Method, system, device and medium for reducing noise of touch sensor panel

Abstract

Provided are a method, system, device, and medium for reducing noise of a touch sensor panel attached to a display panel. The method includes: sensing a first test noise signal of a first frequency F1 at a first receiving electrode of the touch sensor panel, and sensing a second test noise signal of a second frequency F2 at a second receiving electrode of the touch sensor panel when a reference signal is input to the display panel, wherein a difference between the second frequency F2 and the driving frequency is less than a predetermined threshold; determining a noise compensation gain of the second test noise signal with respect to power and phase of the first test noise signal based on the sensing results; measuring a signal processing gain of an output signal of a predetermined signal processing chain portion after the second receiving electrode with respect to power and phase of an input signal with respect to the second frequency F2; and determining a noise compensation signal to be applied after the predetermined signal processing chain portion when a display signal is input to the display panel based on the noise compensation gain and the signal processing gain.

Description

Technical Field

[0001] The present application relates to the field of touch displays, and more particularly, to methods, systems, touch display electronic systems, electronic devices, and non-transitory storage media for reducing noise of a touch sensor panel attached to a display panel. Background Art

[0002] Currently, touch screens are commonly used to simply operate computing systems or terminal devices.

[0003] A touch screen may include a touch sensor panel attached to a display panel, which is a transparent plate having a touch-sensitive surface. This touch sensor panel, attached to the display panel, is placed in front of, for example, a display screen, serving as the touch-sensitive surface and covering the visible side of the display screen. When a user simply touches the touch screen with a finger, for example, the touch screen recognizes the touch and the touch location, allowing the computing system or terminal device to operate. Capacitive touch screens are a common type of touch screen.

[0004] To identify a touch and its location, a touch sensor panel attached to a display panel typically includes a driving unit and a sensing unit, a plurality of driving electrodes, and a plurality of receiving electrodes, also known as sensing electrodes. The driving unit applies a driving signal to the plurality of driving electrodes to operate the touch sensor panel attached to the display panel, while the sensing unit receives a sensing signal from the plurality of receiving electrodes, including information about the amount of capacitance change associated with a touch applied to the touch surface, to detect a touch and its location.

[0005] However, touch sensors are susceptible to noise from the displays they are part of. Noise capacitively coupled to the receive electrodes through the cathode (resistive layer) can severely impact performance, resulting in inaccurate or inaccurate touch detection and touch location.

[0006] There is a need to mitigate or alleviate noise to a touch sensor panel attached to a display panel. Summary of the Invention

[0007] According to one aspect of the present disclosure, a method for reducing noise of a touch sensor panel attached to a display panel is provided, comprising: sensing a first test noise signal of a first frequency F1 as a reference noise signal at a first receiving electrode of the touch sensor panel as a reference receiving electrode, and sensing a second test noise signal of a second frequency F2 at a second receiving electrode of the touch sensor panel, when a reference signal is input to the display panel; wherein a difference between the second frequency F2 and a driving frequency of a driving signal at a driving electrode of the touch sensor panel is less than a predetermined threshold; determining, based on a result of the sensing, a noise compensation gain of the second test noise signal with respect to power and phase of the first test noise signal for the second frequency F2; measuring a signal processing gain of an output signal of a predetermined signal processing chain portion after the second receiving electrode with respect to power and phase of an input signal for the second frequency F2; and determining, based on the noise compensation gain and the signal processing gain, a noise compensation signal to be applied after the predetermined signal processing chain portion when a display signal is input to the display panel.

[0008] In one embodiment, the method further includes: identifying individual harmonic frequencies of noise, wherein the individual harmonic frequencies of noise are frequencies of sub-harmonics of a horizontal synchronization signal HSync of a display panel, and determining a value of the second frequency F2 based on the driving frequency and the individual harmonic frequencies of noise, so that a difference between the second frequency F2 and the driving frequency is less than a predetermined threshold, wherein the predetermined signal processing chain portion is a portion or all of a complete signal processing chain after the second receiving electrode, and wherein the reference signal is a signal comprising only noise.

[0009] In one embodiment, the step of measuring the signal processing gain of the output signal of the predetermined signal processing chain part after the second receiving electrode with respect to the input signal with respect to the power and phase for the second frequency F2 includes: determining the power Ai and phase θi of the input signal of the predetermined signal processing chain part; determining the power Ao and phase θo of the output signal of the predetermined signal processing chain part; comparing the power and phase of the output signal with the power and phase of the input signal to obtain the power ratio Ao / Ai of the output signal to the input signal and the phase difference θ oi , where θ oi =θo-θi; determine the signal processing gain Among them A filt (F2) = Ao / Ai, θ filt (F2) = θo - θi.

[0010] In one embodiment, the step of determining, based on the noise compensation gain and the signal processing gain, a noise compensation signal to be applied after the predetermined signal processing chain portion when the display panel inputs a display signal includes: determining, based on the noise compensation gain and the signal processing gain, a product of the noise compensation gain and the signal processing gain as a comprehensive gain; sensing a first actual noise signal of a first frequency F1 at the first receiving electrode when the display panel inputs a display signal; converting the first actual noise signal of the first frequency F1 into a first actual noise signal of a second frequency F2; multiplying the first actual noise signal of the second frequency F2 by the comprehensive gain to calculate the power and phase of a predicted noise signal of the predetermined signal processing chain portion after the second receiving electrode; setting the noise compensation signal to reduce or offset the calculated power and phase of the predicted noise signal; wherein the method further includes: applying the noise compensation signal to the actual signals sensed at the predetermined signal processing chain portion after the second receiving electrode when the display panel inputs a display signal.

[0011] In one embodiment, the first receiving electrode and the second receiving electrode are the same receiving electrode, the first frequency F1 and the second frequency F2 are different, wherein the difference between the first frequency F1 and the driving frequency is greater than the predetermined threshold, and the second frequency F2 is a times the first frequency F1, where a is a positive integer.

[0012] In one embodiment, the step of determining the noise compensation gain of the second test noise signal with respect to the first test noise signal with respect to power and phase for the second frequency F2 based on the sensing result includes: determining the power A1 and phase θ1 of the first test noise signal; determining the power A2 and phase θ2 of the second test noise signal; comparing the power and phase of the first test noise signal after being biased to the second frequency F2 with the power and phase of the second test noise signal to obtain a power ratio A2 / A1 and a phase residual θr of the second test noise signal to the first test noise signal biased to the second frequency F2, where θr=θ2-θ1*a; and obtaining the noise compensation gain G based on the power ratio and the phase residual. c (Ac,θc|F2)=A(F2)e jθc(F2) , where A(F2)=A2 / A1, θc(F2)=θ2-θ1*a.

[0013] In one embodiment, the first receiving electrode and the second receiving electrode are different receiving electrodes, and the first frequency F1 and the second frequency F2 are the same.

[0014] In one embodiment, the step of determining the noise compensation gain of the second test noise signal with respect to the first test noise signal with respect to power and phase for the second frequency F2 based on the sensing result includes: determining the power A1 and phase θ1 of the first test noise signal; determining the power A2 and phase θ2 of the second test noise signal; and comparing the power and phase of the first test noise signal with the power and phase of the second test noise signal to obtain a power ratio A2 / A1 of the second test noise signal to the first test noise signal and a phase difference θ. d , where θ d =θ2-θ1; Based on the power ratio and phase difference, the noise compensation gain is obtained Where A(F2)=A2 / A1, θ d (F2) = θ2 - θ1.

[0015] In one embodiment, the step of sensing a noise signal including a first test noise signal and a second test noise signal at a receiving electrode of the touch sensor panel when a reference signal is input to the display panel includes: sensing an average value over time of power and phase of the first test noise signal and the second test noise signal as a result of the sensing.

[0016] According to another aspect of the present disclosure, a system for reducing noise of a touch sensor panel attached to a display panel is provided, comprising: a sensing device configured to sense a first test noise signal of a first frequency F1 as a reference noise signal at a first receiving electrode of the touch sensor panel serving as a reference receiving electrode, and to sense a second test noise signal of a second frequency F2 at a second receiving electrode of the touch sensor panel, when a reference signal is input to the display panel; wherein a difference between the second frequency F2 and a driving frequency of a driving signal at a driving electrode of the touch sensor panel is less than a predetermined threshold; a first gain determining device configured to determine, based on a result of the sensing, a noise compensation gain of the second test noise signal with respect to power and phase of the first test noise signal with respect to the second frequency F2; a second gain determining device configured to measure a signal processing gain of an output signal of a predetermined signal processing chain portion after the second receiving electrode with respect to power and phase of an input signal with respect to the second frequency F2; and a compensation device configured to determine, based on the noise compensation gain and the signal processing gain, a noise compensation signal to be applied after the predetermined signal processing chain portion when a display signal is input to the display panel.

[0017] In one embodiment, the various harmonic frequencies of the noise are identified, wherein the various harmonic frequencies of the noise are frequencies of sub-harmonics of the horizontal synchronization signal HSync of the display panel, and the value of the second frequency F2 is determined based on the driving frequency and the various harmonic frequencies of the noise, so that the difference between the second frequency F2 and the driving frequency is less than a predetermined threshold, wherein the predetermined signal processing chain part is part or all of the complete signal processing chain after the second receiving electrode, and wherein the reference signal is a signal including only noise.

[0018] In one embodiment, the second gain determination device is configured to: determine the power Ai and phase θi of the input signal of the predetermined signal processing chain part; determine the power Ao and phase θo of the output signal of the predetermined signal processing chain part; compare the power and phase of the output signal with the power and phase of the input signal to obtain the power ratio Ao / Ai of the output signal to the input signal and the phase difference θ oi , where θ oi =θo-θi; determine the signal processing gain

[0019] Among them A filt (F2) = Ao / Ai, θ filt (F2) = θo - θi.

[0020] In one embodiment, the compensation device is configured to: determine the product of the noise compensation gain and the signal processing gain as a comprehensive gain based on the noise compensation gain and the signal processing gain; when the display panel inputs a display signal, sense the first actual noise signal of the first frequency F1 at the first receiving electrode; convert the first actual noise signal of the first frequency F1 into a first actual noise signal of the second frequency F2; multiply the first actual noise signal of the second frequency F2 by the comprehensive gain to calculate the power and phase of the predicted noise signal of the predetermined signal processing chain part after the second receiving electrode; set the noise compensation signal to reduce or offset the calculated power and phase of the predicted noise signal; and when the display panel inputs a display signal, apply the noise compensation signal to the actual signals sensed at the predetermined signal processing chain part after the second receiving electrode.

[0021] In one embodiment, the first receiving electrode and the second receiving electrode are the same receiving electrode, the first frequency F1 and the second frequency F2 are different, wherein the difference between the first frequency F1 and the driving frequency is greater than the predetermined threshold, and the second frequency F2 is a times the first frequency F1, where a is a positive integer.

[0022] In one embodiment, the first gain determination device is configured to: determine the power A1 and phase θ1 of the first test noise signal; determine the power A2 and phase θ2 of the second test noise signal; compare the power and phase of the first test noise signal after being biased to the second frequency F2 with the power and phase of the second test noise signal, and obtain a power ratio A2 / A1 of the second test noise signal to the first test noise signal biased to the second frequency F2 and a phase residual θr, where θr=θ2-θ1*a; and obtain a noise compensation gain G based on the power ratio and the phase residual. c (Ac, θc|F2)=A(F2)e jθc(F2) , where A(F2)=A2 / A1, θc(F2)=θ2-θ1*a.

[0023] In one embodiment, the first receiving electrode and the second receiving electrode are different receiving electrodes, and the first frequency F1 and the second frequency F2 are the same.

[0024] In one embodiment, the first gain determining device is configured to: determine the power A1 and phase θ1 of the first test noise signal; determine the power A2 and phase θ2 of the second test noise signal; compare the power and phase of the first test noise signal with the power and phase of the second test noise signal to obtain a power ratio A2 / A1 of the second test noise signal to the first test noise signal and a phase difference θ d , where θ d =θ2-θ1; Based on the power ratio and phase difference, the noise compensation gain is obtained Where A(F2)=A2 / A1, θ d (F2) = θ2 - θ1.

[0025] In one embodiment, the sensing device is configured to sense time-averaged values of power and phase of the first test noise signal and the second test noise signal as a result of the sensing.

