CN112703547A

CN112703547A - Touch display panel and bending detection method

Info

Publication number: CN112703547A
Application number: CN201880096014.4A
Authority: CN
Inventors: 朱剑磊
Original assignee: Shenzhen Royole Technologies Co Ltd
Current assignee: Shenzhen Royole Technologies Co Ltd
Priority date: 2018-10-30
Filing date: 2018-10-30
Publication date: 2021-04-23
Also published as: WO2020087298A1

Abstract

A touch display panel (10) comprises a display area (AA), a non-display area (NA) and a bending detection unit (WU). The display area (AA) comprises a plurality of pixel units (PX), the non-display area (NA) is arranged in the peripheral area of the display area (AA), a display circuit (DS) used for the pixel units (PX) to perform image display is arranged, the bending detection unit (WU) is arranged in the non-display area (NA) and is electrically connected with the display circuit (DS), and the bending of the touch display panel (10) is detected under the driving of a bending detection driving signal provided when the display circuit (DS) works. Further provided is a bending detection method of the touch display panel (10).

Description

Touch display panel and bending detection method

Technical Field

The invention relates to the technical field of touch control, in particular to a touch control display panel capable of identifying bending operation and a bending detection method thereof.

Background

Touch display panels are increasingly applied to electronic products, and meanwhile, the electronic products have increasingly flexible requirements for the touch display panels, for example, flexible touch display panels are required for electronic books and mobile communication terminals. How to simply detect the bending of the touch panel becomes a problem to be solved urgently.

Disclosure of Invention

To solve the foregoing problems, a touch display panel capable of performing bending detection is provided.

A touch display panel comprises a display area, a non-display area and a bending detection unit. The display area includes a plurality of pixel units, the non-display area set up in the display area peripheral region is provided with and is used for a plurality of pixel units carry out image display's display circuit, the detection unit buckles, buckle the detection unit set up in the non-display area and electric connection display circuit, and be in the detection of buckling of touch-control display panel under the drive of the bending detection drive signal that the display circuit during operation provided.

A bending detection method of the touch display panel comprises the following steps:

applying a bend detection driving signal to a bend detection unit, the bend detection unit applying the bend detection driving signal from the display circuit;

receiving a bending detection sensing signal corresponding to the bending detection driving signal through a bending detection unit;

and identifying whether the touch display panel is bent or not according to the sensing signal.

Compared with the prior art, the bending detection unit is arranged in the non-display area, and the two detection electrodes in the bending detection unit are respectively and electrically connected with the display circuit and the touch circuit, so that the complexity of wiring of the bending detection electrodes is effectively reduced, the space of the bending detection electrodes occupying the touch display panel is saved, and the cost is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic plan view illustrating a touch display panel according to an embodiment of the invention;

FIG. 2 is a schematic plan view of the non-display area shown in FIG. 1;

FIG. 3 is a schematic diagram illustrating a specific circuit structure of the display driving unit;

FIG. 4 is a schematic cross-sectional view of the touch display panel shown in FIG. 1;

FIG. 5 is a schematic plan view of the first and second electrodes shown in FIG. 4;

FIG. 6 is a timing diagram illustrating the touch circuit of FIGS. 1-3 identifying a bending of the touch display panel;

FIG. 7 is a flow chart of the touch circuit identifying bending of the touch display panel;

FIG. 8 is a schematic side view of a touch display panel in a planar state;

fig. 9-10 are schematic side views of the touch display panel in a bent state.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are only a few embodiments of the present invention, and not all embodiments. The embodiments of the present invention, all other embodiments obtained by those skilled in the art without any inventive work, shall fall within the scope of the present invention.

The structure and the working principle of the touch display panel are specifically described below with reference to the accompanying drawings.

Please refer to fig. 1, which is a schematic plan view of a touch display panel according to an embodiment of the present invention.

As shown in fig. 1, the touch display panel 10 includes a display area AA and a non-display area NA.

The display area AA includes a plurality of pixel units PX for image display and a touch unit TU for sensing a touch operation.

The non-display area NA is provided with a display circuit DS, a touch circuit TC and a timing control circuit TCON, the display circuit DS is used for driving the pixel unit PX to perform image display, the touch circuit TC is used for driving the touch unit TU to perform sensing of touch operation applied to the touch display panel 10, and the timing control circuit TCON is used for outputting a synchronous control signal SYNC to control the operating states of the display circuit DS and the touch circuit TC. In this embodiment, the synchronous control signal SYNC is used to control the display circuit DS and the touch circuit TC to synchronously perform image display, touch operation and bending detection of the touch display panel 10.

