KR101653721B1 - Method for calibrating touch input sensing error caused by stray capacitance on image pixel - Google Patents

Abstract

Discloses a method of calibrating a touch input measurement result of an input / output device using a common electrode included in a display device as a sensing electrode. The display state of each image pixel of the display device generates a parasitic capacitance that affects the touch input measurement result. The storage unit can store the numerical value of the influence of different parasitic capacitances in each display state. The processing unit corrects the touch input measurement result using the stored values. The value of the parasitic capacitance caused by a specific image pixel changes during one frame for updating the display device once, and therefore it is corrected by considering this.

Description

[0001] The present invention relates to a method for calibrating a touch input sensing error caused by parasitic capacitance of an image pixel,

The present invention relates to a method of calibrating a touch input sensing error due to a parasitic capacitance caused by an image pixel in a touch input sensing apparatus and an apparatus therefor.

User devices, which are called smart phones, smart pads, and laptop computers, have recently been disclosed as user devices that receive commands from a user and output the results corresponding to the commands to a display device. Particularly, in these user devices, a user input device for inputting a user's command may include a device disposed near the display screen of the user device and covering the entire area of the display screen. Examples of such a user input device include a so-called pressure sensitive type touch panel, an electrostatic type touch panel, and a stylus pen touch panel (hereinafter, simply referred to as a pen touch panel). The above touch panels are products based on different technologies (hereinafter referred to as touch input technology). Since each of the above technologies has its advantages and disadvantages, an attempt has been made to provide a more convenient user input experience by providing a combination of advantages of each other. The basic operating principle of each of the above technologies is disclosed in various documents.

The display device may be included in a common electrode connected to the reference potential. This common electrode can be used in a time division manner as a sensing electrode used in capacitive touch input. At this time, the value of the parasitic capacitance formed between the sensing electrode and the image pixels may be changed according to the display state of each image pixel of the display device when the sensing electrode is used. There is a problem that an unexpected error may occur in the output value of the touch input device when the value of the parasitic capacitance continuously changes.

The present invention provides a method and apparatus for correcting a touch input sensing error due to a parasitic capacitance caused by an image pixel in a touch input sensing apparatus.

According to an aspect of the present invention, there is provided an input / output device including a display unit including a plurality of pixel groups and a touch input sensing unit including a plurality of sensing electrodes. This apparatus includes a first pixel group Gk (Pk) whose display state is updated in a first time period T (pk) belonging to a first frame X having a predetermined time and including a plurality of image pixels, ); A first parasitic capacitance value Cs (Gk, k) formed between the first sensing electrode (Vcom, k) of the plurality of sensing electrodes and the first pixel group in accordance with the display state of the first pixel group, X-1), Cs (Gk, X)); And a touch sensing signal output unit for sensing whether or not a touch input is made using the capacitance change of the first sensing electrode. At this time, a first value Cs (Gk, X-1) of the first parasitic capacitance before the first time interval and a second value Cs (Gk, X-1) of the first parasitic capacitance after the first time period (Gk, X)) from the storage unit and multiplies the first value Cs (Gk, X-1) and the second value Cs (Gk, X) by a predetermined weight, To thereby correct the value output from the touch sensing signal output unit.

According to another aspect of the present invention, there is provided an input / output device including a display unit having a plurality of pixel groups each including a plurality of image pixels and a touch input sensing unit including a plurality of sensing electrodes, The input / output control device can be provided. At this time, the processing unit updates the display state of the first pixel group Gk among the plurality of pixel groups at a first time interval T (tk) belonging to a first frame X having a predetermined time . The storage unit stores the value of the first parasitic capacitance formed between the first sensing electrode (Vcom, k) of the plurality of sensing electrodes and the first pixel group according to the display state of the first pixel group (Cs (Gk, X-1), Cs (Gk, X)). And the processing section determines whether or not the first value Cs (Gk, X-1) of the first parasitic capacitance before the first time interval and the second value of the first parasitic capacitance after the first time interval (Cs (Gk, X)) from the storage unit and multiplying the first value Cs (Gk, X-1) and the second value Cs (Gk, X) by a predetermined weight And a value output from a touch sensing signal output unit for sensing whether or not the touch input is performed using the change in capacitance of the first sensing electrode is calibrated by using a representative value added thereto.

According to another aspect of the present invention, there is provided an input / output control apparatus including a processing section and a storage section, the input / output control apparatus including a display section having a plurality of pixel groups each including a plurality of image pixels and a touch input sensing section including a plurality of sensing electrodes It is possible to provide an input / output control method for controlling the apparatus. At this time, the storage unit may store the difference between the first sensing electrode (Vcom, k) among the plurality of sensing electrodes and the first pixel group according to the display state of the first pixel group (Gk) among the plurality of pixel groups (Cs (Gk, X-1), Cs (Gk, X)) of the first parasitic capacitance to be formed. Updating the display state of the first pixel group (Gk) in a first time period (T (tk) belonging to a first frame (X) having a predetermined time; (Cs (Gk, X-1)) of the first parasitic capacitance before the first time interval and a second value (Cs (Gk, X-1) of the first parasitic capacitance after the first time period , X) from the storage unit and multiplies the first value Cs (Gk, X-1) and the second value Cs (Gk, X) by a predetermined weight, A step of calibrating a value output from a touch sensing signal output unit that senses whether or not a touch input is performed using the capacitance change of the first sensing electrode.

