KR102219770B1 - Electronic device having a touch sensor and driving method thereof - Google Patents

Abstract

The present invention relates to an electronic device having a touch sensor including a display panel, a touch screen, and a touch screen controller. The display panel displays an image. The touch screen is located in the display panel. The touch screen controller outputs a touch drive signal during a touch screen driving period sensing the touch screen and senses touch data and auxiliary touch data from the touch screen. The touch screen controller varies frequencies for sensing touch data and auxiliary touch data.

Description

Electronic device having a touch sensor and its driving method {ELECTRONIC DEVICE HAVING A TOUCH SENSOR AND DRIVING METHOD THEREOF}

The present invention relates to an electronic device having a touch sensor and a driving method thereof.

Various electronic devices, such as home appliances and portable information devices, are being replaced with touch sensors from button-type switches in accordance with the trend of lightening and slimming. Accordingly, electronic devices such as recently released display devices have a touch sensor (or touch screen).

Touch sensors are essentially adopted in portable information devices such as smart phones, and are widely applied to notebook computers, computer monitors, and home appliances. Recently, a technology for incorporating a touch sensor into a pixel array of a display panel (hereinafter referred to as “in-cell touch sensor”) has been proposed.

In-cell touch sensor technology can install touch sensors on a display panel without increasing the thickness of the display panel. In an electronic device having an in-cell touch sensor, a period for driving sub-pixels (also referred to as a “display driving period”) and a period for driving the touch sensors in order to reduce mutual influence due to coupling of the sub-pixels and the touch sensors Time-division (also referred to as "touch screen driving period").

In-cell touch sensor technology uses electrodes connected to sub-pixels of a display panel as electrodes of touch sensors. For example, in the in-cell touch sensor technology, an example of dividing a common electrode for supplying a common voltage to pixels of a liquid crystal display and using it as an electrode of touch sensors has been proposed.

However, in the conventionally proposed in-cell touch sensor technology, it is difficult to cope with a problem in which noise is introduced when a touch is being performed (or when a finger approaches). Therefore, the conventional in-cell touch sensor technology is required to improve the noise problem.

The present invention for solving the problems of the above-described background art is to provide an in-cell touch sensor technology or an add-on mutual sensing technology capable of generating or selecting an optimal driving frequency. In addition, the present invention is to improve the signal-to-noise ratio (SNR) by implementing a device that is adaptive in real time to noise.

The present invention relates to an electronic device having a touch sensor including a display panel, a touch screen, and a touch screen controller as a means for solving the above problems. The display panel displays an image. The touch screen is located in the display panel. The touch screen controller outputs a touch drive signal during a touch screen driving period sensing the touch screen and senses touch data and auxiliary touch data from the touch screen. The touch screen controller varies frequencies for sensing touch data and auxiliary touch data.

The touch screen controller may calculate the presence or absence (or degree) of noise between the touch data and the auxiliary touch data, and change the driving frequency of the touch drive signal based on the frequency used by the data with the least noise.

The touch screen controller may obtain touch data by sensing all lines of the touch screen, and then additionally sense M (M is 2 or more) lines to obtain auxiliary touch data.

The touch screen controller may additionally sense M lines (where M is 2 or more), but may classify sections for obtaining auxiliary touch data to be discontinuous.

A sensing section in which touch data is obtained by sensing a line of the touch screen and a sensing section in which auxiliary touch data is obtained may be divided.

The touch screen control unit receives a noise calculation unit that calculates the presence (or degree) of noise between the touch data and the auxiliary touch data, and receives the frequency information used by the data with the least noise from the noise calculation unit and changes the driving frequency of the touch drive signal. It may include a frequency generator.

In another aspect, the present invention relates to a method of driving an electronic device having a touch sensor. A method of driving an electronic device having a touch sensor includes the steps of: supplying a touch drive signal generated based on an f0th frequency to a touch screen and sensing the touch screen to obtain touch data for all lines; Supplying a touch drive signal generated based on an f1th frequency different from the f0th frequency to the touch screen and sensing a selected line of the touch screen to obtain first auxiliary touch data; Supplying a touch drive signal generated based on an f2 frequency different from the f0 and f1 frequencies to the touch screen and sensing a selected line of the touch screen to obtain second auxiliary touch data; And analyzing noise between the touch data, the first auxiliary touch data, and the second auxiliary touch data, changing the driving frequency to a frequency with the lowest noise, generating a touch driving signal based on the changed driving frequency, and supplying it to the touch screen. It may include steps.

The first and second auxiliary touch data may be obtained from a line overlapping the line from which the touch data was acquired.

The present invention has an effect of providing an in-cell touch sensor technology or an add-on mutual sensing technology capable of generating or selecting an optimal driving frequency (selecting the most sensitive driving frequency) based on the presence (or degree) of noise. In addition, the present invention has the effect of improving the signal-to-noise ratio (SNR) by implementing a device adaptive to noise in real time by detecting the presence or absence of noise and changing a driving frequency based on the detected data.

