Multi-channel scanner for near-eye display

Abstract

A multi-channel scanner that may be used, for example, for a near-eye display is disclosed. A multi-channel scanner angularly scans the light beam, forming an image in the angular domain. The multi-channel scanner includes a light source, a tiltable reflector, and a multi-channel coupler that couples light emitted by the light source to the tiltable reflector, receives reflected light, and couples it back to the tiltable reflector to double a scan angle. The multi-channel coupler then couples the light reflected at least twice from the tiltable reflector to the exit pupil of the scanner. A pupil replication waveguide arranged at the exit pupil of the scanner expands the image in the angular domain. Multiple reflections of the light beam from the tiltable reflector can increase the angular scanning range of the display and the associated field of view without increasing the angular scanning range of the tiltable reflector.

Description

[0001] Description of divisional application

[0002] This application is a divisional application with an application date of September 24, 2020, application number 202080069206.3, and invention name “Multi-channel scanner for near-eye display”. Technical Field

[0003] The present disclosure relates to wearable head-mounted devices, and more particularly to components and modules for wearable visual display head-mounted devices. Background Art

[0004] Head-mounted displays (HMDs), helmet-mounted displays (HMDs), near-eye displays (NEDs), and the like are increasingly being used to display virtual reality (VR), augmented reality (AR), and mixed reality (MR) content. These displays are finding applications in diverse fields, including entertainment, education, training, and biomedical sciences, to name a few. The displayed VR / AR / MR content can be three-dimensional (3D) to enhance the experience and match virtual objects with real-world objects observed by the user. The user's eye position and gaze direction and / or orientation can be tracked in real time, and the displayed image can be dynamically adjusted based on the user's head orientation and gaze direction to provide a better immersive experience in the simulated or augmented environment.

[0005] Head-mounted displays require compact display devices. Because the display of an HMD or NED is typically worn on the user's head, a large, bulky, unbalanced, and / or heavy display device would be cumbersome and potentially uncomfortable for the user to wear.

[0006] Projector-based displays (e.g., scanning projector displays) provide an angular image that can be viewed directly by the user's eye without an intermediate screen or display panel. A pupil-replicating waveguide is used to deliver the angular image to the user's eye. The lack of a screen or display panel in a scanning projector display enables the size and weight of the display to be reduced. Images are acquired by scanning a beam across the display's field of view (FOV). Summary of the Invention

[0007] Scanning projector displays require an optical scanner, which is typically based on a tiltable reflector. The scanner should be able to scan a light beam across the entire field of view (FOV) of the display. As the light beam is scanned, its brightness and / or color can change in coordination with the scan to provide an angular image. The light beam can be scanned in two directions, for example, in X and Y viewing angles. When the frame rate is high enough, the eye integrates the scanned light beam, allowing the user to see the displayed image essentially without flicker.

[0008] One challenge in constructing a scanning display with a tiltable reflector is the angular scanning range required for the tiltable reflector. A large scanning range requires a trade-off between other parameters, including bending stiffness and scanning rate (frequency). Thin, flexible hinges cannot support the larger mirrors needed to provide the desired beam size and image quality. According to the present disclosure, the beam can be made to impinge on the same tiltable reflector multiple times, thereby increasing the scanning range without having to increase the maximum tilt angle of the reflector.

[0009] The present invention relates to a multi-channel scanner for scanning a light beam and a near-eye display for providing an image in an angular region at the eye box.

[0010] According to the present disclosure, a multi-channel scanner for scanning a light beam is provided. The multi-channel scanner includes: a light source for providing a light beam; a tiltable reflector for reflecting the light beam provided by the light source by tilting the tiltable reflector at a variable angle; and a multi-channel coupler for receiving the light beam from the light source and coupling the light beam to the tiltable reflector; receiving the light beam reflected twice at the variable angle from the tiltable reflector for the first time and redirecting the light beam back to the tiltable reflector; and receiving the light beam reflected a second time from the tiltable reflector and coupling the light beam to an exit pupil of the multi-channel scanner.

[0011] The multi-channel coupler may include: a reflective polarizer for reflecting light having a first polarization state and transmitting light having a second polarization state, the second polarization state being orthogonal to the first polarization state; and a first quarter-wave plate (QWP) disposed in an optical path between the reflective polarizer and the tiltable reflector and configured to convert the polarization state of the light between the first polarization state and the second polarization state after dual-pass propagation through the first QWP. In operation, a light beam having the second polarization state propagates through the reflective polarizer and the first QWP in sequence, strikes the tiltable reflector for the first time, is reflected by the tiltable reflector to propagate through the first QWP again, thereby converting to the first polarization state, is reflected by the reflective polarizer, propagates through the first QWP and strikes the tiltable reflector for a second time, is reflected by the tiltable reflector to propagate through the first QWP, thereby converting back to the second polarization state, and propagates through the reflective polarizer to an exit pupil.

[0012] The multi-channel coupler may include a first lens element having positive optical power and including a convex surface proximate to a tiltable reflector, the convex surface supporting a reflective polarizer. Optionally, the multi-channel coupler may further include a second lens element arranged between the first lens element and the exit pupil. In operation, a light beam provided by the light source then propagates sequentially through the second lens element, passes through the first lens element, impinges on the tiltable reflector, is reflected by the reflective polarizer to impinge on the tiltable reflector a second time and is reflected by the tiltable reflector, propagates through the first lens element, propagates through the second lens element, and impinges on the exit pupil of the multi-channel coupler. In some embodiments, the second lens element may include: a first coaxial optical surface and a second coaxial optical surface, the first optical surface facing the first lens element; a side surface, between the first optical surface and the second optical surface, for inputting the light beam provided by the light source into the second lens element; and a buried turning mirror, within the second lens element in the optical path of the light beam input through the side surface of the second lens element, for redirecting the light beam toward the first optical surface of the second lens element.

[0013] In some embodiments, the multi-channel scanner may include: a polarization beam splitter (PBS) for reflecting light having a first polarization state and transmitting light having a second polarization state. A first curved reflector and a second curved reflector may be arranged on adjacent surfaces near the PBS for reflecting a light beam emitted from the PBS back into the PBS, wherein the first curved reflector and the reflective polarizer are arranged on opposite sides of the PBS, and wherein the second curved reflector and the tiltable reflector are arranged on opposite sides of the PBS. A second QWP may be arranged in an optical path between the PBS and the first curved reflector and configured to convert the polarization state of light between the first polarization state and the second polarization state when propagating through the dual channels of the second QWP. A third QWP may be arranged in an optical path between the PBS and the second curved reflector and configured to convert the polarization state of light between the first polarization state and the second polarization state when propagating through the dual channels of the second QWP. In operation, a light beam provided by a light source may propagate in sequence as follows: through an opening in a first curved reflector, through a second QWP, impinge on a PBS while in a first polarization state, be reflected by the PBS toward a tiltable reflector, propagate through the first QWP, be reflected a first time by the tiltable reflector, propagate through the first QWP again, thereby converting to a second polarization state, propagate through the PBS and a third QWP, impinge on a second curved reflector, propagate through the third QWP again, thereby converting to the first polarization state, and be reflected by the PBS toward a reflective polarizer. The light beam reflected by the PBS toward the reflective polarizer in the first polarization state may optionally propagate back to the PBS, be reflected by the PBS toward a second curved reflector, propagate through the third QWP, be reflected by the second curved reflector to propagate through the third QWP again, thereby converting to a second polarization state, propagate through the PBS, pass through the first QWP, and be reflected a second time by the tiltable reflector toward the PBS. The light beam reflected a second time by the tiltable reflector can optionally propagate through the first QWP again, thereby being converted to the first polarization state, reflected by the PBS toward the first curved reflector, propagate through the second QWP, reflected by the first curved reflector, propagate through the second QWP again, thereby being converted to the second polarization state, propagating through the PBS, and propagating to the exit pupil through the reflective polarizer.