[0026] According to another aspect of the present disclosure, a touch display electronic system is provided, comprising: a display panel configured to have display pixels; a touch input device comprising a driving unit, a sensing unit, a control unit, and a touch sensor panel attached to the display panel, wherein the touch sensor panel comprises a plurality of driving electrodes and a plurality of receiving electrodes, the driving unit being configured to apply a driving signal to the plurality of driving electrodes, the sensing unit receiving a sensing signal from the plurality of receiving electrodes, the sensing unit further comprising a signal processing chain for filtering and processing the signals received by the plurality of receiving electrodes; the control unit executing the methods described in the various embodiments of the present application.

[0027] According to another aspect of the present disclosure, an electronic device is provided, including: a memory for storing instructions; and a processor for reading the instructions in the memory and executing the methods described in the various embodiments of the present application.

[0028] According to another aspect of the present disclosure, a non-transitory storage medium is provided, on which instructions are stored. When the instructions are read by a processor, the processor is caused to execute the method according to various embodiments of the present application.

[0029] In this way, through various embodiments of the present application, the power and phase of a noise signal of a specific frequency at any position in the signal processing chain after each receiving electrode can be reduced or offset to reduce or offset noise interference when sensing the driving signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0031] Figure 1A A schematic diagram illustrating an example of a touch sensor board attached to a display panel and its structure in a capacitive touch input device of a touch display electronic system to which embodiments of the present application are applicable.

[0032] Figure 1B Shown as Figure 1A The schematic circuit diagram of the sensing part is shown.

[0033] Figure 1C Shown as Figure 1B A schematic block diagram of a specific configuration of the signal processing part is shown.

[0034] Figure 1D A schematic diagram showing the waveforms of the fundamental wave and harmonics is shown.

[0035] Figure 2 The frequency spectrum waveforms of different noise modes are shown.

[0036] Figure 3A A flow chart of a method for reducing noise of a touch sensor panel attached to a display panel according to an embodiment of the present application is shown.

[0037] Figure 3B A specific example flow chart of the steps of determining a noise compensation signal applied after a predetermined signal processing chain portion when a display panel inputs a display signal based on the noise compensation gain and the signal processing gain is shown.

[0038] Figure 4A It shows how to determine the phase residual θr when determining the gain between the nth harmonic noise signal and the mth harmonic noise signal with respect to power and phase according to an embodiment of the present application.

[0039] Figure 4B A schematic diagram showing the gain of the third harmonic noise within the band and the first harmonic noise outside the band, and the gain of the fourth harmonic noise within the band and the first harmonic noise outside the band according to an embodiment of the present application is shown.

[0040] Figure 5 A schematic diagram illustrating noise compensation gains in terms of power and phase of second test noise signals sensed at N second receiving electrodes relative to a first test noise signal sensed at a first receiving electrode according to an embodiment of the present application is shown.

[0041] Figure 6 The waveform of a signal sensed before applying the noise signal compensation method according to an embodiment of the present application and the waveform of a signal obtained after applying the noise signal compensation method are shown.

[0042] Figure 7 A block diagram of a system for reducing noise of a touch sensor panel attached to a display panel according to an embodiment of the present application is shown.

[0043] Figure 8 A block diagram of a touch display electronic system according to an embodiment of the present application is shown.

[0044] Figure 9 A block diagram of an exemplary computer system suitable for implementing embodiments of the present application is shown.

[0045] Figure 10 A schematic diagram of a non-transitory computer-readable storage medium according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0046] Reference will now be made in detail to specific embodiments of the present application, examples of which are illustrated in the accompanying drawings. Although the present application will be described in conjunction with specific embodiments, it will be understood that the present application is not intended to be limited to the described embodiments. On the contrary, it is intended to cover variations, modifications, and equivalents within the spirit and scope of the present application as defined by the appended claims. It should be noted that the method steps described herein can be implemented by any functional block or functional arrangement, and any functional block or functional arrangement can be implemented as a physical entity or a logical entity, or a combination of the two.

[0047] As previously mentioned, touch sensors are affected by the noise of the display they are part of. Current attempts to mitigate this effect involve introducing several filtering stages and applying a drive signal at a quiet point in the signal spectrum (i.e., a location unaffected by noise) as judiciously as possible. This drive signal is then applied through a bandpass filter to filter out any other signals other than the drive signal at that frequency. However, because noise typically exists throughout the entire spectrum, it is often difficult to find a quiet point in the signal spectrum to apply the drive signal. Alternatively, after the aforementioned filtering signal processing, the display's noise contribution to the touch sensor may still exist, for example, within the bandpass range of the bandpass filter.

[0048] This application aims to introduce a mechanism to reduce or alleviate display noise into the traditional signal processing mechanism.

[0049] Figure 1A A schematic diagram illustrating an example of a capacitive touch sensor panel attached to a display panel and its structure of a touch input device 100 of a touch display electronic system applicable to an embodiment of the present application is shown.

[0050] See also Figure 1A The touch input device 100 includes a driver 12, a sensor 11, a controller 13, and a touch sensor panel 10 attached to a display panel. The touch display electronic system may also include a display panel (not shown) having display pixels. The touch sensor panel 10 attached to the display panel may be positioned above the display panel (not shown) to cover the display panel. The display panel is typically a liquid crystal display panel. The touch sensor panel 10 attached to the display panel includes a plurality of drive electrodes TX1 to TXn and a plurality of receiving electrodes (sense electrodes) RX1 to RXm. Here, n and m are positive integers and may have the same or different values, and their sizes may vary depending on the shape of the touch sensor panel attached to the display panel. To operate the touch sensor panel 10 attached to the display panel, the driver 12 applies drive signals to the plurality of drive electrodes TX1 to TXn, and the sensor 11 receives sense signals from the plurality of receiving electrodes RX1 to RXm, including information about the amount of capacitance change associated with a touch applied to the touch surface, to detect a touch and the touch position.

[0051] Figure 1A The touch sensor panel 10 attached to the display panel is shown as having a plurality of drive electrodes TX1 to TXn and a plurality of receive electrodes RX1 to RXm forming an orthogonal array. However, embodiments of the present application are not limited to this form of touch sensor panel attached to the display panel. The plurality of drive electrodes TX1 to TXn and the plurality of receive electrodes RX1 to RXm can be arranged in any number of dimensions, such as diagonal lines, concentric circles, or three-dimensional random arrangements.

[0052] The plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be arranged to intersect each other. The drive electrodes TX may include a plurality of drive electrodes TX1 to TXn extending in a first axial direction, and the receiving electrodes RX may include a plurality of receiving electrodes RX1 to RXm extending in a second axial direction intersecting the first axial direction. In the touch sensor panel 10 attached to the display panel, the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed on the same layer. For example, the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed on the upper surface of the display panel. Alternatively, the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed on different layers. For example, any one of the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed on the upper surface of the display panel, while the other one may be formed within the display panel.

[0053] The multiple drive electrodes TX1 to TXn and the multiple receiving electrodes RX1 to RXm can be formed from a transparent conductive material (e.g., indium tin oxide (ITO) or antimony tin oxide (ATO), composed of tin oxide (SnO2) and indium oxide (In2O3). However, this is merely an example; the drive electrodes TX and the receiving electrodes RX can also be formed from other transparent conductive materials or non-transparent conductive materials. For example, the drive electrodes TX and the receiving electrodes RX can be formed from at least one of silver ink, copper, nanosilver, and carbon nanotubes (CNTs). Furthermore, the drive electrodes TX and the receiving electrodes RX can be formed from a metal mesh.

[0054] The driving unit 12 may apply a driving signal to the driving electrodes TX1 to TXn. The driving signal may be applied sequentially to the first driving electrode TX1 to the nth driving electrode TXn, one at a time. This process of applying the driving signal may be repeated. Alternatively, the driving signal may be applied to multiple driving electrodes simultaneously.

[0055] The sensing unit 11 can detect the presence or absence of a touch and the touch position by receiving a sensing signal through the receiving electrodes RX1 to RXm, which includes information about the capacitance (Cm) 14 generated between the drive electrodes TX1 to TXn to which the drive signal is applied and the receiving electrodes RX1 to RXm. For example, the sensing signal can be a signal resulting from the drive signal applied to the drive electrode TX being coupled via the capacitance (Cm) 14 generated between the drive electrode TX and the receiving electrode RX. As described above, the process of sensing the drive signal applied to the first to nth drive electrodes TX1 to TXn through the receiving electrodes RX1 to RXm can be referred to as scanning the touch sensor panel 10 attached to the display panel.

[0056] For example, the sensing unit 11 may include a receiver (not shown) connected to each of the receiving electrodes RX1 to RXm via a switch. The switch is turned on during a period of sensing a signal of the corresponding receiving electrode RX so that the receiver can sense the sensing signal from the receiving electrode RX.

[0057] The receiver may include an amplifier (not shown) and a feedback capacitor coupled between the negative (-) input of the amplifier and the output of the amplifier, i.e., a feedback path. Here, the positive (+) input of the amplifier may be connected to ground. In addition, the receiver may further include a reset switch connected in parallel with the feedback capacitor. The reset switch may reset the current-to-voltage conversion performed by the receiver. The negative input of the amplifier is connected to the corresponding receiving electrode RX, and may be converted into a voltage by integration after receiving a current signal including information about the capacitance (Cm) 14. In addition to the receiver, the sensing unit 11 may also include an ADC and a processor. The sensing unit 11 may also include an analog-to-digital converter (ADC) that converts the data integrated by the receiver into digital data. The digital data is then input to a processor (not shown) and can be processed to obtain touch information of the touch sensor panel 10 attached to the display panel.

[0058] exist Figure 1A In the embodiment of the present invention, the driving unit 12 and the sensing unit 11 can constitute a touch detection device capable of detecting whether the touch sensor panel 10 attached to the display panel is touched and the touch position. The touch detection device may further include a control unit 13. The control unit 13 can perform the function of controlling the operation of the driving unit 12 and the sensing unit 11. For example, the control unit 13 can generate a driving control signal and send it to the driving unit 12 so that the driving signal is applied to the preset driving electrode TX at a predetermined time. In addition, the control unit 13 can generate a sensing control signal and send it to the sensing unit 11 so that the sensing unit 11 receives a sensing signal from the preset receiving electrode RX at a predetermined time and performs a predetermined function.

[0059] As described above, each intersection of the driving electrode TX and the receiving electrode RX generates a capacitance (Cm) of a predetermined value, and the value of this capacitance can change when an object such as a finger approaches the touch sensor panel 10 attached to the display panel. Figure 1A In the above description, capacitance may represent mutual capacitance (Cm). The sensing unit 11 can sense this electrical characteristic to detect whether the touch sensor panel 10 attached to the display panel is touched and / or the touch location. For example, it can sense whether the surface of the touch sensor panel 10 attached to the display panel, which is formed by a two-dimensional plane defined by a first axis and a second axis, is touched and / or the touch location.

[0060] More specifically, when the touch sensor panel 10 attached to the display panel is touched, it can detect the position of the touch in the second axis direction by detecting the drive electrodes TX to which the drive signals are applied. Similarly, when the touch sensor panel 10 attached to the display panel is touched, it can detect a change in capacitance from the received signals received by the receive electrodes RX to detect the position of the touch in the first axis direction.

[0061] The above describes the operation of the touch sensor panel 10 attached to the display panel, which senses the touch position based on the change in mutual capacitance between the drive electrode TX and the receive electrode RX. However, the touch screens to which the embodiments of the present invention can be applied are not limited to this. The touch position can also be sensed based on the change in self-capacitance. In addition to the above methods, any touch sensing method can be used, such as surface capacitance, projected capacitance, resistive film, surface acoustic wave (SAW), infrared, optical imaging, dispersive signal technology, and acoustic pulse recognition. The structures and operations of the various touch sensor panels attached to the display panel are not detailed here.

[0062] Figure 1B Shown as Figure 1A Schematic circuit diagram of the sensing unit 11 is shown.

[0063] Among them, the driving signal source is Figure 1B denoted by S in FIG, and the sensing portion 11 performs a touch detection operation using the timing control portion 9 as a timing generator.

[0064] In this figure, the capacitive elements C11-C1n correspond to the capacitive elements C11-C1n in the figure. Figure 1AThe (electrostatic) capacitance element is formed between the driving electrode TX and the receiving electrode RX.

