Collimated visual display with elliptical front projection screen
A front-projection display system having a screen with improved brightness and/or resolution of an image displayed on outer portions thereof. The screen has a display surface that is generally a convex shape having a curvature of the display surface in the vertical direction of an image projected thereon that is less than a curvature of the display surface in the horizontal direction.
1. A front projection display system comprising:
a screen having a convex-shaped display surface; and
a reflector for reflecting an image displayed on the screen;
wherein the reflector and screen each have a horizontal axis and a vertical axis, the screen being vertically offset from the reflector; and
wherein the display surface has a curvature in a vertical direction that is less than a curvature of the display surface in a horizontal direction.
2. A front projection display system as set forth in claim 1 , wherein the convex shape corresponds to an ellipsoidal segment.
3. A front projection display system as set forth in claim 1 , wherein the ellipsoidal segment corresponds to a portion of a prolate spheroid such that a horizontal extent of the screen is parallel to an equator of the spheroid.
4. A front-projection display system as set forth in claim 3 , wherein the horizontal extent of the ellipsoidal segment includes a portion of the equator.
5. A front projection display system as set forth in claim 1 , wherein the screen is a toroid with an elliptical cross section in the vertical direction.
6. A front projection display system as set forth in claim 1 , wherein the screen is a toroid with an elliptical cross section in the vertical direction, and a rotation axis that is tilted relative to the mirror reflector.
7. A front projection display system as set forth in claim 1 , wherein the curvature of the display surface in the vertical direction of the image that is less than a curvature of the display surface in the horizontal direction of the image reduces the incident angle of light impinging onto the screen, as compared to a spherical screen thereby resulting in a higher resolution image and improved luminance uniformity across the screen.
8. A front-projection display system as set forth in claim 1 , further comprising at least one projector for projecting the image onto the display surface of the screen.
9. A front-projection display system as set forth in claim 1 , wherein the reflector is a collimating mirror.
10. A front-projection display system as set forth in claim 9 , wherein the collimating mirror is spherical.
11. A front-projection display system as set forth in claim 1 , wherein the screen is a front projection screen.