Driver circuit

Abstract

The invention provides a driver circuit. The driver circuit is used for driving the touch display panel. The touch display panel includes a sensor. The driver circuit includes a timing control circuit and a touch sensing circuit. The time sequence control circuit is used for outputting a touch driving signal to the sensor. The sensor generates a sensing signal according to the touch driving signal. The touch sensing circuit is coupled to the timing control circuit and is used for receiving the sensing signal. The time sequence control circuit determines the time sequence of the touch driving signal according to the noise interval signal so as to drive the sensor to generate a sensing signal.

Description

Technical Field

[0001] The invention relates to a driver circuit for driving a touch display panel. Background Art

[0002] A touch display device is an electronic device that integrates touch and display functions, allowing users to directly operate the display interface by touch while viewing the electronic device, thereby providing a good user experience. However, due to the trend of thinning electronic devices, the coupling capacitance between the touch device and the display device has increased, and the mutual interference has become more and more serious, which may affect the display data used to drive the display panel and the sensing data generated by the touch panel. In addition, noise signals may also affect the accuracy of the sensing data. Summary of the invention

[0003] The present invention provides a driver circuit, the driving method of which can at least solve the above-mentioned problem of interference affecting display data or sensing data.

[0004] The driver circuit of the embodiment of the present invention is used to drive a touch display panel. The touch display panel includes a sensor. The driver circuit includes a timing control circuit and a touch sensing circuit. The touch sensing circuit is used to output a touch drive signal to the sensor. The sensor generates a sensing signal according to the touch drive signal. The touch sensing circuit is coupled to the timing control circuit and is used to receive the sensing signal. The timing control circuit determines the timing of the touch drive signal according to the noise interval signal to drive the sensor to generate the sensing signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 A schematic structural diagram of a touch display panel according to an embodiment of the present invention is shown.

[0006] Figure 2 A block diagram of a driver circuit according to an embodiment of the present invention is shown.

[0007] Figure 3 A block diagram of a driver circuit according to another embodiment of the present invention is shown.

[0008] Figure 4 Show Figure 3 Schematic diagram of the waveforms of various signals in the driver circuit.

[0009] Figure 5 A schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention is shown.

[0010] Figure 6 A schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention is shown.

[0011] Figure 7A schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention is shown.

[0012] Figure 8 A schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention is shown.

[0013] Fig. 9A and Fig. 9B Schematic diagrams showing waveforms of various signals in driver circuits according to different embodiments of the present invention.

[0014] Fig.10 A schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention is shown.

[0015] Fig.11 A block diagram of a driver circuit according to another embodiment of the present invention is shown.

[0016] Fig.12 A block diagram of a driver circuit according to another embodiment of the present invention is shown.

[0017] Fig.13 A schematic diagram showing a horizontal synchronization signal and a noise interval signal and count values ​​of the horizontal synchronization signal and the noise interval signal in different touch sensing frames according to an embodiment of the present invention is shown.

[0018] Fig.14A and Fig. 14B Schematic overview showing filter arrangements for different embodiments of the invention.

[0019] Fig.15 A schematic diagram showing a noise interval signal and its count value according to an embodiment of the present invention.

[0020] Fig.16 A schematic diagram showing noise interval signals and count values ​​thereof in different touch sensing frames according to an embodiment of the present invention is shown.

[0021] Fig.17 A schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention is shown.

[0022] Fig.18 A schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention is shown.

[0023] Fig.19 A schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0024] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0025] The following embodiments are provided to explain the present invention in detail, but the present invention is not limited to the provided embodiments, and the provided embodiments may be appropriately combined. The terms "coupling / coupled" or "connecting / connected" used in the specification (including claims) of the present invention may refer to any direct or indirect connection method. For example, "a first device is coupled to a second device" should be interpreted as "the first device is directly connected to the second device" or "the first device is indirectly connected to the second device through other devices or connection means." In addition, the term "signal" may refer to current, voltage, charge, temperature, data, electromagnetic waves, or any one or more signals.

[0026] Figure 1 A schematic structural diagram of a touch display panel according to an embodiment of the present invention is shown. Figure 2 FIG. 1 is a block diagram showing a driver circuit according to an embodiment of the present invention. Figure 1 and Figure 2 The touch display panel 100 includes a touch circuit 110 , a display circuit 120 and a shielding layer 130 .

[0027] The touch circuit 110 includes a driving electrode 112_TX and a sensing electrode 114_RX. The driving electrode 112_TX and the sensing electrode 114_RX serve as a sensor 116 (e.g., a mutual capacitance touch screen) for sensing a capacitance change generated when an object touches the touch display panel 100, i.e., the capacitance to be measured C2, but the present invention is not limited thereto. In an embodiment, such as a self-capacitive touch screen, the sensor 116 may not be divided into a driving electrode and a sensing electrode, and all are sensing electrodes. The display circuit 120 includes a gate line 122_G. A shielding layer 130 is included between the touch circuit 110 and the display circuit 120. The shielding layer 130 is, for example, connected to the cathode of an organic light emitting diode for transmitting a reference voltage ELVSS. As the trend of thinning the panel increases the parasitic capacitance C1, the degree of voltage coupling interference will also increase.

