Systems and methods for integrating into vehicle virtual display systems using field-emitting cavities and curved components

Abstract

In some embodiments, a display system and method for generating a virtual or light field image includes a display and a field-emitting cavity. The field-emitting cavity modulates the optical depth of the virtual image. In some embodiments, the components of the display system are curved. The focal plane of the virtual image is curved and can approximate a portion of a human horopter. In some embodiments, the display system is integrated into a portion of a vehicle. The components of the display system can move relative to each other such that the display system is foldable or bendable when not in use.

Description

[Technical Field]

[0001] This application claims priority to application no. PCT / US23 / 83862, filed December 13, 2023, entitled "Systems and Methods for Integrating Virtual Display Systems Using Field Evolving Cavities Integrated in a Vehicle," which is incorporated herein by reference in its entirety.

[0002] The present invention relates generally to light field displays, and more particularly to a system for creating compact light field displays through various optical depths. [Background technology]

[0003] In today's society, advances in electronics and microfabrication have led to increased traction for more immersive light-field and / or autostereoscopic three-dimensional (3D) displays. Unlike stereoscopic 3D, light-field displays manipulate wavefronts to generate depth perception at the monocular level. This can eliminate accommodation-vergence mismatch and reduce eye strain. Breakthroughs have been made to realize more realistic light-field experiences, which can be described by four main methods for creating such experiences, each with its own weaknesses and advantages: super multi-view display, computational, multifocal, and holographic. Super multi-view display methods provide light fields in a very compact form but are limited to very small viewing zones and low resolution. Computational methods increase resolution but produce haze and temporal flicker artifacts. Holographic methods can suffer from color non-uniformity and fringing or specular artifacts. Multifocal methods are not scalable but can produce clean images. Additionally, devices using multifocal methods can be bulky. However, common to all current light field display methods are the following problems: wide bandwidth requirements; dependence on expensive and / or sophisticated components that are not easily mass-produced, such as adjustable lenses; poor color uniformity, small field of view or viewing zone, low brightness, haze and diffraction artifacts, limited depth range; and the possible need to wear special glasses. These challenges significantly limit the use or manufacture of light field displays in commercial and / or industrial settings. Therefore, what is needed, in some embodiments, is a complete class of optical methods that use a set of reflectors positioned within a cavity to multiplex different liquid crystal displays (LCDs) or different portions of a single LCD onto different optical focal planes. This allows the light field within the cavity to adapt to a certain optical depth before exiting the cavity's exit pupil, while solving the aforementioned problems associated with other light field display methods.

[0004] The present invention aims to provide users with a device that is a compact system for creating light field displays at or through various optical depths. The present invention is intended to provide users with a device that addresses the aforementioned problems associated with current methods of light field display. The present invention is intended to provide users with a device that is less expensive and easier to manufacture at or for commercial and / or industrial levels. The present invention is intended to provide users with a device that reduces artifacts without reducing the clarity of the light field display. The present invention is intended to provide users with a device that allows users to generate content for a light field display more easily than conventional stereoscopic displays. The present invention is intended to provide users with a device that does not require additional accessories or specialized components (e.g., special glasses or a rendering engine) to be utilized by the user to view the content of the light field display. The present invention is intended to provide users with a device that can reduce the optical path difference to each focal plane of a light field display and minimize light loss from polarized light. The present invention is intended to provide users with a device that can change the display focal plane without any mechanical movement. Summary of the Invention

[0005] The present invention is a system for creating a compact light field display through various optical depths. The present invention primarily includes a housing. The housing contains multiple panels in various arrangements that enable the present invention to generate light field displays of various degrees or ranges. The present invention also includes a relay panel. The present invention includes a cover case over the housing.

[0006] Achieving accurate light field displays typically requires sophisticated optical structures using costly light sources and spatial modulators, such as laser scanners, tunable lenses, liquid crystal-on-silicon (LCoS) reflectors, or digital micromirror devices (DMDs). Therefore, these existing methods do not provide true optical depth. This means that there are wavefront inaccuracies in the form of diffractive color inaccuracies, speckle, or haze. One class of display systems and methods revolves around the concept of field-emission (FE) cavities. These cavities prepare light to provide true optical depth without wavefront distortion, and therefore, the images provided by such systems are as accurate as conventional display panels. This method uses conventional LCD or organic light-emitting diode (OLED) panel displays in a manner that provides multiple optical focal planes simultaneously or sequentially, in opaque or intensified (transparent) devices. The systems can also be conveniently packaged in small form factors well suited for desktop applications. The cavities provide regular two-dimensional (2D) images and optically combine them into a 3D light field, eliminating the need for a complex rendering engine. The method is also scalable to large scale displays for commercial use.

[0007] In some embodiments, a system includes: a curved display for emitting light; a field emission cavity for directing light from the display along a path to generate a virtual image. The field emission cavity has: a semi-reflector positioned along the path; a curved reflector positioned along the path to reflect the light; and an aperture optical element for transmitting the light away from the field emission cavity. The path traverses the semi-reflector at least two times.

[0008] In some embodiments, the system further comprises a vehicle, and the curved display and field emission cavity are mounted to a portion of the vehicle.

[0009] In some embodiments, the part of the vehicle is selected from the group consisting of a seat, a roof, a center console, or a dashboard.

[0010] In some embodiments, the curved display and field emission cavity are attached using a mechanical joint that allows relative movement between (i) the portion and (ii) the curved display and field emission cavity.

[0011] In some embodiments, the mechanical joint is selected from the group consisting of a hinge, a track, a ball joint, a gimbal joint, an extension joint, an articulated arm, a mechanical linkage, and combinations thereof.

[0012] In some embodiments, the aperture optic comprises an absorptive polarizer and an anti-reflective layer.

[0013] In some embodiments, at least two of the curved display, the curved reflector, and the semi-reflector are joined by a mechanical joint such that the system is at least partially foldable.

[0014] In some embodiments, at least one of the curved display, the semi-reflector, the aperture optic, and the curved reflector is flexible.

[0015] In some embodiments, the system further comprises a handle for controlling the mechanical joint.

[0016] In some embodiments, the system further comprises an interaction interface for controlling the position or orientation of the virtual image.

[0017] In some embodiments, the system further comprises: a housing containing the curved display and the field emission cavity; a mechanical joint that allows relative movement between (i) the portion and (ii) the curved display and the field emission cavity; and a handle, the mechanical joint operably connected to the housing and the portion of the vehicle, and the handle operably connected to the housing such that a user can use the handle to move the position or orientation of the housing relative to the vehicle.

[0018] In some embodiments, the system further comprises an interaction interface for controlling the position or orientation of the virtual image.

[0019] In some embodiments, the aperture optic comprises a quarter wave plate.

[0020] In some embodiments, the lateral size of the virtual image is 1 to 3 times the lateral size of the curved display.

[0021] In some embodiments, the depth of the virtual image to the headbox is 1 to 3 times greater than the distance from the headbox to the curved display.

[0022] In some embodiments, the semi-reflector and the curved display are oriented at an angle to each other in the range of 35 to 55 degrees.

[0023] In some embodiments, the content on the curved display is entertainment content.

[0024] In some embodiments, the curved display is not in the viewer's direct line of sight.

[0025] In some embodiments, the virtual image focal plane approximates the human horopter.

[0026] In some embodiments, the system has a mass of between 1500 and 5000 grams.

[0027] In some embodiments, the display content is pre-compensated to mitigate distortions produced by the system.

[0028] In some embodiments, the system further comprises a quarter wave plate disposed along the optical path, and the semi-reflector is a polarization dependent semi-reflector.

[0029] In some embodiments, the system further comprises a camera for capturing information about the viewer.

[0030] In some embodiments, a system includes a display housing for a portable display device, the display housing having an entrance opening for directing light from the portable display device to a field emission cavity, the field emission cavity having a semi-reflector positioned to direct the incident light thereon, the system further including a reflector, wherein when a portable display device displaying content is placed within the display housing, a virtual image based on the content is generated.

[0031] In some embodiments, the display housing is shaped to accommodate a tablet, smartphone, or laptop.

[0032] In some embodiments, the system further comprises a vehicle, and the display housing and the field emission cavity are mounted to the vehicle.

[0033] In some embodiments, the display housing and the field emission cavity are attached to the vehicle via a mechanical joint.

[0034] In some embodiments, the mechanical joint is selected from the group consisting of a hinge, a track, a ball joint, a gimbal joint, an expansion joint, and a mechanical linkage.

[0035] In some embodiments, the system further comprises an interactive interface for controlling content and system parameters.

[0036] In some embodiments, the display housing includes a plurality of adjustable clamps for setting the position of the portable display device based on information about the portable display device.

[0037] In some embodiments, the system includes: a housing; a field emission cavity mounted within the housing for directing light from a light source along a path to generate a virtual image based on the light source, the field emission cavity having an entrance aperture for receiving the light; a semi-reflector positioned along the path; a curved reflector positioned along the path to reflect the light; and an aperture optical element for transmitting the light away from the field emission cavity, the path traversing the semi-reflector at least two times.

[0038] In some embodiments, the system further comprises a vehicle, and the housing is mounted to the vehicle.

[0039] In some embodiments, the system further comprises a light source, the light source being a curved display mounted within the housing and arranged to emit light through an entrance aperture into the field-generating cavity.

[0040] In some embodiments, the depth of the virtual image to the headbox is greater than the distance between the curved display and the headbox.

[0041] In some embodiments, the lateral size of the virtual image is greater than the lateral size of the curved display.

[0042] In some embodiments, the system further comprises a web camera for capturing information about the viewer. [Brief explanation of the drawings]

[0043] The patent on file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0044] The following description, with reference to the accompanying drawings, illustrates in greater detail aspects of embodiments of the disclosed apparatus, methods, and systems, by way of example, which are intended to be non-limiting and illustrative. [Figure 1] 1 illustrates a light field display based on a three-layer field emission cavity; a non-limiting example of a 3D model of a three-layer light field display prototype is shown, with a front view shown on the left, a rear top view shown in the center, and a front side view shown on the right. [Figure 2] 1 shows a generalized block diagram of a cavity-based light field system in the present disclosure. A block diagram of an FE cavity-based light field display system is shown, in which the cavity generates light at multiple focal planes, feeds it to a relay mechanism, and then projects it to the outside world. [Figure 3A] Illustrated is an example of a Class I FE cavity with a primary exit pupil. The display is arranged in one dimension or axis (either vertical or horizontal), and light from each layer bounces from each reflector exactly once. This means there is no round trip or loop that the light travels before exiting the cavity. Non-limiting examples of different designs under the Class I FE cavity category are shown, ranging from simple layers to more complex multi-layers. [Figure 3B] Illustrated is an example of a Class I FE cavity with a primary exit pupil. The display is arranged in one dimension or axis (either vertical or horizontal), and light from each layer bounces from each reflector exactly once. This means there is no round trip or loop that the light travels before exiting the cavity. Non-limiting examples of different designs under the Class I FE cavity category are shown, ranging from simple layers to more complex multi-layers. [Figure 3C] Illustrated is an example of a Class I FE cavity with a primary exit pupil. The display is arranged in one dimension or axis (either vertical or horizontal), and light from each layer bounces from each reflector exactly once. This means there is no round trip or loop that the light travels before exiting the cavity. Non-limiting examples of different designs under the Class I FE cavity category are shown, ranging from simple layers to more complex multi-layers. [Figure 4] This figure shows an example of a Class II FE cavity with a first-order exit pupil, such that Class II displays can be arranged in two dimensions (both horizontally and vertically) to form the cavity. The term "first-order" refers to the fact that light bounces off each mirror or reflector no more than once. This is an example of a more complex Class II FE cavity, showing how multiple displays can be incorporated along two axes to avoid the loss of spatial resolution that occurs when splitting displays within a Class I cavity. The orange arrows indicate the luminous flux exiting the cavity pupil. [Figure 5] Examples of Class I and Class II FE cavities are shown with first- and second-order exit pupils designed to reduce the optical path difference to each focal plane and minimize light loss; "second-order" means that light can bounce off the reflector up to two times. Examples of FE cavities with higher-order exit pupils are shown, designed to reduce the optical path difference to each focal plane and minimize light loss by using polarization. [Figure 6] An example of an FE cavity with a dynamically translating (mechanically translating) part used to adjust or sweep the focal plane through a range of depths is shown. An example of an FE cavity with a mechanically translating part is shown to dynamically adjust or sweep the focal plane through a range of depths. [Figure 7]An example of an FE cavity with a switchable mirror element and a switchable diffuser for changing the focal depth of the exiting light is shown. An example of a display cavity is shown that uses a switchable mirror (profiles 22 and 23 in FIG. 6) and a switchable diffuser (profile 24 in FIG. 6) to change the display focal plane without overall mechanical motion. [Figure 8] An example is shown that uses a switchable liquid crystal layer to switch the path that light takes inside different sections of the FE cavity.An example of an FE cavity is shown that uses a switchable liquid crystal layer to change the display focal plane without any mechanical movement. [Figure 9] Examples of wedge-type (or angled) FE cavities used to generate multiple focal planes are shown, in which the display panel normal vectors may be at angles other than multiples of 90 degrees relative to each other. Examples of compact Class I and II wedge cavities used to generate multiple focal planes in smaller form factors are shown. [Figure 10] Examples are given in which one or all of the depths are shifted using slabs or prisms with higher refractive index. It is also shown how prismatic films can improve the brightness at the focal plane. Examples are given in which materials with different refractive indexes within the cavity volume or prismatic films are used to passively adjust or enhance the depth and brightness at the focal plane. [Figure 11] Examples of relay systems used to relay light from the cavity to the outside world are shown. The display can be used as a far-standing display or very close to the head, such as on a desktop. The relay can be fully transparent or opaque, curved or flat, with one piece or multiple switching sections. Illustrated is how the output of the display cavity can be relayed to a viewer as part of an entertainment system or magnified monitor. The left column shows entertainment system modalities, while the right column shows magnified near-head display modalities. [Figure 12]We present an example of a compressed FE cavity based on a switchable mirror. The cavity thickness (L) can be reduced by sequentially turning on and off the reflectors. We demonstrate how a compressed architecture with a switchable mirror in a Class I FE cavity can compress the system size. [Figure 13] This shows an exploded view of a prototype model of a three-layer light field display. A 3D model of the prototype system is shown. The left panel is the back of the exploded model, and the right panel is the front of the display, with the light field emerging from the green reflector on top. [Figure 14A] 1 shows an embodiment in which an aperture optical element is placed at the cavity exit pupil of a field-emitting cavity. [Figure 14B] 1 illustrates an embodiment in which an aperture optical element is located at the enclosure exit pupil of the system enclosure. [Figure 15] 1 illustrates an embodiment of a field emission cavity in which elements of the present invention are configured as a light pipe that is segmented to produce multiple depths or images. [Figure 16] An embodiment of the invention is shown in which a field emission cavity is in optical communication with a mirror, which produces a virtual image at the same depth as or closer to the viewer's reflection. [Figure 17] 1 illustrates an embodiment of the present invention in which a field emission cavity is integrated into the roof of a vehicle. [Figure 18A] Various embodiments of the display system shown in FIG. 17 are shown, which use polarization dependent reflectors or semi-reflectors. [Figure 18B] Various embodiments of the display system shown in FIG. 17 are shown, which use polarization dependent reflectors or semi-reflectors. [Figure 18C] Various embodiments of the display system shown in FIG. 17 are shown, which use polarization dependent reflectors or semi-reflectors. [Figure 18D]Various embodiments of the display system shown in FIG. 17 are shown, which use polarization dependent reflectors or semi-reflectors. [Figure 18E] Various embodiments of the display system shown in FIG. 17 are shown, which use polarization dependent reflectors or semi-reflectors. [Figure 18F] Various embodiments of the display system shown in FIG. 17 are shown, which use polarization dependent reflectors or semi-reflectors. [Figure 19A] 1 illustrates exemplary ways in which a display system may be integrated into a vehicle, including mechanically articulated or motorized couplings. [Figure 19B] 1 illustrates exemplary ways in which a display system may be integrated into a vehicle, including mechanically articulated or motorized couplings. [Figure 19C] 1 illustrates exemplary ways in which a display system may be integrated into a vehicle, including mechanically articulated or motorized couplings. [Figure 19D] 1 illustrates exemplary ways in which a display system may be integrated into a vehicle, including mechanically articulated or motorized couplings. [Figure 19E] 1 illustrates exemplary ways in which a display system may be integrated into a vehicle, including mechanically articulated or motorized couplings. [Figure 19F] 1 illustrates exemplary ways in which a display system may be integrated into a vehicle, including mechanically articulated or motorized couplings. [Figure 20A] 1 illustrates an exemplary application of the disclosed display system and field emission cavity. [Figure 20B] 1 illustrates an exemplary application of the disclosed display system and field emission cavity. [Figure 20C] 1 illustrates an exemplary application of the disclosed display system and field emission cavity. [Figure 20D] 1 illustrates an exemplary application of the disclosed display system and field emission cavity. [Figure 20E]1 illustrates an exemplary application of the disclosed display system and field emission cavity. [Figure 21A] 1 illustrates an embodiment of a display system that uses a field-emitting cavity or curved elements in a curved display panel. [Figure 21B] 1 illustrates an embodiment of a display system that uses a field-emitting cavity or curved elements in a curved display panel. [Figure 21C] 1 illustrates an embodiment of a display system that uses a field-emitting cavity or curved elements in a curved display panel. [Figure 21D] 1 illustrates an embodiment of a display system that uses a field-emitting cavity or curved elements in a curved display panel. [Figure 21E] 1 illustrates an embodiment of a display system that uses a field-emitting cavity or curved elements in a curved display panel. [Figure 21F] 1 illustrates an embodiment of a display system that uses a field-emitting cavity or curved elements in a curved display panel. [Figure 21G] 1 illustrates an embodiment of a display system that uses a field-emitting cavity or curved elements in a curved display panel. [Figure 21H] 1 illustrates an embodiment of a display system that uses a field-emitting cavity or curved elements in a curved display panel. [Figure 22A] 1 shows a table of various types of movement of a display system in a vehicle. [Figure 22B] 1 shows a table of various types of movement of a display system in a vehicle. [Figure 23A] 1 illustrates various embodiments of the general location of a display system within a vehicle and some mechanisms for coupling the display system to the vehicle. [Figure 23B] 1 illustrates various embodiments of the general location of a display system within a vehicle and some mechanisms for coupling the display system to the vehicle. [Figure 23C] 1 illustrates various embodiments of the general location of a display system within a vehicle and some mechanisms for coupling the display system to the vehicle. [Figure 23D] 1 illustrates various embodiments of the general location of a display system within a vehicle and some mechanisms for coupling the display system to the vehicle. [Figure 23E] 1 illustrates various embodiments of the general location of a display system within a vehicle and some mechanisms for coupling the display system to the vehicle. [Figure 23F] 1 illustrates various embodiments of the general location of a display system within a vehicle and some mechanisms for coupling the display system to the vehicle. [Figure 24A] Further exemplary mechanical coupling mechanisms are shown, including telescoping arms, articulating joints and arms, and hinges. [Figure 24B] Further exemplary mechanical coupling mechanisms are shown, including telescoping arms, articulating joints and arms, and hinges. [Figure 24C] Further exemplary mechanical coupling mechanisms are shown, including telescoping arms, articulating joints and arms, and hinges. [Figure 24D] Further exemplary mechanical coupling mechanisms are shown, including telescoping arms, articulating joints and arms, and hinges. [Figure 24E] Further exemplary mechanical coupling mechanisms are shown, including telescoping arms, articulating joints and arms, and hinges. [Figure 25A] 1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 25B] 1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 25C] 1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 25D] 1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 25E]1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 25F] 1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 25G] 1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 25H] 1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 25I] 1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 25J] 1 illustrates various locations within a vehicle where a display system may be integrated. [Figure 26A] 1 illustrates a typical method of rotating display system components used for a foldable display system in a vehicle. [Figure 26B] 1 illustrates a typical method of rotating display system components used for a foldable display system in a vehicle. [Figure 26C] 1 illustrates a typical method of rotating display system components used for a foldable display system in a vehicle. [Figure 27A] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27B] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27C] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27D] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27E]10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27F] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27G] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27H] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27I] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27J] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27K] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27L] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27M] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27N] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 27O] 10A-10C illustrate various mechanisms for articulating components of a display system to produce a foldable or curved display system. [Figure 28] 1 illustrates an exemplary embodiment of a display system controlled by an interactive interface. DETAILED DESCRIPTION OF THE INVENTION

