Patent Publication Number: US-2021183338-A1

Title: Deformable electronic device, foldable display device and method of controlling the same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. application Ser. No. 16/049,789, filed on Jul. 30, 2018, the content of which is hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure relates to a method of controlling a foldable display device, and more particularly, to a deformable electronic device. 
     2. Description of the Prior Art 
     In recent years, foldable or deformable electronic devices have become one of the focuses of the new generation electronic technology. The demand of the foldable display device that can be integrated in the electronic device is therefore increased. A foldable display device means the device can be curved, folded, stretched, flexed, rollable, or the like. Since foldable/deformable electronic device may have variable display areas in accordance with its deformable display region, the manufactures need to develop suitable controlling method of the foldable/deformable electronic device in order to improve the function and performance of the electronic device. 
     SUMMARY OF THE DISCLOSURE 
     In some embodiments, a method of controlling a foldable display device is provided. The foldable display device includes a flexible substrate and a display layer disposed on the flexible substrate. The display layer includes a first display portion, a second display portion, and a foldable display portion connecting the first display portion and the second display portion. The method includes providing a first predetermined angle, sensing a folding angle between the first display portion and the second display portion, comparing the folding angle with the first predetermined angle, providing a first display status of the foldable display device when the folding angle is less than the first predetermined angle, and providing a second display status of the foldable display device when the folding angle is equal to or greater than the first predetermined angle. 
     In some embodiments, a method of controlling a deformable electronic device is provided. The deformable electronic device includes a deformable substrate and a display layer disposed on the deformable substrate. The method includes providing a first predetermined deformation datum, sensing a deformation value of the deformable electronic device, comparing the deformation value with the first predetermined deformation datum, providing a first display status of the deformable electronic device when the deformation value is less than the first predetermined deformation datum, and providing a second display status of the deformable electronic device when the deformation value is equal to or greater than the first predetermined deformation datum. 
     In some embodiments, a deformable electronic device is provided. The deformable electronic device includes a deformable substrate, an electronic layer disposed on the deformable substrate, a memory unit configured to store a first predetermined deformation datum, a bending sensor unit configured to sense a deformation value of the deformable electronic device, and a processing unit. The processing unit is configured to compare the deformation value with the first predetermined deformation datum, to provide a first operating status of the deformable electronic device when the deformation value is less than the first predetermined deformation datum, and to provide a second operating status of the deformable electronic device when the deformation value is equal to or greater than the first predetermined deformation datum. 
     These and other objectives of the present disclosure will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top-view schematic diagram of an electronic device according to a first embodiment of the present disclosure. 
         FIG. 2  is a side-view schematic diagram illustrating the folding appearance of the electronic device according to the first embodiment of the present disclosure. 
         FIG. 3  is a partial enlargement of a top-view of the electronic device shown in  FIG. 1 . 
         FIG. 4  is a sectional schematic diagram of the electronic device shown in  FIG. 3  along line A-A′. 
         FIG. 5  is a partial enlargement of a top-view of an electronic device according to a variant embodiment of the first embodiment of the present disclosure. 
         FIG. 6  is a sectional schematic diagram of the electronic device shown in  FIG. 5  along line B-B′. 
         FIG. 7  is a flow chart illustrating the method of controlling the electronic device shown in  FIG. 1 . 
         FIG. 8  is a schematic diagram showing the appearance of different display statuses of the electronic device shown in  FIG. 1 . 
         FIG. 9  is a flow chart showing a method of controlling the electronic device according to a second embodiment of the present disclosure. 
         FIG. 10  is a schematic diagram illustrating the appearance of the electronic device in different display statuses. 
         FIG. 11  is a schematic diagram illustrating the appearance of an electronic device according to a variant embodiment of the second embodiment of the present disclosure. 
         FIG. 12  is a flow chart showing a method of controlling an electronic device according to a third embodiment of the present disclosure. 
         FIG. 13  is a schematic diagram illustrating the appearance of the electronic device in different display statuses. 
         FIG. 14  is a flow chart showing a method of controlling an electronic device according to a forth embodiment of the present disclosure. 
         FIG. 15  is a flow chart showing a method of controlling an electronic device according to a fifth embodiment of the present disclosure. 
         FIG. 16  is a flow chart showing a method of controlling an electronic device according to a sixth embodiment of the present disclosure. 
         FIG. 17  is a schematic top-view of the deformable substrate of the electronic device of the sixth embodiment of the present disclosure. 
         FIG. 18  is a schematic diagram illustrating the appearances of the electronic device in different display statuses of the sixth embodiment of the present disclosure. 
         FIG. 19  is a schematic diagram illustrating the appearances of an electronic device in different display statuses according to a seventh embodiment of the present disclosure. 
         FIG. 20  is a flow chart showing the method of controlling an electronic device according to an eighth embodiment of the present disclosure. 
         FIG. 21  is a schematic diagram illustrating the appearances of the electronic device in different display statuses of the eighth embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure may be understood by reference to the following detailed description, taken in conjunction with the drawings as described below. It is noted that, for purposes of illustrative clarity and being easily understood by the readers, various drawings of this disclosure show a portion of the display device, and certain elements in various drawings may not be drawn to scale. In addition, the number and dimension of each device shown in drawings are only illustrative and are not intended to limit the scope of the present disclosure. 
     Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will understand, electronic equipment manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms “include”, “comprise” and “have” are used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to . . . ”. 
