TW201717185A - Touch display system, and driving apparatus and driving method thereof - Google Patents

Abstract

A touch display system, and a driving apparatus and a driving method thereof are provided. The driving apparatus includes at least one gate driver, at least one source driver, a common voltage generator and a switching circuit. The gate driver drives the gate lines by turns in a scanning order. An output terminal of the common voltage generator outputs a common voltage. The switching circuit electrically connects a plurality of common lines of the touch display panel to the output terminal of the common voltage generator by turns according to the scanning order of the gate driver.

Description

Touch display system, driving device and driving method thereof

The present invention relates to a display system, and more particularly to a touch display system, a driving device thereof and a driving method.

In an in-cell touch panel (hereinafter referred to as a touch panel), a common electrode (a capacitor electrode shared by a plurality of pixels) provides a common voltage during display driving ( Common voltage) VCOM gives the liquid crystal capacitors of these pixels, and the common electrode can also be used as a touch sensing electrode during touch driving. The common voltage generator can provide a common voltage VCOM to the common electrode in the touch display panel via the common electrode line during display driving.

In conjunction with the scan timing of the gate driver of the touch display panel, the source driver can feed the pixel data voltage into the corresponding pixel (pixel) via the source line of the touch display panel during display driving. A parasitic capacitance is often formed between the source line and the common electrode. The AC component of the signal transmitted to the source line leaks to the common electrode line via the common electrode, causing the current of the common voltage generator to increase. Furthermore, the leakage of the AC component of the signal of the source line to the common electrode will increase the power consumption of the source driver.

The invention provides a touch display system and a driving device and a driving method thereof to reduce the current of the common voltage generator.

An embodiment of the present invention provides a driving device for a touch display panel, including at least one gate driver, at least one source driver, a common voltage generator, and a switching circuit. The gate driver is coupled to the plurality of gate lines of the touch display panel. The gate drivers alternately drive the gate lines in a scanning sequence. The source driver is coupled to the plurality of source lines of the touch display panel. The common voltage generator has an output for outputting a common voltage. The switch circuit is electrically connected to the output of the common voltage generator to receive the common voltage. The switching circuit cooperates with the scanning sequence of the gate driver during the display driving, and electrically connects the plurality of common electrode lines of the touch display panel to the output end of the common voltage generator.

An embodiment of the invention provides a driving method of a touch display panel. The driving method includes: driving, by at least one gate driver, a plurality of gate lines of the touch display panel in a scanning order; driving the plurality of source lines of the touch display panel by the at least one source driver; The output of the generator provides a common voltage; and the switching circuit cooperates with the scanning sequence of the gate driver, and the plurality of common electrode lines of the touch display panel are electrically connected to the output of the common voltage generator.

An embodiment of the invention provides a touch display system including a touch display panel and a driving device. The touch display panel includes a plurality of gate lines, a plurality of source lines, and a plurality of common electrode lines. The driving device includes at least one gate driver, at least one source driver, a common voltage generator, and a switching circuit. A gate driver is coupled to the gate lines, wherein the gate drivers alternately drive the gate lines in a scanning order. A source driver is coupled to the source lines. The common voltage generator has an output for outputting a common voltage. The switching circuit is electrically connected to the output of the common voltage generator to receive a common voltage. The switching circuit cooperates with the scanning sequence of the gate drivers during display driving, and electrically connects the common electrode lines to the output of the common voltage generator.

Based on the above, the touch display system, the driving device and the driving method thereof can electrically connect the plurality of common electrode lines of the touch display panel to the output end of the common voltage generator, thereby reducing the common The current of the voltage generator.

The above described features and advantages of the invention will be apparent from the following description.

The term "coupled (or connected)" as used throughout the specification (including the scope of the claims) may be used in any direct or indirect connection. For example, if the first device is described as being coupled (or connected) to the second device, it should be construed that the first device can be directly connected to the second device, or the first device can be A connection means is indirectly connected to the second device. In addition, wherever possible, the elements and/ Elements/components/steps that use the same reference numbers or use the same terms in different embodiments may refer to the related description.

FIG. 1 is a schematic diagram showing the 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, common electrodes CE_1_1, CE_s_1, CE_1_t, and CE_s_t shown in FIG. 1) and m source lines (such as data lines, such as FIG. 1). Source lines SL_1, SL_2, ..., SL_i, ..., SL_j, SL_j+1, ..., SL_m), n gate lines (or scan lines, such as the gate line GL_1 shown in Fig. 1, shown) GL_2, ..., GL_k, ..., GL_s, GL_s+1, ..., GL_n) and m*n pixels (for example, pixels P_1_1, P_2_1, ..., P_i_1, ..., P_j_1, P_j+1_1, ..., P_m_1 shown in Fig. 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, n can be determined according to design requirements.

