Segmented ellipsoidal projection system

• US 5,175,575 A
• Filed: 01/28/1992
• Issued: 12/29/1992
• Est. Priority Date: 01/28/1992
• Status: Expired due to Fees

• Current Assignee: Contraves USA-SSI
• Original Assignee: Contraves USA-SSI
• Inventors: Gersuk, Stephen H.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Dowling, William C.
• Application Number:
  US07/827,154
• Time in Patent Office: 336 Days
• Field of Search: 353/94, 353/30, 353/11, 359/451, 359/459, 359/449, 359/443, 352/69, 352/70, 352/71
• US Class Current: 353/94
• CPC Class Codes: G03B 21/56 Projection screens
• CPC Class Codes: G03B 37/04 with cameras or projectors providing touching or overlapping fields of view

Abstract

The present invention is a projection system which includes a plurality of screen segments, each defining a surface in the shape of an ellipsoidal segment such that each surface has a first focal point and a second focal point. The screen segments are arranged such that an edge of the surface of one of the screen segments is essentially adjacent along its entire length to an edge of the surface of another screen segment. The projection system also includes a plurality of projectors, equal to the number of screen segments. Each of the projectors projects an image upon one of the screen segments from the second focal point of that screen segment. Preferably, the screen segments are arranged such that the first focal points of their surfaces essentially coincide with each other.

Claims

1. A projection system comprising:

a plurality of screen segments, each defining a surface in the shape of an ellipsoidal segment such that each surface has a first focal point and a second focal point, said screen segments arranged such that an edge of the surface of one of the screen segments is essentially adjacent along its entire length to an edge of the surface of another screen segment; and

a plurality of projectors equal to the number of screen segments wherein each of said projectors projects an image upon one of the screen segments from the second focal point of that screen segment.

2. A projection screen as described in claim 1 wherein the screen segments are arranged such that the first focal point of each surface essentially coincide with each other.

3. A projection system as described in claim 2 wherein the surface of each screen segment is a high-gain surface.

4. A projection system as described in claim 3 wherein each projector is a CRT projector.

5. A projection system as described in claim 4 wherein each surface provides a horizontal field of view of 60°

as measured from the first focal point.

6. A projection system as described in claim 5 wherein each surface provides a vertical field of view of 40°

as measured from the first focal point.

7. A projection system as described in claim 6 wherein each surface segment provides an eye relief of 144" as measured from the focal point.

8. A projection system as described in claim 7 wherein there are four screen segments.

9. A projection system as described in claim 7 wherein there are six screen segments.

10. A method for forming a projection system comprising the steps of:

placing a plurality of ellipsoidal screens adjacent each other such that they each essentially have a same first focal point;

choosing a viewpoint on an ellipsoidal screen which provides sufficient eye relief for observers; and

selecting a second focal point sufficiently far from the viewpoint to a projector at the second focal point to illuminate the entire corresponding screen, and sufficiently high to avoid blocking light of any other projectors that are used to illuminate other corresponding screens.

11. A method as described in claim 10 including after the selecting step, the step of repeating the choosing and selecting step for every other ellipsoidal screen.