CN203102245U - A capacitive embedded touch screen and display device - Google Patents

Abstract

The utility model discloses a capacitive embedded touch screen and a displaying device. A touch control driving signal line is arranged between every two adjacent rows of pixel units in a thin film transistor (TFT) array substrate, at least one data signal line in the TFT array substrate serves as a touch control reading signal line, a touch control electrode and a touch control switching unit are arranged in a set area in the overlapping position of the touch control reading signal lines, time division multiplex access is carried out on the data signal lines, and the data signal lines serve as the touch control reading signal lines to output voltage signals of a touch control electrode coupling, and a touch control function is realized. Based on an existing preparing process of the TFT array substrate, the touch screen is manufactured without the need of an additional process, production cost is saved, and production efficiency is improved. Meanwhile, the data signal lines serve as the touch control reading signal lines, an additional driving chip integrated circuit (IC) used for independently controlling the touch control signal lines is not needed, and manufacturing cost is saved.

Description

A capacitive embedded touch screen and display device

technical field

The utility model relates to the field of display technology, in particular to a capacitive embedded touch screen and a display device.

Background technique

With the rapid development of small and portable electronic devices, the market demand for touch screen (Touch Screen Panel) is increasing day by day. At present, touch screens can be divided into three types according to their composition: Add on Mode Touch Panel, On Cell Touch Panel, and In Cell Touch Panel. Among them, the plug-in touch screen is produced separately from the touch screen and Liquid Crystal Display (LCD), and then bonded together to form a touch-enabled LCD screen. The plug-in touch screen has high production costs and low light transmittance. Low, thick modules and other shortcomings. The embedded touch screen embeds the touch electrodes of the touch screen inside the liquid crystal display, which can reduce the overall thickness of the module and greatly reduce the production cost of the touch screen, and is favored by major panel manufacturers.

The current capacitive in-cell touch screen is realized by directly adding touch driving signal lines and touch sensing signal lines on the existing TFT (Thin Film Transistor, Thin Film Field Effect Transistor) array substrate, that is, on the TFT On the surface of the array substrate, two layers of strip-shaped ITO (Indium Tin Oxides, indium tin metal oxide) electrodes intersecting each other in different planes are made. The intersections of different planes of the strips of ITO electrodes form inductive capacitors. Its working process is: when the touch driving signal is applied to the ITO electrode as the touch driving signal line, the voltage signal coupled by the touch sensing signal line through the inductive capacitance is detected. During this process, when a human body touches the touch screen, the human body The electric field will act on the sensing capacitor, causing the capacitance value of the sensing capacitor to change, thereby changing the voltage signal coupled from the touch sensing signal line, and the position of the touch point can be determined according to the change of the voltage signal.

The structure design of the above-mentioned capacitive embedded touch screen needs to add a new film layer on the existing TFT array substrate due to the addition of the touch driving signal line and the touch sensing signal line, resulting in the need to add a new film layer when making the TFT array substrate. process, which increases production costs and is not conducive to improving production efficiency.

Utility model content

The embodiment of the utility model provides a capacitive embedded touch screen and a display device, which are used to realize a capacitive embedded touch screen with lower cost and higher production efficiency.

A capacitive embedded touch screen provided by an embodiment of the present invention includes a thin film transistor TFT array substrate with data signal lines, and a plurality of pixel units arranged in a matrix are arranged in the TFT array substrate;

The TFT array substrate has a touch driving signal line between adjacent rows of pixel units;

At least one data signal line in the TFT array substrate is used as a touch reading signal line;

The TFT array substrate has a touch electrode and a touch switch unit located in the area defined by the intersection of the touch read signal line and the touch drive signal line; the touch electrode is electrically connected to the adjacent touch drive signal line, and The touch switching unit is electrically connected to the adjacent touch reading signal line;

In the display time period, apply a grayscale signal to the touch reading signal line, and the touch switching unit is in the off state; in the touch time period, apply a touch driving signal to the touch driving signal line, and the touch switching unit is in the on state state, the touch driving signal is output to the touch reading signal line after passing through the touch electrode.

A display device provided by an embodiment of the present invention includes a capacitive embedded touch screen provided by an embodiment of the present invention.

