Polarization multiplexing optics for head mounted display systems

Abstract

The present invention generally relates to techniques for improving the performance and efficiency of display systems (e.g., laser scanning beam display systems or other types of display systems of HMD systems or other devices (e.g., microdisplays)). Display systems of the present disclosure may use polarization multiplexing that allows for improved diffractive optics optimization. In at least some embodiments, the display system may selectively polarize light according to a wavelength (e.g., color) or field of view. An optical combiner may include polarization sensitive diffractive optical elements, each of which is optimized for a subset of colors or a portion of the entire field of view, thereby providing improved correction optics for a display system.

Description

Technical Field

[0001] The present invention relates generally to display systems and, more particularly, to improving the efficiency and performance of display systems. Background Art

[0002] The current generation of virtual reality ("VR") experiences are created using a head-mounted display ("HMD") that can be tethered to a stationary computer (e.g., a personal computer ("PC"), laptop, or game console), combined with and / or integrated or self-contained with a smartphone and / or its associated display. Typically, an HMD is a display device worn on the user's head that has a small display device in front of one eye (monocular HMD) or each eye (binocular HMD). The display unit is typically miniaturized and may include, for example, a CRT, LCD, liquid crystal on silicon (LCoS), OLED technology, or a laser scanning beam display. Binocular HMDs have the potential to display a different image to each eye. This capability is used to display stereoscopic images.

[0003] With the development of smart phones, high-definition televisions, and other electronic devices, the demand for displays with enhanced performance has increased. The increasing popularity of virtual reality and augmented reality systems, especially those using HMDs, has further increased this demand. Virtual reality systems typically completely surround the wearer's eyes and replace the actual or physical view (or actual reality) in front of the wearer with a "virtual" reality, while augmented reality systems typically provide a translucent or transparent overlay of one or more screens in front of the wearer's eyes so that the actual view is enhanced with additional information, and mediated reality systems can similarly present information combining real world elements with virtual elements to the viewer.

[0004] For augmented reality applications, a see-through optical combiner can be provided that combines a virtual image and the real world and delivers it simultaneously to the user's eyes. This technology for light combiners, once using highly efficient diffractive optics, can be easily manufactured and has other advantages. However, designing a diffractive optical combiner that provides a high level of correction over the entire field of view and / or at multiple wavelengths can be a significant challenge. Summary of the invention

[0005] A head mounted display system can be summarized as including: a support structure; and a display system connected to the support structure. The display system includes: a display light source; a selective polarization optical device for receiving light from the display light source and outputting light of a first color in a first polarization state and light of a second color in a second polarization state, the second polarization state being orthogonal to the first polarization state; and a light combiner positioned to receive light from the selective polarization optical device and provide an image to an observer's eye. The light combiner includes: a first polarization sensitive diffractive optical element (PSDOE), the first polarization sensitive diffractive optical element including a first diffraction pattern, the first diffraction pattern diffracting light of a first polarization state and passing light of a second polarization state without diffraction, the first diffraction pattern providing optimized correction for the first color; and a second PSDOE including a second diffraction pattern, the second diffraction pattern diffracting light of a second polarization state and passing light of the first polarization state without diffraction, the second diffraction pattern providing optimized correction for the second color. Each of the selective polarization optical device, the first PSDOE, and the second PSDOE may include a multi-twist delay. At least one of the selective polarization optical device, the first PSDOE and the second PSDOE may include a multi-twist retarder. At least one of the selective polarization optical device, the first PSDOE and the second PSDOE may include a liquid crystal material. The selective polarization optical device can be used to output light of a third color in a second polarization state, and the second diffraction pattern can provide optimized correction for the second color and the third color. The first color can be red, and the second color and the third color can be green and blue, respectively. The first color can be red, and the second color can be green or blue. The light combiner can include an in connector and an out connector. The support structure can include eyeglass lenses. The display light source can include a laser scanning beam system or a micro display.

[0006] A head mounted display system can be summarized as including: a support structure; and a display system connected to the support structure. The display system includes: a display light source; a selective polarization optical device for receiving light from the display light source having a total field of view, and outputting light of a first field of view portion of the total field of view in a first polarization state and light of a second field of view portion of the total field of view in a second polarization state, the second polarization state being orthogonal to the first polarization state; and a light combiner positioned to receive light from the selective polarization optical device and provide an image to an observer's eye. The light combiner includes: a first polarization sensitive diffractive optical element (PSDOE), the first polarization sensitive diffractive optical element including a first diffraction pattern, the first diffraction pattern diffracting light of a first polarization state and passing light of a second polarization state without diffraction, the first diffraction pattern providing optimized correction for the first field of view portion; and a second PSDOE including a second diffraction pattern, the second diffraction pattern diffracting light of a second polarization state and passing light of the first polarization state without diffraction, the second diffraction pattern providing optimized correction for the second field of view portion. The first field of view portion may include an angular range of 0 degrees to M degrees, and the second field of view portion may include an angular range of M degrees to N degrees, where N is the angular range of the field of view of the HMD system, and M is less than N. The first field of view portion and the second field of view portion may be combined to form a total field of view. The first field of view portion may be surrounded by the second field of view portion. The first field of view portion may include a first half of the total field of view, and the second field of view portion may include a second half of the total field of view. The first field of view portion and the second field of view portion may at least partially overlap each other. Each of the selective polarization optical device, the first PSDOE, and the second PSDOE may include a multi-twist delay. At least one of the selective polarization optical device, the first PSDOE, and the second PSDOE may include a multi-twist delay. At least one of the selective polarization optical device, the first PSDOE, and the second PSDOE may include a liquid crystal material. The optical combiner may include an in connector and an out connector. The support structure may include eyeglass lenses. The display light source may include a laser scanning beam system or a microdisplay. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the drawings, the same reference numerals represent similar elements or actions. The sizes and relative positions of the elements in the drawings are not necessarily drawn to scale. For example, the shapes and angles of the various elements are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve the readability of the drawings. In addition, the particular shapes of the elements shown in the drawings are not necessarily intended to convey any information about the actual shape of the particular element, and may be selected solely for ease of identification in the drawings.

[0008] Figure 1 is a schematic diagram of a networked environment that includes one or more systems suitable for performing at least some of the techniques described in this disclosure.

[0009] Figure 2 is a diagram illustrating an example environment in which at least some of the described techniques are used with an example head-mounted display device that is tethered to a video rendering computing system and provides a virtual reality display to a user.

[0010] Figure 3 is a front view of an example HMD device with a binocular display subsystem.

[0011] Figure 4 A top view of an HMD device with a binocular display subsystem and various sensors is shown according to an example embodiment of the present disclosure.

[0012] Figure 5 is a schematic block diagram of a display system including a spatially varying polarizer according to one non-limiting illustrated embodiment.

[0013] Figure 6 is a schematic diagram of a scanning beam display system according to one non-limiting illustrated embodiment.

[0014] Figure 7 is a schematic diagram of a scanning beam display system including a spatially varying polarizer that is selectively adjusted based on a user's determined or inferred gaze location according to one non-limiting embodiment.

[0015] Figure 8 is a schematic diagram of a display system including a waveguide-based optical system and a spatially varying polarizer according to one non-limiting illustrated embodiment.