[0065] A driving signal source S (also as shown) is arranged for each of the capacitive elements C11-C1n. Figure 1A The driving part 12 in Figure 1B In the example shown, the drive signal source S includes a switch control section 111, two switching elements 112 and 115, two inverting (logical negation) circuits 1131 and 1132, and an operational amplifier 114. The switch control section 111 controls the on / off state of the switching element 112, thereby controlling the connection state between the power supply +V and the inverting circuits 1131 and 1132. The input of the inverting circuit 1131 is connected to one end of the switching element 112 (the end on the side opposite to the side facing the power supply +V) and the output of the inverting circuit 1132. The output of the inverting circuit 1131 is connected to the input of the inverting circuit 1132 and the input of the operational amplifier 114. Thus, these inverting circuits 1131 and 1132 function as an oscillator circuit that outputs a predetermined pulse signal. The operational amplifier 114 is connected to the two power supplies +V and -V. The on / off state of the switching element 115 is controlled in response to the timing control signal CTL1 supplied by the timing control section 9. More specifically, one end (on the side facing the drive electrode) of each of the capacitive elements C11 to C1n is connected to the output end (on the side facing the supply source of the drive signal Vcom) of the operational amplifier 114 or to the ground via the switch element 115. Thus, the drive signal Vcom is supplied from each drive signal source S to each of the capacitive elements C11 to C1n.

[0066] The sensing section 11 (voltage detector DET) includes an amplifying section 81, an analog / digital (A / D) conversion section 83, a signal processing section 84, a frame memory 86, a coordinate extraction section 85, and the above-mentioned resistor R. In addition, an input terminal Tin of the sensing section 11 is commonly connected to the other end (on the side facing the receiving electrode) of each of the capacitive elements C11 to C1n.

[0067] The amplification section 81 is a section that amplifies the detection signal Vdet input from the input terminal Tin, and includes an operational amplifier 811 for signal amplification and two resistors 812 and 813. The positive input terminal (+) of the operational amplifier 811 is connected to the input terminal Tin, and the output terminal of the operational amplifier 811 is connected to the input terminal of the A / D conversion section 83, which will be described later. One end of the resistor 812 and one end of the resistor 813 are connected to the negative input terminal (-) of the operational amplifier 811, while the other end of the resistor 812 is connected to the output terminal of the operational amplifier 811, and the other end of the resistor 813 is connected to the ground. Thus, the amplification section 81 functions as a non-inverting amplifier circuit.

[0068] Resistor R is arranged between connection point P on the positive input terminal (+) side of operational amplifier 811 and ground. Resistor R prevents the receiving electrode from floating, thereby maintaining a stable state. This has the following advantages: in sensing unit 11, the signal value of detection signal Vdet is prevented from becoming unstable and fluctuating, and static electricity is discharged to ground through resistor R.

[0069] The A / D conversion section 83 samples the analog detection signal Vdet amplified by the amplification section 81 at a predetermined timing (sampling timing ts), and supplies the detection signal Sin obtained by the sampling to the signal processing section 84. The sampling timing ts (sampling frequency fs) in the A / D conversion section 83 is controlled by the timing control signal CTL2 supplied from the timing control section 9.

[0070] The signal processing section 84 performs pre-signal processing (e.g., pre-signal processing such as digital noise elimination processing or processing for converting frequency information into position information) on the detection signal Sin obtained by sampling and output from the A / D conversion section 83. As will be described in detail later, the signal processing section 84 also performs a predetermined operation process for eliminating (reducing) noise using a known waveform (e.g., a rectangular wave or a sawtooth wave) and a known fundamental frequency f0 of the drive signal Vcom used for detection. In this case, such noise is roughly divided into two types, namely, noise caused by the image signal writing operation (internal noise) and noise caused by the external environment (external noise). In addition, reference will be made later to Figure 1C The configuration of the signal processing section 84 is described in detail.

[0071] The coordinate extraction section 85 determines an object detection result based on the detection signal output from the signal processing section 84 (the detection signal Sout obtained by eliminating (reducing) the internal noise or external noise described above) and outputs the object detection result to the output terminal Tout. The object detection result includes the result of detecting whether the receiving electrode is contacted by an object and, if so, the position coordinates of the contact position.

[0072] Figure 1C Shown as Figure 1B A schematic block diagram of a specific configuration of the signal processing section 84 is shown.

[0073] In this example, the signal processing section 84 includes three band-pass filters (BPFs) 841A, 843A, and 845A, three amplification operation sections 841B, 843B, and 845B, and absolute value conversion sections 841C, 843C, and 845C. The signal processing section 84 further includes three low-pass filters (LPFs) 841D, 843D, and 845D, three binarization sections 841E, 843E, and 845E, and a majority selection section 840. In addition, Figure 1C A configuration example is illustrated in the case where the drive signal Vcom is a rectangular wave.

[0074] The band-pass filter BPF 841A is a filter that selectively allows passage of a signal (detection signal S11; fundamental wave detection signal) that is included in the detection signal Sin obtained by sampling and input from the A / D conversion section 83 and has a frequency that is the same as or close to the fundamental frequency f0 of the drive signal Vcom. The band-pass filter BPF 841A corresponds to a specific example of the "first band-pass filter" in the present disclosure.

[0075] The bandpass filter BPF 843A is a filter that selectively allows a signal (detection signal S13; harmonic detection signal) contained in the detection signal Sin obtained by sampling and having a frequency that is the same as or close to a frequency three times the fundamental frequency f0 of the drive signal Vcom (harmonic frequency (or harmonic frequency) 3f0) to pass through. The bandpass filter BPF 845A is a filter that selectively allows a signal (detection signal S15; harmonic detection signal) contained in the detection signal Sin obtained by sampling and having a frequency that is the same as or close to a frequency five times the fundamental frequency f0 of the drive signal Vcom (harmonic frequency 5f0) to pass through. These bandpass filters BPF 843A and 845A correspond to specific examples of the “plurality of second bandpass filters” in the present disclosure.

[0076] In addition, in this case, as an example, the drive signal Vcom is a rectangular wave, so the pass frequencies of the signal in the bandpass filters BPF843A and 845A (second bandpass filter) are harmonic frequencies 3f0 and 5f0 (frequencies that are the same as or close to the frequency of three times or more odd multiples of f0). On the other hand, in the case where the drive signal Vcom is a sawtooth wave, as shown below, the pass frequencies of the signal in the bandpass filters BPF843A and 845A (second bandpass filter) are harmonic frequencies 2f0, 3f0, 4f0, etc. (frequencies that are the same as the frequency of two times or more integer multiples of f0).

[0077] Amplification operation section 841B performs an amplification operation to multiply detection signal S11, which has passed through bandpass filter BPF 841A, by 1 (×1). In other words, detection signal S11 is not actually amplified during the amplification operation performed by amplification operation section 841B. On the other hand, amplification operation sections 843B and 845B perform amplification operations to multiply detection signals S13 and S15, which have passed through bandpass filter BPF 843A and bandpass filter BPF 845A, by 3 times (×3) and 5 times (×5), respectively. Consequently, detection signals S13 and S15 are amplified.

[0078] The absolute value conversion parts 841C, 843C and 845C perform absolute value conversion relative to the 0 (zero) voltage value (processing of inverting the negative part of the signal waveform relative to 0V as the center) on the detection signals obtained through the amplification operation and output from the amplification operation parts 841B, 843B and 845B.

[0079] Low-pass filters LPF 841D, 843D, and 845D perform predetermined low-pass filter LPF processing on the detection signals S21, S23, and S25 obtained by the absolute value conversion section and output from the absolute value conversion sections 841C, 843C, and 845C, to generate detection signals S31, S33, and S35, respectively. More specifically, low-pass filters LPF 841D, 843D, and 845D selectively allow only the frequency of the signal corresponding to the touch to be detected to pass (extract only the frequency of the signal). Alternatively, a bandpass filter BPF or an envelope detection circuit may be used instead of such a low-pass filter LPF.

[0080] The binarization parts 841E, 843E and 845E binarize the detection signals S31, S33 and S35 that have passed through the low-pass filters LPF 841D, 843D and 845D, respectively, by comparing the detection signals S31, S33 and S35 with predetermined thresholds to generate detection signals S41, S43 and S45.

[0081] The majority selection part 840 performs a predetermined majority rule operation using the detection signals S41, S43, and S45 output from the binarization parts 841E, 843E, and 845E, respectively, so as to output the final detection signal Sout for touch detection to the coordinate extraction part (not shown). More specifically, the detection signal determined by the majority of the three detection signals S41, S43, and S45 (in this case, two or more of the detection signals S41, S43, and S45 have the same value) is used and output as the detection signal Sout. In this case, the majority selection part 840 and the above-mentioned coordinate extraction part correspond to a specific example of the "sensing part" in the present invention. The above signal processing part 84 can be called a filter chain or a signal processing chain because it includes multiple filters.

[0082] As described above, when a driving signal is applied to the driving electrode, the sensing unit determines whether a touch exists and the position (eg, coordinates) of the touch on the display panel through the above structure and processing.

[0083] However, external noise can cause changes in the external electric field by contacting (or approaching) a conductive detection object (e.g., the drive electrodes and receiving electrodes) of the touch sensor. Furthermore, the display signal from the display panel can also affect the external electric field, causing errors or failures in touch position detection. In the prior art, attempts have been made to mitigate the effects of external noise by changing the frequency of the drive signal (driving frequency) to a quieter point when external noise is difficult to distinguish from the detected drive signal.

[0084] However, as we all know, due to the sinusoidal characteristics of the signal, the sinusoidal voltage is applied to the nonlinear load (that is, in the electronic circuit, the voltage and current are not linearly related. During the input and operation of the load, the relationship between voltage and current is constantly changing. The so-called nonlinearity means that the relationship between the independent variable and the variable is not linear, but a curve or other relationship). Therefore, the fundamental current will also be distorted to produce harmonics, regardless of the drive signal, display signal or noise signal.

[0085] Figure 1D The waveform diagram of the fundamental wave and harmonics is shown. The sinusoidal component equal to the longest oscillation period is called the fundamental wave, and the frequency corresponding to this period is called the fundamental frequency. Sinusoidal components with frequencies equal to integer multiples of the fundamental frequency are called harmonics. That is, the frequency of a harmonic must be an integer multiple of the frequency of the fundamental wave. For example, a harmonic that is twice the fundamental frequency is called the second harmonic, a harmonic that is three times the fundamental frequency is called the third harmonic, a harmonic that is four times the fundamental frequency is called the fourth harmonic, a harmonic that is five times the fundamental frequency is called the fourth harmonic, a harmonic that is N times the fundamental frequency is called the Nth harmonic, and so on (where N is a positive integer). The fundamental wave can also be called the first harmonic. Of course, no matter how many harmonics there are, they are all sinusoidal waves. Both noise signals and drive signals can include the fundamental wave (also called the first harmonic) and harmonics due to nonlinear loads in the circuit. Of course, these different harmonics have different frequencies. When referring to a certain frequency of noise below, it can be understood that the noise is the noise corresponding to a certain harmonic of that frequency.

[0086] Noise is noticeable across the entire frequency spectrum due to its multiple harmonics. Figure 2The frequency spectrum waveforms of different noise modes are shown. It can be seen that the inter-harmonic bandwidth of aggressive noise modes such as "Zebra10" may be less than 14kHz. That is, the noise has a fundamental wave and multiple harmonics, and the bandwidth intervals between these fundamental waves and multiple harmonics may be less than 14kHz, which is relatively narrow. Therefore, while ensuring a reporting rate of, for example, 300kHz (the frequency at which detection results are reported) and low power consumption requirements, it is extremely difficult to select a quiet point in the spectrum of the driving frequency (that is, a spectrum point that is not interfered with by noise) as the frequency of the driving signal. Considering that the driving frequency needs to be constant for all display modes, this problem is more prominent because the harmonics of other display modes will occupy some gaps in the spectrum.

