Backing layer for flexible displays

Abstract

The present invention provides an electronic device including a flexible display and a foldable housing. [Solution] The display may include a foldable cover glass, an array of pixels configured to display an image through the foldable cover glass, and a backing layer configured to support the array of pixels. The backing layer may have an elastic modulus in the range of 50 GPa to 300 GPa and may be formed from glass or other suitable material. The backing layer may have higher rigidity in the non-flexed region of the display and lower rigidity in the flexed region of the display. The change in rigidity can be achieved by using different thicknesses, different materials, different embedding structures, or different carbon fiber weaves. The glass backing layer may have chamfered edges covered with a coating that is trimmed to align with other layers, such as a metal backplate.

Description

TECHNICAL FIELD

[0001] This application claims priority to U.S. Patent Application No. 19 / 574,138 filed on March 20, 2026, U.S. Provisional Patent Application No. 63 / 813,488 filed on May 28, 2025, and U.S. Provisional Patent Application No. 63 / 781,874 filed on April 1, 2025, the entire contents of these applications are incorporated herein by reference in their entirety. The present invention relates generally to electronic devices, and more particularly to electronic devices having displays.

BACKGROUND ART

[0002] Electronic devices often include displays. Portability can be a concern for some devices, which tends to limit the space available for the display.

SUMMARY OF THE INVENTION

[0003] The electronic device may include a flexible display having a first display portion and a second display portion that rotate relative to each other about a bending axis. The flexible display may be mounted in a foldable housing having a first housing portion and a second housing portion joined by a hinge overlapping the bending axis. The foldable housing may be operable in a flat (e.g., open) state and a folded (e.g., closed) state.

[0004] The display may include a foldable cover glass, an array of pixels configured to display an image through the foldable cover glass, and a backing layer configured to support the array of pixels. The backing layer may have an elastic modulus in the range of 50 GPa to 300 GPa and may be formed from glass or other suitable material. The backing layer may have higher rigidity in the non-flexed region of the display and lower rigidity in the flexed region of the display. The change in rigidity can be achieved by using different thicknesses, different materials, different embedding structures, or different carbon fiber weaves.

[0005] The glass backing layer may have chamfered edges covered with a coating that is trimmed to align with other layers, such as a metal backplate. The glass backing layer may have localized changes in compressive strength resulting from localized ion exchange at the outer periphery of the glass backing layer. [Brief explanation of the drawing]

[0006] [Figure 1] This is a schematic diagram illustrating an exemplary electronic device according to several embodiments.

[0007] [Figure 2] This is a perspective view of an exemplary electronic device having a display according to several embodiments.

[0008] [Figure 3] This is a side view of an exemplary electronic device according to several embodiments.

[0009] [Figure 4] This is a side view of an exemplary electronic device having a cover glass, pixel array, backing layer, and backplate according to several embodiments.

[0010] [Figure 5]This is a side view of an exemplary electronic device having a backing layer with chamfered edges covered by a coating trimmed to align with a backplate, according to several embodiments.

[0011] [Figure 6] This is a side view of an exemplary electronic device having a backing layer and a cover glass with a coating-covered periphery, according to several embodiments.

[0012] [Figure 7] This is a side view of an exemplary electronic device having a backing layer with a periphery and a cover glass, which are covered by a coating and bonded by an intervening support structure, according to several embodiments.

[0013] [Figure 8] This is a top view of a backing layer having a light-transmitting window according to several embodiments.

[0014] [Figure 9] This is a side view of a backing layer having glass fibers embedded in a first polymer in the non-flexible region and embedded in a second polymer in the flexible region, according to several embodiments.

[0015] [Figure 10] This is a top view of a backing layer having carbon fibers having a first weave in the non-flexible region and a second weave in the flexible region, according to several embodiments.

[0016] [Figure 11] This is a top view of a backing layer having a slit in the bending region according to several embodiments.

[0017] [Figure 12] This is a side view of a backing layer having pillars embedded in the polymer in a non-flexible region, according to several embodiments.

[0018] [Figure 13] FIG. 2 is a side view of an exemplary electronic device having a cover layer, an array of pixels, and a backing layer that replaces a back plate, in accordance with some embodiments.

[0019] [Figure 14] FIG. 3 is a side view of an exemplary glass backing layer having glass portions separated by a gap filled with a polymer material in a bending region, in accordance with some embodiments.

[0020] [Figure 15] FIG. 4 is a side view of an exemplary glass backing layer having a plurality of glass layers and a polymer filler material, in accordance with some embodiments. MODE FOR CARRYING OUT THE INVENTION

[0021] The electronic device may be provided with a display. The display can be used to display images to a user. The display may be formed from light emitting diode pixels or other pixel arrays. For example, the device may have an organic light emitting diode display, or a display formed from an array of micro light emitting diodes (e.g., diodes formed from crystalline semiconductor dies).