[0014] In some embodiments, the multi-channel scanner may further include a first lens element in the optical path between the PBS and the tiltable reflector, and a second lens element in the optical path between the PBS and the reflective polarizer. In some embodiments, the multi-channel coupler includes a first coupler portion for coupling light provided by the light source to the tiltable reflector, and the multi-channel coupler may include a reflector for reflecting light from the tiltable reflector back to the tiltable reflector. The multi-channel coupler may further include a second coupler portion, the second coupler portion including a pupil auto-relay for relaying light reflected by the tiltable reflector back to the tiltable reflector for a first time, and the multi-channel coupler may optionally include a third coupler portion for relaying light reflected by the tiltable reflector for a second time to an exit pupil of the multi-channel scanner.

[0015] According to the present disclosure, a near-eye display for providing an angular domain image at an eye box is provided. The near-eye display includes: a light source for providing a light beam; a tiltable reflector for reflecting the light beam provided by the light source by tilting the tiltable reflector at a variable angle; a pupil replicating waveguide for receiving the light beam tilted by the tiltable reflector and expanding the light beam above the eye box by providing multiple portions of the light beam above the eye box; and a multi-channel coupler for receiving the light beam from the light source and coupling the light beam to the tiltable reflector; receiving the light beam reflected twice at the variable angle from the tiltable reflector for the first time and redirecting the light beam back to the tiltable reflector; and receiving the light beam reflected a second time from the tiltable reflector and coupling the light beam to the pupil replicating waveguide.

[0016] In an embodiment where the light source and the multi-channel coupler are arranged on opposite sides of the pupil replica waveguide, the pupil replica waveguide may include an opening therein for transmitting a light beam provided by the light source for coupling to the multi-channel coupler. The tiltable reflector may include a tiltable micro-electromechanical system (MEMS) reflector. The multi-channel coupler may include a pupil auto-repeater for relaying light first reflected by the tiltable reflector back to the tiltable reflector.

[0017] According to the present disclosure, a near-eye display for providing an angular image at an eye box is also provided. The near-eye display includes: a first light source for providing a first light beam; a second light source for providing a second light beam; a tiltable reflector for reflecting the first light beam and the second light beam at variable angles; and a pupil replicating waveguide for receiving the first light beam and the second light beam tilted by the tiltable reflector and expanding the first light beam and the second light beam above the eye box by providing multiple portions of the first light beam and the second light beam above the eye box. The pupil replicating waveguide includes a polarization-selective inner coupler for inner coupling light in a first polarization state while transmitting light in a second polarization state, the second polarization state being orthogonal to the first polarization state. The near-eye display further includes a pupil replica waveguide for receiving a light beam tilted by the tiltable reflector and expanding the light beam above the eye box by providing multiple portions of the light beam above the eye box; and a multi-channel coupler for receiving a light beam from a light source and coupling the light beam to the tiltable reflector; for receiving the light beam reflected from the tiltable reflector for a first time at a twice variable angle and redirecting the light beam back to the tiltable reflector; and for receiving the light beam reflected from the tiltable reflector for a second time and coupling the light beam to the pupil replica waveguide. The first light source and the second light source may be arranged on opposite sides of the pupil replica waveguide from the first curved reflector and the second curved reflector.

[0018] In an embodiment where the first light source and the second light source and the first and second curved reflectors are arranged on the same side of the pupil replica waveguide, the near-eye display may further include a first folding mirror in the optical path between the first light source and the first curved reflector; and a second folding mirror in the optical path between the second light source and the second curved reflector.

[0019] Furthermore, the present invention relates to a near-eye display for providing an angular image at an eye box having the near-eye display, comprising:

[0020] - a first light source for providing a first light beam;

[0021] - a second light source for providing a second light beam;

[0022] a tiltable reflector for reflecting the first light beam and the second light beam at a variable angle;

[0023] a pupil replicating waveguide for receiving the first and second light beams tilted by the tiltable reflector and expanding the first and second light beams above the eye box by providing a plurality of portions of the first and second light beams above the eye box, the pupil replicating waveguide comprising a polarization selective incoupler for incoupling light in a first polarization state while transmitting therethrough light in a second polarization state orthogonal to the first polarization state;

[0024] a first curved reflector for receiving a first light beam from a first light source and reflecting the first light beam in a second polarization state toward a tiltable reflector and through a polarization-selective inner coupler; and

[0025] - a second curved reflector for receiving a second light beam from a second light source and reflecting the second light beam in a second polarization state toward the tiltable reflector and through the polarization selective inner coupler.

[0026] After reflection from the tiltable reflector, the first and second light beams are in a first polarization state, whereby the first and second light beams are in-coupled into the pupil replicating waveguide.

[0027] In one embodiment, the first light source and the second light source are arranged on opposite sides of the pupil replicating waveguide from the first curved reflector and the second curved reflector. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Exemplary embodiments will now be described with reference to the accompanying drawings, in which:

[0029] Figure 1 is a schematic block diagram of a near-eye display including a multi-channel scanner of the present disclosure;

[0030] Figure 2 is a schematic diagram of a polarization-based multichannel coupler that uses polarization diversity to ensure double reflection of the beam from the same tiltable reflector;

[0031] Figure 3 is a three-dimensional view of an input coupler of a pupil replicating waveguide including a small opening in the input coupler for propagating a light beam;

[0032] Figure 4A and Figure 4B It includes Figure 2 Polarization configuration of the multi-channel scanner and for non-tilted ( Figure 4A ) and tilt ( Figure 4B ) of a tiltable reflector Figure 3 Ray tracing cross-sectional view of a near-eye display with an input coupler;

[0033] Figure 5A and Figure 5B It includes Figure 2 The polarization configuration of the multi-channel scanner and includes a non-tilted ( Figure 5A ) and tilt ( Figure 5B ) ray tracing cross-sectional diagram of a near-eye display with a small buried mirror and a tiltable reflector;

[0034] 6A to 6Dis a ray traced cross-sectional diagram of a near-eye display including a multi-channel scanner based on a polarization beam splitter (PBS), showing the following light propagation: from the light source to the tiltable reflector to the reflective polarizer ( Figure 6A ); from the reflective polarizer back to the tiltable reflector ( Figure 6B ); returns from the tiltable reflector through the reflective polarizer and reaches the pupil replica waveguide ( Figure 6C ); and shows the optical path of the entire fold ( Figure 6D );

[0035] Figure 6E yes 6A to 6D A ray-traced cross-section of a near-eye display showing the primary light rays propagating through the system.

[0036] Figure 7 is a schematic block diagram of an embodiment of a multi-channel scanner including a reflective polarizer for redirecting a reflected light beam back to a tiltable reflector;

[0037] Figure 8 is a schematic block diagram of an embodiment of a multi-channel scanner including an automatic pupil repeater for redirecting a reflected light beam back to a tiltable reflector;

[0038] Figure 9A and Figure 9B is a ray-traced cross-section of a near-eye display ( Figure 9A ) and 3D wireframes ( Figure 9B ), the near-eye display comprising a pair of curved reflectors for reflecting a light beam to a tiltable reflector through a pupil replicating waveguide;

[0039] Figure 10A and Figure 10B is a ray traced 3D solid image of a near-eye display ( Figure 10A ) and 3D wireframes ( Figure 10B ), the near-eye display comprising four curved reflectors for reflecting a light beam toward a tiltable reflector through a pupil replicating waveguide;

[0040] Figure 11A and Figure 11B is a ray-traced cross-sectional diagram of a near-eye display comprising a pair of curvilinear reflectors for reflecting a light beam onto a tiltable reflector and through a pupil replica waveguide, wherein for non-tilted ( Figure 11A ) and tilt ( Figure 11B ), the light source and the curved reflector being arranged on the same side of the pupil replica waveguide;