1 is a block diagram schematically showing a configuration of a display device according to a first embodiment of the present invention.
2 is an exemplary view schematically showing a touch sensor of a touch screen.
3 is an exemplary view showing a touch screen made of a common electrode.
4 is a waveform diagram illustrating an in-cell touch method of time division driving technology.
5 is an exemplary view showing a touch screen to describe a sensing concept for each line of a self-touch sensing method.
6 is an exemplary view for explaining a block of the driving circuit shown in FIG. 5.
7 is a diagram for describing a driving system of a self-touch sensing method.
8 is an exemplary view for explaining the operation of the driving circuit shown in FIG. 6.
9 is a view showing the inner block of the microcontroller according to the first embodiment of the present invention.
10 is a waveform diagram showing a signal output from a microcontroller and an operation of a touch screen driving circuit according to the first embodiment of the present invention.
11 is a view showing a sensing operation for obtaining touch data and auxiliary touch data according to the first embodiment of the present invention.
12 is a diagram illustrating a sensing operation for obtaining touch data and auxiliary touch data according to a second embodiment of the present invention.
13 is a flowchart illustrating a sensing operation for obtaining touch data and auxiliary touch data according to a third embodiment of the present invention.
14 is a view showing an example of changing the driving frequency according to the present invention.

Hereinafter, specific details for carrying out the present invention will be described with reference to the accompanying drawings.

An electronic device having a touch sensor according to the present invention is implemented as a television, a set-top box, a navigation system, a video player, a Blu-ray player, a personal computer (PC), a home theater, and a mobile phone.

An electronic device having a touch sensor according to the present invention is implemented based on, for example, a display device having a display panel. The display panel may be a flat panel display panel such as a liquid crystal display panel, an organic light emitting display panel, an electrophoretic display panel, and a plasma display panel, but is not limited thereto. However, in the following description, for convenience of description, a liquid crystal display panel will be described as an example.

<First Example>

1 is a block diagram schematically showing the configuration of a display device according to a first embodiment of the present invention, FIG. 2 is an exemplary view schematically showing a touch sensor of a touch screen, and FIG. 3 is a touch screen made of a common electrode. And FIG. 4 is an exemplary waveform diagram for explaining a time division driving technique of an in-cell touch method.

1, the display device according to the first embodiment of the present invention includes a timing controller 20, a data driving circuit 12, a scan driving circuit 14, a liquid crystal display panel DIS, and a touch screen. TSP), a touch screen driving circuit 30 and a microcontroller 40 are included.

The timing controller 20 controls the data driving circuit 12 and the scan driving circuit 14. The timing controller 20 is digital with timing signals such as a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a data enable signal (Data Enable, DE), and a main clock (MCLK) from a host system (not shown). Video data (RGB) is supplied.

The timing controller 20 is a scan driving circuit based on scan timing control signals such as a gate start pulse (GSP), a gate shift clock, and a gate output enable signal (GOE). Control (14). The timing controller 20 is a data driving circuit based on data timing control signals such as a source sampling clock (SSC), a polarity control signal (Polarity, POL), and a source output enable signal (Source Output Enable, SOE). Control 12.

The data driving circuit 12 converts digital video data RGB input from the timing controller 20 into an analog positive/negative gamma compensation voltage to generate a data voltage. The data driving circuit 12 supplies a data voltage through the data lines D1 to Dm.

The scan driving circuit 14 sequentially generates gate pulses (or scan pulses) synchronized with the data voltage. The scan driving circuit 14 supplies a gate pulse through the gate lines G1 to Gn.

The liquid crystal display panel DIS displays an image based on a gate pulse supplied from the scan driving circuit 14 and a data voltage supplied from the data driving circuit 12. The liquid crystal display panel DIS includes a liquid crystal layer formed between two substrates. The liquid crystal display panel DIS may be implemented in any known liquid crystal mode, such as a twisted nematic (TN) mode, a vertical alignment (VA) mode, an in plane switching (IPS) mode, and a fringe field switching (FFS) mode.

Sub-pixels of the liquid crystal display panel DIS are defined by data lines (D1 to Dm, where m is an integer greater than or equal to 2) and gate lines (G1 to Gn, where n is an integer greater than or equal to 2). One sub-pixel is a TFT (Thin Film Transistor) formed at the intersections of the data line and the gate line, a pixel electrode charging the data voltage, and a storage capacitor (Cst) connected to the pixel electrode to maintain the voltage of the liquid crystal cell. ), etc.

