TW202340922A - Touch sensing signal readout method, touch display device and information processing device which is a method for decreasing the circuit area occupied by the compensation capacitors - Google Patents

Abstract

The present invention mainly discloses a touch sensing signal readout method for execution by a control chip, such as a touch chip or a TDDI chip. In particular, the method of the present invention is to reset and charge the compensation capacitor multiple times during a capacitance integration period of a detection cycle, so that the control chip can still effectively compensate for the parasitic capacitance derived from a touch sensor of a touch sensing unit while reducing the capacitance value of its internal compensation capacitor. Therefore, when the touch sensing signal readout method of the present invention is applied, the circuit area occupied by the compensation capacitors inside the touch chip and/or the TDDI chip can be greatly reduced, thereby also significantly reducing the chip manufacturing cost.

Description

Touch sensing signal reading method, touch display device and information processing device

The present invention relates to the field of touch technology, and in particular, to a touch sensing signal reading method that helps reduce compensation capacitance.

It is known that the use of display driver and touch integrated (Touch and Display Driver Integrated, TDDI) single chips in mobile electronic devices with small and medium-sized touch display panels (such as smartphones or tablet computers) has become a mainstream trend. At the same time, as mobile electronic devices become thinner and thinner, the traditional lamination structure of touch panels (diaphragms) and display panels is no longer used, but is replaced by in-cell touch display panels. . In an in-cell touch display panel, each common electrode (V _COM electrode) is divided into a plurality of micro-metal plates to serve as a plurality of touch sensors. Then, a plurality of touch sensors are coupled to a plurality of gate lines and a plurality of source lines, thus forming an embedded touch sensing unit. Electronic engineers in the relevant technical field know that in the in-cell touch panel, each of the micro-metal plates (ie, touch sensors) has a large parasitic capacitance. At the same time, the gate lines and source lines Each also has parasitic capacitance. Therefore, the existing technology will add a parasitic capacitance compensation solution in a touch chip or a display driver and touch integrated (TDDI) chip.

Figure 1 is a block diagram of a conventional touch device. As shown in Figure 1, the touch device 1a includes: an (embedded) touch sensing unit 10a, a driving circuit 11a, a sensing signal readout circuit 12a, and a control unit 13a, wherein the touch The sensing unit 10a includes a plurality of touch sensors 1Sa, a plurality of gate lines 10Ga, and a plurality of source lines 10Sa. Furthermore, the sensing signal readout circuit 12a includes a plurality of charge amplification circuits.

FIG. 2 is a circuit topology diagram of a conventional charge amplification circuit, and FIG. 3 is a working timing diagram of multiple control signals. As shown in FIG. 2 , the charge amplification circuit 121a includes: an operational amplifier 1211a, an integrating capacitor CFa, a first switch SW1a, a second switch SW2a, and a capacitance compensation unit 1212a. The capacitance compensation unit 1212a includes: a third switch SW3a, a fourth switch SW4a, a fifth switch SW5a and a compensation capacitor CENa. It is worth noting that FIG. 2 also shows the first parasitic capacitance CP1a and the second parasitic capacitance CP2a. The first parasitic capacitance CP1a represents the touch sensor 1Sa (ie, the micro metal plate divided from the common electrode) and the gate electrode. The parasitic capacitance of the line 10Ga and the source line 10Sa, and the second parasitic capacitance CP2a represents the parasitic capacitance of the touch sensor 1Sa to ground.

When there is a finger touch, the capacitance value sensed by the charge amplification circuit 121a from the touch sensor 1Sa is ΔC, which is represented by the capacitance CDLa in the circuit of FIG. 2 . In other words, when there is a finger touch, the capacitance value of the touch sensor 1Sa becomes larger, so that the capacitance value of the capacitor CDLa becomes larger, and the output voltage Vout of the charge amplifier circuit 121a also becomes larger. According to the principle of circuit theory, the change in output voltage can be calculated using the following formula (1): ……………………………(1)

During the process of reading the capacitance change of the touch sensor 1Sa, as shown in Figures 2 and 3, an excitation signal V _STIM is transmitted to the positive input terminal of the operational amplifier 1211a and the first parasitic capacitance CP1a, thereby This method realizes compensation for the parasitic capacitance of the touch sensor 1Sa, the gate line 10Ga, and the source line 10Sa. At the same time, the capacitance compensation unit 1212a is enabled to compensate for the parasitic capacitance of the touch sensor 1Sa to ground. When the capacitance compensation unit 1212a works, it first charges the compensation capacitor CENa, and then discharges the compensation capacitor CENa to the touch sensor 1Sa, thereby eliminating the parasitic capacitance of the touch sensor 1Sa to ground.