[0041] Figure 12A 、 Figure 12B and Figure 12C is a front view of a multi-emitter light source useful in near-eye displays disclosed herein;

[0042] Figure 13A is a graph of the aspect ratio of the field of view (FOV) of a scanning projector display as a function of the beam tilt angle;

[0043] Figure 13B yes Figure 13A Schematic diagram of FOV at zero tilt;

[0044] Figure 13C yes Figure 13A Schematic diagram of FOV with non-zero tilt angle;

[0045] Figure 14A is an isometric view of the head-mounted display headset of the present disclosure;

[0046] Figure 14B is included Figure 14A Block diagram of a virtual reality system with a head-mounted device. DETAILED DESCRIPTION

[0047] Although the present teachings have been described in conjunction with various embodiments and examples, it is not intended that the present teachings be limited to these embodiments. On the contrary, it will be understood by those skilled in the art that the present teachings encompass various alternative forms and equivalent forms. All statements herein listing the principles, aspects, and embodiments of the present disclosure, as well as specific examples thereof, are intended to encompass structural and functional equivalents thereof. Furthermore, it is intended that such equivalents include both currently known equivalents and equivalents developed in the future, i.e., any element developed to perform the same function, regardless of structure.

[0048] As used herein, unless expressly stated, the terms "first," "second," etc., do not imply a sequential order, but rather are used to distinguish one element from another. Similarly, unless expressly stated, the order of method steps does not imply the order in which they are performed. Figure 1-Figure 3 、 Figure 4A-4B 、 Figure 5A-5B 、 Figures 6A-6E 、 Figure 7 、 Figure 8 、 Figure 9A-9B 、 Figures 10A-10B and Figures 11A-11B In the drawings, like reference numerals denote like elements.

[0049] refer to Figure 1 , the near-eye display 100 includes a multi-channel scanner 130 optically coupled to a pupil replicating waveguide 136. The multi-channel scanner 130 can be used to provide an image to the pupil replicating waveguide 136 in an angular domain by scanning a light beam 102 of variable brightness and / or color across the FOV of the display. The light beam 102 is emitted by a light source 104.

[0050] The multi-channel scanner 130 includes a tiltable reflector 106 for reflecting a light beam 102 provided by a light source 102. The light beam 102 is scanned or directed by tilting the tiltable reflector 106 at a variable angle. The tiltable reflector 106 may include a microelectromechanical (MEMS) reflector that is tilted at a controllable angle by applying a control signal to its electrodes. For example, the MEMS reflector may include a mirror and / or a grating. The multi-channel scanner 130 also includes a multi-channel coupler 140 that is configured to receive the light beam 102 from the light source 102 and couple the light beam 102 to the tiltable reflector 106. The multi-channel coupler 140 guides the light beam 102 to the tiltable reflector 106 and receives the light beam 102 reflected from the tiltable reflector 106 for a first time (event 131) at twice the tilt angle of the tiltable reflector 106, and redirects the light beam 102 back to the tiltable reflector 106 for a second reflection. The portion 141 of the multi-channel coupler 140 that couples the light beam 102 back to the tiltable reflector 106 may comprise, for example, a mirror or an automatic pupil repeater. Examples of both of these will be considered further below.

[0051] The multi-channel coupler 140 redirects the light beam 102 back to the tiltable reflector 106 and receives the light beam 102 reflected from the tiltable reflector a second time (event 132) at an increased angle of four times the variable angle and couples the light beam to the exit pupil 134 of the multi-channel scanner 130. The increased angle of the light beam 102 is due to the multiple reflections from the tiltable reflector 106. A pupil replica waveguide 136 can be arranged near the exit pupil 134 to receive the light beam at four times the variable tilt angle of the tiltable reflector 106. In some embodiments, the multi-channel coupler 140 has an optical magnification factor greater than or less than 1 between the light source 104 and the exit pupil 102, in which case the angle of the light beam 102 at the exit pupil 134 can be different than four times the tilt angle of the tiltable reflector 106, but is typically greater than the tilt angle of the tiltable reflector 106.

[0052] In some embodiments, the multi-channel coupler 140 can be based on a polarization diversification configuration that ensures double reflection of the light beam 102 from the tiltable mirror 106. Figure 2 The multi-channel coupler 240 includes a reflective polarizer 208 for reflecting light having a first polarization state and transmitting light having a second polarization state, the second polarization state being orthogonal to the first polarization state. For example, the first polarization state and the second polarization state can be orthogonal linear polarization states or opposite circular polarization states.

[0053] A quarter wave plate (QWP) 211 is disposed in the optical path between the reflective polarizer 208 and the tiltable reflector 106 and is configured to convert the polarization state of light between a first polarization state and a second polarization state while propagating through the dual channels of the QWP 211 . In operation, the light beam 102 having the second polarization state PS2 propagates sequentially through the pupil replica waveguide 136, passes through the reflective polarizer 208 and the QWP 211, impinges on the tiltable reflector 106 and is reflected by the tiltable reflector for the first time (event 231) to propagate through the QWP 211 again, thereby being converted to the first polarization state PS1, is reflected by the reflective polarizer 208, propagates through the QWP 211 and impinges on the tiltable reflector for the second time, is reflected by the tiltable reflector for the second time (event 232) to propagate through the QWP 211, thereby being converted back to the second polarization state PS2, thereby propagating through the reflective polarizer 208 toward the pupil replica waveguide 136, where it is in-coupled to propagate in the pupil replica waveguide 136.

[0054] It should be understood that this is for illustration only. Figure 2 The light beam 102 is shown as being vertically separated. In a practical device, according to the law of reflection, the light beam 102 can propagate along the same path to the tiltable reflector 106 at a normal angle of incidence, and can deviate from the same path to the tiltable reflector 106 at a non-zero angle of incidence. An internal coupler can be used, such as Figure 3 The grating intracoupler 342 is shown to couple the light beam 102 into the pupil replica waveguide 136. To ensure that the light beam 102 is not coupled into the pupil replica waveguide 136 upon first incidence, the grating intracoupler 342 may include an opening 343. The light beam 102 may be focused on the opening 343 to propagate through the grating intracoupler 342 substantially without loss.

[0055] Now we will consider Figure 2 Implementation of the polarization-based multi-channel coupler 240. Figure 4A and Figure 4B, the near-eye display 400 includes a multi-channel scanner 430 coupled to the pupil replication waveguide 136. The multi-channel scanner 430 includes a light source 404, a tiltable reflector 406, and a multi-channel coupler 440. The light source 404 is arranged on the pupil replication waveguide 136 opposite the tiltable reflector 406 and the multi-channel coupler 440. The multi-channel coupler 440 includes a first lens element 414 having positive optical power (i.e., focusing power). The first lens element 414 includes a convex surface proximate to the tiltable reflector 406 and may include a concave opposite surface coaxial with the convex surface. The convex surface supports a reflective polarizer 408, which may have the same shape as the convex surface of the first lens element 414. The QWP 411 is arranged between the reflective polarizer 408 and the tiltable reflector 406. The QWP 411 may be supported by a window of a housing (not shown) of the tiltable reflector 406 , and may even be supported by the tiltable reflector 406 itself, or may be laminated to the reflective polarizer 408 .

