PATENT DOCUMENT

Publication Number: US-10955880-B2
Application Number: US-202016849830-A
Country: US
Kind Code: B2

Title: Folding electronic devices with geared hinges

Abstract:
An electronic device has a foldable display. First and second portions of an electronic device housing for the device may be joined using a hinge. A flexible display may overlap the first housing portion and the second housing portion and may bend along a bend axis as the first and second housing portions are rotated relative to each other using the hinge. The hinge may include toothed members such as gears and a rack member. The rack member may have a surface with curved portions. The gears may include rotating gears that walk along the curved portions of the rack member as the electronic device is folded and unfolded. The hinge may include gears that are fixedly attached to the first and second housing portions and that engage the rotating gears. Linkage members may hold together gears and the rack member.

Claims:
What is claimed is: 
     
       1. A foldable electronic device, comprising:
 a housing having a first housing portion and a second housing portion that rotate with respect to each other; 
 a flexible display that overlaps the first and second housing portions; and 
 a hinge coupled between the first and second housing portions, wherein 
 the hinge includes a rack member and includes a first hinge portion and a second hinge portion each of which has a first gear, a second gear, and a linkage member that couples the first and second gears of that hinge portion to the rack member. 
 
     
     
       2. The foldable electronic device defined in  claim 1  wherein the second gear of the first hinge portion is fixedly attached to the first housing portion and wherein the second gear of the second hinge portion is fixedly attached to the second housing portion. 
     
     
       3. The foldable electronic device defined in  claim 2  wherein the rack member has rack member teeth that engage teeth on the first gear of the first hinge portion and that engage teeth on the first gear of the second hinge portion. 
     
     
       4. The foldable electronic device defined in  claim 3  wherein the second gear of the first hinge portion has teeth that engage the teeth of the first gear of the first hinge portion and wherein the second gear of the second hinge portion has teeth that engage the teeth of the first gear of the second hinge portion. 
     
     
       5. The foldable electronic device defined in  claim 1  wherein the flexible display comprises an organic light-emitting diode display with a first portion that is supported on a surface of the first housing portion and a second portion that is supported on a surface of the second housing portion. 
     
     
       6. A foldable electronic device, comprising:
 a first support structure; 
 a second support structure; 
 a flexible display that has a first portion supported by the first support structure and a second portion supported by the second support structure and that bends as the first and second support structures rotate relative to each other during folding and unfolding of the flexible display; and 
 a hinge having a toothed member with a curved surface, wherein the hinge has a first hinge portion with first and second gears, wherein the first gear of the first hinge portion walks along the curved surface and has a second hinge portion with first and second gears, wherein the first gear of the second hinge portion walks along the curved surface. 
 
     
     
       7. The foldable electronic device defined in  claim 6  wherein the second gear of the first hinge portion is coupled to the first support structure and does not rotate relative to the first support structure during the folding and unfolding of the flexible display and wherein the second gear of the second hinge portion is coupled to the second support structure and does not rotate relative to the second support structure during the folding and unfolding of the flexible display. 
     
     
       8. The foldable electronic device defined in  claim 7  wherein the curved surface has a first portion that is curved along a first arc and has a second portion that is curved along a second arc that is distinct from the first arc. 
     
     
       9. The foldable electronic device defined in  claim 7  wherein the curved surface forms a single continuous arc that engages the first gear of the first hinge portion and the first gear of the second hinge portion. 
     
     
       10. The foldable electronic device defined in  claim 7  wherein the curved surface has first teeth in a first region that engage teeth on the first gear of the first hinge portion and has second teeth in a second region that engage teeth on the first gear of the second hinge portion. 
     
     
       11. The foldable electronic device defined in  claim 10  wherein the first hinge portion has a first linkage member that holds the first gear of the first hinge portion against the first region and that holds the first gear against the second gear of the first hinge portion and wherein the second hinge portion has a second linkage member that holds the first gear of the second hinge portion against the second region and that holds the first gear of the second hinge portion against the second gear of the second hinge portion. 
     
     
       12. The foldable electronic device defined in  claim 6  wherein the flexible display comprises an organic light-emitting diode display. 
     
     
       13. The foldable electronic device defined in  claim 12  wherein the first gear of the first hinge portion and the first gear of the second hinge portion are rotatable gears. 
     
