Foldable display device and method for operating a foldable display device

Abstract

The present invention relates to a foldable display device (100) having a first housing section (102), a second housing section (103), and a hinge arrangement (106) that connects the first housing section (102) to the second housing section (104) so ​​as to be rotatable about a folding axis. A display (108) extends continuously over at least part of a first main surface of the first housing section (102) and at least part of a second main surface of the second housing section (104). A sensor arrangement (110) is arranged in the hinge arrangement (106) and / or in the display (108) for measuring mechanical stress.

Description

State of the art

[0001] The present invention relates to a foldable display device and a method for operating a foldable display device.

[0002] Since the first introduction of foldable wireless telephones in the 1990s, such as the TZ-104 / TZ-1501 from Nippon Electric Company (NEC ® ) and the StarTac ® from Motorola ®This class of phone had temporarily declined in importance before the introduction of foldable phones, which, for example, used a housing section to house a microphone and keyboard and a housing section that could be rotated relative to it to accommodate a small display and speaker. This can be partly attributed to the development of smart phones or smartphones with large displays and the ability to implement various functions on them, such as a keyboard for operating a wireless phone. The development of foldable or flexible displays, for example using organic light-emitting diodes (OLEDs), has opened up new possibilities for the design of foldable wireless phones and brought them back into focus for manufacturers and consumers.It is now possible for a display to extend across both parts of a foldable phone, thus creating a foldable phone with its inherent compactness on the one hand and the generous display size typical of smartphones on the other.

[0003] In addition to the foldable display, hinges or pivot joints, which are designed for relative rotation of the above-mentioned housing parts, represent an important, sometimes very complex and also vulnerable element of foldable telephones or other foldable electronic devices with foldable displays.

[0004] JP 2 596 215 B2 describes a portable and foldable radio telephone having an earpiece housing and a microphone housing connected to each other by a hinge. An earpiece plate for supporting an ear is attached to the earpiece housing by means of a compression spring. An actuating rod projects from the earpiece plate toward the earpiece housing. Part of the actuating rod forms a rack that meshes with a gear arranged on the earpiece housing and is connected to a variable resistor. By changing the variable resistor, the pressure applied by the ear against the earpiece is measured, for example. At higher pressures, the output volume of a loudspeaker in the earpiece housing is increased to warn the user and prevent the hinge from breaking.

[0005] US 2015 / 241 925 A1 shows a strain gauge sensor arranged in a flexible hinge of a mobile terminal for detecting a length variation of the flexible hinge transversely to a rotation axis thereof in order to control switching on and off of a screen of a flexible display of the mobile terminal.

[0006] Also known are arrangements and methods for detecting mechanical forces or deformation states of mobile electrical devices caused by the user and applications on the mobile electronic device triggered as a result, see e.g. US 2009 / 184 921 A1 or US 2011 / 167 391 A1.

[0007] However, the known solutions are not suitable for detecting mechanical stresses in rigid hinges of foldable electrical devices with foldable displays in order to prevent overloading of the hinge.

[0008] Based on the prior art, there is a need to provide a foldable display device with a rigid hinge arrangement and a tension sensor that enables accurate detection of mechanical tensions of the rigid hinge arrangement. Disclosure of the invention

[0009] With the present invention, mechanical stresses in a display device can be measured to prevent damage to the display and / or to detect gestures for controlling the display device.

[0010] According to the invention, a foldable display device having the features of patent claim 1 and a method for operating the foldable display device having the features of patent claim 13 are therefore provided.

[0011] The basic idea is to arrange a stress sensor suitable for detecting mechanical stress in the vicinity of a hinge that is substantially rigid along a rotation axis for a foldable display device in order to enable precise detection of stresses in the uniaxially rigid hinge arrangement and / or in a display of the display device and thus to be able to accurately estimate a load on the hinge arrangement and / or the display, but also to create the possibility of gesture recognition via mechanical stresses in the hinge arrangement or in the display.

[0012] A foldable display device comprises a first housing section and a second housing section. The housing sections together form a housing of the display device. By dividing the housing into the two housing sections, the display device can be folded. The housing sections are preferably each of the same size and uniform shape. The housing sections each support a section of a continuous foldable display.

[0013] The foldable display device is, for example, a foldable smartphone, foldable tablet, laptop, or the like. Accordingly, the display device can have a touchscreen as a display. Furthermore, the display device can have a variety of other input and / or output devices, as well as processors, memories, etc., as is common with devices of this type.

[0014] A hinge assembly connects the first housing section to the second housing section so that it can rotate about a folding axis. Thus, the display device can be transferred from a first folded state to a second unfolded or opened state.

[0015] A display, which is preferably foldable and / or flexible, extends continuously over at least a portion of a first main surface of the first housing section and at least a portion of a second main surface of the second housing section. Thus, unfolding the display device can provide a large continuous display (screen).

[0016] According to the invention, a sensor arrangement serves to measure a mechanical stress in the hinge arrangement and / or in the display. The sensor arrangement preferably comprises a plurality of stress sensors.

[0017] A preferred control device of the display device is configured to detect sensor signals from the sensor arrangement and to control the display device depending on the detected sensor signals. For example, optical and / or acoustic warning signals can be emitted if a measured voltage is equal to or greater than a first threshold value. This can prevent damage to the hinge arrangement and / or the display.

[0018] The sensor arrangement may comprise a plurality of sensors for measuring mechanical stress in the hinge assembly and / or the display. Thus, mechanical loads on the hinge assembly and / or the display can be measured, for example, to warn a user before reaching a breaking point and prevent damage to the display device.

[0019] The control device can preferably be configured to detect sensor signals from the sensor array and, based on the sensor signals, recognize a gesture performed by a user. The display device can then be controlled depending on the recognized gesture. For example, a user can initiate a control function by twisting the display or the housing sections.

[0020] The sensor arrangement is preferably configured to measure an extension and / or compression of the display and / or the hinge arrangement. For this purpose, the sensor arrangement can comprise a plurality of suitable sensors, each of which can be arranged in a suitable manner on the hinge arrangement and / or on the display.

[0021] Preferably, at least one sensor of the sensor arrangement is designed to measure a mechanical tension between the first housing section and the second housing section. When the display device is unfolded, for example, lateral edges of the housing sections can come into contact with one another, so that pressure can be generated between the edges, which in turn can exert a lever effect on the hinge arrangement. To prevent damage to the hinge, a limit value can be specified; upon reaching this limit value, a visual and / or acoustic warning can be issued.