[0028] For example, common interference occurs at the moment of signal transition of the touch driving signal, and another common interference occurs during the display data update, such as the moment of signal transition on the gate line 122_G. The driver circuit 200 of the embodiment of the present invention is used to drive the touch display panel 100, and its driving method can solve the problem of the above interference affecting the sensing data or display data.

[0029] Specifically, when the image data is to be updated, the timing control circuit 210 will first output a horizontal synchronization signal. Due to signal coupling, it is easy to generate a surge (which can be regarded as a noise signal) on the reference voltage. At this time, if the touch drive signal S_TX is triggered to transmit data, the signal output by the analog front-end circuit will be saturated, so that the demodulator circuit outputs an erroneous demodulated signal.

[0030] In view of this, at least in order to solve this problem, the driver circuit 200 of the embodiment of the present invention can determine the timing of the touch driving signal S_TX according to the noise interval signal S_ND to avoid transmitting the signal at the time point when the reference voltage surge is generated, thereby preventing the touch driving signal S_TX from being affected by the noise signal on the reference voltage, and further reducing the interference of the sensing signal by the noise signal.

[0031] On the other hand, the interference of touch control on display may also occur during the period of display data update, that is, when the gate signal is turned on. Due to the interference of coupling, the instantaneous transition of the touch drive signal S_TX is likely to cause data signal jitter. If the data signal has not stabilized before the end of the update time, that is, before the gate signal is turned off, it is easy to cause display color deviation.

[0032] In view of this, at least to solve this problem, the timing control circuit 210 of the embodiment of the present invention can determine the timing and slew rate of the touch driving signal S_TX according to the forbidden interval signal S_PD, so as to reduce the interference of the touch driving signal on the data signal when the gate signal transitions.

[0033] Specifically, the driver circuit 200 includes a timing control circuit 210 and a touch sensing circuit 220. The touch sensing circuit 220 is coupled to the timing control circuit 210. The timing control circuit 210 outputs a touch driving signal S_TX to the sensor 116 (e.g., the driving electrode 112_TX). Then, the sensor 116 (e.g., the sensing electrode 114_RX) generates a sensing signal S_RX according to the touch driving signal S_TX and transmits it to the touch sensing circuit 220. The touch sensing circuit 220 receives the sensing signal S_RX and performs operations such as demodulation and filtering on the sensing signal S_RX, thereby generating sensing data S_D.

[0034] In an embodiment of the present invention, the timing control circuit 210 may receive a noise duration signal S_ND or a prohibit duration signal S_PD, and determine the timing of the touch drive signal S_TX according to the noise duration signal S_ND or the prohibit duration signal S_PD to drive the sensor 116 to generate the sensing signal S_RX. In an embodiment, the timing control circuit 210 may also determine the slew rate of the touch drive signal S_TX according to the prohibit duration signal S_PD. Therefore, through the driving method of the embodiment of the present invention, the driver circuit 200 can solve the problem of the above-mentioned interference affecting the sensing data or display data.

[0035] First, it is explained that the timing control circuit can determine the timing of the touch driving signal according to the noise interval signal to drive the sensor to generate the sensing signal.

[0036] Figure 3 A block diagram of a driver circuit according to another embodiment of the present invention is shown. Figure 4 Show Figure 3 Please refer to the waveform diagram of each signal in the driver circuit. Figure 3 and Figure 4 The driver circuit 300 includes a display driver circuit 310 and a touch driver circuit 320. The display driver circuit 310 is coupled to the touch driver circuit 320. The display driver circuit 310 is used to output a noise interval signal S_ND, a disable interval signal S_PD, a horizontal synchronization signal Hsync, and a vertical synchronization signal Vsync to the touch driver circuit 320.

[0037] Specifically, the display driver circuit 310 is used to drive the touch display panel 100 to display an image. The display driver circuit 310 is coupled to the timing control circuit 322. The display driver circuit 310 is used to output a noise interval signal S_ND and a prohibition interval signal S_PD to the timing control circuit 322. The display driver circuit 310 includes a signal generating circuit 312. The signal generating circuit 312 is used to generate a noise interval signal S_ND and a prohibition interval signal S_PD to the touch driver circuit 320. In addition, referring to the common knowledge in the art, sufficient teaching, suggestions and implementation descriptions can be obtained for the hardware structure of the signal generating circuit 312.

[0038] The noise interval signal S_ND is used to indicate that the reference voltage ELVSS is interfered by the noise signals 410 and 420 in the noise interference interval T1. The reference voltage ELVSS is, for example, a reference voltage for driving a display pixel of the touch display panel 100. For example, the display pixel of the touch display panel 100 includes an organic light emitting diode, and the reference voltage ELVSS can be applied to the cathode of the organic light emitting diode as an operating voltage of the display pixel. The noise signals 410 and 420 are noises that interfere with the reference voltage ELVSS.

