Driver circuit

Abstract

A driver circuit is configured to drive a display panel to perform a display function and a touch function. The driver circuit includes a touch driving circuit. The touch driving circuit is configured to output a synchronous driving signal to an element of the display panel in a touch sensing phase. The synchronous driving signal includes a first level. The voltage level of the element changes from the second level to the first level at a first slew rate. The first slew rate is greater than 0 volts per microsecond and less than 0.5 volts per microsecond. The second level is less than the first level.

Description

Technical Field

[0001] The present disclosure relates to a driver circuit, and more particularly, to a driver circuit capable of driving a display panel to perform a display function and a touch function. Background Art

[0002] Touch with display driver integration (TDDI) is a touch technology solution that integrates a panel driver integrated circuit (IC) and a touch panel IC into a single chip. For automotive TDDI applications, due to safety issues, the electromagnetic interference (EMI) test items must be more stringent than the EMI test items of other TDDI products. However, in the prior art, it is necessary to apply the same signal as the touch drive signal to most of the components of the display panel to reduce the touch drive load, which will aggravate the EMI problem. Summary of the invention

[0003] The present disclosure relates to a driver circuit capable of reducing electromagnetic interference effects when a signal level changes.

[0004] The present disclosure provides a driver circuit configured to drive a display panel to perform a display function and a touch function. The driver circuit includes a touch driver circuit. The touch driver circuit is configured to output a synchronous drive signal to an element of the display panel during a touch sensing phase. The synchronous drive signal includes a first level. The voltage level of the element changes from a second level to a first level at a first slew rate. The first slew rate is greater than 0 volts per microsecond (V / μs) and less than 0.5V / μs. The second level is less than the first level.

[0005] In an embodiment of the present disclosure, the voltage level of the element is first changed from the second level to the third level, and then changed from the third level to the first level. The third level is greater than the second level and less than the first level.

[0006] In an embodiment of the present disclosure, the first level is a positive voltage, the second level is a negative voltage, and the third level is a ground voltage.

[0007] In the embodiments of the present disclosure, the voltage level of the element is changed in a step-rising, linear-rising or non-linear-rising manner.

[0008] In an embodiment of the present disclosure, the voltage level of the element changes from the first level to the second level at a second slew rate. The second slew rate is less than 0 V / μs and greater than -0.5 V / μs.

[0009] In an embodiment of the present disclosure, the voltage level of the element is first changed from the first level to the third level, and then changed from the third level to the second level. The third level is greater than the second level and less than the first level.

[0010] In the embodiments of the present disclosure, the voltage level of the element is changed in a step-falling, linear-falling or non-linear-falling manner.

[0011] In an embodiment of the present disclosure, the element includes a touch sensing line, a gate line, a source line, a common electrode or a guard ring of a display panel.

[0012] In an embodiment of the present disclosure, the synchronous driving signal has the same frequency, phase and amplitude as the touch driving signal applied to the touch sensor of the display panel in the touch sensing phase.

[0013] The present disclosure provides a driver circuit configured to drive a display panel to perform a display function and a touch function. The driver circuit includes a pad and a multiplexing circuit. The pad is coupled to the display panel. The multiplexing circuit is configured to receive a synchronous drive signal, a common signal, and a level transition signal, and output one of the synchronous drive signal, the common signal, and the level transition signal to the pad during a touch sensing phase. The synchronous drive signal has a first level, and the common signal has a second level. The voltage level of the pad changes from the second level to the first level according to the level transition signal.

[0014] The second level is lower than the first level.

[0015] In an embodiment of the present disclosure, the multiplexing circuit is further configured to receive a system voltage signal having a third level. The third level is greater than the second level and less than the first level. The voltage level of the pad is first changed from the second level to the third level, and then changed from the third level to the first level.

[0016] In an embodiment of the present disclosure, the first level is a positive voltage, the second level is a negative voltage, and the third level is a ground voltage.