The source lines SL_1 to SL_m are perpendicular to the gate lines GL_1 to 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 illustrates an example circuit diagram of a pixel P_m_1, and other pixels may be analogized with reference to a pixel P_m_1. A gate driver (not shown) is coupled to the gate lines GL_1 GL GL_n of the touch display panel 100. A gate driver (not shown) can alternately drive (scan) each of the gate lines GL_1 GL GL_n one by one during display driving. A source driver (not shown) is coupled to the source lines SL_1 SLSL_m of the touch display panel 100. In accordance with the scanning timing/sequence of the gate driver (not shown), the source driver (not shown) can write the source driving signal to the plurality of pixels of the touch display panel 100 during the display driving to display the image.

During the touch driving, the common electrodes CE_1_1 CECE_s_t can be used as the sensing electrodes of the touch panel. The driving device (not shown) can output a driving signal to the driving electrode lines of the touch display panel 100 (for example, the source lines SL_1 SLSL_m or the additionally configured wires) during the touch driving, and the driving device (not shown) The common electrodes CE_1_1 CECE_s_t may be sensed during the touch driving to detect a touch event of the touch display panel 100.

FIG. 2 is a block diagram showing a circuit of a touch display system 20 according to an embodiment of the invention. The touch display system 20 includes a touch display panel 100 and a driving device 200. The touch display panel 100 shown in FIG. 2 can refer to the related description of the touch display panel 100 shown in FIG. 1 , and therefore will not be described again. The driving device 200 includes at least one gate driver 210, at least one source driver 220, a common voltage generator 230, a switching circuit 240, and a sensing circuit 250. The gate driver 210 is coupled to the gate lines GL_1 GL GL_n (for example, the gate lines GL_1, GL_2, GL_h, and GL_h+1 shown in FIG. 2). The gate driver 210 can alternately drive the gate lines GL_1 GL GL_n in a certain scanning order. The source driver 220 is coupled to the source lines SL_1 SLSL_m (eg, the source lines SL_1 and SL_2 shown in FIG. 2). In accordance with the scanning timing/sequence of the gate driver 210, the source driver 220 can write the source driving signals to the plurality of pixels of the touch display panel 100 via the source lines SL_1 SLSL_m during display driving to display images.

The common voltage generator 230 has an output for outputting a common voltage VCOM. The switch circuit 240 is electrically connected to the output of the common voltage generator 230 to receive the common voltage VCOM. The switch circuit 240 is electrically connected to a common electrode line of the touch display panel 100 (for example, the common electrode lines CEL_1, . . . , CEL_t shown in FIG. 2). The switch circuit 240 can selectively electrically connect one or more of the common electrode lines CEL_1 C CEL_t to the output of the voltage generator 230 during display driving. The switch circuit 240 can selectively electrically connect the common electrode lines CEL_1 C CEL_t to the sensing circuit 250 during touch driving. Switch circuit 240 can be any routing circuit or switching circuit, such as a switch, a demultiplexer, etc., depending on various design requirements.

In some application scenarios, the switch circuit 240 can simultaneously electrically connect all the common electrode lines CEL_1 C CEL_t to the output end of the voltage generator 230 such that the common voltage VCOM can be simultaneously transmitted via the common electrode lines CEL_1 C CEL_t during display driving. To all of the common electrodes CE_1_1 to CE_s_t (for example, the common electrodes CE_1_1, . . . , CE_1_t shown in FIG. 2). A parasitic capacitance is often formed between the source lines SL_1 to SL_m and the common electrodes CE_1_1 to CE_s_t. For example, a parasitic capacitance C1 is formed between the source line SL_1 and the common electrode CE_1_1, a parasitic capacitance C2 is formed between the source line SL_2 and the common electrode CE_1_1, and a parasitic capacitance C3 is formed between the source line SL_1 and the common electrode CE_1_t, and the source line is formed. A parasitic capacitance C4 is formed between SL_2 and the common electrode CE_1_t. The AC component of the signal transmitted to the source lines SL_1 to SL_m leaks to the common electrode lines CEL_1 to CEL_t via the parasitic capacitance and the common electrodes CE_1_1 to CE_s_t, causing the current of the common voltage generator 230 to increase. Further, leakage of the AC component of the signals of the source lines SL_1 to SL_m to the common electrodes CE_1_1 to CE_s_t increases the power consumption of the source driver 220.

