Enhanced contrast projection screen

• US 20050057803A1
• Filed: 10/26/2004
• Published: 03/17/2005
• Est. Priority Date: 03/10/2003
• Status: Active Grant

• Current Assignee: Andrew Arthur Hunter, Andrew L Van Brocklin, Antonio S. Cruz-Uribe, John Christopher Rudin, William J. Allen
• Original Assignee: Andrew Arthur Hunter, Andrew L Van Brocklin, Antonio S. Cruz-Uribe, John Christopher Rudin, William J. Allen
• Inventors: Rudin, John Christopher, Allen, William J., Van Brocklin, Andrew L., Hunter, Andrew Arthur, Cruz-Uribe, Antonio S.
• Granted Patent: US 7,072,108 B2
• Time in Patent Office: Days
• US Class Current: 359/443
• CPC Class Codes: G02B 26/026 based on the rotation of particles under the influence of an external field, e.g. gyricons, twisting ball displays based on orientable dipolar particles G02F1/172; based on electrophoresis G02F1/167
• CPC Class Codes: G03B 21/56 Projection screens
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167

Abstract

A projection screen is provided that includes a display surface having a plurality of elements. Each element has an optical property that is responsive to an appropriate applied voltage. The display surface may be configured so that the optical properties of each element may be coordinated with the projected image.

Claims

1. A projection screen for displaying a projected image with enhanced contrast, comprising a display surface having a plurality of display regions, where each display region has an optical property that may be changed by applying an appropriate voltage to the display region, and where the display surface is configured to coordinate the optical property of each display region with content of a corresponding portion of the projected image.

2. The projection screen of claim 1, where the optical property includes reflectivity, and the projected image is reflected on the projection screen.

3. The projection screen of claim 1, where the optical property includes transmissivity, and the projected image is transmitted through the projection screen.

4. The projection screen of claim 1, where the projection screen includes a plurality of electrodes associated with the plurality of display regions, and where the display regions are configured so that application of the appropriate voltage to the electrodes changes the optical properties of the associated display regions.

5. The projection screen of claim 4, further comprising a display controller configured to coordinate display region optical properties with content of the corresponding portion of the projected image.

6. The projection screen of claim 4, where each display region includes one or more pixel elements, each pixel element including a plurality of pigmented particles and a suspension matrix, and where the application of the appropriate voltage changes the reflectivity of the pixel element by changing the disposition of the particles within the suspension matrix.

7. The projection screen of claim 6, where the application of the appropriate voltage collects the particles adjacent at least one electrode.

8. The projection screen of claim 4, where each display region includes one or more pixel elements, each pixel element including a plurality of at least bichromic particles so that the application of the appropriate voltage changes the orientation of the particles within the pixel element.

9. The projection screen of claim 8, where the at least bichromic particles include a black face and a white face.

11. The projection screen of claim 5, where the display controller includes a reflectance processor and at least one electrode controller associated with each display region.

12. The projection screen of claim 11, where each electrode controller is responsive to a control image projected onto the display region associated with the electrode controller.

13. The projection screen of claim 12, where the control image includes infrared radiation.

14. The projection screen of claim 12, where each electrode controller includes a photodetector.

18. The projection screen of claim 14, where the electrode controller is configured to detect ambient light levels using the photodetectors and to adjust display region optical properties to compensate for non-uniform light levels across the projection screen.

10. (Cancelled)

15. (Cancelled)

16. (Cancelled)

17. (Cancelled)

19. A display system, comprising:

a projector configured to project an image;

a projection screen including;

a plurality of pixel elements, where the pixel elements are configured so that the optical properties of a particular pixel element may be altered; and

a display controller configured to modify pixel element optical properties to coordinate with the portion of the projected optical image incident on that pixel element.

25. The display system of claim 19, where the display controller is configured to modify pixel element optical properties by projecting a control image as nonvisible radiation.

26. The display system of claim 25, where the display screen includes an electrode controller that is responsive to the nonvisible radiation.

27. The display system of claim 19, where the optical properties of the pixel elements depends upon the disposition of pigmented particles within the pixel element.

28. The display system of claim 27, where the pigmented particles are optically and electrically anisotropic.

31. The display system of claim 25, where the pixel elements include electrophoretic cells.

32. The display system of claim 19, where the pixel elements incorporate a plurality of selectable color characteristics.

20. (Cancelled)

21. (Cancelled)

22. (Cancelled)

23. (Cancelled)

24. (Cancelled)

29. (Cancelled)

30. (Cancelled)

33. A method of making an active projection screen, comprising:

providing a surface that incorporates a plurality of cells, each cell configured so that the optical properties of the cell may be varied; and

providing a display controller that is capable of individually coordinating the optical properties of each cell with an optical characteristic of a portion of an image projected thereon.

34. A method of coordinating the optical properties of a screen with a projected image, comprising:

providing a screen having a plurality of display regions, each display region configured so that the one or more optical properties of that display region are individually controllable;

projecting the projected image onto the screen; and

synchronizing the optical properties of each display region with an optical characteristic of a portion of the projected image projected onto that display region.

40. The method of claim 34, where synchronizing the optical properties of each display region includes applying nonvisible radiation to each display region which is indicative of an optical characteristic of the portion of the projected image projected onto that display region.

41. The method of claim 34, where synchronizing the optical properties of each display region includes transmitting image data to to each display region using a hardwire connection, the image data being indicative of an optical characteristic of the portion of the projected image projected onto that display region.

35. (Cancelled

36. (Cancelled)

37. (Cancelled)

38. (Cancelled)

39. (Cancelled)

42. (Cancelled)

43. A projection screen, comprising:

means for displaying a projected image, including a plurality of optical elements;

means for changing the optical properties of each optical element

means for coordinating the optical properties of each optical element with a corresponding portion of the projected image based on content of the corresponding portion of the projected image.