[0017] In an embodiment of the present disclosure, the voltage level of the pad is changed in a step-up, linear, or non-linear manner.

[0018] In an embodiment of the present disclosure, a voltage level of the pad is changed from a first level to a second level according to a level conversion signal.

[0019] In an embodiment of the present disclosure, the voltage level of the pad is first changed from the first level to the third level, and then changed from the third level to the second level. The third level is greater than the second level and less than the first level.

[0020] In an embodiment of the present disclosure, the voltage level of the pad is changed in a step-down, linear-down, or non-linear-down manner.

[0021] In an embodiment of the present disclosure, the pad is coupled to a touch sensing line, a gate line, a source line, a common electrode, or a guard ring of the display panel.

[0022] In an embodiment of the present disclosure, the synchronous driving signal has the same frequency, phase and amplitude as the touch driving signal applied to the touch sensor of the display panel in the touch sensing phase.

[0023] In order to make the above contents more easily understood, several embodiments are described in detail below with accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present disclosure includes accompanying drawings to provide a further understanding of the present disclosure, and the accompanying drawings are incorporated in and constitute a part of this specification. The accompanying drawings illustrate exemplary embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure.

[0025] Figure 1 is a block diagram showing an electronic device according to an embodiment of the present disclosure.

[0026] Figure 2 The present invention is shown in Figure 1 A schematic diagram of the display panel is shown.

[0027] Figure 3 is a waveform diagram of a synchronous driving signal according to an embodiment of the present disclosure.

[0028] Figure 4 is a waveform diagram of a synchronous driving signal according to another embodiment of the present disclosure.

[0029] Figure 5 is a circuit diagram showing a driver circuit according to an embodiment of the present disclosure.

[0030] Fig. 6A is a block diagram showing a signal generating circuit according to an embodiment of the present disclosure.

[0031] Figure 6B According to the embodiment of the present disclosure Fig. 6A The waveform diagram of the level conversion signal shown.

[0032] Figure 7 According to the embodiment of the present disclosure Fig. 6A Circuit diagram of the signal generating circuit shown.

[0033] Fig. 8A is a block diagram showing a signal generating circuit and a processing circuit according to an embodiment of the present disclosure.

[0034] Figure 8B According to the embodiment of the present disclosure Fig. 8A The waveform diagram of the level conversion signal shown.

[0035] Fig.9A , Fig. 9B and Fig. 9C are respectively shown according to the embodiments of the present disclosure Fig. 8A Circuit diagram of the processing circuit shown.

[0036] Fig.10 is a circuit diagram showing a switching circuit according to an embodiment of the present disclosure.

[0037] Fig.11 The present invention is shown in Fig.10 Graph showing a waveform of a control signal of a switch circuit shown in FIG.

[0038] Fig.12 is a circuit diagram showing a switching circuit according to another embodiment of the present disclosure.

[0039] [Explanation of Symbols]