[0045] All illustrations in the drawings are for the purpose of illustrating selected versions of the invention and are not intended to limit the scope of the invention.

[0046] In traditional binocular or stereoscopic vision, a display system provides two offset images to a viewer's left and right eyes separately. These two-dimensional images are then combined in the viewer's brain, along with the accommodation of the eye lenses, to give the viewer the perception of 3D depth. If the true optical depth (wavefront curvature) does not match the parallax provided by the stereoscopic image, the viewer experiences a slightly uncomfortable inaccuracy. This is because the lenses in his / her eyes tell the brain that the image is at a certain distance, while the parallax tells the brain that it is different. This is known as accommodation-vergence mismatch. Lightfield display systems modify the wavefront to provide both parallax and accommodation cues. Traditional methods of providing lightfield displays have been limited by cost, image accuracy, bandwidth, the need to wear a headset or glasses, bulkiness, and manufacturability.

[0047] To overcome this trade-off between perceived content realism and manufacturability, this invention uses a field-emission cavity built around a conventional LCD or OLED panel display to generate digital content at one or more display focal depths, which is then relayed to the outside world. This approach does not require adjustable lenses or powerful computational rendering engines; it does not necessarily rely on freeform optics, can be manufactured cost-effectively, and provides a light-field experience to any number of users within a large viewing zone.

[0048] general purpose The present invention provides a multi-layered light field experience with image accuracy comparable to high-quality displays in a mass-producible manner. The objective of the present invention is to realize a compact, practical, transparent or opaque light field display that does not suffer from accommodation-vergence conflicts and provides true optical depth. Such displays have widespread utility in a variety of contexts, as further detailed below. Light fields can be used as entertainment displays for commercial applications or in industrial use cases, such as navigation or biomedical use cases. In near-head use cases, the present invention provides a virtual depth or optical space that can appear like a virtual window and provide a sense of scale, despite having small pupils. For example, the present invention can magnify a 13-inch exit pupil located 10 inches from the head to appear as a 60-inch monitor located 3 meters away from the user.

[0049] In a preferred embodiment, the present invention comprises a system enclosure 5, a field-emitting cavity 1, and a relay mechanism 3, as shown in FIGS. 1-13. The system enclosure 5 is used to house other components of the present invention. Accordingly, the field-emitting cavity 1 and the relay mechanism 3 are mounted within the system enclosure 5. The field-emitting cavity 1 is a compact body that serves to modify a light field display. Furthermore, the field-emitting cavity 1 comprises a cavity exit pupil 2, at least one display panel 6, and at least one optical tuning mechanism 7. The display panel 6 generates an initial light field display that is modified by the optical tuning mechanism 7, and the modified light field display is then output by the cavity exit pupil 2. In addition, the display panel 6 and the optical tuning mechanism 7 are configured in a specific optical arrangement that enables the generation of at least one light field display 6 having at least one focal plane along at least one optical path. The optical path specifically traverses from the display panel 6 to the cavity exit pupil 2. The relay mechanism 3 is used to transfer the modified light field display from the cavity exit pupil 2 to the enclosure exit pupil 4 of the system enclosure 5, and thus the cavity exit pupil 2 is in optical communication with the enclosure exit pupil via the relay mechanism 3.

[0050] Figure 1 shows a field-emission cavity 1 for a prototype model of the present invention. The cavity exit pupil 2 is also shown in Figure 1, enclosed by a dashed rectangular frame. The relay mechanism 3, in this case a simple mirror or a switchable mirror, relays the cavity exit pupil 2 to an enclosure exit pupil 4. The enclosure exit pupil 4 also allows light exiting this pupil to reach the user directly without further manipulation. This enclosure exit pupil 4 is also shown in Figure 1 by a dashed rectangular frame.

[0051] Technical explanation Aspects of the disclosed apparatus, methods, and systems describe various methods, systems, components, and techniques that enable the display of digital content at two or more focal planes, contributing to a significant reduction in the size and cost of light field display systems. The disclosed apparatus, methods, and systems function by generating digital content at multiple depths within a field-emitting cavity 1 and relaying this content to a user's eye, as shown in FIG.

[0052] First, digital content is generated within a field-emitting cavity 1 at one or more depths. This can be done in a variety of ways, details of which are described in the section entitled "Field-Emission Cavity Design." A relay mechanism 3 is then used to allow users to view the digital content in different modalities, details of which are described in the section entitled "Relay Mechanism and Application Modalities."

[0053] Furthermore, the techniques described herein can be used in new modalities of near-head displays, as well as in large-scale displays such as desktop monitors, television sets, and head-up displays. Details of this application extension are provided in the section entitled "Relay Mechanisms and Application Modalities." The thickness of the field-emitting cavity 1 can be reduced by using sequential relays inside and outside the field-emitting cavity 1, details of which are described in the section entitled "Compression Design." Details of a non-limiting example of a working prototype are provided in the section entitled "Prototype Model."

[0054] The present invention has four main aspects: (1) the design of the field-emitting cavity 1 required to generate one or more focal planes from one or more display panels; (2) how to generate various adjustable focal planes (i.e., light fields with adjustable planes) by changing the cavity placement or using adjustable mirrors or LCD layers; (3) elaboration of the means for relaying light from the cavity exit pupil 2 to the enclosure exit pupil 4; and (4) elaboration of the compression design and near-head use cases.

[0055] Field emission cavity design To provide true optical depth at different layers of the light field, an optical mechanism is required to prepare or manipulate the curvature of the light wavefront, either true or correct for that depth. The various embodiments of the field-emitting cavity 1 illustrated in Figures 3-13 are cavities or air gaps, each containing at least one display panel 6 (such as a liquid crystal display (LCD), thin film transistor (TFT), light-emitting diode array (LED), organic light-emitting diode array (OLED), active matrix organic light-emitting diode (AMOLED), or projection onto a flat screen or other display) and / or at least one mirror 8 and / or at least one half-mirror 9 and / or multiple switchable mirrors 13 or at least one liquid crystal cell layer 16, positioned and assembled to emit bundles of light with diverging vertices at different depths from the cavity exit pupil 2. These vertices can be from different displays at different depths within the field-emitting cavity 1, or from a single display panel 6 along the entire length of the field-emitting cavity 1. The cavity exit pupil 2 delivers light to a relay mechanism 3, resulting in different or the same reference vertices (depending on the type of relay) of different focal plane divergence that are presented to the user. The relay mechanism 3 may be a simple flat surface, or a freeform curved surface as described further herein, or may be a geometric or diffractive waveguide, or any other suitable relay means. The relay mechanism 3 may be translucent, opaque, or have adjustable transparency (e.g., a switchable mirror).

[0056] Because there are theoretically an infinite number of these types of field-emitting cavities, determining the class of a field-emitting cavity 1 is based on the dimensionality of the display configuration. If all of the display panels 6 are aligned along a single axis (e.g., the y-axis), the field-emitting cavity 1 is defined as Class I. More specifically, the display panels 6 are aligned along a single axis, and the single axis is aligned either perpendicular or parallel to the cavity exit pupil 2. Alternatively, if all of the display panels 6 are aligned in both the x and y dimensions, the field-emitting cavity 1 is Class II. More specifically, multiple display panels 6 are aligned along a pair of axes, where the pair of axes are aligned perpendicular to each other and where each of the pair of axes is aligned either perpendicular or parallel to the cavity exit pupil 2. Furthermore, the order of the cavity exit pupil 2 is the maximum number of times a light beam from any pixel of the display panel 6 is reflected before exiting the cavity exit pupil 2. Any field-emitting cavity 1 having at least one display panel 6 positioned at an angle in x and y that is not a multiple of 90 degrees is still considered a Class II cavity, but is referred to as a Class II wedge cavity or angled cavity. More specifically, the display panel 6 is positioned along an adjustment axis, and the adjustment axis is positioned at an angle relative to the cavity exit pupil 2.

[0057] The following description and drawings in Figures 3-13 provide non-limiting examples of Class I field-emitting cavities that can be used to generate digital content at multiple focal depths using a single display panel 6 or multiple display panels 6 in a parallel arrangement. In all of these configurations, the display panel 6 can use various display technologies, such as OLED, LCD, LED, AMOLED, or any display technology or projection screen that provides a 2D image. In non-limiting examples of these concepts, the display panel 6 can be replaced with an LCoS (Liquid Crystal on Silicon) spatial light modulator illuminated by continuous RGB light, or a DMD (Digital Mirror Device) spatial light modulator illuminated by a display. Therefore, in this disclosure, "display panel" refers to any architecture that provides an array of light that can be focused or collimated to create an image.

[0058] 3-9, the reflector may be a polarization-dependent reflector, a semi-transparent reflector, a thin-film pellicle reflector, a beamsplitter cube, or other suitable reflector. In all of these configurations, light from different portions of the display panel 6 or from different panels 6 may be polarized to increase the output light efficiency of the light emission cavity 1. More specific examples are provided in the figures throughout this disclosure.

[0059] 3A, 3B, and 3C show some non-limiting examples of designs for Class I of field-emission cavities 1. In general, optical tuning mechanism 7 can comprise at least one mirror 8 and at least one beam splitter plate 9. As can be seen from the section of FIG. 3, certain cavity configurations may be arranged to reflect the optical path using mirror 8, and certain cavity configurations may be further arranged to reflect the optical path using beam splitter plate 9, to pass the optical path through beam splitter plate 9, or a combination thereof.

[0060] Section 5 of Figure 3A shows a Class I embodiment of a field-emitting cavity 1 with a single display panel 6 at the bottom, generating only a single depth (included for theoretical support). Light exits the cavity exit pupil 2 directly without bouncing off a reflector or other optical surfaces. This is the zero-order cavity exit pupil 2. The orange arrow indicates the light flux exiting the dashed line, which is the cavity exit pupil 6 in all figures in this disclosure. In all figures, only light exiting the light-emitting cavity 1 is shown with a red or blue arrow. Wasted light is not shown in these drawings for simplicity. Also, for any beamsplitter plate 9, the reflectivity percentage can be selected to maximize brightness uniformity across all layers. This does not change the architecture of the design, and therefore, reflectivity percentages are not specified throughout this disclosure. For simplicity, reflectivity percentages can be assumed to be 50% for all designs.

[0061] Section 6 of FIG. 3A shows an embodiment of a Class I field-emitting cavity 1 with a single display panel 6 on the right wall, generating digital content simultaneously at two different depths. By incorporating a beam splitter plate 9 (a half-mirror sheet) and a mirror 8, light is combined and redirected out of the cavity exit pupil 2. Light from the top of the display panel 6 reflects off the mirror 8, passes through the beam splitter plate 9, and half of its intensity is output through the cavity exit pupil 2. Light from the bottom of the display panel 6 reflects off the beam splitter plate 9, and half of its intensity is directed toward the cavity exit pupil 2. This is therefore a Class I field-emitting cavity 1 of the first order, with the intensity at each focal plane being half of the original intensity of the display panel 6. In some examples of this type of field-emitting cavity 1, one or more of the reflectors can be shifted up or down to change the desired depth output to the cavity exit pupil 2.

[0062] Section 7 of FIG. 3A shows an extension of section 6 of FIG. 3A, in which a single display panel 6 is used to generate digital content simultaneously at three different depths. In some embodiments, the optical efficiency of the field-emission cavity 1 may vary for different depths, and the brightness of the display panel 6 may be adjusted to accommodate this variation. For example, if the beam splitter plate 9 has 50% reflectivity and 50% transmittance, light from the top of the display panel 6 passes through two beam splitter plates 9 and is therefore reduced in intensity to 25% of the display panel's intensity; light from the middle section passes through two beam splitter plates 9 and has 25% of the display panel's intensity, while light from the bottom section passes through only one beam splitter plate 9 and is therefore 50% of the display panel's intensity. To compensate for this variation in intensity across the focal depth, the brightness of the bottom section may be electronically reduced by 50% via a signal provided to the display panel 6. Such brightness adjustment can be applied to the various configurations of Figures 3-13 to provide uniform brightness to different layers of the light field.

