Patent Publication Number: US-2023135394-A1

Title: Composite Display Cover

Description:
RELATED APPLICATION 
     This application is a division of and claims priority to U.S. patent application Ser. No. 16/910,513, filed Jun. 24, 2020, the entire disclosure of which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Devices such as smart devices, wireless devices (e.g., cellular phones and tablet devices), consumer electronics, and the like can be implemented for use in a wide range of industries and for a variety of different applications. Typically, such devices include some form of display screen for outputting visual content and for receiving input, such as touch input from a user. To accommodate modern devices that implement a variety of form factors and functional configurations, display technologies have evolved that seek to provide thin display profiles that are also durable. This is particularly challenging for flexible devices, such as folding devices that require a display that can fold into different configurations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the techniques for composite display cover are described with reference to the following Figures. The same numbers may be used throughout to reference like features and components shown in the Figures: 
         FIG.  1    depicts an environment in which techniques for composite display cover may be employed in accordance with one or more implementations of the techniques described herein. 
         FIG.  2 A  depicts an implementation of a client device in the context of a folding device in an open orientation in accordance with one or more implementations of the techniques described herein. 
         FIG.  2 B  depicts an implementation of a client device in the context of a folding device in a folded orientation in accordance with one or more implementations of the techniques described herein. 
         FIG.  3    depicts an enlarged cross section of a display structure that illustrates various components of the display structure in accordance with one or more implementations of the techniques described herein. 
         FIG.  4    depicts an enlarged cross section of a display structure that represents a variation on the implementation described in  FIG.  3    in accordance with one or more implementations of the techniques described herein. 
         FIG.  5    depicts an enlarged partial cross section of the display structure that represents a preformed curved implementation in accordance with one or more implementations of the techniques described herein. 
         FIG.  6    illustrates an example method of fabricating a composite display cover and applying the display cover to a display in accordance with one or more implementations of the techniques described herein. 
         FIG.  7    illustrates various components of an example device that can used to implement the techniques of composite display cover as described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Implementations for composite display cover are described and provide improved protection and durability to device displays as compared with conventional display protection technologies. The described composite display cover, for instance, utilizes an ultra-thin glass layer with a polymer film applied directly to the glass layer and a hard coat applied to the polymer film. The polymer film, for instance, is applied to the glass layer without an adhesive. Further, the composite display cover can be attached to a display, such as via an adhesive layer that adheres the glass layer to a surface of the display. Generally, by adhering the polymer film directly to the glass layer without a separate adhesive, increased scratch and abrasion resistance is achieved as compared with conventional display protection techniques that utilize additional adhesive layers. For instance, typical adhesive layers utilized by conventional display technologies are soft and are thus prone to damage that results from user contact and/or contact with external objects. In at least some implementations, the hard coat is implemented utilizing a base material that is impregnated with nanoparticles to increase durability and/or to optimize a modulus of elasticity of the hard coat. Generally, the various layers of the composite display cover achieve a flexible structure that supports a variety of different display orientations, such as for foldable devices. Accordingly, by implementing a flexible composite display cover without an additional adhesive layer, the implementations described herein provide increased damage resistance than is experienced with conventional display technologies. 
     While features and concepts of composite display cover can be implemented in any number of different devices, systems, environments, and/or configurations, implementations of composite display cover are described in the context of the following example devices, systems, and method. 
       FIG.  1    depicts an environment  100  in which techniques for composite display cover may be employed. The environment  100  includes a client device  102  that includes a display structure  104  and device components  106 . Generally, the client device  102  may be implemented in a variety of different ways, such as a smartphone, a tablet device, a laptop, a wearable computing device (e.g., a smartwatch or a fitness tracker), and so forth. These examples are not to be construed as limiting, however, and the client device  102  can be implemented in a variety of different ways and form factors. Further example attributes of the client device  102  are discussed below with reference to the device  700  of  FIG.  7   . 
