Display system with multiple light paths for performing concave

Abstract

The present invention discloses an electronic device, which may include a display module that produces a concave image having a high-resolution area and a low-resolution area. The module may include a reflective display panel that produces a first reflected light during a first time period and a second reflected light during a second time period. The first reflected light may be reflected from a beam splitter to form the low-resolution area of ​​the concave image. The second reflected light may be transmitted by the beam splitter, reduced by a lens, and redirected by an optical steering element to produce the high-resolution area at an adjustable desired position in the concave image. The reflective display panel may be replaced by an emissive display panel group that simultaneously displays the high-resolution area and the low-resolution area in the concave image. These emissive display panel groups may be replaced by front-illuminated reflective display panels.

Description

[0001] This patent application claims priority to U.S. Provisional Patent Application No. 62 / 939,214, filed on November 22, 2019, which is hereby incorporated by reference in its entirety. Background Art

[0002] The present disclosure relates generally to optical systems and, more particularly, to optical systems for displays.

[0003] An electronic device may include a display that presents an image close to a user's eyes. For example, devices such as virtual reality and augmented reality headsets may include a display with optical elements that allow a user to view the display.

[0004] Designing devices such as these can be challenging. If care is not taken, the components used to display content can be unsightly and bulky, and may not exhibit the desired level of optical performance. Summary of the invention

[0005] An electronic device such as a head mounted device may have one or more near eye displays that produce images for a user. The head mounted device may be a pair of virtual reality glasses, or may be an augmented reality headset that allows an observer to view both computer generated images and real world objects in the observer's surroundings.

[0006] The near-eye display may include a display module that generates light and an optical system that redirects light from the display module toward an eye box. The optical system may include a waveguide having an input coupler and an output coupler. The light provided to the eye box may include a concave image having a high-resolution area and a low-resolution area. The display module may generate the concave image and may adjust the position of the high-resolution area over time (e.g., so that the high-resolution area overlaps the center of the viewer's gaze as the viewer's gaze changes).

[0007] The display module may include a light source that generates illumination light, a reflective display panel (e.g., a liquid crystal on silicon (LCOS) or a digital micromirror device (DMD) panel), a polarizing beam splitter, a lens, and an optical steering element such as an adjustable mirror or a switchable liquid crystal steering device. The reflective display panel may reflect the illumination light as a first reflected light during a first time period and may reflect the illumination light as a second reflected light during a second time period. The beam splitter may reflect the first reflected light toward the optical system as a low-resolution area of ​​a concave image, but may transmit the second reflected light. The lens may reduce the second reflected light transmitted by the polarizing beam splitter to generate reduced light. The optical steering element may redirect the reduced light through the beam splitter and toward the optical system as a high-resolution area of ​​the concave image. The control circuit may adjust the optical steering element to change the position of the high-resolution area in the concave image over time.

[0008] In another suitable arrangement, the optical system may include a first group of emitting display panels and a second group of emitting display panels, such as micro light emitting diode (uLED) display panels, micro organic light emitting diode (uOLED) display panels, and vertical cavity surface emitting laser (VCSEL) array display panels. The first group of emitting display panels may generate a first illumination light. The beam splitter may reflect the first illumination light toward the optical system as a low-resolution area of ​​a concave image. The second group of emitting display panels may generate a second illumination light. The lens may reduce the second illumination light to generate reduced light. The optical steering element may redirect the reduced light toward the beam splitter. The beam splitter may transmit the reduced light redirected by the optical steering element toward the optical system as a high-resolution area of ​​the concave image. The control circuit may adjust the optical steering element to change the position of the high-resolution area in the concave image over time. If desired, the first group of emitting display panels and the second group of emitting display panels may be replaced with front-illuminated LCOS display panels. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is an illustration of an illustrative system with a display according to some embodiments.

[0010] Figure 2 is a top view of an illustrative optical system having a display module with multiple optical paths for performing dynamic concave operation according to some embodiments.

[0011] Figure 3 According to some embodiments, Figure 2 Illustration of an illustrative concave image with adjustable high resolution area output by an optical system of the type shown.

[0012] Figure 4 is a diagram of an illustrative display module having a reflective display panel for producing a concave image with adjustable high resolution areas, according to some embodiments.

[0013] Figure 5 is a diagram of an illustrative display module having an emissive display panel for producing a concave image with an adjustable high resolution area, according to some embodiments.

[0014] Figure 6 According to some embodiments, Figure 5 Illustration of an exemplary front-lit reflective display panel in a display module of the type shown. DETAILED DESCRIPTION

[0015] Figure 1An exemplary system having a device with one or more near-eye display systems is shown in FIG. 1 . System 10 may be a head-mounted device having one or more displays, such as near-eye display 14 mounted within a support structure (housing) 20. Support structure 20 may have the shape of a pair of glasses (e.g., a support frame), may form a housing having the shape of a helmet, or may have other configurations for facilitating mounting and securing components of near-eye display 14 on a user's head or near an eye. Near-eye display 14 may include one or more display modules, such as display module 14A, and one or more optical systems, such as optical system 14B. Display module 14A may be mounted in a support structure, such as support structure 20. Each display module 14A may emit light 22 (image light), which is redirected toward the user's eye at eye box 24 using an associated one of optical systems 14B.

[0016] Control circuitry 16 may be used to control the operation of system 10. Control circuitry 16 may include storage and processing circuitry for the operation of system 10. Circuitry 16 may include storage devices such as hard drive storage devices, non-volatile memory (e.g., electrically programmable read-only memory configured to form a solid-state drive), volatile memory (e.g., static or dynamic random access memory), etc. The processing circuitry in control circuitry 16 may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, graphics processing units, application specific integrated circuits, and other integrated circuits. Software code (instructions) may be stored on memory in circuitry 16 and run on processing circuitry in circuitry 16 to implement operations for system 10 (e.g., data acquisition operations, operations involving the use of control signals to condition components, image rendering operations that produce image content for display to a user, etc.).

