Liquid crystal panel device having a touch panel and method for driving the same

1. A liquid crystal panel device including a touch panel, comprising:

a liquid crystal panel;

a touch panel positioned on the liquid crystal panel;

a signal line having one end connected to the liquid crystal panel; and

a touch controller for receiving analog signals generated by contacting the touch panel to determine X/Y coordinates,

wherein the touch controller detects one of a rising edge and a falling edge of a liquid crystal common voltage transmitted through the signal line and wherein when the one of the rising edge and the falling edge of the liquid crystal common voltage transmitted through the signal line is detected, the touch controller enters a stand by mode for a predetermined period.

2. The device according to claim 1 , wherein the touch controller includes an analog-to-digital converter for converting the analog signals generated by the contact of the touch panel into digital signals, and a CPU for operating the X and Y coordinates corresponding to a contacted position based on the converted analog signals.

3. The device according to claim 1 , wherein the touch controller extracts only stable components of the analog signals.

4. The device according to claim 1 , further comprising a system for receiving the X and Y coordinate signals from the touch controller for displaying position data corresponding to a contacted position on the liquid crystal panel.

5. The device according to claim 4 , wherein the system is an application system.

6. A liquid crystal panel device having a touch panel, comprising:

a liquid crystal panel;

a touch panel positioned on the liquid crystal panel;

an analog-to-digital converter for converting signals from the touch panel into digital signals;

a CPU for generating a X/Y coordinate signals based on the digital signals;

a communication line for transmitting the X/Y coordinates signals;

an application system for displaying position data on the liquid crystal panel based on transmitted X/Y coordinate signals; and

a signal line for transmitting a common voltage signal from the liquid crystal panel to the CPU, wherein the CPU detects one of a rising edge and a falling edge of the common voltage signal and places the analog to digital converter into a stand by mode.

7. The device according to claim 6 , wherein the analog-digital converter extracts only stable components of the analog signals.

8. A method for driving a liquid crystal panel device having a touch panel, comprising:

inputting a liquid crystal common voltage to a touch controller;

detecting one of a rising edge and a falling edge of the liquid crystal common voltage by the touch controller; when the one of the rising edge and the falling edge of the liquid crystal common voltage is detected, entering the touch controller in a stand by mode for a first predetermined period and receiving analog signals generated by contacting a touch panel after the first predetermined period;

converting the received analog signals into digital signals by the touch controller; and

outputting X and Y coordinates corresponding to contact position on the touch panel based on the digital signals by the touch controller.

9. The method according to claim 8 , further comprising receiving the analog signals generated by the contacting of the touch panel after the stand by mode for a second predetermined period from the polarity reversal of a liquid crystal driving voltage to prevent receipt of unstable component signals among the signals generated by the contacting of the touch panel.

10. The device according to claim 1 , wherein the touch controller does not receive the analog signals generated by contacting the touch panel at the stand by mode.

11. The device according to claim 6 , wherein the analog-to-digital converter does not convert the signals from the touch panel at the stand by mode.

12. The method according to claim 8 , wherein the touch controller does not receive the analog signals generated by contacting the touch panel at the stand by mode.