The present invention can provide a method of correcting a touch input sensing error due to a parasitic capacitance caused by an image pixel and an apparatus therefor in the touch input sensing apparatus.

1 illustrates a cross-sectional structure of an input / output panel constituting an integrated input / output device in which a touch input device and a display device are combined according to an embodiment of the present invention.
2 illustrates a structure of an integrated input / output device according to an embodiment of the present invention.
FIG. 3 shows in more detail the configuration near the four VCOM electrodes on the upper left of FIG.
Fig. 4A shows the structure near the image pixel N11 shown in Fig. 3 in more detail.
FIG. 4B shows the structure near VCOM, 11 shown in FIG. 3 in more detail.
FIG. 5A is a diagram for explaining the configuration and operation principle of a circuit for detecting whether touch input has been performed on a specific common electrode VCOM, xx according to an embodiment of the present invention.
5B shows an example in which the waveform of the periodic voltage signal Vdp is provided in the form of a periodic AC waveform without a DC component
Fig. 5C shows a circuit structure according to an embodiment of the present invention for eliminating the influence of parasitic capacitance in the circuit of Fig. 4B.
FIG. 6 illustrates a display unit 1000 according to an embodiment of the present invention and a structure thereof in a matrix form.
FIG. 7 shows only the pixel group Gk among the pixel groups shown in FIG.
8 is a timing chart showing a timing chart in which a display state update of the pixel groups G1 to GN occurs in one frame and a rule for detecting information about a touch input to be detected by the Vcoms adjacent to the pixel groups G1 to GN As shown in Fig.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Also, the singular forms as used below include plural forms unless the phrases expressly have the opposite meaning.

1 illustrates a cross-sectional structure of an input / output panel constituting an integrated input / output device in which a touch input device and a display device are combined according to an embodiment of the present invention.

The input / output panel 1050 includes a thin film transistor array substrate 1020, a color filter array substrate 1030, a liquid crystal display panel having a liquid crystal layer 1040 filled between the two substrates 1020 and 1030, (BLU) 1060 formed on the lower side of the display unit 1020. [

The thin film transistor array substrate 1020 includes gate lines and data lines formed to cross each other on the first substrate 1021, thin film transistors formed at intersections of the gate lines and the data lines, A TFT array 1023 including pixel electrodes connected to the thin film transistors, and an alignment film 1025 coated thereon. The gate lines and the data lines are supplied with signals from the driving circuits through respective pad portions, and the thin film transistors can supply pixel voltage signals to the pixel electrodes in response to the scan signals supplied to the gate lines.

The color filter array substrate 1030 includes color filters 1033 formed on a second substrate 1031 in units of a liquid crystal cell, a black matrix 1035 for separating color filters and reflecting external light, A common electrode (Vcom) 1037 for supplying a common reference voltage to the common electrode (Vcom) 1037, and an alignment film 1039 applied thereon. At this time, the common electrode (Vcom) 1037 may be divided into several parts. That is, a plurality of common electrodes may exist. In an embodiment of the present invention, the plurality of common electrodes may be utilized as an element for touch input sensing.

2 illustrates a structure of an integrated input / output device according to an embodiment of the present invention.

The integrated input / output device may include an input / output panel 1050, a timing controller 1101, a data driver 1102, a gate driver 1103, a host computer 1120, and a touch IC. 2, only a first substrate 1021 and a plurality of common electrodes (Vcom) 1037 having gate lines and data lines in the input / output panel 1050 are shown for the sake of convenience.

The input / output panel 1050 may include a color filter array, a thin film transistor array, a liquid crystal layer disposed therebetween, and a spacer for maintaining the cell gap of the liquid crystal layer. The color filter array may include an upper substrate, a color filter formed on one surface of the upper substrate, a black matrix, and a common electrode (Vcom) formed on the color filter and the black matrix. The thin film transistor array includes a lower substrate and a plurality of data lines (DL) 1104 and a plurality of gate lines (GL) 1105, gate lines 1105, A thin film transistor formed in a region where the data line 1104 intersects and a pixel defined by the intersection of the gate line 1105 and the data line 1104. [ A lower polarizer may be disposed on the other surface of the lower substrate.

The backlight unit may be disposed below the input / output panel 1050. The backlight unit may include a plurality of light sources to uniformly irradiate the input / output panel 1050 with light. The backlight unit may be implemented as a direct type backlight unit or an edge type backlight unit. The light source of the backlight unit may include at least one of a hot cathode fluorescent lamp (HCFL), a cold cathode fluorescent lamp (CCFL), an external electro fluorescent lamp (EEFL), and a light emitting diode (LED).

The data driver 1102 can sample and latch the digital video data RGB under the control of the timing controller 1101. [ The data driver 1102 may convert the digital video data RGB to a positive / negative gamma compensation voltage to invert the polarity of the data voltage. The positive / negative polarity data voltages output from the data driver 1102 may be synchronized with gate pulses output from the gate driver 1103. Each of the source driver ICs of the data driver 1102 may be connected to the data lines 1104 of the input / output panel 1050 by a COG (Chip On Glass) process or a TAB (Tape Automated Bonding) process. The source drive IC may be integrated in the timing controller 1101 and implemented as a one-chip IC together with the timing controller 1101.