A black matrix, a color filter, and the like are formed on the upper substrate of the liquid crystal display panel DIS. A thin film transistor, a pixel electrode, and a common electrode are formed on the lower substrate of the liquid crystal display panel DIS. The liquid crystal display panel DIS may be implemented in a color filter on TFT (COT) structure. In this case, the black matrix and the color filter may be formed on the lower substrate of the liquid crystal display panel DIS.

The common electrode to which the common voltage is supplied may be formed on the upper or lower substrate of the liquid crystal display panel DIS. Polarizing plates are attached to the upper and lower substrates of the liquid crystal display panel DIS, respectively, and an alignment layer for setting a pretilt angle of the liquid crystal is formed on an inner surface in contact with the liquid crystal.

A column spacer is formed between the upper and lower substrates of the liquid crystal display panel DIS to maintain a cell gap of the liquid crystal cell. A backlight unit is disposed under the rear surface of the lower polarizing plate of the liquid crystal display panel DIS. The backlight unit is implemented in an edge type or a direct type to provide light to the liquid crystal display panel DIS.

The touch screen driving circuit 30 senses the presence or absence of a touch using a touch screen TSP. The touch screen driving circuit 30 includes a driving circuit for generating a driving voltage for driving the touch sensor and a sensing circuit for sensing the touch sensor and generating data for detecting the presence or absence of a touch and coordinate information. The driving circuit and the sensing circuit of the touch screen driving circuit 30 may be formed in the form of one integrated circuit (IC) or may be separated by function.

The touch screen driving circuit 30 is formed on an external substrate connected to the liquid crystal display panel DIS. The touch screen driving circuit 30 is connected to the touch screen TSP through sensing lines L1 to Li, where i is a positive integer. The touch screen driving circuit 30 senses the presence or absence of a touch and a location based on a variation in capacitance between touch sensors formed on the touch screen TSP.

A variation in capacitance occurs between a location where the user's finger is in contact and a location where the user's finger is not in contact, and the touch screen driving circuit 30 senses the presence or absence of a touch in a manner that senses the capacitance. The touch screen driving circuit 30 generates touch data on the presence or absence of a touch and the location and transmits it to the microcontroller 40.

The microcontroller 40 controls the touch screen driving circuit 30. The microcontroller 40 receives a first touch synchronization signal ITsync from the timing controller 20. The microcontroller 40 generates a second touch synchronization signal Tsync that controls the touch screen driving circuit 30 based on the first touch synchronization signal ITsync.

The microcontroller 40 exchanges touch data or other signals based on the interface IF defined between the touch screen driving circuit 30 and the like. The microcontroller 40 transmits touch data to a host system (not shown). Meanwhile, in the above description, the microcontroller 40 and the touch screen driving circuit 30 are shown as separate blocks, but this may be formed by the touch screen controllers 30 and 40 formed in the form of one integrated circuit (IC). .

As shown in FIG. 2, the touch screen TSP is implemented to be embedded in the display area AA of the liquid crystal display panel DIS in an in-cell self touch (hereinafter abbreviated as self-touch) method. Can be. The self-touch sensing type touch screen TSP uses an electrode formed in a block (or point) form by an electrode formed inside the liquid crystal display panel DIS as a touch sensor.

"C1, C2, C3, C4" formed in the display area AA of the liquid crystal display panel DIS means a touch sensor (or touch sensor block), and "L1, L2, L3, L4 ~ Li" is a touch sensor It means the sensing line connected to. Hereinafter, an example of configuring a touch sensor with a common electrode will be described.

As shown in FIG. 3, the self-touch sensing type touch screen TSP has M-th subpixels (for example, 32 horizontal subpixels) formed inside the liquid crystal display panel DIS. * The common electrodes COM included in 32 vertical subpixels) form one touch sensor. That is, the touch sensors C1, C2, C3, and C4 are defined by the common electrodes COM separately formed on the liquid crystal display panel DIS.

As shown in FIGS. 1 to 4, a display device having a self-touch sensing type touch screen includes a display driving period Td for displaying an image on the liquid crystal display panel DIS and a touch sensing touch screen TSP. The screen driving period Tt is divided in time. That is, the display driving period Td and the touch screen driving period Tt are time-division driven.

The touch screen driving circuit 30 supplies the touch driving signal Tdrv through the sensing lines L1 to Li connected to the self-touch sensing touch screen TSP.

As described above, the touch driving signal Tdrv is supplied to the sensing lines L1 to Li during the touch screen driving period Tt. On the other hand, the common voltage Vcom is supplied to the sensing lines L1 to Li during the display driving period Td. The touch drive signal Tdrv is generated in the form of an AC signal. The time division driving of the display driving period Td and the touch screen driving period Tt is performed by the touch synchronization signal Tsync.