     
       14. The foldable electronic device defined in  claim 13  wherein the second gear of the first hinge portion is attached to the first support structure and rotates with the first support structure and wherein the second gear second hinge portion is attached to the second support structure and rotates with the second support structure. 
     
     
       15. The foldable electronic device defined in  claim 14  wherein the first hinge portion has a first linkage member and wherein the second hinge portion has a second linkage member. 
     
     
       16. The foldable electronic device defined in  claim 15  wherein the first linkage member holds the first gear of the first hinge portion against the curved surface while the first gear of the first hinge portion walks along the curved surface and wherein the second linkage member holds the first gear of the second hinge portion against the curved surface while the first gear of the second hinge walks along the curved surface. 
     
     
       17. A foldable electronic device, comprising:
 a housing having a first housing portion and a second housing portion that rotate with respect to each other; 
 a flexible display having a first portion that overlaps the first housing portion and a second portion that overlaps the second housing portion; and 
 a hinge with toothed structures, wherein the hinge has a first hinge portion coupled to the first housing portion and a second hinge portion coupled to the second housing portion, wherein the first hinge portion is configured to allow the flexible display to bend about a first pivot point as the first housing portion is rotated and wherein the second hinge portion is configured to allow the flexible display to bend about a second pivot point as the second housing portion is rotated. 
 
     
     
       18. The foldable electronic device defined in  claim 17  wherein the toothed structures comprise: first and second gears in the first hinge portion and first and second gears in the second hinge portion. 
     
     
       19. The foldable electronic device defined in  claim 18  wherein the toothed structures include a rack member with a curved surface and wherein the first gear of the first hinge portion and the first gear of the second hinge portion have teeth that engage teeth on the curved surface of the rack. 
     
     
       20. The foldable electronic device defined in  claim 19  wherein the second gear of the first hinge portion is fixedly attached to the first housing portion and has teeth that engage the teeth of the first gear of the first hinge portion and wherein the second gear of the second hinge portion is fixedly attached to the second housing portion and has teeth that engage the teeth of the first gear of the second hinge portion. 
     
     
       21. A foldable electronic device, comprising:
 a housing having a first housing portion and a second housing portion that rotate with respect to each other; 
 a flexible display having a first portion that overlaps the first housing portion and a second portion that overlaps the second housing portion; and 
 a hinge with toothed structures including a rack member with a curved surface, wherein the hinge is coupled between the first and second housing portions and is configured to allow the flexible display to bend about a pivot point as the first and second housing portions are rotated with respect to each other. 
 
     
     
       22. The foldable electronic device defined in  claim 21  wherein the toothed structures comprise first and second gears in a first hinge portion and first and second gears in a second hinge portion, wherein a second gear of the first hinge portion is fixedly attached to the first housing portion, wherein the second gear of the second hinge portion is fixedly attached to the second housing portion, and wherein the second gear of the first hinge portion and the second gear of the second housing portion have teeth that engage teeth on the curved surface of the rack.