Please refer to fig. 2, which is a schematic plan view of the non-display area shown in fig. 1.

The display circuit DS includes a plurality of display drive units DU that sequentially output drive signals that control the pixel units PX to receive image signals.

Further, referring to fig. 4, the non-display area NA further includes a plurality of first electrodes W1 and a plurality of second electrodes W2 arranged in a row along the first direction F1 and insulated from each other, the second electrodes W2 and the plurality of first electrodes W1 form a plurality of capacitors, and the capacitors serve as the bending detection unit WU to detect the bending state of the touch display panel 10 and output a bending detection signal. In this embodiment, the first electrode W1 is configured to receive the bending detection driving signal, and when the first electrode W1 receives the bending detection driving signal, an electric field is formed by a capacitor formed with the second electrode W2, and a bending detection sensing signal is output corresponding to the second electrode W2. Whether the touch display panel 10 is bent or not and the specific position of the transmission bending can be known by identifying the bending detection induction signal. Preferably, the bending detection driving signal is applied by the display circuit DS, that is, the bending detection unit WU detects the bending state of the touch display panel 10 under the driving of the display circuit DS.

In the present embodiment, the plurality of display driving units DU are electrically connected to the first electrode W1. Preferably, the display circuit DS includes M display driving units DU, wherein N display driving units DU are electrically connected to the first electrode W1, the number M, N is an integer greater than 1, and M is greater than N.

In this embodiment, the display driving unit DU is a scan driving unit and outputs an image scanning signal, and accordingly, the first electrode W1 receives an electric signal from the display driving unit DU as a bending detection driving signal. And the display circuit DS further comprises a data driving circuit SU for providing an image signal to the pixel unit PX when the pixel unit receives the scan signal.

The first electrode W1 forms a capacitor with the second electrode W2 and generates an electric field after receiving the image scanning signal, and the bending detection sensing signal is formed by detecting whether the electric field generated by the first electrode W1 and the second electrode W2 changes, and the touch circuit TC receives the bending detection sensing signal through the second electrode W2 to identify the bending state and the bending position of the touch display panel 10.

Please refer to fig. 3, which is a schematic diagram of a circuit structure of an exemplary display driving unit DU.

The display driving unit DU includes an input terminal STV, a first transistor T1, a pull-up point PU, a first capacitor C, a second transistor T2, a third transistor T3, a fourth transistor T4, a scan clock signal CKV, and a scan signal output terminal Gout.

Specifically, the gate and the drain of the first transistor T1 are directly electrically connected and are also electrically connected to the input terminal STV for receiving the start signal. The source of the first transistor T1 is electrically connected to the gate of the second transistor T2 through the pull-up point PU. The source of the second transistor T2 receives the scan clock signal CKV, and the drain of the second transistor T2 is electrically connected to the scan signal output terminal Gout.

The first capacitor C is electrically connected to the pull-up point PU and the scan signal output terminal Gout.

The gate of the third transistor T3 and the gate of the fourth transistor T4 are directly electrically connected to receive the reset signal Sre, the drain of the third transistor T3 and the drain of the fourth transistor T4 are electrically connected to the ground terminal VSS, the source of the third transistor T3 is electrically connected to the pull-up point PU, and the source of the fourth transistor T4 is electrically connected to the scan signal output terminal Gout.

The input terminal STV is configured to receive an enable signal, and the enable signal is configured to control the first transistor T1 to be turned on and transmit the enable signal to the second transistor T2 through the pull-up point PU.

The second transistor T2 is in a turned-on state under the control of the enable signal, and the scan clock signal is transmitted to the scan signal output terminal Gout as the scan signal through the second transistor T2.

The first capacitor C is used to keep the pull-up point PU in a high voltage state to accurately maintain the second transistor T2 in a conducting state.

It can be understood that the circuit of the display driving unit DU is not limited to the above-mentioned 4T1C circuit structure composed of 4 transistors and 1 capacitor, and for example, other circuit structures capable of implementing display driving, such as 4T2C composed of 4 transistors and 2 capacitors, may also be used, and are not described herein again.

In this embodiment, the pull-up point PU is also electrically connected to the first electrode W1, i.e. the voltage signal of the pull-up point PU is used as the bending detection driving signal of the first electrode W1. Specifically, please refer to fig. 4 for the connection between the pull-up point PU and the first electrode W1.