[0039] The horizontal synchronization signal Hsync is used to indicate a scanning interval of any pixel row of the touch display panel 100. For example, one pixel row of the touch display panel 100 is scanned in a time interval between two square waves of the horizontal synchronization signal Hsync.

[0040] On the other hand, the touch driver circuit 320 includes a timing control circuit 322 and a touch sensing circuit 324. The timing control circuit 322 is used to output a touch driving signal S_TX to the sensor 116. The sensor 116 generates a sensing signal S_RX according to the touch driving signal S_TX. The touch sensing circuit 324 is coupled to the timing control circuit 322. The touch sensing circuit 324 is used to receive the sensing signal S_RX and receive a demodulation signal RX_dem from the timing control circuit 322 to perform a demodulation operation on the sensing signal S_RX to generate sensing data S_D.

[0041] The touch sensing circuit 324 includes an analog front end (AFE) circuit 242, a demodulator circuit 244, a filter circuit 246, and an accumulator circuit 248. The AFE circuit 242 receives a sensing signal S_RX. The AFE circuit 242 performs operations such as signal capture, analog filtering, analog-to-digital conversion (ADC), or power amplification on the sensing signal S_RX. The demodulator circuit 244 uses the demodulated signal RX_dem to demodulate the sensing signal S_RX. Then, the filter circuit 246 performs a filtering operation on the demodulated sensing signal S_RX. The accumulator circuit 248 can accumulate the filtered sensing signal S_RX to generate sensing data S_D.

[0042] In the present embodiment, the timing control circuit 322 determines the timing of the touch drive signal S_TX according to the noise interval signal S_ND to drive the sensor 116 to generate the sensing signal S_RX. The touch drive signal S_TX drives the sensor 116 to generate the sensing signal S_RX during the enabling period T2. That is, according to the indication of the noise interval signal S_ND, the timing control circuit 322 can know that the reference voltage ELVSS is interfered by the noise signals 410 and 420 during the noise interference interval T1. Therefore, the timing control circuit 322 sets the enabling period T2 of the touch drive signal S_TX to be non-overlapping in time with the noise interference interval T1 of the noise interval signal S_ND according to the noise interval signal S_ND. In this way, the interference of the sensing signal S_RX by the noise signals 410 and 420 can be reduced, thereby improving the accuracy of the sensing data S_D.

[0043] On the other hand, the demodulated signal RX_dem has a first level LV1 and a second level LV2. The demodulated signal RX_dem has a first level LV1 during the first demodulation period T3. For example, the first level LV1 and the second level LV2 are, for example, voltage values ​​of 1 and -1 volt, respectively, and the demodulator circuit 244 performs a demodulation operation on the sensing signal S_RX using the voltage value 1 during the first demodulation period T3. In the present embodiment, the timing control circuit 322 sets the first demodulation period T3 of the demodulated signal RX_dem to overlap in time with the enabling period T2 of the touch drive signal S_TX according to the noise interval signal S_ND, and the duty cycle of the demodulated signal RX_dem and the touch drive signal S_TX are both set to 30%, so that the touch sensing circuit 324 can obtain a larger signal amount. Figure 4 In the embodiment, the first demodulation period T3 and the enabling period T2 substantially completely overlap in time.

[0044] In addition, since the enabling period T2 of the touch driving signal S_TX does not overlap with the noise interference period T1 of the noise interval signal S_ND in time, the first demodulation period T3 of the demodulation signal RX_dem does not overlap with the noise interference period T1 of the noise interval signal S_ND in time. In other words, the timing control circuit 322 can also set the first demodulation period T3 of the demodulation signal RX_dem to not overlap with the noise interference period T1 of the noise interval signal S_ND in time according to the noise interval signal S_ND.

[0045] about Figure 3The timing controller 322 may be a processor with computing capabilities. Alternatively, the timing controller 322 may be designed using a hardware description language (HDL) or any other digital circuit design method familiar to those skilled in the art, and may be a hardware circuit implemented using a field programmable gate array (FPGA), a complex programmable logic device (CPLD), or an application-specific integrated circuit (ASIC). In addition, sufficient instruction, suggestions, and implementation instructions may be obtained for the hardware structures of the AFE circuit 242, the demodulator circuit 244, the filter circuit 246, and the accumulator circuit 248 by referring to the common knowledge in the art.

[0046] Figure 5 FIG. 2 is a schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention. Figures 3 to 5 ,exist Figure 4 In the embodiment, the first demodulation period T3 of the demodulation signal RX_dem is set to completely overlap with the enabling period T2 of the touch driving signal S_TX in time, and the duty cycles of the demodulation signal RX_dem and the touch driving signal S_TX are both 30%, but the present invention is not limited thereto.

[0047] exist Figure 5 In the embodiment, the duty cycle of the demodulation signal RX_dem is set to 50%, the duty cycle of the touch driving signal S_TX is still maintained at 30%, and the first demodulation period T3' of the demodulation signal RX_dem is set to at least partially overlap with the enabling period T2 of the touch driving signal S_TX in time.

