PATENT DOCUMENT

Publication Number: US-11822081-B2
Application Number: US-202016904602-A
Country: US
Kind Code: B2

Title: Optical module for head-mounted device

Abstract:
An optical module for a head-mounted device is configured to present content to a user. The optical module includes an optical module housing assembly, a display assembly, and an eye camera. The optical module housing assembly has a first end and a second end. The lens is connected to the optical module housing assembly and positioned at the first end of the optical module housing assembly. The display assembly is connected to the optical module housing assembly and is positioned at the second end of the optical module housing assembly. The display assembly is configured to cause the content to be displayed to the user through the lens. The eye camera is connected to the optical module housing assembly and is positioned at the second end of the optical module housing assembly. The eye camera is configured to obtain images through the lens.

Claims:
What is claimed is: 
     
       1. An optical module for a head-mounted device that is configured to present content to a user, the optical module comprising:
 an optical module housing assembly that has a first end and a second end, wherein the optical module housing assembly includes a wall that extends around an axis to define an internal space between the first end and the second end; 
 a lens that is connected to the optical module housing assembly and is positioned at the first end of the optical module housing assembly; 
 a display assembly that is connected to the optical module housing assembly and is positioned at the second end of the optical module housing assembly; and 
 an infrared emitter that is coupled to the wall within the optical module housing assembly at the second end of the optical module housing assembly near the display assembly such that the infrared emitter extends around an optical axis, 
 wherein the display assembly is configured to emit light corresponding to the content along the axis of the optical module housing assembly and through the lens to be displayed to the user. 
 
     
     
       2. The optical module of  claim 1 , wherein the optical module housing assembly includes a first portion that is connected to a second portion, and the lens is engaged by the first portion of the optical module housing assembly and the second portion of the optical module housing assembly such that the lens is retained between the first portion and the second portion and restrained from moving relative to the optical module housing assembly. 
     
     
       3. The optical module of  claim 1 , wherein the lens and the display assembly are connected to the optical module housing assembly in a side-by-side arrangement. 
     
     
       4. The optical module of  claim 1 , wherein the internal space of the optical module housing assembly extends between the lens and the display assembly. 
     
     
       5. The optical module of  claim 4 , further comprising:
 a vent port that allows air to travel between the internal space and an outside environment; and 
 a filter element that restrains foreign particles from entering the internal space. 
 
     
     
       6. The optical module of  claim 4 , further comprising:
 a dust trap that is located in the internal space and is configured to retain foreign particles. 
 
     
     
       7. The optical module of  claim 6 , wherein the dust trap includes an adhesive element configured to retain the foreign particles. 
     
     
       8. The optical module of  claim 1 , wherein the lens is a catadioptric lens. 
     
     
       9. The optical module of  claim 1 , wherein the lens is a part of a catadioptric optical system. 
     
     
       10. The optical module of  claim 1 , further comprising:
 an eye camera that is connected to the optical module housing assembly and is positioned at the second end of the optical module housing assembly, wherein the eye camera is configured to obtain images through the lens. 
 
     
     
       11. The optical module of  claim 10 , further comprising:
 a fiducial marker that is formed on the lens and is visible in images obtained by the eye camera for use in calibration. 
 
     
     
       12. The optical module of  claim 1 , wherein the infrared emitter includes an emissive component configured to emit infrared radiation within one or more wavelength bands. 
     
     
       13. The optical module of  claim 12 , wherein the emissive component includes an infrared light emitting diode. 
     
     
       14. An optical module for a head-mounted device that is configured to present content to a user, the optical module comprising:
 an optical module housing assembly that has a first end and a second end, the optical module housing assembly including a first portion that is connected to a second portion; 
 a lens that is connected to the optical module housing assembly, is positioned at the first end of the optical module housing assembly, and is retained between the first portion of the optical module housing assembly and the second portion of the optical module housing assembly, wherein projections are defined on the lens and channels are defined on the first portion of the optical module housing assembly such that the projections are located in the channels and engage the first portion of the optical module housing assembly within the channels to secure the lens relative to the optical module housing assembly and restrain movement of the lens relative to the optical module housing assembly; and 
 a display assembly that is connected to the optical module housing assembly and is positioned at the second end of the optical module housing assembly, wherein the display assembly is configured to cause the content to be displayed to the user through the lens. 
 
     
     
       15. An optical module for a head-mounted device that is configured to present content to a user, the optical module comprising:
 an optical module housing assembly; 
 a lens that is connected to the optical module housing assembly; 
 a display assembly that is connected to the optical module housing assembly, wherein the display assembly is configured to cause the content to be displayed to the user through the lens, and the optical module housing assembly, the lens, and the display assembly cooperate to define an enclosed internal space; and 
 an infrared emitter that is located between the lens and the display assembly in the enclosed internal space, wherein the infrared emitter includes an emissive component that is oriented toward the lens and is configured to emit infrared radiation away from the display assembly and through the lens. 
 
     
     
       16. The optical module of  claim 15 , wherein the infrared emitter includes a flexible circuit and the emissive components are connected to the flexible circuit. 
     
     
       17. The optical module of  claim 16 , wherein the emissive components are arranged in an array around an optical axis of the optical module housing assembly and are located between the lens and the display assembly along the optical axis. 
     
     
       18. The optical module of  claim 15 , wherein the optical module housing assembly defines an optical pathway opening that is adjacent to the display assembly and is configured to allow light to pass from the display assembly to the lens, a base surface that extends around the optical pathway opening, wherein the infrared emitter is located on the base surface, and a peripheral wall that is located outward from the base surface and extends around the optical pathway opening. 
     
     
       19. The optical module of  claim 15 , further comprising:
 an eye camera that is configured to obtain images that show reflected portions of the infrared radiation that is emitted by the infrared emitter. 
 
     
     
       20. The optical module of  claim 19 , wherein the eye camera is connected to the optical module housing assembly and is configured to obtain the images through the lens. 
     
     
       21. The optical module of  claim 15 , wherein the lens is a catadioptric lens. 
     
     
       22. The optical module of  claim 15 , wherein the lens is a part of a catadioptric optical system. 
     
     
       23. An optical module for a head-mounted device that is configured to present content to a user, the optical module comprising:
 an optical module housing assembly that defines an internal space: 
 a lens that is connected to the optical module housing assembly, wherein the display assembly is configured to cause the content to be displayed to the user through the lens; 
 a display assembly that is connected to the optical module housing assembly, wherein the display assembly is configured to cause the content to be displayed to the user through the lens: and 
 an infrared emitter that is located between the lens and the display assembly in the internal space of the optical module housing assembly, the infrared emitter including a flexible circuit and emissive components that are connected to the flexible circuit and are configured to emit infrared radiation, wherein the infrared emitter is configured to emit infrared radiation through the lens, and the flexible circuit extends through an electrical port that is formed through the optical module housing assembly and a sealing element is formed on the flexible circuit and is engaged with the optical module housing assembly at the electrical port. 
 
     
     
       24. An apparatus, comprising:
 a housing that has a ring-like configuration that extends along an optical axis; 
 a lens that is connected to the housing; 
 a display that is connected to the housing and is oriented to emit light corresponding to content along the optical axis and toward the lens; 
 infrared light emitting diodes that include emissive components that are located in the housing and oriented away from the display and toward the lens to emit infrared radiation through the lens; and 
 a camera that is connected to the housing and configured to obtain images showing the infrared radiation. 
 
     
     
       25. The apparatus of  claim 24 , wherein the lens is arranged on the optical axis and the infrared light emitting diodes are arranged in an array around the optical axis. 
     
     
       26. The apparatus of  claim 24 , wherein the infrared light emitting diodes include a first group of light emitting diodes that are configured to emit the infrared radiation in a first wavelength band and a second group of light emitting diodes that are configured to emit the infrared radiation in a second wavelength band. 
     