[0056] The multi-channel coupler 440 may further include a second lens element 416 disposed between the first lens element 414 and the exit pupil located adjacent the pupil replicating waveguide 136. In operation, the light source 404 provides a light beam 402 that is focused onto an opening 343 in the input coupler 342 of the pupil replicating waveguide 136 ( Figure 3 ). Beam 402( Figure 4A and Figure 4B ) propagates through opening 343 and is coupled to multi-channel coupler 440. Light beam 402 then propagates sequentially through second lens element 416, through first lens element 414, impinges on and is reflected by tiltable reflector 406, is reflected by reflective polarizer 408 to impinge on and is reflected by tiltable reflector 406 a second time, propagates through first lens element 414, propagates through second lens element 416, and impinges on the exit pupil of multi-channel scanner 430 located at the pupil replicating waveguide. First lens element surface 414 and second lens element surface 416 can be optimized to provide the necessary collimation of light beam 402 at pupil replicating waveguide 136. The above optical path is described with reference to Figure 2 The configuration is defined by the position and orientation of the reflective polarizer 408 and QWP 411.

[0057] Now go to Figure 5A and Figure 5B, the near-eye display 500 includes a multi-channel scanner 530 coupled to a pupil replicating waveguide 536. The multi-channel scanner 530 includes a light source 504, a tiltable reflector 506, and a multi-channel coupler 540. The light source 504 is arranged on the same side of the pupil replicating waveguide 536 as the tiltable reflector 506 and the multi-channel coupler 540. The multi-channel coupler 540 includes a first lens element 514 having positive optical power. The first lens element 514 includes a convex surface proximate to the tiltable reflector 506 and may include a concave opposite surface coaxial with the convex surface. The convex surface supports a reflective polarizer 508, which may have the same shape as the convex surface of the first lens element 514. The QWP 511 is arranged between the reflective polarizer 508 and the tiltable reflector 506. The QWP 511 may be supported by a window of a housing (not shown) of the tiltable reflector 506 , and may even be supported by the tiltable reflector 506 itself, or may be laminated to the reflective polarizer 408 .

[0058] The multi-channel coupler 540 may further include a second lens element 516 having a first coaxial optical surface 521 and a second coaxial optical surface 522, wherein the first optical surface 521 faces the first lens element 514. A side surface 520 may be disposed between the first optical surface 521 and the second optical surface 522 for inputting the light beam 502 provided by the light source 504 into the second lens element 516. A turning mirror 518 may be embedded in the second lens element 516 in an optical path of the light beam 502 input through the side surface 520 of the second lens element 516 for redirecting the light beam 502 toward the first optical surface 521 of the second lens element 516 and further passing through the first lens element 514.

[0059] The light beam 502 propagates through the side surface 520 and is reflected by the embedded turning mirror 518. The light beam 402 then propagates sequentially through the first surface 521 of the second lens element 516, through the first lens element 514, impinges on and is reflected by the tiltable reflector 506, is reflected by the reflective polarizer 508 to impinge on and is reflected by the tiltable reflector 506 again, propagates through the first lens element 514, propagates through the second lens element 516, and impinges on the exit pupil of the multi-channel scanner 530 located at the pupil. The surfaces of the first 514 and second 516 lens elements can be optimized to provide the necessary collimation of the light beam 502 at the pupil replica waveguide 536. The above optical path is defined by the position and orientation of the reflective polarizer 508 and the QWP 511, which are arranged in the same manner as above with reference to FIG. Figure 2 The configuration described is similar to the configuration settings.

[0060] refer to Figures 6A to 6E, the near-eye display 600 includes a multi-channel scanner 630 coupled to a pupil replica waveguide 636. The multi-channel scanner 630 includes a light source 604, a tiltable reflector 606 (e.g., a packaged MEMS tiltable reflector with a window 607), and a multi-channel coupler 640. Similar to Figure 4A and Figure 4B The multi-channel coupler 440 and Figure 5A and Figure 5B The multi-channel coupler 540, Figures 6A to 6E The multi-channel coupler 640 uses Figure 2 The invention provides a polarization-based dual reflection configuration as it includes a reflective polarizer 608 for reflecting light having a first polarization state and transmitting light having a second polarization state orthogonal to the first polarization state, and a first QWP 611 disposed in the optical path between the reflective polarizer 608 and the tiltable reflector 606.

[0061] The multi-channel coupler 540 further includes a polarization beam splitter (PBS) 658 for reflecting light having a first polarization state and transmitting light having a second polarization state, and a first curved reflector 661 and a second curved reflector 662 adjacent to adjacent surfaces of the PBS 658 for reflecting light beams leaving the PBS 658 back into the PBS 658. The first curved reflector 661 and the reflective polarizer 608 may be disposed on opposite sides of the PBS 658, i.e., Figures 6A to 6E The first curved reflector 661 and the second curved reflector 662 can be arranged below and above the PBS 658, and the second curved reflector 662 and the tiltable reflector 606 can be arranged on the other opposite sides of the PBS 658, that is, on the right and left sides of the PBS 658. The first curved reflector 661 and the second curved reflector 662 can each include a concave lens having a reflective coating on the convex surface of the concave lens at its distal end (i.e., farthest from the PBS 658). The reflective coating can include several coatings spaced apart in the optical axis direction of the reflector. Some of these coatings can be dichroic to selectively reflect light of a specific color channel of the image to be displayed. Such a configuration can be used to compensate for chromatic aberration in the system.

[0062] The multi-channel coupler 540 also includes a second QWP 612 disposed in the optical path between the PBS 658 and the first curved reflector 661 and configured to convert the polarization state of light between the first and second polarization states during dual-pass propagation through the second QWP 612, and a third QWP 613 disposed in the optical path between the PBS 658 and the second curved reflector 662 and configured to convert the polarization state of light between the first and second polarization states during dual-pass propagation through the third QWP 613. The multi-channel coupler 540 may also include a first lens element 671 in the optical path between the PBS 658 and the tiltable reflector 606, and a second lens element 672 in the optical path between the PBS 658 and the reflective polarizer 608. The propagation of light through the multi-channel coupler 540 involves seven passes through the PBS 658 and will be described below. Figure 6A 、 Figure 6B and Figure 6C Consider the several steps described in sequence.

[0063] Figure 6A The first three channels of the light beam 602 emitted by the light source 604 through the PBS 658 are shown in FIG. Figures 6B to 6E The first polarization state is perpendicular to Figures 6A to 6E The first linear polarization state is oriented, while the second polarization state is Figures 6A to 6E The linear polarization state of the light source 604 ( Figure 6A ) is circularly polarized. Light beam 602 is focused to propagate through opening 643 in first curved reflector 661. Light beam 602 then propagates through second QWP 612 and, while in a first polarization state, impinges on PBS 658, is reflected by PBS 658 toward tiltable reflector 606, propagates through first QWP 611, is reflected a first time by tiltable reflector 606, propagates through first QWP 611 again, thereby converting to a second polarization state, propagates through PBS 658 and third QWP 613, impinges on second curved reflector 662, propagates through third QWP 613 again, thereby converting back to the first polarization state, and is accordingly reflected by PBS 658 toward reflective polarizer 608.

[0064] Figure 6B6 shows the next two passes of the light beam 602 through the PBS 658. The light beam 602, which is reflected by the PBS 658 toward the reflective polarizer 608 in the first polarization state, propagates back to the PBS 658 as shown, reflects by the PBS 658 toward the second curved reflector 662, propagates through the third QWP 613, reflects by the second curved reflector 662 to propagate through the third QWP 613 again, thereby converting to the second polarization state, propagates through the PBS 658, passes through the first QWP 611, and is reflected a second time by the tiltable reflector 606 toward the PBS 658.

[0065] Figure 6C 6 shows the final two passes of the light beam 602 through the PBS 658. The light beam 602, reflected a second time by the tiltable reflector 606, propagates through the first QWP 611 again, thereby being converted to a first polarization state, is reflected by the PBS 658 to the first curved reflector 661, propagates through the second QWP 612, is reflected by the first curved reflector 661, propagates through the second QWP 612 again, thereby being converted to a second polarization state, propagates through the PBS 658, and propagates through the reflective polarizer 608 to the exit pupil located near the pupil replica waveguide 636.

