TWI662461B - Touch control apparatus - Google Patents

Abstract

An embodiment of the present disclosure provides a touch display device including a first substrate, a second substrate, a liquid crystal layer disposed between the first substrate and the second substrate, a common electrode, and a plurality of pixel units; And a plurality of touch sensing electrodes disposed above the common electrode, the plurality of touch sensing electrodes are arranged in a two-dimensional array. By adopting the device provided by the embodiment of the present disclosure, it is possible to reduce noise and improve the frame update rate of touch detection scanning.

Description

Touch display device

The present invention relates to the field of touch technology, and in particular, to a touch display device.

Currently, capacitive touch screens are widely used in various electronic products, and have gradually penetrated into various areas of people's work and life. The size of capacitive touch screens is gradually increasing, from 3 inches to 6.1 inches for smart phones to about 10 inches for tablet computers. The application fields 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 update rate of touch detection scanning pictures, large volume, and complicated manufacturing technology.

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

A touch display device provided by an embodiment of the present disclosure includes a first substrate, a second substrate, a liquid crystal layer disposed between the first substrate and the second substrate, a common electrode, and a plurality of pixel units; and A plurality of touch-sensing electrodes disposed above the common electrode The plurality of touch sensing electrodes are arranged in a two-dimensional array, and the plurality of touch sensing electrodes are located on the same side of the common electrode relative to the liquid crystal layer.

The shape of the touch sensing electrode may be a regular polygon, a rhombus, a strip, a circle, or an ellipse.

Optionally, the touch sensing electrodes have sawtooth edges.

The material of the plurality of touch sensing electrodes may be indium tin oxide (ITO) or graphene.

Preferably, the touch display device further comprises: a touch control chip, the touch control chip and each of the plurality of touch sensing electrodes are respectively connected by wires, and the touch control chip is covered with glass (Chip-on-Glass) pressure welding to the first substrate or the second substrate.

Preferably, the wires are arranged on the same layer of the plurality of touch-sensing electrodes; or the wires are arranged on different layers of the plurality of touch-sensing electrodes, and the plurality of touch-sensing electrodes are connected through through holes.

The touch display device may further include a flexible circuit board which is pressure-welded to the first substrate or the second substrate and connected to the touch control chip.

Preferably, the touch control chip is configured to detect a self-capacitance of each touch sensing electrode, and determine a touch position according to a two-dimensional self-capacitance change array.

The touch control chip may include: a driving / receiving unit configured to drive a touch sensing electrode with a voltage source or a current source, and receiving sensing data of the touch sensing electrode; and a signal processing unit configured to be based on the sensing The data calculates the self-capacitance of each touch sensing electrode.

Preferably, the driving / receiving unit is configured to drive the touch sensing electrode in a follow-up driving manner.

The sensing data may represent a voltage, a frequency, or a power amount of a touch sensing electrode.

The voltage source or current source may have two or more frequencies.

Preferably, the touch control chip is configured to detect the self-capacitances of all touch-sensing electrodes simultaneously, or to detect the self-capacitances of each touch-sensing electrode in groups.

The touch control chip may also be configured to adjust the sensitivity and / or dynamic range of touch detection through parameters of the voltage source or current source, the parameters including any one or combination of amplitude, frequency, and timing.

Preferably, the touch display device has an In-Plane Switching structure, and the plurality of touch sensing electrodes are located on the same side of the common electrode relative to the liquid crystal layer; or

The touch display device has a twisted nematic (Nematic) structure, the plurality of touch sensing electrodes are located on the other side of the common electrode relative to the liquid crystal layer.

According to the solution of the embodiment of the present disclosure, the A layer of touch sensing electrodes arranged in a two-dimensional array is arranged on the common electrode, and the error caused by noise superimposed on the electrodes in the prior art is solved under the premise of achieving multi-touch. With the solution of the embodiment of the present disclosure, the influence of power supply noise can be greatly eliminated, and radio frequency (RF) interference and interference from the liquid crystal display portion and the like can also be reduced.