FIG. 5 is an exemplary view showing a touch screen to explain a sensing concept for each line of a self-touch sensing method, FIG. 6 is an exemplary view for explaining a block of the driving circuit shown in FIG. 5, and FIG. 7 is a self-touch sensing It is a diagram for explaining the driving system of the method, and FIG. 8 is an exemplary diagram for explaining the operation of the driving circuit shown in FIG. 6.

As shown in FIG. 5, driving circuits 12a to 12c and 30a to 30c for driving the touch screen TSP are disposed on one side (lower) of the touch screen TSP. The touch sensing area of the touch screen TSP may be divided into three areas based on, for example, the vertical direction y. As described above, the reason why the touch sensing area is separately illustrated in the vertical direction y is to show that the design can be changed according to the physical range that the driving circuit can drive.

The first driving circuits 12a and 30a are disposed in the left area to sense the first touch channel TCH1, and the second driving circuits 12b and 30b are disposed in the center area to sense the second touch channel TCH2. Then, the third driving circuits 12c and 30c are disposed in the right area to sense the third touch channel TCH3.

The first to third driving circuits 12a to 12c and 30a to 30c include data driving circuits 12a to 12c and touch screen driving circuits 30a to 30c, respectively. That is, the data driving circuits 12a to 12c and the touch screen driving circuits 30a to 30c are each combined one by one to be implemented as an integrated circuit (IC) in the form of an integrated driving circuit.

The first to third driving circuits 12a to 12c and 30a to 30c may time-division sensing the touch screen TSP line by line by an internal or external mux unit. For example, the sensing area of the touch screen TSP may be divided into 16 areas based on the horizontal direction x. As described above, the reason why the touch sensing area is separately illustrated in the horizontal direction x is to show that a design change may occur according to a physical range in which one driving circuit can be driven.

The first to third driving circuits 12a to 12c and 30a to 30c are formed by a mux unit included inside or outside the first mux line MUX1 to the 16th mux line MUX16 of the touch screen TSP. Alternatively, the I-th mux line (I is an integer greater than or equal to 2) may be sequentially sensed, and the sensing of the touch screen TSP may start from the top and proceed in the y2 direction to be completed from the bottom.

As shown in FIG. 6, the integrated driving circuit 50 may be configured such that the data driving circuit 12a is disposed in the center and the touch screen driving circuits 30aL and 30aR are disposed on the left and right sides thereof. The data pads SPAD of the data driving circuit 12a are connected to the data lines of the liquid crystal display panel, and the touch pads TPADL and TPADR of the touch screen driving circuits 30aL and 30aR are connected to the sensing lines of the touch screen. .

As shown in FIG. 7, when the data driving circuits 12a to 12c and the touch screen driving circuits 30a to 30c are implemented in the form of an integrated driving circuit 50, they have the following driving system.

The timing controller 20 generates a first touch synchronization signal ITsync. The timing controller 20 controls the microcontroller 40 based on the first touch synchronization signal ITsync.

The microcontroller 40 generates a second touch synchronization signal Tsync, a clock signal CLK, and a pulse width modulation signal PWM_TX based on the first touch synchronization signal ITsync supplied from the timing controller 20. . The microcontroller 40 controls the integrated driving circuit 50 based on the second touch synchronization signal Tsync, the clock signal CLK, and the pulse width modulated signal PWM_TX.

The integrated driving circuit 50 drives the touch screen based on the second touch synchronization signal Tsync, the clock signal CLK, and the pulse width modulated signal PWM_TX. The integrated driving circuit 50 exchanges touch data sensed from the touch screen and the like through an interface IF defined together with the microcontroller 40.

The self-touch sensing method described above can be implemented in a structure capable of dividing the touch sensor of the touch screen (TSP) into electrode units and sensing all points (All Point Sensing). In addition, it is possible to minimize the load on the liquid crystal display panel (LFD: Load Free Driving) by supplying a touch drive signal, a voltage, and a signal having the same phase (data signal, gate signal, and common voltage).

As shown in FIGS. 7 and 8, the integrated driving circuit 50 performs touch sensing using switched-capacitor circuits as a charge transferring method. This circuit is composed of a first stage having a pre-amp and the like and a second stage having an integrator/sample and hold amp.

_{The first stage acquires the first gain voltage V OUT1} using a non-inverting pre-amp or the like. _{The first gain voltage V OUT1} output from the first stage is expressed as Equation 1 below.

[Equation 1]

In Equation 1, C _{P _ RX} denotes initial capacitance, C _Finger denotes the capacitance of the finger due to touch, and V _mod denotes the modulation voltage (drive voltage) that forms the driving pulse signal. ), C _CR means the capacitance for charge removal to remove the initial capacitance, C _FB means the feedback capacitance to convert the amount of charge into a voltage, and V _CR means the charge removal It means the reference voltage.

In the second stage, the second gain voltage V _OUT2 is acquired using an integrator/sample and hold amp. _{The second gain voltage V OUT2} output from the second stage is expressed as Equation 2 below.

