Correction of Angle Uniformity of Dimming Device

Abstract

By applying a voltage different from the voltage nominally used to achieve a specific transmittance level, such as on-axis transmission of light, to the pixels of a segmented dimming device, an optical system is operated, and a technique for reducing angular transmittance variations in the operation of the segmented dimming device is described. The voltage applied to the pixels of the segmented dimming device can be selected to achieve a target observed transmittance level using a preconfigured and / or calibrated set of voltages that take into account the angular dependence of the transmittance of the dimming device.

Description

Background Art

[0001]

[0001] Modern computing and display technologies have facilitated the development of systems for so-called “virtual reality” or “augmented reality” experiences, where digitally reproduced images or portions thereof are presented to a user in a way that they appear to be real or are perceived as real. Virtual reality, i.e., “VR” scenarios, typically involve presenting digital or virtual image information without transparency to other actual real-world visual inputs, and augmented reality, i.e., “AR” scenarios, typically involve presenting digital or virtual image information as an augmentation to the visualization of the actual world around the user.

[0002]

[0002] Despite these advances in display technologies, improved methods, systems, and devices related to augmented reality systems, particularly display systems, are needed in the art.

Summary of the Invention

[0003]

[0003] The present disclosure generally relates to techniques for improving optical systems under various ambient light conditions. More particularly, embodiments of the present disclosure provide systems and methods for operating an augmented reality (AR) device that includes a dimming element to compensate for angular transmittance variations of the dimming element. Although the present invention is described with reference to AR devices, the present disclosure is applicable to various applications in computer vision and image display systems.

[0004]

[0004] In one aspect, a method of operating an optical system is described herein. In some examples, the method of this aspect includes a step of identifying a set of angular dependent transmittance levels for light passing through pixels of a segmented dimming device, where the segmented dimming device exhibits a field of view transmittance variation for applying the same voltage to all pixels of the segmented dimming device; a step of determining a set of voltages to apply to the pixels of the segmented dimming device, the step of determining the set of voltages including the step of using the set of angular dependent transmittance levels; and a step of applying a set of voltages to the pixels of the segmented dimming device of the optical system to achieve a light transmittance through the segmented dimming device corresponding to the set of angular dependent transmittance levels, for example, to enable predictability and / or uniformity of transmittance across an angle. In some examples, different types of segmented dimming devices may be used with the systems and methods described herein. For example, the segmented dimming device may include an electrically controlled birefringent liquid crystal panel. The segmented dimming device may exhibit transmittance variations for symmetric or asymmetric fields of view or angles of transmission.

[0005]

[0005] In some examples, the step of determining a set of voltages includes a step of determining light reception coordinates associated with the pixels of the segmented dimming device and a step of rendering a set of voltages using one or more look-up tables based on the light reception coordinates. For example, each look-up table may be associated with a corresponding angular dependent transmittance level or a linear range of transmittance. As another example, the look-up table can include coefficients representing specific transmittance levels stored for discrete angular positions, which can be used to generate the desired set voltage to apply to the pixels of the segmented dimming device. Using appropriately configured look-up tables, voltages for achieving a target transmittance level can be determined for application to the pixels of the segmented dimming device despite variations that may occur due to non-uniformity of angular transmission.

[0006] As used herein, the light reception coordinates can optionally include one or more distance coordinates or one or more angular coordinates. For example, the light reception coordinates can include Cartesian coordinates (e.g., X, Y coordinates), or one or more angles corresponding to the transmission angles through the pixels of a segmented dimming device such as a vertical transmission angle and a horizontal transmission angle. Optionally, the method in this aspect further includes the step of identifying the position of the eye for collecting the light transmitted through the segmented dimming device. In some examples, the step of determining a set of voltages includes the step of using a set of angle-dependent transmittance levels and the position of the eye. By determining the position of the eye (e.g., the light reception position of the light transmitted through the pixels of the segmented dimming device), the light reception coordinates can be determined for each pixel, such as a pair of transmission angles (e.g., horizontal and vertical transmission angles) for each pixel. For each pixel, the angle can be applied to one or more look-up tables associated with the angle-dependent transmittance levels or used in other ways to determine the output voltage to be applied to the pixel. In an example, a set of voltages includes the voltages for each of the pixels of the segmented dimming device. Optionally, to achieve uniform dimming across the segmented observer, the set of angle-dependent transmittance levels is the same level for all pixels of the segmented dimming device. Optionally, the set of angle-dependent transmittance levels includes independent transmittance levels for different pixels of the segmented dimming device, which can be useful for achieving different dimming levels for different regions of the segmented dimming device. In some cases, the step of specifying a set of angle-dependent transmittance levels includes the step of specifying a bias level, an offset level, or a normalization factor for pairing the set of angle-dependent transmittance levels with the transmittance levels associated with different segmented dimming devices of different optical systems. Such bias levels, offset levels, or normalization factors can be useful for ensuring that different segmented dimming devices (e.g., for the user's left and right eyes) are properly aligned with each other to reduce the binocular luminance error.

[0007] Optionally, the method of this aspect may include or further include the step of determining the temperature of the segmented dimming device, and the step of determining a set of voltages includes the step of using a set of angle-dependent transmittance levels and temperatures. For example, the angular transmittance non-uniformity of the segmented dimming device may vary at different temperatures. Optionally, each look-up table is associated with a corresponding angle-dependent transmittance level and a corresponding temperature or temperature range. In this way, despite variations that may occur due to non-uniformity of angular transmission or temperature fluctuations, a voltage can be determined for applying to the pixels of the segmented dimming device to achieve a target transmittance level. In some examples, the step of determining a set of voltages includes the step of determining the light reception coordinates associated with the pixels of the segmented dimming device and the step of rendering a set of voltages using one or more look-up tables based on the light reception coordinates.

[0008]

[0008] The method of this aspect may include or further include the step of generating a look-up table that provides voltage outputs for different pixels of the segmented dimming device as a function of the light reception coordinates of the light transmitted through the different pixels of the segmented dimming device to achieve each of a plurality of different angle-dependent transmittance levels. Such a look-up table may be generated, for example, as part of a calibration step of the segmented dimming device and may be executed before or after assembling the segmented dimming device into a display system.

[0009]

[0009] Optionally, the method of this aspect may include or further include the step of generating a look-up table that provides voltage outputs for different pixels of the segmented dimming device as a function of the light reception coordinates and temperature of the light transmitted through the different pixels of the segmented dimming device to achieve each of a plurality of different angle-dependent transmittance levels and different temperatures.

[0010]

[0010] In another aspect, an optical system is provided herein. Examples of optical systems of this aspect are segmented dimming devices that include a plurality of pixels, the segmented dimming devices showing a field of view transmittance variation for applying the same voltage to all pixels of the segmented dimming device, and a segmented dimming device that is in electrical communication with the segmented dimming device and is configured to supply a set of voltages to the pixels of the segmented dimming device to control the transmittance level of light passing through the pixels of the segmented dimming device. Optionally, the set of voltages includes voltages for each of the pixels of the segmented dimming device. Optionally, the segmented dimming device includes an electrically controlled birefringent liquid crystal panel.

[0011]

[0011] Optionally, the optical system of this aspect can include or further include one or more processors. For example, the one or more processors may be programmed with instructions that, when executed, cause the one or more processors to perform the steps of identifying a set of angle-dependent transmittance levels for light passing through the pixels of the segmented dimming device, determining a set of voltages to apply to the pixels of the segmented dimming device, where the step of determining the set of voltages includes using the set of angle-dependent transmittance levels, and controlling the voltage controller to apply a set of voltages to the pixels of the segmented dimming device of the optical system.

[0012]

[0012] In some examples, the step of determining a set of voltages includes determining received light coordinates associated with the pixels of the segmented dimming device and rendering a set of voltages using one or more look-up tables based on the received light coordinates, where the look-up tables are associated with corresponding angle-dependent transmittance levels. Optionally, the received light coordinates include one or more distance coordinates or one or more angle coordinates.

[0013]

[0013] In some examples, the operation may include or further include a step of identifying a receiver position for collecting light transmitted through the segmented dimming device. For example, the step of determining a set of voltages may include using a set of angle-dependent transmittance levels and the receiver position. Optionally, the receiver position corresponds to the position of the user's eye in the optical system. In some examples, the step of determining a set of voltages includes identifying the angle of each pixel of the segmented dimming device based on the position of the user's eye, and applying the angle to a look-up table associated with the angle-dependent transmittance level of the pixel to determine the output voltage to be applied to the pixel.

