CN106557210B - Driving device, touch driving method and touch display system - Google Patents

Abstract

A touch driving device, a touch driving method and a touch display system. The touch display system includes a touch display panel, a common voltage generator and a touch driving device. The touch driving device includes a driving circuit, a capacitor and a sensing circuit. The output end of the driving circuit is electrically connected to the driving electrode line of the touch display panel. During touch driving, the driving circuit outputs a driving signal to the driving electrode line. The first end of the capacitor is electrically connected to the common electrode line of multiple pixels of the touch display panel. The input end of the sensing circuit is electrically connected to the second end of the capacitor. During touch driving, the sensing circuit senses the common electrode line via the capacitor to detect a touch event of the touch display panel.

Description

Driving device, touch driving method and touch display system

technical field

The present invention relates to a touch device, in particular to a touch drive device, a touch drive method and a touch display system.

Background technique

In an in-cell touch display panel (hereinafter referred to as a touch display panel), the common electrode (common electrode, a capacitive electrode shared by a plurality of pixels) transmits a common voltage ( common voltage) VCOM to the liquid crystal capacitance of these pixels, and the common electrode can also be used as a touch sensing electrode during touch driving. Generally speaking, the manufacturing process of the display driver of the touch display panel is made by a high-voltage manufacturing process, that is to say, the common voltage VCOM of the common electrode may be a high voltage (eg, 8V). Therefore, the touch driver (or touch driving device) coupled to the common electrode must also be fabricated in a high-voltage manufacturing process so as to withstand the high voltage level of the common voltage VCOM. In any event, integrated circuits manufactured by high voltage manufacturing processes are generally very expensive compared to integrated circuits manufactured by low voltage manufacturing processes. If the touch driver (or the touch driving device) manufactured by the low voltage manufacturing process is matched with the display driver manufactured by the high voltage manufacturing process, the high voltage of the common electrode may damage the touch driver.

SUMMARY OF THE INVENTION

The present invention provides a touch driving device, a touch driving method and a touch display system, so that the touch driving device can be manufactured using a low-voltage manufacturing process, and the touch driving device of the low-voltage manufacturing process can utilize a common high-voltage The electrodes serve as touch sensing electrodes.

Embodiments of the present invention provide a touch driving device including a driving circuit, a capacitor and a sensing circuit. The output end of the driving circuit is electrically connected to the driving electrode lines of the touch display panel. During the touch driving, the driving circuit outputs driving signals to the driving electrode lines. The first end of the capacitor is electrically connected to a common electrode line of a plurality of pixels of the touch display panel. The input end of the sensing circuit is electrically connected to the second end of the capacitor. During the touch driving, the sensing circuit senses the common electrode line through the capacitor, so as to detect the touch event of the touch display panel.

In an embodiment of the present invention, the above-mentioned common electrode line is also electrically connected to the common voltage generator. During display driving, the common voltage generator supplies the common voltage to the common electrodes of the pixels through the common electrode lines, and the sensing circuit does not sense the common electrodes. During the touch driving, the common voltage generator does not supply the common voltage to the common electrode, and the sensing circuit senses the common electrode through the capacitor and the common electrode line to detect the touch event.

Embodiments of the present invention provide a touch driving method. The touch driving method includes: outputting a driving signal to a driving electrode line of a touch display panel by a driving circuit during a touch driving period; filtering out a DC component of a common electrode line of a plurality of pixels of the touch display panel by a capacitor, and transmitting a common electrode line of the touch display panel. The AC component of the electrode line; and the AC component of the common electrode line transmitted by the sensing circuit during the touch driving period, so as to detect the touch event of the touch display panel.

In an embodiment of the present invention, the above-mentioned touch driving method further includes: supplying a common voltage to the common electrodes of the pixels through a common electrode line from a common voltage generator during display driving, wherein the sensing circuit does not sense during display driving. detecting the common electrode; and not supplying the common voltage to the common electrode during the touch driving, wherein the sensing circuit senses the common electrode through the capacitor and the common electrode line to detect the touch event during the touch driving.

Embodiments of the present invention provide a touch display system including a touch display panel, a common voltage generator, and a touch driving device. The touch display panel includes a plurality of pixels, at least one driving electrode line and at least one common electrode line. The common voltage generator is electrically connected to the common electrode line. The touch driving device includes a driving circuit, a capacitor and a sensing circuit. The output end of the driving circuit is electrically connected to the driving electrode line, so as to output the driving signal to the driving electrode line during the touch driving period. The first end of the capacitor is electrically connected to the common electrode line of the pixels. The input end of the sensing circuit is electrically connected to the second end of the capacitor. During the touch driving period, the sensing circuit senses the common electrode line through the capacitor, so as to detect the touch event of the touch display panel.

