Waveguide illuminator

Abstract

An optical system for an augmented reality head-mounted display eyepiece, the optical system being configured to deliver an image to an eye, wherein the optical system comprises an optical device. The optical device is configured to receive light output from a light source. The optical device is further arranged relative to a spatial light modulator so that the light received from the light source propagates through the optical device and illuminates the spatial light modulator. The light illuminating the spatial light modulator is redirected back through the optical device and coupled into at least one waveguide through at least one coupling optical element. At least a portion of the coupled light is emitted from at least one waveguide through at least one coupling optical element and directed to the user's eye.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Serial No. 62 / 597,359, filed on December 11, 2017, entitled “WAVEGUIDE ILLUMINATOR,” and U.S. Provisional Patent Application Serial No. 62 / 624,109, filed on January 30, 2018, entitled “WAVEGUIDE ILLUMINATOR,” the entire disclosure of each of the above applications is hereby incorporated by reference into this document.

[0003] Incorporation by Reference

[0004] This application incorporates by reference the entire contents of each of the following patent applications: U.S. Serial No. 14 / 555,585, filed on November 27, 2014, published as U.S. Serial No. 2015 / 0205126, published on July 23, 2015; U.S. Serial No. 14 / 690,401, filed on April 18, 2015, published as U.S. Serial No. 2015 / 0302652, published on October 22, 2015; U.S. application serial number 14 / 212,961, filed on March 14, 2014, now U.S. Patent Serial Number 9,417,452, published on August 16, 2016; U.S. application serial number 14 / 331,218, filed on July 14, 2014, now U.S. published serial number 2015 / 0309263, published on October 29, 2015; and U.S. Provisional Application Serial Number 62 / 597,359, filed on December 11, 2017. Technical Field

[0005] The present disclosure relates to display systems having common optics for both spatial light modulator illumination and image projection. Background Art

[0006] Modern computing and display technologies have facilitated the development of systems for so-called "virtual reality" or "augmented reality" experiences, in which digitally reproduced images, or portions thereof, are presented to a user in a manner that appears real or can be perceived as real. Virtual reality or "VR" scenes typically involve the presentation of digital or virtual image information that is opaque to other actual real-world visual input; augmented reality or "AR" scenes typically involve the presentation of digital or virtual image information as an enhancement of a visualization of the actual world around the user. Mixed reality or "MR" scenes are AR-type scenes and typically involve virtual objects that are integrated into and responsive to the natural world. For example, an MR scene may include AR image content that appears to be obscured by objects in the real world or is otherwise perceived to interact with objects in the real world.

[0007] refer to Figure 1 , depicting an augmented reality scene 10. A user of AR technology sees a real-world park-like setting 20, which features people, trees, buildings in the background, and a concrete platform 30. The user also perceives that he / she "sees" "virtual content," such as a robotic statue 40 standing on the real-world platform 30, and a flying cartoon-like avatar character 50 that appears to be an avatar of a bumblebee. These elements 50, 40 are "virtual" because they do not exist in the real world. Because the human visual perception system is complex, it is extremely challenging to produce AR technology that helps virtual image elements to be comfortable, natural, and richly presented among other virtual or real-world image elements.

[0008] The systems and methods disclosed herein address various challenges associated with AR and VR technologies.

[0009] Polarizing beam splitters may be used in display systems to direct polarized light to a light modulator, which then directs the light to a viewer. In general, there is a continuing desire to reduce the size of display systems, and therefore the size of components of display systems, including components utilizing polarizing beam splitters. Summary of the invention

[0010] The systems, methods and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0011] Details of one or more embodiments of the subject matter described in this specification are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. It is noted that the relative sizes of the following drawings may not be drawn to scale.

[0012] Various examples of head-mounted display systems with common optics for both spatial light modulator illumination and image projection are described herein.

[0013] Example:

[0014] 1. A head mounted display system configured to project light into eyes of a user to display augmented reality image content in the user's field of view, the head mounted display system comprising:

[0015] a frame configured to be supported on the user's head;

[0016] at least one light source configured to output light;

[0017] a spatial light modulator configured to receive light from the at least one light source;

[0018] an eyepiece disposed on the frame, the eyepiece being configured to direct light from the spatial light modulator into an eye of the user to display augmented display image content to the user's field of view, at least a portion of the eyepiece being transparent and disposed at a position in front of the user's eye when the user wears the head mounted display, wherein the transparent portion transmits light from a portion of the physical environment in front of the user toward the user's eye to provide a view of the portion of the physical environment in front of the user, the eyepiece comprising:

[0019] (a) at least one waveguide;

[0020] (b) at least one in-coupling optical element configured to couple light from the spatial light modulator into the at least one waveguide; and

[0021] (c) at least one out-coupling optical element configured to couple light guided within the waveguide out of the waveguide and direct the light toward an eye of the user; and

[0022] an optical device having an optical power, the optical device being arranged to receive light output from the light source, the optical device being arranged relative to the spatial light modulator such that the light received from the light source propagates through the optical device and illuminates the spatial light modulator,

[0023] Wherein, the head-mounted display system is configured so that the light irradiating the spatial light modulator is redirected back through the optical device and coupled into the at least one waveguide through the at least one coupling-in optical element, and at least a portion of the coupled light is emitted from the at least one waveguide through the at least one coupling-out optical element and guided to the user's eyes.

[0024] 2. A head-mounted display system according to Example 1, wherein the at least one light source includes a multi-color light source configured to emit different colors of light at different times.

[0025] 3. A head-mounted display system according to any of the above examples, wherein the at least one light source includes a red-green-blue (RGB) light source configured to emit red, green, and blue light at different times.

[0026] 4. A head-mounted display system according to any of the above examples, wherein the at least one light source includes a cyan, magenta, and yellow (CMY) light source configured to emit cyan, magenta, and yellow light at different times.

[0027] 5. The head mounted display system according to any of the above examples, comprising:

[0028] a plurality of laterally displaced light emitters configured to output light;

[0029] light collecting optics configured to collect light from the plurality of light emitters;

[0030] Diffuser; and

[0031] A plurality of holes are adjacent to the diffuser.

[0032] 6. The head-mounted display system according to any of the above examples further includes a coupling optical device, which is arranged relative to the light emitter to collect light output from the light source.

[0033] 7. A head-mounted display system according to Example 6, wherein the coupling optical device includes a compound parabolic concentrator (CPC).

[0034] 8. A head-mounted display system according to any of the above examples, wherein the spatial light modulator comprises a reflective spatial light modulator.

[0035] 9. A head-mounted display system according to any of the above examples, wherein the spatial light modulator comprises a liquid crystal spatial light modulator.

[0036] 10. A head-mounted display system according to any of the above examples, wherein the spatial light modulator comprises a vertically aligned liquid crystal spatial light modulator.

[0037] 11. A head-mounted display system according to any of the above examples, wherein the spatial light modulator includes a deflection-based spatial light modulator.

[0038] 12. A head-mounted display system according to any of the above examples, wherein the spatial light modulator includes a movable mirror array.

[0039] 13. The head-mounted display system according to any of the above examples further includes a light absorber, so that in a closed state, light is guided to the light absorber by the movable reflector array, and in an open state, light is guided to the corresponding coupling optical element.

[0040] 14. A head-mounted display system according to any of the above examples, wherein the at least one waveguide includes a material that is transparent to visible light and has a refractive index sufficient to guide light in the waveguide by total internal reflection.

[0041] 15. A head-mounted display system according to any of the above examples, wherein the at least one waveguide comprises a waveguide stack.

[0042] 16. A head-mounted display system according to Example 15, wherein different waveguides in the waveguide stack are configured to output light having different corresponding colors.

[0043] 17. A head-mounted display system according to Example 15 or 16, wherein the first waveguide, the second waveguide, and the third waveguide in the waveguide stack are configured to output a first color light, a second color light, and a third color light, respectively, and the first color light, the second color light, and the third color light are red light, blue light, and green light, respectively.

[0044] 18. A head-mounted display system according to any of Examples 15 to 16, wherein different waveguides in the waveguide stack are configured to output light with different wavefronts, and the light with different wavefronts has at least one of different divergence, convergence, and collimation amounts, as if projected from different distances from the user's eyes.

[0045] 19. A head-mounted display system according to any of the above examples, wherein at least one waveguide is configured to couple in light of a specific polarization.

[0046] 20. A head-mounted display system according to any of the above examples, wherein the coupling optical element includes at least one of a diffractive optical element and a reflector.

[0047] 21. A head-mounted display system according to any of the above examples, wherein the at least one coupling-in optical element includes a plurality of color-selective coupling-in optical elements configured to couple in different corresponding colors.

[0048] 22. A head-mounted display system according to Example 21, wherein the multiple coupling optical elements include a first coupling optical element and a second coupling optical element, and the second coupling optical element is arranged above the first coupling optical element so that light of a first color can be coupled into a first waveguide by the first coupling optical element to be guided therein, and light of a second color different from the first color can propagate through the first coupling optical element to reach the second coupling optical element, and can be coupled into a second waveguide by the second coupling optical element to be guided therein.

[0049] 23. A head-mounted display system according to Example 22, wherein the multiple coupling optical elements include a third coupling optical element, which is arranged above the first coupling optical element and the second coupling optical element so that light of a third color different from the first color and the second color can propagate through the first coupling optical element and the second coupling optical element to reach the third coupling optical element, and can be coupled into a third waveguide to be guided therein.

[0050] 24. A head-mounted display system according to Example 23, wherein the first color includes one of red, green, and blue, wherein the second color includes one of red, green, and blue different from the first color, and wherein the third color includes one of red, green, or blue different from the first color and the second color.

[0051] 25. A head-mounted display system according to any of the above examples, wherein the at least one coupling optical element includes a coupling optical element configured to couple light of multiple colors into a waveguide of the at least one waveguide to guide the light therein.

[0052] 26. A head-mounted display system according to any of the above examples, wherein the at least one light source includes a light source arranged relative to the optical device and the spatial light modulator to guide light to the coupling optical element configured to couple multiple colors of light into a waveguide in the at least one waveguide, and the light source is configured to emit different colors of light at different times.

[0053] 27. A head-mounted display system according to any of the above examples, wherein the at least one coupling optical element includes a coupling optical element configured to couple red light, green light, and blue light into a waveguide of the at least one waveguide to guide the light therein.

[0054] 28. A head-mounted display system according to any of the above examples, wherein the at least one coupling optical element is configured to couple in light of a predetermined polarization.

[0055] 29. A head-mounted display system according to any of the above examples, wherein the at least one coupling-in optical element includes a plurality of coupling-in optical elements that are laterally shifted relative to each other.

[0056] 30. A head-mounted display system according to Example 29, wherein the multiple coupling optical elements include a first coupling optical element configured to couple light of multiple colors into a first waveguide of the at least one waveguide to guide the light therein, and a second coupling optical element configured to couple light of multiple colors into a second waveguide of the at least one waveguide to guide the light therein, and the first coupling optical element and the second coupling optical element are laterally shifted relative to each other.

[0057] 31. A head-mounted display system according to Example 29 or 30, wherein the at least one light source includes a first light source arranged relative to the optical device and the spatial light modulator to guide light to the first coupling optical element and a second light source arranged relative to the optical device and the spatial light modulator to guide light to the second coupling optical element.

[0058] 32. A head-mounted display system according to Example 30, wherein the at least one light source includes a first light source arranged relative to the optical device and the spatial light modulator to guide light into the first coupling optical element, and the first light source is configured to emit different colors of light at different times.

[0059] 33. A head-mounted display system according to Example 32, wherein the at least one light source includes a second light source arranged relative to the optical device and the spatial light modulator to guide light into the second coupling optical element, and the second light source is configured to emit different colors of light at different times.

[0060] 34. A head-mounted display system according to Example 33, wherein the eyepiece is configured so that light coupled out of the first waveguide and light coupled out of the second waveguide have different amounts of convergence, divergence, and at least one of collimation, and thus appear to originate from different depth planes.

[0061] 35. A head-mounted display system according to any one of Examples 31 to 34, wherein the eyepiece is configured so that light coupled out of the first waveguide is collimated and light output from the second waveguide is divergent.

[0062] 36. A head-mounted display system according to any one of Examples 31 to 34, wherein the eyepiece is configured so that light coupled out of the first waveguide diverges a first amount, and light coupled out of the second waveguide diverges a second amount, wherein the second amount is different from the first amount.

[0063] 37. A head-mounted display system according to any of the above examples, wherein the at least one coupling optical element includes a coupling optical element configured to couple red light, green light, and blue light into a waveguide to guide the light therein.

[0064] 38. A head-mounted display system according to any of the above examples, wherein the at least one light source includes a light source arranged relative to the optical device and the spatial light modulator to guide light into the at least one coupling optical element, the at least one coupling optical element is configured to couple red light, green light, and blue light into a waveguide of the at least one waveguide, and the at least one light source is configured to emit different red light, green light, and blue light at different times.

[0065] 39. A head-mounted display system according to Example 31, wherein the first light source is a first color light source and the second light source is a second color light source having a color different from the first color.

[0066] 40. A head-mounted display system according to Example 39, wherein the first light source is a red light source and the second color light source is one of a green light source and a blue light source.

[0067] 41. A head-mounted display system according to any of the above examples, wherein the at least one coupling optical element includes multiple coupling optical element groups, each group includes multiple color-selective coupling optical elements configured to couple different corresponding colors, and each group in the multiple groups is laterally shifted relative to each other.

[0068] 42. A head-mounted display system according to Example 41, wherein the multiple coupling optical elements include a first coupling optical element and a second coupling optical element, and the second coupling optical element is arranged above the first coupling optical element so that light of a first color can be coupled into a first waveguide by the first coupling optical element to be guided therein, and light of a second color different from the first color can propagate through the first coupling optical element to reach the second coupling optical element, and can be coupled into a second waveguide by the second coupling optical element to be guided therein.

[0069] 43. A system according to Example 42, wherein the multiple coupling optical elements include a third coupling optical element, which is arranged above the second coupling optical element so that a third color different from the first color and the second color can propagate through the first coupling optical element and the second coupling optical element to reach the third coupling optical element and can be coupled into a third waveguide to be guided therein.

[0070] 44. A head-mounted display system according to Example 43, wherein the first color includes one of red, green, and blue, wherein the second color includes one of red, green, and blue different from the first color, and wherein the third color includes one of red, green, or blue different from the first color and the second color.

[0071] 45. A head-mounted display system according to any of the above examples, wherein the at least one coupling optical element includes a first coupling optical element group and a second coupling optical element group, the first coupling optical element group includes a plurality of color-selective coupling optical elements configured to couple different corresponding colors, the second coupling optical element group includes a plurality of color-selective coupling optical elements configured to couple different corresponding colors, and the first group and the second group are laterally shifted relative to each other.

[0072] 46. ​​A head-mounted display system according to Example 45, wherein the first plurality of coupling optical elements includes a first coupling optical element and a second coupling optical element, and the second coupling optical element is arranged above the first coupling optical element so that light of a first color can be coupled into a first waveguide by the first coupling optical element to be guided therein, and a second color different from the first color can propagate through the first coupling optical element to reach the second coupling optical element, and can be coupled into a second waveguide by the second coupling optical element to be guided therein.

[0073] 47. A head-mounted display system according to Example 46, wherein the first plurality of coupling optical elements includes a third coupling optical element, which is arranged above the first coupling optical element and the second coupling optical element so that a third color different from the first color and the second color can propagate through the first coupling optical element and the second coupling optical element to reach the third coupling optical element and can be coupled into a third waveguide to be guided therein.

[0074] 48. A head-mounted display system according to Example 47, wherein the first color includes one of red, green, and blue, wherein the second color includes one of red, green, and blue different from the first color, and wherein the third color includes one of red, green, or blue different from the first color and the second color.

[0075] 49. A head-mounted display system according to Example 48, wherein the second plurality of coupling optical elements includes a fourth coupling optical element and a fifth coupling optical element, the fifth coupling optical element being disposed above the fourth coupling optical element so that light of a fourth color can be coupled into a fourth waveguide by the fourth coupling optical element to be guided therein, and a fifth color different from the first color can propagate through the fourth coupling optical element to reach the fifth coupling optical element, and can be coupled into the fifth waveguide by the second coupling optical element to be guided therein.

[0076] 50. A head-mounted display system according to Example 49, wherein the second plurality of coupling optical elements includes a sixth coupling optical element, which is arranged above the fourth coupling optical element and the fifth coupling optical element so that a sixth color different from the first color and the second color can propagate through the fourth coupling optical element and the fifth coupling optical element to reach the sixth coupling optical element and can be coupled into a sixth waveguide to be guided therein.

[0077] 51. A head-mounted display system according to Example 50, wherein the eyepiece is configured so that light coupled out of the first waveguide, the second waveguide, and the third waveguide has at least one of a different amount of convergence, divergence, and collimation than light coupled out of the fourth waveguide, the fifth waveguide, and the sixth waveguide, and thus appears to originate from a different depth than light output from the fourth waveguide, the fifth waveguide, and the sixth waveguide.

[0078] 52. A head-mounted display system according to Example 51, wherein the eyepiece is configured so that light coupled out from the first waveguide, the second waveguide, and the third waveguide is collimated, and light output from the fourth waveguide, the fifth waveguide, and the sixth waveguide is divergent.

[0079] 53. A head-mounted display system according to Example 52, wherein the eyepiece is configured so that light coupled out of the first waveguide, the second waveguide, and the third waveguide diverges, and light output from the fourth waveguide, the fifth waveguide, and the sixth waveguide diverges by different amounts.

[0080] 54. A head-mounted display system according to any one of Examples 45 to 53, wherein the at least one light source includes a first light source arranged relative to the optical device and the spatial light modulator to guide light into the first coupling optical element group, and the first light source is configured to emit different colors of light at different times.

[0081] 55. A head-mounted display system according to any one of Examples 45 to 54, wherein the at least one light source includes a second light source arranged relative to the optical device and the spatial light modulator to direct light to the second coupling optical element group, and the second light source is also configured to emit different colors of light at different times.

[0082] 56. A head-mounted display system according to any of the above examples, wherein the at least one out-coupling optical element comprises a diffractive optical element.

[0083] 57. A head-mounted display system according to any of the above examples, wherein the at least one outcoupling element is configured to increase the size of the eye movement range along at least one first axis.

[0084] 58. The head-mounted display system of Example 57 further comprises an orthogonal pupil expander, the orthogonal pupil expander comprising at least one light redirection element in or on the at least one waveguide, the at least one light redirection element being configured to increase the size of the eye movement range along a second axis orthogonal to the at least one first axis.

[0085] 59. A head-mounted display system according to Example 58, wherein the at least one light redirection element comprises a diffractive optical element.

[0086] 60. A head-mounted display system according to any of the above examples, wherein at least a portion of the at least one waveguide extends between the at least one light source and the optical device, and light from the at least one light source guided through the optical device propagates through the portion of the at least one waveguide to reach the optical device.

[0087] 61. A head-mounted display system according to any of the above examples, wherein the at least one waveguide has a first side and a second side opposite to the first side, and the optical device and the spatial light modulator are arranged on the first side so that light from the spatial light modulator is guided to the first side.

[0088] 62. A head-mounted display system according to Example 61, wherein the at least one light source is disposed on the first side so that light from the at least one light source is incident on the first side before propagating through the optical device to reach the spatial light modulator.

[0089] 63. A head-mounted display system according to Example 61, wherein the at least one light source is disposed on the second side so that light from the at least one light source is incident on the second side before propagating through the optical device to reach the spatial light modulator.

[0090] 64. A head-mounted display system according to Example 63, wherein the at least one waveguide is disposed between the at least one light source and the optical device.

[0091] 65. The head-mounted display system according to any of the above examples further includes a light source coupling optical element, which is arranged relative to a portion of the at least one waveguide adjacent to the at least one light source so as to receive light from the at least one light source and couple the light from the at least one light source into the portion of the at least one waveguide to be guided therein.

[0092] 66. The system of Example 65 further comprises an out-coupling optical element relative to the portion of the light source adjacent to the at least one waveguide, configured to direct light guided in the portion of the at least one waveguide out of the portion of the at least one waveguide, through the optical device and to the spatial light modulator.

[0093] 67. A head-mounted display system according to Example 66, wherein the head-mounted display system is configured so that at least a portion of the light coupled into the optical device from the portion of the at least one waveguide adjacent to the at least one light source is incident on the spatial light modulator, propagates through the optical device again, is incident on a second portion of the at least one waveguide, is again guided therein, is coupled out therefrom and is guided to the user's eyes.

[0094] 68. The head-mounted display system of any one of Examples 65 to 67, further comprising an isolator to reduce crosstalk from the portion of the at least one waveguide adjacent to the light source to the second portion of the at least one waveguide.

[0095] 69. A head-mounted display system according to Example 68, wherein the isolator comprises one of an opaque surface and a reflective surface.

[0096] 70. The system of Example 58, wherein the isolator is disposed in at least one of the waveguides.

[0097] 71. A head-mounted display system according to any one of Examples 65 to 70, wherein the at least one waveguide has a first side and a second side opposite to the first side, and the optical device and the spatial light modulator are arranged on the first side of the at least one waveguide.

[0098] 72. A head-mounted display system according to Example 71, wherein the at least one light source is disposed on the first side of the at least one waveguide so that light from the at least one light source is incident on the first side of the at least one waveguide to be guided therein, and the light guided in the portion of the at least one waveguide is coupled out from the first side of the at least one waveguide and reaches the optical device and the spatial light modulator located on the first side.

[0099] 73. A head-mounted display system according to Example 71, wherein the at least one light source is disposed on the second side of the at least one waveguide so that light from the at least one light source is incident on the second side of the at least one waveguide before propagating through the optical device to reach the spatial light modulator.

[0100] 74. A head-mounted display system according to Example 71 or 73, wherein the at least one waveguide is disposed between the at least one light source and the optical device.

[0101] 75. The head-mounted display system according to any of the above examples further includes at least one waveguide, which is optically coupled to the at least one light source to receive light from the at least one light source to guide the light from the at least one light source therein, and couple the light guided therein into the optical device, so that at least a portion of the light coupled into the optical device from the at least one waveguide is incident on the spatial light modulator, propagates through the optical device again and is incident on the at least one waveguide, is guided therein, is coupled out therefrom and is guided to the user's eyes.

[0102] 76. The head-mounted display system according to Example 75 further includes a coupling element, which is arranged on the at least one waveguide to receive light from the light source and couple the light from the light source into the at least one waveguide to be guided therein.

[0103] 77. The head-mounted display system according to Example 76 further includes a coupling element, which is arranged on the at least one waveguide to receive the light guided in the at least one waveguide from the light source, and couple the light guided in the at least one waveguide out of the at least one waveguide and reach the spatial light modulator through the optical device.

[0104] 78. The head-mounted display system of any one of Examples 75 to 77, further comprising an isolator to reduce crosstalk between the at least one waveguide and the at least one waveguide.

[0105] 79. A head-mounted display system according to Example 78, wherein the isolator includes at least one of an opaque surface and a reflective surface.

[0106] 80. A head-mounted display system according to Example 78 or 79, wherein the isolator is disposed in or on the at least one waveguide.

[0107] 81. A head-mounted display system according to any one of Examples 75 to 80, wherein the at least one waveguide has a first side and a second side opposite to the first side, and the optical device and the spatial light modulator are arranged on the first side of the at least one waveguide.

[0108] 82. A head-mounted display system according to Example 81, wherein the at least one light source is disposed on the first side of the at least one waveguide so that light from the at least one light source is incident on the first side of the at least one waveguide to be guided therein, and the light guided in the at least one waveguide is coupled out of the first side of the at least one waveguide to reach the optical device and the spatial light modulator on the first side.

[0109] 83. A head-mounted display system according to Example 81, wherein the at least one light source is disposed on the second side of the at least one waveguide so that light from the at least one light source is incident on the second side of the at least one waveguide to guide the light therein, and the light guided in the at least one light guide is coupled out of the first side of the at least one waveguide to reach the optical device and the spatial light modulator on the first side.

[0110] 84. A head-mounted display system according to Example 81 or 83, wherein the at least one waveguide is disposed between the at least one light source and the optical device.

[0111] 85. A head-mounted display system according to any of the above examples, wherein the optical device includes one or more lenses.

[0112] 86. A head-mounted display system according to any of the above examples, wherein the optical device includes multiple lenses.

[0113] 87. A head-mounted display system according to any of the above examples, wherein the optical device has positive optical power.

[0114] 88. A head-mounted display system according to any of the above examples, wherein the optical device includes one or more refractive optical elements.

[0115] 89. A head-mounted display system according to any of the above examples, wherein the spatial light modulator is configured to modulate polarization.

[0116] 90. The head-mounted display system according to any of the above examples further includes a polarizer located in the optical path between the spatial light modulator and the user's eyes.

[0117] 91. A head-mounted display system according to Example 90, wherein the polarizer is arranged in the optical path between the optical device and the at least one coupling optical element.

[0118] 92. The head-mounted display system according to any of the above examples further includes a polarizer, which is arranged between the at least one light source and the spatial light modulator.

[0119] 93. A head-mounted display system according to any of the above examples, wherein the at least one light source includes a polarized light source.

[0120] 94. A head-mounted display system according to any of the above examples, wherein the polarizer is arranged between the optical device and the spatial light modulator.

[0121] 95. A head-mounted display system according to Example 94, wherein the polarizer is directly disposed on the spatial light modulator.

[0122] 96. A head-mounted display system according to any of the above examples, wherein the polarizer comprises a wire grid polarizer.

[0123] 97. A head-mounted display system according to Example 90, wherein the polarizer is a circular polarizer.

[0124] 98. The head-mounted display system according to any of the above examples further includes a variable optical element with adjustable optical focal length.

[0125] 99. A head-mounted display system according to Example 98, wherein the variable optical element includes a lens or a mirror.

[0126] 100. A head-mounted display system according to Example 98 or 99, wherein the variable optical element is configured to have a first state and a second state, wherein in the first state, the variable optical element has an optical focal length that is different from that in the second state.

[0127] 101. A head-mounted display system according to Example 100, wherein the variable optical element has a negative optical power in the first state and has a zero optical power in the second state.

[0128] 102. A head-mounted display system according to Example 100, wherein the variable optical element has positive optical power in the first state and has zero optical power in the second state.

[0129] 103. A head-mounted display system according to Example 100, wherein the variable optical element has a first negative optical focal length in the first state and a different second negative optical focal length in the second state.

[0130] 104. A head-mounted display system according to Example 100, wherein the variable optical element has a first positive optical power in the first state and a different second positive optical power in the second state.

[0131] 105. A head-mounted display system according to Example 100, wherein the variable optical element has a first negative optical focal length in the first state and a second positive optical focal length in the second state.

[0132] 106. A head-mounted display system according to Example 98, wherein the variable optical element includes a liquid lens.

[0133] 107. The head-mounted display system according to any of the above examples further includes an adjustable dimmer, which includes an optical element that provides variable attenuation of light transmitted through it.

[0134] 108. The head-mounted display system according to any of the above examples further includes a prescription lens configured to provide refractive correction for the user's eyes.

[0135] 109. The head-mounted display system according to any of the above examples further includes a static lens arranged in a path between the at least one waveguide and the user's eyes.

[0136] 110. A head-mounted display system according to Example 91, wherein the polarizer is configured to also function as a polarizer to allow light to propagate from the light source toward the optical device.

[0137] 111. The head-mounted display system according to any of the above examples further includes a color filter array, which is arranged on the side of the waveguide adjacent to the user, wherein the color filter array includes multiple different color filters.

[0138] 112. A head-mounted display system according to Example 111, wherein the color filter array includes an absorptive material disposed between the color filters, which is configured to reduce the propagation and reflection of stray light.

[0139] 113. A head-mounted display system according to any of the above examples, wherein a polarizer can be arranged in the optical path of the light source and is configured to transmit light of a first polarization and reflect light of a second polarization, wherein a portion of the reflected light of the second polarization is directed toward the light source to obtain the first polarization.

[0140] 114. A head-mounted display system according to Example 113, wherein a portion of the reflected light of the second polarization that is directed toward the light source obtains the first polarization by reflecting from a coupling optical device configured to collect light from the light source.

[0141] 115. The head-mounted display system according to any of the above examples further includes a quarter-wave plate.

[0142] 116. The head-mounted display system according to any of the above examples further includes a compensator configured to provide a more consistent orthogonal rotation of the light.

[0143] 117. A head-mounted display system according to any of the above examples, wherein the optical device and the spatial light modulator are tilted relative to each other.

[0144] 118. A head-mounted display system according to any of the above examples, wherein the coupling optical device, optical device, and spatial light modulator are tilted relative to the eyepiece.

[0145] 119. A head-mounted display system according to any of the above examples, wherein the coupling optical device, optical device, and spatial light modulator are tilted relative to the eyepiece.

[0146] 120. In the head-mounted display system described in any of the above examples, light from the light source is configured to be recycled or reused.

[0147] 121. The head-mounted display system according to any of the above examples further includes a polarizer, which is configured to transmit light with a first polarization from the light source to the optical device and reflect light with a different second polarization back to the light source.

