Polarized light emitting devices and methods

• US 20050035361A1
• Filed: 08/15/2003
• Published: 02/17/2005
• Est. Priority Date: 08/15/2003
• Status: Abandoned Application

• Current Assignee: Charles M. Peterson, Gene C. Koch
• Original Assignee: Charles M. Peterson, Gene C. Koch
• Inventors: Peterson, Charles M., Koch, Gene C.
• Application Number:
  US10/641,164
• Publication Number:
  US 20050035361A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

An organic light emitting device (OLED) including a reflective electrode or reflective backing that emits polarized light, a linear polarizer and/or a band-pass filter may be combined such that substantially all of the light from the OLED is transmitted through the linear polarizer and/or the band-pass filer while ambient light is substantially absorbed. A colored linear polarizer may be to provide the functions of the linear polarizer and the band-pass filer. A light dispersion element also may be included.

Claims

1. A light emitting device comprising:

a band-pass filter;

a linear polarizer; and

an organic light emitting device having a light emitter,

wherein the linear polarizer is adjacent the band-pass filter, and

wherein the light emitter emits polarized light.

2. The device of claim 1,

wherein the polarized light has a predetermined spectrum, and

wherein the band-pass filter transmits light of the predetermined spectrum and absorbs light outside the predetermined spectrum.

3. The device of claim 2, wherein the band-pass filter and the linear polarizer are formed separately.

4. The device of claim 2, wherein the band-pass filter and the linear polarizer are a single film.

5. The device of claim 4, wherein the single film is a dyed polarizing film.

6. The device of claim 2, further comprising an element that alters an angular emission pattern of light emitted from a front surface of the organic light emitting device.

7. The device of claim 6, wherein the element, the band-pass filter and the linear polarizer are a single film.

8. The device of claim 1, wherein the polarized light includes red, green and blue components.

9. The device of claim 1, further comprising an element that alters an angular emission pattern of light emitted from a front surface of the organic light emitting device.

10. The device of claim 9,

wherein the element is a holographic diffuser film that is polarization preserving and

wherein the holographic diffuser film is between the organic light emitting device and the linear polarizer.

11. The device of claim 9,

wherein the element is a holographic diffuser film that has low reflectivity and low scattering;

and

wherein the linear polarizer is between the organic light emitting device and the holographic diffuser film.

12. The device of claim 1, wherein the light emitter is a liquid crystal emitter.

13. The device of claim 12, wherein the light emitter is a nematic liquid crystal emitter.

14. The device of claim 1, wherein the polarized light is plane polarized light.

15. The device of claim 1, further comprising at least one anti-reflective film.

16. The device of claim 1, further comprising an optical compensation film.

17. The device of claim 1, further comprising a reflector, wherein the light emitter is between the reflector and the linear polarizer.

18. A rear projection system comprising the light emitting device of claim 1.

22. The method of claim 18, further comprising:

reflecting the plane polarizing light propagating away from a direction that allows viewing such that the reflected light is propagating in a direction that allows viewing.

19. A method of providing an image comprising:

energizing an organic light emitting device to produce plane polarized light having a predetermined spectrum;

linearly polarizing the plane polarized light; and

absorbing light outside a spectrum of the plane polarized light.

20. The method of claim 19, wherein the linearly polarizing and absorbing substantially attenuates light not emitted from the organic light emitting device.

21. The method of claim 20, wherein attenuated light includes ambient light.

23. A light emitting device comprising:

a band-pass filter; and

an organic light emitting device having a light emitter,

wherein the light emitter emits light having a narrow spectrum,

wherein the band-pass filter transmits light of the narrow spectrum and absorbs light outside the narrow spectrum.

24. The device of claim 23, further comprising a linear polarizer.

25. The device of claim 24, wherein the band-pass filter and the linear polarizer are formed separately.

26. The device of claim 24, wherein the band-pass filter and the linear polarizer are a single film.

27. The device of claim 26, wherein the single film is a dyed polarizing film.

28. The device of claim 24, further comprising an element that alters an angular emission pattern of light emitted from a front surface of the organic light emitting device.

29. The device of claim 28, wherein the element, the band-pass filter and the linear polarizer are a single film.

30. The device of claim 23, wherein the narrow spectrum includes red, green and blue components.

31. The device of claim 30, wherein each of the red, green and blue components have a bandwidth of a few nm.

32. The device of claim 30, wherein the narrow bandwidth results from feedback that causes stimulated emission in the light emitter.

33. The device of claim 23, further comprising an element that alters an angular emission pattern of light emitted from a front surface of the organic light emitting device.

34. The device of claim 33, wherein the element is a holographic diffuser film that is polarization preserving and the holographic diffuser film is between the organic light emitting device and the linear polarizer.

35. The device of claim 33,

wherein the element is a holographic diffuser film that has low reflectivity and low scattering;

and

wherein the linear polarizer is between the organic light emitting device and the holographic diffuser film.

36. The device of claim 23, wherein the light emitter is a liquid crystal emitter.

37. The device of claim 36, wherein the light emitter is a nematic liquid crystal emitter.

38. The device of claim 23, wherein the light is plane polarized light.

39. The device of claim 23, further comprising a reflector, wherein the light emitter is between the reflector and the band-pass filter.

40. The device of claim 39, further comprising at least one anti-reflective film.

41. The device of claim 23, further comprising an optical compensation film.

42. A rear projection system comprising the light emitting device of claim 23.

43. A method of providing an image comprising:

energizing an organic light emitting device to produce polarized light of a narrow spectrum; and

filtering the reflected light and the polarized light propagating in a direction that allows viewing such that light of outside the narrow spectrum is absorbed.

44. A light emitting device comprising:

a linear polarizer;

a reflector;

a band-pass filter; and

an organic light emitting device having a light emitter,

wherein at least one of the polarizer and the band-pass filter is between the reflector and the light emitter.

45. A projection system comprising:

a projector including an organic light emitting device having a light emitter;

a projection screen including a linear polarizer; and

projection optics between the projector and the projection screen,

wherein the light emitter is selectively energized so as to produce an image that is projected by the projection optics on the projection screen.

46. The system of claim 45, wherein the projection screen further comprises a band-pass filter.

47. The system of claim 46, wherein the projection screen further comprises an element that alters an angular emission pattern of light.

48. The system of claim 45, wherein the projection screen further comprises an element that alters an angular emission pattern of light.

49. The system of claim 48, wherein the element comprises at least one of a dyed micro-optic film and a dyed lenticular array.

50. The system of claim 45, wherein the projection screen further comprises an optical compensation film.

51. The system of claim 45, wherein the light emitter has a narrow emission spectrum.

52. The system of claim 45, wherein the projection screen is a rear projection screen.