[0087] Some existing technologies, such as Figure 1C In the example, a filter chain (or signal processing chain) is formed by adding multiple bandpass filters to the signal processing circuit after the receiving electrode. For example, the first bandpass filter has a first bandpass range that includes the driving frequency (or fundamental frequency) of the driving signal. This allows the first bandpass filter to pass a fundamental detection signal included in the sensing signal sensed by the receiving electrode, where the fundamental detection signal has the same frequency as the fundamental frequency of the touch sensor driving signal or frequencies around its spectrum, while filtering out signals in frequency ranges outside the fundamental frequency of the driving signal (including noise in frequency ranges outside the fundamental frequency of the driving signal). Multiple second bandpass filters can each allow two or more harmonic detection signals included in the sensing signal and having the same frequency as the harmonic frequency of the touch sensor driving signal to pass, thereby further reducing noise received by the receiving electrode.

[0088] However, as mentioned above, noise is significant across the entire spectrum. Therefore, various noises may also exist within the first bandpass range of the first bandpass filter, making it difficult to reduce or eliminate such noise within the first bandpass range of the first bandpass filter, or to reduce or eliminate noise within other bandpass ranges of other bandpass filters.

[0089] However, the inventors of this application discovered that because these noise interferences are harmonically related, there may be a certain specific, relatively fixed relationship between the noise signals at frequencies outside the first passband (out-of-band frequencies) and the noise signals at frequencies within the first passband (in-band frequencies). Therefore, the noise at in-band frequencies appearing in the first passband can be estimated using the noise at the out-of-band frequencies. This allows the derivation and introduction of a noise compensation signal to reduce or offset the impact of the in-band noise interference (within the first passband).

[0090] Furthermore, the inventors of the present application have discovered that noise of a certain frequency sensed at one receiving electrode may be spatially correlated with noise of the same frequency sensed at another receiving electrode. That is, there may be a certain specific, relatively fixed relationship between the noise signal sensed at one receiving electrode and the noise signal sensed at another receiving electrode. Therefore, the noise of the same in-band frequency within the first passband range at one receiving electrode can be used to estimate the noise of the same in-band frequency at another receiving electrode. Thus, a noise compensation signal is derived and introduced to reduce or offset the impact of in-band noise interference (within the first passband range) at the other receiving electrode.

[0091] In addition, due to Figure 1C As shown, a filter chain (or signal processing chain) formed by multiple band-pass filters is usually added to the signal processing circuit after the receiving electrode. Therefore, in order to introduce a noise compensation signal after or somewhere in the signal processing circuit after the receiving electrode (rather than at the receiving electrode) to reduce or offset the impact of noise interference, it is necessary to consider the signal processing applied to the noise by the filter chain (or signal processing chain) itself.

[0092] Next, various embodiments of the present application are described in detail with reference to the accompanying drawings.

[0093] Figure 3A A flow chart of a method 300 for reducing noise of a touch sensor panel attached to a display panel according to an embodiment of the present application is shown.

[0094] like Figure 3A As shown, the method 300 includes: step 310, in the case where a reference signal is input to the display panel, sensing a first test noise signal of a first frequency F1 as a reference noise signal at a first receiving electrode of the touch sensor panel as a reference receiving electrode, and sensing a second test noise signal of a second frequency F2 at a second receiving electrode of the touch sensor panel, wherein a difference between the second frequency F2 and the driving frequency of the driving signal at the driving electrode of the touch sensor panel is less than a predetermined threshold; step 320, based on the sensing result, determining a noise compensation gain of the second test noise signal with respect to power and phase of the first test noise signal for the second frequency F2; step 330, measuring a signal processing gain of an output signal of a predetermined signal processing chain portion after the second receiving electrode with respect to power and phase of an input signal for the second frequency F2; and step 340, determining a noise compensation signal to be applied after the predetermined signal processing chain portion when a display signal is input to the display panel based on the noise compensation gain and the signal processing gain.

[0095] In one embodiment, the predetermined signal processing chain portion is a part or the entirety of the complete signal processing chain after the second receiving electrode.

[0096] In case it is desired to perform noise compensation after the complete signal processing chain, the predetermined signal processing chain portion may be as follows: Figure 1C The signal processing section 84 shown in FIG. 8 , the output signal of the predetermined signal processing chain section may be as follows: Figure 1C The signal Sout shown, the input signal of the predetermined signal processing chain part can be as follows Figure 1C The signal Sin shown is then measured in step 330, with respect to power and phase of the output signal Sout of the predetermined signal processing chain section after the second receiving electrode relative to the input signal Sin at the second frequency F2. Knowing this signal processing gain, the change (gain) of the signal from the receiving electrode through the predetermined signal processing chain section can be determined. Furthermore, in step 320, the change (gain) of the noise signal from the first test noise signal at the first frequency F1 at the reference receiving electrode to the second test noise signal at the second frequency F2 at the second receiving electrode is already known. Thus, the actual noise signal after the second receiving electrode to the predetermined signal processing chain section can be predicted based on the first actual noise signal measured at the reference receiving electrode at the first frequency F1, thereby setting a corresponding noise compensation signal to reduce or offset this predicted actual noise signal. Thus, in step 340, based on the noise compensation gain and the signal processing gain, a noise compensation signal to be applied after the predetermined signal processing chain section when a display signal is input from the display panel is determined. This allows noise compensation to be performed after the complete signal processing chain, i.e., at the end of the signal processing chain (after the multiplexing section 840).

[0097] In case it is desired to perform noise compensation after the band pass filter BPF 841A in the signal processing chain, the predetermined signal processing chain portion may be as follows: Figure 1C The portion of the signal processing section 84 shown may be, for example, after the bandpass filter BPF 841A. Thus, the output signal of the predetermined signal processing chain portion may be as follows: Figure 1C As shown in the signal S11, the input signal of the predetermined signal processing chain part can be as follows Figure 1CThe signal Sin shown is shown in FIG30 . In step 330 , the signal processing gain of the output signal S11 of the predetermined signal processing chain section after the second receiving electrode relative to the input signal Sin for the second frequency F2 is measured, with respect to power and phase. Knowing this signal processing gain allows the change (gain) in the signal from the receiving electrode through the predetermined signal processing chain section to be determined. Furthermore, in step 320 , the change (gain) in the noise signal from the first test noise signal at the first frequency F1 at the reference receiving electrode to the second test noise signal at the second frequency F2 at the second receiving electrode is already known. Thus, the actual noise signal after the second receiving electrode to the predetermined signal processing chain section can be predicted based on the first actual noise signal measured at the reference receiving electrode at the first frequency F1, thereby setting a corresponding noise compensation signal to reduce or offset this predicted actual noise signal. Thus, in step 340 , based on the noise compensation gain and the signal processing gain, a noise compensation signal to be applied after the predetermined signal processing chain section when the display panel inputs a display signal is determined, thereby enabling noise compensation after the bandpass filter BPF 841A.

[0098] That is to say, by considering the gain of the output signal of the predetermined signal processing part to the input signal, it is possible to consider performing noise compensation after the complete signal processing chain or at any position in the complete signal processing chain, rather than performing noise compensation at the receiving electrode, that is, placing noise compensation in the signal processing chain.

[0099] In one embodiment, various harmonic frequencies of noise are identified, where the various harmonic frequencies of the noise are frequencies of sub-harmonics of the horizontal synchronization signal HSync of the display panel. A value of a second frequency F2 is determined based on the drive frequency and the various harmonic frequencies of the noise, such that the difference between the second frequency F2 and the drive frequency is less than a predetermined threshold. The reference signal is a signal consisting solely of noise. Thus, to reduce or offset noise interference with the drive signal at the drive frequency, it is important to focus on and eliminate harmonic noise at and near the drive frequency. Therefore, the harmonic frequencies of the noise to be reduced or offset, i.e., the value of the second frequency F2, are determined based on the values of the various harmonic frequencies of the noise itself and the drive frequency.

[0100] In one embodiment, the step 330 of measuring the signal processing gain of the output signal of the predetermined signal processing chain portion after the second receiving electrode with respect to the input signal with respect to power and phase for the second frequency F2 includes: determining the power Ai and phase θi of the input signal of the predetermined signal processing chain portion; determining the power Ao and phase θo of the output signal of the predetermined signal processing chain portion; comparing the power and phase of the output signal with the power and phase of the input signal to obtain a power ratio Ao / Ai of the output signal to the input signal and a phase difference θ oi , where θ oi=θo-θi; determine the signal processing gain

[0101] Among them A filt (F2) = Ao / Ai, θ filt (F2) = θo - θi. The following will not be repeated j meaning.

[0102] Of course, when calculating the gain of the predetermined signal processing chain part itself, it is also possible to first calculate the gain of the output signal of the specific circuit in the predetermined signal processing chain part itself relative to the input signal, and then multiply the multiple gains calculated for these specific circuits.

[0103] Figure 3B A specific example flow chart of step 340 of determining a noise compensation signal applied after a predetermined signal processing chain portion when a display panel inputs a display signal based on the noise compensation gain and the signal processing gain is shown.

[0104] In one embodiment, step 340 of determining a noise compensation signal to be applied after a predetermined signal processing chain portion when a display panel inputs a display signal based on the noise compensation gain and the signal processing gain includes: step 3401, determining the product of the noise compensation gain and the signal processing gain as a comprehensive gain based on the noise compensation gain and the signal processing gain; step 3402, sensing a first actual noise signal of a first frequency F1 at a first receiving electrode when a display signal is input by the display panel; step 3403, converting the first actual noise signal of the first frequency F1 into a first actual noise signal of a second frequency F2; step 3404, multiplying the first actual noise signal of the second frequency F2 by the comprehensive gain to calculate the power and phase of a predicted noise signal of the predetermined signal processing chain portion after the second receiving electrode; step 3405, setting the noise compensation signal to reduce or offset the power and phase of the calculated predicted noise signal.

[0105] The method further includes applying noise compensation signals to actual signals sensed at predetermined signal processing chain portions after the second receiving electrode, respectively, in a case where the display panel inputs a display signal.

[0106] Next, these steps 3401-3405 are described in detail.

[0107] In step 3401, the product of the noise compensation gain and the signal processing gain is used as a comprehensive gain to comprehensively consider the change (gain) from the first test noise signal of the first frequency F1 at the reference receiving electrode to the second test noise signal of the second frequency F2 at the second receiving electrode after passing through the predetermined signal processing chain. The product method is usually used to combine the effects of the two gains on the signal. The noise compensation gain is expressed as, for example, G c (Ac, θc|F2)=A(F2)e jθc(F2) , then the comprehensive gain

[0108] In step 3402 , when a display signal is inputted from a display panel, a first actual noise signal of a first frequency F1 is sensed at a first receiving electrode, denoted as S1 ( F1 ).

[0109] In step 3403, the first actual noise signal at the first frequency F1 is converted to the first actual noise signal at the second frequency F2, denoted as S1(F2). Since the frequency of the first actual noise signal measured at the reference receiving electrode is the first frequency F1, it needs to be converted to the second frequency F2. This allows, in step 3403, the power and phase of the predicted noise signal for the predetermined portion of the signal processing chain after the second receiving electrode to be calculated by multiplying the signal by the integrated gain, given the same frequencies. This conversion is typically achieved by shifting the phase. For example, if the second frequency F2 is a times the first frequency F1, then the phase of the first actual noise signal at the first frequency F1 is multiplied by a (also referred to as offsetting the phase by a) to obtain the phase of the first actual noise signal at the second frequency F2. Of course, we will discuss the case where the first and second frequencies F1 and F2 are actually equal. In this case, no actual conversion is required. Specifically, the phase of the first actual noise signal at the first frequency F1 does not need to be multiplied by a. Instead, the first actual noise signal at the first frequency F1 is directly used as the first actual noise signal at the second frequency F2.

[0110] In step 3404, the first actual noise signal of the second frequency F2 is multiplied by the integrated gain to calculate the power and phase of the predicted noise signal of the predetermined signal processing chain portion after the second receiving electrode. Here, since the actual noise signal after the predetermined signal processing chain portion after the second receiving electrode is not measured and therefore unknown (because the second frequency F2 of the actual noise signal is equal to or close to the driving frequency, it is impossible to accurately separate the actual noise signal of the second frequency F2 and the driving signal through actual measurement), it is necessary to multiply the measured and converted first actual noise signal of the second frequency F2 by the integrated gain to predict what kind of noise signal the first actual noise signal of the second frequency F2 at the second receiving electrode should change to or gain after passing through the predetermined signal processing chain portion. For example, if the first actual noise signal of the second frequency F2 is S1(F2), the predicted noise signal is Sp = S1(F2)*G all .