     
       27. The apparatus of  claim 24 , wherein the housing defines a first end, the housing defines a second end, the lens is at the first end of the housing, the display is at the second end of the housing, and the camera is at the second end of the housing. 
     
     
       28. The apparatus of  claim 27 , wherein the housing defines an internal space, and the infrared light emitting diodes are in the internal space of the housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 62/893,396, filed on Aug. 29, 2019, the content of which is hereby incorporated by reference in its entirety herein for all purposes. 
    
    
     FIELD 
     The present disclosure relates generally to the field of head-mounted devices. 
     BACKGROUND 
     Head-mounted devices include display screens and optics that guide light from the display screens to a user&#39;s eyes. By guiding light to each of the user&#39;s eye&#39;s separately, content can be displayed to the user in stereo vision, for example, as part of a computer-generated reality (CGR) experience. 
     SUMMARY 
     One aspect of the disclosure is an optical module for a head-mounted device that is configured to present content to a user. The optical module includes an optical module housing assembly, a display assembly, and an eye camera. The optical module housing assembly has a first end and a second end. The lens is connected to the optical module housing assembly and positioned at the first end of the optical module housing assembly. The display assembly is connected to the optical module housing assembly and is positioned at the second end of the optical module housing assembly. The display assembly is configured to cause the content to be displayed to the user through the lens. The eye camera is connected to the optical module housing assembly and is positioned at the second end of the optical module housing assembly. The eye camera is configured to obtain images through the lens. 
     In some implementations of the optical module, the optical module housing assembly includes a first portion that is connected to a second portion, and the lens is retained between the first portion and the second portion. In some implementations of the optical module, projections are defined on the lens and channels are defined on the first portion of the optical module housing assembly such that the projections are located in the channels and engage the first portion of the optical module housing assembly within the channels to secure the lens relative to the optical module housing assembly and restrain movement of the lens relative to the optical module housing assembly. In some implementations of the optical module, the lens and the display assembly are connected to the optical module housing assembly in a side-by-side arrangement. In some implementations of the optical module, the optical module housing assembly defines an internal space between the lens and the display assembly. 
     In some implementations of the optical module, the optical module also includes a vent port that allows air to travel between the internal space and an outside environment, and a filter element that restrains foreign particles from entering the internal space. In some implementations of the optical module, the optical module also includes a dust trap that is located in the internal space and is configured to retain foreign particles. 
     In some implementations of the optical module, the optical module also includes a fiducial marker that is formed on the lens and is visible in images obtained by the eye camera for use in calibration. In some implementations of the optical module, the lens is a catadioptric lens. In some implementations of the optical module, the lens is a part of a catadioptric optical system. 
     Another aspect of the disclosure is an optical module for a head-mounted device that is configured to present content to a user. The optical module includes an optical module housing assembly that defines an internal space, a lens that is connected to the optical module housing assembly, a display assembly that is connected to the optical module housing assembly. The display assembly is configured to cause the content to be displayed to the user through the lens. An infrared emitter is located between the lens and the display assembly in the internal space of the optical module housing assembly. The infrared emitter is configured to emit infrared radiation through the lens. 
     In some implementations of the optical module, the infrared emitter includes a flexible circuit and emissive components that are connected to the flexible circuit and are configured to emit infrared radiation. In some implementations of the optical module, wherein the emissive components are arranged in an array around an optical axis of the optical module housing assembly. In some implementations of the optical module, the flexible circuit extends through an electrical port that is formed through the optical module housing assembly and a sealing element is formed on the flexible circuit and is engaged with the optical module housing assembly at the electrical port. In some implementations of the optical module, the optical module housing assembly defines an optical pathway opening that is adjacent to the display assembly and is configured to allow light to pass from the display assembly to the lens, a base surface that extends around the optical pathway opening, wherein the infrared emitter is located on the base surface, and a peripheral wall that is located outward from the base surface. 
     In some implementations of the optical module, the optical module also includes an eye camera that is configured to obtain images that show reflected portions of the infrared radiation that is emitted by the infrared emitter. In some implementations of the optical module, the eye camera is connected to the optical module housing assembly and is configured to obtain the images through the lens. In some implementations of the optical module, the lens is a catadioptric lens. In some implementations of the optical module, the lens is a part of a catadioptric optical system. 
     Another aspect of the disclosure is a head-mounted device that is configured to present content to a user. The head-mounted device includes a housing, a first optical module that is located in the housing, and a second optical module that is located in the housing. An interpupillary distance adjustment assembly supports the first optical module and the second optical module with respect to the housing to allow adjustment of a distance between the first optical module and the second optical module. The head-mounted device also includes a first front-facing camera that is connected to the first optical module and is movable in unison with the first optical module by the interpupillary distance adjustment assembly, and a second front-facing camera that is connected to the second optical module and is movable in unison with the second optical module by the interpupillary distance adjustment assembly. Adjustment of the distance between the first optical module and the second optical module by the interpupillary distance adjustment assembly also adjusts a distance between the first front-facing camera and the second front-facing camera. 
     In some implementations of the head-mounted device, the housing includes one or more optically-transmissive panels through which the first front-facing camera and the second front-facing camera may obtain images of an environment. 
     In some implementations of the head-mounted device, an optical axis of the first front-facing camera is aligned with an optical axis of the first optical module and an optical axis of the second front-facing camera is aligned with an optical axis of the second optical module. 
     In some implementations of the head-mounted device, the first front-facing camera is connected in a fixed relationship with respect to the first optical module, and the second front-facing camera is connected in a fixed relationship with respect to the second optical module. 
     In some implementations of the head-mounted device, the interpupillary distance adjustment assembly maintains a first spacing between an optical axis of the first optical module and an optical axis of the second optical module generally equal to a second spacing between an optical axis of the first front-facing camera and an optical axis of the second front facing camera during adjustment of the distance between the first optical module and the second optical module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram that shows an example of a hardware configuration for a head-mounted device. 
         FIG.  2    is a top view illustration that shows the head-mounted device, including a device housing and a support structure. 
         FIG.  3    is a rear view illustration taken along line A-A of  FIG.  2    that shows the device housing. 
         FIG.  4    is a perspective view illustration that shows an optical module of the head-mounted device. 
         FIG.  5    is an exploded side view diagram showing components of an optical module according to an example. 
         FIG.  6    is a front view that shows the lens according to an example. 
         FIG.  7    is a cross-section view taken along line B-B of  FIG.  6    showing the lens. 
         FIG.  8    is a front view illustration that shows a housing body of an optical module housing assembly 
         FIG.  9    is a cross-section view illustration taken along line C-C of  FIG.  8    showing the housing body. 
         FIG.  10    is a front view illustration that shows a retainer of the optical module housing assembly. 
         FIG.  11    is a cross-section view illustration taken along line D-D of  FIG.  10    showing the retainer. 
         FIG.  12    is a front view illustration that shows an infrared emitter. 
         FIG.  13    is a cross-section view illustration showing a portion of the infrared emitter and a peripheral wall of the housing body. 
         FIG.  14    is a cross-section view illustration that shows the optical module. 
         FIG.  15    is a cross-section view illustration that shows the optical module according to an alternative implementation in which an optical axis of the eye camera is angled toward an optical axis of the optical module. 
         FIG.  16    is a cross-section view illustration that shows the optical module according to an alternative implementation in which the infrared emitter is located outside of the housing body of the optical module housing assembly. 
         FIG.  17    is a side-view illustration that shows a display module according to an implementation. 
