TWI493420B - Capacitive touch screen - Google Patents

Description

Capacitive touch screen

The present invention relates to the field of touch technologies, and in particular, to a capacitive touch screen.

At present, capacitive touch screens are widely used in various electronic products, and have gradually penetrated into various fields of work and life. The size of capacitive touch screens is increasing, from 3 inches to 6.1 inches for smartphones to 10 inches for tablets. The application of capacitive touch screens can be extended to smart TVs. However, the existing capacitive touch screens generally have problems such as poor anti-interference performance, low scanning frequency, large volume, and complicated manufacturing process.

In view of this, the embodiments of the present disclosure provide a capacitive touch screen capable of solving at least one of the above problems.

The capacitive touch screen provided by the embodiment of the present disclosure includes: a substrate; a plurality of sensing electrodes disposed on the substrate, the plurality of sensing electrodes being arranged in a two-dimensional array; Connected to a touch control wafer on the substrate, the touch control wafer and each of the plurality of sensing electrodes are respectively connected by wires.

Preferably, the substrate is a glass substrate, the touch control wafer is connected to the substrate by a chip-on-Glass (COG) method; or the substrate is a flexible substrate, and the touch control wafer is a chip-on-film (COF) method is attached to the substrate; or the substrate is a printed circuit board, and the touch control wafer is connected by a chip-on-board (COB) Onto the substrate.

Preferably, the touch control wafer is configured to detect a self capacitance of each of the sensing electrodes.

Preferably, the touch control wafer is configured to detect a self-capacitance of each of the sensing electrodes by: driving the sensing electrodes with a voltage source or a current source; and detecting a voltage or a frequency or a quantity of the sensing electrodes.

Preferably, the touch control chip is configured to detect a self-capacitance of each of the sensing electrodes by: driving and detecting the sensing electrodes while driving the remaining sensing electrodes; or driving and detecting the sensing electrodes while driving the sensing The sensing electrode around the electrode.

Preferably, for each sensing electrode, the voltage source or current The sources have the same frequency; or for each sensing electrode, the voltage or current source has two or more frequencies.

Preferably, the touch control wafer is configured to detect the self-capacitance of each of the sensing electrodes by: simultaneously detecting all of the sensing electrodes; or detecting the sensing electrodes in groups.

Preferably, the touch control wafer is configured to determine a touch location based on a two dimensional array of capacitance changes.

Preferably, the touch control chip is further configured to adjust a sensitivity or a dynamic range of touch detection by parameters of the voltage source or current source, the parameters including any one or combination of amplitude, frequency, and timing.

Preferably, the shape of the sensing electrode is a rectangle, a diamond, a triangle, a circle or an ellipse.

Preferably, the capacitive touch screen comprises a plurality of touch control wafers connected to the substrate, each touch control wafer for detecting a corresponding one of the plurality of sensing electrodes.

Preferably, the time synchronization or non-synchronization of each touch control wafer.

Preferably, the wires are arranged in the same layer of the plurality of sensing electrodes; or the wires are arranged in different layers of the plurality of sensing electrodes.

According to the capacitive touch screen of the embodiment of the present disclosure, a plurality of sensing electrodes arranged in a two-dimensional array are used, and the premise of implementing multi-touch is adopted. The error caused by the transmission of noise between the electrodes in the prior art is solved, and the signal-to-noise ratio is significantly improved. With the solution of the embodiment of the present disclosure, the power supply noise of the touch screen is greatly eliminated, and the interference of the radio frequency (RF) and other noise sources from the liquid crystal display module can be weakened.

According to the capacitive touch screen of the embodiment of the present disclosure, the touch control chip and each of the sensing electrodes are respectively connected by wires and connected to the substrate by COG, COF or COB, thereby avoiding the difficulty of the number of pins. It also reduces the overall volume. In addition, by detecting each of the sensing electrodes simultaneously or in groups, the scanning time can be significantly reduced, thereby avoiding problems that may be caused by the large number of sensing electrodes.