Description:
This application claims the benefit of provisional patent application No. 62/868,590, filed Jun. 28, 2019, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to electronic devices, and, more particularly, to electronic devices with displays. 
     BACKGROUND 
     Electronic devices often include displays. A touch screen display may be used in a cellular telephone or other portable device to display information for a user and to gather user input. 
     If care is not taken, a display may not offer sufficient screen real estate to display information of interest to a user. At the same time, it can be difficult to enlarge the size of electronic devices too much to accommodate larger displays, because this can make devices bulky. 
     SUMMARY 
     An electronic device may have a foldable display. A foldable housing or other support structure may be used in supporting the foldable display during folding and unfolding. First and second support structures may be joined at a hinge. The hinge allows the support structures to rotate relative to each other during folding and unfolding. 
     The hinge may include toothed members such as gears and a rack member. The rack member may have a surface with curved portions. The gears may include rotating gears that walk along the curved portions of the rack member as the electronic device is folded and unfolded. The hinge may include gears that are fixedly attached to the first and second housing portions and that engage the rotating gears. Linkage members may hold together the rotating gears, fixed gears, and the rack member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device in accordance with an embodiment. 
         FIG. 3  is a cross-sectional side view of an illustrative electronic device in accordance with an embodiment. 
         FIG. 4  is side view of an illustrative electronic device with a foldable display in accordance with an embodiment. 
         FIG. 5  is a perspective view of an illustrative hinge mechanism for an inwardly folding electronic device in accordance with an embodiment. 
         FIGS. 6, 7, and 8  are side views of the illustrative hinge mechanism of  FIG. 5  in use during device folding in accordance with an embodiment. 
         FIG. 9  is a perspective view of an illustrative hinge mechanism for an outwardly folding electronic device in accordance with an embodiment. 
         FIG. 10  is a side view of the illustrative hinge mechanism of  FIG. 9  in use during device folding in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device may have a display. The display may have an array of pixels for displaying images for a user. The display may be an organic light-emitting diode display, a micro-light-emitting diode display formed from an array of crystalline semiconductor light-emitting diode dies, and/or may be any other suitable display. A two-dimensional touch sensor such as a capacitive touch sensor or other touch sensor may be incorporated into the display (e.g., by forming capacitive sensor electrodes from thin-film display circuitry) and/or a touch sensor layer may be laminated to an array of pixels in the display. 
     The display of the electronic device may be operated in unexpanded and expanded configurations. In the unexpanded configuration, portability of the device is enhanced. In the expanded configuration, viewable display area is increased, making it easier to provide touch input and to view images on the display. 
     A perspective view of an illustrative electronic device of the type that may include an expandable display is shown in  FIG. 1 . Device  10  may be a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a desktop computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch device, a wristband device, a pendant device, a headphone or earpiece device, a head-mounted device such as glasses, goggles, a helmet, or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which equipment is mounted in a kiosk, in an automobile, airplane, or other vehicle, a removable external case for electronic equipment, an accessory such as a remote control, computer mouse, track pad, wireless or wired keyboard, or other accessory, and/or equipment that implements the functionality of two or more of these devices. In the illustrative configuration of  FIG. 1 , device  10  is a portable electronic device such as a cellular telephone or tablet computer. This configuration may sometimes be described herein as an example. 
     As shown in  FIG. 1 , device  10  may have a housing such as housing  12 . Housing  12  may be formed from materials such as polymer, glass, metal, crystalline materials such as sapphire, ceramic, fabric, foam, wood, other materials, and/or combinations of these materials. Device  10  may have any suitable shape. In the example of  FIG. 1 , device  10  has front face F with a rectangular outline, opposing rear face R, and sidewall portions (sidewalls) W. Portions W may be formed as extensions of the housing structures on front face F, rear face R, and/or may be formed using one or more separate sidewall members (as examples). Sidewall structures may be planar (e.g., to form vertical sidewalls extending between front F and rear R) and/or may have curved cross-sectional profiles. Input-output devices such as one or more buttons may be mounted on housing  12  (e.g., on sidewall portions W). 