[0111] In step 3405, after the power and phase of the predicted noise signal for the predetermined signal processing chain portion after the second receive electrode are predicted, a noise compensation signal is set to reduce or offset the power and phase of the calculated predicted noise signal. For example, if the predicted noise signal is Sp, the noise compensation signal is set to -Sp.

[0112] Then, when the display panel inputs a display signal, the noise compensation signal is applied to the actual signal sensed at the predetermined signal processing chain portion after the second receiving electrode, for example, if the actual signal is Sa, then Sa=Sp.

[0113] Next, two embodiments of calculating the noise compensation gain are described. Of course, the embodiments of calculating the noise compensation gain are not limited to the embodiments described in detail below.

[0114] In the first embodiment, since the interference noise signal is harmonically related to the sub-harmonics of the clock update signal (horizontal synchronization signal, HSync, used to indicate the start of scanning 1 line) of the display pixel of the display panel, for the interference noise frequency close to the carrier of the drive signal (that is, it can be regarded as an in-band frequency), these sub-harmonics of the interference noise exist at the lower part of the spectrum. These noise signals at out-of-band frequencies are unrelated to the drive signal itself, but are related to the interference noise close to the carrier of the drive signal. Therefore, these noise signals at out-of-band frequencies can be used to estimate the expected noise content at a specific in-band frequency in real time. Here, since the first bandpass filter has a first bandpass range, the first bandpass range includes the drive frequency of the drive signal and can be called the in-band frequency. The first bandpass range or in-band frequency can be only the drive frequency of the drive signal itself, or it can include frequencies close to the drive frequency of the drive signal in addition to the drive frequency of the drive signal. The first bandpass filter allows the fundamental detection signal of the in-band frequency to pass through, while filtering out signals in a frequency range other than the fundamental frequency of the driving frequency of the driving signal (including noise in a frequency range other than the fundamental frequency of the driving frequency of the driving signal). Therefore, after the driving frequency of the driving signal is determined or set, the range of the in-band frequency can be determined.

[0115] The inventors of this application discovered that because these noise interferences are harmonically related, there may be a certain specific, relatively fixed relationship between the noise signal at frequencies outside the first passband (out-of-band frequencies) and the noise signal at frequencies within the first passband (in-band frequencies). Therefore, it is desirable to estimate the noise at in-band frequencies appearing in the first passband using the noise at the out-of-band frequencies. This allows the derivation and introduction of a noise compensation signal to reduce or offset the impact of the in-band noise interference (within the first passband).

[0116] In this embodiment, because it is desired to estimate in-band noise within the first passband range occurring at the same receive electrode using out-of-band noise at the same receive electrode, the first receive electrode and the second receive electrode are equivalent to being the same receive electrode, and the first frequency F1 (which is considered an in-band frequency because its difference from the drive frequency is less than a predetermined threshold) is different from the second frequency F2. The difference between the first frequency F1 and the drive frequency is greater than the predetermined threshold (i.e., the first frequency F1 is an out-of-band frequency), and the second frequency F2 is a times the first frequency F1, where a is a positive integer. Here, it is required that the in-band noise frequency F2 be an integer multiple (a times) of the out-of-band noise frequency F1. This is because, when the in-band noise frequency F2 is an integer multiple (a times) of the out-of-band noise frequency F1, it is more appropriate to estimate the in-band noise at the in-band frequency F2 using the noise at the out-of-band frequency F1.

[0117] For example, if the driving signal frequency is 300 kHz and the horizontal synchronization signal HSync is 137 kHz, the noise signal is correlated with the harmonics of the HSync signal. Therefore, it is assumed that the fundamental frequency of the noise signal is HSync / 10 = 13.7 kHz. Therefore, the second harmonic of the noise signal is 27.4 kHz, the third harmonic is 41.1 kHz, the fourth harmonic is 54.8 kHz, ..., the 21st harmonic is 287.7 kHz, the 22nd harmonic is 301.4 kHz, .... Since the driving signal frequency for the Zebra 10 display mode is 300 kHz, it is assumed that the in-band frequency range (bandpass range) is 285-305 kHz. Then the frequency of the harmonic of the in-band noise interference close to 300KHz can be the 21st harmonic or the 22nd harmonic of 287.7KHz or 301.4KHz (for example, F2 = 287.7KHz or 301.4KHz). Then, the harmonic of the out-of-band noise interference can be any other noise lower than the harmonic of 260-270kHz at the lower part of the spectrum (for example, F1 takes a certain frequency less than 260-270kHz). Specifically, it is assumed that the 21st harmonic of the noise of 287.7KHz within the in-band range is determined (m = 21). To eliminate the 21st harmonic of 287.7 kHz noise within the in-band frequency range (m=21), the 3rd harmonic, 7th harmonic, or fundamental wave (n=3, 7, or 1) of the out-of-band frequency F1 (=41.1 kHz, 95.9 kHz, or 13.7 kHz) can be used, because 21 is an integer multiple of 3 (a=7 times), 21 is also an integer multiple of 7 (a=3 times), and 21 is also an integer multiple of 1 (a=21 times). Of course, the above values are only examples and are not limiting.

[0118] In order to calculate the noise compensation gain, based on the sensing result, the step of determining the noise compensation gain of the second test noise signal with respect to the first test noise signal with respect to the power and phase for the second frequency F2 includes: determining the power A1 and the phase θ1 of the first test noise signal; determining the power A2 and the phase θ2 of the second test noise signal; comparing the power and the phase of the first test noise signal after being biased to the second frequency F2 with the power and the phase of the second test noise signal, and obtaining a power ratio A2 / A1 of the second test noise signal to the first test noise signal biased to the second frequency F2 and a phase residual θr, where θr=θ2-θ1*a; and obtaining the noise compensation gain G based on the power ratio and the phase residual. c (Ac, θc|F2)=A(F2)e jθc(F2) , where A(F2)=A2 / A1, θc(F2)=θ2-θ1*a.

[0119] Here, note that the first test noise signal of the first frequency F1 is biased to the second frequency F2. This is mainly because the second frequency F2 is different from the first frequency F1. Therefore, in order to uniformly test and predict the noise of the second frequency F2, both the test noise signal and the actual measurement signal are uniformly converted to the second frequency F2 to determine the gain and compensation processing.

[0120] Here, since m / n = a, and therefore F2 / F1 = a, the phase of the mth harmonic noise signal, θ2, and the phase of the nth harmonic noise signal, θ1, should also satisfy θ2 = θ1 * a. However, due to measurement errors or circuit structure, there will actually be a residual error θr between the two measured phases, namely θ2 = θ1 * a + θr. However, because this residual θr is usually caused by measurement errors or circuit structure, which are usually relatively fixed, it is usually constant. Therefore, the residual θr is measured and calculated to form the noise compensation gain formula Gc = (A2 / A1) * exp j*θr , we can well know the relatively constant relationship between the power and phase of the out-of-band noise and the in-band noise.

[0121] Figure 4A It shows how to determine the phase residual θr when determining the gain between the nth harmonic noise signal and the mth harmonic noise signal with respect to power and phase according to an embodiment of the present application.

[0122] Figure 4A A polar coordinate is shown, where the points on it represent the power magnitude of the gain (the distance from the dot) and the phase angle (the angle rotated counterclockwise from 0 degrees). Here, the power magnitude can be a normalized value. Suppose you want to know the relationship between the phase of the noise of the nth harmonic measured at the out-of-band frequency F1 and the phase of the noise of the mth harmonic measured at the in-band frequency F2 which is 3 times the out-band frequency F1. That is, assume that the in-band frequency F2 is 3 times the out-band frequency F1 (that is, m / n=3, that is, a=3). As Figure 4A As shown, the circle indicates the position of the phase θ1 of the noise measured at the out-of-band frequency F1. The complex sine wave of the Discrete Fourier Transform (DFT) is offset by 3*θ1 (i.e., the phase shift is 3*θ1), and the phase position 3*θ1 indicated by the box is obtained. The star indicates the position of the phase θ2 of the noise measured at the in-band frequency F2. In order to determine the residual θr of the phase between the nth harmonic noise signal and the mth harmonic noise signal, the residual θr = θ2-θ1*3 is calculated, as shown in FIG. Figure 4A The portion indicated by the counterclockwise arrow shows the magnitude of the residual θr.

[0123] Figure 4BA schematic diagram showing the gain of the third harmonic noise within the band and the first harmonic noise outside the band, and the gain of the fourth harmonic noise within the band and the first harmonic noise outside the band according to an embodiment of the present application is shown.

[0124] like Figure 4B It can be seen from the position of the circular icon in the polar coordinates that in the multi-frame signal, by comparing the power and phase of the in-band 3rd harmonic noise signal with the out-band, for example, 1st harmonic (fundamental) noise signal (where 3 is an integer multiple of 1, i.e. a=3 / 1=3), the position of the circular icon in the figure shows the gain of the 3rd harmonic noise signal compared to the 1st harmonic noise signal. It can be seen from the figure that the power of the 3rd harmonic noise signal is approximately 0.8 times the power of the 1st harmonic noise signal, that is, the ratio A of the power amplitude of the noise of the in-band frequency F2 to the power amplitude of the noise of the out-band frequency F1 is approximately 0.8. That is to say, the 3rd harmonic noise of the in-band frequency F2 is approximately 0.8 times the power of the out-band noise of the 1st harmonic of the out-band frequency F1. In terms of phase, the phase θ2 of the 3rd harmonic noise signal of the in-band frequency F2 is approximately 340 degrees (or θ1) larger than the phase θ1 of the 1st harmonic noise signal of the out-band frequency F1 multiplied by 3. π is about 180 degrees), that is, the residual θr=θ2-θ1*3=340 degrees (or ). That is, the power amplitude of the noise of the in-band frequency F2 and the gain of the noise of the out-band frequency F1 is G=0.8e j340° or

[0125] In the above example, if the display signal is actually applied, by measuring the power A1' and phase θ1' of the actual 1st harmonic noise at the out-of-band frequency (that is, the signal at the frequency of the 1st harmonic), based on the gain G= jθr , multiply the actual 1st harmonic noise power amplitude A1' measured at the out-of-band frequency by A = 0.8 times to obtain the estimated power A3' of the noise signal (3rd harmonic noise) at the actual in-band frequency, that is, A3' = A1' * A, and add θ1' * 3 to (that is, it can be rotated counterclockwise in polar coordinates) θr = 340 degrees ( π is 180 degrees), that is, the phase θ3′=θ1′*3+θr of the noise signal (third harmonic noise) at the estimated actual in-band frequency can be obtained.

[0126] Here, in one embodiment, due to the application of a multi-frame signal (such as Figure 4BCalculating G for each frame of signal will result in multiple G points corresponding to multiple frames of signal. Therefore, the average values of the power A2 and phase θ2 of the sensed nth harmonic noise signal and mth harmonic noise signal over time (i.e., over multiple frames of signal) can be calculated as the power A2 and phase θ2 of the nth harmonic noise signal and mth harmonic noise signal, and the corresponding ratio A and difference θr can be calculated. This makes the calculation results more accurate.

[0127] In addition, if Figure 4B As can be seen from the cross icon, in the multi-frame signal, by comparing the power and phase of the in-band 4th harmonic noise signal with the out-band, for example, 1st harmonic (fundamental) noise signal (where 4 is an integer multiple of 1), it can be seen that the power of the in-band 4th harmonic noise signal in the multi-frame signal is approximately 0.2 times the power of the out-band 1st harmonic noise signal, that is, the ratio A of the power amplitude of the noise of the in-band frequency F2 to the power amplitude of the noise of the out-band frequency F1 is 0.2. In terms of phase, the phase of the in-band 4th harmonic noise signal in the multi-frame signal is approximately 220 degrees larger than the phase of the out-band 1st harmonic noise signal after multiplying the phase by 4 ( π is about 180 degrees). That is, the power amplitude of the 4th harmonic noise signal of the in-band frequency F2 and the gain of the 1st harmonic (fundamental) noise signal of the out-band frequency F1 is G = 0.2e j220° or

[0128] In the above example, if the display signal is actually applied, by measuring the power and phase of the actual 1st harmonic noise of the out-of-band frequency (i.e., the signal at the frequency of the 1st harmonic), based on the gain obtained by the previous measurement, the power and phase of the estimated 4th harmonic noise of the in-band frequency (i.e., the noise signal at the frequency of the 4th harmonic) can be obtained, so that the 4th harmonic noise of the in-band frequency at the receiving electrode can be estimated, in preparation for the subsequent reduction or cancellation.