[0022] A schematic diagram of an exemplary electronic device having a display is shown in Figure 1. Device 10 may be a mobile phone, tablet computer, laptop computer, wristwatch device, or other wearable device, television, standalone computer display or other monitor, computer display with an embedded computer (e.g., desktop computer), vehicle, kiosk, or system incorporated into other embedded electronic devices, media player, or other electronic device. Configurations in which device 10 is a mobile phone, tablet computer, or other portable electronic device may be described herein as examples. This is illustrative. In general, device 10 may be any suitable electronic device having a display.

[0023] Device 10 may include a control circuit 20. The control circuit 20 may include memory and processing circuits to support the operation of device 10. The memory and processing circuits may include storage devices such as non-volatile 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. The processing circuits of the control circuit 20 may be used to collect inputs from sensors and other input devices and may also be used to control output devices. The processing circuits may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors and other wireless communication circuits, power management units, audio chips, application-specific integrated circuits, etc. During operation, the control circuit 20 may use displays and other output devices to provide visual and other outputs to the user.

[0024] To support communication between device 10 and external equipment, the control circuit 20 can communicate using a communication circuit 22. Circuit 22 may include an antenna, a high-frequency transceiver circuit (wireless transceiver circuit), other wireless communication circuits and / or wired communication circuits. Circuit 22, which may also be referred to as the control circuit and / or control and communication circuit, can support bidirectional wireless communication between device 10 and external equipment via a wireless link (for example, circuit 22 may include high-frequency transceiver circuits such as a wireless local area network transceiver circuit configured to support communication via a wireless local area network link, a short-range communication transceiver circuit configured to support communication via a short-range communication link, a mobile phone transceiver circuit configured to support communication via a mobile phone link, or a transceiver circuit configured to support communication via any other suitable wired or wireless communication link). Wireless communication may be supported via, for example, a Bluetooth® link, a WiFi® link, a wireless link operating at frequencies from 6GHz to 300GHz, a 60GHz link, or other millimeter-wave links, a mobile phone link, a wireless local area network link, a personal area network communication link, or other wireless communication links. Device 10 may optionally include power circuits for transmitting and / or receiving wired and / or wireless power, and may also include a battery or other energy storage device. For example, device 10 may include coils and rectifiers for receiving wireless power provided in the circuits within device 10.

[0025] Device 10 may include input / output devices such as device 24. Input / output device 24 may be used to collect user input, collect information about the environment surrounding the user, and / or provide output to the user. Device 24 may include one or more displays, such as display 14. Display 14 may be an organic light-emitting diode display, a liquid crystal display, an electrophoretic display, an electrowetting display, a plasma display, a micro-electromechanical system display, a display having a pixel array formed from a crystalline semiconductor light-emitting diode die (sometimes referred to as a micro-LED), and / or other displays. Configurations in which display 14 is an organic light-emitting diode display or a micro-LED display may be described herein as an example.

[0026] The display 14 may have an array of pixels configured to display an image for the user. The pixels may be formed as part of a flexible display panel. This allows the device 10 to be folded and unfolded around a bending axis. For example, the flexible (bendable) display within the device 10 may be folded so that the device 10 can be placed in a compact shape for storage and unfolded when it is desired to view an image on the display.

[0027] The sensors 16 within the input / output device 24 may include force sensors (e.g., strain gauges, capacitive force sensors, resistive force sensors, etc.), audio sensors such as microphones, touch sensors such as capacitive sensors, and / or proximity sensors (e.g., two-dimensional capacitive touch sensors incorporated into the display 14, two-dimensional capacitive touch sensors overlapping the display 14, and / or touch sensors forming buttons, trackpads, or other input devices not associated with the display), and other sensors. If necessary, sensor 16 may include optical sensors such as optical sensors that emit and detect light, ultrasonic sensors, optical touch sensors, optical proximity sensors, and / or other touch sensors and / or proximity sensors, monochromatic and color ambient light sensors, image sensors, fingerprint sensors, temperature sensors, sensors for measuring three-dimensional non-contact gestures ("air gestures"), pressure sensors, sensors for detecting position, orientation, and / or motion (e.g., magnetic sensors such as accelerometers and compass sensors, gyroscopes, and / or inertial measurement units including some or all of these sensors), health sensors, high-frequency sensors, depth sensors (e.g., structured optical sensors and / or depth sensors based on stereo imaging devices that capture three-dimensional images), optical sensors such as self-mixed sensors and optical detection and ranging (lidar) sensors that collect time-of-flight measurements, humidity sensors, moisture sensors, gaze tracking sensors, and / or other sensors. In some configurations, device 10 may use sensor 16 and / or other input / output devices to collect user input. For example, a button can be used to collect button press input, a touch sensor superimposed on a display can be used to collect user touchscreen input, a touchpad can be used to collect touch input, a microphone can be used to collect audio input, and an accelerometer can be used to monitor when a finger touches the input surface, and thus can be used to collect finger press input.

