Method for operating a display panel with electrically-controlled waveguide-routing

• US 6,078,704 A
• Filed: 01/20/1999
• Issued: 06/20/2000
• Est. Priority Date: 09/09/1994
• Status: Expired due to Term

• Current Assignee: Gemfire Corp. (Medtronic Plc)
• Original Assignee: Gemfire Corp. (Medtronic Plc)
• Inventors: Bischel, William K., Field, Simon J., Dyer, Mark J., Brinkman, Michael J., Deacon, David A. G., DeWath, Edward J.
• Primary Examiner(s): Healy, Brian
• Application Number:
  US09/233,764
• Time in Patent Office: 517 Days
• Field of Search: 385/1, 385/2, 385/3, 385/4, 385/5, 385/7, 385/8, 385/10, 385/14, 385/15, 385/17, 385/37, 385/40, 385/41, 385/42, 385/49, 385/50, 385/130, 385/131, 385/132, 385/11-13, 385/16, 385/18, 385/19, 385/20 , 385/21, 385/22, 385/147, 385/33, 385/116, 385/901
• US Class Current: 385/4
• CPC Class Codes: G02F 1/011 in optical waveguides, not otherwise provided for in this subclass
• CPC Class Codes: G02F 1/3558 Poled materials, e.g. with periodic poling; Fabrication of domain inverted structures, e.g. for quasi-phase-matching [QPM]
• CPC Class Codes: G02F 1/377 in an optical waveguide structure
• CPC Class Codes: G02F 2201/30 grating
• CPC Class Codes: G02F 2201/305 diffraction grating
• CPC Class Codes: G02F 2201/307 Reflective grating, i.e. Bragg grating
• CPC Class Codes: G09F 9/305 being the ends of optical fibres G09F9/302 takes precedence
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

A flat panel display is based on a new switching technology for routing laser light among a set of optical waveguides and coupling that light toward the viewer. The switching technology is based on poled electro-optical structures. The display technology is versatile enough to cover application areas spanning the range from miniature high resolution computer displays to large screen displays for high definition television formats. The invention combines the high brightness and power efficiency inherent in visible semiconductor diode laser sources with a new waveguide electro-optical switching technology to form a dense two-dimensional addressable array of high brightness light emissive pixels.

Claims

1. A method for displaying an image, comprising the steps of:

guiding optical energy along a first optical energy path in a material;

coupling optical energy out of said first path and into a waveguide defining a first secondary optical energy path in said material and transverse of said first path; and

projecting optical energy out of a plane defined locally by said first path and said first secondary path in response to energy received from said first secondary path.

2. A method according to claim 1, further comprising the steps of:

coupling optical energy out of said first path and into a waveguide defining a second secondary optical energy path in said material; and

projecting optical energy out of a plane defined locally by said first path and said second secondary path in response to energy received from said second secondary path.

3. A method according to claim 2, wherein said steps of coupling optical energy into a waveguide defining a first secondary path and coupling optical energy into a waveguide defining a second secondary path occur at different times.

4. A method according to claim 1, wherein said step of coupling optical energy out of said first path and into a waveguide defining said first secondary path comprises the step of controllably coupling optical energy out of said first path and into said waveguide defining said first secondary path.

5. A method according to claim 4, wherein said step of controllably coupling comprises the steps of applying a control signal to divert optical energy out of said first path and into said waveguide defining said first secondary path.

6. A method according to claim 1, wherein said step of projecting optical energy out of a plane in response to energy received from said first secondary path comprises the step of reflecting optical energy received from said first secondary path.

7. A method according to claim 1, wherein said step of projecting optical energy out of a plane in response to energy received from said first secondary path comprises the step of exciting a phosphor to emit optical energy out of said plane in response to energy received from said first secondary path.

8. A method according to claim 7, wherein said energy received from said first secondary path includes energy at a first frequency, and wherein said step of exciting a phosphor to emit optical energy out of said plane in response to energy received from said first secondary path comprises the step of exciting said phosphor to emit optical energy at a second frequency higher than said first frequency.

9. A display method, comprising the steps of:

guiding optical energy along a first waveguide segment;

reflecting optical energy out of said first waveguide segment at a first reflector position and into a first secondary optical path transverse to said first waveguide segment; and

emitting optical energy out of a plane defines locally by said first waveguide segment and said first secondary optical path in response to energy received at a first pixel position from said first secondary optical path.

10. A method according to claim 9, further comprising the step of guiding propagation of said optical energy in at least one dimension along said first secondary path.

