KR100456154B1 - Apparatus for driving of touch panel - Google Patents

Abstract

The present invention relates to a driving apparatus of a touch panel to compensate for errors in touch coordinates and detection coordinates generated according to changes in the use environment and use time of the touch panel.

The present invention compensates for the X-axis voltage value detected from the X-axis electrode by connecting the touch panel with a spacer spread between the upper plate where the X-axis electrodes are formed and the lower plate where the Y-axis electrodes are formed, and the X-axis electrode and the base voltage source. A first compensation circuit configured to be connected between the Y axis electrode and a base voltage source, a second compensation circuit configured to compensate for a Y axis voltage value detected from the Y axis electrode, and according to a use time and an environment of the touch panel; And a touch controller configured to control first and second compensation circuits to compensate voltage values of the X and Y axes detected from the X and Y axis electrodes.

By such a configuration, the present invention compensates for the change in the detected voltage value according to the use time and the use environment of the touch panel so that an error occurs in the touched X-axis and Y-axis voltage values and the detected X-axis and Y-axis voltage values. Can be prevented.

Description

Touch panel driving device {APPARATUS FOR DRIVING OF TOUCH PANEL}

The present invention relates to a driving device of a touch panel, and more particularly, to a driving device of a touch panel to compensate for an error in touch coordinates and detection coordinates generated according to a change in the use environment and use time of the touch panel.

Typically, the touch panel is a cathode ray tube (CRT), a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) and It is a computer peripheral device installed on a display surface of a display device such as an electroluminescent device (ELD) and presses a touch panel while a user watches the display device to input predetermined information into a computer.

1 and 2, a conventional driving device of a touch panel includes a touch panel 10, which is an input device for recognizing a position of a display device, and a driving unit for driving the touch panel 10.

The touch panel 10 is sprayed between the X-axis electrode 52 formed on the upper substrate 12, the Y-axis electrode 54 formed on the lower substrate 16, and the upper substrate 12 and the lower substrate 16. The spacer 20 is provided.

The upper substrate 12 of the touch panel 10 has a material of polyethylene terephthalate (hereinafter referred to as "PET") film. The first transparent conductive layer 14 is formed on the lower front surface of the upper substrate 12.

The lower substrate 16 of the touch panel 10 may be made of any one of glass, plastic, and PET film. The second transparent conductive layer 18 is formed on the upper front surface of the lower substrate 16.

The first and second transparent conductive layers 14 and 18 include indium tin oxide (hereinafter referred to as "ITO") and indium zinc oxide (Indium-Zinc-Oxide), which are transparent conductive materials. Formed by printing silver (Ag) on a transparent conductive layer formed of one of the following: " IZO ") and indium-tin-zinc-oxide (hereinafter referred to as " ITZO "). do.

As shown in FIG. 2, the left and right X-electrodes 52A and 52B are formed at the left and right edges of the first transparent conductive layer 14, and the upper and lower edges of the second transparent conductive layer 18 are formed. Upper Y-electrodes and lower Y-electrodes 54A, 54B are formed.

The spacer 20 is sprayed between the two substrates of the upper and lower substrates 12 and 16 on which the electrodes 52A, 52B, 54A, and 54B are formed so as to maintain a constant gap.

As such, the first transparent conductive layer 14 formed on the upper substrate 12 is the second transparent conductive layer 18 formed on the lower substrate 16 when the upper substrate 12 is pressed by a stylus pen or finger. By short-circuit), a signal having a current amount or voltage level varied by the current and voltage applied to the X-axis electrode and the Y-axis electrodes 52 and 54 is generated.

The driving unit of the touch panel includes first and second switches 24 and 26 for selectively switching the power source voltage Vcc and the base voltage source GND of the electrode layers of the first and second transparent conductive layers 14 and 18, And a touch controller 30 for supplying a coordinate signal input from the touch panel 10 to the system 40.

