Apparatus and method for driving a liquid crystal display device

Abstract

An apparatus for driving an LCD device includes an image display unit having liquid crystal cells in respective regions defined by a plurality of gate and data lines; an over-driving apparatus to detect a signal of a moving image based on a source data and to detect modulated data based on the detected signal, the modulated data changes a response speed of a liquid crystal based on the detected signal; a gate driver to supply scan signals to the gate lines; a data driver to convert the modulated data into analog video signals and to supply the analog video signals to the data lines; and a timing controller to align the modulated data and to generate data control signal and gate control signal, the timing controller outputs the aligned data and the data control signal to the data driver and outputs the gate control signal to the gate driver.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 illustrates a related art apparatus for driving a liquid crystal display (LCD) device;

FIG. 2 illustrates a response speed and luminance of a liquid crystal cell of FIG. 1;

FIG. 3 is a block diagram illustrating a related art over-driving apparatus;

FIG. 4 illustrates a response speed and luminance of a liquid crystal cell in a related art over-driving apparatus shown in FIG. 3;

FIG. 5 illustrates an exemplary apparatus for driving an LCD device according to a first exemplary embodiment of the present invention;

FIG. 6 is a block diagram illustrating an exemplary over-driving apparatus according to the first exemplary embodiment of the present invention;

FIG. 7 is a block diagram illustrating an exemplary over-driving data generator of the over-driving apparatus according to the first exemplary embodiment of the present invention;

FIGS. 8A to 8D are graphs illustrating a plurality of over-driving data listed in an exemplary look-up table;

FIG. 9 is a block diagram illustrating an exemplary over-driving apparatus according to a second exemplary embodiment of the present invention;

FIG. 10 is a block diagram illustrating an exemplary motion filter of an over-driving data generator according to the second exemplary embodiment of the preset invention;

FIG. 11 is a block diagram illustrating an exemplary over-driving data generator of the over-driving apparatus according to the second exemplary embodiment of the present invention; and

FIGS. 12 and 13 illustrate changes in the boundary waveforms generated by filtering according to the second exemplary embodiment of the present invention.

Claims

1. An apparatus for driving an liquid crystal display (LCD) device, comprising: an image display unit including liquid crystal cells formed in respective regions defined by a plurality of gate lines and a plurality of data lines;an over-driving apparatus to detect a signal of a moving image based on externally supplied source data and to detect modulated data in accordance with the detected signal, wherein the modulated data changes a response speed of a liquid crystal based on the detected signal;a gate driver to supply scan signals to the gate lines;a data driver to convert the modulated data into analog video signals and to supply the analog video signals to the data lines; anda timing controller to align the modulated data and to generate data control signal and gate control signal, wherein the timing controller outputs the aligned data and the data control signal to the data driver and outputs the gate control signal to the gate driver.

2. The apparatus as claimed in claim 1, wherein the over-driving apparatus includes: a memory to store the source data supplied in a frame unit format;a motion detector to detect a motion size signal that corresponds to a speed of the moving image using the source data of a current frame and the source data of a previous frame stored in the memory;an over-driving data generator to generate a plurality of over-driving data using a plurality of look-up tables and to selectively output a respective one of the plurality of over-driving data in accordance with the motion size signal; anda mixing unit to mix the source data of the current frame with the over-driving data generated by the over-driving data generator and to output the modulated data.

3. The apparatus as claimed in claim 2, wherein the over-driving data generator includes: a plurality of look-up tables to respectively output different over-driving data by receiving the source data of the current frame and the source data of the previous frame; anda selector to selectively output a respective one of the over-driving data among the plurality of over-driving data based on the motion size signal.

4. The apparatus as claimed in claim 1, wherein the over-driving apparatus includes: a first memory to store the source data supplied in a frame unit format;a motion detector to detect a motion size signal that corresponds to a speed of the moving image using the source data of the current frame and the source data of the previous frame stored in the first memory;a motion filter to filter the source data of the current frame based on the motion size signal to generate undershoot in a boundary of the display image;a second memory to store the filtered data of the current frame supplied in a frame unit format;an over-driving data generator to generate a plurality of over-driving data using a plurality of look-up tables and to selectively output a respective one of the plurality of over-driving data based on the motion size signal; anda mixing unit to mix the filtered data of the current frame with the over-driving data generated by the over-driving data generator and to output modulated data.

5. The apparatus as claimed in claim 4, wherein the over-driving data generator includes: a plurality of look-up tables to respectively output different over-driving data by receiving the filtered data of the current frame and the filtered data of the previous frame; anda selector to selectively output a respective one of the over-driving data among the plurality of over-driving data based on the motion size signal.

6. The apparatus as claimed in claim 4, wherein the motion filter includes: a boundary detector to detect a boundary of the moving image from the source data of the current frame and to output a boundary signal; andan undershoot generator to filter the boundary signal to generate undershoot in the boundary of the moving image based on the motion size signal.

7. A method for driving an liquid crystal display (LCD) device having an image display unit to display an image, the method comprising the steps of: detecting a signal of a moving image from externally supplied source data and generating modulated data based on the detected signal, wherein the modulated data changes a response speed of a liquid crystal based on the detected signal;supplying scan signals to respective gate lines; andconverting the modulated data into analog video signals at a time when the conversion is synchronized with the scan signals and supplying the analog video signals to respective data lines.

8. The method as claimed in claim 7, wherein the detecting step further includes: storing the source data supplied in a frame unit format;detecting a motion size signal that corresponds to a speed of the moving image using the source data of a current frame and the source data of a previous frame;generating a plurality of over-driving data using a plurality of look-up tables and selectively outputting a respective one of the plurality of over-driving data in accordance with the motion size signal; andoutputting the modulated data by mixing the source data of the current frame with the selected over-driving data.

9. The method as claimed in claim 8, wherein the step of generating the plurality of over-driving data further includes: respectively outputting different over-driving data by receiving the source data of the current frame and the source data of the previous frame; andselectively outputting a respective one of the over-driving data among the plurality of over-driving data based on the motion size signal.

10. The method as claimed in claim 7, wherein the detecting step further includes: storing the source data supplied in a frame unit format;detecting a motion size signal that corresponds to a speed of the moving image using the source data of the current frame and the source data of the previous frame;filtering the source data of the current frame to generate undershoot in a boundary of the display image in accordance with the motion size signal;storing the filtered data of the current frame supplied in a frame unit format;generating a plurality of over-driving data using a plurality of look-up tables and selectively outputting a respective one of the plurality of over-driving data in accordance with the motion size signal; andoutputting the modulated data by mixing the filtered data of the current frame with the selected over-driving data.

11. The method as claimed in claim 10, wherein the step of generating the plurality of over-driving data includes: respectively outputting different over-driving data by receiving the filtered data of the current frame and the filtered data of the previous frame; andselectively outputting a respective one of the over-driving data among the plurality of over-driving data based on the motion size signal.

12. The method as claimed in claim 10, wherein the filtering step further includes: detecting a boundary of the moving image from the source data of the current frame and outputting a boundary signal; andfiltering the boundary signal to generate undershoot in the boundary of the moving image based on the motion size signal.