[0148] 122. The head-mounted display system according to any of the above examples further includes a coupling element between the light source and the polarizer, which converts at least some of the light of the second polarization reflected by the polarizer into light of the first polarization.

[0149] 123. A head-mounted display system according to any of the above examples, wherein the light source includes a plurality of laterally displaced light emitters configured to output light.

[0150] 124. The head-mounted display system according to any of the above examples further includes a focusing optical device or a coupling element configured to collect light from the multiple light emitters.

[0151] 125. The head-mounted display system according to any of the above examples further includes a diffuser in the optical path between the light source and the optical device.

[0152] 126. The head-mounted display system according to any of the above examples further includes one or more holes between the light source and the optical device.

[0153] 127. The head-mounted display system according to any of the above examples further includes a plurality of holes between the light source and the optical device.

[0154] 128. The head-mounted display system according to any of the above examples further includes a diffuser and a plurality of holes between the light source and the optical device, wherein the diffuser is adjacent to the holes.

[0155] 129. A head-mounted display system according to any of the above examples, wherein the light source includes one or more laser diodes.

[0156] 130. The head-mounted display system according to any of the above examples further includes a coupling optical device, which is arranged relative to the light source to collect light output from the light source.

[0157] 131. A head-mounted display system according to Example 130, wherein the coupling optical device includes a compound parabolic concentrator (CPC).

[0158] 132. The head-mounted display system according to any of the above examples further includes a focusing optical device, which is arranged relative to the light source to collect light output from the light source.

[0159] 133. A head-mounted display system according to any of the above examples, wherein the focusing optical device includes one or more lenses.

[0160] 134. A head-mounted display system according to any of the above examples, wherein the focusing optical device includes multiple lenses.

[0161] 135. The head-mounted display system according to any of the above examples further includes a quarter-wavelength delay device between the light source and the optical device.

[0162] 136. A head-mounted display system according to any of the above examples, wherein a polarizer is attached to the spatial light modulator.

[0163] 137. A head-mounted display system according to any of the above examples, wherein the polarizer is adhered to the spatial light modulator by an adhesive.

[0164] 138. A head-mounted display system according to any of the above examples, wherein the polarizer is attached to the spatial light modulator using a mechanical fixing device.

[0165] 139. A head-mounted display system according to any of the above examples, wherein a compensator is attached to the spatial light modulator.

[0166] 140. A head-mounted display system according to any of the above examples, wherein the compensator is adhered to the spatial light modulator by an adhesive.

[0167] 141. A head-mounted display system according to any of the above examples, wherein the compensator is adhered to the spatial light modulator using a mechanical fixing device.

[0168] 142. A head-mounted display system according to any of the above examples, wherein a delay device is attached to the spatial light modulator.

[0169] 143. A head-mounted display system according to any of the above examples, wherein the delay device is adhered to the spatial light modulator by an adhesive.

[0170] 144. A head-mounted display system according to any of the above examples, wherein the delay device is adhered to the spatial light modulator using a mechanical fixing device.

[0171] 145. A head-mounted display system according to any of the above examples, wherein a quarter-wave delay device is attached to the spatial light modulator.

[0172] 146. A head-mounted display system according to any of the above examples, wherein the quarter-wave delay device is adhered to the spatial light modulator by an adhesive.

[0173] 147. A head-mounted display system according to any of the above examples, wherein the quarter-wave delay device is adhered to the spatial light modulator using a mechanical fixing device.

[0174] 148. A head-mounted display system according to any of the above examples, wherein the polarizer includes a wire grid polarizer.

[0175] 149. The head-mounted display system according to any of the above examples further includes a circular polarizer between the spatial light modulator and the coupling optical element.

[0176] 150. A head-mounted display system according to Example 149, wherein the circular polarizer includes a linear analyzer and a quarter-wave retarder.

[0177] 151. The head-mounted display system according to any of the above examples further includes a single polarizer between the optical device and the at least one waveguide and between the light source and the optical device.

[0178] 152. A head-mounted display system according to any of the above examples, wherein the light absorber includes an absorbing material.

[0179] 153. A head-mounted display system according to any of the above examples, wherein the light absorber includes an absorbing material surrounding the filters in the filter array.

[0180] 154. In the head-mounted display system according to any of the above examples, the light source is laterally arranged relative to the at least one waveguide so that light from the light source is guided into the optical element without propagating through the at least one waveguide.

[0181] 155. A head-mounted display system according to any of the above examples, wherein the light source is disposed on a transparent layer extending laterally relative to the at least one waveguide so that light from the light source is guided into the optical device without propagating through the at least one waveguide.

[0182] 156. A head-mounted display system according to any of the above examples, wherein the light source is disposed on a transparent layer, the transparent layer being closer to a side of the at least one waveguide that is closer to the environment in front of the user than to a side of the at least one waveguide that is closer to the user's eyes, and the transparent layer extending laterally relative to the at least one waveguide so that light from the light source is guided into the optical device without propagating through the at least one waveguide.

[0183] 157. A head-mounted display system according to any of the above examples, wherein the light source is arranged on a transparent layer, the transparent layer is closer to the side of the at least one waveguide that is closer to the user's eyes than to the side of the at least one waveguide that is closer to the environment in front of the user, and the transparent layer extends laterally relative to the at least one waveguide so that light from the light source is guided into the optical device without propagating through the at least one waveguide.

[0184] 158. A head-mounted display system according to any of the above examples, wherein the transparent layer includes cover glass.

[0185] 159. The head-mounted display system according to any of the above examples further includes a plurality of color filters that are laterally shifted relative to each other, and the color filters are laterally aligned relative to a plurality of coupling-in optical elements, and the plurality of coupling-in optical elements are laterally shifted relative to each other so that light propagating through the corresponding color filters is incident on the corresponding coupling-in optical elements.

[0186] 160. In the head-mounted display system described in any of the above examples, the multiple color filters include a color filter array.

[0187] 161. The head-mounted display system according to any of the above examples further includes a polarizer, which is arranged in the optical path between the spatial light modulator and the optical device.

[0188] 162. The head-mounted display system according to any of the above examples further includes a polarizer, which is arranged in the optical path between the spatial light modulator and the optical device.

[0189] 163. The head-mounted display system according to any of the above examples further includes a compensator, which is arranged in the optical path between the spatial light modulator and the optical device.

[0190] 164. The head-mounted display system according to any of the above examples further includes a delay device, which is arranged in the optical path between the spatial light modulator and the optical device.

[0191] 165. The head-mounted display system according to any of the above examples further includes a quarter-wavelength delay device, which is arranged in the optical path between the spatial light modulator and the optical device.

[0192] 166. The head-mounted display system according to any of the above examples further includes a first circular polarizer located between the at least one waveguide and the optical device having optical focal length.

[0193] 167. A head-mounted display system according to Example 166, wherein the first circular polarizer is located between the light source and the optical device having optical focal length.

[0194] 168. The head-mounted display system according to any of the above examples further includes a second circular polarizer located between the optical device with optical focal power and the spatial light modulator.

[0195] 169. The head-mounted display system of Example 168 further comprises a delay device located between the second circular polarizer and the spatial light modulator.

[0196] 170. The head-mounted display system of Example 168 or 169 further comprises a third circular polarizer located between the second circular polarizer and the spatial light modulator.

[0197] 171. The head-mounted display system according to Example 170 further includes a delay device located between the second circular polarizer and the third circular polarizer.

[0198] 172. The head-mounted display system according to any of the above examples further includes a compensator located between the optical device with optical focal length and the spatial light modulator.

[0199] 173. The head-mounted display system of any one of Examples 168 to 171, further comprising a compensator located between the second circular polarizer and the spatial light modulator.

[0200] 174. The head-mounted display system of any one of Examples 170 to 171, further comprising a compensator located between the third circular polarizer and the spatial light modulator.

[0201] 175. The head-mounted display system according to any of the above examples further includes a cover glass located between the optical device with optical focal power and the spatial light modulator.

[0202] 176. The head-mounted display system of any one of Examples 168 to 174, further comprising a cover glass located between the second circular polarizer and the spatial light modulator.

[0203] 177. The head-mounted display system of any one of Examples 170 to 174, further comprising a cover glass located between the third circular polarizer and the spatial light modulator.

[0204] 178. The head-mounted display system of any one of Examples 172 to 174, further comprising a cover glass located between the compensator and the spatial light modulator.

[0205] 179. The head-mounted display system according to any of the above examples further includes at least one optical surface that is tilted relative to the at least one waveguide to redirect light reflected from the optical surface.

[0206] 180. The head-mounted display system according to any of the above examples further includes at least one optical surface that is tilted relative to the spatial light modulator to redirect light reflected from the optical surface.

[0207] 181. The head-mounted display system according to any of the above examples further includes at least one optical surface that is tilted relative to at least one polarizer or retarder to redirect light reflected from the optical surface.

[0208] 182. The head-mounted display system according to any of the above examples further comprises at least one optical surface whose normal is tilted relative to the optical axis of the optical device having optical power to redirect light reflected from the optical surface.

[0209] 183. A head-mounted display system according to any of Examples 179 to 182, wherein the tilted at least one optical surface redirects the reflected light away from a coupling optical element of the at least one waveguide.

[0210] 184. A head-mounted display system according to any of Examples 179 to 183, wherein the tilted at least one optical surface redirects the reflected light so that a small amount of the reflected light is coupled into and guided within the at least one waveguide.

[0211] 185. A head-mounted display system according to any of Examples 179 to 184, wherein the tilted at least one optical surface redirects the reflected light so that a small amount of the reflected light is directed to the user's eyes.

[0212] 186. A head-mounted display system according to any of Examples 179 to 185, wherein the tilted at least one optical surface redirects at least some of the reflected light toward the light source.

[0213] 187. The head-mounted display system of any one of Examples 179 to 186, further comprising a light absorber to receive at least some of the reflected light from at least one of the tilted optical surfaces.

[0214] 188. A head-mounted display system according to any of Examples 179 to 187, wherein at least one of the tilted optical surfaces is on the cover glass.

[0215] 189. A head-mounted display system according to any of Examples 179 to 188, wherein the at least one optical surface that is tilted is on one or more of: at least one retarder, at least one polarizer, or at least one compensator.

[0216] 190. A head-mounted display system according to any of the above examples, wherein the cover glass is wedge-shaped.

[0217] 191. A head-mounted display system according to any of the above examples, wherein at least one delay device, at least one polarizer, or at least one compensator is wedge-shaped.

[0218] 192. The head-mounted display system according to any of the above examples further includes a polarization rotator, which is arranged relative to the light source to rotate the polarization of light emitted therefrom.

[0219] 193. The head-mounted display system according to Example 166 or 167 further includes a polarization rotator disposed between the light source and the first circular polarizer.

[0220] 194. A head-mounted display system according to any of the above examples, wherein the at least one coupling-in optical element includes a first coupling-in optical element and a second coupling-in optical element, and the head-mounted display system further includes a first color filter and a second color filter respectively associated with the first coupling-in optical element and the second coupling-in optical element.

[0221] 195. A head-mounted display system according to Example 194, wherein the first color filter transmits more light of the first color than the second color filter, and the second color filter transmits more light of the second color than the first color filter.

[0222] 196. A head-mounted display system according to Example 194 or 195, wherein the at least one waveguide includes a first waveguide and a second waveguide, wherein the first coupling optical element couples more light of the first color into the first waveguide than the second color filter, and the second coupling optical element couples more light of the second color into the second waveguide than the first color.

[0223] 197. A head-mounted display system according to any one of Examples 194 to 196, wherein the first color filter and the second color filter are laterally aligned with the corresponding first coupling optical element and second coupling optical element.

[0224] 198. The head-mounted display system according to any one of Examples 194 to 197 further includes a first light source and a second light source, wherein the first light source and the second light source are configured to guide light through the first color filter and the second color filter, respectively, to reach the first coupling optical element and the second coupling optical element, respectively.

[0225] 199. The head-mounted display system of any one of Examples 194 to 197 further comprises a first light source and a second light source, wherein the first color filter is disposed in a first light path between the first light source and the first coupling optical element, and the second color filter is disposed in a second light path between the second light source and the second coupling optical element.

[0226] 200. A head-mounted display system according to Example 198 or 199, wherein the first light source includes a first color light source configured to emit a first color, and the second light source includes a second color light source configured to emit a second color.

[0227] 201. A head-mounted display system according to Example 198 or 199, wherein the first light source and the second light source comprise broadband color light sources configured to emit both the first color and the second color. BRIEF DESCRIPTION OF THE DRAWINGS

[0228] Figure 1 An augmented reality (AR) view seen by a user through an AR device is shown.

[0229] Figure 2 A conventional display system for simulating three-dimensional imagery for a user is shown.

[0230] FIG. 3A to FIG. 3C The relationship between the radius of curvature and the focal radius is shown.

[0231] Figure 4A A representation of the accommodation-vergence response of the human visual system is shown.

[0232] Figure 4B Examples of different accommodation and convergence states of a pair of eyes of a user are shown.

[0233] Figure 4C An example of a representation of an overhead view of content viewed by a user via a display system is shown.

[0234] Figure 4D Another example of a representation of an overhead view of content viewed by a user via a display system is shown.

[0235] Figure 5 Aspects of a method for simulating three-dimensional imagery by modifying wavefront divergence are shown.

[0236] Figure 6 An example of a waveguide stack for outputting image information to a user is shown.

[0237] Figure 7 An example of an outgoing light beam output by a waveguide is shown.

[0238] Figure 8 An example of a stacked waveguide assembly is shown where each depth plane includes an image formed using multiple different component colors.

[0239] Fig. 9A A cross-sectional side view of an example of a stacked waveguide group that each includes an in-coupling optical element is shown.

[0240] Fig. 9B Shows Fig. 9A A perspective view of an example of one or more stacked waveguides.

[0241] Fig. 9C Shows Fig. 9A and Fig. 9B A top plan view of an example of one or more stacked waveguides.

[0242] Fig.9D An example of a wearable display system is shown.

[0243] Fig.10 is a side view of a projector assembly including a polarizing beam splitter, wherein a light source injects light into one side of the beam splitter and projection optics receives light from the other side of the beam splitter.

[0244] Fig.11A is a side view of an augmented reality display system including a light source, a spatial light modulator, an optic for illuminating the spatial light modulator and projecting an image of the spatial light modulator (SLM), and a display for outputting image information to a user. The system includes an in-coupling optical element for coupling light from the optic into a waveguide, and an out-coupling optical element for coupling light out of the waveguide to an eye.

[0245] Fig. 11B yes Fig.11A A top view of an augmented reality display system is shown, which shows a waveguide with in-coupling optical elements, out-coupling optical elements and a light source disposed thereon. The top view also shows an orthogonal pupil expander.

[0246] Fig. 11C yes Fig.11A Side view of an augmented reality display system with a shared polarizer / analyzer and a polarization-based spatial light modulator (e.g., liquid crystal on silicon SLM).

[0247] Fig. 12A is a side view of an augmented reality display system, the system including a multi-color light source (e.g., a time-division multiplexed RGB LED or laser diode), a spatial light modulator, optics for illuminating the spatial light modulator and projecting an image of the spatial light modulator to an eye, and a waveguide stack, different waveguides including different color selective coupling-in optics and coupling-out optics.

[0248] Fig. 12B yes Fig. 12A A side view of an augmented reality display system, the system further comprising a MEMS (micro-electromechanical) based SLM, such as a movable mirror array (e.g., a digital light processing (DLP) TM ) technology) and light absorbers.

[0249] Fig. 12C yes Fig. 12B A top view of a portion of an augmented reality display system schematically showing the lateral arrangement of an in-coupling optical element and a light absorber and one of the light sources.

[0250] Fig.13A is a perspective view of an augmented reality display system including a waveguide stack, different waveguides including different coupling-in optical elements, wherein the coupling-in optical elements are laterally displaced relative to each other. One or more light sources, also laterally displaced relative to each other, are configured to direct light to a corresponding coupling-in optical element by propagating the light through an optical device, reflecting the light from a spatial light modulator, and causing the reflected light to propagate the optical device again.

[0251] Fig. 13B yes Fig.13A A side view of the illustrated example showing the laterally displaced in-coupling optics and light source as well as the optics and spatial light modulator.

[0252] Fig. 13C yes Fig.13A and Fig. 13B A top view of an augmented reality display system is shown, illustrating one or more laterally displaced in-coupling optical elements and associated one or more laterally displaced light sources.

[0253] Fig.14A is a side view of an augmented reality display system comprising a waveguide stack, different waveguides comprising different coupling-in optical elements, wherein the coupling-in optical elements are laterally displaced relative to each other (in this example, in the z-direction).

[0254] Fig. 14B yes Fig.14A A top view of a display system is shown showing the laterally displaced in-coupling optics and light source.

[0255] Fig. 14C yes Fig.14A and Fig. 14B An orthogonal side view of the display system is shown.

[0256] Fig.15 FIG. 1 is a top view of an augmented reality display system, the system comprising a waveguide stack, wherein different waveguides include different coupling optical elements. The light source and the coupling optical element are different FIG. 14A to FIG. 14CThe alternative configuration shown is arranged.

[0257] Fig.16A is a side view of an augmented reality display system comprising a plurality of in-coupling optical element groups laterally displaced relative to one another, each group comprising one or more color selective optical in-coupling optical elements.

[0258] Fig. 16B yes Fig.16A A top view of the display system in FIG.

[0259] Fig.17 is a side view of an augmented reality display system including a waveguide divided by a reflective surface that can couple light guided in a portion of the waveguide adjacent a light source out of the portion of the waveguide and into an optic toward a spatial light modulator. In this example, the optics and light source are shown disposed on the same side of the waveguide.

[0260] Fig.18 is a side view of an augmented reality display system including a waveguide for receiving light from a light source and directing the light directed in the waveguide into an optic and toward a spatial light modulator. The display system additionally includes a waveguide that receives light from the spatial light modulator and propagates through the optics again. The waveguide includes a reflective surface that couples light out. The waveguide also includes a reflective surface that couples light in. In this example, the optics and the light source are shown as being disposed on the same side of the waveguide.

[0261] Fig.19 is a side view of an augmented reality display system including adaptive optical elements or variable focus optical elements. A first variable optical element between the waveguide stack and the eye can change the divergence and collimation of light coupled out of the waveguide and directed to the eye to change the depth at which objects appear to be located. A second variable optical element on the opposite side of the waveguide stack can compensate for the effect of the first optical element on light from the augmented reality display system and the environment in front of the user. The augmented reality display system further includes prescription lenses to provide ophthalmic correction, such as refractive correction, for users with myopia, hyperopia, astigmatism, etc.

[0262] Fig. 20A 1 is a side view of an augmented reality display system including a color filter array. One or more laterally displaced incoupling optical elements are located on different waveguides, and the laterally displaced color filters are aligned with the corresponding incoupling optical elements.

[0263] Fig. 20B shows a polarizer with an analyzer between the optics and the spatial light modulator Fig. 20A Augmented reality display system.

[0264] Fig. 20CShows something like Fig. 20A and Fig. 20B The augmented reality display system shown, however, uses a deflection-based spatial light modulator, such as a movable micro-mirror-based spatial light modulator.

[0265] Fig.20D Such as Fig. 20C A top view of a portion of an augmented reality display system is shown schematically illustrating a laterally displaced light source and corresponding laterally displaced in-coupling optics above a color filter array.

[0266] Fig.20E shows how a deflection-based spatial light modulator can direct light away from the corresponding coupling optical element and toward the surrounding Fig.20D On a mask of a color filter in a color filter array of an augmented reality display system.

[0267] Fig.20F is a side view of an augmented reality display system including a cover glass disposed on a user side of a waveguide stack and a light source disposed on a world side of the cover glass.

[0268] Figure 20G is a side view of an augmented reality display system including a cover glass disposed on the world side of a waveguide stack and a light source disposed on the world side of the cover glass.

[0269] Fig.21 is a side view of an augmented reality display system including a light source equipped with a light recycler configured to recycle light, such as light of one polarization.

[0270] Fig. 22 is a side view of one or more light sources propagating light through corresponding focusing optics and one or more apertures. The light may also be propagated through a diffuser positioned adjacent to the one or more apertures.

[0271] Fig.23A is a side view of a portion of an augmented reality display system, the system comprising a light source, an optical device having optical power, a waveguide for receiving and outputting image information to an eye of a user, wherein the system further comprises one or more retarders and polarizers configured to reduce reflections from optical surfaces that may enter the waveguide as ghosts.

[0272] Fig. 23B Such as Fig.23A A side view of a portion of an augmented reality display system is shown with an additional retarder and polarizer configured to reduce reflections that can produce ghosting.

[0273] Fig.23C Such as Fig.23A and Fig. 23B A side view of an augmented reality display system is shown having a retarder and polarizer configured to reduce reflections that can produce ghosting.

[0274] Fig.24 is a side view of an augmented reality display system that utilizes an angled surface, such as an angled surface on a cover glass, to direct reflections so that they are not directed into the user's eyes, thereby potentially reducing ghost reflections.

[0275] Fig.25 yes Fig.24 An embodiment of the system wherein the sloped surface on the cover glass is configured to direct reflections toward a light absorber that absorbs the light. DETAILED DESCRIPTION

[0276] Reference will now be made to the drawings, in which like reference numerals refer to like parts throughout the drawings. Unless otherwise indicated, the drawings are schematic and are not necessarily drawn to scale.

[0277] Figure 2 A conventional display system for simulating three-dimensional imagery for a user is shown. It should be understood that the user's eyes are spaced apart, and when viewing a real object in space, each eye has a slightly different view of the object, and may form an image of the object at a different location on the retina of each eye. This may be referred to as binocular disparity, and may be used by the human visual system to provide a sense of depth. Conventional display systems simulate binocular disparity by presenting two distinct images 190, 200 having slightly different views of the same virtual object, one for each eye 210a, 210b, corresponding to views of the virtual object that cause each eye to see the virtual object as a real object at a desired depth. These images provide binocular cues that the user's visual system can interpret to infer a sense of depth.

[0278] Continue to refer Figure 2, the images 190, 200 are spaced a distance 230 from the eyes 210a, 210b along the z-axis. The z-axis is parallel to the visual axis of the viewer with the eyes fixated on an object at optical infinity directly in front of the viewer. The images 190, 200 are flat and located at a fixed distance from the eyes 210a, 210b. Based on the slightly different views of the virtual objects in the images presented to the eyes 210a, 210b, respectively, the eyes can naturally rotate so that the image of the object falls on corresponding points on the retina of each eye, thereby maintaining a single binocular vision. The rotation can cause the line of sight of each eye 210a, 210b to converge to the point in space where the virtual object is perceived. Therefore, providing three-dimensional imagery generally involves providing binocular cues that can manipulate the convergence of the user's eyes 210a, 210b, and the human visual system interprets these cues to provide a sense of depth.

[0279] However, generating a realistic and comfortable sense of depth is challenging.It will be appreciated that light from objects at different distances from the eye have wavefronts with different amounts of divergence. FIG. 3A to FIG. 3C The relationship between distance and light divergence is shown. The distance between the object and the eye 210 is represented by distances R1, R2, and R3 in descending order. Figures 3A to 3C As shown, as the distance to the object decreases, the light becomes more divergent. Conversely, as the distance increases, the light becomes more collimated. In other words, the light field generated by a point (an object or a portion of an object) can be considered to have a spherical wavefront curvature that is a function of the distance of the point from the user's eye. As the distance between the object and the eye 210 decreases, the curvature increases. Although in order to FIG. 3A to FIG. 3C Although only a single eye 210 is shown for clarity in the illustrative and other figures herein, the discussion regarding eye 210 may apply to both eyes 210a and 210b of the viewer.

[0280] Continue to refer FIG. 3A to FIG. 3C, light from an object being looked at by a viewer's eye can have different degrees of wavefront divergence. Due to different amounts of wavefront divergence, light can be focused differently by the lens of the eye, which in turn may require the lens to assume different shapes to form a focused image on the retina of the eye. In the absence of a focused image formed on the retina, the resulting retinal blur acts as an accommodation cue that causes the shape of the lens of the eye to change until a focused image is formed on the retina. For example, an accommodation cue can trigger the ciliary muscle surrounding the lens of the eye to relax or contract, thereby adjusting the force applied to the suspensory ligaments that hold the lens, thereby causing the shape of the lens of the eye to change until the retinal blur of the looked object is eliminated or minimized, thereby forming a focused image of the looked object on the retina of the eye (e.g., the fovea). The process by which the lens of the eye changes shape may be referred to as accommodation, and the shape of the lens of the eye required to form a focused image of the looked object on the retina of the eye (e.g., the fovea) may be referred to as an accommodation state.

[0281] Reference now Figure 4A , shows a representation of the accommodation-convergence response of the human visual system. Movement of the eyes to fixate on an object causes the eyes to receive light from the object, where the light forms an image on each retina of the eye. The presence of retinal blur in the image formed on the retina can provide accommodation cues, and the relative positions of the images on the retina can provide convergence cues. Accommodation cues cause accommodation to occur, resulting in the lenses of the eyes each assuming a specific accommodation state that forms a focused image of the object on the retina of the eye (e.g., the fovea). On the other hand, convergence cues cause convergence movement (eye rotation) to occur so that the images formed on each retina of each eye are at corresponding retinal points that maintain single binocular vision. At these positions, the eyes can be considered to have assumed a specific convergence state. Continue to refer to Figure 4A , accommodation can be understood as the process by which the eye achieves a specific accommodation state, and vergence can be understood as the process by which the eye achieves a specific vergence state. Figure 4A As shown, if the user looks at another object, the accommodation and convergence states of the eyes may change. For example, if the user looks at a new object at a different depth on the z-axis, the accommodation state may change.

[0282] Without being limited by theory, it is believed that a viewer of an object may perceive the object as "three-dimensional" due to a combination of convergence and accommodation. As described above, the convergence action of the two eyes relative to each other (i.e., the rotation of the eyes to bring the pupils closer or farther away from each other so that the eyes' line of sight converges to focus on an object) is closely related to the accommodation of the lens of the eye. Under normal circumstances, changing the shape of the lens of the eye to change the focus from one object to another at a different distance will automatically cause a matching change in vergence to the same distance, according to a relationship known as the "accommodation-convergence reflex." Likewise, under normal circumstances, a change in vergence will trigger a matching change in the shape of the lens.

[0283] Reference now Figure 4B , examples of different accommodation and convergence states of eyes are shown. A pair of eyes 222a is looking at an object at optical infinity, while a pair of eyes 222b is looking at an object 221 that is less than optical infinity. It is noteworthy that the convergence state of each pair of eyes is different, with the pair of eyes 222a looking straight ahead, while the pair of eyes 222 converge on the object 221. The accommodation state of the eyes forming each pair of eyes 222a and 222b is also different, as represented by the different shapes of the lenses 220a, 220b.

[0284] However, many users of conventional "3-D" display systems find that these conventional systems are not comfortable, or that they cannot perceive a sense of depth at all, because of the mismatch between the accommodation and convergence states in these displays. As described above, many stereoscopic or "3-D" display systems display a scene by providing a slightly different image to each eye. Such systems are uncomfortable for many viewers because, among other factors, they can only provide different presentations of the scene and cause changes in the eye's convergence state without a corresponding change in the accommodation state. Instead, the image is shown by a display located at a fixed distance from the eye so that the eye views all image information in a single accommodation state. This arrangement works by causing a change in the convergence state without a matching change in the accommodation state, which violates the "accommodation-convergence reflex." It can be considered that this mismatch causes discomfort to the viewer. Display systems that provide a better match between accommodation and convergence can form a more realistic and comfortable three-dimensional image simulation.

[0285] Without being limited by theory, it is believed that the human eye can generally interpret a limited number of depth planes to provide depth perception. Therefore, a highly convincing simulation of perceived depth can be achieved by providing the eye with different presentations of images corresponding to each of these limited number of depth planes. In some embodiments, the different presentations can provide both vergence cues and matching accommodation cues, thereby providing a physiologically correct accommodation-vergence match.

[0286] Continue to refer Figure 4B, two depth planes 240 are shown, corresponding to different distances in space from the eyes 210a, 210b. For a given depth plane 240, convergence cues can be provided by displaying an image of an appropriate different perspective for each eye 210a, 210b. In addition, for a given depth plane 240, the light forming the image provided to each eye 210a, 210b can have a wavefront divergence corresponding to the light field produced by a point at a distance from the depth plane 240.

[0287] In the illustrated embodiment, the distance along the z-axis that the depth plane 240 contains point 221 is 1m. As used herein, the distance or depth along the z-axis can be measured using a zero point located at the exit pupil of the user's eye. Therefore, the depth plane 240 located at a depth of 1m is at a distance of 1m relative to the user's eye exit pupil on the visual axis of these eyes, where the eyes point to optical infinity. As an approximation, the depth or distance along the z-axis can be measured as: the distance from the display in front of the user's eye (e.g., from the surface of the waveguide) plus the distance value between the device and the exit pupil of the user's eye. This value may be referred to as the exit pupil distance, and corresponds to the distance between the exit pupil of the user's eye and the display worn by the user in front of the user's eye. In practice, the exit pupil distance value may be a standardized value commonly used for all viewers. For example, the exit pupil distance is 20mm, and the depth plane at a depth of 1m may be located at a distance of 980mm in front of the display.