[0066] Figure 6D The entire optical path of a light beam 602 in a near-eye display 600 is shown. Figure 6E ] represents the entire optical path of the chief ray 699 of the light beam 602. In summary, the chief ray 699 passes through the optical path of one cube width seven times. Figure 6A The first three passes through the cube are described in Figure 6B The next two channels are described in Figure 6C The last two channels are described in . Additionally, the pupil of tiltable reflector 606 is first relayed to reflective polarizer 602, then relayed back to itself (doubling the reflection angle), and then relayed back to reflective polarizer 608, this time transmitting into pupil replica waveguide 636.

[0067] Figure 4A and Figure 4B Multi-channel coupler 440, Figure 5A and Figure 5B 540 and Figures 6A to 6EThe 640 performs similar functions: first, coupling the light beam emitted by the light source to the tiltable reflector; second, coupling the light beam reflected by the tiltable reflector back to the tiltable reflector; and third, coupling the light beam reflected multiple times from the tiltable reflector to the exit pupil or pupil replica waveguide. Therefore, the above-mentioned multi-channel couplers can be described as each having a first coupler part, which is responsible for coupling the light provided by the light source to the tiltable reflector; a second coupler part, which is used to couple the light reflected by the tiltable reflector back to the tiltable reflector; and a third coupling part, which is used to couple the light reflected multiple times from the tiltable reflector to the exit pupil. Different parts of the multi-channel coupler can share the same optical elements. This is considered below Figure 7 and Figure 8 Shown in.

[0068] First reference Figure 7 And further reference Figure 4A 、 Figure 4B 、 Figure 5A and Figure 5B , multi-channel coupler 740( Figure 7 )express Figure 4A and Figure 4B The multi-channel coupler 440 and Figure 5A and Figure 5B The first portion 781 of the multi-channel coupler 740 ( Figure 7 ) couples the light provided by the light source 704 to Figure 7 The first portion 781 may include, for example, the opening 343 in the pupil replicating waveguide 136 and the first 414 and second 416 lens elements ( Figure 4A and Figure 4B ); or buried turning mirror 518 and first 514 and second 516 lens elements ( Figure 5A and Figure 5B ). Part II 782( Figure 7 ) couples light reflected by the tiltable reflector 706 at twice the tilt angle α back to the tiltable reflector 706. Light is coupled through the reflector, which reflects light from the tiltable reflector 706 back to the tiltable reflector 706. For example, the reflective polarizer 408 ( Figure 4A and Figure 4B ) reflects the light beam 402 back to the tiltable reflector 406; and Figure 5A and 5B Reflective polarizer 508 ( Figure 5A and 5B ) reflects the light beam 502 back to the tiltable reflector 506. The third portion 783 of the multi-channel coupler 740 ( Figure 7) couples the second reflected light to the exit pupil located near the pupil replication waveguide 736 at four times the tilt angle α. The third portion 783 may also include a first lens element 414 and a second lens element 416 ( Figure 4A and Figure 4B ); and a first lens element 514 and a second lens element 516 ( Figure 5A and Figure 5B ).

[0069] Now refer to Figure 8 And further reference Figures 6A to 6E , multi-channel coupler 840( Figure 8 )represent Figures 6A to 6E Multi-channel coupler 640. Multi-channel coupler 840 ( Figure 8 ) couples the light provided by the light source 804 to the tiltable reflector 806, which is Figure 8 The first portion 881 may include, for example, the opening 643 in the first curved reflector 661, the PBS 658, and the first lens element 671 ( Figure 6A ). Part II 882( Figure 8 ) couples the light 802* reflected by the tilt mirror at twice the tilt angle α back to the same position on the tilt mirror 706. In the multi-channel coupler 840, the light is coupled through the pupil automatic repeater, which relays the light 802* first reflected by the tiltable reflector 806 back to the same position on the tiltable reflector 806. The pupil automatic relay Figure 6A and 6B The multi-channel coupler 640 is represented by the first lens element 671; PBS 658; the second curved reflector 662 and the second lens element 672, which returns the light beam 602 to the same position on the tiltable reflector 606. The third portion 883 of the multi-channel coupler 840 ( Figure 8 ) couples the light reflected at the second time with the tilt angle α four times higher to the exit pupil. The third portion 883 may also include a first lens element 671, a PBS 658, a first curved reflector 661, and a second lens element 672 ( Figure 6C ). The third portion 883 is also a pupil relay and therefore returns the light to the same position as at zero tilt angle at four times the tilt angle α. The use of pupil relay(s) and / or pupil auto-relay(s) is advantageous because it allows reducing the size of the tiltable mirrors 606, 806 and the size of the grating-internal couplers of the pupil replica waveguides 636, 836.

[0070] refer to Figure 9A, the near-eye display 900 includes a first light source 903 for providing a first light beam 901 and a second light source 904 for providing a second light beam 902. A tiltable reflector 906 is configured to reflect the first light beam 901 and the second light beam 902 at variable angles. A pupil replicating waveguide 936 is configured to receive the first light beam 901 and the second light beam 902 tilted by the tiltable reflector 906 and expand the first light beam 901 and the second light beam 902 onto the eye box 990 by providing multiple portions of the first light beam 901 and the second light beam 902 onto the eye box 990, thereby enabling a user of the near-eye display 900 to comfortably view images in the angular region provided by the near-eye display 900. The pupil replicating waveguide 936 includes a polarization-selective in-coupler 942 for in-coupling light in a first polarization state into the pupil replicating waveguide 936 while transmitting light in a second polarization state orthogonal to the first polarization state.

[0071] The near-eye display 900 further includes a first curved reflector 961 configured to receive the first light beam 901 from the first light source 903 and reflect the first light beam 901 in the second polarization state to the tiltable reflector 906 and through the polarization-selective inner coupler 942. Since the first light beam 901 generated by the first light source 903 is in the second polarization state, the first light beam 901 is substantially not coupled into the pupil replica waveguide 936 and propagates through the inner coupler 942.

[0072] Similarly, the second curved reflector can be configured to receive the second light beam 902 from the second light source 904 and reflect the second light beam 902 in the second polarization state to the tiltable reflector 906 and through the polarization selective inner coupler 942 without substantially coupling to the pupil replicating waveguide 936. The first 903 and second 904 light sources are arranged on opposite sides of the pupil replicating waveguide of the first curved reflector 961 and the second 962 curved reflector. The first curved reflector 961 and the second curved reflector 962 can be similar to Figures 6A to 6E It is constructed by curved reflector 661 and curved reflector 662.

[0073] After reflection from the tiltable reflector, the first and second light beams are converted to the first polarization state. The conversion can be facilitated by (multiple) dedicated polarization conversion elements arranged in the optical path between the tiltable reflector 906 and the pupil replication waveguide 936. In some embodiments, the conversion can be performed even without a polarization conversion element. For example, in an embodiment where the first and second polarization states are opposite-handed circular polarization states, since the phase relationship between the X and Y components of the optical field remains unchanged upon reflection, while the propagation directions are opposite, upon reflection from the tiltable reflector 906 or any reflector for TAT materials, a conversion from the second polarization state to the first polarization state occurs, thereby changing the positive hand of the circular polarization to the negative hand. Therefore, the first and second light beams 901, 902 are coupled into the pupil replication waveguide 936 via the inner coupler 942.

[0074] The first light beam 901 and the second light beam 902, generated by the first light source 903 and the second light beam 904, respectively, are scanned over different portions of the field of view (FOV) of the near-eye display 900, thereby expanding the overall FOV. Portions of the FOV can overlap, thereby providing redundancy that can be used to provide increased spatial resolution, overall brightness, etc.