         FIG.  18    is a top-view illustration that shows interpupillary adjustment mechanisms that each support one of the optical modules. 
         FIG.  19    is a side view illustration that shows one of the interpupillary adjustment mechanisms. 
         FIG.  20    is a top-view cross-section illustration that shows front-facing cameras that are supported by each of the optical modules. 
         FIG.  21    is an illustration that shows connection of the eye camera and the infrared emitter to a computing device by an optical module jumper board. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure herein relates to head-mounted devices that are used to show computer-generated reality (CGR) content to users. Head-mounted devices and intended to be worn by users on their heads, and typically with display devices and associated optical components located near the user&#39;s eyes. Some head-mounted devices utilize an optical architecture that requires a specific distance (or a relatively small range of distances) between a display screen and a lens assembly and a specific approximate distance between the lens assembly and a user&#39;s eye. The systems and methods herein relate to structural features of optical modules and head-mounted devices that accommodate significant reductions in these distances, which reduces the overall package size of the device. 
       FIG.  1    is a block diagram that shows an example of a hardware configuration for a head-mounted device  100 . The head-mounted device  100  is intended to be worn on the head of a user and includes components that are configured to display content to the user. Components that are included in the head-mounted device  100  may be configured to track motion of parts of the user&#39;s body, such as the user&#39;s head and hands. Motion tracking information that is obtained by components of the head-mounted device can be utilized as inputs that control aspects of the generation and display of the content to the user, so that the content displayed to the user can be part of a CGR experience in which the user is able to view and interact with virtual environments and virtual objects. In the illustrated example, the head-mounted device  100  includes a device housing  102 , a face seal  104 , a support structure  106 , a processor  108 , a memory  110 , a storage device  112 , a communications device  114 , sensors  116 , a power source  118 , and optical modules  120 . The head-mounted device  100  includes two of the optical modules  120 , to display content to the user&#39;s eyes. The optical modules  120  may each include an optical module housing  122 , a display assembly  124 , and a lens assembly  126 . 
     The device housing  102  is a structure that supports various other components that are included in the head-mounted device. The device housing  102  may be an enclosed structure such that certain components of the head-mounted device  100  are contained within the device housing  102  and thereby protected from damage. 
     The face seal  104  is connected to the device housing  102  and is located at areas around a periphery of the device housing  102  where contact with the user&#39;s face is likely. The face seal  104  functions to conform to portions of the user&#39;s face to allow the support structure  106  to be tensioned to an extent that will restrain motion of the device housing  102  with respect to the user&#39;s head. The face seal  104  may also function to reduce the amount of light from the physical environment around the user that reaches the user&#39;s eyes. The face seal  104  may contact areas of the user&#39;s face, such as the user&#39;s forehead, temples, and cheeks. The face seal  104  may be formed from a compressible material, such as open-cell foam or closed cell foam. 
     The support structure  106  is connected to the device housing  102 . The support structure  106  is a component or collection of components that function to secure the device housing  102  in place with respect to the user&#39;s head so that the device housing  102  is restrained from moving with respect to the user&#39;s head and maintains a comfortable position during use. The support structure  106  can be implemented using rigid structures, elastic flexible straps, or inelastic flexible straps. 
     The processor  108  is a device that is operable to execute computer program instructions and is operable to perform operations that are described by the computer program instructions. The processor  108  may be implemented using a conventional device, such as a central processing unit, and provided with computer-executable instructions that cause the processor  108  to perform specific functions. The processor  108  may be a special-purpose processor (e.g., an application-specific integrated circuit or a field-programmable gate array) that implements a limited set of functions. The memory  110  may be a volatile, high-speed, short-term information storage device such as a random-access memory module. 
     The storage device  112  is intended to allow for long term storage of computer program instructions and other data. Examples of suitable devices for use as the storage device  112  include non-volatile information storage devices of various types, such as a flash memory module, a hard drive, or a solid-state drive. 
     The communications device  114  supports wired or wireless communications with other devices. Any suitable wired or wireless communications protocol may be used. 
     The sensors  116  are components that are incorporated in the head-mounted device  100  to provide inputs to the processor  108  for use in generating CGR content. The sensors  116  include components that facilitate motion tracking (e.g., head tracking and optionally handheld controller tracking in six degrees of freedom). The sensors  116  may also include additional sensors that are used by the device to generate and/or enhance the user&#39;s experience in any way. The sensors  116  may include conventional components such as cameras, infrared cameras, infrared emitters, depth cameras, structured-light sensing devices, accelerometers, gyroscopes, and magnetometers. The sensors  116  may also include biometric sensors that are operable to physical or physiological features of a person, for example, for use in user identification and authorization. Biometric sensors may include fingerprint scanners, retinal scanners, and face scanners (e.g., two-dimensional and three-dimensional scanning components operable to obtain image and/or three-dimensional surface representations). Other types of devices can be incorporated in the sensors  116 . The information that is generated by the sensors  116  is provided to other components of the head-mounted device  100 , such as the processor  108 , as inputs. 
     The power source  118  supplies electrical power to components of the head-mounted device  100 . In some implementations, the power source  118  is a wired connection to electrical power. In some implementations, the power source  118  may include a battery of any suitable type, such as a rechargeable battery. In implementations that include a battery, the head-mounted device  100  may include components that facilitate wired or wireless recharging. 
     In some implementations of the head-mounted device  100 , some or all of these components may be included in a separate device that is removable. For example, any or all of the processor  108 , the memory  110 , and/or the storage device  112 , the communications device  114 , and the sensors  116  may be incorporated in a device such as a smart phone that is connected (e.g., by docking) to the other portions of the head-mounted device  100 . 
     In some implementations of the head-mounted device  100 , the processor  108 , the memory  110 , and/or the storage device  112  are omitted, and the corresponding functions are performed by an external device that communicates with the head-mounted device  100 . In such an implementation, the head-mounted device  100  may include components that support a data transfer connection with the external device using a wired connection or a wireless connection that is established using the communications device  114 . 
     The components that are included in the optical modules support the function of displaying content to the user in a manner that supports CGR experiences. The optical modules  120  are each assemblies that include multiple components, which include the optical module housing  122 , the display assembly  124 , and the lens assembly  126 , as will be described further herein. 
     Other components may also be included in each of the optical modules. Although not illustrated in  FIGS.  2 - 3   , the optical modules  120  may be supported by adjustment assemblies that allow the position of the optical modules  120  to be adjusted. As an example, the optical modules  120  may each be supported by an interpupillary distance adjustment mechanism that allows the optical modules  120  to slide laterally toward or away from each other. As another example, the optical modules  120  may be supported by an eye relief distance adjustment mechanism that allows adjustment of the distance between the optical modules  120  and the user&#39;s eyes. 
       FIG.  2    is a top view illustration that shows the head-mounted device  100 , including the device housing  102 , the face seal  104 , and the support structure  106 .  FIG.  3    is a rear view illustration taken along line A-A of  FIG.  2   . In the illustrated example, the device housing  102  is a generally rectangular structure having a width that is selected to be similar to the width of the head of a typical person, and a height selected so as to extend approximately from the forehead to the base of the nose of a typical person. This configuration is an example, and other shapes and sizes may be used. 
     An eye chamber  328  is defined by the device housing  102  and is bordered by the face seal  104  at its outer periphery. The eye chamber  328  is open to the exterior of the head-mounted device  100  to allow the user&#39;s face to be positioned adjacent to the eye chamber  328 , which is otherwise enclosed by the device housing  102 . The face seal  104  may extend around part or all of the periphery of the device housing  102  adjacent to the eye chamber  328 . The face seal  104  may function to exclude some of the light from the environment around the head-mounted device  100  from entering the eye-chamber  328  and reaching the user&#39;s eyes. 