[0288] Reference now Figure 4C and Figure 4D , show examples of matched accommodation and convergence distances and mismatched accommodation and convergence distances, respectively. Figure 4C As shown, the display system can provide an image of a virtual object to each eye 210a, 210b. The image can cause the eyes 210a, 210b to present a convergence state, in which the eyes converge on point 15 on the depth plane 240. In addition, the image can be formed by light having a wavefront curvature corresponding to the real object at the depth plane 240. Therefore, the eyes 210a, 210b present an accommodation state, in which the image is focused on the retinas of these eyes. Therefore, the user can perceive that the virtual object is located at point 15 on the depth plane 240.

[0289] It should be understood that each of the accommodation state and the convergence state of the eyes 210a, 210b is associated with a specific distance on the z-axis. For example, an object at a specific distance from the eyes 210a, 210b causes the eyes to assume a specific accommodation state based on the distance of the object. The distance associated with a specific accommodation state may be referred to as the accommodation distance A. dSimilarly, there is a specific vergence distance V associated with the eyes being in a specific vergence state or position relative to each other. d In cases where the accommodation distance and the vergence distance match, the relationship between accommodation and vergence can be considered physiologically correct. This is considered the most comfortable situation for the viewer.

[0290] However, in stereoscopic displays, the accommodation distance and the convergence distance may not always match. Figure 4D As shown, the image displayed to the eyes 210a, 210b can be displayed with a wavefront divergence corresponding to the depth plane 240, and the eyes 210a, 210b can present a specific accommodation state in which they focus on points 15a, 15b on the depth plane. However, the image displayed to the eyes 210a, 210b may provide a convergence cue, which causes the eyes 210a, 210b to converge on a point 15 that is not located on the depth plane 240. Therefore, in some embodiments, the accommodation distance corresponds to the distance from the exit pupil of the eyes 210a, 210b to the depth plane 240, while the convergence distance corresponds to the larger distance from the exit pupil of the eyes 210a, 210b to the point 15. The accommodation distance is different from the convergence distance. Therefore, there is an accommodation-convergence mismatch. This mismatch is considered undesirable and may cause discomfort to the user. It should be understood that the mismatch corresponds to the distance (e.g., V d -A d ) and can be characterized using diopters.

[0291] In some embodiments, it should be appreciated that a reference point other than the exit pupil of the eye 210a, 210b may be used to determine the distance used to determine the accommodation-vergence mismatch, as long as the same reference point is used for both the accommodation distance and the vergence distance. For example, the distance from the cornea to the depth plane, from the retina to the depth plane, from the eyepiece (e.g., a waveguide of a display device) to the depth plane, etc. may be measured.

[0292] Without being limited by theory, it is believed that users may still perceive accommodation-convergence mismatches of up to about 0.25 diopters, up to about 0.33 diopters, and up to about 0.5 diopters as physiologically correct without the mismatch itself causing noticeable discomfort. In some embodiments, the display systems disclosed herein (e.g., Figure 6 In some embodiments, the display system 250 presents an image to a viewer with an accommodation-convergence mismatch of about 0.5 diopters or less. In some other embodiments, the accommodation-convergence mismatch of the image provided by the display system is about 0.33 diopters or less. In some other embodiments, the accommodation-convergence mismatch of the image provided by the display system is about 0.25 diopters or less, including about 0.1 diopters or less.

[0293] Figure 5 Aspects of a method for simulating three-dimensional imagery by modifying wavefront divergence are shown. The display system includes a waveguide 270 configured to receive light 770 encoded with image information and output the light to a user's eye 210. The waveguide 270 can output light 650 having a defined amount of wavefront divergence that corresponds to the wavefront divergence of a light field generated by a point on a desired depth plane 240. In some embodiments, the same amount of wavefront divergence is provided for all objects presented on the depth plane. Additionally, it will be shown that image information from a similar waveguide can be provided to the user's other eye.

[0294] In some embodiments, a single waveguide may be configured to output light having a set amount of wavefront divergence that is consistent with the wavefront divergence of a single depth plane or a finite number of depth planes, and / or the waveguide may be configured to output light of a finite wavelength range. Thus, in some embodiments, a waveguide stack may be utilized to provide different amounts of wavefront divergence and / or output light of different wavelength ranges for different depth planes. As used herein, it will be understood that at a depth plane, the contour of a planar or curved surface may be followed. In some embodiments, advantageously for simplicity, the depth plane may follow the contour of a plane.

[0295] Figure 6 An example of a waveguide stack for outputting image information to a user is shown. Display system 250 includes a waveguide stack or stacked waveguide assembly 260, which can be used to provide a three-dimensional perception to the eye / brain using waveguides 270, 280, 290, 300, 310. It should be understood that in some embodiments, display system 250 can be considered a light field display. In addition, waveguide assembly 260 can also be referred to as an eyepiece.

[0296] In some embodiments, the display system 250 may be configured to provide a substantially continuous vergence cue and a plurality of discontinuous accommodation cues. The vergence cues may be provided by displaying a different image to each eye of the user, and the accommodation cues may be provided by outputting light that forms an image with selectable discrete amounts of wavefront divergence. In other words, the display system 250 may be configured to output light with variable wavefront divergence levels. In some embodiments, each discrete wavefront divergence level corresponds to a particular depth plane and may be provided by a particular one of the waveguides 270, 280, 290, 300, 310.

[0297] Continue to refer Figure 6, the waveguide assembly 260 may also include features 320, 330, 340, 350 located between the waveguides. In some embodiments, the features 320, 330, 340, 350 may be one or more lenses. The waveguides 270, 280, 290, 300, 310 and / or features (e.g., lenses) 320, 330, 340, 350 may be configured to send image information to the eye at various wavefront curvature levels or light divergence levels. Each waveguide level may be associated with a particular depth plane and may be configured to output image information corresponding to that depth plane. The image injection device 360, 370, 380, 390, 400 may be used as a light source for the waveguide and may be used to inject image information into the waveguides 270, 280, 290, 300, 310, as described herein, each waveguide may be configured to distribute incident light across each corresponding waveguide for output toward the eye 210. Light exits the output surfaces 410, 420, 430, 440, 450 of the image injection devices 360, 370, 380, 390, 400 and is injected into the respective input surfaces 460, 470, 480, 490, 500 of the waveguides 270, 280, 290, 300, 310. In some embodiments, each of the input surfaces 460, 470, 480, 490, 500 may be an edge of the respective waveguide, or may be a portion of the major surface of the respective waveguide (i.e., one of the waveguide surfaces that directly faces the world 510 or the viewer's eye 210). In some embodiments, a single beam (e.g., a collimated beam) may be injected into each waveguide so as to output the entire field of view of the cloned collimated beam directed toward the eye 210 at a particular angle (and divergence) corresponding to the depth plane associated with the particular waveguide. In some embodiments, one of the image injection devices 360, 370, 380, 390, 400 may be associated with one or more (three) waveguides 270, 280, 290, 300, 310 and inject light into these waveguides.

[0298] In some embodiments, the image injection devices 360, 370, 380, 390, 400 are discrete displays that each generate image information for injection into a respective waveguide 270, 280, 290, 300, 310. In some other embodiments, the image injection devices 360, 370, 380, 390, 400 are outputs of a single multiplexed display that may, for example, pipe the image information to each of the image injection devices 360, 370, 380, 390, 400 via one or more optical conduits (e.g., fiber optic cables). It will be appreciated that the image information provided by the image injection devices 360, 370, 380, 390, 400 may include light of different wavelengths or colors (e.g., different component colors as discussed herein).

[0299] In some embodiments, the light injected into the waveguides 270, 280, 290, 300, 310 is provided by a light projector system 520, which includes a light module 530, which may include a light emitter such as a light emitting diode (LED). The light from the light module 530 may be directed to a light modulator 530 (e.g., a spatial light modulator) via a beam splitter 550 and modified by the light modulator 530. The light modulator 530 may be configured to change the perceived intensity of the light injected into the waveguides 270, 280, 290, 300, 310 to encode the light with image information. Examples of spatial light modulators include liquid crystal displays (LCDs), including liquid crystal on silicon (LCOS) displays. It should be understood that the image injection devices 360, 370, 380, 390, 400 are shown schematically, and in some embodiments, these image injection devices can represent different optical paths and positions in a common projection system that is configured to output light into an associated one of the waveguides 270, 280, 290, 300, 310. In some embodiments, the waveguides of the waveguide assembly 260 can act as ideal lenses while relaying the light injected into the waveguides out to the user's eyes. In this concept, the object can be the spatial light modulator 540, and the image can be an image on a depth plane.

[0300] In some embodiments, the display system 250 may be a scanning fiber display that includes one or more scanning fibers configured to project light into one or more waveguides 270, 280, 290, 300, 310 and ultimately into the viewer's eye 210 in various patterns (e.g., raster scans, spiral scans, Lissajous patterns, etc.). In some embodiments, the image injection devices 360, 370, 380, 390, 400 shown may schematically represent a single scanning fiber or a scanning fiber bundle that is configured to inject light into one or more of the waveguides 270, 280, 290, 300, 310. In some other embodiments, the image injection devices 360, 370, 380, 390, 400 shown may schematically represent one or more scanning fibers or one or more scanning fiber bundles, each of which is configured to inject light into an associated one of the waveguides 270, 280, 290, 300, 310. It should be understood that the one or more optical fibers may be configured to transmit light from the optical module 530 to the one or more waveguides 270, 280, 290, 300, 310. It should be understood that one or more intervening optical structures may be provided between the one or more scanning optical fibers and the one or more waveguides 270, 280, 290, 300, 310 to, for example, redirect light emitted from the scanning optical fibers into the one or more waveguides 270, 280, 290, 300, 310.

[0301] The controller 560 controls the operation of one or more of the stacked waveguide assemblies 260, including the operation of the image injection devices 360, 370, 380, 390, 400, the light source 530, and the light modulator 540. In some embodiments, the controller 560 is part of the local data processing module 140. The controller 560 includes programming (e.g., instructions in a non-transitory medium) that regulates the timing and provision of image information to the waveguides 270, 280, 290, 300, 310 according to, for example, any of the various schemes disclosed herein. In some embodiments, the controller can be a single integrated device, or a distributed system connected by wired or wireless communication channels. In some embodiments, the controller 560 can be a processing module 140 or 150 ( Fig.9D ) part.

[0302] Continue to refer Figure 6, the waveguides 270, 280, 290, 300, 310 may be configured to propagate light within each respective waveguide by total internal reflection (TIR). The waveguides 270, 280, 290, 300, 310 may each be planar or have another shape (e.g., curved), having a top major surface and a bottom major surface and an edge extending between these top major surfaces and the bottom major surfaces. In the illustrated configuration, the waveguides 270, 280, 290, 300, 310 may each include an outcoupling optical element 570, 580, 590, 600, 610 that is configured to extract light from the waveguide by redirecting light propagating within each respective waveguide out of the waveguide, thereby outputting image information to the eye 210. Although referred to as an "outcoupling optical element" in this description, the outcoupling optical element need not be an optical element and may also be a non-optical element. The extracted light may also be referred to as outcoupled light, and the outcoupling optical element may also be referred to as a light extraction optical element. At the location where light propagating in the waveguide strikes the light extraction optical element, the extracted light beam can be output by the waveguide. As further discussed herein, the outcoupling optical element 570, 580, 590, 600, 610 can be, for example, a grating that includes a diffractive optical feature. Although shown as being disposed at the bottom major surface of the waveguide 270, 280, 290, 300, 310 for ease of description and clarity of depiction, in some embodiments, as further discussed herein, the outcoupling optical element 570, 580, 590, 600, 610 can be disposed at the top major surface and / or the bottom major surface, and / or can be disposed directly in the body of the waveguide 270, 280, 290, 300, 310. In some embodiments, the outcoupling optical element 570, 580, 590, 600, 610 can be formed in a material layer attached to a transparent substrate to form the waveguide 270, 280, 290, 300, 310. In some other embodiments, the waveguides 270, 280, 290, 300, 310 may be a single piece of material and the outcoupling optical elements 570, 580, 590, 600, 610 may be formed on a surface and / or in the interior of the piece of material.

[0303] Continue to refer Figure 6As discussed herein, each waveguide 270, 280, 290, 300, 310 is configured to output light to form an image corresponding to a particular depth plane. For example, the waveguide 270 closest to the eye may be configured to transmit collimated light injected into such waveguide 270 to the eye 210. The collimated light may represent an optical infinity focal plane. The next upstream waveguide 280 may be configured to emit collimated light that propagates through a first lens 350 (e.g., a negative lens) before reaching the eye 210; such a first lens 350 may be configured to produce a slightly convex wavefront curvature so that the eye / brain interprets the light from the next upstream waveguide 280 as coming from a first focal plane that is closer to the eye 210 from optical infinity inward. Similarly, the third upstream waveguide 290 has its output light pass through the first lens 350 and the second lens 340 before reaching the eye 210. The combined optical power of the first lens 350 and the second lens 340 can be configured to produce another wavefront curvature increment so that the eye / brain interprets light from the third waveguide 290 as light from a second focal plane that is closer inward toward the person from optical infinity than light from the next upstream waveguide 280.

[0304] The other waveguide layers 300, 310 and lenses 330, 320 are similarly configured, with the highest waveguide 310 in the stack sending its output through all the lenses between it and the eye to obtain an aggregate focal power that represents the focal plane closest to the person. In order to compensate for the lens stack 320, 330, 340, 350 when viewing / interpreting light from the world 510 on the other side of the stacked waveguide assembly 260, a compensating lens layer 620 can be provided on top of the stack to compensate for the aggregate focal power of the lens stack 320, 330, 340, 350 below. This configuration provides as many perceived focal planes as there are available waveguide / lens pairs. Both the outcoupling optics of the waveguide and the focusing aspects of the lens can be static (i.e., not dynamic or electro-active). In some alternative embodiments, one or both of them can be dynamic by using electro-active features.

[0305] In some embodiments, two or more of the waveguides 270, 280, 290, 300, 310 may have the same associated depth plane. For example, multiple waveguides 270, 280, 290, 300, 310 may be configured to output image sets to the same depth plane, or multiple subsets of waveguides 270, 280, 290, 300, 310 may be configured to output image sets to the same one or more depth planes, one image set per depth plane. This may provide the advantage of forming a stitched image to provide an extended field of view at those depth planes.

[0306] Continue to refer Figure 6, the outcoupling optical elements 570, 580, 590, 600, 610 can be configured to redirect light out of their respective waveguides and output the light with an appropriate amount of divergence or collimation for a particular depth plane associated with the waveguide. Therefore, waveguides with different associated depth planes can have different configurations of outcoupling optical elements 570, 580, 590, 600, 610, which output light with different amounts of divergence depending on the associated depth plane. In some embodiments, the light extraction optical elements 570, 580, 590, 600, 610 can be volume features or surface features that can be configured to output light at specific angles. For example, the light extraction optical elements 570, 580, 590, 600, 610 can be volume holograms, surface holograms, and / or diffraction gratings. In some embodiments, the features 320, 330, 340, 350 may not be lenses; instead, they may simply be spacers (e.g., cladding and / or structures for forming air gaps).

[0307] In some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 are diffractive features that form a diffraction pattern, or "diffractive optical elements" (also referred to herein as "DOEs"). Preferably, the DOE has a sufficiently low diffraction efficiency that only a portion of the beam is deflected toward the eye 210 through each intersection of the DOE, while the remainder continues to move through the waveguide via TIR. Thus, the light carrying the image information is split into multiple related exit beams that exit the waveguide at multiple locations, resulting in a fairly uniform exit pattern toward the eye 210 for a particular collimated beam that bounces around within the waveguide.

[0308] In some embodiments, one or more DOEs may be switchable between an "on" state in which they actively diffract and an "off" state in which they do not appreciably diffract. For example, a switchable DOE may include a polymer dispersed liquid crystal layer in which droplets include a diffractive pattern in a host medium, and the refractive index of the droplets may be switched to substantially match the refractive index of the host material (in which case the pattern does not appreciably diffract incident light), or the droplets may be switched to a refractive index that does not match the refractive index of the host medium (in which case the pattern actively diffracts incident light).

[0309] In some embodiments, a camera assembly 630 (e.g., a digital camera, including visible light and infrared light cameras) may be provided to capture images of the eye 210 and / or tissue surrounding the eye 210, for example, to detect user input and / or monitor a physiological state of the user. As used herein, a camera may be any image capture device. In some embodiments, the camera assembly 630 may include an image capture device and a light source that projects light (e.g., infrared light) into the eye, which may then be reflected by the eye and detected by the image capture device. In some embodiments, the camera assembly 630 may be attached to the frame 80 ( Fig.9D ) and can be in electrical communication with processing modules 140 and / or 150, which can process image information from camera assembly 630. In some embodiments, one camera assembly 630 can be used for each eye to monitor each eye separately.

[0310] Reference now Figure 7 , shows an example of an outgoing beam output by a waveguide. One waveguide is shown, but it should be understood that the waveguide assembly 260 ( Figure 6 ) may function similarly, where the waveguide assembly 260 includes multiple waveguides. Light 640 is injected into the waveguide 270 at the input surface 460 of the waveguide 270 and propagates within the waveguide 270 by TIR. At the point where the light 640 strikes the DOE 570, a portion of the light exits the waveguide as an exit beam 650. The exit beam 650 is illustrated as being substantially parallel, but as discussed herein, depending on the depth plane associated with the waveguide 270, the exit beam 650 may also be redirected at an angle (e.g., to form a diverging exit beam) to propagate to the eye 210. It should be understood that a substantially parallel exit beam may be indicative of a waveguide having an out-coupling optical element that couples light out to form an image that appears to be disposed at a depth plane that is a relatively large distance from the eye 210 (e.g., optical infinity). Other waveguides or other sets of outcoupling optical elements may output more divergent exit beam patterns that would require the eye 210 to adjust to a closer distance to focus them on the retina, and these beam patterns may be interpreted by the brain as light coming from a distance closer to the eye 210 than optical infinity.

[0311] In some embodiments, a full color image may be formed at each depth plane by superimposing images in each component color (eg, three or more component colors). Figure 8An example of a stacked waveguide assembly is shown, wherein each depth plane includes an image formed using a plurality of different component colors. The illustrated embodiment shows depth planes 240a to 240f, but more or fewer depths are also contemplated. Each depth plane may have three or more component color images associated therewith, including: a first image of a first color G; a second image of a second color R; and a third image of a third color B. Different depth planes are represented in the figure by different numbers of diopters (dpt) after the letters G, R, and B. For example, the number after each letter represents the diopters (1 / m), or the inverse of the distance of the depth plane from the viewer, and each box in the figure represents a separate component color image. In some embodiments, in order to account for differences in the eye's focus on light of different wavelengths, the precise placement of the depth planes of different component colors may vary. For example, different component color images of a given depth plane may be placed on depth planes corresponding to different distances from the user. Such an arrangement may increase visual acuity and user comfort and / or may reduce chromatic aberration.

[0312] In some embodiments, light of each component color may be output by a single dedicated waveguide, and therefore, each depth plane may have multiple waveguides associated with it. In such embodiments, each box in the figure including the letters G, R, or B may be understood to represent a separate waveguide, and three waveguides may be provided for each depth plane, with three component color images provided for each depth plane. Although for ease of description, the waveguides associated with each depth plane are shown as being adjacent to each other in the figure, it should be understood that in a physical device, the waveguides may all be arranged to have one waveguide stack per level. In some other embodiments, multiple component colors may be output by the same waveguide, so that, for example, only a single waveguide may be provided for each depth plane.

[0313] Continue to refer Figure 8 , in some embodiments, G is green, R is red, and B is blue. In some other embodiments, other colors associated with other wavelengths of light (including magenta and cyan) may be used in addition to red, green, or blue, or these colors may replace one or more of red, green, or blue.

[0314] It should be understood that references throughout this disclosure to light of a given color will be understood to include light of one or more wavelengths within a wavelength range that is perceived by a viewer as light of the given color. For example, red light may include light of one or more wavelengths within a range of about 620 nm to 780 nm, green light may include light of one or more wavelengths within a range of about 492 nm to 577 nm, and blue light may include light of one or more wavelengths within a range of about 435 nm to 493 nm.

[0315] In some embodiments, the light source 530 ( Figure 6 ) can be configured to emit light at one or more wavelengths (e.g., infrared and / or ultraviolet wavelengths) outside the visual perception range of a viewer. In addition, the incoupling, outcoupling, and other light redirection structures of the waveguide of the display 250 can be configured to direct this light out of the display and toward the user's eye 210, e.g., for imaging and / or user stimulation applications.

[0316] Reference now Fig. 9A In some embodiments, it may be necessary to redirect the light impinging on the waveguide to couple the light into the waveguide. An incoupling optical element may be used to redirect the light and couple the light into its corresponding waveguide. Although referred to as an incoupling optical element in the specification, the incoupling optical element need not be an optical element and may also be a non-optical element. Fig. 9A A cross-sectional side view of an example of a stacked waveguide set 660 is shown, each stacked waveguide including an incoupling optical element. The waveguides may each be configured to output light of one or more different wavelengths, or light of one or more different wavelength ranges. It should be understood that stack 660 may correspond to stack 260 (except that light from one or more of image injection devices 360, 370, 380, 390, 400 is injected into the waveguide from a location where it is desired to redirect light for incoupling. Figure 6 ), and the waveguide of the stack 660 shown can correspond to a portion of the waveguides 270, 280, 290, 300, 310.

[0317] The stacked waveguide group 660 shown includes waveguides 670, 680, and 690. Each waveguide includes an associated coupling optical element (which may also be referred to as a light input region on the waveguide), wherein, for example, a coupling optical element 700 disposed on a major surface (e.g., top major surface) of the waveguide 670, a coupling optical element 710 disposed on a major surface (e.g., top major surface) of the waveguide 680, and a coupling optical element 720 disposed on a major surface (e.g., top major surface) of the waveguide 690. In some embodiments, one or more of the coupling optical elements 700, 710, 720 may be disposed on the bottom major surface of the corresponding waveguide 670, 680, 690 (particularly in the case where one or more coupling optical elements are reflective deflecting optical elements). As shown, the coupling optical elements 700, 710, 720 may be disposed on the top major surface (or the top of the next waveguide) of their corresponding waveguides 670, 680, 690, particularly in the case where those coupling optical elements are transmissive deflecting optical elements. In some embodiments, the coupling-in optical elements 700, 710, 720 can be disposed in the body of the respective waveguides 670, 680, 690. In some embodiments, as discussed herein, the coupling-in optical elements 700, 710, 720 are wavelength selective such that they selectively redirect light of one or more wavelengths while transmitting light of other wavelengths. Although shown on one side or corner of their respective waveguides 670, 680, 690, it should be understood that in some embodiments, the coupling-in optical elements 700, 710, 720 can be disposed in other areas of their respective waveguides 670, 680, 690.

[0318] As shown, the coupling optical elements 700, 710, 720 can be laterally offset from each other. In some embodiments, each coupling optical element can be offset so that the coupling optical element receives light without the light propagating through another coupling optical element. For example, each coupling optical element 700, 710, 720 can be configured to receive light from a different image injection device 360, 370, 380, 390, and 400, such as Figure 6 As shown, the coupling optical element 700, 710, 720 may be separated (eg, laterally spaced) from the other coupling optical elements 700, 710, 720 so that the coupling optical element does not substantially receive light from the other coupling optical elements 700, 710, 720.

[0319] Each waveguide further includes an associated light distribution element, wherein, for example, a light distribution element 730 disposed on a major surface (e.g., top major surface) of the waveguide 670, a light distribution element 740 disposed on a major surface (e.g., top major surface) of the waveguide 680, and a light distribution element 750 disposed on a major surface (e.g., top major surface) of the waveguide 690. In some other embodiments, the light distribution elements 730, 740, 750 may be disposed on the bottom major surface of the associated waveguides 670, 680, 690, respectively. In some other embodiments, the light distribution elements 730, 740, 750 may be disposed on the top major surface and the bottom major surface of the associated waveguides 670, 680, 690, respectively; or, the light distribution elements 730, 740, 750 may be disposed on different surfaces of the top major surface and the bottom major surface in different associated waveguides 670, 680, 690, respectively.

[0320] The waveguides 670, 680, 690 may be spaced apart and separated by layers of, for example, gas, liquid, and / or solid material. For example, as shown, layer 760a may separate waveguides 670 and 680; layer 760b may separate waveguides 680 and 690. In some embodiments, layers 760a and 760b are formed of a low refractive index material (i.e., a material having a refractive index lower than the material forming the immediately adjacent waveguide in waveguides 670, 680, 690). Preferably, the refractive index of the material forming layers 760a, 760b is 0.05 or more less, or 0.10 or more less, than the refractive index of the material forming waveguides 670, 680, 690. Advantageously, the lower refractive index layers 760a, 760b may serve as cladding layers that facilitate total internal reflection (TIR) ​​of light through waveguides 670, 680, 690 (e.g., TIR between the top major surface and the bottom major surface of each waveguide). In some embodiments, the layers 760a, 760b are formed of air. Although not shown, it is understood that the top and bottom of the illustrated waveguide set 660 may include an adjacent cladding layer.

[0321] Preferably, for ease of manufacturing and other considerations, the materials forming waveguides 670, 680, 690 are similar or the same, and the materials forming layers 760a, 760b are similar or the same. In some embodiments, the materials forming waveguides 670, 680, 690 can be different between one or more waveguides, and / or the materials forming layers 760a, 760b can be different, while still maintaining the various refractive index relationships described above.

[0322] Continue to refer Fig. 9A , light rays 770, 780, 790 are incident on the waveguide group 660. It should be understood that light rays 770, 780, 790 may be injected through one or more image injection devices 360, 370, 380, 390, 400 ( Figure 6 ) are injected into waveguides 670, 680, and 690.

[0323] In some embodiments, the light rays 770, 780, 790 have different characteristics, such as different wavelengths or different wavelength ranges, which may correspond to different colors. The incoupling optical elements 700, 710, 720 each deflect incident light so that the light propagates through a corresponding one of the waveguides 670, 680, 690 by TIR. In some embodiments, the incoupling optical elements 700, 710, 720 each selectively deflect light of one or more specific wavelengths while transmitting other wavelengths to the underlying waveguide and associated incoupling optical element.

[0324] For example, the coupling-in optical element 700 can be configured to deflect light 770 having a first wavelength or wavelength range, while transmitting light 780 and 790 having different second and third wavelengths or wavelength ranges, respectively. The transmitted light 780 impinges upon and is deflected by the coupling-in optical element 710, which is configured to deflect light of the second wavelength or wavelength range. The light 790 is deflected by the coupling-in optical element 720, which is configured to selectively deflect light of the third wavelength or wavelength range.

[0325] Continue to refer Fig. 9A , the deflected light rays 770, 780, 790 are deflected so that they propagate through the corresponding waveguides 670, 680, 690; that is, the coupling-in optical element 700, 710, 720 of each waveguide deflects light into the corresponding waveguide 670, 680, 690 to couple the light into the corresponding waveguide. The light rays 770, 780, 790 are deflected at certain angles that cause the light to propagate through the corresponding waveguides 670, 680, 690 by TIR. The light rays 770, 780, 790 propagate through the corresponding waveguides 670, 680, 690 by TIR until they impinge on the corresponding light distribution elements 730, 740, 750 of the waveguides.

[0326] Reference now Fig. 9B , showing Fig. 9A 670, 680, 690 by TIR. Then, the light rays 770, 780, 790 are incident on the light distribution elements 730, 740, 750, respectively. The light distribution elements 730, 740, 750 deflect the light rays 770, 780, 790 so that the light rays 770, 780, 790 propagate toward the out-coupling optical elements 800, 810, 820, respectively.

[0327] In some embodiments, the light distribution elements 730, 740, 750 are orthogonal pupil expanders (OPEs). In some embodiments, the OPEs deflect or distribute light to the outcoupling optical elements 800, 810, 820, and in some embodiments, may also increase the beam or spot size of the light as it propagates to the outcoupling optical elements. In some embodiments, the light distribution elements 730, 740, 750 may be omitted, and the incoupling optical elements 700, 710, 720 may be configured to deflect light directly to the outcoupling optical elements 800, 810, 820. For example, referring to Fig. 9A , the light distribution elements 730, 740, 750 can be replaced by outcoupling optical elements 800, 810, 820, respectively. In some embodiments, the outcoupling optical elements 800, 810, 820 are exit pupils (EP) or exit pupil expanders (EPE), which direct light to the eye 210 ( Figure 7 ). It should be understood that the OPE can be configured to increase the size of the eye box in at least one axis, and the EPE can increase the eye box in an axis that intersects (e.g., is orthogonal) to the axis of the OPE. For example, each OPE can be configured to redirect a portion of the light that illuminates the OPE to the EPE of the same waveguide, while allowing the remainder of the light to continue to propagate along the waveguide. When the OPE is illuminated again, another portion of the remaining light is redirected to the EPE, and the remainder of the portion continues to propagate further along the waveguide, and so on. Similarly, when the EPE is illuminated, a portion of the illuminated light is directed out of the waveguide toward the user, and the remainder of the light continues to propagate through the waveguide until it illuminates the EP again, at which time another portion of the illuminated light is directed out of the waveguide, and so on. Therefore, each time a portion of the light is redirected by an OPE or EPE, a single beam of coupled-in light can be "copied", thereby forming a field of the cloned beam, such as Figure 6 In some embodiments, the OPE and / or EPE may be configured to modify the size of the light beam.

