This relates generally to electronic devices, and, more particularly, to electronic devices such as head-mounted devices.
Electronic devices such as head-mounted devices may have displays for displaying images. The displays may be housed in a head-mounted support structure.
A head-mounted device may have a head-mounted frame with lens openings. The head-mounted device may have left and right lenses mounted in the lens openings. The lenses may include waveguides that help guide images from projectors to eye boxes for viewing by a user.
The head-mounted frame may include an internal frame member that provides the frame with structural support. The frame member may, for example, be a metal frame member. The metal frame member, which may sometimes be referred to as a metal frame structure or metal frame, may have mounting structures such as tabs to which the projectors are attached.
Circuitry such as strain gauge circuitry and cabling may be coupled to the metal frame member. A protective polymer such as thermoset epoxy may be used to encapsulate and protect the circuitry. The protective polymer may encapsulate the strain gauge, the cabling, and/or other circuitry so that this circuitry need not be exposed to elevated temperatures during subsequent injection molding operations. After the protective polymer structures have been formed, injection molding may be used to apply one or more shots of thermoplastic polymer to the metal frame member and the projective polymer on the frame member to form the head-mounted frame.
Electronic devices such as head-mounted devices may include displays and other components for presenting content to users. A head-mounted device may have head-mounted support structures that allow the head-mounted device to be worn on a user's head. The head-mounted support structures may support optical components such as displays for displaying visual content and front-facing cameras for capturing real-world images. In an illustrative configuration, optical components such as waveguides may be used to provide images from display projectors to eye boxes for viewing by a user.
The head-mounted device may have sensors. For example, a strain gauge sensor may be used to monitor for potential deformation of the support structures (e.g., twisting, bending, etc.). Deformation of the support structures (e.g., deformation of a glasses frame member or other head-mounted support structure due to excessive force such as force from a drop event) may potentially lead to optical component misalignment and image distortion. By monitoring for frame bending and other support structure deformations using strain gauge sensor circuitry, corrective actions may be taken to prevent undesired image distortion. For example, digital image warping operations may be performed on digital image data being provided to the projectors and/or other actions may be taken to compensate for the deformation. In this way, the head-mounted device may compensate for the measured support structure deformation.
A schematic diagram of an illustrative system that may include a head-mounted device is shown in
As shown in
During operation, the communications circuitry of the devices in system 8 (e.g., the communications circuitry of control circuitry 12 of device 10), may be used to support communication between the electronic devices. For example, one electronic device may transmit video data, audio data, and/or other data to another electronic device in system 8. Electronic devices in system 8 may use wired and/or wireless communications circuitry to communicate through one or more communications networks (e.g., the internet, local area networks, etc.). The communications circuitry may be used to allow data to be received by device 10 from external equipment (e.g., a tethered computer, a portable device such as a handheld device or laptop computer, online computing equipment such as a remote server or other remote computing equipment, or other electrical equipment) and/or to provide data to external equipment.
Device 10 may include input-output devices 22. Input-output devices 22 may be used to allow a user to provide device 10 with user input. Input-output devices 22 may also be used to gather information on the environment in which device 10 is operating. Output components in devices 22 may allow device 10 to provide a user with output and may be used to communicate with external electrical equipment.
As shown in
Displays 14 are used to display visual content for a user of device 10. The content that is presented on displays 14 may include virtual objects and other content that is provided to displays 14 by control circuitry 12. This virtual content may sometimes be referred to as computer-generated content. Computer-generated content may be displayed in the absence of real-world content or may be combined with real-world content. For example, an optical coupling system may be used to allow computer-generated content to be optically overlaid on top of a real-world image. In particular, device 10 may have a see-through display system that provides a computer-generated image to a user through a beam splitter, prism, holographic coupler, diffraction grating, or other optical coupler (e.g., an output coupler on a waveguide that is being used to provide computer-generated images to the user) while allowing the user to view real-world objects through the optical coupler and other transparent structures (e.g., transparent waveguide structures, vision-correction lenses and/or other lenses, etc.).