11. A method according to claim 10, comprising the step of guiding propagation of said optical energy in two dimensions along said first secondary path.

12. A method according to claim 9, comprising the steps of:

reflecting optical energy out of said first waveguide segment and into respective secondary optical paths at a plurality of reflector positions along said first waveguide segment including said first reflector position; and

emitting optical energy out of planes each defined locally by said first waveguide segment and its respective secondary optical path in response to energy received at respective pixel positions from said secondary optical paths including said first optical path.

13. A method according to claim 12, wherein said step of reflecting optical energy out of said first waveguide segment at a plurality of reflector positions comprises the step of controllably reflecting optical energy out of said first waveguide segment.

14. A method according to claim 9, wherein said step of emitting optical energy out said plane in response to energy received at said first pixel position comprises the step of reflecting out of said plane said energy received at said first pixel position.

15. A method according to claim 9, wherein said step of emitting optical energy out said plane in response to energy received at said first pixel position comprises the step of exciting a phosphor at said first pixel position to re-radiate optical energy out of said planar waveguide.

16. A method according to claim 15, wherein said phosphor is an upconversion phosphor.

17. A method according to claim 9, wherein said step of guiding optical energy along a first waveguide segment comprises the step of restricting optical energy propagation in two dimensions.

18. A method comprising the steps of:

guiding optical energy along a first optical energy path in a material;

controllably diverting optical energy out of said first path at a plurality of diverting positions along said first path;

upconverting optical energy received from said diverting positions; and

radiating upconverted optical energy out of said material at a plurality of distinct positions, each corresponding to a respective one of said diverting positions.

19. A method according to claim 18, wherein said distinct positions comprise pixel positions of a display.

20. A method according to claim 18, wherein said step of controllably diverting optical energy out of said first path at a plurality of diverting positions along said first path comprises the step of diverting optical energy out of said first path in a predefined sequence of the diverting positions along said first path.

21. A method according to claim 18, wherein said step of guiding optical energy along a first optical energy path in a material comprises the step of carrying said optical energy along a first waveguide in said material,

further comprising the step of guiding optical energy diverted out of said first path at each given one of said diverting positions, toward the distinct position corresponding to the given diverting position.

22. A method according to claim 21, wherein said step of carrying optical energy along a first waveguide in said material comprises the step of guiding optical energy propagation in two dimensions,

and wherein said step of guiding optical energy diverted out of said first path at each given one of said diverting positions comprises the step of guiding optical energy propagation in at least one dimension.

23. A method according to claim 18, wherein said step of guiding optical energy comprises the step of guiding infrared optical energy,

wherein said step of upconverting optical energy comprises the step of converting infrared optical energy to visible optical energy,

and wherein said step of radiating upconverted optical energy comprises the step of radiating said visible optical energy.

24. A method for displaying an image, comprising the steps of:

guiding optical energy along a plurality of optical energy paths in a material;

controllably diverting optical energy out of each of said paths at a plurality of diverting positions along each of said paths;

upconverting optical energy received from said diverting positions; and

radiating upconverted optical energy out of said material at a plurality of pixel positions, each corresponding to a respective one of said diverting positions.

25. A method according to claim 24, wherein said step of guiding optical energy along a plurality of optical energy paths comprises the step of guiding said optical energy along a plurality of said optical paths simultaneously.

26. A method according to claim 24, wherein said step of controllably diverting optical energy out of each of said paths at a plurality of diverting positions along each of said paths comprises the step of diverting optical energy out of each given one of said paths at the diverting positions along the given path in a predefined sequence of the diverting positions along the given path.

27. A method according to claim 26, further comprising the step of modulating the optical energy guided along each given one of said paths in accordance with image information corresponding to said predefined sequence of the diverting positions along the given path.

28. A method according to claim 24, wherein said step of guiding optical energy along a plurality of optical energy paths in a material comprises the step of carrying said optical energy along a plurality of first waveguides in said material,

further comprising the step of guiding optical energy diverted out of said paths at each given one of said diverting positions, toward the pixel position corresponding to the given diverting position.

29. A method according to claim 28, wherein said step of carrying said optical energy along a plurality of first waveguides in said material comprises the step of restricting optical energy propagation in at least two dimensions,

and wherein said step of guiding optical energy diverted out of said paths at each given one of said diverting positions comprises the step of restricting optical energy propagation in at least a first dimension.