     Device  10  may have one or more displays such as display  14 . In the example of  FIG. 1 , display  14  covers front face F. Display  14  may also be mounted on other portions of device  10 . For example, one or more displays such as display  14  may cover all of front face F, part of front face F, some or all of rear face R, and/or some or all of sidewalls W. Portions of housing  12  (e.g., support structures such as first and second housing portions that rotate relative to each other) may be used in supporting display  14 . Housing  12  may include outwardly facing structures that form external device surfaces and/or may include frame structures, supporting plates, and/or other internal support structures. In some configurations, some or all of display  14  may be covered with flexible or rigid transparent members that serve as protective display cover layers. Such transparent display cover layer structures, which may sometimes be referred to as housing structures, may overlap at least some of display  14  and may serve as a display cover layer. If desired, transparent thin-film structures may serve as protective display layers (e.g., scratch-resistance layers, oleophobic anti-smudge coating layers, etc.). 
     Display  14  may have a planar shape, a shape with a curved cross-sectional profile, or other suitable shape. In the example of  FIG. 1 , front face F has a planar shape and lies in the X-Y plane. Display  14  may have a rectangular footprint (outline when viewed from above) or other suitable footprint. Device  10  may be elongated along longitudinal axis  56  (e.g., parallel to the Y axis of  FIG. 1 ) or along other directions (e.g., parallel to the X axis of  FIG. 1 ). The thickness of device  10  in dimension Z, may be less than the width of device  10  in dimension X and less than the length of device  10  in dimension Y (as an example). 
     To help accommodate a user&#39;s desire for compactness while accommodating a user&#39;s desire for large amounts of display real estate, device  10  can have structures that allow the shape and size of device  10  and display  14  to be adjusted. In particular, device  10  may have a display and associated housing structures that support folding motions, sliding motions, scrolling motions, and/or other behavior that allows device  10  to be adjusted during use. 
     When expanded, display  14  exhibits an expanded viewable area. In particular, the portion of display  14  that is viewable by a user of device  10  when device  10  is expanded (sometimes referred to as the expanded viewable area of display  14 ) is larger than the unexpanded viewable area of display  14  that is presented to a user of device  10  when device  10  is unexpanded. In general, device  10  may use any suitable arrangement that allows display and/or device size and/or shape to be adjusted (e.g., between a first configuration such as an unexpanded viewable area configuration in which a first amount of display  14  is visible to a user viewing the front face of device  10  or other side of device  10  and a second configuration such as an expanded viewable area configuration in which a second amount of display  14  that is greater than the first amount is visible to a user viewing the front face of device  10  or other side of device  10 ). These arrangements may exhibit inward and/or outward folding, scrolling, sliding, and/or other housing and display movements as device  10  and display  14  are transitioned between unexpanded and expanded states. Illustrative configurations in which device  10  is expanded and unexpanded using folding mechanisms are described herein as an example. 
     When compact size is desired in a folding configuration, device  10  can be adjusted to be compact by folding portions of device  10  together. Device  10  and display  14  may, as an example, be folded inwardly and/or outwardly about bend axis  58 . In inwardly folding configurations, two halves of display  14  face each other when device  10  is folded. In outwardly folding configurations, two halves of display  14  face away from each other when device  10  is folded. When a large screen size is desired, device  10  and display  14  can be unfolded. 
     A schematic diagram of an illustrative electronic device is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include control circuitry  30 , communications circuitry  32 , and input-output devices  34 . 
     Control circuitry  30  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid-state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  30  may be used to gather input from sensors and other input devices and may be used to control output devices. The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors and other wireless communications circuits, power management units, audio chips, application specific integrated circuits, etc. 
     To support communications between device  10  and external electronic equipment, control circuitry  30  may communicate using communications circuitry  32 . Communications circuitry  32  may include antennas, radio-frequency transceiver circuitry, and other wireless communications circuitry and/or wired communications circuitry. Circuitry  32 , which may sometimes be referred to as control circuitry and/or control and communications circuitry, may, for example, support wireless communications using wireless local area network links, near-field communications links, cellular telephone links, millimeter wave links, and/or other wireless communications paths. 
     Input-output devices  34  may be used in gathering user input, in gathering information on the environment surrounding the user, and/or in providing a user with output. 