[0022] The sensor arrangement can preferably be configured to measure expansion and / or compression in a foldable region of the display at the hinge arrangement. To create a continuous display, a region of the display at the hinge arrangement must be flexible or foldable. Adverse mechanical stresses can occur here when folding and / or unfolding the display devices. These mechanical stresses can be measured by a suitable arrangement of sensors in the region between the first and second housing sections.

[0023] When folded, the display can be positioned either externally or internally with respect to the hinge arrangement. If the display is positioned internally, the display is not visible from the outside when folded and is largely protected from external influences. Conversely, the display can be positioned externally, so that the display is visible even when folded. Accordingly, when the display is folded, the display either compresses or expands in the area of ​​the hinge arrangement.

[0024] According to a preferred embodiment, the display may include a first portion on the first housing portion, a second portion on the second housing portion, and a central portion on the hinge assembly connecting the first portion and the second portion. The central portion may be flexible and / or foldable as described above.

[0025] According to a preferred embodiment, the display can have bend sections between the first section and the middle section, and between the second section and the middle section. The mechanical load on the display can be particularly high at the bend sections. Accordingly, sensors can preferably be arranged at each of the bend sections.

[0026] Particularly preferably, a sensor is arranged on the display on both sides of the folding axis.

[0027] A method for operating a foldable display device comprises a step of detecting a sensor signal from a sensor arrangement that indicates a voltage in a display and / or a hinge arrangement of the display device. In a second step, the sensor signal is compared with a predetermined criterion. The criterion can, for example, be the reaching of a limit value. If the criterion is met, a function for controlling the display device is triggered. This function can, for example, be the output of a visual and / or acoustic warning.

[0028] Advantageous embodiments and further developments emerge from the further subclaims and from the description with reference to the figures.

[0029] The present invention is explained in more detail below with reference to the exemplary embodiments shown in the schematic figures. They show: Fig. 1A, Fig. 1B, Fig. 1C Side views of a foldable portable telephone according to a first embodiment of the invention. Fig. 2, Fig. 3, Fig. 4, Fig. 5 a plan view, a side view and two enlarged side views of sections of an electronic device according to a second embodiment of the invention. Fig. 6 is a perspective sectional view of a locking structure of a foldable electronic device according to an embodiment of the invention. Fig. 7 is an exploded perspective view of an electronic device according to an embodiment of the invention. Fig. 8, Fig. 9 is a perspective view and an exploded view of a foldable electronic device according to a fifth embodiment of the invention. Fig. 10, Fig. 11, Fig. 12 is an exploded view of a mobile electronic terminal with a flexible screen, a schematic illustration of a hinge in a folded state, and a schematic illustration of an outer side of the hinge in a flattened state according to an embodiment of the invention. Fig. 13 is a perspective view of a foldable electronic device according to an embodiment of the invention. Fig. 14 is a schematic exploded view of a foldable display device according to an embodiment of the invention. Fig. 15, Fig. 16 a hinge of a foldable electronic device in a stretched or folded state. Fig. 17 a control device for foldable electrical devices. Fig. 18 a method for controlling foldable electrical devices. Fig. 19 a circuit diagram of a sensor for measuring mechanical stresses. Fig. 20 a sectional view of a voltage sensor. Fig. 21 Two different torsion-based deformation states of a foldable device.

[0030] The accompanying figures are intended to provide a further understanding of embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the noted advantages will become apparent upon review of the drawings. Elements of the drawings are not necessarily shown to scale relative to one another.

[0031] In the figures of the drawing, identical, functionally identical and acting elements, features and components are provided with the same reference symbols, unless otherwise stated.

[0032] Fig. 1A, Fig. 1B and Fig. 1C show side views of a display device 100 embodied as a foldable portable telephone according to a first embodiment of the invention. The foldable portable telephone comprises a body housing as a first housing section 102, a folding housing 104 as a second housing section 104, and a hinge assembly 106 that rotatably connects the body housing 102 to the folding housing 104. Fig. 1A shows a folded state in which a main surface of the folding housing 104 rests on a main surface of the main housing 102. In particular, the main surfaces of the two housings 102, 104, each configured as a foldable display screen 108, touch each other.

[0033] As in Fig. As shown in Figure 1C, the folding case 104 and the main body 102 touch each other at contact portions 112 when the foldable portable phone is fully opened. A tension sensor 110 is arranged at at least one of the contact portions 112. The tension sensor 110 is configured and arranged at the respective contact portion 112 to measure a respective contact pressure of the contact portions 112 against each other and output a corresponding tension measurement signal. In other words, the tension sensor 110 measures a contact pressure of the folding case 104 against the main body 102 in the open state of the phone.

[0034] Fig. Figure 2 shows a plan view of an electronic device 100 designed as a foldable phone with a foldable display 108 according to a second embodiment of the invention. The electronic device 100 comprises a first side 102 and a second side 104, which are pivotally arranged relative to each other at a pivoting portion 106 serving as a hinge.

[0035] Fig. 3 shows a side view of the foldable phone 100 from Fig. 2. Fig. 4 and Fig. 5 each show enlarged side views of sections of the telephone 100 from Fig. 2 and Fig. 3.

[0036] As in Fig. 3, the first side 102 has a first surface 102A and a second surface 102B. Similarly, the second side 104 has a first surface 104A and a second surface 104B. The electronic device 100 includes a foldable display 108 that extends over the first surface 102A of the first side 102 and the first surface 104A of the second side 104.

[0037] As in Fig. 4 and Fig. 5, the electronic device 100 can be folded. To this end, the electronic device 100 includes a hinge assembly 106 having a first hinge 212 slidably coupled to the first side 102 and a second hinge 214 slidably coupled to the second side 104. The hinge assembly 106 defines an outline of the display 108 when the electronic device 100 is folded. The first hinge 212 has a first folding stop 216 coupled to a hinge cylinder running along a short axis of the electronic device 100 by a first pin 218. The second hinge 214 has a second folding stop 220 coupled to another hinge cylinder running along the short axis of the electronic device 100 by a second pin 222.The first hinge 212 and the first side 102 are pivotable about the first pin 218, and the second hinge 214 and the second side 104 are pivotable about the second pin 222. . Fig. 4A and Fig. 4B show the hinge assembly 106 in different pivot positions.