[Equation 2]

In Equation 2, CF denotes a feedback capacitance for converting an amount of charge into a voltage, and Cs denotes a storage capacitance.

_{The integrated driving circuit 50 applies a driving pulse signal (V MOD} ) to a pre-amp connected to the sensing lines (L1 to Li) of the touch screen (TSP) when a finger is in contact and when the finger is not touched. Depending on the output voltage of the pre-amp (Pre AMP) stage varies.

The driving pulse signal V _MOD is in phase with the pulse width modulated signal PWM_TX output from the microcontroller 40 and the voltage level is a different signal. The integrated driving circuit 50 may perform charge removal in order to subtract the initial capacitance. The output value of the pre-amp is accumulated through an integrator according to the number of _{driving pulse signals V MOD.}

Meanwhile, in the above description, sensing the presence and location of a touch of the touch screen TSP using a self-touch sensing method has been described as an example. However, the touch screen (TSP) may sense the presence or absence of a touch and a location using a mutual touch sensing or an Add On Mutual Sensing method. In this case, it is referred to that, on the liquid crystal display panel DIS, Tx lines for transmitting a touch driving signal and Rx lines for receiving a capacitance value varied by a touch are formed.

As described above, the self-touch sensing method described in the present invention may be implemented based on self-capacitance or mutual capacitance.

9 is a view showing the internal block of the microcontroller according to the first embodiment of the present invention, Figure 10 is a waveform showing the operation of the signal and the touch screen driving circuit output from the microcontroller according to the first embodiment of the present invention Is also.

7, 10, and 11, the microcontroller 40 and the integrated driving circuit 50 may be defined as a communication interface (SPI IF) in a serial peripheral interface bus (Serial Peripheral Interface Bus) method. . As described above, the microcontroller 40 and the integrated driving circuit 50 may also be integrated into one integrated circuit, and when they are integrated, an interface (SPI IF) existing between them is omitted.

The microcontroller 40 includes a noise calculation unit 44 and a frequency generation unit 46. Other configurations such as interface circuits and control circuits are omitted. The noise calculator 44 calculates the presence (or degree) of noise (or detects touch data using a driving frequency with low noise) based on the analysis of the touch data. The frequency generator 46 generates or selects an optimal driving frequency based on the presence (or degree) of noise.

The noise calculating unit 44 receives (or reads) auxiliary touch data AUX1 and AUX2 together with touch data from the integrated driving circuit 50. The number of auxiliary touch data AUX1 and AUX2 may be M (M is 2 or more), but in the present invention, two are set for convenience of description.

The touch data (Touch Raw Data) and auxiliary touch data (AUX1, AUX2) read from the integrated driving circuit 50 are stored in the first storage unit 41 and the second storage unit 42. The first storage unit 41 and the second storage unit 42 are physically separated for ease of description, and they may be stored in the same storage unit. The storage unit may be implemented as a memory or a register.

The touch data (Touch Raw Data) is data that can be obtained through sensing progressed from the first mux line (MUX1) to the 16th mux line (MUX16) of the touch screen (TSP). On the other hand, the auxiliary touch data AUX1 and AUX2 are auxiliary data MUXa, which can be obtained through sensing of two selected lines among the first mux line MUX1 to the 16th mux line MUX16 of the touch screen TSP. MUXb).

The noise calculation unit 44 calculates the degree of noise based on the analysis of touch data (Touch Raw Data) and auxiliary touch data (AUX1, AUX2), and calculates (or detects) the driving frequency used by the data with the least noise. )do. The presence or absence of noise can be confirmed by analyzing the entire touch data (Touch Raw Data) generated while varying the driving frequency.

For example, the touch data (Touch Raw Data), the first auxiliary touch data (Aux1), and the second auxiliary touch data (Aux2) or more three data read by the noise calculating unit 44 are sensed based on different driving frequencies. Data. The noise calculator 44 compares and analyzes the three pieces of data and extracts data having the least noise among them. In addition, the noise calculator 44 transmits driving frequency information used by the data having the least noise to the frequency generator 46.

The frequency generator 46 serves to generate or select an optimal driving frequency based on driving frequency information used by data having the least noise. More specifically, the frequency generator 46 generates or selects a touch drive signal with an operation frequency that minimizes the influence of noise while changing or changing to a driving frequency with no noise or relatively low noise (a kind of frequency hopping). Plays a role.

For example, the frequency generator 46 includes the f0th frequency (PWM(f0)) used by the touch data (Touch Raw Data), the f1th frequency (PWM(f1)) used by the first auxiliary touch data (Aux1), and the second It has information on the f2th frequency (PWM(f2)) used by the auxiliary touch data Aux2.

