KR100955377B1 - Driving method of liquid crystal display panel - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of driving a liquid crystal display panel, wherein a pulse width or a pulse size of a scan signal applied to the gate lines is adjusted so that the length difference between the link lines connecting the gate lines and the gate driver of the liquid crystal display panel is adjusted. As a result, the delay and distortion of the scan signal can be compensated, thereby preventing the characteristics of the scan signal from changing for each gate line.

Description

DRIVING METHOD OF LIQUID CRYSTAL DISPLAY PANEL}

1 is an exemplary view showing a configuration in which a liquid crystal display panel and a gate driver are combined.

FIG. 2A is an exemplary diagram showing a waveform of a scan signal applied to gate lines connected to an edge of a flexible film in FIG. 1; FIG.

2B is an exemplary view showing a waveform of a scan signal applied to gate lines connected to a central portion of a flexible film in FIG.

3 is an exemplary view showing waveforms of scan signals applied to gate lines through a method of driving a liquid crystal display panel according to a first embodiment of the present invention;

4 is an exemplary view showing waveforms of scan signals applied to gate lines through a method of driving a liquid crystal display panel according to a second embodiment of the present invention;

** Explanation of Signs of Major Parts of Drawings **

GOE: Gate Output Enable Signal

SC_EDGE1, SC_EDGE2, SC_CENTER, SC_MID1, SC_MID2: Scan Signal

a to e: first to fifth low potential intervals

A to E: first to fifth high potential sections

The present invention relates to a method of driving a liquid crystal display panel, and more particularly, to a method of driving a liquid crystal display panel to compensate for a difference in characteristics of a scan signal applied to gate lines of a liquid crystal display panel.

In general, a liquid crystal display panel includes a thin film transistor (TFT) array substrate having pixel electrodes and a color filter (CF) substrate having a common electrode. The liquid crystal layer is formed in the spaced space between the TFT array substrate and the CF substrate.

On the TFT substrate, data lines for transmitting a video signal supplied from a data driver to a pixel and gate lines for transmitting a scan signal supplied from a gate driver to a pixel cross each other. Pixels are formed in a rectangular region where the gate lines intersect with the gate lines, and the switching elements and the pixel electrodes are separately formed in the pixels, and the switching elements and the pixel electrodes are electrically connected to each other.

The gate driver sequentially applies a scan signal to the gate lines according to a gate start pulse, and switching devices corresponding to the gate line to which the scan signal is applied have a turn-on state. The liquid crystal layer is driven by applying a video signal supplied through the data lines to the pixel electrode.

In addition, the pixels are individually provided with a storage capacitor to charge the video signal, and then to the pixel electrode of the pixel during the turn-off period of the switching elements in which the scan signal is applied to the next gate line. The driving of the liquid crystal layer is maintained by supplying a charged video signal.

In order to couple the gate driver and the data driver with the liquid crystal display panel, a tape carrier package (TCP) method is commonly used.

The TCP method is a method in which a driving circuit is mounted on a thin flexible film made of a polymer material and combined with a liquid crystal display panel, which will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a configuration in which a liquid crystal display panel and a gate driver are combined.

Referring to FIG. 1, a flexible film 120 having a gate line 110 for supplying a scan signal is uniformly spaced apart from one another on a liquid crystal display panel 100 and mounted with a driving circuit 130. One side and a portion of the liquid crystal display panel 100 overlap each other and are electrically connected to each other.

In addition, link lines 140 are formed at edges of the liquid crystal display panel 100 to individually connect the gate lines 110 and the flexible film 120.

The link lines 140 are electrically connected to the driving circuit 130 mounted on the flexible film 120 through the conductive lines patterned on the flexible film 120.

The link lines 140 are connected to the gate lines 110 arranged on the liquid crystal display panel 100 from the flexible film 120 which is partially overlapped with one side of the liquid crystal display panel 100. It is patterned to be a chatchat flesh.

That is, a plurality of flexible films 120 on which the driving circuit 130 is mounted are coupled to the liquid crystal display panel 100 so as to correspond to the number of the gate lines 110. In general, the gate lines 110 are liquid crystals. As the display panel 100 is arranged to be uniformly spaced apart, the width of the flexible film 120 is smaller than the width of the corresponding gate lines 110.