[0016] Fig. 9 is a schematic diagram of a display system including a waveguide-based optical system using polarization multiplexing over wavelength according to one non-limiting illustrated embodiment.

[0017] Fig.10 is a schematic diagram of a display system including a waveguide-based optical system using polarization multiplexing across a field of view, according to one non-limiting illustrated embodiment.

[0018] Fig.11A is a schematic diagram of a total field of view of an HMD system, the HMD system comprising a first field of view portion surrounded by a second field of view portion, wherein a light combiner of the HMD system comprises a first polarization-sensitive diffractive optical element optimized for the first field of view portion and a second polarization-sensitive diffractive optical element optimized for the second field of view portion.

[0019] Fig. 11Bis a schematic diagram of a total field of view of an HMD system including a first field of view portion positioned adjacent to a second field of view portion, wherein a light combiner of the HMD system includes a first polarization-sensitive diffractive optical element optimized for the first field of view portion and a second polarization-sensitive diffractive optical element optimized for the second field of view portion. DETAILED DESCRIPTION

[0020] In the following description, certain specific details are set forth to provide a thorough understanding of the various disclosed embodiments. However, one skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details, or using other methods, components, materials, etc. In other instances, well-known structures associated with computer systems, server computers, and / or communication networks are not shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0021] Throughout the specification and following claims, the word "comprising" is synonymous with "including" and is inclusive or open-ended (ie, does not exclude other unrecited elements or methodological acts) unless the context requires otherwise.

[0022] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment. Thus, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout the specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0023] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise.

[0024] The titles and abstracts of the disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

[0025] The present invention generally relates to techniques for improving the performance and efficiency of display systems, such as laser scanning beam display systems or other types of display systems (e.g., microdisplays). For many types of optics, such as diffractive optics used in augmented reality (AR) systems, it can be difficult to provide correction over the entire field of view or over a wide range of wavelengths (e.g., red, green, blue). The display systems of the present disclosure can use polarization multiplexing that allows better optimization of diffractive optics. In at least some embodiments, the display system can polarize light according to wavelength or field of view. The light combiner can include multiple polarization-sensitive diffractive optical elements, each of which is optimized for a subset of colors or a portion of the entire field of view, thereby providing improved corrective optics for the display system.

[0026] First, refer to Figure 1-4 Discuss example head mounted display device applications for the techniques described herein. Then, refer to Figure 5-1 1 , discusses example implementations of display systems that include features of the present disclosure.

[0027] Example Head-Mounted Display System and Environment

[0028] Figure 1 1 is a schematic diagram of a networked environment 100 that includes a local media presentation (LMR) system 110 (e.g., a gaming system) that includes a local computing system 120 and a display device 180 (e.g., an HMD device with two display panels) that is suitable for performing at least some of the techniques described herein. Figure 1 In the illustrated embodiment, the local computing system 120 is connected to the computer via a transmission link 115 (which may be wired or tethered, for example, via Figure 2 The local computing system 120 is communicatively connected to the display device 180 by one or more cables (cable 220) as shown, or alternatively may be wireless. In other embodiments, whether together with or in place of the HMD device 180, the local computing system 120 may provide encoded image data for display to a panel display device (e.g., a TV, console, or monitor) via a wired or wireless link, and each display device includes one or more addressable pixel arrays. In various embodiments, the local computing system 120 may include a general-purpose computing system, a game console, a video stream processing device, a mobile computing device (e.g., a cell phone, a PDA, or other mobile device), a VR or AR processing device, or other computing system.

[0029] In the illustrated embodiment, the local computing system 120 has components including one or more hardware processors (e.g., a centralized processing unit or "CPU") 125, memory 130, various I / O ("input / output") hardware components 127 (e.g., a keyboard, a mouse, one or more game controllers, speakers, a microphone, an IR transmitter and / or receiver, etc.), a video subsystem 140 including one or more dedicated hardware processors (e.g., a graphics processing unit or "GPU") 144 and video memory (VRAM) 148, a computer-readable memory 150, and a network connection 160. Also in the illustrated embodiment, an embodiment of the eye tracking subsystem 135 runs in the memory 130 in order to perform at least some of the described techniques,

[0030] For example, by using CPU 125 and / or GPU 144 to perform automated operations for implementing the described techniques, and memory 130 may optionally further execute one or more other programs 133 (e.g., to generate video or other images to be displayed, such as a game program). As part of the automated operations for implementing at least some of the techniques described herein, the eye tracking subsystem 135 and / or programs 133 running in memory 130 may store or retrieve various types of data included in the example database data structure of memory 150, in which example, the data used may include various types of image data information in database ("DB") 154, various types of application data in DB 152, various types of configuration data in DB 157, and may include additional information, such as system data or other information.

[0031] In the depicted embodiment, the LMR system 110 is also communicatively connected via one or more computer networks 101 and network links 102 to an example network-accessible media content provider 190, which may further provide content to the LMR system 110 for display, whether in conjunction with or in lieu of the image generation program 133. The media content provider 190 may include one or more computing systems (not shown), each of which may have components similar to those of the local computing system 120, including one or more hardware processors, I / O components, local storage devices, and memory, although some details are not shown for the network-accessible media content providers for the sake of brevity.

[0032] It should be understood that although Figure 1In the illustrated embodiment, the display device 180 is described as being distinct and separate from the local computing system 120, but in certain embodiments, some or all components of the local media presentation system 110 may be integrated or housed within a single device, such as a mobile gaming device, a portable VR entertainment system, an HMD device, etc. In such an embodiment, the transmission link 115 may, for example, include one or more system buses and / or video bus architectures.

[0033] As an example involving operations performed locally by the local media presentation system 120, assume that the local computing system is a gaming computing system, such that the application data 152 includes one or more gaming applications executed by the CPU 125 using the memory 130, and various video frame display data is generated and / or processed by the image generation program 133, such as in conjunction with the GPU 144 of the video subsystem 140. In order to provide a high-quality gaming experience, a large amount of video frame data (corresponding to a high image resolution for each video frame, and a high "frame rate" of approximately 60-180 such video frames per second) is generated by the local computing system 120 and provided to the display device 180 via the wired or wireless transmission link 115.

[0034] It will also be understood that computing system 120 and display device 180 are only illustrative and are not intended to limit the scope of the present invention. Computing system 120 may alternatively include multiple interactive computing systems or devices, and may be connected to other devices not shown, including connecting via one or more networks such as the Internet, via the Web, or via a dedicated network (e.g., a mobile communication network, etc.). More generally, a computing system or other computing node may include any combination of hardware or software that can interact and perform the functions of the type, including but not limited to desktop or other computers, game systems, database servers, network storage devices and other network devices, PDAs, cellular phones, wireless phones, pagers, electronic organizers, Internet appliances, TV-based systems (e.g., using set-top boxes and / or personal / digital video recorders), and various other consumer products including appropriate communication capabilities. Display device 180 may similarly include one or more devices with one or more display panels of various types and forms, and optionally include various other hardware and / or software components.

