MULTILAYER DISPLAY WITH INTEGRATED EDGE COVERING

A display that is suitable for use with a mobile computing device is disclosed. The display includes multiple layers that are bonded in a stack that has side surfaces. Operation of the display may be negatively affected if the side surfaces are exposed to liquids or debris. Accordingly, a film affixed at, or close to, the top of the stack is folded around the side surfaces and attached to a back surface of the stack to cover the side surfaces. This covering can also block light if it is colored, and may help bind layers of the stack together to prevent delamination.

FIELD OF THE DISCLOSURE

The present disclosure relates to a display for a mobile computing device and more specifically, to a display that includes multiple layers with one of the layers extending past and folded over edges of the other layers.

BACKGROUND

The dimensions of displays in mobile computing devices are becoming larger to meet consumer expectations and demands. It is desirable that as displays are enlarged, the overall dimensions of mobile computing devices remain the same to allow for convenient handheld operation and portability. To meet this goal, the edges of a display can be arranged closer to the edges of the mobile computing device. The edges of the mobile computing device, however, are susceptible to exposure and stress, and the close arrangement leaves less space for shielding and protecting the edges of the display. Accordingly, new displays for mobile computing devices are needed.

SUMMARY

In one general aspect, the present disclosure describes a display. The display includes a cover glass and a display module. The display module includes multiple layers that are aligned and adhered together to define a plurality of (e.g., four) side surfaces. The display also includes a film that has a transparent central portion and a plurality of (e.g., four) edge portions. The transparent central portion is affixed between the cover glass and a front surface of the display module. The edge portions are each folded around one of the side surfaces and affixed to the back surface of the display module.

In another general aspect, the present disclosure describes a method for fabricating a display. The method includes attaching a film to a front surface of an organic light emitting diode (OLED) display module using optically clear adhesive (OCA) so that edge portions of the film extend past side surfaces of the OLED display module. An adhesive film is affixed to the edge portions of the film and the edge portions of the film are folded around the side surfaces of the OLED display module and flush with the back surface of the OLED display module. The folded edge portions are then bonded to the back surface of the OLED display module using the adhesive film so that the side surfaces are covered by the film.

In another general aspect, the present disclosure describes a mobile computing device. The mobile computing device includes a bezel that defines sides of the mobile computing device and a cover glass that defines a front surface of the mobile computing device. The mobile computing device also includes a display module that is affixed between the cover glass and the bezel. The display module includes multiple layers that are laminated together to define a front surface, a back surface, and side surfaces of the display module. The display module also includes a film that has a transparent central portion affixed between the front surface of the display module and the cover glass. The film has edge portions that are folded around the side surfaces of the display module and that are affixed to the back surface of the display module.

The components in the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding parts throughout the several views.

DETAILED DESCRIPTION

The present disclosure embraces a display module (i.e., display) for a mobile computing device. The display has multiple layers. One of the multiple layers is used to cover the edges of the display. The covering can protect the edges of the display from contact with liquids or other contaminants (e.g., debris). Additionally, the covering may block light emitted from the edges of the display from leaking out of the mobile computing device. Finally, the covering may help prevent the multiple layers from delaminating (e.g., one or more layers separating and/or peeling) if, for example, the mobile computing device experiences an impact (e.g., is dropped).

When the disclosed display is used in a mobile computing device, other edge covering/protecting structures may not be required. Eliminating these other structures can allow the edges of the display to be positioned closer to the edges of the mobile computing device. As a result, the display area of a mobile computing device may be increased without increasing the overall dimensions of the mobile computing device.

FIG. 1illustrates a mobile computing device according to an embodiment of the present disclosure. A front surface of the mobile computing device100is defined by a cover glass110. A bezel120surrounds the cover glass110and defines side surfaces (i.e., sides) of the mobile computing device100and defines a back surface (opposite to the front surface—not shown) of the mobile computing device100.

A display is situated within a volume defined by the cover glass110and the bezel120and during operation, the display projects visual information through the cover glass110to a user. The display area may be made larger by extending its edges towards the sides of the bezel120. As the display's edges are extended towards the sides of the bezel, more of the cover glass must be used for display instead of support. This may result in supporting architectures that leave the display exposed to liquid and/or contaminants. For example, liquids and/or contaminants may reach the display through a gap formed between the cover glass110and the bezel120. This gap may be very small (e.g., less than 0.1 millimeters) but may still allow liquids or containments to enter the volume defined by the cover glass110and the bezel120where the display is situated.