     Display  14  of input-output devices  34  has an array of pixels for displaying images to users. Display  14  may be a light-emitting diode display (e.g., an organic light-emitting diode or a display with a pixel array having light-emitting diodes formed from crystalline semiconductor dies), an electrophoretic display, a liquid crystal display, or other display. Display  14  may include a two-dimensional capacitive touch sensor or other touch sensor for gathering touch input. Display  14  may have a substrate formed from a flexible dielectric (e.g., a sheet of polyimide or other bendable polymer layer) and/or may have rigid substrate structures. Flexible display arrangements may be used to provide display  14  with the ability to alter size and shape by folding, scrolling, sliding, etc. If desired, some or all of display  14  may include rigid (non-flexible) display structures. 
     Devices  34  may include sensors  36 . Sensors  36  may include force sensors (e.g., strain gauges, capacitive force sensors, resistive force sensors, etc.), audio sensors such as microphones, capacitive touch sensors, capacitive proximity sensors, non-capacitive touch sensors, ultrasonic sensors, sensors for detecting position, orientation, and/or motion (e.g., accelerometers, magnetic sensors such as compass sensors, gyroscopes, and/or inertial measurement units that contain some or all of these sensors), muscle activity sensors (EMG), heart rate sensors, electrocardiogram sensors, and other biometric sensors, radio-frequency sensors (e.g., radar and other ranging and positioning sensors), humidity sensors, moisture sensors, and/or other sensors. 
     Sensors  36  and other input-output devices  34  may include optical components such as light-emitting diodes (e.g., for camera flash or other blanket illumination, etc.), lasers such as vertical cavity surface emitting lasers and other laser diodes, laser components that emit multiple parallel laser beams (e.g., for three-dimensional sensing), lamps, and light sensing components such as photodetectors and digital image sensors. For example, sensors  36  in devices  34  may include optical sensors such as depth sensors (e.g., structured light sensors and/or depth sensors based on stereo imaging devices that can optically sense three-dimensional shapes), optical sensors such as self-mixing sensors and light detection and ranging (lidar) sensors that gather time-of-flight measurements and/or other measurements to determine distance between the sensor and an external object and/or that can determine relative velocity, monochromatic and/or color ambient light sensors that can measure ambient light levels, proximity sensors based on light (e.g., optical proximity sensors that include light sources such as infrared light-emitting diodes and/or lasers and corresponding light detectors such as infrared photodetectors that can detect when external objects are within a predetermined distance), optical sensors such as visual odometry sensors that gather position and/or orientation information using images gathered with digital image sensors in cameras, gaze tracking sensors, visible light and/or infrared cameras having digital image sensors configured to gather image data, optical sensors for measuring ultraviolet light, and/or other optical sensor components (e.g., light sensitive devices and, if desired, light sources), photodetectors coupled to light guides, associated light emitters, and/or other optical components (one or more light-emitting devices, one or more light-detecting devices, etc.). 
     Input-output devices  34  may also include audio components. The audio components may include one or more microphones to sense sound (e.g., an audio sensor in sensors  36  to sense audio signals) and may include sound-emitting components such as tone generators and one or more speakers. As shown in  FIG. 2 , for example, input-output devices  34  may include speaker  38 . Speakers may be used to support speaker-phone operations and/or may be used as ear speakers when device  10  is being held to a user&#39;s ear to make a telephone call, to listen to a voicemail message, or to listen to other audio output. 
     In addition to sensors  36 , display  14 , and speaker  38 , input-output devices  34  may include user input devices such as buttons and other devices  40 . Devices  40  may include, for example, optical components such as light-based output devices other than display  14  that are used to provide visual output to a user. The light-based output devices may include one or more light-emitting diodes, one or more lasers, lamps, electroluminescent devices, and/or other light emitting components. Devices  40  may also include power transmitting and/or receiving circuits configured to transmit and/or receive wired and/or wireless power signals and output components such as haptic output devices and other output components (e.g., electromagnetic actuators or other actuators that can vibrate to provide a user with a haptic alert and/or haptic feedback associated with operation of a touch sensor or other input devices). 
     A cross-sectional side view of device  10  taken along line  60  of  FIG. 1  and viewed in direction  62  is shown in  FIG. 3 . As shown in  FIG. 3 , housing  12  may have one or more portions such as sidewall portions  12 W, front portion  12 F on front face F of device  10 , and rear portion  12 R on rear face R of device  10 . These portions may be formed from metal (e.g., aluminum, stainless steel, or other metals) or may be formed from polymer, glass, ceramic, and/or other materials. 