In addition, according to the scheme of the embodiment of the present disclosure, it is possible to detect simultaneously Multiple touch-sensing electrodes, thereby reducing the time required to complete a touch-detection scan, and improving the screen update rate of the touch-detection scan.

11‧‧‧ the first substrate

15‧‧‧LCD layer

19‧‧‧ touch sensing electrode

23‧‧‧ Insulation

31‧‧‧Flexible Circuit Board (FPC)

13‧‧‧second substrate

17‧‧‧ Common electrode

21‧‧‧touch control chip

25‧‧‧Anisotropic conductive film (ACF)

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings used in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are just some embodiments of the present invention. For those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIGS. 1a and 1b are schematic side views of a touch display device according to the first embodiment of the present disclosure; FIG. 1c is a plan view showing a common electrode layer according to the first embodiment of the present disclosure; and FIGS. A schematic side view of a touch display device of Example 2; and FIG. 3 is a schematic view of a touch display device of Example 3 according to the present disclosure Illustration.

In order to make the purpose, features and advantages of this disclosure more Obviously, the technical solutions of the embodiments of the present disclosure will be described below with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present invention. Based on the embodiments of the present disclosure, any other embodiments obtained by those skilled in the art without paying creative labor shall fall within the protection scope of the present invention. For ease of explanation, the cross-sectional view showing the structure is not partially enlarged according to the general scale. Moreover, the drawings are only exemplary, which should not limit the protection scope of the present invention. In addition, the actual production should include three-dimensional dimensions of length, width, and depth.

Example one

Embodiment 1 of the present disclosure provides a touch display device including a first substrate 11, a second substrate 13, a liquid crystal layer 15 disposed between the first substrate and the second substrate, a common electrode 17, and a plurality of A pixel unit; and a plurality of touch-sensing electrodes 19 disposed above the common electrode 17, the plurality of touch-sensing electrodes 19 are arranged in a two-dimensional array.

The display touch screen may have an In-Plane Switching (IPS) structure. At this time, the plurality of touch sensing electrodes are located on the same side of the common electrode relative to the liquid crystal layer. The display touch screen may also have a twisted nematic (Twisted Nematic (TN for short) structure, at this time, the plurality of touch sensing electrodes are located on the other side of the common electrode opposite to the liquid crystal layer.

FIG. 1a is a touch display device according to the first embodiment of the present disclosure. A schematic side view of an example of placement. The touch display device has an IPS structure.

FIG. 1b is a touch display device according to the first embodiment of the present disclosure. Side view of another example of the setting. The touch display device has a TN structure.

The common electrode 17 belongs to a liquid crystal display portion of a touch display device It is driven by a common voltage (Vcom) and forms an electric field across liquid crystals in different areas on the screen with different pixel units, thereby controlling the light throughput in different areas.

As an example, the touch display shown in Figures 1a and 1b The device also includes a color filter layer. Each pixel unit includes three sub-pixel units, which respectively correspond to red, green, and blue. Each sub-pixel unit includes a thin film transistor (Thin Film Transistor).

FIG. 1c shows a touch control according to a first embodiment of the present disclosure. An example of a touch-sensing electrode layer of a display device. The shape of the touch sensing electrode may be a regular polygon, a rhombus, a bar, a circle, or an ellipse. The shape of the touch-sensing electrode may also be an arbitrary triangle or an irregular shape. In addition, the edges of the touch sensing electrodes may have sawtooth. Preferably, the material of the touch sensing electrode is a metal oxide such as indium tin oxide (ITO) or graphene.

Those skilled in the art should understand that the diagram of each touch sensing electrode Cases can be consistent or inconsistent. For example, the touch-sensing electrode in the middle adopts a diamond structure, and the edge adopts a triangular structure. In addition, the sizes of the touch-sensing electrodes may be the same or different. For example, the size of the touch-sensing electrode inside is larger and the size of the edge is smaller, which is beneficial to the touch accuracy of the traces and edges.

In an existing in-cell touch display device, The touch control section includes a row electrode and a column electrode. The row / column electrodes extend from one side to the opposite side of the screen, occupying a long space, and the noise on each row / column will be superimposed. For example, when multiple fingers are placed on the same row or column, the noise of each finger will be superimposed on the row or column, increasing the amplitude of the noise.

