Diffractive Optical Device and System

• US 20090097122A1
• Filed: 09/07/2006
• Published: 04/16/2009
• Est. Priority Date: 09/14/2005
• Status: Abandoned Application

• Current Assignee: Mirage Innovations Limited
• Original Assignee: Mirage Innovations Limited
• Inventors: Niv, Yehuda
• Application Number:
  US11/991,491
• Publication Number:
  US 20090097122A1
• Time in Patent Office: Days
• US Class Current: 359/575
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/4272 having plural diffractive elements positioned sequentially along the optical path
• CPC Class Codes: G02B 5/1866 Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/2848 having refractive means, e.g. imaging elements between light guides as splitting, branching and/or combining devices, e.g. lenses, holograms

Abstract

An optical relay device for transmitting light striking the optical relay device at a plurality of angles within a field-of-view is provided. The device comprises a light-transmissive substrate, an input optical element and an output optical element. The input element diffracts the light to propagate within the light-transmissive substrate via total internal reflection, and the output element diffracts the light out of the substrate. The output element is characterized by planar dimensions selected such that at least a portion of one or more outermost light rays within the field-of-view is directed to a two-dimensional region being at a predetermined distance from the substrate.

Claims

1. An optical relay device for transmitting light striking the optical relay device at a plurality of angles within a field-of-view, the device comprising:

a light-transmissive substrate engaging a plane spanned by a longitudinal direction and a transverse direction;

an input optical element designed and constructed for redirecting the light such that the light propagates within said light-transmissive substrate via total internal reflection; and

an output optical element, laterally displaced from said input optical element, and being designed and constructed for redirecting the light out of said light-transmissive substrate;

said output optical element being characterized by planar dimensions defined by a length along said longitudinal direction and a width along said transverse direction, wherein said length and said width are selected such that at least a portion of at least one outermost light ray within the field-of-view is directed to a predetermined two-dimensional region characterized by a predetermined length L_EB along said longitudinal direction and a predetermined width W_EB along said transverse direction, and being at a predetermined distance from said light transmissive substrate.

2. The device of claim 1, wherein said predetermined distance is from about 15 millimeters to about 35 millimeters.

3. The device of claim 2, wherein said W_EB is from about 4 millimeters to about 9 millimeters.

4. The device of claim 2, wherein said L_EB is from about 5 millimeters to about 13 millimeters.

5. The device of claim 1, wherein said width of said output optical element is smaller than a width of said input optical element.

6. The device of claim 1, wherein at least one of said input optical element and said output optical element is a diffractive optical element.

26. The device of claim 1, wherein a length of said input optical element equals from about X to about 3X where X is a minimal unit hop-length characterizing propagation of an outermost light ray within said light transmissive substrate via total internal reflection.

27. The device of claim 1, wherein the light is characterized by a spectrum inclusively defined between a shortest wavelength and a longest wavelength.

28. The device of claim 27, wherein a length of said input optical element equals from about X to about 3X where X is a unit hop-length characterizing propagation of a light ray having said shortest wavelength within said light transmissive substrate via total internal reflection.

30. The device of claim 6, wherein at least one diffractive optical element comprises a grating described by non-uniform diffraction efficiency function.

31. The device of claim 30, wherein said grating has a periodic linear structure in at least one direction, said periodic linear structure being characterized by non-uniform duty cycle.

32. The device of claim 30, wherein said grating has a periodic linear structure in at least one direction, said periodic linear structure being characterized by non-uniform modulation depth.

33. The device of claim 30, wherein said grating has a periodic linear structure in at least one direction, said periodic linear structure being characterized by non-uniform duty cycle and non-uniform modulation depth.

34. The device of claim 31, wherein said non-uniform diffraction efficiency function is monotonic across said at least one direction.

35. The device of claim 30, wherein said non-uniform diffraction efficiency function is selected such that when a light ray impinges on said grating a plurality of times, a predetermined and substantially constant fraction of the energy of said light is diffracted at each impingement.

36. The device of claim 30, wherein said grating is formed in said light transmissive substrate.

37. The device of claim 30, wherein said grating is attached to said light transmissive substrate.

7. An optical relay device for transmitting light striking the optical relay device at a plurality of angles within a field-of-view, the device comprising:

a light-transmissive substrate engaging a plane spanned by a longitudinal direction and a transverse direction;

an input optical element designed and constructed for redirecting the light such that the light propagates within said light-transmissive substrate via total internal reflection;

a first output optical element, laterally displaced from said input optical element, and being designed and constructed for redirecting light corresponding to a first partial field-of-view out of said light-transmissive substrate; and

a second output optical element, laterally displaced from said input optical element and said first output optical element, and being designed and constructed for redirecting light corresponding to a second partial field-of-view out of said light-transmissive substrate;

each of said first and said second output optical elements being characterized by planar dimensions defined by a length along said longitudinal direction and a width along said transverse direction, wherein a length and a width of said first output optical element are selected such that at least a portion of at least one outermost light ray within said first partial field-of-view is directed to a first two-dimensional region, and a length and a width of said second output optical element are selected such that at least a portion of at least one outermost light ray within said second partial field-of-view is directed to a second two-dimensional region, each of said first and said second two-dimensional regions being characterized by a predetermined length L_EB along said longitudinal direction and a predetermined width W_EB along said transverse direction, and being at a predetermined distance from said light transmissive substrate.

