Patent Description:
<CIT> describes a foldable display apparatus for minimizing stress applied to a bending area of a display panel. The foldable display apparatus can include a display panel configured to include a display area which includes a first display area, a second display area, and a bending area which is defined between the first and second display areas, a housing configured to include a first housing member, which supports a first area of the display panel corresponding to the first display area, and a second housing member which supports a second area of the display panel corresponding to the second display area, and a hinge part connected between the first and second housing members, and configured to enable the display panel to be folded or unfolded with respect to the bending area.

Aspects of the present invention are defined in the accompanying claims.

The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements or delineate the scope of the specification. Its sole purpose is to present a selection of concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later.

A device and methods are presented. The electronic device comprises a body and a flexible display stack. The display stack and the body are in a movable connection via fastening areas and fastening components. In aspects, the fastening areas and components include magnets. The methods disclosed relate to the way the display stack is fixed to the body, via magnets brought in proximity to each other and via studs locking into grooves.

The detailed description provided below in connection with the appended drawings is intended as a description of the present aspects and is not intended to represent the only forms in which the present invention may be constructed or utilized. However, the same or equivalent functions and sequences may be accomplished by different aspects.

The aspects described below are not limited to implementations which solve any or all of the disadvantages of known devices and covers. Although the present examples are described and illustrated herein as being implemented with a stack of few layers connected to a body, the devices described are provided as an example and not a limitation. As those skilled in the art will appreciate, the presented aspects are suitable for application in a variety of bendable devices comprising multiple stacks of layers, and the individual elements can be a schematic representation of various parts of a device, such as a display or a touch screen. These parts may comprise a plurality of different layers and other elements in between the body and the display stack.

In bendable or flexible electronic devices, such as FOLED (Flexible Organic Light Emitting Diode) devices, the display part of the device has to be attached to the main body in a way that does not prevent or resist bending of the device.

<FIG> is a schematic illustration of a bendable device <NUM> which comprises a display stack <NUM> and a body <NUM>. The device <NUM> may be, but is not limited to, a bendable electronic device, a bendable handheld electronic device or a foldable electronic device. Structural features of devices according to aspects are described in more detail with reference to <FIG>; and the side view of <FIG> serves to illustrate the mechanism of relative movement that occurs when the device <NUM> is bent. When a device <NUM> is bent or folded, and the display stack <NUM> is movably fixed to the body <NUM>, movement of the display stack <NUM> occurs relative to the body <NUM> similar to relative movement of pages of a stack of papers when bent. This movement occurs due to different neutral axes for the stack <NUM> and body <NUM>. A neutral axis of bending is the axis where no compression or extension occurs, and it is usually lies inside the structure that is being bent. Unless the stack <NUM> and the body <NUM> are in a rigid connection along the whole surface, they bend as two individual structures. The first neutral axis <NUM> of the flexible display stack normally lies above the second neutral axis <NUM> of the body <NUM>, which leads to their relative movement. This relative movement is present in aspects described below which provide a movable connection between at least parts of the display stack <NUM> and the body <NUM>. The approximate neutral axis <NUM> and possible bending direction are shown in <FIG> by dashed lines and arrows.

<FIG> shows a bendable device <NUM> according to an aspect. The device <NUM> may be, but is not limited to, a bendable electronic device, a bendable handheld electronic device or a foldable electronic device. This Figure is a side cross-section view of the device <NUM>. The device <NUM> comprises a display stack <NUM> which comprises at least one active layer <NUM> and a supporting layer <NUM> on the bottom. The display stack <NUM> may also comprise a window layer <NUM> on the top. This provides protection of the other layers and the internal parts of the device <NUM>. The supporting layer <NUM> may comprise stainless steel or other metal. The supporting layer <NUM> also has a bending region and comprise rigid material, as discussed in more detail below.

The device <NUM> further comprises and a body portion <NUM> with a bending region <NUM>. The bending region <NUM> may be an extendable hinge, a hinge with rotating elements or any other hinge. A particular type of hinge may be appropriate for the desired type of bending of the device <NUM>. Alternatively, the bending region <NUM> may be an elastic component, for example a rubber component. The bending region <NUM> may have any width or shape. In an aspect, the region <NUM> may span across the body <NUM> of the device <NUM>. The body <NUM> may also comprise more than one extendable region <NUM>, for example if the device <NUM> is bendable about more than one axis.