The gate driver 1103 sequentially outputs gate pulses (or scan pulses) in the display mode under the control of the timing controller 1101, and shifts the swing voltage of the output to the gate high voltage and the gate low voltage. The gate pulse output from the gate driver 1103 may be sequentially supplied to the gate lines 1105 in synchronization with the data voltage output from the data driver 1102. The gate high voltage may be a voltage equal to or higher than the threshold voltage of the thin film transistor T and the gate low voltage may be lower than the threshold voltage of the thin film transistor T. [ The gate drive ICs of the gate driver 1103 are connected to the gate lines 1105 of the lower substrate of the input / output panel 1050 through a TAP process or connected to the gate lines 1105 of the input / And may be formed directly on the lower substrate.

The timing controller 1101 uses a timing signal from the host computer 1120 to generate a data timing control signal for controlling the operation timing of the data driver 1102 and the polarity of the data voltage and an operation timing of the gate driver 1103 And generate a gate timing control signal for controlling.

The gate timing control signal may include a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal (GOE), and the like. The gate start pulse GSP is applied from the gate driver 1103 to the first gate driver IC which outputs the gate pulse first in every frame period, so as to control the shift start timing of the gate driver IC. The gate shift clock GSC is a clock signal commonly input to the gate drive ICs of the gate driver 1103 to shift the gate start pulse GSP. The gate output enable signal GOE can control the output timing of the gate drive ICs of the gate driver 1103.

The data timing control signal includes a source start pulse (SSP), a source sampling clock (SSC), a polarity control signal (POL), and a source output enable signal (SOE) . ≪ / RTI > The source start pulse SSP may be applied to the first source drive IC that samples the data first in the data driver 1102 to control the data sampling start timing. The source sampling clock SSC is a clock signal that controls the sampling timing of data in the source drive ICs based on the rising or falling edge. The polarity control signal POL can control the polarity of the data voltage output from the source drive ICs. The source output enable signal SOE can control the output timing of the source drive ICs. The source start pulse SSP and the source sampling clock SSC may be omitted if digital video data RGB is input to the data driver 1102 through the Low Voltage Differential Signaling (LVDS) interface.

The host computer 1120 transmits the digital video data RGB of the input image and the timing signals Vsync, Hsync, DE and MCLK necessary for the display driving through an interface such as an LVDS interface and a TMDS (Transition Minimized Differential Signaling) To the timing controller 1101.

In one embodiment of the present invention, the timing controller 1101, the data driver 1102, and the gate driver 1103 may be included in one DDI chip 2 (FIG. 6A). 6A shows an example in which the DDI chip 2 includes a timing controller 1101, a data driver 1102, and a gate driver 1103 for convenience of explanation.

Hereinafter, the common electrode 1037 may be referred to as a " VCOM electrode 1037 ". In this case, the common electrodes may be arranged in the form of an M * N matrix. In the example of FIG. 2, M = 6 and N = 6. Hereinafter, the common electrode 1037 intersecting in the p-th row and the q-th column may be denoted as VCOM, pq. For example, the common electrode 1037 intersecting in the second row and the third column may be denoted as VCOM, 23.

In one embodiment, the common electrodes 1037 may be used as a part for screen output in the first time period and as a part for confirming whether the touch input is performed in the second time period.

FIG. 3 shows in more detail the configuration in the vicinity of the four VCOM electrodes A1, B1, C1, and D1 on the upper left side of FIG.

The plurality of data lines DL1, DL2, DL3, ... extend in the vertical direction in the drawing, and the plurality of gate lines GL1, GL2, GL3, ... extend in the left- have. By controlling the potentials applied to the data lines DL1, DL2, DL3, ... and the gate lines GL1, GL2, GL3, ..., It is possible to control the image output from the image pixel. Here, the image pixels existing at the intersection are denoted by Nxy. For example, an image pixel at a node where the data line DL1 and the gate line GL1 intersect is denoted by N11.

In FIG. 3, two data lines and two gate lines are illustrated as one VCOM electrode. However, the number of data lines and gate lines passing through the area occupied by one VCOM electrode may be larger or smaller.

Fig. 4A shows the structure near the image pixel N11 shown in Fig. 3 in more detail.

Referring to FIG. 4A, the electric signal applied through the data line DL1 affects the transistor T11, in which the gate line GL1 adjusts the gate voltage of the transistor T11. At this time, the data line DL1, the gate line GL1, the transistor T11, and the pixel electrode VCOM 11 exist in the vicinity of the image pixel N11. There are various capacitors 61 to 66 between these components. Some of these capacitors 61-66 are intentionally formed, and others may be capacitors that occur unintentionally. In FIG. 4A, a total of six capacitors 61 to 66 are modeled, but they may be modeled by different numbers. Hereinafter, an explanation will be given on the assumption that six models are modeled.

Nevertheless, the touch input sensing characteristics are determined by the capacitors (64, 65, 66) directly connected to the VCOM, 11 and the capacitance (? Cx, 11) formed between the VCOM, 11 and the touch input tool I can understand. At this time, from the viewpoint of touch input processing, the capacitors 61 to 66 and the like can be collectively regarded as parasitic capacitors C11.

The parasitic capacitor C11 may be regarded as a capacitor having the nodes n11 to n12 as the first pole and the nodes n21 to n24 as the second pole.