     Display  14  may be visible on front face F of device  10  and/or other portions of device  10 . For example, a viewer who is viewing device  10  in the −Z direction of  FIG. 3  (e.g., a user viewing device  10  from the front) may view the pixels of display  14  on front face F that face the user in the +Z direction). Display  14  may be overlapped by transparent portions of housing  12 , may have portions that are supported on the outermost surface of housing  12 , and/or may have portions that protrude from housing  12 . In some configurations, rigid protective transparent materials may form a display cover layer that protects display  14 . To allow bending about bend axis  58  of  FIG. 1 , such rigid display cover layer structures may be provided in multiple parts (e.g., first and second parts that are supported by first and second respective halves of housing  12  that bend about a hinge aligned with axis  58 ). Display  14  may also be protected by attaching protective films to the outermost surface of display  14  and/or by incorporating protective films into display  14 . As an example, a clear polymer film may overlap the pixels of display  14  to help protect the circuitry of the pixels from damage and/or thin-film organic and/or inorganic layers may be incorporated into display  14  to help protect display  14 . In some arrangements, display  14  may include flexible protective material (e.g., a bendable polymer thin film, bendable inorganic thin-film layers, etc.). This allows the protective material to bend about bend axis  58 . Transparent materials that overlap display  14  (e.g., to protect display  14 ) may be formed from sapphire or other crystalline material, glass, polymer, transparent ceramic, inorganic dielectric materials such as transparent metal oxide thin films and/or other inorganic materials, and/or other transparent material and/or other flexible and/or rigid transparent materials. 
     The walls of housing  12  may separate interior region  44  of device  10  from exterior region  50  surrounding device  10 . Interior region  44  may include electrical components such as components  46 . Components  46  may include integrated circuits, discrete components, a battery, wireless circuit components such as a wireless power coil, and/or other components (see, e.g., control circuitry  30 , communications circuitry  32 , and input-output devices  34  of  FIG. 2 ). Components  46  may be interconnected using signal paths such as paths formed from traces on printed circuits (see, e.g., printed circuit  48 ). 
     To accommodate the sometimes-competing desires for compact device size and large screen size, device  10  can be adjusted between a first state in which display  14  is unexpanded and a second state in which display  14  is expanded and therefore larger than when unexpanded. Device  10  may, for example, accommodate display bending. In an illustrative configuration, display  14  may be folded inwardly so that left and right halves of display  14  face each other. As shown in  FIG. 4 , when display  14  is formed on surface  63  of housing  12  of  FIG. 4 , first and second halves of display  14  may face each other when device  10  is folded inwardly. In another illustrative configuration, display  14  may be folded outwardly so that left and right halves of display  14  face away from each other (e.g., when display  14  is formed on surface  61  of housing  12  of  FIG. 4 ). If desired, device  10  may support both inward and outward folding. 
     To allow device  10  to fold about bend (folding) axis  58 , device  10  may have a hinge that is aligned with bend axis  58 . The hinge may be formed from geared structures and/or other hinge structures that are coupled between respective first and second portions of device  10 . The hinge may allow the first and second portions of device  10  to rotate relative to each other about bend axis  58 . 
     An exploded perspective view of an illustrative hinge is shown in  FIG. 5 . As shown in  FIG. 5 , one or more hinges such as hinge  100  may be coupled between one or more first housing portions such as first housing portion  12 - 1  and one or more second housing portions such as second housing portion  12 - 2 . Display  14  may be a flexible display that has a first portion coupled to first housing portion  12 - 1  and a second portion coupled to second housing portion  12 - 2  to allow display bending as device  10  is bent about hinge axis  58 . 
     Hinge  100  may have one or more structures such as first portion  100 - 1  to couple first housing portion  12 - 1  to rack member  72  and may have one or more structures such as second portion  100 - 2  to couple second housing portion  12 - 2  to rack member  72 . Hinge  100  allows portions  12 - 1  and  12 - 2  and corresponding halves of a supported flexible display to rotate relative to each other. In the illustrative configuration of  FIG. 5 , device  10  is folded and portions  12 - 1  and  12 - 2  are folded and facing each other. When desired to unfold device  10 , portion  12 - 1  may be moved in direction  108  while portion  12 - 2  is moved correspondingly in direction  110 . 
     Rack member  72 , which may sometimes be referred to as the hinge&#39;s central gear or a toothed hinge member, may have a geared surface such as toothed surface  102 . Surface  120  may have a curved cross-sectional profile (e.g., the profile of surface  120  may follow an arc). Surface  102  may have teeth  76  and may be characterized by a radius of curvature (with respect to axis  70 ) of about 1-5 mm, 1-3 mm, at least 1 mm, less than 3 mm, less than 7 mm, less than 5 mm, or other suitable size. 
