Flexible display device for user equipment

Abstract

In some examples, the present disclosure provides a flexible display device for a user device, wherein the display device comprises a deformable display surface and an actuation structure for deforming the deformable surface, the actuation structure comprising: an actuation layer comprising a plurality of individually addressable conductive actuators, each of the plurality of individually addressable conductive actuators configured to deform a selected portion of the display surface in a first direction; a biasing layer comprising a plurality of elastic biasing portions, each of the plurality of elastic biasing portions configured to correspond to an actuator of the actuation layer and to accompany deformation of the deformable surface at the selected portion, each of the elastic biasing portions configured to urge the corresponding actuator of the actuation layer in a second direction opposite to the first direction. The actuation layer is disposed between the deformable display surface and the biasing layer.

Description

TECHNICAL FIELD

[0001] Aspects of the present invention relate generally to a flexible display surface, and more particularly but not exclusively to a deformable flexible display surface for use in mobile devices such as smart devices. BACKGROUND

[0002] Electronic devices such as cellular telephones, media players, and computers are often equipped with displays. Some electronic devices can employ flexible display technology that allows the display to be bent. For example, a flexible display can be formed using flexible organic light-emitting diode (OLED) display technology that enables the display screen to be folded or rolled about an axis. For example, a display can be folded from a closed configuration to an open configuration for a user device. In the open configuration, the user device can assume the form factor of a tablet device, while in the closed configuration, the user device can assume the form factor of a mobile device such as a mobile phone.

[0003] Interaction between a device and a person is enabled by an interface that allows a user to control the device. In the context of a device having a display, such a user interface can take the form of a graphical user interface that enables a user to interact with the device through information presented to the user on the display. The presented information can take a variety of different forms, from simple textual indications to complex three-dimensional graphical renderings for games, and the like.

[0004] While displays can be used to fold or bend, and some displays even to present information to a user in a curved form (e.g., a curved display or television display), the display forms a generally flat, uniform, or smooth surface. Thus, the information presented to the user is adapted for display on such a uniform surface, and in the case of a device having a touch display or the like, any user input that is directly input using the display reflects the fact that the surface is smooth. SUMMARY

[0005] According to a first aspect, there is provided a flexible display device for a user equipment, the display device comprising a deformable display surface and an actuation structure for deforming the deformable surface, the actuation structure comprising: an actuation layer comprising a plurality of individually addressable electrically conductive actuators, each of the plurality of individually addressable electrically conductive actuators being arranged to deform a selected portion of the display surface in a first direction; a biasing layer comprising a plurality of elastic biasing portions, each of the plurality of elastic biasing portions being arranged to correspond to an actuator of the actuation layer and to urge the corresponding actuator of the actuation layer in a second direction opposite to the first direction in conjunction with a deformation of the deformable surface at the selected portion; wherein the actuation layer is arranged between the deformable display surface and the biasing layer.

[0006] Each actuator is addressable to deform a selected portion of the display surface, and the corresponding biasing portion urges the actuator back to its initial position, which corresponds to a state in which the selected portion of the display surface is not deformed. The structure can be used in mobile devices that require a thin, low-cost structure that does not interfere with the touch functionality of the device. The actuation layer and the biasing layer do not require complex electronic components and are therefore easy to manufacture. In other words, the elastic biasing portions of the biasing layer can for example be formed by spring-type elements made of an elastic material sheet.

[0007] Each of the individually addressable electrically conductive actuators can comprise a curved arm, which is electrically connected to a feed layer for providing an electric current, wherein the feed layer is arranged between the actuation layer and the biasing layer.

[0008] In other words, the actuators can comprise geometrically curved arms. This shape causes heating due to the electrical resistance effect when an electric current is applied. As a result, the arms can twist and turn, but are (electrically) continuous, for example forming a zigzag shape. The advantages of the geometric shape are manifold: the arms take up less space, and the shape can ensure a faster response compared to the case of straight arms. The arms can have a variety of different shapes and configurations. However, a zigzag / snake / curved shape provides a larger material length for the arm (e.g. compared to a straight arm). Since the material actuation can be based on a contraction (i.e. a change in length when heated), a longer material shape results in a larger shear displacement with respect to the static biasing layer. This results in a larger bending motion of the arm tip. Thus, a relatively small arm can result in a deformation of a selected portion of the display surface in the order of 1 mm - 5 mm, for example in the order of 2 mm - 5 mm.