     The display structure  104  generally represents functionality for visual output by the client device  102  and may optionally be configured to receive input to the client device  102 , such as touch input. The display structure  104  includes a display  108  and a composite display cover  110 . The display  108  may be implemented according to a variety of different display technologies, such as organic light-emitting diode (OLED), light-emitting diode (LED), liquid-crystal display (LCD), and so forth. The composite display cover  110  represents a set of layers of material that are applied to the display  108  and that is fabricated according to techniques for composite display cover described herein, examples of which are detailed below. 
     The device components  106  generally represent different structural and functional components of the client device  102 , such as a device chassis, a printed circuit board (PCB) and various electronic components such as wireless communication components, a camera, a battery, input/output components, and so forth. 
       FIG.  2 A  depicts an implementation of the client device  102  in the context of a folding device in an open orientation. The client device  102  is depicted in an open position  200  including the display structure  104  in a planar orientation. Further depicted is a hinge  202  about which the client device  102  can be folded to assume a closed (e.g., folded) position. For instance,  FIG.  2 B  depicts the client device  102  folded about the hinge  202  to assume a closed position  204 . In the closed position, the display structure  104  is folded internally to the closed position of the client device  102 . Generally, the composite display cover  110  is adhered to the display  108  and is foldable along with the display  108  to enable the client device  102  to assume a variety of different orientations. Additionally or alternatively to the closed position  204  with the display structure  104  folded internally to the client device  102 , the client device  102  may folded outwardly from the open position  200  such that the display structure  104  is folded outwardly and exposed externally to the client device  102 . 
       FIG.  3    depicts an enlarged cross section  300  of the display structure  104  that illustrates the various components of the display structure  104 . For instance, the display structure  104  includes the composite display cover  110  adhered to the display  108 . In this particular example, the composite display cover  110  includes an ultra-thin glass layer (“glass layer”)  302  with a polymer film  304  coating and a hard coat  306  applied to the polymer film  304 . Generally, the glass layer  302  can be implemented using any suitable glass material and thickness, such as within the range of 30-200 micrometers (μm). Further, the polymer film  304  can be formed from a polymer resin such as a colorless polyamide (CPI). The polymer film  304  can be applied to the glass layer  302  using any suitable application technique, such as polymer solution casting, spin coating, dip coating, and so forth. In at least one implementation, the polymer film  304  is applied directly to the glass  302  with no intervening layers, e.g., no adhesive. For instance, the composite display cover  110  does not include an adhesive layer to adhere the polymer film to the glass layer  302 . Further, the glass layer  302  may be chemically strengthened prior to application of the polymer film  304 , such as via an ion exchange process. 
     The hard coat  306  represents a coating configured to reduce damage to the polymer film  304  that may occur during device usage, such as scratches and abrasion that may result from user contact and/or contact with other objects. In at least some implementations, the hard coat  306  is implemented as a coating material filled with inorganic nanoparticles that increase the durability of the hard coat  306  while allowing the hard coat  306  to remain flexible, such as in a folding device scenario as depicted in  FIGS.  2 A,  2 B . Generally, any suitable coating material may be utilized as a base material for the hard coat  306 , such as a flexible polymer, e.g., an acrylate resin. The hard coat  306 , for instance, may be formed by generating a dispersion that includes a polymerizable material along with inorganic nanoparticles that is then polymerized to form the hard coat  306 . Further, the inorganic nanoparticles can be included in various amounts, such as at least 50 weight percentage (wt %) relative to the base material. In at least one implementation, the inorganic nanoparticles are formed from an inorganic material such as silicon dioxide (SiO 2  or silica), indium tin oxide (ITO), antimony tin oxide (ATO), fluorinated tin oxide (FTO), aluminum oxide (Al 2 O 3 ), titanium dioxide (TiO 2 ) zinc oxide (ZnO), etc. The hard coat  306  may be applied to the polymer film  304  utilizing a suitable coating technique, such as solution casting, dip coating, spin coating, and so forth. In at least one implementation, the hard coat  306  has a higher modulus of elasticity than the polymer film  304 . The polymer film  304 , for instance, has a modulus in the range of 6-7 gigapascals (GPa), and the hard coat  306  has a modulus in the range of 20-30 GPa. 