Please refer to fig. 4, which is a schematic side view of the touch display panel shown in fig. 1. As shown in fig. 4, the touch display panel 10 includes a substrate BA corresponding to a display area AA, and a display driving layer SD, a display dielectric layer SM, an encapsulation layer TFE, and a touch dielectric layer TM sequentially disposed on one side of the substrate BA; corresponding non-display area NA, base BA one side sets gradually display circuit DS encapsulation layer TFE and a plurality of detection unit WU of buckling, just encapsulation layer TFE corresponds display circuit DS includes opening V1, pull-up point PU passes through opening V1 electric connection first electrode W1.

The pixel units PX (fig. 1) are disposed in the display medium layer SM, the display driving layer SD is used for disposing the electronic components for driving the pixel units PX, and the encapsulation layer TFE is used for protecting the display driving layer SD, the display medium layer SM and the display circuit DS.

Please refer to fig. 5, which is a schematic plane structure diagram of the first electrode W1 and the second electrode W2 shown in fig. 4.

The plurality of first electrodes W1 are arranged in a parallel and mutually insulated arrangement along the first direction F1, and each first electrode W1 includes a first portion and a second portion, wherein the first portion is a strip-shaped conductive line extending along the first direction F1, and the second portion is a plurality of branch conductive lines extending along the second direction F2, and electrically connected with the first portion and arranged at intervals along the first direction F1. Wherein the second direction F2 is perpendicular to the first direction F1. The second electrode W2 includes third portions and fourth portions, wherein the third portions are stripe-shaped conductive lines extending along the first direction F1, the fourth portions are a plurality of branch conductive lines extending along the second direction F2 while crossing the third portions and being spaced apart along the first direction F1, and wherein the second portions and the fourth portions extend along the second direction F2 in opposite directions and are staggered along the first direction F1. In this embodiment, the first direction F1 is a direction in which the touch display panel 10 bends.

In this embodiment, the plurality of first electrodes W1 in the touch display panel 10 may be sequentially arranged along the first direction F1 as first electrodes W11, W12, W13 … … W1N (not shown). The display driving units DU connected to two adjacent first electrodes W1 are spaced by n display driving units DU, that is, the first electrode W11 is electrically connected to the display driving units DU 1; the first electrode W12 is electrically connected to the display driving unit Dun + 1; the first electrode W13 is electrically connected to the display driving unit DU2n +1, and so on. Note that, the plurality of display drive units DU output image scanning signals in a time-division manner, and correspondingly, the plurality of first electrodes W1 also receive bend detection drive signals supplied to the pull-up points PU in the plurality of display drive units DU in a time-division manner.

In this embodiment, the plurality of first electrodes W1 and the second electrode W2 form a self-contained sensing unit. That is, the plurality of first electrodes W1 sequentially receive the bending scan signal from the touch circuit TC according to a predetermined time length, and then the second electrode W2 receives the bending sensing signal. When the touch display panel 10 is bent, the bending position can be identified by analyzing the bending scanning signal.

Please refer to fig. 6, which is a timing diagram illustrating the touch circuit identifying the bending of the touch display panel 10 as shown in fig. 1-3, and fig. 7 is a flowchart illustrating the touch circuit identifying the bending of the touch display panel 10, and referring to fig. 1-5, the bending detection method will be described in detail, and the bending detection method includes the steps of:

step 701, apply a kink detection driving signal to the kink detection unit WU. When the display driving unit DU in the display circuit applies the bending detection driving signal to the bending detection unit WU during operation, the bending detection unit WU starts to detect the bending of the touch display panel 10 under the driving of the display circuit.

Specifically, each of the display drive units DU applies an image scanning signal sequentially at predetermined time intervals 1H in the order of the position arrangement in accordance with the synchronization control signal SYNC, and at the same time, the plurality of first electrodes W1 in the warp detection unit WU sequentially and continuously obtain a warp detection drive signal from the corresponding display drive unit DU for a predetermined time period. In this embodiment, the predetermined interval time length 1H may be determined according to the scanning time duration required by each display driving unit DU, for example, if the scanning time duration required by each row of display driving units DU is 2H (see fig. 6), the predetermined interval time length is 1H, and the like, and of course, the predetermined interval time length may also be 1/2H, which is not limited thereto. Where H represents one unit time length.

As shown in fig. 6, the bending detection of the touch display panel 10 includes a plurality of consecutive operation periods t, each of which includes a predetermined time period, and one operation period t corresponds to one first electrode W1. Wherein each operation period t is the same as the time duration for which one display driving unit DU outputs the image scanning signal.

For example, at the time period t1, a bend scan signal is applied to the first electrode W1 sorted at the first position; applying a meander scan signal to the first electrode W1 sequenced at the second position for a time period t 2; at the time period t3, a bend scan signal is applied to the first electrode W1 ordered at the third position, and so on, and all the first electrodes W1 sequentially obtain the bend detection driving signals supplied from the display driving unit DU.

