Foldable display device and driving method thereof

Abstract

A foldable display device and a driving method thereof, the foldable display device comprising a display panel (100), at least one capacitive sensor (600) and at least one detection circuit; the display panel (100) comprises at least one bending area (300) configured to bend, the capacitive sensor (600) comprises a first electrode structure and a second electrode structure configured to form a sensing capacitor, and the detection circuit is connected with the first electrode structure and the second electrode structure respectively, the detection circuit is configured to detect a capacitance value of the sensing capacitor, and obtain a bending angle of the foldable display device according to the capacitance value or a capacitance change amount of the sensing capacitor.

Description

Technical Field

[0001] This article relates to, but is not limited to, the field of display technology, specifically to a foldable display device and its driving method. Background Technology

[0002] Organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (QLEDs) are active-matrix display devices with advantages such as self-illumination, wide viewing angle, high contrast, low power consumption, extremely high response speed, thinness, flexibility, and low cost. With the continuous development of display technology, flexible displays using OLEDs or QLEDs as light-emitting devices and controlled by thin-film transistors (TFTs) have become the mainstream products in the display field. Summary of the Invention

[0003] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0004] On one hand, this disclosure provides a foldable display device, including a display panel, at least one capacitive sensor, and at least one detection circuit; the display panel includes at least one bending area configured for bending, the capacitive sensor includes a first electrode structure and a second electrode structure configured to form a sensing capacitor, the detection circuit is connected to the first electrode structure and the second electrode structure respectively, and the detection circuit is configured to detect the capacitance value of the sensing capacitor and obtain the bending angle of the foldable display device based on the capacitance value of the sensing capacitor or the capacitance change.

[0005] In an exemplary embodiment, the display panel further includes a first non-folding area and a second non-folding area disposed on both sides of the bending area, wherein the first electrode structure is connected to the first non-folding area and the second electrode structure is connected to the second non-folding area.

[0006] In an exemplary embodiment, the foldable display device includes a reinforcing layer and a display structure layer disposed on the reinforcing layer. The display structure layer is provided with at least one mounting groove. The mounting groove includes at least a groove bottom surface exposed by the reinforcing layer, a first groove wall located in the first non-folding area, and a second groove wall located in the second non-folding area. The capacitive sensor is disposed in the mounting groove. The first electrode structure is connected to the first groove wall and / or the groove bottom surface, and the second electrode structure is connected to the second groove wall and / or the groove bottom surface.

[0007] In an exemplary embodiment, the first electrode structure includes a first fixing structure and a first electrode. The first fixing structure is connected to the first wall and / or bottom surface of the mounting groove, and the first electrode is disposed on the side of the first fixing structure near the reinforcing layer. The second electrode structure includes a second fixing structure and a second electrode. The second fixing structure is connected to the second wall and / or bottom surface of the mounting groove, and the second electrode is disposed on the side of the second fixing structure away from the reinforcing layer.

[0008] In an exemplary embodiment, the first fixing structure includes a first base frame and a first side frame. The first base frame is a strip shape extending along a first direction, and the first side frame is a strip shape extending along a second direction. The first side frame is connected to the end of the first base frame away from the bending area, and the second direction intersects the first direction. The first side frame is connected to the first groove wall and / or the bottom surface of the mounting groove, and the first electrode is disposed on the side of the first base frame near the reinforcing layer. The second fixing structure includes a second base frame and a second side frame. The second base frame is a strip shape extending along the first direction, and the second side frame is a strip shape extending along the second direction. The second side frame is connected to the end of the second base frame away from the bending area. The second electrode is disposed on the side of the second base frame away from the reinforcing layer, and the second side frame is connected to the second groove wall of the mounting groove, and / or the second base frame is connected to the bottom surface of the mounting groove.

[0009] In an exemplary embodiment, the first fixing structure includes a first side, a second side, a third side, and a fourth side that are sequentially connected and form an annular cavity. The first and third sides extend along a first direction, and the second and fourth sides extend along a second direction, which intersects the first direction. The third side is connected to the bottom surface of the mounting groove, and / or the fourth side is connected to the first wall of the mounting groove. The first electrode is disposed on the side of the first side facing the reinforcing layer, and at least one opening is provided on the second side. The second fixing structure is a strip-shaped support layer extending along the first direction. The strip-shaped support layer is connected to the bottom surface of the mounting groove, and / or the strip-shaped support layer is connected to the second wall of the mounting groove. A first portion of the second electrode near the first non-folding area extends into the annular cavity of the first fixing structure through the opening, such that the orthographic projection of the first electrode on the plane of the foldable display device at least partially overlaps with the orthographic projection of the second electrode on the plane of the foldable display device. A second portion of the second electrode away from the first non-folding area is disposed on the side of the strip-shaped support layer away from the reinforcing layer.

[0010] In an exemplary embodiment, at least one support platform is provided on the side of the third side away from the reinforcing layer, and the support platform is configured to support the second electrode extending into the annular cavity.

[0011] In an exemplary embodiment, the foldable display device further includes a connector, a first housing and a second housing disposed on both sides of the connector, and the display panel further includes a first non-foldable area and a second non-foldable area disposed on both sides of the bending area. The first non-foldable area is connected to the first housing, and the second non-foldable area is connected to the second housing. The first electrode structure and the second electrode structure are disposed on the connector.

[0012] In an exemplary embodiment, the connecting body includes a rotating shaft, a first connecting member, a second connecting member, a first electrode structure, and a second electrode structure respectively sleeved on the rotating shaft; the first connecting member includes a first cylindrical body sleeved on the rotating shaft and a first connecting piece disposed on the first cylindrical body, the first connecting piece being connected to the first housing; the second connecting member includes a second cylindrical body sleeved on the rotating shaft and a second connecting piece disposed on the second cylindrical body, the second connecting piece being connected to the second housing; the first electrode structure includes a third cylindrical body sleeved on the rotating shaft and a third electrode disposed on the third cylindrical body, the third cylindrical body being connected to the first cylindrical body; the second electrode structure includes a fourth cylindrical body sleeved on the rotating shaft and a fourth electrode disposed on the fourth cylindrical body, the fourth cylindrical body being connected to the second cylindrical body; the orthographic projection of the third electrode on a plane perpendicular to the rotating shaft at least partially overlaps with the orthographic projection of the fourth electrode on a plane perpendicular to the rotating shaft.

[0013] In an exemplary embodiment, the detection circuit includes an input module, an output compensation module, a reset module, and a processing module; wherein,

[0014] The input module is connected to a first power line, a first signal line, and a first node, respectively. The first node is connected to the first electrode of the first electrode structure. The input module is configured to output a high-level voltage signal of the first power line to the first node under the control of the first signal line to charge the sensing capacitor.

[0015] The compensation output module is connected to the second signal line, the third signal line, the first node, the second node, and the processing module, respectively. The second node is connected to the second power line and the second electrode of the second electrode structure. The compensation output module is configured to compensate for the basic noise of the detection circuit under the control of the second signal line, and to output the voltage of the first node to the processing module under the control of the second signal line and the third signal line.

[0016] The reset module is connected to the fourth signal line, the second power line, the first node, and the second node respectively, and is configured to output the voltage of the second node to the first node under the control of the fourth signal line, so as to initialize and reset the sensing capacitor.

[0017] The processing module is connected to the compensation output module and is configured to receive and process the signal output by the compensation output module, and output a data signal that is proportional to the capacitance value of the sensing capacitor.

[0018] In an exemplary embodiment, the input module includes a first switch, the control electrode of the first switch is connected to the first signal line, the first electrode of the first switch is connected to the first power line, and the second electrode of the first switch is connected to the first node.

[0019] In an exemplary embodiment, the compensation output module includes a second switch, a third switch, and a compensation capacitor. The control electrode of the second switch is connected to the second signal line, the first electrode of the second switch is connected to the first node, the second electrode of the second switch is connected to the first plate of the compensation capacitor, the second plate of the compensation capacitor is connected to the second node, the control electrode of the third switch is connected to the third signal line, the first electrode of the third switch is connected to the first node, and the second electrode of the third switch is connected to the processing module.

[0020] In an exemplary embodiment, the reset module includes a fourth switch, the control electrode of the fourth switch is connected to the fourth signal line, the first electrode of the fourth switch is connected to the second node, and the second electrode of the fourth switch is connected to the first node.

[0021] In an exemplary embodiment, the processing module includes an integrating amplifier, an analog-to-digital converter, and a feedback capacitor. The feedback capacitor is disposed between the negative input terminal and the output terminal of the integrating amplifier. The positive input terminal of the integrating amplifier is connected to a reference voltage line. The negative input terminal of the integrating amplifier is connected to the compensation output module. The output terminal of the integrating amplifier is connected to the input terminal of the analog-to-digital converter. The output terminal of the analog-to-digital converter outputs a data signal proportional to the capacitance value of the sensing capacitor.

[0022] In an exemplary embodiment, the input module includes a first switch, the compensation output module includes a second switch, a third switch and a compensation capacitor, the reset module includes a fourth switch, and the processing module includes an integrating amplifier, an analog-to-digital converter and a feedback capacitor;

[0023] The control electrode of the first switch is connected to the first signal line, the first electrode of the first switch is connected to the first power line, and the second electrode of the first switch is connected to the first node.

[0024] The control electrode of the second switch is connected to the second signal line, the first electrode of the second switch is connected to the first node, the second electrode of the second switch is connected to the first plate of the compensation capacitor, and the second plate of the compensation capacitor is connected to the second node.

[0025] The control electrode of the third switch is connected to the third signal line, the first electrode of the third switch is connected to the first node, and the second electrode of the third switch is connected to the processing module.

[0026] The control electrode of the fourth switch is connected to the fourth signal line, the first electrode of the fourth switch is connected to the second node, and the second electrode of the fourth switch is connected to the first node.

[0027] The feedback capacitor is disposed between the negative input terminal and the output terminal of the integrating amplifier.

[0028] The positive input terminal of the integrating amplifier is connected to the reference voltage line, the negative input terminal of the integrating amplifier is connected to the compensation output module, the output terminal of the integrating amplifier is connected to the input terminal of the analog-to-digital converter, and the output terminal of the analog-to-digital converter outputs a data signal proportional to the capacitance value of the sensing capacitor.

[0029] On the other hand, this disclosure also provides a driving method for driving the aforementioned foldable display device, comprising:

[0030] Obtain the folding angle of the foldable display device;

[0031] Color shift correction is performed on the folded area based on the folding angle.