[0038] According to the invention, a respective tension sensor 110 is arranged on at least one of the folding stops 216 and 220. The tension sensor 110 is configured and arranged on the respective first or second folding stop 216 or 220 in such a way as to measure a respective contact pressure of the first and second folding stops 216 and 220 against each other and to output a corresponding tension measurement signal.

[0039] Alternatively or additionally, a further voltage sensor 110 or further voltage sensors 110 may be arranged on a side of the display 108 facing the hinge assembly 106, as shown in Fig. 5A and Fig. 5B for various pivot positions of the electronic device 100. Alternatively or additionally, further stress sensors 110 are arranged on a side of the display 108 facing away from the hinge assembly 106, on or in a bending section 226, central section 228, etc. of the display 108, in order to measure a respective mechanical stress, i.e., a respective elongation or compression, of the bending section 226, central section 228, etc., and to output a corresponding stress measurement signal.

[0040] Fig. 6 shows a perspective sectional view of a locking structure of a foldable electronic device 108 according to a third embodiment of the invention.

[0041] When the foldable electronic device 100 is unfolded at a predetermined angle, e.g., when a first housing portion 102 and a second housing portion 104 are unfolded during a pivoting movement, a first plate coupling part 308 coupled to a first hinge plate 306 in a hinge housing 310 may be tilted by a specified angle, e.g., about 60 degrees or about 70 degrees. Similarly, a second plate coupling part 314 coupled to a second hinge plate 312 in the hinge housing 310 may be tilted by a predetermined angle, e.g., about -60 degrees or about -70 degrees.

[0042] The first housing section 102 and the second housing section 104 can be unfolded in opposite directions by 60 degrees and -60 degrees or 70 degrees and -70 degrees in a folded state. Accordingly, an interior angle between the first plate coupling part 308 and the second plate coupling part 314 can be 120 degrees or 140 degrees. During this process, at least a portion of the first plate coupling part 308 and at least a portion of the second plate coupling part 314 are brought into contact with each other. Preferably, curved portions of the first plate coupling part 308 are brought into contact with fastening parts of the second plate coupling part 314. A display 108 arranged on the first and second housing sections 102 and 104 is unfolded with a folding angle of the first and second housing sections 102 and 104.

[0043] According to the invention, a respective voltage sensor (not shown) is arranged on at least some of the parts where the first plate coupling part 308 and the second plate coupling part 314 are brought into contact with each other during the unfolding of the foldable electronic device 100. The voltage sensor is designed and arranged to measure a respective contact pressure and output a corresponding voltage measurement signal.

[0044] Alternatively or additionally, one or more stress sensors 110 may be arranged on a side of the display 108 facing the first and second hinge plates 306 and 312, or on a side of the display 108 facing away from the first and second hinge plates 306 and 312, on or in a bending section 226, central section 228, etc. of the display 108, in order to measure a respective mechanical stress, i.e. a respective elongation or compression, of the bending section 226, central section 228, etc. and to output a corresponding stress measurement signal.

[0045] The hinge plates 306 and 312 with the plate coupling parts 308 and 314 form a hinge assembly 106.

[0046] Fig. 7 shows an exploded perspective view of an electronic device 100 according to a fourth embodiment of the invention.

[0047] The electronic device 100 includes a foldable display 108, a panel 402, a first housing 102, and a second housing 104, and a hinge portion 106 is disposed between the first housing 102 and the second housing 104.

[0048] The display 108 includes a first region 410, a central region 228, and a second region 414. The plate 402 includes a first plate 416, a second plate 418, and a middle plate 420. The first plate 416 and the second plate 418 are rigid plates. The middle plate 420 is a flexible plate. The middle plate 420 has a size corresponding to the size of the central region 228 of the display 108. Alternatively, the middle plate 420 has a size corresponding to the size of the hinge region 106.

[0049] The first plate 416 of the plate 402 is fixed to the first housing 102. The second plate 418 is fixed to the second housing 104. An adhesive element is arranged at least partially between the first plate 416 of the plate 402 and the first housing 102 and between the second plate 418 of the plate 402 and the second housing 104. The adhesive element is arranged between the first plate 416 and the first region 410 of the display such that the first region 410 of the display is fixed to the first plate 416. The adhesive element is arranged between the second plate 418 and the second region 414 of the display such that the second region 414 of the display is fixed to the lower plate 418.

[0050] The middle plate 420 is fixed to the hinge portion 106 by the bonding member and extends or contracts during the pivoting operations of the first and second housings 102 and 104. The bonding member is disposed between the middle plate 420 and the central portion 228 of the display, and the central portion 228 of the display is fixed to the middle plate 420. The magnitude of the extension force (the degree of extension) of the middle plate 420 and the magnitude of the extension force of the central portion 228 of the display are the same or similar.

[0051] The middle plate 420 is formed of, for example, a metal, e.g., stainless steel, and has a small specific thickness or less, and, as shown, has a lattice pattern to facilitate easy folding and to achieve a structure robust against mechanical stress due to folding and unfolding operations.

[0052] At least one stress sensor 110 is arranged on a side of the display 108 facing the plate 402 or on a side of the display facing away from the first plate 402, on or in the central region 228 of the display or in the vicinity thereof, in order to measure a respective mechanical stress, that is to say a respective elongation or compression, of the central region 228 of the display 108 and to output a corresponding stress measurement signal.

[0053] Alternatively or additionally, one or more suitably designed tension sensors can be arranged on a side of the plate 402 that faces the display, or on a side of the plate 402 that faces away from the display, on or in the middle plate 420 of the plate 402. Alternatively or additionally, at least two tension sensors 110 are arranged to the left and right of a first axis 424 of the hinge region 106, preferably at the same height or axially symmetrically, on or in the central region 228 of the display 400 and / or on or in the middle plate 420 of the plate 402, in order to preferably detect twists orto detect an opposite tensioning of the first housing 102 and the second housing 104 about a second axis 426 which is perpendicular to the first axis 424, and / or a third axis 428 which is perpendicular to the first and second axes 424 and 426, for example for protection against overload and / or for gesture recognition via, for example, opposite tension measurement signals.