The supporting layer <NUM> comprises one or more fastening areas <NUM>, and the body <NUM> comprises one or more fastening components <NUM>. The fastening components <NUM> are configured to be operable in a movable connection with the fastening areas <NUM>. They are shown on <FIG> only schematically and may have any appropriate shape, size and properties to provide a movable connection. The term "movable connection" herein refers to a connection which allows free movement of connected elements in at least one direction within a limited range.

The above aspects can provide a technical effect of easy bending due to movable connection points, while preventing detachment of the display stack at any point during bending.

In an aspect, the device <NUM> is bendable about at least one axis in the bending region <NUM>. This axis can be, for example, the axis of a hinge. At least one of the fastening components <NUM> and at least one of the fastening areas <NUM> are positioned within <NUM> centimeters from the bending region <NUM> and opposite to each other. Since the display stack <NUM> can be likely to detach near the bending region <NUM>, this aspect can have an effect of reliable fastening the stack <NUM> near the bending region <NUM>. In an aspect, the body <NUM> and the stack <NUM> are bendable more than <NUM> degrees. This provides substantially a foldable device.

The body <NUM> may optionally comprise a casing <NUM>, as shown in <FIG>. The casing <NUM> comprises the bending region <NUM> of the body <NUM> and enclose the body <NUM> and the display stack <NUM> at least from the bottom and two opposite sides. The casing <NUM> may also include a frame which encloses at least two edges of the stack <NUM>. The frame is not shown on the figure but could be, for example, a stripe on the top parts of the casing <NUM> covering its edges and extending slightly over the window layer <NUM>. This can prevent the stack <NUM> from moving vertically. In an aspect, the casing and the frame comprise metal and/or plastic.

The terms 'top' and 'bottom' are used for clarity and relate to the positioning on the figures only. The bottom supporting layer <NUM> may be positioned on any geometric side of the device <NUM>.

Active layers <NUM> of the display stack <NUM> may comprise an active display layer and an active touch sensing layer, for example if the device <NUM> is a bendable touch screen device. One of the layers of the display stack <NUM> may also be a polarizing layer, for example if the display stack is an LCD (Liquid Crystal Display) stack. In an aspect, layers of the display stack <NUM> are fixed to each other and to the window layer <NUM> by an optically clear adhesive, such as LOCA (liquid optically clear adhesive). Layers of the display stack <NUM> are thereby laminated to each other with a transparent adhesive. On <FIG>, the adhesive is schematically illustrated as a dotted filling between layers of the stack <NUM>.

The term 'bendable' used herein includes both a bending radius that is large with respect to the display thickness and also small with respect to the display thickness. For example, bendable displays include displays that are <NUM> thin and may operate in a bent form in which the bend radius is <NUM> or less than <NUM>. In the latter bend radius of less than <NUM>, the display may be described as foldable, similar to a folded sheet of paper. Furthermore, 'bendable' refers to dynamic bending, and includes both elastic and inelastic plasticity. Aspects of the device <NUM> can apply to display devices as well as any other devices which include displays. The display may be, for example, a flexible organic light emitting diode (OLED) display, an LCD or an electronic paper display.

The body <NUM> of the device <NUM> may comprise other elements required for operation of the device <NUM>. For example, if the device <NUM> is an electronic device, the body <NUM> of the device may comprise elements such as a controller, a processing unit, and a memory.

According to an aspect, the display stack <NUM> has an electric connection with the body <NUM>. The electric connection can be implemented as a flexible connector, for example via a flexible printed circuit (FPC), to the hardware of the device <NUM> located in the body <NUM>. The connection can be implemented inside the device <NUM> and made with one of the active layers <NUM> of the display stack <NUM>. The body <NUM> may have an opening which allows the flexible connector to extend through the opening into the space between the display stack <NUM> and the body <NUM>, and move without damage or loss of connection inside that space when the device <NUM> is bent.

In an aspect, thickness of the display stack may be between <NUM> and <NUM> millimeters.

