KR101746855B1 - Touch Screen Device and Display Device using the same - Google Patents

Abstract

An embodiment of the present invention is a touch panel comprising a plurality of capacitors; And a capacitance measuring unit for detecting a change in capacitance of the touch panel using a phase locked loop feedback structure to determine a touched position.

Description

[0001] The present invention relates to a touch screen device and a display device using the touch screen device.

An embodiment of the present invention relates to a touch screen device and a display device using the touch screen device.

In recent years, display devices such as liquid crystal displays (LCDs), electroluminescent displays, and plasma display panels have attracted attention because of their high response speed, low power consumption, and excellent color recall . Such display devices have been used in various electronic products such as televisions, computer monitors, notebook computers, mobile phones, display parts of refrigerators, personal digital assistants, and automated teller machines. These display devices are increasingly in demand for an input device that is convenient and simple and can reduce malfunctions. In accordance with such a demand, a touch screen device has been proposed in which a user directly touches a screen with a hand or a pen to input information.

The capacitive method, which is one of the touch screen devices, is a method of detecting the touched position by applying a driving signal to the touch electrode and counting the phase delay characteristics of the charging and discharging of the capacitance before and after the touch by the user.

There are various methods of measuring the capacitance in the capacitive method, but it is largely divided into the relaxation oscillator method and the charge transfer method. In the case of the relaxation oscillator method, the presence or absence of the touch is determined by counting the time during which the delay occurs in accordance with the change in the capacitance before and after the application of the driving signal in synchronism with the system clock. In this case, the design is simple and is mainly used to measure the change in capacitance.

However, in the conventional relaxation oscillator system, a bias circuit for supplying a current source must be added, and the supplied current must be low and constant. However, when the current source is not constant or a small current value is selected, there is a problem that charging time is changed and it is sensitive to external noise, so that it is difficult to discriminate the presence or absence of touch in the device.

An embodiment of the present invention for solving the above-described problems of the related art is a circuit for preventing deterioration in detection accuracy of a circuit due to an external condition such as temperature, humidity, operating voltage and the like while improving performance of a capacitance measuring circuit, The present invention provides a touch screen device capable of simplifying the configuration and operating without constructing an external component in the external of the touch system, and a display device using the touch screen device.

According to an embodiment of the present invention, there is provided a touch panel including a plurality of capacitors; And a capacitance measuring unit for detecting a change in capacitance of the touch panel using a phase locked loop feedback structure to determine a touched position.

The capacitance measuring unit may include a count control unit for measuring a driving signal applied to the touch panel for a predetermined time and outputting a current frequency level as an analog signal and a comparator for comparing the analog signal corresponding to the current frequency outputted from the count control unit with a reference signal, A charge pump section for converting the phase difference of the digital pulse signal output from the phase frequency detecting section into a phase difference of an analog voltage signal and outputting the phase difference; And a frequency divider for dividing the phase difference of the frequency clock output from the voltage control oscillation unit and feeding back the frequency difference to the phase frequency detection unit.

The capacitance measuring unit may include a noise canceling unit that removes noise due to the phase difference of the analog voltage signal converted by the charge pump unit.

The division value of the frequency divider can be reset at least once when the feedback loop of the phase locked loop is turned.

The division value of the frequency divider can be set prior to the capacitance change of the touch panel under the control of the count control section.

The capacitance measuring unit may include a processor unit for detecting a voltage level difference measured before and after touching the touch panel from the phase difference of the analog voltage signal output from the noise removing unit to determine whether or not the touch is detected.

The capacitance measuring unit may include a processor unit which detects the number of pulse counts measured before and after the touch on the touch panel from the phase difference of the frequency clock output from the voltage control oscillating unit to determine whether or not the touch is detected.

In another aspect, an embodiment of the present invention is a touch screen device manufactured according to any one of claims 1 to 6; And a display panel to which a touch screen device is attached.

The display panel may be a liquid crystal panel.

The display panel may be an organic electroluminescence panel.

Embodiments of the present invention can improve performance of the capacitance measuring circuit and simplify a complicated circuit configuration while preventing the detection accuracy of the circuit from being deteriorated due to external conditions such as temperature, humidity, operating voltage, The present invention provides a touch screen device capable of operating without constructing additional components outside the display device and a display device using the touch screen device.