In the circuit model shown in Fig. 4A, the parasitic capacitor C11 is connected to three points of VCOM, 11, a data line DL1, and a gate line GL1. One terminal of the parasitic capacitor C11 may be regarded as a portion connected to the VCOM 11 and the other terminal may be regarded as a portion connected to the data line DL1 and the gate line GL1.

Since the amount of charge flowing between the VCOM 11 and the capacitors 64, 65 and 66 changes together according to the variable electrical properties of the data line DL1 and the gate line GL1, the parasitic capacitor? And the symbol Δ is also included.

FIG. 4B shows the structure near VCOM, 11 shown in FIG. 3 in more detail.

Four picture pixels N11, N12, N21 and N22 can be formed because the two data lines DL1 and DL2 and the two gate lines GL1 and GL2 pass through the VCOM 11. Therefore, four parasitic capacitors C11, C12, C21 and C22 can be connected to the VCOM 11. A capacitance (? Cx, 11) may be formed between the VCOM 11 and the touch input tool 17 when a touch input is present in the VCOM 11. At this time, since the value of the capacitance? Cx, 11 varies depending on the presence or proximity of the touch input tool 17, the symbol?

FIG. 5A is a diagram for explaining the configuration and operation principle of a circuit for detecting whether touch input has been performed on a specific common electrode VCOM, xx according to an embodiment of the present invention.

The touch input sensing circuit 10 shown in FIG. 5A may include an operational amplifier 215 and an integrating capacitor Cf connected between the inverting input terminal and the output terminal of the operational amplifier 215. At this time, the voltage signal Vdp may be input to the non-inverting input terminal of the operational amplifier 215. [ For convenience, the input terminal 11 of the touch input sensing circuit 10 can be defined. The input terminal 11 may be the same terminal as the inverting input terminal of the operational amplifier 215. The input terminal 11 may be connected to VCOM, xx.

The voltage signal Vdp may be a signal having periodicity. Furthermore, the DC component may be a periodic signal having zero (zero), that is, an AC periodic signal. Or the voltage signal Vdp may not be a periodic signal, but may be a signal having a component of the frequency fc.

5A, the magnitude of the current flowing through the nodes Nx and xx is equal to the sum of the capacitances Cx and xx formed between the common electrodes VCOM and xx and the finger 17 and the parasitic capacitances Cp and xx It can be influenced by the size of the capacitance. This equivalent capacitance can be named Cxe. The parasitic capacitances Cp and xx represent the result of modeling all the parasitic capacitances connected to the common electrodes VCOM and xx as one capacitor. For example, in the case of the common electrode VCOM 11 shown in FIG. 4B, the parasitic capacitances Cp and xx may be modeled by one capacitor with the influence of the four parasitic capacitors C11, C12, C21 and C22.

In FIG. 5A, the process of determining whether or not a touch input has been made on the common electrodes VCOM, xx may be periodically updated, and when the update is necessary, the switch SWr may be reset to the on state for a while .

FIG. 5B shows an example in which the waveform of the periodic voltage signal Vdp shown in FIG. 5A is provided in the form of a periodic AC waveform without a DC component

5B shows an AC sine wave, FIG. 5B shows an AC triangle wave, and FIG. 5C shows an AC square wave. In each case, the output voltage Vo of the operational amplifier 215 outputs a waveform of the same or similar type as the AC sine wave, the AC triangle wave, and the AC square wave. The output voltage Vo may have a frequency component different from the center frequency fc, and the other frequency components may be (1) a frequency component inherent in the voltage signal Vdp, or (2) a voltage May be a frequency component generated by distortion from the signal (Vdp), or (3) a frequency component provided by noise introduced from the outside.

At this time, the amplitude of the output voltage Vo may be proportional to the magnitude of the above-described equivalent capacitance Cxe and tend to be inversely proportional to the magnitude of the integral capacitor Cf. Therefore, since the size of the integral capacitor Cf is known in advance, the magnitude of the equivalent capacitance Cxe can be calculated by measuring the amplitude of the output voltage Vo. At this time, if the values of the parasitic capacitances Cp and xx can be known in advance, the values of the capacitances Cx and xx formed between the electrode pads VCOM and xx and the finger 17 can be obtained.

The amplitude of the output voltage Vo can be directly measured in the case where the waveform of the periodic voltage signal Vdp is provided in the form of a periodic AC waveform having no DC component, Can be mixed to measure the output voltage. In this case, only the frequency component equal to the sinusoidal wave among the components of the output voltage Vo can be extracted. (Sin (2? Fc)) equal to the center frequency fc of the voltage signal Vdp can be used as the sinusoidal wave. As a result, the noise components of the frequency components other than the center frequency fc can be eliminated.

Fig. 5C shows a circuit structure according to an embodiment of the present invention for eliminating the influence of parasitic capacitance in the circuit of Fig. 4B.

The voltage of the inverting input terminal (-) of the operational amplifier 215 is regarded as equal to the voltage of the non-inverting input terminal (+). Therefore, the voltage of one node (Nx, 11) of the parasitic capacitance (Cp, 11) connected to the inverting input terminal (-) and the same node (Nx, 11) is the same as the voltage signal (Vdp).

At this time, when the voltage signal Vdp is applied to the other node n2 of the parasitic capacitance Cp, the potential difference across the parasitic capacitance Cp becomes 0, so that the parasitic capacitances Cp, 11), and therefore can operate as if the parasitic capacitance Cp, 11 does not exist.

