Spherical image projection system using a convex reflecting image dispersing element

• US 6,409,351 B1
• Filed: 02/12/2001
• Issued: 06/25/2002
• Est. Priority Date: 02/12/2001
• Status: Active Grant

• Current Assignee: Ligon, Thomas R.
• Original Assignee: Ligon, Thomas R.
• Inventors: Ligon, Thomas R.
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US09/781,935
• Time in Patent Office: 498 Days
• Field of Search: 353/98, 353/99, 353/79, 353/46, 353/50, 353/51, 353/122, 353/28, 434/285, 434/286, 434/44
• US Class Current: 353/98
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G03B 21/00 Projectors or projection-type viewers; Accessories therefor devices for changing pictures G03B23/00
• CPC Class Codes: G09F 19/18 involving the use of optical projection means, e.g. projection of images on clouds projection apparatus per se G03B

Abstract

A projection system employs a convex reflecting mirror to disperse a projected image onto the inner surface of a screen enclosing a spherical or other three-dimensional space. When the screen is a spherical, translucent rear-projection screen, the projection system produces a display of substantially spherical form viewable from outside the enclosed space. When the screen is opaque and of spherical or other three-dimensional form, the projection system produces a three-dimensional image surrounding a viewer.

Claims

1. An apparatus for displaying images, the apparatus comprising:

a screen having an inner surface substantially enclosing a three-dimensional space;

first projection means for projecting a first image; and

a first mirror having a first convex surface positioned within the three-dimensional space for reflecting and dispersing the first image projected by the first projection means onto the inner surface of the screen.

2. The apparatus in accordance with claim 1 wherein the three-dimensional space is substantially spherical.

3. The apparatus in accordance with claim 1 wherein the first convex surface is one of ellipsoidal or spherical geometry.

4. The apparatus in accordance with claim 1 wherein the screen has an outer surface and is formed of translucent material such that the first image dispersed onto the inner surface of the screen appears on the outer surface of the screen.

5. The apparatus in accordance with claim 2 further comprising a base attached to the screen and substantially enclosing the first projection means.

6. The apparatus in accordance with claim 4

wherein the three-dimensional space is substantially spherical, and

wherein the first convex surface is one of ellipsoidal or spherical geometry.

7. The apparatus in accordance with claim 1 wherein the screen is substantially opaque.

8. The apparatus in accordance with claim 1

wherein the screen has an aperture,

wherein the first projection means resides outside the substantially enclosed three-dimensional space, and

wherein the first projection means projects the first image through the aperture in the screen and onto the first convex surface of the first mirror.

9. The apparatus in accordance with claim 1

wherein the first projection means resides substantially within the three-dimensional space.

10. The apparatus in accordance with claim 1 wherein the three-dimensional space is substantially spherical.

11. The apparatus in accordance with claim 1

wherein the screen forms a hollow sphere having a central axis, and

wherein the first projection means and the first mirror and lie along the central axis.

12. The apparatus in accordance with claim 1 further comprising a light baffle positioned within the three-dimensional space and surrounding a portion of a path the first image follows between the first projection means and the first mirror for absorbing light reflected by the inner surface of the screen.

13. The apparatus in accordance with claim 1 further comprising:

second projection means for projecting a second image; and

a second mirror having a second convex surface positioned within the three-dimensional space;

a third mirror mounted within the substantially enclosed three-dimensional space for reflecting the second image projected by the second projection means onto the second convex surface of the second mirror,

wherein the second mirror is positioned for reflecting and dispersing the second image onto the inner surface of the screen.

14. The apparatus in accordance with claim 13 wherein the first image is reflected and dispersed onto one half of the inner surface of the screen and the second image is reflected and dispersed onto another half of the translucent screen.

15. The apparatus in accordance with claim 14 wherein the screen is substantially spherical.

16. The apparatus in accordance with claim 15 wherein the screen has an outer surface and is formed of translucent material such that the first and second images dispersed onto the inner surface of the screen appear on the outer surface of the screen.

17. The apparatus in accordance with claim 16 further comprising a base substantially enclosing the first and second projection means, the screen being supported by the base and having at least one aperture through which the first and second projectors project the first and second images.

18. The apparatus in accordance with claim 17

wherein the three-dimensional space is substantially spherical having a central axis,

wherein the first projection means, the first mirror and the second mirror lie along the central axis, with the first mirror residing between the first projection means and the second mirror, and

wherein the second projection means directs the second image along a path intersecting the central axis.

19. An apparatus for displaying images, the apparatus comprising:

a substantially hemispherical screen having an inner surface defining a substantially hemispherical space;

a first mirror positioned within the hemispherical space;

first projection means for projecting a first image onto the first mirror such that the first mirror reflects the first image;

a second mirror having a first convex surface positioned within the hemisphere for reflecting and dispersing the first image reflected by the first mirror onto the inner surface of the screen.

20. The apparatus in accordance with claim 19 wherein the first convex surface is one of ellipsoidal or spherical geometry.

21. The apparatus in accordance with claim 19 wherein the hemispherical screen has an outer surface and is formed of translucent material such that the first image reflected and dispersed onto the inner surface of the screen appears on the outer surface of the screen.

22. The apparatus in accordance with claim 19 further comprising:

second projection means for projecting a second image;

a third mirror positioned within the hemispherical space for reflecting the second image projected by the projection means; and

a fourth mirror having a second convex surface positioned within the hemisphere for reflecting and dispersing the second image reflected by the third mirror onto the inner surface of the screen.

23. The apparatus in accordance with claim 22 wherein the first image is reflected and dispersed onto one half of the inner surface of the screen and the second image is reflected and dispersed onto another half of the screen.

24. The apparatus in accordance with claim 22 wherein the screen has an outer surface and is formed of translucent material such that the first and second images dispersed onto the inner surface of the screen appear on the outer surface of the screen.