     It will be understood that when an element or layer is referred to as being “on” or “connected to” another element or layer, it can be directly on or directly connected to the other element or layer, or intervening elements or layers may be presented. In contrast, when an element is referred to as being “directly on” or “directly connected to” another element or layer, there are no intervening elements or layers presented. 
     It should be noted that the technical features in different embodiments described in the following can be replaced, recombined, or mixed with one another to constitute another embodiment without departing from the spirit of the present disclosure. 
     Referring to  FIG. 1  to  FIG. 8 ,  FIG. 1  is a top-view schematic diagram of a deformable electronic device according to a first embodiment of the present disclosure,  FIG. 2  is a side-view schematic diagram illustrating the folding appearance of the deformable electronic device according to the first embodiment of the present disclosure,  FIG. 3  is a partial enlargement of a top-view of the electronic device shown in  FIG. 1 ,  FIG. 4  is a sectional schematic diagram of the electronic device shown in  FIG. 3  along line A-A′,  FIG. 5  is a partial enlargement of a top-view of an electronic device according to a variant embodiment of the first embodiment of the present disclosure,  FIG. 6  is a sectional schematic diagram of the electronic device shown in  FIG. 5  along line B-B′,  FIG. 7  is a flow chart illustrating the method of controlling the electronic device shown in  FIG. 1 , and  FIG. 8  is a schematic diagram showing the appearance of different display statuses of the electronic device shown in  FIG. 1 . As shown in  FIG. 1  and  FIG. 2 , the electronic device ED of the first embodiment of the present disclosure is a deformable electronic device. As an example, the deformable electronic device ED may include a deformable display device that could display images. The term “deformable” means that at least a part of the electronic device ED/deformable display device could be deformed, curved, bended, folded, stretched, flexed, and/or rolled. For example, a portion of the electronic device ED may be curved, bended, folded, stretched, flexed, and/or rolled along a specific direction, but not limited thereto. In this embodiment, the deformable display device may be a foldable display device  100  for explanation the present disclosure. 
     The deformable electronic device of the present disclosure can include a deformable substrate, and an electronic layer disposed on the deformable substrate. According to some embodiments, the electronic layer can include a display layer and can display images. According to some embodiments, the electronic layer can have no display function; for example, can include an antenna, such as a liquid crystal antenna. 
     For easy explanation, an example is taken when the electronic layer is a display layer, and the deformable electronic device can be foldable. Thus, the deformable electronic device ED is a foldable display device  100 , as shown in  FIG. 1 . The foldable display device  100  can be folded along at least one folding axis, for example, along the folding axis FX 1  of a first direction D 1 . 
     In this embodiment, the deformable electronic device ED (the foldable display device  100 ) includes a deformable substrate  102  and a display layer  104  disposed on a first surface  102   a  of the deformable substrate  102 , wherein the display layer  104  represents the electronic layer mentioned above. The deformable substrate  102  maybe a foldable substrate or a flexible substrate and may have a first folding axis FX 1 , and the display layer  104  may include a foldable display portion PF. The foldable display portion PF may be curved, bended, folded, stretched, flexed, and/or rolled along the first folding axis FX 1 . The first folding axis FX 1  may be in parallel to a first direction D 1  shown in  FIG. 1 . The display layer  104  may also include a first display portion P 1  and a second display portion P 2 , and the foldable display portion PF is connected between the first display portion P 1  and the second display portion P 2  . In this embodiment, the foldable display portion PF is positioned and connected between the first display portion P 1  and the second display portion P 2  in a second direction D 2 . The second direction D 2  may be perpendicular to the first direction D 1 , but not limited thereto. 
     As mentioned above, according to some embodiments, the electronic layer can have no display function; for example, can include a medium layer and a circuit layer. The medium layer can be a liquid crystal layer, the circuit layer can be formed by a thin film process, and can include TFTs, and thus the deformable electronic device ED can be a deformable antenna, such as a liquid crystal antenna. In addition, similar to the display layer  104 , an electronic layer  104 E can be disposed on a first surface  102   a  of the deformable substrate  102 . The electronic layer  104 E may include a foldable portion (as marked by “PF” in  FIG. 1 ), which may be folded along the first folding axis FX 1 . The first folding axis FX 1  may be in parallel to a first direction D 1  shown in  FIG. 1 . The electronic layer  104 E may also include a first portion (marked by P 1 ) and a second portion (marked by P 2 ), and the foldable portion PF is connected between the first portion P 1  and the second portion P 2 . In this embodiment, the foldable portion PF is positioned and connected between the first portion P 1  and the second portion P 2  in a second direction D 2 . The second direction D 2  may be perpendicular to the first direction D 1 , but not limited thereto. 
     According to a first embodiment, as shown in  FIG. 2 , the deformable electronic device ED can be a foldable display device  100 , and the deformable substrate  102  can be a flexible substrate. In other embodiments, the deformable electronic device ED can be a stretchable display device or a rollable display device (not shown). The foldable display device  100  may further include a control element  106  (such as an integrated circuit (IC)) disposed on the first surface  102   a  (marked in  FIG. 2  and  FIG. 4 ) of the deformable substrate  102 . The control element  106  maybe electrically connected to the display layer  104  via a plurality of wirings  120  to control display related functions . A second folding axis FX 2  may be included between the display layer  104  and the control element  106 . The portion of the deformable substrate  102  having the control element  106  may be bent along the second folding axis FX 2  backwardly to a rear surface (the second surface  102   b ) of the deformable substrate  102 . Accordingly, the control element  106  will not occupy the front side of the foldable display device  100 . The area of the foldable display device  100  may be reduced. In some embodiments, the control element  106  can be disposed on a flexible printed circuit board (not shown) and electrically connected to the wirings (not shown) on the substrate structure  102  by a chip on film (COF) technique. The flexible printed circuit board can also be bent to the second surface  102   b  of the deformable substrate  102 . Thus, the control element  106  does not occupy the first surface  102   a  of the deformable substrate  102 , and the area of the peripheral region may be reduced. 