11‧‧‧Capacitive touch screen

10‧‧‧Touch Control Wafer

15‧‧‧Optical adhesive

16‧‧‧Substrate

17‧‧‧Anisotropic conductive film

18‧‧‧ Coverage

19‧‧‧Induction electrodes

22‧‧‧ Busbar

2a-2d‧‧‧Different sensing electrodes

21‧‧‧ Touch

24‧‧‧ drive source

23‧‧‧Time Control Unit

T‧‧‧ time sequence

D1-DN‧‧‧Induction electrode

Dk-Dn‧‧‧Group2 electrode

D1-Dj‧‧‧Group1 electrode

42‧‧‧The capacitance to ground of the sensing electrode

41‧‧‧ drive source

45‧‧‧Charge receiving module

44‧‧‧ Noise

50‧‧‧Control logic

S1-S3‧‧‧ controlled switch

51‧‧‧Voltage source

6‧‧‧Signal Processing Unit

501‧‧‧Power Common Mode Noise

502‧‧‧ touch zone

52‧‧‧reference voltage

53-55‧‧‧ drive source

56‧‧‧Adjacent electrodes

57‧‧‧Measured electrode

58‧‧‧ adjacent electrodes

59‧‧‧Signal receiving unit

70‧‧‧Fat finger normal touch

71‧‧‧ Finger hovering touch

72‧‧‧Active/passive pen or small conductor

73‧‧‧With glove touch

1 is a schematic view of a capacitive touch screen provided by the embodiment of the present disclosure; FIG. 2 is a plan view of the sensing electrode array according to an embodiment of the present disclosure; and FIGS. 3 to 6 are sensing according to an embodiment of the present disclosure. Electrode driving method; FIG. 7 is a four application scenario of a capacitive touch screen according to an embodiment of the present disclosure; FIG. 8 is a signal flow diagram of a touch control wafer according to an embodiment of the present invention; FIG. 9A is a center of gravity The algorithm calculates an example of the coordinates of the touch position; Figure 9B shows the coordinates of the touch position using the center of gravity algorithm in the case of noise.

In the following, the technical solutions of the embodiments of the present disclosure will be described in conjunction with the accompanying drawings in the embodiments of the present disclosure. It is to be understood that the described embodiments are only a part of the embodiments of the invention. Any other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without any creative work should fall within the protection scope of the present invention. For ease of explanation, the cross-sectional view showing the structure is not partially enlarged in accordance with the general scale. Moreover, the drawings are merely exemplary and should not be construed as limiting the scope of the invention. In addition, the actual production should include three-dimensional dimensions of length, width and depth.

FIG. 1 is a schematic diagram of a capacitive touch screen provided by an embodiment of the present disclosure. As shown in FIG. 1 , the capacitive touch screen 11 includes: a substrate 16; a plurality of sensing electrodes 19 disposed on the substrate, the plurality of sensing electrodes 19 are arranged in a two-dimensional array; and connected to the substrate 16 The touch control wafer 10 is connected to each of the sensing electrodes 19 by wires.

The substrate 16 may be transparent, such as a glass substrate or a flexible substrate; it may also be opaque, such as a printed circuit board. A plurality of sensing electrodes 19 are disposed on the substrate 16, and the plurality of sensing electrodes 19 are arranged in a two-dimensional array, which may be a rectangular array or a two-dimensional array of any other shape. For a capacitive touch screen, each of the sensing electrodes 19 is a capacitive sensor, and the capacitance of the capacitive sensor changes when the corresponding position on the touch screen is touched.

Optionally, a cover layer 18 is disposed above the sensing electrode 19 A cover lens is used to protect the sensing electrode 19.

Each of the sensing electrodes 19 is connected to the touch control wafer 10 by wires, and the touch control wafer 10 is connected to the substrate 16. Since each of the sensing electrodes 19 is connected by a wire, the number of pins of the touch control wafer 10 is large, and therefore, the connection of the touch control wafer 10 to the substrate 16 can avoid the difficulty of conventional packaging. Specifically, the touch control wafer 10 may be a chip-on-glass (COG) or a chip-on-film (COF) or a chip-on-board (Chip-on-Board). COB) is connected to the substrate. According to the present embodiment, an anisotropic conductive film (ACF) 17 may be present between the touch control wafer 10 and the substrate 16.

