View-based optical correction using a spatially varying polarizer

Abstract

An optical system is provided. The optical system includes a gaze tracker and a correction portion, the gaze tracker being operable to track a user's gaze and outputting data representing the gaze, and the correction portion including a plurality of spatially varying polarizers. A first polarizer of the spatially varying polarizer has a first control input, the first control input being configured to receive a first control signal, the first control signal indicating whether the first polarizer is activated or inactivated. The first polarizer, when activated, provides a first optical correction to light passing through at a position corresponding to a first area of ​​a virtual image. The optical system includes a controller configured to receive data representing a gaze, determine whether to perform a first optical correction on the light based on the gaze, and output a first control signal indicating that the first polarizer is to be activated in response to determining that the first optical correction is to be performed on the light.

Description

Technical Field

[0001] The present disclosure relates to an optical correction system that uses a spatially varying polarizer to perform viewing-based optical correction. Background Art

[0002] A head mounted display device (HMD) is a display device worn on the user's head, having one or more display units for presenting visual content to the user. HMDs are becoming increasingly popular to provide virtual reality (VR) or augmented reality (AR) experiences, or to facilitate gaming or presentation of audiovisual media. The display units are typically miniaturized, and may include, for example, CRT, LCD, liquid crystal on silicon (LCos), or OLED technology. Some HMDs are binocular and have the potential to display different images to each eye. This capability is used to display stereoscopic images to present a more immersive user experience.

[0003] Conventional HMDs do not take into account the user's perspective or field of view. Conventional HMDs display visual content to the user without adapting the virtual image light to the user's perspective or field of view. Summary of the invention

[0004] The head-mounted display can be summarized as including a virtual image display unit and an optical system for modifying the virtual image light. The optical system can modify the virtual image light to enhance the user experience or viewing, or improve the angular resolution of the virtual image light. The optical system can perform optical correction to modify the focal length of the virtual image light or sharpen the virtual image light. In particular, the optical system can align, modify or manipulate the light in a specific portion of the virtual image light that the user is watching or viewing. This portion of the virtual image light may fall within the user's current field of view. Therefore, the optical correction can be positioned to this portion of the virtual image light.

[0005] The optical correction performed by the optical system can be based on the user's gaze angle or direction or the user's field of view. For example, the user's gaze angle or direction or field of view can be detected by a gaze tracker of the head-mounted display. The optical system can include a left optical subsystem and a right optical subsystem that are respectively operable to modify the virtual image light received from the virtual image display to correct left-eye and right-eye viewing.

[0006] The optical system includes one or more spatially variable polarizers, each of which is operably in an activated (on) state or an inactivated (off) state based on a controller input. The spatially variable polarizer can be formed by a multi-twisted retarder (MTR) and is customized to provide a precise level of delay in a single film. The spatially variable polarizer can be configured to be used as a correction optical device and cause the light passing therethrough to undergo refraction (according to the refractive index) or diffraction (according to the diffraction pattern). The spatially variable polarizer can be formed as a polarization-oriented lens and has an electrically controllable focal length for focusing the light passing therethrough, and can collimate the light passing therethrough. Due to its spatially variable characteristics, the multi-twisted retarder provides a switchable localized optical correction. The localized optical correction can operate on a portion of the virtual image light that falls within the user's current field of view. The localized optical correction can operate on a portion of the virtual image light that falls within the user's current field of view, which is different from other portions of the virtual image light that falls outside the user's current field of view, thereby optimizing the optical correction within the current field of view.

[0007] Each spatially varying polarizer may be formed to have a diffraction pattern characteristic, a light collimation characteristic, a light focusing characteristic, or an aberration correction characteristic, etc., to operate on the light passing through the spatially varying polarizer. A subset of two or more spatially varying polarizers may have a specific diffraction characteristic, a light collimation characteristic, a light focusing characteristic, or an aberration correction characteristic, etc., in combination, to operate on the light passing through the subset.

[0008] The spatially varying polarizers are switchable between on and off states. The controller can switch on or off individual spatially varying polarizers, a subset of spatially varying polarizers, or all available spatially varying polarizers to implement and perform corresponding optical corrections. The controller can switch various spatially varying polarizers between on and off states to switch between different available optical corrections for different portions of the virtual image. During viewing, the controller receives an indication of the user's gaze from a gaze tracker or from other sources. As the user's gaze changes and as the user's gaze changes from one area to the next, the controller switches between the spatially varying polarizers to implement localized optical corrections for portions of the virtual image light that fall within the user's current field of view.

[0009] The optical system can be summarized as including: a gaze tracker for tracking a user's gaze and outputting data representing the gaze; a correction portion including a plurality of spatially varying polarizers, a first spatially varying polarizer of the plurality of spatially varying polarizers having a first control input, the first control input being configured to receive a first control signal of a plurality of control signals, the first control signal indicating whether the first spatially varying polarizer is activated or inactivated, the first spatially varying polarizer being operable when activated to provide a first optical correction to light passing through the correction portion at a location corresponding to a first region of a plurality of regions of a virtual image; and a controller configured to receive data representing a user's gaze; determine, based on the gaze, whether to perform a first optical correction on light passing through the correction portion at a location corresponding to the first region; and output a first control signal indicating that the first spatially varying polarizer is to be activated in response to determining that the first optical correction is performed on light passing through the correction portion at a location corresponding to the first region. The first region of the plurality of regions of the virtual image can be within a field of view of the user's gaze. The controller may be configured to determine a gaze change based on data representing the user's gaze; and determine to perform a second optical correction on light passing through the correction portion at a position corresponding to a second region of the plurality of regions of the virtual image through a second spatially varying polarizer of the plurality of spatially varying polarizers. The second spatially varying polarizer of the plurality of spatially varying polarizers may have a second control input configured to receive a second control signal of the plurality of control signals, the second control signal indicating whether the second spatially varying polarizer is activated or inactivated, and wherein the controller is configured to output a second control signal indicating that the second spatially varying polarizer is activated in response to determining that the second optical correction is performed on light passing through the correction portion at a position corresponding to the second region. The controller may be configured to output a first control signal indicating that the first spatially varying polarizer is to be inactivated in response to determining that the second optical correction is performed on light passing through the correction portion at a position corresponding to the second region. The first spatially varying polarizer and the second spatially varying polarizer may be in a stacked arrangement such that light passing through the correction portion is irradiated on the second spatially varying polarizer after having passed through the first spatially varying polarizer. Providing the first optical correction may include performing diffraction according to a diffraction pattern, light collimation, light focusing, image sharpening, angular resolution modification, focal length modification, or aberration correction.The spatially varying polarizer of the plurality of spatially varying polarizers may include a multi-twist retarder (MTR).