The other node n2 of the parasitic capacitance Cp 11 may be connected to the data lines DL1 and DL2 and the gate lines GL1 and GL2 in FIG. Therefore, the switches SW1-1, SW1-2, SW1-3, and SW1-3 are turned on so that the voltage signal Vdp may be provided to the data lines DL1 and DL2 and the gate lines GL1 and GL2, respectively, SW1-4) can be installed. In the other time periods, the switches SW1-1, SW1-2, SW1-3 and SW1-4 supply the data lines DL1 and DL2 and the gate lines GL1 and GL2, respectively, To the signal sources S_DL1, S_DL2, S_GL1, and S_GL2. At this time, the DC voltage DC1 may be superimposed on the voltage signal Vdp at the terminal b of the switch SW1-1 and the terminal b of the switch SW1-2 may be supplied with The DC voltage DC2 may be superimposed on the voltage signal Vdp and the DC voltage DC3 may be superimposed on the voltage signal Vdp at the terminal b of the switch SW1-3, The DC voltage DC4 may be superimposed on the voltage signal Vdp at the terminal b of the switch SW1-4. At this time, at least some of the DC voltage DC1, the DC voltage DC2, the DC voltage DC3, and the DC voltage DC4 may be different values, or they may all be the same value, Value. Even if a DC voltage is applied to the voltage signal Vdp provided to the terminal b of the switches SW1-1, SW1-2, SW1-3, and SW1-4, the voltage across the parasitic capacitance Cp, 11 does not change with time , There is no current flowing through the parasitic capacitance Cp, 11, and therefore, it can operate as if the parasitic capacitance Cp, 11 does not exist.

The switch SW1 may also be connected to the VCOM 11. By the switch SW1, VCOM, 11 can be put into a floating state in a time period in which touch input is sensed. In the other time periods, not only the VCOM 11 but all the VCOM electrodes can be connected to the predetermined reference potential Vref2.

In FIGS. 5A and 5C, reference numeral 10 may be referred to as a 'touch sensing signal output unit'.

<Examples>

FIG. 6 illustrates a display unit 1000 according to an embodiment of the present invention and a structure thereof in a matrix form.

The display may be logically partitioned in matrix form in the x and y directions.

In Fig. 6, a total of N rows are divided. And is divided into a plurality of columns. When the column is total M, the display unit 1000 may be divided into a total of M * N regions, and each region may be referred to as one pixel group. A group of pixels may include a plurality of image pixels. At this time, the one image pixel may be a concept corresponding to the image pixel of the sign Nyy shown in Fig. In FIG. 6, only the pixel groups in the first column are denoted by reference numerals G1 to GN. G1 to GN shown in FIG. 6 correspond to one pixel group, and G1 to GN correspond to a total of N pixel groups.

6, a plurality of data lines extending along the y-axis direction along the x-axis and a plurality of gate lines extending along the y-axis along the y-axis may be arranged. The data lines and the gate lines may be arranged in a manner similar to that shown in Fig. Although two data lines and two gate lines are arranged in one area in FIG. 3, a larger number of data lines and gate lines may be arranged in FIG. Each of the data lines extends in the y-direction, and each of the gate lines may extend in the x-direction.

In addition, one Vcom electrode may be disposed in the vicinity of each pixel group. At this time, the Vcom electrodes may be arranged in the form of an M * N matrix, and the plurality of Vcom electrodes may be physically separated from each other. The width of one Vcom electrode may be similar to the area occupied by one pixel group.

FIG. 7 shows only the pixel group Gk among the pixel groups shown in FIG.

In Fig. 7, b data lines may be arranged along the x-axis direction. And a number of gate lines may be arranged along the y-axis direction. b / 3 of the b data lines may be data lines allocated for red color pixels, b / 3 green color pixels, and b / 3 blue color pixels. For example, a = 40, b = 120. Therefore, a total of 4800 image pixels (R + G + B) may be arranged in the pixel group Gk.

At this time, if a desired data signal is applied to the b data lines, and only one of the a gate lines is sequentially activated in one direction, the image display values of the a * b image pixels can be sequentially updated. The method of updating the image display value of such an image pixel can follow a method well known in the art.

The touch sensing signal output unit 10 may be connected to the common electrode (sensing electrode) Vcom, k. At this time, a capacitance may be formed using Vcom, k as a single electrode, and this capacitance may have a different value in the case where a touch input tool such as a human finger is nearby or not. Further, this capacitance may change every time the value of a * b image pixels in the pixel group Gk disposed adjacent to Vcom, k is changed.

In the context of the touch sensing signal output section 10, the capacitance that changes every time the value of a * b image pixels is changed can be regarded as a parasitic capacitance. At this time, the overall parasitic capacitance formed by the pixel group Gk can be expressed as Cs (Gk). Cs (Gk) is a value that can be changed each time the display state of the pixel group Gk is changed. And Cs (Gk) is a value that can be stored in a predetermined storage unit after being calculated by a control unit that applies a signal to b data lines.

6, the control unit for changing the display state of the pixel groups G1 first updates the display state of the pixel group G1, and sequentially outputs the pixel group G2, the pixel group G3, ..., (Gk), ..., and the pixel group GN can be updated. The minimum time at which the display states of the pixel group G1 to the pixel group GN are all updated can be referred to as one 'frame' time.

