Display system using conjugate optics and accommodation features and method of displaying and viewing an image

• US 6,008,945 A
• Filed: 09/19/1997
• Issued: 12/28/1999
• Est. Priority Date: 09/19/1996
• Status: Expired due to Fees

• Current Assignee: Fergason Patent Properties
• Original Assignee: James L. Fergason
• Inventors: Fergason, James L.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): MACK, RICKY LEVERN
• Application Number:
  US08/933,647
• Time in Patent Office: 830 Days
• Field of Search: 359/630, 359/631, 359/633, 359/637
• 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
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00

Abstract

A display system including a retro-reflector, and optical means including a projection lens and an accommodation feature for directing light from an image source to the retro-reflector, light reflected by the retro-reflector being provided for viewing, said optical means and retro-reflector being cooperative to establish a conjugate optics path including the accommodation feature along which the light is directed to the eye or eyes of a viewer for viewing of an image, the accommodation feature includes a conjugation lens means and it and the retro-reflector are cooperatively positioned such that as light passes back through the conjugation lens means along the same path it would have followed had the retro-reflector been placed at the image plane of the projection lens had the conjugation lens means not been in position. A servo system for moving the projection lens and the retro-reflector according to a transfer function also may be included.

Claims

1. A display system including a retro-reflector, and optical means including an accommodation feature for directing light from an image source to the retro-reflector, said optical means including focusing optics for focusing an image from the image source relative to the retro-reflector, light reflected by the retro-reflector being provided for viewing, said optical means and retro-reflector being cooperative to establish a conjugate optics path including the accommodation feature along which the light is directed to the eye or eyes of a viewer for viewing of an image, and a beamsplitter in the conjugate optics path.

2. The system of claim 1, said retro-reflector comprising plural retro-reflectors.

3. The system of claim 1, wherein said retro-reflector at least substantially maintains the characteristic of the light incident thereon, including the results of focusing by the focusing optics, while reflecting the light to the eye(s) of the viewer, and wherein said optical means includes means for providing plural optical paths to provide a stereoscopic or three dimensional image.

4. The system of claim 3, wherein said beamsplitter is positioned to direct light from the focusing optics into the conjugate optics path by reflection or transmission of light toward the retro-reflector and from the retro-reflector to the eye(s) for viewing.

5. The system of claim 1, wherein light directed to the retro-reflector from the focusing optics is reflected such that the light continues to have substantially the same direction it had when it impinged on the retro-reflector so that optically the lens of the eye can appear to be in effect at the focusing optics and the retina of the eye can appear to be in effect at the source of the image.

6. The system of claim 1, wherein plural image sources respectively provide images from respective image acquiring devices positioned and focused to represent depth information, said optical means includes means for providing plural optic al paths to provide a stereoscopic or three dimensional image, and said accommodation feature being operative to provide depth characteristic for the viewed image.

7. The system of claim 1, said accommodation feature comprising at least one focusing device.

8. The system of claim 7, said at least one focusing device comprising a lens.

9. The system of claim 8, said focusing device comprising an auto-focusing device.

10. The system of claim 7, said optical means comprising a projection lens means for projecting an image from a source toward the retro-reflector, further comprising a camera lens for obtaining an image for projection, and said at least one focusing device of said accommodation feature comprising means for at least substantially maintaining equal the effective focus of the projection lens means and the camera lens.

11. The system of claim 10, said retro-reflector being positioned in proximity to the image plane of the projection lens means including the accommodation feature.

12. The system of claim 11, further comprising means for changing the position of the retro-reflector to follow the focal plane of the projection optics.

13. A display system including a retro-reflector, and optical means including an accommodation feature for directing light from an image source to the retro-reflector, light reflected by the retro-reflector being provided for viewing, said optical means and retro-reflector being cooperative to establish a conjugate optics path including the accommodation feature along which the light is directed to the eye or eyes of a viewer for viewing of an image,

said accommodation feature comprising at least one focusing device,

said optical means comprising a projection lens means for projecting an image from a source toward the retro-reflector, further comprising a camera lens for obtaining an image for projection, and said at least one focusing device of said accommodation feature comprising means for at least substantially maintaining equal the effective focus of the projection lens means and the camera lens,

said retro-reflector being positioned relatively close to the image plane of the projection lens means including the accommodation feature, and

further comprising a beam splitter to direct light from the focusing optics into the conjugate optics path by reflection or transmission of light toward the retro-reflector and from the retro-reflector to the eye(s) for viewing.

14. The system of claim 13, said accommodation feature comprising a conjugation lens between the beamsplitter and the retro-reflector.

15. A display system comprising a display source, optics for focusing an image from the display source in the far field using a projection lens, a retro-reflector in proximity to which such image is focused, and conjugation lens means to refocus the image to a point much closer to the optics, whereby to permit the retro-reflector to be positioned at the closer image point.

16. The system of claim 15, wherein the conjugation lens means and retro-reflector are cooperatively positioned such that as light passes back through the conjugation lens means along the same path it would have followed had the retro-reflector been placed at the image plane of the projection lens had the conjugation lens means not been in position.

17. The system of claim 16, further comprising a servo system for moving the projection lens and the retro-reflector according to a transfer function.

18. The system of claim 17, wherein the transfer function is given by the formula:

##EQU2## where;

D=The distance between the conjugation lens and the retro-reflector (see FIG.

     18)

C=The distance between the conjugation lens and the LCD (see FIG.

     18)

F₁ =The focal length of the projection lens

F₂ =The focal length of the conjugation lens

R=The distance projection lens and its image focal plane (see FIG.

     18).

19. A method for displaying an image for viewing comprising focusing an image from a display source in the far field using a projection lens, a beamsplitter, a retro-reflector, and conjugation lens means to refocus the image to a point much closer to the optics than the far field image point of the projection lens, whereby the retro-reflector may be positioned at the closer image point, wherein the conjugation lens means and retro-reflector are cooperatively positioned such that as light passes back through the conjugation lens means along the same path it would have followed had the retro-reflector been placed at the image plane of the projection lens had the conjugation lens means not been in position, and using a servo system for moving the projection lens and the retro-reflector according to a transfer function given by the formula:

##EQU3## where;

D=The distance between the conjugation lens and the retro-reflector (see FIG.

     18)

C=The distance between the conjugation lens and the LCD (see FIG.

     18)

F₁ =The focal length of the projection lens

F₂ =The focal length of the conjugation lens

R=The distance projection lens and its image focal plane (see FIG.

     18).

20. A display system including a retro-reflector, and optical means including an accommodation feature for directing light from an image source to the retro-reflector, light reflected by the retro-reflector being provided for viewing, said optical means and retro-reflector being cooperative to establish a conjugate optics path including the accommodation feature along which the light is directed to the eye or eyes of a viewer for viewing of an image,

said accommodation feature comprising at least one focusing device,

said optical means comprising a projection lens means for projecting an image from a source toward the retro-reflector,

said retro-reflector being positioned relatively close to the image plane of the projection lens means including the accommodation feature, and

further comprising a beam splitter to direct light from the focusing optics into the conjugate optics path by reflection or transmission of light toward the retro-reflector and from the retro-reflector to the eye(s) for viewing.