Currently, for the multiple charge amplification circuits integrated in the sensing signal readout circuit 12a in the touch chip and/or the TDDI chip, the capacitance value of the compensation capacitor CENa carried by each charge amplification circuit is about 1 to 10 pF. Dozens of charge amplification circuits will be integrated inside the chip, resulting in dozens of compensation capacitors CENa occupying a considerable area of the chip, resulting in high manufacturing costs for the chip. Therefore, it is necessary to improve the sensing signal readout circuit 12a in the touch chip and/or the TDDI chip so that it can still maintain the same performance while reducing the capacitance value of the compensation capacitor CENa (ie, reducing the capacitance value). Capacitance compensation function.

It can be seen from the above description that a new touch sensing signal reading method is urgently needed in this field.

The main purpose of the present invention is to provide a touch sensing signal reading method for execution by a control chip, such as a touch chip or a TDDI chip, so that the control chip can still effectively reduce the capacitance value of the compensation capacitor. Compensates for parasitic capacitance derived from touch sensors. Therefore, when the touch sensing signal readout method of the present invention is applied, the circuit area occupied by the compensation capacitor inside the touch chip and/or the TDDI chip can be greatly reduced, thereby significantly reducing the chip manufacturing cost.

In order to achieve the above object, the present invention proposes an embodiment of the touch sensing signal reading method, which is executed by a control chip and is used to read at least one touch sensing unit from a plurality of touch sensors. Touch sensing signal; wherein, the control chip has a sensing signal readout circuit, the sensing signal readout circuit includes a plurality of charge amplification circuits and a plurality of capacitance compensation units respectively coupled to the plurality of charge amplification circuits; The touch sensing signal reading method includes the following steps: In a first time interval, an integrating capacitor of the charge amplification circuit is reset, and a compensation capacitor of the capacitance compensation unit is reset; In a second time interval, the charge amplification circuit is controlled to read a touch sensing signal from the touch sensor to integrally charge the integrating capacitor, and at the same time the capacitance compensation unit is enabled to charge the charge amplification circuit Provide a capacitor compensation; Within the second time interval, the resetting and integral charging of the compensation capacitor are repeated multiple times; and In a third time interval, the charge amplifier circuit is controlled to output a sensing voltage.

In one embodiment, the charge amplification circuit includes: An operational amplifier has a positive input terminal, a negative input terminal and an output terminal, and the two ends of the integrating capacitor are coupled to the negative input terminal and the output terminal respectively; A first switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the negative input terminal, the second terminal is coupled to the output terminal, and the control terminal is coupled to a first control signals; and A second switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the touch sensor, the second terminal is coupled to the negative input terminal, and the control terminal is coupled to a second control signal; and A reference capacitor, two ends of which are coupled to the touch sensor and a ground terminal respectively; Wherein, within the first time interval, the first control signal has a high level and the second control signal has a low level.

In one embodiment, the capacitance compensation unit includes: A third switch has a first end, a second end and a control end, the first end is coupled to a bias voltage, and the control end is coupled to a third control signal; wherein the compensation capacitor has a first end and a second end, the second end of the third switch is coupled to the first end of the compensation capacitor, and the second end of the compensation capacitor is coupled to a compensation signal; A fourth switch has a first end, a second end and a control end, the first end is coupled to the first end of the compensation capacitor, the second end is coupled to the ground end, and the control end coupled to a fourth control signal; and A fifth switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the first terminal of the compensation capacitor, and the second terminal is coupled to the first terminal of the second switch. terminal, and the control terminal is coupled to a fifth control signal; Wherein, within the first time interval, the third control signal controls the switching state of the third switch, the fourth control signal controls the switching state of the fourth switch, and the fifth control signal controls the switching state of the third switch. state, and the compensation signal has a voltage level.

In an embodiment, within the second time interval, the first control signal controls the switching state of the first switch, the second control signal controls the switching state of the second switch, and the third control signal controls the switching state of the second switch. The switching state of the three switches, the fourth control signal controls the switching state of the fourth switch, and the fifth control signal controls the switching state of the fifth switch, while changing the voltage level of the compensation signal multiple times, thereby Implement the reset and integral charging of the compensation capacitor multiple times.

The present invention also provides a touch display device, which includes a control circuit and a touch display panel, wherein the touch display panel includes a display panel and a touch sensing unit having a plurality of touch sensors. The control circuit The chip has a sensing signal readout circuit, which includes a plurality of charge amplification circuits and a plurality of capacitance compensation units respectively coupled to the plurality of charge amplification circuits; it is characterized in that the control circuit executes a A touch sensing signal reading method is used to read at least one touch sensing signal from the touch sensing unit; the touch sensing signal reading method includes the following steps: In a first time interval, an integrating capacitor of the charge amplification circuit is reset, and a compensation capacitor of the capacitance compensation unit is reset; In a second time interval, the charge amplification circuit is controlled to read a touch sensing signal from the touch sensor to integrally charge the integrating capacitor, and at the same time the capacitance compensation unit is enabled to charge the charge amplification circuit Provide a capacitor compensation; Within the second time interval, the resetting and integral charging of the compensation capacitor are repeated multiple times; and In a third time interval, the charge amplifier circuit is controlled to output a sensing voltage.