[0040] 100: Electronic devices

[0041] 110, 510: Driver circuit

[0042] 112: Touch drive circuit

[0043] 114_1~114_N:pad group

[0044] 120: Display panel

[0045] 121: Gate line

[0046] 122: Touch sensing line

[0047] 123: Source line

[0048] 124: Touch sensor

[0049] 125: Protection ring

[0050] 127: Common electrode

[0051] 200: Synchronous drive signal

[0052] 300, 300A: Level conversion signal

[0053] 410F, 410R: Straight line

[0054] 421F, 421R, 422F, 422R, 423F, 423R, 424F, 424R: Curve

[0055] 430F, 430R: Marking

[0056] 512, 620: Multiplexing circuit

[0057] 514: Sensing circuit

[0058] 516: Digital-to-Analog Converter (DAC) Circuit

[0059] 600: Signal generating circuit

[0060] 601: Voltage selection signal

[0061] 602: Timing selection signal

[0062] 610: Voltage divider circuit

[0063] 700: Processing circuit

[0064] 1000, 1200: Switching circuit

[0065] 1010_1~1010_N: first switch

[0066] 1020_1~1020_N: Second switch

[0067] 1030_1~1030_N: Output terminals

[0068] 1040: Soft start circuit

[0069] 1110, 1120, 1130, 1140: virtual frame

[0070] AVSS: system voltage signal

[0071] HV1: High level

[0072] LV1: First level / low level

[0073] LV2: Second level

[0074] LV3: The third level

[0075] RX: Pad

[0076] S1_1, S1_2, S1_3~S1_N, S2_1, S2_2, S2_3~S2_N: control signals

[0077] TX: touch drive signal

[0078] VCOM: common signal DETAILED DESCRIPTION

[0079] The following embodiments are provided to explain the present disclosure in detail, but the present disclosure is not limited to the provided embodiments, and the provided embodiments may be appropriately combined. The terms "coupled / coupled" or "connected / connected" used in the specification (including claims) of the present application may refer to any direct or indirect means of connection. For example, "a first device is coupled to a second device" should be interpreted as "a first device is directly connected to a second device" or "a first device is indirectly connected to a second device via other devices or connection means". The term "signal" may refer to current, voltage, charge, temperature, data, electromagnetic waves, or any one or more signals. In addition, the term "and / or" may refer to "at least one of..." For example, "a first signal and / or a second signal" should be interpreted as "at least one of a first signal and a second signal".

[0080] Figure 1 is a block diagram showing an electronic device according to an embodiment of the present disclosure. Figure 2 The present invention is shown in Figure 1 A schematic diagram of the display panel is shown. Figure 1 and Figure 2 , the electronic device 100 includes a driver circuit 110 and a display panel 120. In an embodiment, the driver circuit 110 may be an integrated circuit chip (IC chip), which may drive the display panel 120 to perform a display function, a touch sensing function, and / or a fingerprint sensing function.

[0081] The display panel 120 includes a touch sensing line 122, a touch sensor 124, a gate line 121, a source line 123, or a guard ring 125. The touch sensing line 122 is coupled to the touch sensor 124. The display panel 120 may also include other elements or devices (e.g., a pixel circuit or a fingerprint sensor) to perform a display function, a touch sensing function, and / or a fingerprint sensing function. For simplicity, Figure 2 Other elements or devices are not shown.

[0082] The driver circuit 110 drives and controls the touch sensor 124 to sense the touch event of the display panel 120 through the touch scan line and the touch sensing line 122. In the present embodiment, an in-cell touch sensor is taken as an example, but the present disclosure is not limited thereto. For the in-cell touch sensor, the touch sensor 124 may be a touch sensing electrode in the touch sensing phase, and the touch sensor 124 may be a common electrode 127 in the display phase. The display panel 120 including the in-cell touch sensor does not have a touch scan line. For other types of touch sensors, the display panel 120 may have a touch scan line for transmitting a touch drive signal.

[0083] The driver circuit 110 includes a touch drive circuit 112. The touch drive circuit 112 is configured to output a synchronous drive signal 200 to a specific element of the display panel 120 in a touch sensing phase. The specific element may include a touch sensing line 122, a common electrode 127, a gate line 121, a source line 123, and / or a guard ring 125 of the display panel 120. In the touch sensing phase, the synchronous drive signal 200 is applied to the touch sensing line 122, the common electrode 127, the gate line 121, the source line 123, and the guard ring 125 for non-load driving (loading free driving, LFD). The synchronous drive signal 200 has the same frequency, phase, and amplitude as the touch drive signal applied to the touch sensor 124 of the display panel 120 in the touch sensing phase.

