KR101504031B1 - Touchscreen - Google Patents

Abstract

The present invention relates to a touch screen device. According to an embodiment of the present invention, the touch screen device includes a panel part including first electrodes in multiple columns extended in a first direction and second electrodes in multiple rows extended in a second direction, crossing the first direction; an operating part sequentially providing two predetermined operating signals to a pair of first electrodes, in an adjacent row among the first electrodes in the rows, in the second direction; and a sensing circuit part detecting a capacitance change of a node capacitor generated in a crossing point of the first and second electrodes. The sensing circuit part includes a differential part including a differential operation amplifier and a differential resistance. The node capacitor forms the differential operation amplifier, the differential resistance, and a predetermined differential circuit to differentiate the operating signals.

Description

TOUCH SCREEN DEVICE {TOUCHSCREEN}

The present invention relates to a touch screen device.

A touch screen device such as a touch screen and a touch pad is an input device attached to a display device and capable of providing an intuitive input method to a user and is widely applied to various electronic devices such as a mobile phone, a PDA (Personal Digital Assistant) . In particular, as the demand for smart phones has recently increased, the adoption rate of touch screens has been increasing as a touch screen device capable of providing various input methods in a limited form factor.

The touch screen applied to a portable device can be divided into a resistance film type and a capacitance type according to a method of detecting a touch input. Among them, the capacitance type has a relatively long life and can easily implement various input methods and gestures Due to its merits, its application rate is increasing. In particular, the capacitance type is widely applied to a device such as a smart phone because it is easy to implement a multi-touch interface as compared with the resistance film type.

The capacitance type touch screen includes a plurality of electrodes having a predetermined pattern, and a plurality of nodes, in which a capacitance change is generated by a touch input, are defined by the plurality of electrodes. A plurality of nodes distributed on a two-dimensional plane generate self-capacitance or mutual-capacitance changes by touch input, and a weighted average calculation method is applied to the capacitance change generated in a plurality of nodes. Etc. can be applied to calculate the coordinates of the touch input.

Recently, as the size of the touch screen has increased, the number of electrodes provided in the touch panel has been increasing. However, as the number of electrodes increases, the scan rate for determining the touch is decreased.

In the following prior art documents, Patent Document 1 discloses an apparatus and method for driving a touch screen. It discloses a method of sequentially applying a driving signal to a plurality of driving electrodes, At the same time, the contents of applying the drive signal are not disclosed.

Korean Patent Publication No. 2013-0033562

SUMMARY OF THE INVENTION The present invention is directed to a touch screen device capable of increasing a touch scan rate by simultaneously applying a driving signal to a pair of electrodes among a plurality of driving electrodes .

According to a first technical aspect of the present invention, there is provided a plasma display panel comprising: a panel portion including a plurality of rows of first electrodes extending in a first direction and a plurality of rows of second electrodes extending in a second direction intersecting the first direction; A driving circuit for sequentially supplying predetermined two driving signals to a pair of first electrodes of adjacent rows among the first electrodes of the plurality of rows in the second direction; And a sensing circuit for detecting a capacitance change of a node capacitor generated at an intersection of the first electrode and the second electrode; Wherein the sensing circuit unit includes a differential unit having a differential operational amplifier and a differential resistance and the node capacitor comprises a differential operational amplifier and a differential resistance and a differential circuit to constitute a differential circuit, Lt; / RTI >

The phases of the two driving signals may differ by 90 degrees.

The two driving signals include a first driving signal and a second driving signal, and the phase difference between the first driving signal and the second driving signal may repeat +90 degrees and -90 degrees at predetermined intervals.

One end of the node capacitor is connected to the inverting terminal of the differential operational amplifier, a common voltage is applied to the non-inverting terminal of the differential operational amplifier, and the differential resistance may be disposed between the inverting terminal and the output terminal of the differential operational amplifier.

The sensing circuit unit may include: an integrating unit for integrating a voltage output from the differential unit; As shown in FIG.

Wherein the integrating unit includes: a current control circuit connected to the differential unit; And at least four integration circuits coupled to the current control circuitry; . ≪ / RTI >

The current control circuit may change integration times of the four integration control circuits.