     In the illustrated example, the support structure  106  is a headband type device that is connected to left and right lateral sides of the device housing  102  and is intended to extend around the user&#39;s head. Other configurations may be used for the support structure  106 , such as a halo-type configuration in which the device housing  102  is supported by a structure that is connected to a top portion of the device housing  102 , engages the user&#39;s forehead above the device housing  102 , and extends around the user&#39;s head, or a mohawk-type configuration in which a structure extends over the user&#39;s head. Although not illustrated, the support structure  106  may include passive or active adjustment components, which may be mechanical or electromechanical, that allow portions of the support structure  106  to expand and contract to adjust the fit of the support structure  106  with respect to the user&#39;s head. 
     The optical modules  120  are located in the device housing  102  and extend outward into the eye chamber  328 . Portions of the optical modules  120  are located in the eye chamber  328  so that the user can see the content that is displayed by the optical modules  120 . The optical modules  120  are located within the eye chamber  328  at locations that are intended to be adjacent to the user&#39;s eyes. As an example, the head-mounted device  100  may be configured to position portions of the lens assemblies  126  of the optical modules  120  approximately 15 millimeters from the user&#39;s eyes. 
       FIG.  4    is a perspective view illustration that shows one of the optical modules  120 , including the optical module housing  122 , the display assembly  124 , and the lens assembly  126 . The display assembly  124  and the lens assembly  126  are each connected to the optical module housing  122 . In the illustrated example, the lens assembly  126  is positioned at a front end of the optical module  120 , and the display assembly  124  is positioned at a rear end of the optical module  120 . The optical module housing  122  defines an internal space between the display assembly  124  and the lens assembly  126  to allow light to travel from the display assembly  124  to the lens assembly  126  within an environment that is sealed and protected from external contaminants while protecting sensitive components from damage. 
     The display assembly  124  includes a display screen that is configured to display content, such as images, according to signals received from the processor  108  and/or from external devices using the communications device  114  in order to output CGR content to the user. As an example, the display assembly  124  may output still images and/or video images in response to received signals. The display assembly  124  may include, as examples, an LED screen, an LCD screen, an OLED screen, a micro LED screen, or a micro OLED screen. 
     The lens assembly  126  includes one or more lenses that direct light to the user&#39;s eyes in a manner that allows viewing of CGR content. In some implementations, the lens assembly  126  is a catadioptric optical system that utilizes both reflection and refraction in order to achieve desired optical properties in a small package size. Reflection, in some implementations, may be achieved by internal reflection at boundaries between material layers of a single lens. Thus, in some implementations, the lens assembly  126  may be implemented using a single multi-layered catadioptric lens. 
     The lens assembly  126  may be positioned partially within the optical module housing  122 . As will be explained further herein, the optical module housing  122  may include two or more components that are configured to retain the lens assembly in a desired position and orientation. 
       FIG.  5    is an exploded side view diagram showing components of an optical module  520  according to a first example.  FIG.  5    is a schematic view intended to show the positional relationships between various features and does not include specific structural details of the components of the optical module  520 . The optical module  520  can be implemented in the context of a head-mounted display (e.g., the head-mounted device  100 ) and may be implemented according to the description of the optical module  120  and the further description herein. The optical module  520  includes an optical module housing assembly  522 , a display assembly  524 , a lens  526 , an eye camera  530 , and an infrared emitter  532 . As will be described further herein, these components are arranged along an optical axis  521  of the optical module  520  such that images generated using the display assembly are projected to the user along the optical axis  521 . 
     Although the lens  526  is described as a single element herein, it should be understood that the lens  526  may be part of an assembly of optical elements or may be an assembly of optical elements, as described with respect to the lens assembly  126 . Thus, for example the lens  526  may be a catadioptric lens or the lens  526  may be part of a catadioptric optical system. 
     The optical module housing assembly  522  may include multiple parts that are connected to each other. In the illustrated example, the optical module housing assembly  522  includes a housing body  534  and a retainer  536 . The housing body  534  is configured to be connected to other structures within the housing of a head-mounted display (e.g., in the device housing  102  of the head-mounted device  100 ). The housing body  534  is also provides a structure to which other components of the optical module  520  may be attached, including the display assembly  524 , the eye camera  530  and the infrared emitter  532 . The primary portions of the optical module housing assembly  522 , such as the housing body  534  and the retainer  536 , may be made from a rigid material, such as plastic or aluminum. The optical module housing assembly  522  is arranged around the optical axis  521 , and both visible light and infrared radiation may be incident on surfaces of the optical module housing assembly  522 . For this reason, portions of the optical module housing assembly  522  may be coated with materials (e.g., paints or other coating materials) that exhibit low reflectance of both visible and infrared wavelengths of electromagnetic radiation. 
     The retainer  536  is connected to an outer (e.g., user-facing) end of the housing body  534  of the optical module  520 . As examples, the retainer  536  may be connected to the housing body  534  by fasteners or by an adhesive. The retainer  536  and the housing body  534  of the optical module housing assembly  522  are configured such that the lens  526  is retained between the retainer  536  and the housing body  534 , as will be explained further herein. The retainer  536  and the housing body  534  have ring-like configurations along the optical axis  521  to allow light from the display assembly  524  to pass through the lens  526  and toward the user. 
     The display assembly  524  includes a seal  538 , a bezel  540 , a display module  542 , a thermal interface  544 , and a heat sink  546 . The display assembly  524  is connected to the optical module housing assembly  522 . As an example, the display assembly  524  may be connected to the optical module housing assembly  522  by screws or other fasteners that allow disassembly of the display assembly  524  from the optical module housing assembly  522  (e.g., to allow for inspection and/or repair). The seal  538  is a sealing material of any suitable type that is configured to prevent foreign particle (e.g., dust) intrusion at the interface of the display assembly  524  with the optical module housing assembly  522 . The bezel  540  is a structural component that supports the display module  542  and protects it from damage. As an example, bezel  540  may be connected to the heat sink  546  (e.g., by screws or other fasteners) to capture the display module  542  and the heat sink  546 . The seal  538  may be engaged with the bezel  540  and the optical module housing assembly  522  to seal the interface between them. 
     The seal  538  and the bezel  540  have a ring-like configuration with central openings along the optical axis  521  in order to avoid blocking light emission from the display module  542  toward the lens  526 . 
     The display module  542  includes a display screen that displays images (e.g., by emitting light using a grid of light-emitting elements to define a picture). The display module  542  may be implemented using any suitable display technology, including light-emitting diode-based display technologies, organic light-emitting diode-based display technologies, and micro light-emitting diode-based display technologies. In some implementations, a layer of cover glass is attached (e.g., by laminating) to the display surface of the display module  542  to provide strength, to serve as a mounting feature, and to serve as a sealing interface. 
     The thermal interface  544  is a thermally conductive and electrically non-conductive material that is located between the display module  542  and the heat sink  546  to promote heat transfer from the display module  542  to the heat sink  546 . The thermal interface  544  is a compliant material that is able to fill in gaps that would otherwise be present between the display module  542  and the heat sink  546 , and which would reduce the efficiency of heat transfer. As an example, the thermal interface may be dispensable thermal gel that is applied to the display module  542  or the heat sink  546 . A reworkable material may be used for the thermal interface  544 , such as a material that is applied by room-temperature vulcanization. 
     The heat sink  546  is a rigid structure (e.g., formed from metal) that readily conducts heat and is configured to release heat to the ambient environment. As an example, the heat sink  546  may incorporate structures that increase surface area, such as fins, to promote heat dissipation, and/or may include features that conduct heat away from heat-generating components (e.g., the display module  542 ), such as a heat pipe. 
       FIG.  6    is a front view illustration that shows the lens  526  according to an example, and  FIG.  7    is a cross-section view illustration taken along line B-B of  FIG.  6    showing the lens  526 . The lens  526  is an optical element (or combination of multiple optical elements, e.g., multiple lenses) that is configured to refract and/or reflect light that is incident on the lens  526 . In the illustrated example, the lens  526  is formed from molded transparent plastic, by glass may be used. Surface configurations that cause refraction and/or reflection of light (e.g., convexity and concavity) are not shown in the figures for simplicity and clarity, and these features may be defined as needed for desired performance of the optical system. 