[0054] Fig. 8 and Fig. 9 show a perspective view and an exploded view of a foldable electronic device 100 according to a fifth embodiment of the invention, respectively.

[0055] Referring to Fig. 8 and Fig. 9, in the foldable electronic device 100, two or more panels are pivotally connected via a hinge 502 for unfolding or folding. A hinge housing 504 is disposed at a portion where the hinge 502 is connected, preventing intrusion of foreign matter and providing aesthetic appeal. During opening / closing of the foldable electronic device 100, mechanical stress may be generated in a folding portion 506 in which a flexible display 108 is folded.

[0056] The foldable electronic device 100 includes the flexible display 108, a hinge assembly 106, first and second supports 512 and 514, first and second printed circuit boards 516 and 518, a battery 520, and first and second outer casings 102 and 104.

[0057] The hinge assembly 106 allows the foldable electronic device 100 to be unfolded or folded. The hinge assembly 106 includes a first hinge frame 526, a second hinge frame 528, one or more hinges 502, and the hinge housing 504.

[0058] The first hinge frame 526 and the second hinge frame 528 are portions in which each side of the hinge assembly 106 is fixed during opening / closing of the foldable electronic device 100, and are connected to the outer casings 102 and 104 or the first and second supports 512 and 514 coupled to the outer casings 102 and 104, respectively. The first hinge frame 526 and the second hinge frame 528 are coupled to the first outer casing 102 or the first support 512, and the second outer casing 104 or the second support 514, respectively, to support the first outer casing 102 and the second outer casing 104 when the flexible display 108 is folded or unfolded around the folding portion 506 of the foldable electronic device 100.

[0059] The hinge 502 pivotally connects the first hinge frame 526 and the second hinge frame 528. The first hinge frame 526 has first grooves 526a, in each of which a portion of the hinge 502 sits and is coupled to a side facing the second hinge frame 528. The second hinge frame 528 has second grooves 528a, in each of which another portion of the hinge 502 sits and is coupled to a side facing the second hinge frame 528. The first grooves 526a and the second grooves 528a are formed to be aligned at positions that are symmetrical to each other around the folding portion 506. The first grooves 526a and the second grooves 528a are formed at positions symmetrical to each other about a first axis 530 of the folding portion 506 - a center line on which the foldable electronic device 100 is folded.The hinge 502 is arranged at a position that overlaps the folding portion 506 when the foldable electronic device 100 is folded from above the front surface or the upper surface in . Fig. 8 and Fig. 9 is considered.

[0060] In further developments of the invention, the hinge assembly 106 may include a plurality of hinges 502 to ensure a stronger coupling force than that of the first hinge frame 526 and the second hinge frame 526.

[0061] The first hinge frame 526 is arranged on one side and the second hinge frame 528 is arranged on an opposite side relative to the first axis 530 of the folding portion 506 of the foldable electronic device 100. The first hinge frame 526 is connected to the folding portion 506 via a first adhesive element (not shown) in a plan view. Fig. 9 is attached to a back side of a first portion 532 of the flexible display 108, and the second hinge frame 528 is attached to a back side of a second portion 534 of the flexible display 108 via a second adhesive element, not shown.

[0062] At least one voltage sensor 110 is arranged on a surface visible to a viewer of Fig. 9 or a side of the display 108 facing away therefrom or in the display 108 and on one side of the first axis 530 on or in the first region 532 or the second region 534 of the display 108 and in the vicinity of the folding section 506 and designed to measure a respective mechanical stress, that is to say a respective elongation or compression, of the folding section 506 of the display 108 and to output a corresponding stress measurement signal.

[0063] Alternatively or additionally, at least one voltage sensor 110 is arranged on a side of the hinge assembly 106 facing the viewer or a side facing away therefrom and on a side of the first axis 530 on or in the first hinge frame 526 and / or the second hinge frame 528, on a side of the first support 512 and / or the second support 514 facing the viewer or a side facing away therefrom and on a side of the first axis 530 on or in the first support 512 and / or the second support 514 and / or on a side of the first outer housing 102 and / or the second outer housing 104 facing the viewer or a side facing away therefrom and on a side of the first axis 530 on or in the first outer housing 102 and / or the second outer housing 104.

[0064] In order to detect twisting or opposite tensioning of the first region 532 and the second region 534 of the display 108, the first hinge frame 526 and the second hinge frame 528, the first support 512 and the second support 514 and / or the first outer housing 102 and the second outer housing 104 about a second axis 538, which is perpendicular to the first axis 530, and / or a third axis 540, which is perpendicular to the first and second axes 530 and 538, for example for protection against overload and / or for gesture recognition, in further developments of the invention at least two suitable tension sensors 110 are arranged to the left and right of the first axis 530, preferably at the same height or axially symmetrically.

[0065] Fig. 10 shows an exploded view of a mobile electronic terminal 100 with a flexible screen 108 as a foldable display device according to a sixth embodiment of the invention. Fig. Figure 11 shows a schematic representation of a hinge 106 in a folded state and Fig. 12 shows a schematic representation of an outer side of the hinge 106 in a flattened state.

[0066] Referring to the Fig. 10, Fig. 11 and Fig. 12, the mobile electronic terminal of the sixth embodiment comprises a first side housing 102 and a second side housing 104 and the hinge 106. The first side housing 102 and the second side housing 104 are located in a plan view in Fig. 10 on a left or right side of the mobile electronic device when the mobile electronic device is flattened.

[0067] The hinge 106 of the mobile electronic terminal is arranged between the first side housing 102 and the second side housing 104 to connect the first side housing 102 and the second side housing 104. The flexible screen 108 is arranged on an outer side of the mobile electronic terminal. A first supporting plate 608 of the flexible screen 108 of the first side housing 102 is arranged as a sliding plate to be slidable. A second supporting plate 610 of the flexible screen 108 of the second side housing 104 is arranged to be fixed.

[0068] The hinge 106 includes a central supporting portion 612, a first connecting portion 614, and a second connecting portion 616. The first connecting portion 614 and the second connecting portion 616 are rotatably mounted on a first side and a second side, respectively, of the central supporting portion 612 with respect to a first axis 618.