Input-output circuitry 22 may include sensors 16. Sensors 16 may include, for example, three-dimensional sensors (e.g., three-dimensional image sensors such as structured light sensors that emit beams of light and that use two-dimensional digital image sensors to gather image data for three-dimensional images from light spots that are produced when a target is illuminated by the beams of light, binocular three-dimensional image sensors that gather three-dimensional images using two or more cameras in a binocular imaging arrangement, three-dimensional lidar (light detection and ranging) sensors, three-dimensional radio-frequency sensors, or other sensors that gather three-dimensional image data), cameras (e.g., infrared and/or visible digital image sensors), gaze tracking sensors (e.g., a gaze tracking system based on an image sensor and, if desired, a light source that emits one or more beams of light that are tracked using the image sensor after reflecting from a user's eyes), touch sensors, capacitive proximity sensors, light-based (optical) proximity sensors, other proximity sensors, force sensors, sensors such as contact sensors based on switches, gas sensors, pressure sensors, moisture sensors, magnetic sensors, audio sensors (microphones), ambient light sensors, microphones for gathering voice commands and other audio input, sensors that are configured to gather information on motion, position, and/or orientation (e.g., accelerometers, gyroscopes, compasses, and/or inertial measurement units that include all of these sensors or a subset of one or two of these sensors), strain gauge sensors, and/or other sensors.
User input and other information may be gathered using sensors and other input devices in input-output devices 22. If desired, input-output devices 22 may include other devices 24 such as haptic output devices (e.g., vibrating components), light-emitting diodes and other light sources, speakers such as ear speakers for producing audio output, circuits for receiving wireless power, circuits for transmitting power wirelessly to other devices, batteries and other energy storage devices (e.g., capacitors), joysticks, buttons, and/or other components.
Electronic device 10 may have housing structures as shown by illustrative support structures 26 of
During operation of device 10, images are presented to a user's eyes in eye boxes 30. Eye boxes 30 include a left eye box that receives a left image and a right eye box that receives a right image. Device 10 may include a left display system with a left display 14 that presents the left image to the left eye box and a right display system with a right display 14 that presents the right image to the right eye box. In an illustrative configuration, each display system may have an optical combiner assembly that helps combine display images (e.g., computer-generated image 32 of
As an example, each display system may have a corresponding projector 36, a waveguide 38, and an optical coupler (e.g., a prism and/or other optical coupling element(s)) to couple an image from the projector into the waveguide from the projector. An output coupler on each waveguide may be used to couple the image out of that waveguide towards a respective eye box after the waveguide has guided the image to a location overlapping the eye box.
In the illustrative configuration of
Support structures 26-2 may be configured to support left and right glasses lenses 54. Optional lower frame portions 56 may run along the lower edge of each lens 54 to help support the bottom of lenses 54. Lenses 54 may contain embedded waveguides for laterally transporting images from display projectors to locations that overlap eye boxes 30 (
During use of device 10, device 10 may be subjected to undesirably larger forces (e.g., during drop events). These excessive forces may cause structures 26 to bend or otherwise deform, which could lead to misalignment between the optical components of device 10. Consider, for example, a scenario in which nose bridge portion 52 of structures 26-2 bends about the Y axis of
Sensor measurements (e.g., using sensors 16) may be used in measuring deformations to structures 26 and/or other sources of optical system misalignment, so that control circuitry 12 can take corrective action. As an example, frame deformations may be measured using strain gauge circuitry mounted in nose bridge portion 52 and/or other areas of the frame. The strain gauge circuitry may include one or more strain gauges (e.g., one or more sets of strain gauge sensor electrodes that exhibit measurable changes in resistance when bent). The strain gauge circuitry may measure support structure deformation (e.g., frame twisting, frame bending, etc.). In an illustrative scenario, which may sometimes be described herein as an example, the frame of device 10 may have an internal support member such as a metal frame member (e.g., a metal frame structure, metal frame, metal frame portion, etc.) to which a strain gauge is attached. Bending and/or twisting may be measured about any suitable dimensions (e.g., about axis X, axis Y, and/or axis Z).