An embodiment of the present invention will now be described with reference to FIG.

8 is a timing chart showing a timing chart in which the display state update of the pixel groups G1 to GN occurs in the one frame described above and information about the touch input for which Vcoms adjacent to the pixel groups G1 to GN are sensed And the like.

In the frame X, the display state update of each of the pixel groups G1 to GN is sequentially performed for each pixel group, and the update time periods are spaced apart from each other by a predetermined time. That is, the pixel group G1 is updated in the interval T (p ₁ ), and the pixel group Gk is updated in the interval T (p _k ). The interval T (p _k-1 ) and the interval T (p _k ) may be spaced apart from each other on the time axis by the interval T (t _k-1 ). (k = 1, 2, ..., N)

During the N time periods of the interval (T (t ₁ )) to the interval (T (t _N )), it is detected whether all the Vcom shown in FIG. The touch input signal is detected during N time periods (T ( _tk ), k = 1, ..., N) and it is determined whether or not touch input is performed. Therefore, only one time period T ( _tk ) The SNR is higher than when the touch input signal is detected and it is determined whether the touch input is to be performed.

At this time, when it is detected whether all the Vcom are touch input during N time periods of the interval T (t ₁ ) to the interval T (t _N ), the parasitic capacitance The result value of the touch input may be influenced by the touch sensor Cs. At this time, as described above, Cs is a value that can be calculated and stored by the control unit, so that the affected result value can be corrected using the stored Cs value.

However, there is a problem that occurs at this time. To examine this problem, an example of the case of the pixel group Gk shown in Figs. 6 and 7 is given. The display state of the pixel group Gk changes in the section T (p _k ) shown in Fig. The change of the display state of the pixel group Gk can be completed at time tk. Therefore, the value of the parasitic capacitance (Cs (Gk)) generated by the pixel group (Gk) are different each other before and after the period (T (p _k)). During the interval that the value of the parasitic capacitance (Cs (Gk)) generated by the pixel group (Gk) change during the (T (p _k)).

That is, the frame (X) of the interval (T (p _k)) before the value of the parasitic capacitance (Cs (Gk)) generated by the pixel group (Gk), the parasitic that was updated in the previous frame (X-1) And the value of the capacitance Cs (Gk, X-1). However, the frame (X) of the interval (T (p _k)) Then, the value of the parasitic capacitance (Cs (Gk)) generated by the pixel group (Gk) is a section of the frame (X) (T (p _k) (Cs (Gk, X)) during a period of time (t). In other words, since the value of the parasitic capacitance Cs (Gk) generated by the pixel group Gk changes during the frame X time period, when the detection result of the touch input on each of the Vcom is corrected, (Cs (Gk)) is fixed to one value and can not be used.

In order to solve this problem, the following method may be used to compensate for the influence of the parasitic capacitance caused by the pixel group Gk to update the touch input result.

First, the touch input sensing process is performed on the common electrode Vcom, k corresponding to the pixel group Gk during the frame (X) period. That is, the process of one cycle of detecting information on the touch input to the common electrode Vcom, k over the period T (t ₁ ) to the period T (t _N ) is performed. When the process of this one cycle is completed, information about the touch input can be generated. That is, when the frame X ends, the sensing value output by the touch input sensing process can be obtained.

At this time, the value of the parasitic capacitance Cs (Gk, X-1) due to the pixel group Gk updated in the frame X-1 and the value of the parasitic capacitance Ck (Cs (Gk, X)) can be stored in the storage unit.

Next, the value of the parasitic capacitance Cs (Gk, X-1) of the pixel group Gk updated and stored in the frame X-1 and the value of the parasitic capacitance Cs (Gk, X) of the parasitic capacitors Ck (Gk, Gk) are obtained in the storage unit. In the frame X, the parasitic capacitance value of the pixel group Gk can be changed to a completely new value after time tk.

Next, the values of the parasitic capacitance Cs (Gk, X-1) by the pixel group Gk and the parasitic capacitance Cs (Gk, X) by the pixel group Gk are respectively assigned weight values? The value of Cs (Gk, X, average) is calculated by giving β. For example, the following Equation 1 can be given. At this time, as the value of k increases, alpha increases and beta decreases.

(Gk, X) / N (Xk, X) = Cs (Gk, X, average)

Then, the sensed value output by the touch input sensing process is calibrated using the calculated average value Cs (Gk, X, average).

Here, the common electrode Vcom, k may be a sensing electrode.

For example, an embodiment will be described below assuming that N = 32, M = 20, a = 40, and b = 120 in FIG. In this case, k = 1, 2, 3, 4,, ,,,, in FIG. At this time, if the output value of the touch input sensing result through the touch input sensing process for Vcom, k is referred to as Rk, Rk can be calibrated using the value of Cs (Gk, X, average). For example, the Rk value may be scaled by Cs (Gk, X, average). Specifically, for example, given by Cs (Gk, X, average) = {(k-1) * Cs (Gk, X-1) + (N- . That is, in equation (1), α = k-1 and β = N-k + 1 can be set.

In addition, various implementations can be derived according to concrete values of N, M, a, and b and a frame update period, but it should be understood that these embodiments do not depart from the basic idea of the present invention described above.