     The lens  526  includes a lens body  648  and projections  649  that extend outward from the lens body  648 . The lens body  648  extends from an outer surface  750  (oriented toward the user) to an inner surface  751  (oriented toward the display assembly  524 . The lens body  648  will typically have a width (or range of widths) that is greater than the height of the lens body  648  as measured along the optical axis  521  of the optical module  520 . The lens body  648  may be formed in any shape (as viewed from an end along the optical axis  521 ), such as generally cylindrical, oval, rounded rectangle, or irregular. The projections  649  may have a height (in the direction of the optical axis  521 ) that is less than the height of the lens body  648 , such as 10 percent to 50 percent of the height of the lens body  648 . As will be explained herein, the projections  649  facilitate alignment and retention of the lens  526  relative to the optical module housing assembly  522 . 
     In the illustrated example, a peripheral wall of the lens body  648  extends from the outer surface  750  to the inner surface  751  without tapering, so that the peripheral wall is generally in alignment with the optical axis  521  and the outer surface  750  and the inner surface  751  are generally the same in shape and size (e.g., except for minor deviations such as the projections  649 ). In other implementations, the peripheral wall of the lens body  648  may be tapered. For example, the peripheral wall of the lens body  648  may be tapered progressively away from the optical axis  521  in a direction of travel extending from the outer surface  750  to the inner surface  751 , so that that the size of the outer surface  750  is smaller than the size of the inner surface  751 . 
       FIG.  8    is a front view illustration that shows the housing body  534  of the optical module housing assembly  522 , and  FIG.  9    is a cross-section view illustration taken along line C-C of  FIG.  8    showing the housing body  534 . The housing body  534  includes a base portion  852 , an optical pathway opening  853  that is formed through the base portion  852 , a peripheral wall  854  that extends around the optical pathway opening  853 . 
     The base portion  852  extends generally perpendicular to the optical axis  521  of the optical module  520 . The base portion  852  may incorporate features that allow attachment of other components to the optical module housing assembly  522 . As one example, the display assembly  524  may be attached to the base portion  852  (e.g., by fasteners or adhesives). As another example, the eye camera  530  may be attached to the base portion  852  (e.g., by fasteners or adhesives). 
     The peripheral wall  854  extends outward from the base portion  852  in a direction that is generally toward the user and generally aligned with the optical axis  521  of the optical module  520 . As viewed along the optical axis  521 , the shape and size of the peripheral wall  854  is similar to that of the outer periphery of the lens  526 , since the peripheral wall  854  is part of the structure that supports and retains the lens  526 , as will be described further herein. A vent port  855  is formed through the peripheral wall  854  and may extend, for example, between inner and outer surfaces of the peripheral wall  854  in a direction that is generally perpendicular to the optical axis  521  of the optical module  520 . An electrical port  856  is formed through the peripheral wall  854  and may extend, for example, between inner and outer surfaces of the peripheral wall  854  in a direction that is generally perpendicular to the optical axis  521  of the optical module  520 . 
     A base surface  857  is defined on the base portion  852  and is located inward from the peripheral wall  854 . The base surface  857  is adjacent to and extends around the optical pathway opening  853 , which is an opening that is defined by the housing body  534  to allow light to travel from the display assembly  524  to the lens  526 . A camera opening  858  is formed through the base surface  857  and is adjacent to, but separate from, the optical pathway opening  853 . The camera opening  858  extends through the base surface  857  in a direction that is generally toward the user. As examples the camera opening  858  may extend through the base surface  857  in a direction that is generally aligned with the optical axis  521  of the optical module  520 , or within 45 degrees of parallel to the optical axis  521  of the optical module  520 . 
       FIG.  10    is a front view illustration that shows the retainer  536  of the optical module housing assembly  522 , and  FIG.  11    is a cross-section view illustration taken along line D-D of  FIG.  10    showing the retainer  536 . The retainer  536  includes a peripheral wall  1060  that extends around an optical pathway opening  1061 . The peripheral wall  1060  includes an upper inner periphery portion  1062  that borders and extends around the optical pathway opening  1061 . The upper inner periphery portion  1062  is configured to receive the lens body  648  of the lens  526 . Channels  1063  are formed in the upper inner periphery portion  1062  and are open to the optical pathway opening  1061 . The size and position of the channels  1063  corresponds to the size and position of the projections  649  of the lens  526  such that the projections  649  can be received in the channels  1063  to secure the lens  526  relative to the housing body  534  and restrain relative movement. The peripheral wall  1060  includes a lower inner periphery portion  1064  that borders and extends around the optical pathway opening  1061 . The lower inner periphery portion  1064  is configured for connection to the peripheral wall  854  of the housing body  534 . 
       FIG.  12    is a front view illustration that shows the infrared emitter  532 . The infrared emitter  532  includes a flexible circuit  1266 , emissive components  1267 , an electrical connector  1268 , and a sealing element  1269 . The flexible circuit  1266  is a flexible substrate that has electrical conductors formed on it. The flexible substrate may be nonconductive polymer film. The electrical conductors may be conductive traces formed from copper. As an example, the flexible circuit  1266  may be formed by multiple layers of nonconductive polymer film with conductive traces formed between adjacent layers of the film. As will be explained further herein, the shape of the flexible circuit  1266  may be arranged such that is conforms to the shape of a portion of the optical module housing assembly  522  such that the infrared emitter may be located in or connected to the optical module housing assembly  522 . In the illustrated example, the flexible circuit  1266  has a c-shaped configured that allows the flexible circuit  1266  to extend around the optical axis  521  of the optical module  520  so that the emissive components  1267  may be arranged around the optical axis  521  in an array without blocking the optical path (pathway along which light may travel) between the display assembly  524  and the lens  526  of the optical module  520 . 
     The emissive components  1267  are components that are configured to emit infrared radiation within one or more wavelength bands. The infrared radiation that is emitted by the emissive components  1267  and reflected by the user&#39;s eye may be imaged by the eye camera  530  for use in imaging tasks. 
     The emissive components  1267  may be for example, infrared light emitting diodes. In one implementation, the emissive components  1267  include a first group of components that are configured to emit infrared radiation in a first wavelength band and a second group of components that are configured to emit infrared radiation in a second wavelength band. The first and second wavelength bands may correspond to different imaging tasks. As an example, the first wavelength band may be configured for use in biometric identification by iris scanner (e.g., a wavelength band including 850 nanometers), and the second wavelength band may be configured for use in eye gaze direction tracking (e.g., a wavelength band including 940 nanometers). 
     The electrical connector  1268  of the infrared emitter  532  is a standard component of any suitable type that allows connection to other components to provide electrical power and, optionally, operating commands, to the infrared emitter  532 . The sealing element  1269  is formed on the flexible circuit  1266  between the electrical connector  1268  and the emissive components  1267 . As best seen in  FIG.  13   , which is a cross-section view illustration showing the flexible circuit and a portion of the peripheral wall  854  of the housing body  534  of the optical module housing assembly  522 , the flexible circuit  1266  extends through and is surrounded by the sealing element  1269 . The sealing element  1269  is formed from a resilient flexible material that is configured to engage a portion of the optical module housing assembly  522  to allow the flexible circuit  1266  to exit the interior of the optical module housing assembly  522  without providing a pathway along which foreign particles (e.g., dust particles) may enter the interior of the optical module housing assembly  522 . As an example, the sealing element  1269  may be formed from silicone that is overmolded onto the flexible circuit  1266  such that the flexible circuit extends through the sealing element  1269 . In the illustrated example, the flexible circuit  1266  extends through the electrical port  856  of the housing body  534  such that the sealing element  1269  is located in the electrical port  856  and is engaged with the housing body  534  ad the electrical port  856  to define a seal and occupy the electrical port  856  to prevent entry of foreign particles. 
       FIG.  14    is a cross section view illustration that shows the optical module  520 . 
     The lens  526  is disposed between the housing body  534  and the retainer  536 . The housing body  534  is connected to the retainer  536  such that the lens  526  is located between the housing body  534  and the retainer  536 . Thus, the housing body  534  and the retainer  536  engage the lens  526  such that the lens  526  is restrained from moving relative to the housing body  534  and the retainer  536 . To protect the lens  526  from damage (e.g., if the head-mounted device  100  is dropped), a layer of adhesive may be present between the lens  526  and portions of the housing body  534  and/or the retainer  536 . The adhesive that is used for this purposes is strong to secure the lens  526  in a desired alignment and is flexible and elastic to cushion the lens  526  in the event of vibration or impact shock, and to allow the lens  526  to return to its original position. 