[0048] Specifically, in the present embodiment, the timing control circuit 322 sets the first demodulation period T3' of the demodulation signal RX_dem to at least partially overlap with the enable period T2 of the touch drive signal S_TX in time according to the noise interval signal S_ND. In addition, the timing control circuit 322 sets the first demodulation period T3' of the demodulation signal RX_dem to at least partially overlap with the noise interference interval T1 of the noise interval signal S_ND in time according to the noise interval signal S_ND. In addition, the timing control circuit 322 also determines the duty cycle of the demodulation signal RX_dem according to the noise interval signal S_ND, for example, setting the duty cycle of the demodulation signal RX_dem to 50%. In this way, the spectrum energy of the demodulated sensing signal S_RX can be more concentrated on the main frequency, so it has a higher resistance to noise outside the main frequency.

[0049] Figure 6 FIG. 2 is a schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention. Figure 3 , Figure 4 and Figure 6 ,exist Figure 4 In the embodiment, the enabling period T2 of the touch driving signal S_TX is set to not overlap with the noise interference period T1 of the noise period signal S_ND in time, and the duty cycle of the touch driving signal S_TX is 30%, but the present invention is not limited thereto.

[0050] exist Figure 6 In the embodiment, the duty cycle of the touch driving signal S_TX is set to 50%, and the enabling period T2 of the touch driving signal S_TX is set to at least partially overlap with the noise interference period T1 of the noise period signal S_ND in time.

[0051] Specifically, in the present embodiment, the timing control circuit 322 sets the enabling period T2' of the touch driving signal S_TX to at least partially overlap with the noise interference period T1 of the noise period signal S_ND in time according to the noise period signal S_ND. In addition, the timing control circuit 322 also determines the duty cycle of the touch driving signal S_TX according to the noise period signal S_ND, for example, setting the duty cycle of the touch driving signal S_TX to 50%.

[0052] On the other hand, the demodulation signal RX_dem has a first level LV1, a second level LV2 and a third level LV3. The demodulation signal RX_dem has the first level LV1 during the first demodulation period T3, and the demodulation signal RX_dem has the third level LV3 during the second demodulation period T4. The signal levels LV1 and LV3 of the demodulation signal RX_dem during the first demodulation period T3 and the second demodulation period T4 are different. For example, the first level LV1, the second level LV2 and the third level LV3 are, for example, voltage values ​​of 1, -1, and 0 volts, respectively. The demodulator circuit 244 performs a demodulation operation on the sensing signal S_RX during the second demodulation period T4 using a voltage value of 0, indicating that the demodulator circuit 244 stops performing a demodulation operation on the sensing signal S_RX during the second demodulation period T4. In this way, the interference of the noise signals 410 and 420 on the sensing signal S_RX can be reduced, thereby improving the accuracy of the sensing data S_D.

[0053] In the present embodiment, the timing control circuit 322 sets the second demodulation period T4 of the demodulation signal RX_dem to overlap at least partially with the enable period T2' of the touch driving signal S_TX in time according to the noise interval signal S_ND. In addition, the timing control circuit 322 also sets the second demodulation period T4 of the demodulation signal RX_dem to overlap with the noise interference period T1 of the noise interval signal S_ND in time according to the noise interval signal S_ND. Figure 6 In the embodiment, the second demodulation period T4 and the noise interference interval T1 substantially completely overlap in time.

[0054] Figure 7 FIG. 2 is a schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention. Figure 3 , Figure 6 and Figure 7 ,exist Figure 6 In the embodiment of the present invention, the second demodulation period T4 of the demodulation signal RX_dem is set to overlap with the noise interference period T1 of the noise period signal S_ND in time, but the present invention is not limited thereto.

[0055] exist Figure 7 In the embodiment of the present invention, the second demodulation period T4' of the demodulation signal RX_dem is set to overlap at least partially in time with the noise interference period T1 of the noise period signal S_ND. Specifically, in the present embodiment, the timing control circuit 322 sets the second demodulation period T4' of the demodulation signal RX_dem to overlap at least partially in time with the noise interference period T1 of the noise period signal S_ND according to the noise period signal S_ND. In this way, the interference of the noise signals 410 and 420 on the sensing signal S_RX can be reduced, thereby improving the accuracy of the sensing data S_D.

[0056] exist Figures 5 to 7 In the embodiment of the present invention, the timing control circuit 322 can determine the timing and working cycle of the touch driving signal S_TX and the demodulation signal RX_dem according to the noise interval signal S_ND, or control the demodulator circuit 244 to stop demodulating the sensing signal S_RX in the noise interference interval T1. Through this driving method, the interference of the noise signals 410 and 420 on the sensing signal S_RX can be reduced, thereby improving the accuracy of the sensing data S_D.

[0057] Next, it is described that the display driver circuit 310 can output the noise interval signal S_ND at a fixed time, or can output the noise interval signal S_ND according to the degree of interference of the image frame.