The touch display device provided in the embodiment of the present disclosure has Touch sensing electrodes arranged in a two-dimensional array, each electrode is only a unit in the array. Each row / column is composed of different cells. There is no physical connection between cells, which will not cause noise to overlap. Therefore, the touch display device according to the embodiment of the present disclosure reduces the amplitude of the maximum noise and improves the signal-to-noise ratio.

Example two

The touch display device according to the second embodiment of the present disclosure further includes A touch control chip 21, each of which is connected to each of the plurality of touch sensing electrodes 19 by a wire, and the touch control chip 21 is in a chip-on-glass manner Pressure welding to the first substrate 11 or the second substrate 13.

Figure 2a is a touch display device according to a second embodiment of the present disclosure A schematic side view of an example of placement. The touch display device has an IPS structure.

Figure 2b is a touch display device according to the second embodiment of the present disclosure Side view of another example of the setting. The touch display device has a TN structure.

According to this embodiment, the common electrode 17 and the touch sensing electrode There is an insulating layer 23 between 19, and an anisotropic conductive film (ACF) 25 may exist between the touch control wafer 21 and the substrate.

Since each touch sensing electrode 19 has a wire connected to the touch control chip 21, the number of pins of the touch control chip 21 will increase significantly. Pressure bonding the touch control wafer 21 to the substrate in a glass-on-chip manner can avoid the difficulties of conventional packaging. If conventional packaging methods are used, hundreds of pins require complex packaging structures, such as expensive Ball Grid Array (BGA). In addition, since the BGA can only be used on a printed circuit board (PCB) or a flexible circuit board (FPC), the touch control chip 21 and the touch sensing electrodes 19 need to be connected through the FPC.

Preferably, the wires connecting the touch control chip 21 and each touch sensing electrode 19 are arranged on a touch sensing electrode layer; or they are arranged on a layer different from the touch sensing electrode layer, and each touch sensing electrode 19 is connected through a hole. Since the touch sensing electrode is generally formed by etching a conductive layer (such as a metal oxide such as ITO or a metal) on the substrate, and the touch control chip is also located on the substrate, the connecting wire between the two can be completed by one etching The manufacturing technology is simple.

In general, the wires should be as uniform as possible and the traces should be as short as possible. this In addition, the routing range of the wires is as narrow as possible under the premise of ensuring a safe distance, thereby leaving more area for the touch sensing electrodes.

Optionally, each touch sensing electrode can be connected to the sink through a wire The busbar and the busbar connect the wires to the touch control chip directly or after a certain sequence. For large-screen touch display devices, the number of touch sensing electrodes may be very large. In this case, you can use a single touch control chip to control all touch-sensing electrodes; you can also control the touch-sensing electrodes in different areas by partitioning the screen and using multiple touch-control chips. Synchronize. At this time, the bus can be divided into several bus sets to connect with different touch control chips. Each touch control chip controls the same number of touch sensing electrodes, or controls a different number of touch sensing electrodes.

For descriptions of other components in this embodiment, please refer to other implementations. For example, it will not be repeated here.

Example three

In the touch display device according to the third embodiment of the present disclosure, The touch control chip 21 is configured to detect a self-capacitance of each touch sensing electrode, and determine a touch position according to a two-dimensional self-capacitance change array.

As an example, the self-capacitance of the touch sensing electrode can be The capacitance of the touch sensing electrode to ground.

Preferably, the touch control chip 21 includes a driving / receiving unit configured to use a voltage source or a current source Driving a touch sensing electrode, and receiving sensing data of the touch sensing electrode; and a signal processing unit configured to calculate a self-capacitance of each touch sensing electrode according to the sensing data.

FIG. 3 is a schematic diagram of a touch display device according to a third embodiment of the present disclosure.

Optionally, the touch display device shown in FIG. 3 further includes a flexible circuit board (FPC) 31 which is pressure-welded to the first substrate 11 or the second substrate 13 and connected to the touch control chip 21. And host side.