Hereinafter, an input / output device according to an embodiment of the present invention will be described with reference to the accompanying drawings. The input / output device may include a display unit including a plurality of pixel groups and a touch input sensing unit including a plurality of sensing electrodes. A first pixel group Gk whose display state is updated in a first time period T (pk) belonging to a first frame X including a plurality of image pixels and having a predetermined time; A first parasitic capacitance value Cs (Gk, k) formed between the first sensing electrode (Vcom, k) of the plurality of sensing electrodes and the first pixel group in accordance with the display state of the first pixel group, X-1), Cs (Gk, X)); And a touch sensing signal output unit that senses whether or not a touch input is performed using the capacitance change of the first sensing electrode. (Cs (Gk, X-1)) of the first parasitic capacitance before the first time interval and a second value (Cs (Gk, X-1) of the first parasitic capacitance after the first time interval , X) from the storage unit and multiplies the first value Cs (Gk, X-1) and the second value Cs (Gk, X) by a predetermined weight, So that the value output from the touch sensing signal output unit can be corrected.

At this time, the display unit may include a plurality of common electrodes provided in a divided form, and the plurality of sensing electrodes may be the plurality of common electrodes.

At this time, the first frame includes a plurality of display unit update time intervals T (pk), k = 1, ..., N assigned to update the display state of the display unit, (T (tk), k = 1, ..., N) assigned to detect the touch input. The plurality of display unit update time periods and the plurality of touch input sensing time periods may be interlaced with each other.

The plurality of sensing electrodes may have the same DC potential during the plurality of display unit update periods, and may be connected to the touch sensing signal output unit during the plurality of touch input sensing periods.

Hereinafter, an input / output control apparatus according to another embodiment of the present invention will be described. The apparatus may include an input / output device including a display unit having a plurality of pixel groups each including a plurality of image pixels and a touch input sensing unit including a plurality of sensing electrodes, and may include a processing unit and a storage unit. The processing unit is configured to update the display state of the first pixel group Gk among the plurality of pixel groups at a first time interval T (tk) belonging to a first frame X having a predetermined time ; The storage unit may store a value of a first parasitic capacitance formed between the first sensing electrode (Vcom, k) of the plurality of sensing electrodes and the first pixel group, according to the display state of the first pixel group Cs (Gk, X-1), Cs (Gk, X)); And the processing section determines whether or not the first value Cs (Gk, X-1) of the first parasitic capacitance before the first time interval and the second value of the first parasitic capacitance after the first time interval (Cs (Gk, X)) from the storage unit and multiplying the first value Cs (Gk, X-1) and the second value Cs (Gk, X) by a predetermined weight And a value output from a touch sensing signal output unit for sensing whether or not the touch input is performed using the change in capacitance of the first sensing electrode may be calibrated using a representative value added thereto.

At this time, the display unit may include a plurality of common electrodes provided in a divided form, and the plurality of sensing electrodes may be the plurality of common electrodes.

At this time, the first frame includes a plurality of display unit update time intervals T (pk), k = 1, ..., N assigned to update the display state of the display unit, (Tk), k = 1, ..., N) assigned to detect a touch input, and a plurality of touch input sensing time periods (T The liver may be interlaced with each other.

At this time, the plurality of sensing electrodes may all have the same DC potential during the plurality of display unit update periods, and may be connected to the touch sensing signal output unit during the plurality of touch input sensing periods.

Hereinafter, an input / output control method according to another embodiment of the present invention will be described. This method is characterized in that the input / output control apparatus including the processing section and the storage section includes a display section having a plurality of pixel groups each including a plurality of image pixels and a touch input sensing section including a plurality of sensing electrodes to be. The storage unit may be formed between the first sensing electrode (Vcom, k) of the plurality of sensing electrodes and the first pixel group according to the display state of the first pixel group (Gk) among the plurality of pixel groups The values of the first parasitic capacitance Cs (Gk, X-1), and Cs (Gk, X) may be stored in advance. At this time, the processing unit updates the display state of the first pixel group Gk in a first time period T (tk) belonging to a first frame X having a predetermined time; (Cs (Gk, X-1)) of the first parasitic capacitance before the first time interval and a second value (Cs (Gk, X-1) of the first parasitic capacitance after the first time period , X) from the storage unit and multiplies the first value Cs (Gk, X-1) and the second value Cs (Gk, X) by a predetermined weight, And calibrating a value output from the touch sensing signal output unit that senses whether or not the touch input is performed using the capacitance change of the first sensing electrode.

The embodiments illustrated in the present specification are intended to facilitate understanding of the present invention and any other kinds of embodiments to which the inventive aspects set forth in the claims of the present invention may be applied may be applied to the present invention. The invention set forth in the claims herein should not be construed as limited by the embodiments disclosed herein.