[0084] Figure 3 is a waveform diagram of a synchronous driving signal according to an embodiment of the present disclosure. Figures 1 to 3 , the synchronous drive signal 200 can be output to the display panel 120 via the pad RX of the driver circuit 110. The synchronous drive signal 200 can be a sine wave or a square wave, and in this embodiment, a sine wave is taken as an example. The synchronous drive signal 200 includes a high level HV1 and a low level LV1 (first level). The synchronous drive signal 200 is transmitted from the driver circuit 110 to the display panel 120 via the pad RX. The touch sensing signal of the touch sensor 124 can also be transmitted from the display panel 120 to the driver circuit 110 via the same pad RX. For the sake of simplicity, Figure 1 Only one pad RX is shown in FIG. 1 , but the number of pads RX is not intended to limit the present disclosure.

[0085] Taking the common electrode 127 as an example, the touch sensor 124 is used as a common electrode in the display phase and has a second level LV2. The second level LV2 may be a common voltage used for reference in the display phase. In the touch sensing phase, the touch sensor 124 is used as a touch sensing electrode and a touch drive signal that can be regarded as the same as the synchronous drive signal 200 is applied. Therefore, for the voltage rising phase, the voltage level of the common electrode 127 changes from the second level LV2 to the first level LV1. The second level LV2 is less than the first level LV1.

[0086] In this embodiment, during the display phase, the touch sensor 124 serving as the common electrode 127 operates in the negative voltage domain, while during the touch sensing phase, the touch sensor 124 serving as the touch sensing electrode operates in the positive voltage domain. Therefore, the first level is a positive voltage and the second level is a negative voltage. The voltage level of the common electrode 127 can first change from the second level LV2 to the third level LV3, and then change from the third level LV3 to the first level LV1. The third level LV3 is greater than the second level LV2 and less than the first level LV1. For example, the third level LV3 can be the ground voltage.

[0087] For the voltage drop phase, the voltage level of the common electrode 127 changes from the first level LV1 to the second level LV2. The voltage level of the common electrode 127 first changes from the first level LV1 to the third level LV3, and then changes from the third level LV3 to the second level LV2.

[0088] Figure 4 is a waveform diagram of a synchronous drive signal according to another embodiment of the present disclosure. Refer to Figure 4 , in this embodiment, for the voltage rise phase, the voltage level of the common electrode 127 changes in a stepwise rising, linearly rising, or non-linearly rising manner to reduce the electromagnetic interference (EMI) effect. For the voltage drop phase, the voltage level of the common electrode 127 changes in a stepwise falling, linearly falling, or non-linearly falling manner to reduce the EMI effect.

[0089] Specifically, for the voltage rise phase, the voltage level of the common electrode 127 changes in the form of a straight line 410R (i.e., linearly rising manner) at a first conversion rate. The first conversion rate is greater than 0 volts per microsecond (V / μs) and less than 0.5 V / μs. That is, 0 V / μs < SR1 < 0.5 V / μs, where SR1 is the first conversion rate. The voltage level of the common electrode 127 can also change in the form of curves 421R, 422R, 423R, or 424R (i.e., non-linearly rising manner). The equivalent conversion rate of the non-linearly rising manner is greater than 0 V / μs and less than 0.5 V / μs. Additionally, as indicated by the mark 430R (i.e., stepwise rising manner), the voltage level of the common electrode 127 can also change step by step. The equivalent conversion rate of the stepwise rising manner is greater than 0 V / μs and less than 0.5 V / μs.

[0090] For the voltage drop phase, the voltage level of the common electrode 127 changes at a second conversion rate in the form of a straight line 410F (i.e., a linear drop manner). The second conversion rate is less than 0 V / μs and greater than -0.5 V / μs. That is, -0.5 V / μs < SR2 < 0 V / μs, where SR2 is the second conversion rate. The voltage level of the common electrode 127 can also change in the form of curves 421F, 422F, 423F, or 424F (i.e., a non-linear drop manner). The equivalent conversion rate of the non-linear drop manner is less than 0 V / μs and greater than -0.5 V / μs. Additionally, as indicated by the mark 430F (i.e., a stepped drop manner), the voltage level of the common electrode 127 can also change step by step. The equivalent conversion rate of the stepped drop manner is less than 0 V / μs and greater than -0.5 V / μs.