For the description of other components in this embodiment, please refer to other embodiments, which will not be repeated here.

Embodiment 4

In the touch display device according to the fourth embodiment of the present disclosure, the touch control chip 21 is configured to detect the self-capacitances of all touch-sensing electrodes at the same time, or to detect the self-capacitances of each touch-sensing electrode in groups.

In the prior art, since the touch control part includes row electrodes and column electrodes, a scanning method of one line after another is adopted, and the touch detection time of each frame is very long. This disadvantage is particularly disadvantageous for the In-Cell touch display device: in order to reduce the interaction between the liquid crystal display part and the touch control part, the touch control part stops working when the liquid crystal display part works; the liquid crystal display part stops working when the touch control part works. For example, an In-Cell touch display device with an operating frequency of 60 Hz (that is, 16.7 ms per frame) usually requires a display scan time of 10-12 ms, and the scan time for touch detection is very short. Therefore, the signal-to-noise ratio of the existing in-cell touch display devices is relatively low. In the touch display device provided in the fourth embodiment of the present disclosure, each touch sensing electrode is connected to a touch control chip, and in parallel scanning, theoretically, only the time required to detect a line in the prior art can reach the original Signal-to-noise ratio. For example, for an In-Cell touch display device with 16 rows and 28 columns, assuming that the touch detection time of each row is T, the touch detection scan time required in the prior art is 16T. With the structure provided by the embodiment of the present disclosure, the shortest touch detection time per frame is only 1T.

For descriptions of other components in this embodiment, please refer to other implementations. For example, it will not be repeated here.

Example 5

The touch display device according to Embodiment 5 of the present disclosure further includes Display control circuit. The touch display device performs the first step in a loop, the first step includes: the display control circuit scans one frame, and then the touch control circuit provided by the touch control chip 21 scans one frame. That is, one frame display scan is performed first, and then one frame touch detection scan is performed, and so on.

Alternatively, the touch display device performs the second step in a loop, The second step includes: the touch control circuit scans one frame, and then the display control circuit scans one frame. That is, one frame of touch detection scan is performed first, and then one frame of display scan is performed, and so on.

Further, the display scan of each frame can be divided into multiple segments, Each segment performs a touch detection scan to make the touch detection frequency multiple times the display frequency, thereby improving the screen update rate of the touch detection scan. That is That is to say, each frame scanning of the display control circuit is performed in sections; the touch control circuit performs one frame scanning before, during, and after each frame scanning of the display control circuit.

For descriptions of other components in this embodiment, please refer to other implementations. For example, it will not be repeated here.

Example Six

In the touch display device according to Embodiment 6 of the present disclosure, all The driving / receiving unit is configured to drive the touch sensing electrode in a follow-up driving manner.

Specifically, the following driving manner may include any one or a combination of the following:

A. The driving / receiving unit is configured to, for each touch sensing electrode, simultaneously drive the remaining touch sensing electrodes according to a signal applied to the touch sensing electrodes.

B. The driving / receiving unit is configured to, for each touch sensing electrode, simultaneously drive the touch sensing electrodes around the touch sensing electrode according to a signal applied to the touch sensing electrode.

C. The driving / receiving unit is configured to, for each touch sensing electrode, simultaneously drive a common electrode according to a signal applied to the touch sensing electrode.

D. The driving / receiving unit is configured to, for each touch sensing electrode, simultaneously drive a data line of a corresponding pixel unit according to a signal applied to the touch sensing electrode.

Since each touch sensing electrode 19 has a wire connected to the touch control chip 21, the number of wires is very large. In the case of limited area, the wiring will become thin, resulting in an increase in impedance and affecting the quality of the detection signal. The following driving method can reduce the voltage difference between the detected electrode and the non-detected electrode, which is beneficial to reduce the capacitance of the detected electrode and prevent false touches caused by water droplets.

For the description of other components in this embodiment, please refer to other embodiments, which will not be repeated here.

Example Seven

In the touch display device according to Embodiment 7 of the present disclosure, the sensing data may represent a voltage, a frequency, or a power amount of a touch sensing electrode.