The first switch 24 of the first transparent conductive layer 14 is applied to the power supply voltage source (Vcc) supplied to the touch panel 10 under the upper substrate 12 in response to the control of the touch controller 30. The switching is performed to either the right X-electrode 52B formed at the right edge and the upper Y-electrode 54A formed at the upper edge of the second transparent conductive layer 18 coated on the lower substrate 16.

The second switch 26 of the first transparent conductive layer 14 coated with the base voltage source GND supplied to the touch panel 10 under the upper substrate 12 in response to the control of the touch controller 30. Switching is performed either to the left X-electrode 52A formed at the left edge and the lower Y-electrode 54B formed at the lower edge of the second transparent conductive layer 18 applied to the upper portion of the lower substrate 16.

The touch controller 30 calculates and supplies coordinate values according to the X-axis and Y-axis coordinate signals of the touch point supplied from the touch panel 10 to the system 40. In addition, the touch controller 30 controls the first and second switches 24 and 26 according to the X-axis coordinate mode and the Y-axis coordinate mode to control the supply of power (Vcc, GND) to the touch panel 10. .

To this end, the touch controller 30 is an analog-to-digital converter (hereinafter referred to as "ADC") that converts any analog voltage detected by the touch panel 10 into a digital voltage, and The interface integrated circuit 36 which makes the microcomputer 34 corresponding to the digital voltage values of the X and Y axes converted by the ADC 32 and the microcomputer 34 and another external system 40 compatible with each other. Interface integrated circuit (hereinafter referred to as "interface IC").

The ADC 32 converts the detected X-axis analog voltage value into an X-axis digital voltage value by applying pressure on the upper substrate 12 with a pen. In addition, the ADC 32 converts the detected Y-axis analog voltage value into a Y-axis digital voltage value by applying pressure on the upper substrate 12 with a pen.

The microcomputer 34 is also called a microcomputer and receives the digital voltage values of the X and Y axes converted by the ADC 32. In addition, the microcomputer 34 switches the digital voltage value converted by the ADC 32 to the X-axis or Y-axis coordinates. The microcomputer 34 supplies the first and second control signals CS1 to the first and second switches 24 and 26 that selectively supply the power voltage source Vcc and the ground voltage source GND to the electrode layers of the X and Y axes. , CS2).

The interface IC 36 is connected between the microcomputer 34 and the system 40 of the liquid crystal display device in which the touch panel 10 is embedded. The interface IC 36 converts the X and Y axis voltage values converted by the ADC 32 into the external system 40 connected to the touch panel 10 in response to the microcomputer 34. send.

The touch controller 34 converts a power supply voltage input from the system 40 into a power suitable for driving the touch panel 10, and supplies the coordinate signal input from the touch panel 10 to the system 40. do.

In order to detect the X-axis voltage value of the touch panel 10 as described above, the driving unit of the touch panel is switched to the right X-electrode 52B of the first transparent conductive layer 14 by switching the first switch 24. The power source Vcc is supplied from the power source voltage source Vcc, and the left X-electrode 52A is connected to the base voltage source GND via the first resistor R1. When a predetermined voltage is applied between the X-electrodes 52A and 52B, an electric flow is generated between the X-electrodes 52A and 52B.

In addition, the driver of the touch panel detects the Y-axis voltage value of the touch panel 10. The upper Y-electrode 54A is switched from the power source voltage source Vcc to the voltage Vcc by switching of the first switch 24. Is supplied, and the lower Y-electrode 54B is connected to the ground voltage source GND via the resistor R2. When a predetermined voltage is applied between the Y-electrodes 54A and 54B, an electric flow is generated between the Y-electrodes 54A and 54B.