[0091] Figure 5 is a circuit diagram showing a driver circuit according to an embodiment of the present disclosure. Refer to Figure 5 , the driver circuit 510 includes a pad RX, a multiplexing circuit 512, a sensing circuit 514, and a digital-to-analog converter (DAC) circuit 516. The pad RX is coupled to the display panel 120. The multiplexing circuit 512 is an input and output (I / O) multiplexer that can receive and output signals through the pad RX. The pad RX can be coupled to the touch sensing line 122, the touch sensor 124, the common electrode 127, the gate line 121, the source line 123, or the guard ring 125.

[0092] In the touch sensing phase, the DAC circuit 516 outputs a touch driving signal TX, and the touch driving signal TX is transmitted to the multiplexing circuit 512 through the virtual short-circuit characteristic of the amplifier. The multiplexing circuit 512 outputs the touch driving signal TX to the touch sensor 124 of the display panel 120 through the pad RX. Next, the touch sensing signal from the touch sensor 124 is transmitted to the sensing circuit 514 via the pad RX and the multiplexing circuit 512.

[0093] On the other hand, the multiplexing circuit 512 is configured to receive a synchronous driving signal 200, a common signal VCOM, a level shift signal 300, and a system voltage signal AVSS. In an embodiment, the touch driving signal TX and the synchronous driving signal 200 can come from the same signal source. In the touch sensing phase, the multiplexing circuit 512 outputs one of the synchronous driving signal 200, the common signal VCOM, the level shift signal 300, and the system voltage signal AVSS to the pad RX.

[0094] Refer again to Figure 4, the synchronous driving signal 200 has a first level LV1, the common signal VCOM has a second level LV2, and the system voltage signal AVSS has a third level LV3. In addition, Figure 4 Also shown is the waveform of the level conversion signal 300. Taking the pad RX coupled to the touch sensor 124 as an example, the touch sensor 124 may be a touch sensing electrode in the touch sensing phase, and the touch sensor 124 may be a common electrode 127 in the display phase. When the multiplexing circuit 512 outputs the common signal VCOM, the level conversion signal 300, the system voltage signal AVSS, and the synchronous driving signal 200 to the pad RX in the touch sensing phase, the voltage level of the pad RX changes from the second level LV2 to the first level LV1 through the third level LV3 according to the waveform of the level conversion signal 300.

[0095] like Figure 4 As shown, the level transition signal 300 can increase in a step-up, linear-up, or non-linear-up manner, or decrease in a step-down, linear-down, or non-linear-down manner. Therefore, in the voltage-up state or the voltage-down state, the voltage level of the pad RX changes in the same manner as the level transition signal 300. That is, the voltage level of the pad RX increases in a step-up, linear-up, or non-linear-up manner, or decreases in a step-down, linear-down, or non-linear-down manner.

[0096] Fig. 6A is a block diagram showing a signal generating circuit according to an embodiment of the present disclosure. Figure 6B According to the embodiment of the present disclosure Fig. 6A The waveform diagram of the level conversion signal is shown. Figure 5 , Fig. 6A and Figure 6B , the driver circuit 510 may further include a signal generating circuit 600 .

[0097] In this embodiment, the signal generating circuit 600 generates the level conversion signal 300 according to the voltage selection signal 601 and the timing selection signal 602. The level conversion signal 300 is generated and output to the multiplexing circuit 512. Figure 6B As shown, the generated level conversion signal 300 changes in a step-up or step-down manner. The voltage selection signal 601 and the timing selection signal 602 may come from a touch controller or a timing controller.