[0032] In an exemplary embodiment, obtaining the folding angle of the foldable display device includes:

[0033] Acquire and store the initial data signal output by the detection circuit when the foldable display device is in an unbent state;

[0034] Acquire the bending data signal output by the detection circuit when the foldable display device is in a bent state;

[0035] The bending angle of the foldable display device is obtained based on the initial data signal and the bending data signal.

[0036] In an exemplary embodiment, obtaining the bending angle of the foldable display device based on the initial data signal and the bending data signal includes:

[0037] Calculate the difference between the initial data signal and the bent data signal;

[0038] The bending angle of the foldable display device is obtained based on the difference and a pre-set bending angle coefficient.

[0039] In an exemplary embodiment, the bending angle coefficient is obtained by a calibration process, which includes:

[0040] Prepare foldable display devices;

[0041] Place the foldable display device in a fully unfolded state and acquire the initial data signal output by the detection circuit;

[0042] The foldable display device is placed in a fully engaged state, and the engagement data signal output by the detection circuit is obtained;

[0043] The bending angle coefficient is obtained based on the initial data signal and the combined data signal.

[0044] After reading and understanding the accompanying diagrams and detailed descriptions, the other aspects can be understood. Attached Figure Description

[0045] The accompanying drawings are used to provide an understanding of the technical solutions of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the technical solutions of this disclosure and do not constitute a limitation on the technical solutions of this disclosure.

[0046] Figure 1 This is a schematic diagram of the structure of a display device;

[0047] Figure 2 This is a schematic diagram of the structure of a foldable display device according to an exemplary embodiment of the present disclosure;

[0048] Figure 3a and Figure 3b This is a schematic diagram of a foldable display device in a folded state;

[0049] Figures 4a to 4d This is a schematic diagram of the structure of a capacitive sensor, which is an exemplary embodiment of the present disclosure.

[0050] Figure 5a and Figure 5b This is a schematic diagram of a structure in which a capacitive sensor is disposed on a display panel according to the present disclosure;

[0051] Figure 6 This is a schematic diagram of another structure of a display panel with a capacitive sensor as disclosed in this disclosure;

[0052] Figure 7 This is a schematic diagram of the structure of another foldable display device according to an exemplary embodiment of the present disclosure;

[0053] Figures 8a to 8c This is a schematic diagram of the structure of a connector as an exemplary embodiment of the present disclosure;

[0054] Figure 9 This is a schematic diagram of the structure of a detection circuit as an exemplary embodiment of the present disclosure;

[0055] Figure 10 This is a schematic diagram of the structure of the input module, which is an exemplary embodiment of this disclosure.

[0056] Figure 11 This is a schematic diagram of the compensation output module structure as an exemplary embodiment of the present disclosure;

[0057] Figure 12 This is a schematic diagram of the reset module structure as an exemplary embodiment of the present disclosure;

[0058] Figure 13 This is a schematic diagram of the processing module structure as an exemplary embodiment of the present disclosure;

[0059] Figure 14 This is a schematic diagram of another detection circuit according to an exemplary embodiment of the present disclosure;

[0060] Figure 15 This is a timing diagram of a detection circuit as an exemplary embodiment of the present disclosure.

[0061] Explanation of reference numerals in the attached figures:

[0062] 10—First fixing structure; 11—First substrate; 12—First electrode;

[0063] 20—Second fixing structure; 21—Second substrate; 22—Second electrode;

[0064] 31—First shell; 32—Second shell; 33—Connector;

[0065] 34—Shaft; 41—First cylinder; 42—First connecting piece;

[0066] 51—Second cylinder; 52—Second connecting piece; 61—Third cylinder;

[0067] 62—Third electrode; 71—Fourth cylinder; 72—Fourth electrode;

[0068] 100—Display panel; 101—Reinforcing layer; 102—First adhesive layer;

[0069] 103—Display substrate layer; 104—Second adhesive layer; 105—Touch substrate layer;

[0070] 106—Third adhesive layer; 107—Cover plate layer; 200—First non-folded area;

[0071] 201—First display area; 202—First border area; 300—Bending area;

[0072] 400—Second non-folded area; 401—Second display area; 402—Second border area;

[0073] 500—Installation slot; 501—First slot wall; 502—Second slot wall;

[0074] 510—bottom of the tank; 600—capacitive sensor. Detailed Implementation

[0075] To make the objectives, technical solutions, and advantages of this disclosure clearer, embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. Note that the implementation methods can be carried out in many different forms. Those skilled in the art will readily understand that the methods and content can be varied in various forms without departing from the spirit and scope of this disclosure. Therefore, this disclosure should not be construed as limited to the content described in the following embodiments. Without conflict, the embodiments and features in the embodiments of this disclosure can be arbitrarily combined with each other.

[0076] The scale of the figures in this disclosure can be used as a reference in actual manufacturing processes, but is not limited thereto. For example, the aspect ratio of the channel, the thickness and spacing of each film layer, and the width and spacing of each signal line can be adjusted according to actual needs. The number of pixels in the display substrate and the number of sub-pixels in each pixel are not limited to the quantities shown in the figures. The figures described in this disclosure are only schematic diagrams of the structure, and one aspect of this disclosure is not limited to the shapes or values ​​shown in the figures.

[0077] The ordinal numbers “first,” “second,” and “third” used in this specification are used to avoid confusion among the constituent elements, not to limit their quantity.

[0078] In this specification, for convenience, terms such as "middle," "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are used to indicate orientation or positional relationships in conjunction with the accompanying drawings. This is solely for the purpose of facilitating the description and simplification, and does not imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this disclosure. The positional relationships of the constituent elements may be appropriately varied depending on the orientation of each constituent element being described. Therefore, the use of terms not limited to those described in the specification may be appropriately replaced as needed.

[0079] In this specification, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection, an indirect connection via an intermediate component, or a connection within two components. Those skilled in the art will understand the specific meaning of these terms in this disclosure based on the specific circumstances.

[0080] In this specification, a transistor is a device that includes at least three terminals: a gate electrode, a drain electrode, and a source electrode. A transistor has a channel region between the drain electrode (drain electrode terminal, drain region, or drain electrode) and the source electrode (source electrode terminal, source region, or source electrode), and current can flow through the drain electrode, the channel region, and the source electrode. Note that in this specification, the channel region refers to the region through which current primarily flows.

[0081] In this specification, the first electrode can be the drain electrode and the second electrode can be the source electrode, or vice versa. In cases where transistors with opposite polarities are used or the current direction changes during circuit operation, the functions of the "source electrode" and "drain electrode" may sometimes be interchanged. Therefore, in this specification, the "source electrode" and "drain electrode" can be interchanged, and the "source terminal" and "drain terminal" can be interchanged.

[0082] In this specification, "electrical connection" includes the situation where components are connected together by elements that have a certain electrical function. There are no particular limitations on what constitutes an "electrical function," as long as it allows for the transmission and reception of electrical signals between the connected components. Examples of "electrical functions" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements with various functions.

[0083] In this specification, "parallel" refers to the state where the angle formed by two straight lines is greater than or equal to -10° and less than 10°, and therefore also includes the state where the angle is greater than or equal to -5° and less than 5°. Similarly, "perpendicular" refers to the state where the angle formed by two straight lines is greater than or equal to 80° and less than 100°, and therefore also includes the state where the angle is greater than or equal to 85° and less than 95°.

[0084] In this specification, the terms "film" and "layer" may be interchanged. For example, "conductive layer" may sometimes be replaced with "conductive film." Similarly, "insulating film" may sometimes be replaced with "insulating layer."

[0085] In this specification, triangles, rectangles, trapezoids, pentagons, or hexagons are not strictly defined; they can be approximate triangles, rectangles, trapezoids, pentagons, or hexagons. Small deformations due to tolerances are possible, as are chamfered corners, curved edges, and other variations.

[0086] In this disclosure, “about” means a value that is not strictly limited and allows for process and measurement errors.

[0087] With the development of display technology, flexible display devices can change screen size through winding, folding, and bending, forming rollable, bendable, foldable, and sliding displays. These can be applied not only to mobile devices such as smartphones and tablet computers, but also to televisions, vehicle displays, and wearable devices, expanding their application areas. Among these, foldable displays, due to their bendable and foldable characteristics, allow for thinner, lighter, and more portable displays, and are increasingly being used in foldable phones and other electronic devices.

[0088] Figure 1 This is a schematic diagram of the structure of a display device. Figure 1As shown, the display device may include a timing controller, a data driver, a scan driver, a light-emitting driver, and a pixel array. The timing controller is connected to the data driver, the scan driver, and the light-emitting driver. The data driver is connected to multiple data signal lines (D1 to Dn), the scan driver is connected to multiple scan signal lines (S1 to Sm), and the light-emitting driver is connected to multiple light-emitting signal lines (E1 to Eo). The pixel array may include multiple sub-pixels Pxij, where i and j can be natural numbers. At least one sub-pixel Pxij may include a circuit unit and a light-emitting device connected to the circuit unit. The circuit unit may include at least one scan signal line, at least one data signal line, at least one light-emitting signal line, and a pixel driving circuit. In an exemplary embodiment, the timing controller may provide grayscale values ​​and control signals of specifications suitable for the data driver to the data driver, provide clock signals, scan start signals, etc. of specifications suitable for the scan driver to the scan driver, and provide clock signals, emission stop signals, etc. of specifications suitable for the light-emitting driver to the light-emitting driver. The data driver can use grayscale values ​​and control signals received from the timing controller to generate data voltages to be provided to data signal lines D1, D2, D3, ..., Dn. For example, the data driver can sample grayscale values ​​using a clock signal and apply data voltages corresponding to the grayscale values ​​to data signal lines D1 to Dn in pixel rows, where n can be a natural number. The scan driver can generate scan signals to be provided to scan signal lines S1, S2, S3, ..., Sm by receiving clock signals, scan start signals, etc., from the timing controller. For example, the scan driver can sequentially provide scan signals with on-level pulses to scan signal lines S1 to Sm. For example, the scan driver can be configured as a shift register and can generate scan signals by sequentially transmitting scan start signals in the form of on-level pulses to the next stage circuit under the control of a clock signal, where m can be a natural number. The light-emitting driver can generate transmit signals to be provided to light-emitting signal lines E1, E2, E3, ..., Eo by receiving clock signals, transmit stop signals, etc., from the timing controller. For example, an LED driver can sequentially provide transmit signals with cutoff level pulses to LED signal lines E1 to Eo. For example, the LED driver can be configured as a shift register and can generate transmit signals by sequentially transmitting transmit stop signals in the form of cutoff level pulses to the next stage circuit under the control of a clock signal, where o can be a natural number.