[0328] Therefore, reference Fig. 9A and Fig. 9BIn some embodiments, the waveguide group 660 includes waveguides 670, 680, 690 for each component color; coupling optical elements 700, 710, 720; light distribution elements (e.g., OPE) 730, 740, 750; and outcoupling optical elements (e.g., EP) 800, 810, 820. The waveguides 670, 680, 690 can be stacked with an air gap / cladding between each waveguide. The coupling optical elements 700, 710, 720 redirect or deflect the incident light (where different coupling optical elements receive light of different wavelengths) into their waveguides. The light then propagates at a certain angle, which will cause TIR within the corresponding waveguide 670, 680, 690. In the example shown, light ray 770 (e.g., blue light) is deflected by the first incoupling optical element 700 in the manner previously described, and then continues to bounce along the waveguide, interacting with the light distribution element (e.g., OPE) 730 and then the outcoupling optical element (e.g., EP) 800. Light rays 780 and 790 (e.g., green and red light, respectively) will propagate through the waveguide 670, where light ray 780 impinges on and is deflected by the incoupling optical element 710. Light ray 780 then bounces along the waveguide 680 via TIR, proceeds to its light distribution element (e.g., OPE) 740, and then reaches the outcoupling optical element (e.g., EP) 810. Finally, light ray 790 (e.g., red light) propagates through the waveguide 690 and impinges on the incoupling optical element 720 of the waveguide 690. The light incoupling optical element 720 deflects the light 790 so that it propagates through TIR to the light distribution element (e.g., OPE) 750 and then propagates through TIR to the outcoupling optical element (e.g., EP) 820. The outcoupling optical element 820 then finally couples the light 790 out to the viewer, who also receives outcoupled light from the other waveguides 670, 680.

[0329] Fig. 9C Shows Fig. 9A and Fig. 9B A top plan view of an example of multiple stacked waveguides. As shown, the waveguides 670, 680, 690 and the associated light distribution elements 730, 740, 750 and associated outcoupling optical elements 800, 810, 820 of each waveguide can be vertically aligned. However, as discussed herein, the coupling-in optical elements 700, 710, 720 are not vertically aligned; instead, the coupling-in optical elements are preferably non-overlapping (e.g., laterally spaced apart as shown in the top view). As further discussed herein, this non-overlapping spatial arrangement facilitates one-to-one injection of light from different resources into different waveguides, thereby allowing a particular light source to be uniquely coupled to a particular waveguide. In some embodiments, arrangements including non-overlapping spatially separated coupling-in optical elements may be referred to as shifted pupil systems, and the coupling-in optical elements within these arrangements may correspond to sub-pupils.

[0330] Fig.9D An example of a wearable display system 60 that can integrate the various waveguides and related systems disclosed herein is shown. In some embodiments, the display system 60 is Figure 6 The system 250, wherein Figure 6 Some parts of the system 60 are schematically shown in more detail. For example, Figure 6 The waveguide assembly 260 can be part of the display 70.

[0331] Continue to refer Fig.9D , the display system 60 includes a display 70, and various mechanical and electronic modules and systems that support the functions of the display 70. The display 70 can be coupled to a frame 80, which can be worn by a display system user or viewer 90, and is configured to position the display 70 in front of the user 90. In some embodiments, the display 70 can be regarded as glasses. In some embodiments, a speaker 100 is coupled to the frame 80 and is configured to be positioned near the ear canal of the user 90 (in some embodiments, another speaker (not shown) can be selectively positioned near the other ear canal of the user to provide stereo / shaped sound control). The display system 60 may also include one or more microphones 110 or other devices for detecting sound. In some embodiments, the microphone is configured to allow the user to provide input or commands to the system 60 (e.g., selection of voice menu commands, natural language questions, etc.), and / or may allow audio communication with other people (e.g., other users of similar display systems). The microphone may be further configured as a peripheral sensor to collect audio data (e.g., sound from the user and / or the environment). In some embodiments, the display system 60 may further include one or more outward-facing environmental sensors 112 configured to detect objects, stimuli, people, animals, locations, or other aspects of the world around the user. For example, the environmental sensors 112 may include one or more cameras, which may be positioned, for example, facing outward to capture images similar to at least a portion of the general field of view of the user 90. In some embodiments, the display system may also include peripheral sensors 120a, which may be separate from the frame 80 and attached to the body of the user 90 (e.g., on the head, torso, limbs, etc. of the user 90). In some embodiments, the peripheral sensors 120a may be configured to acquire data characterizing the physiological state of the user 90. For example, the sensors 120a may be electrodes.

[0332] Continue to refer Fig.9D, the display 70 is operably coupled to a local data processing module 140 via a communication link 130 (such as via a wired lead or a wireless connection), and the local data processing module 140 can be installed in various configurations, such as fixedly attached to the frame 80, fixedly attached to a helmet or hat worn by the user, embedded in headphones, or otherwise removably attached to the user 90 (e.g., in a backpack configuration, in a belt-coupled configuration). Similarly, the sensor 120a can be operably coupled to the local processing and data module 140 via a communication link 120b (e.g., via a wired lead or a wireless connection). The local processing and data module 140 may include a hardware processor and digital memory, such as non-volatile memory (e.g., flash memory or a hard drive), both of which can be used to assist in the processing, caching, and storage of data. Optionally, the local processor and data module 140 may include one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, etc. Such data includes a) data captured by sensors (which may, for example, be operably coupled to the frame 80 or otherwise attached to the user 90), such as image capture devices (such as cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, radios, gyroscopes, and / or other sensors disclosed herein; and / or b) data (including data related to virtual content) acquired and / or processed using the remote processing module 150 and / or remote data repository 160, which data may be transmitted to the display 70 after such processing or retrieval. The local processing and data module 140 may be operably coupled to the remote processing module 150 and the remote data repository 160 via communication links 170, 180 (such as via a wired or wireless communication link) so that these remote modules 150, 160 are operably coupled to each other and available as resources to the local processing and data module 140. In some embodiments, the local processing and data module 140 may include one or more of an image capture device, a microphone, an inertial measurement unit, an accelerometer, a compass, a GPS unit, a radio, and / or a gyroscope. In some other embodiments, one or more of these sensors may be attached to the frame 80, or may be an independent structure that communicates with the local processing and data module 140 via a wired or wireless communication path.

[0333] Continue to refer Fig.9DIn some embodiments, the remote processing module 150 may include one or more processors configured to analyze and process data and / or image information, for example, including one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, etc. In some embodiments, the remote data repository 160 may include a digital data storage facility that can be obtained through the Internet or other network configurations in a "cloud" resource configuration. In some embodiments, the remote data repository 160 may include one or more remote servers that provide information to the local processing and data module 140 and / or the remote processing module 150, such as information for generating augmented reality content. In some embodiments, all data is stored in the local processing and data module, and all calculations are performed, allowing full autonomous use from the remote module. Optionally, an external system (e.g., a system of one or more processors, one or more computers) including a CPU, GPU, etc. can perform at least a portion of the processing (e.g., generating image information, processing data), and provide information to the modules 140, 150, 160, and receive information from the modules 140, 150, 160, for example, via a wireless or wired connection.

[0334] Fig.10 1 is a schematic diagram showing a projector assembly 1000 that utilizes a polarizing beam splitter (PBS) 1020 to illuminate a spatial light modulator (SLM) 1030 and redirects light from the SLM 1030 to an eyepiece (not shown) through projection optics 1040. The projector assembly 1000 includes an illumination source 1010, which may include, for example, a light emitting diode (LED), a laser (e.g., a laser diode), or other type of light source. The light may be collimated by collimating optics. The illumination source 1010 may emit polarized, unpolarized, or partially polarized light. In the design shown, the illumination source 1010 may emit polarized light 1012 having p-polarization. A first optical element 1015 (e.g., a prepolarizer) is aligned to allow light having a first polarization (e.g., p-polarization) to pass therethrough.

[0335] The light is directed to the polarization beam splitter 1020. Initially, the light propagates through the interface 1022 (e.g., polarization interface) of the PBS 1020, which is configured to transmit light of a first polarization (e.g., p-polarization). Therefore, the light continues to reach the spatial light modulator 1030 and is incident on the spatial light modulator 1030. As shown, the SLM 1030 is a reflective SLM that is configured to back-reflect the incident light and selectively modulate the light. The SLM 1030, for example, includes one or more pixels that may have different states. The light incident on each pixel can be modulated based on the state of the pixel. Therefore, the SLM 1030 can be driven to modulate the light to provide an image. In this example, the SLM 1030 can be a polarization-based SLM that modulates the polarization of the light incident thereon. For example, in the on state, the pixels of the SLM 1030 change the input light from a first polarization state (e.g., p-polarization state) to a second polarization state (e.g., s-polarization state), thereby displaying a bright state (e.g., a white pixel). The second polarization state may be the first polarization state modulated (e.g., rotated) by 90°. In the on state, light having the second polarization state is reflected by the interface 1022 and propagates downward to the projector optics 1040. In the off state, the SLM 1030 does not change the polarization state of light incident thereon, e.g., does not rotate the input light from the first polarization state, and thus displays a dark state (e.g., a black pixel). In the off state, light having the first polarization state is transmitted through the interface 1022 and propagates upward back to the illumination source 1010 instead of the user's eye.

[0336] After reflecting from SLM 1030, a portion of light 1014 (e.g., modulated light) reflects from interface 1022 and exits PBS 1020 to be directed to the user's eye. The emitted light propagates through projector optics 1040 and is imaged onto incoupling grating (ICG) 1050 of the eyepiece (not shown).

[0337] Fig.11A A system (eg, augmented reality display system) 1100A for presenting an image to a user's eye 210 and for viewing the world 510 is shown, the system having Fig.10The system 1100 includes a light source 1110, a spatial light modulator (SLM) 1140, and a waveguide 1120, the system being arranged such that light from the light source 1110 illuminates the SLM 1140, and light reflected from the SLM 1140 is coupled into the waveguide 1120 to be directed to the eye 210. The system 1100A includes an optical device 1130, which is arranged to both illuminate the SLM 1140 and project an image of the SLM 1140. For example, light from the light source 1110 propagates through the optical device 1130 in a first direction, reaches the SLM 1140, and illuminates the SLM 1140. Light reflected from the SLM 1140 propagates through the optical device 1130 again in a second direction opposite to the first direction, and is then directed to the waveguide 1120 and coupled into the waveguide.

[0338] The light source 1110 may include a light emitting diode (LED), a laser (e.g., a laser diode), or other types of light sources. The light source 1110 may be a polarized light source, but the light source 1110 is not necessarily limited thereto. In some embodiments, a polarizer 1115 may be located between the light source 1110 and the SLM 1140. As shown, the polarizer 1115 is located between the light source 1110 and the waveguide 1120. The polarizer 1115 may also be a light recycler that transmits light of a first polarization and reflects light having a second polarization back to the light source 1110. Such a polarizer 1115 may be, for example, a wire grid polarizer. A coupling optical device 1105 such as a non-imaging optical element (e.g., a conical compound parabolic concentrator (CPC, lens)) may be disposed relative to the light source 1110 to receive light output from the light source 1110. The coupling optical device 1105 may collect light from the light source 1110, and in some cases, may reduce the divergence of light emitted from the light source 1110. The coupling optics 1105 can, for example, collimate the light output from the light source 1110. The coupling optics 1105 can collect light that matches the angular spectrum field of view of the system 1100A. Thus, the coupling optics 1105 can match the angular spectrum of the light output by the light source 1110 to the field of view of the system 1100A. The coupling optics 1105 can have an asymmetric profile to asymmetrically operate on the light emitted from the light source 1110. For example, the coupling optics 1105 can reduce the divergence by different amounts in orthogonal directions (e.g., x and z directions). Such asymmetry in the coupling optics 1105 can address asymmetry in the light emitted from the light source 1110, which can, for example, include a laser diode that emits light over a wider angular range along a direction (e.g., x or z) opposite to the orthogonal direction (e.g., z or x, respectively).

[0339] As described above, system 1100A includes an optical device 1130 disposed in the optical path between light source 1110 and SLM 1140, which is configured to illuminate SLM 1140. Optical device 1130 may include a transmissive optical device that transmits light from light source 1110 to SLM 1140. Optical device 1130 may also be configured to project an image of SLM 1140 or an image formed by SLM 1140 into waveguide 1120. The image may be projected into the eye in eye 210. In some designs, optical device 1130 may include one or more lenses or optical elements having optical power. Optical device 1130 may, for example, have positive optical power. Optical device 1130 may include one or more refractive optical elements, such as a refractive lens. Other types of optical elements may also be used.

[0340] SLM 1140 may be reflective, modulating and reflecting light therefrom. SLM 1140 may be a polarization-based SLM configured to modulate polarization. SLM 1140 may, for example, include a liquid crystal (LC) SLM (e.g., a liquid crystal on silicon (LCOS) SLM). LC SLM may, for example, include twisted nematic (TN) liquid crystal. SLM 1140 may be substantially similar to reference Fig.10 SLM 1030. SLM 1140 may include, for example, one or more pixels configured to selectively modulate light incident on the pixel depending on the pixel state. For some types of SLM 1140, the pixel may modulate a light beam incident thereon, for example, by changing the polarization state, such as rotating the polarization (e.g., rotating the orientation of linearly polarized light).

[0341] As described above, SLM 1140 can be an LCOS SLM 1140. In a crossed polarizer configuration, LCOS SLM 1140 can be nominally white. When the pixel is off (e.g., 0 voltage), it has a bright state, and when the pixel is on (e.g., a voltage above a threshold turn-on voltage), it has a dark state. In this cross-polarization configuration, light leakage is minimized when the pixel is on and when the pixel is in a dark state.

[0342] In the parallel polarizer configuration, the LCOS SLM 1140 is nominally black. When the pixel is off (e.g., 0 voltage), it has a dark state, and when the pixel is on (e.g., a voltage above the threshold turn-on voltage), it has a light state. In this parallel polarizer configuration, light leakage is minimized when the pixel is off and when the pixel is in the dark state. The dark state can be (re)optimized using the rub direction and the compensator angle. The compensator angle can refer to the angle of the compensator between the optics 1130 and the SLM 1140, for example, Fig. 20B shown.

[0343] The dynamic range and throughput of the parallel polarizer configuration can be different from that of the crossed polarizer configuration. In addition, the parallel polarizer configuration can be optimized for contrast, unlike the crossed polarizer configuration.

[0344] The system 1100A includes a waveguide 1120 for outputting image information to the eye 210. The waveguide 1120 can be substantially similar to the waveguides 270, 280, 290, 300, 310, 670, 680, and 690 discussed above. The waveguide 1120 can include a substantially transparent material having a refractive index sufficient to guide light in the waveguide. As shown, the waveguide 1120 can include a first side 1121 and a second side 1123 opposite the first side 1121, and corresponding upper and lower major surfaces and edges around them. The first major surface 1121 and the second major surface 1123 can be sufficiently flat so that image information can be preserved when propagating light from the SLM 1140 to the eye 210, so that an image formed by the SLM 1140 can be injected into the eye. The optical device 1130 and the SLM 1140 can be located on the first side 1121 of the waveguide 1120. The light source 1110 may be disposed on the second side 1123 such that light from the light source 1110 is incident on the second side 1123 before propagating through the waveguide 1120 and reaching the SLM 1140 through the optical device 1130. Thus, the waveguide 1120 may be disposed between the light source 1110 and the optical device 1130. In addition, at least a portion of the waveguide 1120 may extend between the light source 1110 and the optical device 1130, whereby the light propagates through a portion of the waveguide 1120 to reach the optical device 1130. Thus, light emitted from the light source 1110 may be guided through the waveguide 1120, enter and pass through the optical device 1130, and be incident on the SLM 1140. The SLM 1140 reflects the light back such that the light passes through the optical device 1130 and reaches the waveguide 1120.

[0345] The system 1100A also includes a coupling optical element 1160 for coupling light from the optical device 1130 into the waveguide 1120. The coupling optical element 1160 can be disposed on a major surface (e.g., the upper major surface 1123) of the waveguide 1120. In some designs, the coupling optical element 1160 can be disposed on the lower major surface 1121 of the waveguide 1120. In some designs, the coupling optical element 1160 can be disposed in the body of the waveguide 1120. Although the coupling optical element 1160 is shown as being located on a side or corner of the waveguide 1120, the coupling optical element 1160 can also be disposed in / on other areas of the waveguide 1120. The coupling optical element 1160 can be based on the above reference Fig. 9A , Fig. 9B and Fig. 9C The coupling-in optical elements 700, 710, 720 described are similar. The coupling-in optical element 1160 may be a diffractive optical element or a reflector. Other structures may also be used as the coupling-in optical element 1160. The coupling-in optical element 1160 may be configured to guide light incident thereon into the waveguide 1120 at a sufficiently large grazing angle (e.g., greater than the critical angle) relative to the upper major surface 1123 and the lower major surface 1121 of the waveguide 1120, thereby guiding the light in the waveguide 1120 by total internal reflection. In addition, the coupling-in optical element 1160 may operate over a wide wavelength range and thus be configured to couple multiple colors of light into the waveguide 1120. For example, the coupling-in optical element 1160 may be configured to couple red light, green light, and blue light into the waveguide 1120. The light source 1110 may emit red, green, and blue light at different times.

[0346] The system 1100A includes a light distribution element 1170 disposed on or in the waveguide 1120. The light distribution element 1170 may be substantially the same as described above with respect to Fig. 9B The light distribution elements 730, 740, and 750 described are similar. For example, the light distribution element 1170 can be an orthogonal pupil expander (OPE). The light distribution element 1170 can be configured to distribute light along the x direction, for example, toward Fig. 11B The light propagating in the z-direction shown in the top view of FIG. 11 is deflected and spread out within the waveguide 1120. Thus, the light distribution element 1170 can be configured to increase the size of the eye movement field along the z-axis; see Fig. 11B The light distributing element 1170 may, for example, include one or more diffractive optical elements configured to diffract light incident on the diffractive optical elements propagating within the waveguide 1120, thereby redirecting the light in substantially orthogonal directions, for example. Other configurations are also possible.

[0347] like Fig. 11B As shown, the system 1100A may also include an outcoupling optical element 1180 for coupling light out of the waveguide 1120 to the eye 210. The outcoupling optical element 1180 may be configured to redirect light propagating within the waveguide 1120 by total internal reflection (TIR) ​​at an angle more perpendicular to the upper major surface 1123 and / or the lower major surface 1121 of the waveguide 1120 so that the light is not guided within the waveguide 1120. Instead, the light is guided out of the waveguide 1120, for example, through the lower major surface 1121. The outcoupling optical element 1180 may, for example, include one or more diffractive optical elements configured to diffract light incident on the diffractive optical element propagating within the waveguide 1120, thereby, for example, redirecting the light out of the waveguide 1120. Other configurations are also possible.

[0348] Fig. 11BThe position of the light-incoupling optical element 1160, which is disposed laterally with respect to the light distribution optical element (e.g., an orthogonal pupil expander) 1170 and the light-extracting optical element 1180, is also shown. Fig. 11B The position of the light source 1110, which is disposed laterally with respect to the light-incoupling optical element 1160, the light distribution optical element (e.g., an orthogonal pupil expander) 1170, and the light-extracting optical element 1180, is also shown.

[0349] In operation, the light source 1110 of the system 1100A emits light into the coupling optical device 1105 and passes through the polarizer 1115. Thus, the light can be polarized, for example, linearly polarized in a first direction. The polarized light can be transmitted through the waveguide 1120, enter the second major surface of the waveguide 1120, and exit from the first major surface of the waveguide 1120. The light can propagate to the SLM 1140 through the optical device 1130. The optical device 1130 quasi-collimates and / or selects the light from the light source 1110 so as to illuminate the SLM 1140, which can include a polarization-based modulator that modulates the polarization of the light incident on the modulator, such as by selectively rotating the orientation of the modulator pixel by pixel depending on the pixel state. For example, a first pixel can be in a first state and rotate the polarization, while a second pixel can be in a second state and not rotate the polarization. The light between the coupling optical device 1105 and the optical device 1130 can illuminate the SLM 1140 fairly uniformly. After being incident on the SLM 1140, the light is reflected back through the optics 1130. The optics 1130 can be configured to project an image from the SLM 1140 into the waveguide 1120 and ultimately into the eye 210 so that the image is visible to the eye 210. In some designs, the retina of the eye 210 is an optical conjugate of the SLM 1140 and / or the image formed by and / or on the SLM 1140. The optical power of the optics 1130 helps project the image on the SLM 1140 into the eye 210 and onto the retina of the eye 210. In some embodiments, for example, the optical power provided by the outcoupling optics 1180 can help and / or affect the image ultimately formed in the eye 210. As the light reflected from the SLM 1140 travels through the optics toward the waveguide 1120, the optics 1130 acts as a projection lens. The optics may roughly act as a Fourier transform of an image on the SLM 1140 to a plane in the waveguide 1120 adjacent to the coupling-in optical element 1160. The two lights propagating together through the optics 1130 (a first light from the light source 1110 to the SLM 1140 and a second light from the SLM 1140 to the waveguide 1120) may roughly act as imaging the pupil of the coupling optics 1105. The alignment and orientation of the light source 1110 (and possibly the coupling optics 1105 and / or the polarizer 1115), the optics 1130, and the SLM 1140 are such that light from the light source 1110 reflected from the SLM 1140 is directed onto the coupling-in optical element 1160. The pupil associated with the coupling optics 1105 may be aligned with the coupling-in optical element 1160. The light may propagate through an analyzer 1150 (e.g., a polarizer) in the optical path between the SLM 1140 and the eye 210. As shown in FIG. Fig.11AAs shown, an analyzer (e.g., polarizer) 1150 may be disposed in the optical path between the optical device 1130 and the coupling-in optical element 1160. The analyzer 1150 may, for example, be a linear polarizer oriented to transmit light of a first polarization (P polarization) and block light of a second polarization (S polarization), or to transmit light of the second polarization and block light of the first polarization. The analyzer 1150 may be a clean-up polarizer and further block light of a polarization blocked by another polarizer between the SLM 1140 and the analyzer 1150 or within the SLM 1140. The analyzer 1150 may, for example, be a circular polarizer that acts as an isolator to mitigate reflections from the waveguide 1120, particularly the coupling-in optical element 1160, back toward the SLM 1140. As any polarizer disclosed herein, the analyzer 1150 may include a wire grid polarizer, such as an absorptive wire grid polarizer. Such a polarizer may provide significant absorption of unwanted light, thereby increasing contrast. Some such polarizers can be made to include one or more dielectric layers on top of the wires and / or multilayer films. In some embodiments, the SLM 1140 can be a liquid crystal on silicon (LCOS) SLM and can include an LC cell and a retarder (e.g., a compensator). In some embodiments, the analyzer 1150 can be a compensator designed to provide a more consistent polarization rotation (e.g., 90°) of the SLM 1140 for different incident angles and different wavelengths. The compensator can be used to improve the contrast of the display by improving the rotated polarization of light incident across a range of incident angles and wavelengths. The SLM 1140 can, for example, include a TN LCOS that is configured to rotate incident light of a first polarization (e.g., s-polarization) of a first pixel to a second polarization (e.g., p-polarization) so that when the light propagates through the analyzer 1150, a bright pixel state is produced. Conversely, the SLM 1140 may be configured to not rotate incident light of a first polarization (e.g., s-polarization) of a second pixel to a second polarization (e.g., p-polarization) so that when the light would be attenuated or blocked by the analyzer 1150, the reflected light maintains the first polarization to produce a dark pixel. In this configuration, the orientation of the polarizer 1115 closer to the light source 1110 along the light path may be different from (e.g., orthogonal to) the analyzer 1150 farther along the light path to the light source 1110. Other, such as opposite, configurations are also possible.

[0350] The light is then deflected, for example, by coupling into optical element 1160 to be guided in waveguide 1120, where it propagates by TIR. The light then strikes light distribution element 1170, which deflects the light in another direction (e.g., more toward the z direction), causing the size of the eye movement field along the z-axis direction to increase, as shown in FIG. Fig. 11BAs shown. Thus, the light is deflected toward the outcoupling optical element 1180, which causes the light to be directed out of the waveguide 1120 toward the eye 210 (e.g., the user's eye as shown). The light coupled out in the z direction by different portions of the outcoupling optical element 1180 causes an increase in the size of the eye movement range along a direction at least parallel to the z axis, as shown. Fig. 11B It is noted that in this configuration, the optics 1130 is used both to illuminate the SLM 1140 and to project an image onto the incoupling optics 1160. Thus, the optics 1130 can be used as a projection optics to distribute (e.g., evenly) light from the light source 1110, as well as an imaging optics to provide an image of the SLM 1140 and / or an image formed by the SLM 1140 into the eye. Fig.11A / Fig. 11B The system 1100A in some cases can be compared to Fig.10 The system 1000 is more compact. In some cases, it is not necessary to use Fig.10 The PBS 1020 shown may reduce the cost and / or size of the system. In addition, without the PBS 1020, the system may be more symmetrical and easier to design by shortening the back focal length of the optics 1130.

[0351] As mentioned above, alternative configurations are possible. Fig. 11C For example, in some designs, system 1100C can be configured to pass light having a polarization that is not rotated by SLM 1140. In one embodiment, for example, SLM 1140 is a liquid crystal (LC) based SLM and can include vertical alignment (VA) LC on silicon (LCoS). The SLM 1140 can have a first pixel in a first state that does not rotate the polarization and a second pixel in a second state that rotates the polarization. Fig. 11C In the configuration shown, a single shared analyzer / polarizer 1155 is utilized. The analyzer 1155 can transmit light of a first polarization (e.g., s-polarization) and attenuate or reduce the transmission of a second polarization (e.g., p-polarization). Thus, light incident on a first pixel in a first state of non-rotating polarization orientation (e.g., s-polarized light) is reflected by the SLM 1140 and propagates through the analyzer 1155 to the waveguide 1120. Conversely, light incident on a second pixel in a second state of rotating polarization orientation (e.g., s-polarized light) is reflected by the SPM 1140 and is attenuated, reduced, or does not propagate through the analyzer 1155 to the waveguide 1120. This configuration can allow Fig.11A The polarizer 1115 and analyzer 1150 are shown integrated into a shared optical element ( Fig. 11C The polarizer 1155 shown in FIG. 1 can be simplified by reducing the number of optical components. Fig.11A / Fig. 11B The system 1100. The analyzer 1155 can be disposed between the waveguide 1120 and the optical device 1130. In other embodiments, separate analyzer / polarizers and analyzer / polarizers can be used, such as Fig.11A / Fig. 11B As shown in system 1100. Fig.11A and Fig. 11B A polarizer 1115 between the light source 1110 and the waveguide 1120 is shown, as is an analyzer 1140 between the optics 1130 and the waveguide 1120 .

[0352] Various other configurations may be employed that utilize optical device 1130 to both illuminate SLM 1140 and image the image formed by SLM 1140. For example, although FIG. 11A to FIG. 11C A single waveguide 1120 is shown, but one or more waveguides may be used, such as a waveguide stack (possibly different waveguides for different colors of light). Fig. 12A A cross-sectional side view of an example system 1200A is shown, including a stack 1205 including waveguides 1120, 1122, 1124, each of which includes an in-coupling optical element 1260, 1262, 1264. Waveguides 1120, 1122, 1124 can each be configured to output one or more different wavelengths of light, or one or more different wavelength ranges of light. Stack 1205 can be substantially similar to stacks 260 and 660 ( Figure 6 and Fig. 9A ), and the waveguides 1120, 1122, 1124 of the stack 1205 shown may correspond to a portion of the waveguides 670, 680, 690, however, the stack 1205 and the waveguides 1120, 1122, 1124 are not necessarily limited thereto. Fig. 12A As shown, coupling optical elements 1260, 1262, 1264 can be associated with, included in or on waveguides 1120, 1122, 1124, respectively. Coupling optical elements 1260, 1262, 1264 can make color selective and can mainly shift or redirect certain wavelengths into corresponding waveguides 1120, 1122, 1124 to guide these wavelengths therein. As shown, since coupling optical elements 1260, 1262, 1264 are color selective, coupling optical elements 1260, 1262, 1264 do not need to be laterally shifted and can be stacked on each other. Wavelength multiplexing can be used to couple specific colors into corresponding waveguides. For example, a red coupling optical element may couple red light into a waveguide designated for propagating red light, but not blue or green light, which are instead coupled into other waveguides by other blue or green selective waveguides, respectively.