[0063] Section 8 of FIG. 3A shows a final extension of section 6 of FIG. 3A, where a single display panel 6 is used to generate digital content at any number of depths.

[0064] Section 9 of Figure 3B shows an extension of section 6 of Figure 3A, in which two field-emitting cavities 1 (each generating content at two depths) are combined to generate digital content at four different depths simultaneously.

[0065] Section 10 of Figure 3B shows an extension of sections 8 and 9 of Figures 3A and 3B, where multiple cavities 1 shown in section 8 of Figure 3A are combined as shown in section 9 of Figure 3B to generate digital content at multiple depths simultaneously.

[0066] Section 11 of FIG. 3C shows an extension of section 9 of FIG. 3, where two display panels 6 are placed back-to-back to provide a more compact form factor.

[0067] FIG. 4 shows a non-limiting example of a design of a class II field-emission cavity 1 with a cavity exit pupil 2.

[0068] Section 12 of Figure 4 shows an embodiment of a simple Class II field-emitting cavity 1 comprising two display panels 6 arranged perpendicular to each other and combined with a single beam splitter plate 9. The advantage of this arrangement is that the two display panels 6 can simultaneously generate digital content at two similar depths. By adjusting the position of one display panel 6, the depth separation between the two focal planes can be easily adjusted.

[0069] Section 13 of Figure 4 shows a simple Class II embodiment of a field emission cavity 1 with four display panels 6 combined to generate digital content simultaneously at four different depths.

[0070] Section 14 of FIG. 4 shows a final extension of section 13 of FIG. 4 to generate digital content at multiple different depths simultaneously.

[0071] Section 15 of Figure 4 shows an embodiment of a simple class II field emission cavity 1 with four central display panels 6 that combine to generate digital content simultaneously at four different depths.

[0072] Section 16 of Figure 4 shows an embodiment of a simple Class II field emission cavity 1 with six display panels 6 combined to generate digital content simultaneously at six different depths.

[0073] FIG. 5 shows examples of a Class I field-emission cavity 1 and a Class II field-emission cavity 1 with higher-order exit pupils 2. These non-limiting examples illustrate how polarization and multiple reflections from the same surface can create a more compact cavity with a larger number of output focal planes. In general, the optical tuning mechanism 7 can further comprise at least one polarization-dependent beam splitter plate 10 and at least one quarter-wave plate 11. As can be seen from the section of FIG. 5, certain cavity configurations can be configured to reflect a light path with a first polarization using the polarization-dependent beam splitter plate 10, to pass a light path with a second polarization through the polarization-dependent beam splitter plate 10, or a combination thereof, where the first polarization is opposite to the second polarization. Certain cavity configurations can further be configured to switch a light path from a first linear polarization to a second linear polarization using a combination of the quarter-wave plate 11 and mirror 8, where the first linear polarization is perpendicular to the second linear polarization.

[0074] Section 17 of Figure 5 shows an embodiment of a Class II field-emission cavity 1 comprising two polarized display panels 6 combined with a polarization-dependent beam splitter plate 10. The polarization-dependent beam splitter (PDBS) plate 10 is a beam splitter plate or reflector sheet that fully reflects one polarization of light and fully transmits the other, perpendicularly polarized light. The two display panels 6 have the advantage of being able to simultaneously generate digital content at two similar depths. By adjusting the position of one display panel 6, the depth separation between the two focal planes can be easily adjusted. Another advantage is that utilizing the polarization of the display panels 6 in conjunction with the PDBS plate 10 minimizes light loss.

[0075] Section 18 of Figure 5 shows an embodiment of a second-order Class II field-emission cavity 1 that uses a PDBS plate 10 and a wave plate 11 to efficiently generate two different focal planes (image depths). In this embodiment, light from a vertical display panel 6 has horizontal polarization and strikes a PDBS plate 10 that reflects only light with horizontal polarization. This light (schematically indicated by a red arrow) therefore travels upward and passes through a quarter-wave plate 11 (shown in purple). This quarter-wave plate 11 changes the horizontal polarization to clockwise circular polarization, which then strikes a half-mirror on top of the horizontal display (shown in blue) and reflects it back with counterclockwise polarization. The quarter-wave plate 11 then converts the counterclockwise circular polarization to vertical linear polarization (schematically indicated by a red arrow). This light passes through the PDBS plate 10 and exits through the cavity exit pupil 2. Light from the horizontal display panel 6 has a counterclockwise polarization and is converted to vertical polarization by passing through the quarter-wave plate 11 and passes through the PBDS plate 10. This method of using the quarter-wave plate 11 along the reflective surface 8 can be widely used in many other configurations for the field-emission cavity 1, as shown in Figures 5-10. The function is identical to that described for this configuration; the wave plate 11, together with the reflective surface 8, reflects and rotates the polarized light by 90 degrees. Thus, if light with horizontal polarization passes through these layers, the light is reflected back with vertical polarization, and vice versa. If vertically polarized light reflects off this structure, the light is reflected with horizontal polarization.

[0076] Section 19 of Figure 5 shows an embodiment of a second-order Class II field-emitting cavity 1, which includes a single display panel 6 combined with a series of beam splitter plates 9 and mirrors 8. This has the advantage that a single display panel 6 can be used to generate digital content simultaneously at two similar depths. The depth separation between the two focal planes can be adjusted by adjusting the position of the central beam splitter plate 9. This embodiment is a Class I field-emitting cavity 1 because the display panel 6 exists only in one dimension. This embodiment has a second-order cavity exit pupil 2 because light from the lower portion of the display panel 6 reflects once from the lower beam splitter plate 9 and then again by a horizontally-planar half mirror (also passing through the lower beam splitter plate 9 before exiting). Higher-order field-emitting cavities 1 can offer more flexibility in terms of design and form factor, but tend to be less optically efficient.

[0077] Section 20 of Figure 5 shows an embodiment of a second-order Class II field-emission cavity 1 comprising two display panels 6 combined with a series of PDBS plates 10. Light from the left display panel 6 is x-polarized and is reflected from reflector 8 to the cavity exit pupil 2. Light from the right display panel 6 is x-polarized; it is reflected downward, passes through waveplate 11, hits bottom mirror 8, passes through waveplate 11 again, shifts the polarization to y-polarization, and then passes through PDBS plate 10.

[0078] Section 21 of Figure 5 shows an embodiment of a second-order Class II field-emission cavity 1 in which light from the right display panel 6 is configured to be x-polarized, resulting in light reflecting off the PDBS plate 10. Light from the bottom display panel 6 passes through waveplate 11 with its polarization rotated and passes through the angled PDBS plate 10 to the cavity exit pupil 2. Light from the right display panel 6 is reflected downwards by the PDBS plate 10, rotates the polarization of the waveplate 11, is partially reflected by the bottom beamsplitter plate 9, and then passes through the angled PDBS plate 10 to the cavity exit pupil 2.

[0079] 6, the optical tuning mechanism 7 may further comprise at least one mechanical actuator 12. As can be seen from the section of FIG. 6, certain cavity arrangements may be arranged to translate the display panel 6 using a mechanical actuator 12, and / or certain cavity arrangements may be arranged to translate the waveplate 11 and mirror 8 combination using another mechanical actuator 12.

[0080] Section 22 of Figure 6 shows an embodiment of a Class I field-emitting cavity 1 with a single display panel 6 that is swept through multiple physical positions to generate digital content at multiple depths. This field-emitting cavity 1 can be used as part of an adaptive display panel 6, where the position of the display panel 6 is adjusted to correspond to the user's convergence depth, and the field-emitting cavity 1 can be continuously swept (to generate a light field) while continuously updating the displayed digital content, or it can simply be set to match the perceived depth of the digital content if the digital content is at a known depth. This mechanical motion can be combined with a curved relay to increase the optical range of depth variation. This is usually necessary because mechanical translation with a wide range is usually impractical. Various means, such as mechanical stages, piezoelectric transducers, or voice coils, can be considered for these mechanical translations.

[0081] Section 23 of Figure 6 shows an embodiment of a field emission cavity 1 that combines the embodiment shown in section 22 of Figure 6 with the embodiment shown in section 17 of Figure 5, which simultaneously generates digital content at two different depths, one of which is dynamically adjustable.

[0082] Section 24 of Figure 6 shows an extension of section 23 of Figure 6, including a movable mirror 8 to enable faster movement of the dynamically adjustable focal plane. This allows digital content to be generated simultaneously at two different depths, one of which is dynamically adjustable. While faster movement can be achieved by using a higher-order field-emitting cavity 1, the speed of depth movement is generally slower when mechanical motion is used. The translation speed is typically a direct function of the order. In the example of section 24 of Figure 6, the adjustability or movement speed is doubled as light strikes the right mirror 8 and returns, resulting in a delta deformation of the mirror 8's position, or the display panel 6, through the round trip of light. Simultaneous movement of the right display panel 6 and left mirror 8 can quadruple the speed and range of depth movement in this example.

[0083] 7, the optical tuning mechanism 7 may further comprise a plurality of switchable mirrors 13 in serial optical communication with one another and positioned offset from one another. As can be seen from the section of FIG. 7, a particular cavity arrangement may be arranged to selectively alternate between reflecting the optical path with at least one particular mirror from the plurality of switchable mirrors 13 and allowing the optical path to pass through the particular mirror.

[0084] Section 25 of Figure 7 shows an embodiment of a field-emission cavity 1 that utilizes a polarized display panel 6 and a stack of polarization-dependent switchable liquid crystal mirrors 13 to generate digital content at multiple depths, each determined by which switchable mirrors 13 (which reflect light) are activated. There are many technologies that provide functionality for the switchable mirrors 13; a non-limiting example of a switchable mirror 13 is a liquid crystal cell (LCC) placed on top of a polarization-dependent reflector. If incident light has the same polarization as the polarization axis of the reflective surface, the light reflects from the switchable mirror 13. When the LCC is turned on, such that the LCC cross-polarizes the incident light with the reflective polarizer, the light passes through and the mirror becomes transparent. Other technologies use photorefractive or other electro-optical materials for the switchable mirror 13.

[0085] Section 26 of Figure 7 shows a variation of section 25 of Figure 7, which utilizes a folded structure to double the depth separation provided at the output focal plane compared to the physical separation of the switchable mirrors 13. The depth exiting the cavity exit pupil 2 is defined by which switchable mirrors 13 are turned on to reflect light. These switchable mirrors 13 can be switched on and off at speeds comparable to the switching speed of liquid crystal materials (tens of nanoseconds). With this architecture, each frame can be reflected from a different depth from the field-emitting cavity 1, and therefore different layers within the light field can be electronically and sequentially scanned. While sequential layer scanning by turning on one of the switchable mirrors 13 at a time is not necessarily the most efficient way to scan the entire depth of the light field, computational techniques can be used to turn on and off the switchable mirrors 13 within the field-emitting cavity 1 in a way that increases the overall light efficiency or brightness of the depths used. For example, if content exists only at the nearest depth, there is no need to allocate more empty frames to other, deeper depths. In other words, the signals supplied to the display panel 6 and the switchable mirror 13 can be processed in such a way as to dynamically maximize the frame rate and brightness at the active depth.

[0086] Section 27 of Figure 7 shows an embodiment of a field-emitting cavity 1 that uses a microlens array to collimate a display panel 6 and project digital content onto a stack of switchable diffusers. This embodiment generates digital content at multiple depths, each determined by which diffuser is set to be diffusive. Furthermore, if the switchable diffusers are driven to achieve spatially varying diffusion, it is possible to generate a non-planar diffusing surface, thereby generating a non-planar output focal plane. The spatially varying depth of this output focal plane can then be dynamically adjusted to match the spatially varying depth of the digital content being displayed. There are many technologies available for switchable diffusers, and most of these technologies rely on polymer-stabilized cholesteric texture (PSCT) light shutter technology. Another way to implement section 27 of Figure 7 is to use a polarization-dependent diffuser that scatters light with one polarization and transmits light with the other, perpendicular polarization. This requires a layer of liquid crystal on top of the lenslets to rotate the polarization, which corresponds to different diffusers that diffuse light at different depths. While this is theoretically feasible, such an arrangement is most likely to produce haze artifacts for deeper layers.

[0087] 8, the optical tuning mechanism 7 includes at least one liquid crystal cell layer 16. As can be seen from the section of FIG. 8, the particular cavity arrangement is arranged to use the liquid crystal cell layer 16 to switch the light path from a first linear polarization to a second linear polarization, to use the liquid crystal cell layer 16 to adjust the refractive index of the light path, or a combination thereof, where the first linear polarization is perpendicular to the second linear polarization.

[0088] Section 28 of Figure 8 shows an extension of section 25 of Figure 7, where different depths are generated by the birefringence of the transmissive liquid crystal cell layer 16 disposed on top of the display panel 6. As more or fewer of the stack of liquid crystal cell layers 16 are activated, the apparent refractive index between the display panel 6 and the cavity exit pupil 2 can be dynamically adjusted. This extension therefore allows digital content to be generated at multiple different depths. The amount of refractive index required depends on the design of the optical relay mechanism 3 coupled to the cavity exit pupil 2. When the optical relay mechanism 3 expands the perceived depth, small variations in the optical path can result in large shifts in the focal plane depth perceived by the user.

[0089] Section 29 in Figure 8 shows an alternative to section 28 in Figure 8, which provides significantly larger depth steps compared to section 25 in Figure 7, thereby providing a greater depth variation range for the focal plane. This is an embodiment of a Class I field-emission cavity 1 with a single-polarization display panel 6, where light passes through a liquid crystal cell layer 16 that can rotate the incident polarization. As shown in Figure 8, the remaining structure of the field-emission cavity 1 (with the polarization-dependent beamsplitter plate 10 and quarter-wave plate 11 / mirror 8) allows for the use of a liquid crystal cell (LCC) layer 16 to switch between two output depths. In some embodiments, the LCC layer 16 does not have a 2D matrix on it, but rather rotates the polarization by 90 degrees once biased. Thus, digital content can be generated in two different planes, the selection of which is determined by the state of the liquid crystal cell layer 16 (and the physical structure of the cavity). In the illustrated embodiment, the display panel 6 generates horizontally polarized light (blue arrows). When the LCC layer 16 is off, the light passes through the LCC layer 16 with the same polarization, then passes through the polarization-dependent beam splitter plate 10, then hits the quarter-wave plate 11 and reflector 8, then reflects with vertical polarization, then hits the beam splitter plate 9, and exits the cavity exit pupil 2 (Beam I). When the LCC layer 16 is on (electrically biased), the polarization rotates 90 degrees, becomes vertical, reflects off the beam splitter plate 9, goes upwards, reflects off the quarter-wave plate 11 / mirror structure 8, resulting in horizontal polarization, and passes through the polarization-dependent beam splitter plate 10 (Beam II).

[0090] Section 30 of FIG. 8 shows an extension of section 28 of FIG. 8, enabling a single display panel 6 to generate digital content at three different depth planes, the selection of which is determined by the state of the two liquid crystal cell layers 16 (and the physical configuration of the field-emission cavity 1). Additionally, compared to section 25 of FIG. 7, significantly larger depth steps are provided, thereby providing a greater depth variation range for the focal plane. Each liquid crystal cell layer 16 acts like a 2D optical valve, preserving angular information and determining which path light takes depending on its polarization state. Based on the state of the LCC layer 16, three depths can be generated: I, II, and III. For example, considering that the display panel 6 has horizontal polarization, in this design, depth I is generated when LCC1 is on (LCC2 is not used for depth I). Depth II is generated when LCC1 is off and LCC2 is off. Depth III is generated when LCC1 is off and LCC2 is on. In theory, this design can be extended to an infinite number of field-emitting cavities, but each time another field-emitting cavity is added, some light is lost, reducing efficiency.

