Projection screen apparatus

• US 6,788,460 B2
• Filed: 04/12/2002
• Issued: 09/07/2004
• Est. Priority Date: 04/15/1998
• Status: Expired due to Fees

• Current Assignee: Duke University
• Original Assignee: Duke University
• Inventors: Walker, Dale S., Knox, Richard M.
• Primary Examiner(s): MAHONEY, CHRISTOPHER E
• Application Number:
  US10/120,785
• Publication Number:
  US 20030038999A1
• Time in Patent Office: 879 Days
• Field of Search: 359/455, 359/456, 359/457, 359/619
• US Class Current: 359/456
• CPC Class Codes: G02B 5/1876 Diffractive Fresnel lenses; Zone plates; Kinoforms G02B5/1842, G02B5/1847 take precedence; optical systems having diffractive correction means G02B27/0037; Fresnel lenses operating by refraction G02B3/08
• CPC Class Codes: G02B 5/1885 Arranged as a periodic array
• CPC Class Codes: G03B 21/625 Lenticular translucent screens

Abstract

Screen apparatuses are provided which include a first lens or holographic optical element layer and a second mask layer. The first layer substantially collimates image light rays to impinge on the mask layer. The mask layer provides an array or matrix of projecting members. Each of the projecting members receives and focuses the substantially collimated light rays to corresponding focal points. The mask layer includes a mask that blocks light transmission except where openings are located. The openings allow the light focused through the focal joints to substantially pass through the mask to form an image. The screen apparatuses can be advantageously employed in display apparatuses.

Claims

1. A screen apparatus, comprising:

a first layer adapted to substantially collimate light;

a second continuous layer positioned proximate the first layer adapted to receive the substantially collimated light from the first layer and to converge the received substantially collimated light, the second continuous layer comprising an array of projecting members that are spaced between about 5 and 100 microns apart, continuous with the second layer; and

a third layer adjacent the second layer and remote from the array of projecting members that are spaced between about 5 and 100 microns apart, having openings adapted to receive and to pass the converging light as image light, the first layer, the second continuous layer and the third layer being sufficiently large to provide a screen apparatus for a computer monitor or a television.

2. The screen apparatus of claim 1, wherein the projecting members comprise an array of surfaces adapted to accept and focus the substantially collimated light.

3. The screen apparatus of claim 1, wherein the third layer comprises a mask portion adapted to substantially block light transmission except at the plurality of openings.

4. The screen apparatus of claim 1, wherein the projecting members comprise hemispheres.

5. The screen apparatus of claim 1, wherein each of the projecting members is adapted to substantially focus light at a corresponding focal point.

6. The screen apparatus of claim 5, wherein each focal point is proximate one of the plurality of openings.

7. The screen apparatus of claim 1, wherein the first layer comprises a Fresnel lens.

8. The screen apparatus of claim 1, wherein the first layer comprises discontinuous steps.

9. The screen apparatus of claim 1, wherein the projecting members comprise an array of spherical sectors.

10. The screen apparatus of claim 1, wherein the first and second layers are spaced apart by an air gap.

11. The screen apparatus of claim 1, wherein the third layer comprises a black adhesive material.

12. The screen apparatus of claim 1, wherein the third layer is adapted to absorb light that is not used as the image light.

13. The screen apparatus of claim 1, wherein the first layer comprises a holographic optical element.

14. A computer monitor comprising the screen apparatus of claim 1.

15. A television comprising the screen apparatus of claim 1.

16. A folded optical system comprising the screen apparatus of claim 1.

17. The image projection system of claim 1, wherein regions between the openings are adapted to exclude light that is not the image light.

18. A method of manufacturing a projection screen, comprising:

imaging a master that comprises photosensitive material;

providing a first layer for collimating light;

providing a second layer;

forming a matrix of projecting members that are spaced between about 5 and 100 microns apart in a first surface of, and continuous with, the second layer by replicating the master;

providing a mask layer on a second surface of the second layer that is remote from the first surface; and

forming openings in the mask layer at selected positions thereof.

19. The method of claim 18, further comprising positioning the first layer parallel to the second layer.

20. The method of claim 18, wherein the openings are formed with a laser.

21. The method of claim 18 wherein the openings are formed with an excimer laser.

22. The method of claim 18, wherein each of the projecting members has a corresponding focal point.

23. The method of claim 18, wherein laser light is directed through the first layer, the second layer and the mask so that the projecting members focus the laser light to form the openings.

24. The method of claim 18, wherein the placing comprises positioning the first layer generally parallel to the second layer.

25. The method of claim 18, wherein the placing comprises positioning the first layer spaced apart from second layer.

26. The method of claim 18, wherein the openings are formed through the mask layer at selected positions such that light can pass through the openings.

27. The method of claim 18, further comprising forming the mask layer on the second layer.

28. The method of claim 18, wherein the openings are formed about the focal points of the projecting members.

29. The method of claim 18, wherein the first layer, the second layer, the projecting members, and the mask layer are comprised in a folded optical system.

30. The method of claim 18, wherein providing the first layer comprises providing a holographic optical element.

31. The method of claim 30, further comprising providing an air gap between the holographic optical element and the second layer.

32. The method of claim 30, further comprising substantially minimizing a gap between the holographic optical element and the second layer for reducing effects of chromatic dispersion.

33. The method of claim 18, further comprising forming the projecting members to control magnification of image light differently in vertical and horizontal directions.