Wherein the current control circuit includes: a first switch and a second switch each having one end connected to the output terminal of the differential section; A first diode and a second diode each having an anode and a cathode connected to the other end of the first switch; And a third diode and a fourth diode each having an anode and a cathode connected to the other end of the second switch, respectively; .

Wherein each of the four integrating circuits comprises: an operational amplifier having a non-inverting terminal to which a common voltage is applied; And a feedback capacitor disposed between the inverting and output terminals of the operational amplifier; . ≪ / RTI >

The inversion stages of each of the four operational amplifiers included in each of the four integration circuits may be respectively connected to the cathodes of the first diode, the anodes of the second diodes, the cathodes of the third diodes, and the anodes of the fourth diodes .

The common voltage applied to the operational amplifier may vary by a predetermined diode turn-on voltage.

A voltage obtained by subtracting the diode turn-on voltage from the common voltage is applied to a non-inversion terminal of the operational amplifier connected to the first diode and the third diode, and an operational amplifier connected to the second diode and the fourth diode And a voltage obtained by adding the diode turn-on voltage to the common voltage may be applied to the non-inversion stage.

The first and second switches are driven by a first clock signal and a second clock signal, respectively, and the clock signals of the first and second switches have the same period and a phase difference of 180 degrees.

The period of the first and second clock signals may be half the period of the two driving signals.

The sensing circuit unit may include: a buffer unit for delaying a voltage output from the differential unit for a predetermined time and transmitting the delayed voltage to the integrating unit; As shown in FIG.

According to a second technical aspect of the present invention, there is provided a plasma display panel comprising: a panel portion including a plurality of rows of first electrodes extending in a first direction and a plurality of rows of second electrodes extending in a second direction intersecting the first direction; A driving circuit for sequentially supplying predetermined two driving signals to a pair of first electrodes of adjacent rows among the first electrodes of the plurality of rows in the second direction; And a sensing circuit for detecting a capacitance change of a node capacitor generated at an intersection of the first electrode and the second electrode; And the phases of the two driving signals may differ by 90 degrees.

According to an embodiment of the present invention, a touch scan rate can be increased by simultaneously applying a driving signal to a pair of electrodes of a plurality of driving electrodes.

In addition, after the change in capacitance generated in the pair of electrodes is detected by a plurality of integration circuits, the output voltages of the plurality of integration circuits can be subtracted to effectively remove the common noise.

1 is a perspective view illustrating an appearance of an electronic device having a touch screen device according to an embodiment of the present invention.
2 is a diagram illustrating a panel unit that may be included in a touch screen device according to an exemplary embodiment of the present invention.
3 is a cross-sectional view of a panel unit that may be included in a touch screen device according to an embodiment of the present invention.
4 is a diagram illustrating a touch screen device according to an exemplary embodiment of the present invention.
5 is a detailed circuit diagram of a first embodiment of the sensing circuit unit 330 employed in the touch screen device of the present invention.
FIG. 6 is a diagram showing waveforms output from the main part of FIG. 5 and waveforms representing clock signals provided to the switch; FIG.
7 is a detailed circuit diagram of a second embodiment of the sensing circuit unit employed in the touch screen device of the present invention.
8 is a diagram showing a waveform outputting the main part of FIG. 7 and a waveform representing a clock signal provided to the switch.
9 is a diagram illustrating a driving signal according to an embodiment of the present invention.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

1 is a perspective view illustrating an appearance of an electronic device having a touch screen device according to an embodiment of the present invention.

1, the electronic device 100 according to the present embodiment includes a display device 110 for outputting a screen, an input unit 120, an audio unit 130 for audio output, 110 may be integrated with the contact sensing device.