[0069] An outer side of the central supporting portion 612 has a curve 620 that matches a bend of the flexible screen 108. Grids 622 are provided on a first side and a second side with respect to the first axis 618, respectively. The first connecting portion 614 and the second connecting portion 616 are formed in a comb shape. The comb shape of the first connecting portion 614 has a fixed connecting portion and first combs 624, which are respectively inserted into the grids 622 of the first side of the central supporting portion 612. The comb shape of the second connecting portion 616 has a fixed connecting portion and second combs 626, which are respectively inserted into the grids 620 of the second side of the central supporting portion 612.

[0070] Further, restricting portions 628 are disposed in the grids 620, and the restricting portions 628 are connected to each other between grid walls to further enhance structural strength. The first and second combs 624 and 626 are supported when the mobile electronic terminal is in a flattened state to support the first connecting portion 614 and the second connecting portion 616 on the side of the respective combs 624 and 626, and the first and second combs 624 and 626 are restricted and protected when the mobile electronic terminal is in a folded state.

[0071] The first connecting portion 614 and the second connecting portion 616 are provided with or without a supporting portion for the flexible foldable screen 108, as needed. The fixed connecting portion of the first connecting portion 614 and the fixed connecting portion of the second connecting portion 616 are both provided with parts that are connected to the first side housing 102 and the second side housing 104.

[0072] At least one voltage sensor 110 is connected to a viewer of Fig. 10 or a side of the first or second side housing 102 and 104 facing away therefrom or in the first or second side housing 102 and 104 and in a vicinity of a side of the first axis 618 and designed to measure a respective mechanical stress, that is to say a respective extension or compression, of the first or second side housing 102 and 104, for example with respect to, e.g. parallel to, a second axis 632 which is perpendicular to the first axis 618, and / or a third axis 634 which is perpendicular to the first axis 618 and to the second axis 632, and to output a corresponding stress measurement signal.

[0073] Alternatively or additionally, at least one voltage sensor 110 is shown in a plan view in Fig. 12 on or in the central supporting section 612 preferably symmetrically about the first axis 618 and preferably in a vicinity of one of two ends of the central supporting section 612 at preferably a same height or axisymmetrically arranged and designed to measure a respective mechanical stress, that is to say a respective extension or compression, of the first or second side housing 102 and 104, for example with respect to, e.g. parallel to, the second axis 632 and to output a corresponding stress measurement signal.

[0074] To avoid twisting or opposite clamping in plan view in Fig. 10, Fig. 11 and Fig. 12 of a top and bottom part of the first side housing 102 and the second side housing 104 and / or the hinge 106 about the second axis 632 and / or the third axis 634, for example for protection against overload and / or for gesture recognition, in further developments of the invention at least two suitable voltage sensors 110 are suitably arranged to the left and right of the first axis 618, preferably at the same height or axially symmetrically on or in the first side housing 102 or the second side housing 104 and / or on or in the central section 612 of the hinge 106.

[0075] Fig. 13 shows a perspective view of a foldable electronic device 100 according to a seventh embodiment of the invention.

[0076] The foldable electronic device 100 includes a hinge assembly 106. The hinge assembly 106 couples a first housing 102 and a second housing 104 and can rotate the second housing 104 within a predetermined rotational range about the first housing 102 or, conversely, can rotate the first housing 102 within a predetermined rotational range about the second housing 104. The hinge assembly 106 includes, among other things, a first bracket 708 and a second bracket 710 coupled to a portion of the first housing 102 and a portion of the second housing 104, respectively. The first and second brackets 708 and 710 can rotate together with the first housing 102 and the second housing 104 as the foldable electronic device 100 rotates from a folded to an unfolded state or from the unfolded state to the folded state.

[0077] At least one voltage sensor 110 is arranged on a surface visible to a viewer of Fig. 13 or a side of the first or second carrier 708 and 710 facing away therefrom, on or in the first carrier 708 or second carrier 710 and in a vicinity of a side of a first axis 714, suitably arranged and designed to measure a respective mechanical stress, that is to say a respective extension or compression, of the first carrier 708 or the second carrier 710 or of the first housing 102 and the second housing 104, for example with respect to, e.g. parallel to, a second axis 716 which is perpendicular to the first axis 714, or a third axis 718 perpendicular to the first and second axes 714 and 716, and to output a corresponding stress measurement signal.

[0078] To avoid twisting or opposite tensioning of the Fig. 13, in order to detect the first and second housings 102 and 104 around the second axis 716 and / or third axis 716, for example for protection against overload and / or for gesture recognition, in further developments of the invention at least two voltage sensors 110 are arranged and designed to the left and right of the first axis 714 on or in the first and second supports 708 and 710 at at least one end of the foldable electronic device 100 along the first axis 714 and in a vicinity of the first axis 714, preferably at the same height or axially symmetrically.

[0079] Fig. 14 shows a schematic exploded view of a foldable display device 100 according to an eighth embodiment of the invention.

[0080] As in Fig. 14, the foldable display device 100 includes a first cover 102, a second cover 104, a hinge 106, and a display panel 108.

[0081] The first cover 102 and the second cover 104 serve as supporting units. That is, the first cover 102 and the second cover 104 are base members for supporting the display panel 108 and various components of the foldable display device 100. Furthermore, the first cover 102 and the second cover 104 include a receiving unit 810 that receives various components for driving the foldable display device 100.

[0082] A pair of hinge shafts 812 are provided to correspond to the first cover 102 and the second cover 104, respectively. That is, when the first cover 102 and the second cover 104 move, the respective hinge shaft 812 serves as a rotational center axis of the components coupled to the respective hinge shaft 812.

[0083] A pair of rotatable plates 814 are provided to be coupled to one end of the pair of hinge shafts 812. Further, the pair of rotatable plates 814 correspond to the first cover 102 and the second cover 104, respectively. That is, the pair of rotatable plates 814 has a plurality of fastening grooves that are fastened to a first fastening unit 816 of the first cover 102 and a second fastening unit 818 of the second cover 104. In the preferred case, the pair of rotatable plates 814 is fixed to the first fastening unit 816 and the second fastening unit 818 by a screw connection. Further, when the foldable display device 100 is folded or unfolded, the pair of rotatable plates 814 rotates according to the movement of the first cover 104 and the second cover 106.