[0075] refer to Figure 10A and Figure 10B , the near-eye display 1000 is similar to Figure 9A and Figure 9B The near-eye display 900 of FIG. 1 is similar to that of FIG. 1 , and includes similar elements, such as a pupil replicating waveguide 1036 , a tiltable mirror 1006 , and the like. Figure 10A and Figure 10B The near-eye display 1000 includes not two but four light sources 1003, 1004, 1053, 1054 for providing not two but four light beams 1001, 1002, 1051 and 1052 that are reflected by tiltable reflectors 1061, 16062, 1063 and 1064 respectively and scanned by the tiltable reflector 1006 over their corresponding FOV portions.

[0076] Go to Figure 11A and Figure 11B , the near-eye display 1100 is similar to Figure 9A and Figure 9B The near-eye display 900 is of the type shown in FIG. 1 and includes similar elements, namely, light sources 1103 and 1104, a pupil replica waveguide 1136 with a polarization-selective input coupler 1142, curved reflectors 1161 and 1162, and a tiltable reflector 1106 for reflecting, at variable angles, the light beams 1101 and 1102 emitted by the light sources 1103 and 1104, respectively, and collimated by the curved reflectors 1161 and 1162, respectively. Figure 11A and Figure 11BThe near-eye display 1100 further includes fold mirrors 1191 and 1192 disposed in the optical paths between the light sources 1103 and 1104 and the curved reflectors 1161 and 1162, respectively. The fold mirrors 1191 and 1102 enable the light sources 1103 and 1104 to be disposed on the same side of the pupil replicating waveguide as the curved reflectors 1161 and 1162, thereby reducing the number of passages of the light beams 1101 and 1102 through the pupil replicating waveguide 1136. The light sources 1103 and 1104 can each include a group of separate emitters (source group 1 and source group 2, respectively); to this end, Figure 1 Light source 104, Figure 4A and Figure 4B 404, Figure 5A and Figure 5B 504, Figures 6A to 6E 604, Figure 7 704, Figure 8 804, Figure 9A and Figure 9B 903 and 904 and Figure 10A 1003, 1004, 1053 and 1054 may each include multiple emitters. Several emitters may be provided for each color channel.

[0077] refer to Figure 12A 、 Figure 12B and Figure 12C , four red emitters 1200R may be provided for the red (R) color channel (dark shaded circles); four green emitters 1200G may be provided for the green (G) color channel (medium shaded circles); and four blue emitters 1200B may be provided for the blue (B) color channel (light shaded circles). Each of the emitters 1200R, 1200G, and 1200B may be a ridge emitter sharing a common semiconductor substrate. To name a few examples, the emitters 1200R, 1200G, and 1200B may be arranged in a line pattern ( Figure 12A ), with a zigzag pattern ( Figure 12B ), or in a honeycomb pattern ( Figure 12C ) to set it.

[0078] Having multiple emitters illuminating the same tiltable reflector enables scanning of the light beams produced by the emitters to be performed together as a group. When the light source comprises multiple individual emitters, the illumination beam comprises multiple sub-beams that co-propagate at slight angles to each other. In some embodiments, the maximum angular cone of the sub-beams can be less than 5 degrees, or less than 2 degrees, or less than 1 degree. Multiple emitters and, in some cases, multiple light sources can be used to provide redundancy in the event of failure of some light sources, improve image resolution, increase overall image brightness, etc. The multiple light sources can each be equipped with its own collimator.

[0079] Figure 1Near-eye display 100, Figure 4A and Figure 4B 400, Figure 5A and Figure 5B 500, Figures 6A to 6E 600, Figure 9A and Figure 9B 900, Figure 10A and Figure 10B 1000 and Figure 11A and Figure 11B The 1100 provides low-tilt coupling of (multiple) light beams to a tiltable reflector. Here, the term "low-tilt" refers to a low angle of incidence at the tiltable reflector, i.e., normal incidence, when at a nominal (e.g., center or zero) tilt angle. 13A to 13C One advantage of having a low tilt angle is shown in FIG. Figure 13A , the aspect ratio of the FOV of a projector using a tiltable reflector is plotted as a function of the tilt angle, that is, the angle of incidence at the tiltable reflector when in the nominal or center position. The aspect ratio is plotted for four cases: 75 degrees by 50 degrees on-axis FOV; 60 degrees by 40 degrees on-axis FOV; 45 degrees by 30 degrees on-axis FOV; and 30 degrees by 20 degrees on-axis FOV. The aspect ratio drops from 1.5 at zero tilt (i.e., normal incidence) to about 1.1 at 40 degrees of tilt.

[0080] Figure 13B The zero-tilt scan angle region 1300B and the associated inset rectangular field of view 1302B are shown. The zero-tilt FOV 1302B solid angle covers most of the angle region 1300B. By comparison, Figure 13C A 40-degree tilt scan angle region 1300C and an associated inset rectangular FOV 1302C are shown. The solid angle of FOV 1302C occupies a smaller percentage of angular region 1300C and is almost twice as small as the zero-tilt FOV 1302B, and has a different aspect ratio. Thus, low-tilt coupling improves the utilization of the tiltable reflector's scan range, enabling a wider field of view to be achieved with the same tiltable reflector scan range. Note that Figure 1 and Figure 2 The tiltable reflector 106, Figure 4A and Figure 4B 406, Figure 5A and Figure 5B 506, Figures 6A to 6E 606, Figure 7 706, Figure 8 806, Figure 9A and Figure 9B 906, Figure 10A and Figure 10B 1006 and Figure 11A and Figure 11B1106 can be implemented as a MEMS tiltable reflector.

[0081] Embodiments of the present disclosure may include or be implemented in conjunction with an artificial reality system. Before being presented to the user, the artificial reality system adjusts the sensory information about the external world obtained through senses such as visual information, audio, touch (body) information, acceleration, balance, etc. in some way. As a non-limiting example, artificial reality may include virtual reality (VR), augmented reality (AR), mixed reality (MR), mixed reality, or some combination and / or derivative thereof. Artificial reality content may include fully generated content or generated content combined with captured (e.g., real-world) content. Artificial reality content may include video, audio, body or tactile feedback or some combination thereof. Any of these contents may be presented in a single channel or multiple channels, such as in a stereoscopic video that produces a three-dimensional effect for the audience. In addition, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof for, for example, creating content in artificial reality and / or otherwise using it in artificial reality (e.g., performing activities in artificial reality). Artificial reality systems that provide artificial reality content can be implemented on a variety of platforms, including wearable displays such as HMDs connected to a host computer system, standalone HMDs, near-eye displays with eyeglass form factors, mobile devices or computing systems, or any other hardware platform capable of providing artificial reality content to one or more viewers.

[0082] refer to Figure 14A , HMD 1400 is an example of an AR / VR wearable display system that surrounds the user's face for greater immersion in an AR / VR environment. For example, HMD 1400 is Figure 1 100, Figure 4A and Figure 4B 400, Figure 5A and Figure 5B 500, Figures 6A to 6E 600, Figure 9A and Figure 9B 900, Figure 10A and Figure 10B 1000 and Figure 11A and Figure 11B1100 embodiment. The function of the HMD 1400 is to enhance the view of the physical, real-world environment with computer-generated images and / or generate a completely virtual 3D image. The HMD 1400 may include a front body 1402 and a strap 1404. The front body 1402 is configured to be placed in front of the user's eyes in a secure and comfortable manner, and the strap 1404 can be stretched to secure the front body 1402 on the user's head. A display system 1480 can be disposed in the front body 1402 for presenting AR / VR images to the user. The side 1406 of the front body 1402 can be opaque or transparent.