[0009] In one implementation, each of the arms can further comprise a mechanical connection to the display surface. For example, such a mechanical connection can be a glue dot that fixedly connects an end portion of an arm to a selected portion of the display surface. Fixing the end of an arm to the display surface can maximize the amount of deformation of the display surface for a given deflection of the arm. Each of the actuators is configured to deform upon application of an electrical current and / or thermal energy. In one example, application of an electrical signal causes resistive heating in the arm, thereby increasing the temperature of the material from which the arm is made, which in turn causes deformation by contraction of the material, etc. In another example, the arm can be heated indirectly by a heat source.

[0010] The actuation layer can be formed of a shape memory alloy or a polymer material. The biasing layer can be formed of a metallic material. Alternatively, the biasing layer can be formed of a shape memory alloy or a polymer material. In one implementation, the actuators are regularly distributed in an array over a region of the actuation layer corresponding to a region of the deformable display surface.

[0011] The display can be deformed to mimic behavior, for example to make keys of a keyboard protrude. Thus, in order to be able to provide such functionality, regularity of the actuators is advantageous. Of course, irregular distribution of actuators can also be provided.

[0012] The actuation layer and the biasing layer can be mechanically connected. For example, the layers can be fixed by glue dots or other mechanical fixings (e.g. rivets).

[0013] According to one example, each of the plurality of individually addressable electrically conductive actuators can comprise a magnetic portion. The magnetic portion of the actuator can be arranged to interact with a static sensor.

[0014] In other words, the magnetic portion can comprise a magnet arranged on a magnetized region of an arm forming the actuator or of the arm. The sensor can be arranged in another layer (e.g. a feed layer) such that the sensor is static (relative to the magnetic portion). Thus, movement of the arm can be sensed by the interaction between the magnetic portion and the sensor (which can be a Hall effect sensor, for example). This can detect, for example, the force or speed with which a deformed portion of the display is pressed. This provides a variety of applications in the field of gaming as well as in the field of simulating keypads and keyboards, etc.

[0015] According to a second aspect, there is provided a method for deforming a selected portion of a touch display of a user device, the method comprising: applying a current to a first actuator disposed at a first location in an actuation layer of a display apparatus of the user device to induce resistive heating of the first actuator, thereby deforming the selected portion of the touch display in a first direction; removing the current to ensure that an elastic biasing element at the first location is able to return the selected portion of the touch display to an undeformed state.

[0016] The actuation layer can be made of a shape memory effect alloy or a polymer material for inducing deformation according to a temperature-induced phase transition curve. For example, the material can shrink upon exceeding a threshold temperature, thereby causing the arms made of the material to deform. A second actuator disposed at the first location in the actuation layer can be applied with a current to induce resistive heating of the second actuator, thereby deforming the selected portion of the touch display in a second direction.

[0017] In other words, the actuator can be composed of two layers of smart material that can be configured to deform or bend in opposite directions, depending on the application of a current to one or more of the layers. For example, one layer can be used to shrink upon application of a current, thereby inducing the actuator to deform upwards, while application of a current to the smart material in the other layer (due to removal of the current in the first layer) can cause it to shrink, thereby inducing the actuator to deform downwards. Thus, response times can be shortened (e.g. for cases where a torsional deformation is to be imparted), and different degrees of deformation can be imparted by adjusting the degree of resistive heating in the layers, thereby controlling the amount of bending of the layers.

[0018] In one example, the method can further comprise: applying a current to a third actuator disposed at a second location in the actuation layer to induce resistive heating of the third actuator, thereby deforming a second selected portion of the touch display in the first direction; removing the current to ensure that an elastic biasing element at the second location is able to return the second selected portion of the touch display to an undeformed state.

[0019] Advantageously, since the actuators are individually addressable, they can be energized in groups to deform various portions of the display (at the same time or at different times, etc.).

[0020] The method can further comprise generating a measurement representative of a force applied to the selected portion of the touch display when it is in a deformed state. In this way, an analog measurement of the force applied can be determined. This can give rise to a number of different use cases for the deformable display surface described herein.