[0084] At least one voltage sensor 110 is arranged on a surface visible to a viewer of Fig. 14 or a side of a rotatable plate 814 facing away therefrom, on or in the rotatable plate 814 and in a vicinity of a respective hinge shaft 812 and / or on or in a respective hinge shaft 812, suitably arranged and designed to measure a respective mechanical stress, that is to say a respective expansion or compression, of the respective rotatable plate 814 or of the first cover 102 and the second cover 104, for example with respect to, e.g. parallel to, a first axis 822 which is perpendicular to the hinge shafts 812, or a second axis 824 perpendicular to the hinge shafts 812 and the first axis 822, and to output a corresponding stress measurement signal.

[0085] To avoid twisting or opposite tensioning of the Fig. 14, or of the first cover 102 and the second cover 104 about the first axis 822 and / or second axis 824, for example for protection against overload and / or for gesture recognition, in further developments of the invention at least two voltage sensors 110 are arranged and designed in a suitable manner on or in each rotatable plate 814 and / or on or in a respective hinge shaft 812 on or in the vicinity of at least one end of the foldable display device 100, parallel to or along the hinge shafts 812, preferably at the same height or axially symmetrically.

[0086] Fig. 15 and Fig. 16 show a hinge 106 of a foldable electronic device according to a ninth embodiment of the invention in a stretched or folded state.

[0087] The hinge 106 includes a trajectory limiting device and a synchronization device. The trajectory limiting device is used to limit a direction of rotation of the hinge 106, and the synchronization device is used to realize the rotation of the hinge 106. The trajectory limiting device includes a hinge support 902, a first slider 904, and a second slider 906. The first slider 904 has a first hollow shaft 908, and the second slider 906 has a second hollow shaft 910. The synchronization device includes a cylindrical gear set 912, a first deflection wheel 914, and a second deflection wheel 916. The first deflection wheel 914 can have a wheel end 918 and a deflection end 920. Likewise, the second deflection wheel 916 can also have a corresponding wheel end 922 and a deflection end 924.The gear end 918 of the first idler gear 914 engages a first end gear 926 of the cylindrical gear set 912, and the gear end 922 of the second idler gear 916 engages a second end gear 928 of the cylindrical gear set 912; the idler end 920 of the first idler gear 914 mates with the first hollow shaft 908, and the idler end 924 of the second idler gear 916 mates with the second hollow shaft 910.

[0088] Against this background, when an external force is applied to the foldable electronic device provided with the hinge 106 and the force is further transmitted to the first slider 904, the wheel end 918 can transmit force to the cylindrical gear set 912 by displacing the deflection end 920 of the first deflection wheel 914 in the first hollow shaft 908, and the force is further transmitted to the wheel end 922 of the second deflection wheel 916 to drive the deflection end 924 of the second deflection wheel 916 to be displaced in the second hollow shaft 910.

[0089] Due to the limitation of the first hollow shaft 908 and the second hollow shaft 910, the hinge 106 can be arranged between the Fig. 15 and the condition shown in Fig. 16 or between the state shown in Fig. 16 and the condition shown in Fig. 15, that is, the angle of the first slider 904 relative to the hinge support 902 and the angle of the second slider 906 relative to the hinge support 902 are substantially equal at the same time (that is, the difference between the angle between the first slider 904 and the hinge support 902 and the angle between the second slider 906 and the hinge support 902 is relatively small and within an allowable range), and substantially synchronous movement between the first slider 904 and the second slider 906 is achieved. As an example, only the force applied to the first slider 904 is described here. A force may also be transmitted to the second slider 906, or a force may be transmitted to the first slider 904 and the second slider 906.

[0090] From the foregoing, it can be seen that the cylindrical gear set 912 allows a force to be substantially linear when the force is transmitted from the first slider 904 side to the second slider 906 side or from the second slider 906 side to the first slider 904 side. Thus, when the first slider 904 and the second slider 906 are opposed to each other, the first slider 904 and the second slider 906 can be driven to rotate with respect to the hinge bracket 902 by a cooperation of the cylindrical gear set 912, the first idler gear 914, and the second idler gear 916. This can prevent torque generated in the synchronization device and the travel path limiting device due to the misalignment of the first slider 904 and the second slider 906, and is beneficial for extending the service life of the hinge structure.

[0091] The hinge 106 has a first stop 930 and a second stop 932 for the first deflection wheel 914 and the second deflection wheel 916, respectively.

[0092] For the purpose of detecting an overload of the hinge 106 and / or for gesture detection by rotating the first deflection wheel 914 and the second deflection wheel 916 against the first and second stops 930 and 932, as shown in Fig. 15, a first suitably designed tension sensor 110 is suitably arranged on or in at least one of the first and second stops 930 and 932 or at another suitable location, for example, of the hinge support 902.

[0093] For the further or alternative purpose of detecting an overload of the hinge 106 and / or for gesture recognition by detecting a rotation of the first and second deflection wheels 914 and 916 about a first axis 936, which is perpendicular to the axes of rotation of the first and second end wheels 926 and 928, and / or a second axis 938, which is perpendicular to the axes of rotation of the first and second end wheels 926 and 928 and the first axis 936, in a further development of the invention, two suitably designed tension sensors 110 are suitably arranged along the axes of rotation of the first and second end wheels 926 and 928 to the left and right of these axes of rotation, preferably at a common height or axially symmetrically opposite one another.

[0094] For the above-mentioned purposes, alternatively or additionally, at least one second suitable tension sensor 110 is suitably arranged on or in at least one of the wheel ends 918 and 922 or one of the deflecting ends 920 and 924.

[0095] Fig. Figure 17 shows a control device according to the present invention for foldable electrical devices, which e.g. have been described above with reference to Fig. 1 to 16 and have voltage sensors. All described embodiments have in common that a foldable display device has at least one hinge for rotatably connecting at least two housing halves of the foldable display device along a transition region between the two housing halves, in which the hinge is located, wherein the hinge is rigidly constructed along the transition region.

[0096] The control device 1000 is operatively connected to at least one stress sensor 110 for detecting mechanical stresses in the foldable display device in order to control at least one function and / or at least one device of the foldable display device depending on a stress measurement signal of the at least one stress sensor 110.

[0097] According to a preferred embodiment of the invention, the foldable display device comprises a user alarm device 1004 which is connected to the control device 110 and can be activated by the control device 110 when at least one voltage measurement signal exceeds a certain threshold value in order to warn a user of the foldable display device of damage to the foldable display device and in particular to a hinge.