[0035] It should also be understood that although various entries are shown as being stored in or on memory when used, these entries or portions thereof may be transferred between memory and other storage devices for purposes of memory management or data integrity. Thus, in some embodiments, some or all of the described techniques may be performed by hardware including one or more processors or other configured hardware circuits or memory or memory, such as when configured by one or more software programs and / or data structures (e.g., by executing software instructions of one or more software programs and / or by storing such software instructions and / or data structures). Some or all of the components, systems, and data structures may also be stored (e.g., as software instructions or structured data) on a non-transitory computer-readable storage medium, such as a hard disk or flash drive or other non-volatile storage device, volatile or non-volatile memory (e.g., RAM), a network storage device, or a portable media product (e.g., a DVD disk, a CD disk, an optical disk, etc.) to be read by an appropriate drive (e.g., RAM) or through an appropriate connection. In some embodiments, the systems, components, and data structures may also be transmitted as a generated data signal (e.g., as part of a carrier wave or other analog or digital propagation signal) on various computer-readable transmission media, including wireless-based and wire / cable-based media, and may take various forms (e.g., as part of a single or multiplexed analog signal, or as multiple discrete digital packets or frames). In other embodiments, such a computer program product may also take other forms. Therefore, the present invention may be implemented with other computer system configurations.

[0036] Figure 2 An example environment 200 is shown in which at least some of the described techniques are used with an example HMD device 202 that is connected to a video rendering computing system 204 via a tethered connection 220 (or wireless connection in other embodiments) to provide a virtual reality display to a human user 206. The user wears the HMD device 202 and receives display information of a simulated environment that is different from the actual physical environment from the computing system 204 through the HMD device, where the computing system acts as an image rendering system that provides images of the simulated environment to the HMD device for display to the user, such as images generated by a game program and / or other software program executed on the computing system. In this example, the user is also able to move within a tracked volume 201 of the actual physical environment 200, and may also have one or more I / O ("input / output") devices to allow the user to further interact with the simulated environment, which in this example includes handheld controllers 208 and 210.

[0037] In the illustrated example, the environment 200 may include one or more base stations 214 (two are shown, labeled base stations 214a and 214b), which may help track the HMD device 202 or controllers 208 and 210. As the user moves the position of the HMD device 202 or changes the orientation of the HMD device 202, the position of the HMD device is tracked to allow the corresponding portion of the simulated environment to be displayed to the user on the HMD device, and the controllers 208 and 210 may also use similar techniques to track the position of the controllers (and optionally use this information to help determine or verify the position of the HMD device). After the tracked position of the HMD device 202 is known, the corresponding information is sent to the computing system 204 via the tether 220 or wirelessly, which uses the tracked position information to generate one or more next images of the simulated environment for display to the user.

[0038] A variety of different position tracking methods may be used in various embodiments of the present disclosure, including but not limited to acoustic tracking, inertial tracking, magnetic tracking, optical tracking, combinations thereof, and the like.

[0039] In at least some embodiments, the HMD device 202 may include one or more optical receivers or sensors that may be used to implement tracking functionality or other aspects of the present disclosure. For example, the base stations 214 may each sweep an optical signal over the tracked volume 201. Each base station 214 may generate more than one optical signal, as required by each particular embodiment. For example, while a single base station 214 is typically sufficient for six-degree-of-freedom tracking, in some embodiments, multiple base stations (e.g., base stations 214a, 214b) may be required or desired to provide robust room-scale tracking for the HMD device and peripherals. In this example, the optical receivers are incorporated into the HMD device 202 and / or other tracked objects, such as controllers 208 and 210. In at least some embodiments, the optical receivers may be paired with accelerometers and gyroscope inertial measurement units ("IMUs") on each tracked device to support low latency sensor fusion.

[0040] In at least some embodiments, each base station 214 includes two rotors that scan linear beams across the tracked volume 201 on orthogonal axes. At the beginning of each scanning cycle, the base station 214 can transmit an omnidirectional light pulse (referred to as a "sync signal") that is visible to all sensors on the tracked object. Thus, each sensor calculates a unique angular position in the scanned volume by timing the duration between the sync signal and the beam signal. Sensor distance and direction can be resolved using multiple sensors fixed to a single rigid body.

[0041] One or more sensors located on the tracked object (e.g., HMD device 202, controllers 208 and 210) may include optoelectronics capable of detecting modulated light from the rotor. For visible light or near infrared (NIR) light, a silicon photodiode and appropriate amplifier / detector circuitry may be used. Because environment 200 may contain static and time-varying signals (optical noise) having similar wavelengths to the base station 214 signal, in at least some embodiments, the base station light may be modulated in such a way that it is easily distinguished from any interfering signals, and / or the sensor may be filtered for radiation of any wavelength other than the base station signal.

[0042] Inside-out tracking is also a type of positional tracking that can be used to track the position of the HMD device 202 and / or other objects (e.g., controllers 208 and 210, tablet computers, smart phones). Inside-out tracking differs from outside-in tracking in the location of the camera or other sensor used to determine the position of the HMD. For inside-out tracking, the camera or sensor is located on the HMD, or on the object being tracked, while in outside-out tracking, the camera or sensor is placed at a fixed location in the environment.

[0043] HMDs that use inside-out tracking use one or more cameras to "look outside" to determine how their position has changed relative to the environment. As the HMD moves, the sensors readjust their position in the room, and the virtual environment responds accordingly in real time. This type of positional tracking can be implemented with or without markers placed in the environment. Cameras placed on the HMD observe features of the surrounding environment. When markers are used, the markers are designed to be easily detected by the tracking system and are placed in specific areas. With "markerless" inside-out tracking, the HMD system uses unique features that are initially present in the environment (e.g., natural features) to determine position and orientation. The HMD system's algorithms recognize specific images or shapes and use them to calculate the device's position in space. Data from accelerometers and gyroscopes can also be used to increase the accuracy of positional tracking.

[0044] Figure 3 Information 300 shows a front view of an example HMD device 344 when worn on the head of a user 342. The HMD device 344 includes a front-facing structure 343 supporting a front-facing or forward-facing camera 346 and a plurality of sensors 348a-348d (collectively, 348) of one or more types. As an example, some or all of the sensors 348 can help determine the position and orientation of the device 344 in space, such as light sensors, to detect and use information from one or more external devices (not shown, for example, Figure 2344). As shown, the forward camera 346 and sensor 348 are directed forward toward the actual scene or environment (not shown) in which the user 342 is operating the HMD device 344. The actual physical environment may include, for example, one or more objects (e.g., walls, ceilings, furniture, stairs, cars, trees, tracking markers, or any other type of object). The specific number of sensors 348 may be less than or greater than the number of sensors shown. The HMD device 344 may further include one or more additional components that are not attached to the forward-facing structure (e.g., inside the HMD device), such as an IMU (inertial measurement unit) 347 electronic device that measures and reports specific forces, angular rates, and / or magnetic fields around the HMD device 344 (e.g., using a combination of accelerometers and gyroscopes, and optionally, a magnetometer). The HMD device may also include additional components not shown, including one or more display panels and optical lens systems that are oriented toward the user's eyes (not shown) and optionally have one or more internal motors connected to change the alignment or other positioning of the one or more optical lens systems and / or display panels within the HMD device, as described below with respect to Figure 4 discussed in more detail.