[0021] According to a third aspect, there is provided a user device comprising a flexible display apparatus as provided herein. The deformable display surface can be a touch surface for receiving user input. In one example, the user device further comprises a processor communicatively coupled to a memory, the processor configured to generate an output signal indicative of a degree of deformation of a selected portion of the display surface. The processor can be further configured to determine an amount of deformation of the selected portion based on a deflection measurement of the selected portion generated by the magnetic induction structure. BRIEF DESCRIPTION OF DRAWINGS

[0022] For a more complete understanding of the present application, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings in which:

[0023] Figure 1 A schematic diagram of a flexible display apparatus according to one example is shown;

[0024] Figure 2 A schematic diagram of a portion of an actuation layer according to one example is shown;

[0025] Figure 3 A schematic diagram of a deformation process of an arm of an actuator according to one example is shown;

[0026] Figure 4 Another schematic diagram of a deformation process of an arm of an actuator according to one example is shown;

[0027] Figure 5 A schematic diagram of a portion of a flexible display apparatus according to one example is shown; Figure 2 A schematic diagram of the underside of the portion shown;

[0028] Figure 6 A schematic diagram of a deformation process of an arm of an actuator according to one example is shown;

[0029] Figure 7 A schematic diagram of a user device according to one example is shown. DETAILED DESCRIPTION

[0030] The exemplary embodiments are described in sufficient detail to enable those skilled in the art to implement and practice the systems and processes described herein. It is to be understood that the examples described herein can be provided by many alternative forms of implementation and that the exemplary embodiments are to not be construed as limited to the examples set forth herein. Thus, while the embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the figures and described in detail herein as examples. It is in no way intended that the application be limited to the specific embodiments described herein. Rather, it is intended to cover any and all alternatives, equivalents, and equivalents modifications following within the scope of the appended claims. In all the drawings, like reference numerals refer to like parts throughout the several views of the drawings, and in which:

[0031] The terminology used herein to describe embodiments is not intended to limit the scope. The articles "a", "an" and "the" are singular in that they have a referent, but the use of the singular herein does not exclude the presence of more than one referent. In other words, unless the context clearly indicates otherwise, an element referred to in the singular can be one or more. It is further to be understood that the term "comprise" as used herein is used to specify the presence of stated features, integers, steps, operations, elements, and / or components but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0032] Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted to have the ordinary meaning as understood by those of ordinary skill in the relevant art. Methods and materials are described herein for use in the experiments described herein and for the production of further examples unless otherwise indicated.

[0033] User devices can include mobile devices such as mobile phones or tablets, etc. Generally, due to size and to the demands placed on their cost and functionality, such devices use components that are low cost, mass producible, reasonably power efficient, electromagnetically friendly, and do not generate audible noise. In the case of flexible displays for such devices, such displays should also allow for some degree of deformation, enabling the flexibility suggested by the device, and can also need to enable touch input and / or haptic feedback. Thus, there are constraints on flexible display devices that hinder modifications that can help improve the user experience.

[0034] According to one example, a flexible display device for a user device is provided. The display device comprises a deformable display surface and an actuation structure for deforming the deformable surface. The actuation structure comprises an actuation layer comprising a plurality of individually addressable conductive actuators. Each of the actuators is arranged to deform a selected portion of the display surface in a first direction. For example, the actuators can be used to deform a selected portion of the flexible display in a direction perpendicular to the plane of the display surface. In one example, a biasing layer is provided, the biasing layer comprising a plurality of elastic biasing portions, each of the plurality of elastic biasing portions being arranged to correspond to an actuator of the actuation layer and for accompanying deformation of the deformable surface at the selected portion. Each of the elastic biasing portions can be used to urge the corresponding actuator of the actuation layer in a second direction opposite to the first direction. For example, the elastic biasing portions can be used to restore the actuators to a state corresponding to no deformation of the selected portion of the display. In other words, in the case where deformation is induced, the actuators and corresponding elastic biasing portions can be in a first state. In the case where no deformation is induced, the actuators and corresponding elastic biasing portions can be in a second state. In one example, the actuation layer is disposed between the deformable display surface and the biasing layer.

