Enhanced resolution for image generation

• US 7,417,617 B2
• Filed: 04/26/2004
• Issued: 08/26/2008
• Est. Priority Date: 05/18/1999
• Status: Expired due to Fees

• Current Assignee: Dimension Technologies Inc.
• Original Assignee: Dimension Technologies Inc.
• Inventors: Eichenlaub, Jesse B.
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): Shapiro; Leonid
• Application Number:
  US10/832,029
• Publication Number:
  US 20040196253A1
• Time in Patent Office: 1,583 Days
• Field of Search: 345/102, 345/204
• US Class Current: 345/102
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/0068 arranged in a single integral body or plate, e.g. laminates or hybrid structures with other optical elements G02B5/1885, G02B17/002, G02B30/27 take precedence
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0237 Switching ON and OFF the backlight within one frame
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: H04N 13/32 using arrays of controllable light sources; using moving apertures or moving light sources

Abstract

Images with enhanced resolution are created with a display device comprising a non-transmissive light valve including addressable pixels, a light source that directs light to the light valve, and a lens positioned between the light valve and the light source, the lens directing light from the light source to the pixels on the light valve and the light valve directing light to viewing optics. The light valve is an integrated circuit ferroelectric liquid crystal device (ICFLCD), or other light valve arrays such as a digital light processor (DLP) display, having an array of addressable pixels. Such light valves may be mounted in a head mounted display.

Claims

1. A display device comprising:

a reflective light valve comprising a plurality of pixels, the reflective light valve comprising

a reflective layer, a pixel layer, and a transparent layer adjacent the pixel layer, the transparent layer comprising a plurality of front lenses such that a front lens is situated in front of each pixel; and

a light source that directs light to the front lenses.

2. The device of claim 1, wherein the light valve is an integrated circuit ferroelectric liquid crystal device.

3. The device of claim 1, wherein the front lenses are lenslets, each lenslet positioned in front of each pixel of the light valve.

4. The device of claim 1 wherein the pixel layer comprises a liquid crystal material.

5. The device of claim 3, wherein the lenslets have a focal length equal to approximately twice the distance between the lenslet surface and the reflecting layer of the light valve.

6. The device of claim 1, further comprising a reflector positioned between the light source and the light valve.

7. The device of claim 1, comprising a prism including a partially reflective surface disposed between the light source and the light valve.

8. The device of claim 1 comprising a relay lens disposed between the light valve and the front lenses.

9. The device of claim 1, comprising a rotating color filter wheel having discrete transparent sections of different colors disposed between the light source and viewing optics.

10. The device of claim 9, farther comprising a rotating prism located between the light source and viewing optics.

11. The device of claim 10, further comprising means for synchronizing the rotation of the color filter wheel and the prism.

12. The device of claim 10, comprising a bundle of optical fibers having opposite bundle ends directing the beam of light to the light valve.

13. The device of claim 1, wherein the light valve comprises a digital light processor.

14. The device of claim 1, wherein the light source comprises red, green and blue light sources.

15. The device of claim 14, further comprising means for synchronizing the red, green and blue light sources and the light valve.

16. The display device of claim 1, the reflective light valve comprising:

a plurality of addressable pixels, each pixel comprising a plurality of pixel areas; and

the front lens directs light from the light source to a different one of the pixel areas of each of the pixels on the light valve.

17. The device of claim 1, wherein an outer surface of the front lenses is concave.

18. The device of claim 1, wherein an outer surface of the front lenses is convex.

19. The device of claim 1, wherein the front lens is a flys eye lens array or a lenticular lens array spaced from the light valve.

20. The device of claim 19, comprising a relay lens disposed between the light valve and the front lens.

21. The display device of claim 1, in which:

the front lenses are sized and positioned such that each front lens is situated in front of a plurality of pixels arranged in an array; and

wherein the light source comprises a plurality of light-source groups so that each light-source group flashes in succession;

the light sources and lenses positioned relative to each other so that an image of each light-source group is imaged onto a section of each array of pixels resulting in a focused light-source image being formed on each pixel array in succession.

22. The display of claim 21, wherein the lens is a lens molded into etched bireficingent inorganic crystals.

23. The display of claim 22, further comprising a beamsplitter intermediate the polarizing filter and lens array.

24. The display of claim 21, further comprising a single collimating lens and a polarizing filter between the light source and the lens array.