[0045] The example of the HMD device 344 shown is supported on the head of the user 342 based at least in part on one or more straps 345 connected to the housing of the HMD device 344 and extending all or partly around the head of the user. Although not shown here, the HMD device 344 may also have one or more external motors, for example connected to one or more straps 345, and the automatic corrective action may include using the motor to adjust the straps to modify the alignment or other positioning of the HMD device on the user's head. It should be understood that the HMD device may include other support structures (e.g., nose piece, chin strap, etc.) not shown here, whether in addition to or in lieu of the straps shown, and some embodiments may include motors connected to one or more such other support structures to similarly adjust their shape and / or position to modify the alignment or other positioning of the HMD device on the user's head. Other display devices that are not fixed to the user's head may be similarly connected to one or more structures or portions thereof that affect the positioning of the display device, and in at least some embodiments may include motors or other mechanical actuators to similarly modify their shape and / or position to modify the alignment or other positioning of the display device relative to one or more pupils of one or more users of the display device.

[0046] Figure 4 A simplified top plan view 400 of an HMD device 405 is shown that includes a pair of near-eye display systems 402 and 404. The HMD device 405 may be, for example, Figure 1-3 The same or similar HMD device or a different HMD device shown in , and the HMD devices discussed herein can be further used in the examples discussed below. Figure 4 The near-eye display systems 402 and 404 of the embodiment include display panels 406 and 408 (e.g., OLED microdisplays), respectively, and optical lens systems 410 and 412, each having one or more optical lenses. The display systems 402 and 404 can be mounted to or otherwise positioned within a housing (or frame) 414, which includes a front-facing portion 416 (e.g., with a lens 416 disposed adjacent to the display panel 406 and 408). Figure 3 The two display systems 402 and 404 can be placed in an eyeglass device fixed to the housing 414, and the eyeglass device can be worn on the head 422 of the wearer user 424, with the left and right eyeglass arms 418 and 420 resting on the user's ears 426 and 428, respectively, and the nose piece 492 can rest on the user's nose 430. Figure 4 In the example of FIG. 4 , the HMD device 405 can be partially or completely supported on the user's head by the nose display and / or the left and right ear mirror arms, although in some embodiments a strap (not shown) or other structure can be used to secure the HMD device to the user's head, such as Figure 2 and 3 . The shape and size of the housing 414 can be designed to position each of the two optical lens systems 410 and 412 in front of one of the user's eyes 432 and 434, respectively, so that the target position of each pupil 494 is vertically and horizontally centered in front of the corresponding optical lens system and / or display panel. Although the housing 414 is shown in a simplified manner similar to glasses for illustrative purposes, it should be understood that more complex structures (e.g., goggles, integrated headbands, helmets, straps, etc.) can actually be used to support and position the display systems 402 and 404 on the head 422 of the user 424.

[0047] Figure 4 The HMD device 405 and other HMD devices discussed herein are capable of presenting a virtual reality display to a user, for example via a corresponding video presented at a display rate such as 30 or 60 or 90 frames (or images) per second, while other embodiments of similar systems can present an augmented reality display to a user. Figure 4Each of the displays 406 and 408 can generate light that is transmitted and focused onto the eyes 432 and 434 of the user 424 through the corresponding optical lens systems 410 and 412, respectively. The pupil 494 of each eye, through which the light enters the eye, typically has a pupil size ranging from 2 mm (millimeters) in diameter in very bright conditions to as much as 8 mm in dark conditions, while the larger iris containing the pupil can have a size of about 12 mm - the pupil (and closed iris) can also typically move several millimeters in the visible part of the eye under an open eyelid in the horizontal and / or vertical direction. When the eyeball rotates about its center (resulting in a three-dimensional volume in which the pupil can move), this direction will also cause the pupil to move to different depths from the optical lenses or other physical elements of the display for different horizontal and vertical positions. The light entering the user's pupil is viewed by the user 424 as an image and / or video. In some implementations, the distance between each of optical lens systems 410 and 412 and the user's eyes 432 and 434 can be relatively short (e.g., less than 30 mm, less than 20 mm), which advantageously makes the HMD device appear brighter to the user because the weight of the optical lens system and the display system is relatively close to the user's face, and can also provide a larger field of view to the user. Although not shown here, some embodiments of such an HMD device can include various additional internal and / or external sensors.

[0048] In the illustrated embodiment, Figure 4 The HMD device 405 also includes hardware sensors and additional components, such as one or more accelerometers and / or gyroscopes 490 (e.g., as part of one or more IMU units). As discussed in more detail elsewhere herein, the values ​​from the accelerometers and / or gyroscopes can be used to locally determine the orientation of the HMD device. In addition, the HMD device 405 may include one or more front-facing cameras, such as a camera 485 outside the front 416, and its information can be used as part of the operation of the HMD device, such as for providing AR functions or positioning functions. In addition, the HMD device 405 may also include other components 475 (e.g., electronic circuits for controlling the display of images on the display panels 406 and 408, internal memory, one or more batteries, position tracking devices that interact with external base stations, etc.), as discussed in more detail elsewhere herein. Other embodiments may not include one or more of components 475, 485, and / or 490. Although not shown here, some embodiments of such HMD devices may include various additional internal and / or external sensors to track various other types of movements and positions of the user's body, eyes, controllers, etc.

[0049] In the embodiment shown, Figure 4The HMD device 405 of the embodiment also includes hardware sensors and additional components that can be used by the disclosed embodiments as part of a technique for determining a user's pupils or gaze direction, which can be provided to one or more components associated with the HMD device for use, as discussed elsewhere herein. The hardware sensors in this example include one or more eye tracking components 472 of an eye tracking subsystem mounted on or near the display panels 406 and 408 and / or on the inner surface 421 located near the optical lens systems 410 and 412 for obtaining information about the actual position of the user's pupils 494, such as for each pupil separately in this example.

[0050] Each eye tracking component 472 may include one or more light sources (e.g., IR LEDs) and one or more light detectors (e.g., silicon photodiodes). Figure 4 Only four full eye tracking assemblies 472 are shown, but it should be understood that a different number of eye tracking assemblies may actually be provided. In some embodiments, a total of eight eye tracking assemblies 472 are provided, four eye tracking assemblies for each eye of the user 424. In addition, in at least some embodiments, each eye tracking assembly includes a light source directed toward one of the eyes 432 and 434 of the user 424, a light detector positioned to receive light reflected by the user's corresponding eye, and a polarizer positioned and configured to prevent light reflected via specular reflection from being applied to the light detector.

[0051] As discussed in greater detail elsewhere herein, information from eye tracking assembly 472 can be used to determine and track the gaze direction of a user during use of HMD device 405. Additionally, in at least some embodiments, HMD device 405 can include one or more internal motors 438 (or other movement mechanisms) that can be used to move 439 the alignment and / or other positioning (e.g., in vertical, horizontal left-right, and / or horizontal front-to-back directions) of one or more optical lens systems 410 and 412 and / or display panels 406 and 408 within the housing of HMD device 405 to personalize or otherwise adjust a target pupil location for one or both of near-eye display systems 402 and 404 to correspond to an actual location of one or both of pupils 494. Such motors 438 can be controlled, for example, by user manipulation of one or more controls 437 on housing 414 and / or by user manipulation of one or more associated separate I / O controllers (not shown). In other embodiments, HMD device 405 can control the alignment and / or other positioning of optical lens systems 410 and 412 and / or display panels 406 and 408 without requiring such motor 438, such as by using an adjustable positioning mechanism (e.g., a screw, a slider, a ratchet, etc.) that is manually changed by a user using controller 437. Figure 4 Motor 438 is shown for only one of the near-eye display systems, but in some embodiments, each near-eye display system can have its own one or more motors, and in some embodiments, one or more motors can be used to control (e.g., independently) each of multiple near-eye display systems.