Accordingly, the first transparent conductive layer 14 of the upper substrate 12 and the second transparent conductive layer 18 of the lower substrate 16 when the upper substrate 12 is pressed by a mechanism such as a stylus pen or a finger. ) Is short-circuited. At this time, the voltage values of the X and Y axes are coordinates of the X and Y axes on the touch panel 10 by different values of positions where the first transparent conductive layer 14 and the second transparent conductive layer 18 are pressed and shorted. You get

As described above, in the conventional touch panel driving apparatus, the voltage value detected by the touch panel 10 is changed according to a time change of the touch panel 10 and an environment change such as temperature. An error occurs in the coordinate value touched by the 60 and the detected coordinate value, that is, the command corresponding to the mouse cursor 62 and the coordinate value. That is, the driving device of the conventional touch panel cannot accurately detect the touched coordinate value due to the use time of the touch panel 10, the use temperature, and the deterioration and aging of the material. Therefore, the system 40 executes a corresponding command or an application program related thereto by the errored coordinate value, and thus an error occurs in executing the user's command.

Accordingly, an object of the present invention is to provide a touch panel driving device capable of compensating for an error in touch coordinates and detection coordinates generated according to a change in the use environment and use time of the touch panel.

1 is a view showing a driving device of a conventional touch panel.

FIG. 2 is a diagram illustrating an electrode structure of the touch panel illustrated in FIG. 1.

3 is a diagram illustrating an error between pen touch coordinates and detected coordinates generated in a driving apparatus of a conventional touch panel.

4 is a view showing a driving device of a touch panel according to an embodiment of the present invention.

FIG. 5 is a view illustrating an electrode structure of the touch panel illustrated in FIG. 4.

FIG. 6A is a circuit diagram illustrating a first buffer shown in FIG. 5. FIG.

FIG. 6B is a circuit diagram illustrating a second buffer shown in FIG. 5. FIG.

FIG. 7 is a block diagram illustrating a microcomputer shown in FIG. 5. FIG.

8 is a view illustrating that an error generated in pen touch coordinates and detected coordinates is compensated by a driving apparatus of a touch panel according to an exemplary embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

10, 110: touch panel 12, 112: upper substrate

14, 114: first transparent conductive layer 16, 116: lower substrate

18, 118: second transparent conductive layer 20, 120: spacer

24, 124: first switch 26, 126: second switch

30, 130: touch controller 32, 132: ADC

34, 134: micom 36, 136: interface IC

40, 140: system 52, 152: X-axis electrode

60, 160: pen 62, 162: mouse cursor

155, 157: buffer 170: comparison unit

172: memory unit 174: compensation unit

In order to achieve the above object, a driving apparatus of a touch panel according to an embodiment of the present invention is a touch panel in which a spacer is spread between an upper plate on which X-axis electrodes are formed and a lower plate on which Y-axis electrodes are formed, and the X-axis electrode and a base voltage source A first compensation circuit connected between the first compensation circuit to compensate the X-axis voltage value detected from the X-axis electrode, and a first compensation circuit connected between the Y-axis electrode and the base voltage source to compensate the Y-axis voltage value detected from the Y-axis electrode. 2 compensating circuits and controlling the first and second compensating circuits according to the use time and the use environment of the touch panel to compensate voltage values of the X and Y axes detected from the X and Y axes electrodes, respectively. It has a touch controller.

In the driving device of the touch panel, the first compensation circuit is connected between the first reference resistor and the X-axis electrode and the first reference resistor connected between the X-axis electrode and the base voltage source to control the touch controller. Responsive to the first reference resistor and the X-axis electrode.

In the driving device of the touch panel, the second compensation circuit is connected between the second reference resistor and the Y-axis electrode and the second reference resistor connected between the Y-axis electrode and the base voltage source to control the touch controller. And a second buffer connecting the second reference resistor and the Y-axis electrode in response.

In the driving device of the touch panel, the touch controller controls an analog-digital converter for converting the analog voltage value detected from the X-axis electrode and the Y-axis electrode into a digital voltage value, and the first and second compensation circuits. In addition, the microcomputer receives the digital voltage value from the analog-to-digital converter and detects the X-axis coordinates and the Y-axis coordinates of the touch panel, and directly transfers the X-axis coordinates and the Y-axis coordinates detected from the micom to the system. A circuit is provided.