[0353] In some embodiments, the light source 1110 can be a multi-color light source capable of emitting different colors of light at different times. For example, the light source 1110 can emit red, green, and blue (RGB) light, and can be configured to emit red and no more than negligible amounts of green and blue in a first time period, emit green and no more than negligible amounts of red and blue in a second time period, and emit blue and no more than negligible amounts of red and green in a third time period. These cycles can be repeated, and the SLM 1140 can be coordinated to generate an appropriate pixel state pattern for a particular color (red, green, or blue) to provide the appropriate image color component for a given image frame. The different waveguides 1120, 1122, 1124 of the stack 1205 can each be configured to output light having different individual colors. For example, as Fig. 12A As shown, waveguides 1120, 1122, 1124 can be configured to output blue, green and red light, respectively. Of course, other colors are possible, for example, light source 1110 can emit other colors, and color-selective coupling-in optical elements 1260, 1262, 1264; coupling-out optical elements, etc. can be configured for these other colors. In addition, the individual red, green and blue emitters can be close enough to effectively act as a single pupil light source. The red, green and blue emitters can be combined with lenses and dichroic separators to form a single red, green and blue pupil source. Multiplexing of a single pupil can be extended beyond or in addition to color selectivity and can include the use of polarization-sensitive gratings and polarization switching. These color or polarization gratings can also be used in conjunction with multiple display pupils to increase the number of layers that can be addressed.

[0354] The different incoupling optical elements 1260, 1262, 1264 in the different waveguides 1120, 1122, 1124 may be disposed above and / or below each other and may be laterally aligned (e.g., along the Fig. 12A1122), as opposed to being laterally displaced and misaligned relative to one another. Thus, in some embodiments, for example, different coupling-in optical elements 1260, 1262, 1264 can be configured such that light of a first color can be coupled into waveguide 1120 by coupling-in optical element 1260 to be guided therein, light of a second color different from the first color can propagate through coupling-in optical element 1260 to the next coupling-in optical element 1262, and can be coupled into waveguide 1122 by coupling-in optical element 1262 to be guided therein. Light of a third color different from the first color and the second color can propagate through coupling-in optical elements 1260 and 1262 to coupling-in optical element 1264, and can be coupled into waveguide 1124 to be guided therein. Additionally, coupling-in optical elements 1260, 1262, 1264 can be polarization selective. For example, different coupling-in optical elements 1260 , 1262 , 1264 may be configured such that light of a specific polarization is coupled into a waveguide by the corresponding polarization selective coupling-in optical element 1260 , 1262 , 1264 , or propagates through the coupling-in optical element 1260 , 1262 , 1264 .

[0355] Depending on the configuration, SLM 1140 may include a polarization-based SLM that modulates polarization. System 1200A may include a polarizer and / or an analyzer to modulate light injected into stack 1205 pixel by pixel, for example, depending on the state of each pixel (e.g., whether the pixel rotates the polarization orientation). Various aspects of such a system employing a polarization-based SLM are discussed above, and any of these features may be employed in conjunction with any other features described herein. However, other designs are still possible.

[0356] For example, a deflection-based SLM 1140 may be employed. For example, the SLM 1140 may include one or more movable optical elements, such as movable mirrors, which may reflect and / or deflect light in different directions depending on the state of the optical elements. The SLM 1140 may, for example, include one or more pixels including such optical elements as micro-mirrors or reflectors. The SLM 1140 may, for example, integrate a digital light processing (DLP) system using a digital micro-mirror device (DMD). TM )technology. Fig. 12BAn example of a system 1200B using such a deflection-based SLM 1140 is shown. System 1200B includes a deflection-based SLM 1140 and a light absorber 1250. The light absorber 1250 may include an absorbing material or structure configured to absorb light. The deflection-based SLM 1140 may include one or more micro-movable mirrors that can be selectively tilted to deflect light in different directions. For example, the deflection-based SLM 1140 may be configured to deflect light from the light source 1110 incident thereon to the coupling-in optical element 1260, 1262, 1264 when a given pixel is in a bright state. As described above, the light is therefore coupled into one of the optical elements 1260, 1262, 1264, into one of the respective waveguides 1120, 1122, 1124, for example depending on the color of the light, and is guided to the eye 210. In contrast, when a given pixel is in a dark state, light from the light source 1110 can be deflected to the light absorber 1250 and is not coupled into one of the respective waveguides 1120, 1122, 1124 by one of the coupling-in optical elements 1260, 1262, 1264 and is not directed to the eye 210. Instead, the light can be absorbed by the absorbing material comprising the light absorber 1250. In some embodiments, the analyzer 1150 can be a polarizer (e.g., a "clean-up" polarizer) that is used to eliminate unwanted reflections from the coupling-in optical elements 1260, 1262, 1264. The polarizer is useful because the optical device 1130 can include plastic optical elements that have birefringence and can change polarization. The "clean-up" polarizer can attenuate or remove light (e.g., reflection) with an unwanted polarization so that it is not directed onto the waveguides 1120, 1122, 1124. Other types of light conditioning elements may also be disposed between the SLM 1140 and the waveguides 1120, 1122, 1124, such as between the optical device 1130 and the waveguides 1120, 1122, 1124. For example, such light conditioning elements may also include a circular polarizer (i.e., a linear polarizer and a retarder such as a quarter wave plate). The circular polarizer may reduce the amount of reflection from the waveguides 1120, 1122, 1124 or the coupling optical element 1260, 1262, 1264 that is re-incident on the waveguides 1120, 1122, 1124 and coupled into the waveguides 1120, 1122, 1124. The reflected light may be circularly polarized and may have an opposite circular polarization to the incident light (e.g., upon reflection, right-handed circularly polarized light is converted to left-handed circularly polarized light, or vice versa). The retarder in the circular polarizer can transform circularly polarized light into linearly polarized light, such as the orthogonal polarization of the polarizer, which is attenuated (eg, absorbed) by the linear polarizer in the circular polarizer. Clean-up polarizers can be used in polarization-independent modulators (such as DMDs).As described above, the clean-up polarizers may be used to suppress reflections and / or improve coupling of light into the coupling-in optical elements 1260, 1262, 1264 in an optimal polarization state.

[0357] Fig. 12B A side view or cross-sectional view of such a system 1200B is shown, and Fig. 12C A top view of the lateral arrangement of the incoupling optical element 1264, the light absorber 1250, and the light source 1110 is shown. Depending on the state of a particular pixel, the SLM 1140 may be configured to reflect, deflect, and / or direct light from the light source 1110 to the lateral position of the incoupling optical element 1264 (and other incoupling optical elements 1260, 1262) or the light collector 1250.

[0358] In some designs, the light absorber 1250 may include an energy collection system. The light absorber 1250 may, for example, include a light energy conversion element configured to convert light energy into electrical energy. The light energy conversion element may, for example, include a solar cell. The light energy conversion element may, for example, include a photodetector that generates an electrical output when light is incident thereon. The light energy conversion element may be electrically connected to an electrical component, such as a conductive wire, to direct the electrical output so as to provide power to the system 1200B and / or possibly charge one or more batteries.

[0359] Laterally shifted non-color selective or broadband or multicolor incoupling optics may be used in some designs. For example, Fig.13A is a perspective view of a system 1300 including a stack 1305 including a waveguide. The stack 1305 can be substantially similar to the reference Fig. 12A Each waveguide in the stack 1305 may include coupling-in optical elements 1360, 1362, 1364, however, Fig. 12A In contrast to the design shown, the coupling-in optical elements 1360, 1362, 1364 are laterally displaced relative to each other. Fig.13A , Fig. 13B and Fig. 13C As shown, the light sources 1110, 1112, 1114 are also laterally displaced relative to each other and can be configured to direct light to respective coupling optical elements 1360, 1362, 1364 by propagating the light through the optical device 1130, reflecting the light from the SLM 1140, and propagating the reflected light through the optical device 1130 again. Fig. 13B The system 1300 is shown such that the light source 1114 is located behind the light source 1110 and is therefore not Fig. 13B. The light sources 1110, 1112, 1114 may correspond to coupling-in optical elements 1360, 1362, 1364, respectively. In one design, for example, the light sources 1110, 1112, 1114 and the corresponding coupling-in optical elements 1360, 1362, 1364 are disposed approximately equidistant from (symmetrically about) the center of the optical device 1130 along a common (optical) axis. The common (optical) axis may intersect the center of the optical device 1130. In one design, for example, the light sources 1110, 1112, 1114 and the corresponding coupling-in optical elements 1360, 1362, 1364 are not disposed approximately equidistant from (symmetrically about) the center of the optical device 1130 along a common (optical) axis.

[0360] The coupling-in optical elements 1360, 1362, 1364 can be configured to couple light having multiple colors into their respective waveguides. Therefore, these coupling-in optical elements 1360, 1362, 1364 can be referred to herein as broadband, multi-color, or non-color selective coupling-in optical elements 1360, 1362, 1364. For example, in some cases, each of these coupling-in optical elements 1360, 1362, 1364 is configured to couple red, green, and blue light into an associated waveguide including the coupling-in optical element 1360, 1362, 1364 so that such colored light is guided in the waveguide by TIR. Such broadband coupling-in optical elements 1360, 1362, 1364 can, for example, operate across a wide range of wavelengths, such as in the visible range, or can select wavelengths or wavelength regions that are distributed, for example, across the visible range. Thus, such broadband or multi-color or non-color selective coupling optical elements 1360, 1362, 1364 can be configured to divert light of various different colors (e.g., red, green, and blue) into the waveguide to be guided within the waveguide by TIR. Although red, green, blue (RGB) is mentioned herein, for example, in conjunction with light sources, coupling optical elements, waveguides, etc., other colors or color systems may be used in addition or alternatively, for example, including but not limited to magenta, cyan, yellow (CMY).

[0361] like Fig.13A As shown, light sources 1110, 1112, 1114 are shown as being located above the uppermost waveguide and displaced relative to each other (e.g., in the x and z directions). Similarly, three incoupling optical elements 1360, 1362, 1364 are shown as being located on three respective waveguides and displaced relative to each other (e.g., in the x, y, and z directions). Fig. 13B yes Fig.13AA side view of system 1300 is shown showing coupling optical elements 1360, 1362, 1364 that are laterally spatially displaced relative to each other (e.g., along the x and z directions) and some of the light sources 1110, 1112, 1114 that are laterally displaced relative to each other (e.g., along the x and z directions). Fig. 13B Optics 1130 and SLM 1140 are also shown.

[0362] Fig. 13C yes Fig.13A and Fig. 13B A top view of an augmented reality display system is shown, showing coupling-in optical elements 1360, 1362, 1364 and associated light sources 1110, 1112, 1114. In this design, the coupling-in optical elements 1360, 1362, 1364 and associated light sources 1110, 1112, 1114 are arranged in a circular pattern around the center of a common (optical) axis. As shown, the light sources 1110, 1112, 1114 and the corresponding coupling-in optical elements 1360, 1362, 1364 are arranged approximately equidistantly around the center of the common (optical) axis, but this is not necessarily the case. In some designs, the center point can correspond to the center of the optical device 1130 along a common (optical) axis that intersects the center of the optical device 1130 and / or a position along the optical axis of the optical device 1130. Also as a result, the non-color selective incoupling optical elements 1360, 1362, 1364 and the light sources 1110, 1112, 1114 are laterally displaced relative to each other (eg, in the x and z directions).

[0363] Other lateral positioning arrangements are possible. FIG. 14A to FIG. 14C An alternative configuration of a system 1400 including a stack 1405 including waveguides is shown in which the incoupling optical elements 1360, 1362, 1364 and the light sources 1110, 1112, 1114 are laterally displaced relative to each other. Fig.14A is a side view, and Fig. 14B yes Fig.14A A top view of system 1400 is shown. Fig.14A Laterally displaced incoupling optics 1360, 1362, 1364 and light sources 1110, 1112, 1114 are shown. Fig. 14C yes Fig.14A and Fig. 14B An orthogonal side view of system 1400 is shown.

[0364] Fig.14A and Fig. 14CThe side view of shows how the coupling-in optical elements 1360, 1362, 1364 are arranged on separate waveguides within the stack 1405 so that light can be coupled into the corresponding waveguide by the corresponding laterally displaced coupling-in optical elements 1360, 1362, 1364. Fig.14A and Fig. 14C In the embodiment of the present invention, the coupling optical elements 1360, 1362, 1364 are shown as being disposed in the upper major surface of the waveguide. However, the coupling optical elements 1360, 1362, 1364 may be alternatively disposed on the lower major surface of each waveguide or in the body of the waveguide. Various configurations are possible.

[0365] As in Fig. 14B As shown in the top view of FIG. 1 , the coupling optical elements 1360, 1362, 1364 are arranged in a row and are laterally displaced relative to each other in the z direction but not in the x direction. Similarly, the light sources 1110, 1112, 1114 are arranged in a row and are also laterally displaced relative to each other in the z direction but not in the x direction. The coupling optical elements 1360, 1362, 1364 are laterally displaced relative to the light sources 1110, 1112, 1114 in the x direction.

[0366] Other configurations are possible. Fig.15 is a top view of system 1500 showing an alternative configuration of light sources 1110, 1112, 1114 and coupling optical elements 1360, 1362, 1364. Fig. 13C All of the light sources 1110, 1112, 1114 shown are roughly located on one side (e.g., in an annular pattern) and all of the coupling-in optical elements 1360, 1362, 1364 are roughly located on one side (i.e., the opposite side). Instead, the light sources 1110, 1112, 1114 and the coupling-in optical elements 1360, 1362, 1364 are interspersed or alternated along the circumference of the annular pattern.

[0367] However, in some embodiments, the coupling-in optical elements 1360, 1362, 1364 and the associated one or more light sources 1110, 1112, 1114 are also arranged in a circular pattern about a center point. Thus, the light sources 1110, 1112, 1114 and the corresponding coupling-in optical elements 1360, 1362, 1364 can be arranged approximately equidistant from the center. In some designs, the center can correspond to the center of the optical device 1130 along a common center axis that intersects the center of the optical device 1130 and / or a position along the optical axis of the optical device. Thus, light from the first light source 1110 can be coupled into the coupling-in optical element 1360 via the optical device 1130 across the center or center axis or optical axis of the optical device 1130 (e.g., Fig.151405). Similarly, light from the second light source 1112 can be coupled into the coupling optical element 1362 via the optical device 1130 across the center or central axis or optical axis of the optical device 1130. Similarly, light from the third light source 1114 can be coupled into the coupling optical element 1364 via the optical device 1130 across the center or central axis or optical axis of the optical device 1130. As a result, the non-color selective coupling optical elements 1360, 1362, 1364 and the light sources 1110, 1112, 1114 are laterally shifted relative to each other (e.g., in the x and z directions). The optical device 1130 can be designed so that the focal point is more into the stack 1405 so that the positions of the sub-pupil and the coupling optical elements 1360, 1362, 1364 are closer in the y direction. In this configuration, the coupling optical elements 1360, 1362, 1364 can be smaller because they are closer to the focal point of the optical device 1130. Light source 1110 may be located on the user side of stack 1405 (e.g., similar to Fig.17 and Fig.18 ), thereby shortening the distance or optical path between the light source 1110 and the optical device 1130.

[0368] Such as FIG. 12A to FIG. 15 In the various embodiments shown above, stacks including multiple waveguides (e.g., stacks 1205, 1305, 1405, such as stack 1205 including waveguides 1120, 1122, 1124, stack 1305 including waveguides (not labeled), and stack 1405 including waveguides (not labeled)) can be included to process different colors (e.g., red, green, and blue). Different waveguides can be used for different colors. Similarly, multiple stacks can be included to provide different optical properties to the light coupled out of the corresponding stacks. For example, FIG. 12A to FIG. 12B The waveguides 1120, 1122, 1124 of the stack 1205 can be configured to output light having optical properties (e.g., optical power that provides a particular wavefront shape) that may be associated with the apparent depth from which the light appears to be emitted. For example, wavefronts with different amounts of divergence, convergence, or collimation can appear to be projected from different distances relative to the eye 210. Thus, multiple stacks can be included in different stacks that are configured such that the light coupled out by the outcoupling optical element has different amounts of convergence, divergence, or collimation and therefore appears to originate from different depths. In some designs, different stacks can include different lenses, such as diffractive lenses or other diffractive optical elements, to provide different amounts of optical power to different stacks. Thus, different stacks will produce different amounts of convergence, divergence, or collimation, and therefore, light from different stacks appears to be associated with different depth planes or objects at different distances relative to the eye 210.

[0369] Fig.16A16 is a side view of a system 1600 including stacks 1605, 1610, 1620. Fig.16A As shown, system 1600 includes three stacks 1605, 1610, 1620, but this is not necessarily the case. Systems with fewer or more stacks can be envisioned. Each of stacks 1605, 1610 and 1620 includes one or more (e.g., three) waveguides. Fig.16A Also shown are groups of coupling-in optical elements 1630, 1640, 1650. The first group 1630 is associated with the first stack 1605, the second group 1640 is associated with the second stack 1610, and the third group 1650 is associated with the third stack 1620. The groups 1630, 1640, 1650 are laterally displaced relative to each other. The groups 1630, 1640, 1650 each include a color selective coupling-in optical element configured to couple in different respective colors, substantially similar to Fig. 12A The coupling optical elements 1260, 1262, 1264 are shown. Fig.16A As shown, the coupling optical elements within each of the groups 1630, 1640, 1650 are not laterally displaced relative to each other, but this is not necessarily the case. A system in which the coupling optical elements in a group are laterally displaced relative to each other can be envisioned. The system 1600 can be configured so that the light coupled out of each of the stacks 1605, 1610, 1620 has a different amount of optical focality. For example, the waveguides in the stack can include coupling optical elements or diffractive lenses with a given optical focality. The optical focality of different stacks 1605, 1610, 1615 can be different so that light from one stack appears to originate from a different depth than light from another stack. For example, the optical focality of one stack can cause the light from the stack to be collimated, while the optical focality of another stack can cause the light from the stack to diverge. Divergent light can appear to originate from an object that is close to the eye 210, while collimated light can appear to originate from an object at a long distance. Thus, the light coupled out of the first stack 1605, the second stack 1610, and the third stack 1620 can have different amounts of at least one of convergence, divergence, and collimation, and thus appear to originate from different depths. In some embodiments, the light coupled out of one of the stacks can be collimated, while the light coupled out of a different stack can be divergent. The light coupled out of one of the other stacks may also be divergent, but by different amounts.

[0370] like Fig.16AAs shown, the light source 1110 can be arranged relative to the optical device 1130 and the SLM 1140 to guide the light into the coupling optical element group 1630, the light source 1112 can be arranged relative to the optical device 1130 and the SLM 1140 to guide the light into the coupling optical element group 1640, and the light source 1114 can be arranged relative to the optical device 1130 and the SLM 1140 to guide the light into the coupling optical element group 1650. The light sources 1110, 1112, and 1114 can be configured to emit light of different colors at different times. Similarly, since the color selective coupling optical elements adopt the above-mentioned manner, different colors of light can be coupled into different waveguides in the stack. For example, if blue light is emitted from the second light source 1112, the optical device 1130 and the SLM 1140 will guide the blue light to the second coupling optical element group 1640. Light can propagate through the first red coupling-in optical element and the second green coupling-in optical element in the second group 1640 and be redirected by the third blue coupling-in optical element in the second group 1640 into the third waveguide in the second stack 1610. The waveguide in the second stack 1610 can include coupling-out optical elements or other optical elements (e.g., diffractive lenses) having optical power to provide a light beam to the eye 210 associated with a particular depth plane or object distance associated with the second stack 1610.

[0371] Fig. 16B yes Fig.16A 16. A top view of the system 1600 in FIG. Different incoupling optical element groups 1630, 1640, 1650 are shown as being laterally displaced relative to each other (e.g., along the x-direction). Similarly, light sources 1110, 1112, 1114 are shown as being laterally displaced relative to each other (e.g., along the x-direction).

[0372] Various variations of the above system are possible. For example, the position of the light source 1110 relative to the one or more waveguides and the optical device 1130 can be different. For example, Fig.17 11 to 17 are side views of system 1700 in which light source 1110 is located in a different position relative to waveguide 1720 and optical device 1130 than in FIGS. Fig. 11B In addition, Fig.17A design is shown with a waveguide 1720 divided into a first portion 1720a and a second portion 1720b. The waveguide 1720 may further include a reflector 1730 configured to couple light directed in the first portion 1720a adjacent to the light source 1110 out of the first portion 1720a and into the optics 1130 toward the SLM 1140. Additionally or alternatively, the system 1700 may include a diffractive outcoupling optical element to couple light in the first portion 1720a of the waveguide 1720 out of the first portion 1720a and into the optics 1130 toward the SLM 1140. The reflector 1730 may be opaque and include an isolator that reduces crosstalk between the first portion 1720a and the second portion 1720b. The waveguide 1720 has a first side 1721 and a second side 1723 opposite to the first side 1721, and the optical device 1130 and the SLM 1140 are arranged on the first side 1721 so that light from the SLM 1140 is guided onto the first side 1721. In this example, the light source 1110 is arranged on the first side 1721 of the waveguide 1720 so that the light from the light source 1110 is incident on the first side 1721 before propagating through the optical device 1130 to reach the SLM 1140. The system 1700 may further include a coupling-in optical element 1710, which is arranged on or in the first portion 1720a. The coupling-in optical element 1710 may be configured to receive light from the light source 1110 and couple the light into the first portion 1720a. The in-coupling optical element 1710 may include a diffractive optical element or reflector configured to turn light incident thereon into the first portion 1720a at an angle to guide the light in the first portion 1720a by TIR.

[0373] The reflector 1730 can be configured to direct light guided in the first portion 1720a out of the first portion 1720a and toward the optics 1130 and SLM 1140. (As described above, in some embodiments, a diffractive optical element can additionally or alternatively be used to direct light in the first portion 1720a out of the first portion 1720a and toward the optics 1130 and SLM 1140.) Thus, the reflector 1730 can be a mirror, a reflective grating, one or more coatings that reflects light of the waveguide 1720 toward the SLM 1140. The light emitted from the first portion 1720a by the reflector 1730 propagates through the optics 1130, is incident on the SLM 1140, and propagates through the optics 1130 again, being incident on the second portion 1720b. As described above, light reflected from the SLM 1140 and transmitted through the optical device 1130 can be incident on the coupling-in optical element 1160, which then turns the light to be guided in the second portion 1720b. The light guided in the second portion 1720b can be coupled out of the second portion 1720b by the coupling-out optical element 1180 (not shown) and guided to the eye 210.

[0374] As described above, the reflector 1730 can be an isolator that reduces crosstalk between the first portion 1720a and the second portion 1720b. The reflector 1730 can include an opaque surface and / or a reflective surface. The reflector 1730 can be disposed within the waveguide 1720 and, in some cases, can define one side of the first portion 1720a and the second portion 1720b.

[0375] Instead of having the first portion 1720a and the second portion 1720b of the waveguide 1720, separate waveguides may be used. Fig.181 is a side view of a system 1800 including a first waveguide 1822 for receiving light from a light source 1110 and guiding the light guided therein to an optical device 1130 and toward an SLM 1140. The system 1800 additionally includes a second waveguide 1820 that receives the light from the SLM 1140 after it propagates again through the optical device 1130. The first waveguide 1822 includes an in-coupling optical element 1730a and an out-coupling optical element 1730b, respectively. These in-coupling optical elements 1730a and out-coupling optical elements 1730b may include reflective surfaces that are oriented to couple light into and out of the waveguide 1822. The in-coupling optical element 1730a may, for example, include a reflective surface surface that is arranged to receive light from the light source 1110 and is oriented (e.g., tilted) to guide the light into the waveguide 1822 at an angle so that the light is guided in the waveguide 1822 by TIR. The out-coupling optical element 1730b may, for example, include a reflective surface that is oriented (e.g., tilted) to guide the light guided within the waveguide 1822 at a certain angle so that the light is emitted from the waveguide 1822. The out-coupling optical element 1730b may be positioned so that the light diverted out of the waveguide 1822 is guided into the optical device 1130, reflected by the SLM 1140, propagated through the optical device 1130 again, and incident on the in-coupling optical element 1730c of the second waveguide 1820.

[0376] The coupling-in optical element 1730c in the second waveguide 1820 may include a reflective surface that may be positioned and oriented (e.g., tilted) to receive light incident thereon from the SLM 1140 and to deflect light incident thereon from the SLM 1140 to guide the light in the second waveguide 1820 via TIR. Fig.18 The optical device 1130 and the light source 1110 are shown disposed on the same side of the waveguides 1820, 1822. The system 1800 may further include an isolator that reduces crosstalk between the waveguide 1822 and the waveguide 1820. The isolator may include an opaque surface and / or a reflective surface. The isolator may be disposed on at least one of the waveguides 1820, 1822 or on at least one of the waveguides 1820, 1822.

[0377] Various designs such as those discussed above may include other features or components. Fig.19For example, a side view of a system 1900 is shown, which includes a variable focus optical element (or adaptive optical element) 1910, 1920. The variable focus optical element 1910, 1920 may include an optical element configured to provide a variable optical power by changing. The variable focus optical element 1910, 1920 may include multiple states, such as a first state and a second state, wherein in the first state, the variable focus optical element 1910, 1920 has a different optical power than when in the second state. For example, the variable focus optical element 1910, 1920 may have a negative optical power in the first state and may have zero optical power in the second state. In some embodiments, the variable focus optical element 1910, 1920 has a positive optical power in the first state and has zero optical power in the second state. In some embodiments, the variable focus optical element 1910, 1920 has a first negative optical power or a first positive optical power in the first state, and has a different second negative optical power or second positive optical power in the second state. Some adaptive optical elements or variable focus optical elements 1910, 1920 may have more than two states and may provide a continuous power profile.

[0378] The variable focus optical elements 1910, 1920 may include a lens (eg, a variable lens) and be transmissive. Figure 7Transmissive or transparent adaptive optical elements or variable focus optical elements 1910, 1920 are shown in FIG. The variable focus optical elements 1910, 1920 may include liquid lenses (e.g., movable membranes and / or electrowetting). The variable focus lens may also include a liquid crystal lens, such as a switchable liquid crystal lens, such as a switchable liquid crystal polarization lens, which may include a diffractive lens, for example. Alverez lenses may also be used. Other types of variable focus optical elements 1910, 1920 may be used. Examples of variable focus optical elements may be found in U.S. Application No. 62 / 518,539, filed on June 12, 2017, entitled “AUGMENTED REALITY DISPLY HAVING MULTI-ELEMENT ADAPTIVE LENS FOR CHANGING DEPTH PLANES”, the entire contents of which are hereby incorporated by reference. The variable focus optical elements 1910, 1920 may have an electrical input that receives an electrical signal that controls the amount of optical focus exhibited by the variable focus optical elements 1910, 1920. The variable focus optical elements 1910, 1920 may have positive optical power and / or negative optical power. In addition to variable focus elements (e.g., polarization switches, geometric phase (GP) lenses, fluid lenses, etc.), the variable focus elements 1910, 1920 may also include fixed lenses (e.g., diffractive lenses, refractive lenses, etc.) to generate a desired depth plane in the light field.

[0379] A first variable focus optical element 1910 may be disposed between the stack 1905 and the eye 210. The stack 1905 may include different waveguides for different colors as described above. The first variable optical element 1910 may be configured to introduce different amounts of optical power, negative optical power, and / or positive optical power. The variable optical power may be used to change the divergence and / or collimation of light coupled out of the stack 1905 to change the depth at which virtual objects projected into the eye 210 by the system 1900 appear to be located. Thus, a four-dimensional (4D) light field may be formed.

[0380] The second variable focus optical element 1920 is located on the side of the stack 1905 opposite the first variable focus optical element 1920. The second variable focus optical element 1920 can thus compensate for the effect of the first optical element 1910 on light received from the system 1900 and the world 510 in front of the eye 210. Thus, the view of the world can be virtually unchanged or change as desired.

[0381] The system 1900 may further include a static or variable prescription or correction lens 1930. Such a lens 1930 may provide refractive correction for the eye 210. In addition, if the prescription lens 1930 is a variable lens, it can provide different refractive corrections for multiple users. Variable focus lenses are discussed above. The eye 210 may have myopia, hyperopia, and / or astigmatism, for example. The lens 1930 may have a prescription (e.g., optical power) that reduces the refractive error of the eye 210. The lens 1930 may be spherical and / or cylindrical, and may be positive or negative. The lens 1930 may be disposed between the stack 1905 and the eye 210 so that light from the world 510 and from the stack 1905 passes through the correction provided by the lens 1930. In some embodiments, the lens 1930 may be disposed between the eye 210 and the first variable focus optical element 1910. Other positions of the lens 1930 are also possible. In some embodiments, the prescription lens may be variable and allow for multiple user prescriptions to be implemented.

[0382] In some designs, the system 1900 may include an adjustable dimmer 1940. In some embodiments, the adjustable dimmer 1940 may be disposed on a side (e.g., the world side) of the waveguide stack 1900 opposite the eye 210. Thus, the adjustable dimmer 1940 may be disposed between the waveguide stack 1900 and the world 510. The adjustable dimmer 1940 may include an optical element that provides a variable attenuation of light transmitted therethrough. The adjustable dimmer 1940 may include an electrical input to control the attenuation level. In some cases, the adjustable dimmer 1940 is configured to increase the attenuation when the eye 210 is exposed to bright light, such as when the user goes outdoors. Thus, the system 1900 may include a light sensor to sense the brightness of the ambient light, and control the electronics to drive the adjustable dimmer 1940 to change the attenuation based on the light level sensed by the light sensor.