Circuitry 70 may include circuits 76, 80, and 84 coupled using signal paths 78 and 82. Circuit 80 may include strain gauge circuitry (e.g., a strain gauge formed on a flexible printed circuit). The strain gauge may be coupled to a central region of upper portion 90 of frame member 86 to monitor for deformation of the frame member. Circuits 76 and 84 may include integrated circuits and other components for forming control circuitry 12, displays 14 (e.g., projectors 36 of
To provide device 10 with desired strength and rigidity, the glasses frame formed from structures 26 may include an outer portion covering one or more inner supporting portions. In particular, structures 26 may include an internal frame member such as frame member 86 of
Frame member 86 may be formed from a rigid material such as metal, carbon-fiber composite material or other fiber composites (e.g., polymer containing embedded stiffening fibers of glass, carbon, or other fiber materials), may include a stiff polymer, glass, ceramic, etc. In an illustrative configuration, which may sometimes be described herein as an example, frame member 86 may be formed from metal (e.g., aluminum, titanium, steel, magnesium, and/or other elemental metals and/or metal alloys) and may sometimes be referred to as a metal frame, metal member, or metal frame member. Metal frame member 86 may be machined (e.g., using a computer numerical control tool or other suitable shaping equipment) and/or may be otherwise shaped into a desired final configuration.
In the example of
A central region of portion 90 of frame member 86 may, if desired, include one or more planar surfaces. These surfaces may be characterized by respective surface normals. For example, the top surface of portion 90 may have a surface normal oriented along the −Y direction and the side surfaces of portion 90 may have surface normals oriented orthogonally (e.g., along the + and −Z directions, respectively). The strain gauge of circuit 80 may have a flexible printed circuit with strain gauge sensor traces. The flexible printed circuit may have a first portion with first traces attached to the top surface and a second portion with second traces attached to one of the side surfaces of portion 90. In this way, the strain gauge may measure bending of member 86 so that corrective actions may be taken to prevent undesired image distortion.
If desired, portion 90 may have a cable routing recess (e.g., a cable channel) that receives a cable forming paths 78 and 80. The channel may be sealed using a protective polymer layer (sometimes referred to as a protective polymer portion, protective polymer frame portion, protective polymer, etc.). Some of the protective polymer material that is used in sealing the cabling of circuitry 70 into the cable channel may be used to encapsulate and protect circuit 80. As shown in
After using the protective polymer to seal paths 78 and 82 into the cable channels on the underside of portion 90 and to form a protective structure such as member 96 that covers and protects circuit 80, higher-temperature polymer molding operations may be performed. In an illustrative example, first and second shots of a thermoplastic polymer are applied over the structures of
Initially, a first shot of injection-molded polymer (sometimes referred to as a rear frame shot or first molded polymer portion) such as first shot 100 of
As shown in
After first shot 100 has been applied, a subsequent second shot of injection-molded polymer may be applied.
During the operations of block 120, circuitry 70 is formed by soldering and/or otherwise electrically connecting circuits 76, 80, and 84 together using cables such as coaxial cable bundles and/or other signal paths 78 and 82.
During the operations of block 122, frame member 86 may be formed by machining and/or otherwise shaping a block of metal (e.g., using a CNC tool). Frame member 86 may be provided with a downwardly facing C-shape of the type shown in
After attaching circuitry 70 to frame member 86 (e.g., to route cables associated with paths 78 and 82 in a channel on the underside of portion 90 and to attach the strain gauge flexible printed circuit portion to the planar surfaces at the center of portion 90), protective polymer 96 may be applied. In particular, during the operations of block 124, a protective polymer such as epoxy (e.g., ultraviolet-light cured thermoset epoxy or other polymer that may be applied at relatively low temperatures) may be molded onto components 72. In this way, protective structures such as protective structure 96 may be formed on the frame member that cover and encapsulate sensitive circuitry such as circuit 80 (e.g., the strain gauge traces and associated integrated circuits for the strain gauge such as an amplifier and analog-to-digital converter).