     The vent port  855  is formed through the peripheral wall  854  of the housing body  534  and allows air to enter and exit an internal space  1470  of the optical module  520 . The internal space  1470  is defined within the optical module housing assembly  522  by the housing body  534  and the retainer  536  and between the lens  526  and the display assembly  524 . The internal space  1470  is sealed from the outside environment except at the vent port  855 . The vent port  885  is a passage that allows air to travel between the internal space  1470  and the outside environment that is located around the optical module  520 . By allowing air to enter and exit the internal space  1470 , air pressure within the internal space  1470  remains at or near ambient (e.g., outside the optical module  520 ) air pressure. To exclude foreign particles from the internal space  1470 , a filter element  1471  is connected to the vent port  885  such that any air that passes through the vent port  855  must pass through filter element  1471 . The filter element  1471  is configured to restrain foreign particles from entering the internal space through the vent port  885  (e.g., by preventing entry of foreign particles that are larger than a pore size of the filter material). As examples, the filter element  1471  may be located in or on the vent port  855 . The filter element  1471  has a small pore size that is intended to exclude small particles (e.g., dust particles) from the internal space  1470 . As one example, the filter element  1471  may be formed from a polytetrafluoroethylene (PTFE) filter material. To capture particles that are present inside the internal space  1470 , a dust trap  1472  may be located in the internal space  1470 , for example, connected to an internal surface of the housing body  534 . The dust trap  1472  is configured to retain foreign particles on its surface, so that the foreign particles do not instead settle on surfaces where they may cause an optical aberration. As an example, the dust trap  1472  may be an adhesive element, such as a sheet coated in adhesive material, to which airborne particles that are inside the internal space  1470  may become affixed, which prevents the particles from attaching to the display assembly  524 , or the lens  526 , which could cause optical aberrations that are perceptible to the user (e.g., a visual artifact similar to a dead pixel). 
     The eye camera  530  is a still image camera or video camera that is configured to obtain images. When in use, the images that are obtained by the eye camera  530  include a visual representation of part of or all of the user&#39;s eye, so that the obtained images may be used for biometric identification (e.g., verifying the identity of the user based on an image of the user&#39;s eye) and gaze tracking. In the implementations that are discussed herein, the eye camera  530  is sensitive to infrared light (i.e., electromagnetic radiation in the infrared portion of the electromagnetic spectrum). Thus, the eye camera  530  may be configured to obtain images that show reflected portions of the infrared radiation that is emitted by the infrared emitter  532 , and these reflected portions of infrared radiation, as represented in the images, are useful for observing and identifying features of the user&#39;s eye, which may be done using a machine vision-based system that is implemented in software that is executed by the head-mounted device  100 . In alternative implementations, the eye camera  530  may instead by implemented using a visible spectrum camera or may be supplemented using the visible spectrum camera in addition to an infrared spectrum camera. 
     The eye camera  530  is connected to the housing body  534  of the optical module housing assembly  522  adjacent to the camera opening  858  of the housing body  534  such that an optical axis  1431  of the eye camera  530  extends through the camera opening  858 . In the illustrated example, the eye camera  530  is oriented such that an optical axis  1431  of the eye camera  530  is substantially aligned with the optical axis  521  of the optical module  520 . However, the eye camera  530  is positioned near an outer periphery of the lens  526  and is therefore offset and outward from the optical axis  521  of the optical module  520 . Thus, the housing body  534  and/or the eye camera  530  may be configured (e.g., by an inclined mounting surface) such that the optical axis  1431  of the eye camera  530  is angled toward the optical axis  521  of the optical module  520 , as shown in  FIG.  15   , which is a cross-section view illustration that shows the optical module  520  according to an alternative implementation. 
     Returning to  FIG.  14   , in some implementations, a fiducial marker  1465  may be formed on the lens  526 . The fiducial marker  1465  is any manner of marking that can be perceived and located in images obtained by the eye camera  530 . The fiducial marker  1465  is visible in images obtained by the eye camera  530  for use in calibration. The head-mounted device  100  is calibrated to account for manufacturing conditions, user attributes, and/or other factors that may cause visual aberrations. During an initial calibration, the position of the fiducial marker  1465  is determined and stored. The lens  526  may shift with respect to other components, such as the optical module housing assembly  522 , for example, if the head-mounted device  100  is dropped. The changed position of the lens  526  can be identified by comparing the position of the lens  526  in images obtained by the eye camera  530  with the position of the lens  526  in the images that was obtained at the time of calibration. In response to determining that the lens position has changed, calibration is performed again to address any visual aberrations that may have resulted from the shift in position of the lens  526 . 
     The infrared emitter  532  is located on the base surface  857  of the housing body  534  and extends around the optical axis  521  within the internal space  1470  that is defined within the optical module housing assembly  522  by the housing body  534  and the retainer  536  and between the lens  526  and the display assembly  524 . The display assembly  524  is connected to the housing body  534  of optical module housing assembly  522  adjacent to the optical pathway opening  853  of the housing body  534 . 
     In one implementation, the optical module  520  includes the optical module housing assembly  522 , the display assembly  524 , the lens  526 , and the eye camera  530 . The lens  526  is positioned at a first end of the optical module housing assembly  522 , the display assembly and the eye camera  530  are positioned at a second end of the optical module housing assembly  522 , and the internal space  1470  is defined within the optical module housing assembly  522  between the first end and the second end. The lens  526  is positioned such that it is able to obtain images of the user&#39;s eye through the lens  526 . The lens  526  may be connected to the optical module housing assembly  522  such that it is positioned adjacent to the display assembly  524 , such as in a side-by-side arrangement with respect to the display assembly  524 . 
     In one implementation, the optical module  520  includes the optical module housing assembly  522 , the display assembly  524 , the lens  526 , and the infrared emitter  532 . The lens  526  is positioned at a first end of the optical module housing assembly  522 , the display assembly is positioned at a second end of the optical module housing assembly  522 , and the internal space  1470  is defined within the optical module housing assembly  522  between the first end and the second end. The infrared emitter  532  is positioned in the internal space  1470  between the lens  526  and the display assembly  524 . The infrared emitter  532  is positioned such that is able to project infrared radiation onto the user&#39;s eye through the lens  526 . The optical module  520  also includes the eye camera  530 , which is connected to the optical module housing assembly  522  such that the infrared emitter  532  is positioned between (e.g., along the optical axis  521 ) the eye camera  530  and the lens  526 . 
     The lens  526  may be connected to the optical module housing assembly  522  such that it is positioned adjacent to the display assembly  524 , such as in a side-by-side arrangement with respect to the display assembly  524 . 
     In the implementation shown in  FIG.  14   , the infrared emitter  532  is located on the base surface  857  of the housing body  534  in the internal space  1470 .  FIG.  16    is a cross-section view illustration that shows the optical module  520  according to an alternative implementation in which the infrared emitter  532  is located outside of the housing body  534  of the optical module housing assembly  522 . In this implementation, the infrared emitter  532  is connected (e.g., by an adhesive) to an exterior surface of the housing body  534  such that it is positioned adjacent to and extends around the display assembly  524 . 
     An infrared-transmissive panel  1673  is formed in the housing body  534  to allow infrared radiation that is emitted by the infrared emitter  532  to travel through the optical module housing assembly  522  and the lens  526 . The infrared-transmissive panel  1673  is formed from a material that allows infrared radiation to pass through it without significant losses. As examples, the infrared-transmissive panel  1673  may be formed from glass or from an infrared transmissive plastic. In the illustrated example, the infrared-transmissive panel  1673  extends through an aperture that is formed through the base surface  857 . The infrared-transmissive panel  1673  may be a single panel that extends along the base surface  857  adjacent to all of the emissive components  1267  of the infrared emitter  532 , or may be multiple panels that extend through separate apertures that are formed through the base surface  857  adjacent to individual ones of the emissive components  1267 . In some implementations, the infrared-transmissive panel  1673  may be omitted in favor of forming part or all of the optical module housing assembly  522  (e.g., the housing body  534 ) from an infrared-transmissive material. 