[0098] In an alternative embodiment of the invention or a further development of the invention, the foldable display device additionally comprises a gesture recognition device 1006, which is operatively connected to the control device 1000 and configured to recognize gestures performed by the user using the foldable display device. A first gesture and further gestures are defined by a single or multiple pushing apart of the housing halves and a single or multiple exceeding of at least one of the voltage threshold values ​​assigned to the first and further gestures, which is detected by the control device 1000. A further or several further gestures are defined by a specific duration or several durations of exceeding at least one of the further voltage threshold values ​​assigned to the several gestures, which is detected by the control device 1000.Another or several further gestures are defined by voltage measurement signals from several voltage measurement sensors that are the same or differ in some way, i.e., in terms of size, time shift, etc., which can be detected by the control device 1000.

[0099] In alternative embodiments of the invention or a further development of the invention, the foldable display device additionally has an activation device 1008, which is operatively connected to the control device 1000 and is designed to activate the foldable display device, e.g. to switch it on, when, for example, the Fig. 1C, the contact sections 112 strike or abut against each other with a certain contact pressure.

[0100] The control device 1000 and the other Fig. The devices shown in Figure 17 are implemented either partially or completely as hardware in, for example, the form of an electrical circuit or as instructions executable in a processing device, for example in the form of software, etc.

[0101] Fig. Figure 18 illustrates a method according to the invention for controlling foldable display devices, which have been described above with reference to Fig. 1 to 16 and have voltage sensors. The Fig. The method shown in Figure 18 is preferably carried out by a Fig. 17 shown control device 1000.

[0102] In a first step S1 of the method, at least one voltage signal is received from a voltage sensor of the foldable display device.

[0103] In a subsequent second step S2, the voltage measurement signal is compared or evaluated with at least one predetermined criterion, and it is determined whether the criterion is met or not. The predetermined criterion is a specific threshold value, a specific voltage measurement signal curve, such as increasing, decreasing, constant, having a sequence of a specific number or duration of maxima or minima, and / or similar. In the case of multiple voltage signals from multiple voltage sensors, the at least one criterion is whether voltage measurement signals have the same or opposite signs, different magnitudes, etc., or represent the same or differ in some way, i.e., in terms of magnitude, time-shifted, etc., voltage measurement signals that can be assigned, for example, to specific events and gestures.

[0104] If the at least one criterion is met in step S2, the method proceeds to a step S3 in which a function of the foldable display device is triggered and / or at least one device of the foldable display device, such as the user alarm device 1004, the gesture recognition device 1006 and / or the activation device 1006, is controlled.

[0105] The stress sensors described above are stress sensors that measure mechanical stress based on resistance changes, such as strain gauges or piezoresistive components, voltage changes, e.g. piezoelectric, capacitance changes, triboelectric changes and / or optical changes, etc.

[0106] Due to the limited installation space in the hinge area illustrated in the above embodiments, extremely compact voltage sensors are particularly advantageous. Two implementations for the voltage sensors are therefore particularly highlighted in the applications described here in the foldable display device.

[0107] In the first realization of the voltage sensor, which is Fig. 19, a semiconductor chip 1100, particularly preferably in silicon-based CMOS technology, is used, on which a first current mirror arrangement 1110 and / or a second current mirror arrangement 1120 are arranged.

[0108] Here, the first current mirror arrangement 1110 can measure normal stresses along the

[100] or

[010] crystal plane, while the second current mirror arrangement 1120 is arranged at a 45° angle and therefore enables the measurement of shear stresses, i.e., stresses along the

[110] or [] crystal plane. By integrating the first current mirror arrangement 1110 and the second current mirror arrangement 1120 on a single semiconductor chip 1100, various direction-dependent stress states can be used for overload detection and / or gesture control in the foldable display device. Such a semiconductor chip 1100 can be built very small using CMOS technology, namely with areas of less than 1 mm 2, allowing integration even in limited space in the hinge area of ​​the foldable display. For mechanical and electrical contact, the semiconductor chip is either soldered to a (preferably flexible) circuit board located in the hinge area using flip-chip technology, or the semiconductor chip is glued to a suitable location and electrically connected with a flexible cable.

[0109] In the second preferred embodiment of the voltage sensor, a capacitive sensor 110 is used, as shown by way of example in Fig. 20. A vertically integrated MEMS-ASIC chip is arranged on the surface 1258 located in the hinge area of ​​the foldable display device via an adhesive 1256. MEMS and ASIC are mechanically connected to one another via an external conductive bonding connection 1110, preferably arranged in the form of a frame at the edge of the chip to protect the interior of the MEMS-ASIC chip from environmental influences (e.g., particles, moisture), and via internal conductive bonding connections 1222 (in Fig. 20, only one is shown as an example) are also electrically connected to one another in order to control the MEMS chip or to process the MEMS signals in the ASIC. The MEMS element consists of a MEMS substrate 1106, preferably made of silicon, one or more insulation layers 1247 (preferably oxides and / or nitrides), one or more conductive wiring layers 1228, for example made of polycrystalline silicon, and optionally further conductive functional layers 1246, preferably made of silicon. In this exemplary embodiment, an upper electrode region 1216 is formed in the functional layer 1246, which is essentially free, i.e., detached from the MEMS substrate, and is only connected to the MEMS substrate or a wiring level arranged thereon in a lateral suspension region 1255. Evaluation electrodes 1218 are arranged in the wiring level 1228.

[0110] If the mechanical stress distribution in the hinge area on surface 1258 changes during use of the foldable display device, this leads to small changes in the distance between the upper electrode area 1216 and the evaluation electrodes 1218. The resulting capacitance changes can be detected by the vertically integrated evaluation circuit. The vertically integrated evaluation circuit is an ASIC, preferably in CMOS technology, which consists of an ASIC substrate 1212 with a transistor area 1234 and a wiring area 1230 formed from several metal and insulation layers 1232. The electrical inputs and outputs of the ASIC are routed via through-silicon vias (TSVs) 1236 to the rear of the ASIC in a redistribution layer (RDL).Solder contacts 1242 are arranged on the back of the ASIC via suitable metallization intermediate layers (UBM, under bump metal, not shown separately). These can be connected to a circuit board 1244 arranged in the foldable display device via a flexible electrical line 1260. As an alternative to mechanical mounting using adhesive and electrical contacting using a flexible cable, it is also possible to solder the vertically integrated MEMS ASIC component to a circuit board or a flexible circuit board that is mechanically connected to the surface 1258.