Step 702, receiving a bending detection sensing signal by the bending detection unit WU, wherein the bending detection sensing signal corresponds to the bending detection driving signal.

Specifically, the bending detection unit WU detects the bending state of the touch display panel 10 and receives the bending detection sensing signal from the second electrode W2, and the second electrode W2 and the first electrode W1 form the self-contained bending detection unit WU, so that when the bending detection driving signal is applied to the first electrode W1, the bending detection unit WU outputs the bending detection sensing signal from the second electrode W2.

And 703, identifying whether the touch display panel 10 is bent or not according to the bending detection sensing signal.

In this embodiment, the received bending detection sensing signal is processed to obtain a processed bending detection sensing signal, and whether the touch display panel is bent or not is determined by comparing the processed bending detection sensing signal value with a preset threshold value. For example, a timer may be disposed in the touch circuit TC, when a bending occurs, the capacitance value in the detected bending sensing signal changes, the capacitance integral value corresponding to the bending time node also changes, the preset threshold is set as a capacitance integral average value of a period of time, and when the processed bending sensing signal value is greater than the preset threshold, it is determined that the touch display panel is bent at this time point.

Please refer to fig. 8-10, which are schematic side views of a display panel in a planar state and a bent state, respectively.

As shown in fig. 8 to 9, when the display panel is in a bent state, the capacitance between the plurality of first electrodes W1 and the plurality of second electrodes W2 may be decomposed into a first capacitance C1 and a second capacitance C2.

The first capacitor C1 acts as the main capacitor when the bending radius r is large, and the second capacitor C2 acts as the main capacitor when the bending radius r is small.

When the display panel is in a planar state, the second capacitor C2 cannot be detected, and only the first capacitor C1 needs to be detected.

For example, as shown in fig. 10, when bending is performed with a bending radius r of 5mm, the total bending length is pi r, the width of the first electrode W1 and the second electrode W2 is L, and the distance is W, then a total of pi r/(W + L) capacitors are close to each other on the total bending length, and the radius of the metal top surface after bending is 5mm-H, because of bending, the distance between electrodes of each capacitor is expressed as: Δ W ═ pi H/(pi r/(W + L)) ═ H ═ W + L)/r, and based on the capacitance value calculation formula C ═ kS/d, the change value of the capacitance when the touch display panel 10 is in the bent state can be obtained as:

preferably, when one touch display panel 10 is in the bending state, the bending range includes at least 2 capacitors, and then L ═ 1/2 × pi r and W ═ 5 μm, Δ C/C ≈ 18.6% is obtained, that is, when the capacitance value corresponding to the capacitor formed by the first electrode W1 and the second electrode W2 changes by more than 18.6%, the touch display panel 10 can be considered to be in the bending state.

Step 704, determining a bending position of the touch display panel 10 according to the bending detection sensing signal.

Specifically, since each first electrode W1 corresponds to one of the display drive units DU, and the time when the corresponding display drive unit DU outputs the image scanning signal corresponds to the acquired bending detection drive signal for each first electrode W1, the position of the first electrode W1 can be obtained by identifying the time when the bending detection drive signal is acquired. That is, the position where the kink occurred can be obtained by the time when the image scanning signal is output when the kink occurred, wherein the time when the image scanning signal is output can be determined by the time when the image driving unit DU from the output of the synchronization control signal SYNC to the corresponding position outputs the image scanning signal, for example, the time DT when the kink occurred can be obtained by the ratio (DT/T) of DT to T of the first electrode W1 and the corresponding position of the image driving unit DU

As shown in fig. 6, the value of the sensing signal processed in the time period t2 exceeds the preset threshold, that is, it can be confirmed that the capacitance of the first electrode W12 at the second position changes due to bending, and thus it can be confirmed that the position where the touch display panel 10 is bent is the first electrode W12 at the second position, that is, the position of the first electrode W1 corresponding to the image driving unit DUn +1 is bent.

Compared with the prior art, the bending detection unit WU is arranged in the non-display area, the two detection electrodes in the bending detection unit are respectively and electrically connected with the display circuit DS and the touch circuit TC, so that the display circuit DS receives a bending detection driving signal and outputs a corresponding bending detection sensing signal to the touch circuit TC, and the touch circuit TC can identify whether the touch display panel 10 sends bending and bending positions through the bending detection signal, so that the complexity of wiring of the bending detection electrodes is effectively reduced, the space occupied by the bending detection electrodes on the touch display panel is saved, and the cost is reduced.