As shown in FIG. 1, in the case of a mobile device, the touch sensing device is generally integrated with the display device, and the touch sensing device must have a high light transmittance such that the screen displayed by the display device can transmit. Therefore, the contact sensing device is transparent to a base substrate of a transparent film material such as PET (polyethylene terephthalate), PC (polycarbonate), PES (polyethersulfone), PI (polyimide), PI (polyimide), PMMA (polymethylmethacrylate) Can be realized by forming a sensing electrode with a material such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), ZnO (Zinc Oxide), Carbon Nano Tube (CNT), or Graphene have. A wiring pattern connected to a sensing electrode formed of a transparent conductive material is disposed in a bezel region of the display device. Since the wiring pattern is visually shielded by the bezel region, it is also formed of a metal material such as silver (Ag) or copper It is possible.

Since the touch sensing device according to the present invention is assumed to operate according to the capacitance method, it may include a plurality of electrodes having a predetermined pattern. A capacitance detection circuit for detecting a change in capacitance generated in the plurality of electrodes; an analog-to-digital conversion circuit for converting the output signal of the capacitance detection circuit into a digital value; And an arithmetic circuit for judging whether or not the input signal is an output signal.

2 is a diagram illustrating a panel unit that may be included in a touch screen device according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the panel unit 200 includes a substrate 210 and a plurality of electrodes 220 and 230 provided on the substrate 210. Although not shown in FIG. 2, each of the plurality of electrodes 220 and 230 may be electrically connected to a wiring pattern of a circuit board attached to one end of the substrate 210 through wiring and a bonding pad. A controller integrated circuit is mounted on the circuit board to detect a sensing signal generated by the plurality of electrodes 220 and 230, and to determine a touch input therefrom.

A plurality of electrodes 220 and 230 may be provided on one side or both sides of the substrate 210. A plurality of electrodes 220 and 230 having rhombic or diamond patterns are shown in FIG. , Triangle, and the like.

The plurality of electrodes 220 and 230 include a first electrode 220 extending in the X-axis direction and a second electrode 230 extending in the Y-axis direction. The first electrode 220 and the second electrode 230 may be provided on both sides of the substrate 210 or alternatively may be provided on different substrates 210. If the first electrode 220 and the second electrode 230 are all provided on one surface of the substrate 210 A predetermined insulating layer may be partially formed at the intersection of the first electrode 220 and the second electrode 230. [

In addition to the area where the plurality of electrodes 220 and 230 are formed, the area where the wiring connected to the plurality of electrodes 220 and 230 is provided is not limited to the predetermined area for visually shielding the wiring formed of the opaque metal material. May be formed on the substrate 210.

An apparatus electrically connected to the plurality of electrodes 220 and 230 to sense a touch input detects a capacitance change generated at the plurality of electrodes 220 and 230 by a touch input and senses a touch input therefrom. The first electrode 220 may be coupled to a channel defined by D1 through D8 in the controller integrated circuit to receive a predetermined driving signal. The second electrode 230 may be connected to a channel defined by S1 through S8, The device can be used to detect the detection signal. At this time, the controller integrated circuit may detect a change in mutual-capacitance generated between the first electrode 220 and the second electrode 230 as a sensing signal, And the second electrode 230 can detect the change in capacitance at the same time.

3 is a cross-sectional view of a panel unit that may be included in a touch screen device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of the panel unit 200 shown in FIG. 2 cut in the YZ plane. In FIG. 3, the cover 210 includes a plurality of sensing electrodes 220 and 230, Cover Lens). The cover lens 240 is provided on the second electrode 230 used for detecting a sensing signal and receives a touch input from a touch object 250 such as a finger.

When a driving signal is sequentially applied to the first electrode 320 through the channels D1 to D8, coupled capacitance is generated between the first electrode 220 and the second electrode 230 to which the driving signal is applied. When a driving signal is sequentially applied to the first electrode 220, a capacitance change is generated in the coupling capacitance generated between the first electrode 220 and the second electrode 230 adjacent to the region where the contact object 250 is in contact, Lt; / RTI > The capacitance change may be proportional to the area of the overlapped region between the contact object 250 and the first electrode 220 and the second electrode 230 to which the driving signal is applied. In FIG. 3, The coupling capacitance generated between the first electrode 220 and the second electrode 230 connected to each other is affected by the contact object 250.

4 is a diagram illustrating a touch screen device according to an exemplary embodiment of the present invention. 4, the touch screen apparatus includes a panel unit 310, a driving circuit unit 320, a sensing circuit unit 330, a signal converting unit 340, and a calculating unit 350.