     Referring to  FIG. 1 , the electronic device ED may further include other components, for example, a processing unit  108  and a control module  112 . The processing unit  108  may be electrically connected to the control element  106 , so as to provide operation signals. The control module  112  may include an actuator power  114 , a gyroscope  116 , a power management  118 , and a memory unit  117 . The actuator power  114  may provide power to actuate or deform the electronic device ED or the foldable display device  100 , such as changing the folding angle θ of the foldable display device  100 , but not limited there to. The gyroscope  116  may detect the operation condition or deformation state of the electronic device ED or the foldable display device  100 . The power management  118  may manage the power consumption of the electronic device ED or the foldable display device  100 . The memory unit  117  may store deformation information or folding information, such as predetermined deformation data and predetermined angles, which will be described below. Any other suitable external or internal elements or units may be included in the electronic device ED or the foldable display device  100  of the present disclosure. 
     Referring to  FIG. 2 , the foldable display device  100  can be folded with various folding angles. The portion of the deformable substrate  102  having the control element  106  may be omitted in  FIG. 2 , so as other following figures. The folding angle θ may range from 0° to 360°. In this embodiment, the deformable substrate  102  is a flexible substrate. When the folding angle θ is 0°, the foldable display device  100  is totally folded, a portion of the first surface  102   a  of the flexible substrate  102  corresponding to the first display portion P 1  faces a portion of the first surface  102   a  corresponding to the second display portion P 2 , and a portion of the second surface  102   b  corresponding to the first display portion P 1  and a portion of the second surface  102   b  corresponding to the second display portion P 2  are at two opposite sides. When the folding angle θ is 90°, the portion of the flexible substrate  102  corresponding to the first display portion P 1  is substantially perpendicular to the portion of the flexible substrate  102  corresponding to the second display portion P 2 . That is, the first display portion P 1  is substantially perpendicular to the second display portion P 2 . When the folding angle θ is 180°, the flexible substrate  102  is shown as a flat plate. The folding angle θ may be 360°, such that the display layer  104  are disposed at the outer side of the foldable display device  100  and the flexible substrate  102  is sandwiched between the display layer  104 . 
     Referring to  FIG. 3  and  FIG. 4 , a portion of the foldable display portion PF of the foldable display device  100  is shown. The flexible substrate  102  may include a substrate film  1021  and a supporting film  1022 , and the substrate film  1021  can be adhered to the supporting film  1022  through a glue layer  1023 . The display layer  104  is disposed on the deformable substrate  102  and may include a plurality of switch elements and a plurality of light emitting elements LE. For example, in this embodiment, the switch elements may include thin film transistors TFT electrically connected to corresponding light emitting elements LE, and the light emitting elements LE may be one kinds of organic light emitting diodes (OLED), micro light-emitting diode (micro-LED), mini-LED, and quantum dot LED (QLED), but not limited thereto. Any suitable light emitting elements may be adopted in the display layer  104 . 
     The deformable electronic device ED can include a bending sensor unit configured to sense a deformation value of the deformable electronic device ED. In some embodiments, the bending sensor unit can be disposed on the flexible substrate  102 , for example, disposed on the display layer  104 . In some embodiments, the bending sensor unit can be integrated in the display layer, that is, can be manufactured by the same procedures forming the conductive layer in the display layer. 
     For example,  FIG. 3  and  FIG. 4  show a bending sensor unit of resistance-type, and the bending sensor unit can be disposed on the display layer  104  in this embodiment. In some embodiments, the bending sensor unit can be disposed on the foldable display portion PF of the display layer  104 . The bending sensor unit can include a plurality of bending sensors BS, and  FIG. 3  and  FIG. 4  show two bending sensors BS. In detail, the foldable display device  100  may include a bending sensor layer  130  disposed on the display layer  104 , and the bending sensor layer  130  may include a conductive layer  131  and an insulating layer  132  covering the conductive layer  131 . In this embodiment, the conductive layer  131  forms the bending sensors BS. Each bending sensor BS may show as a conductive line. Furthermore, each bending sensor BS may include one or more openings OP in the conductive line, which may release stress when the foldable display device  100  is folded, so as to reduce crack probability. The conductive layer  131  may include metal material(s) and/or metal oxide material(s), but not limited thereto. Examples of the metal material may include Mg, Ca, Al, Ag, W, Cu, Ni, Cr, or an alloy of one or more of the above-mentioned material . Examples of the metal oxide material may include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide, or indium oxide. In some embodiments, the conductive layer  131  may include nanosilver wires. In addition, the conductive layer  131  can be a single layer or multiple layers. For example, the conductive layer  131  can be Mo/Al/Mo multiple layers or Ti/Cu/Ti multiple layers. 