[0089] This disclosure provides a foldable display device, including a display panel, at least one capacitive sensor, and at least one detection circuit; the display panel includes at least one bending region configured for bending, the capacitive sensor includes a first electrode structure and a second electrode structure configured to form a sensing capacitor, the detection circuit is connected to the first electrode structure and the second electrode structure respectively, and the detection circuit is configured to detect the capacitance value of the sensing capacitor and obtain the bending angle of the foldable display device based on the capacitance value or the capacitance change of the sensing capacitor.

[0090] In one exemplary embodiment, a capacitance sensor can be disposed on the display panel, a first electrode structure is connected to a first non-folding area, and a second electrode structure is connected to a second non-folding area. The first electrode structure and the second electrode structure form a sensing capacitor that can change its capacitance value with the bending angle, so that the detection circuit can obtain the bending angle of the foldable display device based on the amount of capacitance change of the sensing capacitor.

[0091] Figure 2 This is a schematic diagram of the structure of a foldable display device as an exemplary embodiment of this disclosure. Figure 2 As shown, in an exemplary embodiment, the foldable display device may include a display panel 100, at least one capacitive sensor 600, and at least one detection circuit. Figure 2 (Not shown in the image) A capacitance sensor 600 is disposed on the display panel 100 and configured to form a sensing capacitor whose capacitance value can change with the bending angle. A detection circuit is connected to the capacitance sensor 600 and configured to detect the capacitance value of the sensing capacitor and obtain the bending angle of the foldable display device based on the amount of capacitance change of the sensing capacitor.

[0092] In an exemplary embodiment, the display panel 100 may be rectangular in shape. The display panel 100 may include at least a first non-folding area 200, a bending area 300, and a second non-folding area 400 sequentially arranged along a first direction D1. The first non-folding area 200 is located on the side opposite to the first direction D1 of the bending area 300, and the second non-folding area 400 is located on one side of the bending area 300 along the first direction D1. In the exemplary embodiment, the bending area refers to the area where the display panel needs to bend when bent, and the non-folding area refers to the area where the display panel does not bend or bends only slightly when bent.

[0093] In an exemplary embodiment, the bending area 300 can be a strip shape extending along a third direction D3, and the first non-folding area 200 and the second non-folding area 400 can be rectangular. The first non-folding area 200 may include a first display area 201 and a first border area 202 located on at least one side of the first display area 201 in the third direction D3, and the second non-folding area 400 may include a second display area 401 and a second border area 402 located on at least one side of the second display area 401 in the second direction D2, wherein the third direction D3 intersects with the first direction D1.

[0094] In an exemplary embodiment, the display panel 100 may include a plurality of bent areas 300, or the display panel 100 may include at least one bent area 300 and at least one non-folded area disposed along a third direction D3. The number, division method, and positional relationship of the bent areas and non-folded areas can be determined according to actual needs, and are not limited herein. In the following exemplary embodiments, the display panel is described as including three parts (a bent area and a first non-folded area and a second non-folded area on both sides of the bent area).

[0095] Figure 3a and Figure 3b This is a schematic diagram of a foldable display device in a folded state. In an exemplary embodiment, the display device may be provided with a hinge that extends along a third direction D3, and the non-folding area can be deflected relative to the hinge to achieve folding. In an exemplary embodiment, the foldable display device can achieve an inward folding state, such as... Figure 3a As shown, or, the foldable display device can achieve an outward folding state, such as... Figure 3b As shown. When a foldable display device is folded, whether inward or outward, color distortion typically occurs in the bending area and its vicinity as the folding angle changes, resulting in a poor user experience. Currently, one reason why the color distortion problem in the bending area has not been effectively solved is the lack of means to monitor the bending angle in real time. Traditional angle sensors are unsuitable for thinner display devices due to their large size (typically ≥25mm in diameter) and the need for high voltage / current drive.

[0096] In an exemplary embodiment, the first electrode structure may include a first electrode as one plate of a sensing capacitor, and the second electrode structure may include a second electrode as the other plate of a sensing capacitor. The orthographic projection of the first electrode on the plane of the foldable display device and the orthographic projection of the second electrode on the plane of the foldable display device at least partially overlap, and the overlapping area of ​​the first electrode and the second electrode has a one-to-one correspondence with the bending angle.

[0097] In an exemplary embodiment, when the foldable display device is not bent, the orthographic projections of the first electrode and the second electrode on the plane of the foldable display device have a first overlapping area; when the foldable display device is bent, the orthographic projections of the first electrode and the second electrode on the plane of the foldable display device have a second overlapping area. In an exemplary embodiment, the first overlapping area may be larger than the second overlapping area.

[0098] In an exemplary embodiment, the capacitive sensor 600 can be a strip shape extending along the first direction D1. A portion of the capacitive sensor 600 is disposed on the side of the first frame area 202 near the bending area 300, and another portion of the capacitive sensor 600 is disposed on the side of the second frame area 402 near the bending area 300. The middle portion of the capacitive sensor 600 is disposed in the bending area 300. That is, the first end of the capacitive sensor 600 is located in the first frame area 202, and the second end of the capacitive sensor 600 extends along the first direction D1, crosses the bending area 300, and is located in the second frame area 402.

[0099] In the exemplary embodiments of this disclosure, by providing a capacitive sensor on the display panel, when the foldable display device is bent, the capacitive sensor can change its capacitance value with the bending angle. The amount of capacitance change of the capacitive sensor has a one-to-one correspondence with the bending angle of the foldable display device. The detection circuit can obtain the bending angle of the foldable display device by detecting the amount of capacitance change of the capacitive sensor.

[0100] Figures 4a to 4d This is a schematic diagram of a capacitive sensor structure according to an exemplary embodiment of the present disclosure. In an exemplary embodiment, the capacitive sensor may include a first electrode structure and a second electrode structure disposed opposite to each other. The first electrode structure may include a first substrate 11 and a first electrode 12, and the second electrode structure may include a second substrate 21 and a second electrode 22. The first electrode 12 is disposed on the side of the first substrate 11 facing the second substrate 21, and the second electrode 22 is disposed on the side of the second substrate 21 facing the first substrate 11. The orthographic projection of the first electrode 12 on the second substrate 21 and the orthographic projection of the second electrode 22 on the second substrate 21 at least partially overlap, such that the first electrode 12 and the second electrode 22 form a sensing capacitance.

[0101] Figure 4a This is a schematic diagram showing the relative positions of the first and second electrodes when the foldable display device is not bent. Figure 4b for Figure 4a A top view. (e.g.) Figure 4a and Figure 4bAs shown, the first electrode 12 and the second electrode 22 can be rectangular. The first electrode 12 has a first length L1 and a first width W1, and the second electrode 22 has a second length L2 and a second width W2. There is a distance d between the first electrode 12 and the second electrode 22. In an exemplary embodiment of this disclosure, the length is the dimension of the first direction D1, the width is the dimension of the third direction D3, and the distance is the dimension of the second direction D2, which intersects the first direction D1 and the third direction D3.

[0102] In an exemplary embodiment, the first length L1 of the first electrode 12 may be less than the second length L2 of the second electrode 22, and the first width W1 of the first electrode 12 may be less than the second width W2 of the second electrode 22. When the foldable display device is not bent, the orthographic projection of the first electrode 12 on the second substrate 21 may be within the range of the orthographic projection of the second electrode 22 on the second substrate 21. Thus, the overlap length of the orthographic projections of the first electrode 12 and the second electrode 22 on the second substrate 21 is the first length L1, and the overlap width of the orthographic projections of the first electrode 12 and the second electrode 22 on the second substrate 21 is the first width W1.

[0103] According to the capacitance calculation formula, when the foldable display device is not bent, the initial capacitance value C0 of the sensing capacitor formed by the first electrode 12 and the second electrode 22 is:

[0104]

[0105] Where ε is the dielectric constant of the medium between the plates, and k is the electrostatic constant.

[0106] Figure 4c This is a schematic diagram showing the relative positions of the first and second electrodes when the foldable display device is bent. Figure 4d for Figure 4c A top view. (e.g.) Figure 4c and Figure 4d As shown, when the foldable display device is bent, the second substrate 21 and the second electrode 22 are moved a distance ΔL in the first direction D1 by a pulling force in the first direction D1, causing the size of the overlapping area of ​​the first electrode 12 and the second electrode 22 to change. In an exemplary embodiment, it can be assumed that the distance d between the first electrode 12 and the second electrode 22 remains approximately constant, and the first width W1 of the first electrode 12 and the second width W2 of the second electrode 22 remain approximately constant.

[0107] In an exemplary embodiment, the change in the size of the overlapping area of ​​the first electrode 12 and the second electrode 22 is equivalent to a change in the overlap length between the first electrode 12 and the second electrode 22. After the second electrode 22 moves a distance ΔL in the first direction D1, the overlap length of the orthographic projection of the first electrode 12 and the second electrode 22 on the second substrate 21 is a third length L3, where the third length L3 = the first length L1 - the moving distance ΔL. The overlap width W of the orthographic projection of the first electrode 12 and the second electrode 22 on the second substrate 21 remains the first width W1.

[0108] According to the capacitance calculation formula, when the foldable display device is bent, the bending capacitance C1 of the sensing capacitor formed by the first electrode 12 and the second electrode 22 is:

[0109]

[0110] The difference between the initial capacitance value C0 and the bending capacitance value C1, C0-C1, is:

[0111]

[0112] According to the aforementioned capacitance calculation formula, when the foldable display device is not bent, the initial capacitance C of the sensing capacitor is proportional to the first length L1. When the foldable display device is bent, the bending capacitance C1 of the sensing capacitor is proportional to the third length L3. The difference between the capacitance of the sensing capacitor when the foldable display device is not bent and the capacitance of the sensing capacitor when the foldable display device is bent is proportional to the moving distance ΔL (i.e., the difference between the first length L1 and the third length L3), that is, ΔC∝ΔL, ΔC=C0-C1, ΔL=L1-L3. Thus, when the bending angle of the foldable display device is proportional to the moving distance ΔL of the second electrode 22, there is a relationship that the change in capacitance of the sensing capacitor when the foldable display device is bent is proportional to the bending angle of the foldable display device. Therefore, the bending angle of the foldable display device can be obtained from the change in capacitance of the capacitance sensor (the difference between the initial capacitance C and the bending capacitance C1).