[0017] The system 10 may include input-output circuitry such as an input-output device 12. The input-output device 12 may be used to allow data to be received by the system 10 from an external device (e.g., a tethered computer, a portable device (such as a handheld device or laptop), or other electrical device), and to allow a user to provide user input to the head mounted device 10. The input-output device 12 may also be used to collect information about the environment in which the system 10 (e.g., the head mounted device 10) is operating. Output components in the device 12 may allow the system 10 to provide output to the user, and may be used to communicate with external electronic devices. The input-output device 12 may include sensors and other components 18 (e.g., image sensors for capturing images of real-world objects digitally merged with virtual objects on a display in the system 10, accelerometers, depth sensors, light sensors, tactile output devices, speakers, batteries, wireless communication circuits for communicating between the system 10 and external electronic devices, etc.). In one suitable arrangement, sometimes described herein as an example, the components 18 may include a gaze tracking sensor that collects gaze image data from the user's eyes at the eye box 24 to track the direction of the user's gaze in real time. For example, the gaze tracking sensor may include an infrared or other light emitter that emits infrared or other light toward the eyebox, and an image sensor that senses the infrared or other light reflected from the user's eyes (e.g., where the sensed light identifies the gaze direction of the user's eyes).

[0018] Display module 14A may include a reflective display (e.g., a liquid crystal on silicon (LCOS) display, a digital micromirror device (DMD) display, or other spatial light modulator), an emissive display (e.g., a micro light emitting diode (uLED) display, an organic light emitting diode (OLED) display, a laser-based display, etc.), or other types of displays. The light source in display module 14A may include a uLED, an OLED, an LED, a laser, a combination thereof, or any other desired light emitting component.

[0019] Optical system 14B may form a lens that allows an observer (see, e.g., an observer's eye at eyebox 24) to observe an image on display 14. There may be two optical systems 14B associated with the user's respective left and right eyes (e.g., to form a left lens and a right lens). A single display 14 may produce images for both eyes, or a pair of displays 14 may be used to display images. In a configuration with multiple displays (e.g., a left-eye display and a right-eye display), the focal length and position of the lenses formed by the components in optical system 14B may be selected so that any gaps that exist between the displays will not be visible to the user (e.g., so that the images of the left and right displays overlap or merge seamlessly).

[0020] If desired, optical system 14B may include components (e.g., an optical combiner, etc.) to allow real-world image light from a real-world image or object 25 to be optically combined with a virtual (computer-generated) image such as the virtual image in image light 22. In this type of system (sometimes referred to as an augmented reality system), a user of system 10 can view both real-world content and computer-generated content overlaid on top of the real-world content. Camera-based augmented reality systems may also be used in device 10 (e.g., an arrangement in which a camera captures a real-world image of object 25 and digitally merges that content with virtual content at optical system 14B).

[0021] If desired, system 10 may include wireless circuitry and / or other circuitry to support communication with a computer or other external device (e.g., a computer that provides image content to display 14). During operation, control circuitry 16 may provide image content to display 14. The content may be received remotely (e.g., from a computer or other content source coupled to system 10) and / or may be generated by control circuitry 16 (e.g., text, other computer-generated content, etc.). The content provided to display 14 by control circuitry 16 may be viewed by an observer at eyebox 24.

[0022] Figure 2 Yes, you can Figure 1 A top view of an exemplary display 14 used in the system 10 is shown. Figure 2 As shown, the near-eye display 14 may include one or more display modules, such as display module 14A, and an optical system, such as optical system 14B. Optical system 14B may include optical elements, such as one or more waveguides 26. Waveguide 26 may include one or more stacked substrates (e.g., stacked planar and / or curved layers, sometimes referred to herein as waveguide substrates) formed of optically transparent materials such as plastic, polymer, glass, etc.

[0023] If desired, the waveguide 26 may also include one or more layers of holographic recording media (sometimes referred to herein as holographic media, grating media, or diffraction grating media) on which one or more diffraction gratings (e.g., holographic phase gratings, sometimes referred to herein as holograms) are recorded. The holographic recording may be stored as an optical interference pattern (e.g., alternating regions of different refractive indices) within a photosensitive optical material such as a holographic medium. The optical interference pattern may produce a holographic phase grating that, when illuminated by a given light source, diffracts light to produce a three-dimensional reconstruction of the holographic recording. The holographic phase grating may be a non-switchable diffraction grating encoded with a permanent interference pattern, or may be a switchable diffraction grating in which the incident light may be modulated by controlling an electric field applied to the holographic recording medium. If desired, multiple holographic phase gratings (holograms) may be recorded within the same volume of holographic medium (e.g., superimposed within the same volume of holographic medium). The holographic phase grating may be, for example, a volume hologram or a thin film hologram in a grating medium. The grating medium may include photopolymers, gelatin such as dichromated gelatin, silver halide, holographic polymer dispersed liquid crystal, or other suitable holographic media.

[0024] The diffraction grating on the waveguide 26 may include a holographic phase grating such as a volume hologram or a thin film hologram, a meta-grating, or any other desired diffraction grating structure. The diffraction grating on the waveguide 26 may also include a surface relief grating formed on one or more surfaces of a substrate in the waveguide 26, a grating formed by a pattern of a metal structure, etc. The diffraction grating may, for example, include a plurality of multiplexed gratings (e.g., holograms) at least partially overlapping within the same volume of grating medium (e.g., for diffracting light of different colors and / or diffracting light from different input angle ranges at one or more corresponding output angles).

[0025] Optical system 14B may include collimating optics, such as imaging optics 34. Imaging optics 34 (sometimes referred to herein as imaging lens 34) may include one or more lens elements that help direct image light 22 toward waveguide 26. If desired, display module 14A may be mounted on Figure 1 The optical system 14B may be mounted within the support structure 20, while the optical system 14B may be mounted between portions of the support structure 20 (eg, to form a lens that is aligned with the eye box 24). Other mounting arrangements may be used if desired.

[0026] like Figure 2 As shown, display module 14A may generate light 22 associated with image content to be displayed to eyebox 24. Light 22 may be collimated using a lens such as that in imaging optics 34. Optical system 14B may be used to present light 22 output from display module 14A to eyebox 24.