[0028] If necessary, the electronic device 10 may include additional components (see, for example, other devices 18 in the input / output device 24). Additional components may include a tactile output device, an audio output device such as a speaker, a light source such as a light-emitting diode for a status indicator, a light-emitting diode for illuminating the housing and / or part of the display structure, other optical output devices, and / or other circuits for collecting inputs and / or providing outputs. Device 10 may also include a battery or other energy storage device, a connector port for supporting wired communication with an auxiliary device and receiving wired power, and other circuit configurations.

[0029] Figure 2 is a perspective view of an electronic device 10 in an exemplary configuration where device 10 is a portable electronic device such as a mobile phone or a tablet computer. As shown in Figure 2, device 10 may have a display such as a display 14. The display 14 may cover part or all of the front of device 10. A touch sensor circuit, such as a two-dimensional capacitive touch sensor circuit, may be incorporated into the display 14.

[0030] The display 14 can be mounted within the housing 12. The housing 12 can form front and rear housing walls, side wall structures, and / or internal support structures (e.g., frames, optional intermediate plate members, etc.) for the device 10. Glass structures, transparent polymer structures, and / or other transparent structures covering the display 14 and other parts of the device 10 can provide structural support for the device 10 and may sometimes be referred to as housing structures. For example, a transparent housing portion, such as a glass or polymer housing structure covering and protecting the pixel array within the display 14, can function as a display cover layer for the pixel array, while also functioning as a housing wall on the front of the device 10. In configurations where the display cover layer is formed from glass, the display cover layer may also be referred to as a display cover glass or display cover glass layer. The portions of the housing 12 on the side and rear walls of the device 10 may be formed from glass or other transparent and / or opaque structures. The side and rear wall structures may be formed as extensions to the front of the housing 12 (e.g., as integral parts of the display cover layer) and / or may include separate housing wall structures.

[0031] Device 10 may be a foldable electronic device that folds along one or more bending axes, such as a bending axis 28. In the example of Figure 2, device 10 includes a first part 48 and a second part 48 joined by a bendable portion 50. The parts 48 of device 10 (e.g., parts 48 of the display 14 and the housing 12, sometimes referred to as the non-bending region of device 10) may rotate relative to each other around the axis 28. When one part 48 rotates relative to another part 48 (e.g., during folding and unfolding of device 10), the bendable portion 50 of the display 14 may bend and flex (e.g., while the part 48 remains flat).

[0032] The housing 12 may have a flexible structure (e.g., a bendable housing wall structure) and / or a hinge structure such as a hinge 30. Depending on the type of hinge used, the hinge 30 may have a hinge axis aligned with the display bending axis 28 or offset relative to the display bending axis 28. The bending axis 28 may be, for example, the bending axis on which the display 14 bends, while the hinge 30 can bend around the hinge bending axis. In some configurations, such as a teardrop hinge configuration, the hinge bending axis of the hinge 30 may be aligned with the display bending axis 28 of the display 14. In other configurations, such as a fixed-length hinge configuration (e.g., a roller hinge), the hinge bending axis may be offset from the display bending axis 28. The device 10 may include one or more translation modules to facilitate the translation of the display 14 relative to the housing 12 in order to accommodate the offset between the display bending axis 28 and the hinge bending axis.

[0033] A flexible housing structure overlapping the hinge 30 and / or the bending axis 28 may allow the housing 12 to bend around the hinge bending axis. For example, a portion 48 of the housing 12 may be located on one side of the hinge 30, and another portion 48 of the housing 12 may be located on the opposite side of the bending hinge 30. The portions 48 of the housing 12 may be configured to rotate relative to each other around the hinge 30. The hinge 30 may be a roller hinge including one or more rollers, each having a longitudinal axis extending parallel to the bending axis 28. This is merely an example. If desired, the hinge 30 may include other types of hinge structures.

[0034] When the housing 12 is bent around the hinge 30, the flexibility of the display 14 allows the display 14 to bend around the axis 28. In an exemplary configuration, the housing 12 and the display 14 can be bent 180°. This allows the display 14 to be folded on its own (for example, so that the first part 48 and the second part 48 of the display 14 face each other). The ability to place the device 10 in a folded configuration in this way can help make the device 10 compact so that it can be stored efficiently. If it is desired to view an image on the display 14, the device 10 can be unfolded around the axis 28 to place the device 10 in the unfolded (e.g., flat) configuration shown in Figure 2. This allows the display 14 to be placed flat, and the user can view a flat image on the display 14. The ability of the display 14 to fold on its own allows the device 10 to exhibit inward folding behavior. The display 14 may, if desired, have sufficient flexibility to allow the device 10 to be folded outward and / or inward.

[0035] The device 10 in Figure 2 has a rectangular contour (around the rectangle) with four corners. As shown in Figure 2, the first pair of parallel edges (e.g., the left and right edges of the device 10 in the example of Figure 2) may be longer than the second pair of parallel edges (e.g., the upper and lower edges of the device 10 in Figure 2) which are oriented perpendicular to the first pair of parallel edges. In this type of configuration, the housing 12 is elongated along a longitudinal axis perpendicular to the bending axis 28. The housing 12 may have other shapes if desired (e.g., a shape in which the housing 12 has a longitudinal axis extending parallel to the bending axis 28). In the type of configuration shown in Figure 2, the length of the device 10 along its longitudinal axis can be reduced by folding the device 10 around the axis 28.