[0383] Different types of adjustable dimmers 1940 may be employed. Such adjustable dimmers 1940 may include variable liquid crystal switches with polarizers, electrochromic materials, photochromic materials, etc. The adjustable dimmer 1940 may be configured to adjust the amount of light entering and / or transmitted through the stack 1905 from the world 510. The adjustable dimmer 1940 may be used in some cases to reduce the amount of light from the surrounding environment that propagates through the waveguide stack 1900 to the eye 210, which would otherwise provide glare and reduce the user's ability to perceive virtual objects / images injected into the eye 210 from the stack 1905. Such adjustable dimmers 1940 may reduce incident bright ambient light from washing out the image projected into the eye 210. Thus, the contrast of the virtual objects / images presented to the eye 210 may be increased by virtue of the adjustable dimmer 1940. Conversely, if the ambient light is low, the adjustable dimmer 1940 can be adjusted to reduce the attenuation so that the eye 210 can more easily see objects in the world 510 in front of the user. Dimming or attenuation can be performed across the system or localized to one or more parts of the system. For example, multiple localized parts can be dimmed or set to attenuate light from the world 510 in front of the user 210. These localized parts can be separated from each other by parts that do not have such increased brightness adjustment or attenuation. In some cases, only a portion is dimmed or caused to provide increased attenuation relative to other parts of the eyepiece. Other components can be added in different designs. The arrangement of the components can also be different. Similarly, one or more components in the system can be excluded.

[0384] Fig. 20A An example of another configuration is shown. Fig. 20AA side view of a system 2000 is shown, the system 2000 including laterally displaced incoupling optical elements 1360, 1362, 1364 on different waveguides, and a color filter array 2030 including laterally displaced color filters 2040, 2042, 2044 aligned with the respective incoupling optical elements 1360, 1362, 1364. The color filter array 2030 may be disposed on one side of the stack 2005 adjacent the eye 210 and the optics 1130. The color filter array 2030 may be located between the stack 2005 and the optics 1130. The color filter array 2030 may be disposed in or on a cover glass 2050 located between the stack 2005 and the optics 1130. The color filter array 2030 may include one or more different color filters 2040, 2042, 2044, such as red, green, and blue filters, that are laterally displaced relative to each other. The system 2000 includes light sources 1110, 1112, 1114 that are laterally displaced relative to each other. These light sources 1110, 1112, 1114 may include light sources of different colors, such as red, green, and blue light sources. The color filters 2040, 2042, 2044 may be transmissive or transparent color filters. In some embodiments, the color filters 2040, 2042, 2044 include absorptive color filters, however, the color filters 2040, 2042, 2044 may also include reflective color filters. The color filters 2040, 2042, 2044 in the color filter array 2030 may be separated and / or surrounded by a mask, such as an opaque mask that reduces stray light propagation. The filters in the filter array 2030 can be used to reduce or eliminate unwanted reflections within the system, such as unwanted reflections from the waveguides and / or coupling optical elements 1360, 1362, 1364, by preventing these unwanted reflections from re-entering the waveguides for different colors through the coupling optical elements 1360, 1362, 1364 for different colors. Examples of color filter arrays can be found in U.S. application serial number 15 / 683,412, filed on August 22, 2017, entitled “PROJECTOR ARCHITECTURE INCORPORATING ARTIFACT MITIGATION,” the entire contents of which are hereby incorporated by reference; and in U.S. application serial number 62 / 592,607, filed on November 30, 2017, entitled “PROJECTOR ARCHITECTURE INCORPORATING ARTIFACT MITIGATION,” the entire contents of which are hereby incorporated by reference.The mask may be a black mask and may include an absorbing material to reduce the propagation and reflection of stray light. The light sources 1110, 1112, 1114 may be arranged relative to the optical device 1130 and the SLM 1140 to couple light into corresponding color filters 2040, 2042, 2044 in the color filter array 2030. For example, the color filter array 2030 may include first, second, and third (e.g., red, green, and blue) color filters 2040, 2042, 2044 that are arranged to receive light from the first, second, and third light sources 1110, 1112, 1114, respectively. The first, second, and third (e.g., red, green, and blue) color filters 2040, 2042, 2044 may be aligned (e.g., along the x and z directions) with respective coupling-in optical elements 1360, 1362, 1364. Thus, light from the first light source 1110 will be directed through the first color filter 2040 and to the first coupling-in optical element 1360, light from the second light source 1112 will be directed through the second color filter 2042 and to the second coupling-in optical element 1362, and light from the third light source 1114 will be directed through the third color filter 2044 and to the third coupling-in optical element 1364. In some embodiments, the coupling-in optical elements 1360, 1362, 1364 may be color specific. For example, the first coupling-in optical element 1360 and the second coupling-in optical element 1362 may be configured to couple light of a corresponding first color and a second color into the first waveguide and the second waveguide, respectively. Similarly, the first coupling-in optical element 1360, the second coupling-in optical element 1362, and the third coupling-in optical element 1364 may be configured to couple light of a corresponding first color, a second color, and a third color into the first waveguide, the second waveguide, and the third waveguide, respectively. The first coupling optical element 1360 may be configured to couple more light of the first color than the second color (or third color) into the first waveguide. The second coupling optical element 1362 may be configured to couple more light of the second color than the first color (or third color) into the second waveguide. The third coupling optical element 1364 may be configured to couple more light of the third color than the first color or the second color into the second waveguide. In other configurations, the coupling optical elements 1360, 1362, 1364 may be broadband. For example, the first coupling optical element 1360 may be configured to couple light of the first color, the second color, and the third color into the first waveguide. The second coupling optical element 1362 may be configured to couple light of the first color, the second color, and the third color into the second waveguide. The third coupling optical element 1364 may be configured to couple light of the first color, the second color, and the third color into the third waveguide. However, the plurality of color filters 2040, 2042, 2044 may be color specific, selectively transmitting light of a specific color. For example, the first color filter 2040 may transmit more of the first color than the second color (and the third color).The second color filter 2042 can transmit more second colors than the first color (and the third color). The third color filter 2044 can transmit more third colors than the first color and the second color. Similarly, the first color filter 2040, the second color filter 2042 and the third color filter 2044 can be color filters that selectively transmit the first color, the second color and the third color respectively. Therefore, the first color filter 2040, the second color filter 2042 and the third color filter 2044 can be bandpass filters that selectively pass the first color, the second color and the third color respectively. In some embodiments, the first light source 1110, the second light source 1112 and the third light source 1114 can selectively emit the first color, the second color and the third color respectively. For example, the first light source 1110 can emit more first colors than the second color (and the third color). The second light source 2042 can emit more second colors than the first color (and the third color). The third light source 2044 can emit more third colors than the first color and the second color. The color filters 2040, 2042, 2044 can reduce the amount of stray light that is inadvertently directed to a particular coupling optical element. In other embodiments, one or more of the light sources 1110, 1112, 1114 are broadband light sources. For example, the first light source 1110 can emit a first color and a second color (and possibly a third color). The second light source 1112 can also emit a first and a second color and a second color (and possibly a third color). The third light source 1114 can also emit a color and a second color (and possibly a third color). Although in. Figures 20A to 20G Three color filters are shown, but more or fewer color filters may also be included. For example, in some embodiments, two color filters (instead of three) may be used. Therefore, the two colors corresponding to the two color filters can be selectively transmitted by the color filters. In some such embodiments, two corresponding coupling optical elements can be used and aligned with the two color filters. In some embodiments, the two coupling optical elements selectively couple the two colors into two corresponding waveguides, respectively. In some embodiments, two light sources can be used instead of three. Variations of other components and other numbers of components may be used. In addition, the color filters 2040, 2042, 2044 may or may not be integrated in a single array.

[0385] As described above, the components and their locations and arrangements may vary. For example, although Fig. 20A The analyzer 1150 is shown disposed between the optics 1130 and the stack 1905, but the analyzer 1150 may be located at a different position. Fig. 20BAn analyzer 1150 is shown positioned between the optics 1130 and the SLM 1140. In some designs, the analyzer (e.g., polarizer) 1150 can be attached directly to the SLM 1140. For example, the analyzer 1150 can be bonded or mechanically coupled to the SLM 1140. For example, the analyzer 1150 can be glued, bonded to the SLM 1140 (e.g., to the SLM window) using an adhesive. Thus, although Fig. 20B A gap is shown between the analyzer 1150 and the SLM 1140, but in some designs, no gap exists between the analyzer 1150 and the SLM 1140. The analyzer 1150 can be mechanically bonded to the SLM 1140 (e.g., using a mechanical fixture), and in this case, a gap may or may not be included between the analyzer 1150 and the SLM 1140. Birefringence from the optics 1130 can be cleaned up by positioning the polarizer directly on the SLM 1140 as described above. In some embodiments, the analyzer 1150 can also be included between the optics 1130 and the coupling-in optical elements 1360, 1362, 1364 to clean up the polarization of light exiting the optics 1130 (e.g., as Fig. 20B 1140, for example, between the optical device 1130 and the SLM 1140. As used herein, a quarter-wave plate may refer to a quarter-wave retarder, regardless of whether the quarter-wave retarder includes a plate, a film, or other structure for providing a quarter-wave retardation. Fig. 20B In, for example, a retarder (e.g., a quarter wave plate) can be disposed between the analyzer 1150 and the SLM 1140. The retarder (e.g., a quarter wave plate) can be used for oblique ray management. For example, the retarder (e.g., a quarter wave plate) can, for example, compensate for changes caused by wavelength differences and incident angle differences on the SLM 1140. As described above, a compensator can be included, and the compensator can provide a more consistent polarization rotation (e.g., 90 degrees) of the SLM 1140 for different incident angles and different wavelengths. The compensator can be used to increase the contrast of the display by providing a more consistent orthogonal rotation. As described above, the compensator can be attached or bonded to the SLM 1140. For example, glue, cement, or other adhesive can be used. The compensator can also be attached to the SLM 1140 using a mechanical fixture. A gap may or may not be included between the compensator or the SLM 1140. Additionally or alternatively, other conditioning optics may also be included and bonded to the SLM 1140 as described above with respect to the analyzer 1150 and / or compensator.

[0386] In some embodiments, a large angular spread (e.g., 70 degrees) may be used. The angular spread may refer, for example, to the angle of light entering the optics 1130 from the light sources 1110, 1112, 1114, and / or the angle of light exiting the optics 1130 into the coupling-in optical elements 1360, 1362, 1364. In these embodiments, a thinner SLM 1140 may be used. For example, if the SLM 1140 is a liquid crystal (LC) SLM (e.g., a liquid crystal on silicon (LCOS) SLM), the LC layer may be made thinner to accommodate the large angular spread.

[0387] The second pass delay through the polarizer and analyzer 1150 may need to be half a wavelength. The polarizer may be located between the optical device 1130 and the analyzer 1150. The second pass delay may be a function of the ratio of the refractive index of the LCOS SLM 1140 to the thickness of the LCOS SLM 1140. For a given LCOS SLM 1140 refractive index and a given LCOS SLM 1140 thickness, entering and exiting the LCOS SLM 1140 at a large angle makes the optical path length greater than entering and exiting the LCOS SLM 1140 at a small angle. The optical path length is related to the thickness of the LCOS SLM 1140. In one example, the LCOS SLM may have a first refractive index and a first thickness. For small angles, the second pass delay of the LCOS SLM having the first refractive index and the first thickness may be half a wavelength. For large angles, the second pass delay of the LCOS SLM having the first refractive index and the first thickness may not be half a wavelength (e.g., may be greater than half a wavelength). The thickness of the LCOS SLM may be changed from a first thickness to a second thickness, wherein the second thickness is less than the first thickness. For small angles, the secondary pass delay of the LCOS SLM having the first refractive index and the second thickness may not be a half wavelength (e.g., may be less than a half wavelength). For large angles, the secondary pass delay of the LCOS SLM having the first refractive index and the second thickness may be a half wavelength.

[0388] In addition, despite Fig. 20A and 20B The use of a polarization-based SLM 1140 is shown, but other types of SLMs may also be utilized. For example, Fig. 20C The use of a deflection-based SLM 1140, such as a movable micro-mirror-based SLM, is shown. As described above, such an SLM 1140 may include a digital light processing (DLP TM) and digital micromirror device (DMD) technology. As described above, the deflection-based SLM 1140 can couple light from one of the light sources 1110, 1112, 1114 into the corresponding coupling optical element 1360, 1362, 1364, depending on the state of the pixel of the SLM 1140. In one state, the light from the light source 1110, 1112, 1114 will be guided to the corresponding coupling optical element 1360, 1362, 1364, such as Fig.20D In another state, light from light sources 1110, 1112, 1114 will be directed away from coupling-in optical elements 1360, 1362, 1364, as shown. Fig.20E As shown. In some embodiments, when in the off state, the black absorptive mask between the color filters 2040, 2042, 2044 in the color filter array 2030 can be used as a light absorber. As described above, the color filters 2040, 2042, 2044 can be surrounded and / or separated by a mask such as an absorptive mask (e.g., a black mask). The mask can include an absorptive material so that more incident light is absorbed than reflected from it. The mask can also be opaque.

[0389] Other variations are also possible. Although the light sources are shown as emitters 1110, 1112, 1114 (e.g., LEDs, laser diodes) coupled to coupling optics 1105 such as non-imaging optical coupling elements (e.g., compound parabolic concentrators (CPCs) or cones), other configurations are also possible. For example, the coupling optics 1105 (e.g., CPC) can be tilted relative to the waveguide stack. In some cases, the projector (i.e., optics 1130 and SLM 1140) can be tilted relative to the eyepiece (e.g., waveguide stack). In some embodiments, the lens optics 1130 is tilted relative to the SLM 1140 to reduce distortion, such as trapezoidal distortion. A Scheimenplug configuration can be used to reduce such distortion. Components can be tilted as needed (e.g., optics 1130 and / or spatial light modulator 1140), for example, to fit more conformally to the head and / or face. As described above, one or more light emitters and / or coupling optics 1105 can be tilted. In some configurations, the components comprising the waveguide can be tilted so that the side closer to the eye 210 (e.g., the temporal side) is closer to the eye 210 to increase the perceived field of view of the entire binocular system (at the expense of binocular overlap).

[0390] As mentioned above, the components and their positions and arrangements may vary. For example, Fig.20F2005 and 1130. In some designs, the light sources 1110, 1112, 1114 can be disposed on the world side of the cover glass 2050 and configured to propagate light through the cover glass 2050 to the optics 1130 and the SLM 1140. As shown, the cover glass 2050 can extend laterally (e.g., parallel to the x-axis) beyond the stack 2005 so that light emitted by the light sources 1110, 1112, 1114 enters the optics 1130 without propagating through the waveguides in the stack 2005. Although the system 2000F shows a deflection-based SLM 1140, similar light source configurations can also be used for non-deflection-based SLMs or any other configurations or features disclosed herein.

[0391] Figure 20G 2000G includes a cover glass 2060 disposed on the world side of the stack 2005 (i.e., opposite the side of the stack 2005 adjacent to the optics 1130). In some designs, the light sources 1110, 1112, 1114 can be disposed on the world side of the cover glass 2050 and configured to propagate light through the cover glass 2050 to the optics 1130 and the SLM 1140. As shown, the cover glass 2060 can extend laterally (e.g., parallel to the x-axis) beyond the stack 2005 so that light emitted by the light sources 1110, 1112, 1114 enters the optics 1130 without propagating through the waveguides in the stack 2005. Although the system 2000G shows a deflection-based SLM 1140, similar light source configurations can also be used for non-deflection-based SLMs or any other configurations or features disclosed herein.

[0392] In addition, as described above, configurations that promote light recycling may be employed. For example, Fig.211 is a partial side view of a system 2100 equipped with a configuration for performing light recycling on light from a light source 1110. The light source 1110 may be disposed relative to a polarizer 1115 configured to recycle light having an undesirable polarization. The polarizer 1115 may, for example, include a wire grid polarizer that transmits light of a first polarization and back-reflects light of a second opposite polarization. Thus, light 2110 is emitted from the light source 1110 and impinges on the polarizer 1115. The polarizer 1115 may transmit light of a first polarization, for which a projector (not shown) is configured for use. For example, an SLM may properly process the light of the first polarization. Light 2120 of a second polarization is reflected back toward the light source 1110 and may be recycled. After reflecting at various angles from a portion (e.g., a sidewall) of a coupling optical device (not shown), a non-imaging optical device such as a compound parabolic concentrator (CPC), the polarization of the light 2120 may be changed to rotate the polarization. Some light with suitable polarization (e.g., polarization orientation) that can be passed by polarizer 1115 can be generated. Multiple reflections can change the polarization of light, and can make the light exit with a desired polarization. Then, the recycled light 2130 is emitted back toward polarizer 1115. As more and more desired polarizations are generated, this configuration can improve efficiency, such as energy efficiency. In addition, additionally or alternatively, a retarder can be used to change the polarization state of reflection and reuse light.

[0393] Fig. 22Another configuration is shown that includes light sources 1110, 1112, 1114 and corresponding focusing optics 2210, 2212, 2214. The focusing optics 2210, 2212, 2214 may include lenses or other optics to collect light from the light sources 1110, 1112, 1114. The light sources 1110, 1112, 1114 may be laser diodes or other emitters that emit light across a wide range of angles. The focusing optics 2210, 2212, 2214 may be used to collect a large portion of the light. The light sources 1110, 1112, 1114 may emit light asymmetrically. For example, light may be emitted at a wider range of angles in one direction (e.g., the x or z direction) other than the orthogonal direction (e.g., the z or x direction). Therefore, the focusing optics 2210, 2212, 2214 may be asymmetrical. For example, the focusing optics 2210, 2212, 2214 can have different optical powers in different possible orthogonal directions. The focusing optics 2210, 2212, 2214 can include, for example, lenses such as anamorphic lenses. The focusing optics 2210, 2212, 2214 can also include non-imaging optics. Apertures 2220, 2222, 2224 can be included. For example, when the light source 1110, 1112, 1114 is a laser such as a laser diode, a diffuser 2230 can also be included near the aperture 2220, 2222, 2224. With the diffuser adjacent to the aperture 2220, 2222, 2224, the aperture appears to be located at the location of the laterally displaced light source. The aperture 2220, 2222, 2224 can be matched with an in-coupling optical element on one or more waveguides via the above-mentioned optics and SLM. For example, each hole 2220, 2222, 2224 can be matched with a corresponding coupling optical element. Similarly, in some embodiments, such as Fig.16A As shown, each hole 2220, 2222, 2224 can be matched with a corresponding (eg, color-selective) coupling optical element group.

[0394] Various system variations and configurations are possible. For example, although linearly polarized light is described as propagating through the optical device 1130 to the SLM 1140 and then propagating back to the waveguide stack through the optical device, in some designs, circularly polarized light may be used instead. For example, circularly polarized light may be directed into the optical device 1130. A retarder such as a quarter wave plate may be provided so that the light propagates through the retarder before being incident on the SLM. The retarder (e.g., a quarter wave plate) may be provided between the optical device 1130 and the SLM 1140. In some cases, as described above, the retarder (e.g., a quarter wave plate) may be bonded to the SLM 1140, for example using an adhesive or a mechanical fixture. The retarder (e.g., a quarter wave plate) may transform the linearly polarized light after reflection from the SLM 1140 into circularly polarized light. Therefore, in some embodiments, the circularly polarized light may propagate through the optical device 1130 again toward the stack. For example, another retarder (e.g., a quarter wave plate) adjacent to the analyzer 1150 can transform circularly polarized light into linearly polarized light, which may or may not propagate through the analyzer depending on the linear polarization (e.g., orientation), specifically. The pixels of the SLM 1140 may have states that may be changed to rotate or not rotate the polarization. Other configurations are also possible.

[0395] Fig.23Ais a side view of an augmented reality display system 2300 that includes a light source 2305, a polarization rotator 2307, an optical device (e.g., a lens) 2320 having optical power, polarizers 2312, 2335 such as linear polarizers (e.g., horizontal or vertical polarizers), retarders 2315, 2330, 2340 such as quarter-wave retarders (e.g., quarter-wave plates), and at least one waveguide 2348 for outputting image information to a user. Such a configuration can be used to illuminate a reflective spatial light modulator (not shown) so that light emitted from the light source 2305 is reflected from the spatial light modulator and coupled into at least one waveguide 2348 to be directed to the user's eyes. The configuration and placement of these elements, particularly polarizers and retarders, can reduce or eliminate reflections from optical surfaces within the system, such as surfaces of the optical device 2320, which may otherwise cause ghost images to be visible to the user. For example, optical elements that are polarization selective and / or have delays (e.g., polarizers 2312, 2335 and retarders 2315, 2330, 2340) can be arranged and configured to transform linearly polarized light into circularly polarized light, which changes from left-handed to right-handed, or from right-handed to left-handed, when reflected from an optical surface. Similarly, such optical elements that are polarization selective and / or have delays (e.g., polarizers 2312, 2335 and retarders 2315, 2330, 2340) can be arranged and configured to transform circularly polarized light into linearly polarized light, which can be attenuated or filtered by a polarizer (e.g., a linear polarizer). Such optical elements that are polarization selective and have delays (e.g., polarizers 2312, 2335 and retarders 2315, 2330, 2340) can be used to manufacture circular polarizers that transform linearly polarized light into circularly polarized light or transform circularly polarized light into linearly polarized light. For example, a circular polarizer may include a linear polarizer and a quarter-wave retarder. A circular polarizer may be used to transform linearly polarized light into circularly polarized light having a first state (e.g., handedness) and to filter out circularly polarized light having a second state (e.g., handedness) that is different from the first state. For example, a circular polarizer may be used to transform linearly polarized light having a particular orientation into left-handed circularly polarized light and to filter out right-handed circularly polarized circularly polarized light. A circular polarizer may also be used to transform linearly polarized light having a particular orientation into right-handed circularly polarized light and to filter out left-handed circularly polarized circularly polarized light. Other configurations of circular polarizers or optical elements that include retarders that can be used to transform linearly polarized light into circularly polarized light and then back again and that can selectively filter linearly polarized light may be used to reduce back reflections from optical surfaces, as described below in conjunction with Fig.23A and Fig. 23B discussed.

[0396] It is worth noting that in Fig.23A and Fig. 23BLeft-handed and right-handed circular polarizations are shown in FIG. 1 with clockwise and counterclockwise arrows, respectively. In addition, horizontal and vertical linear polarizations are shown using horizontal arrows and dots, respectively.

[0397] As mentioned above, Fig.23A A configuration of an augmented reality display system 2300 is shown in which polarizers 2312, 2335, such as linear polarizers (e.g., horizontal polarizers) and retarders 2315, 2330, 2340, such as quarter-wave retarders (e.g., quarter-wave plates) are arranged to reduce back reflections from optical surfaces, such as surfaces of an optical device 2320, in the path of light that illuminates a spatial light modulator (not shown) and reflects from the spatial light modulator. The first polarizer 2312 and the first retarder 2315 are disposed between the light source 2305 and the optical device 2320. The first polarizer 2312 is disposed between the light source 2305 and the first retarder 2315. Similarly, the first retarder 2315 is disposed between the first polarizer 2312 and the optical device 2320.

[0398] As shown, light source 2305 emits light as represented by light ray 2310. In some embodiments, light ray 2310 can propagate through polarization rotator 2307. Rotator 2307 is optional and can be used to rotate the polarization of light (e.g., light ray 2310) from light source 2305. In various embodiments, rotator 2307 can rotate the polarization angle (e.g., linear polarization angle). For example, rotator 2307 can rotate the linear polarization of light ray 2310 to an orientation aligned with first polarizer 2312 so that the light is transmitted through first polarizer 2312. In some embodiments, polarization rotator 2307 can include a retarder, such as a half-wave retarder in some cases. The optical axis of the half-wave retarder can be oriented to rotate the polarization of light from light source 2305 from vertical to horizontal or from horizontal to vertical. Alternatively, polarization rotator 2307 can be configured to rotate the polarization angle of linearly polarized light emitted from light source 2305 by different amounts. Polarization rotator 2307 does not need to be included in the system. For example, in an embodiment where the light source 2305 emits light having the same polarization as the first polarizer 2312, the polarization rotator 2307 may not be included. As shown, light, such as light ray 2310, propagates through the polarizer 2312, shown here as a horizontal polarizer. In the case where the light from the light source 2305 is not polarized, the light transmitted through the horizontal polarizer 2312, as shown by light ray 2310, is linearly polarized (e.g., horizontally polarized) after propagating through the polarizer 2312. Although a horizontal linear polarizer is used in this example, it should be understood that a vertical linear polarizer can be used to apply the principles taught. Alternatively, a linear polarizer with a different orientation other than vertical or linear can also be used.

[0399] Horizontally polarized light 2310 travels through a retarder 2315, shown here as a quarter-wave retarder. The retarder 2315 can include sufficient delay to transform linearly polarized light into circularly polarized light. For example, as shown by the curved (e.g., clockwise) arrow, horizontally polarized light can be transformed into left-handed circularly polarized light. In this example, the combination of polarizer 2312 and retarder 2315 (e.g., a quarter-wave retarder) forms a circular polarizer, referred to herein as a first circular polarizer, which can transform light of a specific linear polarization (e.g., horizontal or vertical polarization) into a specific circular polarization (e.g., left-handed or right-handed circular polarization, or right-handed or left-handed polarization). Depending on the configuration, the circular polarizer can also block light with a specific circular polarization (e.g., right-handed or left-handed circular polarization).

[0400] In some embodiments, various optical elements have birefringence. In some such cases, the retarder 2315 can include a delay sufficient to transform linear polarized light into circularly polarized light, and need not be a quarter wave plate. A delay greater than or less than a quarter wavelength can be included in the retarder 2315, as the delay can be contributed by other optical elements. Similarly, the delay can be distributed among multiple optical elements. As another example, multiple retarders can be used to provide the appropriate delay.

[0401] The circularly polarized light 2310 (here left-handed circularly polarized) then propagates through the optics 2320. Undesirable reflections may occur at any interface in the system with media having different refractive indices, such as an air to material interface. These reflections can become problematic where they are allowed to enter the at least one waveguide 2348, as this reflected light may be directed into the user's eye and form a "ghost" image that is visible in the user's eye. For example, where a display utilizes at least one waveguide 2348 to project a first image into a viewer's eye, a second, faint, duplicate image that is displaced (e.g., laterally displaced) relative to the first image may also be visible to the user. Such "ghost" images are formed by reflections from optical surfaces and directed into the user's eye and may be distracting or otherwise degrade the viewing experience. For example, if Fig.23AAs shown, light such as reflected light 2325 can be reflected from a lens within the optical device 2320. The light can be guided toward at least one waveguide 2348, which is configured to guide the light into the user's eye to present an image to it. However, in this case, the handedness of the circularly polarized light is reversed. For example, when reflected from the lens, the direction of the circular polarization is changed (e.g., from left-handed to right-handed). Then, the right-handed reflected light 2325 travels through the retarder 2315 and is transformed into linearly polarized light, which has a linear polarization different from (e.g., orthogonal to) the linear polarization transmitted by the polarizer 2312. For example, in this case, the light reflected from the optical surface of the lens is transformed by the retarder 2315 into a vertical linear polarization orthogonal to the polarization transmitted by the horizontal linear polarizer 2312. The horizontal linear polarizer 2312 selectively allows horizontally polarized light to pass and filters out vertically polarized light. Thus, the horizontal linear polarizer 2312 attenuates and / or does not transmit the reflected light 2325 and prevents the reflected light 2325 from reaching the at least one waveguide 2348, or causes at least a reduced amount of such reflected light to reach the at least one waveguide 2348 or to be coupled therein, for example, by a coupling-in optical element (e.g., one or more coupling-in gratings). The results are similar for left-handed circularly polarized light reflected from a different optical surface of the optical device 2320 or other optical surfaces on a different optical element.

[0402] As shown, the display system 2300 further includes a second retarder 2330 (e.g., a quarter-wave retarder or a quarter-wave plate) and a second polarizer 2335 (e.g., a linear polarizer) disposed between the optical device 2320 and the spatial light modulator (not shown). In some embodiments, the second retarder 2330 and the second linear polarizer 2335 can form a second circular polarizer. The second retarder 2330 is disposed between the optical device 2320 and the second polarizer 2335. Similarly, the second polarizer 2335 is disposed between the second retarder 2330 and the spatial light modulator. Therefore, after propagating through the optical device 2320, the light 2310 can propagate through the second retarder 2330 (e.g., a quarter-wave retarder). The second retarder 2330 is configured (e.g., appropriately orienting the optical axis) so that the light 2310 is transformed from left-handed circular polarization to horizontal linear polarization. Similarly, the second retarder 2330 converts the circularly polarized light back to the original linear polarization state output by the first polarizer 2312. As will be discussed below, the second retarder 2330 and second polarizer 2312 can be used to reduce "ghost" images caused by light reflected from the spatial optical modulator that propagates through an optical surface (e.g., on an electric optical device or lens 2320) as it travels to at least one light guide 2348.