[0027] Optical system 14B may include one or more optical couplers, such as input coupler 28, cross coupler 32, and output coupler 30. Figure 2 In the example of FIG. 1 , input coupler 28, cross coupler 32, and output coupler 30 are formed at or on waveguide 26. Input coupler 28, cross coupler 32, and / or output coupler 30 may be completely embedded within a substrate layer of waveguide 26, may be partially embedded within a substrate layer of waveguide 26, may be mounted to waveguide 26 (e.g., mounted to an outer surface of waveguide 26), etc.

[0028] Figure 2 The examples of are merely illustrative. One or more of these couplers (e.g., cross coupler 32) may be omitted. Optical system 14B may include multiple waveguides stacked laterally and / or vertically relative to each other. Each waveguide may include one, two, all, or no couplers of couplers 28, 32, and 30. If desired, waveguide 26 may be at least partially curved or bent.

[0029] The waveguide 26 may guide the light 22 downward along its length via total internal reflection. The input coupler 28 may be configured to couple the light 22 from the display module 14A (imaging optics 34) into the waveguide 26, while the output coupler 30 may be configured to couple the light 22 from inside the waveguide 26 to outside the waveguide 26 and toward the eyebox 24. For example, the display module 14A may emit the light 22 toward the optical system 14B in the direction +Y. When the light 22 strikes the input coupler 28, the input coupler 28 may redirect the light 22 so that the light propagates within the waveguide 26 toward the output coupler 30 (e.g., in the direction X) via total internal reflection. When the light 22 strikes the output coupler 30, the output coupler 30 may redirect the light 22 out of the waveguide 26 toward the eyebox 24 (e.g., backward along the Y axis). For example, where the cross-coupler 32 is formed at the waveguide 26, the cross-coupler 32 may redirect the light in one or more directions as the light 22 propagates downward along the length of the waveguide 26.

[0030] The input coupler 28, the cross coupler 32, and the output coupler 30 may be based on reflective and refractive optics, or may be based on holographic (e.g., diffractive) optics. In an arrangement where the couplers 28, 30, and 32 are formed by reflective and refractive optics, the couplers 28, 30, and 32 may include one or more reflectors (e.g., arrays of micromirrors, partial mirrors, or other reflectors). In an arrangement where the couplers 28, 30, and 32 are based on holographic optics, the couplers 28, 30, and 32 may include a diffraction grating (e.g., a volume hologram, a surface relief grating, etc.).

[0031] It may be desirable to display a high-resolution image using display 14. However, in practice, the sensitivity of the human eye may only be sufficient to understand the difference between higher-resolution image data and lower-resolution image data near the center of its field of view (e.g., a user may be less sensitive to low-resolution image data in portions of an image at the periphery of the user's field of view). In practice, providing high-resolution image data across the entire field of view may consume an excessive amount of processing resources, optical resources, and space within display 14, particularly given that a user may only be sensitive to high-resolution image data near the center of the field of view. Therefore, display 14 may be a concave display that displays only critical portions of an image at a high resolution to help reduce the burden on system 10.

[0032] Generally speaking, the display module 14A (eg, Figure 3 Increasing the physical size of the display panel 38 will increase the maximum resolution of the image that can be displayed using the light 22. However, in compact systems such as Figure 1 In systems 10 of FIG. 1 , space is often at a premium. Therefore, it is desirable to be able to provide high resolution images while also conserving processing and optical resources in system 10 without further increasing the size of display module 14A (eg, display panel 38).

[0033] In order to provide a high resolution image without placing an undesirable burden on the resources of system 10 and without further increasing the size of display module 14A, display module 14A may be configured to perform a dynamic concave operation on light 22. Display module 14A may, for example, display a portion of an image near the center of the user's field of view at a higher resolution, while displaying a portion of the image away from the center of the user's field of view at a lower resolution. As the user's gaze changes over time, display module 14A may adjust the portion of the image produced at the higher resolution so that the portion remains at the center of the user's gaze. The gaze tracking component (e.g., Figure 1 The image sensor in component 18 of the image sensor 22 can actively track the position of the user's gaze over time. Information about the user's gaze direction can be used to shift the position of the higher resolution portion of the image to follow the center of the user's gaze. Thus, the image in light 22 can be a concave image (e.g., a dynamic concave image, in which the higher resolution portion of the image is repositioned over time to follow / track the user's gaze).

[0034] Figure 3 is a diagram showing a concave image that may be produced by display module 14A. Figure 2 The light 22 may include a concave image, such as Figure 3 Concave image 40 (eg, as generated by display module 14A). Concave image 40 may include pixels 43. Figure 3As shown, concave image 40 may include lower resolution pixels 43 in region 42 (sometimes referred to herein as lower resolution region 42, low resolution region 42, or low resolution portion 42) and higher resolution pixels 43 in region 44 (sometimes referred to herein as higher resolution region 44, high resolution region 44, or high resolution portion 44). Display module 14A may, for example, optically provide pixels in region 42 that have a higher magnification and therefore a lower resolution and a lower pixel pitch, while optically providing pixels in region 44 that have a lower magnification and therefore a higher resolution and a higher pixel pitch. Region 42 may, for example, be a peripheral region extending around the perimeter of region 44 (e.g., along the perimeter of the user's gaze at any given time). Region 44 may, for example, be located at the center of the user's gaze at any given time. Figure 1 The component 18 can collect gaze tracking data that identifies the location of the user's gaze. When the user's gaze direction changes over time, the control circuit 16 ( Figure 1 ) display module 14A may be adjusted to shift the position of region 44 (eg, based on gaze tracking data) to align region 44 with the center of the user's gaze, as indicated by arrow 46.

