Light collimating device

• US 20050259198A1
• Filed: 08/01/2005
• Published: 11/24/2005
• Est. Priority Date: 03/26/2002
• Status: Active Grant

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Trinium Technologies
• Inventors: Wojciechowski, Timothy J., Lubart, Neil D., Lash, Thomas E.
• Granted Patent: US 7,345,824 B2
• Time in Patent Office: Days
• US Class Current: 349/113
• CPC Class Codes: G02B 17/002 Arrays of reflective systems
• CPC Class Codes: G02B 27/0972 Prisms prisms per se G02B5/04
• CPC Class Codes: G02B 27/0983 being curved
• CPC Class Codes: G02B 27/30 Collimators
• CPC Class Codes: G02F 1/133524 Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Abstract

A collimating device and a transflector for use in a system having a backlight is disclosed herein. In one embodiment of the application, the collimating device and the transflector each include an immersing layer, a reflecting layer, and an optical element layer formed from a plurality of three-dimensional, optical elements. Each optical element is tapered such that a small area end has a horizontal plane cross-sectional area that is less than that of a wide area end. The optical elements of the collimating device are tapered towards the backlight and the optical elements of the transflector are tapered away from the backlight. The reflecting layer has apertures which correspond to the position and shape of the light input ends of the optical elements.

Claims

1. A collimating device for use in a system having a backlight, the collimating device comprising:

an immersing layer;

a reflecting layer; and

an optical element layer formed from a plurality of three-dimensional, optical elements, each optical element having a light input end and a light output end, each optical element being tapered towards the backlight such that the light input end has a horizontal plane cross-sectional area that is less than that of the light output end, and

wherein the reflecting layer has apertures therein which correspond to the position and shape of the light input ends of the optical elements.

2. The collimating device of claim 1, wherein the optical elements are surrounded by air.

3. The collimating device of claim 1, wherein the optical element layer is formed from a polymer having a first index of refraction and the optical elements are surrounded by a second polymer having a second index of refraction, the first index of refraction being higher than the second index of refraction.

4. The collimating device of claim 1, wherein the light output end of each optical element abuts the light output end of at least one other optical element of the optical element layer.

5. The collimating device of claim 1, wherein the immersing layer has a first and second side and the reflecting layer has a first and second side, and

wherein the first side of the immersing layer is in contact with the second side of the reflecting layer.

6. The collimating device of claim 5, wherein the light input ends of the optical elements extend such that the light input ends contact the second side of the reflecting layer.

7. The collimating device of claim 5, wherein the light input ends of the optical elements extend through the apertures of the reflecting layer and contact the second side of the immersing layer.

8. The collimating device of claim 1, wherein the immersing layer has a first and second side and the reflecting layer has a first and second side, and

wherein the first side of the reflecting layer is in contact with the second side of the immersing layer and the light input ends of the optical elements are in contact with the first side of the immersing layer.

9. The collimating device of claim 1, wherein the reflecting layer is a metal layer.

10. The collimating device of claim 1, wherein the immersing layer is an immersing polymer layer

11. The collimating device of claim 1, wherein each optical element has a polygonal horizontal plane cross-section.

12. The collimating device of claim 1, wherein each optical element is lenticular shaped and has a horizontal plane cross-section that is rectangular with length equal to that of the lenticular channel.

13. The collimating device of claim 1, wherein each optical element has a compound parabolic concentrator structure.

14. The collimating device of claim 1, wherein each optical element has a circular approximation of a compound parabolic concentrator structure.

15. An optical layer having a light input side and a light output side, the optical layer comprising:

a plurality of three-dimensional, light collimating elements,

wherein each optical element has a polygonal horizontal plane cross-section, and

wherein each optical element is tapered, such that a vertical plane cross-section of the optical element is an approximation of a compound parabolic concentrator.

16. The optical layer of claim 15, wherein the taper of the optical element has at least one linear section.

17. The optical layer of claim 16, wherein the taper has a curved section defined by an arc of a circle, and the slope of the curved section matches the slope of the at least one linear section at the intersection point of the curved section and the at least one linear section.