FIG. 2illustrates a side section view of a portion of the mobile computing device100close to an edge113of the cover glass110. In this example, no practical room (i.e., space, volume, etc.) exists for a supporting feature (i.e., ledge, shelf) in the bezel120to support the cover glass110at an edge113. Instead, the cover glass110is affixed at its back surface112(i.e., opposite to a front surface111) to the bezel120through a bonded stack that includes a display module210and a film200. The film has properties that allow it to be folded (i.e., flexible), to seal against liquids and dust/debris (i.e., impervious), and to be viewed through (i.e., transparent).

A first portion (i.e., central portion)270of the film200is positioned between a front surface250of the display module210and the back surface112of the cover glass110. A second portion (i.e., edge portion)280of the film200is folded (i.e., wrapped) around a side surface (i.e., side)230of the display module and into a position that is flush with (i.e., along the surface of) at least a portion of a back surface245of the display module210.

The display module210includes layers240. The layers may include layers for a particular function and layers for support and/or mechanical connection. The edge portion280of the film200covers the side230of the display module210so that the layers240are not exposed to liquids and/or contaminants. In other words, the edge portion280of the film200forms a barrier that is impermeable to the liquids and/or contaminants. Without the covering (i.e., seal, barrier, etc.) provided by the edge portion280, liquids or contaminants (e.g., dust, debris, food particles, etc.) could pass through a gap220defined between the cover glass110and the bezel120and affect the electrical operation of one or more of the layers240of the display module210or affect the mechanical integrity (e.g., bonding) of one or more of the layers240of the display module210. Additionally, when the film is affixed to the front surface250and the back surface245of the display module210, the layers240may experience a compressive stress260(e.g., in an area adjacent to a side230) that prevents the layers240from delaminating (e.g., as a result of an impact). In other words, when the display module has suffered a peel force, the film can provide a compressive stress by the side area of material elongation to avoid delamination.

The side section view ofFIG. 2may be any portion of the mobile computing device100close to an edge113of the cover glass10. In other words, the side surface230of the display module210shown inFIG. 2could be any side surface (e.g., a top side surface, a bottom side surface, a left side surface, a right side surface) of the display module.

A front view of the film200as it appears before it is folded is shown inFIG. 3. The central portion of the film270is aligned with the display. Accordingly, the central portion270has a height310and a width315that correspond to the display area of display module210. Additionally, the central portion270is transparent so the display may be viewed through the film200. The edge portion280of the film200surrounds the central portion270and extends, by a width320, to the edges of the film. The width320of the edge portion280may correspond to a height of the side surface230of the display module210(i.e., dimension between front surface250and back surface245). The width320of the edge portion280may also correspond to the portion of the film that is positioned flush with the back surface245of the display. For example, the width320may be selected to cover an edge230of the display module210and to provide a bonding area between the back surface245of the display module and the bezel. The bonding area can affect the strength of the bond and can affect the compressive stress260(i.e., the force per unit area) resulting from the bond. In some embodiments, the edge portion280is colored opaque to prevent light from the edge230of the display module210from being transmitted into view of a user of the mobile device. For example, the edge portion280may be inked (or painted) black to block light from a side230of the display module210so that it does not propagate (i.e., escape, leak) through the cover glass110and/or through the gap220.

The film is typically shaped (e.g., cut) to facilitate folding multiple (e.g., four) edge portions around corresponding side surfaces of the display module210.FIG. 4Aillustrates a front view of a film200with four edge portions. The four edge portions may include a top edge portion401A (e.g., to correspond with a top side surface of a display module); a bottom edge portion401B (e.g., to correspond with a bottom side surface of a display module); a left edge portion401C (e.g., to correspond with a left side surface of a display module); and a right edge portion401D (e.g., to corresponds with a right side surface of a display module). The edge portions401A,401B,401C,401D may be opaque and as shown, each edge portion may have a trapezoidal shape. The trapezoidal edge portions can be arranged so that one of the edges of each trapezoidal edge portion defines an edge of the central portion470of the film400. When shaped and arranged this way, the edge portions401A,401B,401C,401D may be folded without any overlap.

FIG. 4Bgraphically illustrates possible steps for folding the film ofFIG. 4A. While not shown, the display module may be aligned with the central portion prior to the steps of folding. In a first step411of folding, the left edge portion401C and the right edge portion401D of the unfolded film400may be folded towards the central portion470to form a partially folded film410. In a second step of folding412, the top edge portion401A and a bottom edge portion401B may be folded towards the central portion to form a folded film420. No edge portions in the folded film420overlap.

An aspect of the present disclosure is folding the film without overlap. Preventing overlap may be advantageous by providing a substantially flat surface for bonding the display module to the bezel. In general, the present disclosure embraces all film shapes, modifications (e.g., cuts), and/folding steps that prevent or mitigate edge portion overlap while providing cover and mechanical support to the display module. Accordingly, the present disclosure is not limited to the particular shape and folding process shown as examples inFIGS. 4A and 4B.