For this reason, when information indicating that the first auxiliary touch data Aux1 is data with the least noise is transmitted from the noise calculation unit 44, the frequency generation unit 46 modulates the pulse width of the f1 frequency PWM(f1). Outputs a signal (PWM_TX).

The integrated driving circuit 50 displays a screen during the first display driving period Td1 when displaying an image on the liquid crystal display panel. On the other hand, the integrated driving circuit 50 senses the touch screen (TSP) based on the pulse width modulated signal (PWM_TX) transmitted from the frequency generator 46 during the first touch screen driving period (Tt1) and transmits the touch data. And transmits the generated touch data to the microcontroller 40.

The integrated driving circuit 50 drives at least one of the f0th frequency (PWM(f0)), the f1th frequency (PWM(f1)) and the f2th frequency (PWM(f2)) in response to the pulse width modulated signal (PWM_TX). A touch drive signal is generated with a frequency, and the generated touch drive signal is output. At this time, the f0th frequency (PWM(f0)), the f1th frequency (PWM(f1)), and the f2th frequency (PWM(f2)) are defined as a fixed frequency or a variable that changes for each N (N is an integer of 1 or more) frames. It can be defined by frequency.

The reason for using a variable frequency is that the use environment of the device is not always constant. Therefore, if a reference frequency or a variable frequency capable of varying the frequency within a certain range of a set frequency is used, it is possible to find an appropriate optimal frequency in the use environment of the device.

In addition, in FIG. 10, Tsync means a touch synchronization signal, PWM_TX means a waveform of a touch drive signal, MUX means a timing (or section) accumulated by sensing the touch screen (TSP), and ADC (ADC 1 ^st ~ ADC 16 ^th , AUX1, AUX2) means the timing (or period) of converting the sensed analog state touch data into a digital state, and SPI (SPI 1 ^st ~ SPI 16 ^th , AUX1, AUX2) is digital It refers to the timing (or interval) of transferring data data converted to a state to the microcontroller through the SPI interface.

Hereinafter, various examples and descriptions are added to aid in understanding a sensing operation for obtaining touch data and auxiliary touch data.

11 is a view showing a sensing operation for obtaining touch data and auxiliary touch data according to the first embodiment of the present invention, and FIG. 12 is a sensing operation for obtaining touch data and auxiliary touch data according to the second embodiment of the present invention. It is a diagram showing the operation.

The first embodiment of the present invention supplies a touch drive signal generated based on the f0-th frequency f0 to the touch screen TSP and senses the touch screen TSP, as shown in FIG. 11A. Touch data MUX1 to MUX16 from the 1 mux line MUX1 to the 16th mux line MUX16 are obtained.

Next, as shown in (b) of FIG. 11, the touch drive signal generated based on the f1-th frequency f1 is supplied to the touch screen TSP, and the eighth mux line MUX8 of the touch screen TSP is sensed. Thus, the eighth mux line MUX8 is obtained as the first auxiliary touch data AUX1.

Next, as shown in (b) of FIG. 11, the touch drive signal generated based on the f2 frequency f2 is supplied to the touch screen TSP, and the eighth mux line MUX8 of the touch screen TSP is sensed. Thus, the eighth mux line MUX8 is obtained as the second auxiliary touch data AUX2.

The first embodiment of the present invention obtains touch data (MUX1 to MUX16) by sequentially sensing all lines of the touch screen (TSP) as above, and then additionally continuously sensing the selected two lines to provide auxiliary touch data (AUX1, AUX2). ). However, the auxiliary touch data AUX1 and AUX2 are redundantly sensed with the lines obtained by the touch data MUX1 to MUX16. In the above example, an intermediate mux line is selected and sensed as an example. However, in some cases, another mux line may be selected and sensed.

Hereinafter, other embodiments of the present invention are also based on the device described in the first embodiment of the present invention, but since there is only a difference in the sensing method, the description of the device is omitted to avoid duplication of description, and the difference in the sensing method. It will be explained mainly.

<Second Example>

The second embodiment of the present invention supplies a touch drive signal generated based on the f0-th frequency f0 to the touch screen TSP, and senses the touch screen TSP, as shown in FIG. 12A. Touch data MUX1 to MUX8 from the 1 mux line MUX1 to the eighth mux line MUX8 are obtained.

Next, as shown in (b) of FIG. 12, the touch drive signal generated based on the f1-th frequency f1 is supplied to the touch screen TSP, and the eighth mux line MUX8 of the touch screen TSP is sensed. Thus, the eighth mux line MUX8 is obtained as the first auxiliary touch data AUX1.

Next, as shown in (c) of FIG. 12, the touch driving signal generated based on the f2 frequency f2 is supplied to the touch screen TSP, and the eighth mux line MUX8 of the touch screen TSP is sensed. Thus, the eighth mux line MUX8 is obtained as the second auxiliary touch data AUX2.