[0010] The head-mounted display system can be summarized as including: a support structure; a display; a gaze tracker for tracking the gaze of a user and outputting data representing the gaze; an optical system including a first optical subsystem and a second optical subsystem, each of the first optical subsystem and the second optical subsystem including a correction portion, the correction portion including a plurality of spatially varying polarizers, a first spatially varying polarizer among the plurality of spatially varying polarizers having a first control input, the first control input being configured to receive a first control signal among a plurality of control signals, the first control signal indicating whether the first spatially varying polarizer is activated or inactivated, the first spatially varying polarizer being operable when activated to provide a first optical correction to light passing through the correction portion at a position corresponding to a first region among a plurality of regions of a virtual image; and a controller configured to: for each of the first optical subsystem and the second optical subsystem, receive data representing the gaze of the user; determine whether to perform a first optical correction on light passing through the correction portion at a position corresponding to the first region based on the gaze; and in response to determining that the first optical correction is performed on light passing through the correction portion at a position corresponding to the first region, output a first control signal indicating that the first spatially varying polarizer is to be activated. For each of the first optical subsystem and the second optical subsystem, a first area of ​​the plurality of areas of the virtual image may be within the field of view of the user's gaze. The controller may be configured to, for each of the first optical subsystem and the second optical subsystem, determine a gaze change based on data representing the gaze; and determine to perform a second optical correction on light passing through the correction portion at a position corresponding to a second area of ​​the plurality of areas of the virtual image by a second spatially varying polarizer in the plurality of spatially varying polarizers. For each of the first optical subsystem and the second optical subsystem, a second spatially varying polarizer in the plurality of spatially varying polarizers may have a second control input configured to receive a second control signal in the plurality of control signals, the second control signal indicating whether the second spatially varying polarizer is activated or inactivated, and wherein, for each of the first optical subsystem and the second optical subsystem, the controller is configured to: in response to determining to perform a second optical correction on light passing through the correction portion at a position corresponding to the second area. For each of the first optical subsystem and the second optical subsystem, the controller is configured to: output a second control signal indicating that the second spatially varying polarizer is to be activated. The controller may be configured to, for each of the first optical subsystem and the second optical subsystem, output a first control signal indicating that the first spatially varying polarizer is to be inactivated in response to determining that the second optical correction is performed on the light passing through the correction portion at a position corresponding to the second region. For each of the first optical subsystem and the second optical subsystem, the first spatially varying polarizer and the second spatially varying polarizer may be stacked so that the light passing through the correction portion is irradiated on the second spatially varying polarizer after having passed through the first spatially varying polarizer.For each of the first optical subsystem and the second optical subsystem, providing the first optical correction may include: performing diffraction according to a diffraction pattern, light collimation, light focusing, image sharpening, angular resolution modification, focal length modification, or aberration correction. For each of the first optical subsystem and the second optical subsystem, a spatially varying polarizer in the plurality of spatially varying polarizers may include a multi-twist retarder (MTR). BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A top plan view of a head mounted display with an optical system is shown in accordance with one or more implementations.

[0012] Figure 2 Shows Figure 1 Diagram of the optical subsystem of the head mounted display optical system.

[0013] Figure 3 Shows Figure 1 A top-down perspective view of the exterior of a head-mounted display.

[0014] Figure 4 A schematic block diagram of a head mounted display is shown.

[0015] Figure 5 Shows the connection to the reference Figure 4 Describe the correction part of the controller.

[0016] Figure 6 An example of field-based optical correction performed by multiple spatially varying polarizers is shown.

[0017] Figure 7 is an exemplary surface phase diagram for a spatially varying polarizer according to one non-limiting illustrated embodiment.

[0018] Figure 8 is another exemplary surface phase diagram for a spatially varying polarizer according to one non-limiting illustrated embodiment. DETAILED DESCRIPTION

[0019] In the following description, certain specific details are set forth to provide a thorough understanding of the various disclosed embodiments. However, one skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures associated with computer systems, server computers, and / or communication networks are not shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0020] Unless the context requires otherwise, throughout the specification and the claims that follow, the word "comprising" is synonymous with "including" and is inclusive or open-ended (i.e., does not exclude other unrecited elements or methodological actions). Unless otherwise specified or contradicted by context, the term "set" (e.g., "set of items") as used herein should be interpreted as comprising a non-empty set of one or more components or instances.

[0021] Reference throughout this specification to "one embodiment" or "an example" means that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment. Thus, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout the specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0022] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise.

[0023] The titles and abstracts of the disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

[0024] Figure 1 A top plan view of a head mounted display device (HMD) 100 is shown according to one or more embodiments. The HMD 100 is configured to present virtual reality (VR) to a user 104, for example via a corresponding video presented at a display rate such as 30 frames (or images) per second or 90 frames per second, while other embodiments of similar systems may present an augmented reality display to the user 104. The HMD 100 provides corrected virtual image light 102 to a left eye 105l and a right eye 105r of the user 104. The HMD 100 includes one or more virtual image display units 106 mounted on or within a frame 108. The virtual image display unit 106 generates virtual image light 102 for causing the user to perceive visual content. The HMD 100 may also include left and right lens groups 107l and 107r disposed on the emission side of the virtual image display unit 106. The left and right lens groups 1071 and 107r may focus, collimate, or modify the virtual image light 102 after it is emitted from the virtual image display unit 106. The left and right lens groups 1071 and 107r may include, for example, a Fresnel lens that refracts or collimates the virtual image light 102.