[0036] Figure 3 is a side cross-sectional view of an exemplary foldable electronic device. The device 10 in Figure 3 may be bent around a bending axis 28. The bending axis 28 may be aligned with the display cover layer 14CG or other structures within the device 10. For example, the bending axis 28 may pass through a portion of the display cover layer 14CG, or it may be located above or below the layer 14CG.

[0037] As shown in Figure 3, the display 14 includes an array of pixels P that form a display panel 14P beneath the inward-facing surface of the display cover layer 14CG. The display panel 14P may be, for example, a flexible organic light-emitting diode display or a micro-LED display in which light-emitting pixels are formed on a flexible substrate layer (e.g., a flexible layer of polyimide or a sheet of other flexible polymer). The flexible support layer for the display 14 may also be formed from flexible glass, flexible metal, and / or other flexible structures.

[0038] The display cover layer 14CG may be formed from polymers, glass, crystalline materials such as sapphire, other materials, and / or combinations thereof. To increase flexibility, a portion of layer 14CG overlapping the bending axis 28 may be locally thinned (for example, this portion may be thinner than the portion of layer 14CG that does not overlap the bending axis 28). The thickness of layer 14CG (for example, the unthinned portion of layer 14CG) may be 50-200 microns, 70-150 microns, 100-200 microns, 100-600 microns, at least 100 microns, at least 200 microns, less than 600 microns, less than 400 microns, less than 250 microns, less than 150 microns, less than 100 microns, at least 50 microns, or other suitable thicknesses.

[0039] In the example shown in Figure 3, the housing 12 has a portion that forms a rear housing wall on the rear surface R of the device 10 and a portion that forms a side wall 12W of the device 10. The rear housing wall of the housing 12 may form a support layer for components within the device 10. The housing 12 may have one or more internal support layers (e.g., frame structures such as an optional intermediate plate). These internal support layers and the rear housing wall may have a first portion and a second portion coupled to the opposing sides of the hinge 30, or they may be sufficiently flexible to bend around the bending axis 28.

[0040] The electrical components 32 may be mounted inside the device 10 (for example, between the display 14 and the rear of the housing 12). The components 32 may include circuits of the type shown in Figure 1 (e.g., control circuit 20, communication circuit 22, input / output device 24, battery, etc.). The display 14 may be mounted on the front F of the device 10. When the device 10 is folded around the axis 28, the display cover layer 14CG, the display panel 14P, and other structures of the device 10 that overlap the bending axis 28 may bend and flex to adapt to the folding.

[0041] Figure 4 is a side view of device 10 showing exemplary layers of the display 14. As shown in Figure 4, the display 14 may include a display layer 14P having an array of pixels P. The pixels P may be located on a display substrate such as a substrate 80. The substrate 80 may be a layer of polyimide or other suitable polymer. The pixels P can display an image through a display cover layer 14CG. The display cover layer 14CG overlaps the display layer 14P and can protect the display layer 14P.

[0042] The display layer 14P may be supported by one or more backing layers, such as backing layer 34 and backing layer 36. The backing layer 36 may be a thin metal plate that is solid in the non-flexible region 48 and has slots or other openings in the flexible region 50 to enhance flexibility along the flex axis 28. In other configurations, the backing layer 36 may be formed from glass, sapphire, diamond, zirconia, carbon fiber, titanium, polymer, and / or other suitable materials.

[0043] If desired, one or more additional backing layers, such as a backing layer 34, may be interposed between the backing layer 36 (sometimes referred to as a backplate or metal backplate) and the substrate 80 of the display layer 14P. The modulus of elasticity of the backing layer 34 may be, for example, 50 GPa to 300 GPa or other suitable modulus. The backing layer 34 may be formed from glass (e.g., aluminosilicate glass, soda-lime glass, borosilicate glass, lithium, aluminosilicate, etc.), sapphire, diamond, zirconia, fiber-reinforced materials (glass fiber, carbon fiber, etc.), titanium, polymers, electroactive polymers, non-Newtonian materials, shape memory alloys, and / or other suitable materials. A configuration in which the backing layer 34 is formed from glass may be described herein as an example. Glass may have a higher modulus of elasticity than polyimide and polyethylene terephthalate, and therefore may provide better rigidity than the polymer behind the display layer 14P while maintaining sufficient elasticity to adapt to the folding and unfolding of the device 10. If desired, the non-flexible region 48 of the backing layer 34 may have a higher stiffness or modulus of elasticity than the flexible region 50. This can be achieved by changes in material, thickness, fiber orientation, embedding structure, and / or other changes to the flexible region 50 relative to the non-flexible region 48.