Next, as shown in (d) of FIG. 12, a touch drive signal generated based on the f0-th frequency f0 is supplied to the touch screen TSP, and the ninth mux line MUX9 is sensed by sensing the touch screen TSP. Touch data (MUX9 to MUX16) from to the 16th mux line (MUX16) are obtained.

As described above, the present invention obtains touch data and auxiliary touch data different only from the touch data and the driving frequency during the sensing period, which is the touch screen driving period, and detects the presence or absence of noise by comparing the data values. In addition, a touch drive signal is generated based on the driving frequency used for the data value with the least noise.

Meanwhile, as previously described, the touch data MUX1 to MUX16 and the auxiliary touch data AUX1 and AUX2 are used as indicators for using the driving frequency with the least noise when sensing the touch screen.

Meanwhile, in the above description, it has been described as an example that the touch driving signal generated based on the f0th frequency f0 is always used during a period in which normal (or regular) touch data is sensed. However, if the f1th frequency (f1) or f2th frequency (f2) through the previous sensing has the lowest noise, the f1th frequency (f1) or the f2th frequency (f2) during the period of sensing normal (or normal) touch data Of course, a touch drive signal may be generated based on.

Hereinafter, a method for a sensing operation for obtaining touch data and auxiliary touch data according to the present invention will be described.

13 is a flowchart illustrating a sensing operation for obtaining touch data and auxiliary touch data according to a third embodiment of the present invention, and FIG. 14 is a view showing an example of changing a driving frequency according to the present invention.

First, a touch drive signal generated based on the f0-th frequency f0 is supplied to the touch screen, and normal touch data for all mux lines is obtained by sensing the touch screen (S110). During this period, a device having a touch sensor performs a normal touch operation.

Next, the touch drive signal generated based on the f1 frequency f1 is supplied to the touch screen, and the first mux line Mux1 of the touch screen is sensed to transmit the first mux line Mux1 to the first auxiliary touch data ( It is obtained as an auxiliary Mux1) (S120). During this period, a device having a touch sensor performs a first auxiliary touch operation.

Next, the touch driving signal generated based on the f2 frequency f2 is supplied to the touch screen, and the second mux line Mux2 of the touch screen is sensed to transmit the second mux line Mux2 to the second auxiliary touch data ( It is obtained as an auxiliary Mux2) (S130). During this period, the device having the touch sensor performs a second auxiliary touch operation.

Next, the noise between the normal touch data (Normal Mux), the first auxiliary touch data (Aux 1 Mux) and the second auxiliary touch data (Aux 2 Mux) is analyzed, and the noise of the driving frequency used for which data is small is calculated. (Or detect).

For example, if the noise of the f0th frequency f0 used for the normal touch data (Normal Mux) is the lowest, the driving frequency is set to the f0th frequency f0 as before (S151; f0(NEW) = f0( PRE)). Accordingly, a touch drive signal for performing a normal touch operation in the next touch frame is generated based on the f0th frequency f0.

On the other hand, if the noise of the f1 frequency f1 used for the first auxiliary touch data (Aux 1 Mux) is the lowest, the driving frequency is set as the f1 frequency f1 as a new one (S153; f0 (NEW). ) = f1(PRE)). Accordingly, a touch drive signal for performing a normal touch operation in the next touch frame is generated based on the f1th frequency f1.

On the other hand, if the noise of the f2 frequency f2 used for the second auxiliary touch data Aux 2 Mux is the lowest, the driving frequency is set to a new f2 frequency f2 unlike the previous one (S155; f0 (NEW) ) = f2(PRE)). Accordingly, a touch drive signal for performing a normal touch operation in the next touch frame is generated based on the f2th frequency f2.

Next, the touch drive signal generated based on the driving frequency with the lowest noise is supplied to the touch screen, and normal touch data for all mux lines (Full Mux) is obtained by sensing the touch screen (S160). During this period, a device having a touch sensor performs a normal touch operation.

In summary, the present invention senses all mux lines at the f0th frequency f0 in order to secure normal touch data (Touch Raw Data). In addition, the first auxiliary touch data (Aux 1 Mux) and the second auxiliary touch data (Aux 2 Mux) are respectively sensed at the f1 frequency f1 and the f2 frequency f2.

In the subsequent analysis process, by comparing the values of the touch data (if at least one of the touch data values is different, it is determined that there is noise), it is possible to know whether or not noise has occurred. At this time, if the frequency for sensing the touch data is set as f1th frequency f1 <f0th frequency f0 <f2th frequency f2, noise tendency with respect to the driving frequency can be known.

For example, in the case of hopping only at three frequencies, the driving frequency of the touch driving signal is continuously variable in an adaptive form by finding a frequency with the least noise in the form of FIG. 14. For example, f0(150Hz) -> f1(100Hz) -> f2(200Hz) -> f0(150Hz) -> f2(200Hz) -> f1(100Hz). Note that frequency hopping occurs repeatedly.