     Inverse gear  78  of first hinge portion  100 - 1  may have teeth  80  that engage teeth  76  in a first region of surface  120 . The radius of gear  78  may be 0.8 mm, at least 0.4 mm, less than 1.2 mm, or other suitable size. A first pin may couple gear  78  to linkage member  84 . The first pin may be received in opening  82  of gear  78  and opening  88  of linkage member  84 . A second pin may be received in opening  74  of member  72  and opening  86  of member  84 . A third pin may be received in opening  90  of linkage member  84  and opening  96  of satellite gear  92  (sometimes referred to as a fixed gear). The radius of gear  92  may be 0.8 mm, at least 0.4 mm, less than 1.2 mm, or other suitable size. The coupling pins that are used to couple the gears of hinge  100  are not shown in  FIG. 5  to avoid over-complicating the drawing. Second hinge portion  100 - 2  may have the same structures as first hinge portion  100 - 1 . For example, portion  100 - 2  may have a satellite gear with teeth that engage teeth  76  in a second region of surface  120 , etc. 
     The ratio of the radius of gear  78  to the radius of gear  92  may be 1.0, at least 0.1, at least 0.5, at least 0.7, at least 1, less than 1.5, less than 2, less than 10, or other suitable ratio. The ratio of the radius of gear  78  to the radius of gear  92  may be 0.25, at least 0.02, at least 0.07, at least 0.15, less than 0.5, less than 1.0, less than 2.0, less than 10, less than 20, or other suitable ratio. The number of teeth of gear  78 , gear  92 , and member  72  may be 20, at least 3, at least 7, at least 10, at least 15, less than 200, less than 75, less than 30, or other suitable number. The width (e.g., the dimension parallel to axis  58  of  FIG. 5 ) of gear  78 , gear  92 , and member  72  may each be between 1-100 mm, at least 0.5 mm, at least 1.5 mm, at least 5 mm, at least 10 mm, at least 50 mm, at least 100 mm, less than 500 mm, less than 50 mm, less than 25 mm, less than 4 mm, or other suitable width. Gear  78 , gear  92 , and member  72  may have teeth that fully overlap or that partially overlap (e.g., by less than 90%, less than 60%, less than 30%, or other suitable amount of partial overlap). The height of each tooth may be 0.1-10 mm, at least 0.2 mm, at least 0.5 mm, at least 1 mm, less than 20 mm, less than 10 mm, less than 3 mm, or other suitable size. 
     In hinge portion  100 - 1 , a hinge structure retention member such as linkage member  84  holds the toothed structures of hinge  100  together during hinge operation. In particular, linkage member holds gear  78  against member  72  so that teeth  80  of gear  78  engage teeth  76  of member  72  as gear  78  walks along curved surface  102 . Linkage member  84  also holds gear  78  against gear  92 , so that teeth  80  engage teeth  94  of gear  92 . Satellite gear  92  may be welded to housing portion  12 - 1  or otherwise fixedly attached to housing portion  12 - 1  (e.g., using adhesive, using fasteners, using structures that are formed integrally with portion  12 - 1 , etc.). The gears of hinge portion  100 - 2  are coupled between member  72  and housing portion  12 - 2  in the same fashion. With this arrangement, gear  92  rotates with housing portion  12 - 1 . 
     A flexible display may be mounted to surfaces  106 - 1  and  106 - 2  of portions  12 - 1  and  12 - 2 , respectively. During operation, hinge  100  allows first housing portion  12 - 1  to rotate about bend axis  58  with respect to second housing portion  12 - 2 . The outer perimeter of hinge  100  passes along curved surface  104 . Tip portions  108 - 1  and  108 - 2  of portions  12 - 1  and  12 - 2  and/or nearby portions of an attached flexible display may be located at the effective pivoting points of the hinge. As a result, tip portions  108 - 1  and  108 - 2  rotate about these pivoting points during folding and unfolding. During operation, the flexible display that is attached to surfaces  106 - 1  and  106 - 2  therefore bends evenly without an excessively small bend radius or undesired stretching. 
       FIGS. 6, 7, and 8  are cross-sectional side views of hinge  100  showing how display  14  may bend during folding of device  10 . In the configuration of  FIG. 6 , device  10  has been folded in half and display  14  has been bent 180° from its unfolded state. Portions  12 - 1  and  12 - 2  and corresponding surfaces  106 - 1  and  106 - 2  have retreated away from each other in the unfolded state to allow sufficient room for display  14  to bend without kinking. In the configuration of  FIG. 7 , housing portion  12 - 1  has been moved in direction  108  and housing portion  12 - 2  has been moved in direction  110  to begin to unfold device  10 . During unfolding, linkage member  84  pivots about pin  74 P in opening  74 , gear  78  rotates about pin  82 P in opening  82  while walking along the curved toothed surface of rack member  72 . As gear  78  walks along the surface of rack member  72 , pin  82 P in opening  82  traces out an arc corresponding to the curved shape of the surface of rack member  72 . Gear  92  is fixed to housing portion  12 - 1  and therefore does not rotate relative to housing portion  12 - 1 . Linkage member  84  holds gear  78  in engagement with rack member  72  and holds gear  92  in engagement with gear  78 . The engagement of gear  92  and gear  78  restricts the angle A of housing portion  12 - 1  and display  14  relative to horizontal axis  112  versus the location of a pivot point associated with gear  92  traveling along pivot point arc  114 . When device  10  is completely unfolded, surfaces  106 - 1  and  106 - 2  are joined and form a continuous planar support surface for display  14  as shown in  FIG. 8 . 