[0113] Figure 5a and Figure 5b This is a schematic diagram illustrating a structure in which a capacitive sensor is disposed on a display panel, as an exemplary embodiment of the present disclosure. Figure 5a This is a schematic diagram showing the relative positions of the first and second electrodes when the foldable display device is not bent. Figure 5bThis is a schematic diagram showing the relative positions of the first and second electrodes when the foldable display device is bent. In an exemplary embodiment, the display panel may include at least a reinforcing layer 101 and a display structure layer disposed on the reinforcing layer 101. In an exemplary embodiment, the display structure layer may include at least a display substrate layer 103, a touch substrate layer 105, and a cover layer 107. The display substrate layer 103 can be connected to the reinforcing layer 101 via a first adhesive layer 102, the touch substrate layer 105 can be connected to the surface of the display substrate layer 103 away from the reinforcing layer 101 via a second adhesive layer 104, and the cover layer 107 can be connected to the surface of the touch substrate layer 105 away from the reinforcing layer 101 via a third adhesive layer 106.

[0114] In an exemplary embodiment, the reinforcing layer 101 may be made of stainless steel (SUS), the first adhesive layer 102 may be made of foam, the second adhesive layer 104 and the third adhesive layer 106 may be made of optical adhesive (OCA), a polarizer may be provided on the surface of the display substrate layer 103 away from the reinforcing layer 101, the cover layer 107 may include a cover layer (CPL) and a hardening layer (H / C), the cover layer is connected to the touch substrate layer 105 through the third adhesive layer 106, and the hardening layer is disposed on the side of the cover layer away from the reinforcing layer 101, which is not limited in this disclosure.

[0115] In an exemplary embodiment, the thickness of the reinforcing layer 101 can be approximately 120 μm to 170 μm, for example, approximately 150 μm. The thickness of the first adhesive layer 102 can be approximately 140 μm to 180 μm, for example, approximately 160 μm. The thickness of the display substrate layer 103 can be approximately 120 μm to 170 μm, for example, approximately 144 μm. The thickness of the polarizer can be approximately 80 μm to 120 μm, for example, approximately 99 μm. The thickness of the second adhesive layer 104 can be approximately 80 μm to 120 μm, for example, approximately 100 μm. The thickness of the touch substrate layer 105 can be approximately 30 μm to 70 μm, for example, approximately 50 μm. The thickness of the third adhesive layer 106 can be approximately 80 μm to 120 μm, for example, approximately 100 μm. The thickness of the cover layer 107 can be approximately 70 μm to 110 μm, for example, approximately 90 μm.

[0116] In an exemplary embodiment, on a plane parallel to the display panel, the display substrate layer may include a plurality of pixel units arranged in a matrix. At least one pixel unit may include a first sub-pixel emitting a first color light, a second sub-pixel emitting a second color light, and a third sub-pixel emitting a third color light. At least one sub-pixel may include a circuit unit and a light-emitting device. The circuit unit may include a scan signal line, a data signal line, a light-emitting signal line, and a pixel driving circuit. The pixel driving circuit is connected to the scan signal line, the data signal line, and the light-emitting signal line, respectively. The pixel driving circuit is configured to receive the data voltage transmitted by the data signal line and output a corresponding current to the light-emitting device under the control of the scan signal line and the light-emitting signal line. The light-emitting device in the sub-pixel is connected to the pixel driving circuit of the sub-pixel, and the light-emitting device is configured to emit light of a corresponding brightness in response to the current output by the pixel driving circuit of the sub-pixel.

[0117] In an exemplary embodiment, on a plane perpendicular to the display panel, the display substrate layer may include a driving circuit layer disposed on the substrate, a light-emitting structure layer disposed on the side of the driving circuit layer away from the substrate, and an encapsulation layer disposed on the side of the light-emitting structure layer away from the substrate. In an exemplary embodiment, the substrate may be a flexible substrate. The driving circuit layer may include multiple signal lines and pixel driving circuits. The pixel driving circuits may include multiple transistors and storage capacitors. The light-emitting structure layer may include multiple film layers constituting a light-emitting device. The multiple film layers may include an anode, a pixel definition layer, an organic light-emitting layer, and a cathode. The anode is connected to the drain electrode of the driving transistor through a via. The organic light-emitting layer is connected to the anode, and the cathode is connected to the organic light-emitting layer. The organic light-emitting layer emits light of a corresponding color under the driving of the anode and cathode. The encapsulation layer may include a first encapsulation layer, a second encapsulation layer, and a third encapsulation layer stacked together. The first and third encapsulation layers may be made of inorganic materials, and the second encapsulation layer may be made of organic materials. The second encapsulation layer is disposed between the first and third encapsulation layers to ensure that external moisture cannot enter the light-emitting structure layer.

[0118] In an exemplary embodiment, the touch substrate layer may include a plurality of touch units on a plane parallel to the display panel. On a plane perpendicular to the display panel, the touch substrate layer may include an insulating layer and a touch electrode layer.

[0119] In an exemplary embodiment, a mounting slot 500 is provided on the display panel, configured to mount and fix the capacitive sensor 600. The mounting slot 500 can be a strip shape extending along a first direction D1. The first end of the mounting slot 500 can be located within a first non-folding area 200, and the second end of the mounting slot 500 can be located within a second non-folding area 400. The area between the first end and the second end of the mounting slot 500 spans a bending area 300. In an exemplary embodiment, the first end of the mounting slot 500 can be located within a first border area 202 in the first non-folding area 200, and the second end of the mounting slot 500 can be located within a second border area 402 in the second non-folding area 400, to avoid affecting the normal display of the display area.

[0120] In an exemplary embodiment, the first adhesive layer 102, display substrate layer 103, second adhesive layer 104, touch substrate layer 105, third adhesive layer 106, and cover layer 107 within the mounting groove 500 are removed, exposing the surface of the reinforcing layer 101. This results in the first end of the mounting groove 500 having a first groove wall 501 facing the bending region 300, the second end of the mounting groove 500 having a second groove wall 502 facing the bending region 300, and the bottom of the mounting groove 500 having a groove bottom surface 510 facing the second direction D2. The first groove wall 501 exposes the film layer end face of the first non-folded region 200 (excluding the reinforcing layer 101), the second groove wall 502 exposes the film layer end face of the second non-folded region 400 (excluding the reinforcing layer 101), and the groove bottom surface 510 exposes the surface of the reinforcing layer 101.

[0121] In an exemplary embodiment, the cross-sectional shape of the mounting groove 500 in a plane parallel to the foldable display device can be rectangular, trapezoidal, or polygonal.

[0122] In an exemplary embodiment, the cross-sectional shape of the mounting groove 500 in a plane perpendicular to the foldable display device can be rectangular, trapezoidal, or polygonal.

[0123] In an exemplary embodiment, the capacitive sensor may include a first electrode structure and a second electrode structure that are relatively disposed and whose relative positions can change with the bending angle. The first electrode structure and the second electrode structure are configured to form a sensing capacitor whose capacitance value can change with the bending angle. The first electrode structure may include a first fixing structure 10, a first substrate 11, and a first electrode 12. The second electrode structure may include a second fixing structure 20, a second substrate 21, and a second electrode 22. The first fixing structure 10 may be connected to the first groove wall 501 of the mounting groove 500, i.e., the first fixing structure 10 is connected to the first non-folded area 200. The first substrate 11 is disposed on the side of the first fixing structure 10 near the reinforcing layer 101, and the first electrode 12 is disposed on the side of the first substrate 11 near the reinforcing layer 101. The second fixing structure 20 may be connected to the second groove wall 502 of the mounting groove 500, i.e., the second fixing structure 20 is connected to the second non-folded area 400. The second substrate 21 is disposed on the side of the second fixing structure 20 away from the reinforcing layer 101, and the second electrode 22 is disposed on the side of the second substrate 21 away from the reinforcing layer 101.

[0124] In an exemplary embodiment, the first fixing structure 10 may include a first bottom frame and a first side frame. The first bottom frame may be a strip shape extending along a first direction D1, and the first side frame may be a strip shape extending along a second direction D2. The first side frame is connected to the end of the first bottom frame away from the bending area 300. The first base 11 may be disposed on the side of the first bottom frame near the reinforcing layer 101, and the first side frame may be connected to the first groove wall 501 of the mounting groove 500.

[0125] In an exemplary embodiment, the first side frame may be connected to the bottom surface 510 of the mounting groove 500 located in the first non-folded area 200, while the first side frame is not connected to the first groove wall 501 of the mounting groove 500. Alternatively, the first side frame may be connected to both the first groove wall 501 of the mounting groove 500 and the bottom surface 510 of the groove located in the first non-folded area 200.

[0126] In an exemplary embodiment, the first fixing structure 10 and the first base 11 may be an integral structure.

[0127] In an exemplary embodiment, the second fixing structure 20 may include a second bottom frame and a second side frame. The second bottom frame may be a strip shape extending along the first direction D1, and the second side frame may be a strip shape extending along the second direction D2. The second side frame is connected to the end of the second bottom frame away from the bending area 300. The second base 21 may be disposed on the side of the second bottom frame away from the reinforcing layer 101. The second side frame may be connected to the second groove wall 502 of the mounting groove 500.

[0128] In an exemplary embodiment, the second bottom frame may be connected to the bottom surface 510 of the mounting groove 500 located in the second non-folded area 400, while the second side frame is not connected to the second groove wall 502 of the mounting groove 500. Alternatively, the second bottom frame may be connected to both the second groove wall 502 of the mounting groove 500 and the bottom surface 510 of the groove in the second non-folded area 400.

[0129] In an exemplary embodiment, the second fixing structure 20 and the second base 21 may be an integral structure.

[0130] In an exemplary embodiment, the orthographic projection of the first electrode 12 of the first electrode structure onto the reinforcing layer 101 at least partially overlaps with the orthographic projection of the second electrode 22 of the second electrode structure onto the reinforcing layer 101, such that the first electrode 12 and the second electrode 22 form a sensing capacitor.