The panel unit 310 includes a first axis X1-Xm extending in the transverse direction of FIG. 4, and a second axis X4-Xm extending in the longitudinal direction of FIG. 4 Capacitance changes C11 to Cmn are generated at the intersections of the first electrodes to which the driving signals generated by the driving circuit unit 320 are applied and the second electrodes that are adjacent to the first electrodes including the plurality of second electrodes Y1 to Yn do. The driving circuit unit 320, the sensing circuit unit 330, the signal conversion unit 340, and the operation unit 350 may be implemented as a single integrated circuit (IC).

The driving circuit unit 320 applies a predetermined driving signal to the plurality of first electrodes X1 to Xm of the panel unit 310. [ The driving signal may be a square wave, a sine wave, a triangle wave, or the like having a predetermined period and amplitude. The touch screen apparatus according to the present embodiment applies two driving signals having different phases to a pair of adjacent ones of the plurality of first electrodes X1 to Xm, And applies the other two driving signals to sequentially repeat the above operation for the plurality of first electrodes X1 to Xm. In contrast, the two drive signals may have a phase difference of 90 degrees with respect to each other.

For example, the driving signals TX1 and TX2 are respectively applied to the first electrodes X1 and X2 arranged in the first row and the second row, and then the first electrodes X3 and X3 arranged in the third row and the fourth row, And the driving signal TX1 and the driving signal TX2, respectively.

4, a circuit for generating and applying a driving signal is separately connected to each of the plurality of first electrodes. However, the driving signal generating circuit may include at least two driving signal generating circuits, and may include a plurality of first electrodes X1- It is also possible to apply a driving signal to Xm.

The sensing circuit unit 330 may include an integrating circuit for sensing the electrostatic capacitance change C11-Cmn from the plurality of second electrodes Y1-Yn, and the integrating circuit may include at least one operational amplifier and a capacitor CF. The sensing circuit unit 330 converts the capacitance change C11-Cmn output from the plurality of second electrodes Y1-Yn into an analog signal such as a voltage signal and outputs the analog signal. When sequentially applying a driving signal to a pair of adjacent ones of the plurality of first electrodes X1 to Xm, the capacitance change C11 to Cmn can be simultaneously detected from the plurality of second electrodes, And may be provided by n number of the two electrodes Y1 to Yn.

The signal converting unit 340 generates a digital signal S _D from the analog signal generated by the integrating circuit. In one example, the signal conversion unit 340 is TDC (Time-to- to convert this analog signal output from sensing circuit 330 to a voltage form by measuring the arrival time to the predetermined reference voltage level to a digital signal S _D Digital Converter) circuit or an ADC (Analog-to-Digital Converter) circuit for measuring the amount of change of the level of the analog signal outputted by the sensing circuit unit 330 for a predetermined time and converting it into a digital signal S _D .

The operation unit 350 determines the touch input applied to the panel unit 510 using the digital signal S _D. The number, coordinates, and gesture operation of the touch input applied to the panel unit 310 can be determined using the digital signal S _D.

FIG. 5 is a circuit diagram showing in detail the first embodiment of the sensing circuit unit 330 employed in the touch screen device of the present invention. FIG. 6 is a waveform diagram showing the waveforms output from the main part of FIG. Fig.

In Fig. 5, the driving signal Tx1 and the driving signal Tx2 are generated in the driving circuit portion, and the driving signal Tx1 is 90 degrees out of phase with the driving signal Tx2. In addition, the node capacitors Cm1 and Cm2 equivalently express the coupled electrostatic capacitance generated at the adjacent electrode among the plurality of first electrodes, and the first drive signal Tx1 and the drive signal Tx2 are applied to one end of the node capacitors Cm1 and Cm2, respectively .

The sensing circuit portion may include a differentiating portion 333 and an integrating portion 335.

The differential portion 333 may include an operational amplifier OPA0 having an inversion terminal coupled to the other end of the node capacitors Cm1 and Cm2 and a resistor R disposed between the inversion and output ends of the operational amplifier, The common voltage VCM may be applied. Further, the differentiating unit 333 may further include a predetermined resistor connected to the output terminal of the operational amplifier OAP0, and the current output from the operational amplifier OPA0 may be adjusted by a predetermined resistor.