[0058] Figure 8 FIG. 2 is a schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention. Figure 8 In this embodiment, regardless of whether the noise signals 810, 820, and 830 are greater than the threshold, the display driver circuit 310 outputs the noise interval signal S_ND to the timing control circuit 322 at a fixed frequency according to the horizontal synchronization signal Hsync. The fixed frequency is, for example, the same as the frequency of the horizontal synchronization signal Hsync, but the present invention is not limited thereto.

[0059] Fig. 9A and Fig. 9B Schematic diagrams showing waveforms of various signals in the driver circuits of different embodiments of the present invention. Fig. 9A and Fig. 9B , Fig. 9A and Fig. 9B The figure shows the situation that the reference voltage ELVSS is interfered by the noise signal in the noise interference interval when the image has different interference levels. When the noise signal is greater than the threshold, the display driver circuit 310 outputs the noise interval signal S_ND to the timing control circuit 322 .

[0060] For example, in Fig. 9A In the embodiment, the noise signals 910A and 930A are greater than the threshold, and the noise signal 920A is less than or equal to the threshold. When the noise signals 910A and 930A are greater than the threshold, the display driver circuit 310 outputs the noise interval signal S_ND to the timing control circuit 322. When the noise signal 920A is less than or equal to the threshold, the display driver circuit 310 does not output the noise interval signal S_ND to the timing control circuit 322.

[0061] exist Fig. 9BIn the embodiment, the noise signals 910B and 920B are greater than the threshold, and the noise signal 930B is less than or equal to the threshold. When the noise signals 910B and 920B are greater than the threshold, the display driver circuit 310 outputs the noise interval signal S_ND to the timing control circuit 322. When the noise signal 930B is less than or equal to the threshold, the display driver circuit 310 does not output the noise interval signal S_ND to the timing control circuit 322.

[0062] Fig.10 FIG. 2 is a schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention. Fig.10 Generally speaking, the reference voltage ELVSS is usually changed during the vertical front edge (proch) period 1010 to reduce the impact on display quality. Fig.10 The reference voltage ELVSS is shown to have a larger voltage change 1020 during the vertical front period 1010. When the reference voltage ELVSS has a larger voltage change 1020 during the vertical front period 1010, the display driver circuit 310 outputs a noise interval signal S_ND to the timing control circuit 322. The timing control circuit 322 can decide whether to ignore the sensing data S_D according to the noise interval signal S_ND. In another embodiment, if the voltage change 1020 is not caused by noise but is a voltage adjustment of the reference voltage ELVSS, the timing control circuit 322 can decide not to ignore the sensing data S_D according to the noise interval signal S_ND.

[0063] exist Figure 3 In the embodiment of the present invention, the driver circuit 300 may be implemented in at least two semiconductor chips, wherein the first semiconductor chip includes the timing control circuit 322 and the touch sensing circuit 324, and the second semiconductor chip includes the display driver circuit 310. However, the present invention is not limited thereto.

[0064] Fig.11 FIG. 2 is a block diagram showing a driver circuit according to another embodiment of the present invention. Fig.11 The driver circuit 1100 can be implemented in a single semiconductor chip 1100A. The semiconductor chip 1100A includes a timing control circuit 1122, a touch sensing circuit 1124, and a display driver circuit 1110.

[0065] Fig.12 FIG. 2 is a block diagram showing a driver circuit according to another embodiment of the present invention. Fig.12 In this embodiment, the touch driver circuit 1220 can collect information about the reference voltage ELVSS being interfered by the noise signal according to the noise interval signal S_ND, and perform operations such as filter setting, rescanning or data correction.

[0066] Specifically, the driver circuit 1200 includes a display driver circuit 1210 and a touch driver circuit 1220. The touch driver circuit 1220 includes a timing control circuit 1222, a touch sensing circuit 1224, a storage circuit 1226, and a digital circuit 1228. The digital circuit 1228 is coupled to the timing control circuit 1222, the touch sensing circuit 1224, and the storage circuit 1226. The storage circuit 1226 receives the noise interval signal S_ND and is used to store information DNI that the reference voltage ELVSS is interfered by the noise signal. The digital circuit 1228 can perform operations such as filter setting, rescanning, or data correction according to the information DNI stored in the storage circuit 1226.

[0067] Fig.13 A schematic diagram showing a horizontal synchronization signal and a noise interval signal and count values ​​of the horizontal synchronization signal and the noise interval signal in different touch sensing frames according to an embodiment of the present invention is shown. Fig.14A and Fig. 14B A schematic diagram showing filter settings for different embodiments of the present invention is shown. Figures 12 to 14B , the digital circuit 1228 includes a parameter setting block 282. The parameter setting block 282 can count the number of noise interference intervals T1 of different touch sensing frames according to the noise interval signal S_ND. Then, the parameter setting block 282 adjusts the filtering parameters of the filter circuit 246' according to the counting result. For example, the parameter setting block 282 can adjust the filter parameters according to the counting result. Fig.14A and Fig. 14B The filter function shown.