34. A screen apparatus, comprising:

a sheet of at least partially transmissive material having a first surface and a second surface, the sheet being sufficiently large to provide a screen apparatus for a computer monitor or a television, wherein the first surface comprises a non-planar surface forming a predetermined distribution of localized positive optical power units, the second surface has a layer of at least partially absorbing material formed thereon, and the predetermined distribution of localized positive optical power units are spaced between about 5 and 100 microns apart.

35. The screen apparatus according to claim 34, wherein a viewing angle of the screen apparatus is smaller in a vertical direction than in a horizontal direction.

36. The screen apparatus according to claim 34, wherein the predetermined distribution of localized positive optical power units are configured to exhibit at least two different magnifications.

37. The screen apparatus according to claim 34, wherein the predetermined distribution of localized positive optical power units are configured to provide sufficient power to ablate the partially absorbing layer when a source of laser energy is passed therethrough.

38. The screen apparatus according to claim 34, wherein the predetermined distribution of localized positive optical power units are configured so that, when light is passed therethrough, the light is focused sufficiently to expose the partially absorbing layer for photolithography.

39. The screen apparatus according to claim 34, wherein the localized positive optical power units comprise a plurality of projecting members.

40. The screen apparatus according to claim 39, wherein the plurality of projecting members are substantially uniform in size and shape.

41. The screen apparatus according to claim 39, wherein the plurality of projecting members are hemispheres.

42. The screen apparatus according to claim 39, wherein the plurality of projecting members are cylindrical sectors.

43. The screen apparatus according to claim 34, wherein the plurality of projecting members each have substantially the same transmissivity.

44. The screen apparatus according to claim 34, further comprising an optical element optically coupled to the sheet and configured to receive light from an image engine.

45. The screen apparatus according to claim 44, wherein the optical element substantially collimates the light received from the image engine.

46. The screen apparatus according to claim 44, wherein the optical element comprises a holographic optical element.

47. The screen apparatus according to claim 45, wherein a distance between the sheet and the holographic optical eminent is minimized to reduce chromatic dispersion.

48. The screen apparatus according to claim 44, wherein the optical element comprises a Fresnel lens.

49. The screen apparatus according to claim 44, wherein the sheet focuses the light received from the optical element.

50. A folded optical system comprising the screen apparatus of claim 44.

51. The screen apparatus according to claim 50, further comprising:

a projection apparatus for producing an image on a display surface optically coupled to the sheet, the projection apparatus including;

an image engine;

an optical device; and

an optical system capable of transmitting light from the image engine to the display surface such that the light travels an image path which reaches the optical device twice on its way to the display surface, for reflecting light from the display surface at one instance, and for passing through the display surface at another instance, wherein the optical device is reflective of some light and transmissive of other light.

52. The screen apparatus according to claim 34, wherein the layer formed of at least partially absorbing material comprises a plurality of openings, wherein each opening is substantially aligned with a respective one of the localized positive optical power units.

53. The screen apparatus according to claim 52, wherein a ratio of a thickness of the layer formed of at least partially absorbing material to a size of the plurality of openings is configured to allow passage of image light through the openings while absorbing other light in regions of the at least partially absorbing layer between the openings.

54. The screen apparatus according to claim 34, wherein the layer formed of at least partially absorbing material comprises one of carbon or another black or light absorbing material impregnated in glue or cement.

55. The screen apparatus according to claim 34, wherein the layer formed of at least partially absorbing material comprises a black adhesive material.

57. The screen apparatus according to claim 34, wherein the layer formed of at least partially absorbing material comprises a photosensitive material.

58. A computer monitor comprising the screen apparatus of claim 34.

59. A television comprising the screen apparatus of claim 34.

60. The screen apparatus according to claim 34, wherein the sheet is rigid.

61. The screen apparatus according to claim 34, wherein the sheet is non-rigid.

62. The screen apparatus according to claim 34, wherein the second surface comprises an approximately planar surface.

56. The screen apparatus according to claim wherein the layer formed of at least partially absorbing material is deposited on the second surface using one of co-extrusion, lamination, deposition, or another layering process.

63. A method of forming a screen apparatus, comprising:

forming a master by imaging a photosensitive material;

forming a predetermined distribution of localized positive optical power units that are spaced between about 5 and 100 microns apart in a first surface of a sheet of at least partially transmissive material that is sufficiently large to provide a screen apparatus for a computer monitor or a television, by replicating the master;

forming a layer of at least partially absorbing material on a second surface of the sheet that is opposite the first surface; and

forming openings in the at least partially absorbing layer by irradiating the at least partially absorbing layer with light through the first surface of the sheet, wherein the localized positive optical power units focus the light so that the openings are created in the at least partially absorbing layer that are substantially aligned with the localized positive optical power units.

64. The screen apparatus according to claim 63, wherein a ratio of a thickness of the at least partially absorbing layer to a size of the opening is configured to allow passage of image light through the openings while absorbing other light in regions of the at least partially absorbing layer between the openings.

65. The screen apparatus according to claim 63, wherein the at least partially absorbing layer comprises one of carbon or another black or an at least partially absorbing material impregnated in glue or cement, and wherein the step of forming openings in the at least partially absorbing layer by irradiating the at least partially absorbing layer with a light comprises abating the openings with coherent light.

66. The screen apparatus according to claim 63, wherein the step of forming the at least partially absorbing layer on the second surface of the sheet comprises depositing the at least partially absorbing layer on the second surface of the substrate using one of co-extrusion, lamination, deposition, or another layering process.

67. The screen apparatus according to claim 63, wherein the at least partially absorbing layer comprises a photosensitive material;

and the step of forming openings in the at least partially absorbing layer by irradiating the at least partially absorbing layer with light through the first surface of the substrate comprises forming lightened areas in the photosensitive material through which light can pass.