18. The optical layer of claim 15, wherein the tapered light collimating elements are surrounded by air.

19. The optical layer of claim 15, wherein the light collimating elements are formed from a polymer having a first index of refraction and the tapered light collimating elements are surrounded by a second polymer having a second index of refraction, the first index of refraction being higher than the second index of refraction.

20. The optical layer of claim 15, wherein each light collimating element has a lenticular shape and a rectangular cross-section.

21. The optical layer of claim 15, wherein the light collimating elements are in contact with each other at a light output side of the light collimating film.

22. The optical layer of claim 15, wherein the light collimating elements contact each other in a common polymer sheet.

23. A transflector configured to reflect light arriving from a first direction and to transmit light arriving from a second direction opposite the first direction, the transflector comprising:

at least one immersing layer, including a first immersing layer having a first and second side, wherein the first side faces a backlight that projects light in the first direction and the second side faces light arriving from the second direction;

at least one reflective layer, including a first reflective layer having a first and second side, wherein the first side faces the backlight and the second side faces light arriving from the second direction;

at least one optical element layer, including a first optical element layer having a first set of optical elements, wherein each of the first set of optical elements are tapered towards the light arriving from the second direction, such each optical element has a small area end and a large area end,

wherein the large area end of each of the first set of optical elements contacts the large area end of another of the first set of optical elements, and

wherein the first reflective layer has apertures therein which correspond to the positioning and shape of the small area ends of each of the first set of optical elements.

24. The transflector of claim 23, wherein the first side of the first reflective layer is in contact with the second side of the first immersing layer, and the small area ends of the first set of optical elements are in contact with the second side of the first reflective layer.

25. The transflector of claim 23, wherein the first side of the first immersing layer is in contact with the second side of the first reflective layer, and the small area ends of the first set of optical elements are in contact with the second side of the first immersing layer.

26. The transflector of claim 23, wherein the first side of the first reflective layer is in contact with the second side of the first immersing layer, and the small area ends of the first set of optical elements extend through the apertures of the first reflective layer and contact the second side of the first immersing layer.

27. The transflector of claim 23,

wherein the at least one optical element layer includes a second optical element layer having a second set of optical elements, each of the second set of optical elements being tapered towards the backlight, such that each optical element has a small area end and a large area end and the large area ends of the second set of optical elements are adjacent to the large area ends of the first set of optical elements;

wherein the at least one reflective layer includes a second reflective layer having a first side and a second side, such that the first side faces the backlight and the second side faces light arriving from the second direction, the second reflective layer further having apertures therein which correspond to the positioning and shape of the small area ends of each of the second set of optical elements;

wherein the at least one immersing layer includes a second immersing layer having a first side and a second side, such that the first side faces the backlight and the second side faces light arriving from the second direction.

28. The transflector of claim 27, wherein the first side of the second immersing layer is in contact with the second side of the second reflective layer, and the small area ends of the second set of optical elements are in contact with the first side of the second reflective layer.

29. The transflector of claim 27, wherein the first side of the second reflective layer is in contact with the second side of the second immersing layer, and the small area ends of the second set of optical elements are in contact with the first side of the second immersing layer.

30. The transflector of claim 27, wherein the first side of the second immersing layer is in contact with the second side of the second reflective layer, and the small area ends of the second set of optical elements extend through the apertures of the second reflective layer and contact the first side of the second immersing layer.

31. The transflector of claim 28, wherein the first set of optical elements and the second set of optical elements are surrounded by air.

32. The transflector of claim 28, wherein the first and second optical elements are formed from a first polymer having a first index of refraction, and the first set of optical elements and the second set of optical elements are surrounded by a second polymer having a second index of refraction.

33. The transflector of claim 32, wherein the first index of refraction is greater than the second index of refraction.

34. A light collimating device for use in a system having a backlight, the light collimating device comprising:

at least one optical element layer, including a first optical element layer having three-dimensional optical elements with horizontal plane rectangular bases that extend across the optical element layer,

wherein the optical elements are tapered along a curved path towards the backlight.

35. The light collimating device of claim 34, wherein the at least one optical element layer includes a second optical element layer having three-dimensional optical elements with horizontal plane rectangular bases that extend across the optical element layer,

wherein the optical elements of the second optical element layer are tapered along a curved path towards the backlight.