[0035] Because concave image 40 has a higher resolution in region 44 than in region 42, a user (e.g., Figure 2 The concave image 40 may be perceived as a high-resolution image by the user (e.g., at the eyebox 24 of the display module 14A) (e.g., because the user's eyes are sensitive to higher resolutions within the region 44 and are insensitive to lower resolutions within the region 42). This may allow the image displayed at the eyebox 24 to effectively appear to be a high-resolution image without increasing the size of the display module 14A or the processing and optical resources of the system 10, even if the user changes their gaze direction over time (e.g., the concave may be performed dynamically by the display module 14A without placing any increased burden on other components in the system 10). Figure 3 The examples are merely illustrative. Regions 44 and 42 may have any desired shape and / or size. Concave image 40 may have any desired shape and / or size and may include any desired number of pixels 43 (sometimes referred to herein as image pixels 43).

[0036] Figure 4 The display module 14A is to generate a concave image such as Figure 3 FIG. 1 is an illustration of a display module 14A in an example of a reflective display of a dynamic concave image 40. Figure 4As shown, display module 14A may include an illumination source, such as light source 50. Light source 50 may have one or more light-emitting components (elements) for generating output light. The light-emitting element may be, for example, a light-emitting diode (e.g., red, green, and blue light-emitting diodes, white light-emitting diodes, infrared light-emitting diodes, and / or light-emitting diodes of other colors), OLED, uLED, etc. Light sources such as lasers (e.g., VCSEL) or lamps may also be used to provide illumination.

[0037] exist Figure 4 In the example of , display module 14A is a reflective display module, such as a liquid crystal on silicon (LCOS) display module, a micro-electromechanical system (MEM) display module (sometimes referred to as a digital micromirror device (DMD)), or other display module (e.g., a spatial light modulator). An optical component such as a prism 62 may be optically interposed between light source 50 and reflective display panel 66. Reflective display panel 66 is a reflective spatial light modulator and may be, for example, an LCOS display panel, a DMD panel (e.g., a panel having an array of micromirrors each corresponding to a given display pixel), etc.

[0038] Display module 14A may include primary optics 88 and secondary optics 86. Primary optics 88 (sometimes referred to herein as lower resolution optics 88 or low resolution optics 88) may include reflective display panel 66, prism 62, lens 60, mirror 58, and lens 56. Lens 60 may include one or more lens elements arranged in any desired manner. Lens 56 may include one or more lens elements arranged in any desired manner. Prism 62 may include a polarizing beam splitter, such as polarizing beam splitter 64. Polarizing beam splitter 64 may transmit a first polarized light while reflecting a second polarized light. Secondary optics 86 (sometimes referred to herein as higher resolution optics 86 or high resolution optics 88) may include lens 74, optical steering element 76 (sometimes referred to herein as steerable element 76 or steerable optical element 76), mirror 80, and lens 81. Display module 14A may also include lens 52 and beam splitter 54 (e.g., a half-mirror beam splitter). Lens 52 may include one or more lens elements arranged in any desired manner. Lens 74 may include one or more lens elements arranged in any desired manner. Lens 81 may include one or more lens elements arranged in any desired manner. If desired, lenses 60, 56, 81, and / or 52 may be omitted. If desired, display module 14A may include other optical components (e.g., polarizers, beam splitters, mirrors, wave plates, optical coatings, lenses, lens elements, etc.).

[0039] Figure 4The display module 14A may use a plurality of different optical paths (eg, a first optical path for generating the low-resolution region 42 and a second optical path different from the first optical path for generating the high-resolution region 44) to generate Figure 3 For example, a first optical path extending from the light source 50 through the primary optics 88 to the imaging optics 34 may be used to produce a low-resolution region 42 of the concave image 40, while a second optical path extending from the light source 50 through the primary optics 88 and the secondary optics 86 to the imaging optics 34 may be used to produce a high-resolution region 44 of the concave image 40. The display module 14A may generate alternating image frames using light following the first optical path and the second optical path (e.g., such that only one of the high-resolution region 44 or the low-resolution region 42 is displayed at any given time). The display module 14A may alternate between the first optical path and the second optical path at a sufficiently high rate that it appears to the user as if both the high-resolution region 44 and the low-resolution region 42 of the concave image 40 are being displayed simultaneously.

[0040] For example, Figure 4 As shown, light source 50 may generate illumination light 68 (e.g., illumination light including a color combination such as red light, green light, and blue light). Illumination light 68 may pass through lens 52 (e.g., a collimating lens), through beam splitter 54, and through lens 56 to reflector 58. Illumination light 68 may be reflected from reflector 48 and pass through lens 60 and prism 62 to reflective display panel 66. If desired, a polarizer may be interposed along the optical path to provide illumination light 68 with a given polarization so that the light is transmitted through polarizing beam splitter 64 to reflective display panel 66. In another suitable arrangement, a portion of illumination light 68 may pass through polarizing beam splitter 64 without an additional polarizer optically interposed between prism 62 and light source 50.

[0041] Illumination light 68 may reflect from different display pixels P on reflective display panel 66 to produce reflected light 68'. Reflection from reflective display panel 66 may change the polarization of the light (relative to illumination light 68) such that reflected light 68' is then reflected by polarizing beam splitter 68 toward imaging optics 34 (rather than being transmitted by polarizing beam splitter 68). Reflected light 68' passes through imaging optics 34 to Figure 2 The light following the optical path (eg, the first optical path as shown by light 68 and 68') may be generated within a relatively large field of view 70 (eg, a field of view extending across the entire field of view of the concave image 40). Figure 3 The low-resolution region 42 of the concave image 40 is shown.

[0042] The illumination light may follow a different optical path (eg, a second optical path) to produce Figure 34. For example, when the high resolution area 44 is to be displayed, the polarization of the illumination light 68 reflected from the reflective display panel 66 can be adjusted (e.g., using a switchable polarizer interposed between the prism 62 and the reflective display panel 66 or elsewhere in the optical path) to produce a reflected light 72 having a polarization transmitted by the polarizing beam splitter 64. The reflected light 72 is then transmitted by the polarizing beam splitter 64 and reflected from the reflector 58 through the lens 56. The reflected light 72 is then reflected from the beam splitter 54 and passes through the lens 74. The lens 74 may include a demagnification lens element that reduces the magnification of the reflected light 72 (e.g., the reflected light 72 may have half the magnification when incident on the lens 74 or less than the magnification when incident on the lens 74). This reduction in magnification can be used to reduce the size / pitch of the image pixels in the reflected light 72, thereby increasing the effective resolution of the light relative to the reflected light 68'. The reflected light 72 that has passed through the lens 74 is sometimes referred to herein as demagnified light.