[0131] like Figure 5a and Figure 5b As shown, when the foldable display device is not bent, the overlap length between the first electrode 12 and the second electrode 22 is the first length L1. Since the first electrode structure is connected to the first non-folding area 200 and the second electrode structure is connected to the second non-folding area 400, when the foldable display device is bent, the first non-folding area 200 and the second non-folding area 400 deflect relative to the bending area 300, causing the first electrode structure and the second electrode structure to also deflect relative to the bending area 300, and the relative positions of the first electrode structure and the second electrode structure change. For the second electrode structure, due to the difference in arc length between the film layer where the second electrode 22 is located and the film layer where the reinforcing layer 101 is located under different bending angles, when the bending angle is θ°, the moving distance ΔL of the second electrode 22 relative to the first electrode 12 is π*(R2-R1)*θ° / 180°, where R1 is the bending radius of the reinforcing layer 101 within the bending area 300 and R2 is the bending radius of the second electrode 22 within the bending area 300. Since the thickness of each film layer in the display panel is a constant, the moving distance ΔL is proportional to the bending angle θ°, i.e., ΔL∝θ°.

[0132] In an exemplary embodiment, when fully folded (bending angle θ° is 180°), the movement distance ΔL of the second electrode 22 relative to the first electrode 12 is π*(R2-R1), that is, the movement distance ΔL is the difference of half the circumference, and the overlap length of the first electrode 12 and the second electrode 22 is the third length L3, the third length L3 = the first length L1 - the movement distance ΔL.

[0133] In an exemplary embodiment, since the difference between the initial capacitance of the capacitive sensor when the foldable display device is not bent and the bending capacitance of the capacitive sensor when the foldable display device is bent is proportional to the moving distance ΔL of the second electrode 22 relative to the first electrode 12, and the moving distance ΔL of the second electrode 22 relative to the first electrode 12 when the foldable display device is bent is proportional to the bending angle θ°, the difference between the initial capacitance of the capacitive sensor when the foldable display device is not bent and the bending capacitance of the capacitive sensor when the foldable display device is bent is proportional to the bending angle θ°. The bending angle θ° of the foldable display device can be obtained based on the difference between the initial capacitance C and the bending capacitance C1 of the capacitive sensor.

[0134] In an exemplary embodiment, the first substrate and the second substrate may be made of insulating materials, such as any one or more of silicon oxide (SiOx), silicon nitride (SiNx), and silicon oxynitride (SiON), and may be a single layer, multiple layers, or composite layers. The first electrode and the second electrode may be made of copper foil or other materials with good conductivity, and the second electrode has good elasticity and flexibility; however, this disclosure does not limit the specific materials used.

[0135] Figure 6 This is a schematic diagram of another embodiment of the present disclosure showing a capacitive sensor mounted on a display panel, illustrating the relative positions of the first and second electrodes when the foldable display device is not bent. In this exemplary embodiment, the structure of the foldable display device is similar to that of the aforementioned exemplary embodiment. The foldable display device includes a display panel and a capacitive sensor. A mounting slot 500 is provided on the display panel, configured to fix the capacitive sensor. The capacitive sensor may include a first electrode structure and a second electrode structure whose relative positions can change.

[0136] In an exemplary embodiment, the first electrode structure may include a first fixing structure 10, a first base 11, and a first electrode 12. The first fixing structure 10 may be an annular cavity structure and is connected to the first groove wall 501 of the mounting groove 500. The first base 11 and the first electrode 12 are disposed within the cavity of the first fixing structure 10.

[0137] In an exemplary embodiment, the first fixing structure 10 may include a first side, a second side, a third side, and a fourth side that are sequentially connected and form an annular cavity. The first side and the third side extend along a first direction D1, and the second side and the fourth side extend along a second direction D2. The first side is located on the side of the annular cavity away from the reinforcing layer 101, the third side is located on the side of the annular cavity close to the reinforcing layer 101, the second side is located on the side of the annular cavity close to the bending area 300, and the fourth side is located on the side of the annular cavity away from the bending area 300 and is connected to the first groove wall 501 of the mounting groove 500.

[0138] In an exemplary embodiment, a first substrate 11 is disposed on the side of the first side facing the reinforcing layer 101, and a first electrode 12 is disposed on the side of the first substrate 11 facing the reinforcing layer 101. In a possible exemplary embodiment, the first substrate 11 may be integral with the first side, and the first electrode 12 may be disposed on the side of the first side facing the reinforcing layer 101.

[0139] In an exemplary embodiment, at least one opening may be provided on the second side, the opening extending through the second side, the opening being configured to allow the second electrode 22 of the second electrode structure to extend into the annular cavity, such that the orthographic projection of the first electrode 12 on the reinforcing layer 101 and the orthographic projection of the second electrode 22 on the reinforcing layer 101 at least partially overlap.

[0140] In an exemplary embodiment, at least one support platform may be provided on the third side, the support platform being configured to support the second electrode 22 extending into the annular cavity.

[0141] In an exemplary embodiment, the third side may be connected to the bottom surface 510 of the groove in the first non-folded area 200.

[0142] In an exemplary embodiment, the second electrode structure may include a second fixing structure 20, a second substrate 21, and a second electrode 22. The second fixing structure 20 may be a strip-shaped support layer extending along a first direction D1. The strip-shaped support layer may be connected to the bottom surface 510 of the mounting groove 500, and / or, the strip-shaped support layer may be connected to the second groove wall 502 of the mounting groove 500. The first portion of the second electrode 22 and the second substrate 21 near the first non-folded region 200 extends into the annular cavity of the first fixing structure 10, such that the orthographic projection of the first electrode 12 on the reinforcing layer 101 at least partially overlaps with the orthographic projection of the second electrode 22 on the reinforcing layer 101, and the first electrode 12 and the second electrode 22 form a sensing capacitor. The second portion of the second electrode 22 and the second substrate 21 away from the first non-folded region 200 may be disposed on the side of the strip-shaped support layer away from the reinforcing layer 101. In one possible exemplary embodiment, the second substrate 21 may be integral with the strip support layer, the first part of the second electrode 22 near the first non-folded region 200 extends into the annular cavity of the first fixing structure 10, and the second part of the second electrode 22 away from the first non-folded region 200 may be disposed on the side of the strip support layer away from the reinforcing layer 101.

[0143] The structures shown in the foregoing exemplary embodiments of this disclosure are merely illustrative examples. In the exemplary embodiments, the corresponding structures can be modified according to actual needs. For example, the depth of the mounting groove can be set according to the height of the capacitive sensor, and only part of the film layer between the reinforcing layer and the cover layer can be removed, with the cover layer covering the mounting groove. Alternatively, the reinforcing layer in the area where the mounting groove is located can have a slightly protruding local structure to facilitate the fixation and adhesion of the capacitive sensor. Furthermore, the first electrode structure and the second electrode structure can be other structural forms that can change their relative positional relationship with the bending angle, which are not limited herein.

[0144] In another exemplary embodiment, a capacitive sensor can be disposed on the housing that carries the display panel. The first electrode structure and the second electrode structure form a sensing capacitor that can change its capacitance value with the bending angle, so that the detection circuit can obtain the bending angle of the foldable display device based on the capacitance value of the sensing capacitor.

[0145] Figure 7 This is a schematic diagram of another foldable display device according to an exemplary embodiment of the present disclosure. In an exemplary embodiment, the foldable display device may include a display panel, a housing supporting the display panel, at least one capacitive sensor, and at least one detection circuit. The capacitive sensor is configured to form a sensing capacitor whose capacitance value changes with the bending angle. The detection circuit is connected to the capacitive sensor and configured to detect the capacitance value of the sensing capacitor and obtain the bending angle of the foldable display device based on the capacitance value. Figure 7 As shown, in an exemplary embodiment, the structure of the display panel 100 can be similar to that of the aforementioned exemplary embodiment, and may include at least a first non-folding area 200, a bending area 300, and a second non-folding area 400, with the first non-folding area 200 and the second non-folding area 400 located on opposite sides of the bending area 300. The housing supporting the display panel may include a first housing 31, a second housing 32, and a connector 33 connecting the first housing 31 and the second housing 32. In an exemplary embodiment, the position of the first non-folding area 200 may correspond to the position of the first housing 31 and be connected to the first housing 31; the position of the second non-folding area 400 may correspond to the position of the second housing 32 and be connected to the second housing 32; and the position of the connector 33 may correspond to the position of the bending area 300 and be connected only to the first housing 31 and the second housing 32.

[0146] In an exemplary embodiment, the first electrode structure and the second electrode structure of the capacitive sensor can be disposed on the connector 33. The first electrode structure and the second electrode structure form a sensing capacitor that can change the capacitance value with the bending angle, so that the detection circuit can obtain the bending angle of the foldable display device according to the capacitance value of the sensing capacitor.

[0147] Figure 8aThis is a schematic diagram of the structure of a connector, which is an exemplary embodiment of the present disclosure. Figure 8b for Figure 8a Top view, Figure 8c for Figure 8a A side view. (e.g.) Figures 8a to 8c As shown, in an exemplary embodiment, the connector may include a pivot 34, and a first connector, a second connector, a first electrode structure, and a second electrode structure respectively sleeved on the pivot 34. The first connector and the second connector are configured such that the first housing and the second housing can deflect relative to the pivot 34 to achieve folding of the display device. The first electrode structure and the second electrode structure are configured to form a sensing capacitor whose capacitance value changes with the bending angle, so that the detection circuit can obtain the bending angle of the foldable display device based on the capacitance value of the sensing capacitor.

[0148] In an exemplary embodiment, the rotating shaft 34 may be a cylinder extending along a third direction D3, and the material of the rotating shaft 34 may be an insulating material to ensure insulation between the first electrode structure and the second electrode structure.

[0149] In an exemplary embodiment, the first connector may include a first cylindrical body 41 and a first connecting piece 42 disposed on the first cylindrical body 41. The first cylindrical body 41 may be a cylindrical body extending along a third direction D3, and the first cylindrical body 41 may be sleeved on one end of the rotating shaft 34 (such as the end along the third direction D3), forming a sliding connection structure between the first cylindrical body 41 and the rotating shaft 34. The first connecting piece 42 may be a plate-like body, and the plate-like body may be parallel to the plane (D1-D3 plane) when the display panel is fully unfolded. The first connecting piece 42 may be disposed on the side of the first cylindrical body 41 near the first housing 31, and fixedly connected to the first housing 31 through a slot structure provided on the first housing 31.

[0150] In an exemplary embodiment, the second connector may include a second cylindrical body 51 and a second connecting piece 52 disposed on the second cylindrical body 51. The second cylindrical body 51 may be a cylindrical body extending along a third direction D3, and the second cylindrical body 51 may be sleeved on one end of the rotating shaft 34 (such as the end opposite to the third direction D3), forming a sliding connection structure between the second cylindrical body 51 and the rotating shaft 34. The second connecting piece 52 may be a plate-like body, and the plate-like body may be parallel to the plane (D1-D3 plane) when the display panel is fully unfolded. The second connecting piece 52 may be disposed on the side of the second connector 332 near the second housing 32, and fixedly connected to the second housing 32 through a slot structure provided on the second housing 32.