The beneficial effects of the utility model embodiment include:

In the capacitive embedded touch screen and display device provided by the embodiment of the present invention, a touch driving signal line is provided between adjacent rows of pixel units in the TFT array substrate; at least one data signal line in the TFT array substrate is used as The touch reading signal line; the touch electrode and the touch switching unit are arranged in the area defined by the intersection of the touch reading signal line and the touch driving signal line; the touch electrode is electrically connected to the adjacent touch driving signal line connected, and electrically connected to the adjacent touch reading signal line through the touch switching unit. In the display time period, apply a grayscale signal to the touch reading signal line, and the touch switching unit is in the off state; in the touch time period, apply a touch driving signal to the touch driving signal line, and the touch switching unit is in the on state state, the touch driving signal is output to the touch reading signal line after passing through the touch electrode. Since the data signal line is used for time-division multiplexing, it is used as the touch reading signal line to receive the voltage signal coupled by the touch electrode to realize the touch function. On the basis of the existing TFT array substrate preparation process, no additional process is required. It can be made into a touch screen, which saves the production cost and improves the production efficiency. Moreover, using the data signal line as the touch reading signal line can avoid adding a driving chip IC for separately controlling the touch reading signal line, and can save production cost.

Description of drawings

Fig. 1 and Fig. 2 are respectively the structural schematic diagrams of the TFT array substrate in the capacitive in-cell touch screen provided by the embodiment of the utility model;

FIG. 3 is a schematic diagram of a circuit structure of a pixel unit provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of the driving sequence of the touch screen provided by the embodiment of the present invention;

FIG. 5 is a schematic diagram of distribution of touch electrodes and touch sub-electrodes in a touch screen provided by an embodiment of the present invention.

Detailed ways

The specific implementation manners of the capacitive in-cell touch screen and the display device provided by the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

The thickness and shape of each layer of film in the drawings do not reflect the true proportion of the TFT array substrate, and the purpose is only to illustrate the content of the utility model.

A capacitive embedded touch screen provided by an embodiment of the present invention includes a thin film transistor TFT array substrate with data signal lines, as shown in Figure 1, and a plurality of pixel units 01 arranged in a matrix are arranged in the TFT array substrate ;

The TFT array substrate has a touch driving signal line 02 located between adjacent rows of pixel units;

At least one data signal line Data in the TFT array substrate is used as the touch reading signal line 03;

The TFT array substrate has a touch electrode 04 and a touch switch unit 05 located in the area defined by the intersection of the touch reading signal line 03 and the touch driving signal line 02; the touch electrode 04 and the adjacent touch driving signal line 02 is electrically connected, and is electrically connected to the adjacent touch reading signal line 03 through the touch switching unit 05;

During the display time period, the touch switching unit is in the off state, applying a grayscale signal to the touch reading signal line; The touch driving signal is output to the touch reading signal line after passing through the touch electrode.

The above-mentioned capacitive embedded touch screen provided by the embodiment of the utility model uses the time-division multiplexing of the data signal line as the touch reading signal line to receive the voltage signal coupled by the touch electrode to realize the touch function, and can be used in the existing On the basis of the preparation process of the TFT array substrate, the touch screen can be manufactured without additional process, which saves the production cost and improves the production efficiency. Moreover, using the data signal line as the touch reading signal line can avoid adding a driving chip IC for separately controlling the touch reading signal line, and can save production cost.

Generally, the touch precision of a touch screen is usually at the millimeter level, while the display precision of a TFT array substrate is usually at the micron level. Much fewer gate signal lines and data signal lines are required. Therefore, in the specific implementation of the above-mentioned touch screen provided by the embodiment of the present invention, only the spacing between the touch driving signal lines can be set to be the same; or only the spacing between the touch reading signal lines can be set to be the same ; It is also possible to set the spacing between the touch driving signal lines to be the same, and at the same time set the spacing between the touch reading signal lines to be the same. For example, as shown in FIG. 1 , there are two rows of pixel units 01 between each touch driving signal line 02 , and two columns of pixel units 01 between each touch reading signal line 03 . Preferably, during specific implementation, the spacing between each touch driving signal line and the spacing between each touch reading signal line can be set to be the same, so as to unify the touch accuracy of the touch screen. The accuracy referred to in the embodiments of the present invention refers to the size of a touch electrode of a touch screen or a pixel electrode of a display screen.