[0044] The backing layer 34 may have a uniform thickness across the non-flexible region 48 and the flexible region 50, or it may have a variable thickness (for example, a reduced thickness in the flexible region 50 relative to the non-flexible region 48). The thickness T1 of layer 14CG (for example, the unthinned portion of layer 14CG) may be 30-50 microns, 50-200 microns, 70-150 microns, 100-200 microns, 100-600 microns, at least 100 microns, at least 200 microns, less than 600 microns, less than 400 microns, less than 250 microns, less than 150 microns, less than 100 microns, at least 50 microns, or other suitable thicknesses. The thickness T2 of layer 34 may be 30-90 microns, 50-150 microns, 100-200 microns, 300-400 microns, less than 400 microns, greater than 400 microns, or other suitable thicknesses. The thickness T2 may be greater than the thickness T1 if desired. As shown in Figure 4, the cover glass 14CG may have chamfered edges such as chamfered edge 40, and the backing layer 34 may have chamfered edges such as chamfered edge 38. The chamfered edges 40 and 38 can help avoid sharp corners of the glass where stress tends to concentrate.

[0045] If desired, the backing layer 34 may be strengthened by ion exchange to create compressive stress in the glass. For example, the compressive stress of the backing layer 34 may be 400 MPa to 500 MPa, 350 MPa to 550 MPa, greater than 400 MPa, less than 500 MPa, or other suitable compressive stress. In some configurations, a localized ion exchange process can be performed on the backing layer 34, which may result in non-uniform ion concentrations in different areas of the layer 34. For example, the glass layer 34 may undergo a first ion exchange process to obtain a chemically strengthened surface 72. If the outer edge of the glass layer 34 is trimmed after the first ion exchange process, this may result in exposed tension on the peripheral surface 70. To compensate for this exposed tension, a localized ion exchange process can be performed on the peripheral edge of the layer 34, such as the surface 70. This may include printing a potassium nitrate slurry onto the edge surface 70 and performing ion exchange locally on the edge surface 70. Due to this localized ion exchange process, layer 34 may have different ion concentrations and compressive stresses at its upper surface 72 compared to its edge surface 70.

[0046] The strength of the display 14 can be increased by replacing the polymer backing layer behind the display substrate 80 with a layer having a higher modulus of elasticity, such as backing layer 34, while still allowing the display 14 to bend and flex within region 50. If desired, layer 34 may be replaced with the polymer substrate 80 on which the pixels P are formed. For example, glass, such as glass backing layer 34, may be used as the substrate on which the pixels P are directly formed (for example, organic light-emitting diodes may be grown on a glass substrate such as backing layer 34, or formed directly by another method). If desired, a configuration in which the backing layer 34 is replaced with a metal backplate 36 can also be used. This type of configuration will be described in more detail with reference to Figure 11.

[0047] Figure 5 shows an example in which a coating such as coating 42 is applied to the outer edge surface 70 of the glass layer 34. The coating 42 may be a resin (e.g., UV-curing resin, thermosetting resin, photocuring resin, etc.) that covers the edge surface 70 of the layer 34 (including the chamfered edge 38). The coating 42 may partially or completely encase the periphery of the backing layer 34. Once cured, the outer portion of the coating 42 can be trimmed using a laser or other cutting tool so that the layer 34 has the desired shape and size. For example, the coating 42 may be trimmed to align with the peripheral surface of the backing layer 36, as shown in Figure 5.

[0048] The example in Figure 5, in which the coating 42 is applied only to the outer peripheral surface 70 of the backing layer 34, is for illustrative purposes only. If desired, the coating 42 may also coat the upper surface 90 and the opposing lower surface 92 of the backing layer 34.

[0049] Figure 6 shows an example in which a coating such as coating 84 is also applied to the outer edge surface 88 of the cover glass 14CG. The coating 84 may be a resin (e.g., UV-curing resin, thermosetting resin, photocuring resin, etc.) that covers the edge surface 88 of the cover glass 14CG (including the chamfered edge 40). The coating 84 can partially or completely encase the periphery of the cover glass 14CG. Once cured, the outer portion of the coating 84 can be trimmed using a laser or other cutting tool so that the cover glass 14CG has the desired shape and size. For example, the coating 84 may be trimmed to align with the edge of the coating 42 of the backing layer 34 and the peripheral surface of the backing layer 36.

[0050] In some configurations, the coating 84 may be optically transparent so that light from the pixels P can pass through the coating 84. This allows the pixels P in the display layer 14P to extend to the outermost edge of the device 10, as shown in the example in Figure 6. However, this is merely illustrative. If desired, the space between the coating 84 and 42 may be filled with a support structure to make the edges of the device 10 more rigid. This type of arrangement configuration is shown in Figure 7.

[0051] As shown in Figure 7, the coating 84 may be applied to the outer edge 88 of the cover glass 14CG, and the coating 42 may be applied to the outer surface 70 of the backing layer 34. The gap between the coatings 42 and 84 may be filled by a support structure such as a support structure 86. The support structure 86 may be formed from a metal, polymer, or other suitable material. In some configurations, the support structure 86 may be a molded polymer (e.g., a low-pressure injection-molded polymer or other suitable polymer).