In addition, conventional flexible circuit board (FPC) connections require space on the touch control chip and FPC on the hard side, which is not conducive to system simplification. With the COG method or the COF method, the touch control chip and the touch screen are integrated, which significantly reduces the distance between the two, thereby reducing the overall volume. In addition, since the sensing electrode is generally formed by etching indium tin oxide (ITO) on the substrate, and the touch control wafer is also located on the substrate, the connection between the two can be completed by one ITO etching, which greatly simplifies manufacturing. Process.

2 is a top plan view of an array of sensing electrodes in accordance with an embodiment of the present disclosure. Those skilled in the art should understand that FIG. 2 shows only one arrangement of the sensing electrodes. In a specific implementation, the sensing electrodes can be arranged in any two-dimensional array. In addition, the spacing of the sensing electrodes in either direction may be equal or unequal. Those skilled in the art should also pay attention to The number of sensing electrodes can be more than the number shown in FIG.

Those skilled in the art will appreciate that Figure 2 shows only one shape of the sensing electrode. According to other embodiments, the shape of the sensing electrode may be rectangular, rhombic, triangular, circular or elliptical, or may be irregular. The touch sensing electrodes may also have serrations on the edges. The patterns of the sensing electrodes may be uniform or inconsistent. For example, the sensing electrode in the middle has a diamond structure and the edge has a triangular structure. In addition, the size of each sensing electrode may be uniform or inconsistent. For example, the inner sensing electrode has a larger size and the smaller edge size, which is advantageous for the touch precision of the trace and the edge.

Each of the sensing electrodes has a lead drawn from the gap between the sensing electrodes. In general, the wires are as uniform as possible and the traces are as short as possible. In addition, the wire routing range is as narrow as possible while maintaining a safe distance, leaving more area for the sensing electrode, making the sensing more accurate.

Each of the sensing electrodes can be connected to the bus bar 22 by wires, and the bus bar 22 connects the wires directly or after a certain order to the pins of the touch control chip. For large screen touch screens, the number of sensing electrodes can be very large. In this case, all of the sensing electrodes can be controlled with a single touch control wafer; the sensing electrodes of different regions can be separately controlled by multiple touch control wafers by partitioning the screen, and time synchronization can be performed between the plurality of touch control wafers. At this time, the bus bar 22 can be divided into a plurality of bus bar sets to be connected to different touch control wafers. Each touch control wafer controls the same number of sensing electrodes or controls a different number of sensing electrodes.

For the sensing electrode array shown in Fig. 2, the wiring can be implemented on the same layer of the sensing electrode array. For other types of sensing electrode arrays, if the same layer routing is difficult to implement, the wires may be disposed in another layer different from the layer in which the sensing electrode array is located, and the sensing electrodes are connected through the via holes.

The sensing electrode array shown in Fig. 2 is based on the self-capacitance touch detection principle. Each sensing electrode corresponds to a specific position on the screen. In Fig. 2, 2a-2d indicate different sensing electrodes. 21 denotes a touch. When a touch occurs at a position corresponding to a certain sensing electrode, the electric charge on the sensing electrode changes. Therefore, by detecting the electric charge (current/voltage) on the sensing electrode, it is possible to know whether the sensing electrode has touched. event. In general, this can be achieved by converting an analog quantity to a digital quantity by an analog digital converter (ADC). The amount of charge change of the sensing electrode is related to the area covered by the sensing electrode. For example, the amount of charge change of the sensing electrodes 2b and 2d in FIG. 2 is larger than the amount of charge change of the sensing electrodes 2a and 2c.

Each of the positions on the screen has corresponding sensing electrodes, and there is no physical connection between the sensing electrodes. Therefore, the capacitive touch screen provided by the embodiments of the present disclosure can achieve true multi-touch, avoiding the prior art. The problem of ghost points in self-capacitance touch detection.

The sensing electrode layer can be combined with the display screen by surface bonding, or the sensing electrode layer can be made inside the display screen, such as an in-cell touch screen, and the sensing electrode layer can be displayed. The upper surface, such as an on-cell touch screen.