In an embodiment of the present invention, the above-mentioned common voltage generator supplies a common voltage to the common electrodes of the pixels through the common electrode lines during display driving, and the sensing circuit does not sense the common electrodes. During the touch driving period, the common voltage generator does not supply the common voltage to the common electrode, and the sensing circuit senses the common electrode through the capacitor and the common electrode line to detect the touch event.

In an embodiment of the present invention, the above-mentioned common voltage is greater than the operating voltage of the sensing circuit.

Based on the above, the embodiment of the present invention utilizes a capacitor to filter out the DC component of the common electrode line of the touch display panel, and transmits the AC component of the common electrode line to the sensing circuit of the touch driving device. Therefore, the touch driving device can be manufactured using a low-voltage manufacturing process, and the touch driving device of the low-voltage manufacturing process can utilize the common electrode having a high voltage as a touch sensing electrode.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following specific embodiments are given and described in detail as follows in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram illustrating a circuit layout of an in-cell touch display panel.

FIG. 2 is a schematic circuit block diagram illustrating a touch display system according to an embodiment of the present invention.

3 is a schematic flowchart illustrating a touch driving method of the touch display system shown in FIG. 2 according to an embodiment of the present invention.

FIG. 4 is an equivalent circuit diagram of the touch display panel shown in FIG. 2 during a touch driving period.

Description of Drawing Symbols

100: Touch display panel

200: Touch Display System

210: Common Voltage Generator

220: Touch driver

221: Drive circuit

222: Sensing circuit

ΔCM: Change in capacitance value

C, RXC, TXC: capacitor

CE_1_1, CE_s_1, CE_1_t, CE_s_t: common electrode

CEL: Common Electrode Line

CM: mutual tolerance

DL: Drive Electrode Line

GL_1, GL_2, GL_k, GL_s, GL_s+1, GL_n: gate lines

P_1_1, P_2_1, P_i_1, P_j_1, P_j+1_1, P_m_1, P_1_2, P_2_2, P_i_2, P_j_2, P_j+1_2, P_m_2, P_1_k, P_2_k, P_i_k, P_j_k, P_j+1_k, P_m_k, P_1_h, P_j_h, P_i_h, P_j_2_h P_j+1_h, P_m_h, P_1_h+1, P_2_h+1, P_i_h+1, P_j_h+1, P_j+1_h+1, P_m_h+1, P_1_n, P_2_n, P_i_n, P_j_n, P_j+1_n, P_m_n: Pixels

RXR, TXR: Resistors

S310～S330: Steps

SL_1, SL_2, SL_i, SL_j, SL_j+1, SL_m: source lines

Detailed ways

The term "coupled (or connected)" as used throughout this specification (including the claims) may refer to any direct or indirect means of connection. For example, if a first device is described as being coupled (or connected) to a second device, it should be interpreted that the first device can be directly connected to the second device, or the first device can be connected to the second device through other devices or indirectly connected to the second device by a connecting means. In addition, where possible, components/components/steps using the same reference numerals in the drawings and embodiments represent the same or similar parts. Components/components/steps that use the same reference numerals or use the same terminology in different embodiments may refer to the relevant descriptions of each other.

FIG. 1 is a schematic diagram illustrating a circuit layout of an in-cell touch display panel (hereinafter referred to as a touch display panel 100 ). The touch display panel 100 shown in FIG. 1 is composed of two substrates, and a liquid crystal material is filled between the two substrates as a liquid crystal layer. The touch display panel 100 is provided with s*t common electrodes (for example, the common electrodes CE_1_1, CE_s_1, CE_1_t and CE_s_t shown in FIG. 1 ) and m source lines (or data lines, for example, FIG. 1 ) The shown source lines SL_1, SL_2, . . . , SL_i, . GL_2, ..., GL_k, ..., GL_s, GL_s+1, ..., GL_n) and m*n pixels (eg pixels P_1_1, P_2_1, ..., P_i_1, ..., P_j_1, P_j+1_1, ..., P_m_1 shown in Figure 1 , P_1_2, P_2_2, …, P_i_2, …, P_j_2, P_j+1_2, …, P_m_2, …, P_1_k, P_2_k, …, P_i_k, …, P_j_k, P_j+1_k, …, P_m_k, …, P_1_h, P_2_h, … , P_i_h, …, P_j_h, P_j+1_h, …, P_m_h, P_1_h+1, P_2_h+1, …, P_i_h+1, …, P_j_h+1, P_j+1_h+1, …, P_m_h+1, …, P_1_n , P_2_n, …, P_i_n, …, P_j_n, P_j+1_n, …, P_m_n). Wherein, the s, t, i, j, m, k, s, and n are integers. The s, t, i, j, m, k, s, and n can be determined according to design requirements.