Preferably, in the touch screen provided by the embodiment of the present invention, when setting the touch driving signal lines, each touch driving signal line and the gate signal line in the TFT array substrate can be arranged on the same layer and ensure that the two are insulated from each other. , that is, the touch drive signal lines that are insulated from each other are prepared at the same time as the gate signal lines are prepared. In this way, no additional preparation process is required when preparing the TFT array substrate, and the gate can be formed by only one patterning process. The pattern of the signal line and the touch driving signal line can save the preparation cost and increase the added value of the product. Of course, gate signal lines and touch driving signal lines can also be prepared on different film layers, which is not limited here.

Further, when the above-mentioned touch screen provided by the embodiment of the present utility model is actually implemented, as shown in FIG. 2 , the specific structure of the touch switch unit 05 can be the first TFT device T1; wherein, the gate of the first TFT device T1 can be It is electrically connected to the touch scanning signal line 06 , the drain is electrically connected to the touch reading signal line 03 , and the source is electrically connected to the touch electrode 04 . Preferably, the specific implementation of the touch scanning signal line 06 may be to use the gate signal line Gate in the gap between the same pixel units 01 as the touch driving signal line 02 in the TFT array substrate as the touch scanning signal line 06, the touch scanning signal line 06 may also be separately provided in the TFT array substrate. The function of the set touch scanning signal line 06 is to control the on or off state of the touch switching unit 05. During the touch time period, by sequentially applying the touch scanning signal to each touch scanning signal line 06, the position of the touch point can be located. The vertical coordinate is the coordinate in the y direction, and the horizontal coordinate of the touch point, that is, the coordinate in the x direction can be obtained by detecting the change of the voltage signal on the touch reading signal line 03 column by column, so as to realize the touch function.

In addition, in actual implementation, the touch scanning signal line 06 can also be omitted, and the gate of the first TFT device T1 can be connected to the touch driving signal line 02. In this way, the touch driving signal line 02 has the function of controlling touch switching. The effect of the on or off state of cell 05. Similarly, during the touch time period, by sequentially applying touch driving signals to each touch driving signal line 02, the longitudinal coordinate of the touch point, that is, the y-direction coordinate, can be detected by detecting the voltage on the touch reading signal line 03 column by column. The signal change can obtain the horizontal coordinate of the touch point, that is, the x-direction coordinate, so as to realize the touch function.

The specific structure of the above-mentioned touch switching unit 05 is only a schematic illustration, of course, the specific structure of the touch switching unit 05 may also be other structures, which are not limited here.

Preferably, the first TFT device in the touch screen provided by the embodiment of the present invention can adopt the same LTPS (Low Temperature Poly-silicon, low-temperature polysilicon) technology as the second TFT device connected to the pixel electrode and the data signal line in the array substrate. In this way, on the basis of the existing TFT array substrate preparation process, the touch screen can be produced without adding additional process steps, which saves production costs and improves production efficiency.

Further, during specific implementation, the first TFT device serving as the touch switch unit and the second TFT device connected to the pixel electrode and the data signal line in the TFT array substrate form an inverter structure. Specifically, the inverter structure may be that the first TFT device is a P-type TFT device, and the second TFT device is an N-type TFT device. Of course, it is also possible that the first TFT device is an N-type TFT device, and the second TFT device is a P-type TFT device, which is not limited here.

Taking the first TFT device as a P-type TFT device and the second TFT device as an N-type TFT device as an example, the specific working process of the touch screen provided by the embodiment of the present invention will be described in detail below.

For example, as shown in FIG. 3 , a schematic diagram of the circuit structure of a pixel unit, the P-type first TFT device T1 and the N-type second TFT device T2 share the gate signal line Gate as the touch scanning signal line and the gate signal line Gate as the touch control signal line. Read the data signal line Data of the signal line.

The driving timing of the circuit structure in Figure 3 is shown in Figure 4, specifically:

First, divide the display time of each frame on the touch screen into a display time period and a touch time period. For example, the time for a touch screen to display a frame is 16.7ms, select 5ms as the touch time period, and the other 11.7ms as the display time period. Of course, the durations of the two can also be appropriately adjusted according to the processing capability of the IC chip, which is not specifically limited here.