[0151] In an exemplary embodiment, the first electrode structure may include a third cylindrical body 61 and a third electrode 62. The third cylindrical body 61 may be a cylindrical body extending along a third direction D3, and may be sleeved on the rotating shaft 34, located at the end of the first cylindrical body 41 near the second cylindrical body 51, and connected to the first cylindrical body 41. The third electrode 62 may be a plate-like body, and may be parallel to a plane perpendicular to the rotating shaft (D1-D2 plane), and the third electrode 62 is connected to the third cylindrical body 61.

[0152] In an exemplary embodiment, the second electrode structure may include a fourth cylindrical body 71 and a fourth electrode 72. The fourth cylindrical body 71 may be a cylindrical body extending along a third direction D3, and may be sleeved on the rotating shaft 34, located at the end of the second cylindrical body 51 near the first cylindrical body 41, and connected to the second cylindrical body 51. The fourth electrode 72 may be a plate-like body, and may be parallel to a plane perpendicular to the rotating shaft (D1-D2 plane), and the fourth electrode 72 is connected to the fourth cylindrical body 71.

[0153] In an exemplary embodiment, the third electrode 62 and the fourth electrode 72 are disposed in the middle of the rotating shaft 34 and are adjacent to each other. The third electrode 62 can serve as one plate of a sensing capacitor, and the fourth electrode 72 can serve as the other plate of a sensing capacitor. The orthographic projection of the third electrode 62 on a plane perpendicular to the rotating shaft and the orthographic projection of the fourth electrode 72 on a plane perpendicular to the rotating shaft overlap at least partially, so that the overlapping area of ​​the third electrode 62 and the fourth electrode 72 can change with the bending angle, thereby forming a sensing capacitor whose capacitance value changes with the bending angle. The overlapping area of ​​the third electrode 62 and the fourth electrode 72 has a one-to-one correspondence with the bending angle.

[0154] In an exemplary embodiment, when the first and second housings deflect relative to the axis of rotation, the first and second housings, on the one hand, cause the first and second non-folding areas to fold relative to the axis of rotation, and on the other hand, cause the first and second cylindrical bodies to rotate relative to the axis of rotation. Correspondingly, the first and second cylindrical bodies respectively cause the third and fourth cylindrical bodies to rotate, and the third and fourth cylindrical bodies respectively cause the third and fourth electrodes to deflect. Since the rotation directions of the first and second cylindrical bodies are opposite, the rotation directions of the third and fourth electrodes are also opposite, and the size of their overlapping area changes.

[0155] In an exemplary embodiment, when the foldable display device is bent, the overlapping area of ​​the third electrode and the fourth electrode changes because they rotate in opposite directions. The size of the overlapping area is proportional to the bending angle, and the size of the bending capacitance value is proportional to the bending angle. Therefore, the bending angle of the foldable display device can be obtained based on the capacitance value of the sensing capacitor.

[0156] In an exemplary embodiment, the capacitance value of the sensing capacitor at different bending angles can be quantified by calibration. This allows the bending angle information to be obtained by looking up a table after acquiring the capacitance value of the sensing capacitor in real time.

[0157] In an exemplary embodiment, the third electrode 62 and the fourth electrode 72 can be triangular, trapezoidal, or fan-shaped on a plane perpendicular to the axis of rotation. The third electrode 62 and the fourth electrode 72 can be made of copper foil or other materials with good conductivity, which are not limited herein.

[0158] The structures shown in the foregoing exemplary embodiments of this disclosure are merely illustrative examples. In the exemplary embodiments, the corresponding structures can be modified according to actual needs. For example, the first and third cylinders can be an integral structure connected to each other, and the second and fourth cylinders can be an integral structure connected to each other. Alternatively, multiple first and second cylinders can be included, and multiple first and second cylinders can be alternately arranged along a third direction. Furthermore, the first and second electrode structures can be disposed at the ends of the rotating shaft. Moreover, the first and second electrode structures can be designed as modular structures, which can be quickly assembled and fixed to the rotating shaft (hinge) of the display device through a bayonet structure or other means; this disclosure does not impose any limitations on these aspects.

[0159] Figure 9 This is a schematic diagram of a detection circuit according to an exemplary embodiment of the present disclosure. In an exemplary embodiment, the detection circuit is connected to a first electrode (or a third electrode) in a first electrode structure and a second electrode (or a fourth electrode) in a second electrode structure, respectively, and is configured to detect the capacitance value of a sensing capacitor, and obtain the bending angle of the foldable display device based on the capacitance change (or capacitance value) of the sensing capacitor. Figure 9 As shown, in an exemplary embodiment, the detection circuit may include an input module, an output compensation module, a reset module, and a processing module.

[0160] In an exemplary embodiment, the input module is connected to the first power line VDD, the first signal line S1, and the first node N1, respectively. The first node N1 is connected to the first electrode 12 of the sensing capacitor. The input module is configured to output a high-level voltage signal of the first power line VDD to the first node N1 under the control of the first signal line S1, thereby charging the sensing capacitor.

[0161] In an exemplary embodiment, the compensation output module is connected to the second signal line S2, the third signal line S3, the first node N1, the second node N2, and the processing module, respectively. The second node N2 is connected to the second electrode 22 of the sensing capacitor and the second power supply line VSS. The compensation output module is configured to compensate for the fundamental noise of the detection circuit under the control of the second signal line S2, and to output the voltage of the first node N1 to the processing module under the control of the second signal line S2 and the third signal line S3.

[0162] In an exemplary embodiment, the reset module is connected to the second power line VSS, the fourth signal line S4, the first node N1, and the second node N2. The reset module is configured to output the voltage of the second node N2 to the first node N1 under the control of the fourth signal line S4, to initialize the sensing capacitor and release the charge on the capacitor plates of the sensing capacitor.

[0163] In an exemplary embodiment, the processing module is connected to the compensation output module. The processing module is configured to receive and process the signal output by the compensation output module, and output a data signal Data that is proportional to the capacitance value of the sensing capacitor.

[0164] Figure 10 This is a schematic diagram of the structure of the input module, which is an exemplary embodiment of this disclosure. Figure 10 As shown, in an exemplary embodiment, the input module may include a first switch SW1. The control electrode of the first switch SW1 is connected to the first signal line S1, the first electrode of the first switch SW1 is connected to the first power line VDD, and the second electrode of the first switch SW1 is connected to the first node N1. When the first signal line S1 outputs a disconnect signal, the first switch SW1 is disconnected; when the first signal line S1 outputs a conduction signal, the first switch SW1 is turned on, causing a high-level voltage signal from the first power line VDD to be applied to the first node N1. Since the first node N1 is connected to the first electrode 12 of the sensing capacitor, the sensing capacitor is charged.

[0165] Figure 11 This is a schematic diagram of the compensation output module structure as an exemplary embodiment of this disclosure. Figure 11As shown, in an exemplary embodiment, the compensation output module may include a second switch SW2, a third switch SW3, and a compensation capacitor Cb. The control electrode of the second switch SW2 is connected to the second signal line S2, the first electrode of the second switch SW2 is connected to the first node N1, the second electrode of the second switch SW2 is connected to the first plate of the compensation capacitor Cb, and the second plate of the compensation capacitor Cb is connected to the second node N2. The control electrode of the third switch SW3 is connected to the third signal line S3, the first electrode of the third switch SW3 is connected to the first node N1, and the second electrode of the third switch SW3 is connected to the processing module. When the second signal line S2 outputs a disconnect signal, the second switch SW2 is disconnected; when the second signal line S2 outputs a conduction signal, the second switch SW2 is conducted, causing the compensation capacitor Cb to compensate for the basic noise of the detection circuit. When the third signal line S3 outputs a disconnect signal, the third switch SW3 is disconnected; when the third signal line S3 outputs a conduction signal, the third switch SW3 is conducted, outputting the compensated voltage of the first node N1 to the processing module.

[0166] Figure 12 This is a schematic diagram of the reset module structure as an exemplary embodiment of this disclosure. Figure 12 As shown, in an exemplary embodiment, the reset module may include a fourth switch SW4. The control electrode of the fourth switch SW4 is connected to the fourth signal line S4, the first electrode of the fourth switch SW4 is connected to the second node N2, and the second electrode of the fourth switch SW4 is connected to the first node N1. When the fourth signal line S4 outputs a disconnect signal, the fourth switch SW4 is disconnected; when the fourth signal line S4 outputs a conduction signal, the fourth switch SW4 is conducted, causing the voltage of the second node N2 to be applied to the first node N1. Since the first node N1 is connected to the first electrode 12 of the sensing capacitor, and the second node N2 is connected to the second electrode 22 of the sensing capacitor and the second power line VSS, the low-level voltage signal of the second power line VSS is simultaneously applied to the first electrode 12 and the second electrode 22 of the sensing capacitor, thus initializing the sensing capacitor and releasing the charge on the two capacitor plates.

[0167] Figure 13 This is a schematic diagram of the processing module structure as an exemplary embodiment of this disclosure. Figure 13 As shown, in an exemplary embodiment, the processing module may include an integrating amplifier (AMP), an analog-to-digital converter (ADC), and a feedback capacitor Cf. The feedback capacitor Cf is disposed between the negative input terminal and the output terminal of the integrating amplifier. The positive input terminal of the integrating amplifier is connected to the reference voltage line Vref. The negative input terminal of the integrating amplifier is connected to the compensation output module. The output terminal of the integrating amplifier is connected to the input terminal of the ADC. The output terminal of the ADC outputs a data signal Data that is proportional to the capacitance value of the sensing capacitor.

[0168] Figure 14 This is a schematic diagram of another detection circuit as an exemplary embodiment of this disclosure. Figure 14 As shown, the detection circuit may include four switches (first switch SW1 to fourth switch SW4), two capacitors (compensation capacitor Cb and feedback capacitor Cf), an integrating amplifier AMP and an analog-to-digital converter ADC. The detection circuit is connected to seven signal lines (first signal line S1, second signal line S2, third signal line S3, fourth signal line S4, first power supply line VDD, second power supply line VSS and reference voltage line Vref).