25. The display device of claim 21, in which the front lenses are embedded in birefringent material with a refractive index approximately equal to that of the lens for light linearly polarized in one direction.

26. The display of claim 25, wherein the direction is within the plane of the transparent layer.

27. The display of claim 25, the birefringent material comprising a layer of liquid crystal material.

28. The display of claim 25, the birefringent material further comprising retarding layers of crystals such as calcite or various plastics.

29. The display of claim 21, wherein the lens is a lens molded into etched bireficingent organic retarding films.

30. The display of claim 21, wherein the lens is immersed in a layer of liquid crystal material.

31. The display of claim 21, farther comprising a polarizing filter between the lens array and the viewing optics.

32. The display of claim 1 in which the reflective layer and the pixel layer are combined into one layer.

33. A head mounted display system comprising:

a right eye light valve and a left eye light valve, each light valve comprising a plurality of pixels, the reflective light valve comprising a reflective layer, a pixel layer, and a transparent layer, the transparent layer comprising a plurality of lenses such that a lens is situated in front of each pixel; and

a light source that directs light to the lenses.

34. A method of generating a high resolution color image comprising sequentially directing light of different colors from a light source to a light valve having a plurality of pixels and comprising a reflective layer, a pixel layer, and a transparent layer, the transparent layer comprising a plurality of front lenses such that a front lens is situated in front of each pixel.

35. The method of claim 34, in which transparent layer comprises at least one lens embedded in birefringent material.

36. The method of claim 34, wherein the step of sequentially directing light of different colors farther comprises turning a colored light in the light source on and off in succession, and changing a transmissivity of the pixels to create red, green, and blue color components of the image in succession.

37. The method of claim 34, further comprising focusing light from the light source to the pixels on the light valve, and directing light from the light valve to viewing optics.

38. The method of claim 34, wherein the light valve is an integrated circuit ferroelectric liquid crystal device.

39. The method of claim 38, wherein the light valve has a pixel response time of 0.1 ms or shorter.

40. The method of claim 34, wherein the front lenses are a flys eye lens or lenticular lens adjacent the valve.

41. The method of claim 34, in which the step of directing light of different colors comprises directing light from the light source through a rotating color filter wheel having discrete sections of different color transparencies.

42. The method of claim 41, further comprising directing light from the color filter wheel to a rotating prism and focusing a beam of light.

43. The method of claim 42, further comprising synchronizing rotation of the color filter wheel and the prism and sequentially providing focused beams of light of different color transparencies.

44. The method of claim 43, further comprising sequentially directing the focused beams of light of different color transparencies to bundle ends of bundles of fibers, and directing focused beams of light from opposite ends of the bundles to the pixels of the light valve.

45. The method of claim 34, comprising directing light of different colors from the light source to pixels of a right eye non-transmissive light valve and to pixels of a left eye non transmissive light valve to modulate intensity of light to create different color components of an image in succession, and providing light alternately to the light valves.

46. The method of claim 34, wherein the right eye and left eye light valves are disposed in a head mounted display.

47. A display device comprising a light valve comprising a front lens, a pixel layer, and a transparent layer adjacent to the pixel layer between the front lens and the pixel layer;

the transparent layer comprising;

a liquid crystal first polarization rotator that turns the polarization direction of light by 90 degrees when turned on;

a first layer of birefringent material thick enough to cause the images of spots to be seen to be displaced by a distance ‘

d’

when the polarization rotator turns on and off, located adjacent to the first rotator;

a liquid crystal second polarization rotator which turns the polarization direction of light by 90 degrees when turned on, located adjacent to the first layer of birefringent material; and

a second layer of birefringent material with sufficient thickness to cause images of the spots to be displaced in the vertical direction ‘

d’

;

when the second polarization rotator is turned on.

48. The display of claim 47, wherein the birefringent material is a thickness t capable of displacing the images a distance ‘

d’

.

49. The display of claim 47, wherein the birefringent material is a thickness t capable of displacing images a distance equal to a ½

a pixel.

50. The display of claim 47, further comprising a single collimating lens and polarizing filter between the lens array and the viewing optics.

51. The display of claim 47, the birefringent material further comprising a second liquid crystal layer.

52. The display of claim 47, further comprising a liquid crystal polarization rotator adjacent the polarization filter.

53. The display of claim 47, the birefringent material further comprising retarding layers of crystals such as calcite or various plastics.