[0091] Section 31 of Figure 9 shows a compact wedge cavity extension of section 12 of Figure 4, using a single display 6 instead of two display panels 6 to generate digital content simultaneously at two similar depths. The depth separation between the two focal planes can be easily adjusted by adjusting the position of the single polarization-dependent beamsplitter plate 10. Another advantage is that light loss is minimized by utilizing the polarization of the display panel 6 in conjunction with the polarization-dependent beamsplitter plate 10 and waveplate 11.

[0092] Section 32 of Figure 9 shows a compact Class II variation of section 12 of Figure 4 that uses two polarized display panels 6 and a polarization-dependent beam splitter plate 10 to generate digital content simultaneously at two similar depths. By adjusting the position of the display panels 6, the depth separation between the two focal planes can be easily adjusted.

[0093] Section 33 of Figure 9 shows a compact Class I wedge for a field-emitting cavity that uses a polarized display panel 6 to generate digital content at two depths simultaneously. The angle allows light to exit the cavity exit pupil 2 at a desired angle.

[0094] Depth and brightness enhancement mechanism The depth of each layer within the light field can be adjusted by using glass or other high-index materials within the field-emitting cavity 1 or at the cavity exit pupil 2. Additionally, the brightness of a layer can be increased by using prismatic films on the display. The display panel 6 within the field-emitting cavity 1 typically has a Gaussian wide-angle profile with a peak intensity at the center, which is not necessarily beneficial in cavity-based light fields where reflections from the display panel 6 may be at oblique angles. Placing prismatic films on the display panel 6 can help tilt the peak intensity of the Gaussian profile to a desired angle, resulting in a brighter output for that layer of the screen. The reason a high-index glass window reduces depth is because it refracts light into a smaller cone than the original cone, so the perceived depth appears slightly smaller or not as deep.

[0095] 10, the optical tuning mechanism 7 may further include at least one prismatic film 17 and at least one high refractive index material 18. As can be seen from the section of FIG. 10, certain cavity arrangements may be arranged to increase the brightness of the optical path using prismatic film 17, and / or certain cavity arrangements may be arranged to decrease the depth of the focal plane along the optical path using a piece of high refractive index material 18.

[0096] Section 34 of Figure 10 shows an example where prismatic film 17 can increase brightness by tilting the peak of the Gaussian profile of intensity towards the reflector. Prismatic film 17 is useful whenever the cavity exit pupil 2 views the display panel 6 at any angle other than 90 degrees.

[0097] Section 35 of Figure 10 shows an example of a first order Class I field-emitting cavity 1 with the cavity exit pupil 2, both of which are perceived as slightly less deep inside the field-emitting cavity 1 due to the high refractive index 18 at the cavity exit pupil 2.

[0098] Section 36 of FIG. 10 shows an example of a first order Class I field emitting cavity 1 with a cavity exit pupil 2 where the deeper focal plane is slightly deeper relative to the cavity exit pupil 2 due to the high refractive index 18 on the display panel 6.

[0099] Section 37 of Figure 10 shows an example of a first order Class I field emitting cavity 1 with a cavity exit pupil 2, where the deeper focal plane is slightly deeper than the cavity exit pupil 2 due to the high refractive index 18 on the back surface of the reflector 8 at closer depths.

[0100] Section 38 of Figure 10 shows an example of a first order Class I field-emitting cavity 1 at the cavity exit pupil 2, where the deeper focal plane is significantly less deep relative to the cavity exit pupil 2 due to the high refractive index 18 throughout the bottom section of the field-emitting cavity 1. Essentially, the bottom reflector 8 is replaced with a high refractive index prism 18.

[0101] Relay mechanism and application modalities As previously mentioned, the cavity exit pupil 2 delivers light to a relay mechanism 3, resulting in different divergence reference vertices for different focal planes that are presented to the user. The relay mechanism 3 can be an off-axis visor, a geometric or diffractive waveguide, a birdbath design beam splitter, or any other suitable relay means.

[0102] 11 and the following description provide non-limiting examples of relay mechanisms 3 that can be used to direct the output of a field-emitting cavity 1 toward a viewer. In one example, light exits the cavity exit pupil 2 onto a visor and travels toward the eye. In another example, light exits a smaller cavity and is fed into a larger waveguide, which then redirects the light toward the viewer.

[0103] Referring to FIG. 11 , a diagram is shown illustrating how the output of the field emission cavity 1 can be relayed to a viewer as part of an entertainment system or amplified monitor. The left column illustrates entertainment system modalities, and the right column illustrates amplified near-head display modalities. Generally, a near-head mount 20 is operably coupled to the system enclosure 5, and the near-head mount 20 is used to position the system enclosure 5 adjacent to a user's head. Additionally, an entertainment stand 21 is operably coupled to the system enclosure 5, and the entertainment stand 21 is used to position the system enclosure 5 offset from the user's head. Additionally, at least one audio output device 19 is electronically connected to the display panel 6.

[0104] Reference numeral 39 in FIG. 11 indicates a viewer of either the near modality 20 or the entertainment system modality 21, where the viewer is further than 60 centimeters (cm) from the display.

[0105] Reference number 40 in FIG. 11 denotes a generalized display cavity (ie at least one field emission cavity 1) for generating digital content (stereoscopic or 2D) at one or more depths.

[0106] Reference numeral 41 in FIG. 11 denotes the casing of at least one field emission cavity 1 (ie, the system enclosure 5) which holds the rest of the electronics of the system.

[0107] Reference numeral 42 in FIG. 11 shows an example of an angled reflector relay (i.e., relay mechanism 3) in which a reflective, semi-reflective, or switchable mirror surface is used to relay the cavity exit pupil 2 to the enclosure exit pupil 4, i.e., to the observer.

[0108] Reference numeral 43 in Figure 11 shows an example of a curved angled reflector relay (i.e., relay mechanism 3) in which a curved reflective, semi-reflective, or switchable mirror surface is used to relay the cavity exit pupil 2 to the enclosure exit pupil 4, i.e., to the observer. The curvature of this relay can vary the depth of the content coming from the original depth of the cavity to a greater or closer distance.

[0109] Reference numeral 44 in FIG. 11 denotes coupling optics that couple the cavity exit pupil 2 to the entrance pupil of the waveguide (ie, relay mechanism 3).

[0110] Reference numeral 45 in Figure 11 denotes geometric or diffractive waveguides (i.e., relay mechanisms 3) that redirect the output of the FE cavity (made of an array of LCoS and reflectors or DMD and reflectors or LCD panels and reflectors or projectors) to the viewer. These waveguides can be multimode geometric waveguides, diffractive waveguides, or real single-mode confinement waveguides.

[0111] 11 indicates a compression relay system (i.e., relay mechanism 3), which will be described in more detail in the next section of this disclosure. The compression relay system helps to have a more compact form factor for the display.

[0112] Compression Design A single reflector can be bulky both inside the FE cavity 1 and as a relay. Figure 12 shows some non-limiting examples of such compact designs based on spatial stacking of switchable mirrors.

[0113] 12 , an operable combination of at least one field emission cavity 1 and relay mechanism 3 may comprise a plurality of switchable mirrors in serial optical communication with one another and offset from one another. Further, the plurality of switchable mirrors may include a plurality of first switchable mirrors 14 and a plurality of second switchable mirrors 15, such that the plurality of first switchable mirrors 14 are distributed among the plurality of second switchable mirrors 15. As can be seen from the section of FIG. 12 , a particular cavity arrangement is arranged to selectively alternate between reflecting a light path in a first polarization using at least one designated first switchable mirror from the plurality of first switchable mirrors 14 and passing the light path through the designated first switchable mirror, and a particular cavity arrangement is further arranged to selectively alternate between reflecting a light path in a second polarization using at least one designated second switchable mirror from the plurality of second switchable mirrors 15 and passing the light path through the designated second switchable mirror. The first plurality of switchable mirrors 14 and the second plurality of switchable mirrors 15 are thereby configured to compress the occupancy volume of the operating combination of at least one field-emission cavity 1 and relay mechanism 3. Section 47 of FIG. 12, similar to section 6 of FIG. 3A, illustrates an exemplary system without compression, having a Class I FE cavity 1 and two depths. Light exits the cavity exit pupil 2 (shown by the blue dashed line), reflects off reference numeral 42 of FIG. 12 (i.e., relay mechanism 3), and exits the enclosure exit pupil 4 (shown by the red dashed line). Light I from deeper depths comes from depth I, while light II comes from a closer distance inside the field-emission cavity 1. The system is required to have a minimum thickness of L, mandated by the dimensions of the display panel 6. For the same dimensions of the display panel 6, section 48 of FIG. 12 reduces the thickness by half (L / 2). This compression is obtained by means of the temporal switching of switchable mirrors or by having a stack of relays that are transparent to one another by polarization.Thus, in section 48 of Figure 12, the deeper depth I has two sections Ia and Ib relayed at two different distances; the distances in the relays are such that Ia and Ib both have the same depth as depth I, but span the same enclosure exit pupil 4 size as section 47 of Figure 12. The same occurs for closer depth II. Depth II is diced into two relays with thinner thicknesses, extending the enclosure exit pupil 4. This approach can be expanded for further compression. Furthermore, section 49 of Figure 12 shows the case where the thickness relative to section 47 of Figure 12 is compressed by a factor of three. Here, each depth level is spatially multiplexed into three sections, compensated for by the height of the three relay switchable mirrors 14, 15. For example, the paths traveled by sections Ia, Ib, and Ic to the enclosure exit pupil 4 (shown by the dashed red lines) are equal, and therefore they all have the same depth as depth I. However, they exit at different heights, expanding the enclosure exit pupil 4 back to the size of the enclosure exit pupil 4 in section 47 of FIG.

[0114] Prototype example Figure 13 shows an exploded 3D model of the prototype system, which is not shown in the detail in Figure 1, and has three depths, from rear to left and front to right. The parts are as follows:

[0115] Reference numeral 50 in FIG. 13 (i.e., a component of the system enclosure 5) is a side holder of the assembly. Reference numeral 51 in FIG. 13 (i.e., a component of the optical tuning mechanism 7) is a reflective or semi-reflective surface. Reference numeral 52 in FIG. 13 is a simple reflective mirror that functions as the relay mechanism 3. Reference numeral 51 in FIG. 13 (i.e., a component of the system enclosure 5) is a top cap that only protects the relay mechanism 3. Reference numeral 54 in FIG. 13 (i.e., the display panel 6) is an LCD panel divided into three depths. Reference numeral 55 in FIG. 13 (i.e., a component of the system enclosure 5) is a back cover of the FE cavity 1.

[0116] Advantages and improvements over existing methods The component arrangements, methods, and assemblies herein provide various advantages and improvements over existing 3D systems.

[0117] Ergonomic advantages and improvements Accommodation-Vergence Conflict Mitigation - The invention described herein can generate digital content at multiple depths with true monocular optical wavefronts. The flexibility of displaying digital content at multiple depths allows for the presentation of digital content at optical depths that match or resemble the binocular disparity depth cues presented to the viewer, thereby helping to resolve accommodation-vergence conflicts experienced by the viewer. Mitigating accommodation-vergence conflicts makes digital content more comfortable to view over time and enhances the realism experienced by users viewing the digital content.

[0118] Reduced size - The present invention offers flexibility in terms of packaging compared to systems that use projectors, as it allows for the light path to be folded. This allows for smaller systems.

[0119] Unlike autostereoscopic 3D systems, where the viewing zone distance and angle are limited and sometimes only a few viewers can see the 3D content, the present invention allows a viewing angle of up to 150 degrees (depending on the number of depths) and has no limit on the number of users.

[0120] The FE cavity 1 can be combined with any type of panel and light engine so as not to be limited to a specific technology, and if necessary, autostereoscopic displays can also be used as engines to increase their performance in depth accuracy.

[0121] Reduced Cost - In contrast to using eye-tracking based accommodative displays or holographic displays, the present invention can utilize readily available components (flat display panels) that are ready for mass production, significantly reducing overall system costs and technical challenges.

[0122] Because the FE cavity 1 system allows for true optical depth, the enclosure exit pupil 4 can be located very close to the eye without eye fatigue, since the true optical depth of the image can be placed far back. Unlike stereoscopic displays, this opens up entirely new possibilities for near-temporal displays, where the size of the display can be expanded without having to wear anything or have a large screen.

[0123] o For most of the designs herein with passive glass reflectors or even switchable mirrors, the image provided by the FE cavity 1 is free of artifacts such as haze, color non-uniformity, distortion, and moiré artifacts.

[0124] Performance benefits and improvements Bandwidth Reduction - The invention described herein allows for the accommodation-vergence conflict to be resolved or mitigated without the need to present the entire 5D plenoptic function to the viewer. This reduces the complexity of content rendering and can improve system frame rates compared to full light-field displays. Bandwidth can be reduced by several orders of magnitude.

[0125] Flexibility in Optical Efficiency - The present invention is flexible in that if optical efficiency is a priority, a design with high light throughput can be chosen. If display brightness is not required, there is further flexibility to add more display planes or to use a simpler cavity design.

[0126] o Spatial Resolution Flexibility - The present invention is flexible in that it can maintain spatial resolution by using multiple display panels 6. When spatial resolution is not needed (e.g., when individual pixels are not yet resolvable by the user), the present invention can utilize unnecessary spatial resolution to render different depth planes and improve the user experience.

[0127] Scalability - The FE cavity 1 is advantageously scalable in architecture, number of planes, and extension to different display systems.

[0128] Compatibility - The invention presented here offers significant advantages in compatibility at both the software and hardware levels. At the software level, the light source can ultimately be a 2D screen, so feeding the display system can easily provide a conventional standard signal. This also simplifies rendering, as there is no fundamental need for significant computational processing of the input due to depth-providing optics. The hardware architecture is essential for a wide variety of existing 2D display systems.

[0129] ● Functional advantages and improvements Monitor Magnification - Because the depth of the systems disclosed herein is true optical depth, the eyes can accommodate and view these 3D contents without discomfort at any given distance of the display. For example, if the display is 20 cm away from the head, but the indicated depth is still 2 meters, the viewer will perceive the image as being 2 meters away and be able to use the monitor even at such a close distance. This is useful for magnifying small monitors using the true optical depth provided by the disclosed systems.

[0130] Head-up displays - Since the depth can be much farther than the actual position of the display, relays can be made semi-transparent, making them a perfect case for large-scale overlay of images with the real world, especially in the context of head-up displays.

[0131] Entertainment - The Light Field experience provides a better sense of presence with accurate optical depth and artifact-free images, which can be used for home entertainment, gaming, and commercial entertainment applications.

[0132] Commercial Applications Many commercial applications become possible with dramatic precision in depth, screen transparency, and immersion. Below is a non-exhaustive list of possible applications:

[0133] Navigation Use the heads-up display for turn-by-turn directions while driving / steer / etc. without having to look at the road or get lost on your phone or another navigation device.

[0134] Medical Better exploration of 3D data files using light field displays.

[0135] ●Workplace ergonomics The enlarged display can replace a large display without the need to install any hardware or have a large screen. The 3D nature of the display can provide office volume with pixel accuracy equivalent to today's standard monitors.

[0136] Entertainment The layered nature of the FE cavity 1 facilitates content generation from the gaming and video industry, as rendering in several layers to provide a 3D effect is much easier (less computationally demanding) than rendering an entire 3D environment.

[0137] 〇FE Cavity 1 is well suited to standalone game consoles, as true depth will engage viewers with a new experience.

[0138] ●Design Preview the look and feel of objects that have not been physically prototyped and visualize content for modeling and design in AR or VR without the need to wear a headset, which is crucial as developers cannot wear a headset for hours, but can use the invention with true optical depth.

[0139] In any of the field emission cavity embodiments described above, an aperture optical element 70 can be added to assist and modify the optical properties of the light in the optical path. Figures 14A and 14B show two illustrative examples.

[0140] In Figure 14A, light exiting field-emitting cavity 1 passes through aperture optical element 70 located at cavity exit pupil 2. The light, modified by aperture optical element 70, exits system enclosure 5 through enclosure exit pupil 4. Similar to the illustrative example of Figure 14B, field-emitting cavity 1 emits light through its cavity exit pupil 2. The light passes through aperture optical element 70 located at enclosure exit pupil 4, is modified thereby, and proceeds to the observer.