3 to 7 illustrate a sensing electrode driving method according to an embodiment of the present disclosure. As shown in FIG. 3, the sensing electrode 19 is driven by a source The 24 drive, drive source 24 can be a voltage source or a current source. For different sensing electrodes 19, the driving source 24 does not necessarily have to have the same structure. For example, a voltage source may be partially used, and a current source may be partially used. Further, for different sensing electrodes 19, the frequency of the driving source 24 may be the same or different. The timing control unit 23 controls the timing at which the respective driving sources 24 operate.

There are various options for the driving timing of each of the sensing electrodes 19. Hereinafter, n sensing electrodes (D1, D2, ..., Dj, Dk, ..., Dn) will be described as an example.

As shown in Figure 4A, all of the sensing electrodes are driven simultaneously and simultaneously detected. In this way, the time required to complete a scan is the shortest, and the number of driving sources is the largest (consistent with the number of sensing electrodes). As shown in Fig. 4B, the driving sources of the sensing electrodes are divided into groups, each of which sequentially drives the electrodes in a specific region. This method can achieve drive source multiplexing, but it will increase the scan time, but by selecting the appropriate number of packets, the drive source multiplexing and scan time can be compromised.

Figure 4C shows the scanning of conventional mutual capacitance touch detection. Assuming that there are n drive channels (TX), the scan time of each TX is Ts, and the time of scanning one frame is n*Ts. With the sensing electrode driving method of the embodiment, all the sensing electrodes can be detected together, and the time for scanning one frame is only Ts. That is to say, the scheme of the present embodiment can increase the scanning frequency by n times as compared with the conventional mutual capacitance touch detection.

For a mutual capacitive touch screen with 40 drive channels, if the scan time of each drive channel is 500us, the scan time of the entire touch screen (one frame) is 20ms, that is, the frame rate is 50Hz. 50Hz often does not meet the requirements of a good experience. Embodiment of the disclosed embodiment The solution can solve this problem. By using the sensing electrodes arranged in a two-dimensional array, all the electrodes can be simultaneously detected, and the frame rate reaches 2000 Hz with the detection time of each electrode being maintained at 500 us. This greatly exceeds the application requirements of most touch screens. The extra scan data can be utilized by the digital signal processing terminal for, for example, anti-interference or optimized touch trajectory for better results.

The In-Cell touch screen uses the field blanking time of each frame to scan, but the field blanking time per frame is only 2-4ms, and the conventional mutual capacitance based scanning time is often 5ms or more. In order to realize the use of the In-Cell screen, the scanning time of the mutual capacitance touch detection is generally reduced, specifically, the scanning time of each channel is reduced. This method reduces the signal-to-noise ratio of the In-Cell screen and affects the touch experience. The solution of the embodiments of the present disclosure can solve this problem. For example, an In-Cell screen with 10 drive channels and a regular mutual capacitance touch detection scan time of 4ms, each channel has a scan time of 400us. By employing the solution of the embodiment of the present disclosure, all electrodes are simultaneously driven and detected, and all electrodes are scanned for only 400 us. For the above In-Cell screen, if the touch detection scan time is kept constant for 4 ms, there is still a lot of time remaining. The saved time can be used for other detections such as multiple repeated detection or variable frequency detection, thereby greatly improving the signal-to-noise ratio and anti-interference ability of the detection signal, so as to obtain a better detection effect.

Preferably, the self capacitance of each of the sensing electrodes is detected. The self-capacitance of the sensing electrode can be its capacitance to ground.

As an example, a charge detection method can be employed. As shown in Fig. 5, the drive source 41 supplies a constant voltage V1. Voltage V1 can be positive pressure, Negative pressure or ground. S1 and S2 represent two controlled switches, 42 represents the capacitance of the sensing electrode to ground, 45 represents the charge receiving module, and the charge receiving module 45 can clamp the input voltage to the specified value V2 and measure the input or output. The amount of charge. First, S1 is closed and S2 is turned off, and the upper plate of Cx is charged to the voltage V1 supplied from the driving source 41; then S1 is turned off and S2 is closed, and Cx is charged and exchanged with the charge receiving module 45. Let the charge transfer amount be Q1, and the upper plate voltage of Cx becomes V2, then C=Q/ΔV, and Cx=Q1/(V2-V1), thereby achieving capacitance detection.