     As further depicted in the cross section  300 , the composite display cover  110  is attached (e.g., laminated) to the display  108  via an adhesive layer  308  which includes an optically clear adhesive that bonds the composite display cover  110  to the display  108 . In at least one implementation, the display  108  is implemented as a foldable plastic OLED that is flexible to assume a variety of different orientations. To provide sufficient rigidity to the display structure  104 , the display  108  is adhered to a back support  310  via an adhesive layer  312 . The back support  310  can be formed from a rigid material of suitable flexibility, such as a thin stainless-steel sheet. Although not depicted here, the hard coat  306  may be coated with an anti-fingerprint coating to reduce persistence of fingerprints and other staining substances on the surface of the display structure  104 . 
     In at least one implementation, the composite display cover  110  is applied to the display  108  to optimize the location of a neutral axis of the display. For instance, a location of the neutral axis of the display  108  can be optimized via application of the composite display cover  110 , which may reduce mechanical stress on the display  108  when the display  108  is manipulated between different folded positions, such as depicted in  FIGS.  2 A,  2 B . 
       FIG.  4    depicts an enlarged cross section  400  of the display structure  104  that represents a variation on the implementation described in  FIG.  3   . The cross section  400  illustrates various components of the display structure  104  discussed in  FIG.  3   , but in this implementation, the display structure  104  includes a polymer film  304   a  on a top surface of the glass  302 , and a polymer film  304   b  on a bottom surface of the glass  302 . In at least one implementation, the polymer films  304   a ,  304   b  are applied directly to the glass  302  with no intervening layers, e.g., no adhesive. 
       FIG.  5    depicts an enlarged partial cross section  500  of the display structure  104  that represents a variation on the implementations described in  FIGS.  3 ,  4   . In this particular implementation, the display structure  104  is constructed in a preformed curved shape prior to installation on the client device  102 . The display structure  104 , for instance, can be formed on a curved mandrel prior to installation on the client device  102 . Generally, by forming the display structure  104  in a curved orientation prior to installation, stress on the display structure  104  caused by assuming a folded orientation can be reduced. This implementation of the display structure  104  includes the various layers detailed above. In this particular implementation, the curved orientation may represent a default, stressless orientation of the display structure  104 . 
     The various implementations depicted and discussed above may be combined and iterated in various ways to provide a wide variety of different composite display covers and display structures to accommodate a variety of different usage scenarios. 
       FIG.  6    illustrates an example method  600  of fabricating a composite display cover and applying the display cover to a display according to various implementations. The order in which the method is described is not intended to be construed as a limitation, and any number or combination of the described method operations can be performed in any order to perform a method, or an alternate method. 
     At  602 , a polymer film is applied directly to a glass layer without a separate adhesive. As discussed above, the polymer film can include a colorless material such as a polyamide that is applied using a suitable application technique, such as solution casting, dip coating, spin coating, and so forth. Further, the polymer film can be applied to a single side or both sides of the glass layer. In at least one implementation, the glass layer is chemically strengthened prior to applying the polymer film to the glass layer, such as via an ion exchange process. 
     At  604 , a hard coat is applied to the polymer film. Generally, the hard coat represents a base material such as an acrylate resin that is impregnated with particles (e.g., nanoparticles) of a different material, such as an inorganic material. Further, the hard coat can be applied to the polymer film using a suitable application technique, such as solution casting, dip coating, spin coating, and so forth. 
     At  606 , the glass layer is adhered to a display. The glass layer, polymer film, and hard coat, for instance, make up a composite display cover that is attached to a display, such as via an optically clear adhesive. 
     At  608 , the display is attached to an apparatus. In at least one implementation, a backing support layer (e.g., a stainless-steel layer) is attached to the display opposite the composite display cover and in conjunction with attachment to an associated device, such as the client device  102 . 
     In at least one implementation, the method  600  can be performed with the various components (e.g., the display  108  and the composite display cover  110 ) in a curved (e.g., folded or partially folded) orientation to generate the display structure  104  in a curved orientation. For instance, in such an implementation, the curved orientation represents a default unstressed orientation of the composite display cover  110  and/or the display structure  104 . 
     In addition to providing protection and durability to the display  108 , the composite display cover  110  can be utilized to optimize a neutral axis location of the display  108 . For instance, applying the composite display cover  110  to the display  108  can shift a location of the neutral axis (e.g., an axis across a width of the display  108 ) to reduce stress on the display  108  that may occur when the display structure  104  is manipulated between different folded and unfolded orientations. 