[0169] In an exemplary embodiment, the detection circuit may include a first node N1 and a second node N2. The first node N1 is connected to the first electrode 12 of the sensing capacitor, the second electrode of the first switch SW1, the first electrode of the second switch SW2, the first electrode of the third switch SW3, and the second electrode of the fourth switch SW4, respectively. The second node N2 is connected to the second electrode 22 of the sensing capacitor, the second power line VSS, the first electrode of the fourth switch SW4, and the second plate of the feedback capacitor Cf, respectively.

[0170] In an exemplary embodiment, the control terminal of the first switch SW1 is connected to the first signal line S1, the first terminal of the first switch SW1 is connected to the first power line VDD, and the second terminal of the first switch SW1 is connected to the first node N1. When a conduction signal is applied to the first signal line S1, the first switch SW1 is turned on, applying a high-level voltage signal of the first power line VDD to the first node N1 to charge the sensing capacitor.

[0171] In an exemplary embodiment, the control electrode of the second switch SW2 is connected to the second signal line S2, the first electrode of the second switch SW2 is connected to the first node N1, the second electrode of the second switch SW2 is connected to the first plate of the compensation capacitor Cb, and the second plate of the compensation capacitor Cb is connected to the second node N2. When a conduction signal is applied to the second signal line S2, the second switch SW2 is turned on, and the compensation capacitor Cb compensates for the basic noise of the detection circuit.

[0172] In an exemplary embodiment, the control terminal of the third switch SW3 is connected to the third signal line S3, the first terminal of the third switch SW3 is connected to the first node N1, and the second terminal of the third switch SW3 is connected to the negative input terminal of the integrating amplifier. When a conduction signal is applied to the third switch SW3, the third switch SW3 conducts, outputting the compensated voltage of the first node N1 to the integrating amplifier AMP.

[0173] In an exemplary embodiment, the control electrode of the fourth switch SW4 is connected to the fourth signal line S4, the first electrode of the fourth switch SW4 is connected to the second node N2, and the second electrode of the fourth switch SW4 is connected to the first node N1. When a conduction signal is applied to the fourth signal line S4, the fourth switch SW4 is turned on, applying the voltage of the second node N2 to the first node N1, thus initializing the first electrode 12 and the second electrode 22 in the sensing capacitor.

[0174] In an exemplary embodiment, the positive input terminal of the integrating amplifier AMP is connected to the reference voltage line Vref, the negative input terminal of the integrating amplifier AMP is connected to the third switch SW3, the output terminal of the integrating amplifier AMP is connected to the input terminal of the analog-to-digital converter ADC, and the feedback capacitor Cf is disposed between the negative input terminal and the output terminal of the integrating amplifier AMP.

[0175] In an exemplary embodiment, the input terminal of the analog-to-digital converter (ADC) is connected to the output terminal of the integrating amplifier (AMP), and the output terminal of the ADC outputs a data signal Data that is proportional to the capacitance value of the sensing capacitor.

[0176] In an exemplary embodiment, the first power line VDD is a continuously supplied high-level voltage signal, the second power line VSS is a low-level voltage signal, and the reference voltage line Vref is a continuously supplied reference voltage signal.

[0177] Figure 15 This is a timing diagram of a detection circuit as an exemplary embodiment of the present disclosure. The following is a description of its operation... Figure 14 The operation of the example detection circuit illustrates an exemplary embodiment of this disclosure. In an exemplary embodiment, the operation of the detection circuit may include:

[0178] In the first stage A1, also known as the reset stage, the fourth signal line S4 outputs a conduction signal to turn on the fourth switch SW4, while the first signal line S1, the second signal line S2, and the third signal line S3 output de-conversion signals to turn off the first switch SW1, the second switch SW2, and the third switch SW3. The low-level voltage signal output by the second power line VSS initializes the sensing capacitor, releasing the charge on the first electrode 12 and the second electrode 22 in the sensing capacitor.

[0179] The second stage, A2, is called the charging stage. The first signal line S1 outputs a conduction signal to turn on the first switch SW1. The second signal line S2, the third signal line S3, and the fourth signal line S4 output de-conversion signals to turn off the second switch SW2, the third switch SW3, and the fourth switch SW4. The high-level voltage signal output by the first power line VDD charges the sensing capacitor.

[0180] The third stage, A3, is called the compensation stage. The second signal line S2 outputs a conduction signal, which turns on the second switch SW2. The first signal line S1, the third signal line S3, and the fourth signal line S4 output a disconnection signal, which turns off the first switch SW1, the third switch SW3, and the fourth switch SW4. The compensation capacitor Cb compensates for the basic noise of the detection circuit to improve the accuracy of the output signal.

[0181] The fourth stage, A4, is called the sensing stage. The second signal line S2 and the third signal line S3 output conduction signals to turn on the second switch SW2 and the third switch SW3. The first signal line S1 and the fourth signal line S4 output de-energization signals to turn off the first switch SW1 and the fourth switch SW4. The processing module obtains and processes the voltage of the compensated first node N1 and outputs a data signal Data that is proportional to the capacitance value of the sensing capacitor.

[0182] As can be seen from the structure and operation of the aforementioned foldable display device, the foldable display device provided by the exemplary embodiments of this disclosure, by setting a capacitance sensor on the display panel, can change the capacitance value of the capacitance sensor with the bending angle when the foldable display device is bent. There is a one-to-one correspondence between the capacitance change (or capacitance value) of the capacitance sensor and the bending angle of the foldable display device. The detection circuit can obtain the bending angle of the foldable display device by detecting the capacitance value or capacitance change of the capacitance sensor. It has the advantages of simple structure, small size, low operating voltage / current, and high bending angle detection accuracy, and can be applied to the bending angle detection of thin and light display devices.

[0183] This exemplary embodiment also provides a driving method for a foldable display device, configured to drive the aforementioned foldable display device. In an exemplary embodiment, the driving method for the foldable display device may include:

[0184] S1. Obtain the folding angle of the foldable display device;

[0185] S2. Correct the color deviation of the folded area according to the folding angle.

[0186] In an exemplary embodiment, step S1 may include:

[0187] S11. Acquire and store the initial data signal output by the detection circuit when the foldable display device is in an unbent state;

[0188] S12. Obtain the bending data signal output by the detection circuit when the foldable display device is in a bent state;

[0189] S13. Obtain the bending angle of the display panel based on the initial data signal and the bending data signal.

[0190] In an exemplary embodiment, step S13 may include:

[0191] S131. Calculate the difference between the initial data signal and the bent data signal;

[0192] S132. Obtain the bending angle of the foldable display device based on the difference and the preset bending angle coefficient.

[0193] In an exemplary embodiment, the bending angle coefficient is obtained by a calibration process and pre-stored in the timing controller (T-Con) or source driver IC in the foldable display device.

[0194] In an exemplary embodiment, the calibration process may include the following operations.

[0195] S100, Prepare a foldable display device.

[0196] In an exemplary embodiment, the foldable display device may include a display panel, a capacitive sensor, and a detection circuit. The capacitive sensor is disposed on the display panel, and the detection circuit is connected to the capacitive sensor. In an exemplary embodiment, the detection circuit may be disposed separately, integrated on the display substrate layer, or integrated into a T-Con or SourceDriver IC; this disclosure does not limit the scope of the invention.

[0197] S200. Place the foldable display device in a fully flattened state (i.e., the foldable display device is in an unfolded state) and acquire the initial data signal Data0 output by the detection circuit.

[0198] In an exemplary embodiment, acquiring the initial data voltage Data0 output by the detection circuit may include: powering on the detection circuit, and then... Figure 15 The timing output shows the corresponding control signal. The detection circuit goes through the reset stage, charging stage, compensation stage and sensing stage, and outputs the initial data signal Data0, which is proportional to the initial capacitance value C0 of the sensing capacitor. That is, the initial data signal Data0 ∝ the initial capacitance value C0.

[0199] In an exemplary embodiment, since the foldable display device is in an unbent state, theoretically the overlap length of the first electrode and the second electrode is at its maximum value, the corresponding overlap area S0 = W1 * L1, and the corresponding initial data signal Data0 is:

[0200]

[0201] Where K is the ratio coefficient between the data signal and the capacitance value.

[0202] S300, Place the foldable display device in a fully engaged state (i.e., the foldable display device is in a bent state and the bending angle θ is 180°), and obtain the engagement data voltage Data180 output by the detection circuit.

[0203] In an exemplary embodiment, acquiring the paired data voltage Data180 output by the detection circuit may include: after the display panels are paired, the detection circuit is powered on, and according to... Figure 15 The timing output shows the corresponding control signal. The detection circuit goes through the reset stage, charging stage, compensation stage and sensing stage, and outputs the connected data signal Data180, which is proportional to the connected capacitor value C180. That is, the connected data signal Data180 is ∝ the connected capacitor value C180.

[0204] In an exemplary embodiment, since the foldable display device is in a bent state and the bending angle θ is 180°, theoretically the overlap length of the first electrode and the second electrode is at its minimum, the corresponding overlap area S180 = W1 * L3, and the corresponding matching data signal Data180:

[0205]

[0206] S400: Obtain the bending angle coefficient based on the initial data signal and the combined data signal.

[0207] Since the moving distance ΔL of the first electrode relative to the second electrode is π*(R2-R1), the bending angle coefficient A can be obtained.

[0208]

[0209] For the completed foldable display device, ε, k, d, R1, R2, W1, and K are all fixed values, and therefore the bending angle coefficient A is a constant.

[0210] When the foldable display device is in a bent state and the bending angle θ is greater than 0 and less than 180°, the moving distance ΔLθ of the first electrode relative to the second electrode is π*(R2-R1)*θ / 180. The bending data voltage Dataθ output by the detection circuit is proportional to the bending capacitance value Cθ, that is, the bending data voltage Dataθ∝ the bending capacitance value Cθ.

[0211] The difference between the initial data voltage Data0 and the bent data voltage Dataθ, ΔData, is proportional to the difference between the initial capacitance value C0 and the bent capacitance value Cθ, ΔC, as follows:

[0212]

[0213] In this way, the correspondence between the bending angle θ and the data change value △Data is obtained. Based on the bending data voltage Dataθ that is proportional to the bending capacitance value Cθ detected in real time, the difference △Data between the initial data voltage Data0 and the bending data voltage Dataθ (proportional to the difference △C between the initial capacitance value C0 and the bending capacitance value Cθ) can be calculated. The bending angle θ of the foldable display device can then be obtained using the bending angle coefficient A.