[0043] The steerable element 76 can redirect the reflected light 72 in a desired direction (e.g., to reduce the light). The steerable element 76 can be adjusted to move the reflected light 72 to a desired location in the concave image 40. For example, the steerable element 76 can be placed in a first state in which the reflected light 72 is directed (oriented) in a first direction toward the reflector 80, as shown by arrow 82. In this first state, the light is reflected from the reflector 80, and all image pixels in the light are focused within the image 83 (sometimes referred to herein as the concave image 83 or the high-resolution image 83). The light is then transmitted through the prism 62 and the polarizing beam splitter 64 to reach the concave image 40. Figure 2 4 and waveguide 26, wherein the light forms a high resolution region 44 at a first location within concave image 40. Similarly, steerable element 76 can be placed in a second state in which reflected light 72 is directed (oriented) in a second direction toward mirror 80, as indicated by dashed arrow 84. In this second state, the light is reflected from mirror 80, and all image pixels in the light are focused within image 87 (sometimes referred to herein as concave image 87 or high resolution image 87) that is spatially offset from image 83. The light is then transmitted through prism 62 and polarizing beam splitter 64 to reach Figure 2 The imaging optics 34 and waveguide 26 of the concave image 40 form a high resolution region 44 at a second location within the concave image 40. By switching the steerable element 76 between the first state and the second state, the position of the high resolution region 44 of the concave image 40 can be adjusted over time (e.g., as Figure 3 For example, the adjustment may be performed to adjust the user's gaze direction as it changes over time (e.g., based on the user's Figure 1The high resolution region 44 is realigned with the center of the user's gaze using the gaze tracking data collected by the component 18 of the image processing unit 10. If desired, an optional polarizing element may be interpolated at any desired position on the optical path of the reflected light 72 to provide light having a polarization transmitted by the polarizing beam splitter 64 after passing through the lens 81.

[0044] Figure 4 An example is shown in which the steerable element 76 has only two states for clarity. In general, the steerable element 76 may have any desired number of states for directing the reflected light 72, and therefore the high-resolution area 44, to any desired number of locations within the concave image 40. The steerable element 76 may be a liquid crystal steering element (e.g., an adjustable liquid crystal prism or other switchable liquid crystal steering device), an adjustable aperture, or any other desired steerable element that optically directs the direction of the reflected light 72. The state of the steerable element 76 may be controlled, for example, by a control path 78 (e.g., from Figure 1 The steerable element 76 may be controlled by a control signal received by the control circuit 16 of the control circuit 16. This example is merely illustrative. In another suitable arrangement, the steerable element 76 may be omitted, and the reflector 80 may be a steerable reflector (e.g., a MEM reflector or other actuated reflector) that is directed to redirect the reflected light 72 to a different location in the concave image 40. If desired, the components of the primary optical device 88 and / or the secondary optical device 86 may be arranged in other ways. The light associated with the arrows (light rays) 82 and 84 and the reflected light 68' may together form Figure 2 The light 22 (for example, including Figure 3 of the concave image 40).

[0045] In this way, the display module 14A can perform dynamic concave operation by splitting the illumination light 68 between a first optical path that extends through the primary optics 88 (e.g., as shown by reflected light 68') for producing the low-resolution region 42 of the concave image 40, and a second optical path that extends through the secondary optics 86 in addition to extending through the primary optics 88 (e.g., as shown by reflected light 72 and arrows 82 and 84). The secondary optics 86 include a steerable element, such as the steerable element 76, for adjusting the position of the high-resolution region 44 of the concave image 40 (e.g., so that the user continues to see the high-resolution image at the center of their gaze regardless of the direction of their gaze over time). Since the remainder of the image has a lower resolution (e.g., the low-resolution region 42), this can allow the user to perceive a higher-resolution image without undesirably increasing the size of the reflective display panel 66 and the prism 62 to accommodate all of the pixels that would otherwise be required to produce such a high-resolution image.

[0046] The display module 14A includes a reflective display panel. Figure 4 The example of is merely illustrative. In another suitable arrangement, display module 14A may include an emissive display panel for generating concave image 40. Figure 5 is a diagram showing how display module 14A may include an emissive display panel. Figure 5 As shown, primary optics 88 may include illumination optics 100, prism 62, and polarizing beam splitter 64. Secondary optics 86 may include illumination optics 102, lens 112, mirror 114, steerable element 76, mirror 80, and lens 81.

[0047] The illumination optical device 100 may include an emission display panel 106 and a prism 110. The emission display panel 106 may include an array of emission light sources, such as LEDs, OLEDs, uLEDs, lasers, etc. The emission display panel 106 in the illumination optical device 100 may include a first emission display panel 106A, a second emission display panel 106B, and a third emission display panel 106C. The emission display panels 106A, 106B, and 106C may each emit an illumination light 120 of a corresponding wavelength range (e.g., color). For example, the emission display panel 106A may emit red light, the emission display panel 106B may emit green light, and the emission display panel 106C may emit blue light. The prism 110 may combine the light emitted by the emission display panels 106A, 106B, and 106C into an illumination light 120 (e.g., the illumination light 120 may include red light, green light, blue light, etc.). The illumination light 120 is reflected from the polarization beam splitter toward the illumination optical device 34. A polarizer may be inserted in the optical path of illumination light 120 (e.g., between the light source array and prism 110, between prism 62 and prism 110, etc.) to provide illumination light 120 having a given polarization that is reflected (rather than transmitted) by polarizing beam splitter 64. Emissive display panels 106A, 106B, and 106C may each include an array of display pixels P (e.g., where each emissive light source in the panel forms a corresponding display pixel). Display pixels P generate Figure 3 The image pixels 43 of the low resolution region 42 in the concave image 40 (e.g., the illumination light 120 may be provided to Figure 2 The light 22 of the waveguide 26 forms a low resolution region 42 of the concave image 40).