     In the examples shown in  FIGS.  14 - 16   , the optical module  120  is shown as including a single eye camera, which is represented by the eye camera  530 . The optical module  120  could instead include more than one eye camera (e.g., two eye cameras), with each of the eye cameras being configured to obtain images showing infrared radiation that is reflected from the eye of the user. The eye cameras are located at different locations (e.g., opposite lateral sides of the eye of the user) and may be oriented at different angular orientations. The images output by multiple eye cameras may provide a more complete view of the eye of the user. 
       FIG.  17    is a side-view illustration that shows the display module  542  according to an implementation. The display module  542  includes a silicon wafer  1775  and a display element layer  1776  (e.g., an organic light-emitting diode layer) that is located on the silicon wafer  1775 . The display element layer  1776  may be covered by a glass layer  1777 . A display connector  1778  includes a first portion  1779  and a second portion  1780 . The first portion  1779  of the display connector  1778  is a flexible connector (e.g., a two-layer flexible connector) that is connected to silicon wafer  1775  by an electrical connection  1781  that connects individual conductors formed on the silicon wafer  1775  with individual conductors formed on the first portion  1779  of the display connector  1778 . As an example, the electrical connection  1781  may include an anisotropic film that bonds the display connector  1778  to the silicon wafer  1775  while allowing electrical communication. 
     The second portion  1780  of the display connector  1778  is a multi-layer (e.g., six layer) flexible connector, of the type commonly referred to as a “rigid flex” connector. The second portion  1780  may include a cavity  1782  that is defined by removal of one or more of the layers of the multi-layer structure of the second portion  1780 . A driver integrated circuit  1783  is located in the cavity  1782  in order to protect the driver integrated circuit  1783 . The function of the driver integrated circuit  1783  is to receive display signals in a first format (e.g., encoded or multiplexed) and interpret the signals into a second format that is usable by the display element layer  1776  of the display module  542  to output images. A connector  1784  (e.g., a micro-coaxial connector) may be located on and electrically connected to the second portion  1780  of the display connector  1778  in order to connect the display module  542  to other components (e.g., to a computing device that provides content to be displayed). 
       FIG.  18    is a top-view illustration that shows interpupillary distance adjustment mechanisms  1885  that each support one of the optical modules  520  (i.e., left and right optical modules) with respect to the device housing  102 . The interpupillary distance adjustment mechanisms  1885  are an example of an interpupillary distance adjustment assembly that is configured to adjust a distance between the optical modules  520  that display content to the left eye and the right eye of the user, in order to match the spacing between the optical modules  520  with the spacing between the user&#39;s eyes. 
     The optical modules  520  may be supported such that the optical axis  521  of each of the optical modules  520  extends generally in a front-to-back direction of the device housing  102 . The interpupillary distance adjustment mechanisms  1885  include support rods  1886  and actuator assemblies  1887  that are configured to cause movement of the optical modules  520  along the support rods  1886  in response to a control signal. The actuator assemblies  1887  may include conventional motion control components such as electric motors that are connected to the optical modules  520  by components such as lead screws or belts to cause movement. Mounting brackets  1888  may be connected to the optical modules  520  such that the support rods  1886  are connected to the mounting brackets  1888 , such as by extending through apertures  1889  that are formed through the mounting brackets  1888 . The interpupillary distance adjustment mechanisms  1885  may also include biasing elements such as springs that are engaged with the mounting brackets  1888  to reduce or eliminate unintended motion of the mounting brackets  1888  and/or the optical modules  520  with respect to the support rods  1886 . The support rods  1886  may be angled relative to a lateral (e.g., side-to-side) dimension of the device housing  102  such that they move toward the user as they move outward. As an example, the support rods may be angled by five degrees relative to the lateral dimension. 
       FIG.  19    is a side view illustration that shows one of the interpupillary distance adjustment mechanisms  1885 . The support rods  1886  may include upper and lower support rods for each of the optical modules that support the optical modules  520  such that the optical axis  521  of each optical module  520  is angled slightly downward, such as by five degrees. Springs  1990  (e.g., leaf springs) may be seated in the apertures  1889  of the mounting brackets  1888  and located forward from the support rods  1886  to bias the optical modules  520  toward the user. 
       FIG.  20    is a top-view cross-section illustration that shows front-facing cameras  2091  that are supported by each of the optical modules  520 . Openings or optically-transmissive panels  2092  (e.g., clear plastic) are included in the device housing  102  such that the front-facing cameras  2091  are able to obtain images of the surrounding environment through the optically-transmissive panels  2092 . A single panel or separate panels may be used for the optically-transmissive panels  2092 , and as such the device housing  102  may include one or more of the optically-transmissive panels  2092 . Thus, the device housing  102  may include one or more of the optically-transmissive panels  2092  through which the front-facing cameras may obtain images of an environment from a point of view that simulates the point of view of the user. The front-facing cameras  2091  may be connected to and supported by a corresponding one of the optical modules  520 . The front-facing cameras  2091  may be positioned such that they are located on and substantially aligned with the optical axis  521  of a corresponding one of the optical modules  520  (e.g., the optical axes of the front-facing cameras  2091  may be substantially aligned with the optical axes of the optical modules  520 ). The front-facing cameras  2091  are oriented away from the user and are supported such that they are moved by the interpupillary distance adjustment mechanisms  1885 . Accordingly, when the user adjusts the interpupillary distance between the optical modules  520 , the distance between the front-facing cameras  2091  is also adjusted. Thus, images from the front-facing cameras  2091 , when displayed to the user, have been captured at the user&#39;s own interpupillary distance and therefore are presented more accurately in stereo vision. Thus, in some implementations, the optical axis of a first one of the front-facing cameras  2091  is aligned with an optical axis of a first one of the optical modules  520  and an optical axis of a second one of the front-facing cameras  2091  is aligned with an optical axis of a second one of the optical modules  520 . Thus, in some implementations, a first one of the front-facing cameras  2091  is connected in a fixed relationship with respect to a first one of the optical modules  520 , and a second one of the front-facing cameras  2091  is connected in a fixed relationship with respect to a second one of the optical modules  520 . Thus, in some implementations, the interpupillary distance adjustment mechanisms a first spacing between an optical axis of a first one of the optical modules  520  and an optical axis of a second one of the optical modules  520  generally equal to a second spacing between an optical axis of a first one of the front-facing cameras  2091  and an optical axis of a second one of the front facing cameras  2091  during adjustment of the distance between the optical modules  520 . 
       FIG.  21    is an illustration that shows connection of the eye camera  530  and the infrared emitter  532  to a computing device  2193  by an optical module jumper board  2194 . The computing device  2193  may be, for example, a computing device that incorporates the processor  108  of the head-mounted device  100 . The optical module jumper board  2194  has a data connection to the computing device  2193  over which signals and data to and from the eye camera  530  and the infrared emitter  532  are transmitted. The optical module jumper board  2194  also has separate data connections to each of the eye camera  530  and the infrared emitter  532 . Additional components could be included in the optical module  520  and connected to the optical module jumper board  2194  by additional separate connections. The optical module jumper board  2194  may be mounted to the optical module  520 , and therefore, moves in unison with the optical module  520  during interpupillary distance adjustment. As a result, the number and size of electrical connections that are made to components that are not mounted to the optical module (e.g., the computing device  2193 ) is decreased. The optical module jumper board  2194  may be, as examples, a rigid flex circuit board, a flexible circuit board, or a printed component board. 
     A physical environment refers to a physical world that people can sense and/or interact with without aid of electronic systems. Physical environments, such as a physical park, include physical articles, such as physical trees, physical buildings, and physical people. People can directly sense and/or interact with the physical environment, such as through sight, touch, hearing, taste, and smell. 
     In contrast, a computer-generated reality (CGR) environment refers to a wholly or partially simulated environment that people sense and/or interact with via an electronic system. In CGR, a subset of a person&#39;s physical motions, or representations thereof, are tracked, and, in response, one or more characteristics of one or more virtual objects simulated in the CGR environment are adjusted in a manner that comports with at least one law of physics. For example, a CGR system may detect a person&#39;s head turning and, in response, adjust graphical content and an acoustic field presented to the person in a manner similar to how such views and sounds would change in a physical environment. In some situations (e.g., for accessibility reasons), adjustments to characteristic(s) of virtual object(s) in a CGR environment may be made in response to representations of physical motions (e.g., vocal commands). 