Accordingly, the link lines 140 are patterned in a buccal shape in order to connect the flexible film 120 on which the driving circuit 130 is mounted and the gate lines 110 corresponding to the link lines 140. The link lines 140 which individually connect the flexible film 120 and the gate lines 110 have different lengths. In this case, the link lines 140 connecting the edges of the flexible film 120 to the gate lines 110 may be link lines 140 connecting the center portion of the flexible film 120 to the gate lines 110. The length is long compared to the patterning.

As described above, when the lengths of the link lines 140 are different, the internal resistance and parasitic capacitance of the link lines 140 are different from each other.

The scan signal has a pulse shape having a predetermined size and width, and is sequentially shifted from the driving circuit 130 to the gate lines 110 through the link lines 140.

However, as described above, since the internal resistance and parasitic capacitance of the link lines 140 are different from each other, the scan signals applied to the gate lines 110 have different characteristics.

FIG. 2A illustrates an example of a waveform of a scan signal CS1 applied to gate lines 110 connected to an edge of the flexible film 120, and FIG. 2B illustrates a center portion of the flexible film 120. FIG. 2 shows an example of a waveform of the scan signal CS2 applied to the gate lines 110 to be connected.

2A and 2B, the lengths of the link lines 140 connecting the edges of the flexible film 120 and the gate lines 110 have a central portion and a gate line 110 of the flexible film 120. The waveform of the scan signal CS1 applied to the gate lines 110 connected to the edge of the flexible film 120 is longer than the length of the link lines 140 connecting the plurality of lines. Compared to the waveform of the scan signal CS2 applied to the gate lines 110 connected to the central portion of the C1), the internal resistance and parasitic capacitance of the link lines 140 are more affected, and thus delayed and distorted.

As described above, when the waveform of the scan signal is differently applied to the gate lines 110 according to the length difference between the link lines 140, the thin film is provided in the pixels corresponding to the gate lines 110 separately. A difference in on / off characteristics of switching elements such as a transistor may be caused to cause a driving failure of the liquid crystal display panel 100.

In addition, the characteristics of the video signal supplied from the data lines to the pixels are changed for each of the gate lines 110, so that a luminance difference occurs for each of the gate lines 110 of the liquid crystal display panel 100. ), Poor picture quality such as flicker may occur.

Accordingly, the present invention has been devised to solve the above-described problems, and an object of the present invention is to drive a liquid crystal display panel capable of compensating for a characteristic difference of a scan signal applied to gate lines of the liquid crystal display panel. To provide a method.

The driving method of the liquid crystal display panel for achieving the object of the present invention is to drive the liquid crystal display panel in which the gate lines are spaced at regular intervals, the gate driver is coupled to one side, the gate from the gate driver At least one of a pulse width and a pulse size of the scan signal shifted and applied to the lines may be changed and applied.

The driving method of the liquid crystal display panel according to the present invention as described above will be described in more detail with reference to the accompanying drawings.

3 is an exemplary view showing waveforms of scan signals applied to gate lines through a method of driving a liquid crystal display panel according to a first embodiment of the present invention. Here, the scan signals SC_EDGE1 and SC_EDGE2 are waveforms applied to the gate lines 110 connected to both edge regions of the flexible film 120 shown in FIG. 1, and the scan signals SC_CENTER are flexible films. The waveform is applied to the gate lines 110 connected to the central region of the 120. In addition, when the scan signals SC_MID1 and SC_MID2 divide the flexible film 120 into first to fourth blocks having the same area, the boundary areas of the first block and the second block, the third block and the fourth block are divided. Referring to FIG. 3, the waveforms of the scan signals SC_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER are applied to the gate driver. It is applied to the gate lines from the gate driver in synchronization with a signal (Gate Output Enable: GOE).

That is, the waveforms of the scan signals SC_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER are synchronized with the first to fifth low potential periods a to e of the gate output enable signal GOE, respectively. It is output as 5 high potential section (A ~ E). In this case, waveforms of the scan signals SC_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER may be output at high potential in the high potential section of the gate output enable signal GOE according to a design condition of the gate driver.