In one embodiment, the charge amplification circuit includes: An operational amplifier has a positive input terminal, a negative input terminal and an output terminal, and the two ends of the integrating capacitor are coupled to the negative input terminal and the output terminal respectively; A first switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the negative input terminal, the second terminal is coupled to the output terminal, and the control terminal is coupled to a first control signals; and A second switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the touch sensor, the second terminal is coupled to the negative input terminal, and the control terminal is coupled to a second control signal; and A reference capacitor, two ends of which are coupled to the touch sensor and a ground terminal respectively; Wherein, within the first time interval, the first control signal has a high level and the second control signal has a low level.

In one embodiment, the capacitance compensation unit includes: A third switch has a first end, a second end and a control end, the first end is coupled to a bias voltage, and the control end is coupled to a third control signal; wherein the compensation capacitor has a first end and a second end, the second end of the third switch is coupled to the first end of the compensation capacitor, and the second end of the compensation capacitor is coupled to a compensation signal; A fourth switch has a first end, a second end and a control end, the first end is coupled to the first end of the compensation capacitor, the second end is coupled to the ground end, and the control end coupled to a fourth control signal; and A fifth switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the first terminal of the compensation capacitor, and the second terminal is coupled to the first terminal of the second switch. terminal, and the control terminal is coupled to a fifth control signal; Wherein, within the first time interval, the third control signal controls the switching state of the third switch, the fourth control signal controls the switching state of the fourth switch, and the fifth control signal controls the switching state of the third switch. state, and the compensation signal has a voltage level.

In an embodiment, within the second time interval, the first control signal controls the switching state of the first switch, the second control signal controls the switching state of the second switch, and the third control signal controls the switching state of the second switch. The switching state of the three switches, the fourth control signal controls the switching state of the fourth switch, and the fifth control signal controls the switching state of the fifth switch, while changing the voltage level of the compensation signal multiple times, thereby Implement the reset and integral charging of the compensation capacitor multiple times.

The present invention also provides an information processing device, which has the touch display device of the present invention as described above.

In one embodiment, the information processing device is one selected from the group consisting of a smart phone, a smart watch, a tablet computer, a notebook computer, an all-in-one computer, a smart display device, and an access control device. electronic devices.

In order to enable the review committee to further understand the structure, characteristics, purpose, and advantages of the present invention, drawings and detailed descriptions of preferred embodiments are attached below.

FIG. 4 is a front view of an information processing device applying a touch sensing signal reading method of the present invention. As shown in FIG. 4 , the information processing device 1 is a full-screen smart phone, and it has a control chip 1C and a touch sensing unit 10 . The present invention provides a touch sensing signal reading method for execution by the control chip 1C, such as a touch chip or a TDDI chip, so that the control chip 1C can still effectively sense the signal while reducing the capacitance value of the compensation capacitor. Parasitic capacitances derived from a plurality of touch sensors included in the touch sensing unit are compensated. FIG. 5 is a block diagram of the touch sensing unit 10 and the control chip 1C shown in FIG. 4 . As shown in FIG. 5 , the touch sensing unit 10 includes: a plurality of touch sensors 1S, a plurality of gate lines 10G, and a plurality of source lines 10S. Moreover, the control chip 1C includes: a driving circuit 11, a sensing signal readout circuit 12, and a control unit 13, wherein the sensing signal readout circuit 12 includes a plurality of charge amplification circuits and a plurality of charge amplification circuits. A plurality of capacitance compensation units are respectively coupled to the circuit.

Figure 6 is a circuit topology diagram of a charge amplification circuit and a capacitance compensation unit. To explain in more detail, the charge amplification circuit 121 includes: an operational amplifier 12OP, an integrating capacitor CF, a first switch S1, a second switch S2, and a reference capacitor. FIG. 6 also shows a first parasitic capacitance CP1 and a second parasitic capacitance CP2. The first parasitic capacitance CP1 represents the parasitic capacitance of the touch sensor 1S, the gate line 10G and the source line 10S, and the second parasitic capacitance CP2 represents the parasitic capacitance of touch sensor 1S to ground. It is worth noting that when there is a finger touch, there is a capacitance difference ΔC between the reference capacitance and the sensing capacitance derived from the touch sensor 1S due to the finger touch. In the circuit of Figure 6, the capacitance CDL is express.

As shown in FIG. 6 , the operational amplifier 12OP has a positive input terminal, a negative input terminal and an output terminal, and the two ends of the integrating capacitor CF are coupled to the negative input terminal and the output terminal respectively. On the other hand, the first switch SW1 has a first terminal, a second terminal and a control terminal. The first terminal is coupled to the negative input terminal, the second terminal is coupled to the output terminal, and the control terminal is coupled to the negative input terminal. Receive a first control signal S1. Moreover, the second switch SW2 has a first terminal, a second terminal and a control terminal. The first terminal is coupled to the touch sensor 1S, the second terminal is coupled to the negative input terminal, and the control terminal The terminal is coupled to a second control signal S2.