The folded edge portions may be held to the front surface250and the back surface245of the display module210in various ways.FIG. 5illustrates a side section view of the film along the A-A′ cut plane indicated inFIG. 4A. The film400includes a transparent central portion470and a left edge portion401C and a right edge portion401D that are colored by ink450to be opaque. The film may be a thin (e.g., in the range of 0.03-0.1 millimeters (mm)) sheet of a polymer such as, but not limited to, polyethylene terephthalate (PET) or colorless polyimide (CPI).

For attachment (e.g., bonding) to a front surface250of the display module210, a layer of optically clear adhesive (OCA)440may be applied to at least a portion of the central portion470of the film470. The OCA may include a film (e.g., tape) or liquid type of adhesive. For example, a double-sided OCA tape may be applied to the central portion of the film400.

For attachment (e.g., bonding) to a back surface245of the display module210, an adhesive film430may be applied to at least a portion of the edge portions (i.e., the left and right edge portions as shown in this view) of the film. For example, a double sided tape430may applied to the edge portions. The tape need not be transparent because the edge portions of the film are attached (i.e., affixed) to the back surface245of the display module210.

The principles described thus far may be embodied variously in a mobile computing device (e.g., laptop, tablet, smartphone). A detailed view of a first possible embodiment is shown inFIG. 6.FIG. 6illustrates a side section view of a portion of a mobile computing device600. The mobile computing device includes a cover glass601, a bezel610, and a display module.

The display module includes a touch sensor that includes a first touch-sensor layer640and a second touch-sensor layer635. The display module also includes an organic light emitting diode (OLED) display that includes a first (i.e., back) OLED layer655, a second (i.e., front) OLED layer650, and a polarizer645. The back OLED layer655is a substrate (e.g., polyimide substrate) onto which the active OLED elements, the controlling electronics (e.g., thin film transistors (TFT)) and traces are disposed. The front OLED layer650covers the active OLED elements (i.e., film OLED) to protect (i.e., isolate) them from oxygen and moisture. A sponge layer660(e.g., double-sided tape) and a layer of copper foil665provide covering for a portion of the second OLED layer of the display module. The sponge layer provides protection for the film OLED and absorbs mechanical stress.

The mobile computing device600also includes a film. A central portion of the film625is attached between the second touch-sensor layer635and the cover glass601using two layers of OCA620,630. The edge portion670of the film is folded around the side surfaces of the display module and affixed to the first OLED layer655. As shown, the edge portion670is colored opaque to block light. The cover glass, the film, and the layers of the display module are attached to the bezel610using a layer of adhesive615(e.g., double sided tape).

In another possible embodiment, an existing layer of the display module may be modified to function as the film. This approach may simplify fabrication and reduce size of the resulting assembly by eliminating the single purpose film. A detailed view of this embodiment is shown inFIG. 7.FIG. 7illustrates a side section view of a portion of a mobile computing device700. The mobile computing device includes a bezel710, a cover glass701, and layers of a display module affixed there between. The layers of the display module are laminated together. The layers include a font touch sensor layer725and a back touch sensor layer730. The layers also include a polarizer735and two layers for an OLED display (i.e., a front layer of the OLED display740, a back layer of the OLED display745). The layers also include a sponge layer750(e.g., double sided tape) and a layer of copper foil760. The cover glass is affixed to the layers using a layer of OCA720. The cover glass701and layers are affixed to the bezel710using a layer of adhesive715(e.g., double-sided tape). A portion770of the front touch sensor layer725is folded around the sides of the layers and attached to the back layer of the OLED display745on one side and attached to the layer of adhesive715on the opposite side.

FIG. 8is a flow chart of a method for fabricating a display. The method800includes attaching810(e.g., using OCA) a film to a front surface of an OLED display module so that edge portions of the film extend past side surfaces of the OLED display module. Next, an adhesive film is affixed820to the edge portions of the film. The edge portions of the film are folded830around the side surfaces of the OLED display module and flush (i.e., in line with and contiguous with) with a back surface of the OLED display module. The folded edge portions are then bonded840to the back surface of the OLED display module so that the side surfaces of the OLED display module are covered by the film.

The display fabricated using the disclosed method may be affixed between a cover glass and a bezel to become part of a mobile computing device. In a possible embodiment, the film serves a single purpose (e.g., a covering for the sides of the display module) is added to a display module after the display module is fabricated (e.g., laminated). In another possible embodiment the film is a layer of the display module that serves a dual purpose and is added to the display module during its fabrication. For example, a layer of the touch sensor can be enlarged to serve as both a part of the touch sensor for the display and to serve as a side covering when the display is integrated with (i.e., assembly into) the mobile computing device.

