Projection device and screen

1. A projection unit comprising:

a projector including a wide-angle lens system, the projector positioned substantially adjacent a display surface and configured to generate an image on the display surface; and

a moveable element supporting the projector configured to enable selective lateral positioning of the projector;

wherein the projector further comprises a focus device adapted to bring the image into focus when the projector is in one of a first lateral position and a second lateral position.

2. The projection unit of claim 1 , wherein the moveable element is configured to position the projector in one of a storage position and an operation position.

3. The projection unit of claim 2 , where the projector is configured to project an image at a steep angle to a wall in the operation position.

4. The projection unit of claim 2 , where the projector is configured to project an image at a steep angle to a screen in the operation position.

5. The projection unit of claim 4 , wherein the projector is configured to project an image to the screen at an angle of at least 30 degrees.

6. The projection unit of claim 1 , further comprising a screen positioned substantially adjacent the projector.

7. The projection unit of claim 6 , wherein the screen is moveable between at least a first position and a second position.

8. The projection unit of claim 1 , wherein the wide angle lens system includes a relay lens stage adapted to generate a distorted intermediate image and a wide angle lens stage adapted to substantially cancel the distortion of the distorted intermediate image.

9. The projection unit of claim 1 , wherein the wide angle lens system defines an image path whereby the image path includes a change in direction.

10. The projection unit of claim 7 , wherein the image path includes an approximately 180-degree change in direction.

11. The projection unit of claim 1 , wherein the projector includes an image source.

12. The image source of claim 11 , wherein the image source is a digital micromirror device, microelectromechanical system, grating light valve device, liquid crystal display device, or liquid crystal on silicon device.

13. The projection unit of claim 1 , wherein the projection unit is a front projection display device.

14. The projection unit of claim 1 , wherein the lens system is integrated within the projector.

15. A projection unit comprising:

a body, wherein the body comprises

a selectively-positionable screen to display an image, the screen positionable in a first position and a second position; and

a laterally-moveable projector positioned substantially adjacent the screen and configured to project an image to the screen, the laterally-moveable projector further adapted to be positioned in first lateral position and a second lateral position;

wherein the first lateral position of the projector and second lateral position of the projector are operable positions.

16. The projector unit of claim 15 , wherein one of the first lateral position of the projector and the second lateral position of the projector is a storage position.

17. The projector unit of claim 15 , wherein the projector is mounted on a slidable element.

18. The projector unit of claim 17 , wherein the slidable element is a drawer.

19. The projector unit of claim 15 , where the projector is configured to project an image at a steep angle to the screen.

20. The projector unit of claim 15 , wherein the projector includes a lens system having at least two planar direction changing elements.

21. The projector unit of claim 15 , wherein the projector includes a lens system having a wide angle lens stage.

22. The projector unit of claim 15 , wherein screen is a Fresnel-lens type screen.

23. The projector unit of claim 15 , wherein one of the first screen position and the second screen position is a rolled position.

24. A system comprising:

a moveable screen; and

a front projector slidably coupled to said movable screen, said front projector including a lens system having at least two folds and projecting an image onto said moveable screen at an angle of at least 30 degrees;

wherein the lens system creates the at least two folds via first prism and a second prism.

25. The system of claim 24 wherein the lens system further comprises a wide angle lens system having a first stage to create a distorted intermediate image and a second, wide angle lens stage that causes distortion to substantially cancel the distortion of the intermediate image and to project a substantially non-distorted image corresponding to the intermediate image on said screen.

26. The system of claim 24 wherein the movable screen may be positioned in a rolled position.

27. The system of claim 24 wherein the front projector slides perpendicular to said movable screen.

28. The system of claim 24 wherein the front projector is removably coupled to the system.

29. The system of claim 24 wherein the front projector is coupled to said moveable screen by a slidable drawer.

30. The front projection display device of claim 24 , wherein the front projector is configured to project the image onto said moveable screen at an angle between 30 and 80 degrees toward the screen.

31. The front projection display device of claim 24 , wherein the screen is configured to receive the image from a substantially steep angle and reflect the light back along a substantially horizontal plane.

32. The front projection display device of claim 24 , wherein the screen is a Fresnel lens type screen.