Directed reflectors and systems utilizing same

• US 6,507,441 B1
• Filed: 10/16/2000
• Issued: 01/14/2003
• Est. Priority Date: 10/16/2000
• Status: Expired due to Fees

• Current Assignee: Optid Optical Identification Technologies Limited
• Original Assignee: Optid Optical Identification Technologies Limited
• Inventors: Drori, Avishai, Karoubi, Reouven, Arieli, Yoel, Glaser-Inbari, Isaia, Eisenberg, Naftali P.
• Primary Examiner(s): MACK, RICKY LEVERN
• Application Number:
  US09/688,120
• Time in Patent Office: 820 Days
• Field of Search: 359/619, 359/625, 359/626, 359/627
• US Class Current: 359/627
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 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 3/0062 Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
• CPC Class Codes: G02B 5/13 plural curved refracting elements forming part of a unitary body

Abstract

A wide angle directed reflector is disclosed. The directed reflector includes a lenticular layer including at least one array of lenslets, each of which having a focal length, The directed reflector further includes a reflective layer which is disposed relative to the lenticular layer. The lenticular layer and the reflective layer are constructed, designed and relatively disposed such that light incident at an angle of incidence on the lenticular layer is reflected by the reflective layer and redirected through the lenticular layer at a substantially constant angle relative to the angle of incidence.

Claims

1. A wide angle directed reflector comprising:

(a) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length; and

(b) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence, said substantially constant angle being substantially greater than zero, thereby rendering the directed reflector a non-retroreflector.

2. The wide angled directed reflector of claim 1, wherein each of said lenslets functions as a rear telecentric lenslet.

3. The wide angle directed reflector of claim 1, wherein said angle of incidence on said lenticular layer ranges at least +/−

20 degrees from a normal angle of incidence.

4. The wide angle directed reflector of claim 1, wherein said reflective layer includes an array of concave corrugated reflective elements.

5. The wide angle directed reflector of claim 1, wherein each of said lenslets has a diameter less than about 1 mm.

6. The wide angle directed reflector of claim 1, wherein each of said lenslets has a diameter less than about 0.5 mm.

7. The wide angle directed reflector of claim 1, wherein each of said lenslets has a diameter less than about 0.1 mm.

8. The wide angle directed reflector of claim 1, wherein each of said lenslets of said lenticular layer is selected from the group consisting of a diffractive lenslet, a refractive lenslet, and a combination diffractive-refractive lenslet.

9. The wide angle directed reflector of claim 1, wherein said reflective layer is a corrugated planar reflector.

10. A wide angle directed reflector comprising:

(a) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length; and

(b) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence and wherein said reflective layer includes an array of concave reflective elements.

11. The wide angle directed reflector of claim 10, wherein said substantially constant angle is substantially zero and therefore the directed reflector is a retroreflector.

12. The wide angle directed reflector of claim 10, wherein said substantially constant angle is substantially greater than zero and therefore the directed reflector is a non-retroreflector.

13. The wide angle directed reflector of claim 10, wherein lenslets of said at least one array of lenslets and said concave reflective elements of said array of concave reflective elements are optically co-aligned.

14. The wide angle directed reflector of claim 10, wherein a distance between a lenslet of said lenslets and a respective concave reflective element of said concave reflective elements is selected such that a center of said concave reflective element is located at a focal plane of said lenslet.

15. The wide angle directed reflector of claim 14, wherein said lenticular layer and said reflective layer are integrated into a single layer.

16. A wide angle directed reflector comprising:

(a) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length; and

(b) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence and, wherein each of said lenslets of said lenticular layer includes a convex face and an opposing flat face.

17. A wide angle directed reflector comprising:

(a) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length; and

(b) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence and wherein said lenticular layer and said reflective layer are integrated into a single layer.

18. A wide angle directed reflector comprising:

(a) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length; and

(b) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence and wherein each lenslet of said array of lenslets includes a pair of opposing convex faces.

19. A wide angle directed reflector comprising:

(a) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length; and

(b) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence and wherein said lenticular layer includes an external array of lenslets and an internal array of lenslets.

20. The wide angle directed reflector of claim 19, wherein each lenslet of each of said external array of lenslets and said internal array of lensiets includes a convex face and a planar opposing face.

21. The wide angle directed reflector of claim 20, wherein respective lenslets of said external array of lenslets and said internal array of lenslets form lenslet pairs such that said planar opposing faces thereof face one another.

22. The wide angle directed reflector of claim 21, wherein said reflective layer is planar.

23. The wide angle directed reflector of claim 22, wherein for each of said lenslet pairs, incident light passing through an aperture of a lenslet of said external array of lenslets and then through a respective internal lenslet of said internal array of lenslets is rendered normal to said reflective layer.

24. A wide angle controllable directed reflector comprising:

(a) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length;

(b) a reflective layer being disposable relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that, for a given relative orientation of said lenticular layer and said reflective layer, light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence; and

(c) a directed reflection controlling mechanism being designed and constructed to controllably alter said given relative orientation of, or distance between, said lenticular layer and said reflective layer, such that light incident at said angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at an angle different than said substantially constant angle relative to said angle of incidence.

25. The wide angle controllable directed reflector of claim 24, wherein said directed reflection controlling mechanism is designed and constructed to reciprocally alter said given relative orientation of, or said distance between, said lenticular layer and said reflective layer.

26. The wide angle controllable directed reflector of claim 24, wherein said angle of incidence on said lenticular layer ranges at least +/−

20 degrees from a normal angle of incidence.

27. A light modulating wide angle directed reflector comprising:

(a) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length;

(b) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence; and

(c) a light modulating layer being disposed relative to said lenticular layer and said reflective layer, said light modulating layer being for modulating light passing through and reflected from the light modulating wide angle directed reflector.