[0014]

[0014] In some examples, the set of angle-dependent transmittance levels is the same level for all pixels of the segmented dimming device. In other examples, the set of angle-dependent transmittance levels includes independent transmittance levels for different pixels of the segmented dimming device. Optionally, the step of identifying a set of angle-dependent transmittance levels includes identifying a bias level, an offset level, or a normalization factor for pairing the set of angle-dependent transmittance levels with transmittance levels associated with different segmented dimming devices of different optical systems. For example, it may be desirable to ensure that the transmittance levels used for the left and right eyes match appropriately to avoid user discomfort. In some examples, to achieve uniformity between different segmented dimming devices, the values within one or more look-up tables can be normalized with respect to each other over the entire range of transmittance levels for all angle values to reduce the perceived difference in transmittance levels. It may further be desirable to adjust the bias level, offset level, or normalization factor across a population of different segmented dimming devices to enable uniformity between devices.

[0015]

[0015] In some examples, the operation further includes determining the temperature of the segmented dimming device. Optionally, the step of determining a set of voltages includes using a set of angle-dependent transmittance levels and temperature. Optionally, the step of determining a set of voltages includes determining the light-receiving coordinates associated with the pixels of the segmented dimming device and rendering a set of voltages using one or more look-up tables based on the light-receiving coordinates, where the look-up tables are associated with the corresponding angle-dependent transmittance levels at the temperature.

[0016]

[0016] More advantages are achieved by the present invention than by the prior art. For example, by operating the dimming element according to the techniques described herein, more uniform dimming across the user's field of view, reduction of angular transmittance variations across different dimming regions, and reduction of dichoptic luminance mismatches (e.g., left eye / right eye mismatches) are made possible. Embodiments of the present invention use a segmented dimming device to attenuate world light according to a dimming level that matches a target dimming level despite the dimming device exhibiting non-uniformity of angular transmittance, enabling AR and virtual reality (VR) capabilities in a single device. Other advantages of the present disclosure will be readily apparent to those skilled in the art.

[0017]

[0017] The accompanying drawings, which are included to provide a further understanding of the disclosure, are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the detailed description serve to explain the principles of the disclosure. It is not attempted to show structural details of the disclosure in more detail than may be necessary for a fundamental understanding of the disclosure and as may be required to enable one skilled in the art to practice various implementations of the disclosure.

Brief Description of the Drawings

[0018]

Figure 1

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[0019]

[0029] Wearable optics and devices such as optical see-through (OST) augmented reality (AR) devices can be difficult to operate under extreme light conditions. For example, in the presence of a bright light source (e.g., the sun), the light source can stimulate the user's eyes, and dark regions of the device's field of view can become difficult for the user to see. Further, when virtual content is being displayed on a wearable optic, virtual content that overlaps with a bright light source can be invalidated by the world light associated with the bright light source, while virtual content displayed elsewhere within the device's field of view can be unobservable due to potential stimulation of the user's eyes by the world light.

[0020]

[0030] The embodiments and examples described herein solve these and other problems by using a segmented dimming device (e.g., a left and right segmented dimming device) in front of the user's eyes to dim world light at different spatial positions within the device's field of view. As an example, the segmented dimming device can use liquid crystal technology such as an electrically controlled birefringence (ECB) liquid crystal display where a voltage is applied across the pixels of the ECB liquid crystal display to reduce transmitted light. The segmented dimming device can also be referred to as a pixelated dimming device in that it can include a plurality of pixels or different regions that can be independently dimmed.

[0021]

[0031] However, a segmented dimming device may exhibit angular transmittance variations for applying the same voltage across all pixels. That is, for the fixed voltage applied to the pixels of the segmented dimming device, the amount of light transmitted through the pixels may vary as a function of the transmission angle. Such angular variations can cause unwanted artifacts, such as observed dimming of the transmitted light in different regions of the dimming device that is more or less than desired. The aspects described herein reduce angular variations in transmittance by applying a voltage to the pixels of the segmented dimming device that is different from the voltage nominally used to achieve a particular transmittance level, for example, for on-axis transmission of light. The voltage applied to the pixels of the segmented dimming device can be selected to achieve a target observed transmittance level using a preconfigured and / or calibrated set of voltages that take into account the angular dependence of the transmittance of the dimming device.

[0022]

[0032] In the following description, various embodiments and examples are described. For purposes of explanation, specific configurations and details are set forth to provide a thorough understanding of the embodiments and examples. However, it will also be apparent to one of ordinary skill in the art that the embodiments and examples can be practiced without specific details. Additionally, well-known features may be omitted or simplified in order not to obscure the described embodiments and examples.

[0023]

[0033] Some of the figures in this specification follow a numbering rule where the first digit or digits correspond to the figure number and the remaining single digit identifies an element or component of the figure. Similar elements or components between different figures can be identified by using similar numbers. For example, 101 can refer to the element "101" in Figure 1, and a similar element can be referred to as 201 in Figure 2. As will be understood, the elements shown in various embodiments of this specification can be added, exchanged, and excluded to provide some additional embodiments of the present disclosure. Further, the proportions and relative scales of the elements shown in the figures are intended to illustrate specific embodiments of the present disclosure and should not be construed in a limiting sense.

[0024]

[0034] Figure 1 shows a wearable device 101 and a corresponding scene 150 (e.g., a head-mounted display device) as seen through the wearable device 101, according to some embodiments of the present disclosure. Scene 150 is shown, and a user of AR technology perceives a setting 107 such as a real-world park featuring various real-world objects 130 such as people, trees, buildings, and a specific platform 120 in the background. In addition to these items, the user of AR technology also "sees" various virtual objects 142 such as an image 142-2 of a robot standing on the specific platform 120 in the real world and a character 142-1 of a comic-like avatar passing by, even though these elements (character 142-1 and image 142-2) do not exist in the real world. Due to the extreme complexity of human visual perception and the nervous system, it is difficult to generate virtual reality (VR) or AR technology that facilitates a comfortable and natural-rich presentation of virtual image elements among other virtual or real-world image elements.

[0025]

[0035] During operation, the projector 114 of the wearable device 101 can project virtual light 122 (e.g., light associated with virtual content) onto the eyepiece 102 of the wearable device 101, which can project a light irradiation field (e.g., an angular representation of the virtual content) onto the retina of the user's eye so that the user perceives the corresponding virtual content as being located at a certain position within the user's environment. For example, the virtual light 122 injected into the eyepiece 102 and decoupled by the eyepiece 102 towards the user's eye can cause the user to perceive that the character 142-1 is located on the first virtual depth plane 110-1 and that the image 142-2 is located on the second virtual depth plane 110-2. The user perceives the virtual content together with world light 132 corresponding to one or more world objects 130 such as the platform 120.

[0026]

[0036] In some embodiments, the wearable device 101 can include various lens assemblies, waveguides, diffractive elements, or other optical structures. In the illustrated example, the wearable device 101 includes a first lens assembly 105-1 disposed on the user side of the eyepiece 102 (the side closest to the user's eye of the eyepiece 102) and a second lens assembly 105-2 disposed on the world side of the eyepiece 102 (the side farthest from the user's eye of the eyepiece 102). Each of the lens assemblies 105-1, 105-2 may be configured to add optical power to the light passing therethrough to converge and / or diverge the light in a desired manner. Although FIG. 1 shows a single projector 114 and a single corresponding optical stack (including the eyepiece 102 and the lens assemblies 105), it should be understood that the wearable device 101 may include an optical stack for each eye having one or more projectors configured to inject virtual light into each respective optical stack.

[0027]

[0037] Figure 2 shows an exemplary wearable device 201 incorporating a segmented dimming device 203 (or simply "dimming device") aligned with the eyepiece 202 according to some embodiments of the present disclosure. In some embodiments, the segmented dimming device 203 may be transparent or translucent when the wearable device 201 is in an inactive mode or an off mode such that one or more world objects 230 can be seen when the user looks through the eyepiece 202 and the segmented dimming device 203. As shown, the eyepiece 202 and the dimming device 203 may be arranged side by side and may form a device field of view that is visible when the user looks through the eyepiece 202 and the dimming device 203. Figure 2 shows a single eyepiece 202 and a single dimming device 203 for purposes of illustration, but it should be understood that the wearable device 201 can include two eyepieces and two dimming devices, one for each eye of the user.