[0403] The third retarder 2340 (e.g., a quarter-wave retarder or a quarter-wave plate) is disposed between the second polarizer 2335 and the spatial light modulator. Therefore, the third retarder 2340 is disposed between the second retarder 2330 and the spatial light modulator. In addition, in the various embodiments shown, the second polarizer 2335 is located between the second retarder 2330 and the third retarder 2340. As shown, when propagating through the second polarizer 2335, the light 2310 is linearly polarized, and in some embodiments, the second retarder 2330 / second polarizer 2335 can transform the light into the original linear polarization (e.g., horizontal polarization) of the first polarizer 2312. The linearly polarized light is incident on the third retarder 2340. The third retarder 2340 is configured to transform the light back into circularly polarized light, and in some embodiments, transform it into the same polarization as output by the first retarder 2315 (in this example, for example, left-handed circularly polarized light). In some implementations, the spatial light modulator is configured to operate on circularly polarized light. In some embodiments, the spatial light modulator is a reflective spatial light modulator that reflects incident circularly polarized light back as circularly polarized light. In some embodiments, the circularly polarized light reflected from the spatial light modulator can have the same handedness as the circularly polarized light incident on the spatial light modulator (e.g., left-handed circular polarization), which may depend on whether the spatial light modulator pixel is in an "on" or "off" state. In some embodiments, the spatial light modulator can reflect circularly polarized light with a different handedness than the circularly polarized light incident thereon (e.g., right-handed circular polarization), which may depend on whether the spatial light modulator pixel is in an "on" or "off" state. However, other types of spatial light modulators may also be used.

[0404] Fig.23ALight (shown as light ray 2342) reflected from the spatial light modulator and traveling toward the waveguide 2385 is shown. The reflected light ray 2342 is shown as left-handed circularly polarized light. The light ray 2342 propagates through the third retarder 2340. The third retarder 2340 transforms the circularly polarized light into linearly polarized light. In this example, the left-handed circularly polarized light is transformed into horizontally polarized light. The linearly polarized light is transmitted through the second polarizer 2335. In this example, the horizontally polarized light propagates through the second polarizer 2335. The linearly polarized light is incident on the second retarder 2330 and is transformed into circularly polarized light. In this example, the horizontally polarized light is transformed into left-handed polarized light and is transmitted to the optical device 2320. Also here, reflections from optical surfaces, such as surfaces of the optical device 2320 having optical power, can form a ghost image by reflecting back from the spatial light modulator into at least one waveguide 2348 and reaching the user's eye. As described above, undesired reflections may occur at any interface with a medium having a different refractive index, such as an air to material interface. As described above, including a second retarder 2330 and a polarizer 2335 can attenuate these reflections and reduce the possibility of ghost reflections. For example, Fig.23A Light reflected from the optical surface of optical device 2320 (shown as light ray 2346) is shown. In this example, the action of reflecting from the surface causes reflected light ray 2346 to switch the circular polarization handedness from left-handed circular polarization to right-handed circular polarization. The switched circularly polarized light is attenuated by the second circular polarizer formed by the second retarder 2330 and the polarizer 2335. For example, Fig.23A As shown, reflected circularly polarized light 2346 is incident on the second retarder 2330 and is converted by the second retarder into linearly polarized light having a linear polarization different from (e.g., orthogonal to) the linear polarization selectively transmitted by the second linear polarizer 2335. In this case, for example, right-handed circularly polarized light reflected from the optical surface of the optical device 2320 is converted by the retarder 2330 into a vertical linear polarization, which is orthogonal to the polarization selectively transmitted by the polarizer 2335. The second polarizer 2335 attenuates or blocks transmission of the linearly polarized light. In this example, the light 2346 is vertically polarized, and the second polarizer 2335 is a horizontal polarizer that selectively passes horizontally polarized light and filters out vertically polarized light.

[0405] In contrast, light 2342 propagating through the optical device 2320 and incident on the first retarder 2315 is circularly polarized and has a different handedness from the light reflected from the optical surface of the optical device 2320. This light 2342 guided toward the at least one waveguide 2348 has a polarization (e.g., left-handed polarization) that is transformed by the first retarder 2315 into a linear polarization (e.g., horizontal linear polarized light) that is selectively transmitted by the first polarizer 2312. In this way, the light 2342 can reach and be coupled into the at least one waveguide 2348 and guided to the user's eyes.

[0406] exist Fig.23A In the example shown, a first circular polarizer formed by a first polarizer 2312 and a first retarder 2315 and a second circular polarizer formed by a second retarder 2330 and a second polarizer 2335 are used to reduce reflections that may cause "ghosting". The two circular polarizers are located on opposite sides of the optical device 2320, one closer to the light source 2305 and the other closer to the spatial light modulator. An additional retarder 2340 is included between the second circular polarizer (e.g., the second polarizer 2335) and the spatial light modulator to convert light into circularly polarized light. However, various modifications are possible. For example, only one circular polarizer may be included. Alternatively, additional circular polarizers or other types of polarization optical devices may be included.

[0407] Fig. 23B shows that it can be added to Fig.23A The third circular polarizer in the augmented reality system 2300 is shown. In particular, Fig. 23B A second circular polarizer including a second polarizer 2335 and a second retarder 2330 and the third retarder 2340 described above is shown, and a spatial light modulator 2375 is further shown. The spatial light modulator (SLM) 2375 may include a liquid crystal spatial light modulator (e.g., liquid crystal on silicon or LCOS). In some embodiments, the SLM 2375 may be covered by a cover glass 2370.

[0408] Fig. 23B Also shown is a third circular polarizer, which includes a fourth retarder 2345, such as a quarter-wave retarder (e.g., a quarter-wave plate), and a third polarizer 2355, such as a linear polarizer disposed between the second circular polarizer including the second polarizer 2335 and the second retarder 2330 and the spatial light modulator 2375. The third polarizer 2355 is located between the fourth retarder 2345 and the spatial light modulator 2375. An additional fifth retarder 2360, such as a quarter-wave retarder (e.g., a quarter-wave plate), and a compensator 2365 are disposed between the third circular polarizer including the fourth retarder 2345 and the third polarizer 2355 and the spatial light modulator 2375 or more specifically Fig. 23B The fifth retarder 2360 is located between the third polarizer 2355 and the compensator 2365. The compensator 2365 is located between the fifth retarder 2360 and the spatial light modulator 2375 or more specifically the cover glass 2370.

[0409] Fig. 23B Light from light source 2305 is shown, for example, light ray 2310 (eg, Fig.23A ), how it can propagate through the second circular polarizer including the retarder 2330, the second polarizer 2335 and the third retarder 2340 to reach the third circular polarizer including the fourth retarder 2345 and the third polarizer 2355. The light 2310 from the light source 2305 is incident on the third circular polarizer, specifically on the fourth retarder 2345, after propagating through the second circular polarizer including the second retarder 2330 and the second polarizer 2335. The fourth retarder 2345 can transform the circularly polarized light of the light 2310 into linearly polarized light. Fig. 23B In the example shown, the light 2310 is circularly polarized (e.g., left-handed circularly polarized) and is converted into linearly polarized light (e.g., horizontally polarized light) by the fourth retarder 2345. The linearly polarized light proceeds through the third polarizer 2355, which is Fig. 23B The linearly polarized light propagates through the fifth retarder 2360, which may include a quarter-wavelength retarder that converts the linearly polarized light into circularly polarized light. Fig. 23B In the example shown, horizontal linear polarized light 2310 incident on the fifth retarder 2360 is transformed into left-handed circularly polarized light. The circularly polarized light is incident on the compensator 2365 and propagates through the compensator 2365. The compensator 2365 may include a polarization element that adjusts the polarization to a desired polarization. The compensator 2365 can be used to offset the birefringence of various optical elements in the system. For example, due to the delay contribution of one or more optical elements, the light may be slightly elliptically polarized. In various embodiments, the light output from the compensator 2365 is circularly polarized light. Fig. 23B In the example shown, the light output from the compensator 2365 is left-handed circularly polarized light. In various embodiments, the compensator 2365 can be used to compensate for residual delay within an SLM, which can include, for example, a liquid crystal (e.g., LCOS) SLM unit. The compensator can introduce in-plane delay and / or out-of-plane delay. In some embodiments, the compensator 2365 can include a combination of optical retarders that, when combined, produce a delay that can potentially offset the residual delay from the SLM (e.g., an LCOS panel).

[0410] exist Fig. 23BIn [the figure], the light after passing through compensator 2365 is incident on cover glass 2370 and SLM 2375. The light incident on cover glass 2370 and SLM 2375 is shown as left-handed circularly polarized light. Depending on the type and state of the spatial modulator, SLM 2375 may reflect circularly polarized light with the same handedness. For example, when the pixels of SLM 2375 are in the "on" state (although in some embodiments, this state may be the undriven state), SLM 2375 may introduce a quarter-wavelength delay each time the light passes through SLM 2375. Thus, upon reflection, the incident circularly polarized light may remain circularly polarized. In various configurations, the handedness may also remain the same. For example, as Fig. 23B shown, the incident left-handed circularly polarized light may remain left-handed circularly polarized upon reflection. The circularly polarized light reflected from SLM 2375, represented by ray 2342, may pass through cover glass 2370 and compensator 2365 and be incident on fifth retarder 2360, which transforms the circularly polarized light into linearly polarized light. In Fig. 23B the example shown, the circularly polarized light incident on fifth retarder 2360 is left-handed, and fifth retarder 2360 transforms the circularly polarized light into horizontally polarized light. Third polarizer 2355 may be configured to selectively transmit the polarization of the light output by fifth retarder 2360. Thus, in Fig. 23B the example where the light output from fifth retarder 2360 is horizontally polarized as shown, third polarizer 2355 selectively transmits the horizontally polarized light. The linearly polarized light transmitted by polarizer 2355 is incident on fourth retarder 2345 and is transformed into circularly polarized light. In Fig. 23B the example shown, the circularly polarized light is left-handed circularly polarized. As described above in connection with Fig.23A this, the light may travel through a second circular polarizer including second retarder 2330 and second polarizer 2335, optical device 2320, and a first circular polarizer including first polarizer 2312 and first retarder 2315 to reach at least one waveguide 2348 and enter the user's eye.

[0411] However, the light reflected from the optical surface may be attenuated by the third circular polarizer, thereby reducing the likelihood that such reflections reach at least one waveguide 2348 and are directed to the user's eye to produce ghosting. For illustration, Fig. 23BAn example light 2343 is shown that is reflected from the optical surface of the third retarder 2340, for example, from the interface between air and the third retarder 2340. As described above, reflection can occur at any interface between media with different refractive indices, such as an air to material interface or an interface between different dielectric layers. However, the handedness of the circularly polarized light is reversed upon reflection. For example, when reflected from the surface of the third retarder 2340, the direction of the circular polarization changes (for example, from left-handed to right-handed). The right-handed reflected light 2343 then travels through the fourth retarder 2345 and is transformed into linearly polarized light having a different, for example, orthogonal, linear polarization than the polarization selectively transmitted by the third polarizer 2355. In this case, for example, the light reflected from the optical surface of the third retarder 2340 is transformed by the fourth retarder 2345 into a vertical linear polarization that is orthogonal to the polarization selectively transmitted by the third polarizer 2355. The third polarizer 2355 selectively allows horizontally polarized light to pass and filters out vertically polarized light. Thus, the third polarizer 2355 attenuates and / or does not transmit reflected light 2343 and prevents reflected light 2343 from reaching at least one waveguide 2348 (e.g., by reflecting from another surface), or causes at least a reduced amount of such reflected light to reach at least one waveguide 2348 or be coupled into it.

[0412] For circularly polarized light reflected from different optical surfaces, the results may be similar. For example, Fig. 23B The reflection of incident light 2310 from the optical surface of the fourth retarder 2345 is shown. The reflection 2350 from the fourth retarder 2345 switches the handedness of polarization. For example, the incident light 2310 shown as left-handed circular polarization is transformed into light 2350 shown as having right-handed circular polarization upon reflection. The reflected light 2350 propagates through the third retarder 2340 and is transformed into vertically polarized light. The vertically polarized light is selectively attenuated or filtered out by the second polarizer 2335.

[0413] As described above, a pixel of the SLM 2375 can, for example, be in an "on" state (although in some embodiments it can be a non-actuated state), in which state light incident on that pixel of the SLM 2375 is reflected therefrom and coupled into the at least one waveguide 2348 and directed to the user's eye. However, a pixel of the SLM 2375 can be in an "off" state (which can be an actuated state in some embodiments), in which state light incident on the pixel of the SLM 2375 is not coupled into the at least one waveguide 2348 and is not coupled into the user's eye. For example, in such an "off" state, various embodiments of the SLM 2375 do not introduce any delay upon reflection. Thus, in Fig. 23BIn the example shown, circularly polarized light incident on SLM 2375 may remain circularly polarized when reflected from SLM 2375. However, this handedness of the circularly polarized light may change when reflected from SLM 2375. For example, Fig. 23B The light 2310 shown, which is left-handed circularly polarized incident on the SLM 2375, can be transformed into right-handed circularly polarized light when reflected from the SLM 2375. However, this reflected light can be selectively attenuated by the third polarizer 2355. For example, the right-handed circularly polarized light reflected from the SLM 2375 can propagate through the cover glass 2370, the compensator 2365, and the fifth retarder 2360. The fifth retarder 2360 can transform the right-handed circularly polarized light into vertically polarized light, which is selectively attenuated by the third polarizer 2355, which can include a horizontal polarizer. Therefore, in various embodiments, when the pixels of the SLM are in the "off" state, the fifth retarder 2360 can transform the light reflected from the pixels of the SLM 2375 into a linear polarization that is orthogonal to the linear polarization selectively transmitted by the third polarizer 2355. Thus, the third polarizer 2355 can selectively attenuate the linearly polarized light, thereby reducing or blocking light from the pixels of the SLM 2375 from reaching the at least one waveguide 2348 and being directed into the eye.

[0414] Variations in configuration, such as polarization optical elements, are possible. For example, more or fewer circular polarizers may be included. In various embodiments, for example, Fig.23C As shown, the third circular polarizer is excluded including the fourth retarder 2345 and the third polarizer 2355. In this particular embodiment, the fourth retarder 2345, the third polarizer 2355 and the fifth retarder 2360 are not included in the system. Fig.23C A design of an augmented reality system 2300 is shown, the system comprising Fig.23A and Fig. 23B Components shown, but not including fourth retarder 2345, third polarizer 2355, and fifth retarder 2360. However, despite the exclusion of the third circular polarizer, the augmented reality display system is still configured to reduce ghost images. For example, the second circular polarizer reduces reflections that would otherwise cause ghosting. For illustration, Fig.23CLight reflected from the third retarder 2340 is shown, shown as light ray 2380. The action of reflecting from the surface of the third retarder 2340 causes the circularly polarized reflected light ray 2380 to switch handedness. In this example, the polarization switches from left-handed circular polarization to right-handed circular polarization. The switched circularly polarized light 2380 then propagates through the compensator 2365 and is incident on the cover glass 2370 and the SLM 2375. As described above, the SLM 2375 can reflect circularly polarized light of the same handedness. Therefore, the incident right-handed circularly polarized light can remain right-handed circularly polarized upon reflection. The circularly polarized light reflected from the SLM 2375, represented by light ray 2382, can then propagate through the cover glass 2370 and the compensator 2365 and be incident on the third retarder 2340. The switched circularly polarized light 2382 is attenuated by the second circular polarizer, particularly by the third retarder 2340 and the polarizer 2335. For example, as Fig.23C As shown, circularly polarized light 2382 reflected from the SLM 2375 is incident on the third retarder 2340 and is converted by the third retarder 2340 into linearly polarized light having a linear polarization different from, e.g., orthogonal to, the linear polarization selectively transmitted by the second linear polarizer 2335. In this case, for example, right-handed circularly polarized light 2382 is converted by the third retarder 2340 into a vertical linear polarization that is orthogonal to the polarization selectively transmitted by the second polarizer 2335. The second polarizer 2335 attenuates or blocks the transmission of such linearly polarized light.

[0415] By tilting the optical surfaces in the system, it is also possible to potentially reduce reflections that could cause ghost reflections. Fig.24 An example configuration with angled optical surfaces for reducing reflections that can produce ghost reflections is shown. Fig.24 An augmented reality display system 2400 is shown that includes a light source 2305 that emits light represented by light ray 2310, which propagates through any number of polarizers, retarders, lenses, and / or other optical components as it travels toward a spatial light modulator (SLM). Fig.242312 and the first retarder 2315 and the lens 2320 that may form the first circular polarizer are shown. However, additional components may be included, or components may be excluded or arranged or configured in a different manner. In the example shown, the SLM 2375 includes a cover glass 2370. The cover glass 2370 may be a contributing factor to the reflection that produces a ghost image. Therefore, in some embodiments, the shape of the cover glass 2370 may be designed to guide the reflection that may produce a ghost image so that it is not guided into the user's eyes. As shown, the cover glass 2370 has a tiltable surface so that the surface is not parallel to other components or optical surfaces of the system (e.g., SLM 2375, the first retarder 2315, the first polarizer 2312, at least one waveguide 2348, etc. or their optical surfaces). The main surface of the cover glass 2370 may, for example, have a tilted normal so as not to be aligned or parallel to the optical axis of the augmented reality display system 2400 or the optical components therein (e.g., the optical device 2320). By tilting, reflections from the optical surface of the cover glass 2370 can be directed away from the at least one waveguide 2348 or a coupling optical element (e.g., a coupling grating or a diffractive optical element) used to couple light into the at least one waveguide 2348, and the likelihood of reflections from the cover glass 2370 entering the at least one waveguide 2348 is reduced. As shown, the reflected light 2405 is directed back toward the light source 2305 and away from the at least one waveguide 2348, where such light can ultimately reach the user's eyes. In some embodiments, the reflected light 2405 can be directed back to the light source and at least a portion is recycled at the light source 2305.

[0416] although Fig.24 A cover glass 2370 is shown with an angled surface, but optical surfaces that are tilted to prevent reflections from being coupled into at least one waveguide 2348 may be included on any system component where undesirable reflections may occur. Thus, optical surfaces on other components such as polarizers, retarders, etc. may be tilted to reduce reflections that are coupled into at least one waveguide 2348 and reach the user's eye. Variations in the shape and size of the cover glass 2370 or other optical components are possible. The cover glass 2370 or other optical component may be thinner, for example. Similarly, the cover glass 2370 or other optical component may have a thickness similar to that of the optical component 2370. Fig.24 Different aspect ratios (length to thickness ratio) are shown. In some embodiments, the cover glass 2370 or other optical component is wedge-shaped. However, other shapes are also possible.

[0417] Other arrangements are possible. For example, Fig.25 Shows something like Fig.24An embodiment of an augmented reality display system 2500 of the system 2400 shown, but further includes a light absorber 2505 to absorb light directed to the light absorber. The system 2500 includes a tilted cover glass 2370 to direct reflections 2510 from the cover glass 2370 to the light absorber 2505, rather than directing them back to the light source 2305. The light absorber 2505 may include an absorptive material or structure configured to absorb light. Depending on the embodiment, the position of the light absorber 2505 may be changed, for example, depending on the angle of the tilted cover glass 2370. As described above, the method can be applied to other optical surfaces in the system. In addition, the shape and size of the optical elements can be different.

[0418] A variety of variations of augmented reality displays are possible. Variations in polarization optical elements are possible. For example, although a horizontal polarizer is used, in some embodiments, a vertical polarizer or a combination of a horizontal polarizer and a vertical polarizer may be used. In addition, polarizers characterized by polarizations other than vertical or horizontal polarizations may be used. Similarly, the light shown in the figures need not be horizontally polarized, but may also be vertically polarized. Similarly, in different embodiments, light shown as vertically polarized may be horizontally polarized, or light shown as horizontally polarized may be vertically polarized. Linearly polarized light having polarizations other than vertical or horizontal may also be used.

[0419] In addition, the retarder can be configured in different ways. For example, the polarized light in the figure does not have to be left-handed circularly polarized, it can also be right-handed circularly polarized light and / or right-handed polarized light can be left-handed circularly polarized. Other variations are also possible. Different retarder configurations can be used to produce combinations of left-handed and / or right-handed polarized light different from those shown. In addition, in some embodiments, elliptically polarized light can be used instead of circularly polarized light. For example, a retarder can be used to transform elliptically polarized light into linearly polarized light, or to transform linearly polarized light into elliptically polarized light. Linear polarizers can be used to filter light and can be used to reduce ghost reflections such as those described herein.

[0420] In some embodiments, other types of polarization elements and their configurations are used. For example, the retarder is not limited to a quarter-wave retarder or a quarter-wave plate. For example, in some embodiments, various optical elements have birefringence. In some such cases, any one or more of the retarders 2315, 2330, 2340 may include a delay sufficient to transform linear polarized light into circularly polarized light, and need not be a quarter-wave retarder. Any one or more of the retarders 2315, 2330, 2340 may include a delay of more or less than a quarter wavelength because the delay may be contributed by other optical elements. Similarly, the delay may be distributed among multiple optical elements. As another example, multiple retarders may be used to provide an appropriate delay. In addition, as described above, in some embodiments, elliptically polarized light may be used instead of circularly polarized light. For example, a retarder may be used to transform elliptically polarized light into linearly polarized light, or to transform linearly polarized light into elliptically polarized light. Linear polarizers may be used to filter light and may be used to reduce ghost reflections such as those described herein.

[0421] In addition, the optical component can take the form of an optical layer, sheet and / or film and a stack or one or more layers, sheets and / or films. Thus, different polarizing elements with different numbers, positions and arrangements can be used. For example, one or more of the retarder and / or polarizer can include a film.

[0422] In some embodiments, the spatial light modulator can operate in a different manner. For example, the spatial light modulator can operate on light other than circularly polarized light and / or can output light other than circularly polarized light.

[0423] In the above description, the present disclosure has been described with reference to specific embodiments of the present disclosure. However, it is obvious that various modifications and changes can be made to the present disclosure without departing from the broader spirit and scope of the present disclosure. Therefore, the description and drawings should be regarded as illustrative rather than restrictive.

[0424] In fact, it should be understood that the systems and methods of the present disclosure each have several innovative aspects, none of which alone is responsible for or claims the desired properties disclosed herein. The various features and processes described above can be used independently of one another, or can be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of the present disclosure.

[0425] Certain features described in this specification by the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually in multiple embodiments, or in any suitable sub-combination. In addition, although features may function in certain combinations as described above, and may even be initially claimed in this manner, one or more features in a claimed combination may be excluded from the combination in certain circumstances, and a claimed combination may involve sub-combinations or variations of sub-combinations. No single feature or group of features is essential or indispensable for each embodiment.

[0426] It should be understood that, unless otherwise expressly stated, or understood in other ways in the context of use, conditional terms such as "can", "may", "could", "for example", etc. used herein are generally intended to express that certain embodiments include, while other embodiments do not include certain features, elements and / or steps. Therefore, such conditional terms are generally not intended to imply that features, elements and / or steps are necessary for one or more embodiments in any way, nor are they intended to imply that one or more embodiments must include logic for determining whether to include these features, elements and / or steps or whether to perform these features, elements and / or steps in any particular embodiment with or without author input or prompting. The terms "include", "comprise", "have", etc. are synonyms and are used inclusively in an open manner and do not exclude other elements, features, actions, operations, etc. In addition, the term "or" has an inclusive meaning (rather than an exclusive meaning) when used, so when used, for example, to connect a list of elements, the term "or" represents one, some or all of the elements in the list. In addition, unless otherwise specified, the articles "one", "an" and "said" used in this application and the appended claims should be interpreted as meaning "one or more" or "at least one". Similarly, although the operations are shown in the drawings as taking a specific order, it should be recognized that these operations do not need to be performed in the specific order shown or in sequence, or all the operations shown need to be performed to achieve the desired results. In addition, the drawings may schematically show one or more example processes in the form of a flow chart. However, other operations not shown may be incorporated into the example methods and processes schematically illustrated. For example, one or more additional operations may be performed before, after, between, or in parallel with any of the operations shown. In addition, in other embodiments, the operations may be rearranged or sequenced. In some cases, multitasking and parallel processing are advantageous. In addition, the separation of various system components in the above-mentioned embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. In addition, other embodiments are within the scope of the following claims. In some cases, the actions listed in the claims can be performed in different orders and still achieve the desired results.

[0427] Thus, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

Claims

1. A head-mounted display system configured to project light into a user's eyes to display augmented reality image content in the user's field of view, the head-mounted display system include: a frame configured to be supported on the user's head; at least one light source configured to output light; a spatial light modulator configured to receive light from the at least one light source; an eyepiece disposed on the frame, the eyepiece being configured to direct light from the spatial light modulator into an eye of the user to display augmented display image content to the user's field of view, at least a portion of the eyepiece being transparent and disposed at a position in front of the user's eye when the user wears the head mounted display, wherein the transparent portion transmits light from a portion of the physical environment in front of the user toward the user's eye to provide a view of the portion of the physical environment in front of the user, the eyepiece comprising: (a) at least one waveguide; (b) at least one in-coupling optical element configured to couple light from the spatial light modulator into the at least one waveguide; and (c) at least one out-coupling optical element configured to couple light guided within the waveguide out of the waveguide and direct the light toward an eye of the user; and an optical device having an optical power, the optical device being arranged to receive light output from the light source, the optical device being arranged relative to the spatial light modulator such that the light received from the light source propagates through the optical device and illuminates the spatial light modulator, wherein the head mounted display system is configured such that light illuminating the spatial light modulator is redirected back through the optical device and coupled into the at least one waveguide through the at least one coupling-in optical element, and at least a portion of the coupled light is emitted from the at least one waveguide through the at least one coupling-out optical element and directed to the user's eye, and The at least one waveguide has a first side and a second side opposite to the first side, the optical device and the spatial light modulator are on the first side, and the at least one light source is on the second side of the at least one waveguide.

2. The head mounted display system according to claim 1, in, The at least one light source comprises a multi-color light source configured to emit different colors of light at different times.

3. A head mounted display system according to any one of the preceding claims, in, The at least one light source includes a red-green-blue (RGB) light source configured to emit red, green, and blue light at different times.

4. The head mounted display system according to claim 1 or 2, in, The at least one light source includes a cyan, magenta, yellow (CMY) light source configured to emit cyan, magenta, and yellow light at different times.

5. The head mounted display system according to claim 2, include: a plurality of laterally displaced light emitters configured to output light; light collecting optics configured to collect light from the plurality of laterally displaced light emitters; Diffuser; as well as A plurality of holes are adjacent to the diffuser.

6. The head mounted display system of claim 5, further comprising coupling optics disposed relative to the laterally displaced light emitters to collect light output from the light source.

7. The head mounted display system according to claim 6, in, The coupling optics include a compound parabolic concentrator (CPC).

8. The head mounted display system according to claim 1, in, The spatial light modulator comprises a reflective spatial light modulator.

9. The head mounted display system according to claim 1, in, The spatial light modulator comprises a liquid crystal spatial light modulator.

10. The head mounted display system according to claim 1, in, The spatial light modulator comprises a vertically aligned liquid crystal spatial light modulator.

11. The head mounted display system according to claim 1, in, The spatial light modulator comprises a deflection-based spatial light modulator.

12. The head mounted display system according to claim 1, in, The spatial light modulator includes an array of movable mirrors.

13. The head mounted display system of claim 12, further comprising a light absorber, such that in a closed state, light is directed by the movable mirror array to the light absorber, and in an open state, light is directed to a corresponding coupling optical element.

14. The head mounted display system according to claim 1, in, The at least one waveguide comprises a material transparent to visible light having a refractive index sufficient to guide light in the waveguide by total internal reflection.

15. The head mounted display system according to claim 1, in, The at least one waveguide comprises a waveguide stack.

16. The head mounted display system according to claim 15, in, Different waveguides in the waveguide stack are configured to output light having different corresponding colors.

17. The head mounted display system according to claim 15 or 16, in, The first waveguide, the second waveguide, and the third waveguide in the waveguide stack are configured to output a first color light, a second color light, and a third color light, respectively, and the first color light, the second color light, and the third color light are red light, blue light, and green light, respectively.

18. A head mounted display system according to any one of claims 15 to 16, in, Different waveguides in the waveguide stack are configured to output light with different wavefronts, the light with different wavefronts having different amounts of divergence, convergence, and at least one of collimation, as if projected from different distances from the user's eyes.

19. The head mounted display system according to claim 1, in, The at least one waveguide is configured to couple in light of a specific polarization.

20. The head mounted display system according to claim 1, in, The coupling-in optical element includes at least one of a diffractive optical element and a reflector.

21. The head mounted display system according to claim 1, in, The at least one coupling-in optical element includes a plurality of color selective coupling-in optical elements configured to couple in different respective colors.

22. The head mounted display system according to claim 21, in, The multiple color selective coupling optical elements include a first coupling optical element and a second coupling optical element, wherein the second coupling optical element is arranged above the first coupling optical element so that light of a first color can be coupled into a first waveguide by the first coupling optical element to be guided therein, and light of a second color different from the first color can propagate through the first coupling optical element to reach the second coupling optical element, and can be coupled into a second waveguide by the second coupling optical element to be guided therein.