[0098] Figure 7 According to the embodiment of the present disclosure Fig. 6A The circuit diagram of the signal generating circuit shown. Figure 7The signal generating circuit 600 includes a voltage dividing circuit 610 and a multiplexing circuit 620. The voltage dividing circuit 610 includes a resistor string and a buffer to generate multiple voltages. The multiplexing circuit 620 outputs a specific voltage at a specific time according to the voltage selection signal 601 and the timing selection signal 602 to be used as the level conversion signal 300.

[0099] Fig. 8A is a block diagram showing a signal generating circuit and a processing circuit according to an embodiment of the present disclosure. Figure 8B According to the embodiment of the present disclosure Fig. 8A The waveform diagram of the level conversion signal shown. Fig.9A , Fig. 9B and Fig. 9C are respectively shown according to the embodiments of the present disclosure Fig. 8A Circuit diagram of the processing circuit shown.

[0100] refer to Figure 5 and 8A to 9C The driver circuit 510 may further include a signal generating circuit 600 and a processing circuit 700. In this embodiment, the level conversion signal 300 generated by the signal generating circuit 600 is output to the processing circuit 700. The processing circuit 700 may be as follows: Fig.9A , Fig. 9B and Fig. 9C The slew rate controller or filter circuit shown. Fig.9A A slew rate controller with an amplifier is shown. Fig. 9B A first-order resistance capacitance (RC) filter is shown. Fig. 9C 1 shows a high-order filter with an amplifier. The processing circuit 700 processes the level conversion signal 300 to become smoother, and thus the processing circuit 700 outputs the level conversion signal 300A. Figure 8B As shown, the level transition signal 300A changes in a linear rising, linear falling, non-linear rising or non-linear falling manner.

[0101] In the above embodiments, the level transition of the common electrode is taken as an example for description, and the level transition of other elements (such as a touch sensing line, a gate line, a source line or a guard ring) can be deduced in the same way.

[0102] In the present disclosure, the level transition of a specific element may also be achieved by turning on switches at different times, and this will be described below.

[0103] Back again Figure 3 ,exist Figure 3In the embodiment, when the electronic device 100 enters the touch sensing stage, the synchronous driving signal 200 will be applied to the pad RX, and the voltage level of the pad RX may first increase from the second level LV2 to the third level LV3, and then increase from the third level LV3 to the first level LV1. At the end of the touch sensing stage, the voltage level of the pad RX may first decrease from the first level LV1 to the third level LV3, and then decrease from the third level LV3 to the second level LV2.

[0104] Fig.10 is a circuit diagram showing a switching circuit according to an embodiment of the present disclosure. Fig.11 The present invention is shown in Fig.10 The waveform diagram of the control signal of the switch circuit shown in FIG. Fig.10 and Fig.11 , the driver circuit 110 may include a switch circuit 1000 and a plurality of pads RX. The pads RX are divided into a plurality of pad groups 114_1 to 114_N, where N is a positive integer greater than 1. The pad groups 114_1 to 114_N are coupled to the touch sensing line 122, the touch sensor 124, the common electrode 127, the gate line 121, the source line 123, or the guard ring 125. Each of the pad groups 114_1 to 114_N includes a specific number of pads RX. Fig.10 and Fig.11 , the pads RX are divided into 12 pad groups, ie, N=12, but the present disclosure is not limited thereto.

[0105] The switch circuit 1000 is configured to receive a common signal VCOM and a system voltage signal AVSS and output the common signal VCOM and the system voltage signal AVSS to corresponding pad groups 114_1 to 114_N in a time division manner. The common signal VCOM and the system voltage signal AVSS may have a second level LV2 and a third level LV3, respectively.

[0106] Specifically, the switch circuit 1000 includes a plurality of first switches 1010_1 to 1010_N, a plurality of second switches 1020_1 to 1020_N, and a plurality of output terminals 1030_1 to 1030_N. The output terminals 1030_1 to 1030_N are connected to corresponding pad groups 114_1 to 114_N. The first switches 1010_1 to 1010_N are configured to receive a common signal VCOM, and output the common signal VCOM to the pad groups 114_1 to 114_N when the first switches 1010_1 to 1010_N are turned on. The second switches 1020_1 to 1020_N are configured to receive a system voltage signal AVSS, and output the system voltage signal AVSS to the pad groups 114_1 to 114_N when the second switches 1020_1 to 1020_N are turned on.