[0028]

[0038] During operation, the dimming device 203 is adjusted to reduce the intensity of world light 232 associated with world object 230 that impinges on the dimming device 203, thereby generating a dimming region 236 within the system field of view. The dimming region 236 may be a part or subset of the device field of view and may be partially or fully dimmed. The dimming device 203 may be adjusted according to a plurality of spatially resolved dimming values including the dimming value of the dimming region 236. Further, during operation of the wearable device 201, the projector 214 can project virtual image light 222 (e.g., light associated with virtual content) onto the eyepiece 202 that can be observed by the user along with the world light 232. As described with reference to FIG. 1, by projecting the virtual image light 222 onto the eyepiece 202, a light illumination field can be projected onto the user's retina such that the user perceives the corresponding virtual content to be located at a position within the user's environment.

[0029]

[0039] In some embodiments, the wearable device 201 can include a camera 206 (or "light sensor") configured to detect ambient light 232 and generate a corresponding image (or "luminance image"). In one example, the wearable device 201 can include left and right cameras (e.g., camera 206) disposed near the left and right light-dimming devices (e.g., light-dimming device 203), respectively. For each of the left and right sides, the camera 206 may be arranged such that the ambient light 232 detected by the camera 206 is computationally related to the ambient light 232 hitting the respective (left or right) light-dimming device 203 and / or the eyepiece 202. As described herein, the luminance images (or "left luminance image" and "right luminance image", respectively) captured by the left and right cameras can be combined and analyzed such that left and right 2D luminance maps directly corresponding to the surfaces of the left and right light-dimming devices and / or the viewpoints of the user's left and right eyes are generated.

[0030]

[0040] In the illustrated example, the dimming value of the light-dimming device 203 is calculated to align the dimming region 236 with the ambient light 232 related to the sun, thereby protecting the user's eyes and improving the AR experience. Specifically, the camera 206 can detect the ambient light 232 related to the sun, which can be used to further determine the direction in which the ambient light 232 related to the sun passes through the light-dimming device 203 and / or a part of the device's field of view. In response, the light-dimming device 203 can be adjusted to set the dimming region 236 to cover a part of the device's field of view corresponding to the detected ambient light. As shown, the light-dimming device 203 may be adjusted to reduce the intensity of the ambient light 232 at the center of the dimming region 236 by a greater amount than at the ends of the dimming region 236.

[0031]

[0041] In some examples of the AR device 200, the dimming region 236 or the dimming level of the dimming region 236 is determined based on the position information of the user's eyes. For example, the line-of-sight or eye position information can be detected by an eye tracker 240 attached to the AR device 200, and the dimming device 203 can be adjusted to set the position of the dimming region 236 and / or the dimming level of the dimming region 236 based on the detected eye position and / or line of sight. In some examples, the eye position may be determined as the central position of the eye, which may not change or may not change significantly when the line of sight changes.

[0032]

[0042] Figure 3 shows an example of a wearable device 301 having an eyepiece 302 and a pixelated dimming element (e.g., dimming device 303) on each of the left and right sides of the wearable device 301 according to some examples of the present disclosure. Each dimming device 303 can include a spatial grid of dimming regions (e.g., pixels 370) that can have various levels of transmittance or dimming. Each of the pixels 370 can have an associated size (e.g., width) and an associated spacing (e.g., pitch). The number of pixels 370 within each dimming device 303 may be larger or smaller than the illustrated example (e.g., each dimming device 303 may include a pixel grid of 1028×1028, 500×1000, 50×50, etc.). As illustrated, the spatial grid of dimming elements may include one or more transparent pixels 370-1 that provide complete or maximum transmission of incident light, one or more completely dark pixels 370-2 that provide complete dimming or minimum transmission of incident light, and one or more intermediate dark pixels 370-3 that provide partial dimming of incident light.

[0033]

[0043] Adjacent pixels 370 within the dimming device 303 may be in contact at their boundaries (e.g., when the pitch is equal to the size), or may be separated by a gap (e.g., when the pitch is larger than the size). In various embodiments, the dimming device 303 may use liquid crystal technologies such as dye-doped liquid crystal or guest-host liquid crystal, twisted nematic (TN) liquid crystal or vertical alignment (VA) liquid crystal, or ferroelectric liquid crystal. In some embodiments, the dimming device 303 may include an electrochromic device. In some embodiments, the dimming device 303 can use, among other possibilities, electro-control birefringence (ECB) technologies such as ECB cells.

[0034]

[0044] In use, all of the pixels 370 in the dimming device 303 may be controlled to have the same transmittance level, such as completely transparent or non-dimming characters, completely dark or fully dimming characters, or partially transmissive characters, or the pixels 370 may be controlled to different or independent transmittance levels. As used herein, the transmittance level, also referred to as the dimming level, can correspond to the transmittance, transmittance, or transmittance of the pixels in the dimming device, and can represent the ratio of the incident light passing through the pixels and reaching a light receiver such as the user's eye, such as a transmittance value of 100%, 0%, or greater than 0% and less than 100%. As will be described in more detail herein, the transmittance levels may be different for on-axis light transmission and off-axis light transmission, such as when the transmitted light has a direction perpendicular to the plane of the dimming device. In the examples herein, the transmittance can represent the relative transmittance with respect to the maximum transmittance (defined as 100%) and the minimum transmittance (defined as 0%). By applying a voltage across the pixel (e.g., a voltage difference is applied between the electrodes of the pixel), the transmittance level can be set or adjusted for the pixels of the dimming device. In some cases, the light transmitted axially through the dimming device in a completely transparent state can be set or defined to have a transmittance of 100% (corresponding to the maximum transmittance through the dimming device), even though some amount of light can be scattered and / or absorbed by the dimming device. In some examples, a voltage of 0 volts (0V) may be applied to achieve a completely transparent or 100% on-axis transmittance level.

[0035]

[0045] In some segmented dimming devices, such as those using ECB technology, the actual transmittance values through the pixels of the dimming device may exhibit angular non-uniformity, and furthermore the angular non-uniformity can be asymmetric. That is, the transmittance values may not be uniform over all incident / transmission angles, and the transmittance observed at positive or negative transmission angles with respect to on-axis transmission may be different. For example, a pixel or portion of the dimming device observed from one angle may appear to have a lower or higher transmittance when observed from a different angle. Furthermore, the angular non-uniformity can vary based on the voltage applied across the pixels.

[0036]

[0046] Figure 4 shows a photograph of a pair of segmented dimming devices (e.g., having an 80×80 pixel grid) taken from a camera position that is placed in front of a bright white background and is directly on-axis with the center of the dimming device (e.g., the light passing through the center of the dimming device is perpendicular to the plane of the dimming device). The pixels exhibit the same on-axis transmittance, and the same voltage is applied to all the pixels of the dimming device so that different voltages are used in each row of Figure 4 to achieve different nominal or on-axis transmittance levels. The individual pixels of the dimming device are not visible in the photograph shown in Figure 4. Note that some artifacts are observed at the left and right ends of the dimming device shown in Figure 4 (e.g., due to reflections or unclear regions). The top row of Figure 4 shows the application of a first voltage to all the pixels of the dimming device, which may correspond to a transmittance level of 100% of the on-axis transmittance, and little variation in the angular transmittance is observed across the entire dimming device. The second row of Figure 4 shows the application of a second voltage to all the pixels of the dimming device, which may correspond to a lower transmittance level of the on-axis transmittance, and angular variations are observed as indicated by the circled regions. For example, a portion of the left dimming device in the upper left quadrant and a portion of the right dimming device in the lower right quadrant exhibit a relatively low observed transmittance, while other portions of the dimming device exhibit a more uniform and relatively high observed transmittance. The third row of Figure 4 shows the application of a third voltage to all the pixels of the dimming device, the fourth row of Figure 4 shows the application of a fourth voltage to all the pixels of the dimming device, and as represented by the arrows in the second row of Figure 4, it shows that as the transmittance decreases, the low-observed transmittance regions move towards the center of the dimming device. The bottom row of Figure 4 shows the application of a fifth voltage to all the pixels of the dimming device, which may correspond to an on-axis transmittance of 0% where further angular variations are observed. For example, the portion near the center of the dimming device exhibits a relatively low, zero, or nearly zero observed transmittance, while other portions of the dimming device towards the edge exhibit a higher and non-zero observed transmittance.