During the display period, a high-level display scan signal (a positive voltage signal) is sequentially applied to each gate signal line Gate1, Gate2...Gate n in the touch screen. According to the principle of the inverter, the N-type second TFT device T2 is turned on at this time, and the P-type first TFT device T1 is in the off state; at the same time, a gray-scale signal is applied to the data signal line Data, and the gray-scale signal passes through the N-type The second TFT device T2 is loaded on the display capacitor C2 to realize normal display. Wherein, the display capacitor C2 is formed by the pixel electrode and the common electrode. In this way, even if there is a voltage signal on the touch electrode in the display phase, since the P-type first TFT device T1 is in the off state, the voltage signal on the touch capacitor C1 will not be output to the data signal line Data, and there will be no will interfere with the normal display.

During the touch time period, apply a low-level touch scan signal (a negative voltage signal) to each of the gate signal lines Gate1, Gate2...Gate n in the touch screen as the touch scan signal line in turn. Each touch driving signal line S1, S2...Sn applies a touch driving signal, the touch driving signal can be synchronized with the touch scanning signal, of course, each touch driving signal line S1, S2...Sn can be applied simultaneously The touch driving signal is not limited here, and the touch driving signal will be loaded on the touch electrodes connected thereto. According to the principle of an inverter, at this time, the N-type second TFT device T2 is in the off state, the P-type first TFT device T1 is turned on, and the touch driving signal will be output to the touch panel after passing through the touch capacitor C1. Read signal lines. The touch capacitor C1 is formed by the touch electrode and the common electrode. When a human body touches the touch screen, the human body capacitance ΔC will act on the touch capacitor C1, causing the voltage signal on the touch electrode to change, thereby changing the touch Read the voltage signal received by the signal line. By detecting the change of the voltage signal on the touch read signal line column by column, the horizontal coordinate of the touch point, that is, the x-direction coordinate, can be obtained. The vertical coordinate of the touch point, that is, the coordinate in the y direction, can be obtained through the control scanning signal, so as to obtain the touched position, that is, to realize the touch function. In specific implementation, an IC chip for controlling the data signal line can be added on the basis of the existing IC chip to realize the detection of the output voltage signal and realize the touch function.

According to the above description, it can be seen that by using the principle of the inverter and applying different voltage signals to the gate signal line, a single selection can be made to turn on the N-type TFT device connected to it or turn on the P-type TFT device connected to it. To achieve flexible switching between touch and display.

Specifically, in the above-mentioned touch screen provided by the embodiment of the present invention, when the touch electrode is set in the area defined by the intersection of the touch reading signal line and the touch driving signal line, metal or transparent conductive oxide can be used as the touch electrode s material.

Preferably, during specific implementation, each touch electrode and pixel electrode can be arranged in different layers. Specifically, it is possible to add a layer of film to arrange the touch electrode above the pixel electrode, but it is necessary to ensure that the projection of the touch electrode on the film layer where the pixel electrode is located does not overlap with the pixel electrode. Certainly, if the material of the touch electrodes is transparent conductive oxide, the touch electrodes can also be prepared in the same layer as the pixel electrodes in the TFT array substrate and the two are guaranteed to be insulated from each other.

When the touch electrodes and pixel electrodes are prepared on the same layer, since each touch electrode is only arranged in the area limited by the intersection of the touch reading signal line and the touch driving signal line, in order to ensure the aperture ratio of the touch screen, each The area of each touch electrode will be set relatively small, which is not conducive to improving the touch sensitivity. Therefore, preferably, in the above-mentioned touch screen provided by the embodiment of the present invention, as shown in FIG. 5 , it further includes: at least one of Touch sub-electrode 07. In this way, on the basis of ensuring the aperture ratio of the touch screen, the touch area of each touch electrode can be increased as much as possible, so as to improve the sensitivity of touch sensing.

Based on the same concept of the utility model, the embodiment of the utility model also provides a display device, including the above-mentioned capacitive embedded touch screen provided by the embodiment of the utility model. The display device can be: a mobile phone, a tablet computer, a TV, a monitor, Notebook computers, digital photo frames, navigators and any other products or components with display functions. For the implementation of the display device, reference may be made to the above-mentioned embodiment of the capacitive embedded touch screen, and repeated descriptions will not be repeated.