[0052] The examples in Figures 6 and 7, in which coating 42 is applied only to the outer edge surface 70 of the backing layer 34 and coating 84 is applied only to the outer edge surface 88 of the cover glass 14CG, are merely illustrative. If desired, coating 42 may also coat the upper surface 90 and the opposing lower surface 92 of the backing layer 34. If desired, coating 84 may also coat the upper surface 94 and the opposing lower surface 96 of the cover layer 14CG.

[0053] Figure 8 is a top view of the backing layer 34, showing how a window, such as the light-transmitting window 46, may be formed in the backing layer 34. Since the backing layer 34 is behind the display layer 14P, the backing layer does not need to be transparent. This makes it possible to use an opaque polymer, metal, and / or other material with an appropriate modulus of elasticity behind the display layer 14P without obscuring the light from the display. For example, the backing layer 34 may be an opaque film with a transparent insert that forms a window, such as the window 46.

[0054] Optical components mounted behind the display layer 14P and behind the backing layer 34 may be configured to transmit and / or receive light through the window 46. For example, one or more optical sensors (e.g., the ambient light sensor in sensor 16 in Figure 1, a visible light camera, an infrared camera, and / or any other suitable optical sensor) may be mounted in alignment with the window 46 and configured to detect ambient light through the window 46. Light-emitting devices (e.g., infrared light-emitting diodes, visible light-emitting diodes, camera flash components, and / or other suitable light-emitting devices) may be configured to emit light through the window 46.

[0055] Figure 9 is a side view of a backing layer 34, showing an example in which the backing layer 34 is formed from a fiber-reinforced material such as glass fibers, carbon fibers, and / or any other suitable fiber-reinforced material. As shown in Figure 9, the backing layer 34 may contain fibers such as glass fibers 56 in a polymer matrix such as polymer 52 and polymer 54. To provide additional stiffness, the glass fibers 56 may be oriented perpendicularly (for example, perpendicular to the bending axis 28 and parallel to the Z-axis in Figure 9), if desired.

[0056] The stiffness of the backing layer 34 can also be adjusted by using different types of polymer matrices for the glass fibers 56 at different locations in the layer 34. For example, the polymer 52 in the non-flexible region 48 may be different from the polymer 54 in the flexible region 50. The polymer 52 in the non-flexible region 48 may be a rigid polymer such as polyimide, acrylic, or any other suitable rigid polymer. The polymer 54 in the flexible region 50 may be a flexible polymer such as epoxy, polycarbonate, or any other suitable flexible polymer (for example, a polymer having a lower modulus of elasticity than the polymer 52 in the non-flexible region 48).

[0057] Figure 10 is a top view of a backing layer 34, showing an example in which the backing layer 34 is formed from a fiber-reinforced material such as carbon fibers. As shown in Figure 10, the backing layer 34 may include fibers such as carbon fibers 60 and 62. The carbon fibers 60 and 62 may be formed in a plastic resin if desired (for example, the backing layer 34 may be a carbon fiber-reinforced polymer layer). If desired, the carbon fibers 60 in the non-flexible region 48 may have a different weave than the carbon fibers 62 in the flexible region 50. For example, the carbon fibers 62 in the flexible region 50 may have a weave that promotes bending along the bending axis 28, while the carbon fibers 60 in the non-flexible region 48 may have a weave that is stiffer than the weave of the fibers 62.

[0058] If desired, the carbon fibers may be omitted from certain areas of layer 34, such as the light-transmitting window 46. By omitting the fibers from the window 46, light can be configured to pass through the window 46 of layer 34 without obstruction. The window 46 may be formed from the same resin that binds the carbon fibers 62 and 60, or the window 46 may be filled with another polymer. A configuration in which the window 46 is an air-filled cutout in layer 34 can also be used if desired.

[0059] Figure 11 is a top view of a backing layer 34 showing an example in which the backing layer 34 includes an opening 58 within a bending region 50. The opening 58 may be a slit, recess, hole, and / or other opening in the backing layer 34. If desired, the backing layer 34 may be formed from solid glass in a non-bending region 48 to provide additional rigidity to the region 48. An opening 58 may be formed in the glass of region 50 to allow the layer 34 to bend and flex in region 50. The opening 58 may be a through hole extending through the entire thickness of the glass, or the opening 58 may be a recess extending only partway through the thickness of the glass (e.g., from the top surface of the glass and / or from the bottom surface of the glass).

[0060] In addition to using the opening 58 to increase the flexibility of region 50, or instead, reinforcing materials can be incorporated into the non-flexible region 48 of the backing layer 34. This type of configuration is shown in Figure 12. Figure 12 is a side view of the backing layer 34 showing an example in which reinforcing pillars, such as pillars 76, are incorporated into the non-flexible region 48 of the backing layer 34. The pillars 76 may be elongated rods of material (e.g., metal, glass, plastic, etc.) or other elongated structures formed of material such as material 64 (e.g., glass, polymer, etc.). The longitudinal axis of each pillar 76 may be perpendicular to the bending axis 28 and parallel to the Z-axis in Figure 12. The pillars 76 may not be present in the bending region 50 in order to allow the bending region 50 to bend and flex.