[0037]

[0047] Such angular variations in the observed transmittance for the application of the same voltage across all pixels of the dimming device can cause undesirable artifacts such as dimming world light more or less than desired and difficulty in appropriately applying the desired dimming to different regions of the dimming device. Such angular variations can affect the usefulness of the segmented dimming device when incorporated into a head-mounted AR device and may contribute to eye strain or other undesirable effects. However, by applying a voltage to the pixels of the segmented dimming device to achieve a target observed transmittance that can be different from the on-axis transmittance of the pixels, the angular variation of the observed transmittance can be reduced. For example, in the case of a uniform target transmittance level across all pixels, different voltages can be applied to different pixels so that the observed transmittance level more closely matches the target transmittance level than when the same voltage is applied across all pixels. For example, in the middle row of FIG. 4 where a uniform transmittance of 50% may be desired, the relatively dark pixels in the upper left (left image) and lower right (right image) quadrants can have a smaller voltage applied to them, and although those pixels actually exhibit an on-axis transmittance higher than 50%, they provide a transmittance of 50% as observed at the location where the transmitted light is received (e.g., by the user's eye).

[0038]

[0048] To quantify and determine the appropriate voltage to apply to the pixels of a segmented dimming device to achieve an observed transmittance level that matches the target transmittance level, the data collection configuration 500 shown in FIG. 5 was developed. The data collection configuration 500 includes an LED panel 505 that provides a uniform bright white background, an optical stack 510 that includes a segmented dimming device, and a camera 515 mounted on a three-axis translation stage 520. The zero position of the camera 515 is adjusted so that the angle of view (AOV) 525 of the camera 515 is filled by the optical stack 510. The AOV 530 of the user's eye is shown for reference and is assumed to be smaller than the AOV 525 of the camera 515. In the example shown in FIG. 5, the AOV 525 of the camera 515 is approximately 67°, while the AOV 530 of the user's eye is shown as approximately 60°. In other examples, the AOV of the camera and / or the user's eye can be larger than these values.

[0039]

[0049] During data collection, the segmented dimming device of the optical stack 510 is adjusted to different on-axis transmittance levels, and a luminance image representing the observed transmittance is collected by the camera 515. The inset image 535 in the upper right of FIG. 5 shows an example of a luminance image collected by the camera 515 when the segmented dimming device of the optical stack 510 is set to a relatively low on-axis transmittance level (e.g., 25% or less). Further, the XYZ position of the camera 515 is adjusted using the translation stage 520 to vary the angle of transmission of the light that passes from the LED panel 505 through the optical stack 510 and is collected by the camera 515. For variations in only the Z position (e.g., the distance between the camera 515 and the optical stack 510), the observed angular variation of the transmittance does not appear to change, but the zoom factor is perceived to be closer or farther from the camera depending on the Z position of the optical stack 510. In the case of changes in the Y position and / or X position corresponding to a change in the lateral position of the eye, the observed changes in transmittance are relatively similar but appear to be shifted with respect to the position of the optical stack 510. This observation can confirm that the observed variation in transmittance is angle-dependent rather than position-dependent.

[0040]

[0050] To calibrate a wide field of view to enable adjustment of the horizontal position of the eyes, various techniques can be used. In one example, the observed transmittance data is collected at different X and Y positions of the camera 515, and the data is stitched together to provide an extended set of observed transmittance data that can account for shifts in the light reception position of the transmitted light. For example, multiple positions (e.g., 4 or more, or 5 or more) of the camera 515 can be used, such as an on-axis position having the center of the optical stack 510 and / or one or more on-axis positions having the upper left quadrant of the optical stack 510, the upper right quadrant of the optical stack 510, the lower left quadrant of the optical stack 510, and the lower right quadrant of the optical stack 510. In another example, a camera with a wider field of view can be used, such that a configuration can result where no transformation of the camera 515 is required and thus no stitching of the data is required. However, using a camera with a wider field of view can introduce some distortion, and it may be necessary to apply distortion correction to the acquired image. In one example, the display and observation of a known dot pattern on the optical stack 510 can be used to identify the necessary distortion correction. As another example, the observed transmittance data can be collected at different X and Y positions of the camera 515 as described above, but instead of stitching the data together, a known dot pattern applied to the optical stack 510 can be used to identify the camera position and / or orientation, such that the angular coordinates and the transmittance data can reference the same coordinate system without the need for data stitching.

[0041]

[0051] FIG. 6 provides data showing the transmittance measured through an example optical stack including a segmented dimming device as a function of applied voltage for combinations of three different vertical transmission angles (upper, center, lower) and three different horizontal transmission angles (left, center, right), and the data labeled "center" corresponds to the on-axis transmittance. Here, the applied voltage is represented as a tone having values from 0 to 255, where 0 corresponds to the maximum voltage applied to the dimming device to achieve 0% on-axis transmittance (completely dark state), and 255 corresponds to 0 voltage applied to the dimming device to achieve 100% (maximum) on-axis transmittance (completely transparent state). As shown in FIG. 6, some transmission angles provide a measured transmittance higher than the on-axis transmittance, and some transmission angles provide a measured transmittance lower than the on-axis transmittance. The transmittance at some transmission angles may be higher than the on-axis transmittance at some tones and lower than the on-axis transmittance at other tones. Although only data for nine different transmission angles are shown in FIG. 6, it will be understood that similar transmittance value curves for other transmission angles through the segmented dimming device can be measured as well. In some cases, more or fewer transmittance value curves can be obtained. Further, for transmission angles through the segmented dimming device for which measured transmittance value curves are not available, interpolation between the measured transmittance value curves can be applied to identify appropriate transmittance values.

[0042]

[0052] FIG. 6 shows two examples for adjusting the transmittance values to match the on-axis transmittance values for two different transmission angles, one corresponding to the transmission angle from the "upper left" pixel of the segmented dimming device and the other corresponding to the transmission angle from the "lower right" pixel of the segmented dimming device. As shown, the measured transmittance value for the "upper left" transmission angle is less than the central or on-axis transmittance value, and the measured transmittance value for the "lower right" transmission angle is greater than the central or on-axis transmittance value.

[0043]

[0053] For example, to match the transmittance value of the "upper left" transmission angle to the on-axis transmittance, the tone of the pixels with the "upper left" transmission angle can be increased (the voltage can be decreased) as much as the pixels with the "upper left" transmission angle. Specifically, when set to the voltage corresponding to a tone of about 176, the pixels with the "upper left" transmission angle show a relative transmittance of about 20% measured, and at this voltage, the on-axis relative transmittance is about 40%. To adjust the relative transmittance of the pixels with the "upper left" transmission angle to 40%, instead, the voltage corresponding to a tone of about 216 can be used. As another example, to match the transmittance value of the pixels with the "lower right" transmission angle to the on-axis transmittance, a smaller tone (or a higher voltage) of the pixels with the "lower right" transmission angle can be used. Specifically, when set to the voltage corresponding to a tone of about 156, the pixels with the "lower right" transmission angle show a relative transmittance of about 48% measured, and at this voltage, the on-axis relative transmittance is about 31%. To adjust the relative transmittance of the pixels with the "lower right" transmission angle to 31%, a voltage corresponding to a tone of about 124 can be used.

[0044]

[0054] Similar mappings between the various transmission angles across the segmented dimming device and the voltages or tones used to achieve the target transmittance can be summarized in a look-up table. Such a look-up table can be used, for example, to convert the desired or target transmittance and angular coordinates (e.g., vertical angle and horizontal angle) to the voltages or tones for achieving such desired or target transmittance. In some cases, interpolation between the values in the look-up table can be used to render the appropriate voltage or tone to achieve the target transmittance for one or more input transmission angles.

[0045]

[0055] The segmented dimming device can show the angular variation of the transmittance based on the position where the transmitted light is received. Therefore, it is useful to know the position of the eye where the light transmitted through the segmented dimming device is received in order to determine the transmission angle of each pixel in the segmented dimming device and to determine the appropriate mapping between the transmission angle, the target transmittance, and the voltage or gradation applied to the pixel. The eye tracker may be coupled to or included in a wearable device or an AR device that includes the segmented dimming device in order to determine the position of the eye. In some examples, the eye tracker includes a camera or other optical sensor for detecting eye features and determining the position of the eye, such as the center position of the eyeball.

[0046]

[0056] FIG. 7 shows an example in which a dimming value can be determined for the dimming portion of a segmented dimming device to reduce the transmission from a light source. In the illustrated example, the wearable device includes a left dimming device 703A aligned with the left eyepiece 702A and a right dimming device 703B aligned with the right eyepiece 702B. In this example, the dimming devices 703A and 703B are shown as being disposed on the world side of the eyepieces 702A and 702B, but in some embodiments, it may be desirable to dispose the dimming devices 703A and 703B on the user side (the side closest to the user's eye) of the eyepieces 702A and 702B.