       FIG.  7    illustrates various components of an example device  700 , in which aspects of composite display cover can be implemented. The example device  700  can be implemented as any of the devices described with reference to the previous  FIGS.  1 - 6   , such as any type of a wireless device, mobile phone, client device, companion device, paired device, display device, tablet, computing, communication, entertainment, gaming, media playback, and/or any other type of computing and/or electronic device. For example, the client device  102  described above may be implemented as the example device  700 . 
     The device  700  includes communication transceivers  702  that enable wired and/or wireless communication of device data  704  with other devices. The device data  704  can include any type of audio, video, and/or image data. Example communication transceivers  702  include wireless personal area network (WPAN) radios compliant with various IEEE 702.15 (Bluetooth™) standards, wireless local area network (WLAN) radios compliant with any of the various IEEE 702.11 (WiFi™) standards, wireless wide area network (WWAN) radios for cellular phone communication, wireless metropolitan area network (WMAN) radios compliant with various IEEE 702.16 (WiMAX™) standards, and wired local area network (LAN) Ethernet transceivers for network data communication. 
     The device  700  may also include one or more data input ports  706  via which any type of data, media content, and/or inputs can be received, such as user-selectable inputs to the device, messages, music, television content, recorded content, and any other type of audio, video, and/or image data received from any content and/or data source. The data input ports may include USB ports, coaxial cable ports, and other serial or parallel connectors (including internal connectors) for flash memory, DVDs, CDs, and the like. These data input ports may be used to couple the device to any type of components, peripherals, or accessories such as microphones and/or cameras. 
     The device  700  includes a processor system  708  of one or more processors (e.g., any of microprocessors, controllers, and the like) and/or a processor and memory system implemented as a system-on-chip (SoC) that processes computer-executable instructions. The processor system may be implemented at least partially in hardware, which can include components of an integrated circuit or on-chip system, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a complex programmable logic device (CPLD), and other implementations in silicon and/or other hardware. Alternatively or in addition, the device can be implemented with any one or combination of software, hardware, firmware, or fixed logic circuitry that is implemented in connection with processing and control circuits, which are generally identified at  710 . The device  700  may further include any type of a system bus or other data and command transfer system that couples the various components within the device. A system bus can include any one or combination of different bus structures and architectures, as well as control and data lines. 
     The device  700  also includes computer-readable storage memory  712  (e.g., memory devices) that enable data storage, such as data storage devices that can be accessed by a computing device, and that provide persistent storage of data and executable instructions (e.g., software applications, programs, functions, and the like). Examples of the computer-readable storage memory  712  include volatile memory and non-volatile memory, fixed and removable media devices, and any suitable memory device or electronic data storage that maintains data for computing device access. The computer-readable storage memory can include various implementations of random access memory (RAM), read-only memory (ROM), flash memory, and other types of storage media in various memory device configurations. The device  700  may also include a mass storage media device. 
     The computer-readable storage memory  712  provides data storage mechanisms to store the device data  704 , other types of information and/or data, and various device applications  714  (e.g., software applications). For example, an operating system  716  can be maintained as software instructions with a memory device and executed by the processor system  708 . The device applications may also include a device manager  718 , such as any form of a control application, software application, signal-processing and control module, code that is native to a particular device, a hardware abstraction layer for a particular device, and so on. 
     In this example, the device  700  includes one or more antennas  720  for transmitting and receiving wireless signal. Generally, the one or more antennas  720  may represent multiple antennas positioned at various regions of the client device  102  described above. 
     In this example, the device  700  also includes a camera  722  and device sensors  724 , such as a temperature sensor to monitor device component operating temperatures (to include the antenna modules  720 ), and device sensors such as may be implemented as components of an inertial measurement unit (IMU). The device sensors  724  can be implemented with various motion sensors, such as a gyroscope, an accelerometer, and/or other types of motion sensors to sense motion of the device. The motion sensors can generate sensor data vectors having three-dimensional parameters (e.g., rotational vectors in x, y, and z-axis coordinates) indicating location, position, acceleration, rotational speed, and/or orientation of the device. The device  700  can also include one or more power sources  726 , such as when the device is implemented as a wireless device or collaborative device. The power sources may include a charging and/or power system, and can be implemented as a flexible strip battery, a rechargeable battery, a charged super-capacitor, and/or any other type of active or passive power source. 