The level of the common voltage VCM may correspond to half of the voltage VDD corresponding to the amplitudes of the driving signal Tx1 and the driving signal Tx2, that is, VDD / 2, but the present invention is not limited thereto. have. For example, the common voltage VCM may correspond to the ground voltage. For convenience of description, it is assumed that the voltage level of the VCM corresponds to half of the voltage level of VDD.

The node capacitors Cm1 and Cm2 and the differential portion 333 constitute a kind of differential circuit whereby the voltage V0 output from the operational amplifier OPA0 when the driving signals TX1 and TX2 are applied to the node capacitors Cm1 and Cm2, As shown in FIG. At this time, the amplitude VDD of the drive signals TX1 and TX2 can be set such that the capacitances of the node capacitors Cm1 and Cm2 are saturated during 1/4 period of the drive signals TX1 and TX2. Therefore, the output voltage V0 of the operational amplifier OPA0 can be varied in the range of VCM-alpha to VCM + alpha. At this time, the voltage level of? May be smaller than the voltage level of VCM.

The integrator 335 includes a first integrator 335a and a switch SW2, diodes D3 and D4, operational amplifiers OPA3 and OPA4, feedback amplifiers OP1 and OP2, And a second integrator 335b composed of capacitors CF3 and CF4. At this time, the operational amplifier and the feedback capacitor constitute a predetermined integrating circuit. The total of four integrating circuits included in the integrating unit 335 are the current control circuit composed of the switches SW1 and SW2 and the diodes D1, D2, D3 and D4. The time of integration can be changed by the < / RTI >

In the first integrator 335a, one end of the switch SW1 is connected to the output terminal of the operational amplifier OPA0, and the other end of the switch SW1 is connected to the anode of the diode D1 and the cathode of the diode D2. The cathode of the diode D1 is connected to the inverting terminal of the operational amplifier OPA1, the voltage VCM is applied to the non-inverting terminal of the operational amplifier OPA1, and the feedback capacitor CF1 is disposed between the inverting terminal and the output terminal of the operational amplifier OPA1. In addition, the diode of the diode D2 is connected to the inverting terminal of the operational amplifier OPA2, the voltage VCM is applied to the non-inverting terminal of the operational amplifier OPA2, and the feedback capacitor CF2 is disposed between the inverting terminal and the output terminal of the operational amplifier OPA2.

The configuration and the connection relationship of the second integrator 335b are similar to those of the first integrator 335a, and thus a detailed description thereof will be omitted.

(1), the switch SW1 is turned on. At this time, the maximum voltage level of the voltage V0 is VCM, no current flows through the diode D1, and a current flows through the diode D2 to charge the feedback capacitor CF2, .

(2), the switch SW2 is turned on. Like the (1) section, the maximum voltage level of the voltage V0 is VCM, and no current flows through the diode D3. A current flows through the diode D4 to charge the feedback capacitor CF4 , Whereby the voltage V4 rises.

(3), the switch SW1 is turned on again. At this time, the maximum voltage level of the voltage V0 is VCM +?, No current flows through the diode D2, a current flows through the diode D1 to discharge the feedback capacitor CF1, As a result, the voltage V1 decreases.

(4), the switch SW2 is turned on again. At this time, the maximum voltage level of the voltage V0 is VCM +?, No current flows through the diode D4, and a current flows through the diode D3 to discharge the feedback capacitor CF3, As a result, the voltage V3 decreases.

FIG. 7 is a circuit diagram showing in detail a second embodiment of the sensing circuit part employed in the touch screen device of the present invention, FIG. 8 is a diagram showing a waveform outputting the main part of FIG. 7 and a clock signal provided to the switch .

7, the sensing circuit unit 330 may include a differentiating unit 333, an integrating unit 335, and a buffer unit 337. 5 and FIG. 7, it can be seen that the sensing circuit unit 330 of FIG. 7 further includes a buffer unit 337. Since the configuration and operation of the sensing circuit unit 330 of FIG. 7 are similar to those of the sensing circuit unit 330 of FIG. 5, the buffer unit 337 will be described below.

