the retro-reflector.

34. The system of claim 33, wherein the lens comprises a flat lens array.

35. The system of claim 33, wherein the lens increases the positional accuracy of light transmitted therethrough to enhance the in-focus appearance of an image formed by the light and viewed from the viewing location.

36. The system of claim 33, further comprising an image source via which light is provided the beamsplitter, a remote retro-reflector positioned to receive light from the beamsplitter and to reflect light along a substantially conjugate light path via the beamsplitter for viewing at the viewing location substantially in focus.

37. The system of claim 36, wherein the lens affects light relative to the first-mentioned retro-reflector to superposition the light and image formed as a result of light provided the viewing location via both the respective retro-reflectors.

38. The system of claim 33, wherein the retro-reflector is in such proximity to the viewing location that absent the lens an image at the viewing location from light reflected by the retro-reflector is out of focus and the lens is functional to increase the in-focus of such image at the viewing location.

39. A method for improving the focusing of visual information for viewing, comprising retro-reflecting light from a beamsplitter along at least one conjugate path for viewing via reflection or transmission by the beamsplitter, and focusing light relative to the retro-reflector to enhance the focusing of the visual information for viewing, using a lens to increase positional accuracy of the light directed to and from said retro-reflector, and further comprising using a further retro-reflector for receiving light from said beamsplitter and retro-reflecting such light via said beamsplitter for viewing, said further retro-reflector being relatively remote from said beamsplitter relative to the proximity of said retro-reflector being relatively nearer said beamsplitter, whereby said further retro-reflector reflects light for viewing positional accuracy and said lens increases positional accuracy of light reflected by said retro-reflector.