1 is a schematic diagram of a touch screen device according to an embodiment of the present invention;
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a touch screen device, and more particularly,
3 is a configuration diagram of a touch screen device according to another embodiment of the present invention.
4 is a configuration diagram of a touch screen device for discriminating the presence or absence of a touch through a voltage level difference.
FIG. 5 is a configuration diagram of a touch screen device for determining whether or not a touch is detected through pulse counting. FIG.
FIG. 6 is a waveform diagram showing waveforms transmitted to the processor unit of FIGS. 4 and 5; FIG.
7 is a schematic block diagram of a display device according to an embodiment of the present invention;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a touch screen device according to an embodiment of the present invention. FIG. 2 is a waveform diagram of an output simulation waveform before and after touch of a phase locked loop feedback structure constituting a touch screen device according to an embodiment of the present invention. .

1, in the touch screen device according to an exemplary embodiment of the present invention, a capacitance change of a signal supplying unit 105, a touch panel 110, and a touch panel 110 is detected by a phase locked loop feedback structure, 130, 140, 160, and 170, which determine the position of the capacitor.

The signal supply unit 105 (OSC) supplies a driving signal to the touch panel 110. The driving signal is supplied in the form of voltage or pulse. The driving signal output from the signal supply unit 105 is supplied to the touch panel 110.

The touch panel 110 is composed of a plurality of capacitors Cs_1 to Cs_n. The touch panel 110 is a capacitive type composed of a plurality of capacitors Cs_1 to Cs_n. A plurality of resistors Rx_1 to Rx_n may be connected to the plurality of capacitors Cs_1 to Cs_n included in the touch panel 110 to control a driving signal output from the signal supply unit 105. [

The capacitance measurement units 120, 130, 140, 160 and 170 are connected to a count control unit 120, a phase frequency detection unit 130, a charge pump unit 140, a voltage control oscillation unit 160, (170, Divider).

The count control unit 120 measures the driving signal applied to the touch panel 110 for a predetermined time and outputs the current frequency as an analog signal. For this purpose, the count control unit 120 may measure the driving signal applied to the touch panel 110 for a predetermined time in cooperation with a timer formed inside or outside, and sequentially output the current frequency level to the analog signal.

The phase frequency detector 130 compares an analog signal corresponding to the current frequency outputted from the count controller 120 with a reference signal, detects a phase difference between them, and outputs the phase difference as a phase difference of the digital pulse signal. The phase frequency detector 130 detects a frequency or phase difference by comparing a delay signal according to the capacitance change of the touch panel 110 with a reference signal set therein and outputs the difference as a phase difference of a digital pulse signal.

The charge pump unit 140 converts the phase difference of the digital pulse signal output from the phase frequency detector 130 into the phase difference of the analog voltage signal and outputs the phase difference. The charge pump unit 140 charges / discharges the voltage supplied to the power supply voltage terminal VDD based on the signal input through the gate terminal, and outputs the phase difference of the digital pulse signal output from the phase frequency detector 130 to the analog Converts it into a phase difference of the voltage signal, and outputs it. In the figure, the charge pump section 140 is schematically shown only as two pull-up and pull-down transistors T1 and T2. However, the charge pump unit 140 may be variously designed to stabilize the output of the capacitance measuring units 120, 130, 140, 160, and 170 formed of the phase locked loop feedback structure.

The voltage control oscillation unit 160 converts the phase difference of the analog voltage signal output from the charge pump unit 140 into the phase difference of the frequency clock and outputs the phase difference. The voltage controlled oscillator 160 adjusts the phase difference of the analog voltage signal according to the bias to convert the phase difference of the analog voltage signal into the phase difference of the frequency clock and outputs the phase difference.

The frequency divider 170 divides the phase difference of the frequency clock output from the voltage control oscillator 160 and feeds the divided frequency clock to the phase frequency detector 130. The frequency divider 170 divides the phase difference of the frequency clock output from the voltage control oscillator 160 to stabilize the output of the capacitance measuring units 120, 130, 140, 160, and 170 formed in the phase locked loop feedback structure, And feeds it back to the detection unit 130. The frequency divider 170 is set to the divided value Divided by of the frequency divider 170 by the division selection signal CCL [1: 0] supplied from the count control unit 120. [ The division value Divided by of the frequency divider 170 by the division selection signal CCL [1: 0] supplied from the count control unit 120 can be set as shown in Table 1 below.

According to Table 1 above, when the division selection signal CCL [1: 0] is 0 and 0, the division value of the divider 170 is set to 10 as the default value, The divided value (Divided by) of the frequency divider 170 is set by the number of times of counting the number of divisions by ten.