[0047]

[0057] The wearable device may further include left and right eye trackers 740A and 740B that can determine, for example, the eye position and / or line of sight for use in determining appropriate transmittance levels of the dimming devices 703A and 703B. FIG. 7 shows a left eye position 741A and a right eye position 741B. Based on the eye positions 741A and 741B, the known geometric shape, and the pixel positions of the pixels of the dimming devices 703A and 703B, the transmittance angle as the light receiving coordinates of each pixel can be determined. In some examples, the transmittance angle may be determined as the vertical and horizontal angles (e.g., Cartesian angles) of each pixel. Other angular coordinate systems may be used, such as a polar coordinate system or a cylindrical coordinate system where the transmittance angle of each pixel is determined by a radial angle (representing the angle outward from the on-axis transmittance) and an azimuth angle (representing the position centered on the on-axis transmittance), or a spherical coordinate system where the transmittance angle of each pixel is determined by an inclination, a polar angle, and an azimuth angle. However, the use of angular geometries is not intended to be limiting, and in some examples, Cartesian coordinates or other distance light receiving coordinates can be alternatively or additionally determined and used. In a particular example, when the eye positions 741A and 741B are known, the on-axis relative distances to the left and right dimming devices 703A and 703B can be determined, and using the known geometric shapes of the left and right dimming devices 703A and 703B, a set of light receiving coordinates such as the transmittance angle (e.g., vertical and horizontal angles) of each pixel can be determined using trigonometry.

[0048]

[0058] In FIG. 7, a set of left-side angle-dependent transmittance levels is determined for the left dimming device 703A so as to at least partially reduce the world light emitted from a light source that is moving toward the user's left eye and right eye, a dimming region 736A is formed, and a dimming region 736B is formed. To determine appropriate voltages to be applied to different pixels of the dimming regions 736A and 736B, a set of left-side voltage levels is determined for the left dimming device 703A using a set of angles and angle-dependent target transmittance levels of the pixels of the dimming region 736A as inputs to one or more look-up tables, and a set of right-side voltage levels is determined for the right dimming device 703B using a set of light-receiving coordinates (e.g., angles) and target transmittance levels of the pixels of the dimming region 736B as inputs to one or more look-up tables. In some cases, the left-side voltage and / or the right-side voltage may be offset, a bias voltage may be applied, or they may have a normalization factor applied to ensure that the observed transmittances from left to right match appropriately. For example, a bias level, an offset level, or a normalization factor can be specified to pair a set of angle-dependent transmittance levels with transmittance levels associated with another optical stack or different segmented dimming devices of an optical system.

[0049]

[0059] In some implementations, multiple look-up tables can be used, such as individual look-up tables for each angle-dependent transmittance level. In some examples, some low-value tones (e.g., close to 0) are unusable as they are shifted to higher values to increase the transmittance to match the on-axis transmittance. Similarly, some tones with high values (e.g., close to 255) are unusable as they need to be shifted to lower values to decrease the transmittance to match the on-axis transmittance. Such examples can result in fewer tones than the total number of available tones. Thus, in some examples, a smaller number of angle-dependent transmittance levels than the available gray levels can be used. Such a configuration can also limit the number of look-up tables used. In the example described above with respect to FIG. 5, a fixed number of on-axis tones are used (e.g., representing a specific number of distinct voltages applied to the pixels of the segmented dimming device). As described above, a reduced number of angle-dependent transmittance levels can be used to account for the highest and lowest tones that are shifted, and each angle-dependent transmittance level can include one or more on-axis tones.

[0050]

[0060] Although not shown in FIG. 6, since the measured transmittance level can also vary as a function of temperature, it may also be desirable to generate and use a look-up table of angle-dependent transmittance levels as a function of temperature. In such an example, a temperature sensor can be included in the wearable device and used to identify a look-up table suitable for use in rendering a set of voltages to be applied to the pixels of the segmented dimming device.

[0051]

[0061] Other components of a wearable or AR device or apparatus incorporating a segmented dimming device may be used beyond those shown in the examples described herein. U.S. Patent Application No. 16 / 557,706, filed August 30, 2019 and now issued as U.S. Patent No. 11,170,565, provides additional details of a wearable device including a segmented dimming device and is hereby incorporated by reference in its entirety.

[0052]

[0062] Figure 8 shows a schematic diagram of an exemplary wearable system 800 according to some embodiments of the present disclosure. Wearable system 800 can include a wearable device 801 and at least one remote device 826 that is remote from (e.g., a separate piece of hardware but communicatively coupled to) wearable device 801. Alternatively, wearable system 800 may be referred to as an "optical system" and wearable device 801 may be referred to as an "optical device". While wearable device 801 is being worn by a user (generally as a headset), remote device 826 can be held by the user (e.g., as a handheld controller), or fixedly attached to a helmet or hat worn by the user, incorporated into headphones, or otherwise removably attached to the user in various configurations such as a backpack-type configuration, a belt-coupled configuration, etc.

[0053]

[0063] The wearable device 801 can include a left eyepiece 802A, a left lens assembly 805A, and a left segmented dimming device 803A that are arranged in a parallel configuration and constitute a left optical stack. The left lens assembly 805A can include a housing lens on the user side of the left optical stack and a compensation lens on the world side of the left optical stack. Similarly, the wearable device 801 can include a right eyepiece 802B, a right lens assembly 805B, and a right segmented dimming device 803B that are arranged in a parallel configuration and constitute a right optical stack. The right lens assembly 805B can include a housing lens on the user side of the right optical stack and a compensation lens on the world side of the right optical stack.

[0054]

[0064] In some embodiments, the wearable device 801 can include one or more sensors, including but not limited to a left eye box camera 806A attached directly or near the left eyepiece 802A, a right eye box camera 806B attached directly or near the right eyepiece 802B, and one or more temperature sensors 828 attached to or between the eyepieces 802. The eye box cameras 806A and 806B may be or include an eye tracker or other device for determining the positions of the user's left and right eyes. The wearable device 801 may also include one or more image projection devices, such as a left projector 814A optically coupled to the left eyepiece 802A and a right projector 814B optically coupled to the right eyepiece 802B.

[0055]

[0065] The wearable system 800 can include a processing module 850 for collecting, processing, and / or controlling data and hardware within the system. The components of the processing module 850 may be distributed between the wearable device 801 and the remote device 803. For example, the processing module 850 can include a local processing module 852 on the wearable portion of the wearable system 800 and a remote processing module 856 that is physically separated from the local processing module 852 and communicatively linked to the local processing module. Each of the local processing module 852 and the remote processing module 856 can include one or more processing units (e.g., a central processing unit (CPU), a graphics processing unit (GPU), etc.), a controller (e.g., a voltage controller, a projector controller, etc.), and one or more storage devices such as a non-volatile memory (e.g., a flash memory).

[0056]

[0066] The processing module 850 can collect data captured by various sensors of the wearable system 800, such as cameras 806A and 806B, temperature sensor 828, remote sensor 830, ambient light sensor, microphone, world camera, inertial measurement unit (IMU), accelerometer, compass, global navigation satellite system (GNSS) unit, wireless device, and / or gyroscope. For example, the processing module 850 can receive images 820A and 820B from cameras 806A and 806B. Specifically, the processing module 850 can receive the eye box image 820A from the left eye box camera 806A and the right eye box image 820B from the right eye box camera 806B. In some embodiments, the images 820A and 820B can include a single image, a pair of images, a video including a stream of images, a video including a stream of pairs of images, and the like. The images 820A and 820B may be periodically generated while the power of the wearable system 800 is on and transmitted to the processing module 850, or may be generated in response to commands transmitted by the processing module 850 to one or more of the cameras.

[0057]

[0067] In some embodiments, the processing module 850 can receive ambient light information from the ambient light sensor. The ambient light information can indicate a range of luminance values or spatially resolved luminance values. The temperature sensor 828 can capture the temperature of an optical stack such as the left segmented dimming device 803A and the right segmented dimming device 803B or its components. As another example, the processing module 850 can receive image luminance values projected from one or both of the projectors 814. The remote sensor 830 disposed within the remote device 826 can include any of the above-described sensors having similar functions or different sensors.

[0058]

[0068] Virtual content is delivered to the user of the wearable system 800 using the projectors 814 and the eyepieces 802, along with other components within the optical stack. For example, the eyepieces 802A, 802B can each include a transparent or translucent waveguide configured to guide and emit light generated by the projectors 814A, 814B, respectively. Specifically, the processing module 850 may cause the left projector 814A to output left virtual image light 822A to the left eyepiece 802A and the right projector 814B to output right virtual image light 822B to the right eyepiece 802B. In some embodiments, the projector 814 can include a microelectromechanical systems (MEMS) spatial light modulator (SLM) scanning device. In some embodiments, each of the eyepieces 802A, 802B may include a plurality of waveguides corresponding to different colors. In some embodiments, the lens assemblies 805A, 805B may be coupled and / or integrated with the eyepieces 802A, 802B. For example, the lens assemblies 805A, 805B may be incorporated into a multi-layer eyepiece and may form one or more layers that make up one of the eyepieces 802A, 802B.