[0052] Although the described techniques can be used in some embodiments with a display system similar to that shown, other types of display systems can also be used in other embodiments, including use with a single optical lens and display device, or use with multiple such optical lenses and display devices. Non-exclusive examples of other such devices include cameras, telescopes, microscopes, binoculars, observation mirrors, measuring mirrors, etc. In addition, the described techniques can be used with various display panels or other display devices that emit light to form one or more images viewed by a user through one or more optical lenses, as discussed elsewhere herein. In other embodiments, a user can view one or more images through one or more optical lenses that are produced in a manner different from that produced by a display panel, such as on a surface that partially or completely reflects light from another light source (e.g., a laser scanning beam).

[0053] Example Display System

[0054] Figure 55 is a schematic block diagram of a display system 500 according to one non-limiting illustrated embodiment. Display system 500 can be a display system of a head-mounted display system, such as the head-mounted display system described above, or any other type of display system (e.g., wearable or non-wearable). Display system 500 can include a scanned beam display system or another type of display system (e.g., a microdisplay). In at least some embodiments, display system 500 can be one of two substantially identical display systems provided in a device such as a head-mounted display device.

[0055] The display system 500 includes a display light source 502 optically connected to a pupil relay system 504. The display light source 502 may include a laser scanning beam light source, a microdisplay, or any other suitable display light source. The pupil relay system 504 is positioned to relay a first pupil from the display light source 502 to a second pupil at a viewer's eye 506 (or other image plane, surface, or material). The pupil relay system 504 includes a polarization-sensitive optical device 508 (e.g., a post-scanning optical device), which may include one or more of a waveguide-based optical system, a pancake optical system, a bird bath optical system, a coating-based optical system, or other optical devices. The polarization-sensitive optical device 508 may include one or more components. The efficiency of the polarization-sensitive optical device 508 may be very sensitive to the polarization of the light passing therethrough. That is, different polarizations will significantly change the intensity and stray light, causing the light to escape the polarization-sensitive optical device 508.

[0056] To optimize the polarization of light provided to the polarization-sensitive optics 508, the pupil relay system 504 of the display system 500 also includes a spatially varying polarizer 510 having a polarization that varies spatially as a function of position to compensate for variations in polarization to provide uniformly polarized light, or more generally optimized polarized light, to the polarization-sensitive optics 508. For example, the polarization-sensitive optics 508 can be configured to compensate for or "undo" any polarization produced from compound angles by one or more mirrors or other optical devices. As discussed further below, the spatially varying polarizer 510 can be selectively adjusted in real time to provide optimized performance in a region or field of view based on the user's gaze position.

[0057] The spatially varying polarizer 510 may include a wave retarder formed of a birefringent material. Birefringence is the property of a material having a refractive index that depends on the polarization and propagation direction of the light. The wave retarder changes the polarization state or phase of the light propagating through the wave retarder. The wave retarder may have a slow axis (or extraordinary axis) and a fast axis (ordinary axis). When polarized light travels through the wave retarder, light along the fast axis travels faster than light along the slow axis.

[0058] As described above, the spatially varying polarizer 510 can provide a phase retardation that varies as a function of position (e.g., horizontal position, vertical position, radial position) across the field of view (e.g., on-axis to off-axis), which allows for a more uniform and efficient distribution of light from the display light source 502 to the polarization-sensitive optical device 508. The specific manner in which the retardation of the spatially varying polarizer 510 varies can depend on the specific configuration and materials of the optical system of the display system 500, such as the polarization state of the incident light, the angle of incidence, the materials, the geometry of the various components, etc.

[0059] As an example, the spatially varying polarizer 510 may provide no delay at a first position, and may linearly increase the delay to provide a delay of λ / 4 (or other value) at a second position of the spatially varying polarizer. In general, the spatially varying polarizer 510 may provide a delay that varies in any manner as a function of position, and the amount of delay may be any value (e.g., λ / 20, λ / 10, λ / 4, λ, 2λ). In addition, the amount of delay may increase only in one or more directions, decrease only in one or more directions, or increase and decrease simultaneously. The amount of delay may vary continuously, or may vary in multiple steps. The amount of delay may vary according to any type of function, including, for example, a linear function, a polynomial function, an exponential function, a step function, other types of functions, or combinations thereof.

[0060] In at least some embodiments, the spatially varying polarizer 510 can be formed of a multi-twisted retarder (MTR), which is a wave plate-like retardation film that provides precise and customized levels of broadband, narrowband, or multi-band retardation in a single film. More specifically, the MTR includes two or more twisted liquid crystal (LC) layers on a single substrate, and has a single alignment layer. Subsequent LC layers are directly aligned by previous layers, allowing simple manufacturing, achieving automatic layer alignment, and producing a monolithic film with a continuously varying optical axis.

[0061] Figure 6 6 is a schematic diagram of a scanning beam display system or projector 600 according to one non-limiting illustrated embodiment. The scanning beam display system 600 includes a light source 602, which can be a laser light source that emits a light beam 604. The light source 602 can include two additional light sources, such as a red light source, a green light source, and a blue light source. In this case, the multiple light sources can be combined into a single light beam by a beam combiner. In at least some embodiments, the light source 602 can include one or more color light sources (e.g., red, green, blue) and a light source that emits an invisible light beam such as an infrared beam or an ultraviolet beam, which can be used for various purposes, such as eye tracking.

[0062] The light beam 604 is incident on a scanning platform 606, which may include a micro-electromechanical system (MEMS) based scanner, and is reflected from a scanning mirror 608 of the platform to produce a controlled output light beam 610. The scanning platform 606 may include a diffraction grating, a moving grating, a light valve, a rotating mirror, a movable silicon device, a digital light projector device, a flying spot projector, a liquid crystal on silicon (LCoS) device, or other scanning or modulation device. The scanning platform 606 may be connected to one or more drive circuits, which are selectively controlled by a controller 612 connected to the scanning platform and the light source 602, and the controller 612 may include any suitable control circuit having one or more components. The drive circuit modulates the scanning mirror 608 to deflect the direction of the incident light beam 604 so that the output light beam 610 produces a scan such as a raster scan, thereby producing a display image on an image plane such as a display surface or an observer's eye 614.

[0063] Figure 7 is a schematic diagram of a scanning beam display system or projector 700 according to one non-limiting illustrated embodiment. The scanning beam display system 700 can be used in many aspects with Figure 6 The scanning beam display system 600 of the present invention is similar or identical. Thus, like components are represented by like reference numerals, and for the sake of brevity, such components will not be discussed repeatedly herein.

[0064] The scanned beam display system 700 includes post-scan correction optics 702 ("post-scan optics") and collimation optics 704. The post-scan optics 702 may include one or more optics located in the optical path after the scanning platform 606, which is generally referred to herein as "post-scan". The post-scan correction optics 702 may be designed and configured to correct or adjust for one or more distortion artifacts in the projected image. Examples of such distortions may include smile distortion, pin distortion, barrel distortion, distortion based on off-axis projection, etc. It should be understood that these are merely non-limiting example types of distortions that the post-scan correction optics 702 may correct.