Computing device900includes a processor902, memory904, a storage device906, a high-speed interface908connecting to memory904and high-speed expansion ports910, and a low speed interface912connecting to low speed bus914and storage device906. The processor902can be a semiconductor-based processor. The memory904can be a semiconductor-based memory. Each of the components902,904,906,908,910, and912, are interconnected using various busses, and may be mounted on a common motherboard or in other manners as appropriate. The processor902can process instructions for execution within the computing device900, including instructions stored in the memory904or on the storage device906to display graphical information for a GUI on an external input/output device, such as display916coupled to high speed interface908. In other implementations, multiple processors and/or multiple buses may be used, as appropriate, along with multiple memories and types of memory. Also, multiple computing devices900may be connected, with each device providing portions of the necessary operations (e.g., as a server bank, a group of blade servers, or a multi-processor system).

The memory904stores information within the computing device900. In one implementation, the memory904is a volatile memory unit or units. In another implementation, the memory904is a non-volatile memory unit or units. The memory904may also be another form of computer-readable medium, such as a magnetic or optical disk.

The high speed controller908manages bandwidth-intensive operations for the computing device900, while the low speed controller912manages lower bandwidth-intensive operations. Such allocation of functions is exemplary only. In one implementation, the high-speed controller908is coupled to memory904, display916(e.g., through a graphics processor or accelerator), and to high-speed expansion ports910, which may accept various expansion cards (not shown). In the implementation, low-speed controller912is coupled to storage device906and low-speed expansion port914. The low-speed expansion port, which may include various communication ports (e.g., USB, Bluetooth, Ethernet, wireless Ethernet) may be coupled to one or more input/output devices, such as a keyboard, a pointing device, a scanner, or a networking device such as a switch or router, e.g., through a network adapter.

The computing device900may be implemented in a number of different forms, as shown in the figure. For example, it may be implemented as a standard server920, or multiple times in a group of such servers. It may also be implemented as part of a rack server system924. In addition, it may be implemented in a personal computer such as a laptop computer922. Alternatively, components from computing device900may be combined with other components in a mobile device (not shown), such as device950. Each of such devices may contain one or more of computing device900,950, and an entire system may be made up of multiple computing devices900,950communicating with each other.

Computing device950includes a processor952, memory964, an input/output device such as a display954, a communication interface966, and a transceiver968, among other components. The device950may also be provided with a storage device, such as a microdrive or other device, to provide additional storage. Each of the components950,952,964,954,966, and968, are interconnected using various buses, and several of the components may be mounted on a common motherboard or in other manners as appropriate.

The processor952can execute instructions within the computing device950, including instructions stored in the memory964. The processor may be implemented as a chipset of chips that include separate and multiple analog and digital processors. The processor may provide, for example, for coordination of the other components of the device950, such as control of user interfaces, applications run by device950, and wireless communication by device950.

Processor952may communicate with a user through control interface958and display interface956coupled to a display954. The display954may be, for example, a TFT LCD (Thin-Film-Transistor Liquid Crystal Display) or an OLED (Organic Light Emitting Diode) display, or other appropriate display technology. The display interface956may comprise appropriate circuitry for driving the display954to present graphical and other information to a user. The control interface958may receive commands from a user and convert them for submission to the processor952. In addition, an external interface962may be provided in communication with processor952, so as to enable near area communication of device950with other devices. External interface962may provide, for example, for wired communication in some implementations, or for wireless communication in other implementations, and multiple interfaces may also be used.

The memory964stores information within the computing device950. The memory964can be implemented as one or more of a computer-readable medium or media, a volatile memory unit or units, or a non-volatile memory unit or units. Expansion memory974may also be provided and connected to device950through expansion interface972, which may include, for example, a SIMM (Single In Line Memory Module) card interface. Such expansion memory974may provide extra storage space for device950, or may also store applications or other information for device950. Specifically, expansion memory974may include instructions to carry out or supplement the processes described above, and may include secure information also. Thus, for example, expansion memory974may be provided as a security module for device950, and may be programmed with instructions that permit secure use of device950. In addition, secure applications may be provided via the SIMM cards, along with additional information, such as placing identifying information on the SIMM card in a non-hackable manner.

The computing device950may be implemented in a number of different forms, as shown in the figure. For example, it may be implemented as a cellular telephone980. It may also be implemented as part of a smart phone982, personal digital assistant, or other similar mobile device.