36. The light collimating device of claim 35, wherein the horizontal plane rectangular bases of the first optical element layer are orthogonal to the horizontal plane rectangular bases of the second optical element layer

37. The light collimating device of claim 35, wherein the first optical element layer is disposed between the backlight and the second optical element layer.

38. The light collimating device of claim 35, wherein the second optical element layer includes a metal layer.

39. A light containing region in an optical element layer for transmitting light, the light containing region comprising:

a light input end having a polygonal shape;

a light output end having a polygonal shape;

a plurality of sides, tapered from the light output end to the light input end.

40. The light containing region of claim 39, wherein the plurality of sides include at least one region that is a compound parabolic concentrator.

41. The light containing region of claim 39, wherein the plurality of sides include at least one region that is a circular approximation of a compound parabolic concentrator.

42. The light containing region of claim 39, wherein the sides include at least one linear section.

43. The light containing region of claim 41, wherein the sides include at least a first linear section and a second linear section, and

wherein the first linear section is adjacent the light output end, the second linear section is adjacent the light input end, and the circular approximation of a compound parabolic concentrator is located between the first and second linear sections.

44. The light containing region of claim 41, wherein the plurality of sides include at least one linear section, and

wherein the circular approximation of the compound parabolic concentrator section matches the slope of the at least one linear section at an intersection point of the circular approximation of the compound parabolic concentrator section and the at least one linear section.

45. The light containing region of claim 39, wherein the entire length of each side is an arc of a circle that approximates a compound parabolic concentrator.

46. The light containing region of claim 39, wherein the approximation of a compound parabolic concentrator has an aspect ratio of less than about 1:

1 to greater than about 7.5;

1.

47. The light containing region of claim 39, wherein the light containing region has a rectangular horizontal plane cross-section, such that light emerges from the light output end asymmetrically,

wherein an angular distribution of light output along the length of the rectangular output end is greater than the angular distribution of light along its width.

48. A collimating device for use in a system having a backlight, the collimating device comprising:

a reflecting layer; and

an optical element layer formed from a plurality of three-dimensional, optical elements, each optical element having a light input end and a light output end, each optical element being tapered towards the backlight such that the light input end has a horizontal plane cross-sectional area that is less than that of the light output end, and

wherein the reflecting layer has apertures therein which correspond to the position and shape of the light input ends of the optical elements.

49. The collimating device of claim 48, wherein each optical element has a polygonal horizontal plane cross-section.

50. The collimating device of claim 48, wherein each optical element is lenticular shaped and has a horizontal plane cross-section that is rectangular with length equal to that of the lenticular channel.

51. The collimating device of claim 48, wherein each optical element has a compound parabolic concentrator structure.

52. The collimating device of claim 48, wherein each optical element has a circular approximation of a compound parabolic concentrator structure.

53. A device comprising:

transflective pixels having a reflective surface; and

an optical element layer having a plurality of light containing regions, wherein each light containing region is tapered along a curved path towards the transflective pixels, such that each light containing region has a small area end and a wide are end,

wherein the small area ends are aligned with the transflective pixels.

54. The device of claim 53, further comprising:

a plurality of color filters aligned with the transflective pixels.

55. The device of claim 53, further comprising:

a backlight;

a front polarizer;

a rear polarizer; and

at least one glass layer.

56. The device of claim 55, wherein the at least one glass layer includes a front glass layer.

57. The device of claim 55, wherein the at least one glass layer includes a front glass layer and a rear glass layer.

58. The device of claim 53, wherein the device includes a collimating layer having a plurality of light containing regions and a reflective layer.

59. A method of manufacturing a device having an optical element layer and a reflective layer, the method comprising the steps of:

exposing a side of a photosensitive polymer to laser light with a lens/masking system to form light containing regions in the polymer;

guiding a printing system according to light output through the light containing regions created by a change in index of refraction; and

printing a reflective layer on areas where no light is output.

60. The method of claim 59, further comprising a step of:

depositing a blanket polymer over the reflective layer, thereby immersing the reflective layer.