Meanwhile, in the driving method of the liquid crystal display panel according to the first exemplary embodiment of the present invention, the width of the first to fifth low potential periods a to e of the gate output enable signal GOE is adjusted to adjust the scan signal ( The widths of the first to fifth high potential periods A to E of the SC_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER are individually adjusted.

That is, the widths of the first and fifth low potential sections a and e of the gate output enable signal GOE are adjusted to adjust the first and fifth high potential sections A and R of the scan signals SC_EDGE1 and SC_EDGE2. E) adjusts the width, and the width of the second and fourth low potential sections b and d of the gate output enable signal GOE is the width of the first and fifth low potential sections a and e. The width of the second and fourth high potential sections B and D of the scan signals SC_MID1 and SC_MID2 are narrowly adjusted compared to the widths of the first and fifth high potential sections A and E. The width of the third low potential section c of the gate output enable signal GOE is narrower than the width of the second and fourth low potential sections b and d to scan the scan signal SC_CENTER. The width of the third high potential section (C) is adjusted to be narrower than the width of the second, fourth high potential section (B, D). In this case, the widths of the first to fifth low potential periods a to e of the gate output enable signal GOE are flexible with the gate lines 110 of the liquid crystal display panel 100 shown in FIG. 1. Detects the amount of delay and distortion of the scan signal according to the length difference between the link lines 140 connecting the film 120, and sets the width to compensate for the amount of delay and the distortion of the scan signal. The widths of the first to fifth high potential periods A to E of the SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER are adjusted.

As described above, the widths of the first to fifth low potential periods a to e of the gate output enable signal GOE are individually adjusted so that the scan signals SC_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER are made. By individually adjusting the widths of the first to fifth high potential sections A to E, the conventional problems can be solved. This will be described in detail as follows.

First, referring to FIG. 1, the link lines 140 are patterned in a buccal shape in order to connect the flexible film 120 on which the driving circuit 130 is mounted and the gate lines 110 corresponding thereto. Accordingly, the link lines 140 connecting the edge region of the flexible film 120 and the gate lines 110 connect the center lines of the flexible film 120 with the gate lines 110. The length is longer than that of the pattern, and the internal resistance and parasitic capacitance of the link lines 140 are different from each other.

However, in the related art, since a pulse-shaped scan signal having a constant size and width is sequentially shifted and applied to the gate lines 110 through the link lines 140 from the driving circuit 130, internal resistance and parasitic capacitance are mutually different. Due to the influence of the other link lines 140, the characteristics of the scan signal vary according to the gate lines 110. Accordingly, a difference in on / off characteristics of switching elements such as a thin film transistor, which are separately provided in the pixels corresponding to the gate lines 110, may cause a driving failure of the liquid crystal display panel 100. The characteristics of the video signal supplied from the data lines to the pixels are changed for the gate lines 110, so that a luminance difference occurs for each of the gate lines 110 of the liquid crystal display panel 100. In 100), image quality defects such as flicker may occur.

However, the driving method of the liquid crystal display panel according to the first embodiment of the present invention is a difference in length between the link lines 140 connecting the gate lines 110 and the flexible film 120 of the liquid crystal display panel 100. Detects the amount of delay and distortion of the scan signal and adjusts the width of the low potential section (or high potential section) of the gate output enable signal GOE according to the delay and distortion amount of the scan signal. By individually adjusting the width of the high potential section, the delay and distortion of the scan signal can be compensated to prevent the characteristics of the scan signal from changing for each gate line 110.

4 is a diagram illustrating waveforms of scan signals applied to gate lines through a method of driving a liquid crystal display panel according to a second embodiment of the present invention. Here, the scan signals SC_EDGE1 and SC_EDGE2 are waveforms applied to the gate lines 110 connected to both edge regions of the flexible film 120 shown in FIG. 1, and the scan signal SC_CENTER is flexible. The waveform is applied to the gate lines 110 connected to the central region of the film 120. In addition, when the scan signals SC_MID1 and SC_MID2 divide the flexible film 120 into first to fourth blocks having the same area, boundary areas of the first block and the second block, and the third and fourth blocks, respectively. The waveform is applied to the gate lines 110 connected to the boundary region of the block.