To explain in more detail, the capacitance compensation unit 122 includes: a third switch S3, a fourth switch S4, a fifth switch S5, and a compensation capacitor C _NE , wherein the third switch SW3 has a first terminal. , a second terminal and a control terminal, the first terminal is coupled to a bias voltage V _DDA , and the control terminal is coupled to a third control signal S3. To explain in more detail, the compensation capacitor C _NE has a first end (upper electrode plate) and a second end (lower electrode plate). The second end of the third switch SW3 is coupled to the compensation capacitor C _NE. The first end (upper electrode plate) of the compensation capacitor C _NE is coupled to a compensation signal SC. As shown in Figure 6, the fourth switch SW4 has a first terminal, a second terminal and a control terminal. The first terminal is coupled to the first terminal of the compensation capacitor C _NE , and the second terminal is coupled to The ground terminal and the control terminal are coupled to a fourth control signal S4. Furthermore, the fifth switch SW5 has a first terminal, a second terminal and a control terminal. The first terminal is coupled to the first terminal of the compensation capacitor C _NE , and the second terminal is coupled to the second terminal. The first terminal of the switch SW2 and the control terminal are coupled to a fifth control signal S5.

Figure 7 is a working timing diagram of multiple control signals. Moreover, FIG. 8 is a method flow chart of a touch sensing signal reading method according to the present invention. The touch sensing signal reading method of the present invention first performs step S1: in a first time interval T1, reset an integrating capacitor CF of the charge amplification circuit 121, and at the same time reset the capacitance compensation unit 122. It has a compensation capacitor C _NE to reset. As shown in FIGS. 6 and 7 , in the first time interval T1 , the first control signal S1 has a high level and the second control signal S2 has a low level, so that the integrating capacitor CF of the charge amplification circuit 121 Discharge the output of operational amplifier 12OP, thereby resetting it. At the same time, in the first time interval T1, the third control signal S3 has a high level, the fourth control signal S4 has a low level, the fifth control signal S5 has a low level, and the compensation signal SC has a low level. level, so that the bias voltage V _DDA pushes the compensation capacitor C _NE to discharge to its lower electrode plate, thereby resetting. In other words, within the first time interval T1, the charge amplification circuit 121 and the capacitance compensation unit 122 are reset as a whole.

After the overall reset of the circuit is completed, the method flow then executes step S2: within a second time interval T2, control the charge amplification circuit 121 to read a touch sensing signal from the touch sensor 1S to thereby The integrating capacitor CF is charged, and at the same time, the capacitance compensation unit 122 is enabled to provide a capacitance compensation to the charge amplification circuit 121 . In the process of reading the touch sensing signal (ie, the capacitance change) of the touch sensor 1S, as shown in FIGS. 6 and 7 , an excitation signal V _STIM is transmitted to the positive input terminal of the operational amplifier 12OP and In this way, the lower electrode plate of the first parasitic capacitance CP1 realizes compensation for the parasitic capacitance of the touch sensor 1S, the gate line 10G, and the source line 10S. At the same time, the compensation capacitor CEN provides capacitance compensation to the negative input terminal of the operational amplifier 12OP to compensate for the parasitic capacitance of the touch sensor 1S to ground.

To explain in more detail, during the second time interval T2, the first control signal S1 has a low level and the second control signal S2 has a high level, so that the touch sensor 1S obtains the touch sensing signal ( That is, the capacitance change amount) is input to the negative output terminal of the operational amplifier 12OP through the second switch S2. It is worth noting that, as shown in Figures 7 and 6, in the first stage of the second time interval T2, both the third control signal S3 and the third control signal S4 have a low level, and the third control signal S5 has a high level, and the compensation signal S2 also has a high level (V _DDA ), so that the lower electrode plate of the compensation capacitor C _NE is coupled to a bias voltage V _DDA , and the upper electrode plate of the compensation capacitor C _NE The negative input terminal of the operational amplifier 12OP is coupled through the fifth switch SW5. At this time, the compensation capacitor C _NE is charged by the bias voltage V _DDA , and provides capacitance compensation to the negative input terminal of the operational amplifier 12OP.

Continuing, the method of the present invention then executes step S3: within the second time interval T2, the compensation capacitor C _NE is repeatedly reset and charged a plurality of times. In order to allow the compensation capacitor C _NE to be repeatedly reset and charged multiple times in the second time interval T2, as shown in Figures 6 and 7, the present invention is designed so that the third control signal S3 has the function of conducting in stages. The plurality of pulses of the third switch SW3 causes the fifth control signal S5 to have a plurality of pulses for turning on the fifth switch SW5 in stages, so that the compensation signal SC also has a plurality of pulses.