FIG. 3 is a schematic flow chart illustrating a driving method of a touch display panel according to an embodiment of the invention. Referring to FIG. 1 to FIG. 3, in the embodiment, the output terminal of the common voltage generator 230 supplies the common voltage VCOM to the switch circuit 240 (step S310). In addition, the gate driver 210 alternately drives (scans) the plurality of gate lines GL_1 GL GL_n of the touch display panel 100 in a certain scanning order. The source driver 220 drives the plurality of source lines SL_1 SLSL_m of the touch display panel 100 to write the source driving signals into the plurality of pixels of the touch display panel 100. The switch circuit 240 can electrically connect the plurality of common electrode lines CEL_1 C CEL_t of the touch display panel 100 to the output end of the common voltage generator 230 in accordance with the scanning order of the gate driver 210 (step S320).

As shown in FIG. 1 and FIG. 2, based on the arrangement positions of the common electrodes CE_1_1 to CE_s_t, the gate lines GL_1 GL GL_n are grouped into a plurality of gate line groups, and the gate line groups correspond to each other in a one-to-one manner. Common electrode lines CEL_1 to CEL_t. For example, the gate lines GL_1 GL GL_k shown in FIG. 1 are grouped into the same gate line group, and this gate line group corresponds to the common electrode line CEL_1. By analogy, the gate lines GL_h GL GL_n shown in FIG. 1 are grouped into another gate line group, and this gate line group corresponds to the common electrode line CEL_t.

In step S320, when the gate driver 210 scans the gate lines belonging to one of the gate group groups of the gate lines, the switch circuit 240 selectively corresponds the common electrode lines CEL_1 to CEL_t to One common electrode line of the group of scanned gate lines is electrically connected to an output end of the common voltage generator 230, and the switch circuit 240 selectively de-energizes the remaining common electrode lines of the common electrode lines CEL_1 C CEL_t Connected to the output of the common voltage generator 230. For example, when the gate driver 210 scans to one of the gate lines GL_1 GL GL_k, the switch circuit 240 selectively electrically connects the common electrode line CEL_1 to the output of the common voltage generator 230, and the switch circuit 240 selects The remaining common electrode lines (eg, the common electrode line CEL_t) are non-electrically connected to the output of the common voltage generator 230. By analogy, when the gate driver 210 scans to one of the gate lines GL_h GL GL_n, the switch circuit 240 selectively electrically connects the common electrode line CEL_t to the output terminal of the common voltage generator 230, and the switch circuit 240 selects The remaining common electrode lines (eg, the common electrode line CEL_1) are electrically connected to the output of the common voltage generator 230.

Because the switch circuit 240 can electrically connect the plurality of common electrode lines CEL_1 C CEL_t of the touch display panel 100 to the output end of the common voltage generator 230 in accordance with the scanning order of the gate driver 210, and thus is transmitted to the source line. The AC component of the SL_1~SL_m signal will only leak at least some of the common electrode lines via a small number of common electrodes. For example, when the switch circuit 240 selectively electrically connects the common electrode line CEL_1 to the output end of the common voltage generator 230, the remaining common electrode lines (eg, the common electrode line CEL_t) are in a floating state (not Electrically connected to the output of the common voltage generator 230) such that the AC component of the signals transmitted to the source lines SL_1 SLSL_m does not leak to the common voltage generator via the remaining common electrode lines (eg, the common electrode line CEL_t) 230. By analogy, when the switch circuit 240 selectively electrically connects the common electrode line CEL_t to the output end of the common voltage generator 230, the remaining common electrode lines (eg, the common electrode line CEL_1) are in a floating state (non-electrical connection) To the output of the common voltage generator 230, the AC components of the signals transmitted to the source lines SL_1 SLSL_m are not leaked to the common voltage generator 230 via the remaining common electrode lines (eg, the common electrode line CEL_1). Therefore, the current of the common voltage generator 230 can be effectively reduced. Furthermore, since the AC component of the signals of the source lines SL_1 to SL_m does not leak to the common electrode in the floating state, the power consumption of the source driver 220 can be effectively reduced.