The divided value Divided by of the divider 170 is set to 20 when the divisional selection signal CCL [1: 0] is 0 or 1 and the number of times the count control unit 120 counts 20 The divided value (Divided by) of the frequency divider 170 is set.

The divided value Divided by of the divider 170 is set to 30 when the dividing selection signals CCL [1: 0] are 1 and 0, and the number of times the counting control unit 120 counts 30 times The divided value (Divided by) of the frequency divider 170 is set.

The divided value Divided by of the divider 170 when the dividing selection signal CCL [1: 0] is 1 or 1 is not used and the divided value of the divider 170 is not used It is not used.

Here, the divided value (Divided by) of the frequency divider 170 is reset by the frequency division selection signal CCL [1: 0] supplied from the count control unit 120 every time the feedback loop of the phase locked loop is rotated at least once do. At this time, the divided value of the frequency divider 170 is controlled by the count control unit 120 so that the frequency division value Divided by of the frequency divider 170 is reflected to the phase frequency detection unit 130 Lt; / RTI > change in capacitance.

2, when the frequency of the input signal PWM for sensing is 10 MHz and the frequency division selection signal CCL [1: 0] is 1, 0, it can be seen that the following output occurs.

(A) When the touch panel 110 is not touched (No Touch), the count control section 120 generates a reference output of 100 MHz. (B) When the touch panel 110 is touched (Touch), a comparison output of 300 MHz is generated by the count control unit 120.

On the other hand, in order to compensate for the deterioration in the detection accuracy of the circuit due to external conditions such as temperature, humidity, operating voltage, etc., the touch screen device is configured as follows.

Hereinafter, a touch screen device according to another embodiment will be described.

3 is a block diagram of a touch screen device according to another embodiment of the present invention.

3, in the touch screen device according to another embodiment of the present invention, the capacitance change of the signal supply unit 105, the touch panel 110, and the touch panel 110 is detected as a phase locked loop feedback structure, 130, 140, 160, and 170, which determine the position of the capacitor.

The signal supply unit 105 and the touch panel 110 are the same as those described in the first embodiment, so that the description thereof is omitted.

The capacitance measurement unit 120, 130, 140, 150, 160, and 170 includes a count control unit 120, a phase frequency detection unit 130, a charge pump unit 140, a noise eliminator 150, 160 and a frequency divider 170 are included.

Since the count control unit 120, the phase frequency detection unit 130, the charge pump unit 140, the voltage control oscillation unit 160, and the frequency divider 170 are the same as those described in the embodiment, description thereof will be omitted.

The noise eliminator 150 is a filter for eliminating noise due to the phase difference of the analog voltage signal converted by the charge pump unit 140, and is simplified as a capacitor Cf in the figure. However, the noise eliminator 150 may be variously designed to eliminate noise due to the phase difference of the analog voltage signal converted by the charge pump unit 140. [ As described above, when the noise generated in the phase difference of the analog voltage signal is refined by the noise removing unit 150, the uniformity and the accuracy of the phase difference of the frequency clock outputted from the voltage control oscillating unit 160 are improved.

Meanwhile, the capacitance measuring unit according to the embodiment can determine the touched position by using one of the voltage and the pulse value.

FIG. 4 is a configuration diagram of a touch screen device for discriminating the presence or absence of a touch through a voltage level difference, FIG. 5 is a configuration diagram of a touch screen device for discriminating the presence or absence of a touch through a pulse count, FIG. 6 is a waveform diagram showing waveforms transmitted to the processor unit. FIG.

4, the capacitance measuring unit 120, 130, 140, 150, 160, and 170 according to the embodiment includes the processor unit 180 connected to the noise removing unit 150.

6, when the touch panel 110 is touched, the voltage value V1 before touching and the voltage value V1 before touch are calculated from the noise removing unit 150 included in the capacitance measuring units 120, 130, 140, 150, 160, The voltage value V2 can be detected. The processor unit 180 may be configured to detect a voltage level difference (V_diff = V1 - V2) measured before and after touching the touch panel 110 from the phase difference of the analog voltage signal output from the noise remover 150 It is possible to discriminate whether or not there is a touch using this.

5, the capacitance measuring units 120, 130, 140, 150, 160, and 170 include a processor unit 180 connected to the voltage control oscillator 160.

When the touch panel 110 is touched, the voltage control oscillator 160 included in the capacitance measuring units 120, 130, 140, 150, 160, and 170 outputs a frequency clock C1 The frequency clock C2 can be detected. The processor unit 180 is configured to be able to detect the number of pulse counts (C_diff = C1 - C2) measured before and after touching the touch panel 110 from the phase difference of the digital pulse signal output from the voltage control oscillator 160 It is possible to discriminate whether or not there is a touch using this.