[0111] The arrangement 110 combines several technical advantages, which, when combined, make it particularly advantageous for use in the hinge area of ​​a foldable display device. A first advantage is the small achievable size, since the footprint of the capacitive voltage sensor 110 is less than 1 mm 2This makes it possible to integrate the sensor even in very space-critical positions, such as in the hinge area of ​​a foldable display device. Secondly, the capacitive stress sensors presented here can detect mechanical stresses in various directions. This allows for particularly flexible overload or gesture detection, and suitable software can be used to respond differently to different stress situations caused by the end user. A third advantage is the combination of a large measuring range with simultaneous high signal sensitivity and low power consumption. With regard to all of the aspects mentioned (size, multi-axis capability, performance), the capacitive stress sensors as integrated MEMS-ASIC chips are superior to more widespread approaches such as the use of strain gauges.

[0112] An example of gesture recognition is the case in which a screen action, such as a zoom-in / zoom-out function, is triggered by a torsional movement (twist) imprinted on the frame of the foldable display device and detected by at least one tension sensor arranged in the hinge area. Fig. 21A, Fig. 21B illustrate two different torsion-based deformation states of a foldable display device 100. The foldable display device has a first edge 1226 and a second edge 1330, at which the user typically holds the device with both hands. If the user now exerts an opposing torque on the two edges, a twisted state 1102 results around the hinge axis 1310 of the foldable display device 100, which is oriented parallel to the y-axis. If the user exerts a torque with the opposite sign, a state as in Fig. 21B. The measurement of the torsion state via one or more tension sensors 110 can be used, for example, to implement a zoom-in function in the state of Fig. 21A and a zoom-out function in the state of Fig. 21B.

[0113] Such functionality can thus replace or complement a well-known zoom-to-pinch function, in which the screen content is reduced by pinching (moving the fingers closer together) and enlarged by pinching (moving the fingers apart). This is particularly advantageous for foldable display devices, as these are often held with two hands due to their size. The pinch-to-zoom gesture then requires either holding the device with one hand to perform pinch-to-zoom with the other hand, or performing the pinch-to-zoom gesture with one finger each (typically the thumb) of the left and right hand.While the first type of operation (one-handed holding) carries the risk of the foldable display slipping from the user's hands, two-thumb operation results in significantly less precise input for most people due to the poor coordination between the right and left hands. This can lead to incorrect inputs, for example, due to not touching the screen with both thumbs simultaneously. These disadvantages can be avoided by detecting the housing torsion using at least one tension sensor 110 arranged in or near the hinge area.

[0114] As an alternative to the zoom-in / zoom-out function, the signals measured by at least one voltage sensor 110 can also be used for other forms of gesture recognition and function control, e.g., for scrolling, swiping, opening / closing screen windows, for media control (play, pause, fast forward / rewind) or for controlling computer games.

[0115] In the present invention, several features have been designated "first" and "second." These designations serve only to clearly distinguish the individual features. In particular, they are not intended to imply any spatial or functional arrangement or prioritization.

[0116] When a list of alternatives in this application is marked with the designation “or”, this should be understood to mean both the listed alternatives taken individually and, where appropriate, a combination of several or all of the listed alternatives. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2 596 215 B2

[0004] US 2015 / 241 925 A1

[0005] US 2009 / 184 921 A1

[0006] US 2011 / 167 391 A1

[0006]

Claims

[1] Foldable display device (100) comprising: a first housing portion (102); a second housing section (103); a hinge assembly (106) connecting the first housing portion (102) to the second housing portion (104) for rotation about a folding axis; a display (108) extending continuously over at least a portion of a first major surface of the first housing portion (102) and at least a portion of a second major surface of the second housing portion (104); and a sensor arrangement (110) with one or a plurality of sensors for measuring mechanical stresses in the hinge arrangement (106) and / or in the display (108). [2] The foldable display device (100) of claim 1, further comprising: a control device configured to detect sensor signals from the sensor arrangement (110) and to control the display (108) in dependence on the detected sensor signals. [3] Foldable display device (100) according to claim 1 or 2, wherein the sensor arrangement (110) comprises a plurality of sensors for measuring mechanical stress in the hinge arrangement (106) and / or in the display (108). [4] The foldable display device (100) according to claim 3, wherein the control device is configured: to detect sensor signals of the sensor arrangement (110); to recognize a gesture performed by a user based on the sensor signals; and to control the display device (100) depending on the recognized gesture. [5] Foldable display device (100) according to one of the preceding claims, wherein the sensor arrangement (110) comprises stress sensors configured to measure an extension and / or compression of the display (108) and / or the hinge arrangement (106). [6] Foldable display device (100) according to one of the preceding claims, wherein at least one sensor of the sensor arrangement (110) is designed to measure a mechanical stress between the first housing section (102) and the second housing section (104). [7] Foldable display device (100) according to one of the preceding claims, wherein the sensor arrangement (110) is configured to measure an extension and / or a compression in a foldable region of the display (108) at the hinge arrangement (106). [8] Foldable display device (100) according to one of the preceding claims, wherein the display (108) is arranged outside or inside with respect to the hinge arrangement (106) in a folded state of the display device (100). [9] The foldable display device (100) of claim 8, wherein the display (108) includes a first portion on the first housing portion (102), a second portion on the second housing portion (104), and a middle portion (228) on the hinge assembly (106) connecting the first portion and the second portion. [10] The foldable display device (100) of claim 9, wherein the display has respective folding portions (226) between the first portion and the middle portion (228) and between the second portion and the middle portion (228). [11] Foldable display device (100) according to claim 10, wherein a sensor is arranged on each of the folding sections (226). [12] Foldable display device (100) according to one of the preceding claims, wherein a sensor is arranged on the display (108) on each of the two sides of the folding axis. [13] A method for operating a foldable display device (100) comprising the steps of: Detecting a sensor signal from a sensor arrangement (110) indicative of a voltage in a display (108) and / or a hinge arrangement (106) of the display device (100); Comparing the sensor signal with a predetermined criterion; and if the criterion is met, triggering a function for controlling the display device (100).

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