The source lines SL_1 ˜SL_m are perpendicular to the gate lines GL_1 ˜GL_n. The pixels P_1_1 to P_m_n are distributed on the touch display panel 100 in a matrix manner. FIG. 1 shows an example circuit diagram of the pixel P_m_1 , and other pixels can be inferred with reference to the pixel P_m_1 . A gate driver (not shown) is coupled to the gate lines GL_1 -GL_n of the touch display panel 100 . The gate driver (not shown) may drive (scan) each of the gate lines GL_1 ˜GL_n in turn one by one during the display driving period. A source driver (not shown) is coupled to the source lines SL_1 ˜SL_m of the touch display panel 100 . In accordance with the scanning timing of the gate driver (not shown), the source driver (not shown) can write source driving signals into a plurality of pixels of the touch display panel 100 during display driving to display images.

During the touch driving period, the common electrodes CE_1_1 ˜ CE_s_t can be used as the sensing electrodes of the touch display panel. The driving circuit (described later) can output driving signals to the driving electrode lines (such as source lines SL_1 to SL_m or additionally disposed wires) of the touch display panel 100 during the touch driving period, and the sensing circuit (described later) ) can sense the common electrodes CE_1_1 to CE_s_t during the touch driving period, so as to detect the touch event of the touch display panel 100 .

FIG. 2 is a circuit block diagram illustrating a touch display system 200 according to an embodiment of the present invention. The touch display system 200 shown in FIG. 2 includes the touch display panel 100 , a common voltage generator 210 and a touch driving device 220 . The touch display panel 100 includes a plurality of pixels, at least one driving electrode line (eg, the driving electrode line DL shown in FIG. 2 ) and at least one common electrode line (eg, the common electrode line CEL shown in FIG. 2 ). The common electrode lines CEL are respectively coupled to the common electrodes of the touch display panel 100 in a one-to-one manner (eg, the common electrodes CE_1_1 to CE_s_t shown in FIG. 2 ). For the pixels, driving electrode lines DL, and common electrodes CE_1_1 to CE_s_t of the touch display panel 100 shown in FIG. 2 , reference may be made to the related descriptions of the pixels, driving electrode lines, and common electrodes in FIG.

Referring to FIG. 2 , the common voltage generator 210 is electrically connected to the common electrode line CEL, as shown in FIG. 2 . The touch driving device 220 includes a driving circuit 221 , a sensing circuit 222 and at least one capacitor (eg, the capacitor C shown in FIG. 2 ). The output terminals of the driving circuit 221 are respectively electrically connected to the driving electrode lines (eg, the driving electrode lines DL shown in FIG. 2 ) of the touch display panel 100 in a one-to-one manner. The first terminal of the capacitor C is electrically connected to the common electrode line CEL of the touch display panel 100 , and the second terminal of the capacitor C is electrically connected to the input terminal of the sensing circuit 222 , as shown in FIG. 2 . Other capacitors and common electrode lines can be deduced by referring to the related descriptions of the capacitor C and the common electrode line CEL, and thus will not be repeated.

FIG. 3 is a schematic flowchart illustrating a touch driving method of the touch display system 200 shown in FIG. 2 according to an embodiment of the present invention. Step S310 determines whether the touch display system 200 is operating during the touch driving period or the display driving period. When the touch display system 200 is operating during display driving, step S320 is performed. Step S330 is executed when the touch display system 200 is operating during the touch driving.

In step S320 , that is, during the display driving period, the common voltage generator 210 supplies a common voltage (common voltage) VCOM to the common electrode CE_1_1 of the touch display panel 100 through a common electrode line (eg, the common electrode line CEL shown in FIG. 2 ). ˜CE_s_t, while the sensing circuit 222 does not sense the common electrodes CE_1_1 ˜CE_s_t during display driving. The common voltage generator 210 can be implemented in any manner. For example, in some embodiments, the common voltage generator 210 may be implemented with existing common voltage generating circuits.