The touch display panel and the bending detection method thereof provided by the embodiment of the invention are described in detail above, and a specific example is applied in the description to explain the principle and the embodiment of the invention, and the description of the embodiment is only used to help understanding the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

A touch display panel, comprising:

a display area including a plurality of pixel units;

a non-display area arranged in a peripheral area of the display area and provided with a display circuit for the plurality of pixel units to perform image display; and the number of the first and second groups,

and the bending detection unit is arranged in the non-display area, is electrically connected with the display circuit, and detects the bending of the touch display panel under the driving of a bending detection driving signal provided when the display circuit works.
The touch display panel of claim 1, wherein the display area comprises:

the touch circuit is arranged in the non-display area and used for sensing touch operation, the touch circuit is electrically connected with the bending detection unit, the bending detection unit outputs a corresponding bending detection induction signal to the touch circuit according to a bending detection driving signal provided by the display circuit, and the touch circuit identifies the bending of the touch display panel according to the bending detection induction signal.
The touch display panel of claim 2, wherein the non-display area comprises:

the display circuit comprises a plurality of display driving units, the display driving units are used for outputting image scanning signals to drive the pixel units to display images, the bending detection units are electrically connected with the display driving units, and the bending detection driving signals are obtained from the display driving units when the display driving units output the image scanning signals.
The touch display panel according to claim 3, wherein the bending detection unit comprises a plurality of first electrodes and a second electrode, the plurality of first electrodes and the second electrode form a plurality of capacitors along a first direction, the plurality of first electrodes are respectively electrically connected to a plurality of different display driving units, and the second electrode is electrically connected to the touch circuit.
The touch display panel according to claim 4, wherein the first electrode receives a bending detection driving signal from the display driving unit when the display driving unit outputs the image scanning signal, the second electrode outputs a bending detection sensing signal corresponding to the bending detection driving signal, and the touch circuit identifies the bending state of the touch display panel according to the bending detection sensing signal.
The touch display panel according to claim 5, wherein the touch circuit identifies a bending occurrence position of the touch display panel by a time of the received bending detection sensing signal.
The touch display panel of claim 6, wherein the number of the first electrodes is less than the number of the display driving units, and each of the first electrodes is connected to one of the display driving units.
The touch display panel of claim 7, wherein two of the display driving units electrically connected to two adjacent first electrodes are spaced by the same number of display driving units.
The touch display panel according to claim 6, wherein the plurality of first electrodes are arranged in a parallel and mutually insulated arrangement along a first direction, each of the first electrodes includes a first portion and a second portion, wherein the first portion is a strip-shaped conductive line extending along the first direction, the second portion is a plurality of branch conductive lines extending along a second direction, electrically connected to the first portion, and spaced apart along the first direction, wherein the second direction is perpendicular to the first direction, the second electrode includes a third portion and a fourth portion, the third portion is a strip-shaped conductive line extending along the first direction, the fourth portion is a plurality of branch conductive lines extending along the second direction, intersecting the third portion, and spaced apart along the first direction, the second portion and the fourth portion extend along the second direction, and extend along the opposite direction The first direction is the direction in which the touch display panel bends.
The method for detecting bending of the touch display panel according to any one of claims 1 to 9, comprising the steps of:

applying a bend detection driving signal to a bend detection unit, the bend detection unit applying the bend detection driving signal from the display circuit;

receiving, by a bend detection unit, a bend detection sense signal corresponding to the bend detection drive signal;

and identifying whether the touch display panel is bent or not according to the sensing signal.
The bending detection method according to claim 10, further comprising the step of, after identifying whether the touch display panel is bent:

and determining the bending occurrence position of the touch display panel according to the bending detection induction signal.
The bend detection method according to claim 11, wherein said applying a bend detection driving signal to the bend detection unit is specifically:

the touch control circuit sequentially and continuously applies the bending detection driving signal to the plurality of first electrodes of the bending detection unit according to a preset time length through the display circuit.
The bend detection method according to claim 11, wherein the receiving of the bend detection sensing signal by the bend detection unit is specifically:

and detecting the bending state of the touch display panel through the bending detection unit and receiving the bending detection induction signal from the second electrode.
The bending detection method according to claim 11, wherein the step of identifying whether the touch display panel is bent according to the bending detection sensing signal includes:

and processing the received bending detection induction signal to obtain a processed sensing signal, and determining whether the touch display panel is bent or not by comparing the processed bending detection induction signal value with a preset threshold value.
The method for detecting bending according to claim 11, wherein the determining the bending occurrence position of the touch display panel according to the bending detection sensing signal includes:

the bending occurrence position is obtained by the bending scanning time when bending occurs.