Driving apparatus of display device and method for driving display device

1. An apparatus for driving a display device, the apparatus comprising:

a signal controller which converts an input image signal of a first frame frequency into a plurality of output image signals of a second frame frequency, and outputs the plurality of output image signals; and

a data driver which selects data voltages corresponding to the plurality of output image signals among one group of gray voltages and applies the data voltages to pixels,

wherein the input image signal includes at least a first input image signal and a second input image signal,

the plurality of output image signals includes a first output image signal corresponding to the first input image signal and a second output image signal corresponding to the second input image signal,

frame frequencies of the first output image signal and the second output image signal are different from each other, and

wherein the signal controller calculates an inactive pixel row number based on the second frame frequency and changes the inactive pixel row number to control the horizontal frequencies and the pixel frequencies of the first output image signal and the second output image signal, respectively, to be substantially equal to each other.

2. The apparatus of claim 1 , wherein

the signal controller changes a pixel frequency of the input image signal of the first frame frequency to the plurality of output image signals of the second frame frequency.

3. The apparatus of claim 1 , wherein

the first input image signal is a video image signal, and the second input image signal is a film image signal.

4. The apparatus of claim 3 , wherein

the signal controller includes a frame memory.

5. The apparatus of claim 4 , wherein

the signal controller includes a line memory.

6. A method for driving a display device, the method comprising:

inputting at least two different types of input image signals;

reading the input image signals to confirm the different types of the input image signals;

changing a frame frequency of each type of input image signals into a predetermined frame frequency according to the frame frequency of each type of input image signals;

changing a number of inactive pixel rows in which an image is not displayed according to the predetermined frame frequency to control the horizontal frequencies and the pixel frequencies of the different types of the input image signals, respectively, to be substantially equal to each other; and

outputting the input image signals to display the image.

7. The method for driving a display device of claim 6 , wherein a formula

( v _active+ v _blank1)× f — v 1=( v _active+ v _blank2)× f — v 2 is used in changing the number of inactive pixel rows,

wherein f_v1 is a frame frequency of the input image signal before the changing, f_v2 is a frame frequency of the input image signal after the changing, v_active is a number of active pixel rows, v_blank1 is a number of inactive pixel rows before the changing, and v_blank2 is a number of inactive pixel rows after the changing.

8. The method for driving a display device of claim 6 , wherein inputting at least two different types of input image signals includes inputting a video image signal and a film image signal.

9. The method for driving a display device of claim 8 , wherein changing a frame frequency of each type of input image signal into the predetermined frame frequency includes changing a frame frequency of the video image signal to about 120 Hz and changing a frame frequency of the film image signal to about 72 Hz.