As another example, a current source can also be employed, or its self-capacitance can be obtained by sensing the frequency of the electrodes.

Alternatively, in the case of using a plurality of driving sources, when detecting one sensing electrode, a voltage different from a driving source of the electrode to be measured may be selected for the sensing electrode adjacent to or surrounding the sensing electrode. For the sake of brevity, Figure 6 shows only three sensing electrodes: one electrode to be tested 57 and two adjacent electrodes 56 and 58. Those skilled in the art will appreciate that the following examples are also applicable to the case of more sensing electrodes.

The driving source 54 connected to the electrode to be measured 57 is connected to the voltage source 51 through the switch S2 to drive the electrode 57 to be tested; and the sensing electrodes 56 and 58 adjacent to the electrode 57 to be tested and the driving sources 53 and 55 Connected, they can be connected to voltage source 51 or a specific reference voltage 52 (Vref, for example ground) through switches S1 and S3. If the switches S1 and S3 are connected to the voltage source 51, the electrodes of the electrode to be tested and the electrodes thereof are simultaneously driven by the same voltage source, so that the voltage difference between the electrode to be tested and the peripheral electrode thereof can be reduced, which is advantageous for reducing the electrode to be tested. Capacitance and false touches that help prevent water droplets from forming touch.

Preferably, the touch control wafer is configured to adjust the sensitivity or dynamic range of the touch detection by parameters of the drive source, including any one or combination of amplitude, frequency, and timing. As an example, as shown in FIG. 7, the parameters of the drive source (e.g., drive voltage, current, and frequency) and the timing of each drive source can be controlled by the control logic of the signal drive unit 50 within the touch control wafer. With these parameters, different circuit operating states can be adjusted, such as high sensitivity, medium sensitivity or low sensitivity, or different dynamic ranges.

Different circuit operating states can be applied to different application scenarios. FIG. 7 illustrates four application scenarios of a capacitive touch screen according to an embodiment of the present disclosure: a finger normal touch 70, a finger hovering touch 71, an active/passive pen or small conductor 72, and a gloved touch. 73. In combination with the above parameters, detection of one or more normal touches and one or more small conductor touches can be achieved. It will be understood by those skilled in the art that although the signal receiving unit 59 and the signal driving unit 50 shown in Fig. 6 are separate, in other embodiments, they may be implemented by the same circuit.

Figure 8 shows a signal flow diagram of a touch control wafer in accordance with an embodiment of the present invention. When a touch occurs on the sensing electrode, the capacitance of the sensing electrode changes, and the amount of change is converted into a digital amount by the ADC, and the touch information can be recovered. In general, the amount of capacitance change is related to the area covered by the sensing electrode by the touch object. The signal receiving unit 59 receives the sensing data of the sensing electrode, and recovers the touch information through the signal processing unit.

As an example, the signal processing unit 6 is specifically described below. Data processing method.

Step 61: Acquire sensing data.

Step 62: Filter and reduce noise of the sensing data. The purpose of this step is to eliminate the noise in the original image as much as possible for subsequent calculations. This step can be specifically applied to the airspace, time domain or threshold filtering method.

Step 63: Find the possible touch areas therein. These areas include real touch areas and invalid signals. Invalid signals include large area touch signals, power supply noise signals, floating abnormal signals, and water drop signals. Some of these invalid signals are close to the real touch, some may interfere with the real touch, and some should not be resolved into a normal touch.

Step 64: Exception processing to eliminate the above invalid signal and obtain a reasonable touch area.

Step 65: Calculate according to the data of the reasonable touch area to obtain the coordinates of the touch position.

Preferably, the coordinates of the touch location can be determined from a two-dimensional array of capacitance variations. Specifically, a centroid algorithm can be employed to determine the coordinates of the touch location from the two-dimensional array of capacitance changes.