[0214] In an exemplary embodiment, step S2 may include: the T-Con, Source Driver IC, or external circuit of the foldable display device can perform color deviation correction on the bending area according to the obtained bending angle θ, adjust the color deviation of the bending area, improve the display quality and visual experience, and thus enhance the product competitiveness.

[0215] In exemplary embodiments, the display panel of this disclosure may be OLED, QLED, light-emitting diode display (MicroLED or Mini LED) or quantum dot light-emitting diode display (QDLED), etc. The foldable display device of this disclosure may be any product or component with display function, such as mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, navigator, etc. This disclosure does not limit it.

[0216] While the embodiments disclosed herein are as described above, the content is merely for the purpose of facilitating understanding of this disclosure and is not intended to limit the invention. Any person skilled in the art may make any modifications and changes to the form and details of the implementation without departing from the spirit and scope of this disclosure; however, the patent protection scope of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A foldable display device, comprising a display panel, at least one capacitive sensor, at least one detection circuit, a reinforcing layer, and a display structure layer disposed on the reinforcing layer; the display panel includes at least one bending region configured for bending, a first non-folding region and a second non-folding region disposed on both sides of the bending region, and the display structure layer is provided with at least one mounting groove, the mounting groove including at least a groove bottom surface exposed by the reinforcing layer, a first groove wall located in the first non-folding region, and a second groove wall located in the second non-folding region; the capacitive sensor is disposed in the mounting groove, the capacitive sensor including a first electrode structure and a second electrode structure configured to form a sensing capacitance, the first electrode structure including a first fixing structure and a first electrode, the first fixing structure including a first bottom frame and a first side frame, the first bottom frame being a strip shape extending along a first direction, the first side frame being a strip shape extending along a second direction, and the ends of the first side frame and the first bottom frame away from the bending region. The first electrode is connected to the first mounting groove wall and / or the bottom surface of the mounting groove. The second electrode structure includes a second fixing structure and a second electrode. The second fixing structure includes a second bottom frame and a second side frame. The second bottom frame is a strip shape extending along the first direction, and the second side frame is a strip shape extending along the second direction. The second side frame is connected to the end of the second bottom frame away from the bending area. The second electrode is located on the side of the second bottom frame away from the reinforcing layer. The second side frame is connected to the second groove wall of the mounting groove, and / or the second bottom frame is connected to the bottom surface of the mounting groove. The orthographic projection of the first electrode on the plane of the foldable display device and the orthographic projection of the second electrode on the plane of the foldable display device at least partially overlap, and the overlap area of ​​the first electrode and the second electrode has a one-to-one correspondence with the bending angle. The detection circuit is connected to the first electrode structure and the second electrode structure respectively. The detection circuit is configured to detect the capacitance value of the sensing capacitor and obtain the bending angle of the foldable display device based on the capacitance value or capacitance change of the sensing capacitor.

2. The foldable display device according to claim 1, wherein, The first fixing structure includes a first side, a second side, a third side, and a fourth side that are sequentially connected and form an annular cavity. The first and third sides extend along a first direction, and the second and fourth sides extend along a second direction, which intersects the first direction. The third side is connected to the bottom surface of the mounting groove, and / or the fourth side is connected to the first wall of the mounting groove. The first electrode is disposed on the side of the first side facing the reinforcing layer, and at least one opening is provided on the second side. The second fixing structure is a strip-shaped support layer extending along the first direction. The strip-shaped support layer is connected to the bottom surface of the mounting groove, and / or the strip-shaped support layer is connected to the second wall of the mounting groove. A first portion of the second electrode near the first non-folding area extends into the annular cavity of the first fixing structure through the opening, such that the orthographic projection of the first electrode on the plane of the foldable display device at least partially overlaps with the orthographic projection of the second electrode on the plane of the foldable display device. A second portion of the second electrode away from the first non-folding area is disposed on the side of the strip-shaped support layer away from the reinforcing layer.

3. The foldable display device according to claim 2, wherein, At least one support platform is provided on the side of the third side away from the reinforcing layer, and the support platform is configured to support the second electrode extending into the annular cavity.

4. The foldable display device according to claim 1, wherein, The foldable display device further includes a connector, a first housing and a second housing disposed on both sides of the connector, and the display panel further includes a first non-foldable area and a second non-foldable area disposed on both sides of the bending area. The first non-foldable area is connected to the first housing, and the second non-foldable area is connected to the second housing. The first electrode structure and the second electrode structure are disposed on the connector.

5. The foldable display device according to claim 4, wherein, The connecting body includes a rotating shaft, a first connecting member, a second connecting member, a first electrode structure, and a second electrode structure respectively sleeved on the rotating shaft; the first connecting member includes a first cylindrical body sleeved on the rotating shaft and a first connecting piece disposed on the first cylindrical body, the first connecting piece being connected to the first housing; the second connecting member includes a second cylindrical body sleeved on the rotating shaft and a second connecting piece disposed on the second cylindrical body, the second connecting piece being connected to the second housing; the first electrode structure includes a third cylindrical body sleeved on the rotating shaft and a third electrode disposed on the third cylindrical body, the third cylindrical body being connected to the first cylindrical body; the second electrode structure includes a fourth cylindrical body sleeved on the rotating shaft and a fourth electrode disposed on the fourth cylindrical body, the fourth cylindrical body being connected to the second cylindrical body; the orthographic projection of the third electrode on a plane perpendicular to the rotating shaft at least partially overlaps with the orthographic projection of the fourth electrode on a plane perpendicular to the rotating shaft.

6. The foldable display device according to any one of claims 1 to 5, wherein, The detection circuit includes an input module, a compensation output module, a reset module, and a processing module; wherein, The input module is connected to a first power line, a first signal line, and a first node, respectively. The first node is connected to the first electrode of the first electrode structure. The input module is configured to output a high-level voltage signal of the first power line to the first node under the control of the first signal line to charge the sensing capacitor. The compensation output module is connected to the second signal line, the third signal line, the first node, the second node, and the processing module, respectively. The second node is connected to the second power line and the second electrode of the second electrode structure. The compensation output module is configured to compensate for the basic noise of the detection circuit under the control of the second signal line, and to output the voltage of the first node to the processing module under the control of the second signal line and the third signal line. The reset module is connected to the fourth signal line, the second power line, the first node, and the second node respectively, and is configured to output the voltage of the second node to the first node under the control of the fourth signal line, so as to initialize and reset the sensing capacitor. The processing module is connected to the compensation output module and is configured to receive and process the signal output by the compensation output module, and output a data signal that is proportional to the capacitance value of the sensing capacitor.

7. The foldable display device according to claim 6, wherein, The input module includes a first switch, the control electrode of the first switch is connected to the first signal line, the first electrode of the first switch is connected to the first power line, and the second electrode of the first switch is connected to the first node.

8. The foldable display device according to claim 6, wherein, The compensation output module includes a second switch, a third switch, and a compensation capacitor. The control electrode of the second switch is connected to the second signal line, the first electrode of the second switch is connected to the first node, the second electrode of the second switch is connected to the first plate of the compensation capacitor, the second plate of the compensation capacitor is connected to the second node, the control electrode of the third switch is connected to the third signal line, the first electrode of the third switch is connected to the first node, and the second electrode of the third switch is connected to the processing module.

9. The foldable display device according to claim 6, wherein, The reset module includes a fourth switch, the control electrode of the fourth switch is connected to the fourth signal line, the first electrode of the fourth switch is connected to the second node, and the second electrode of the fourth switch is connected to the first node.

10. The foldable display device according to claim 6, wherein, The processing module includes an integrating amplifier, an analog-to-digital converter, and a feedback capacitor. The feedback capacitor is disposed between the negative input terminal and the output terminal of the integrating amplifier. The positive input terminal of the integrating amplifier is connected to a reference voltage line. The negative input terminal of the integrating amplifier is connected to the compensation output module. The output terminal of the integrating amplifier is connected to the input terminal of the analog-to-digital converter. The output terminal of the analog-to-digital converter outputs a data signal proportional to the capacitance value of the sensing capacitor.

11. The foldable display device according to claim 6, wherein, The input module includes a first switch, the compensation output module includes a second switch, a third switch and a compensation capacitor, the reset module includes a fourth switch, and the processing module includes an integrating amplifier, an analog-to-digital converter and a feedback capacitor. The control electrode of the first switch is connected to the first signal line, the first electrode of the first switch is connected to the first power line, and the second electrode of the first switch is connected to the first node. The control electrode of the second switch is connected to the second signal line, the first electrode of the second switch is connected to the first node, the second electrode of the second switch is connected to the first plate of the compensation capacitor, and the second plate of the compensation capacitor is connected to the second node. The control electrode of the third switch is connected to the third signal line, the first electrode of the third switch is connected to the first node, and the second electrode of the third switch is connected to the processing module. The control electrode of the fourth switch is connected to the fourth signal line, the first electrode of the fourth switch is connected to the second node, and the second electrode of the fourth switch is connected to the first node. The feedback capacitor is disposed between the negative input terminal and the output terminal of the integrating amplifier. The positive input terminal of the integrating amplifier is connected to the reference voltage line, the negative input terminal of the integrating amplifier is connected to the compensation output module, the output terminal of the integrating amplifier is connected to the input terminal of the analog-to-digital converter, and the output terminal of the analog-to-digital converter outputs a data signal proportional to the capacitance value of the sensing capacitor.

12. A driving method for a foldable display device as claimed in any one of claims 1 to 11, comprising: Obtain the folding angle of the foldable display device; Color shift correction is performed on the folded area based on the folding angle.

13. The driving method according to claim 12, wherein, Obtaining the folding angle of the foldable display device includes: Acquire and store the initial data signal output by the detection circuit when the foldable display device is in an unbent state; Acquire the bending data signal output by the detection circuit when the foldable display device is in a bent state; The bending angle of the foldable display device is obtained based on the initial data signal and the bending data signal.

14. The driving method according to claim 13, wherein, The bending angle of the foldable display device is obtained based on the initial data signal and the bending data signal, including: Calculate the difference between the initial data signal and the bent data signal; The bending angle of the foldable display device is obtained based on the difference and a pre-set bending angle coefficient.

15. The method according to claim 14, wherein, The bending angle coefficient is obtained through a calibration process, which includes: Prepare foldable display devices; Place the foldable display device in a fully unfolded state and acquire the initial data signal output by the detection circuit; The foldable display device is placed in a fully engaged state, and the engagement data signal output by the detection circuit is obtained; The bending angle coefficient is obtained based on the initial data signal and the combined data signal.

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