[0068] Specifically, Fig.13 1 shows the count values ​​of the horizontal synchronization signal Hsync and the noise interval signal S_ND of the Kth frame and the K+1th frame of the touch sensing frame. In the Kth frame and the K+1th frame, the count value (square wave number) Hsync_cnt of the horizontal synchronization signal Hsync is N, and the count value (square wave number) S_ND_cnt of the noise interval signal S_ND is M. K, M, and N are integers greater than 1. In the Kth frame, the filter function of the entire filter circuit 246' is set as follows Fig.14A As shown, for example, F×0.5, where F is the default filter function. Considering that the ratio of the count results of the noise interval signal S_ND and the horizontal synchronization signal Hsync is M / N, in the K+1th frame, the filter function of the entire filter circuit 246' can be set as follows Fig. 14B As shown, for example, it is F×(M / N).

[0069] Fig.15 A schematic diagram showing a noise interval signal and its count value according to an embodiment of the present invention is shown. Fig.12 and Fig.15, the digital circuit 1228 includes an abnormality detection block 284. The abnormality detection block 284 can calculate the time length of a single noise interference interval 1510 of the noise interval signal S_ND, or the cumulative time length of multiple noise interference intervals 1510 and 1520 according to the noise interval signal S_ND. Then, the abnormality detection block 284 outputs the calculation result to the timing control circuit 1222.

[0070] Taking the noise interference interval 1510 as an example, when the calculation result (ie, the time length of the noise interference interval 1510) is greater than the first threshold, it indicates that the noise interference is too much, and the timing control circuit 1222 may choose to ignore the sensing data and perform sensing again.

[0071] Taking the noise interference intervals 1510 and 1520 as an example, when the calculation result (i.e., the accumulated time length of the noise interference intervals 1510 and 1520) is greater than the second threshold, it means that the noise interference is accumulated too much, and the timing control circuit 1222 can also choose to ignore the sensing data and re-sensing. The second threshold is greater than the first threshold.

[0072] Fig.16 A schematic diagram showing noise interval signals and their count values ​​in different touch sensing frames according to an embodiment of the present invention is shown. Fig.12 and Fig.16 The abnormality detection block 284 can calculate the number of noise interference intervals T1 of the noise interval signal S_ND in different touch sensing frames according to the noise interval signal S_ND. Then, the abnormality detection block 284 outputs the calculation result to the timing control circuit 1222.

[0073] For example, in this embodiment, the count values ​​of the noise interval signal S_ND in the Kth frame and the K+1th frame of the touch sensing frame are P and Q, respectively, where P and Q are integers greater than 1. The abnormality detection block 284 calculates the difference between P and Q, and outputs the calculation result to the timing control circuit 1222. When the calculation result (i.e., the difference between P and Q) is greater than the threshold, the timing control circuit 1222 can choose to ignore the sensing data and re-perform sensing.

[0074] Fig.17 FIG. 2 is a schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention. Fig.12 and Fig.17 The digital circuit 1228 includes a data processing block 286. The data processing block 286 can calculate the cumulative time length of multiple noise interference intervals T1 according to the noise interval signal S_ND. Then, the data processing block 286 normalizes the sensing data S_D according to the calculation result to output the normalized sensing data S_D0.

[0075] Specifically, in Fig.17 In the second demodulation period T4, the demodulator circuit 244' uses the voltage value 0 to perform a demodulation operation on the sensing signal S_RX, indicating that the demodulator circuit 244' stops performing a demodulation operation on the sensing signal S_RX during the second demodulation period T4. Since the demodulator circuit 244' does not perform a demodulation operation on the sensing signal S_RX during the second demodulation period T4, in order to reduce the impact of data accumulation during this period on the accuracy of the sensing data S_D, the data processing block 286 normalizes the sensing data S_D.

[0076] For example, the data processing block 286 may normalize the sensing data S_D according to the following formula: S_D0=S_D×[1+α×(T1 / T5)], where α is a normalization parameter, T1 is the cumulative time length of multiple noise interference intervals, and T5 is the total sensing time length.

[0077] about Fig.12 The digital circuit 1228 can be designed by a hardware description language (HDL) or any other digital circuit design method familiar to those skilled in the art, and can be a hardware circuit implemented by a field programmable gate array (FPGA), a complex programmable logic device (CPLD), or an application-specific integrated circuit (ASIC). In addition, referring to the common knowledge in the art, sufficient teaching, suggestions, and implementation instructions can be obtained for the hardware structure of the storage circuit 1226.

[0078] Please refer to Figure 3 Next, it is described that the timing control circuit 322 can determine the timing of the touch driving signal S_TX according to the forbidden interval signal S_PD to drive the sensor 116 to generate the sensing signal S_RX. Alternatively, the timing control circuit 322 can also determine the slew rate of the touch driving signal S_TX according to the forbidden interval signal S_PD.