28. The light modulating wide angle directed reflector of claim 27, wherein said modulating layer is disposed between said lenticular layer and said reflective layer.

29. The light modulating wide angle directed reflector of claim 27, wherein said modulating layer forms a part of said reflective layer.

30. The light modulating wide angle directed reflector of claim 27, wherein said angle of incidence on said lenticular layer ranges at least +/−

20 degrees from a normal angle of incidence.

31. The light modulating wide angle directed reflector of claim 27, wherein said light modulating layer and said reflective layer are integrated into a single reflective and light modulating layer.

32. The light modulating wide angle directed reflector of claim 27, wherein said light modulating layer is selected from the group consisting of a light polarizing layer, a polarization fractional-wave retardation plate, an optical filter, and a patterned layer having substantially opaque regions and substantially transparent regions.

33. The light modulating wide angle directed reflector of claim 27, wherein said light modulating layer is disposed between said lenticular layer and said reflective layer.

34. The light modulating wide angle directed reflector of claim 27, wherein said light modulating layer is disposed in front of said lenticular layer.

35. The light modulating wide angle directed reflector of claim 27, wherein said light modulating layer includes a fluid.

36. The light modulating wide angle directed reflector of claim 32, wherein said patterned layer is a code identifying an object with which the light modulating wide angle directed reflector is associatable.

37. The light modulating wide angle directed reflector of claim 36, wherein said code is a bar-code.

38. The light modulating wide angle directed reflector of claim 27, wherein said light modulating layer is transformable from a first light modulating state to a second light modulating state and vice versa.

39. The light modulating wide angle directed reflector of claim 38, wherein said second light modulating state is neutral.

40. A light modulating wide angle directed reflector comprising:

(a) a lenticular layer including at least one array of lenslets;

(b) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence; and

(c) a light modulating layer being disposed relative to said lenticular layer and said reflective layer, said light modulating layer being for modulating light passing through and reflected from the light modulating wide angle directed reflector, said light modulating layer being transformable from a first light modulating state to a second light modulating state and vice versa.

41. The light modulating wide angle directed reflector of claim 40, wherein said angle of incidence on said lenticular layer ranges at least +/−

20 degrees from a normal angle of incidence.

42. An object identification system comprising:

(a) an identifier tag being mountable on an object to be identified, said identifier tag including;

(i) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length;

(ii) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence; and

(iii) a light modulating layer being disposed relative to said lenticular layer and said reflective layer, said light modulating layer being for modulating light passing through and reflected from the light modulating wide angle directed reflector; and

(b) an interrogator device including;

(i) a light source for directing light onto said identifier tag;

(ii) a light detector for receiving light reflected from said identifier tag, said light reflected being modulated by said light modulating layer; and

(iii) a processing unit communicating with said light detector for processing said light reflected so as to yield information corresponding to said light modulating layer, to thereby identify said object.

43. The object identification system of claim 42, wherein said angle of incidence on said lenticular layer ranges at least +/−

20 degrees from a normal angle of incidence.

44. The object identification system of claim 42, wherein said light modulating layer and said reflective layer are integrated into a single reflective and light modulating layer.

45. The object identification system of claim 42, wherein said light modulating layer is selected from the group consisting of a light polarizing layer, polarization modifying layer, an optical filter, and a patterned layer having substantially opaque regions and substantially transparent regions.

46. The object identification system of claim 42, wherein said light modulating layer is disposed between said lenticular layer and said reflective layer.

47. The object identification system of claim 42, wherein said light modulating layer is disposed in front of said lenticular layer.

48. The object identification system of claim 42, wherein said light modulating layer includes a fluid.

49. The object identification system of claim 45, wherein said patterned layer is a code identifying the object.

50. The object identification system of claim 49, wherein said code is a bar-code.

51. The object identification system of claim 42, wherein said light modulating layer is transformable from a first light modulating state to a second light modulating state and vice versa.

52. The object identification system of claim 42, wherein said second light modulating state is neutral.

53. A movement monitoring system for monitoring a movement of an object, the movement monitoring system comprising:

(a) at least one wide angle directed reflector being mountable on the object, said at least one wide angle directed reflector including;

(i) a lenticular layer including at least one array of lenslets, each of said lenslets having a focal length; and

(ii) a reflective layer being disposed relative to said lenticular layer, said lenticular layer and said reflective layer being constructed and designed such that light incident at an angle of incidence on said lenticular layer is reflected by said reflective layer and redirected through said lenticular layer at a substantially constant angle relative to said angle of incidence; and

(b) an optical sensing device, including;

(i) a light source for illuminating said at least one wide angle directed reflector; and

(ii) a detector for receiving light reflected from said at least one directed reflector and being for monitoring changes in a position of at least one diffraction lobe of said light, so as to monitor a movement of the object.

54. The movement monitoring system of claim 53, wherein said angle of incidence on said lenticular layer ranges at least +/−

20 degrees from a normal angle of incidence.

55. The movement monitoring system of claim 53, wherein said at least one-wide angle directed reflector further includes a light modulating layer being disposed relative to said lenticular layer and said reflective layer, said light modulating layer being for modulating light passing through and reflected from the light modulating wide angle directed reflector.

56. The movement monitoring system of claim 53, wherein said at least one wide angle directed reflector includes a plurality of wide angle directed reflectors spaced along the object.

57. The movement monitoring system of claim 53, wherein said at least one wide angle directed reflector is a retroreflector.

58. The movement monitoring system of claim 53, wherein said movement is a vibrational movement.

59. The movement monitoring system of claim 53, wherein the object is an aircraft wing.