[0129] In the second embodiment, the inventors of the present application also discovered that noise of a certain frequency sensed at one receiving electrode may be spatially correlated with noise of the same frequency sensed at another receiving electrode, that is, there may be certain specific, relatively fixed relationships (usually the relationship between signal power and phase) between the noise signal sensed at one receiving electrode and the noise signal sensed at another receiving electrode. Therefore, the noise of the same in-band frequency within the first passband range at one receiving electrode can be used to estimate the noise of the same in-band frequency at another receiving electrode. Thus, a noise compensation signal is derived and introduced to reduce or offset the influence of the in-band noise interference (within the first passband range) at the other receiving electrode.

[0130] As mentioned above, the present application can input only one reference signal to the display panel in the test mode. The reference signal can be a signal that only includes noise (pure noise) and does not include the display signal when the display panel is working normally. In this way, the relationship between the noise signal of the same frequency sensed at one receiving electrode and the noise signal of the same frequency sensed at another receiving electrode can be tested offline (i.e., not in the display working mode). Of course, since the in-band noise associated with the driving signal needs to be eliminated more than the out-of-band noise, it is preferable to select the noise signal of the in-band frequency for measurement rather than measuring all harmonic (frequency) noise. After testing the relationship between the noise signal of the in-band frequency sensed at one receiving electrode and the noise signal of the same frequency sensed at each receiving electrode, a noise compensation signal can be derived and introduced to reduce or offset the influence of the noise interference of the in-band frequency (within the first bandpass range) at each receiving electrode.

[0131] That is, in this embodiment, the first receiving electrode and the second receiving electrode are different receiving electrodes, and the first frequency F1 and the second frequency F2 are the same.

[0132] Of course, in pure noise measurements in test mode, the fundamental wave and multiple harmonics of the noise can first be identified offline in the signal spectrum sensed at the receiving electrode. Since each wave has a frequency, all frequencies of interest of the interfering noise (also called interferers) can be identified. For example, if the noise is identified as having a fundamental wave (1st harmonic), 2nd harmonic, 3rd harmonic, ..., 21st harmonic, etc., the frequencies of these waves are 1 times the fundamental frequency, 2 times the fundamental frequency, 3 times the fundamental frequency, ..., 21 times the fundamental frequency, etc. Assume that these frequencies of the noise are F1, F2, F3, ..., Fx.

[0133] After determining or setting the driving frequency of the driving signal, an in-band frequency range can be determined, assuming it is between f1 and f2. Then, based on the identified noise frequencies, a determination is made as to which frequency within or associated with the in-band frequency range to reduce or cancel. For example, the frequency F1 is determined to be between f1 and f2, or the distance between F1 and the f1-f2 range or the driving frequency is less than a predetermined threshold. Therefore, in step 310, a first frequency F1 of the noise within or associated with the in-band frequency range can be determined based on the frequencies of the identified harmonics of the noise. Thus, when a reference signal is input to the display panel, a first test noise signal of the first frequency F1 is sensed at a first receiving electrode of the touch sensor panel, serving as a reference receiving electrode, and multiple second test noise signals (hereinafter, using a single second test noise signal as an example) of a second frequency F2 (in this example, F2 = F1, and the second frequency F2 is still used hereinafter to provide uniform terminology throughout this application) are sensed at a second receiving electrode of the touch sensor panel.

[0134] For example, if the driving signal frequency is 300kHz and the horizontal synchronization signal HSync is 137kHz, due to the correlation between the noise signal and the harmonics of the horizontal synchronization signal HSync, it is assumed that the fundamental frequency of the noise signal is HSync / 10 = 13.7kHz. Therefore, the frequency of the second harmonic of the noise signal is 27.4kHz, the frequency of the third harmonic of the noise signal is 41.1kHz, the frequency of the fourth harmonic of the noise signal is 54.8kHz, ..., the frequency of the 21st harmonic of the noise signal is 287.7kHz, the frequency of the 22nd harmonic of the noise signal is 301.4kHz, .... Since the driving signal frequency of the display mode Zebra 10 is 300kHz, it is assumed that the in-band frequency range (bandpass range) is 285-305kHz. The frequency of the harmonic of the in-band noise interference near 300kHz can be the 21st or 22nd harmonic of 287.7kHz and 301.4kHz. Therefore, F1 can be selected as 287.7kHz or 301.4kHz. The value of F2 can also be determined by setting the predetermined threshold. For example, the predetermined threshold can be set to 2kHz, so F2 = 301.4kHz and F1 = 301.4kHz, which satisfies the requirement that the difference from 300kHz is less than 2kHz. Of course, the above values are only examples and are not limiting.

[0135] Here, the in-band frequency range (bandpass range) is set as close to the driving frequency of the driving signal as possible, that is, the difference between the upper limit and lower limit of the in-band frequency range (bandpass range) and the driving frequency can be less than a threshold value, so that the interference affecting the driving frequency can be filtered out as much as possible.

[0136] Thus, based on the sensing result, the step of determining the noise compensation gain of the second test noise signal with respect to the first test noise signal with respect to power and phase for the second frequency F2 includes: determining the power A1 and phase θ1 of the first test noise signal; determining the power A2 and phase θ2 of the second test noise signal; and comparing the power and phase of the first test noise signal with the power and phase of the second test noise signal to obtain a power ratio A2 / A1 of the second test noise signal to the first test noise signal and a phase difference θ d , where θ d =θ2-θ1; Based on the power ratio and phase difference, the noise compensation gain is obtained Where A(F2)=A2 / A1, θ d (F2) = θ2 - θ1.

[0137] Figure 5 A schematic diagram illustrating noise compensation gains in terms of power and phase of second test noise signals sensed at N second receiving electrodes relative to a first test noise signal sensed at a first receiving electrode according to an embodiment of the present application is shown.

[0138] Figure 5 A polar coordinate is shown, where points represent the power magnitude of the gain (distance from the origin) and the phase angle (degrees counterclockwise from 0 degrees).

[0139] Here, it is assumed that there are 16 receiving electrodes in total, for example, and the first receiving electrode serving as the reference receiving electrode is the receiving electrode Rx0. The N second receiving electrodes are 16 second receiving electrodes: Rx0, Rx1, Rx2, Rx3, Rx4, Rx5, Rx6, Rx7, Rx8, Rx9, Rx10, Rx11, Rx12, Rx13, Rx14, Rx15, Rx16, Rx17, Rx18, Rx19, Rx20, Rx21, Rx22, Rx23, Rx24, Rx25, Rx26, Rx27, Rx28, Rx29, Rx30, Rx31, Rx32, Rx33, Rx34, Rx35, Rx36, Rx37, Rx38, Rx39, Rx40, Rx41, Rx42 10 、Rx 11 、Rx 12 、Rx 13 、Rx 14 、Rx 15 . Figure 5 16 gains (G(Rx0->Rx0), G(Rx0->Rx1), G(Rx0->Rx2), G(Rx0->Rx3), G(Rx0->Rx4), G(Rx0->Rx5), G(Rx0->Rx6), G(Rx0->Rx7), G(Rx0->Rx8), G(Rx0->Rx9), G(Rx0->Rx0) between the respective noises of the sensed frequency F1 at the 15 second receiving electrodes and the reference noise signal of the sensed frequency F1 at the first receiving electrode) are shown. 10 )、G(Rx0->Rx 11 )、G(Rx0->Rx 12 )、G(Rx0->Rx 13)、G(Rx0->Rx 14 )、G(Rx0->Rx 15 The reference noise signal of the frequency F1 sensed at the first receiving electrode Rx0 and its own gain Rx0->Rx0 are actually equivalent to G(Rx0->Rx0)=1*e j0° , meaning the power ratio is 1, and the phase remains unchanged. Note that the purpose of calculating G(Rx0->Rx0) can be to eliminate the actual noise signal sensed at the first receive electrode Rx0 itself when subsequently reducing or canceling noise. The N second receive electrodes may not include all 16 receive electrodes, but may include some of the 16 receive electrodes.

[0140] In a specific example, suppose that the noise relationship between a first test noise signal at a first receiving electrode and a second test noise signal at a second receiving electrode is desired. The power A1 and phase θ1 of the first test noise signal are determined; the power A2 and phase θ2 of the second test noise signal are determined; and the power and phase of the first test noise signal are compared with the power and phase of the second test noise signal to obtain the power ratio A2 / A1 of the second test noise signal to the first test noise signal and the phase difference θ. d , where θ d =θ2-θ1; Based on the power ratio and phase difference, the noise compensation gain is obtained Where A(F2)=A2 / A1, θ d (F2) = θ2 - θ1. Here, only the method for one second receiving electrode is shown, but in fact, similar methods are also used for other second receiving electrodes.

[0141] Here, since multiple frames of signals can be applied during the test, the power and phase of the sensed first and second test noise signals can be averaged over time (i.e., over multiple frames of signals) to serve as the power and phase of the first and second test noise signals, and the corresponding ratio and difference can be calculated. This makes the calculation results more accurate.

[0142] refer to Figure 5 , Figure 5 The crosses of different shades in the figure represent the positions of the various gains in the polar coordinates of power and phase. From this position, it can be seen that the various gains G i Power A i (i.e., a value between 0 and 1) and the phase θr i (i.e., a value between 0 and 360 degrees), where i is a positive integer and is any one of 1 to N.

[0143] The two calculation embodiments of the noise compensation gain are described above. The measurement points in the calculation of the noise compensation gain can be as follows: Figure 1B In the example shown, Sin is measured after the A / D conversion section, that is, when the reference signal and display signal are input. Of course, it is also possible to measure at another location, as long as the reference signal and display signal are measured at the same location. In this case, the signal processing gain calculation also takes into account the gain of each circuit after the measurement point in the noise compensation gain calculation.

[0144] Note that the above measurement, calculation, and reduction or cancellation steps are all for the noise at a specific frequency F2. If you need to eliminate noise at other frequencies, you can set another frequency and then measure, calculate, and reduce or cancel the noise at that other frequency.

[0145] In addition, in various embodiments of the present application, the step of inputting a reference signal to the display panel to measure the gain and the step of inputting a display signal to the display panel to reduce or offset the estimated actual noise can be performed separately or immediately after each other. For example, the step of measuring the gain can be performed when the touch display is manufactured, while the step of reducing or offsetting the estimated actual noise can be performed when the touch display is tested or actually used. For another example, when the touch display is tested or actually used, the step of measuring the gain and the step of reducing or offsetting the estimated actual noise are performed, so that the gain in the field can be estimated in real time and the corresponding noise reduction or offset can be performed.

[0146] In this way, through the various embodiments of the present application, the power and phase of the noise signal of a specific frequency equal to or similar to the driving frequency of the driving signal after the predetermined signal processing chain part at each receiving electrode can be reduced or offset to reduce or offset the noise interference when sensing the driving signal of the driving frequency.

[0147] Notice, Figure 5 Only the noise for a specific frequency is shown, and the noise of other receiving electrodes Rx1, Rx2, Rx3, Rx4, Rx5, Rx6, Rx7, Rx8, Rx9, Rx10, Rx11, Rx12, Rx13, Rx14, Rx15, Rx16, Rx17, Rx18, Rx19, Rx20, Rx21, Rx22, Rx23, Rx24, Rx25, Rx26, Rx27, Rx28, Rx29, Rx30, Rx31, Rx32, Rx33, Rx34, Rx35, Rx36, Rx37, Rx38, Rx39, Rx40, Rx41, Rx42, Rx43, Rx44, Rx45, Rx46, Rx47, Rx48, Rx49, Rx 10 、Rx 11 、Rx 12 、Rx 13 、Rx 14 、Rx 15The noise interference at the specific frequency is measured and reduced or offset. However, due to the effects of fundamental and harmonic noise, there may be noise at multiple frequencies. If it is necessary to estimate the noise interference at other frequencies, the above-described steps of measuring the noise compensation gain and reducing or offsetting the estimated actual noise can be repeated for each of the other frequencies to reduce or offset the noise interference at the other frequencies.