     A person may sense and/or interact with a CGR object using any one of their senses, including sight, sound, touch, taste, and smell. For example, a person may sense and/or interact with audio objects that create three-dimensional or spatial audio environment that provides the perception of point audio sources in three-dimensional space. In another example, audio objects may enable audio transparency, which selectively incorporates ambient sounds from the physical environment with or without computer-generated audio. In some CGR environments, a person may sense and/or interact only with audio objects. 
     Examples of CGR include virtual reality and mixed reality. 
     A virtual reality (VR) environment refers to a simulated environment that is designed to be based entirely on computer-generated sensory inputs for one or more senses. A VR environment comprises a plurality of virtual objects with which a person may sense and/or interact. For example, computer-generated imagery of trees, buildings, and avatars representing people are examples of virtual objects. A person may sense and/or interact with virtual objects in the VR environment through a simulation of the person&#39;s presence within the computer-generated environment, and/or through a simulation of a subset of the person&#39;s physical movements within the computer-generated environment. 
     In contrast to a VR environment, which is designed to be based entirely on computer-generated sensory inputs, a mixed reality (MR) environment refers to a simulated environment that is designed to incorporate sensory inputs from the physical environment, or a representation thereof, in addition to including computer-generated sensory inputs (e.g., virtual objects). On a virtuality continuum, a mixed reality environment is anywhere between, but not including, a wholly physical environment at one end and virtual reality environment at the other end. 
     In some MR environments, computer-generated sensory inputs may respond to changes in sensory inputs from the physical environment. Also, some electronic systems for presenting an MR environment may track location and/or orientation with respect to the physical environment to enable virtual objects to interact with real objects (that is, physical articles from the physical environment or representations thereof). For example, a system may account for movements so that a virtual tree appears stationery with respect to the physical ground. 
     Examples of mixed realities include augmented reality and augmented virtuality. 
     An augmented reality (AR) environment refers to a simulated environment in which one or more virtual objects are superimposed over a physical environment, or a representation thereof. For example, an electronic system for presenting an AR environment may have a transparent or translucent display through which a person may directly view the physical environment. The system may be configured to present virtual objects on the transparent or translucent display, so that a person, using the system, perceives the virtual objects superimposed over the physical environment. Alternatively, a system may have an opaque display and one or more imaging sensors that capture images or video of the physical environment, which are representations of the physical environment. The system composites the images or video with virtual objects, and presents the composition on the opaque display. A person, using the system, indirectly views the physical environment by way of the images or video of the physical environment, and perceives the virtual objects superimposed over the physical environment. As used herein, a video of the physical environment shown on an opaque display is called “pass-through video,” meaning a system uses one or more image sensor(s) to capture images of the physical environment, and uses those images in presenting the AR environment on the opaque display. Further alternatively, a system may have a projection system that projects virtual objects into the physical environment, for example, as a hologram or on a physical surface, so that a person, using the system, perceives the virtual objects superimposed over the physical environment. 
     An augmented reality environment also refers to a simulated environment in which a representation of a physical environment is transformed by computer-generated sensory information. For example, in providing pass-through video, a system may transform one or more sensor images to impose a select perspective (e.g., viewpoint) different than the perspective captured by the imaging sensors. As another example, a representation of a physical environment may be transformed by graphically modifying (e.g., enlarging) portions thereof, such that the modified portion may be representative but not photorealistic versions of the originally captured images. As a further example, a representation of a physical environment may be transformed by graphically eliminating or obfuscating portions thereof. 
     An augmented virtuality (AV) environment refers to a simulated environment in which a virtual or computer-generated environment incorporates one or more sensory inputs from the physical environment. The sensory inputs may be representations of one or more characteristics of the physical environment. For example, an AV park may have virtual trees and virtual buildings, but people with faces photorealistically reproduced from images taken of physical people. As another example, a virtual object may adopt a shape or color of a physical article imaged by one or more imaging sensors. As a further example, a virtual object may adopt shadows consistent with the position of the sun in the physical environment. 
     There are many different types of electronic systems that enable a person to sense and/or interact with various CGR environments. Examples include head-mounted systems, projection-based systems, heads-up displays (HUDs), vehicle windshields having integrated display capability, windows having integrated display capability, displays formed as lenses designed to be placed on a person&#39;s eyes (e.g., similar to contact lenses), headphones/earphones, speaker arrays, input systems (e.g., wearable or handheld controllers with or without haptic feedback), smartphones, tablets, and desktop/laptop computers. A head-mounted system may have one or more speaker(s) and an integrated opaque display. Alternatively, a head-mounted system may be configured to accept an external opaque display (e.g., a smartphone). The head-mounted system may incorporate one or more imaging sensors to capture images or video of the physical environment, and/or one or more microphones to capture audio of the physical environment. Rather than an opaque display, a head-mounted system may have a transparent or translucent display. The transparent or translucent display may have a medium through which light representative of images is directed to a person&#39;s eyes. The display may utilize digital light projection, OLEDs, LEDs, uLEDs, liquid crystal on silicon, laser scanning light source, or any combination of these technologies. The medium may be an optical waveguide, a hologram medium, an optical combiner, an optical reflector, or any combination thereof. In one embodiment, the transparent or translucent display may be configured to become opaque selectively. Projection-based systems may employ retinal projection technology that projects graphical images onto a person&#39;s retina. Projection systems also may be configured to project virtual objects into the physical environment, for example, as a hologram or on a physical surface. 
     As described above, one aspect of the present technology is the gathering and use of data available from various sources to adjust the fit and comfort of a head-mounted device. The present disclosure contemplates that in some instances, this gathered data may include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, twitter ID&#39;s, home addresses, data or records relating to a user&#39;s health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, or any other identifying or personal information. 
     The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For example, a user profile may be established that stores fit and comfort related information that allows the head-mounted device to be actively adjusted for a user. Accordingly, use of such personal information data enhances the user&#39;s experience. 
     The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of or access to certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country. 
     Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, in the case of storing a user profile to allow automatic adjustment of a head-mounted device, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide data regarding usage of specific applications. In yet another example, users can select to limit the length of time that application usage data is maintained or entirely prohibit the development of an application usage profile. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user may be notified upon downloading an app that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app. 
     Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user&#39;s privacy. De-identification may be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and/or other methods. 
     Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, fit and comfort related parameters may be determined each time the head-mounted device is used, such as by scanning a user&#39;s face as they place the device on their head, and without subsequently storing the information or associating with the particular user.

Metadata:
Filing Date: 20200618
Publication Date: 20231121
Grant Date: 20231121
Priority Date: 20190829
Inventors: MARIC, IVAN S.
QUIJALVO, JAN K.
MIRABELLA, ANNA V.
LIN, WEY-JIUN
FRANKLIN, JEREMY C.
WANG, FORREST C.
MEURSING, MARINUS
TREKELL, Blake N.
ZIMMERMAN, AIDAN N.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B2027/0187", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/014", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/0093", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/62", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/0187", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/015", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/0149", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/014", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/0176", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/0093", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/014", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/015", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/0187", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/62", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 74682246