In the capacitive embedded touch screen and display device provided by the embodiment of the present invention, a touch driving signal line is provided between adjacent rows of pixel units in the TFT array substrate; at least one data signal line in the TFT array substrate is used as The touch reading signal line; the touch electrode and the touch switching unit are arranged in the area defined by the intersection of the touch reading signal line and the touch driving signal line; the touch electrode is electrically connected to the adjacent touch driving signal line connected, and electrically connected to the adjacent touch reading signal line through the touch switching unit. In the display time period, apply a grayscale signal to the touch reading signal line, and the touch switching unit is in the off state; in the touch time period, apply a touch driving signal to the touch driving signal line, and the touch switching unit is in the on state state, the touch driving signal is output to the touch reading signal line after passing through the touch electrode. Since the data signal line is used for time-division multiplexing, it is used as the touch reading signal line to receive the voltage signal coupled by the touch electrode to realize the touch function. On the basis of the existing TFT array substrate preparation process, no additional process is required. It can be made into a touch screen, which saves the production cost and improves the production efficiency. Moreover, using the data signal line as the touch reading signal line can avoid adding a driving chip IC for separately controlling the touch reading signal line, and can save production cost.

Obviously, those skilled in the art can make various changes and modifications to the utility model without departing from the spirit and scope of the utility model. In this way, if these modifications and variations of the utility model fall within the scope of the claims of the utility model and equivalent technologies thereof, the utility model is also intended to include these modifications and variations.

Claims (9)

1. A capacitive embedded touch screen, comprising a thin film transistor TFT array substrate with data signal lines, and a plurality of pixel units arranged in a matrix are arranged in the TFT array substrate, characterized in that, The TFT array substrate has a touch drive signal line between adjacent rows of pixel units; At least one data signal line in the TFT array substrate is used as a touch reading signal line; The TFT array substrate has a touch electrode and a touch switch unit located in the area defined by the intersection of the touch read signal line and the touch drive signal line; the touch electrode and the adjacent touch control The driving signal lines are electrically connected, and are electrically connected with adjacent touch reading signal lines through the touch switching unit; During the display period, a grayscale signal is applied to the touch reading signal line, and the touch switching unit is in an off state; during the touch period, a touch driving signal is applied to the touch driving signal line, so The touch switching unit is in a conducting state, and the touch driving signal is output to the touch reading signal line after passing through the touch electrodes. 2. The capacitive in-cell touch screen according to claim 1, wherein in the TFT array substrate, the gate signal lines located in the same gap between the pixel units as the touch driving signal lines serve as touch control scan signal line; The touch switching unit is a first TFT device; wherein, the gate of the first TFT device is electrically connected to the touch scanning signal line, and the drain is electrically connected to the touch reading signal line, The source is electrically connected to the touch electrode; The first TFT device and the second TFT device connected to the pixel electrode and the data signal line in the TFT array substrate form an inverter structure. 3. The capacitive in-cell touch screen according to claim 2, wherein the first TFT device is a P-type TFT device, and the second TFT device is an N-type TFT device. 4. The capacitive in-cell touch screen according to claim 1, wherein the distances between the touch driving signal lines are the same; and/or the distances between the touch reading signal lines are the same . 5 . The capacitive in-cell touch screen according to claim 1 , wherein each of the touch driving signal lines and the gate signal lines in the TFT array substrate are arranged on the same layer and are insulated from each other. 6. The capacitive in-cell touch screen according to claim 1, wherein the material of the touch electrodes is metal or transparent conductive oxide. 7. The capacitive in-cell touch screen according to claim 6, wherein the material of the touch electrodes is transparent conductive oxide; the touch electrodes are arranged on the same layer as the pixel electrodes in the TFT array substrate and insulated from each other. 8. The capacitive in-cell touch screen according to any one of claims 1-7, further comprising: at least one touch electrode electrically connected to the touch electrode and located at the gap between adjacent pixel units Touch sub-electrodes. 9. A display device, comprising the capacitive in-cell touch screen according to any one of claims 1-8.

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