[0059]

[0069] Voltage 825A may be provided to the dimming device 803A segmented on the left by the processing module 850, and voltage 825B may be provided to the dimming device 803B segmented on the right by the processing module 850. Voltages 825A and 825B can be determined using various information as described above. For example, voltage 825A may be determined using the position of the left eye determined by the left eye box camera 806A and optionally temperature data 832 from the temperature sensor 828, and voltage 825B may be determined using the position of the right eye determined by the right eye box camera 806B and optionally temperature data 832 from the temperature sensor 828. Voltage 825A can be determined by using the light reception coordinates (e.g., transmission angle) associated with each pixel of the left-segmented dimming device 803A determined based on the position of the left eye. Similarly, voltage 825B may be determined by using the angle associated with each pixel of the right-segmented dimming device 803B determined based on the position of the right eye. The processing module 850 can determine voltages 825A and 825B using one or more transmittance look-up tables including angle voltage information and / or temperature-dependent transmittance look-up tables.

[0060]

[0070] FIG. 9 shows a method 900 for operating an optical system according to some examples of the present disclosure. One or more steps of method 900 can be omitted during the execution of method 900, and the steps of method 900 can be executed in any order and / or in parallel. One or more steps of method 900 may be repeated one or more times during operation. One or more steps of method 900 may be executed by one or more processors such as those included in the optical system. Method 900 may be implemented as a computer-readable medium or computer program product including instructions that cause one or more computers to execute the steps of method 900 when the program is executed by the one or more computers.

[0061]

[0071] The optical system described in connection with method 900 can correspond to the wearable systems (e.g., wearable system 800) and / or wearable devices (e.g., wearable devices 101, 201, 301, 801) described in various embodiments. The optical system described in connection with method 900 may be a display device such as an AR device, or in some examples, the optical system may be a device that does not have the function of displaying virtual content such as sunglasses. The optical system may include one or more segmented dimming devices (e.g., dimming devices 203, 303, 703A, 703B, 803A, 803B). The optical system can be configured to receive world light (e.g., world light 132, 232) related to world objects (e.g., world objects 130, 230) at each of the segmented dimming devices according to the spatial dimming technology described herein, and use the segmented dimming devices to reduce the transmittance of the world light.

[0062]

[0072] In step 905, based on the target transmittance level and the light receiving coordinates for receiving the light transmitted through the pixels of the segmented dimming device, a plurality of look-up tables for supplying an output voltage to the pixels of the segmented dimming device can be generated. As described above, different look-up tables can be generated for different target transmittance levels, and each look-up table provides a conversion of the light receiving coordinates (e.g., angular coordinates) to the voltage for providing the target transmittance. Step 905 can correspond to a calibration or data collection step of testing the segmented dimming device to determine its performance characteristics, such as using a data collection configuration 500 as shown in FIG. 5 to enable the determination of a plurality of look-up tables, and specifying the actual angular transmittance level as a function of the applied pixel voltage. In some examples, step 905 can optionally include a step of controlling the temperature of the segmented dimming device during data collection to generate look-up tables for a plurality of temperatures and a plurality of target transmittance levels.

[0063]

[0073] In step 910, the eye position can be captured or determined using an eye tracker or an eye box camera to enable determination of the light reception coordinates (e.g., the transmission angle) in step 915 for receiving the light that has passed through each pixel of the dimming device segmented by the user's eyes of the wearable system or wearable device. In this way, appropriate angle information can be used by the user, which can vary depending on the specific user and / or the specific position or fit of the wearable device on the user's head. In some cases, if an eye tracker or an eye box camera is not used, the eye position may be set as a fixed value, so capturing the eye position in step 910 may be an optional step, and as a result, the light reception coordinates may also be a fixed value. In some cases, an eye tracker or an eye box camera can be used not only to determine the eye position for specifying the light reception coordinates of the transmitted light as described herein, but also, for example, to determine line-of-sight information for other purposes.

[0064]

[0074] In step 920, the target transmittance level of the pixels of the segmented dimming device can be determined. As described above, the target transmittance level can be determined to dim a portion of the segmented dimming device to reduce the intensity associated with bright world objects or to reduce the amount of world light to allow the virtual content generated by the wearable device to be washed out. U.S. Patent Application No. 16 / 557,706, filed on August 30, 2019 and currently issued as U.S. Patent No. 11,170,565, which is hereby incorporated by reference in its entirety, provides additional details on determining the dimming or transmittance level of the pixels of the segmented dimming device, and the techniques described therein can be applied to determine the target transmittance level.

[0065]

[0075] In step 925, a voltage can be determined for applying to the pixels of the segmented dimming device. The voltage can be determined using a set of light reception coordinates for each pixel, using the look-up table determined in step 905, and using the target transmittance level determined in step 920, as determined in step 915. For example, since each look-up table can be associated with a target transmittance level, the target transmittance level for each pixel can be used to determine which look-up table to use for that pixel. Similarly, temperature can optionally be used in combination with the target transmittance level to determine which look-up table to use for that pixel, since each look-up table can be associated with a target transmittance level and a temperature or temperature range. Once the appropriate look-up table is identified, the light reception coordinates can be applied to the look-up table to determine the voltage to apply to the pixel to achieve the target transmittance. Such a process may, in some cases, be repeated for each pixel or group of pixels.

[0066]

[0076] Using the appropriate set of voltages identified for each pixel of the segmented dimming device, in step 930, a voltage can be applied to the pixels of the segmented dimming device so as to achieve an appropriate target transmittance level for each pixel corrected by this method.

[0067]

[0077] FIG. 10 shows an example of a luminance image collected by a camera in a data collection configuration as shown in FIG. 5 when the segmented dimming device is set to a series of different on-axis transmittance levels (e.g., gradations corresponding to 64, 128, 160, and 224 on a scale of 0 to 255) of an uncorrected image at the uppermost stage. The corrected image has its applied voltage adjusted to establish a more uniform transmittance across the segmented dimming device, as described herein. Overall, the corrected image shows a significantly more uniform correction near the center of the segmented dimming device, although some artifacts may still be observed.

[0068]

[0078] Figure 11 shows an exemplary computer system 1100 that includes various hardware elements, according to some embodiments of the present disclosure. The computer system 1100 may be incorporated into or integrated with the apparatuses described herein and / or may be configured to perform some or all of the steps of the methods provided by various embodiments. For example, in various embodiments, the computer system 1100 may be incorporated into the wearable system 800 and / or may be configured to execute the method 900. Note that Figure 11 is only meant to provide a generalized illustration of various components, any or all of which may be suitably utilized. Thus, Figure 11 broadly shows how individual system elements may be implemented in a relatively separated or relatively more integrated manner.

[0069]

[0079] In the illustrated example, the computer system 1100 includes a communication medium 1105, one or more processors 1110, one or more input devices 1115, one or more output devices 1120, a communication subsystem 1119, and one or more memory devices 1125. The computer system 1100 can be implemented using a variety of hardware implementations and embedded system technologies. For example, one or more elements of the computer system 1100 may be implemented as, among other things, field programmable gate arrays (FPGAs), system-on-chips (SoCs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), microcontrollers, and / or hybrid devices such as SoC FPGAs, which are commercially available, for example, from XILINX (registered trademark), INTEL (registered trademark), or LATTICE SEMICONDUCTOR (registered trademark).

[0070]

[0080] The various hardware elements of computer system 1100 may be communicatively coupled via communication medium 1105. Although communication medium 1105 is shown as a single connection for clarity, it should be understood that communication medium 1105 can include various numbers and types of communication media for transferring data between hardware elements. For example, communication medium 1105 can include, among other possibilities, one or more wires (e.g., conductive traces, paths, or leads on a printed circuit board (PCB) or integrated circuit (IC), microstrips, striplines, coaxial cables), one or more optical waveguides (e.g., optical fibers, strip waveguides), and / or one or more wireless connections or links (e.g., infrared wireless communication, wireless communication, microwave wireless communication).