As another example, the driving frequency with the least noise is again set to the f0'th frequency (f0'), and the touch driving of the next cycle is performed. The driving frequencies for performing touch driving at the f0'th frequency f0' and sensing auxiliary touch data are the f1'th frequency f1' and the f2'th frequency f2'. Further, the driving frequency is set to a different f1'th frequency (f1') <f0'th frequency (f0') <f2'th frequency (f2').

By obtaining auxiliary touch data in addition to normal touch data in the manner described above, detecting the presence or absence of noise, and changing a driving frequency based on the detected data, a device adaptive to noise can be implemented in real time.

Meanwhile, in the above driving method, the first embodiment in which normal touch data is obtained through all the mux lines of the touch screen and then auxiliary touch data is obtained through a specific mux line is described as an example.

However, as described in the embodiments of the present invention, the auxiliary touch data can be obtained even while normal touch data is obtained. Meanwhile, a section in which auxiliary touch data is obtained for analysis of the presence or absence of noise and the driving frequency is changed based on this may be performed in J frames (J is an integer greater than or equal to 1) or every frame.

The present invention has an effect of providing an in-cell touch sensor technology or an add-on mutual sensing technology capable of generating or selecting an optimal driving frequency (selecting the most sensitive driving frequency) based on the presence (or degree) of noise. In addition, the present invention has the effect of improving the signal-to-noise ratio (SNR) by implementing a device adaptive to noise in real time by detecting the presence or absence of noise and changing a driving frequency based on the detected data.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above is in other specific forms without changing the technical spirit or essential features of the present invention by those skilled in the art. It will be appreciated that it can be implemented. Therefore, the embodiments described above are illustrative in all respects and should be understood as non-limiting. In addition, the scope of the present invention is indicated by the claims to be described later rather than the detailed description. In addition, all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

20: timing controller 12: data driving circuit
14: scan driving circuit DIS: liquid crystal display panel
TSP: touch screen 30: touch screen drive circuit
40: microcontroller 44: noise calculation unit
46: frequency generator 50: integrated driving circuit
L1 ~ Li: sensing line Tt: touch screen driving period
Tdrv: touch drive signal

Claims (8)

A display panel that displays an image;
A touch screen positioned within the display panel; And
During the touch screen driving period for sensing the touch screen every frame, a reference touch driving signal having a reference driving frequency is output to sense touch data from all lines of the touch screen, and a first driving frequency lower than the reference driving frequency The touch is performed by outputting a first touch driving signal having a and sensing first auxiliary touch data from at least one line of the touch screen, and outputting a second touch driving signal having a second driving frequency higher than the reference driving frequency. Including a touch screen controller for sensing second auxiliary touch data from at least one line of the screen,
The touch screen controller analyzes noise between the touch data, the first auxiliary touch data, and the second auxiliary touch data, and the reference driving frequency of the reference touch driving signal of the next frame based on the frequency used by the data with the least noise. Electronic device having a touch sensor to change to. delete delete The method of claim 1,
An electronic device having a touch sensor, wherein a section in which the first auxiliary touch data and the second auxiliary touch data are obtained is divided to be discontinuous. The method of claim 1,
An electronic device having a touch sensor, wherein a sensing section for obtaining the touch data and a sensing section for obtaining the first and second auxiliary touch data are divided. The method of claim 1,
The touch screen controller
A noise calculator for calculating the presence or absence (or degree) of noise between the touch data and the first and second auxiliary touch data,
And a frequency generator configured to receive frequency information used by data having the least noise from the noise calculator and to change the reference driving frequency of the reference touch driving signal. Supplying a reference touch driving signal generated based on a reference driving frequency to the touch screen during the driving period of the touch screen for every frame and sensing the touch screen to obtain touch data for all lines;
During the touch screen driving period, a first touch driving signal generated based on a first driving frequency lower than the reference driving frequency is supplied to the touch screen, and first auxiliary touch data is transmitted by sensing a selected line of the touch screen. Obtaining step;
During the touch screen driving period, a second touch driving signal generated based on a second driving frequency higher than the reference driving frequency is supplied to the touch screen, and second auxiliary touch data is transmitted by sensing a selected line of the touch screen. Obtaining step; And
Analyzing noise between the touch data, the first auxiliary touch data, and the second auxiliary touch data, and changing the reference driving frequency of the reference touch driving signal of the next frame based on the driving frequency used by the data having the least noise Driving method of an electronic device having a touch sensor comprising a. The method of claim 7,
The method of driving an electronic device having a touch sensor, wherein the first and second auxiliary touch data are obtained from a line overlapping the line from which the touch data is acquired.

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