[0061] Figure 13 is a side view of device 10 showing how the backing layer 34 can replace other backing layers in the display 14, such as a metal backplate (e.g., backing layer 36 in Figure 4). The backing layer 34 may be interposed between the display panel 34 and the rear housing wall of the housing 12. To provide sufficient rigidity without a metal backplate, the backing layer 34 may be thicker in the non-flexible region 48 than in the flexible region 50. For example, the thickness of the backing layer 34 in the non-flexible region 48 may be 90 to 200 microns or other preferred thickness. Recesses, such as recesses 82, may be formed in the flexible region 50 of the backing layer 34 to provide sufficient flexibility to the region 50.

[0062] Figures 14 and 15 are side views of a backing layer 34, illustrating an exemplary embodiment in which the backing layer 34 is formed from a combination of glass and polymer layers. In the example of Figure 14, the backing layer 34 is solid in the non-flexible region 48 and includes glass layers 66 that are alternately arranged with polymer layers 68 in the flexible region 50. Gaps between the glass portions 66 in region 50 (e.g., gaps filled with polymer 68) can allow bending along the bending axis 28.

[0063] In the example shown in Figure 15, the backing layer 34 includes a first layer of glass, such as an upper layer 66A, extending with uniform thickness across a non-flexible region 48 and a flexible region 50. Additional glass layers, such as lower glass layers 66B-1 and 66B-2, can be laminated onto the upper glass layer 66A using a polymer, such as polymer 70. The lower glass layers 66B-1 and 66B-2 may be separated by a gap in region 50, such as a void 74. The void 74 may help to increase the flexibility of the backing layer 34 in region 50. If desired, polymer 70 may fill the void 74.

[0064] Device 10 may operate in a system that uses personally identifiable information. It is well understood that the use of personally identifiable information should adhere to privacy policies and practices that are generally recognized as meeting or exceeding industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of authorized use should be clearly indicated to the user.

[0065] According to one embodiment, the electronic device includes an array of pixels formed on a substrate, a display cover glass overlapping the array of pixels, and a glass backing layer configured to support the substrate, wherein the substrate is interposed between the display cover glass and the glass backing layer, and the substrate, display cover glass, and glass backing layer are configured to bend around a bending axis.

[0066] According to another embodiment, the glass backing layer optionally exhibits a compressive stress of at least 400 MPa.

[0067] According to another embodiment, the glass backing layer optionally has first and second opposing surfaces joined by a peripheral surface, the first surface having a different amount of compressive stress than the peripheral surface.

[0068] According to another embodiment, the electronic device optionally further includes a metal backplate configured to support a glass backing layer, the glass backing layer interposed between the substrate and the metal backplate.

[0069] According to another embodiment, the electronic device optionally further includes a coating on the peripheral surface of the glass backing layer, the coating having a first edge, and the metal backplate having a second edge aligned with the first edge.

[0070] According to another embodiment, the electronic device optionally further includes an additional coating on an additional peripheral surface of the display cover glass, the additional coating having a third edge aligned with the first edge.

[0071] According to another embodiment, the glass backing layer optionally includes a slit that overlaps the bending axis.

[0072] According to another embodiment, the glass backing layer optionally has a reduced thickness in the region overlapping the bending axis compared to other regions of the glass backing layer.

[0073] According to another embodiment, the glass backing layer optionally includes glass portions within a bent region separated by polymer-filled gaps.

[0074] According to another embodiment, the glass backing layer optionally includes a first glass layer having a uniform thickness extending along the bending axis, a second glass layer and a third glass layer overlapping the first glass layer and separated by a gap overlapping along the bending axis, and a polymer material filling the gap and interposed between the first glass layer and the second glass layer, and between the first glass layer and the third glass layer.

[0075] According to one embodiment, the electronic device includes a cover glass configured to fold along a bending axis, an array of pixels configured to display an image through the cover glass, and a backing layer configured to support the array of pixels, wherein the array of pixels is interposed between the cover glass and the backing layer, and the backing layer includes a first region and a second region separated by a bending region aligned with the bending axis, the first region and the second region being more rigid than the bending region.

[0076] According to another embodiment, the backing layer optionally comprises a first type polymer in a first region and a second region, and a second type polymer in a bending region, wherein the first type polymer is different from the second type polymer.

[0077] According to another embodiment, the electronic device optionally further comprises glass fibers embedded in first and second type polymers, wherein the glass fibers are perpendicular to the bending axis.

[0078] According to another embodiment, the backing layer optionally comprises carbon fibers having a first weave in a first region and a second region, and a second weave in a bending region, wherein the first weave is different from the second weave.