       FIG. 5  and  FIG. 6  show a bending sensor unit of capacitive-type, and the bending sensor unit can be disposed on the display layer  104 . In some embodiments, the bending sensor unit can be disposed on the foldable display portion PF of the display layer  104 . The bending sensor unit can include a plurality of bending sensors BS. Referring to  FIG. 5  and  FIG. 6 ,  FIG. 5  is a partial enlargement of a top-view of an electronic device according to a variant embodiment of the first embodiment of the present disclosure, and  FIG. 6  is a sectional schematic diagram of the electronic device shown in  FIG. 5  along line B-B′. The bending sensor is composed of two conductive layers: the first conductive layer  1301  and the second conductive layer  1302 . The first conductive layer  1301  and the second conductive layer  1302  are separated by the insulating layer  132 , and a further protecting layer  140  may be formed on the second conductive layer  1302 . In this variant embodiment, the first conductive layer  1301  may include a plurality of first conductive lines CL 1  extending along the first direction D 1 , the second conductive layer  1302  may include a plurality of second conductive lines CL 2  extending along the second direction D 2 , and one bending sensor BS is defined by an overlapping portion of one first conductive line CL 1  and one second conductive line CL 2 , together with the insulating layer  132  corresponding to the overlapping portion. 
     In some embodiments, the bending sensor may be not disposed on the flexible substrate  102 . Referring back to  FIG. 1 , the control module  112  can optionally include a deformation sensor unit  119 , such as a bending sensor unit, which is not disposed on the flexible substrate  102 , but disposed outside from the flexible substrate  102 . For example, the bending sensor unit can be of optical type or image recognition type. 
     Referring to  FIG. 7  and  FIG. 8 , the method of controlling the foldable display device  100  or the electronic device ED of the first embodiment of the present disclosure may include the following steps. 
     Step S 100 : Provide a first predetermined deformation datum Dp 1 . In this embodiment, the first predetermined deformation datum Dp 1  may be a first predetermined angle θp 1 . The first predetermined deformation datum Dp 1  or the first predetermined angle θp 1  may be set or input by the user or the manufacturer, but not limited there to. For example, the first predetermined deformation datum Dp 1  or the first predetermined angle θp 1  can be stored in the memory unit  117 . The first predetermined angle θp 1  may be in a range from 30° to 90° according to this embodiment, but not limited thereto. In some embodiments, the first predetermined angle θp 1  may be in a range from 10° to 90°. For example, the first predetermined angle θp 1  may be 30°. 
     Step S 102 : Sense a deformation value DV. In this embodiment, the deformation value DV may be the folding angle θ. The folding angle θ may be sensed or detected by the bending sensors BS or the deformation sensor unit  119 , as mentioned above. 
     Step S 104 : Compare the deformation value DV with the first predetermined deformation datum Dp 1 . For example, Step S 104  may include comparing the folding angle θ with the first predetermined angle θp 1  in this embodiment . For example, comparison can be performed by the processing unit  108 . 
     Step S 106 : Provide a first operating status of the electronic device ED or the foldable display device  100  when the deformation value is less than the first predetermined deformation datum. The operating status can be a display status when the deformable electronic device has display function. For example, as shown in  FIG. 8 , the first operating status can be a first display status I. Therefore, Step S 106  may include providing a first display status I when the deformation value DV (such as the folding angle θ) is less than the first predetermined deformation datum Dp 1  (such as the first predetermined angle θp 1 ). For example, when the sensed folding angle θ is 15° or 0°, and the first display status I may be a standby status or a turn-off status of the foldable display device  100 , and the image displayed on the foldable display device  100  in the first display status I can have a gray level less than 50 or near 0. Alternatively, the operating status described in the present disclosure can be a display irrelevant status when the deformable electronic device has no display function. The 50 gray levels mentioned above are taken as an example when the overall gray level of the display device  100  is 255 gray levels. If the display device has different overall gray level, the gray level of the images displayed by the foldable display device  100  under the first display status I may be less than 20% (e.g., 50 gray levels/255 gray levels) of the overall gray level or almost zero gray level (e.g., 0 gray level/255 gray levels). 
     Step S 108 : Provide a second operating status display status of the electronic device ED or the foldable display device  100  when the deformation value is equal to or greater than the first predetermined deformation datum. The operating status can be a display status when the deformable electronic device has display function. For example, as shown in  FIG. 8 , the second operating status can be a second display status II. Therefore, Step S 108  may include providing a second display status II when the deformation value DV (such as the folding angle θ) is greater than or equal to the first predetermined deformation datum Dp 1  (such as the first predetermined angle θp 1 ). For example, when the sensed folding angle θ is 100° or 180°, the second display status II may be a turn-on status of the foldable display device  100 . In this embodiment, the display surface DS of the foldable display device  100  may face upward. The image displayed on the foldable display device  100  in the second display status II can have a gray level greater than 50 and less than 150. The aforementioned values of gray level is exemplified in the case that the overall gray level of the display device  100  is 255 gray. If the display device  100  has different number of overall gray level, the gray level of the image displayed by the foldable display device  100  can be greater than 20% of the overall gray level (e.g., 50 gray levels/255 gray levels) and less than 60% of the overall gray level (e.g., 150 gray levels/255 gray levels) under the second display status II. The foldable display device  100  has a first average luminance in the first display status I and a second average luminance in the second display status II, and the second average luminance is higher than the first average luminance. When the foldable display device  100  is operated in the second display status II, the first display portion P 1 , the foldable display portion PF, and the second display portion P 2  may together display a continuous image. In a variant embodiment, the second display status II may be a start-up status that displays preliminary information. For example, the second display status II may include an information region Rinf and a background region Rbag, as shown in the display status II in  FIG. 11 . The background region Rbag can be darker than the information region Rinf and can have a greater area than the information region Rinf. The information region Rinf may display text, letters, or logos for instance.  FIG. 8  shows another state of the second display status II′ when the folding angle θ is 180°. 
