Field sequential display device and methods of fabricating same

• US 20050156839A1
• Filed: 06/13/2003
• Published: 07/21/2005
• Est. Priority Date: 11/02/2001
• Status: Abandoned Application

• Current Assignee: Disruptive Technologies, Ltd.
• Original Assignee: Disruptive Technologies, Ltd.
• Inventors: Webb, Homer L
• Application Number:
  US10/517,503
• Publication Number:
  US 20050156839A1
• Time in Patent Office: Days
• US Class Current: 345/87
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133622 Colour sequential illumination
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A device adapted for use in a field sequential color display. The device may include first and second polarizers. A light scattering material may be disposed between the first and second polarizers. Additionally, the display may include a light source having a plurality of colors. Portions of the light scattering material are operable for selectable excitation. An excitation of a portion of the light scattering material is operable for controlling an amount of light of a color of the plurality of colors emitted by the display device. Further, sub-frames from which an image frame is composed may be addressed in a segmented fashion, whereby each sub-frame includes a plurality of segments. The light source is correspondingly pulsed in a segmented fashion. A given segment may be illuminated in a different color in each sub-frame. In this way, perceived flicker may be reduced.

Claims

8. A display device comprising:

a first and second polarizer;

a light scattering material disposed between said first and second polarizer; and

a light source having a plurality of colors, wherein portions of said light scattering material are operable for selectable excitation, wherein an excitation of a portion of said light scattering material is operable for controlling an amount of light of a color of said plurality of colors emitted by said display device.

9. The display device as recited in claim 8 further comprises:

a first and second substantially transparent conductive layers disposed between each of said first and second polarizer, wherein said excitation of said portion of said light scattering material layer comprises an electric field applied between a corresponding portion of said first and second substantially transparent conductive layers.

10. The display device as recited in claim 8, wherein said first polarizer forms a substrate, wherein the liquid crystal display device further comprises a driver circuit mounted on said substrate.

11. The display device as recited in claim 8, wherein said second polarizer forms a substrate, wherein the display device further comprises an active element embedded in said substrate.

12. The display device as recited in claim 11 wherein said active device is a varistor.

13. The display device as recited in claim 8, wherein said light scattering material comprises polymer dispersed liquid crystal.

14. A method for manufacturing a display device comprising the steps of:

providing a first and a second polarizer, wherein each of said first and second polarizer comprises a first and a second layer;

coating said second layer of said first polarizer with conductive material; and

depositing a light scattering material layer between said first and second polarizer.

1. A display device comprising:

a polarizer; and

a light scattering material disposed in a transmission path between said polarizer and a polarized light source, wherein said light scattering material is switchable from a first state to a second state in response to an applied electrical field, wherein said light source includes a plurality of independently controllable colors.

2. The display device as recited in claim 1, wherein said light scattering material comprises a Polymer Dispersed Liquid Crystal (PDLC).

3. The display device as recited in claim 1 further comprising:

a substantially transparent conductive layer disposed between said polarizer and said light scattering material.

4. The display device as recited in claim 3, wherein said substantially transparent conductive layer is disposed on said polarizer.

5. The display device as recited in claim 3, wherein said substantially transparent conductive layer is an Indium-Tin Oxide (ITO) layer.

6. The display device as recited in claim 1, wherein in said first state, said light scattering material is substantially non-scattering, wherein in said second state, said light scattering material is substantially scattering.

7. The display device as recited in claim 1, wherein said light scattering material comprises a nematic curvilinear aligned phase (NCAP) polymer dispersed liquid crystal system.

15. The method as recited in claim 14 further comprising the steps of:

making holes through said second polarizer; and

forming a driver and electrodes on said second layer of said second polarizer.

31. The method as recited in claim 14 wherein said second polarizer comprises a third layer, wherein the method further comprises the step of:

printing an active element on said third layer of said second polarizer.

32. The method as recited in claim 14 further comprising the steps of:

coating said first layer of said second polarizer with conductive material; and

etching a cell pattern on said first layer of said second polarizer.

33. The method as recited in claim 15 further comprising the steps of:

coating said first layer of said second polarizer with conductive material; and

etching a cell pattern on said first layer of said second polarizer.

34. The method as recited in claim 31 further comprising the steps of:

coating said first layer of said second polarizer with conductive material; and

etching a cell pattern on said first layer of said second polarizer.

35. The method as recited in claim 14 further comprising the steps of:

printing a crossover insulation pattern on said first layer of said second polarizer; and

printing a crossover electrode pattern on said first layer of said second polarizer.

36. The method as recited in claim 15 further comprising the steps of:

printing a crossover insulation pattern on said first layer of said second polarizer; and

printing a crossover electrode pattern on said first layer of said second polarizer.

37. The method as recited in claim 31 further comprising the steps of:

printing a crossover insulation pattern on said first layer of said second polarizer; and

printing a crossover electrode pattern on said first layer of said second polarizer.

38. The method as recited in claim 32 further comprising the steps of:

printing a crossover insulation pattern on said first layer of said second polarizer; and

printing a crossover electrode pattern on said first layer of said second polarizer.

39. The method as recited in claim 14, wherein said light scattering material comprises polymer dispersed liquid crystal.

16-30. -30. (canceled)

31-1. The method as recited in claim 15, wherein said second polarizer comprises a third layer, wherein the method further comprises the step of:

printing an active element on said third layer of said second polarizer.

40. A display device comprising:

a polarizer; and

a light scattering material disposed on a surface of said polarizer.

41. The display device of claim 40 wherein said light scattering material is positioned to receive polarized light.

42. The display device of claim 41 further comprising a light source including a plurality of independently controllable colors, said light source operable to source said polarized light.

43. The display device of claim 41 further comprising a second polarizer positioned between said light scattering material and a light source having a plurality of independently controllable colors.

44. A method of displaying an image frame comprising:

(a) addressing a sub-frame segment; and

(b) flashing a light source, wherein said light source comprises a plurality of independently controlled portions, and wherein said sub-frame comprises a one or more of said sub-frame segments, said independently controlled portions corresponding to said sub-frame segments, and wherein said image frame comprises a composite of a plurality of sub-frames.

45. The method of claim 44 further comprising:

(c) repeating steps (a) and (b) for each segment of said sub-frame.

46. The method of claim 45 further comprising repeating step (c) for each sub-frame of said composite.

47. The method of claim 44 wherein said each of said independently controlled segments comprise a first color for a first sub-frame of said image frame and a second color for a second sub-frame of said composite.

48. The method of claim 45 wherein said each of said independently controlled segments comprise a first color for a first sub-frame of said image frame and a second color for a second sub-frame of said composite.

49. The method of claim 46 wherein said each of said independently controlled segments comprise a first color for a first sub-frame of said image frame and a second color for a second sub-frame of said composite.

50. The method of claim 44 wherein said segment comprises a full sub-frame.

51. A method for modifying an existing liquid crystal display device that includes a top and bottom substrate assembly, wherein said top substrate assembly includes a polarizer, substrate, conductive layer, and said bottom substrate assembly includes a plurality of transistors, comprising the steps of:

removing the top substrate assembly;

removing up to two-thirds of the transistors from the bottom substrate assembly;

disposing a light scattering material upon interior surface of the bottom substrate assembly;

installing top substrate assembly polarizer, substrate, and conductive layer upon bottom substrate assembly.

52. The method as recited in claim 51 wherein the bottom substrate assembly includes a rubbing layer, the method further comprising the step of:

removing the rubbing layer from the bottom substrate assembly.