[0035] Figure 1 A schematic diagram of a flexible display device provided in one example is shown. In Figure 1 In one example, a user device 113 in the form of a mobile device / smart device comprises a deformable display surface 101. For example, the deformable display surface 101 can comprise an OLED display. An actuation structure is provided for deforming the deformable display surface 101. The actuation structure comprises an actuation layer 107. The actuation layer 107 comprises a plurality of individually addressable conductive actuators, each of the plurality of individually addressable conductive actuators being arranged to deform a selected portion of the display surface 101 in a first direction (A). In Figure 1In the example, the actuation layer 107 comprises a smart memory alloy (SMA) sheet. The SMA sheet 107 may include alloys such as copper-aluminum-nickel and nickel-titanium (NiTi); alloys of zinc, copper, gold, and iron; or iron-based and copper-based materials such as Fe-Mn-Si, Cu-Zn-Al, and Cu-Al-Ni. The SMA sheet 107 exhibits a memory effect, reversibly changing between various states in the presence of temperature variations. For example, at a first temperature, the SMA material may be in a first state; at a second temperature, the SMA material may be in a second state. The state of the material may correspond to the degree of deformation of the material. Thus, for example, at room temperature (e.g., approximately 21 degrees Celsius), the material may be in a static state, in which no significant deformation occurs. When heated (or cooled, depending on the material) to a threshold temperature, the material may deform into the second state. Returning to the first temperature will cause the material to return to its pre-deformed state.

[0036] Accordingly, in Figure 1 In the context of the illustrated example, each of the plurality of individually addressable conductive actuators of the SMA layer 107 can be used to deform individually in the event of a temperature change. Such deformation of one of the individually addressable conductive actuators may cause a selected portion of the display surface 101 to deform along a first direction (A). For example, heating the actuator to a threshold temperature may cause the actuator to deform along said direction (A), thereby causing a corresponding deformation of a portion of the display surface. Once below the threshold temperature, allowing the actuator to return to its pre-deformed state, the corresponding portion of the display surface will also return to its undeformed (e.g., flat) state. In one example, each of the individually addressable conductive actuators of layer 107 is attached to the display surface using adhesive 103, for example, by adhering each of the actuators to a portion of the display surface in the form of adhesive dots, thereby ensuring that the corresponding actuator can deform the selected portion of the display surface. In other words, each of the actuators is fixedly attached to the display surface such that if the actuator is deformed, the portion of the display surface to which the actuator is attached will also deform.

[0037] exist Figure 1In the example of FIG. 1, a biasing layer 111 is provided. The biasing layer 111 comprises a plurality of elastic biasing portions, each of which is arranged to correspond to an actuator of the actuation layer 107. Accordingly, in the event of an actuator deforming, the corresponding elastic biasing portion deforms. In other words, each elastic biasing portion acts to accompany deformation of the deformable surface of the actuator at a selected portion. Thus, when an actuator is heated to a threshold temperature to deform in the direction (A), the elastic biasing portion corresponding to the actuator deforms with the actuator. Once below the threshold temperature, such that the actuator returns to a pre-deformed state, the corresponding elastic biasing portion acts to push the actuator in a second direction (B) opposite to the first direction, such that the actuator returns to its first pre-deformed state. Although the actuator can return to such a state by itself, the action of the elastic biasing portion means that the return to the first state is faster, which is advantageous in the context of the device 113, where deformation of the display surface 101 can be required to be transient, depending on the use case.

[0038] In Figure 1 In the example of FIG. 1, the actuation layer 107 is disposed between the deformable display surface 101 and the biasing layer 111. A further layer in the form of a flexible printed circuit (FPC) layer 109 providing a feed layer can be disposed between the actuation layer 107 and the biasing layer 111. The FPC layer 109 can comprise a plurality of electrical contacts to the actuation layer 107. In other words, in one example, the FPC layer 109 provides an electrical contact for each actuator in the actuator layer 107. The connections can be provided by metal rivets in the rivet layer 105 having a common ground.