[0079] According to another embodiment, the backing layer optionally comprises a polymer material having a first region and a second region with embedded pillars extending over the thickness of the backing layer, wherein the embedded pillars are not present in the bending region.

[0080] According to another embodiment, the backing layer optionally includes a light-transmitting window.

[0081] According to another embodiment, the electronic device includes a foldable glass layer configured to bend along a bending axis, a pixel array configured to display an image through the foldable glass layer, and a backing layer configured to support the pixel array, wherein the pixel array is interposed between the foldable glass layer and the backing layer, and the backing layer has an elastic modulus in the range of 50 GPa to 300 GPa.

[0082] According to another embodiment, the backing layer optionally includes an opaque film having a light-transmitting window.

[0083] According to another embodiment, the backing layer optionally includes a material selected from the group consisting of glass, sapphire, diamond, zirconia, glass fiber, carbon fiber, titanium, electroactive polymer, non-Newtonian material, and shape memory alloy.

[0084] According to another embodiment, the backing layer optionally includes a uniform thickness glass layer having a thickness greater than that of the foldable glass layer.

[0085] The above is merely illustrative, and various modifications may be made to the described embodiments. The aforementioned embodiments may be implemented individually or in any combination.

Claims

1. It is an electronic device, An array of pixels formed on a substrate, A display cover glass overlapping the aforementioned pixel array, An electronic device comprising a glass backing layer configured to support the substrate, wherein the substrate is interposed between the display cover glass and the glass backing layer, and the substrate, the display cover glass, and the glass backing layer are configured to bend around a bending axis.

2. The electronic device according to claim 1, wherein the glass backing layer exhibits a compressive stress of at least 400 MPa.

3. The electronic device according to claim 2, wherein the glass backing layer has first and second opposing surfaces joined by a peripheral surface, and the first surface has a compressive stress of a different amount than that of the peripheral surface.

4. The electronic device according to claim 1, further comprising a metal backplate configured to support the glass backing layer, wherein the glass backing layer is interposed between the substrate and the metal backplate.

5. The electronic device according to claim 4, further comprising a coating on the peripheral surface of the glass backing layer, wherein the coating has a first edge, and the metal backplate has a second edge aligned with the first edge.

6. The electronic device according to claim 5, further comprising an additional coating on an additional peripheral surface of the display cover glass, wherein the additional coating has a third edge aligned with the first edge.

7. The electronic device according to claim 1, wherein the glass backing layer includes a slit that overlaps with the bending axis.

8. The electronic device according to claim 1, wherein the glass backing layer has a reduced thickness in the region overlapping with the bending axis compared to other regions of the glass backing layer.

9. The electronic device according to claim 1, wherein the glass backing layer includes a glass portion within the bending region separated by a polymer-filled gap.

10. The aforementioned glass backing layer is A first glass layer having a uniform thickness extending along the bending axis, The second and third glass layers overlap the first glass layer and are separated by a gap that overlaps the bending axis, The electronic device according to claim 1, comprising a polymer material that fills the gap and is interposed between the first glass layer and the second glass layer, and between the first glass layer and the third glass layer.

11. It is an electronic device, A cover glass configured to fold along the bending axis, An array of pixels configured to display an image through the cover glass, An electronic device comprising: a backing layer configured to support the array of pixels, wherein the array of pixels is interposed between the cover glass and the backing layer, and the backing layer comprises first and second regions separated by a bending region aligned with the bending axis, the first and second regions having higher rigidity than the bending region.

12. The electronic device according to claim 11, wherein the backing layer comprises a first type polymer in the first and second regions and a second type polymer in the bending region, and the first type polymer is different from the second type polymer.

13. The electronic device according to claim 12, further comprising glass fibers embedded in the first and second types of polymers, wherein the glass fibers are perpendicular to the bending axis.

14. The electronic device according to claim 11, wherein the backing layer comprises carbon fibers having a first weave in the first and second regions and a second weave in the bending region, and the first weave is different from the second weave.

15. The electronic device according to claim 11, wherein the backing layer comprises a polymer material having pillars embedded in the first and second regions extending over the thickness of the backing layer, and the embedded pillars are not present in the bending region.

16. The electronic device according to claim 11, wherein the backing layer comprises a light-transmitting window.

17. It is an electronic device, A foldable glass layer configured to bend along the bending axis, A pixel array configured to display an image through the aforementioned foldable glass layer, An electronic device comprising a backing layer configured to support the pixel array, wherein the pixel array is interposed between the foldable glass layer and the backing layer, and the backing layer has an elastic modulus in the range of 50 GPa to 300 GPa.

18. The electronic device according to claim 17, wherein the backing layer includes an opaque film having a light-transmitting window.

19. The electronic device according to claim 17, wherein the backing layer comprises a material selected from the group consisting of glass, sapphire, diamond, zirconia, glass fiber, carbon fiber, titanium, electroactive polymer, non-Newtonian material, and shape memory alloy.

20. The electronic device according to claim 17, wherein the backing layer includes a glass layer of uniform thickness having a thickness greater than that of the foldable glass layer.

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