[0025] The HMD 100 also includes an optical system 112 having selectively variable optical properties for correcting one or more visual conditions of the user. For example, the optical system 112 can be selectively adjusted to locally correct light. Virtual image light 102 emitted from the virtual image display unit 106 travels along an optical path 126 through the optical system 112, and the optical system 112 modifies the virtual image light 102 according to the optical properties of the optical system 112 and emits corrected virtual image light 114 to the left eye 105l and the right eye 105r of the user, respectively.

[0026] The frame 108 is a mounting structure for supporting the HMD 100 on the head of the user 104. The frame 108 includes a body 116 having a front portion 118 and a viewing portion 120 opposite the front portion 118, and the viewing portion 120 is used to be positioned in front of the user's eyes 105l and 105r to view the generated visual content. The HMD 100 includes one or more support structures for selectively mounting the HMD 100 to the user's head. For example, Figure 1 The HMD 100 includes left and right temples 1221 and 122r for resting on the left and right ears 1241 and 124r of the user 104, respectively. In some embodiments, the HMD 100 may include another support structure, such as a strap connected to the body 116 that wraps around the back of the head of the user 104. A nose assembly (not shown) of the HMD 100 may support the body 116 on the nose of the user 104. The shape and size of the frame 108 may be designed to position the optical system 112 in front of one of the user's eyes 105l and 105r. Although the frame 108 is shown in a simplified manner similar to glasses for illustrative purposes, it should be understood that more complex structures (e.g., goggles, integrated headbands, helmets, straps, etc.) may actually be used to support and position the HMD 100 on the head of the user 104.

[0027] The virtual image display unit 106 generates a virtual image light 102 that is transmitted through the optical system 112 and selectively modified by the optical system 112. The virtual image display unit 106 includes a left display unit 1061 for generating image light presented to the left eye 1051 and a right display unit 106r for generating image light presented to the right eye 105r. The virtual image display unit 106 may include a liquid crystal display (LCD), a light emitting diode (LED), a cathode ray tube (CRT), a liquid crystal on silicon (LCOS), or other light emitting technologies that generate the virtual image light 102. Figure 1The virtual image display unit 106 of the illustrated embodiment is located at the front of the HMD 100 and emits light backward toward the eyes of the user 104. In some embodiments, the virtual image display unit 106 may include a waveguide that directs (e.g., reflects, refracts) the virtual image light 102 toward the eye 105l or 105r so that the light emitting element of the virtual image display unit 106 is not directly in front of the eye 105l and 105r so that the user 104 perceives visual content. In some embodiments, the front 118 of the body 116 may be at least partially transparent so that the user 104 can perceive external content for providing an augmented reality experience.

[0028] The HMD 100 includes a gaze tracker 127 that is configured to track the gaze (or direction thereof) of the user 104 or the user's eyes 1051, 105r. Although the gaze tracker 127 is shown as an internal element of the HMD 100, in an alternative embodiment, the gaze tracker 127 may be an external sensor. In addition, the gaze tracker 127 may perform gaze or pupil tracking for each eye 1051 and 105r, respectively, or track the position or direction of the user's 104 head (e.g., as part of head tracking). In addition, the gaze tracker 127 may track various other types of motion and position of the user's body.

[0029] Gaze tracker 127 may output data representing the gaze of user 104. The data may indicate the portion (location or area) on viewing portion 120 at which user 104 is directing his gaze. The portion (location or area) may be the center of viewing portion 120, a quadrant of viewing portion 120, or any other area of ​​viewing portion 120. The data representing the gaze of user 104 may be an angle or coordinates (Cartesian or polar) at which the user's gaze is directed.

[0030] While the described techniques may in some embodiments be used with Figure 1 The technology described herein can be used with the display system shown, but other types of display systems can also be used in other embodiments, including use with a single optical lens and display device, or use with multiple such optical lenses and display devices. Non-exclusive examples of other such devices include cameras, telescopes, microscopes, binoculars, spotting mirrors, mapping mirrors, etc. In addition, the described technology can be used with various display panels or other display devices that emit light to form one or more images viewed by a user through one or more optical lenses. In other embodiments, a user can view one or more images through one or more optical lenses that are produced in a manner other than through a display panel, such as on a surface that partially or completely reflects light from another light source.

[0031] The virtual image light 102 may include a plurality of light rays that propagate along an optical path 126 from each virtual image display unit 106 through the optical system 112 and toward the viewing portion 120. The optical system 112 modifies some or all of the plurality of light rays to provide corrected virtual image light 114. The optical system 112 includes one or more optical subsystems 130 for modifying the virtual image light 102. Although the plurality of optical subsystems 130 include a left optical subsystem 1301 for modifying the virtual image light 102 for the left eye 1051 and a right optical subsystem 130r for modifying the virtual image light 102 for the right eye 105r, one optical subsystem 130 may be used to jointly modify the virtual image light 102 for both eyes 1051, 105r. Each of the left and right optical subsystems 1301 and 130r may be independently adjusted to enhance the viewing experience of the user 104 or to correct visual defects or imperfections in the left eye 1051 and the right eye 105r, respectively.

[0032] Figure 2 According to one or more embodiments, Figure 1 FIG200 is a diagram of an optical subsystem 130 (e.g., optical subsystem 1301 or 130r) of the embodiment of the present invention. The optical subsystem 130 includes a receiving portion 202 and an emitting portion 206, wherein the receiving portion 202 is used to receive an initial virtual image light 204 corresponding to the virtual image light 102 for a single eye, and the emitting portion 206 is used to emit a corrected virtual image light 208. The initial virtual image light 204 may include a plurality of light rays 205, each light ray having a set of specific attributes (e.g., color, direction, brightness) for enabling the user 104 to perceive visual content. A light ray 205 in the plurality of light rays 205 corresponds to a position on an initial virtual image (represented by the initial virtual image light 204). The light ray 205 (or light) may be irradiated on the receiving portion 202 at a position that is consistent with or corresponds to the position on the initial virtual image.