Optionally, the voltage source or current source may have two or more frequencies.

Optionally, the touch control chip may be further configured to adjust the sensitivity and / or dynamic range of touch detection through parameters of the voltage source or current source, the parameters including any one of amplitude, frequency, and timing. Or combination.

For the description of other components in this embodiment, please refer to other embodiments, which will not be repeated here.

Example eight

In the touch display device according to the eighth embodiment of the present disclosure, when the data of the current frame is invalid (when the noise is opposite to the polarity of the driving source, the effective signal is pulled down. If the effective signal after being pulled down cannot be detected, when The data of the previous frame is invalid.) Multi-frame data is used to recover the data of the current frame. Those skilled in the art should understand that, because the touch detection scan frequency is greater than the actually required reporting rate, processing using multiple frames of data will not affect the normal reporting rate.

Similarly, when the noise is beyond the dynamic range of the system to a limited extent, multiple frames of data can also be used to modify the current frame to obtain the correct touch position. The inter-frame processing method is also suitable for radio frequency interference and interference from liquid crystal display parts and the like.

Each embodiment in this specification focuses on the differences between other embodiments, and the same or similar parts between the embodiments can refer to each other.

The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent 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 embodiments disclosed, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims (15)

A touch display device includes: a first substrate, a second substrate, a liquid crystal layer disposed between the first substrate and the second substrate, a common electrode, and a plurality of pixel units; and A plurality of touch sensing electrodes above the electrodes, the plurality of touch sensing electrodes are arranged in a two-dimensional array. The touch display device according to claim 1, wherein the shape of the touch sensing electrode is a regular polygon, a rhombus, a strip, a circle, or an ellipse. The touch display device according to claim 2, wherein edges of the touch sensing electrodes are sawtoothed. The touch display device according to claim 1, wherein a material of the plurality of touch sensing electrodes is indium tin oxide (ITO) or graphene. The touch display device according to claim 1, further comprising: a touch control chip, the touch control chip and each of the plurality of touch sensing electrodes are respectively connected by a wire, and the touch control The wafer is pressure-bonded to the first substrate or the second substrate in a Chip-on-Glass manner. The touch display device according to claim 5, wherein the wires are arranged on the same layer of the plurality of touch sensing electrodes; or the wires are arranged on different layers of the plurality of touch sensing electrodes through a through hole The plurality of touch sensing electrodes are connected. The touch display device according to claim 5, further comprising: a flexible circuit board which is pressure-welded to the first substrate or the second substrate and connected to the touch control chip. The touch display device according to claim 5, wherein the touch control chip is configured to detect a self-capacitance of each touch sensing electrode, and determine a touch position according to a two-dimensional self-capacitance change array. The touch display device according to claim 8, wherein the touch control chip includes a driving / receiving unit configured to drive a touch sensing electrode with a voltage source or a current source, and receive sensing data of the touch sensing electrode And a signal processing unit configured to calculate a self-capacitance of each touch sensing electrode according to the sensing data. The touch display device according to claim 9, wherein the driving / receiving unit is configured to drive the touch sensing electrodes in a follow-up driving manner. The touch display device according to claim 9, wherein the sensing data represents a voltage, a frequency, or a power amount of a touch sensing electrode. The touch display device according to claim 9, wherein the voltage source or current source has two or more frequencies. The touch display device according to claim 8, wherein the touch control chip is configured to detect the self-capacitances of all touch-sensing electrodes at the same time, or to detect the self-capacitances of each touch-sensing electrode in groups. The touch display device according to claim 9, wherein the touch control chip is further configured to adjust a sensitivity and / or a dynamic range of touch detection through a parameter of the voltage source or a current source, the parameter including an amplitude , Frequency, and timing. The touch display device according to any one of claims 1-14, wherein the touch display device has an In-Plane Switching structure, and the plurality of touch sensing electrodes are located opposite to the common electrode. On the same side of the liquid crystal layer; or the touch display device has a twisted nematic structure, and the plurality of touch sensing electrodes are located on the other side of the common electrode opposite to the liquid crystal layer.