[0039] As will be described in more detail below, the actuation structure and the flexible display can be housed in the body of the mobile device 113, defining an electromechanical stack assembly of thin and easy to manufacture (e.g. using photolithography or chemical etching) sheet elements in terms of detail geometry. The actuation (SMA) sheet layer 107 is disposed under the flexible display 101, which can be coupled to the underside of the display 101 by potting. The FPC sheet layer 109 can comprise electrical connections to the actuator SMA sheet layer 107, such that there is one such connection for each actuator, e.g. the connections are achieved by metal rivets and a common ground for the monolithic sheet. The biasing layer 111 can be electrically isolated from the SMA sheet layer 107 and acts to perform a return motion of the actuators when they are deactivated. In one example, in combination with the biasing layer 111, the FPC layer 109 provides a common ground for the SMA sheet layer 107. Figure 1The layers of the described structure can be connected together by glue or the like. The FPC layer 109 can include a pin interface for external control. In one example, in conjunction with Figure 1 The described structure is housed in a cavity of the main body of the mobile device 113 and, as it can be configured to be about 0.8mm - 1.0mm, it does not significantly affect the form factor of the device.

[0040] Figure 2 A schematic diagram showing a portion of the actuation layer 107 provided in one example is shown. In this example, two actuators 201 of the layer 107 are described in more detail. Multiple such actuators can be provided over the area defined by the actuator layer 107 and each actuator 201 can be individually addressable, thus enabling deformation of a selected portion of the display surface 101. Figure 2

[0041] In one example, the actuators 201 include a glue dot 203 to fixedly connect the actuator 201 to a selected portion of the underside of the display surface 101. A rivet dot 205 enables a rivet or other such conductive element to be used to provide an electrical connection between the actuator 201 and the FPC layer 109. This also provides a fixed mounting point for the actuator 201 to the FPC layer 109. As shown in the example of Figure 2 As shown in the example of, each of the individually addressable conductive actuators 201 includes a curved arm 207 that is electrically connected 205 to the feed layer 109 for providing an electrical current. The electrical current provided to the actuator 201 causes heating of the actuator arm 207 due to the resistive effect when an electrical current is applied. In other words, the actuator includes a geometrically twisted arm 207 whose shape causes heating due to the resistive effect when an electrical current is applied. Thus, the arm 207 can twist and turn but is (electrically) continuous, for example forming a zigzag shape as shown. Figure 2 Advantages of the geometric shape include that the arm 207 occupies less space and the shape can ensure a faster response to applied electrical current compared to, for example, a straight arm. Furthermore, the zigzag / serpentine / curved shape provides a greater length of material for the arm (for example, compared to a straight arm). Thus, where the deformation of the actuator 201 is based on material shrinkage (i.e. a change in length of the arm 207 when heated), the greater length of material shape produces a greater shear displacement with respect to the static bias layer 111, resulting in a greater bending motion of the tip of the arm 207 near the portion 203 to which it is fixed to the display surface. Accordingly, a relatively large deformation of the order of 1mm - 5mm, for example of the order of 2mm - 5mm, can be performed on a selected portion of the display surface. Figure 2 ​The shape of the arm 207 shown is not limiting. For example, the arm can be a straight arm, or can include some other zigzag, serpentine, or curved shape, or a combination thereof.

[0042] According to one example, during activation, a specific actuator 201 or actuators are powered by a voltage applied via the appropriate FPC external pin 205 routed to the actuator layer 107. In the case of a single actuator, such routing addresses one power line to the rivet root connection point 205 of the arm 207, while another signal is connected to the surrounding SMA sheet surface 107. Since the SMA material forming the layer 107 is activated by thermal energy increase, the arm 207, due to its higher internal resistance, heats up first (compared to the rest of the layer 107), while the surrounding uniform layer 107 remains inactive. In the current context, activation can refer to material contraction, or activation of some other higher temperature austenitic "memory" state.

[0043] Due to the mutual coupling between the layers of the structure, shear motion is prevented. Accordingly, when the actuator 201 contracts, the lower layer follows the motion, thereby creating a bending action on the arm 207. The tip (usually 203) of the arm 207 will then move in direction A (upward). By providing an array of actuators 201, the entire display surface 1010 can be locally operated in direction A.