     In variant embodiments, referring to  FIG. 7 , Step S 402  can be optionally performed before Step S 102  as following. 
     Step  402 : Trigger the bending sensor unit. For example, when the electronic device ED or foldable display device  100  receives an operation signal, the bending sensor unit is triggered. In some embodiments, the foldable display device  100  can receive a triggering signal by the bending sensors of the bending sensor unit and then perform Step S 102  (sensing the deformation value DV or folding angle). 
     The foldable display device and electronic device of the present disclosure is not limited to the above mentioned embodiment. Further embodiments or variant embodiments of the present disclosure are described below. It should be noted that the technical features in different embodiments described can be replaced, recombined, or mixed with one another to constitute another embodiment without departing from the spirit of the present disclosure. For making it easier to compare the difference between the embodiments and variant embodiments, the following description will detail the dissimilarities among different variant embodiments or embodiments and the identical features will not be redundantly described. 
     Referring to  FIG. 9  and  FIG. 10 ,  FIG. 9  is a flow chart showing a method of controlling the electronic device according to a second embodiment of the present disclosure, and  FIG. 10  is a schematic diagram illustrating the appearance of the electronic device in different display statuses. The method of controlling the foldable display device  100  or the electronic device ED of the second embodiment of the present disclosure may include the following steps. 
     Step S 200 : Provide a first predetermined deformation datum Dp 1 . In this embodiment, the first predetermined deformation datum Dp 1  maybe a first predetermined angle θp 1 . The first predetermined angle θp 1  may be in a range from 30° to 90° according to this embodiment. For example, the first predetermined angle θp 1  may be 30°, but not limited thereto. 
     Step S 202 : Provide a second predetermined deformation datum Dp 2 . In this embodiment, the second predetermined deformation datum Dp 2  maybe a second predetermined angle θp 2 . The second predetermined angle θp 2  maybe in a range from 30° to 180° according to this embodiment. For example, the second predetermined angle θp 2  may be 90°, but not limited thereto. The value of the second predetermined deformation datum Dp 2  may be greater than the value of the first predetermined deformation datum Dp 1 , but not limited thereto. 
     Step S 204 : Sense a deformation value DV. In this embodiment, the deformation value DV may be the folding angle θ. 
     Step S 206 : Compare the deformation value DV with the first predetermined deformation datum Dp 1  and the second predetermined datum Dp 2 . For example, Step S 206  may include comparing the folding angle θ with the first predetermined angle θp 1  and the second predetermined angle θp 2  in this embodiment. 
     Step S 208 : Provide a first display status I (shown in  FIG. 10 ) of the electronic device ED or the foldable display device  100  when the deformation value DV (such as the folding angle θ) is less than the first predetermined deformation datum Dp 1  (such as the first predetermined angle θp 1 ). For example, the folding angle θ is 5°, and the first display status I may be a standby status or a turn-off status. Similar to the above embodiment, an operating status, which may not be a display status, can also be provided according to comparison result of the deformation value with the predetermined deformation datum, and detailed descriptions are omitted. 
     Step S 210 : Provide a second display status II of the electronic device ED or the foldable display device  100  when the deformation value DV (such as the folding angle θ) is greater than or equal to the first predetermined deformation datum Dp 1  (such as the first predetermined angle θp 1 ) but less than the second predetermined datum Dp 2  (such as the second predetermined angle θp 2 ). For example, the sensed folding angle θ is 100°, and the second display status II may be a turn-on status of the foldable display device  100 , and the image displayed on the foldable display device  100  in the second display status II can have a gray level greater than 50. When the foldable display device  100  is operated in the second display status II, the first display portion P 1  and the second display portion P 2  may individually display independent images. For example, the first display portion P 1  may display an image that can provide information to the user, the second display portion P 2  may display a keyboard picture such that the user can operate the second display portion P 2  as a physical keyboard, and the foldable display portion PF may show dark image or be in a turn-off status. 
     Step S 212 : Provide a third display status III of the electronic device ED or the foldable display device  100  when the deformation value DV (such as the folding angle θ) is greater than or equal to the second deformation datum Dp 2  (such as the second predetermined angle θp 2 ). For example, the sensed folding angle θ is 180°, and the first display portion P 1 , the foldable display portion PF, and the second display portion P 2  may together display a continuous image. 
     Referring to  FIG. 11 ,  FIG. 11  is a schematic diagram illustrating the appearance of the electronic device according to a variant embodiment of the second embodiment of the present disclosure. This variant embodiment is different from the second embodiment mainly in that the second display status is different. For example, the second display status II may be a start-up status and may include an information region Rinf and a background region Rbag. The background region Rbag is darker than the information region Rinf and has a greater area than the information region Rinf. The information region Rinf may display text, letters, or logos for instance. In addition, the second display status II may have an average luminance less than the average luminance of the third display status III.  FIG. 11  shows the second display status II when the folding angle θ is 50° and the third display status III when the folding angle θ is 110°. The method of measuring the aforementioned average luminance may include dividing the section of two side lengths of the rectangular display area of the display device  100  into 10 equal parts, measuring the luminance in five data points (1,1), (9,1), (5,5), (1,9), (9,9) respectively, and then calculating the average luminance. The unit area of each data point measured by camera charge-coupled device (CCD) can be, for example, 2 mm*2 mm, 1 mm*1 mm or other suitable size. If the display area is not rectangular, the maximum inner rectangle that can be found in the display area is taken as the calculation benchmark. 