After embedding cables, circuit 80, and/or other circuitry 70 that is potentially sensitive to elevated temperatures in epoxy or other protective polymer during the operations of block 124, frame fabrication may be completed by molding higher temperature polymer onto the frame. In particular, during the operations of block 126, one or more shots of molded polymer such as illustrative shots 100 and 112 of
In some embodiments, sensors may gather personal user information. To ensure that the privacy of users is preserved, all applicable privacy regulations should be met or exceeded and best practices for handling of personal user information should be followed. Users may be permitted to control the use of their personal information in accordance with their preferences.
In accordance with an embodiment, a head-mounted device is provided that includes an internal frame, a cable attached to the internal frame, protective polymer that covers at least part of the cable, a molded polymer frame portion molded over the protective polymer, the molded polymer frame portion is configured to form lens openings, and lenses in the lens openings.
In accordance with another embodiment, the protective polymer includes epoxy, the molded polymer frame portion includes injection-molded thermoplastic polymer, the lenses include waveguides, and the head-mounted device includes projectors configured to provide images that are guided in the waveguides.
In accordance with another embodiment, the head-mounted device includes a strain gauge that is covered by the protective polymer.
In accordance with another embodiment, the protective polymer includes epoxy.
In accordance with another embodiment, the epoxy includes ultraviolet-light-cured thermoset epoxy and the molded polymer frame portion includes thermoplastic polymer.
In accordance with another embodiment, the thermoplastic polymer includes injection-molded thermoplastic polymer and the molded polymer frame portion is configured to form a nose bridge portion.
In accordance with another embodiment, the head-mounted device includes a strain gauge embedded in the protective polymer.
In accordance with another embodiment, the strain gauge is configured to measure deformation of the internal frame.
In accordance with another embodiment, the internal frame includes a metal internal frame.
In accordance with another embodiment, the metal internal frame has a C-shape.
In accordance with another embodiment, the molded polymer frame portion is molded over at least part of the metal internal frame.
In accordance with another embodiment, the thermoplastic polymer includes a rear shot of thermoplastic polymer and a front shot of thermoplastic polymer.
In accordance with another embodiment, the rear shot of thermoplastic polymer is configured to form a lens ledge.
In accordance with another embodiment, the rear shot of polymer is configured to form lens mounting protrusions.
In accordance with another embodiment, the internal frame includes a metal internal frame with tabs, the head-mounted device includes projectors that are attached to the tabs.
In accordance with another embodiment, the lenses include waveguides that guide images received from the projectors.
In accordance with another embodiment, the cable is coupled to the projectors, the head-mounted device includes a strain gauge coupled to the cable, the strain gauge is configured to measure deformation of the metal internal frame, and the protective polymer encapsulates the strain gauge.
In accordance with an embodiment, a head-mounted device is provided that includes a cable, a sensor, a head-mounted frame including a metal frame that supports the cable and the sensor, thermoset polymer that is formed on at least part of the metal frame and that encapsulates at least part of the cable and the sensor, and thermoplastic polymer that is formed over the thermoset polymer and the metal frame, the thermoplastic polymer is configured to from lens openings, and left and right lenses in the lens openings.
In accordance with another embodiment, the thermoset polymer includes epoxy.
In accordance with an embodiment, a head-mounted device is provided that includes a metal frame, projectors attached to opposing sides of the metal frame, a strain gauge at a central region of the metal frame, cabling coupled to the projectors and the strain gauge, epoxy that covers the strain gauge, thermoplastic polymer covering the epoxy and the metal frame, the thermoplastic polymer is configured to form lens openings, and lenses in the lens openings, the lenses include waveguides configured to guide images from the projectors.
The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.
This application is a continuation of international patent application No. PCT/US2022/043367, filed Sep. 13, 2022, which claims priority to U.S. provisional patent application No. 63/246,409, filed Sep. 21, 2021, which are hereby incorporated by reference herein in their entireties.
Number | Date | Country | |
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63246409 | Sep 2021 | US |
Number | Date | Country | |
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Parent | PCT/US22/43367 | Sep 2022 | WO |
Child | 18444114 | US |