In the touch controller of the driving device of the touch panel, the microcomputer stores the initial digital X-axis voltage value between the X-axis electrode and the first compensation circuit, as well as the initial digital between the Y-axis electrode and the second compensation circuit. A memory unit for storing a Y-axis voltage value, a digital X-axis voltage value between the new X-axis electrode and the first compensation circuit from the touch panel and a digital Y-axis voltage between the Y-axis electrode and the second compensation circuit. A comparison unit receiving a value and comparing the initial digital X-axis voltage value and the initial digital Y-axis voltage value stored in the memory; and comparing the new digital X-axis voltage value and the new digital Y-axis voltage value according to the comparison result of the comparison unit. Compensation unit for compensating is provided.

The compensating unit of the microcomputer of the touch controller of the driving device of the touch panel is a difference between the new digital X axis voltage value and the new digital Y axis voltage value and the initial digital X axis voltage value and the initial digital Y axis voltage value stored in the memory. As much as the new digital X-axis voltage value and the new digital Y-axis voltage value is characterized in that the compensation.

In the touch controller of the driving device of the touch panel, the microcomputer further includes a timer for controlling the first and second compensation circuits by detecting the use time of the touch panel.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 4 to 8.

4 and 5, a driving device of a touch panel according to an exemplary embodiment of the present invention includes a touch panel 110, which is an input device for recognizing a position of a display device, and a driving unit for driving the touch panel 110. do.

The touch panel 110 is sprayed between the X-axis electrode 152 formed on the upper substrate 112, the Y-axis electrode 154 formed on the lower substrate 116, and the upper substrate 112 and the lower substrate 116. The spacer 120 is provided.

The upper substrate 112 of the touch panel 110 has a material of polyethylene terephthalate (hereinafter referred to as "PET") film. The first transparent conductive layer 114 is formed on the lower front surface of the upper substrate 112.

The lower substrate 116 of the touch panel 110 may be made of any one of glass, plastic, and PET film. The second transparent conductive layer 118 is formed on the upper front surface of the lower substrate 116.

The first and second transparent conductive layers 114 and 118 include indium tin oxide (hereinafter referred to as "ITO") and indium zinc oxide (Indium-Zinc-Oxide), which are transparent conductive materials. Formed by printing silver (Ag) on a transparent conductive layer formed of one of the following: " IZO ") and indium-tin-zinc-oxide (hereinafter referred to as " ITZO "). do.

As shown in FIG. 5, left and right X-electrodes and right X-electrodes 152A and 152B are formed in the first transparent conductive layer 114, and the upper and lower edges are formed in the second transparent conductive layer 118. Upper Y-electrodes and lower Y-electrodes 154A, 154B are formed.

The spacer 120 is sprayed between the two substrates of the upper and lower substrates 112 and 116 on which the electrodes 152A, 152B, 154A, and 154B are formed so as to maintain a constant distance.

As such, the first transparent conductive layer 114 formed on the upper substrate 112 is the second transparent conductive layer 118 formed on the lower substrate 116 when the upper substrate 112 is pressed by a stylus pen or finger. By short-circuit), a signal having a current amount or voltage level varied by the current and voltage applied to the X-axis electrode and the Y-axis electrodes 152 and 154 is generated according to the pressed position.

First and second switches for selectively switching the power supply voltage source Vcc and the ground voltage source GND of the electrode layers of the first and second transparent conductive layers 114 and 118 according to the embodiment of the present invention. 124 and 126, a first buffer 155 connected between the X-axis electrode 152 and the ground voltage source GND, and a second buffer connected between the Y-axis electrode 154 and the ground voltage source GND. 157 and a touch controller 130 for supplying coordinate signals input from the touch panel 110 to the system 140.