In the embodiment shown in FIG. 2, the switch circuit 240 includes a plurality of switches (such as the switches SW_11, ..., SW_1t and switches SW_21, ..., SW_2t shown in FIG. 2). The switches SW_21 to SW_2t are turned off during the display driving period. The first ends of the switches SW_11-SW_1t are electrically connected to the output of the common voltage generator 230 to receive the common voltage VCOM. The second ends of the switches SW_11 to SW_1t are electrically connected to the common electrode lines CEL_1 to CEL_t in a one-to-one manner. When the gate driver 210 scans to a gate line belonging to one of the plurality of gate group groups, one of the switches SW_11 to SW_1t is turned on to correspond the common electrode lines CEL_1 to CEL_t to One common electrode line of the group of scanned gate lines is electrically connected to the output end of the common voltage generator 230, and the other switches of the switches SW_11 to SW_1t are turned off to leave the remaining common electrode lines of the common electrode lines CEL_1 to CEL_t Electrically connected to the output of the common voltage generator 230. For example, when the gate driver 210 scans to one of the gate lines GL_1 GL GL_k, the switch SW_11 is turned on to electrically connect the common electrode line CEL_1 to the output terminal of the common voltage generator 230, and the switch SW_11 in the switch circuit 240. Other switches of ~SW_1t (eg, switch SW_1t) are turned off to electrically connect the remaining common electrode lines (eg, common electrode line CEL_t) to the output of common voltage generator 230. By the way, when the gate driver 210 scans to one of the gate lines GL_h GL GL_n, the switch SW_1t is turned on to electrically connect the common electrode line CEL_t to the output terminal of the common voltage generator 230, and the switch SW_11 in the switch circuit 240 Other switches of ~SW_1t (eg, switch SW_11) are turned off to electrically connect the remaining common electrode lines (eg, common electrode line CEL_1) to the output of common voltage generator 230.

The plurality of input ends of the sensing circuit 250 are electrically connected to the first ends of the switches SW_21 - SW_2t in a one-to-one manner, and the second ends of the switches SW_21 - SW_2t are electrically connected to the common electrode line CEL_1 - in a one-to-one manner. CEL_t. The switches SW_21 to SW_2t are turned on during the touch driving, and the switches SW_11 to SW_1t are turned off during the touch driving. The sensing circuit 250 senses the plurality of common electrodes CE_1_1 CECE_s_t of the touch display panel 100 via the common electrode lines CEL_1 - CEL_t during the touch driving to detect the touch event of the touch display panel 100. Depending on the design requirements, the sensing circuit 250 may employ different touch sensing operations. For example, but not limited to, the sensing circuit 250 may employ a conventional touch sensing operation, and thus will not be described again.

In summary, the touch display system 20 and the driving device 200 and the driving method thereof according to the above embodiments of the present invention can electrically connect the plurality of common electrode lines CEL_1 C CEL_t of the touch display panel 100 to a common voltage. The output of the generator 230 can therefore effectively reduce the current of the common voltage generator 230.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

20‧‧‧Touch display system
100‧‧‧Touch display panel
200‧‧‧ drive
210‧‧‧gate driver
220‧‧‧Source Driver
230‧‧‧Common voltage generator
240‧‧‧Switch circuit
250‧‧‧Sensor circuit
C1, C2, C3, C4‧‧‧ parasitic capacitance
CE_1_1, CE_s_1, CE_1_t, CE_s_t‧‧‧ common electrode
CEL_1, CEL_t‧‧‧ common 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_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‧‧ ‧ pixels
S310～S320‧‧‧Steps
SL_1, SL_2, SL_i, SL_j, SL_j+1, SL_m‧‧‧ source line
SW_1, SW_t‧‧‧ switch
VCOM‧‧‧Common voltage

FIG. 1 is a schematic diagram showing the circuit layout of an in-cell touch display panel. FIG. 2 is a block diagram showing a circuit of a touch display system according to an embodiment of the invention. FIG. 3 is a schematic flow chart illustrating a driving method of a touch display panel according to an embodiment of the invention.