30. A method according to claim 29, wherein said step of controllably diverting optical energy out of each of said paths at a plurality of diverting positions along each of said paths comprises the step of controllably inducing, at a given one of said diverting positions located along a given one of said first waveguides, an index of refraction structure which restricts optical energy propagation outside the given first waveguide in a second dimension different from said first dimension.

31. A method according to claim 30, wherein said step of controllably diverting optical energy out of each of said paths further comprises the step of controllably inducing a TIR boundary in the given first waveguide at the given diverting position.

32. A method according to claim 29, wherein said step of controllably diverting optical energy out of each of said paths at a plurality of diverting positions along each of said paths comprises the step of controllably inducing a TIR boundary in a given one of said diverting positions located along a given one of said first waveguides.

33. A method according to claim 24, wherein said step of guiding optical energy comprises the step of guiding infrared optical energy,

wherein said step of upconverting optical energy comprises the step of converting infrared optical energy to visible optical energy,

and wherein said step of radiating upconverted optical energy comprises the step of radiating said visible optical energy.

34. A display method comprising the steps of:

providing first optical energy of a first frequency;

frequency converting energy deriving from said first optical energy to produce second optical energy having a second frequency;

introducing into a first waveguide segment in a display material, energy deriving from a member of the group consisting of said first optical energy and said second optical energy;

diverting optical energy out of said first waveguide segment at a plurality of diverting positions along said first waveguide segment; and

re-radiating, at respective pixel positions of said display material, optical energy deriving from the optical energy diverted out of said first waveguide segment each of said diverting positions.

35. A method according to claim 34, wherein said step of diverting optical energy out of said first waveguide segment at a plurality of diverting positions comprises the step of controllably diverting optical energy out of said first waveguide segment at each of said diverting positions.

36. A method according to claim 34, further comprising the step of collecting into respective second waveguide segments, optical energy diverted out of said first waveguide segment at each of said diverting positions.

37. A method according to claim 36, wherein said step of re-radiating optical energy deriving from the optical energy diverted out of said first waveguide segment comprises the step of reflecting, at said respective pixel positions, optical energy deriving from the optical energy collected into each of said second waveguide segments.

38. A method according to claim 34, wherein said step of re-radiating, at respective pixel positions of said display material, optical energy deriving from the optical energy diverted out of said first waveguide segment each of said diverting positions, comprises the step of reflecting, at said respective pixel positions, optical energy deriving from the optical energy diverted out of said first waveguide segment each of said diverting positions.

39. A display method, comprising the steps of:

guiding optical energy along a first waveguide segment in a material;

controllably diverting optical energy out of said first waveguide segment and into a planar waveguide at a first coupling region along said first waveguide segment; and

emitting optical energy out said planar waveguide in response to energy received at a first pixel position from said first coupling region.

40. A method according to claim 39, wherein said step of controllably diverting optical energy out of said first waveguide segment comprises the step of applying an electronic control signal to said first coupling region.

41. A method according to claim 39, wherein said step of emitting optical energy out said planar waveguide in response to energy received at said first pixel position comprises the step of reflecting out of said planar waveguide said energy received at said first pixel position.

42. A method according to claim 39, wherein said step of emitting optical energy out said planar waveguide in response to energy received at said first pixel position comprises the step of exciting a phosphor at said first pixel position to re-radiate optical energy out of said planar waveguide.

43. A method according to claim 42, wherein said phosphor is an upconversion phosphor.

44. A method according to claim 39, wherein said step of guiding optical energy along a first waveguide segment comprises the step of restricting optical energy propagation in at least two dimensions.

45. A method according to claim 39, comprising the steps of:

diverting optical energy out of said first waveguide segment and into a planar waveguide at a plurality of coupling regions along said first waveguide segment including said first coupling region; and

emitting optical energy out said planar waveguide in response to energy received at respective pixel positions corresponding to each of said coupling regions including said first coupling region.

46. A method according to claim 45, wherein said step of diverting optical energy out of said first waveguide segment at a plurality of coupling regions comprises the step of applying an electronic control signal to each of said coupling regions.

47. A method according to claim 45, wherein said step of emitting optical energy out said planar waveguide in response to energy received at respective pixel positions comprises the step of reflecting out of said planar waveguide said energy received at the respective pixel positions.

48. A method according to claim 45, wherein said step of emitting optical energy out said planar waveguide in response to energy received at respective pixel positions comprises the step of exciting a phosphor at the respective pixel positions to re-radiate optical energy out of said planar waveguide.

49. A method according to claim 45, wherein said step of guiding optical energy along a first waveguide segment comprises the step of restricting optical energy propagation in at least two dimensions.