The first switch 124 of the first transparent conductive layer 114 is applied to the power supply voltage source (Vcc) supplied to the touch panel 110 under the upper substrate 112 in response to the control of the touch controller 130. One of the right X-electrode 152B formed at the right edge and the upper Y-electrode 154A formed at the upper edge of the second transparent conductive layer 118 applied on the lower substrate 116 is switched.

The second switch 126 of the first transparent conductive layer 114 coated with the base voltage source GND supplied to the touch panel 110 under the upper substrate 112 in response to the control of the touch controller 130. One of the left X-electrodes 152A formed at the left edge and the lower Y-electrodes 154B formed at the lower edge of the second transparent conductive layer 118 applied to the upper portion of the lower substrate 116 are switched.

As shown in FIG. 6A, the first buffer 155 has a voltage value Rx of the X-axis coordinate detected by the X-axis electrode 152 in response to the first on / off control signal Xcon of the touch controller 130. To compensate. To this end, the driving device of the touch panel further includes a first reference resistor Rfx connected between the first buffer 155 and the ground voltage source GND. Since the first reference resistor Rfx has little error, it is preferable to minimize the change of the voltage value Rx due to the error of the resistance. The first buffer 155 uses a tri-state buffer in which the connection to the first reference resistor Rfx is normally disconnected.

As shown in FIG. 6B, the second buffer 157 has a voltage value Ry of the Y-axis coordinate detected by the Y-axis electrode 154 in response to the second on-off control signal Ycon of the touch controller 130. To compensate. To this end, the driving device of the touch panel further includes a second reference resistor Rfy connected between the second buffer 157 and the ground voltage source GND. Since the second reference resistor Rfy has almost no error, it is preferable to minimize the change of the voltage value Ry due to the error of the resistance. The second buffer 157 uses a tri-state buffer in which the connection to the second reference resistor Rfy is normally interrupted.

The touch controller 130 is an analog-to-digital converter (hereinafter referred to as "ADC") that converts any analog voltage detected by the touch panel 110 into a digital voltage, and an ADC 132. Interface integrated circuit 136 for making the microcomputer (MICOM) 134 responding to the digital voltage values of the X and Y axes converted by (Hereinafter referred to as "interface IC").

The ADC 132 converts the detected X-axis analog voltage value into an X-axis digital voltage value by applying pressure on the upper substrate 112 with a pen. In addition, the ADC 132 converts the detected Y-axis analog voltage value into a Y-axis digital voltage value by applying pressure on the upper substrate 112 with a pen.

The microcomputer 134 is also called a microcomputer and receives the digital voltage values of the X and Y axes converted by the ADC 132. In addition, the microcomputer 134 switches the digital voltage value converted by the ADC 132 to the X-axis or the Y-axis coordinate. The microcomputer 134 supplies the first and second control signals CS1 to the first and second switches 124 and 126 for selectively supplying the power voltage source Vcc and the ground voltage source GND to the electrode layers of the X and Y axes. , CS2).

In addition, the microcomputer 134 uses the internal timer (not shown) and the first and second on / off control signals to the first and second buffers 155 and 157 when a predetermined time elapses after the power is turned on. Will supply (Xcon, Ycon). To this end, the microcomputer 134 stores the X-axis coordinate value and the Y-axis coordinate value, which are initially measured as shown in FIG. 7, and the X-axis, which is a digital voltage value supplied from the ADC 134. The ADC 134 is supplied according to the comparison result of the comparator 170 and the comparator 170 comparing the coordinate value and the Y axis coordinate value with the X axis coordinate value and the Y axis coordinate value stored in the memory unit 172. Compensation unit 174 is provided to compensate for the X-axis coordinate value and the Y-axis coordinate value that is a digital voltage value.