     Referring to  FIG. 12  to  FIG. 13 ,  FIG. 12  is a flowchart showing a method of controlling the electronic device according to a third embodiment of the present disclosure,  FIG. 13  is a schematic diagram illustrating the appearance of the electronic device in different display statuses. The method of controlling the foldable display device  100  or the electronic device ED of the second embodiment of the present disclosure may include the following steps. In this embodiment and the fourth embodiment to the sixth embodiment introduced, the predetermined angles and folding angle are used for representing the predetermined deformation data and deformation value respectively, which may be replaced by other deformation data or values, as the previous embodiments. 
     Step S 300 : Provide a first predetermined angle θp 1 . The first predetermined angle θp 1  may be in a range from 30° to 90° according to this embodiment, but not limited thereto. For example, the first predetermined angle θp 1  may be 45°. 
     Step S 302 : Provide a second predetermined angle θp 2 . The second predetermined angle θp 2  may be in a range from 80° to 170° according to this embodiment, but not limited thereto. For example, the second predetermined angle θp 2  may be 110°. The second predetermined angle θp 2  is greater than the first predetermined angle θp 1  in this embodiment. 
     Step S 304 : Provide a third predetermined angle θp 3 . The third predetermined angle θp 3  maybe in a range from 150° to 200° according to this embodiment, but not limited thereto. For example, the third predetermined angle θp 3  may be 180°. The third predetermined angle θp 3  is greater than the second predetermined angle θp 2  in this embodiment. 
     Step S 306 : Sense a folding angle θ. The folding angle θ may be sensed by the bending sensors BS for example. 
     Step S 308 : Compare the folding angle θ with the first predetermined angle θp 1 , the second predetermined angle θp 2 , and the third predetermined angle θp 3  in this embodiment. 
     Step S 310 : Provide a first display status I of the electronic device ED or the foldable display device  100  when the folding angle θ is less than the first predetermined angle θp 1 . For example, the folding angle θ is 5°, and the first display status I may be a standby status or a turn-off status. 
     Step S 312 : Provide a second display status II of the electronic device ED or the foldable display device  100  when the folding angle θ is greater than or equal to the first predetermined angle θp 1  but less than the second predetermined angle θp 2 . For example, the folding angle θ is 100° and the second display status II may be a turn-on status of the foldable display device  100 . When the foldable display device  100  is operated in the second display status II, the first display portion P 1  and the second display portion P 2  may individually display independent images, which may be similar to the second display status II mentioned in the second embodiment, and detail description will not be repeated. 
     Step S 314 : Provide a third display status III of the electronic device ED or the foldable display device  100  when the folding angle θ is greater than or equal to the second predetermined angle θp 2  but less than the third predetermined angle θp 3 . The third display status III may be similar to the third display status III mentioned in the second embodiment, and detail description will not be repeated. 
     Step S 316 : Provide a fourth display status IV of the electronic device ED or the foldable display device  100  when the folding angle θ is greater than or equal to the third predetermined angle θp 3 . For example, the folding angle θ is 360°. In the fourth display status IV, the first display portion P 1  and the second display portion P 2  may individually display independent images. In some embodiments, the first display portion P 1  and a portion of the foldable display portion PF may display a continuous image together, and the second display portion P 2  and another portion of the foldable display portion PF may display another continuous image together. In some embodiments, the electronic device ED may be designed to display images by only one of the first display portion P 1  or the second display portion P 2  in the fourth display status IV, while the other display portion is turned off. For example, the gyroscope  116  shown in  FIG. 1  may be adopted to detect which display portion faces upward and that display portion may be the one which turns on. In the figure shown in  FIG. 13 , the second display portion P 2  may be designed to display images while the foldable display portion PF and the first display portion P 1  may be turned off in the fourth display status IV for instance. 
     Referring to  FIG. 14 ,  FIG. 14  is a flow chart showing a method of controlling the electronic device according to a fourth embodiment of the present disclosure. The method of this embodiment may include the following steps. 
     Step S 500 : Provide a first predetermined angle θp 1 . The first predetermined angle θp 1  may be input or set by the user or the manufacturer. 
     Step S 502 : Receive a wake-up signal. For example, the wake-up signal may be induced from a touch input or a voice input, but not limited thereto. 
     Step S 504 : Perform signal identification to identify the wake-up signal, and the received wake-up signal may be considered as a user identification signal. If the received wake-up signal passes the identification, then perform Step S 510 . If the received wake-up signal does not pass the identification, then perform Step S 506 . 
     Step S 506 : Check the item “Is the data inputted incorrect for “n” times?” If the answer is true, then perform Step S 508 . The above mentioned value “n” may be inputted or set by the user or the manufacturer. 
     Step S 508 : Give a warning signal to the user when the answer of Step S 506  is “true”. 
     Step S 510 : Sensing a folding angle θ. 
     Step S 512 : Compare the folding angle θ with the first predetermined angle θp 1 . 
     Step  514 : Provide a first display status of the electronic device when the folding angle θ is less than the first predetermined angle θp 1 . 
     Step S 516 : Provide a second display status of the electronic device when the folding angle θ is greater than or equal to the first predetermined angle θp 1 . 