[0033] Optical subsystem 130 also includes correction section 210, which includes one or more spatially varying polarizers 211 as described herein. Correction section 210 corrects initial virtual image light 204 and emits corrected virtual image light 208. At any one time, correction section 210 may correct a portion of initial virtual image light 204. Correction section 210 may correct different portions of initial virtual image light 204 differently. Correction section 210 may correct one or more portions of initial virtual image light 204, but may not apply optical correction to one or more other portions of initial virtual image light 204.

[0034] Note that although Figure 2Three spatially varying polarizers 211 (first, second, and third spatially varying polarizers 211 a , 211 b , 211 c ) are shown in FIG. 1 , but the optical subsystem 130 may include any number of spatially varying polarizers 211 .

[0035] Each spatially varying polarizer 211a, 211b, 211c has a respective input 212a, 212b, 212c operable to receive a respective control signal indicating whether the spatially varying polarizer 211a, 211b, 211c is to be turned on or off. The control signal may have a first state indicating that the spatially varying polarizer 211 is to be turned on and a second state indicating that the spatially varying polarizer 211 is to be turned off. The input 212 may be connected to a controller ( Figure 2 ), and can receive control signals from a controller.

[0036] The spatially variable polarizer 211 can be formed of a multi-twisted retarder (MTR), which is a wave plate-like retardation film that provides precise and customized levels of broadband, narrowband, or multi-band retardation in a single film. More specifically, the MTR includes two or more twisted liquid crystal (LC) layers on a single substrate, with a single alignment layer. Subsequent LC layers are aligned directly through the existing layers, allowing simple manufacturing, enabling automatic layer alignment, and producing a monolithic film with a continuously varying optical axis.

[0037] Due to its spatially varying properties, the multi-twist retarder provides localized optical correction. The localized optical correction can operate on a portion of the virtual image light (e.g., the initial virtual image light) that falls within the user's current field of view. The localized optical correction can operate on a portion of the virtual image light that falls within the user's current field of view that is different from other portions of the virtual image light that fall outside the user's current field of view.

[0038] The spatially varying polarizer 211 may include a wave retarder formed of a birefringent material. Birefringence is the property of a material having a refractive index that depends on the polarization and propagation direction of the light. The wave retarder changes the polarization state or phase of the light propagating through the wave retarder. The wave retarder may have a slow axis (or extraordinary axis) and a fast axis (ordinary axis). When polarized light travels through the wave retarder, the light along the fast axis travels faster than the light along the slow axis.

[0039] The spatially varying polarizer 211 can be configured to function as a corrective optical device. The birefringent material of the spatially varying polarizer 211 can be configured to cause light passing therethrough to undergo refraction (e.g., according to a refractive index). Each spatially varying polarizer 211 can have a diffraction pattern. The spatially varying polarizer 211 can be formed as a polarization-oriented lens and have an electrically controllable focal length. In addition, the spatially varying polarizer 211 can perform collimation on the light passing therethrough.

[0040] As used herein, optical correction includes optically changing or modifying light passing through or through correction portion 210. Correction as used herein with respect to optical modification does not imply pre-correction of light, images, or imperfections in light or images. Optical correction may be used to enhance or improve image visualization for a particular set of environments, or to meet certain user experience criteria or metrics.

[0041] One or more spatially varying polarizers 211 of the correction section 210 may operate as electrically controlled correction optical devices individually, collectively, or in subsets. Each spatially varying polarizer 211 may be formed to have diffraction pattern characteristics, light collimation characteristics, light focusing characteristics, or aberration correction characteristics, etc., to operate on light passing through the spatially varying polarizer 211. In addition, a subset of two or more spatially varying polarizers 211 among the available spatially varying polarizers 211 may have specific diffraction characteristics, light collimation characteristics, light focusing characteristics, or aberration correction characteristics, etc. in combination to operate on light passing through the subset. When a subset is activated (or turned on) and other available spatially varying polarizers 211 are deactivated (or disconnected), the subset may operate on light passing therethrough according to the specific characteristics of the subset.

[0042] Each spatially varying polarizer 211a, 211b, 211c can be formed to perform a specific optical correction as an optical device. In addition or as an alternative, two or more spatially varying polarizers 211 can be formed to perform a specific optical correction as a combination of optical elements. The spatially varying polarizers 211a, 211b, 211c can be layered or stacked, wherein a plurality of light rays 205 are passed from a first spatially varying polarizer 211a to a second spatially varying polarizer 211b, and then to a third spatially varying polarizer 211c. The first spatially varying polarizer 211a and the second spatially varying polarizer 211b are each formed to jointly perform a desired optical correction. The first spatially varying polarizer 211a can be formed to perform a first optical correction on the light 205 impinging on the first spatially varying polarizer 211a. The second spatially varying polarizer 211b can be formed to perform a second optical correction on the light impinging on the second spatially varying polarizer 211b (after having been corrected by the first optical correction). The combination of the first and second optical corrections jointly achieves the desired optical correction.

[0043] Continuing with this example, the third spatially varying polarizer 211c can be turned off so that it does not hinder or interfere with the desired optical correction performed by the first and second spatially varying polarizers 211a, 211b. When turned off, the third spatially varying polarizer 211c may not perform its own optical correction. Alternatively, when turned off, the third spatially varying polarizer 211c may perform a third optical correction. In this case, the first and second optical corrections can be adjusted so as to compensate for the third optical correction (and reverse the effect of the third optical correction) to achieve the optical correction sought.