[0079] Fig.18 FIG. 2 is a schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention. Figure 3 and Fig.18 ,exist Fig.18In FIG. 1 , the signal G_N is a gate signal for driving a gate line in the touch display panel 100, and the signal G_N+1 is a gate signal for driving a gate line next to the gate line in the touch display panel 100. The signal Sout is a waveform of a data line data signal of the touch display panel 100.

[0080] In order to prevent the touch driver circuit 320 from performing a touch sensing operation when the gate signals G_N and G_N+1 are transitioning, thereby causing the touch drive signal S_TX to affect the data signal Sout, the display driver circuit 310 will output a prohibition interval signal S_PD to the timing control circuit 322 when the gate signals G_N and G_N+1 are about to transition. The prohibition interval signal S_PD is used to indicate whether the gate signals G_N and G_N+1 are transitioning. For example, after the enabling period T6 of the prohibition interval signal S_PD, the gate signals G_N and G_N+1 are transitioning, such as rising edges 1810 and 1820. Therefore, the timing control circuit 322 can determine the timing of the touch drive signal S_TX according to the prohibition interval signal S_PD.

[0081] For example, the timing control circuit 322 can set the timing of the touch driving signal S_TX according to the disabled interval signal S_PD to enter the enable period T2 after the enable period T6 of the disabled interval signal S_PD, thereby driving the sensor 116 to generate the sensing signal S_RX. In this way, the interference of the touch driving signal S_TX on the data signal Sout during the gate signal transition can be reduced, thereby improving the accuracy of the data signal Sout.

[0082] Fig.19 FIG. 2 is a schematic diagram showing waveforms of various signals in a driver circuit according to another embodiment of the present invention. Figure 3 and Fig.19 ,exist Fig.19 In order to prevent the touch driver circuit 320 from performing a touch sensing operation when the gate signals G_N and G_N+1 are transitioning, and causing the touch drive signal S_TX to affect the data signal Sout, the display driver circuit 310 will output a prohibition interval signal S_PD to the timing control circuit 322 when the gate signals G_N and G_N+1 are about to transition. The prohibition interval signal S_PD is used to indicate whether the gate signals G_N and G_N+1 are transitioning. For example, after the enabling period T6 of the prohibition interval signal S_PD, the gate signals G_N and G_N+1 are transitioning, such as the rising edges 1810 and 1820.

[0083] Therefore, the timing control circuit 322 can determine the slew rate of the touch driving signal S_TX according to the forbidden interval signal S_PD, so as to reduce the interference of the touch driving signal S_TX on the data signal Sout when the gate signal transitions, thereby improving the accuracy of the data signal Sout.

[0084] In summary, in the embodiment of the present invention, the timing control circuit can determine the timing of the touch drive signal according to the noise interval signal to reduce the interference of the sensing signal by the noise signal. The timing control circuit can also determine the timing and slew rate of the touch drive signal according to the forbidden interval signal to reduce the interference of the data signal by the touch drive signal when the gate signal transitions. Therefore, through the driving method of the embodiment of the present invention, the driver circuit can solve the problem of affecting the sensing data or display data due to parasitic capacitance interference.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A driver circuit for driving a touch display panel, wherein the touch display panel includes a sensor, and the driver circuit includes: A timing control circuit, configured to output a touch drive signal to the sensor, wherein the sensor generates a sensing signal according to the touch drive signal; as well as A touch sensing circuit is coupled to the timing control circuit and is used to receive the sensing signal. The timing control circuit determines the timing of the touch driving signal according to the noise interval signal to drive the sensor to generate the sensing signal. 2 . The driver circuit according to claim 1 , wherein the noise interval signal is used to indicate that the reference voltage is interfered by the noise signal in a noise interference interval, and the reference voltage is a reference voltage used to drive display pixels of the touch display panel.

3. The driver circuit according to claim 1 , wherein the touch driving signal drives the sensor to generate the sensing signal during an enable period, and the timing control circuit sets the enable period of the touch driving signal to not overlap with a noise interference period of the noise period signal in time according to the noise period signal.

4. The driver circuit according to claim 1 , wherein the touch driving signal drives the sensor to generate the sensing signal during an enable period, and the timing control circuit sets the enable period of the touch driving signal to at least partially overlap with a noise interference period of the noise period signal according to the noise period signal.

5. The driver circuit according to claim 1, The touch sensing circuit receives a demodulation signal from the timing control circuit to perform a demodulation operation on the sensing signal to generate sensing data. The demodulated signal has a first demodulation period, and the touch sensing circuit performs the demodulation operation on the sensing signal during the first demodulation period. 6 . The driver circuit according to claim 5 , wherein the timing control circuit sets the first demodulation period of the demodulation signal to at least partially overlap with the enable period of the touch driving signal in time according to the noise interval signal. 7 . The driver circuit according to claim 6 , wherein the timing control circuit sets the first demodulation period of the demodulation signal to at least partially overlap with a noise interference period of the noise period signal in time according to the noise period signal.