As an example, the touch control wafer may include a signal driving/receiving unit configured to drive the respective touch sensing electrodes and receive the sensing data from the respective touch sensing electrodes, and a signal processing unit configured to determine the touch position according to the sensing data. Specifically, the signal driving/receiving unit may be configured to drive the sensing electrode with a voltage source or a current source; the signal processing unit may be configured to calculate its self-capacitance (eg, capacitance to ground) by sensing the voltage or frequency or the amount of electricity of the electrode. And according to the amount of change in self capacitance To determine the touch location.

In addition, the signal driving/receiving unit may be configured to drive the remaining sensing electrodes while driving the sensing electrodes for each of the sensing electrodes, or to drive the sensing electrodes while driving the sensing electrodes for each of the sensing electrodes. Induction electrode.

Figure 9A shows an example of the coordinates of the touch position calculated using the center of gravity algorithm. For the sake of brevity, only the coordinates of one dimension of the touch location are calculated in the following description. Those skilled in the art will appreciate that the same coordinates can be obtained using the same or similar methods. It is assumed that the sensing electrodes 56-58 shown in Fig. 7 are covered by the fingers, and the corresponding sensing data are PT1, PT2, PT3, respectively, assuming that the abscissa is set to the x direction, the ordinate is set to the y direction, and the sensing electrodes are 56-58. The corresponding abscissas are x1, x2, and x3, respectively. Then the abscissa of the finger touch position obtained by the center of gravity algorithm is:

Here, only the one-dimensional center of gravity algorithm is taken as an example, and the actual coordinates can be determined by the two-dimensional center of gravity algorithm.

Optionally, after obtaining the coordinates of the touch location, step 66: analyzing the data of the previous frame to obtain the current frame data by using the multi-frame data.

Optionally, after obtaining the coordinates of the touch location, step 67 may also be performed: tracking the touch trajectory according to the multi-frame data. In addition, event information can be obtained and reported according to the user's operation process.

The capacitive touch screen according to the embodiment of the present disclosure can solve the problem of noise superposition in the prior art under the premise of implementing multi-touch.

Taking the introduction of the power common mode noise at the position 501 in FIG. 7 as an example, the following analyzes the influence of the noise on the calculation of the touch position.

In prior art mutual capacitance touch detection based touch systems, there are multiple drive channels (TX) and multiple receive channels (RX), and each RX is in communication with all TXs. When a common mode interference signal is introduced into the system, the noise is transmitted throughout RX due to the RX connectivity. In particular, when there are multiple noise sources on one RX, the noise of these noise sources will be superimposed, thereby increasing the noise amplitude. The noise causes the voltage signal on the measured capacitance to oscillate, resulting in a false alarm at the non-touch point.

In the capacitive touch screen provided by the embodiments of the present disclosure, there is no physical connection between the sensing electrodes before being connected to the inside of the wafer, and the noise cannot be transmitted and superimposed between the sensing electrodes, thereby avoiding false alarms.

Taking the voltage detection method as an example, the noise causes a voltage change on the touched electrode, thereby causing a change in the sensed data of the touched electrode. According to the self-capacitance touch detection principle, the sensing value caused by the noise and the sensing value caused by the normal touch are proportional to the area covered by the touch electrode.

Figure 9B shows the coordinates of the touch position calculated using the center of gravity algorithm in the presence of noise. It is assumed that the induced values caused by the normal touch are PT1, PT2, and PT3, respectively, and the induced values caused by the noise are PN1, PN2, and PN3 (take the sensing electrodes 56-58 as an example):

There are: PN1=K*PT1, PN2=K*PT2, PN3=K*PT3, where K is a constant.

When the polarity of the voltage of the noise and the driving source is the same, the final sensing data due to voltage superposition is: PNT1=PN1+PT1=(1+K)*PT1 PNT2=PN2+PT2=(1+K)*PT2 PNT3=PN3 +PT3=(1+K)*PT3

Then, the coordinates obtained by the center of gravity algorithm are:

It can be seen that equation (2) is equal to equation (1). Therefore, the capacitive touch screen of the embodiment of the present disclosure is immune to common mode noise. As long as the noise does not exceed the dynamic range of the system, it will not affect the final coordinates.