[0044] Figure 3 A schematic diagram of the deformation process of an arm of an actuator provided in one example is shown. In Figure 3 a, an actuator layer 107 (including an actuator 201) is shown, while the bias layer 111 and the feed layer 109 are also shown. In Figure 3 b, an electrical signal is provided to the connection point 205 of the actuator 201 to cause heating of the arm 207 of the actuator 201. As the arm heats up due to the electrical resistance heating experienced by the arm due to the provided electrical signal, the arm 207 contracts, as shown in Figure 3 c, thereby causing (according to the example of Figure 3 ) the arm to move in the direction shown, in turn causing the selected portion of the display surface 101 to which the point 203 is attached to deform in direction A. Upon removal of the electrical signal, the elastic bias portion in the bias layer 111 corresponding to the activated actuator 201 causes the actuator 201 to return to its pre-deformed (flat) state, thereby causing the display surface to also return to its pre-deformed (flat) state.

[0045] Figure 4 Another schematic diagram of the deformation process of an arm of an actuator provided in one example is shown. In Figure 4 the example of Figure 4a shows a portion of the display surface 101 of the device 113 in an undeformed state. Figure 4 b shows the deformation of a selected portion of the display surface 101 in direction A due to deformation of the arm of the actuator 201 located in a selected position.

[0046] Figure 5 An example is shown provided Figure 2 schematic view of the underside of the portion shown. Figure 5 An elastic biasing portion 501 is shown, in Figure 5 In an example, the elastic biasing portion 501 can take the form of a spring-like element comprising a length of biasing layer 111 which extends substantially over the length of the arm 207 of the actuator 201.

[0047] According to an example, the biasing layer 111 can take the form of an SMA layer which can be used to move the arm 207 of the actuator in direction B upon application of an electrical signal to the material causing it to contract in a direction opposite to that in which the layer 107 experiences contraction upon application of an electrical signal.

[0048] Figure 6 A schematic view of the deformation process of the arm of the actuator is shown provided in an example. In Figure 6 In an example, the layer 111 is provided in the form of an SMA layer. In combination Figure 3 The process of deforming the arm in direction A is performed. However, upon removal of the electrical signal, the elastic biasing portion takes the form of an additional arm in the layer 111 formed of SMA material which is used to contract upon provision of an electrical signal, thereby causing the arm to contract. Due to the relative arrangement of the layers, this contraction causes the arm in the 111 to "pull" on the actuator 201 to return to its pre-deformed (flat) state, thereby causing the display surface to also return to its pre-deformed (flat) state.

[0049] In an example, the deformation of a selected portion of the display surface can be used to emphasise information presented to a user. For example, in the case of a smart device, keys of a virtual keyboard can be caused to pop out of the display by deformation, or certain portions relating to control features of a game can be caused to pop out. Furthermore, the display can be deformed in order to further provide an immersive experience for a user, for example by causing the display to curve at the edges to simulate a curved display (for example).

[0050] In addition to pure mechanical shape changing (morphing) screen deformation, sensing capabilities can be integrated onto the display surface. For example, if the flexible display contains a capacitive touch film (for example), user feedback can be detected depending on the specific screen deformation location. If the flexible display contains a pressure sensing film (for example) or the actuation platform includes a closed loop feedback function (e.g. a small magnet attached to a moving tip of a flexure arm, with a (static) Hall element embedded on the FPC layer, etc.), an analog type UI touch screen can be provided, where subtle movements and actuations of the user can be detected. This would mean that when a portion of the display surface screen is activated to a raised (morphed) state, the display surface can detect these "bumps" pressed by an external force. Some applications can take advantage of this feature, for example, a simulated keyboard or game pad, pedals and other controls. In addition, a haptic effect of a finger press (for example) can be created within the device 113 using a motor or a specific actuator (e.g. a piezoelectric or solenoid actuator) to emphasize the finger contact.

[0051] Figure 7 A schematic diagram of an example provided user device is shown. The user device 700 (e.g. a smart device including a mobile phone or tablet device, etc.) includes a flexible display arrangement 701. The arrangement 701 can be a display arrangement as described above in connection with Figures 1 to 6 The deformable display surface 703 can form a touch surface for receiving user input. In Figure 7 In an example, the user device 700 further includes a processor 705 communicatively coupled to a memory 707. The processor is configured to generate an output signal 708 representing a degree of deformation of a selected portion 709 of the display surface 703, which can be generated according to the processes described above. In one example, the processor can determine the amount of deformation of the selected portion 709 according to a deflection measurement of the selected portion 709 produced by a magnetic induction arrangement 711. As described above, such an arrangement 711 can include a magnet or magnetized portion 712 disposed on an arm of an actuator 713 configured to move in synchronization with the arm when deformation occurs. Movement of the magnet or magnetized portion 712 can be detected by a sensor 715 (e.g. a Hall detector) in order to produce a deflection measurement of the arm and thus the amount of deformation of the selected portion. The measurement can be used to determine the amount of deflection (or deformation) as well as the rate of such deflection, which can be used to provide an indication of the force exerted by the user on the portion 709, etc.