[0065] The post-scanning optics 702 may include one or more of a waveguide-based optical system, a pancake optical system, a bird bath optical system, a coating-based optical system, and the like. The post-scanning optics may include one or more components. The efficiency of the post-scanning optics 702 may be very sensitive to the polarization of the light passing through it. That is, different polarizations will significantly change the intensity and stray light that causes light to leave the post-scanning optics 702. In at least some embodiments, the display system 700 may also include a collimating or beam forming optics 704, which may be used to at least partially regain the loss of undefined focus caused by the post-scanning optics 702.

[0066] The display system 700 also includes polarization compensation optics in the form of a spatially varying polarizer 706 located between the scanning mirror 608 and the post-scan optics 702 to provide polarization compensation for the post-scan optics 702, which, as described above, can be very polarization sensitive. For example, the spatially varying polarizer 706 can be located on, adjacent to, or within the post-scan optics 702. In other embodiments, the spatially varying polarizer 706 is located at other locations in the optical path between the light source 602 and the displayed image (e.g., pre-scan, post-scan, adjacent to the light source, etc.).

[0067] In at least some embodiments, controller 612 can be operably connected to spatially varying polarizer 706 to selectively change the spatially dependent phase retardation of the spatially varying polarizer to any desired configuration. In such embodiments, one or more thin film transistor layers can be provided that allow controller 612 to selectively control the spatially dependent phase retardation of spatially varying polarizer 706. Controller 612 can control the phase retardation at any desired rate, such as only once, periodically, at a rate equal to or a fraction of the frame rate of display system 700, etc.

[0068] In at least some embodiments, the controller 612 can be used to receive gaze tracking information 708, which can be used to selectively adjust the spatially-dependent phase delay of the spatially-varying polarizer 706 so as to be optimized in an optimized region where the user is believed to be currently gazing. Such gaze tracking information can be received from an eye tracking subsystem, from information about the content being displayed (e.g., a focus object), or from any other source that provides information about where the user may be gazing on the display.

[0069] As described above, the efficiency of the post-scanning optical device 702 may be very sensitive to the polarization of the light passing through it. That is, different polarizations will significantly change the intensity and stray light, which causes the light to leave the post-scanning optical device 702. It may be advantageous to optimize the spatially variable polarizer 706 over a relatively small field of view (e.g., 0-10 degrees, 0-30 degrees, other regions), which can provide significantly better performance than optimizing over the entire field of view. Using gaze tracking information, the system can optimize regions for various characteristics (e.g., intensity, stray light) while configuring regions outside the region to have lower performance (e.g., less intensity, more stray light). Since the user's vision is insensitive in the peripheral region, the user may not even feel that the performance of the display is reduced outside the region where the user is looking.

[0070] Figure 8800 includes a waveguide-based optical system and polarization compensation optics in the form of a spatially varying polarizer for use in a head-mounted display system, according to one non-limiting illustrated embodiment. Display system 800 may include a lens or support structure 802 (e.g., a prescription or non-prescription eyeglass lens). Waveguide structure 804 may be at least partially embedded in structure 802 or located near the structure (e.g., before or after the structure). Waveguide 804 may be a rectangular (or other shaped) prismatic structure formed of a material having a refractive index sufficiently different from the refractive index of the surrounding structure (e.g., structure 802) to provide total internal reflection within the waveguide.

[0071] To enable light to connect into the waveguide 804, the display system 800 includes an in connector 806 that is physically connected to a first portion of the waveguide. Similarly, to enable light to connect out of the waveguide 804 toward the viewer's eye 810, the display system 800 includes an out connector 808 that is physically connected to a second portion of the waveguide. The display light connected in through the in connector 806 and out through the out connector 808 can originate from a display light source, such as a projector, a scanning laser projector, a micro display, or other display light source, as described above. As non-limiting examples, the connectors 806 and 808 can include one or more of a diffraction grating, a hologram, a holographic optical element, a volume diffraction grating, a surface relief diffraction grating, and the like. The connectors 806 and 808 can also be reflective connectors or transmissive connectors. As an example, the structure 802 can include a right eye lens, and the in connector 806 can be located near the edge of the eye lens near the display source (e.g., a projector), and the out connector can be positioned toward the center of the eye lens so that the viewer can see the light from the waveguide 804 while viewing a straight area or approximately straight ahead.

[0072] The display system 800 also includes polarization compensation optics in the form of a spatially varying polarizer 812. In the non-limiting example shown, the spatially varying polarizer 812 is located near the connector 806 to provide polarization compensation for light entering the waveguide 804, which, as described above, can be very polarization sensitive. For example, the spatially varying polarizer 812 can be located on the waveguide 804, adjacent to the waveguide 804, or within the waveguide 804 (as shown in dashed lines). In at least some embodiments, the spatially varying polarizer 812 is located near either side of the inlet connector 806 or the outlet connector 808, for example. In other embodiments, the spatially varying polarizer 812 is located elsewhere in the light path between the display light source and the viewer's eye to provide polarization compensation.

[0073] Fig. 9is a schematic diagram of a display system 900 for an augmented reality system that uses polarization multiplexing to provide a waveguide structure optimized in wavelength (e.g., color). Display system 800 includes some components that are similar or identical to components of display system 800, which are identified by the same reference numerals. Display system 900 may include a lens or support structure 802 (e.g., a prescription or non-prescription eyeglass lens). Light combiner structure 902 may be at least partially embedded in structure 802 (e.g., a lens), or positioned near the structure (e.g., before or after the structure). Light combiner 902 may be a rectangular (or other shaped) structure formed of a material having a refractive index that is sufficiently different from the refractive index of the surrounding structure (e.g., structure 802) to provide total internal reflection within at least a portion of the light combiner.

[0074] To enable light to be coupled into the light combiner 902, the display system 900 includes an input connector 806 physically coupled to a first portion of the light combiner 902. Similarly, to enable light to be coupled out of the light combiner 902 toward an eye 810 of an observer, the display system 900 includes an output connector 808 physically coupled to a second portion of the light combiner opposite the first portion. Display light coupled in through the input connector 806 and out through the output connector 808 may originate from an optical engine 908, which may include a display light source 910, such as a projector, a scanning laser projector, a microdisplay, or other display light source, as described above. As non-limiting examples, the connectors 806 and 808 may include one or more of a diffraction grating, a hologram, a holographic optical element, a volume diffraction grating, a surface relief diffraction grating, and the like. The connectors 806 and 808 may also be reflective connectors or transmissive connectors. As an example, structure 802 may include a right eye lens, and in connector 806 may be located near the edge of the eye lens near a display source (e.g., a projector), and out connector 806 may be located toward the center of the eye lens so that a viewer can see light from light combiner 902 while looking straight ahead or approximately straight ahead. Additionally, in at least some embodiments, Fig. 9 The components shown may be used for one eye of a user, and a similar or identical set of components may be provided for the user's other eye to provide a binocular display.