[0048] The illumination optical device 102 may include an emissive display panel 104 and a prism 108. The emissive display panel 104 may include an array of emissive light sources, such as LEDs, OLEDs, uLEDs, uOLEDs, lasers (e.g., VCSELs), etc. The emissive display panels 104 in the illumination optical device 102 may include a first emissive display panel 104A, a second emissive display panel 104B, and a third emissive display panel 104C. The emissive display panels 104A, 104B, and 104C may each emit illumination light 122 of a corresponding wavelength range (e.g., color). For example, the emissive display panel 104A may emit red light, the emissive display panel 104B may emit green light, and the emissive display panel 104C may emit blue light. The emissive display panels 104A, 104B, and 104C may each include an array of display pixels P (e.g., where each emissive light source in the panel forms a corresponding pixel). The display pixels P generate image pixels 43 of the high resolution region 44 in the concave image 40 (e.g., the illumination light 120 may be provided to the image pixel 43 in the concave image 40). Figure 2 The high resolution region 44 of the concave image 40 is formed in the light 22 of the waveguide 26).

[0049] Prism 108 may combine the light emitted by emissive display panels 104A, 104B, and 104C into illumination light 122 (e.g., illumination light 122 may include red light, green light, blue light, etc.). Illumination light 122 is transmitted through lens 112. Lens 112 may include a reduction lens element that reduces the magnification of illumination light 122 (e.g., illumination light 122 may have half the magnification or less than the magnification when incident on lens 112 after passing through lens 112). This reduction in magnification may be used to reduce the size / pitch of image pixels in illumination light 122, thereby increasing the effective resolution of the light (relative to illumination light 120). After being reduced by lens 112, illumination light 122 is reflected from reflector 114 toward steerable element 76.

[0050] The steerable element 76 can redirect the illumination light 122 in a desired direction. The steerable element 76 can be adjusted to move the illumination light 122 to a desired location in the concave image 40. For example, the steerable element 76 can be placed in a first state in which the illumination light 122 is directed (oriented) in a first direction toward the reflector 80, as shown by arrow 124. In this first state, the light is reflected from the reflector 80, and all image pixels in the light are focused within the image 83. The light is then transmitted through the prism 62 and the polarizing beam splitter 64 to the image 83. Figure 2124 may have a polarization that is transmitted by polarizing beam splitter 64), wherein the light forms high resolution region 44 at a first location within concave image 40. Similarly, steerable element 76 may be placed in a second state in which illumination light 122 is directed (oriented) in a second direction toward reflector 80, as indicated by dashed arrow 126. In this second state, the light is reflected from reflector 80, and all image pixels in the light are focused within image 87 that is spatially offset from image 83. The light is then transmitted through prism 62 and polarizing beam splitter 64 to reach Figure 2 The imaging optics 34 and waveguide 26 of the concave image 40 may be configured to be steerable and to have a polarization that is transmitted by the polarizing beam splitter 64 (e.g., light following arrow 124 may have a polarization that is transmitted by the polarizing beam splitter 64), wherein the light forms the high resolution region 44 at a second location within the concave image 40. By switching the steerable element 76 between the first state and the second state, the position of the high resolution region 44 of the concave image 40 may be adjusted over time (e.g., as Figure 3 For example, the adjustment may be performed to adjust the user's gaze as it changes over time (e.g., based on the user's Figure 1 The high resolution region 44 is realigned with the center of the user's gaze using the gaze tracking data collected by the component 18 of the image processing unit 100. If desired, an optional polarization element may be interpolated at any desired location on the optical path of the illumination light 122 to provide illumination light 122 having a polarization transmitted by the polarizing beam splitter 64.

[0051] Figure 5 An example is shown in which the steerable element 76 has only two states for clarity. In general, the steerable element 76 may have any desired number of states for directing the reflected light 72, and therefore the high-resolution area 44, to any desired number of locations within the concave image 40. The steerable element 76 may be a liquid crystal steering element (e.g., an adjustable liquid crystal prism), an adjustable aperture, or any other desired steerable element that directs the direction of the reflected light 72. The state of the steerable element 76 may be determined, for example, by controlling the path 78 (e.g., from Figure 1 The steerable element 76 may be controlled by a control signal received by the control circuit 16 of the control circuit 16. This example is merely illustrative. In another suitable arrangement, the steerable element 76 may be omitted, and the mirror 80 may be a steerable mirror (e.g., a MEM mirror or other actuated mirror) that is directed to redirect the illumination light 122 to a different location in the concave image 40. If desired, the components of the primary optics 88 and / or the secondary optics 86 may be arranged in other ways.

[0052] Using an emissive display panel rather than a reflective display panel to form primary optics 88 and secondary optics 86 may allow display module 14A to simultaneously display high-resolution region 44 of concave image 40 (e.g., displayed using secondary optics 86, primary optics 88, and illumination light 122) and low-resolution region 42 of concave image 40 (e.g., displayed using primary optics 88 and illumination light 120), while Figure 4 The reflective display module displays only high-resolution areas or only low-resolution areas at any given time, but the reflective display module alternates between high-resolution areas or low-resolution areas faster than the human eye can respond. Figure 5 In the embodiment of the present invention, the display module 14A uses an emissive display panel rather than a reflective display panel, and the display module 14A still performs dynamic concave operation by splitting the illumination light 68 between a first optical path that extends through the primary optics 88 (e.g., as shown by illumination light 120) for producing the low-resolution region 42 of the concave image 40, and a second optical path that extends through the secondary optics 86 in addition to extending through the primary optics 88 (e.g., as shown by illumination light 122 and light rays 124 and 126). The secondary optics 86 includes a steerable element, such as the steerable element 74, for adjusting the position of the high-resolution region 44 of the concave image 40 (e.g., so that the user continues to see the high-resolution image at the center of their gaze regardless of the direction of their gaze over time). Since the remainder of the image has a lower resolution (e.g., the low-resolution region 42), this can allow the user to perceive a higher-resolution image without undesirably increasing the size of the reflective display panel 66 and the prism 62 to accommodate all of the pixels that would otherwise be required to produce such a high-resolution image.