     This embodiment is different from the first embodiment mainly in that a step of “receiving a wake-up signal” and a step of “signal identification” are incorporated in the method of controlling the electronic device (or the foldable display device). The user may input a wake-up signal when he starts to use the electronic device, and the electronic device will start up to the following Steps S 510  to S 516  when the wake-up signal passes the signal identification. In other words, a user identification signal is received before determining the folding angle of the electronic device. 
     Referring to  FIG. 15 ,  FIG. 15  is a flow chart showing a method of controlling the foldable display device (or electronic device) according to a fifth embodiment of the present disclosure. The method of controlling the foldable display device (or the electronic device) of this embodiment may include the following steps. 
     Step S 600 : The foldable display device is in an off state. 
     Step S 602 : Receive a wake-up signal. 
     Step S 604 : Perform a signal identification, which includes Steps S 6042  to S 6048 . 
     Step S 6042 : Collect biometric data of the wake-up signal, such as voice data, fingerprint data, iris data, and so on. 
     Step S 6044 : Compare the biometric data with at least one stored data and generate a result. 
     Step S 6046 : Judge whether the biometric data satisfies the preset condition. If the judging result is “yes”, then perform Step S 606 . If the judging result is “no”, then perform Step S 6048 . 
     Step S 6048 : Finish the operation of the foldable display device. 
     Step S 606 : Start up the foldable display device. Step S 606  includes the Step S 6062  to Step S 6066 . 
     Step S 6062 : Pass control signal to an actuator power. 
     Step S 6064 : Turn on the actuator power (power on). 
     Step S 6066 : Change the folding angle by the actuator. 
     Step S 608 : Determine the display status. Step S 608  includes Steps S 6082  to S 6086 . 
     Step S 6082 : Sense the folding angle. For example, the folding angle may be sensed by the bending sensor. 
     Step S 6084 : If the folding angle is greater than or equal to a predetermined angle, then turn on the foldable display device. The predetermined angle can be inputted by the user or the manufacture before usual operation of the foldable display panel. 
     Step S 6086 : Pass the angle data to the foldable display device and adjust the display image. 
     Step S 610 : Finish. 
     Referring to  FIG. 16  to  FIG. 18 ,  FIG. 16  is a method of controlling the electronic device according to a sixth embodiment of the present disclosure,  FIG. 17  is a schematic top-view of the deformable substrate of the electronic device of the sixth embodiment of the present disclosure, and  FIG. 18  is a schematic diagram illustrating the appearances of the electronic device in different display statuses of the six embodiment of the present disclosure. The electronic device ED of this embodiment includes a stretchable display device  200 , and the stretchable display device  200  includes a deformable substrate  102  and a display layer disposed on the deformable substrate  102 . The deformable substrate  102  can have a plurality of stretchable openings  1021  and may be stretchable. The shapes of the openings  1021  are not limited to  FIG. 17 . The openings  1021  may individually have any suitable shapes, such as rectangular shapes, ellipse shapes, round shapes, and so on. By means of stretchable function, the display region of the deformable display device  200  can be varied by stretching. For example, the exposed display region (as marked by the symbol “A”) can be increased when the force is applied along the direction D 2 . In addition, a plurality of deformation sensors  1022  may be disposed in the display layer. For example, the deformation sensors  1022  can be disposed corresponding to the position of the openings, such as around or adjacent to the openings  1021 . The deformation sensors  1022  can detect the deformation degree of the corresponding openings  1021 . Based on the individual detecting results or the integrated detecting results of the deformation sensors  1022 , the processing unit  108  of the deformable electronic device ED can process the detecting results and obtain the dimension (such as width or length) of the exposed display region A, or obtain the area of the exposed display region A of the electronic device ED. 
     The method of controlling the electronic device of this embodiment may include the following steps. 
     Step S 700 : Provide a first predetermined deformation datum. For example, the first predetermined deformation datum can be a dimension or area. In this embodiment, the first predetermined deformation datum may refer to the first predetermined deformation area Ap 1 . 
     Step S 702 : Sense a deformation value of the electronic device ED. In some embodiments, the deformation value can be a dimension or area of the exposed display region A of the stretchable display device  200 . For example, the area of the exposed display region A can be sensed by the deformation sensors  1022  and obtained by the processing unit  108 . 
     Step S 704 : Compare the deformation value with the first predetermined deformation area Ap 1 . For example, compare the area of the exposed display region A with the first predetermined deformation area Ap 1 . 
     Step S 706 : If the deformation value (the area of the exposed display region A) is smaller than the first predetermined deformation datum (first predetermined deformation area Ap 1 ), then provide a first display status I of the electronic device ED. For example, the first display status I may be a turn-off status or dark status. 
     Step S 708 : If the deformation value (the area of the exposed display region A) is greater than or equal to the first predetermined deformation datum (the first predetermined deformation area Ap 1 ), then provide a second display status II of the electronic device ED. For example, the second display status II is a turn-on status, and the electronic device ED may display a continuous image in the whole display region A when it is stretched up to have a big enough display region. 
     In a variant embodiment, the deformation sensors  1022  may be disposed on one or more edges of the deformable substrate  102  of the electronic device ED, such that the deformation sensors  1022  can sense the total length and/or width of the deformable substrate  102 , so as to obtain the area of the display region A. 
     Referring to  FIG. 19 ,  FIG. 19  is a schematic diagram illustrating the appearances of an electronic device in different display statuses according to a seventh embodiment of the present disclosure. The electronic device ED includes a rollable display device  300  and may further include a housing HU. The rollable display device  300  maybe contained in the housing HU when it is not in operation. By means of rollable function, the exposed display region A of the rollable display device  300  can be varied by rolling. 