The memory unit 172 stores the X-axis coordinate values and the Y-axis coordinate values of the touch panel which are initially set digital voltage values. At this time, the X-axis coordinate values of the touch panel are stored in the memory unit 172 by Equation 1 below, and the Y-axis coordinate values are stored by Equation 2 below.

VXL = VRfx / (VRfx + VXL) * VXH ------- ①

VYL = VRfy / (VRfy + VYL) * VYH ------- ②

In Equation (1), VXL is the analog voltage value of the measured X-axis coordinate, VRfx is the resistance value of the first reference resistor Rfx, and VXL is the resistance value XL between the left X-electrodes 152A at the touched point. Is a voltage value due to the resistance value XH between the right X-electrode 152B at the touched point.

In Equation (2), VYL is the analog voltage value of the measured Y-axis coordinate, VRfy is the resistance value of the second reference resistance Rfy, and VYL is the resistance value YL between the lower Y-electrode 154B at the touched point. Is a voltage value due to the resistance value YH between the upper Y-electrodes 154A at the touched point.

In order to measure the voltage value of the X-axis coordinates and the analog voltage value of the Y-axis coordinates by the following equations (1) and (2), the driving device of the touch panel first turns off the first buffer 155 from the microcomputer 134 to the first buffer 155. The control signal Xcon is supplied to analog-to-digital convert the voltage value between the touch panel 110 and the first reference resistor Rfx, and then converts the converted X-axis digital voltage value to the memory unit 172 of the microcomputer 134. After storing, supplying the second on-off control signal (Ycon) from the microcomputer 134 to the second buffer 157 to convert the voltage value between the touch panel 110 and the second reference resistor (Rfy) to analog and digital The converted Y-axis digital voltage value is stored in the memory unit 172 of the microcomputer 134.

The comparison unit 170 converts the X-axis voltage value VXL 'between the touch panel 110 and the first reference resistor Rfx into a digital voltage value by the ADC 134 using Equation 3 below. The X-axis coordinate value VXL 'is compared with the X-axis coordinate value VXL stored in the memory unit 172, and the comparison result is supplied to the compensator 174. In addition, the comparator 170 may convert the Y-axis voltage value VYL 'between the touch panel 110 and the second reference resistor Rfy to the digital voltage value by the ADC 134 using Equation (4) below. The converted Y-axis coordinate value VYL 'is compared with the Y-axis coordinate value VYL stored in the memory unit 172, and the comparison result is supplied to the compensator 174.

ΔVXL = VXL-VXL '-------- ③

ΔVYL = VYL-VYL '-------- ④

The compensator 174 compensates for the ΔVXL value of the above-described equation ③ to the X-axis coordinate value VXL ', which is a digital voltage value supplied from the ADC 134, by using Equation ⑤ below to compensate for the X-axis coordinate. The value VXL 'is supplied to the interface IC 136. In addition, the compensation unit 174 compensates for the ΔVYL value of Equation ④ described above to the Y-axis coordinate value VYL ′, which is a digital voltage value supplied from the ADC 134, by using Equation ⑥ below. The axis coordinate value VYL 'is supplied to the interface IC 136.

VXL '= VXL' ± ΔVXL -------- ⑤

VYL '= VYL' ± ΔVYL -------- ⑥

The interface IC 136 is connected between the microcomputer 134 and the system 140 of the liquid crystal display device in which the touch panel 110 is embedded. The interface IC 136 transmits the X-axis and Y-axis coordinate values VXL 'and VYL' compensated by the microcomputer 134 to the external system 40 in response to the control of the microcomputer 134.

The touch controller 134 converts the power voltage input from the system 140 into a power suitable for driving the touch panel 110, and supplies the coordinate signal input from the touch panel 110 to the system 140. do.