[0053] For example, even if Figure 4 and Figure 5 The display module 14A includes a secondary optical device 86 in addition to a primary optical device 88 for generating image light with a high-resolution area 44. The volume of the secondary optical device 86 plus the volume of the primary optical device 88 is still smaller than that of the reflective display panel 66 ( Figure 4 ) or the emission display panels 106A-106C ( Figure 5 ) is modified to include enough space to fill the volume that would otherwise be required for the entire field of view of image 40 with pixels having the same resolution as high-resolution region 44. By implementing a dynamic fovea, in which high-resolution region 44 tracks the user's gaze over time, the image presented to the user at the eyebox effectively looks the same to the user as if the entire image were generated with high-resolution pixels. This can be used to optimize the apparent image quality of the display to the user while also allowing display module 14A to occupy a relatively small amount of volume, thereby minimizing the volume of system 10.

[0054] If necessary, Figure 5 The emissive display panel 104 and the emissive display panel 106 may be replaced by front-illuminated reflective display panels. Figure 6 Can be used as an alternative Figure 5 106A, 106B, 106C, 104A, 104B, and 104C of the emissive display panels 106A, 106B, 106C, 104A, 104B, and 104C of the front-illuminated reflective display panel. Figure 6 As shown, the front-lit reflective display panel 145 may include a reflective display panel 140, a light guide 142 overlapping the reflective display panel 140, and a light source 144. The reflective display panel 140 may be an LCOS panel or other reflective display panel. The light source 144 may, for example, include LEDs (e.g., red, green, and blue LEDs). The light source 144 may emit light 146 into the light guide 142 (e.g., via a side edge or input face of the light guide 142). The light 146 may propagate downward along the length of the light guide 142 via total internal reflection. The light 146 may couple out of the light guide 142 and toward the reflective display panel 140 at different points along the length (area) of the light guide 142 (e.g., when the incident angle of the light no longer supports total internal reflection or when the light encounters an output coupling feature on or in the light guide 142). The light 146 may be coupled out of the light guide 142 and toward the reflective display panel 140. The light 146 may be transmitted from different display pixels P in the reflective display panel 140 and toward Figure 5 prism 110 or prism 108 (e.g., as Figure 5 of the illumination light 120 or 122).

[0055] According to one embodiment, a display system is provided, the display system being configured to display a concave image having a first area and a second area, the first area having a first resolution, the second area having a second resolution greater than the first resolution, the display system comprising: an optical system configured to orient the concave image toward an eyebox; a light source generating illumination light; a reflective display panel, during a first time period, the reflective display panel being configured to reflect the illumination light as a first reflected light, and during a second time period different from the first time period, the reflective display panel being configured to reflect the illumination light as a second reflected light; a polarization beam splitter, the polarization beam splitter being configured to reflect the first reflected light toward the optical system as the first area of ​​the concave image, and the polarization beam splitter being configured to transmit the second reflected light; a lens, the lens being configured to reduce the second reflected light transmitted by the polarization beam splitter to generate reduced light; and an optical steering element, the optical steering element being configured to redirect the reduced light through the polarization beam splitter and toward the optical system as the second area of ​​the concave image.

[0056] According to another embodiment, the display system includes a control circuit configured to adjust the optical steering element to change the position of the second region in the concave image.

[0057] According to another embodiment, the optical redirecting element comprises an adjustable mirror.

[0058] According to another embodiment, the display system includes a reflector, the optical steering element is configured to redirect the reduced light toward the reflector, and the reflector is configured to pass the reduced light through the polarizing beam splitter and reflect the reduced light toward the optical system as the second area of ​​the concave image.

[0059] According to another embodiment, the optical steering element comprises a switchable liquid crystal steering device.

[0060] According to another embodiment, the display system includes a gaze tracking sensor, which is configured to collect gaze tracking data identifying a gaze direction at the peep box, and the control circuit is configured to adjust the optical steering element to align the position of the second area with the gaze direction identified by the gaze tracking data.

[0061] According to another embodiment, the reflective display panel comprises a liquid crystal on silicon (LCOS) display panel.

[0062] According to another embodiment, the reflective display panel comprises a digital micromirror device display panel.

[0063] According to another embodiment, the display system includes a reflector, which is configured to reflect the illumination light toward the polarization beam splitter, and the reflector is configured to reflect the second reflected light transmitted by the polarization beam splitter toward the lens; and a partial reflector, which is configured to transmit the illumination light, the partial reflector is configured to receive the second reflected light from the reflector, and the partial reflector is configured to reflect the second reflected light toward the lens.

[0064] According to another embodiment, the lens is optically interposed between the partial reflector and the optical steering element, the reflector is optically interposed between the partial reflector and the polarization beam splitter, and the polarization beam splitter is optically interposed between the reflector and the reflective display panel.

[0065] According to another embodiment, the optical system includes a waveguide having an input coupler configured to couple the concave image into the waveguide and an output coupler configured to couple the concave image out of the waveguide and toward the eyebox.

[0066] According to another embodiment, the first reflected light does not pass through the lens and is not redirected by the optical redirecting element.

[0067] According to one embodiment, a display system is provided, the display system being configured to display a concave image having a first area and a second area, the first area having a first resolution, the second area having a second resolution greater than the first resolution, the display system comprising: an optical system configured to orient the concave image toward an eyebox; a polarizing beam splitter; a first group of emitting display panels, the first group of emitting display panels being configured to generate a first illumination light, the polarizing beam splitter being configured to reflect the first illumination light toward the optical system as the first area of ​​the concave image; a second group of emitting display panels, the second group of emitting display panels being configured to generate a second illumination light; a lens, the lens being configured to reduce the second illumination light to generate reduced light; and an optical steering element, the optical steering element being configured to redirect the reduced light toward the polarizing beam splitter, the polarizing beam splitter being configured to transmit the reduced light redirected by the optical steering element, and the reduced light redirected by the optical steering element forming the second area of ​​the concave image.