For example, in the second stage of the second time interval T2, the third control signal S3 flips from a low level to a high level, the fourth control signal S4 remains at a low level, and the fifth control signal S5 switches from a low level to a high level. The high level flips to a low level, and the compensation signal SC also flips from the high level to the low level, so that the lower electrode plate of the compensation capacitor C _NE is coupled to a ground voltage, and the upper electrode of the compensation capacitor C _NE The plate is coupled to the bias voltage V _DDA through the third switch SW3, so that the bias voltage V _DDA pushes the compensation capacitor C _NE to discharge to its lower electrode plate, thereby resetting.

Then, in the third stage of the second time interval T2, as shown in Figures 6 and 7, the third control signal S3 flips from the high level to the low level, and the fourth control signal S4 also maintains the low level. bit, and both the fifth control signal S5 and the compensation signal SC flip from a low level to a high level, so that the lower electrode plate of the compensation capacitor C _NE is coupled to a bias voltage V _DDA , and the compensation capacitor C _NE The upper electrode plate is coupled to the negative input terminal of the operational amplifier 12OP through the fifth switch SW5. At this time, the compensation capacitor C _NE is charged by the bias voltage V _DDA , and provides capacitance compensation to the negative input terminal of the operational amplifier 12OP.

In the fourth stage of the second time interval T2, the third control signal S3 flips from a low level to a high level, the fourth control signal S4 remains at a low level, and the fifth control signal S5 flips from a high level. to a low level, and the compensation signal SC also flips from a high level to a low level, so that the lower electrode plate of the compensation capacitor C _NE is coupled to a ground voltage, and the upper electrode plate of the compensation capacitor C _NE passes through the third The three switches SW3 are coupled to the bias voltage V _DDA , so that the bias voltage V _DDA pushes the compensation capacitor C _NE to discharge to its lower electrode plate, thereby resetting.

To sum up, during the second time interval T2, the charge amplification circuit 121 detects a touch sensing signal from the touch sensor 1S, and uses the integrated capacitance of the touch sensing signal to CF is charged. In contrast, the capacitance compensation unit 122 repeatedly performs integration (first phase), reset (second phase), integration (third phase), and reset (fourth phase) within the second time interval T2. , ‧‧‧, reset (Nth stage). Finally, the method flow executes step S3: controlling the charge amplifier circuit 121 to output a sensing voltage within a third time interval T3. As shown in Figures 6 and 7, in the third time interval T3, the first control signal S1 has a high level, the second control signal S2 has a low level, and the third control signal S3 has a low level. The fourth control signal S4 has a high level, the fifth control signal S5 has a low level, and the compensation signal has a high level.

It should be supplemented that, as shown in FIG. 7 , the excitation signal VSTIM is at a low level during the first time interval T1, and flips to a high level during the second time interval T2. Therefore, V _{STIM_L} and V _{STIM_H} can represent the low-level voltage and the high-level voltage of the excitation signal. Therefore, during the first time interval T1 (ie, the entire circuit is reset), the charge at the negative input terminal of the operational amplifier 12OP can be calculated using the following equation (2): ……………………………(2)

Further, in the first stage of the second time interval T2 (the compensation capacitor C _NE and the integrating capacitor CF are charged simultaneously), the charge at the negative input terminal of the operational amplifier 12OP can be calculated using the following formula (3): ………(3)

Further, in the second stage of the second time interval T2 (the compensation capacitor C _NE is reset), the charge on the upper electrode plate of the compensation capacitor C _NE can be calculated using the following formula (4): ……………………(4)

Further, in the third stage of the second time interval T2 (integration of the compensation capacitor C _NE ), the charge of the upper electrode plate of the compensation capacitor C _NE can be calculated using the following formula (5): ……………………(4)

Therefore, after the compensation capacitor C _NE completes one cycle of reset and integration, the additional charge obtained by the upper electrode plate of the compensation capacitor C _NE can be calculated using the following formula (6): ……………………(6)

By analogy, the compensation capacitor C _NE completes (N-2)/2 cycles ( After resetting and integrating cycle), the additional charge obtained by the upper electrode plate of the compensation capacitor C _NE can be calculated using the following formula (7): ……………………(7)

Assume that the required compensation target value is ( + )/2, then based on the above equations (2), (3) and (7), the following equation (8) can be derived: ……………………………(8)

Further, let , then the above formula (8) can be simplified into the following formula (9): ………………………(9)

Therefore, it can be clearly seen from the above equation (9) that the greater the value of N, the greater the capacitance compensation contributed by the compensation capacitor C _NE . In other words, step S3 of the method of the present invention is to repeatedly perform the reset and integration charging of the compensation capacitor C _NE multiple times within the second time interval, and the compensation capacitor C _NE completes the reset and integration cycle. The greater the number of cycles, the greater the capacitance compensation provided by the compensation capacitor C _NE to the charge amplification circuit 121 in the second time interval T2. Furthermore, according to charge conservation and equation (2) is equal to equation (3), the following equation (10) can be obtained: ………………………(10)