[0044] Optical corrections may be performed on the initial virtual image light 204 in a non-spatially uniform manner. Non-spatially uniform includes applying optical corrections differently or non-uniformly to different portions of the initial virtual image light 204. Non-spatially uniform also includes performing different types of optical corrections on different portions of the initial virtual image light 204 or different locations of the initial virtual image light 204. For example, a first optical correction of the first spatially varying polarizer 211a may focus a first portion (e.g., the center) of the initial virtual image light 204 and defocus a second portion (e.g., the outer periphery or edge) of the initial virtual image light 204. It should be understood that the terms "defocused" or "blurred" may be relative terms, meaning that the focus in such a portion may not be optimized relative to the "focused" portion. Continuing with this example, a second optical correction of the second spatially varying polarizer 211a may optically correct the center of the initial virtual image light 204 in accordance with the user's prescription, and may not perform optical corrections on the periphery or edge of the initial virtual image light 204 in accordance with the user's prescription. The optical correction may perform sharpening on a portion of the initial virtual image light 204 and prohibit sharpening on another portion of the initial virtual image light 204 .

[0045] Figure 3 An exterior 300 of the HMD 100 is shown according to one or more embodiments. The HMD 100 includes a set of straps 302 connected to the body 116. The set of straps 302 can be used to selectively and securely mount the HMD 100 to the head of the user 104 to view visual content. The body 116 can include a control panel 304 for controlling various aspects of the HMD 100. The control panel 304 can include one or more input devices for controlling the optical properties of the optical system 112 to correct the visual content. The visual content can be corrected to improve the experience of the user 104 and / or the visual condition of the user 104 (e.g., myopia, hyperopia, astigmatism).

[0046] The input device may be an electrical device electrically connected to the controller and configured to command the controller to configure the optical correction performed by the correction portion 210 and its one or more spatially varying polarizers 211. As an example, the input device may cause an electrical signal to be sent to the controller in response to an interaction by the user 104, and in response, the controller sends one or more control signals to the corresponding spatially varying polarizers 211a, 211b, 211c to adjust the optical correction performed by the correction portion 210. Non-limiting examples of electrical input devices for the control panel 304 include a keypad with a set of keys for providing alphanumeric input or navigating menus, or a dial or knob electrically connected to the controller. The exterior 300 may include a display 306 for displaying information about the HMD 100, such as the current optical settings of the optical system 112. In some embodiments, the display 306 may be a touch screen input device with which the user 104 can interact to control the optical system 112.

[0047] In some embodiments, the user can adjust the optical settings of the optical system 112 in conjunction with the visual content presented by the virtual image display unit 106. For example, the user wearing the HMD 100 can interact with the control panel 304 or other input device (e.g., handheld controller, mouse, keyboard) to adjust the optical settings according to the menu or other visual content displayed by the virtual image display unit 106. As an example, the user can navigate the menu through the control panel 304 or other input device and provide user input, which causes the optical settings of the optical system 112 to change in response. As another example, the HMD 100 can adjust the optical settings of the optical system 112 in real time in response to the user input about the visual content perceived by the user 104. The user can initiate a visual test of the HMD 100, so that the virtual image display unit 106 displays visual content, such as a test pattern, and prompts the user to provide input about the clarity of the visual content. As a result of receiving the input, the HMD 100 can automatically adjust the optical settings of the optical system 112 to improve the clarity of the visual content, thereby improving the experience of the user 104.

[0048] Figure 44 is a block diagram 400 illustrating the interconnection of various parts of the HMD 100 according to one or more embodiments. The HMD 100 includes a controller 402, which includes one or more processors 404 and a memory 406, which stores a set of instructions that, as a result of execution by the one or more processors 404, causes the HMD 100 to perform one or more operations described herein. As non-limiting examples, the memory 406 may include read-only memory (ROM) and random access memory (RAM), and may be in the form of a solid-state memory or a hard drive. The HMD 100 also includes a communication interface 408 electrically connected to the controller 402 for sending and receiving communications with external devices. The communication interface 408 may include one or more wireless transceivers, such as a Wi-Fi transceiver, a cellular transceiver, a Bluetooth® transceiver, or a wireless communication interface. TM A transceiver, etc., which wirelessly sends communications to and receives communications wirelessly from an external device, such as a network router or a computing device (e.g., a laptop computer, a desktop computer, a tablet computer, a mobile device). The communication interface 408 may include a wired communication port, such as a universal serial bus port, a network interface port, etc., for wired communication with an external device.

[0049] The HMD 100 may include a set of input devices 410 electrically connected to the controller 402 for providing user input to the HMD 100. One or more of the set of input devices 410 may be provided on the exterior 300 of the HMD 100, for example, as part of the control panel 304. The controller 402 may also be electrically connected to the virtual image display unit 106 and / or the display 306 (if included) and configured to control the virtual image display unit 106 and / or the display 306. In some embodiments, the controller 402 may include one or more graphics processing units for generating the virtual image light 102 via the virtual image display unit 106.

[0050] The controller 402 is electrically connected to the optical system 112 and is configured to control the optical system 112 to adjust its optical characteristics as described herein. In particular, the controller 402 is electrically connected to the correction portion 412 of the left optical subsystem 1301 and the correction portion 416 of the right optical subsystem 130r and is configured to control the correction portion 412 of the left optical subsystem 1301 and the correction portion 416 of the right optical subsystem 130r.

[0051] Each correction portion 412, 416 can be as described in reference Figure 2416 to control the spatially varying polarizer 211 thereof. Specifically, the controller 402 sends a signal (e.g., a control signal) to the correction section 412, 416 so that the corresponding correction section 412, 416 performs optical correction by switching its spatially varying polarizer 211 on and off. As described above, the correction section 412, 416 can be controlled to modify its optical properties. The controller 402 can send a signal in response to receiving an input. For example, the controller 402 can adjust the optical properties in response to receiving an input from the input device 410. As another example, the controller 402 can adjust the optical properties in response to receiving an input via the communication interface 408.

[0052] The input received by the controller 402 may have a specific format. The input may indicate a prescription for the right eye and / or a prescription for the left eye. For each respective eye, the input may indicate a refractive power or spherical power (sometimes indicated as SPH or S), a cylindrical power (sometimes indicated as CYL or C), and / or an axis (typically between 0 and 180). The input may include input for the left optical subsystem 1301 and the right optical subsystem 130r.