[0083] In some embodiments, the front body 1402 includes a positioner 1408 and an inertial measurement unit (IMU) 1410 for tracking the acceleration of the HMD 1400, as well as a position sensor 1412 for tracking the position of the HMD 1400. The IMU 1410 is an electronic device that generates data indicating the position of the HMD 1400 based on measurement signals received from one or more position sensors 1412, which generate one or more measurement signals in response to the movement of the HMD 1400. Examples of the position sensor 1412 include one or more accelerometers, one or more gyroscopes, one or more magnetometers, another suitable type of sensor that detects motion, a sensor type used for error correction of the IMU 1410, or some combination thereof. The position sensor 1412 can be located external to the IMU 1410, internal to the IMU 1410, or some combination thereof.

[0084] The localizer 1408 is tracked by the virtual reality system's external imaging device, allowing the virtual reality system to track the position and orientation of the entire HMD 1400. The information generated by the IMU 1410 and position sensor 1412 can be compared with the position and orientation obtained by tracking the localizer 1408 to improve the tracking accuracy of the position and orientation of the HMD 1400. As the user moves and rotates in 3D space, accurate position and orientation are important for presenting an appropriate virtual scene to the user.

[0085] The HMD 1400 may also include a depth camera accessory (DCA) 1411 that captures data describing depth information of a local area surrounding part or all of the HMD 1400. To this end, the DCA 1411 may include a laser radar (LIDAR) or similar device. The depth information may be compared with information from the IMU 1410 to more accurately determine the position and orientation of the HMD 1400 in 3D space.

[0086] The HMD 1400 may also include an eye tracking system 1414 for determining the orientation and position of the user's eyes in real time. The obtained eye position and orientation also allow the HMD 1400 to determine the user's gaze direction and adjust the image generated by the display system 1480 accordingly. In one embodiment, the focus, that is, the convergence angle of the user's eye gaze, is determined. The determined gaze direction and convergence angle can also be used to compensate for visual artifacts in real time based on the viewing angle and eye position. In addition, the determined focus and gaze angle can be used to interact with the user, highlight objects, bring objects to the foreground, create additional objects or pointers, etc. An audio system may also be provided, including, for example, a set of small speakers built into the front body 1402.

[0087] refer to Figure 14B , AR / VR system 1450 includes Figure 14A The HMD 1400 includes an external console 1490 that stores various AR / VR applications, setup and calibration procedures, 3D videos, etc., and an input / output (I / O) interface 1415 for operating the console 1490 and / or interacting with the AR / VR environment. The HMD 1400 can be "tethered" to the console 1490 via a physical cable, or through a user interface such as a A wireless communication link such as Wi-Fi is connected to the console 1490. There may be multiple HMDs 1400, each HMD 1400 having an associated I / O interface 1415, each HMD 1400 and (multiple) I / O interfaces 1415 communicating with the console 1490. In alternative configurations, different and / or additional components may be included in the AR / VR system 1450. Additionally, in some embodiments, in combination with Figure 14A and Figure 14B The functionality of one or more components shown in the description may differ from that described in conjunction with Figure 14A and Figure 14B The described approach is distributed among the components. For example, some or all of the functionality of the console 1415 may be provided by the HMD 1400, and vice versa. The HMD 1400 may be equipped with a processing module capable of performing such functionality.

[0088] As referenced above Figure 14A As described, the HMD 1400 may include an eye tracking system 1414 ( Figure 14B ), an IMU 1410 for determining the position and orientation of the HMD 1400 in 3D space, a DCA 1411 for capturing the external environment, a position sensor 1412 for independently determining the position of the HMD 1400, and a display system 1480 for displaying AR / VR content to the user. The display system 1480 includes ( Figure 14B) electronic display 1425, such as, but not limited to, a liquid crystal display (LCD), an organic light emitting display (OLED), an inorganic light emitting display (ILED), an active matrix organic light emitting diode (AMOLED) display, a transparent organic light emitting diode (TOLED) display, a projector, or a combination thereof. Display system 1480 also includes an optical block 1430, which functions to transmit the image generated by electronic display 1425 to the user's eyes. The optical block may include various lenses, such as refractive lenses, Fresnel lenses, diffractive lenses, active or passive Pancharatnam-Berry phase (PBP) lenses, liquid crystal lenses, pupil replicating waveguides, grating structures, coatings, etc. Display system 1480 may also include a zoom module 1435, which may be part of optical block 1430. Zoom module 1435 functions to adjust the focus of optical block 1430, for example, to compensate for convergence-accommodation conflicts, correct for visual deficiencies of a particular user, offset aberrations of optical block 1430, etc.

[0089] The I / O interface 1415 is a device that allows a user to send an action request and receive a response from the console 1490. An action request is a request to perform a specific action. For example, an action request may be an instruction to start or end capturing image or video data, or an instruction to perform a specific action within an application. The I / O interface 1415 may include one or more input devices, such as a keyboard, a mouse, a game controller, or any other suitable device for receiving an action request and transmitting the action request to the console 1490. The action request received by the I / O interface 1415 is transmitted to the console 1490, and the console 1490 performs the action corresponding to the action request. In some embodiments, the I / O interface 1415 includes an IMU that captures calibration data indicating an estimated position of the I / O interface 1415 relative to an initial position of the I / O interface 1415. In some embodiments, the I / O interface 1415 can provide tactile feedback to the user based on the instructions received from the console 1490. For example, tactile feedback may be provided when an action request is received, or the console 1490 may transmit instructions to the I / O interface 1415 so that the I / O interface 1415 generates tactile feedback when the console 1490 performs an action.

[0090] The console 1490 may provide content to the HMD 1400 for processing based on information received from one or more of the IMU 1410, DCA 1411, eye tracking system 1414, and I / O interface 1415. Figure 14B In the example shown, the console 1490 includes an application storage device 1455, a tracking module 1460, and a processing module 1465. Some embodiments of the console 1490 may have a Figure 14BSimilarly, the functions described further below may be different from those in combination with Figure 14A and Figure 14B The described approach is distributed among the components of console 1490 .

[0091] The application storage 1455 can store one or more applications for execution by the console 1490. An application is a set of instructions that, when executed by the processor, generates content for presentation to the user. The content generated by the application can be responsive to input received from the user via the mobile HMD 1400 or the I / O interface 1415. Examples of applications include gaming applications, presentation and conferencing applications, video playback applications, or other suitable applications.

[0092] Tracking module 1460 can calibrate AR / VR system 1450 using one or more calibration parameters and can adjust one or more calibration parameters to reduce errors in determining the position of HMD 1400 or I / O interface 1415. The calibration performed by tracking module 1460 also takes into account information received from IMU 1410 in HMD 1400 and / or an IMU included in I / O interface 1415 (if any). In addition, if tracking of HMD 1400 is lost, tracking module 1460 can recalibrate some or all of AR / VR system 1450.

[0093] Tracking module 1460 can track the movement of HMD 1400, I / O interface 1415, IMU 1410, or some combination thereof. For example, tracking module 1460 can determine the location of a reference point of HMD 1400 in a map of the local area based on information from HMD 1400. Tracking module 1460 can also use data indicating the location of HMD 1400 from IMU 1410 or data indicating the location of I / O interface 1415 from an IMU included in I / O interface 1415 to determine the location of a reference point of HMD 1400 or a reference point of I / O interface 1415, respectively. Furthermore, in some embodiments, tracking module 1460 can use data indicating the location of HMD 1400 or a portion of HMD 1400 from IMU 1410 and a representation of the local area from DCA 1411 to predict the future location of HMD 1400. The tracking module 1460 provides the estimated or predicted future position of the HMD 1400 or the I / O interface 1415 to the processing module 1465 .

[0094] The processing module 1465 can generate a 3D map of some or all surrounding areas (“local areas”) in the HMD 1400 based on information received from the HMD 1400. In some embodiments, the processing module 1465 determines depth information for the 3D map of the local areas based on information related to techniques used in calculating depth received from the DCA 1411. In various embodiments, the processing module 1465 can use the depth information to update a model of the local areas and generate content based in part on the updated model.