[0141] The aperture optics 70 can include any number of light-modifying devices, including, but not limited to, an anti-reflective layer, a prismatic film 17, a privacy layer, an absorbing polarizer, or a microcurtain layer. The aperture optics 70 may also be used to modify ambient light directed toward the user from the external environment. As an illustrative example, an anti-reflective layer can be used as the aperture optics 70 to remove stray light reflections that may enter the observer's eyes. The aperture optics 70 can have the additional function of protecting components within the system enclosure 5 from the external environment. In some embodiments, the aperture optics 70 can be positioned at both the cavity exit pupil 2 and the enclosure exit pupil 4.

[0142] In this disclosure, the field emission cavity can generate a light field display, or a subsampled light field display, i.e., a light field display that approximately replicates only the full light field emanating from a physical three-dimensional scene. For example, a fractional light field display may generate a single virtual image corresponding to a single focal plane or virtual depth.

[0143] In some embodiments, the field-emission cavity 1 further comprises one or more semi-reflective elements 71 and one or more reflective elements 72. In some embodiments of the present invention, these reflective elements 72 and semi-reflective elements 71 are configured to at least partially fold the light in the optical path back onto itself to selectively adjust the virtual depth position of the virtual image presented to the viewer. In other words, the field-emission cavity 1, reflective elements 72, and semi-reflective elements 71 are configured to fold a portion of the optical path back onto itself to adjust the depth of the focal plane along the optical path. This folding of the optical path back onto itself allows the present invention to further adjust the virtual depth position of the virtual image. Further embodiments include a switchable mirror or mechanical actuator within the field-emission cavity 1 configured to further adjust the virtual depth position of the virtual image.

[0144] 15 shows a further embodiment of a field-emitting cavity 1 in which the semi-reflective element 71 of the system is segmented to create multiple depths through the extended aperture optics 70. In some embodiments, the display panel 6 itself may be segmented. In other embodiments, the reflective optics 72 or the semi-reflective optics 71 may be segmented.

[0145] In this disclosure, a "segmented" element has properties that vary across the surface of the element. A segmented semi-reflective element is, for example, a semi-reflective element whose reflectance coefficient or reflectance varies across its surface. The variation can be smooth, continuous, piecewise constant, or piecewise smooth. A segmented display panel is a display panel that shows different image content in various regions of the display panel. For example, a display panel segmented into two regions can show a first image and a second image. In this way, light emitted from, transmitted through, or reflected from different segments of a segmented element can travel different paths through the display system.

[0146] This segmentation of components creates several segmented elements, such that the segmented display panel 6 can be segmented into a first segmented element and a second segmented element. There is no limit to the number of segmented parts that can be created by the segmented components. Furthermore, similarly, the reflective 72 or semi-reflective 71 optical system can also be segmented into a first segmented element and a second segmented element. Any of the components within the present invention can be segmented in this same manner. Exemplary embodiments with segmented elements are shown in Figures 15 and 17.

[0147] Additionally, the reflective 72 or semi-reflective 71 optics can have gradient properties, such as gradient reflectivity. The reflective 72 or semi-reflective 71 optics, including segmented optics, may be polarization dependent, such that after interacting with the polarization dependent element, light of a first polarization travels a first optical path and light of a second polarization travels a second optical path.

[0148] As shown in Figure 15, light in the optical path may be directed along a cavity formed between two or more reflectors, elements, optics, or components that make up a light pipe. The light in the light pipe is directed down the cavity of the light pipe where it exits the light pipe through aperture optical element 70. The light is directed toward an observer.

[0149] In further embodiments, a light pipe can be created using segmented elements, such as a first segmented element and a second segmented element. In one embodiment, the first segmented element and the second segmented element are comprised of polarization-dependent elements. The polarization-dependent elements of the first segmented element and the second segmented element are configured such that light of a first polarization is directed along the light pipe along a first optical path and light of a second polarization is directed along the light pipe along a second optical path. This allows the light pipe to generate multiple virtual images at multiple depths. In some embodiments, optical paths corresponding to different segmented elements form images at the same depth but at different lateral positions, so that together they form a single virtual image with an extended aperture or field of view. In some embodiments, the polarization-dependent element light pipe is embedded in or integrated into a vehicle.

[0150] A further embodiment, shown in FIG. 16, has a field-emitting cavity 1 with an exit aperture in optical communication with a large mirror 79. The mirror can function as a partial aperture optic. This embodiment further includes a gesture sensor 80, a depth camera 80, or both. The gesture sensor 80 or depth camera 80 is coupled to or integrated with the display system. The gesture sensor 80 or depth camera 80 observes the observer 77 so that the display system can capture, incorporate, or interpret the observer's 77 movements, position, and gestures. The gesture sensor 80 or depth camera 80 relays information about the observer 77 to the display system. The display system can then use this information to dynamically generate and display text or other augmentation effects as a virtual image 81. In some embodiments, the text or augmentation effects can be generated from other sources and can be manipulated by the observer through the depth camera 80 or gesture sensor 80.

[0151] In this embodiment, the field-emitting cavity 1 is configured to generate a virtual image 81, which may include any number of items, such as, but not limited to, text or an image. This virtual image 81 is generated by the field-emitting cavity 1, and the virtual image 81 appears at a similar virtual image depth as an observer's reflection 82 in the mirror. In other words, when an observer looks at their reflection 82 in the mirror, the virtual image 81 generated by the field-emitting cavity 1 appears to be at the same depth or in the same plane as the reflection 82 in the mirror.

[0152] In some embodiments, the field emission cavity 1 can further comprise a retroreflective or retrorefractive element. The retroreflective or retrorefractive element can be configured to cause the virtual image 81 to appear closer to the observer 77 compared to the observer's physical distance to the display. This causes the text or augmentation effect in the virtual image 81 to appear at the same depth as the image of the observer. The viewer can then interact with the virtual image 81 via the gesture sensor 80 or depth camera as if the text or augmentation effect in the virtual image 81 were hovering in mid-air.

[0153] FIG. 17 illustrates a further embodiment in which the field-emission cavity 1 is embedded in or integrated into the roof 75 or ceiling of a vehicle 76. In this further embodiment, similar to embodiment 33 of FIG. 9, the display panel 6 emits light into the field-emission cavity 1, which may have a first element 73 and a second element 74. Both the first element 73 and the second element 74 may be reflective or semi-reflective elements positioned at an angle less than 45 degrees relative to each other. This angle may be designed as desired. In some embodiments, the display panel itself may be segmented, and in some embodiments, either the first element or the second element may be segmented. In some embodiments, the segmented characteristic may be temporally switchable, such that light travels a first path at a first time and subsequent light travels a different path at a second time. In some embodiments, there are no segmented elements. As the light reflects between the two reflective elements, the angle at which the light travels becomes shallower. This creates a light pipe that directs light from the exit of the display system toward an observer 77 who sees a virtual image 78 corresponding to a shallower line of sight. In some embodiments, the virtual image is tilted at a different angle than any of the components of the display system and the roof or ceiling. A viewer does not see the virtual image when looking straight into the roof of the vehicle. In some embodiments, an aperture optical element 70 is used. In some embodiments, a relay mechanism 3 is used. In some embodiments, a component of the display system, such as a second segment element, simultaneously functions as an aperture optical element, a relay mechanism, and an optical tuning mechanism, or a subset thereof.

[0154] In some embodiments, the light path may be affected by a polarization-dependent element. For example, a semi-reflective element may comprise a polarization-dependent grating that directs light of a first polarization along a first path and light of a second polarization along a second path. The polarization of the light may be changed using a quarter-wave plate and a reflective polarizer.

[0155] In some embodiments, the field emission cavity can further include retroreflective or retrorefractive elements so that the virtual image appears closer to the viewer rather than further away. Similar to the embodiment of FIG. 16, a gesture camera or depth sensor can be coupled to the display system to allow the viewer to interact with the virtual image. In some embodiments, the display system is transparent or translucent for a see-through effect, allowing the user to simultaneously see the display content and the environment behind the display system. In some embodiments, a camera captures information about the environment outside the vehicle, and the display system displays that information for a video see-through effect.

[0156] The embodiment of Figure 17 is an example of the wedge cavity described in Figure 9, but it can also be configured as other classes or orders of field-emitting cavities, such that the light path is folded exactly or approximately onto itself. In such cavities, light can be folded as it undergoes multiple reflections from a single element.

[0157] The embodiment of Figure 17 may be integrated into a portion of a vehicle. Although the embodiments described herein depict automobiles or vehicles, the vehicle may take other forms, including, for example, but not limited to, a car, truck, motorcycle, tricycle, tank, aircraft, or watercraft.

[0158] It is important to note that each point in the virtual image is visible to both eyes of a human observer, i.e., light rays from any given point in the virtual image are incident on both eyes simultaneously. The viewer's eyes can be positioned anywhere within a particular volume to view the virtual image. The depth of the virtual image is the depth to which each eye accommodates or focuses. This quantity, called the headbox, spans the lateral dimension. The lateral dimension may be, for example, at least 8 cm, at least 10 cm, at least 15 cm, at least 20 cm, or at least 30 cm. The distance between the display system and the nearest viewing position within the headbox may be, for example, 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, 80 cm, 90 cm, or 100 cm. In some embodiments, the nearest viewing position is greater than 100 cm. This distance is limited in part by the viewing direction required to see the virtual image. The observer 77 is understood to have his or her eyes within the headbox.

[0159] Also, a virtual image is an image in which the imaging rays corresponding to a given point in the image do not physically intersect. Rather, they are divergent or collimated. When the image-forming rays are geometrically projected backward, their projections intersect. This intersection point is the location of the virtual image. (In contrast, an image formed by physically intersecting rays is a real image that can be projected onto a screen or other physical surface without any other focusing element.) In some embodiments, a virtual image is observed by an observer.

[0160] In some embodiments, the first element 73 or the second element 74 in FIG. 17 is polarization-dependent. In some embodiments, they are semi-reflectors or partial reflectors. For example, the first element 73 may be a polarization-changing semi-reflector, which transmits at least a portion of the light incident on it and further converts the polarization of the incident light from one state to another. In some embodiments, the polarization-changing semi-reflector comprises a first wave plate, a beam splitter or other semi-reflector, and a second wave plate. In some embodiments, the wave plate is a quarter-wave plate. When linearly polarized light is incident on this polarization-changing semi-reflector, the transmitted light is linearly polarized, but the direction of polarization is rotated by 90 degrees, i.e., the incident x (y)-polarized light is converted to y (x)-polarized light. The linearly polarized light reflected by this element is also rotated by 90 degrees.

[0161] In some embodiments, either element 73 or 74 is a polarization-changing reflector, an element that reflects light incident thereon and further converts the polarization of the incident light from one state to another. In some embodiments, the polarization-changing reflector comprises a mirror and a wave plate. The wave plate, in some embodiments, is a quarter-wave plate. Incident linearly polarized light is reflected, rotating the polarization direction by 90 degrees.

[0162] The state of polarization under consideration can be linear, circular, or elliptical. In some embodiments, the degree of polarization is included in the state of polarization.

[0163] In some embodiments, first element 73 or second element 74 is a reflective polarizer that transmits light of a first polarization state and reflects light of a second polarization state that is orthogonal to the first polarization state. An example of a reflective polarizer is a wire grid polarizer. In some embodiments, the reflective polarizer is a polarization-dependent beam splitter (PBS).

[0164] In some embodiments, the optical properties of the first element 73 or the second element 74 are controlled by electronic signals. For example, the waveplates in the polarization-changing (semi-)reflector described above may be liquid crystals (LCs), such as nematic or cholesteric LCs. When a first voltage is applied to the waveplate, it transmits light without changing its polarization (thus preserving polarization), and when a second voltage is applied, it changes the polarization from a first state to a second state, such as converting horizontally polarized light to vertically polarized light. The voltage values ​​can be arbitrarily designed, including 0V. For example, if the first element 73 includes a first waveplate, a beam splitter, and a second waveplate, and one of the waveplates is a liquid crystal, the applied voltage affects how the polarization of the transmitted and reflected light changes. At one voltage, the transmitted polarization can be rotated 90 degrees. At a second voltage, it can be rotated 0 degrees. At a third voltage, incident linearly polarized light can be converted to circularly polarized light. Therefore, the type of waveplate and the configuration of the LC can affect the transmitted polarization. As a result, the transmitted light interacts differently with the second element 74.

[0165] 18A-18F illustrate a set of embodiments related to FIG. 17. In FIG. 18A, light having a first polarization state is emitted from display 6 and enters field-emission cavity 1. In all embodiments shown in FIGS. 18A-18F, field-emission cavity 1 includes first element 73 and second element 74, and may include additional optical elements and structures for mechanically supporting the elements. Inside the cavity, the light is first reflected from first element 73, which is a polarization-changing reflector. The light is then reflected by second element 74, which has a reflective polarizer, and then reflected again by first element 73. The polarization state is such that the light is transmitted by second element 74 the second time it enters. The transmitted light passes through aperture optical element 70 and exits the cavity to the outside world. In some embodiments, aperture optical element 70 includes an absorbing polarizer and an anti-reflective layer. In some embodiments, aperture optical element 70 is a transparent material, such as a glass layer.

[0166] When the light is viewed by a viewer, it forms a virtual image 78 that is farther from the viewer than the field-emitting cavity itself. Furthermore, the angle of first element 73 relative to second element 74 is less than 45 degrees, so that the orientation of the virtual image is shallower than relative to the display itself. Furthermore, because the angle is less than 45 degrees, the field-emitting cavity can be made thinner.

[0167] The display system and any electronically addressable or electrically active parts of the cavity are controlled by circuit block 1801. In some embodiments, the circuit block is coupled to the vehicle's electronic system. In some embodiments, the circuit block is an integral part of the display system and functions to provide the content of the virtual image.

[0168] FIG. 18B shows an embodiment in which the display 6 is substantially parallel to the aperture optical element 70. The display sends light through a first element 73, which may be a polarization-changing semi-reflector. The polarization state is rotated 90 degrees and reflected by a second element 74, which may be a reflective polarizer or PBS. The light is then reflected by the first element 73, which rotates the polarization by another 90 degrees to be transmitted by the second element 74, and passes through the aperture optical element 70. A virtual image 78 is formed, which is located at a depth farther than the field-emitting cavity 1 and farther than the display 6 itself. Circuit block 1801 controls the display content. In some embodiments, the polarization-changing semi-reflector includes a first wave plate, a beam splitter, and a second wave plate. In some embodiments, the aperture optical element 70 includes an absorbing polarizer and / or an anti-reflection element. These are merely examples; any suitable configuration of the first element 73, second element 74, and aperture optical element 70 can be used. In some embodiments, a directional coating is introduced into the beam path. The angle between the first and second elements is θ, which is less than 45 degrees.

[0169] In an FEC, light is reflected, or circulated, back and forth between elements of the cavity. Each of these propagations is a pass. For example, an FEC can have a first element and a second element. The first instance of light propagating from the first element to the second element is called a forward pass. When the light, or a selected portion of the light, is reflected back from the second element to the first element, the propagation is called a backward pass, as the light propagates backward toward the light source. In this cavity, a round trip occurs when the light completes one cycle (forward and backward passes) and returns to the first element. In some embodiments, a round trip occurs when the light substantially reverses direction and enters an element more than once. The term "round trip" refers to the number of times light circulates or bounces back and forth between two elements of the cavity, or the number of times light interacts with a single element.

[0170] In some embodiments, light travels one round trip within FEC 1. In some embodiments, the number of round trips may be 2, 3, 4, or 5. The number of round trips substantially determines the monocular depth perceived by the viewer. In some embodiments, the monocular depth is greater than the distance between the observer and the light source. For example, the ratio of monocular depth to distance may be 1.1, 1.5, 2, 2.5, 3, 4.5, or 5. In some embodiments, the ratio may be in a range of 1.1 to 2, 1.5 to 3, or 2 to 5, etc. In some embodiments, the monocular depth is dynamically adjustable by changing the characteristics of the virtual display system.