[0107] The conduction states of the first switches 1010_1 to 1010_N are controlled by control signals S1_1 to S1_N, and the conduction states of the second switches 1020_1 to 1020_N are controlled by control signals S2_1 to S2_N. Taking the first switch 1010_N and the second switch 1020_N as an example, when the first switch 1010_N is turned on according to the control signal S1_N, the common signal VCOM is output to the pad group 114_N via the output terminal 1030_N. When the second switch 1020_N is turned on according to the control signal S2_N, the system voltage signal AVSS is output to the same pad group 114_N via the same output terminal 1030_N. The first switch 1010_N and the second switch 1020_N are not turned on at the same time.

[0108] exist Fig.11 In the embodiment, the dashed boxes 1110 and 1140 indicate that the control signals S1_1, S1_2, S1_3 to S1_N turn on the corresponding first switches 1010_1 to 1010_N in sequence at different times. The first switches 1010_1 to 1010_N are turned on in sequence. The dashed boxes 1120 and 1130 indicate that the control signals S2_1, S2_2, S2_3 to S2_N turn on the corresponding second switches 1020_1 to 1020_N in sequence at different times. The second switches 1020_1 to 1020_N are turned on in sequence. Therefore, the switch circuit 1000 can output the common signal VCOM and the system voltage signal AVSS to the corresponding pad groups 114_1 to 114_N in a time-division manner.

[0109] Therefore, for the voltage rising stage, the voltage levels of pad groups 114_1 to 114_N may change from second level LV2 to first level LV1 via third level LV3 at different times. For the voltage falling stage, the voltage levels of pad groups 114_1 to 114_N may also change from first level LV1 to second level LV2 via third level LV3 at different times.

[0110] In the prior art, all switches for transmitting signals are turned on at the same time, and thus severe EMI effects may occur. However, in this embodiment, since the first switches 1010_1 to 1010_N and the second switches 1020_1 to 1020_N are turned on at different times, EMI effects may be reduced.

[0111] Fig.12 is a circuit diagram showing a switch circuit according to another embodiment of the present disclosure. Fig.12 The switch circuit 1200 of this embodiment is similar to Fig.10 The switch circuit 1000 of the present embodiment and the switch circuit 1200 of the present embodiment Fig.10The main difference of the switching circuit 1000 lies, for example, in that the switching circuit 1200 further includes a plurality of soft start circuits 1040. The soft start circuits 1040 are arranged after the first switches 1010_1 to 1010_N and the second switches 1020_1 to 1020_N, and are configured to reduce the steepness of voltage rise / fall and reduce the inrush current. Each of the soft start circuits 1040 may include a resistor string formed by a plurality of resistors coupled in series.

[0112] In summary, in the present disclosure, the voltage transition between the second level and the first level can be achieved by a digital type ( Fig. 6A ) or an analog type ( Fig. 8A ). The voltage conversion process includes types such as digital ladder type (ramping up or ramping down), diagonal type, exponential type, slow first and then fast, etc. The voltage transition between the second level and the first level can be defined by the conversion rate. According to circuit simulation and actual tests, as long as the conversion rate of any segment within the voltage transition interval is within a specific range (for example, 0V / μs < SR1 < 0.5V / μs or -0.5V / μs < SR2 < 0V / μs), the EMI effect can be reduced. On the other hand, in an embodiment using multiple switches, for the voltage transition between the second level and the first level, the multiple switches switching in groups at different times can also reduce the EMI effect and the inrush current.

[0113] Those skilled in the art can make various modifications and variations to the disclosed embodiments without departing from the scope or spirit of the present disclosure. In summary, the present disclosure aims to cover various modifications and variations as long as they fall within the scope of the above claims and their equivalents.