In step S330 , that is, during the touch driving period, the common voltage generator 110 does not supply the common voltage VCOM to the common electrodes CE_1_1 ˜CE_s_t. During the touch driving period, the driving circuit (also called the TX circuit) 221 outputs the driving signal to the driving electrode lines (eg, the driving electrode lines DL shown in FIG. 2 ) of the touch display panel 100 . According to design requirements, the driving electrode lines DL of the touch display panel 100 may be the source lines SL_1 ˜SL_m shown in FIG. 1 , or additional wires (not shown) disposed on the touch display panel 100 . The capacitor C can filter the DC component of the common electrode line CEL of the touch display panel 100 and transmit the AC component of the common electrode line CEL to the sensing circuit 222 . The sensing circuit (also called the RX circuit) 222 can sense the AC component of the common electrode line CEL transmitted by the capacitor C during the touch driving period. Therefore, the sensing circuit 222 can sense the common electrode CE_1_1 through the capacitor C and the common electrode line CEL during the touch driving period, so as to detect the touch event of the common electrode CE_1_1 of the touch display panel 100 . Other capacitors, common electrode lines, and common electrodes can be deduced by referring to the related descriptions of capacitor C, common electrode line CEL, and common electrode CE_1_1, and thus will not be repeated. The driving circuit 221 and the sensing circuit 222 can be implemented in any manner. For example, in some embodiments, the driving circuit 221 and the sensing circuit 222 may be implemented by existing touch driving circuits and existing touch sensing circuits.

Generally speaking, the manufacturing process of the source driver (not shown) of the touch display panel 100 is manufactured by a high-voltage manufacturing process, so as to output a high voltage to drive the pixels P_1_1 ˜P_m_n. For example, the voltage swing of the source lines SL_1 - SL_m may be 0V to 15V, and the common voltage VCOM of the common electrodes CE_1_1 - CE_s_t may be 8V. Based on the capacitor C to isolate the DC component of the voltage of the common electrode CE_1_1 and the DC component of the voltage of the sensing circuit 222 , the common voltage VCOM of the common electrodes CE_1_1 to CE_s_t shown in FIG. 2 may be greater than the operating voltage of the sensing circuit 222 . In this way, the sensing circuit 222 can be fabricated using a low-voltage manufacturing process without the problem of damaging the sensing circuit 222 due to the high voltage of the common electrodes CE_1_1 ˜CE_s_t. Integrated circuits fabricated in low voltage fabrication processes are generally less expensive and less power consumption than integrated circuits fabricated in high voltage fabrication processes.

FIG. 4 is an equivalent circuit diagram of the touch display panel 100 shown in FIG. 2 during a touch driving period. CM shown in FIG. 4 represents the mutual capacitance between the common electrode CE_1_1 and the corresponding driving electrode line, and the resistor TXR represents the electrical path between the driving circuit (also called TX circuit) 221 and the corresponding driving electrode line (eg, the parasitic resistance of the driving electrode line DL shown in FIG. 2 ), and the capacitor TXC represents the parasitic capacitance of the electrical path between the driving circuit 221 and the corresponding driving electrode line (eg, the driving electrode line DL shown in FIG. 2 ). The resistor RXR represents the parasitic resistance of the electrical path between the sensing circuit (also known as the RX circuit) 222 and the common electrode CE_1_1 (eg, the common electrode line CEL shown in FIG. 2 ), and the capacitor RXC represents the sensing circuit 222 and the common electrode CE_1_1 The parasitic capacitance of the electrical path between them (for example, the common electrode line CEL shown in FIG. 2 ). ΔCM shown in FIG. 4 represents the change amount of the capacitance value of the touch point when the object touches the touch display panel 100 (ie, a touch event occurs). By detecting the mutual capacitance CM and the capacitance value change ΔCM, it is possible to know whether a touch event occurs.