[0095] Processing module 1465 executes applications within AR / VR system 1450 and receives position information, acceleration information, velocity information, predicted future position, or some combination thereof, of HMD 1400 from tracking module 1460. Based on the received information, processing module 1465 determines content to be provided to HMD 1400 for presentation to the user. For example, if the received information indicates that the user has looked to the left, processing module 1465 generates content for HMD 1400 that reflects the user's movement within a virtual environment or within an environment that augments the local area with additional content. Furthermore, processing module 1465 executes an action within an application executing on console 1490 in response to an action request received from I / O interface 1415, and provides feedback to the user that the action has been performed. The feedback provided may be visual or auditory feedback via HMD 1400, or tactile feedback via I / O interface 1415.

[0096] In some embodiments, based on eye tracking information received from the eye tracking system 1414 (e.g., the orientation of the user's eyes), the processing module 1465 determines the resolution of content to be provided to the HMD 1400 for presentation to the user on the electronic display 1425. The processing module 1465 can provide content to the HMD 1400 at a maximum pixel resolution in the foveal region of the electronic display 1425 where the user is gazing. The processing module 1465 can provide lower pixel resolution in other areas of the electronic display 1425, thereby reducing power consumption of the AR / VR system 1450 and conserving computing resources of the console 1490 without compromising the user's visual experience. In some embodiments, the processing module 1465 can also use the eye tracking information to adjust the display position of objects on the electronic display 1425 to prevent convergence-accommodation conflicts and / or to counteract optical distortion and aberrations.

[0097] The hardware for implementing the various illustrative logics, logic blocks, modules, and circuits described in conjunction with the various aspects disclosed herein can be implemented or performed with a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A general-purpose processor can be a microprocessor, but alternatively, the processor can be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. Alternatively, certain steps or methods can be performed by circuits specific to a given function.

[0098] The scope of the present disclosure is not limited by the specific embodiments described herein. In fact, in addition to those embodiments and modifications described herein, various other embodiments and modifications will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Therefore, such other embodiments and modifications are intended to fall within the scope of the present disclosure. In addition, although the present disclosure is described herein in the context of a specific implementation in a specific environment for a specific purpose, it will be appreciated by those of ordinary skill in the art that its usefulness is not limited thereto, and the present disclosure can be advantageously implemented in any number of environments for any number of purposes. Therefore, the claims set forth below should be interpreted in light of the full breadth and spirit of the disclosure described herein.

Claims

1. A near-eye display for providing an angular image at an eye box, the near-eye display comprising: a first light source, configured to provide a first light beam; a second light source, configured to provide a second light beam; a tiltable reflector for reflecting the first light beam and the second light beam at variable angles; a pupil replicating waveguide for receiving the first and second light beams tilted by the tiltable reflector and expanding the first and second light beams above the eye box by providing portions of the first and second light beams above the eye box, the pupil replicating waveguide comprising a polarization-selective inner coupler for incoupling light in a first polarization state while transmitting therethrough light in a second polarization state, the second polarization state being orthogonal to the first polarization state; a first curved reflector for receiving the first light beam from the first light source and reflecting the first light beam in the second polarization state toward the tiltable reflector and through the polarization-selective inner coupler; and a second curved reflector for receiving the second light beam from the second light source and reflecting the second light beam in the second polarization state toward the tiltable reflector and through the polarization-selective inner coupler; wherein after reflection from the tiltable reflector, the first light beam and the second light beam are in the first polarization state, whereby the first light beam and the second light beam are in-coupled into the pupil replicating waveguide.

2. The near-eye display of claim 1 , wherein the first light source and the second light source are arranged on opposite sides of the pupil replicating waveguide from the first curved reflector and the second curved reflector.

3. The near-eye display of claim 1, wherein the first curved reflector and the second curved reflector share a common boundary in the middle thereof.

4. The near-eye display of claim 1, wherein the first polarization state and the second polarization state are opposite-handed circular polarization states.

5. The near-eye display of claim 1 , wherein in operation, the first light beam and the second light beam are scanned by the tiltable reflector over different portions of a field of view (FOV) of the near-eye display. The near-eye display of claim 5 , wherein different FOVs partially overlap to provide a redundancy region.

7. The near-eye display of claim 1 , further comprising: a first folding mirror in an optical path between the first light source and the first curved reflector; as well as A second folding mirror is in an optical path between the second light source and the second curved reflector.

8. The near-eye display of claim 1 , further comprising: a third light source, configured to provide a third light beam; a fourth light source, configured to provide a fourth light beam; a third curved reflector for receiving the third light beam from the third light source and reflecting the third light beam in the second polarization state toward the tiltable reflector and through the polarization-selective inner coupler; and a fourth curved reflector for receiving the fourth light beam from the fourth light source and reflecting the fourth light beam in the second polarization state toward the tiltable reflector and through the polarization-selective inner coupler; wherein after reflection from the tiltable reflector, the third light beam and the fourth light beam are in the first polarization state, whereby the third light beam and the fourth light beam are in-coupled into the pupil replicating waveguide.

9. The near-eye display of claim 8 , wherein the first, second, third, and fourth light sources are arranged on opposite sides of the pupil replicating waveguide from the first, second, third, and fourth curved reflectors.

10. The near-eye display of claim 8, wherein the first curved reflector, the second curved reflector, the third curved reflector, and the fourth curved reflector share a common boundary in between.

11. The near-eye display of claim 8, wherein the first polarization state and the second polarization state are opposite-handed circular polarization states.

12. A near-eye display for providing an angular image at an eye box, the near-eye display comprising: a plurality of light sources for providing a plurality of light beams; a tiltable reflector for reflecting the plurality of first light beams at variable angles; a pupil replicating waveguide comprising a polarization selective inner coupler for incoupling light in a first polarization state while simultaneously transmitting therethrough light in a second polarization state, the second polarization state being orthogonal to the first polarization state; a plurality of adjacent curved reflectors, configured to receive the plurality of light beams from the plurality of light sources, and reflect the plurality of light beams in the second polarization state through the polarization-selective inner coupler to be incident on the tiltable reflector at different angles; wherein after reflection from the tiltable reflector, the plurality of light beams are in the first polarization state, whereby the plurality of light beams are in-coupled into the pupil replicating waveguide.

13. The near-eye display of claim 12, wherein the first polarization state and the second polarization state are opposite-handed circular polarization states.

14. The near-eye display of claim 12, wherein in operation, the plurality of light beams are scanned by the tiltable reflector over different portions of a field of view (FOV) of the near-eye display. The near-eye display of claim 14 , wherein different FOVs partially overlap to provide a redundancy region.

16. The near-eye display of claim 12, wherein at least one of the plurality of light sources comprises a plurality of emitters.

17. The near-eye display of claim 16, wherein the plurality of emitters comprises emitters of different color channels.

18. A method of coupling a light beam into a waveguide of a near-eye display, the waveguide comprising a polarization-selective inner coupler configured to inner couple light in a first polarization state while transmitting light in a second polarization state, the second polarization state being orthogonal to the first polarization state. The method comprises: collimating the light beam using a plurality of curved reflectors to provide a collimated light beam; redirecting the collimated light beam in the second polarization state so that the collimated light beam in the second polarization state is incident on a common tiltable reflector through a polarization selective inner coupler; The tiltable reflector reflects the collimated light beam at a variable angle until it is incident on the polarization selective inner coupler; and The collimated light beam is incoupled by the polarization-selective incoupler, wherein the collimated light is in the first polarization state after reflection from the tiltable reflector.

19. The method of claim 18, further comprising scanning the first and second light beams over different portions of a field of view (FOV) of the near-eye display by the tiltable reflector.

20. The method of claim 19, wherein the first polarization state and the second polarization state are opposite-handed circular polarization states.

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