Claims

1. A driver circuit configured to drive a display panel to perform a display function and a touch function, the driver circuit comprising: A touch driving circuit is configured to output a synchronous driving signal to an element of the display panel in a touch sensing phase, wherein the synchronous driving signal comprises a first level, The voltage level of the element changes from a second level to the first level at a first conversion rate, and the first conversion rate is greater than 0 volts per microsecond (V / μs) and less than 0.5V / μs, and the second level is less than the first level.

2. The driver circuit according to claim 1, wherein the voltage level of the element is first changed from the second level to a third level and then changed from the third level to the first level, and the third level is greater than the second level and less than the first level. 3 . The driver circuit according to claim 2 , wherein the first level is a positive voltage, the second level is a negative voltage, and the third level is a ground voltage. 4 . The driver circuit according to claim 1 , wherein the voltage level of the element changes in a step-up, linear-up, or non-linear manner. 5 . The driver circuit of claim 1 , wherein the voltage level of the element changes from the first level to the second level at a second slew rate, and the second slew rate is less than 0 V / μs and greater than −0.5 V / μs. 6 . The driver circuit according to claim 5 , wherein the voltage level of the element is first changed from the first level to a third level and then changed from the third level to the second level, and the third level is greater than the second level and less than the first level. 7 . The driver circuit according to claim 6 , wherein the first level is a positive voltage, the second level is a negative voltage, and the third level is a ground voltage.

8. The driver circuit according to claim 5, wherein the voltage level of the element changes in a step-down, linear-down, or non-linear-down manner. 9 . The driver circuit of claim 1 , wherein the element comprises a touch sensing line, a gate line, a source line, a common electrode, or a guard ring of the display panel. 10 . The driver circuit of claim 1 , wherein the synchronous driving signal has the same frequency, phase, and amplitude as a touch driving signal applied to a touch sensor of the display panel in the touch sensing phase.

11. A driver circuit configured to drive a display panel to perform a display function and a touch function, the driver circuit comprising: A solder pad coupled to the display panel; as well as a multiplexing circuit configured to receive a synchronous driving signal, a common signal, and a level conversion signal, and output one of the synchronous driving signal, the common signal, and the level conversion signal to the pad in a touch sensing phase, The synchronous driving signal has a first level, the common signal has a second level, and the voltage level of the pad changes from the second level to the first level according to the level conversion signal, and the second level is lower than the first level.

12. The driver circuit according to claim 11, wherein the multiplexing circuit is further configured to receive a system voltage signal having a third level, and the third level is greater than the second level and less than the first level, The voltage level of the pad is first changed from the second level to the third level, and then changed from the third level to the first level. 13 . The driver circuit of claim 12 , wherein the first level is a positive voltage, the second level is a negative voltage, and the third level is a ground voltage. 14 . The driver circuit according to claim 11 , wherein the voltage level of the pad changes in a step-up, linear-up, or non-linear-up manner. 15 . The driver circuit according to claim 11 , wherein the voltage level of the pad is changed from the first level to the second level according to the level conversion signal. 16 . The driver circuit according to claim 15 , wherein the voltage level of the pad is first changed from the first level to a third level and then changed from the third level to the second level, and the third level is greater than the second level and less than the first level. 17 . The driver circuit of claim 16 , wherein the first level is a positive voltage, the second level is a negative voltage, and the third level is a ground voltage. 18 . The driver circuit according to claim 15 , wherein the voltage level of the pad changes in a step-down, linear-down, or non-linear-down manner. 19 . The driver circuit of claim 11 , wherein the pad is coupled to a touch sensing line, a gate line, a source line, a common electrode, or a guard ring of the display panel. 20 . The driver circuit of claim 11 , wherein the synchronous driving signal has the same frequency, phase, and amplitude as a touch driving signal applied to a touch sensor of the display panel in the touch sensing phase.

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