Comparing the above equation (9) and equation (10), it can be seen that even if the area of the compensation capacitor inside the control chip 1C is reduced to only 2/N of the original, when the method of the present invention is applied, the control chip 1C The parasitic capacitance derived from the touch sensor 1S can still be effectively compensated. Therefore, when the touch sensing signal readout method of the present invention is applied, the circuit area occupied by the compensation capacitor inside the touch chip and/or the TDDI chip can be greatly reduced, thereby significantly reducing the chip manufacturing cost.

It should be added that in a feasible embodiment, the excitation signal V _STIM can also be designed to be a high level in the first time interval T1 and flip to a low level in the second time interval T2. In this application example, when performing step S1, the excitation signal V _STIM has a high level, the first control signal S1 has a high level, the third control signal S3 has a low level, and the fourth control signal S4 has a high level. level, the fifth control signal S5 has a low level, and the compensation signal SC has a high level, so that the upper electrode plate of the compensation capacitor C _NE is grounded through the fourth switch SW4, and its lower electrode plate is coupled to the bias voltage V _DDA .

When performing step S2, in the first stage (integration) of the second time interval T2, the excitation signal V _STIM flips from a high level to a low level, the first control signal S1 has a low level, and the second control signal S2 and the fifth control signal S5 both have a high level, and the third control signal S3, the fourth control signal S4 and the compensation signal SC all have a low level, so that the lower electrode plate of the compensation capacitor C _NE is coupled to a ground voltage, And the upper electrode plate of the compensation capacitor C _NE is coupled to the negative input terminal of the operational amplifier 12OP through the fifth switch SW5. At this time, the compensation capacitor C _NE provides capacitance compensation to the negative input terminal of the operational amplifier 12OP.

When performing step S3, in the second phase (C _NE reset) of the second time interval T2, the fifth control signal S5 has a low level, the third control signal S3 maintains a low level, and the fourth control signal S4 and The compensation signal SC flips from a low level to a high level, so that the lower electrode plate of the compensation capacitor C _NE is coupled to a bias voltage V _DDA , and the connection between the upper electrode plate of the compensation capacitor C _NE and the operational amplifier 12OP The fifth switch SW2 is turned off, so that the compensation capacitor C _NE is reset.

Further, in the third stage (C _NE integration) of the second time interval T2, the fourth control signal S4 flips from the high level to the low level, and the third control signal S3 also maintains the low level. The fifth control signal S5 flips from a low level to a high level, and the compensation signal SC flips from a high level to a low level, so that the lower electrode plate of the compensation capacitor C _NE is coupled to a ground voltage, and the compensation The upper electrode plate of the capacitor C _NE is coupled to the negative input terminal of the operational amplifier 12OP through the fifth switch SW5. At this time, the compensation capacitor C _NE provides capacitance compensation to the negative input terminal of the operational amplifier 12OP.

Finally, in the second time interval T2, the resetting and integration of the compensation capacitor C _NE are repeatedly performed multiple times, so that the control chip 1C can effectively compensate the parasitic capacitance derived from the touch sensor 1S.

In this way, the above has completely and clearly explained a touch sensing signal reading method of the present invention; and from the above, it can be known that the present invention has the following advantages:

(1) The present invention discloses a touch sensing signal reading method for execution by a control chip, such as a touch chip or a TDDI chip, so that the control chip can still effectively sense the signal while reducing the capacitance value of the compensation capacitor. To compensate for the parasitic capacitance derived from the touch sensor. Therefore, when the touch sensing signal readout method of the present invention is applied, the circuit area occupied by the compensation capacitor inside the touch chip and/or the TDDI chip can be greatly reduced, thereby significantly reducing the chip manufacturing cost.

(2) The present invention also provides a touch display device, which includes a control circuit and a touch display panel, wherein the touch display panel includes a display panel and a touch sensing unit having a plurality of touch sensors. , the control chip has a sensing signal readout circuit, the sensing signal readout circuit includes a plurality of charge amplification circuits and a plurality of capacitance compensation units respectively coupled to the plurality of charge amplification circuits; characterized in that, the control chip The circuit executes the touch sensing signal reading method of the present invention as described above to read at least one touch sensing signal from the touch sensing unit.

(3) The present invention also provides an information processing device, which has the touch display device of the present invention as described above. Moreover, the information processing device is an electronic device selected from the group consisting of smart phones, smart watches, tablet computers, notebook computers, all-in-one computers, smart display devices, and access control devices.

