Display device with touch panel and method for converting driving frequency of touch panel

1. A method for converting a driving frequency of a touch panel, the method comprising:

receiving a control signal for a display porch time;

changing the display porch time based on the control signal;

changing a duration of a display time based on the changed display porch time;

changing a frequency of a horizontal synchronizing signal based on the changed display porch time; and

generating a touch driving signal synchronized with the horizontal synchronizing signal.

2. The method as claimed in claim 1 , further comprising:

maintaining a display frame rate.

3. The method as claimed in claim 1 , wherein changing the display porch time includes changing a total time of the display porch time in a frame period.

4. A display device with a touch panel, comprising:

a display to display an image;

a touch sensor to sense a touch;

a driver to control the display; and

a touch driver to provide a touch driving signal to the touch sensor, the touch driving signal synchronized with a horizontal synchronizing signal, wherein the touch driver is to provide a control signal of a display porch time to the driver, and wherein the driver is to change the display porch time based on the control signal and is to change a frequency of the horizontal synchronizing signal based on the changed display porch time.

5. The display device as claimed in claim 4 , wherein changing the display porch time changes a cycle of the horizontal synchronizing signal.

6. The display device as claimed in claim 5 , wherein the driver changes the display porch time while a display frame rate is maintained.

7. The display device as claimed in claim 4 , wherein the touch driver is to change a total time of the display porch time in a frame period.

8. A method for converting a driving frequency of a touch panel, the method comprising:

changing a display porch time;

changing a cycle of a horizontal synchronizing signal based on the changed display porch time;

converting a frequency of the touch driving signal synchronized with the horizontal synchronizing signal, which includes a first pulse that repeats at a substantially constant cycle, wherein the touch driving signal includes N second pulses temporally positioned in a corresponding cycle of the horizontal synchronizing signal, a first distance from a first edge of one of the second pulses to a first edge of an adjacent one of the second pulses substantially constant, and wherein converting the frequency of the touch driving signal includes changing the first distance while maintaining a duration of each of the second pulses.

9. The method as claimed in claim 8 , further comprising:

receiving a control signal for the display porch time; and

changing the display porch time based on the control signal.

10. The method as claimed in claim 8 , wherein a distance from the first edge of the N-th second pulse to the first edge of a first pulse starting a next cycle of the horizontal synchronizing signal is greater than the first distance.

11. The method as claimed in claim 8 , wherein a distance from the first edge of the N-th second pulse to the first edge of a first pulse starting a next cycle of the horizontal synchronizing signal substantially equals the first distance.

12. The method as claimed in claim 8 , wherein the N second pulses are positioned in a corresponding period of the horizontal synchronizing signal in a non-overlapping relationship with an expected noise period.

13. The method as claimed in claim 12 , wherein the expected noise period is a noise period expected to be generated by applying at least one of a data signal or a gate signal.

14. The method as claimed in claim 8 , wherein N≧1.