The buffer unit 337 may include a first buffer 337a, a second buffer 337b, a third buffer 337c, and a fourth buffer 337d. The first buffer 337a is provided between the cathode of the diode D1 and the operational amplifier OPA1. The first buffer 337a may include switches SWa1, SWb1, SWc1, SWd1, and a capacitor Cn1. The switch SWa1 is disposed between the cathode of the diode D1 and one end of the capacitor Cn1, the switch SWb1 is disposed between the other end of the capacitor Cn1 and the inversion terminal of the operational amplifier OPA1, and the switch SWc1 is connected between one end of the capacitor Cn1 and the common voltage VCM , The switch SWd1 is disposed between the other end of the capacitor Cn1 and the common voltage (VCM) terminal.

Since the configuration of the second to fourth buffers 337b, 337c and 337d is similar to that of the first buffer 337a, a detailed description will be omitted.

The maximum voltage level of the voltage V0 at this time is VCM, and no current flows through the diode D1, and the diode D2 (1) is turned on. In this state, the switches SW1, SWa1, SWd1, SWa2, SWd2, SWb3, SWC3, SWb4, So that the capacitor Cn2 is charged.

The maximum voltage level is VCM, the current does not flow in the diode D3, and the current (current) flows in the diode D4. In this period, the switches SW2, SWb1, SWc1, SWb2, SWc2, SWa3, SWd3, SWc4, SWd4 are turned on in the And the capacitor Cn4 is charged. On the other hand, the charge charged in the capacitor Cn2 moves to the feedback capacitor CF2, and the voltage V2 decreases.

The maximum voltage level of the voltage V0 is set to VCM + alpha, and the diode D2 is set to have a current value of 3 V. In this period, the switches SW1, SWa1, SWd1, SWa2, SWd2, SWb3, SWC3, SWb4, The current flows through the diode D1 to charge the capacitor Cn1. On the other hand, the charge charged in the capacitor Cn4 moves to the feedback capacitor CF4, and the voltage V4 decreases.

The maximum voltage level of the voltage V0 is set to VCM + alpha, and the diode D4 is set to have a current value of < RTI ID = 0.0 > A current flows through the diode D3 and the capacitor Cn3 is charged. On the other hand, the charge charged in the capacitor Cn1 moves to the feedback capacitor CF1, and the voltage V1 rises.

The switches SW1, SWa1, SWd1, SWa2, SWd2, SWb3, SWC3 and SWb4, SWc4 are turned on in the period (5), the current flows through the diode D2 to charge the capacitor Cn2, The charge charged in the capacitor Cn3 moves to the feedback capacitor CF3 and the voltage V3 rises.

That is, the buffer unit 337 employed in FIG. 7 is for delaying the charge charged in the integrator 335 by a predetermined time, and it can be confirmed by comparing the output waveforms of the voltages V1 to V4 in FIGS. 6 and 8 .

In the embodiments of the touch screen apparatuses shown in Figs. 5 and 7, the common voltage VCM is applied to the non-inverting ends of the operational amplifiers OPA1 to OPA4 employed in the integrating unit. However, in order to prevent the sensitivity of the touch screen device from being lowered by the turn-on voltage of the diodes D1 to D4, a voltage corresponding to the turn-on voltage of the common voltage VCM-diode is applied to the non-inverting ends of the operational amplifiers OPA1 and OPA3 And a voltage corresponding to the turn-on voltage of the common voltage VCM + diode can be applied to the non-inverting ends of the operational amplifiers OPA2 and OPA4.

9 is a diagram illustrating a driving signal according to an embodiment of the present invention. The parasitic resistance and the parasitic capacitance exist in the touch panel. Due to the parasitic resistance and the parasitic capacitance, the driving signals Tx1 and Tx2 of FIGS. 5 and 7 may overlap each other. When the driving signals Tx1 and Tx2 overlap each other, Offset occurs at the final output.