Hereinafter, a display panel to which the screen device according to the embodiment is attached will be described.

7 is a schematic block diagram of a display device according to an embodiment of the present invention.

7, the display device according to an exemplary embodiment of the present invention includes a display panel PNL, a touch panel TPNL, a scan driver SDRV, a data driver DDRV, and a touch panel sensing unit TSC. .

The display panel PNL is constituted by a flat panel display (FPD) such as a liquid crystal display panel, an organic light emitting display panel, a plasma display panel or the like including subpixels SP. When the display panel PNL is a liquid crystal display panel, the sub pixel SP includes a switching transistor driven by a scan signal, a capacitor for storing a data signal as a data voltage, And a liquid crystal layer in which the arrangement of the liquid crystal is changed by the electric field.

The scan driver SDRV is connected to the sub-pixels SP through the scan lines SL1 to SLm to supply the scan signals to the sub-pixels SP. The data driver DDRV is connected to the sub-pixels SP through the data lines DL1 to DLn to supply the data signals to the sub-pixels SP.

The touch panel TPNL is formed in a capacitive manner composed of a plurality of capacitors Cs_1 to Cs_n as shown in Figs. 1 to 4 so as to cause a change in capacitance according to a user's touch.

The touch panel sensing unit TSC receives a driving signal changed in accordance with a touch from the touch panel TPNL through the signal lines TS1 to TSk connected to the touch panel TPNL and receives a value of a capacitance Is detected by the voltage level difference or the frequency count of the frequency clock. Here, the touch panel sensing unit TSC is an example in which devices for sensing the touched position of the touch panel TPNL in FIGS. 1 to 4 are one-chip.

While the present invention has been described with respect to the preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. There is an effect of providing a touch screen device which can operate without constructing additional parts and a display device using the touch screen device. In addition, the present invention provides a touch-sensitive screen device which is resistant to noise by detecting the change in capacitance of the touch panel using a phase locked loop feedback structure, and a display device using the touch screen device.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

105: signal supply unit 110: touch panel
120: Count control unit 130: Phase frequency detection unit
140: charge pump unit 150: noise eliminator
160: Voltage control oscillation unit 170:

Claims (10)

A touch panel including a plurality of capacitors; And
And a capacitance measuring unit for detecting a change in capacitance of the touch panel using a phase locked loop feedback structure to determine a touched position,
Wherein the capacitance measuring unit comprises:
A phase frequency detector for detecting a phase difference between an analog signal corresponding to a current frequency and a reference signal by measuring a drive signal applied to the touch panel for a predetermined time and outputting the phase difference as a phase difference of a digital pulse signal;
A charge pump unit for converting the phase difference of the digital pulse signal output from the phase frequency detector into a phase difference of an analog voltage signal and outputting the phase difference,
A voltage control oscillation unit for converting the phase difference of the analog voltage signal output from the charge pump unit into a phase difference of a frequency clock and outputting the phase difference,
And a frequency divider for dividing the phase difference of the frequency clock output from the voltage control oscillation unit and feeding back the frequency difference to the phase frequency detection unit under the control of the count control unit, Device.
delete The method according to claim 1,
Wherein the capacitance measuring unit comprises:
And a noise eliminator for eliminating noise due to a phase difference of the analog voltage signal converted by the charge pump unit. The method according to claim 1,
Wherein the division value of the frequency divider is expressed by:
And is reset when the feedback loop of the phase locked loop is turned at least once. delete The method of claim 3,
Wherein the capacitance measuring unit comprises:
And a processor unit for detecting a voltage level difference measured before and after the touch on the touch panel from a phase difference of the analog voltage signal output from the noise removing unit to determine whether or not the touch is made. The method according to claim 1,
Wherein the capacitance measuring unit comprises:
And a processor unit for detecting the number of pulse counts measured before and after the touch on the touch panel from the phase difference of the frequency clock output from the voltage control oscillation unit to determine whether or not the touch is detected. A touch screen device manufactured by any one of claims 1, 3, 4, 6, and 7; And
And a display panel to which the touch screen device is attached. 9. The method of claim 8,
In the display panel,
Wherein the display panel is a liquid crystal panel. 9. The method of claim 8,
In the display panel,
Wherein the display panel is an organic electroluminescence panel.

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