[0171] In an embodiment such as Figure 18A, there is one round trip. In the embodiment of Figure 18B, there are two round trips. Mechanisms for introducing more round trips include modifying the properties of the first and second elements. For example, by using a different type of waveplate or LC in the first element, the reflected polarization (after the first round trip) can be reconfigured so that a larger proportion of the light is reflected a second time by the second element. Furthermore, the second element may also include a polarization-altering element, such as a waveplate or LC, to modify the polarization of the light it reflects. Furthermore, both the polarization change and the reflectance and transmittance of these elements can be a function of angle. For example, either element can include a multilayer film. In such an embodiment, the angle of the light ray changes with each round trip, so that the light can be substantially transmitted by the second element after reaching the desired angle.

[0172] FIG. 18C shows an embodiment similar to FIG. 18B. Light from the display 6 passes through a pre-cavity element 1804, which in some embodiments includes a directional coating. The directional coating selectively transmits light rays oriented at angles within a specific angular range and blocks light rays directed outside that range. For example, the directional coating can transmit light rays incident within the ranges of 0-10 degrees, 0-20 degrees, 0-30 degrees, 0-40 degrees, 0-50 degrees, or 0-60 degrees. The directional coating does not provide optical (focusing) power. In some embodiments, the directional coating transmits angular ranges that do not start at zero degrees.

[0173] The light then passes through first element 73, a polarization-changing semi-reflector. It is reflected by second element 74, a reflective polarizer, and travels back and forth within field-emission cavity 1. The light then exits the system through aperture optical element 70. In some embodiments, aperture optical element 70 is an absorbing polarizer or an anti-reflective layer. In some embodiments, aperture optical element 70 is a transparent element, such as a layer of glass or similar material. A virtual image 78 is formed, and its orientation is tilted relative to the display orientation. Circuit block 1801 controls the display content and any active components, such as LC or electro-optical materials, that may be included in first element 73 or second element 74. The angle between the first and second elements is θ, which is less than 45 degrees.

[0174] FIG. 18D shows an embodiment in which the elements of the field-emission cavity 1 are curved. Light from the display 1 enters the cavity through a first element 73, which is a curved, polarization-changing semi-reflector. The polarized light exiting this element is reflected by a curved second element 74, which is a reflective polarizer. The light is then reflected by the first element, rotated in polarization, and then passes through the second element and through the aperture optical element 70 to form a virtual image 78. The curvature of the element generates optical power, allowing the image to be magnified or demagnified and its depth to be adjusted. In some embodiments, the curved element is a coating on a curved substrate. In some embodiments, the curved element is a freeform element, and the curvature or shape of the element is defined by a function.

[0175] In any of these embodiments, the angle between the first element 73 and the second element 74 may be less than 45 degrees. For example, it may be 1, 5, 10, 15, 20, 25, 30, 35, 40, or 44 degrees.

[0176] FIG. 18E illustrates an embodiment in which the field emission cavity includes an electro-optic (EO) material 1803 whose refractive index changes in response to an applied voltage. For example, when a first voltage is applied by circuit block 1801, EO material 1803 has a first refractive index, and when a second voltage is applied, it has a second refractive index. In some embodiments, the refractive index is not uniform but varies linearly across the element, such that a change in applied voltage changes the refractive index, making EO material 1803 an electrically controllable prism. For example, if the lateral refractive index is n(x)=n0+A(V)x, where x is position and A(V) is a function of the applied voltage, light is deflected in a direction that depends on A(V). Thus, light emitted by display 6 passes through first element 73, is reflected by second element 74, is reflected by the first element, and is transmitted through EO material 1803. It is deflected thereby and transmitted through aperture optical element 70. The deflection may be in a first direction 1802A, which produces a first virtual image 78A, or in a second direction 1802B, which produces a second virtual image 78B, depending on the state of the EO material 1803. In some embodiments, the display content is pre-compensated to account for any aberrations introduced by the EO material. That is, the display content may be distorted such that the combination of the distortion and any aberrations results in a sharp virtual image. In some embodiments, the function n(x) is not linear, but rather is a function that varies to minimize aberrations. For example, the function may be a polynomial of degree higher than 1, a logarithmic function, an exponential function, etc.

[0177] 18F shows an embodiment in which light from the display 6 enters the field-emission cavity 1 from the left. The light passes through the second element 74 and is reflected by the first element 73. In some embodiments, upon reflection, the polarization of the light is modified such that it is reflected by the second element and exits the system forming a shallow virtual image 78. The angle θ is less than 45 degrees.

[0178] In any of the above embodiments, a directional coating may cover the display panel to tilt the emitted light in a preferred direction before it enters the field emission cavity.

[0179] An advantage of these embodiments is that the virtual image is tilted at an angle that depends on the angle between the first element 73 and the second element 74. If we call the angle between them θ, then the tilt of the light accumulates by approximately 2θ after each round trip within the FEC. Thus, if θ is in the range of 1 to 30 degrees, the virtual image will be tiled relative to the display by a range of 2 to 60 degrees after one round trip. If θ is in the range of 1 to 10 degrees, the virtual image will be tiled relative to the display by a range of 3 to 30 degrees after two round trips.

[0180] Another advantage is the thinness of the display system. If the lateral direction is W ~ 30 cm and the angle θ is 30 degrees, the thickness of the FEC is approximately W tan θ, or 17 cm. The shallower the angle, the thinner the display system. The thickness of the display may be 5 cm, 10 cm, 20 cm, or 30 cm. Furthermore, the virtual image size may be approximately the same as the display. In some embodiments, the virtual image is, for example, 1.2, 1.5, 2, 2.5, 3, 3.5, or 4 times larger.

[0181] 19A-19F illustrate embodiments in which the above-described display system is integrated into a vehicle. FIG. 19A illustrates an embodiment in which a display system 1900 is integrated into a vehicle. The elements of the display system include the display itself, a field-emitting cavity, and any pre-cavity or post-cavity elements. In some embodiments, the display system includes an aperture optical element as an element. The display system generates a virtual image. In some embodiments, the display system 1900 is integrated into a vehicle part 1901A. In some embodiments, the display system 1900 is overlaid on a window, passing light from an external scene 1902 through it so that a virtual image 78 overlaps the scene, creating an augmented reality (AR) environment. In some embodiments, the display system 1900 is connected to a surface of a vehicle part 1901B. The vehicle parts 1901A and 1901B may be, for example, but not limited to, a roof, a side panel, a door, a seat, a seat back, a window, or a mirror. Because the display system is thin (due to the acute angle between the first and second elements), it is substantially flush with the surface of the vehicle, and any recessed cavity takes up little space to house it when not in use. A bulkier display would extrude more and would typically require a mechanism to fold it down when not in use or to require more space within the vehicle.

[0182] The inventive arrangement is limited by the lateral size, distance to the observer, and viewing direction for viewing an obliquely oriented virtual image. Specifically, an imaginary line extending from the observer's eye to the virtual image must pass through the aperture optic (or the geometric surface on which the aperture optic can be placed). This is not the case, for example, for display systems with relatively small lateral dimensions that are placed close to the observer.

[0183] 19B shows an embodiment in which display system 1900 is set in a first position within a pocket 1905 or recessed area of ​​a vehicle part 1901. The display system is moved by a mechanical track 1904 into position, for example, above a window 1903. Through the window, an exterior scene 1902 is visible. Once the display system is in place, a see-through AR effect is created, and a virtual image 78 is formed over the scene. In some embodiments, the display system creates augmented reality using see-through video, where a camera mounted on an exterior portion of the vehicle captures the exterior scene and displays the captured information on the display of the display system itself.

[0184] 19C shows an embodiment in which the display system 1900 is integrated into a vehicle component 1901, the roof of a car, and the display system is at least partially visible. A mechanical track 1904 slides the display system into place from a recessed cavity in the roof. In some embodiments, the display system functions as a sunroof or window for the vehicle. In some embodiments, there is a separate sunroof 1905, and the display system and sunroof are independently controlled by a first mechanical track 1904A and a second mechanical track 1904B.

[0185] FIG. 19D illustrates an embodiment in which one portion of the display system is mechanically adjustable relative to other components to modify the position and orientation of the virtual image. The display 6 is fixed to a vehicle component 1901, and light from the display is reflected by a first component 73, then reflected by a second component 74, and then transmitted by the first component 73 through an aperture optical element 70. The aperture optical element and the first component are rotatable by a hinge 1906, which has the effect of shifting and rotating the virtual image 78. That is, the rotation changes the viewing experience while using the display system. In some embodiments, the hinge is motorized. In some embodiments, the hinge is directly adjusted by the user. The hinge is an example of a movable joint, including a hinge, ball joint, or track, along with the display system, or its components, which can move relative to the vehicle. The hinge includes at least a first and second portion that move relative to each other. For example, the first portion may be fixed to the vehicle component, and the second portion may be fixed to some or all of the display system.

[0186] 19E shows an embodiment in which the display system 1900 may reside within a recess in a vehicle part 1901. A pair of hinges 1906A, 1906B moves the display system into position in front of a second vehicle part 1901A. A third hinge 1906C moves a panel 1907 to allow movement of the display system. The vehicle parts 1901A and 1901 may be parts of a seat within the vehicle. The circuit block 1801 may be used to control the movement of the hinges and the display system as time t progresses.

[0187] Figure 19F shows an embodiment that combines aspects of Figures 19A and 19D. The entire display system 1901 is connected to a vehicle component 1901 via a hinge 1906, which can be articulated to adjust the entire display system. The position of the resulting virtual image changes, but its position relative to the display system is fixed. In some embodiments, the hinge is instead an articulated arm or ball joint that allows the display system to rotate in multiple directions, i.e., rotate it about different axes of rotation.

[0188] In any of the above embodiments, the mechanical integration arrangements (levers, arms, hinges, and tracks) may be motorized and controllable via buttons integrated into the vehicle, or may be manually adjustable based on viewer actions.

[0189] 20A-20E illustrate an embodiment of a display system in a vehicle. In FIG. 20A, a vehicle 76 houses two display systems 1900, which may be the display systems described above. Light exits the display systems 1900 and is reflected across the vehicle by a mirror 2001. The reflected light is then reflected again by a side window 1903 and incident on the eyes of an observer 77. In some embodiments, the window is curved with a radius of curvature R, so that the window provides optical power and helps collimate the light, forming a virtual image 78 with a very large depth outside the vehicle.

[0190] A similar embodiment is shown in FIG. 20B. A vehicle 76 is integrated with its side display system 1900. In this embodiment, the display system may have additional external components to complete the imager formation. A second element 74 reflects light to a first element 73, which is a polarization-changing semi-reflector. The light is rotated 90 degrees and transmitted by a second reflector, which may also be a reflective polarizer. The light is then viewed by an observer 77 as a virtual image 78. Because the first elements are semi-reflective, they allow light from the external environment to pass through, resulting in an overlaid virtual image creating an AR environment.

[0191] An example of such an environment is shown in Figure 20C. An observer 77 looks out a side window 1903 of a vehicle 76 and sees an external environment scene 1902. A portion 2002 of the scene overlaps with a virtual image 78, which may include annotations. In some embodiments, the annotations are generated at least in part by a GPS module or navigation system.

[0192] FIG. 20D shows an embodiment in which a display system 1900 is fixed to the roof 75 of a vehicle 76 to form a virtual image 78 above the vehicle. In some embodiments, the display system is partially transparent, allowing external light to pass through it, resulting in a simultaneous view of an external scene 1902. In some embodiments, a GPS module 2003 may be electrically coupled to the display system to generate content that depends on the coordinates or orientation of the vehicle relative to the environment. In some embodiments, a simultaneous localization and mapping (SLAM) module is coupled to the display system. The SLAM module uses computational algorithms to map the vehicle's environment while simultaneously tracking the vehicle's position within the environment. Such algorithms include an extended Kalman filter or a particle filter. Such modules are particularly useful for autonomous vehicles.

[0193] FIG. 20E, similar to FIG. 16, illustrates an embodiment in which a display system 1900 is integrated to perform the function of a conventional mirror on a vehicle. In this embodiment, content from the external environment is captured by a camera 2004 fixed to the exterior portion of the scene. In some vehicles, the camera is located approximately in the position of a conventional side mirror, and no side mirrors are present. The camera captures information about the environment to the side of the vehicle and can display it on a display system 1900 fixed to the interior of the vehicle 76, e.g., an interior door 2005. In some embodiments, the camera captures information about the rear of the vehicle and displays it on a display system 1900 fixed to the vehicle by an arm 2006, e.g., instead of a conventional rearview mirror. The advantage of this scenario, compared to a conventional "digital mirror" that is simply a display panel replacing a mirror, is that the depth associated with objects in the external environment can be preserved by the virtual depth of the display system.

[0194] 21A-21J show further embodiments of field-emitting cavities and displays for generating virtual images. In some embodiments, the display is a curved display, and at least one of the elements of the field-emitting cavity is curved. In FIG. 21A, a curved display 6 emits light into a field-emitting cavity 1. In some embodiments, the light first passes through a pre-cavity element 1804, such as a directional coating. The light is reflected by a first element 73, which is at an angle θ to the curved display. In some embodiments, the angle is approximately 45 degrees. In some embodiments, the angle is in the range of 35 to 45 degrees. In some embodiments, the angle is in the range of 45 to 55 degrees. In some embodiments, the first element 73 is a semi-reflector, such as a beam splitter.

[0195] The light is then reflected by second element 74 and directed through first element 73 (i.e., the light enters the first element twice on the same surface). In some embodiments, the second element is a curved reflector. In some embodiments, the geometry of the curved reflector is a freeform surface. The light then exits the field emission cavity through aperture optic 70 and is seen by observer 77, who sees virtual image 78. In some embodiments, the aperture optic is a quarter wave plate or quarter wave film laminated onto a transparent substrate.

[0196] Due to the curvature of the display 6 and the second element 74, the geometric surface of the virtual image 78 is not flat. The geometric surface on which the virtual image is located is called the focal plane. Therefore, the focal plane is not flat in these embodiments. In some embodiments, the focal plane coincides with a portion of the human horopter 2101. The horopter is a locus of points where the location of an image point on the left retina corresponds to the same location on the right retina. The horopter may be an empirical horopter or a theoretical horopter. In some embodiments, the horopter is a binocular horopter. In some embodiments, the horopter is an oculomotor horopter. Image points on the human horopter are fused in the human visual system, so that the observer sees a single, clear image point rather than a blurred vision. Therefore, a curved focal plane that maps to the human horopter provides both monocular and binocular depth cues. In some embodiments, the second element curves according to a freeform shape to match the horopter.

[0197] In some embodiments, the first element 73 is polarization dependent, and a quarter wave plate is disposed between the first element 73 and the second element 74. In some embodiments, such as these, the aperture optics 70 may comprise polarization and anti-reflection elements. In some embodiments, the pre-cavity element 1804 may include a polarization impinging element, such as a polarizer or wave plate, to optimize the brightness of the virtual image.

[0198] In some embodiments, the horizontal dimension of the field emission cavity is in the range of 30 to 40 cm. In some embodiments, the vertical dimension of the field emission cavity is in the range of 15 to 25 cm height. In some embodiments, the depth dimension of the field emission cavity is in the range of 5 cm to 20 cm depth. In some embodiments, the depth of the virtual image is in the range of 1 m to 3 m, and the lateral dimension of the virtual image is in the range of 75 cm to 130 cm.

[0199] In some embodiments, the mass of the field-emitting cavity and display, including the housing and frame, as well as the electronics and cabling for driving the display system, ranges from 1.5 to 5.5 kg. In some embodiments, it ranges from 2.5 to 3.5 kg. Thus, the display system is lighter than a standard display screen providing a comparable image size. The housing supporting the display and field-emitting cavity may be plastic, metal, carbon fiber, aluminum, magnesium, alloy, or composite material. In some embodiments, it is a thermoplastic resin such as polylactic acid, polyethylene terephthalate, acrylonitrile butadiene styrene, polycarbonate, polyvinyl chloride, or polymethyl methacrylate. In some embodiments, the housing mass ranges from 1 kg to 3 kg. The first and second elements and aperture optical elements may be made from optical materials such as fiberglass, polymers, or plastics. In some embodiments, the combined mass of these elements ranges from 0.5 kg to 1 kg, or from 0.5 kg to 2.0 kg.