It must be emphasized that the foregoing disclosed in this case are preferred embodiments. Any partial changes or modifications derived from the technical ideas of this case and easily inferred by those familiar with the art do not deviate from the patent of this case. category of rights.

To sum up, regardless of the purpose, means and effects of this case, it shows that it is completely different from the conventional technology, and that the invention is practical first, and indeed meets the patent requirements for inventions. I sincerely ask the review committee to take a clear look and grant the patent as soon as possible for your benefit. Society is a prayer for the Supreme Being.

1a:Touch device 10a:Touch sensing unit 10Ga: Gate line 10Sa: Source line 1Sa: Touch sensor 11a: Drive circuit 12a: Sensing signal readout circuit 121a: Charge amplification circuit 1211a: Operational amplifier 1212a: Capacitance compensation unit 13a:Control unit SW1a: first switch SW2a: Second switch SW3a: The third switch SW4a: The fourth switch SW5a: fifth switch CFa: integrating capacitor CENa: compensation capacitor CP1a: first parasitic capacitance CP2a: second parasitic capacitance CDLa: capacitor 1:Information processing device 1C: Control chip 10:Touch sensing unit 10G: Gate line 10S: Source line 1S:Touch sensor 11: Drive circuit 12: Sensing signal readout circuit 121: Charge amplifier circuit 122: Capacitor compensation unit 12OP: Operational amplifier 13:Control unit SW1: first switch SW2: Second switch SW3: The third switch SW4: The fourth switch SW5: The fifth switch CF: integrating capacitor CEN: Compensation capacitor CP1: first parasitic capacitance CP2: Second parasitic capacitance CDL: capacitor S1: In a first time interval, reset an integrating capacitor of the charge amplification circuit and reset a compensation capacitor of the capacitance compensation unit. S2: In a second time interval, control the charge amplification circuit to read a touch sensing signal from the touch sensor to integrally charge the integrating capacitor, and at the same time enable the capacitance compensation unit to charge the charge The amplifier circuit provides a capacitive compensation S3: In the second time interval, repeat the reset and integral charging of the compensation capacitor multiple times. S4: Control the charge amplifier circuit to output a sensing voltage within a third time interval

Figure 1 is a block diagram of a conventional touch device; Figure 2 is a circuit topology diagram of a conventional charge amplification circuit; Figure 3 is a working timing diagram of multiple control signals; Figure 4 is a front view of an information processing device applying a touch sensing signal reading method of the present invention; Figure 5 is a block diagram of the touch sensing unit and control chip shown in Figure 4; Figure 6 is a circuit topology diagram of a charge amplification circuit and a capacitance compensation unit; Figure 7 is a working timing diagram of multiple control signals; and FIG. 8 is a method flow chart of a touch sensing signal reading method according to the present invention.

S1: In a first time interval, reset an integrating capacitor of the charge amplification circuit and reset a compensation capacitor of the capacitance compensation unit.

S2: In a second time interval, control the charge amplification circuit to read a touch sensing signal from the touch sensor to integrally charge the integrating capacitor, and at the same time enable the capacitance compensation unit to charge the charge The amplifier circuit provides a capacitive compensation

S3: In the second time interval, repeat the reset and integral charging of the compensation capacitor multiple times.

S4: Control the charge amplifier circuit to output a sensing voltage within a third time interval

Claims (10)