8. A system for providing an image to a user, comprising the optical relay device of claim 7, and an image generating system for providing said optical relay device with collimated light constituting said image.

9. The device of claim 7, wherein a lateral separation between the centers of said first two-dimensional region and said second two-dimensional region is at least 40 millimeters.

10. The device of claim 9, wherein said lateral separation is less than 80 millimeters.

11. The device of claim 9, wherein said planar dimensions are selected such that said portions of said outermost light rays are respectively directed to said first and said second two-dimensional regions, for any lateral separation which is larger than 40 millimeters and smaller than 80 millimeters.

12. The device of claim 9, wherein said planar dimensions are selected such that said portions of said outermost light rays are respectively directed to said first and said second two-dimensional regions, for any lateral separation which is larger than 50 millimeters and smaller than 65 millimeters.

13. The device of claim 9, wherein said planar dimensions are selected such that said portions of said outermost light rays are respectively directed to said first and said second two-dimensional regions, for any lateral separation which is larger than 53 millimeters and smaller than 73 millimeters.

14. The device of claim 9, wherein said planar dimensions are selected such that said portions of said outermost light rays are respectively directed to said first and said second two-dimensional regions, for any lateral separation which is larger than 53 millimeters and smaller than 63 millimeters.

15. The device of claim 9, wherein said planar dimensions are selected such that said portions of said outermost light rays are respectively directed to said first and said second two-dimensional regions, for any lateral separation which is larger than 58 millimeters and smaller than 68 millimeters.

16. The device of claim 9, wherein said planar dimensions are selected such that said portions of said outermost light rays are respectively directed to said first and said second two-dimensional regions, for any lateral separation which is larger than 63 millimeters and smaller than 73 millimeters.

17. The device of claim 7, wherein each of said width of said first output optical element and said width of said second output optical element is smaller than a width of said input optical element.

23. The device of claim 7, wherein said predetermined distance is from about 15 millimeters to about 35 millimeters.

24. The device of claim 23, wherein said width W_EB of each of said first two-dimensional region and said second two-dimensional region is from about 4 millimeters to about 9 millimeters.

25. The device of claim 23, wherein said length L_EB of each of said first two-dimensional region and said second two-dimensional region is from about 5 millimeters to about 13 millimeters.

29. The device of claim 7, wherein at least one of said input optical element, said first output optical element and said second output optical element is a diffractive optical element.

18. An optical relay device for transmitting an image by diffraction to a first eye and a second eye characterized by an interpupillary distance, the device comprising a light transmissive substrate and a plurality of diffractive optical elements located at fixed locations on said light transmissive substrate, the optical relay device being characterized by a field-of-view of at least 16 degrees, and being capable of providing the image for any interpupillary distance from about 40 millimeters to about 80 millimeters.

19. A system for providing an image to a user, comprising the optical relay device of claim 18, and an image generating system for providing said optical relay device with collimated light constituting said image.

20. The device of claim 18, wherein said plurality of diffractive optical elements comprises an input diffractive optical element, a first output diffractive optical element and a second output diffractive optical element, said input diffractive optical element being designed and constructed for diffracting light constituting the image to propagate within said light-transmissive substrate via total internal reflection, and said output diffractive optical elements being designed and constructed for diffracting at least a portion of said light out of said light transmissive substrate.

21. The device of claim 20, wherein said first output diffractive optical element is designed and constructed for diffracting light corresponding to a first partial field-of-view of the image out of said light-transmissive substrate, and said second output diffractive optical element is designed and constructed for diffracting light corresponding to a second partial field-of-view of the image out of said light-transmissive substrate, such that the combination of said first and said second partial field-of-views substantially reconstructs said field-of-view.

22. The device of claim 20, wherein said first and said second diffractive optical elements are characterized by planar dimensions selected such that at least a portion of at least one outermost light ray within said first partial field-of-view is directed to a first two-dimensional region containing the first eye, and at least a portion of at least one outermost light ray within said second partial field-of-view is directed to a second two-dimensional region containing the second eye, each of said first and said second two-dimensional regions being characterized by a predetermined length L_EB along said longitudinal direction and a predetermined width W_EB along said transverse direction, and being at a predetermined distance from said light transmissive substrate.

38. An optical relay device for transmitting light striking the optical relay device at a plurality of angles within a field-of-view, the device comprising:

a light-transmissive substrate engaging a plane spanned by a longitudinal direction and a transverse direction;

an input optical element designed and constructed for redirecting the light such that the light propagates within the light-transmissive substrate via total internal reflection; and

at least one output optical element, laterally displaced from said input optical element, and being designed and constructed for redirecting the light out of said light-transmissive substrate;

each of said input optical element and said at least one output optical element being characterized by planar dimensions defined by a length along said longitudinal direction and a width along said transverse direction, wherein a width of said at least one output optical element is smaller than a width of said input optical element.