[0148] Figure 6 The waveform of a signal sensed before applying the noise signal compensation method according to an embodiment of the present application and the waveform of a signal obtained after applying the noise signal compensation method are shown.

[0149] like Figure 6 As shown in the figure, before the noise signal compensation method, the overall noise power fluctuation range is large, seriously affecting the sensing of touch signals. It is even impossible to see the touch signal in the center of the screen (coordinates x=9, y=9) (the sensed signal z=39.2143). After the noise signal compensation method is used, the overall noise power fluctuation range is greatly reduced, and the touch in the center of the screen becomes more obvious instead of being almost undetectable. Therefore, it helps to detect touches more accurately because the noise interference is reduced.

[0150] In this way, by introducing active noise compensation signals at specific frequencies of interest near the drive frequency at the receive electrodes and in the subsequent signal processing chain, system performance in noisy display conditions is improved. As in-band noise is reduced or canceled, key performance indicators such as the SNppR signal-to-noise ratio are improved.

[0151] Note that the method according to the embodiment of the present application may be implemented by a control unit in a touch input device, or may also be implemented by other processors.

[0152] Figure 7 FIG. 7 is a block diagram illustrating a system 700 for reducing noise of a touch sensor panel attached to a display panel according to an embodiment of the present application.

[0153] like Figure 7As shown, the system 700 includes: a sensing device 710, configured to sense a first test noise signal of a first frequency F1 as a reference noise signal at a first receiving electrode of the touch sensor panel as a reference receiving electrode, and sense a second test noise signal of a second frequency F2 at a second receiving electrode of the touch sensor panel when a reference signal is input to the display panel; wherein a difference between the second frequency F2 and the driving frequency of the driving signal at the driving electrode of the touch sensor panel is less than a predetermined threshold; a first gain determining device 720, configured to determine, based on a result of the sensing, a noise compensation gain of the second test noise signal with respect to the first test noise signal with respect to power and phase for the second frequency F2; a second gain determining device 730, configured to measure a signal processing gain of an output signal of a predetermined signal processing chain portion after the second receiving electrode with respect to power and phase for the input signal with respect to the second frequency F2; and a compensation device 740, configured to determine, based on the noise compensation gain and the signal processing gain, a noise compensation signal to be applied after the predetermined signal processing chain portion when a display signal is input to the display panel.

[0154] In one embodiment, the various harmonic frequencies of the noise are identified, wherein the various harmonic frequencies of the noise are frequencies of sub-harmonics of the horizontal synchronization signal HSync of the display panel, and the value of the second frequency F2 is determined based on the driving frequency and the various harmonic frequencies of the noise, so that the difference between the second frequency F2 and the driving frequency is less than a predetermined threshold, wherein the predetermined signal processing chain part is a part or all of the complete signal processing chain after the second receiving electrode, and wherein the reference signal is a signal including only noise.

[0155] In one embodiment, the second gain determining means 730 is configured to: determine the power Ai and phase θi of the input signal of the predetermined signal processing chain portion; determine the power Ao and phase θo of the output signal of the predetermined signal processing chain portion; compare the power and phase of the output signal with the power and phase of the input signal to obtain a power ratio Ao / Ai of the output signal to the input signal and a phase difference θ oi , where θ oi =θo-θi; determine the signal processing gain Among them A filt (F2) = Ao / Ai, θ filt (F2) = θo - θi.

[0156] In one embodiment, the compensation device 740 is configured to: determine the product of the noise compensation gain and the signal processing gain as a comprehensive gain based on the noise compensation gain and the signal processing gain; when the display panel inputs a display signal, sense the first actual noise signal of the first frequency F1 at the first receiving electrode; convert the first actual noise signal of the first frequency F1 into a first actual noise signal of the second frequency F2; multiply the first actual noise signal of the second frequency F2 by the comprehensive gain to calculate the power and phase of the predicted noise signal of the predetermined signal processing chain part after the second receiving electrode; set the noise compensation signal to reduce or offset the power and phase of the calculated predicted noise signal; and when the display panel inputs a display signal, apply the noise compensation signal to the actual signals sensed at the predetermined signal processing chain part after the second receiving electrode.

[0157] In one embodiment, the first receiving electrode and the second receiving electrode are the same receiving electrode, the first frequency F1 and the second frequency F2 are different, wherein the difference between the first frequency F1 and the driving frequency is greater than a predetermined threshold, and the second frequency F2 is a times the first frequency F1, wherein a is a positive integer.

[0158] In one embodiment, the first gain determination device is configured to: determine the power A1 and phase θ1 of the first test noise signal; determine the power A2 and phase θ2 of the second test noise signal; compare the power and phase of the first test noise signal after being biased to the second frequency F2 with the power and phase of the second test noise signal, and obtain a power ratio A2 / A1 of the second test noise signal to the first test noise signal biased to the second frequency F2 and a phase residual θr, where θr = θ2-θ1*a; and obtain a noise compensation gain G based on the power ratio and the phase residual. c (Ac, θc|F2)=A(F2)e jθc(F2) , where A(F2)=A2 / A1, θc(F2)=θ2-θ1*a.

[0159] In one embodiment, the first receiving electrode and the second receiving electrode are different receiving electrodes, and the first frequency F1 and the second frequency F2 are the same.

[0160] In one embodiment, the first gain determining device 720 is configured to: determine the power A1 and phase θ1 of the first test noise signal; determine the power A2 and phase θ2 of the second test noise signal; compare the power and phase of the first test noise signal with the power and phase of the second test noise signal to obtain a power ratio A2 / A1 of the second test noise signal to the first test noise signal and a phase difference θ d , where θ d =θ2-θ1; Based on the power ratio and phase difference, the noise compensation gain is obtained Where A(F2)=A2 / A1, θ d (F2) = θ2 - θ1.

[0161] In one embodiment, the sensing device 710 is configured to sense the average values of the power and phase of the first test noise signal and the second test noise signal over time as the sensing result.

[0162] Figure 8 FIG2 shows a block diagram of a touch display electronic system 800 according to an embodiment of the present application.

[0163] like Figure 8 As shown, the touch display electronic system 800 includes: a display panel 810, which is configured to have display pixels; a touch input device 820, which includes a driving unit 821, a sensing unit 822, a control unit 823 and a touch sensor board 824 attached to the display panel 810, wherein the touch sensor board 824 includes a plurality of driving electrodes 8241 and a plurality of receiving electrodes 8242, the driving unit 821 is configured to apply a driving signal to the plurality of driving electrodes 8241, the sensing unit 822 receives a sensing signal from the plurality of receiving electrodes 8242, and the sensing unit 822 also includes a signal processing chain 8221 to filter and process the signals received by the plurality of receiving electrodes; the control unit 823 executes the method for reducing the noise of the touch sensor board attached to the display panel according to various embodiments of the present application.

[0164] Figure 9 A block diagram of an exemplary computer system suitable for implementing embodiments of the present application is shown.

[0165] The computer system may include a processor (H1); a storage medium (H2) coupled to the processor (H1) and storing computer-executable instructions therein for performing the steps of the various methods of the embodiments of the present application when executed by the processor.

[0166] The processor (H1) may include, but is not limited to, one or more processors or microprocessors, etc.

[0167] The storage medium (H2) may include, but is not limited to, for example, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, computer storage media (such as hard disk, floppy disk, solid-state drive, removable disk, CD-ROM, DVD-ROM, Blu-ray disc, etc.).

[0168] In addition, the computer system may also include a data bus (H3), an input / output (I / O) bus (H4), a display (H5), and input / output devices (H6) (eg, keyboard, mouse, speakers, etc.).

[0169] The processor (H1) can communicate with external devices (H5, H6, etc.) through an I / O bus (H4) via a wired or wireless network (not shown).

[0170] The storage medium (H2) may also store at least one computer-executable instruction for executing various functions and / or steps of methods in the embodiments described in the present technology when the processor (H1) executes the instruction.

[0171] In one embodiment, the at least one computer executable instruction may also be compiled into or constitute a software product, wherein one or more computer executable instructions are executed by a processor to perform the various functions and / or method steps in the embodiments described in the present technology.

[0172] Figure 10 A schematic diagram of a non-transitory computer-readable storage medium according to an embodiment of the present disclosure is shown.

[0173] like Figure 10 As shown, instructions are stored on the computer-readable storage medium 1020, and the instructions are, for example, computer-readable instructions 1010. When the computer-readable instructions 1010 are executed by the processor, the various methods described above can be executed. The computer-readable storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. For example, the computer-readable storage medium 1020 can be connected to a computing device such as a computer, and then, when the computing device executes the computer-readable instructions 1010 stored on the computer-readable storage medium 1020, the various methods described above can be performed.

[0174] Of course, the above-mentioned specific embodiments are merely examples and not limitations, and those skilled in the art can, according to the concept of the present application, merge and combine some steps and devices from the various embodiments described separately above to achieve the effects of the present application. Such merged and combined embodiments are also included in the present application, and such merges and combinations are not described one by one here.

[0175] Note that the advantages, strengths, and effects mentioned in this disclosure are merely examples and not limitations, and should not be construed as necessarily possessed by each embodiment of this application. Furthermore, the specific details disclosed above are provided for illustrative purposes and to facilitate understanding, not limitations, and the details do not necessarily limit this application to the use of the specific details.

[0176] The block diagrams of the devices, devices, equipment, and systems involved in this disclosure are intended to be illustrative examples only and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "including," "comprising," "including," and the like are open-ended words that mean "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0177] The step flow charts and the above method descriptions in this disclosure are merely illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order given. As will be appreciated by those skilled in the art, the order of the steps in the above embodiments can be performed in any order. Words such as "thereafter," "then," "next," and the like are not intended to limit the order of the steps; these words are only used to guide the reader through the description of these methods. In addition, any reference to an element in the singular, such as using the articles "a," "an," or "the," is not to be construed as limiting the element to the singular.

[0178] In addition, the steps and devices in the various embodiments of this document are not limited to being implemented in a certain embodiment. In fact, according to the concept of this application, relevant partial steps and partial devices in the various embodiments of this document can be combined to conceive new embodiments, and these new embodiments are also included in the scope of this application.

[0179] Each operation of the method described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and / or software components and / or modules, including but not limited to hardware circuits, application specific integrated circuits (ASICs) or processors.

[0180] The various illustrated logic blocks, modules, and circuits may be implemented or described using a general-purpose processor, a digital signal processor (DSP), an ASIC, a field programmable gate array signal (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but as an alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, a microprocessor cooperating with a DSP core, or any other such configuration.

[0181] The steps of the method or algorithm described in conjunction with the present disclosure can be directly embedded in hardware, in a software module executed by a processor, or in a combination of the two. The software module can exist in any form of tangible storage medium. Some examples of storage media that can be used include random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, etc. A storage medium can be coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. In an alternative embodiment, the storage medium can be integral to the processor. A software module can be a single instruction or many instructions and can be distributed over several different code segments, between different programs, and across multiple storage media.

[0182] The methods disclosed herein include actions for implementing the described methods. Methods and / or actions may be interchangeable with one another without departing from the scope of the claims. In other words, unless a specific order of actions is specified, the order and / or use of specific actions may be modified without departing from the scope of the claims.

[0183] The above functions can be implemented by hardware, software, firmware or any combination thereof. If implemented in software, the functions can be stored as instructions on a tangible computer-readable medium. The storage medium can be any available tangible medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices or any other tangible medium that can be used to carry or store desired program codes in the form of instructions or data structures and can be accessed by a computer. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy discs and Blu-ray discs, wherein disks usually reproduce data magnetically, while discs reproduce data optically using lasers.

[0184] Thus, a computer program product can perform the operations presented herein. For example, such a computer program product can be a computer-readable tangible medium having instructions tangibly stored (and / or encoded) thereon, the instructions being executable by a processor to perform the operations described herein. The computer program product can include packaging materials.

[0185] Software or instructions may also be transmitted via a transmission medium. For example, software may be transmitted from a website, server, or other remote source using a transmission medium such as coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, or microwave.