8. The driver circuit according to claim 6, wherein the timing control circuit sets the first demodulation period of the demodulation signal according to the noise interval signal so as not to overlap with a noise interference interval of the noise interval signal in terms of time. 9 . The driver circuit according to claim 5 , wherein the timing control circuit sets the first demodulation period of the demodulation signal to overlap with the enable period of the touch driving signal in time according to the noise interval signal. 10 . The driver circuit according to claim 9 , wherein the timing control circuit sets the first demodulation period of the demodulation signal according to the noise interval signal so as not to overlap with a noise interference interval of the noise interval signal in terms of time. 11 . The driver circuit according to claim 5 , wherein the demodulated signal further has a second demodulation period, and the touch sensing circuit stops performing the demodulation operation on the sensing signal during the second demodulation period. 12 . The driver circuit according to claim 11 , wherein the timing control circuit sets the second demodulation period of the demodulation signal to at least partially overlap with the enable period of the touch driving signal in time according to the noise interval signal. 13 . The driver circuit according to claim 12 , wherein the timing control circuit sets the second demodulation period of the demodulation signal to at least partially overlap with a noise interference period of the noise period signal in terms of time according to the noise period signal. 14 . The driver circuit according to claim 12 , wherein the timing control circuit sets the second demodulation period of the demodulation signal to overlap with a noise interference period of the noise period signal in terms of time according to the noise period signal. 15 . The driver circuit according to claim 11 , wherein signal levels of the demodulated signal during the first demodulation period and the second demodulation period are different. 16 . The driver circuit according to claim 5 , wherein the timing control circuit determines a duty cycle of the touch driving signal according to the noise interval signal. 17 . The driver circuit according to claim 5 , wherein the timing control circuit determines a duty cycle of the demodulated signal according to the noise interval signal.

18. The driver circuit according to claim 2, further comprising: a display driver circuit coupled to the timing control circuit and configured to output the noise interval signal to the timing control circuit, The touch sensing circuit receives a demodulation signal from the timing control circuit to perform a demodulation operation on the sensing signal to generate sensing data.

19. The driver circuit according to claim 18, wherein the display driver circuit outputs the noise interval signal to the timing control circuit at a fixed frequency. 20 . The driver circuit according to claim 18 , wherein when the noise signal is greater than a threshold, the display driver circuit outputs the noise interval signal to the timing control circuit.

21. The driver circuit of claim 18, wherein the reference voltage has a voltage variation during a vertical front porch, and the display driver circuit outputs the noise interval signal to the timing control circuit during the vertical front porch. 22 . The driver circuit according to claim 21 , wherein the timing control circuit determines whether to ignore the sensing data according to the noise interval signal. 23 . The driver circuit according to claim 18 , wherein the driver circuit is implemented in a single semiconductor chip, and the single semiconductor chip includes the timing control circuit, the touch sensing circuit, and the display driver circuit.

24. The driver circuit according to claim 18, wherein the driver circuit is implemented in at least two semiconductor chips, wherein a first semiconductor chip of the at least two semiconductor chips includes the timing control circuit and the touch sensing circuit, and a second semiconductor chip includes the display driver circuit. 25 . The driver circuit according to claim 18 , wherein the touch sensing circuit comprises a filter circuit configured to perform a filtering operation on the demodulated sensing signal to generate the sensing data.

26. The driver circuit according to claim 25, further comprising: A digital circuit is coupled to the timing control circuit, the touch sensing circuit and the display driver circuit, and the digital circuit is used to: The number of noise interference intervals of the noise interval signal of different touch sensing frames is counted according to the noise interval signal, and the filtering parameters of the filter circuit are adjusted according to the counting result.

27. The driver circuit of claim 18, further comprising: A digital circuit is coupled to the timing control circuit, the touch sensing circuit and the display driver circuit, and the digital circuit is used to: calculating the duration of a single noise interference interval of the noise interval signal according to the noise interval signal, and outputting the calculation result to the timing control circuit, When the calculation result is greater than a threshold, the timing control circuit ignores the sensing data and performs sensing again.

28. The driver circuit of claim 18, further comprising: A digital circuit is coupled to the timing control circuit, the touch sensing circuit and the display driver circuit, and the digital circuit is used to: calculating the cumulative time length of the noise interference interval of the noise interval signal for multiple times according to the noise interval signal, and outputting the calculation result to the timing control circuit, When the calculation result is greater than a threshold, the timing control circuit ignores the sensing data and performs sensing again.

29. The driver circuit of claim 18, further comprising: A digital circuit is coupled to the timing control circuit, the touch sensing circuit and the display driver circuit, and the digital circuit is used to: calculating the number of noise interference intervals of the noise interval signal of different touch sensing frames according to the noise interval signal, and outputting the calculation result to the timing control circuit, When the calculation result is greater than a threshold, the timing control circuit ignores the sensing data and performs sensing again.

30. The driver circuit of claim 18, further comprising: A digital circuit is coupled to the timing control circuit, the touch sensing circuit and the display driver circuit, and the digital circuit is used to: The accumulated time lengths of multiple noise interference intervals of the noise interval signal are calculated according to the noise interval signal, and the sensing data is normalized according to the calculation result.

Images