[0075] In the example shown, the optical engine 908 includes a selective polarization optic (SPO) 912 located in front of a light source 910 (e.g., a microdisplay, a scanned beam). The selective polarization optic 912 can be formed of a liquid crystal material, such as the multi-twist retarder (MTR) discussed above, and can be similar or identical to the spatially varying polarizers discussed elsewhere herein. Typically, light from the display source that exits the selective polarization optic is collimated by a collimator 914 and then interacts with the input connector 806 to be directed by the light combiner 902. The light combiner 902 provides optical correction and transmits the light to the output connector 808, where light 920 exits the light combiner 902 and presents an image to the user's eye 810.

[0076] More specifically, the selective polarization optical device 912 receives light 916 including multiple wavelengths or colors C1, C2, C3 (e.g., red, green, blue). The selective polarization optical device 912 is used to receive light 916 from the display light source 910 and output light 918 of a first color (C1) in a first polarization state (P1) and light of at least a second color (C2 or C3) in a second polarization state (P2), the second polarization state being orthogonal to the first polarization state. As a non-limiting example, the selective polarization optical device 912 can convert red light (C1) to a p-polarization state (P1), and can convert green light (C2) and blue light (C3) to an s-polarization state (P2).

[0077] The optical combiner 902 includes a first polarization-sensitive diffractive optical element (PSDOE) 904 and a second polarization-sensitive diffractive optical element 906. Each of the first and second polarization-sensitive diffractive optical elements can be formed of a liquid crystal material, such as a multi-twist retarder, and can be similar to or the same as the spatially varying polarizers discussed elsewhere herein. The first polarization-sensitive diffractive optical element 904 includes a first diffraction pattern that diffracts light of a first polarization state (P1) and passes light of a second polarization state (P2) without diffraction. Similarly, the second polarization-sensitive diffractive optical element 906 includes a second diffraction pattern that diffracts light of a second polarization state (P2) and passes light of the first polarization state (P1) without diffraction. The first diffraction pattern is designed to provide an optimized correction for a first color (C1), and the second diffraction pattern is designed to provide an optimized correction for at least a second color (e.g., C2 and / or C3).

[0078] As described above, it may be difficult to design a diffractive optical element that provides acceptable correction at all desired wavelengths (e.g., 380 to 740 nanometers). By polarizing the light from the light source 910 according to color, each of the first and second polarization-sensitive diffractive optical elements 904 and 906 can be optimized for a narrower wavelength range, which allows more design freedom and is ultimately better corrected by the entire light combiner 902. Continuing with the above example, the first polarization-sensitive diffractive optical element 904 can be optimized only for red light (C1) in the first polarization state (P1) because the first polarization-sensitive diffractive optical element will not see green light or blue light in the second polarization state (P2). Similarly, the second polarization-sensitive diffractive optical element 906 can be optimized only for green light (C2) and blue light (C3) in the second polarization state (P2) because the second polarization-sensitive diffractive optical element will not see red light (C1) in the first polarization state (P1).

[0079] Fig.10 1 is a schematic diagram of a display system 1000 for an augmented reality system that uses polarization multiplexing to provide a waveguide structure optimized over the entire or all field of view of the display system. Display system 1000 includes some components that are similar or identical to those of the display systems described above, which are identified by the same reference numerals. Display system 1000 may include a lens or support structure 802 (e.g., a prescription or non-prescription eyeglass lens). Light combiner structure 1002 may be at least partially embedded in structure 802 (e.g., a lens) or positioned near the structure (e.g., before or after the structure). Light combiner 1002 may be a rectangular (or other shaped) structure formed of a material having a refractive index that is sufficiently different from the refractive index of the surrounding structure (e.g., structure 802) to provide total internal reflection within at least a portion of the light combiner.

[0080] To enable light to be coupled into the light combiner 1002, the display system 1000 includes an input connector 806 physically coupled to a first portion of the light combiner 1002. Similarly, to enable light to be coupled out of the light combiner 1002 toward an eye 810 of an observer, the display system 1000 includes an output connector 808 physically coupled to a second portion of the light combiner opposite the first portion. Display light coupled in through the input connector 806 and out through the output connector 808 may come from an optical engine 1008, which may include a display light source 1010, such as a projector, a scanning laser projector, a microdisplay, or other display light source, as described above. As non-limiting examples, the connectors 806 and 808 may include one or more of a diffraction grating, a hologram, a holographic optical element, a volume diffraction grating, a surface relief diffraction grating, and the like. The connectors 806 and 808 may also be reflective connectors or transmissive connectors. As an example, structure 802 may include a right eye lens, and in connector 806 may be located near the edge of the eye lens near a display source (e.g., a projector), and out connector 806 may be located toward the center of the eye lens so that a viewer can see light from light combiner 1002 while looking straight ahead or approximately straight ahead. In addition, in at least some embodiments, Fig.10 The components shown may be used for one eye of a user, and a similar or identical set of components may be provided for the user's other eye to provide a binocular display.

[0081] In the example shown, the optical engine 1008 includes a selective polarization optic (SPO) 1012 located in front of a light source 1010 (e.g., a microdisplay, a scanned beam). The selective polarization optic 1012 can be formed of a liquid crystal material, such as a multi-twist retarder (MTR). Typically, light from the display source that exits the selective polarization optic 1012 is collimated by a collimator 1014 and then interacts with the connector 806 to be directed by the light combiner 1002. The light combiner 1002 provides optical correction and transmits the light to the output connector 808, where light 1020 exits the light combiner 1002 and presents an image to the user's eye 810.

[0082] More specifically, the selective polarization optical device 1012 receives light 1016 including multiple wavelengths or colors C1, C2, C3 (e.g., red, green, blue) that span the entire or entire field of view to be provided to the user's eye 810. The selective polarization optical device 1012 is used to receive light 1016 from the display light source 1010 and output light 1018 within a first field of view portion (FOV1) in a first polarization state (P1) and light 1019 within a second field of view portion (FOV2) in a second polarization state (P2), the second polarization state being orthogonal to the first polarization state. As a non-limiting example, the selective polarization optical device 1012 can convert light on axis and within a narrow angular range (e.g., within 20 degrees off-axis) to a p-polarization state (P1), and can convert light in the entire field of view outside the narrow angular range to an s-polarization state (P2). Fig.11A An example full field of view 1100 of an HMD system is shown including a first field of view portion 1102 having a narrow angular range surrounded by a second field of view portion 1104 . Fig. 11B Another example of an overall field of view 1100 is shown including a first field of view portion 1106 located adjacent a second field of view portion 1108. It should be appreciated that the illustrated embodiment is provided by way of example only and that other configurations of first and second field of view portions may be used.

[0083] The optical combiner 1002 includes a first polarization-sensitive diffractive optical element (PSDOE) 1004 and a second polarization-sensitive diffractive optical element 1006. Each of the first and second polarization-sensitive diffractive optical elements can be formed of a liquid crystal material, such as a multi-twist retarder. The first polarization-sensitive diffractive optical element 1004 includes a first diffraction pattern that diffracts light of a first polarization state (P1) and passes light of a second polarization state (P2) without diffraction. Similarly, the second polarization-sensitive diffractive optical element 1009 includes a second diffraction pattern that diffracts light of a second polarization state (P2) and passes light of a first polarization state (P1) without diffraction. The first diffraction pattern is designed to provide an optimized correction for a first field of view portion (FOV1), and the second diffraction pattern is designed to provide an optimized correction for a second field of view portion (FOV2).