In the touch panel driving apparatus according to the embodiment of the present invention, the memory unit 172 of the microcomputer 134 receives the first and second on / off control signals Xcon, from the microcomputer 134 by a system maker. Ycon is supplied to the first and second buffers 155 and 157 so that the voltage value between the X-axis electrodes of the touch panel 110 and the first reference resistor Rfx is converted into a digital voltage value and thus the microcomputer 134. The voltage value between the Y-axis electrodes of the touch panel 110 and the second reference resistor Rfy is converted into a digital voltage value and stored in the memory unit 172 of the microcomputer 134. It is stored.

The driving unit of the touch panel in the touch panel driving apparatus according to the embodiment of the present invention, in order to detect the X-axis voltage value of the touch panel 110, the right X-electrode 152B of the first transparent conductive layer 114. Power supply Vcc is supplied from the power supply voltage source Vcc by switching of the first switch 124, and is connected to the ground voltage source GND via the first resistor R1 to the left X-electrode 152A. do. When a predetermined voltage is applied between the X-electrodes 152A and 152B, an electric flow is generated between the X-electrodes 152A and 152B. In addition, in order to detect the Y-axis voltage value of the touch panel 110, the driving unit of the touch panel 110 switches the upper Y-electrode 154A from the power supply voltage source Vcc to the voltage Vcc by switching the first switch 124. Is supplied, and the lower Y-electrode 154B is connected to the ground voltage source GND via the resistor R2. When a predetermined voltage is applied between the Y-electrodes 154A and 154B, an electric flow is generated between the Y-electrodes 154A and 154B. Accordingly, the first transparent conductive layer 114 of the upper substrate 112 and the second transparent conductive layer 118 of the lower substrate 116 when the upper substrate 112 is pressed by a mechanism such as a stylus pen or a finger. ) Is short-circuited. At this time, the voltage values of the X and Y axes are coordinates of the X and Y axes on the touch panel 110 by different values of positions where the first transparent conductive layer 114 and the second transparent conductive layer 118 are pressed and shorted. You get

On the other hand, since the voltage value detected by the touch panel 10 changes according to the temporal change of the touch panel 110 and the environment, such as temperature, an error between the touched coordinate value and the detected coordinate value occurs. In order to solve this problem, in the driving apparatus of the touch panel according to the embodiment of the present invention, when the use time of the touch panel 110 elapses for a predetermined time, a timer inside the microcomputer 134 (not shown) is operated to micom First and second on-off control signals Xcon and Ycon are supplied to the first and second buffers 155 and 157 from 134. Then, the voltage value between the X-axis electrodes of the touch panel 110 and the first reference resistor Rfx is converted into the X-axis digital voltage value VXL 'and supplied to the comparator 170 of the microcomputer 134. In addition, the voltage value between the Y-axis electrodes of the touch panel 110 and the second reference resistor Rfy is converted into a Y-axis digital voltage value VYL 'and supplied to the comparator 170 of the microcomputer 134. The comparison unit 170 stores the X-axis digital voltage value VXL 'and Y-axis digital voltage value VYL' supplied from the ADC 132 and the X-axis digital voltage value VXL and Y stored in the memory unit 172. The comparison result is supplied to the compensator 174 in comparison with the axis digital voltage value VYL. Then, the compensator 174 provides the X-axis digital voltage value VXL 'and the Y-axis digital voltage value VYL' supplied to the comparator 170 with the X-axis digital voltage value ΔVXL and the Y-axis digital voltage value. (ΔVYL) is compensated to supply the coordinates of the compensated X and Y axes to the system 140 via the interface IC 136.

Accordingly, the system 140 displays the coordinates of the compensated X-axis and Y-axis supplied from the interface IC 136 on the display screen to detect and detect the coordinate values touched by the pen 160 as shown in FIG. The coordinate value, that is, the mouse cursor 162 and the command corresponding to the coordinate value are exactly matched. Accordingly, the system 140 executes a corresponding command or a related application program by the compensated coordinate value. In addition, the system 140 supplies power signals and video data required for a display (not shown) on which the touch panel 110 is mounted on a surface.