[0186] In addition, the modules and / or other appropriate means for carrying out the methods and techniques described herein can be downloaded and / or otherwise obtained by the user terminal and / or base station when appropriate. For example, such a device can be coupled to a server to facilitate the transmission of the means for carrying out the methods described herein. Alternatively, the various methods described herein can be provided via a storage component (e.g., RAM, ROM, a physical storage medium such as a CD or a floppy disk) so that the user terminal and / or base station can obtain the various methods when being coupled to the device or providing a storage component to the device. In addition, any other appropriate technology for providing the methods and techniques described herein to a device can be utilized.

[0187] Other examples and implementations are within the scope and spirit of this disclosure and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software performed by a processor, hardware, firmware, hardwiring, or any combination of these. Features that implement the functions can also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations. Moreover, as used herein, including as used in the claims, "or" used in a list of items that begin with "at least one" indicates a separate list, so that, for example, a list of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). In addition, the wording "exemplary" does not mean that the example described is preferred or better than other examples.

[0188] Various changes, substitutions, and modifications of the technology described herein may be made without departing from the teachings of the appended claims. Moreover, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of things, means, methods, and actions described above. Currently existing or later developed processes, machines, manufactures, compositions of things, means, methods, or actions that perform substantially the same function or achieve substantially the same results as the corresponding aspects described herein may be utilized. Accordingly, the appended claims include within their scope such processes, machines, manufactures, compositions of things, means, methods, or actions.

[0189] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0190] The above description has been provided for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for reducing noise of a touch sensor panel attached to a display panel, comprising: In the case where the display panel inputs a reference signal, a first test noise signal of a first frequency F1 as a reference noise signal is sensed at a first receiving electrode of the touch sensor panel as a reference receiving electrode, and a second test noise signal of a second frequency F2 is sensed at a second receiving electrode of the touch sensor panel, wherein a difference between the second frequency F2 and the driving frequency of the driving signal at the driving electrode of the touch sensor panel is less than a predetermined threshold; Based on the sensing result, determining a noise compensation gain of the second test noise signal with respect to the first test noise signal in terms of power and phase for a second frequency F2; Measuring a signal processing gain of an output signal of a predetermined signal processing chain portion after the second receiving electrode relative to an input signal with respect to power and phase for a second frequency F2, wherein the step of measuring a signal processing gain of an output signal of a predetermined signal processing chain portion after the second receiving electrode relative to an input signal with respect to power and phase for the second frequency F2 comprises: determining a power Ai and a phase θi of an input signal of said predetermined signal processing chain portion; Determining the power Ao and phase θo of the output signal of the predetermined signal processing chain portion; Compare the power and phase of the output signal with the power and phase of the input signal to obtain the power ratio Ao / Ai of the output signal to the input signal and the phase difference θ oi , where θ oi =θo-θi; Determining signal processing gain Among them A filt (F2) = Ao / Ai, θ filt (F2) = θo - θi, where j represents the imaginary unit; Based on the noise compensation gain and the signal processing gain, a noise compensation signal applied after the predetermined signal processing chain portion in case the display panel inputs a display signal is determined.

2. The method according to claim 1, further comprising: Identifying the various harmonic frequencies of the noise, wherein the various harmonic frequencies of the noise are frequencies of sub-harmonics of the horizontal synchronization signal HSync of the display panel, and determining the value of the second frequency F2 based on the driving frequency and the various harmonic frequencies of the noise, so that the difference between the second frequency F2 and the driving frequency is less than a predetermined threshold, wherein the predetermined signal processing chain portion is a part or all of the complete signal processing chain after the second receiving electrode, and wherein the reference signal is a signal including only noise.

3. The method according to claim 1, wherein The step of determining, based on the noise compensation gain and the signal processing gain, a noise compensation signal to be applied after the predetermined signal processing chain portion when the display panel inputs a display signal comprises: Based on the noise compensation gain and the signal processing gain, determining a product of the noise compensation gain and the signal processing gain as a comprehensive gain; In a case where the display panel inputs a display signal, sensing a first actual noise signal of a first frequency F1 at the first receiving electrode; Converting the first actual noise signal of the first frequency F1 into a first actual noise signal of the second frequency F2; Multiplying the first actual noise signal of the second frequency F2 by the integrated gain to calculate the power and phase of the predicted noise signal of the predetermined signal processing chain portion after the second receiving electrode; Setting the noise compensation signal to reduce or offset the power and phase of the calculated predicted noise signal; The method further includes: applying the noise compensation signal to actual signals sensed at a predetermined signal processing chain portion after the second receiving electrode when the display panel inputs a display signal.

4. The method according to claim 1, wherein The first receiving electrode and the second receiving electrode are the same receiving electrode, the first frequency F1 is different from the second frequency F2, wherein the difference between the first frequency F1 and the driving frequency is greater than the predetermined threshold, and the second frequency F2 is a times the first frequency F1, wherein a is a positive integer.

5. The method according to claim 3, wherein The step of determining the noise compensation gain of the second test noise signal with respect to the first test noise signal in terms of power and phase for the second frequency F2 based on the sensing result includes: Determining the power A1 and phase θ1 of the first test noise signal; Determining the power A2 and phase θ2 of the second test noise signal; Comparing the power and phase of the first test noise signal after being biased to the second frequency F2 with the power and phase of the second test noise signal, obtaining a power ratio A2 / A1 of the second test noise signal to the first test noise signal biased to the second frequency F2 and a phase residual θr, where θr=θ2-θ1*a; Based on the power ratio and the phase residual, the noise compensation gain G is obtained. c (Ac,θ c |F2)=A(F2)e jθc(F2) , where A(F2)=A2 / A1, θc(F2)=θ2-θ1*a, where j represents the imaginary unit.

6. The method according to claim 1, wherein The first receiving electrode and the second receiving electrode are different receiving electrodes, and the first frequency F1 and the second frequency F2 are the same.

7. The method according to claim 5, wherein: The step of determining the noise compensation gain of the second test noise signal with respect to the first test noise signal in terms of power and phase for the second frequency F2 based on the sensing result includes: Determining the power A1 and phase θ1 of the first test noise signal; Determining the power A2 and phase θ2 of the second test noise signal; Compare the power and phase of the first test noise signal with the power and phase of the second test noise signal to obtain the power ratio A2 / A1 of the second test noise signal to the first test noise signal and the phase difference θ d , where θ d =θ2-θ1; Based on the power ratio and phase difference, the noise compensation gain is obtained Where A(F2)=A2 / A1, θ d (F2) = θ2 - θ1, where j represents an imaginary unit.

8. The method according to claim 1, wherein The step of sensing the noise signal including the first test noise signal and the second test noise signal at the receiving electrode of the touch sensor panel when the reference signal is input to the display panel comprises: The average values of the power and the phase of the first test noise signal and the second test noise signal over time are sensed as a result of the sensing.

9. A system for reducing noise of a touch sensor panel attached to a display panel, comprising a sensing device configured to sense a first test noise signal of a first frequency F1 as a reference noise signal at a first receiving electrode of the touch sensor panel as a reference receiving electrode, and to sense a second test noise signal of a second frequency F2 at a second receiving electrode of the touch sensor panel when a reference signal is input to the display panel, wherein: a difference between the second frequency F2 and the driving frequency of the driving signal at the driving electrode of the touch sensor panel is less than a predetermined threshold; a first gain determining device configured to determine, based on a sensing result, a noise compensation gain of the second test noise signal with respect to the first test noise signal in terms of power and phase for a second frequency F2; The second gain determination device is configured to measure the signal processing gain of the output signal of the predetermined signal processing chain part after the second receiving electrode relative to the input signal with respect to the second frequency F2 in terms of power and phase, wherein the second gain determination device is configured to: determining a power Ai and a phase θi of an input signal of said predetermined signal processing chain portion; Determining the power Ao and phase θo of the output signal of the predetermined signal processing chain portion; Compare the power and phase of the output signal with the power and phase of the input signal to obtain the power ratio Ao / Ai of the output signal to the input signal and the phase difference θ oi , where θ oi =θo-θi; Determining signal processing gain Among them A filt (F2) = Ao / Ai, θ filt (F2) = θo - θi, where j represents the imaginary unit; The compensation device is configured to determine, based on the noise compensation gain and the signal processing gain, a noise compensation signal to be applied after the predetermined signal processing chain portion when the display panel inputs a display signal.

10. The system according to claim 9, wherein: Identifying the various harmonic frequencies of the noise, wherein the various harmonic frequencies of the noise are frequencies of sub-harmonics of the horizontal synchronization signal HSync of the display panel, and determining the value of the second frequency F2 based on the driving frequency and the various harmonic frequencies of the noise, so that the difference between the second frequency F2 and the driving frequency is less than a predetermined threshold, wherein the predetermined signal processing chain portion is a part or all of the complete signal processing chain after the second receiving electrode, and wherein the reference signal is a signal including only noise.

11. The system according to claim 9, wherein: The compensation device is configured as follows: Based on the noise compensation gain and the signal processing gain, determining a product of the noise compensation gain and the signal processing gain as a comprehensive gain; In a case where the display panel inputs a display signal, sensing a first actual noise signal of a first frequency F1 at the first receiving electrode; Converting the first actual noise signal of the first frequency F1 into a first actual noise signal of the second frequency F2; Multiplying the first actual noise signal of the second frequency F2 by the integrated gain to calculate the power and phase of the predicted noise signal of the predetermined signal processing chain portion after the second receiving electrode; Setting the noise compensation signal to reduce or offset the power and phase of the calculated predicted noise signal; In the case where the display panel inputs a display signal, the noise compensation signal is respectively applied to actual signals sensed at a predetermined signal processing chain portion after the second receiving electrode.

12. The system according to claim 9, wherein: The first receiving electrode and the second receiving electrode are the same receiving electrode, the first frequency F1 is different from the second frequency F2, wherein the difference between the first frequency F1 and the driving frequency is greater than the predetermined threshold, and the second frequency F2 is a times the first frequency F1, wherein a is a positive integer.

13. The system according to claim 12, wherein: The first gain determining device is configured to: Determining the power A1 and phase θ1 of the first test noise signal; Determining the power A2 and phase θ2 of the second test noise signal; Comparing the power and phase of the first test noise signal after being biased to the second frequency F2 with the power and phase of the second test noise signal, obtaining a power ratio A2 / A1 of the second test noise signal to the first test noise signal biased to the second frequency F2 and a phase residual θr, where θr=θ2-θ1*a; Based on the power ratio and the phase residual, the noise compensation gain G is obtained. c (Ac,θc|F2)=A(F2)e jθc(F2) , where A(F2)=A2 / A1, θc(F2)=θ2-θ1*a, where j represents the imaginary unit.

14. The system according to claim 9, wherein: The first receiving electrode and the second receiving electrode are different receiving electrodes, and the first frequency F1 and the second frequency F2 are the same.

15. The system according to claim 14, wherein: The first gain determining device is configured to: Determining the power A1 and phase θ1 of the first test noise signal; Determining the power A2 and phase θ2 of the second test noise signal; Compare the power and phase of the first test noise signal with the power and phase of the second test noise signal to obtain the power ratio A2 / A1 of the second test noise signal to the first test noise signal and the phase difference θ d , where θ d =θ2-θ1; Based on the power ratio and phase difference, the noise compensation gain is obtained. Where A(F2)=A2 / A1, θ d (F2) = θ2 - θ1, where j represents an imaginary unit.

16. The system according to claim 9, wherein: The sensing device is configured to: The average values of the power and the phase of the first test noise signal and the second test noise signal over time are sensed as a result of the sensing.

17. A touch display electronic system comprising: a display panel configured to have display pixels; A touch input device comprising a driving unit, a sensing unit, a control unit, and a touch sensor panel attached to a display panel, wherein the touch sensor panel comprises a plurality of driving electrodes and a plurality of receiving electrodes, the driving unit being configured to apply driving signals to the plurality of driving electrodes, the sensing unit receiving sensing signals from the plurality of receiving electrodes, and the sensing unit further comprising a signal processing chain for filtering and processing the signals received by the plurality of receiving electrodes; The control unit executes the method according to any one of claims 1 to 8.

18. An electronic device comprising: a memory for storing instructions; A processor, configured to read instructions in the memory and execute the method according to any one of claims 1 to 8.

19. A non-transitory storage medium having stored thereon instructions, in, When the instructions are read by a processor, the processor is caused to execute the method according to any one of claims 1 to 8.

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