Claims

1. A flexible display device for a user equipment, characterized in that, The display device includes a deformable display surface and an actuating structure for deforming the deformable surface, the actuating structure comprising: An actuation layer includes a plurality of individually addressable conductive actuators, each of which is configured to deform a selected portion of the display surface along a first direction. A bias layer includes a plurality of elastic bias portions, each of which is configured to correspond to an actuator of the actuation layer and to accompany deformation of the deformable surface at a selected portion, each of which is configured to push the corresponding actuator of the actuation layer in a second direction opposite to the first direction. Each of the individually addressable conductive actuators includes a bent arm electrically connected to a feed layer for providing current, wherein the feed layer is disposed between the actuation layer and the bias layer. The actuation layer is disposed between the deformable display surface and the bias layer.

2. The flexible display device according to claim 1, characterized in that, Each of the arms also includes a mechanical connection to the display surface.

3. The flexible display device according to any one of the preceding claims, characterized in that, Each of the actuators is used to deform when an electric current and / or thermal energy is applied.

4. The flexible display device according to claim 1 or 2, characterized in that, The actuation layer is formed of shape memory alloy or polymer material.

5. The flexible display device according to claim 1 or 2, characterized in that, The bias layer is formed of a metallic material.

6. The flexible display device according to claim 1 or 2, characterized in that, The bias layer is formed of shape memory alloy or polymer material.

7. The flexible display device according to claim 1 or 2, characterized in that, The actuators are regularly distributed in an array on the region of the actuation layer corresponding to the region of the deformable display surface.

8. The flexible display device according to claim 1 or 2, characterized in that, The actuation layer and the bias layer are mechanically connected.

9. The flexible display device according to claim 1 or 2, characterized in that, Each of the plurality of individually addressable conductive actuators includes a magnetic portion.

10. The flexible display device according to claim 9, characterized in that, The magnetic portion of the actuator is configured to interact with a static sensor.

11. A method for deforming a selected portion of a touch display of a user device, characterized in that, The method includes: A current is applied to a first actuator located at a first position in the actuation layer of the display device of the user equipment to induce resistive heating of the first actuator, thereby deforming the selected portion of the touch display along a first direction; Remove the current to ensure that the elastic bias element at the first location can restore the selected portion of the touch display to its undeformed state.

12. The method according to claim 11, characterized in that, The actuation layer is made of a shape memory effect alloy or polymer material, which is used to induce a phase transition curve based on temperature.

13. The method according to claim 11 or 12, characterized in that, Also includes: A current is applied to a second actuator located at the first position in the actuation layer to induce resistive heating of the second actuator, thereby deforming the selected portion of the touch display along a second direction.

14. The method according to claim 11 or 12, characterized in that, Also includes: A current is applied to a third actuator located at a second position in the actuation layer to induce resistive heating of the third actuator, thereby deforming a second selected portion of the touch display along the first direction; Remove the current to ensure that the elastic bias element at the second location can restore the second selected portion of the touch display to its undeformed state.

15. The method according to claim 11 or 12, characterized in that, Also includes: A measurement value is generated, which represents the force applied to the selected portion of the touch display when it is in a deformed state.

16. A user equipment, characterized in that, Includes the flexible display device according to any one of claims 1 to 10.

17. The user equipment according to claim 16, characterized in that, The deformable display surface is a touch surface, which is used to receive user input.

18. The user equipment according to claim 16 or 17, characterized in that, It also includes a processor communicatively coupled to the memory, the processor being used to generate an output signal representing the degree of deformation of a selected portion of the display surface.

19. The user equipment according to claim 18, characterized in that, The processor is also configured to determine the amount of deformation of the selected portion based on the deflection measurement value of the selected portion generated by the magnetic induction structure.

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