     The method of controlling the electronic device ED may refer to the flow chart shown in  FIG. 9  and the flow chart shown in  FIG. 16 . A first predetermined deformation datum Dp 1  and a second predetermined deformation datum Dp 2  may be provided. The first predetermined deformation datum Dp 1  and the second predetermined deformation datum Dp 2  may be a dimension or area, and the second predetermined datum Dp 2  is greater than the first predetermined datum Dp 1 . When the electronic device ED is in operation, a deformation value is sensed. For example, the deformation value may be the area of the exposed display region A of this embodiment, thus the first predetermined deformation datum Dp 1  may be a first predetermined deformation area Ap 1  and the second predetermined deformation datum Dp 2  maybe a second predetermined deformation area Ap 2 . If the sensed area of the exposed display region A is less than the first predetermined deformation area Ap 1 , a first display status I is provided to the rollable display device  300 . For example, the first display status I is a turn-off status, as shown in  FIG. 19 . If the sensed area of the exposed display region A is greater an or equal to the first predetermined deformation area Ap 1  but less than the second predetermined deformation area Ap 2 , a second display status II is provided to the rollable display device  300 . For example, the second display status II may be a start-up status or a preliminary display status, thus the rollable display device  300  may only show preliminary information or a few texts in the exposed display region A. In some embodiments, the second display status II maybe a turn-on status. If the sensed area of the display region A is greater than or equal to the second predetermined deformation area Ap 2 , a third display status III is provided to the rollable display device  300 . For example, a continuous image maybe displayed in the whole display region A in the third display status III. In this embodiment, one or more deformation sensors BS may be disposed on the edges of the display device  300  for sensing the display region A. 
     Referring to  FIG. 20  to  FIG. 21 ,  FIG. 20  is a method of controlling an electronic device according to an eighth embodiment of the present disclosure and  FIG. 21  is a schematic diagram illustrating the appearances of the electronic device in different display statuses of the eighth embodiment of the present disclosure. The foldable display device  100  includes two foldable display portions PF 1  and PF 2 . A first foldable display portion PF 1  is disposed between the first display portion P 1  and the second display portion P 2 , and a second foldable display portion PF 2  is disposed between the second display portion P 2  and the third display portion P 3 . The foldable display device  100  can be folded at the first foldable display portion PF 1  and the second foldable display portion PF 2 . The first foldable display portion PF 1  has a first folding angle θF 1  and the second foldable display PF 2  has a second folding angle θF 2 . The method of controlling the electronic device ED or the foldable display device  100  may include the following steps. 
     Step S 900 : Provide a first predetermined angle θp 1  corresponding to the first folding angle θF 1  and a second predetermined angle θp 2  corresponding to the second folding angle θF 2 . For example, the first predetermined angle θp 1  is 45° and the second predetermined angle θp 2  is 315°, but not limited thereto. 
     Step S 902 : Provide a standby display status to the foldable display device  100 . For example, the standby display status is a first display status I of the foldable display device  100  as shown in  FIG. 21 . The standby display status may be provided when the first folding angle θF 1  is less than the first predetermined angle θp 1  and the second folding angle θF 2  is greater than the second predetermined angle θp 2  . For example, when the first folding angle θF 1  is 0° and the second folding angle θF 2  is 360°, the first display portion P 1 , the second display portion P 2 , and the third display portion P 3  are folded to overlap each other. In the first display status I, the third display portion P 3  may be turned on and display images, and the display surface DS is at the portion of the display layer  104  within the third display portion P 3 , while the first display portion P 1 , the second display portion P 2 , the first foldable display portion PF 1 , and the second foldable display portion PF 2  may be turned off. 
     Step S 904 : Sense the first folding angle θF 1 . One or more bending sensors may be used for sensing the first folding angle θF 1  for example. 
     Step S 906 : If the first folding angle θF 1  is greater than or equal to the first predetermined angle θp 1 , then provide a second display status II that corresponds to the first folding angle θF 1 . For example, the first folding angle θF 1  may be about 180°. In the second display status II, the first display portion P 1 , the second display portion P 2  and the first foldable display portion PF 1  are configured as a flat plate with an area greater than that of the third display portion P 3 , and the display surface DS is at the portion of the display layer  104  within the first display portion P 1 , the second display portion P 2  and the first foldable display portion PF 1 . 
     Step S 908 : Sense the second folding angle θF 2 . One or more bending sensors may be used for sensing the second folding angle θF 2  for example. 
     Step S 910 : If the second folding angle θF 2  is greater than the second predetermined angle θp 2 , then keep providing the second display status II that corresponds to the first folding angle θF 1 . 
     Step S 912 : If the second folding angle θF 2  is less than or equal to the second predetermined angle θp 2 , then provide a third display status III. For example, when both the first folding angle θF 1  and the second folding angle θF 2  may be 180°, provide a third display status III. In the third display status III, the first display portion P 1 , the second display portion P 2 , the third display portion P 3 , the first foldable display portion PF 1 , and the second foldable display portion PF 2  maybe configured as a flatplate, and all of these portions may display a continuous image together. 
     According to the present disclosure, one or more predetermined deformation data (such as corresponding to folding angles, display areas, display range and so on) may be preset or pre-input in the electronic device (or the foldable display device), and different operating statuses (such as display statuses) of the electronic device may be provided to respond different deformation values in comparison with corresponding predetermined deformation data. The electronic device of the present disclosure can therefore provide various display functions at different deformation states. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the disclosure. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.