[0071]

[0081] In some embodiments, communication medium 1105 can include one or more buses that connect pins of the hardware elements of computer system 1100. For example, communication medium 1105 can include a bus, called a system bus, that connects processor 1110 and main memory 1135, and a bus, called an expansion bus, that connects main memory 1135 and input device 1115 or output device 1120. The system bus itself may be composed of several buses including an address bus, a data bus, and a control bus. The address bus can carry memory addresses from processor 1110 to the address bus circuitry associated with main memory 1135 so that the data bus can access the data contained in the memory address and return it to processor 1110. The control bus can carry commands from processor 1110 and return status signals from main memory 1135. Each bus can include a plurality of wires for carrying multiple bits of information, and each bus can support serial or parallel transmission of data.

[0072]

[0082] Processor 1110 can include one or more central processing units (CPUs), graphics processing units (GPUs), neural network processors or accelerators, digital signal processors (DSPs), and / or other general-purpose or dedicated processors capable of executing instructions. The CPU can take the form of a microprocessor that can be manufactured on a single IC chip with a metal-oxide-semiconductor field-effect transistor (MOSFET) structure. Processor 1110 can include one or more multi-core processors where each core can read and execute program instructions simultaneously with other cores, improving the speed of programs that support multi-threading.

[0073]

[0083] Input device 1115 can include one or more of various user input devices such as a mouse, keyboard, microphone, as well as various sensor input devices such as an image capture device, pressure sensors (e.g., barometer, tactile sensor), temperature sensors (e.g., thermometer, thermocouple, thermistor), motion sensors (e.g., accelerometer, gyroscope, tilt sensor), light sensors (e.g., photodiode, photodetector, charge-coupled device). Input device 1115 can also include a device for reading and / or receiving removable storage devices or other removable media. Such removable media can include optical discs (e.g., Blu-ray (registered trademark) disc, DVD, CD), memory cards (e.g., CompactFlash (registered trademark) card, Secure Digital (SD) card, memory stick), floppy disks, universal serial bus (USB) flash drives, external hard disk drives (HDD) or solid state drives (SSD), etc.

[0074]

[0084] Output device 1120 can include, without limitation, one or more of various devices that convert information into a human-readable form, such as a display device, a speaker, a printer, a tactile or haptic device, etc. Output device 1120 can also include a device for writing to a removable storage device or other removable media, such as those described with reference to input device 1115. Output device 1120 can also include various actuators for causing physical movement of one or more components. Such actuators may be hydraulic, pneumatic, or electric, and may be controlled using control signals generated by computer system 1100.

[0075]

[0085] Communication subsystem 1119 can include hardware components for connecting computer system 1100 to a system or device located external to computer system 1100 via a computer network or the like. In various embodiments, communication subsystem 1119 can include, among other possibilities, a wired communication device coupled to one or more input / output ports (e.g., a universal asynchronous receiver / transmitter (UART)), an optical communication device (e.g., an optical modem), an infrared communication device, a wireless communication device (e.g., a wireless network interface controller, a BLUETOOTH® device, an IEEE 802.11 device, a Wi-Fi device, a Wi-Max device, a cellular device).

[0076]

[0086] The memory device 1125 can include various data storage devices of the computer system 1100. For example, the memory device 1125 can include various types of computer memories with different response times and capacities, from high-speed response time and low-capacity memories such as processor registers and caches (e.g., L0, L1, L2), to medium-speed response time and medium-capacity memories such as random access memory (RAM), to low-response time and high-capacity memories such as solid state drives and hard drive disks. Although the processor 1110 and the memory device 1125 are shown as separate elements, it should be understood that the processor 1110 can include various levels of on-processor memory such as processor registers and caches that can be utilized by a single processor or shared among multiple processors.

[0077]

[0087] Memory device 1125 can include main memory 1135 that can be directly accessed by processor 1110 via the memory bus of communication medium 1105. For example, processor 1110 can continuously read and execute instructions stored in main memory 1135. Thus, as shown in FIG. 11, various software elements can be loaded into main memory 1135 and read and executed by processor 1110. Typically, main memory 1135 is volatile memory, losing all data when the power is turned off, and thus requiring power to store the stored data. Main memory 1135 can further include a small portion of non-volatile memory that is used to read other software stored in memory device 1125 into main memory 1135 (e.g., firmware such as BIOS). In some embodiments, the volatile memory of main memory 1135 is implemented as RAM such as dynamic random access memory (DRAM), and the non-volatile memory of main memory 1135 is implemented as read-only memory (ROM) such as flash memory, erasable programmable read-only memory (EPROM), or electrically erasable programmable read-only memory (EEPROM).

[0078]

[0088] The computer system 1100 can include software elements shown as currently located within the main memory 1135, which can include an operating system, device drivers, firmware, compilers, and / or other code such as one or more application programs provided by various embodiments of the present disclosure. By way of mere example, one or more steps described with respect to any of the methods above can be implemented as executable instructions 1140 by the computer system 1100. In one example, such instructions 1140 can be received by the computer system 1100 using the communication subsystem 1119 (e.g., via a wireless or wired signal that conveys the instructions 1140), carried by the communication medium 1105 to the memory device 1125, stored within the memory device 1125, loaded into the main memory 1135, and executed by the processor 1110 to perform one or more steps of the described method. In another example, the instructions 1140 can be received by the computer system 1100 using the input device 1115 (e.g., via a removable media reader), carried by the communication medium 1105 to the memory device 1125, stored within the memory device 1125, loaded into the main memory 1135, and executed by the processor 1110 to perform one or more steps of the described method.

[0079]

[0089] In some embodiments of the present disclosure, instruction 1140 is stored in a computer-readable storage medium (or simply a computer-readable medium). Such a computer-readable medium may be non-transitory and thus may be referred to as a non-transitory computer-readable medium. In some cases, the non-transitory computer-readable medium may be incorporated within computer system 1100. For example, the non-transitory computer-readable medium may be one of memory devices 1125 (as shown in FIG. 11). In some cases, the non-transitory computer-readable medium may be separate from computer system 1100. In one example, the non-transitory computer-readable medium may be removable media provided to input device 1115 (as shown in FIG. 11), such as that described with reference to input device 1115, and instruction 1140 is read into computer system 1100 by input device 1115. In another example, the non-transitory computer-readable medium may be a component of a remote electronic device, such as a cellular phone, that can wirelessly transmit a data signal carrying instruction 1140 to computer system 1100 and is received by communication subsystem 1119 (as shown in FIG. 11).

[0080]

[0090] Instruction 1140 can take any suitable form that can be read and / or executed by computer system 1100. For example, Instruction 1140 may be source code (written in a human-readable programming language such as Java, C, C++, C#, Python, etc.), object code, assembly language, machine code, microcode, executable code, etc. In one example, Instruction 1140 is provided to computer system 1100 in the form of source code, and the compiler is used to convert Instruction 1140 from source code to machine language and then load it into main memory 1135 for execution by processor 1110. As another example, Instruction 1140 is provided to computer system 1100 in the form of an executable file having machine code that can be immediately loaded into main memory 1135 for execution by processor 1110. In various examples, Instruction 1140 may be provided to computer system 1100 in encrypted or unencrypted form, compressed or uncompressed form, among other possibilities, as an initialization for an installation package or a broader software deployment.

[0081]

[0091] In one aspect of the present disclosure, a system (e.g., computer system 1100) for executing methods according to various embodiments of the present disclosure is provided. For example, some embodiments can include a system that includes one or more processors (e.g., processor 1110) communicatively coupled to a non-transitory computer-readable medium (e.g., memory device 1125 or main memory 1135). The non-transitory computer-readable medium can store instructions (e.g., Instruction 1140) that, when executed by the one or more processors, cause the one or more processors to execute the methods described in various embodiments.

[0082]

[0092] In another aspect of the present disclosure, a computer program product is provided that includes instructions (e.g., instruction 1140) for performing the methods according to various embodiments of the present disclosure. The computer program product can be tangibly embodied on a non-transitory computer-readable medium (e.g., memory device 1125 or main memory 1135). The instructions can be configured to cause one or more processors (e.g., processor 1110) to perform the methods described in the various embodiments.

[0083]

[0093] In another aspect of the present disclosure, a non-transitory computer-readable medium (e.g., memory device 1125 or main memory 1135) is provided. The non-transitory computer-readable medium can store instructions (e.g., instruction 1140) that, when executed by one or more processors (e.g., processor 1110), cause the one or more processors to perform the methods described in the various embodiments.

[0084]

[0094] The methods, systems, and apparatuses described above are examples. Various configurations can omit, substitute, or add various procedures or components as needed. For example, in an alternative configuration, the method may be performed in a different order than described, and / or various steps may be added, omitted, and / or combined. Also, features described with respect to a particular configuration can be combined in various other configurations. Different aspects and elements of the configurations can be combined in a similar manner. Also, technology is evolving, and thus many of the elements are examples and do not limit the scope of the present disclosure or the claims.