[0053] In at least some embodiments, the HMD 100 includes a gaze tracker 127 configured to track the gaze (or direction thereof) of the user 104 or the user's eyes 105l, 105r. The gaze tracker 127 can perform gaze or pupil tracking for each eye 105l and 105r, respectively, or track the position or direction of the user's 104 head (e.g., as part of head tracking). In addition, the gaze tracker 127 can track various other types of movements and positions of the user's body. The gaze tracker 127 can output data representing the gaze of the user 104. The data can indicate on the display 306 or viewing portion 120 the portion (position or area) at which the user 104 is directing his gaze. The portion (position or area) can be the center, a quadrant, or any other area. The data representing the gaze of the user 104 can be the angle or coordinates (Cartesian or polar coordinates) at which the user's gaze is directed.

[0054] The adjustment of the optical settings of the optical subsystem 112 may be adjusted in real time based on data representing the gaze of the user 104 and / or by feedback provided by the user 104. The controller 402 may initiate a test to determine the adjustment made to the optical settings of the optical system 112. The test may include causing the virtual image display unit 106 to display specific visual content, such as a test pattern or a detailed visual image, and prompting the user to provide feedback via the input device 410 or the control panel 304. The user 104 may provide feedback indicating that various aspects of the visual content (e.g., text, images) do not appear clear. The controller 402 may adjust the optical settings of the optical system 112 and ask the user 104 whether the adjustment improves the clarity of various aspects of the visual content. The process may be iterative and repeated until the user 104 is satisfied with the clarity of the visual content. The test may be performed in response to receiving user input from the user 104 via the input device 410 or the control panel 304. Controller 402 may instruct user 104 to change his or her gaze, apply localized optical correction, and prompt the user to provide feedback via input device 410 or control panel 304 .

[0055] Input through communication interface 408 may be provided by a device (e.g., a laptop, desktop computer, mobile device, controller) as a result of user interaction. A computing device may include a set of instructions (e.g., applications and programs). A user may interact with it to cause the computing device to send a communication including instructions or information indicating information for modifying the optical properties of virtual image light 102 (e.g., to correct the visual condition of user 104). As described above, the user may enter input into input device 410 or a computing device as a prescription provided by a medical professional, and may have a predetermined format.

[0056] The controller 402 may determine signals to be sent to the correction portions 412, 416 in response to receiving input from the input device 410 or the communication interface 408. For example, one or more of the processors 404 may access a data structure stored in the memory 406 that indicates control signals to be sent to the respective correction portions 412, 416. The data structure may be an array, a lookup table, or other reference structure in which input data is associated with corresponding outputs (i.e., control signals) to be sent. In some embodiments, the controller 402 may store information indicative of a current state of the optical system 112 in the memory 406, and the controller 402 may determine adjustments to satisfy the received input from the current state.

[0057] In one embodiment, spatially varying polarizer 211 may be formed with advanced knowledge of the prescription or medical condition of user 104 or a group of potential users of HMD 100, and may be customized for user 104 or the group of potential users. In this case, HMD 100 may be customized for user 104 or the group of potential users, who may be friends of the user or members of the user's family. For example, each spatially varying polarizer 211 may be formed to optically correct for a specific user of the group of potential users. During use, controller 402 may switch to a specific spatially varying polarizer 211 depending on the identity of the user of HMD 100.

[0058] The spatially varying polarizer 211 may be formed to provide optical correction within the range of the user's current prescription. If the user's vision changes or deteriorates over time, the controller 402 of the HMD 100 customized for the user 104 may adjust the optical correction within the range to fine-tune the optical correction and provide an optical correction that is more suitable for the user's modified prescription. The variability of the optical correction provided by the correction portions 412, 416 described herein enables the optical correction to be adapted to new, foreseen, or predictable optical correction needs. For example, local or zone-based optical focusing may be performed based on the user's current prescription and foreseen or predictable prescription changes.

[0059] In some embodiments, the HMD 100 may be configured to detect the visual conditions of the user's eyes 105l and 105r, and automatically adjust the optical system 112 as a result of the detection. In such an embodiment, the HMD 100 may include one or more sensors 424 that detect information about the user's eyes 105l and 105r and provide measurements to the controller 402, which adjusts the optical system 112 accordingly. The HMD 100 may also include one or more light emitting elements 426 connected to the controller 402 for use in conjunction with the sensor 424 to obtain information. The light emitting element 426 may emit light at a certain angle and have certain characteristics (e.g., frequency, intensity) so that the light is reflected and received by the sensor 424. The sensor 424 may determine information about the user's eyes based on the light detected from the user's eyes. As a result of the determined information about the user's 104 eyes, the controller 402 may adjust the optical characteristics of the optical system 112 accordingly.

[0060] Figure 5 Shows the connection to the reference Figure 44. The controller 402 is a correction section 210 of the controller 402 described. The controller 402 has a plurality of outputs 214a, 214b, 214c connected to a plurality of inputs 212a, 212b, 212c of a corresponding plurality of spatially varying polarizers 211a, 211b, 211c, respectively. In the example shown, for the purpose of illustration, three layers of spatially varying polarizers are shown, but in an application, fewer layers (e.g., 1 layer, 2 layers) or more layers (e.g., 5 layers, 10 layers, 20 layers, etc.) may be used as needed. The controller 402 sends a control signal through each output 214, which is used to make the spatially varying polarizer 211 active or inactive.

[0061] Controller 402 has an input connected to an output of gaze tracker 127. Controller 402 receives data representing the user's gaze from gaze tracker 127 and switches multiple spatially varying polarizers 211 between on and off states based on the data. Controller 402 can operate multiple spatially varying polarizers 211 to perform optical corrections to areas where user 104 directs his or her gaze and / or areas outside of the user's gaze. As the user's gaze changes over time during a viewing session, controller 402 can operate multiple spatially varying polarizers 211 in a time-multiplexed manner to change the location where the optical correction is performed so that the optical correction follows the user's gaze.