When the noise is opposite to the voltage of the drive source, the effective signal is pulled low. If the effective signal after the pull-down is detected, it can be seen from the above analysis that the final determined coordinates are not affected. If the valid signal after the pull-down is not detected, the data of the current frame is invalid. However, the scanning frequency of the capacitive touch screen provided by the embodiment of the present disclosure can be high. To achieve N times the normal scanning frequency (N is usually greater than 10), this feature can be used to recover the current frame data using multi-frame data. Those skilled in the art will appreciate that the processing using multi-frame data does not affect the normal reporting rate since the scanning frequency is much larger than the actual required reporting rate.

Similarly, when the noise is limited beyond the dynamic range of the system, multi-frame data can also be used to correct the current frame to get the correct coordinates. The interframe processing method is also applicable to radio frequency and interference from other noise sources such as liquid crystal display modules.

The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the invention. Therefore, the present invention should not be limited to the disclosed embodiments, but the broadest scope consistent with the principles and novel features disclosed herein.

11‧‧‧Capacitive touch screen

10‧‧‧Touch Control Wafer

17‧‧‧Anisotropic conductive film

16‧‧‧Substrate

19‧‧‧Induction electrodes

15‧‧‧Optical adhesive

18‧‧‧ Coverage

Claims (13)

A capacitive touch screen includes: a substrate; a plurality of sensing electrodes disposed on the substrate, the plurality of sensing electrodes are arranged in a two-dimensional array; and a touch control wafer connected to the substrate, the touch control wafer and Each of the plurality of sensing electrodes is connected by a wire. The capacitive touch screen of claim 1, wherein the substrate is a glass substrate, the touch control wafer is connected to the substrate by a chip-on-glass method; or the substrate is flexible a substrate, the touch control wafer is connected to the substrate by a chip-on-Film method; or the substrate is a printed circuit board, and the touch control chip is packaged on a chip (Chip-on- Board) is connected to the substrate. The capacitive touch screen of claim 1, wherein the touch control wafer is configured to detect a self capacitance of each of the sensing electrodes. The capacitive touch screen of claim 3, wherein the touch control wafer is configured to detect a self-capacitance of each of the sensing electrodes by: driving the sensing electrode with a voltage source or a current source; and detecting the sensing The voltage or frequency or amount of electricity of the electrode. The capacitive touch screen of claim 3, wherein the touch control wafer is configured to detect a self-capacitance of each of the sensing electrodes by: driving and detecting the sensing electrodes while driving the remaining sensing electrodes; or The sensing electrode is driven and detected while driving the sensing electrode around the sensing electrode. The capacitive touch screen of claim 4, wherein the voltage source or current source has the same frequency for each sensing electrode; or for each sensing electrode, the voltage source or current source has two or more Frequency of. The capacitive touch screen of claim 3, wherein the touch control wafer is configured to detect a self-capacitance of each of the sensing electrodes by: simultaneously detecting all of the sensing electrodes; or detecting the sensing electrodes in groups. The capacitive touch screen of claim 3, wherein the touch control wafer is configured to determine a touch location based on a two-dimensional array of capacitance changes. The capacitive touch screen of claim 4, the touch control chip is further configured to adjust a sensitivity or a dynamic range of the touch detection by parameters of the voltage source or the current source, the parameters including amplitude, frequency, and Any one or combination of timings. The capacitive touch screen of claim 1, wherein the shape of the sensing electrode is rectangular, diamond, triangular, circular or elliptical. The capacitive touch screen of claim 1, wherein the capacitive touch screen comprises a plurality of touch control wafers connected to the substrate, each of the touch control wafers for detecting the plurality of sensing electrodes A corresponding part of the sensing electrode. The capacitive touch screen as described in claim 11, each touch control crystal The time of the slice is synchronized or not synchronized. The capacitive touch screen of claim 1, wherein the wires are disposed in a same layer of the plurality of sensing electrodes; or the wires are disposed in different layers of the plurality of sensing electrodes.