As such, the apparatus for driving a touch panel according to an exemplary embodiment of the present invention blocks the first and second reference resistors Rfx and Rfy and the X-axis electrodes and the Y-axis electrodes of the touch panel during normal operation of the touch panel. Detects the X and Y axis coordinates of the touch panel and connects the first and second reference resistors Rfx and Rfy to the X and Y axis electrodes of the touch panel according to the usage time and environment of the touch panel. By detecting the X-axis and the Y-axis coordinates of the touch panel, the error between the pen-touched coordinates and the detected coordinates is compensated according to the use time and the use environment of the touch panel, in particular, the temperature.

As described above, the touch panel driving apparatus according to the embodiment of the present invention initially converts the voltage value between the reference resistors connected to the X-axis and Y-axis electrodes, and stores the converted digital voltage value in a memory. Thereafter, the changed voltage value between the touch panel and the reference resistance is detected according to the use time and the use environment of the touch panel to compensate for the modified voltage value. To this end, the present invention is provided with a buffer that can normally block the reference resistance. Accordingly, the present invention compensates for the change in the voltage value detected according to the use time and the use environment of the touch panel to prevent errors occurring in the touched X-axis and Y-axis voltage values and the detected X-axis and Y-axis voltage values. can do.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (7)

A touch panel in which spacers are sprayed between an upper plate on which X-axis electrodes are formed and a lower plate on which Y-axis electrodes are formed; A first compensation circuit connected between the X-axis electrode and a base voltage source to compensate for the X-axis voltage value detected from the X-axis electrode; A second compensation circuit connected between the Y axis electrode and a base voltage source to compensate for the Y axis voltage value detected from the Y axis electrode; And a touch controller controlling the first and second compensation circuits according to the use time and the use environment of the touch panel to compensate voltage values of the X and Y axes detected from the X and Y axis electrodes. Driving device for a touch panel, characterized in that. The method of claim 1, The first compensation circuit, A first reference resistor connected between the X-axis electrode and a ground voltage source, And a first buffer connected between the first reference resistor and the X-axis electrode to connect the first reference resistor and the X-axis electrode in response to the control of the touch controller. . The method of claim 1, The second compensation circuit, A second reference resistor connected between the Y-axis electrode and a ground voltage source, And a second buffer connected between the second reference resistor and the Y-axis electrode to connect the second reference resistor and the Y-axis electrode in response to the control of the touch controller. . The method of claim 1, The touch controller, An analog-digital converter for converting the analog voltage value detected from the X-axis electrode and the Y-axis electrode into a digital voltage value; A microcomputer controlling the first and second compensation circuits and receiving a digital voltage value from the analog-digital converter to detect X-axis coordinates and Y-axis coordinates of the touch panel; And an interface integrated circuit for transmitting the X-axis coordinates and the Y-axis coordinates detected from the microcomputer to the system. The method of claim 4, wherein The microcomputer, A memory unit for storing an initial digital X axis voltage value between the X axis electrode and the first compensation circuit and an initial digital Y axis voltage value between the Y axis electrode and the second compensation circuit; Initial digital X stored in the memory by receiving the digital X-axis voltage value between the new X-axis electrode and the first compensation circuit and the digital Y-axis voltage value between the Y-axis electrode and the second compensation circuit from the touch panel. A comparison unit for comparing the axial voltage value and the initial digital Y-axis voltage value; And a compensator for compensating the new digital X-axis voltage value and the new digital Y-axis voltage value according to the comparison result of the comparator. The method of claim 5, wherein The compensator may be configured such that a difference between the new digital X axis voltage value and the new digital Y axis voltage value and the initial digital X axis voltage value and the initial digital Y axis voltage value stored in the memory is equal to the new digital X axis voltage value and the new digital Y axis voltage value. Driving device for a touch panel, characterized in that for compensating the voltage value. The method of claim 5, wherein The micom further comprises a timer for detecting the use time of the touch panel to control each of the first and second compensation circuits.