However, when the phase difference between the driving signals Tx1 and Tx2 is inverted every predetermined period as in the embodiment of FIG. 9, the above offset can be removed.

5 and 7, the voltages V1 to V4 are finally generated. In the present invention, the voltages V1 and V2 are subtracted, and the voltages V3 and V4 are subtracted to remove the common noise component. The subtraction of the voltages V1 and V2 and the subtraction of the voltages V3 and V4 may additionally be performed at the analog stage by constituting a differential circuit and may be performed at the digital stage after converting the voltages V1 to V4 into digital signals.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Therefore, the spirit of the present invention should not be construed as being limited to the above-described embodiments, and all of the equivalents or equivalents of the claims, as well as the following claims, I will say.

310:
320:
330:
333:
335: Integral part
335a: first integrator
335b: second integrator
337: buffer unit
337a: first buffer
337b: second buffer
337c: third buffer
337d: fourth buffer
340: Signal conversion section
350:

Claims (16)

A panel portion including a plurality of rows of first electrodes extending in a first direction and a plurality of rows of second electrodes extending in a second direction intersecting the first direction;
A driving circuit for sequentially supplying predetermined two driving signals to a pair of first electrodes of adjacent rows among the first electrodes of the plurality of rows in the second direction; And
A sensing circuit for sensing a capacitance change of a node capacitor generated at an intersection of the first electrode and the second electrode; Lt; / RTI >
The sensing circuit unit includes a differential unit having a differential operational amplifier and a differential resistance, and an integrator for integrating a voltage output from the differential unit. The node capacitor includes the differential operational amplifier and differential resistance and a differential circuit Differentiates the drive signal,
Wherein the integrating section includes a current control circuit connected to the differential section and at least four integrating circuits connected to the current control circuit.
The method according to claim 1,
Wherein the phases of the two drive signals are 90 degrees apart.
The method according to claim 1,
Wherein the two driving signals include a first driving signal and a second driving signal,
Wherein the phase difference between the first driving signal and the second driving signal is + 90 degrees and -90 degrees for every predetermined period.
The method according to claim 1,
Wherein the node capacitor is connected to an inverse terminal of the differential operational amplifier, a common voltage is applied to the non-inverting terminal of the differential operational amplifier, and the differential resistance is disposed between the inversion terminal and the output terminal of the differential operational amplifier, .
delete delete The power supply circuit according to claim 1,
Wherein the integrating time points of the four integration control circuits are different.
The power supply circuit according to claim 1,
A first switch and a second switch each having one end connected to the output terminal of the differential section;
A first diode and a second diode each having an anode and a cathode connected to the other end of the first switch; And
A third diode and a fourth diode to which the anode and the cathode are respectively connected to the other end of the second switch; The touch screen device comprising:
9. The integrated circuit of claim 8, wherein each of the four integrating circuits comprises:
An operational amplifier having a non-inverting terminal to which a common voltage is applied; And
A feedback capacitor disposed between the inverting end and the output end of the operational amplifier; The touch screen device comprising:
10. The method of claim 9,
Wherein the inverting end of each of the four operational amplifiers included in each of the four integrating circuits is connected to a cathode of the first diode, an anode of the second diode, a cathode of the third diode, Screen device.
11. The method of claim 10,
Wherein the common voltage applied to the operational amplifier varies by a predetermined diode turn-on voltage.
12. The method of claim 11,
A voltage obtained by subtracting the diode turn-on voltage from the common voltage is applied to the non-inverting terminal of the operational amplifier connected to the first diode and the third diode,
And a voltage obtained by adding the diode turn-on voltage to the common voltage is applied to the non-inverting terminal of the operational amplifier connected to the second diode and the fourth diode.
9. The method of claim 8,
Wherein the first and second switches are driven by a first clock signal and a second clock signal, respectively, the clock signals of the first and second switches having the same period and a phase difference of 180 degrees.
14. The method of claim 13,
Wherein the period of the first and second clock signals is half the period of the two driving signals.
The semiconductor memory device according to claim 1,
A buffer unit for delaying a voltage output from the differential unit for a predetermined time and transmitting the delayed voltage to the integrator; The touch screen device further comprising:
delete

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