[0085]

[0095] In the description, specific details are given to provide a complete understanding of typical configurations including embodiments. However, the configurations can be implemented without these specific details. For example, well-known circuits, processes, algorithms, structures, and technologies are shown without unnecessary detail to avoid obscuring the configuration. This description provides only exemplary configurations and does not limit the scope of the claims, applicability, or configuration. Rather, the foregoing description of the configuration provides those skilled in the art with a possible description for implementing the described technology. Various changes can be made to the functions and arrangements of the elements without departing from the spirit or scope of the present disclosure.

[0086]

[0096] Although several exemplary configurations have been described, various modifications, alternative configurations, and equivalents can be used without departing from the spirit of the present disclosure. For example, the above elements may be components of a larger system, and other rules may take precedence over or modify the application of this technology. Also, several steps can be performed before, during, or after considering the above elements. Accordingly, the above description does not limit the scope of the claims.

[0087]

[0097] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, a reference to "a user" includes one or more such users, and a reference to "one processor" includes one or more processors and references to their equivalents known to those skilled in the art.

[0088]

[0098] Also, as used in this specification and the appended claims, the terms "comprise, comprising" and "contains, containing, include, including, includes" are intended to specify the presence of the stated features, integers, components, or steps, but they do not preclude the presence or addition of one or more other features, integers, components, steps, acts, or groups.

[0089]

[0099] Also, the examples and embodiments described in this specification are for illustrative purposes only, and various modifications or changes may be suggested to those skilled in the art in view of it, which should be included within the spirit and scope of this application, as well as the appended claims.

Claims

1. A method of operating an optical system, comprising: identifying a set of angular-dependent transmittance levels for light passing through pixels of a segmented dimming device, the segmented dimming device exhibiting a field-of-view transmittance variation for applying the same voltage to all pixels of the segmented dimming device; determining a set of voltages to be applied to the pixels of the segmented dimming device, the step of determining the set of voltages including using the set of angular-dependent transmittance levels; applying the set of voltages to the pixels of the segmented dimming device of the optical system to achieve a light transmittance through the segmented dimming device corresponding to the set of angular-dependent transmittance levels; A method comprising the steps of:

2. The method according to claim 1, wherein the step of determining the set of voltages includes determining light reception coordinates associated with the pixels of the segmented dimming device and rendering the set of voltages using one or more look-up tables based on the light reception coordinates, the look-up table being associated with a corresponding angular-dependent transmittance level.

3. The method according to claim 2, wherein the light reception coordinates include one or more distance coordinates or one or more angular coordinates.

4. Further comprising identifying a position of an eye for collecting light transmitted through the segmented dimming device, wherein the step of determining the set of voltages includes using the set of angular-dependent transmittance levels and the position of the eye. The method according to claim 1.

5. The method according to claim 4, wherein the step of determining the set of voltages includes: identifying an angle of each pixel of the segmented dimming device based on the position of the user's eye; and for each pixel, applying the angle to a look-up table associated with the angular-dependent transmittance level of the pixel to determine an output voltage to be applied to the pixel.

6. The method according to claim 1, wherein the set of voltages includes voltages for each of the pixels of the segmented dimming device.

7. The method according to claim 1, wherein the segmented dimming device includes a liquid crystal exhibiting an angular non-uniform transmittance effect.

8. The method according to claim 1, wherein the segmented dimming device includes a liquid crystal exhibiting an angular non-uniform transmittance effect.

8. The method according to claim 1, wherein the segmented dimming device exhibits symmetric or asymmetric field-of-view transmittance variations.

9. The method according to claim 1, wherein the set of angle-dependent transmittance levels is the same level for all pixels of the segmented dimming device.

10. The method according to claim 1, wherein the set of angle-dependent transmittance levels includes independent transmittance levels for different pixels of the segmented dimming device.

11. The method according to claim 1, wherein the step of specifying the set of angle-dependent transmittance levels includes the step of specifying a bias level, an offset level, or a normalization factor for reducing dioptic luminance errors or for pairing the set of angle-dependent transmittance levels with transmittance levels associated with different segmented dimming devices of different optical systems.

12. The method according to claim 1, further comprising the step of determining the temperature of the segmented dimming device, wherein the step of determining the set of voltages includes the step of using the set of angle-dependent transmittance levels and the temperature.

13. The method according to claim 12, wherein the step of determining the set of voltages includes the step of determining the light reception coordinates associated with the pixels of the segmented dimming device and the step of rendering the set of voltages using one or more look-up tables based on the light reception coordinates, the look-up tables being associated with the corresponding angle-dependent transmittance levels at the temperature.

14. For each of a plurality of different angle-dependent transmittance levels, the step of generating a look-up table that provides a voltage output for different pixels of the segmented dimming device as a function of the light reception coordinates of light transmitted through the different pixels of the segmented dimming device to achieve the set of angle-dependent transmittance levels The method according to claim 1, further comprising.

15. For each of a plurality of different angle-dependent transmittance levels and different temperatures, the step of generating a look-up table that provides a voltage output for different pixels of the segmented dimming device as a function of the light reception coordinates and temperature of light transmitted through the different pixels of the segmented dimming device to achieve the angle-dependent transmittance level The method according to claim 1, further comprising.

16. An optical system comprising: A segmented dimming device including a plurality of pixels, the segmented dimming device exhibiting a field-of-view transmittance variation for applying the same voltage to all pixels of the segmented dimming device; A voltage controller configured to communicate electrically with the segmented dimming device and supply a set of voltages to the pixels of the segmented dimming device to control the transmittance level of light passing through the pixels of the segmented dimming device; One or more processors programmed with instructions; Including: When the instructions are executed, causing the one or more processors to: Identify a set of angle-dependent transmittance levels for light passing through the pixels of the segmented dimming device; Determine a set of voltages to apply to the pixels of the segmented dimming device, the step of determining the set of voltages including the step of using the set of angle-dependent transmittance levels; Control the voltage controller to apply the set of voltages to the pixels of the segmented dimming device of the optical system; Including operations to cause execution of: An optical system.

17. The step of determining the set of voltages includes determining the light-receiving coordinates associated with the pixels of the segmented dimming device and rendering the set of voltages using one or more look-up tables based on the light-receiving coordinates, the look-up tables being associated with corresponding angle-dependent transmittance levels. The optical system according to claim 16.

18. The optical system according to claim 17, wherein the light-receiving coordinates include one or more distance coordinates or one or more angle coordinates.

19. The operations further include: Identifying the position of a light receiver for collecting the light transmitted through the segmented dimming device; Including: The step of determining the set of voltages includes using the set of angle-dependent transmittance levels and the position of the light receiver. The optical system according to claim 16.

20. The optical system according to claim 19, wherein the light receiver position corresponds to the position of the user's eye of the optical system.

21. The step of determining the set of voltages includes: Identifying the angle of each pixel of the segmented dimming device based on the position of the user's eye. ​ For each pixel, applying the angle to a look-up table associated with the angular dependent transmittance level of the pixel to determine an output voltage to be applied to the pixel; The optical system according to claim 20, comprising: **Claim 22** The optical system according to claim 16, wherein a set of voltages includes voltages for each of the pixels of the segmented dimming device. **Claim 23** The optical system according to claim 16, wherein the segmented dimming device includes a liquid crystal exhibiting an angular non-uniform transmittance effect. **Claim 24** The optical system according to claim 16, wherein the set of angular dependent transmittance levels is the same level for all pixels of the segmented dimming device. **Claim 25** The optical system according to claim 16, wherein the set of angular dependent transmittance levels includes independent transmittance levels for different pixels of the segmented dimming device. **Claim 26** The step of specifying the set of angular dependent transmittance levels includes specifying a bias level, an offset level, or a normalization factor for reducing a dichoptic luminance error or for pairing the set of angular dependent transmittance levels with transmittance levels associated with different segmented dimming devices of different optical systems. The optical system according to claim 16. **Claim 27** The operation further includes determining a temperature of the segmented dimming device, and the step of determining the set of voltages includes using the set of angular dependent transmittance levels and the temperature. The optical system according to claim 16. **Claim 28** The step of determining the set of voltages includes determining received light coordinates associated with the pixel of the segmented dimming device, and rendering the set of voltages using one or more look-up tables based on the received light coordinates, wherein the look-up table is associated with a corresponding angular dependent transmittance level at the temperature. The optical system according to claim 27.

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