S310~S320‧‧‧Steps

Claims (11)

A driving device for a touch display panel, comprising: at least one gate driver coupled to the plurality of gate lines of the touch display panel, the gate driver driving the gate lines in turn in a scanning sequence; a source driver coupled to the plurality of source lines of the touch display panel; a common voltage generator having an output for outputting a common voltage; and a switching circuit electrically coupled to the common voltage An output of the generator is configured to receive the common voltage, wherein the switch circuit electrically connects the plurality of common electrode lines of the touch display panel to the common circuit in cooperation with the scanning sequence of the gate driver during display driving The output of the voltage generator. The driving device of claim 1, wherein the gate lines are grouped into a plurality of gate line groups, and the gate line groups correspond to the common electrode lines in a one-to-one manner. When the gate driver scans to a gate line belonging to one of the gate group of the gate group, the switch circuit selectively selects the common electrode lines corresponding to the gate a common electrode line of the group of pole lines is electrically connected to the output end of the common voltage generator, and the switch circuit selectively electrically connects the remaining common electrode lines of the common electrode lines to the common voltage The output of the generator. The driving device of claim 1, wherein the switching circuit comprises: a plurality of switches, wherein the first end is electrically connected to the output end of the common voltage generator to receive the common voltage, and the plurality of switches The second end of the switch is electrically connected to the common electrode lines in a one-to-one manner; wherein when the gate driver scans to a gate line belonging to one of the gate group of the gate lines One of the switches is turned on to electrically connect a common electrode line corresponding to the group of scanned gate lines to the output end of the common voltage generator, and the plurality of switches The other switches in the switch are turned off to electrically connect the remaining common electrode lines of the common electrode lines to the output of the common voltage generator. The driving device of claim 1, further comprising: a sensing circuit, wherein the plurality of input ends are electrically connected to the common electrode lines in a one-to-one manner for the purpose of driving through a touch drive The common electrode lines sense a plurality of common electrodes of the touch display panel to detect a touch event of the touch display panel. A method for driving a touch display panel includes: driving, by at least one gate driver, a plurality of gate lines of the touch display panel in a scan order; and driving the touch display panel by at least one source driver a source line; a common voltage is provided by an output of a common voltage generator; and a plurality of common electrode lines of the touch display panel are electrically connected by a switching circuit in cooperation with the scanning sequence of the gate driver Connected to the output of the common voltage generator. The driving method of claim 5, wherein the gate lines are grouped into a plurality of gate line groups, and the gate line groups correspond to the common electrode lines in a one-to-one manner. And the step of electrically connecting the common electrode lines to the output end of the common voltage generator comprises: when the gate driver scans to one of the gate line groups, one of the scanned gate lines When a gate line of the group is electrically connected to the common electrode line of the common electrode line corresponding to the common gate line of the common electrode line by the switch circuit And selectively switching the remaining common electrode lines of the common electrode lines to the output of the common voltage generator by the switching circuit. The driving method of claim 5, further comprising: sensing, by a sensing circuit, a plurality of common electrodes of the touch display panel via the common electrode lines during a touch driving to detect the A touch event of the touch display panel. A touch display system includes: a touch display panel comprising a plurality of gate lines, a plurality of source lines, and a plurality of common electrode lines; and a driving device, the driving device comprising: at least one a gate driver coupled to the gate lines, wherein the gate driver alternately drives the gate lines in a scanning sequence; at least one source driver coupled to the source lines; a common voltage generation And an output circuit for outputting a common voltage; and a switch circuit electrically connected to the output of the common voltage generator to receive the common voltage, wherein the switch circuit cooperates with the gate during a display drive The scanning sequence of the driver electrically connects the common electrode lines to the output of the common voltage generator. The touch display system of claim 8, wherein the gate lines are grouped into a plurality of gate line groups, and the gate line groups correspond to the common electrodes in a one-to-one manner. a line, when the gate driver scans to a gate line belonging to one of the gate group of the gate lines, the switch circuit selectively corresponds to the common electrode line a common electrode line of the scan gate line group is electrically connected to the output end of the common voltage generator, and the switch circuit selectively electrically connects the remaining common electrode lines of the common electrode lines to the The output of the common voltage generator. The touch display system of claim 8, wherein the switch circuit comprises: a plurality of switches, wherein the first end is electrically connected to the output end of the common voltage generator to receive the common voltage, and The second ends of the switches are electrically connected to the common electrode lines in a one-to-one manner; wherein when the gate driver scans to a gate belonging to one of the gate group In the case of a polar line, one of the switches is turned on to electrically connect a common electrode line corresponding to the group of scanned gate lines to the output of the common voltage generator, and The other switches of the switches are turned off to electrically connect the remaining common electrode lines of the common electrode lines to the output of the common voltage generator. The touch display system of claim 8, wherein the driving device further comprises: a sensing circuit, wherein the plurality of input ends are electrically connected to the common electrode lines in a one-to-one manner, so as to During the touch driving, the plurality of common electrodes of the touch display panel are sensed through the common electrode lines to detect a touch event of the touch display panel.