[0200] The curved display 6 and curved second element 74 are selected to produce a clear virtual image without significant aberrations. Furthermore, because the display system is integrated into a portion of the vehicle, such as the rear of a headrest for a rear passenger, the system components must be small enough to fit. The curvature of the elements is necessary to overcome distortion of the virtual image within the viewable area of ​​the image.

[0201] Additionally, the curvature of the second element 74 and the curved display 6 may be shaped to pre-compensate for image distortion. For example, when enlarging an image, barrel distortion may be a resulting aberration: the image may be stretched substantially radially from the center point. The stretching can be modeled by a known transformation of the image content. Pre-compensation can be performed by applying a pincushion transformation to the image content. A pincushion transformation is the inverse of (optically generated) barrel distortion. Typically, the transformation is a geometric distortion, such as polynomial distortion. This is an example of correcting or pre-compensating for distortion lens distortion. Another type of distortion correction is perspective distortion correction. Other types of distortion compensation include perspective distortion compensation, which pre-compensates for distortion based on off-axis reflections of optical elements. This can be pre-compensated using a homography transformation, keystone correction, etc.

[0202] For example, a virtual image may have barrel distortion, which is produced by the non-uniform magnification of different elements of the image as they move through the field emission cavity. Barrel distortion is expressed as f(r)=r(1-kr 2 ), where r is the radial distance from the center of the image and k is a system parameter. To pre-compensate for this barrel distortion, an inverse function g can be applied to the display content itself: g(r)=r / (1-kr 2) To apply this to an image, the algorithm can determine the pixel size of the display content, calculate the center pixel, create a matrix of the same pixel size of the image, and use g(r) to map each pixel value of the original display content to an element in the matrix. The radial distance is calculated by calculating the pixel distance between the mapped pixel and the center pixel. Once all pixels are mapped, the matrix becomes the new pre-compensated display content. The actual functions f and g depend on the specific configuration and shape of the optical elements in the display system. Other types of compensation algorithms can use inverse functions, lookup tables, machine learning algorithms, or neural networks. In some embodiments, pre-compensation may affect the intensity or color profile of the pixels.

[0203] FIG. 21B shows an embodiment in which a curved display 6 emits light into a field-emitting cavity 1. The light is transmitted by a first element 73 and reflected by a second element 74, e.g., a curved reflector. The reflected light then re-enters the first element 73 and exits through an aperture optical element 70, resulting in an observer 77 seeing a virtual image 78 based on the displayed content of the curved display. In some embodiments, the aperture optical element 70 is angled relative to the primary optical axis, deflecting ambient light in a direction based on that angle. In some embodiments, the focal plane of the virtual image is curved, approximating the human horopter.

[0204] FIG. 21C illustrates an embodiment using an EO material 1803. In some embodiments, the EO material 1803 is a liquid crystal that can change the polarization of transmitted light based on an applied voltage. Light from the curved display 6 enters the field emission cavity 1, passes through the EO material 1803, and is incident on the first element 73. The first element 73 is, for example, a polarization-dependent reflector. In some embodiments, it is a reflective polarizer or polarization-dependent beamsplitter. When a first voltage is applied to the EO material, the polarization of light incident on the first element 73 is reflected and then transmitted through the aperture optical element. When a second voltage is applied, the polarization of light incident on the first element 73 is transmitted, strikes the curved second element 74, is reflected by the first element 73, strikes the flat second element 74, passes through the first element 73, and passes through the aperture optical element. In some embodiments, the flat second element 74 is polarization-changing and includes a wave plate, such as a quarter-wave plate. In some embodiments, the aperture optical element 70 includes a polarizer and an anti-reflection layer. In this way, one of two virtual images 78 can be generated, each having a different depth and focal plane.

[0205] In some embodiments, one of the focal points is curved, approximating a portion of the human horopter. The curvature of the focal plane is determined by the curvature of the display panel and the curved second element 74. The shape of the horopter near the point of gaze depends on the point of gaze itself. In some areas of the human field of view, it is convex, and in other areas, it is concave. The horopter also tends to distort vertically, i.e., pitch away from the viewer from bottom to top.

[0206] In Figure 21D, light from curved display 6 passes through first element 73A, then through second element 73B and is reflected by second element 74, which may be, for example, a curved reflector. It then passes through second element 73B (e.g., a quarter-wave plate) and is reflected by first element 73A through an aperture optical element to produce virtual image 78. In some embodiments, first element 73A is a polarization-dependent reflector.

[0207] FIG. 21E shows an embodiment with multiple curved elements. Light from a curved display 6 enters a field-emitting cavity 1. The light strikes a first element 73, which is a curved semi-reflector. The light strikes a second element 74, which is a curved reflector, and is transmitted by the first element through an aperture optic 70 so that an observer 77 sees a virtual image. The combined curvature of the first element 73 and the second element 74 can be used to modify the focal plane, virtual image depth, approximation of the focal plane for a particular horopter, or to correct or pre-compensate for image distortion. In some embodiments, the curved surfaces of each of the elements are oriented approximately vertically. In some embodiments, the aperture optic 70 is curved.

[0208] In Figure 21F, the curved display emits light into a field-emission cavity. The light is transmitted by a first element 73, which is a curved semi-reflector, reflected by a second element 74, which is also a curved semi-reflector, and then travels a round-trip path between the first element 73 and the second element 74 before being transmitted to an observer 77. Any of the elements of the field-emission cavity can have optical power to further focus or collimate the light.

[0209] FIG. 21G illustrates an embodiment using multiple field-emitting cavities. Light from a first curved display 6A is transmitted through a first field-emitting cavity 1A, e.g., the field-emitting cavity described in FIG. 21A. The light then passes through a second curved display 6B, which is semi-transparent so that the light from the first display is transmitted and new display content is emitted. Light from both displays is transmitted to a second field-emitting cavity 1B, e.g., the field-emitting cavity described in FIG. 21F. The result is a set of virtual images 78. In some embodiments, each of the focal planes is curved, each approximating a human horopter.

[0210] Finally, Figure 21H shows an embodiment in which a curved display 6 emits light into a field-emission cavity 1. The field-emission cavity may include a lens element 2102, such as a Fresnel lens, to provide refractive power. The focal length of the lens element may be such that it collimates the light and creates a virtual image that is farther away from the viewer.

[0211] 22A and 22B show a table containing a sequence of three-step movements for deploying a display system from its stowed position in front of a viewer (e.g., the display system 1900 and observer 77 shown in FIGS. 19A-19F, 23A-23F, 24A-24E, and 25A-25J). Each movement is further decomposed into three simple movements: i) translation, ii) rotation, and iii) relative folding movement.

[0212] 23A-23F show different positions for storing the display system 1900 and possible simple movements for bringing the display system 1900 in front of the observer 77. FIG.

[0213] FIG. 23A depicts a side view of an observer 77 and a driver or front passenger 2302. The display system 1900 can be stored in a vertical plane parallel to the line of sight of the observer 77. The display system 1900 can be placed in front of the observer 77 by simple translation. For example, the display system 1900 can be stored in the top of the cockpit 2303A, or behind 2303B of a headrest 2301, or in the bottom 2303C of the rear seat 2501 of the driver or front passenger 2302. The viewer 77 can store or deploy the display system 1900 via an interface 2304.

[0214] 23B depicts a rear view of the observer 77. The display system 1900 can be stored in a position contained within a vertical plane perpendicular to the line of sight of the observer 77. The display system 1900 can be placed in front of the observer 77 by a simple translational movement. For example, the display system 1900 can be stored above the cockpit 2303A, on the side of a headrest 2303B, or below the left or right 2303C of the driver or front passenger 2302. The viewer 77 can store or deploy the display system 1900 via the interface 2304.

[0215] FIG. 23C depicts a side view of the viewer 77 and the driver or front passenger 2302. The display system 1900 can be stored in a vertical plane parallel to the line of sight of the viewer 77. The display system 1900 can be placed in front of the viewer 77 by a simple rotational movement. For example, the display system 1900 can be stored behind the viewer's headrest 2301A, above the cockpit 2303B, or below the headrest 2301B 2303C, or at the bottom 2303D of the rear seat 2501 of the driver or front passenger 2302, or below the viewer's seat 2303E. The viewer 77 can store or deploy the display system 1900 via the interface 2304.

[0216] 23D depicts a rear view of the viewer 77. The display system 1900 can be stored in a location contained within a plane surrounding the viewer 77. The display system 1900 can be placed in front of the viewer 77 by a simple rotational movement. For example, the display system 1900 can be stored behind 2303A the viewer 77, or above the cockpit 2303B, to the side 2303C of the driver or front passenger 2302, or below 2303D the viewer 77. The viewer 77 can store or deploy the display system 1900 via the interface 2304.

[0217] 23E depicts a perspective view and a side view of possible direct attachment points of a support or arm 2305 to the display system 1900. The attachment points may be on the top 2305A, or the side 2305C, or the back 2305C, or the bottom 2305D of the display system 1900.

[0218] 23F depicts a perspective view and a side view of possible attachment points of a support or arm 2305 to a gimbaled mount 2306 that supports the display system 1900. The attachment points may be on the top 2305A, or the side 2305C, or the back 2305C, or the bottom 2305B of the gimbaled mount 2306.

[0219] FIGS. 24A-24E show a set of embodiments for integrating a display system into a vehicle using various articulating or telescoping joints. These are examples of the types of motion described above. FIG. 24A shows a display system 1900 integrated into a vehicle roof 75 via a set of arms 2305 and joints or hinges 1906. The hinges may be one-dimensional hinges or may allow rotation in multiple dimensions. The display system also has a handle 2401 that allows the user to manually adjust its position. An example of a hinge 1906 that allows multiple axes of rotation is shown in FIG. 24B. The end of a first arm 2305A terminates in a first joint element 2402A, such as a socket. The end of a second arm 2305B terminates in a second joint element 2402B, such as a ball.

[0220] Another example of vehicle integration is shown in Figure 24C. The display system 1900 is connected to an arm 2305, the other end of which is connected to a first joint element 2402A. This may be a sleeve that wraps around a second joint element 2402B, which may be a cylinder, for example. The first joint element can rotate about an axis that passes through the second joint element. It can also slide vertically up and down. In any of these embodiments, the joint element can include a notch or locking mechanism for positioning stability and for repeatable placement of the display system in the same orientation.

[0221] 24D shows an embodiment in which the display system 1900 is coupled to a telescoping mechanism 2403 by a hinge 1906. When extended, the telescoping mechanism extends into a first telescoping sleeve 2403A, a second telescoping sleeve 2403B, and a third telescoping sleeve 2403C. In some embodiments, the hinge is a gimbal mounted hinge. In some embodiments, the hinge is an articulation joint or a ball joint.

[0222] 24E shows an embodiment in which the display system is attached to a portion of the vehicle 1901A. This portion is attached to a secondary portion of the vehicle 1901A by a hinge 1906. In the display configuration, the display system is exposed and visible outside the secondary portion, which has a recessed area or compartment 2302. The hinges are flush at 90 degrees and 0 degrees, so there is no gap between the portion of the vehicle and the secondary portion of the vehicle. A non-porous lip 2404 may be provided to hide any seams or gaps when the display system 1900 is extruded and placed into the compartment 2302.

[0223] FIGS. 25A-25J show various locations where a display system can be incorporated into a vehicle. In FIG. 25A, an observer 77 views a display system 1900 mounted behind a headrest 2301 of a seat 2501 used by another passenger 2302 in the vehicle. In some embodiments, a virtual image 78 has a depth that is on the opposite side of the seat 2501 from the observer 77. In this example, the front passenger does not see a virtual image at all. In FIG. 25B, a viewer views a display system 1900 mounted on the seatback of a seat 2501, located below a headrest 2301 used by another passenger 2302. In some embodiments, the virtual image 78 is deeper than the display system. FIG. 25C shows an embodiment in which the display system 1900 replaces the headrest. The front passenger 2302 is protected by padding 2502 that surrounds the display system. The observer 77 is in the same position behind the seat 2501. In Figure 25D, observer 77 views a display system 1900 mounted to the back of a seat 2501 by a linear track 1904 that allows the system to move up and down. In some embodiments, nothing is attached to the headrest 2301.

[0224] FIG. 25E shows an embodiment in which display system 1900 is mounted to vehicle roof 75 by hinge 1906. Handle 2401 can be used by observer 77 to adjust the position of the system. In some embodiments, the viewer is a rear passenger sitting behind seat 2501. In some embodiments, such as FIG. 25F, display system 1900 is mounted directly to vehicle roof 75 for observer 77 sitting behind seat 2501 for another passenger 2501.

[0225] FIG. 25G shows a vehicle-integrated embodiment in which a display system 1900 is mounted to the rear of a seat 2501 and directs light through a first aperture optical element 70A to an area behind a headrest 2301. The light is then reflected by a first element 73, reflected by a second element 74, and transmitted by the first element 73 and a second aperture optical element 70B toward an observer 77. In some embodiments, the light transmitted through the first aperture optical element 70A can be polarized. The first element can be a polarization-dependent semi-reflector, such as a reflective polarizer. The second element can be a reflector and a quarter-wave plate to rotate the polarization. In FIG. 25H, a similar display system 1900 mounted to a seat 2501 directs light vertically through aperture optical element 70, where it is then reflected by a mirror 2001 to an observer.

[0226] Figure 25I shows an embodiment in which two observers 77, possibly seated in the rear seats of a vehicle 76, are simultaneously viewing a display system 1900 integrated between the car seats. Similarly, in Figure 25J, the vehicle 75 is controlled by a passenger who is the driver 2302, and the front passenger is an observer 77 of the display system 1900 integrated into the front of the passenger compartment.

[0227] 26A-26C show the different rotational degrees of freedom that three sequentially attached parts can deploy, each contained in a plane that contains the angle through which the two components connected by the joint can rotate relative to each other.

[0228] 26A shows the case where all rotational degrees of freedom are contained within the same plane 2601, which also means that angles 1906A, 1906B, and 1906C are all coplanar, e.g., in this case, all elements of display system 1900 are deployed sequentially in one direction.

[0229] 26B shows two rotational degrees of freedom 1906A and 1906B contained in a single plane 2601A, and a third rotational degree 1906C contained in a different plane 2601B relative to the first plane 2601A. For example, in this case, the first two elements 73 and 74 of the display system 1900 are deployed in the same direction, while the third element is deployed in a different direction.

[0230] Figure 26C shows the case where all rotational degrees of freedom lie in different planes. For example, first rotation 1906A is contained in plane 2601A, second rotation 1906B is contained in plane 2601B, and third rotation 1906C is contained in plane 2601C. This is the case where all three elements are deployed in different directions.

[0231] FIGS. 27A-27O show exemplary embodiments of a foldable display in which components or elements of the display system (such as the display, first and second elements, aperture optics, etc.) can move or fold relative to one another. Some of these are specific examples of the types of motion in FIGS. 26A-26C. In FIG. 27A, a portion of a vehicle 1901 is connected to a mechanical track 1904. In some embodiments, the mechanical track is a plurality of parallel mechanical tracks. In some embodiments, a rigid guide bar is connected to the tracks so that the tracks move in unison. The display 6 may be a curved display, attached to the track and moving with it. One end of the display has a hinge 1906 that connects to the first element 73 of the field emission cavity. The other end of the first element has another hinge that couples to the second element 74. This element has a hinge 1906 attached to a portion of the vehicle 1901. The position of this hinge is fixed but is free to rotate. In some embodiments, a handle 2401 is connected to a portion of the display system, allowing the user to fold the display. In the display position, the display system generates a virtual image 78. In some embodiments, the focal plane is curved and maps to a portion of the human horopter. The folded configuration of the embodiment of FIG. 27A is shown in FIG. 27B. When the track 1904 is engaged, it slides the display 6 to the right, causing the first element 73 and the second element 74 to rotate about their hinges 1906. When the mechanical track moves the display all the way to the right, the first and second elements are approximately in the same plane as the portion of the vehicle 1901 to which the display and track are mounted. In some embodiments, the track is motorized and engages / disengages with an electrical signal from an interactive interface, lever, or button. In some embodiments, these elements are integrated into the handle 2401.