     The ratio of gear  78  to gear  92  can be selected to help minimize undue stress in display  14  as display  14  is folded an unfolded. For example, this gear ratio can be selected so that the horizontal velocity component of a pivot point such as pivot point  116  is zero or nearly zero as device  10  is folded and unfolded. Pivot point  116  may be located at any suitable location relative to display  14 . In a first embodiment, pivot point  116  is located on a surface of display  14 . In a second embodiment, pivot point  116  is located within display  14 . In a third embodiment, pivot point  116  is located away from the interior of display  14  and away from the surfaces of display  14  (e.g., pivot point  116  is separated from display  14 ). 
     Two opposing movement effects are balanced so as to cancel horizontal motion at pivot point  116  and thereby reduce display stress. A leftward horizontal relative motion of pivot point  116  with respect to pin  96 P arises from the clockwise rotation of housing portion  12 - 1  as device  10  unfolds. An equal and opposite rightward horizontal motion of pivot point  116  arises during clockwise rotation of housing portion  12 - 1  as gear  78  rotates and walks counterclockwise to the right along rack member  72 , thereby causing linkage member  84  to rotate counterclockwise so that gear  92  and pin  96 P move to the right. By balancing these leftward and rightward motions, pivot points associated with flexible display  14  near the hinge of device  10  such as pivot  116  may remain horizontally stationary or nearly stationary as device  10  unfolds, thereby helping to reduce stress on display  14 . 
     In the example of  FIG. 5 , surface  102  of rack member  72  has a circular arc shape and is characterized by a single hinge point. As shown in  FIG. 6 , there is a gap between the opposing surfaces of portions  12 - 1  and  12 - 2  when device  10  is in its folded configuration. With this arrangement, a left-hand pivot point (e.g., point  116 ) travels along a first axis that runs through opening  74  and a right-hand pivot point travels along a second axis that runs through opening  74  during folding and unfolding. The first and second axes are separated by a small non-zero angle. 
     If desired, hinge  100  may be characterized by a double hinge point. As shown in  FIG. 9 , for example, each rack member  72  may have a toothed surface with multiple separate and distinct arcs as shown by multiply curved surface  102 M of rack member  72  of  FIG. 9 . The arcs of the first and second curved surface regions  102 M- 1  and  102 M- 2  of member  72  are not part of a common arc shape as is the case in a single hinge point configuration of the type shown in  FIG. 5 . Hinge portion  100 - 1  may use the teeth of first region  102 M- 1  of surface  102 M. Hinge portion  100 - 2  may use the teeth of second region  102 M- 2  of surface  102 M. 
     The teeth of each curved rack member surface of  FIG. 9  may be engaged by a respective one of rotating gears  78 . A corresponding gear  92  may be fixedly attached to a portion of housing  12  (see, e.g., housing portion  12 - 2  in the example of  FIG. 9 ). A linkage member  84  may be used to couple the gears and member  72  together as described in connection with  FIG. 5 . 
     Curved surface  104 M of  FIG. 9  serves as a visual indicator of the outer perimeter of hinge  100  during motion. With this type of arrangement, the left-hand pivot point of the hinge travels along a first axis that runs vertically and the right-hand pivot point of the hinge travels along a second axis that runs vertically, parallel to the first axis. There may be reduced amounts of horizontal pivot point motion and reduced amounts of stress imposed on display  14  during folding with this type of arrangement. 
       FIG. 10  is a cross-sectional side view of hinge  100  in an illustrative double hinge point configuration, showing how display  14  may be mounted on the outer surfaces of housing portions  12 - 1  and  12 - 2 . In the illustrative configuration of  FIG. 10 , device  10  is an outwardly folding device in which first and second halves of display  14  face away from each other when device  10  is folded. Display  14  of  FIG. 10  may be locally bent along two parallel axes (running into the page of  FIG. 10 ) so that no one portion of display  14  exhibits more than a 90° bend. If desired, hinge structures such as hinge  100  (e.g., hinge  100  of  FIG. 9 ) may be used to allow device  10  to fold inwardly and/or to fold both inwardly and outwardly. 
     Device  10  may be operated in a system that uses personally identifiable information. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     The foregoing is illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20200415
Publication Date: 20210323
Grant Date: 20210323
Priority Date: 20190628
Inventors: WANG, KAI
XIA, ZHIYONG CEDRIC
WITTENBERG, MICHAEL B.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04M1/0268", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1641", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0216", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0017", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0268", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1652", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K5/0226", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0216", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1652", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0017", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0226", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1652", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/0268", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 71143532