The capacitance of capacitor C can be determined according to design requirements. In some embodiments, the capacitance of the capacitor C may be much greater than the mutual capacitance CM to be detected, for example, the capacitance of the capacitor C may be greater than 10 times the mutual capacitance CM. Because the capacitance value of the mutual capacitance CM to be detected is much smaller than the capacitance value of the capacitor C, the change in the overall equivalent capacitance value will be dominated by the mutual capacitance CM. Therefore, connecting the capacitor C in series in the sensing path of the sensing circuit 222 will not affect the value of the mutual capacitance CM to be detected. In other embodiments, the capacitance of the capacitor C may be close to the mutual capacitance CM to be detected, for example, the capacitance of the capacitor C may be less than 10 times the mutual capacitance CM. The capacitor C with a smaller capacitance value can achieve the effect of signal attenuation, and can also suppress the amount of noise, so as to avoid saturation of the sensing circuit 222 caused by large external noise. By adjusting the capacitance of the capacitor C to meet different design requirements, the desired result can be obtained. In some embodiments, the capacitor C and the sensing circuit 222 may be implemented in the same touch integrated circuit. In other embodiments, the capacitor C may also be an external capacitive component of the touch integrated circuit (the sensing circuit 222 ).

To sum up, the above-mentioned embodiments of the present invention can utilize the capacitor C to filter out the DC component of the common electrode line CEL of the touch display panel 100 , and transmit the AC component of the common electrode line CEL to the sensing of the touch driving device 220 . circuit 222. Therefore, the touch driving device 220 can be manufactured using a low-voltage manufacturing process, and the touch driving device 220 of the low-voltage manufacturing process can use the common electrode CE_1_1 with a high voltage as a touch sensing electrode.

Although the present invention has been disclosed above with examples, it is not intended to limit the present invention. Any person of ordinary skill in the art can make some modifications and modifications without departing from the spirit and scope of the present invention. The scope of protection is subject to the claims.

Claims (6)

1. A touch drive device, comprising: a driving circuit, the output terminal of which is electrically connected to a driving electrode line of a touch display panel, so as to output a driving signal to the driving electrode line during a touch driving period; a capacitor, the first end of which is electrically connected to a common electrode line of a plurality of pixels of the touch display panel; a sensing circuit, the input terminal of which is electrically connected to the second terminal of the capacitor, so as to sense the common electrode line through the capacitor during the touch driving period so as to detect a touch event of the touch display panel, wherein, The common electrode line is also electrically connected to a common voltage generator. During a display driving period, the common voltage generator supplies a common voltage to a common electrode of the pixels through the common electrode line, and the sensing circuit does not sense the common voltage. electrode, and the common voltage generator does not supply the common voltage to the common electrode during the touch driving and the sensing circuit senses the common electrode through the capacitor and the common electrode line to detect the touch event. 2 . The touch driving device of claim 1 , wherein the common voltage is greater than an operating voltage of the sensing circuit. 3 . 3. A touch driving method, comprising: a driving circuit outputs a driving signal to a driving electrode line of a touch display panel during a touch driving period; A capacitor filters out a DC component of a common electrode line of a plurality of pixels of the touch display panel, and transmits an AC component of the common electrode line; and The AC component of the common electrode line transmitted by the capacitor is sensed by a sensing circuit during the touch driving period, so as to detect a touch event of the touch display panel; supplying a common voltage to a common electrode of the pixels through the common electrode line by a common voltage generator during a display driving period, wherein the sensing circuit does not sense the common electrode during the display driving period; and The common voltage is not supplied to the common electrode during the touch driving period, wherein the sensing circuit senses the common electrode through the capacitor and the common electrode line to detect the touch event during the touch driving period. 4. The touch driving method of claim 3, wherein the common voltage is greater than an operating voltage of the sensing circuit. 5. A touch display system, comprising: a touch display panel, comprising a plurality of pixels, at least one driving electrode line and at least one common electrode line; a common voltage generator electrically connected to the common electrode line; and A touch driving device includes a driving circuit, a capacitor and a sensing circuit, wherein The output end of the driving circuit is electrically connected to the driving electrode line to output a driving signal to the driving electrode line during a touch driving period, The first end of the capacitor is electrically connected to the common electrode line of the pixels, and The input terminal of the sensing circuit is electrically connected to the second terminal of the capacitor to sense the common electrode line through the capacitor during the touch driving, so as to detect a touch event of the touch display panel, Wherein, the common voltage generator supplies a common voltage to a common electrode of the pixels through the common electrode line during a display driving period and the sensing circuit does not sense the common electrode, and the common voltage is generated during the touch driving period The device does not supply the common voltage to the common electrode and the sensing circuit senses the common electrode through the capacitor and the common electrode line to detect the touch event. 6. The touch display system of claim 5, wherein the common voltage is greater than an operating voltage of the sensing circuit.