<FIG> illustrate an aspect wherein the movable connection in the device <NUM> is implemented using studs and grooves which relates to non-claimed combinations of features which are nevertheless relevant to highlight specific aspects of the invention. According to the aspect, at least one fastening area <NUM> of the supporting layer <NUM> comprises a stud <NUM>, and at least one fastening component <NUM> of the body <NUM> comprises a groove <NUM> shaped to be operable in a movable connection with at least one of the studs <NUM>. <FIG> is an angled view of the unattached supporting layer <NUM> with a stud <NUM> schematically taking place of the fastening area <NUM> according to an aspect. <FIG> shows a side view of the same, wherein the stud is welded <NUM> to the supporting layer <NUM>. The stud <NUM> can be made of stainless steel, which in combination with the supporting layer <NUM> comprising stainless steel provides a possibility to use welding. The stud <NUM> can also be made of any other suitable material, such as metal or plastic. <FIG> shows the stud <NUM> which is configured to be inserted into a groove <NUM> on the body <NUM>. In an aspect, the groove <NUM> is shaped as a keyhole to provide a movable connection with the stud <NUM>. The groove <NUM> may provide a slightly larger space than the radius of the stud <NUM>, allowing the stud <NUM> slight movement in all horizontal directions.

As it is clear to a skilled person, the fastening areas <NUM> comprising studs <NUM> and fastening components <NUM> comprising grooves <NUM> may also comprise other fastening elements.

In an aspect, at least one fastening area <NUM> of the supporting layer <NUM> comprises a magnetic element, and at least one fastening component of the body <NUM> comprises a magnetic element configured to be operable in a movable connection with at least one magnetic element of the supporting layer. The magnetic elements may be areas of magnetic material on the supporting layer <NUM>. In an aspect, the supporting layer <NUM> comprises magnetic material at least in the fastening areas <NUM>. The supporting layer <NUM> may also be made of magnetic material. This allows using a thin supporting layer <NUM>. In aspects presented below referring to <FIG>, the magnetic elements are shown separate from the supporting layer <NUM> for clarity purposes only. As it is clear to a skilled person, similar implementations are possible wherein the supporting layer <NUM> comprises magnetic areas which do not extend outside the layer.

<FIG> illustrate various aspects with magnetic elements mentioned above. These figures are side views of the supporting layer <NUM> on the bottom of the display stack <NUM>. The magnetic elements may comprise neodymium or other rare earth materials, which can provide strong attraction enabling use of small magnets which can be inserted locally. According to an aspect, the magnetic elements comprise soft rubber and have a prolonged shape. The soft rubber comprising magnetic material can be used on areas of bending.

<FIG> shows a magnetic element <NUM> as part of the fastening area of the supporting layer <NUM>. On this figure, the magnetic element <NUM> is shaped as a stripe and may comprise a Halbach array. In an aspect, the thickness of the magnetic element <NUM> is between <NUM> millimeters and <NUM> millimeter. The magnetic field lines are illustrated by dashed lines on the figures. <FIG> shows a magnetic element <NUM> as part of the fastening area of the supporting layer <NUM>. The stripe <NUM> may comprise soft rubber and magnetic material. The soft rubber provides increased flexibility and reduced brittleness when the stripe <NUM> is bent.

<FIG> shows alternative aspects of magnetic elements <NUM> as part of the fastening area <NUM> of the supporting layer <NUM>. The elements <NUM> in this aspect can be smaller and have, for example, a round shape. The supporting layer <NUM> on the left part of <FIG> comprises a magnetic core. The magnetic core can comprise soft iron or other suitable materials. The magnetic core can serve to confine the magnetic field and prevent undesired exposure of parts of the device <NUM>, as well as external objects such as credit cards, to said field. The magnetic core element <NUM> can also be attached to the magnet <NUM> itself, along with an additional magnetic core element <NUM>, as show on the right side of <FIG>. When the magnetic field is limited by the magnetic core <NUM>, <NUM>, attraction force can increase since the magnetic field is concentrated into the soft iron. Increased force can allow using smaller magnets and thereby saving space and weight. It is clear to a skilled person that the structure is not limited by what it presented on the drawings and in particular the aspects shown on <FIG> are presented together for illustrative purposes only. Any combination of magnetic elements and magnetic cores can be used.

In an aspect, magnetic elements <NUM> are magnets. Magnets can have a strong enough attraction force to keep the display stack <NUM> attached to the body <NUM>, yet maintain flexibility on the joint and a movable connection.

According to an aspect, the supporting layer <NUM> of the display stack <NUM> may comprise a bending region itself, as illustrated on <FIG>. This figure is an angled view of a display stack <NUM> wherein the active layers together with a window layer <NUM> are separated from the supporting layer <NUM>, and a hinge is exposed on the supporting layer <NUM>.

<FIG> illustrates an aspect with a possible distribution of fastening components <NUM> on the body <NUM>, and the fastening areas on the supporting layer <NUM> (flipped over in relation to the orientation or the body <NUM> for demonstration purposes). This distribution can be used with studs and magnets.