[0084] As described above, it may be difficult to design a diffractive optical element that provides acceptable correction over the entire field of view of a display system. By polarizing the light from the light source 1010 according to a portion of the field of view of the entire field of view, each of the first and second polarization-sensitive diffractive optical elements 1004 and 1006 can be optimized for a smaller field of view, which allows for more design freedom and ultimately better correction by the entire light combiner 1002. Continuing with the above example, since the first polarization-sensitive diffractive optical element will not see light in a wide field of view (FOV2) in the second polarization state (P2), the first polarization-sensitive diffractive optical element 1004 can be optimized only for a narrow field of view (FOV1) in the first polarization state (P1). Similarly, since the second polarization-sensitive diffractive optical element will not see light in a narrow field of view (FOV1) in the first polarization state (P1), the second polarization-sensitive diffractive optical element 1006 can be optimized only for light in a wide field of view (FOV2) in the second polarization state (P2).

[0085] In at least some embodiments, a controller (e.g., controller 612) can be operably connected to the selective polarization optical device and / or the polarization-sensitive diffractive optical element to selectively change their spatially correlated phase delay to any desired configuration. In such embodiments, one or more thin-film transistor layers can be provided that allow for selective control of the spatially correlated phase delay of the element. The controller can control the phase delay at any desired rate, such as only once, periodically, at a rate equal to the frame rate of the display system or a fraction thereof, etc.

[0086] By using the spatially varying polarizers discussed herein, optical designers have significantly greater freedom to produce optical systems with improved performance and efficiency, which allows display systems to provide a better viewing experience, be less costly, be smaller in size or weight, consume less power, and provide other advantages that will be apparent to those skilled in the art.

[0087] The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments according to the above detailed description. In general, in the following claims, the terms used should not be interpreted as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted as including all possible embodiments and the full range of equivalents granted by these claims. Therefore, the claims are not limited by this disclosure.

Claims

1. A head-mounted display system, comprising: Support structure; as well as A display system connected to the support structure, the display system comprising: Display light source; a selective polarization optical device for receiving light having a total field of view from the display light source and outputting light of a first field of view portion of the total field of view in a first polarization state and light of a second field of view portion of the total field of view in a second polarization state, the second polarization state being orthogonal to the first polarization state; and a light combiner positioned to receive light from the selective polarization optics and provide an image to an eye of an observer, the light combiner comprising: a first polarization-sensitive diffractive optical element PSDOE, the first polarization-sensitive diffractive optical element comprising a first diffraction pattern, the first diffraction pattern diffracting light of the first polarization state and passing light of the second polarization state without diffraction, the first diffraction pattern providing optimized correction for the first field of view portion; and A second PSDOE, the second PSDOE comprising a second diffraction pattern, the second diffraction pattern diffracting light of the second polarization state and allowing light of the first polarization state to pass without diffraction, the second diffraction pattern providing optimized correction for the second field of view portion.

2. The head mounted display system according to claim 1, wherein: The first field of view portion includes an angular range of 0 degrees to M degrees, and the second field of view portion includes an angular range of M degrees to N degrees, wherein N is the angular range of the field of view of the head-mounted display system, and M is less than N.

3. The head mounted display system according to claim 1, wherein: The first field of view portion and the second field of view portion combine to form the total field of view.

4. The head mounted display system according to claim 1, wherein: The first field of view is partially surrounded by the second field of view.

5. The head mounted display system according to claim 1, wherein: The first field of view portion includes a first half of the total field of view, and the second field of view portion includes a second half of the total field of view.

6. The head mounted display system according to claim 1, wherein: The first field of view portion and the second field of view portion at least partially overlap each other.

7. The head mounted display system according to claim 1, wherein: Each of the selective polarization optics, the first PSDOE, and the second PSDOE includes a multi-twist retarder.

8. The head mounted display system according to claim 1, wherein: At least one of the selective polarization optics, the first PSDOE, and the second PSDOE comprises a multi-twist retarder.

9. The head mounted display system according to claim 1, wherein: At least one of the selective polarization optics, the first PSDOE, and the second PSDOE includes a liquid crystal material.

10. The head mounted display system according to claim 1, wherein: The optical combiner includes an input connector and an output connector.

11. The head mounted display system according to claim 1, wherein: The support structure includes an eyeglass lens.

12. The head mounted display system according to claim 1, wherein: The display light source includes a laser scanning beam system or a micro display.

13. A light combiner for receiving light and providing an image to an eye of an observer, the light combiner comprising: a first polarization-sensitive diffractive optical element PSDOE, the first polarization-sensitive diffractive optical element comprising a first diffraction pattern, the first diffraction pattern diffracting light of a first polarization state and passing light of a second polarization state without diffraction, the first diffraction pattern providing an optimized correction for a first field of view portion of the total field of view; as well as A second PSDOE, the second PSDOE comprising a second diffraction pattern, the second diffraction pattern diffracting light of the second polarization state and allowing light of the first polarization state to pass without diffraction, the second diffraction pattern providing optimized correction for a second field of view portion of the total field of view.

14. The optical combiner according to claim 13, wherein: The first field of view portion includes an angular range of 0 degrees to M degrees, and the second field of view portion includes an angular range of M degrees to N degrees, wherein N is the angular range of the field of view of the head-mounted display system, and M is less than N.

15. The optical combiner according to claim 13, wherein: The first field of view portion and the second field of view portion combine to form the total field of view.

16. The optical combiner according to claim 13, wherein: The first field of view is partially surrounded by the second field of view.

17. The optical combiner according to claim 13, wherein: The first field of view portion includes a first half of the total field of view, and the second field of view portion includes a second half of the total field of view.

18. The optical combiner according to claim 13, wherein: The first field of view portion and the second field of view portion at least partially overlap each other.

19. The optical combiner according to claim 13, wherein: Each of the first PSDOE and the second PSDOE includes a multi-twist delay.

20. The optical combiner of claim 13, wherein: At least one of the first PSDOE and the second PSDOE includes a multi-twist delay.

21. The optical combiner of claim 13, wherein: At least one of the first PSDOE and the second PSDOE includes a liquid crystal material.

22. The optical combiner of claim 13, wherein: The optical combiner also includes an input connector and an output connector.

23. The optical combiner of claim 13, wherein: The light combiner is supported by a support structure comprising eyeglass lenses.

24. A head mounted display system, comprising: Display system, including: Display light source; a selective polarization optical device for receiving light having a total field of view from the display light source and outputting light of a first field of view portion of the total field of view in a first polarization state and light of a second field of view portion of the total field of view in a second polarization state, the second polarization state being orthogonal to the first polarization state; and a light combiner positioned to receive light from the selective polarization optics and provide an image to an eye of an observer, the light combiner comprising: a first polarization-sensitive diffractive optical element PSDOE, the first polarization-sensitive diffractive optical element comprising a first diffraction pattern, the first diffraction pattern diffracting light of the first polarization state and passing light of the second polarization state without diffraction, the first diffraction pattern providing optimized correction for the first field of view portion; and A second PSDOE, the second PSDOE comprising a second diffraction pattern, the second diffraction pattern diffracting light of the second polarization state and allowing light of the first polarization state to pass without diffraction, the second diffraction pattern providing optimized correction for the second field of view portion.

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