[0232] FIG. 27C shows a similar embodiment, in which the display 6 is attached to a portion of the vehicle 1901 and fixed in place. A hinge 1906 couples the display to the first and second elements 73, 74 of the display system. In some embodiments, a handle 2401 is used to engage the folding mechanism of the hinge 1906. In some embodiments, the first element 73 is flexible, and the folded configuration of such an embodiment is shown in FIG. 27D. The flexible first element 73 may be a flexible glass or plastic semi-reflector. When the system is folded, the first element 73 folds upon itself so that the entire display system is approximately in the same plane as the portion of the vehicle 1901. In some embodiments, the flexible element may be rollable. In some embodiments, the display is a flexible OLED display that can be rolled and unrolled as part of the folding mechanism. In some embodiments, the components of the display system are piecewise rigid, i.e., a given component is made up of rigid subcomponents joined by hinges that allow the component to fold into a footprint of a size comparable to the subcomponents. In such embodiments, pre-compensation techniques are used to remove seam or edge artifacts in the virtual image. In some embodiments, additional physical components are used to compensate for the seams.

[0233] FIG. 27E shows a folding system in which the display 6 is coupled to a first element 73 and a second element 74 by a series of hinges 1906. The second element 74 is mounted to a portion of the vehicle 1901. In some embodiments, the display is a curved display and the second element is a curved reflector. A series of latches 2701 lock the display in a configuration for viewing a virtual image. FIG. 27F shows the same embodiment in a closed or folded orientation. The latches 2701, which are grouped together on the first element 73, are detached from the portion of the vehicle 1901 so that the hinges 1906 are free to rotate. The elements of the display system are generally in-plane with each other, and two latches 2701 are connected to each other to secure the components in place.

[0234] Figure 27G shows an example of two components of a display system, such as first element 73 and second element 74, that are movable relative to each other and are attached to a portion of joint 2402 by a series of hinges 1906A, 1906B, and 1906C, so that the elements are free to rotate about an axis through that portion.

[0235] FIG. 27H shows an embodiment of a foldable display system having an aperture optical element 70. The display 6 may be curved and is mounted to a portion of a vehicle 1901. The display 6, a first element 73, and a second element 74 are coupled to one another by a series of hinges 1906. The aperture optical element 70 is also coupled to the first element 73 by the hinge 1906. The aperture optical element is also locked in place by a latch 2701 connected to a support bar 2702. The first element is also locked to the portion of the vehicle 1901 by the latch 2701. To fold the aperture optical element, the first latch 2701 is released and the support bar 2702 is folded back to lie alongside the second element 74. The aperture optical element 70 can now be folded and flush with the first element 73. This is shown in FIG. 27I. Here, the system is the same as that shown in FIG. 27E and can be further folded into the geometry of FIG. 27F.

[0236] FIG. 27J shows an embodiment in which the display 6 and the first and second elements 73, 74 of the field emission cavity 1 are substantially parallel to one another. They are connected to one another by a folding linkage 2703. In the viewing position, the linkage is extended. The folded position of this embodiment is shown in FIG. 27K. The folding linkage 2703 folds as the alternating hinges move away from the field emission cavity. In some embodiments, the linkage is motorized. In some embodiments, the linkage is a Scott-Russell type linkage.

[0237] FIG. 27L shows an exemplary embodiment in which the field-emission cavity 1 is attached to a hollow display housing 2704. The display housing is wide enough to allow a portable device 2705 to be inserted into it. In some embodiments, the portable device is a tablet, a foldable laptop, or a smartphone. FIG. 27M shows the operation of the embodiment of FIG. 27L. When the portable device 2705 is inserted into the housing 2704, its display content enters the field-emission cavity 1 as a first light signal 2707A. The light is processed by the cavity elements and exits as a second light signal 2707B to an observer 77 who sees a virtual image 78. The virtual image is based on the display content of the portable device. FIG. 27N shows the display housing 2704 having a top surface 2704A and a bottom surface 2704B. The bottom surface is primarily composed of guide rails to support the portable device 2704, but is mostly transparent to allow light from the device to be transmitted to the field-emission cavity. FIG. 27O shows the underside of the housing. The bottom surface 2704B is a guide track around the edge, which allows the portable device 2705 to be viewed. An adjustable alignment clamp 2706 holds the portable device in place. The alignment clamp has the ability to be adjusted in two or three dimensions to position the device for proper virtual image production. In some embodiments, the position of the adjustment clamp is determined based on electronic signals for an interactive interface or wired or wireless signals from the portable device itself. These various signals contain information about the specific product, model number, dimensions, etc., so that the clamp's position can be optimized for image quality.

[0238] FIG. 28 shows an embodiment in which the display system 1900 is mounted behind a portion of a headrest 2301 and / or seat back 2501, primarily for rear passengers. In this embodiment, the display content may be entertainment content. In some embodiments, the virtual image 78 is located further away than the display system 1900 and the seat 2501. An interactive interface 2304, which may consist of a remote, buttons, a touchscreen, or a gesture sensor, is integrated onto the vehicle door 2301. In some embodiments, the interface is integrated into a different part of the vehicle, such as the center console. The interface allows passengers to modify the display content or change the orientation or position of the display system. In some embodiments, the interface is coupled to mechanisms for moving various mechanical joints and arms coupled to the display system. In some embodiments, the interface allows a user to input information about a portable device used in the embodiments in FIGS. 27L-27O, thereby enabling the insert to optimally position the device for generating the virtual image. In some embodiments, the interface actuates a powered hinge to fold the display system, for example, according to the embodiments of FIGS. 27A-27O. In some embodiments, the display system comprises a field emission cavity and a housing in which the portable device (such as the embodiment of Figures 27L-27O) is placed. In these embodiments, the interactive interface is programmed to allow a user to control system parameters of the display system. The system parameters include parameters for the field emission cavity, such as spacing between components or relative orientation between them. Such control involves using the interactive interface to actuate mechanisms coupling the various components of the display system.System parameters include system properties of display content on the portable device, such as refresh rate, display brightness, color profile, font or image size, etc. In some embodiments, the interactive interface is programmed to control content on the portable device, such as content selection within an entertainment application, active apps being displayed, functions and navigation tools within the application, etc.

[0239] In some embodiments, the display system includes a camera 2004 that is part of the display system or fixed to the vehicle. The camera may be a webcam, whereby an image of a viewer of the display system is captured by the webcam and transmitted to the display system. In some embodiments, the captured image is communicated over a wireless network to another party with whom the viewer is communicating via a videoconferencing application shown on the display system.

[0240] Although the present invention has been described in relation to its preferred embodiments, it should be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.

[0241] Various aspects may be described algorithmically herein. While example algorithms may be provided, the desired functions may be implemented in any suitable manner. Those skilled in the art will appreciate that such functions or algorithms may be implemented, for example, in hardware, software, or a combination of hardware and software. A module (e.g., a “GPS module,” “SLAM module”) may comprise hardware and / or software to implement the disclosed functions or algorithms. For example, in some embodiments, an algorithm may be implemented through a module having one or more processors executing computer code stored on one or more non-transitory computer-readable storage media. In some embodiments, a function is implemented at least in part through a module with dedicated hardware (e.g., ASIC, FPGA). In some embodiments, modules may share components. For example, a first functional module and a second functional module may both utilize a common processor (e.g., through time-sharing or multithreading) or have computer-executable code stored on a common computer storage medium (e.g., in different memory locations).

[0242] In some instances, a module may be identified as a hardware module or a software module. A hardware module includes or shares hardware for implementing the module's functionality. A hardware module may include software, i.e., a software module. A software module comprises information that may be stored, for example, on a non-transitory computer-readable storage medium. In some embodiments, the information may comprise instructions executable by one or more processors. In some embodiments, the information may be used at least in part to configure hardware such as an FPGA. In some embodiments, an algorithm may be recorded as a software module. A capability may be implemented, for example, by reading a software module from a storage medium and executing it on one or more processors, or by reading a software module from a storage medium and using the information to configure hardware.

[0243] As used herein, the terms "machine-readable medium," "computer-readable medium," and similar terms refer to volatile or non-volatile, non-transitory media that store data and / or instructions that cause a machine to operate in a specific fashion. Common forms of machine-readable media include, for example, hard disks, solid-state drives, magnetic tapes, or any other magnetic data storage media, optical disks, or any other optical data storage media, any physical media with a pattern of holes, RAM, PROM, EPROM, FLASH-EPROM, NVRAM, any other memory chip or cartridge, and networked versions thereof.

[0244] These and other various forms of computer-readable media may be involved in carrying one or more sequences of one or more instructions to a processing device for execution. Such instructions embodied on the media are referred to as "instructions" or "code," and the instructions may be grouped together to form a computer program or other grouping. When executed, such instructions may enable the processing device to perform the features or functions of the present application as discussed herein.

[0245] As used herein, a "processing device" may be implemented as a single processor that performs processing operations, or a combination of special-purpose and / or general-purpose processors that perform processing operations. A processing device may include a CPU, GPU, APU, DSP, FPGA, ASIC, SOC, and / or other processing circuitry.

[0246] Various embodiments described herein are illustrated with reference to exemplary block diagrams, flow charts, and other diagrams. As will become apparent to one of ordinary skill in the art after reading this specification, the illustrated embodiments and their various alternatives can be implemented without being limited to the illustrated examples. For example, block diagrams and their accompanying description should not be construed as mandating a particular architecture or configuration.

[0247] Each of the processes, methods, and algorithms described in the previous sections may be embodied in code components executed by one or more computer systems or computer processors comprising computer hardware, and may be fully or partially automated. The methods and algorithms may be implemented partially or entirely in application-specific circuitry. The various features and processes described above may be used independently of one another or combined in several ways. Different combinations and subcombinations are intended to fall within the scope of the present disclosure, and some implementations may omit some method or process blocks. Furthermore, unless the context dictates otherwise, the methods and processes described herein are not limited to any particular sequence, and the associated blocks or states may be performed in other appropriate sequences, in parallel, or in some other manner. Blocks or states may be added to or removed from the disclosed exemplary embodiments. The performance of a particular operation or process may reside within a single machine, but may also be distributed among computer systems or computer processors spread across several computing resources.

[0248] As used herein, the term "or" may be construed in an inclusive or exclusive sense. Additionally, the description of resources, acts, or structures in the singular should not be construed as excluding the plural. Unless otherwise stated or understood otherwise within the context as used, conditional language such as "can," "could," "may," or "might," among others, is intended to generally convey that certain embodiments include certain features, elements, and / or steps, but that other embodiments do not include the specified features, elements, and / or steps.

[0249] Terms and phrases used herein, and variations thereof, unless otherwise expressly stated, should be construed as open-ended rather than limiting. Words such as "conventional," "traditional," "usual," "standard," "known," and similar terms should not be construed as limiting the items described to a given period or to items available at a given time, but instead should be construed to encompass conventional, prior, usual, or standard technology that may be available or known at any time now or in the future. The presence of broader terms such as "one or more," "at least," "not limited to," or other similar terms should not be construed to imply that a narrower case is intended or required in the absence of such broader term.

Claims

1. Light-emitting curved displays; a field emission cavity that directs the light from the display along a path to create a virtual image; Equipped with The field emission cavity comprises: a semi-reflector disposed along said path; a curved reflector positioned along the path to reflect the light; an aperture optical element that transmits the light away from the field emission cavity; and the path crosses the semi-reflector at least twice; system.

2. The system of claim 1 , wherein the system further comprises a vehicle, and the curved display and the field emission cavity are mounted to a portion of the vehicle.

3. The system of claim 2 , wherein the portion of the vehicle is selected from the group consisting of a seat, a roof, a center console, or a dashboard.

4. The system of claim 2 , wherein the curved display and the field emission cavity are attached by a mechanical joint that allows relative movement between (i) the portion, and (ii) the curved display and the field emission cavity.

5. The system of claim 4 , wherein the mechanical joint is selected from the group consisting of a hinge, a track, a ball joint, a gimbal joint, an extension joint, an articulated arm, a mechanical linkage, and combinations thereof.

6. The system of claim 4 , wherein the aperture optic comprises an absorptive polarizer and an anti-reflective layer.

7. The system of claim 2 , wherein at least two of the curved display, the curved reflector, and the semi-reflector are coupled by a mechanical joint such that the system is at least partially foldable.

8. The system of claim 7 , wherein at least one of the curved display, the semi-reflector, the aperture optic, and the curved reflector is flexible.

9. The system of claim 7 further comprising a handle for controlling the mechanical joint.

10. The system of claim 7 , further comprising an interactive interface for controlling the position or orientation of the virtual image.

11. The system further comprises: a housing containing the curved display and the field emission cavity; a mechanical joint that allows relative movement between (i) the portion, (ii) the curved display and the field emission cavity; handle; Equipped with the mechanical joint is operably connected to the housing and the portion of the vehicle; the handle is operably connected to the housing such that a user can use the handle to change the position or orientation of the housing relative to the vehicle; The system of claim 2.

12. The system of claim 1 , further comprising an interactive interface for controlling the position or orientation of the virtual image.

13. The system of claim 1 , wherein the aperture optical element comprises a quarter wave plate.

14. The system of claim 1 , wherein the virtual image has a lateral size that is 1 to 3 times larger than the lateral size of the curved display.

15. The system of claim 1 , wherein a depth of the virtual image to a headbox is 1 to 3 times the distance from the headbox to the curved display.

16. The system of claim 1 , wherein the semi-reflector and the curved display are oriented at an angle relative to each other in the range of 35 to 55 degrees.

17. The system of claim 1 , wherein the content for the curved display is entertainment content.

18. The system of claim 1 , wherein the curved display is not in the direct line of sight of an observer.

19. The system of claim 1 , wherein the virtual image focal plane approximates a human horopter.

20. The system of claim 1 , wherein the system has a mass between 1500 and 5000 grams.

21. The system of claim 1 , wherein the displayed content is pre-compensated to mitigate distortions produced by the system.

22. The system of claim 1 , wherein the system further comprises a quarter wave plate disposed along the optical path, and the partial reflector is a polarization dependent partial reflector.

23. The system of claim 1 , further comprising a camera for capturing information about the viewer.

24. a display housing for a portable display device, the display housing having an entrance opening for directing light from the portable display device to a field emission cavity; The field emission cavity comprises: a semi-reflector positioned to direct said light therethrough; reflector; and When the portable display device displaying content is placed within the display housing, a virtual image based on the content is generated. system.

25. 25. The system of claim 24, wherein the display housing is shaped to accommodate a tablet, smartphone, or laptop.

26. 25. The system of claim 24, wherein the system further comprises a vehicle, and the display housing and the field emission cavity are mounted to the vehicle.

27. 27. The system of claim 26, wherein the display housing and the field emission cavity are attached to the vehicle via a mechanical joint.

28. 28. The system of claim 27, wherein the mechanical joint is selected from the group consisting of a hinge, a track, a ball joint, a gimbal joint, an expansion joint, and a mechanical linkage.

29. 25. The system of claim 24, wherein the system further comprises an interactive interface for controlling the content and a plurality of system parameters.

30. 25. The system of claim 24, wherein the display housing includes a plurality of alignment clamps for setting the position of the portable display device based on information about the portable display device.

31. housing; a field emission cavity mounted within the housing to direct light from a light source along a path to generate a virtual image based on the light source; Equipped with The field emission cavity comprises: an entrance aperture for receiving said light; a semi-reflector disposed along said path; a curved reflector positioned along the path to reflect the light; an aperture optical element that transmits the light away from the field emission cavity; and the path crosses the semi-reflector at least twice; system.

32. 32. The system of claim 31, wherein the system further comprises a vehicle, and the housing is mounted to the vehicle.

33. The system further comprises the light source; 32. The system of claim 31 , wherein the light source is a curved display mounted within the housing and positioned to emit the light through the entrance aperture into the field emission cavity.

34. 34. The system of claim 33, wherein a depth of the virtual image to a headbox is greater than a distance between the curved display and the headbox.

35. 34. The system of claim 33, wherein the virtual image has a lateral size greater than a lateral size of the curved display.

36. 34. The system of claim 33, wherein the system further comprises a web camera for capturing information about the viewer.

Images