<FIG> shows two aspects with distributions of magnetic elements <NUM>, <NUM> across the body <NUM>. This illustrates that the shape, size and positioning of the magnets <NUM> can vary and be tailored to a particular bending device. The circular holes in a magnetic shield <NUM> can provide reduced weight of the body <NUM>.

In an aspect, the fastening areas <NUM> and fastening components <NUM> comprise gel configured to provide a movable connection. In an aspect, the display stack <NUM> is movably fixed to the body <NUM> with combination of the above aspects. The display stack <NUM> may also be partially fixed to the body <NUM> by an adhesive, providing a movable connection only in certain areas of the device <NUM>. The adhesive may be used, for example, to connect the display stack <NUM> to the bending region <NUM> of the body <NUM>, since the relative movement may not occur around the bending region <NUM>.

The device <NUM> according to any of the above aspects may be implemented as a portable electronic device, for example a mobile phone, smart watch, tablet or laptop.

The above aspects can provide a movable connection of the display stack to the body of an electronic device. This can have a technical effect on its repeatable foldability without buckling or other physical deformations of the display stack. A further effect can be that the device can be resistant to fall damage due to the "floating" connection which can absorb shock. The resulting device can also be easy to disassemble e.g. for maintenance.

Devices according to any of the above aspects can be used in flexible electronic devices such as mobile phones, tablets, foldable laptop computers, e-readers and other devices. The devices may be embedded in or attached to a bendable or foldable electronic system.

<FIG> illustrates a method for assembling a bendable electronic device according to an aspect. The bendable electronic device may be a bendable display device. The method comprises providing <NUM> a display stack which comprises a supporting layer on the bottom, wherein the supporting layer comprising one or more studs. A body which comprises a bending region and keyhole-shaped grooves is then provided at <NUM>. The method further comprises movably fixing <NUM> the display stack to the body by inserting the studs into the grooves.

<FIG> illustrates a method for assembling a bendable electronic device according to an aspect. The bendable electronic device may be a bendable display device. The method comprises providing <NUM> a display stack which comprises a supporting layer on the bottom, wherein the supporting layer comprising one or more magnetic areas. A body which comprises a bending region and magnetic elements is then provided at <NUM>. The method further comprises movably fixing <NUM> the display stack to the body by bringing the magnetic elements into proximity or physical contact with the magnetic areas. The magnetic areas comprise separate magnetic elements rigidly attached to the supporting layer.

The methods described above may have an effect of simplified assembly wherein adhesives are not necessary. A further effect is the ease of maintenance, due to the movable connection being more easily removed and then restored; for devices assembled according to the above methods.

The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate.

The methods described herein may be performed by software in machine readable form on a tangible storage medium e.g. in the form of a computer program comprising computer program code means adapted to perform all the steps of any of the media include computer storage devices comprising computer-readable media such as disks, thumb drives, memory etc. and do not include propagated signals. Propagated signals may be present in a tangible storage media, but propagated signals per se are not examples of tangible storage media. The software can be suitable for execution on a parallel processor or a serial processor such that the method steps may be carried out in any suitable order, or simultaneously.

It will be understood that the technical effects described above may relate to one aspect or may relate to several aspects. The aspects are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages.

The term 'comprising' is used herein to mean including the method blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or device may contain additional blocks or elements.

Claim 1:
An electronic device (<NUM>) comprising:
a body (<NUM>) comprising a first bending region (<NUM>)
a flexible display stack (<NUM>) comprising at least one active layer (<NUM>) and a rigid supporting layer (<NUM>);
wherein the rigid supporting layer (<NUM>) is positioned on the bottom of the flexible display stack (<NUM>);
wherein the rigid supporting layer (<NUM>) of the flexible display stack (<NUM>) includes a second bendable region of the supporting layer itself, and one or more fastening areas (<NUM>) on either side and separated from the second bendable region, wherein the second bendable region is different from the first bendable region; and
the body (<NUM>) includes one or more fastening components (<NUM>) operable in a movable connection with respective fastening areas of the rigid supporting layer of the flexible display stack to form a movable connection between the body and the rigid supporting layer;
characterised in that:
the one or more fastening areas (<NUM>) comprise one or more first magnetic elements and the one or more fastening components (<NUM>) comprise one or more second magnetic elements for cooperation with the one or more first magnetic elements and
wherein the rigid supporting layer (<NUM>) comprises a magnetic core (<NUM>) between the magnetic elements and other layers of the flexible display stack (<NUM>).