[0062] The area of ​​the virtual image that was previously outside the user's gaze and is currently being gazed at by the user 104 may experience a change in the optical correction performed thereon, or have had an optical correction removed or applied thereto. Similarly, the area of ​​the virtual image that was previously gazed at by the user and is currently outside the user's gaze may also experience a change in the optical correction performed thereon, or have had an optical correction removed or applied thereto.

[0063] When inactive, the spatially varying polarizer 211 may be optically transparent or may only perform an inherent optical correction associated with the material composition of the spatially varying polarizer 211. Various types of materials have optical properties and are operable to change light. As described herein, the spatially varying polarizer 211 may be formed of two or more twisted liquid crystal layers. When off, the liquid crystal layers of the spatially varying polarizer 211 may still perform an inherent optical correction. When on, the spatially varying polarizer 211 performs the optical correction it has been designed to perform.

[0064] The first, second and third spatially varying polarizers 211a, 211b, 211c are formed to perform the first, second and third optical corrections. In operation, the controller 402 sends control signals to the spatially varying polarizers 211a, 211b, 211c to operate the spatially varying polarizers 211a, 211b, 211c between activated and inactivated states. For example, to activate the first optical correction and deactivate the second and third optical corrections, the controller 402 sends a control signal to the first spatially varying polarizer 211a, which activates the first spatially varying polarizer 211a, and sends respective control signals to the second and third spatially varying polarizers 211b, 211c, which deactivate the second and third spatially varying polarizers 211b, 211c, respectively. The first optical correction may be a combination of the optical correction sought and the optical compensation. The optical compensation may compensate for the inherent optical correction performed by the deactivated second and third spatially varying polarizers 211b, 211c. Thus, light exiting the first spatially varying polarizer 211a and passing through the deactivated second and third spatially varying polarizers 211b, 211c is pre-compensated for the inherent optical correction performed by the deactivated second and third spatially varying polarizers 211b, 211c.

[0065] In another example, the controller 402 can send a control signal to the first spatially varying polarizer 211a, which deactivates the first spatially varying polarizer 211a, and can send corresponding control signals to the second and third spatially varying polarizers 211b, 211c to activate the second and third spatially varying polarizers 211b, 211c. The first optical correction provided by the second and third spatially varying polarizers 211b, 211c is a combination of the second and third optical corrections. The controller 402 can selectively switch the spatially varying polarizer 211 between an activated and inactivated state so that the correction portion 210 provides an optical correction.

[0066] Figure 6 An example of viewing zone-based optical correction performed by multiple spatially varying polarizers 211a-1 is shown. Figure 6In the example of , the first spatially varying polarizer 211a performs optical correction by simultaneously focusing the central area (or part) of the image (or display) and defocusing the peripheral areas (or parts) of the upper left, upper right, lower left and lower right of the image. The optical correction performed by the first spatially varying polarizer 211a on the five areas can be performed separately by the second spatially varying polarizer 211b, the third spatially varying polarizer 211c, the fourth spatially varying polarizer 211d, the fifth spatially varying polarizer 211e and the sixth spatially varying polarizer 211f. The second spatially varying polarizer 211b focuses the central area of ​​the image (or display) without optically correcting the upper left, upper right, lower left and lower right areas. The third spatially varying polarizer 211c defocuses the upper left area without focusing the central area or the remaining peripheral parts. The fourth spatially varying polarizer 211d defocuses the upper right part without focusing the central part or the remaining peripheral parts. The fifth spatially varying polarizer 211e defocuses the lower left portion without focusing the center portion or the remaining peripheral portions. The sixth spatially varying polarizer 211f defocuses the lower right portion without focusing the center portion or the remaining peripheral portions.

[0067] Instead of focusing, the seventh, eighth, ninth, tenth and eleventh spatially varying polarizers 211g, 211h, 211i, 211j, 211k perform optical correction by sharpening the area optically corrected by the second, third, fourth, fifth and sixth spatially varying polarizers 211b, 211c, 211d, 211e, 211f. The twelfth spatially varying polarizer 211l optically corrects the central portion by changing the angular resolution of the image in the central portion. Figure 6 The twelfth spatially varying polarizer 2111 in the example of FIG. 4 does not optically correct other areas of the image.

[0068] Spatially varying polarizer 211 can perform one or more different types of optical corrections or the same optical correction on different areas of the image. Controller 402 switches spatially varying polarizer 211 to achieve various optical effects. For example, as the user's gaze changes, controller 402 can turn on spatially varying polarizer 211 (and turn off other spatially varying polarizers 211) accordingly to keep the area within the user's gaze in focus while defocusing other areas outside of the gaze. Controller 402 can operate spatially varying polarizer 211 to keep areas within the user's gaze sharp or to change their angular resolution or focal length.

[0069] The spatially varying polarizer of the present disclosure can provide a spatially varying polarization defined by a surface phase pattern, or by a combination of two or more surface phase patterns multiplexed together. More generally, any linear or nonlinear function can be used to define the surface of one or more spatially varying polarizers of the present disclosure to provide the desired functionality. Figure 7 and 8 Two non-limiting examples of surface phase diagrams for spatially varying polarizers are shown. Figure 7 In the exemplary surface plot 700 of , the phase varies concentrically from the center of the optic toward the outer periphery between -0.433 wavelengths to +0.433 wavelengths. Figure 8 In the exemplary surface plot 800 of , the phase varies linearly from -1.25E+004 at the bottom of the optic (as shown) to +1.25E+004 at the top of the optic (as shown), where the units are cycles per 2π radians. In applications, two or more spatially varying polarizers may be stacked together. For example, the concentric surface phase plot 700 may be multiplexed with the linear phase plot 800 and the like. Note that although the phase variations of the surface plots 700 and 800 are shown as discrete steps for simplicity, in reality, the phase may vary continuously across the entire surface of the optic. Furthermore, the specific phase values ​​in the surface phase plots 700 and 800 are provided as examples and should not be considered limiting.