23. The head mounted display system according to claim 22, in, The multiple color selective coupling-in optical elements include a third coupling-in optical element, which is arranged above the first coupling-in optical element and the second coupling-in optical element so that light of a third color different from the first color and the second color can propagate through the first coupling-in optical element and the second coupling-in optical element to reach the third coupling-in optical element, and can be coupled into a third waveguide to be guided therein.

24. The head mounted display system according to claim 23, in, The first color includes one of red, green, and blue, wherein the second color includes one of red, green, and blue different from the first color, and wherein the third color includes one of red, green, or blue different from the first color and the second color.

25. The head mounted display system according to claim 1, in, The at least one incoupling optical element includes an incoupling optical element configured to couple light of a plurality of colors into a waveguide of the at least one waveguide to guide the light therein.

26. The head mounted display system according to claim 1, in, The at least one light source includes a light source arranged relative to the optical device and the spatial light modulator to guide light to the coupling optical element configured to couple multiple colors of light into a waveguide of the at least one waveguide, and the light source is configured to emit different colors of light at different times.

27. The head mounted display system according to claim 1, in, The at least one incoupling optical element includes an incoupling optical element configured to couple red light, green light, and blue light into a waveguide of the at least one waveguide to guide the light therein.

28. The head mounted display system according to claim 1, in, The at least one incoupling optical element is configured to incouple light of a predetermined polarization.

29. The head mounted display system according to claim 1, in, The at least one coupling-in optical element comprises a plurality of coupling-in optical elements that are laterally displaced relative to each other.

30. The head mounted display system according to claim 29, in, The multiple coupling optical elements include a first coupling optical element configured to couple light of multiple colors into a first waveguide of the at least one waveguide to guide the light therein, and a second coupling optical element configured to couple light of multiple colors into a second waveguide of the at least one waveguide to guide the light therein, wherein the first coupling optical element and the second coupling optical element are laterally shifted relative to each other.

31. The head mounted display system according to claim 29 or 30, in, The at least one light source includes a first light source arranged relative to the optical device and the spatial light modulator to guide light to the first coupling-in optical element and a second light source arranged relative to the optical device and the spatial light modulator to guide light to the second coupling-in optical element.

32. The head mounted display system according to claim 30, in, The at least one light source includes a first light source disposed relative to the optics and the spatial light modulator to direct light into the first incoupling optical element, the first light source being configured to emit light of different colors at different times.

33. The head mounted display system according to claim 32, in, The at least one light source includes a second light source disposed relative to the optics and the spatial light modulator to direct light into the second incoupling optic, the second light source being configured to emit light of different colors at different times.

34. The head mounted display system according to claim 33, in, The eyepiece is configured such that light coupled out of the first waveguide and light coupled out of the second waveguide have different amounts of at least one of convergence, divergence, and collimation, and thus appear to originate from different depth planes.

35. A head mounted display system according to any one of claims 32 to 34, in, The eyepiece is configured such that light outcoupled from the first waveguide is collimated and light output from the second waveguide is divergent.

36. A head mounted display system according to any one of claims 32 to 34, in, The eyepiece is configured such that light outcoupled from the first waveguide diverges a first amount, and light outcoupled from the second waveguide diverges a second amount, wherein the second amount is different from the first amount.

37. The head mounted display system according to claim 1, in, The at least one incoupling optical element includes an incoupling optical element configured to couple red light, green light, and blue light into the waveguide to guide the light therein.

38. The head mounted display system according to claim 1, in, The at least one light source includes a light source arranged relative to the optical device and the spatial light modulator to guide light into the at least one coupling optical element, the at least one coupling optical element is configured to couple red light, green light, and blue light into a waveguide of the at least one waveguide, and the at least one light source is configured to emit different red light, green light, and blue light at different times.

39. The head mounted display system of claim 31, in, The first light source is a first color light source, and the second light source is a second color light source having a color different from the first color.

40. The head mounted display system of claim 39, in, The first light source is a red light source, and the second color light source is one of a green light source and a blue light source.

41. The head mounted display system of claim 1, in, The at least one coupling-in optical element comprises a plurality of coupling-in optical element groups, each group comprising a plurality of color-selective coupling-in optical elements configured to couple in different respective colors, each group of the plurality of groups being laterally displaced relative to each other.

42. The head mounted display system of claim 41, in, The multiple color selective coupling optical elements include a first coupling optical element and a second coupling optical element, wherein the second coupling optical element is arranged above the first coupling optical element so that light of a first color can be coupled into a first waveguide by the first coupling optical element to be guided therein, and light of a second color different from the first color can propagate through the first coupling optical element to reach the second coupling optical element, and can be coupled into a second waveguide by the second coupling optical element to be guided therein.

43. The head mounted display system of claim 42, in, The multiple color selective coupling optical elements include a third coupling optical element, which is arranged above the second coupling optical element so that a third color different from the first color and the second color can propagate through the first coupling optical element and the second coupling optical element to reach the third coupling optical element and can be coupled into a third waveguide to be guided therein.

44. The head mounted display system of claim 43, in, The first color includes one of red, green, and blue, wherein the second color includes one of red, green, and blue different from the first color, and wherein the third color includes one of red, green, or blue different from the first color and the second color.

45. The head mounted display system of claim 1, in, The at least one coupling-in optical element comprises a first coupling-in optical element group and a second coupling-in optical element group, wherein the first coupling-in optical element group comprises a plurality of color-selective coupling-in optical elements configured to couple in different corresponding colors, and the second coupling-in optical element group comprises a plurality of color-selective coupling-in optical elements configured to couple in different corresponding colors, wherein the first group and the second group are laterally shifted relative to each other.

46. ​​The head mounted display system of claim 45, in, The multiple color selective coupling optical elements include a first coupling optical element and a second coupling optical element, wherein the second coupling optical element is arranged above the first coupling optical element so that light of a first color can be coupled into a first waveguide by the first coupling optical element to be guided therein, and a second color different from the first color can propagate through the first coupling optical element to reach the second coupling optical element, and can be coupled into a second waveguide by the second coupling optical element to be guided therein.

47. The head mounted display system of claim 46, in, The multiple color selective coupling optical elements include a third coupling optical element, which is arranged above the first coupling optical element and the second coupling optical element so that a third color different from the first color and the second color can propagate through the first coupling optical element and the second coupling optical element to reach the third coupling optical element, and can be coupled into a third waveguide to be guided therein.

48. The head mounted display system of claim 47, in, The first color includes one of red, green, and blue, wherein the second color includes one of red, green, and blue different from the first color, and wherein the third color includes one of red, green, or blue different from the first color and the second color.

49. The head mounted display system of claim 48, in, The second plurality of coupling-in optical elements includes a fourth coupling-in optical element and a fifth coupling-in optical element, the fifth coupling-in optical element being arranged above the fourth coupling-in optical element so that light of a fourth color can be coupled into a fourth waveguide by the fourth coupling-in optical element to be guided therein, and a fifth color different from the first color can propagate through the fourth coupling-in optical element to reach the fifth coupling-in optical element, and can be coupled into the fifth waveguide by the second coupling-in optical element to be guided therein.

50. The head mounted display system of claim 49, in, The second plurality of coupling-in optical elements includes a sixth coupling-in optical element, which is arranged above the fourth coupling-in optical element and the fifth coupling-in optical element so that a sixth color different from the first color and the second color can propagate through the fourth coupling-in optical element and the fifth coupling-in optical element to reach the sixth coupling-in optical element and can be coupled into a sixth waveguide to be guided therein.

51. The head mounted display system of claim 50, in, The eyepiece is configured such that light coupled out of the first waveguide, the second waveguide, and the third waveguide has at least one of a different amount of convergence, divergence, and collimation than light coupled out of the fourth waveguide, the fifth waveguide, and the sixth waveguide, and thus appears to originate from a different depth than light output from the fourth waveguide, the fifth waveguide, and the sixth waveguide.

52. The head mounted display system of claim 51, in, The eyepiece is configured such that light outcoupled from the first waveguide, the second waveguide, and the third waveguide is collimated, and light output from the fourth waveguide, the fifth waveguide, and the sixth waveguide is divergent.

53. The head mounted display system of claim 52, in, The eyepiece is configured such that light coupled out from the first waveguide, the second waveguide, and the third waveguide diverges, and light output from the fourth waveguide, the fifth waveguide, and the sixth waveguide diverges by different amounts.

54. A head mounted display system according to any one of claims 45 to 53, in, The at least one light source includes a first light source disposed relative to the optics and the spatial light modulator to direct light into the first set of incoupling optics, the first light source being configured to emit light of different colors at different times.

55. A head mounted display system according to any one of claims 45 to 53, in, The at least one light source includes a second light source disposed relative to the optical device and the spatial light modulator to direct light to the second coupling optical element group, the second light source also being configured to emit light of different colors at different times.

56. The head mounted display system of claim 1, in, The at least one outcoupling optical element comprises a diffractive optical element.

57. The head mounted display system of claim 1, in, The at least one outcoupling optical element is configured to increase a size of the eye field along at least one first axis.

58. The head-mounted display system of claim 57, further comprising an orthogonal pupil expander, the orthogonal pupil expander comprising at least one light redirecting element in or on the at least one waveguide, the at least one light redirecting element being configured to increase a size of the eye movement range along a second axis orthogonal to the at least one first axis.

59. The head mounted display system of claim 58, in, The at least one light redirecting element comprises a diffractive optical element.

60. The head mounted display system of claim 1, in, At least a portion of the at least one waveguide extends between the at least one light source and the optical device, and light from the at least one light source guided through the optical device propagates through the portion of the at least one waveguide to reach the optical device.

61. The head mounted display system of claim 1, in, The at least one waveguide has a first side and a second side opposite the first side, the optical device and the spatial light modulator are arranged on the first side so that light from the spatial light modulator is directed onto the first side.

62. The head mounted display system of claim 61, in, The at least one light source is disposed on the first side such that light from the at least one light source is incident on the first side before propagating through the optical device to the spatial light modulator.

63. The head mounted display system of claim 61, in, The at least one light source is disposed on the second side such that light from the at least one light source is incident on the second side before propagating through the optical device to the spatial light modulator.

64. The head mounted display system of claim 63, in, The at least one waveguide is disposed between the at least one light source and the optical device.

65. The head-mounted display system according to claim 1 further comprises a light source coupling optical element, which is arranged relative to a portion of the at least one waveguide adjacent to the at least one light source so as to receive light from the at least one light source and couple the light from the at least one light source into the portion of the at least one waveguide to be guided therein.

66. The head-mounted display system according to claim 65 further includes an out-coupling optical element relative to the portion of the light source adjacent to the at least one waveguide, which is configured to guide the light guided in the portion of the at least one waveguide out of the portion of the at least one waveguide, through the optical device and to the spatial light modulator.

67. The head mounted display system of claim 66, in, The head mounted display system is configured such that at least a portion of the light coupled into the optical device from the portion of the at least one waveguide adjacent to the at least one light source is incident on the spatial light modulator, propagates through the optical device again, is incident on a second portion of the at least one waveguide, is again guided therein, is coupled out therefrom and is guided to the user's eye.

68. The head-mounted display system of any one of claims 65 to 67, further comprising an isolator to reduce crosstalk from the portion of the at least one waveguide adjacent the light source to the second portion of the at least one waveguide.

69. The head mounted display system of claim 68, in, The isolator includes one of an opaque surface and a reflective surface.

70. The head mounted display system of claim 68, in, The isolator is disposed in the at least one waveguide.

71. The head mounted display system of claim 70, in, The at least one waveguide has a first side and a second side opposite to the first side, and the optical device and the spatial light modulator are arranged on the first side of the at least one waveguide.

72. The head mounted display system of claim 71, in, The at least one light source is disposed on the first side of the at least one waveguide so that light from the at least one light source is incident on the first side of the at least one waveguide to be guided therein, and the light guided in the portion of the at least one waveguide is coupled out from the first side of the at least one waveguide and reaches the optical device and the spatial light modulator located on the first side.

73. The head mounted display system of claim 71, in, The at least one light source is disposed on the second side of the at least one waveguide such that light from the at least one light source is incident on the second side of the at least one waveguide before propagating through the optical device to the spatial light modulator.

74. A head mounted display system according to claim 71 or 73, in, The at least one waveguide is disposed between the at least one light source and the optical device.

75. The head-mounted display system according to claim 1 further comprises at least one waveguide optically coupled to the at least one light source to receive light from the at least one light source to guide the light from the at least one light source therein, and couple the light guided therein into the optical device so that at least a portion of the light coupled into the optical device from the at least one waveguide is incident on the spatial light modulator, propagates through the optical device again and is incident on the at least one waveguide, is guided therein, is coupled out therefrom and is guided to the user's eyes.

76. The head-mounted display system of claim 75, further comprising a coupling element disposed on the at least one waveguide to receive light from the light source and couple the light from the light source into the at least one waveguide to be guided therein.

77. The head-mounted display system according to claim 76 further includes a coupling element, which is arranged on the at least one waveguide to receive the light guided in the at least one waveguide from the light source, and couple the light guided in the at least one waveguide out of the at least one waveguide and reach the spatial light modulator through the optical device.

78. The head-mounted display system of any one of claims 75 to 77, further comprising an isolator to reduce crosstalk between the at least one waveguide and the at least one waveguide.

79. The head mounted display system of claim 78, in, The isolator includes at least one of an opaque surface and a reflective surface.

80. The head mounted display system of claim 79, in, The isolator is disposed in or on the at least one waveguide.

81. The head mounted display system of claim 80, in, The at least one waveguide has a first side and a second side opposite to the first side, and the optical device and the spatial light modulator are arranged on the first side of the at least one waveguide.

82. The head mounted display system of claim 81, in, The at least one light source is disposed on the first side of the at least one waveguide so that light from the at least one light source is incident on the first side of the at least one waveguide to be guided therein, and the light guided in the at least one waveguide is coupled out of the first side of the at least one waveguide to reach the optical device and the spatial light modulator on the first side.

83. The head mounted display system of claim 81, in, The at least one light source is disposed on the second side of the at least one waveguide so that light from the at least one light source is incident on the second side of the at least one waveguide to guide the light therein, and the light guided in the at least one waveguide is coupled out of the first side of the at least one waveguide to reach the optical device and the spatial light modulator on the first side.

84. The head mounted display system of claim 81 or 83, in, The at least one waveguide is disposed between the at least one light source and the optical device.

85. The head mounted display system of claim 1, in, The optical device includes one or more lenses.

86. The head mounted display system of claim 1, in, The optical device includes a plurality of lenses.

87. The head mounted display system of claim 1, in, The optic has positive optical power.

88. The head mounted display system of claim 1, in, The optical device includes one or more refractive optical elements.

89. The head mounted display system of claim 1, in, The spatial light modulator is configured to modulate polarization.

90. The head-mounted display system of claim 1, further comprising a polarizer located in the optical path between the spatial light modulator and the user's eyes.

91. The head mounted display system of claim 90, in, The analyzer is arranged in the beam path between the optical system and the at least one coupling-in optical element.

92. The head-mounted display system of claim 1, further comprising a polarizer disposed between the at least one light source and the spatial light modulator.

93. The head mounted display system of claim 1, in, The at least one light source comprises a polarized light source.

94. The head mounted display system of claim 1, in, The polarizer is disposed between the optical device and the spatial light modulator.

95. The head mounted display system of claim 94, in, The polarizer is arranged directly on the spatial light modulator.

96. The head mounted display system of claim 94, in, The polarizer comprises a wire grid polarizer.

97. The head mounted display system of claim 90, in, The analyzer is a circular polarizer.

98. The head mounted display system of claim 1, further comprising a variable optical element having adjustable optical power.

99. The head mounted display system of claim 98, in, The variable optical element includes a lens or a mirror.

100. The head mounted display system according to claim 98 or 99, in, The variable optical element is configured to have a first state and a second state, wherein in the first state the variable optical element has a different optical power than in the second state.

101. The head mounted display system of claim 100, in, The variable optical element has a negative optical power in the first state and has a zero optical power in the second state.

102. The head mounted display system of claim 100, in, The variable optical element has a positive optical power in the first state and has a zero optical power in the second state.

103. The head mounted display system of claim 100, in, The variable optical element has a first negative optical power in the first state and a second different negative optical power in the second state.

104. The head mounted display system of claim 100, in, The variable optical element has a first positive optical power in the first state and a second, different positive optical power in the second state.

105. The head mounted display system of claim 100, in, The variable optical element has a first negative optical power in the first state and a second positive optical power in the second state.

106. The head mounted display system of claim 98, in, The variable optical element includes a liquid lens.

107. The head mounted display system of claim 1, further comprising an adjustable dimmer comprising an optical element that provides variable attenuation of light transmitted therethrough.

108. The head-mounted display system of claim 1, further comprising prescription lenses configured to provide refractive correction to the user's eyes.

109. The head-mounted display system of claim 1, further comprising a static lens disposed in a path between the at least one waveguide and the user's eye.

110. The head mounted display system of claim 91, in, The analyzer is configured to also function as a polarizer to allow light to propagate from the light source toward the optical device.

111. The head mounted display system of claim 1, further comprising a color filter array disposed on a side of the waveguide adjacent to the user, in, The color filter array includes a plurality of different color filters.

112. The head mounted display system of claim 111, in, The color filter array includes an absorptive material disposed between the color filters configured to reduce propagation and reflection of stray light.

113. The head mounted display system of claim 92, in, A polarizer can be disposed in a light path of the light source and configured to transmit light of a first polarization and reflect light of a second polarization, wherein a portion of the reflected light of the second polarization directed toward the light source acquires the first polarization.

114. The head mounted display system of claim 113, in, A portion of the reflected light of the second polarization directed towards the light source acquires the first polarization by reflection from coupling optics arranged to collect light from the light source.

115. The head-mounted display system of claim 1, further comprising a quarter wave plate.

116. The head mounted display system of claim 1, further comprising a compensator configured to provide a more consistent orthogonal rotation of the light.

117. The head mounted display system of claim 1, in, The optics and the spatial light modulator are tilted relative to each other.

118. The head mounted display system of claim 6, in, The coupling optics, optics, and spatial light modulator are tilted relative to the eyepiece.

119. The head mounted display system of claim 6, in, The coupling optics, optics, and spatial light modulator are tilted relative to the eyepiece.

120. The head mounted display system of claim 1, wherein light from the light source is configured to be recycled or reused.

121. The head-mounted display system of claim 1, further comprising a polarizer configured to transmit light having a first polarization from the light source to the optical device and to reflect light having a different second polarization back to the light source.

122. The head-mounted display system of claim 121, further comprising a coupling element between the light source and the polarizer that converts at least some of the light of the different second polarization reflected by the polarizer into light of the first polarization.

123. The head mounted display system of claim 1, in, The light source includes a plurality of laterally displaced light emitters configured to output light.

124. The head mounted display system of claim 123, further comprising a focusing optical device or coupling element configured to collect light from the plurality of laterally displaced light emitters.

125. The head-mounted display system of claim 1, further comprising a diffuser in the optical path between the light source and the optical device.

126. The head-mounted display system of claim 1, further comprising one or more holes between the light source and the optical device.

127. The head-mounted display system of claim 1, further comprising a plurality of holes between the light source and the optical device.

128. The head-mounted display system of claim 1, further comprising a diffuser and a plurality of holes between the light source and the optical device, the diffuser being adjacent to the holes.

129. The head mounted display system of claim 1, in, The light source includes one or more laser diodes.

130. The head-mounted display system of claim 1, further comprising a coupling optical device disposed relative to the light source to collect light output from the light source.

131. The head mounted display system of claim 130, in, The coupling optics include a compound parabolic concentrator (CPC).

132. The head-mounted display system of claim 1, further comprising a focusing optical device disposed relative to the light source to collect light output from the light source.

133. The head mounted display system of claim 132, in, The focusing optics include one or more lenses.

134. The head mounted display system of claim 132, in, The focusing optics include a plurality of lenses.

135. The head-mounted display system of claim 1, further comprising a quarter-wave retarder between the light source and the optical device.

136. The head mounted display system of claim 92, in, A polarizer is attached to the spatial light modulator.

137. The head mounted display system of claim 92, in, The polarizer is adhered to the spatial light modulator by an adhesive.

138. The head mounted display system of claim 92, in, A polarizer is attached to the spatial light modulator using a mechanical fixture.

139. The head mounted display system of claim 116, in, A compensator is attached to the spatial light modulator.

140. The head mounted display system of claim 116, in, The compensator is adhered to the spatial light modulator by an adhesive.

141. The head mounted display system of claim 116, in, The compensator is adhered to the spatial light modulator using a mechanical fixture.

142. The head mounted display system of claim 1, in, A retarder is attached to the spatial light modulator.

143. The head mounted display system of claim 1, in, The retarder is adhered to the spatial light modulator by an adhesive.

144. The head mounted display system of claim 1, in, The retarder is adhered to the spatial light modulator using a mechanical fixture.

145. The head mounted display system of claim 135, in, A quarter-wave retarder is attached to the spatial light modulator.

146. The head mounted display system of claim 135, in, The quarter wave retarder is adhered to the spatial light modulator by an adhesive.

147. The head mounted display system of claim 135, in, The quarter wave retarder is adhered to the spatial light modulator using a mechanical fixture.

148. The head mounted display system of claim 92, in, The polarizer comprises a wire grid polarizer.

149. The head-mounted display system of claim 1, further comprising a circular polarizer between the spatial light modulator and the coupling-in optical element.

150. The head mounted display system of claim 149, in, The circular polarizer includes a linear analyzer and a quarter-wave retarder.

151. The head-mounted display system of claim 1, further comprising a single polarizer between the optical device and the at least one waveguide and between the light source and the optical device.

152. The head mounted display system of claim 13, in, The light absorber includes an absorbing material.

153. The head mounted display system of claim 13, in, The light absorber includes an absorbing material surrounding the color filters in the color filter array.

154. The head-mounted display system of claim 1, wherein the light source is laterally disposed relative to the at least one waveguide so that light from the light source is directed into the optical element without propagating through the at least one waveguide.

155. The head mounted display system of claim 1, in, The light source is disposed on a transparent layer extending laterally relative to the at least one waveguide such that light from the light source is directed into the optical device without propagating through the at least one waveguide.

156. The head mounted display system of claim 1, in, The light source is disposed on a transparent layer that is closer to a side of the at least one waveguide that is closer to the environment in front of the user than to a side of the at least one waveguide that is closer to the user's eyes, and the transparent layer extends laterally relative to the at least one waveguide so that light from the light source is directed into the optical device without propagating through the at least one waveguide.

157. The head mounted display system of claim 1, in, The light source is disposed on a transparent layer that is closer to a side of the at least one waveguide that is closer to the user's eyes than to a side of the at least one waveguide that is closer to the environment in front of the user, and the transparent layer extends laterally relative to the at least one waveguide so that light from the light source is guided into the optical device without propagating through the at least one waveguide.

158. A head mounted display system according to any one of claims 155 to 157, in, The transparent layer includes the cover glass.

159. The head-mounted display system according to claim 1 further includes a plurality of color filters that are laterally shifted relative to each other, and the color filters are laterally aligned relative to a plurality of coupling-in optical elements, and the plurality of coupling-in optical elements are laterally shifted relative to each other so that light propagating through the corresponding color filters is incident on the corresponding coupling-in optical elements.

160. In the head-mounted display system of claim 159, the plurality of color filters comprises a color filter array.

161. The head-mounted display system of claim 1, further comprising a polarizer disposed in an optical path between the spatial light modulator and the optical device.

162. The head-mounted display system of claim 1, further comprising a polarizer disposed in an optical path between the spatial light modulator and the optical device.

163. The head-mounted display system of claim 1, further comprising a compensator disposed in an optical path between the spatial light modulator and the optical device.

164. The head-mounted display system of claim 1, further comprising a delay device disposed in an optical path between the spatial light modulator and the optical device.

165. The head-mounted display system of claim 1, further comprising a quarter-wave retarder disposed in an optical path between the spatial light modulator and the optical device.

166. The head mounted display system of claim 1, further comprising a first circular polarizer positioned between the at least one waveguide and the optical device having optical power.

167. The head mounted display system of claim 166, in, The first circular polarizer is located between the light source and the optical device having optical power.

168. The head mounted display system of claim 1, further comprising a second circular polarizer positioned between the optical device having optical power and the spatial light modulator.

169. The head-mounted display system of claim 168, further comprising a retarder located between the second circular polarizer and the spatial light modulator.

170. The head-mounted display system of claim 168 or 169, further comprising a third circular polarizer located between the second circular polarizer and the spatial light modulator.

171. The head-mounted display system of claim 170, further comprising a delay device located between the second circular polarizer and the third circular polarizer.

172. The head-mounted display system of claim 1, further comprising a compensator located between the optical device having optical power and the spatial light modulator.

173. The head-mounted display system of any one of claims 168, 169 and 171, further comprising a compensator located between the second circular polarizer and the spatial light modulator.

174. The head-mounted display system of claim 171, further comprising a compensator located between the third circular polarizer and the spatial light modulator.

175. The head mounted display system of claim 1, further comprising a cover glass located between the optical device having optical power and the spatial light modulator.

176. The head-mounted display system of claim 174, further comprising a cover glass located between the second circular polarizer and the spatial light modulator.

177. The head-mounted display system of claim 174, further comprising a cover glass located between the third circular polarizer and the spatial light modulator.

178. The head-mounted display system of claim 174, further comprising a cover glass located between the compensator and the spatial light modulator.

179. The head-mounted display system of claim 1, further comprising at least one optical surface tilted relative to the at least one waveguide to redirect light reflected from the optical surface.

180. The head-mounted display system of claim 1, further comprising at least one optical surface tilted relative to the spatial light modulator to redirect light reflected from the optical surface.

181. The head-mounted display system of claim 1, further comprising at least one optical surface tilted relative to at least one polarizer or retarder to redirect light reflected from the optical surface.

182. The head-mounted display system of claim 1, further comprising at least one optical surface whose normal is tilted relative to an optical axis of the optical device having optical power to redirect light reflected from the optical surface.

183. A head mounted display system according to any one of claims 179 to 182, in, The tilted at least one optical surface redirects the reflected light away from an in-coupling optical element of the at least one waveguide.

184. A head mounted display system according to any one of claims 179 to 182, in, The tilted at least one optical surface redirects the reflected light such that a small amount of the reflected light is coupled into the at least one waveguide and guided therein.

185. A head mounted display system according to any one of claims 179 to 182, in, The tilted at least one optical surface redirects the reflected light so that a smaller amount of the reflected light is directed to the user's eyes.

186. A head mounted display system according to any one of claims 179 to 182, in, The tilted at least one optical surface redirects at least some of the reflected light toward the light source.

187. The head-mounted display system of any one of claims 179 to 182, further comprising a light absorber to receive at least some of the reflected light from the tilted at least one optical surface.

188. A head mounted display system according to any one of claims 179 to 182, in, The at least one optical surface that is tilted is on the cover glass.

189. A head mounted display system according to any one of claims 179 to 182, in, The at least one optical surface that is tilted is on one or more of: at least one retarder, at least one polarizer, or at least one compensator.

190. A head mounted display system according to any one of claims 175 to 178, in, The cover glass is wedge-shaped.

191. The head mounted display system of claim 189, in, At least one retarder, at least one polarizer, or at least one compensator is wedge-shaped.

192. The head-mounted display system of claim 1, further comprising a polarization rotator disposed relative to the light source to rotate the polarization of light emitted therefrom.

193. The head-mounted display system of claim 166 or 167, further comprising a polarization rotator disposed between the light source and the first circular polarizer.

194. The head mounted display system of claim 1, in, The at least one coupling-in optical element includes a first coupling-in optical element and a second coupling-in optical element, and the head-mounted display system further includes a first color filter and a second color filter associated with the first coupling-in optical element and the second coupling-in optical element, respectively.

195. The head mounted display system of claim 194, in, The first color filter transmits more light of a first color than the second color filter, and the second color filter transmits more light of the second color than the first color filter.

196. The head mounted display system of claim 194 or 195, in, The at least one waveguide includes a first waveguide and a second waveguide, wherein the first coupling optical element couples more light of a first color into the first waveguide than the second color filter, and the second coupling optical element couples more light of the second color into the second waveguide than the first color.

197. A head mounted display system according to any one of claims 194 to 195, in, The first color filter and the second color filter are laterally aligned with the respective first coupling-in optical element and the second coupling-in optical element.

198. The head mounted display system of any one of claims 194 to 195, further comprising a first light source and a second light source, in, The first light source and the second light source are arranged to direct light through the first color filter and the second color filter, respectively, to the first coupling-in optical element and the second coupling-in optical element, respectively.

199. The head mounted display system of any one of claims 194 to 195, further comprising a first light source and a second light source, in, The first color filter is arranged in a first light path between the first light source and the first coupling-in optical element, and the second color filter is arranged in a second light path between the second light source and the second coupling-in optical element.

200. The head mounted display system of claim 198, in, The first light source includes a first color light source configured to emit a first color, and the second light source includes a second color light source configured to emit a second color.

201. The head mounted display system of claim 198, in, The first light source and the second light source include broadband color light sources configured to emit both the first color and the second color.

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