Claims (9)

An input / output device including a display unit including a plurality of pixel groups and a touch input sensing unit including a plurality of sensing electrodes,
A first pixel group including a plurality of image pixels, the display state of which is updated in a first time period belonging to a first frame (X) having a predetermined time;
A storage unit for storing a value of a first parasitic capacitance formed between the first sensing electrode of the plurality of sensing electrodes and the first pixel group according to the display state of the first pixel group; And
A touch sensing signal output unit for sensing whether or not a touch input is made using the capacitance change of the first sensing electrode;
/ RTI &gt;
Wherein the first value of the first parasitic capacitance and the second value of the first parasitic capacitance after the first time interval are obtained from the storage unit, 2 values are multiplied by a predetermined weight, and the representative value of the parasitic capacitance is used to correct the value output from the touch sensing signal output unit,
The representative value of the parasitic capacitance is determined by the following equation,
(Gk, X) / N (Gk, X, average) = {留 * Cs
Here, Cs (Gk, X, average) is a representative value of the first parasitic capacitance for the first pixel group Gk and Cs (Gk, X-1) is a representative value of the first parasitic capacitance -1), the first value Cs (Gk, X) of the first parasitic capacitance due to the first group of pixels Gk is greater than the first value Cs The second value of the first parasitic capacitance by the group Gk,? And? Are weights respectively, and N is the number of pixel groups,
Wherein the weighting factor a is k-1 and the weighting factor beta is N-k + 1. The input / output device of claim 1, wherein the display unit includes a plurality of common electrodes provided in a divided form, and the plurality of sensing electrodes are the plurality of common electrodes. The method according to claim 1,
The first frame includes a plurality of display unit update time periods assigned to update the display state of the display unit and a plurality of touch input detection time periods allocated to sense touch input to the plurality of sensing electrodes In addition,
Wherein the plurality of display unit update time periods and the plurality of touch input detection time periods are interlaced with each other,
Input / output device of user equipment. The method of claim 3,
Wherein the plurality of sensing electrodes comprise:
All have the same DC potential during the plurality of display unit update time periods,
Wherein the touch sensing signal output unit is connected to the touch sensing signal output unit during the plurality of touch input sensing periods,
Input / output device of user equipment. An input / output control apparatus for controlling an input / output apparatus including a display unit having a plurality of pixel groups each including a plurality of image pixels and a touch input sensing unit including a plurality of sensing electrodes,
The processing unit is adapted to update a display state of a first one of the plurality of pixel groups in a first time period belonging to a first frame (X) having a predetermined time;
Wherein the storage unit is configured to store a value of a first parasitic capacitance formed between the first sensing electrode of the plurality of sensing electrodes and the first pixel group according to the display state of the first pixel group; And
Wherein the processing section obtains from the storage section a first value of the first parasitic capacitance before the first time interval and a second value of the first parasitic capacitance after the first time interval, And the second value is multiplied by a predetermined weight, and a value output from the touch sensing signal output unit, which senses whether or not the touch input is performed, is calibrated using the representative value added to the first sensing electrode by using the capacitance change of the first sensing electrode ,
The representative value of the parasitic capacitance is determined by the following equation,
(Gk, X) / N (Gk, X, average) = {留 * Cs
Here, Cs (Gk, X, average) is a representative value of the first parasitic capacitance for the first pixel group Gk and Cs (Gk, X-1) is a representative value of the first parasitic capacitance -1), the first value Cs (Gk, X) of the first parasitic capacitance due to the first group of pixels Gk is greater than the first value Cs The second value of the first parasitic capacitance by the group Gk,? And? Are weights respectively, and N is the number of pixel groups,
Wherein, among the weights,? Is k-1 and? Is N-k + 1. 6. The input / output control device according to claim 5, wherein the display unit includes a plurality of common electrodes provided in a divided form, and the plurality of sensing electrodes are the plurality of common electrodes. 6. The method of claim 5,
The first frame includes a plurality of display unit update time periods assigned to update the display state of the display unit and a plurality of touch input detection time periods allocated to sense touch input to the plurality of sensing electrodes In addition,
Wherein the plurality of display unit update time periods and the plurality of touch input detection time periods are interlaced with each other,
I / O controller. 8. The method of claim 7,
Wherein the plurality of sensing electrodes comprise:
All have the same DC potential during the plurality of display unit update time periods,
Wherein the touch sensing signal output unit is connected to the touch sensing signal output unit during the plurality of touch input sensing periods,
I / O controller. An input / output control method for controlling an input / output control apparatus including a processing unit and a storage unit includes a display unit having a plurality of pixel groups each including a plurality of image pixels and a touch input sensing unit including a plurality of sensing electrodes,
Wherein the storage unit stores a value of a first parasitic capacitance formed between the first sensing electrode and the first pixel group among the plurality of sensing electrodes in accordance with a display state of the first pixel group among the plurality of pixel groups In addition,
The processing unit,
Updating a display state of the first pixel group in a first time period belonging to a first frame (X) having a predetermined time; And
Wherein the first value of the first parasitic capacitance and the second value of the first parasitic capacitance after the first time interval are obtained from the storage unit, And correcting a value output from the touch sensing signal output unit that senses whether or not touch input is performed by using a variation of the capacitance of the first sensing electrode by using a representative value obtained by multiplying each of the first sensing electrode and the second sensing electrode by a predetermined weight, However,
The representative value of the parasitic capacitance is determined by the following equation,
(Gk, X) / N (Gk, X, average) = {留 * Cs
Here, Cs (Gk, X, average) is a representative value of the first parasitic capacitance for the first pixel group Gk and Cs (Gk, X-1) is a representative value of the first parasitic capacitance -1), the first value Cs (Gk, X) of the first parasitic capacitance due to the first group of pixels Gk is greater than the first value Cs The second value of the first parasitic capacitance by the group Gk,? And? Are weights respectively, and N is the number of pixel groups,
Wherein, among the weights,? Is k-1 and? Is N-k + 1.

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