[0070] In at least some embodiments, the surface phase diagram of the spatially varying polarizer can be designed to counteract or compensate for undesired polarization caused by at least one other component of the display system (e.g., a display source, a lens, etc.). In such embodiments, the phase distribution or diagram of the optical system (e.g., a lens, or a lens and a display source) can first be determined. The determined phase diagram can then be inverted and applied to the spatially varying polarizer so that the spatially varying polarizer offsets or compensates for undesired effects caused by other components of the optical system.

[0071] The various embodiments described above can be combined to provide further embodiments. Based on the above detailed description, the above and other changes can be made to the embodiments. Generally, in the following claims, the terms used should not be interpreted as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted as including all possible embodiments and the full range of equivalents granted by these claims. Therefore, the claims are not limited by this disclosure.

Claims

1. An optical system, comprising: a gaze tracker operative to track a user's gaze and output data representative of the gaze; a correction portion including a plurality of spatially varying polarizers, a first spatially varying polarizer of the plurality of spatially varying polarizers having a first control input configured to receive a first control signal of a plurality of control signals, the first control signal indicating whether the first spatially varying polarizer is activated or inactivated, the first spatially varying polarizer operating when activated to provide a first optical correction to light passing through the correction portion at a location corresponding to a first region of the plurality of regions of the virtual image; as well as The controller is configured as: receiving said data representing said gaze of said user; determining, based on the gaze, whether to perform the first optical correction on the light passing through the correction portion at a position corresponding to the first area; as well as in response to determining that the first optical correction is to be performed on the light passing through the correction portion at a location corresponding to the first region, outputting the first control signal indicating that the first spatially varying polarizer is to be activated; Wherein, the controller is configured as: determining, based on the data representing the gaze of the user, that the gaze has changed; as well as Based on performing the first optical correction on the light passing through the correction part at a position corresponding to the first area, determining to perform a second optical correction on the light passing through the correction part at a position corresponding to a second area in the multiple areas of the virtual image through a second spatially varying polarizer among the multiple spatially varying polarizers.

2. The optical system according to claim 1, wherein: The first area of ​​the plurality of areas of the virtual image is located within a field of view of the gaze of the user.

3. The optical system according to claim 1, wherein: The second one of the plurality of spatially varying polarizers has a second control input configured to receive a second one of the plurality of control signals, the second control signal indicating whether the second spatially varying polarizer is activated or inactivated, and wherein the controller is configured to: In response to determining that the second optical correction is to be performed on the light passing through the correction portion at a position corresponding to the second region, the second control signal indicating that the second spatially varying polarizer is to be activated is output.

4. The optical system according to claim 1, wherein: The first spatially varying polarizer and the second spatially varying polarizer are stacked so that the light passing through the correction portion is impinged on the second spatially varying polarizer after passing through the first spatially varying polarizer.

5. The optical system according to claim 1, wherein: Providing the first optical correction includes performing diffraction according to a diffraction pattern, light collimation, light focusing, image sharpening, angular resolution modification, focal length modification, or aberration correction.

6. The optical system according to claim 1, wherein: A spatially varying polarizer of the plurality of spatially varying polarizers comprises a multi-twist retarder.

7. A head mounted display system, comprising: Support structure; monitor; a gaze tracker operative to track a user's gaze and output data representative of the gaze; An optical system, comprising a first optical subsystem and a second optical subsystem, each of the first optical subsystem and the second optical subsystem comprising: a correction portion including a plurality of spatially varying polarizers, a first spatially varying polarizer of the plurality of spatially varying polarizers having a first control input configured to receive a first control signal of a plurality of control signals, the first control signal indicating whether the first spatially varying polarizer is activated or inactivated, the first spatially varying polarizer operating when activated to provide a first optical correction to light passing through the correction portion at a location corresponding to a first region of the plurality of regions of the virtual image; and a controller, wherein for each of the first optical subsystem and the second optical subsystem, the controller is configured to: receiving said data representing said gaze of said user; determining, based on the gaze, whether to perform the first optical correction on the light passing through the correction portion at a position corresponding to the first area; and in response to determining that the first optical correction is to be performed on the light passing through the correction portion at a location corresponding to the first region, outputting the first control signal indicating that the first spatially varying polarizer is to be activated; Wherein, for each of the first optical subsystem and the second optical subsystem, the controller is configured to: determining, based on the data representing the gaze, that the gaze has changed; and Based on performing the first optical correction on the light passing through the correction part at a position corresponding to the first area, determining to perform a second optical correction on the light passing through the correction part at a position corresponding to a second area in the multiple areas of the virtual image through a second spatially varying polarizer among the multiple spatially varying polarizers.

8. The head mounted display system according to claim 7, wherein: For each of the first optical subsystem and the second optical subsystem, the first area of ​​the plurality of areas of the virtual image is located within a field of view of the gaze of the user.

9. The head mounted display system according to claim 7, wherein: For each of the first optical subsystem and the second optical subsystem, the second spatially varying polarizer of the plurality of spatially varying polarizers has a second control input configured to receive a second control signal of the plurality of control signals, the second control signal indicating whether the second spatially varying polarizer is activated or inactivated, and wherein the controller is configured to: In response to determining that the second optical correction is to be performed on the light passing through the correction portion at a position corresponding to the second region, the second control signal indicating that the second spatially varying polarizer is to be activated is output.

10. The head mounted display system according to claim 7, wherein: For each of the first optical subsystem and the second optical subsystem, the first spatially varying polarizer and the second spatially varying polarizer are stacked so that the light passing through the correction portion is impinged on the second spatially varying polarizer after passing through the first spatially varying polarizer.

11. The head mounted display system according to claim 7, wherein: For each of the first optical subsystem and the second optical subsystem, providing the first optical correction includes performing diffraction according to a diffraction pattern, light collimation, light focusing, image sharpening, angular resolution modification, focal length modification, or aberration correction.

12. The head mounted display system according to claim 7, wherein: For each of the first optical subsystem and the second optical subsystem, a spatially varying polarizer in the plurality of spatially varying polarizers comprises a multi-twist retarder.

Images