[0068] According to another embodiment, the optical steering element has a first state, in which the reduced light is redirected in a first direction and the second area is located at a first position in the concave image, and the optical steering element has a second state, in which the reduced light is redirected in a second direction different from the first direction and the second area is located at a second position in the concave image different from the first position.

[0069] According to another embodiment, the display system includes a control circuit configured to control the optical steering element to switch between the first state and the second state.

[0070] According to another embodiment, the first group of emissive display panels includes a first micro light emitting diode (uLED) array, a second uLED array, and a third uLED array, and the second group of emissive display panels includes a fourth uLED array, a fifth uLED array, and a sixth uLED array.

[0071] According to another embodiment, the first set of emissive display panels includes a first laser array, a second laser array, and a third laser array, and the second set of emissive display panels includes a fourth laser array, a fifth laser array, and a sixth laser array.

[0072] According to another embodiment, the display system includes a first reflector, which is configured to receive the reduced light from the lens and is configured to reflect the reduced illumination light toward the optical steering element; and a second reflector, which is configured to receive the reduced light redirected by the optical steering element and is configured to reflect the reduced light toward the polarization beam splitter.

[0073] According to one embodiment, a display system is provided, the display system being configured to display a concave image having a first area and a second area, the first area having a first resolution, the second area having a second resolution greater than the first resolution, the display system comprising: an optical system configured to orient the concave image toward an eyebox; a polarizing beam splitter; a first group of front-illuminated reflective display panels, the first group of front-illuminated reflective display panels being configured to generate a first illumination light, the polarizing beam splitter being configured to reflect the first illumination light toward the optical system as the first area of ​​the concave image; a second group of front-illuminated reflective display panels, the second group of front-illuminated reflective display panels being configured to generate a second illumination light; a lens, the lens being configured to reduce the second illumination light to generate reduced light; and an optical steering element, the optical steering element being configured to redirect the reduced light toward the optical system through the polarizing beam splitter, the reduced light redirected by the optical steering element forming the second area of ​​the concave image.

[0074] According to another embodiment, each front-illuminated reflective display panel in the first group of front-illuminated reflective display panels includes: a liquid crystal on silicon (LCOS) display panel; a light source that generates light; and a light guide that propagates the light generated by the light source via total internal reflection, the light guide being configured to couple the light generated by the light source out of the light guide and toward the LCOS display panel, and the LCOS display panel being configured to generate the first illumination light by reflecting the light coupled out of the light guide.

[0075] The foregoing is merely exemplary and various modifications may be made to the embodiments described. The foregoing embodiments may be implemented independently or in any combination.

Claims

1. A display system, the display system being configured to display a concave image, the concave image having a first area and a second area, the first area having a first resolution, the second area having a second resolution greater than the first resolution, the display system comprising: an optical system configured to orient the concave image toward the eyebox; a light source, the light source generating illumination light; Reflective display panel; Polarization beam splitter; a switchable polarizer interposed between the reflective display panel and the polarizing beam splitter, wherein: During a first period of time, the reflective display panel is configured to reflect the illumination light as first reflected light having a first polarization, and During a second time period different from the first time period, the reflective display panel is configured to reflect the illumination light as second reflected light; During the second time period, the switchable polarizer is configured to impart a second polarization to the second reflected light that is different from the first polarization; The polarization beam splitter is configured to reflect the first reflected light toward the optical system as the first region of the concave image, and The polarizing beam splitter is configured to transmit the second reflected light having the second polarization imparted thereto by the switchable polarizer; a lens configured to reduce the second reflected light transmitted by the polarization beam splitter to generate reduced light; and An optical redirection element is configured to redirect the reduced light through the polarizing beam splitter and toward the optical system as the second region of the concave image.

2. The display system according to claim 1, further comprising: A control circuit is provided, wherein the control circuit is configured to adjust the optical steering element to change the position of the second region in the concave image.

3. The display system of claim 2, wherein the optical redirection element comprises an adjustable mirror.

4. The display system according to claim 2, further comprising: A reflector, wherein the optical redirecting element is configured to redirect the reduced light toward the reflector, and wherein the reflector is configured to reflect the reduced light through the polarizing beam splitter and toward the optical system as the second region of the concave image.

5. The display system of claim 4, wherein the optical steering element comprises a switchable liquid crystal steering device.

6. The display system according to claim 2, further comprising: A gaze tracking sensor, wherein the gaze tracking sensor is configured to collect gaze tracking data identifying a gaze direction at the eye box, and wherein the control circuit is configured to adjust the optical steering element to align the position of the second area with the gaze direction identified by the gaze tracking data.

7. The display system according to claim 1, wherein the reflective display panel comprises a liquid crystal on silicon (LCOS) display panel.

8. The display system of claim 1, wherein the reflective display panel comprises a digital micromirror device display panel.

9. The display system according to claim 1, further comprising: a reflector, wherein the reflector is configured to reflect the illumination light toward the polarization beam splitter, and wherein the reflector is configured to reflect the second reflected light transmitted by the polarization beam splitter toward the lens; and A partially reflective mirror, wherein the partially reflective mirror is configured to transmit the illumination light, wherein the partially reflective mirror is configured to receive the second reflected light from the reflector, and wherein the partially reflective mirror is configured to reflect the second reflected light toward the lens.

10. A display system according to claim 9, wherein the lens is optically interposed between the partial reflector and the optical steering element, wherein the reflector is optically interposed between the partial reflector and the polarization beam splitter, and wherein the polarization beam splitter is optically interposed between the reflector and the reflective display panel.

11. The display system of claim 1 , wherein the optical system comprises a waveguide having an input coupler configured to couple the concave image into the waveguide and an output coupler configured to couple the concave image out of the waveguide and toward the eyebox.

12. The display system of claim 1, wherein the first reflected light does not pass through the lens and is not redirected by the optical redirection element.

Images