     The device  700  can also include an audio and/or video processing system  728  that generates audio data for an audio system  730  and/or generates display data for a display system  732 . The audio system and/or the display system may include any devices that process, display, and/or otherwise render audio, video, display, and/or image data. Display data and audio signals can be communicated to an audio component and/or to a display component via an RF (radio frequency) link, S-video link, HDMI (high-definition multimedia interface), composite video link, component video link, DVI (digital video interface), analog audio connection, or other similar communication link, such as media data port  734 . In implementations, the audio system and/or the display system are integrated components of the example device. Alternatively, the audio system and/or the display system are external, peripheral components to the example device. 
     The display system  732  includes a display structure  736 , which represents an implementation of the display structure  104  detailed above. The display structure  736 , for example, includes the display  108  and the composite display cover  110  which may be generated and implemented in various ways, examples of which are presented in the preceding discussion. 
     Although implementations of composite display cover have been described in language specific to features and/or methods, the subject of the appended claims is not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed as example implementations of composite display cover, and other equivalent features and methods are intended to be within the scope of the appended claims. Further, various different examples are described, and it is to be appreciated that each described example can be implemented independently or in connection with one or more other described examples. Additional aspects of the techniques, features, and/or methods discussed herein relate to one or more of the following: 
     An apparatus including: a housing with internal components situated therein; a display attached to the housing; and a composite display cover attached to the display, the composite display cover including: a glass layer adhered to the display; a polymer film applied directly to the glass layer; and a hard coat applied to the polymer film opposite the glass layer. 
     In addition to the above-described apparatus, any one or more of the following: wherein the display and the composite display cover are foldable to assume a folded orientation; wherein the hard coat has a higher modulus of elasticity than the polymer film; wherein the composite display cover does not include a separate adhesive layer between the polymer film and the glass layer; wherein the polymer film is applied to a first side of the glass layer and to a second side of the glass layer opposite the first side; wherein polymer film includes a colorless polyamide applied directly to the glass layer; wherein the hard coat includes a base material impregnated with nanoparticles made of an inorganic substance; wherein the composite display cover is attached to a first side of the display, and wherein the apparatus further includes a back support layer attached to a second side of the display opposite the first side. 
     A composite display cover for attachment to a display, the composite display cover including: a glass layer configured to be adhered to the display; a polymer film attached directly to the glass layer; and a hard coat applied to the polymer film. 
     In addition to the above-described composite display covers, any one or more of the following: wherein the polymer film is attached directly to the glass layer without a separate adhesive; wherein the composite display cover is foldable into a folded orientation while remaining intact; wherein the composite display cover is formed in a curved orientation as a default orientation for the composite display cover; wherein the hard coat includes a base material impregnated with silicon dioxide particles at a mixture of at least 50 weight percentage; wherein the polymer film is adhered directly to a first side of the glass layer and a second side of the glass layer opposite the first side, and without a separate adhesive to adhere to the polymer film to the glass layer. 
     A method for generating a composite display cover for a display, the method including: applying a polymer film directly to a glass layer without a separate adhesive, the glass layer being configured to be adhered to a display; and applying a hard coat to the polymer film. 
     In addition to the above-described methods, any one or more of the following: wherein the glass layer is chemically strengthened prior to applying the polymer film to the glass layer; wherein said applying the polymer film directly to the glass layer includes performing one or more of solution casting, dip coating, or spin coating to apply the polymer film to the glass layer; wherein said applying the polymer film directly to the glass layer includes applying the polymer film directly to a first side of the glass layer and second side of the glass layer opposite the first side; wherein the glass layer is formed in a curved orientation as a default orientation of the glass layer, and wherein the polymer film and the hard coat are applied in the curved orientation; further including adhering the composite display cover to a display to affect a position of a neutral axis of the display.