A touch sensing signal reading method is executed by a control chip for reading at least one touch sensing signal from a touch sensing unit having a plurality of touch sensors; wherein the control chip has a sensor A sensing signal readout circuit, the sensing signal readout circuit includes a plurality of charge amplification circuits and a plurality of capacitance compensation units respectively coupled to the charge amplification circuits; the touch sensing signal readout method includes the following steps: Resetting an integrating capacitor of each of the charge amplifier circuits within a first time interval, and simultaneously resetting a compensation capacitor of each of the capacitance compensation units; In a second time interval, each of the charge amplification circuits is driven to read a touch sensing signal from a touch sensor to integrally charge the integrating capacitor, and at the same time, each of the capacitance compensation units is enabled to charge the integral capacitor. A corresponding charge amplifier circuit provides a capacitance compensation; Within the second time interval, the resetting and integral charging of the compensation capacitor are repeated multiple times; and In a third time interval, each of the charge amplifier circuits is driven to output a sensing voltage. The touch sensing signal reading method according to claim 1, wherein the charge amplification circuit includes: An operational amplifier has a positive input terminal, a negative input terminal and an output terminal, and the two ends of the integrating capacitor are coupled to the negative input terminal and the output terminal respectively; A first switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the negative input terminal, the second terminal is coupled to the output terminal, and the control terminal is coupled to a first control signals; and A second switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the touch sensor, the second terminal is coupled to the negative input terminal, and the control terminal is coupled to a second control signal; and A reference capacitor, two ends of which are coupled to the touch sensor and a ground terminal respectively; Wherein, within the first time interval, the first control signal has a high level and the second control signal has a low level. The touch sensing signal reading method according to claim 2, wherein the capacitance compensation unit includes: A third switch has a first end, a second end and a control end, the first end is coupled to a bias voltage, and the control end is coupled to a third control signal; wherein the compensation capacitor has a first end and a second end, the second end of the third switch is coupled to the first end of the compensation capacitor, and the second end of the compensation capacitor is coupled to a compensation signal; A fourth switch has a first end, a second end and a control end, the first end is coupled to the first end of the compensation capacitor, the second end is coupled to the ground end, and the control end coupled to a fourth control signal; and A fifth switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the first terminal of the compensation capacitor, and the second terminal is coupled to the first terminal of the second switch. terminal, and the control terminal is coupled to a fifth control signal; Wherein, within the first time interval, the third control signal controls the switching state of the third switch, the fourth control signal controls the switching state of the fourth switch, and the fifth control signal controls the switching state of the third switch. state, and the compensation signal has a voltage level. The touch sensing signal reading method according to claim 3, wherein in the second time interval, the first control signal controls the switching state of the first switch, and the second control signal controls the switching state of the second switch. switch state, the third control signal controls the switch state of the third switch, the fourth control signal controls the switch state of the fourth switch, and the fifth control signal controls the switch state of the fifth switch, changing multiple times at the same time The voltage level of the compensation signal enables the reset and integral charging of the compensation capacitor to be performed multiple times. A touch display device includes a control circuit and a touch display panel, wherein the touch display panel includes a display panel and a touch sensing unit with a plurality of touch sensors, and the control chip has a sensor A sensing signal readout circuit, the sensing signal readout circuit includes a plurality of charge amplification circuits and a plurality of capacitance compensation units respectively coupled to the plurality of charge amplification circuits; it is characterized in that the control circuit executes a touch sensing signal The reading method is to read at least one touch sensing signal from the touch sensing unit; the touch sensing signal reading method includes the following steps: Resetting an integrating capacitor of each of the charge amplifier circuits within a first time interval, and simultaneously resetting a compensation capacitor of each of the capacitance compensation units; In a second time interval, each of the charge amplification circuits is driven to read a touch sensing signal from a touch sensor to integrally charge the integrating capacitor, and at the same time, each of the capacitance compensation units is enabled to charge the integral capacitor. A corresponding charge amplifier circuit provides a capacitance compensation; Within the second time interval, the resetting and integral charging of the compensation capacitor are repeated multiple times; and In a third time interval, each of the charge amplifier circuits is driven to output a sensing voltage. The touch display device according to claim 5, wherein the charge amplification circuit includes: An operational amplifier has a positive input terminal, a negative input terminal and an output terminal, and the two ends of the integrating capacitor are coupled to the negative input terminal and the output terminal respectively; A first switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the negative input terminal, the second terminal is coupled to the output terminal, and the control terminal is coupled to a first control signals; and A second switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the touch sensor, the second terminal is coupled to the negative input terminal, and the control terminal is coupled to a second control signal; and A reference capacitor, two ends of which are coupled to the touch sensor and a ground terminal respectively; Wherein, within the first time interval, the first control signal has a high level and the second control signal has a low level. The touch display device according to claim 6, wherein the capacitance compensation unit includes: A third switch has a first end, a second end and a control end, the first end is coupled to a bias voltage, and the control end is coupled to a third control signal; wherein the compensation capacitor has a first end and a second end, the second end of the third switch is coupled to the first end of the compensation capacitor, and the second end of the compensation capacitor is coupled to a compensation signal; A fourth switch has a first end, a second end and a control end, the first end is coupled to the first end of the compensation capacitor, the second end is coupled to the ground end, and the control end coupled to a fourth control signal; and A fifth switch has a first terminal, a second terminal and a control terminal, the first terminal is coupled to the first terminal of the compensation capacitor, and the second terminal is coupled to the first terminal of the second switch. terminal, and the control terminal is coupled to a fifth control signal; Wherein, within the first time interval, the third control signal controls the switching state of the third switch, the fourth control signal controls the switching state of the fourth switch, and the fifth control signal controls the switching state of the third switch. state, and the compensation signal has a voltage level. The touch display device according to claim 7, wherein within the second time interval, the first control signal controls the switching state of the first switch, and the second control signal controls the switching state of the second switch, The third control signal controls the switching state of the third switch, the fourth control signal controls the switching state of the fourth switch, and the fifth control signal controls the switching state of the fifth switch while changing the compensation signal multiple times. The voltage level of the compensation capacitor is thus achieved to perform reset and integral charging of the compensation capacitor multiple times. An information processing device having a touch display device as described in any one of claims 5 to 8. The information processing device of claim 9, wherein the information processing device is selected from the group consisting of smart phones, smart watches, tablet computers, notebook computers, all-in-one computers, smart display devices, and access control devices. An electronic device that forms a group.

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