In the driving method of the liquid crystal display panel according to the first embodiment of the present invention described above, the scan signal SC_EDGE1 is adjusted by adjusting the width of the first to fifth low potential periods a to e of the gate output enable signal GOE. The widths of the first to fifth high potential periods A to E of, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER are individually adjusted.

However, in the driving method of the liquid crystal display panel according to the second embodiment of the present invention, the gate output enable signal (S_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, SC_CENTER) is output in the form of a pulse having a constant width. The low potential section of the GOE is set to have a constant width in the same manner as the driving method of a general liquid crystal display panel, and instead, the first to the fifth high potential sections of the scan signals SC_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER are used. Adjust the pulse size (F ~ J) individually. In this case, the first to fifth pulse sizes F to J of the scan signals SC_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER are individually adjusted by changing the voltage level of the gate high voltage signal Vgh applied to the gate driver. Can be.                     

That is, the first and fifth pulses F and J of the scan signals SC_EDGE1 and SC_EDGE2 are adjusted by changing the voltage level of the gate high voltage signal Vgh applied to the gate driver, and the scan signal SC_MID1. The second and fourth pulse sizes G and I of SC_MID2 are adjusted smaller than the first and fifth pulse sizes F and J, and the third pulse size H of the scan signal SC_CENTER is adjusted. Is smaller than the second and fourth pulse sizes (G, I). In this case, the first to fifth pulse magnitudes F to J of the scan signals SC_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER may be different from the gate lines 110 of the liquid crystal display panel 100 of FIG. 1. The delay and distortion amount of the scan signal according to the length difference between the link lines 140 connecting the flexible film 120 are detected and set to a size capable of compensating the delay and distortion amount of the scan signal.

If the first to fifth pulse sizes F to J of the scan signals SC_EDGE1, SC_EDGE2, SC_MID1, SC_MID2, and SC_CENTER are individually adjusted, a conventional problem can be solved. This will be described in detail as follows.

First, referring to FIG. 1, the link lines 140 are patterned in a buccal shape in order to connect the flexible film 120 on which the driving circuit 130 is mounted and the gate lines 110 corresponding thereto. Accordingly, the link lines 140 connecting the edge region of the flexible film 120 and the gate lines 110 connect the center lines of the flexible film 120 with the gate lines 110. The length is longer than that of the pattern, and the internal resistance and parasitic capacitance of the link lines 140 are different from each other.

However, in the related art, since a pulse-shaped scan signal having a predetermined size and width is sequentially shifted from the driving circuit 130 to the gate lines 110 through the link lines 140, internal resistance and parasitic capacitance are mutually different. Due to the influence of the other link lines 140, the characteristics of the scan signal vary according to the gate lines 110. Accordingly, a difference in on / off characteristics of switching elements such as a thin film transistor, which are separately provided in the pixels corresponding to the gate lines 110, may cause a driving failure of the liquid crystal display panel 100. The characteristics of the video signal supplied from the data lines to the pixels are changed for the gate lines 110, so that a luminance difference occurs for each of the gate lines 110 of the liquid crystal display panel 100, and thus, the liquid crystal display panel 100. ), Poor image quality such as flicker may occur.

However, the driving method of the liquid crystal display panel according to the second exemplary embodiment of the present invention is based on the difference in length between the link lines 140 connecting the gate lines 110 and the flexible film 120 of the liquid crystal display panel 100. By detecting the delay and distortion amount of the scan signal, and individually adjusting the pulse size of the scan signal according to the delay and distortion amount of the scan signal, to compensate the delay and distortion amount of the scan signal to the gate lines 110 It is possible to prevent the characteristics of the scan signal from changing.

As described above, in the method of driving the liquid crystal display panel according to the present invention, the length of the link lines connecting the gate lines and the gate driver of the liquid crystal display panel by adjusting the pulse width or the pulse size of the scan signal applied to the gate lines. The delay and distortion of the scan signal due to the difference can be compensated for, thereby preventing the characteristics of the scan signal from changing for each gate line.

Therefore, there is an effect of minimizing the on / off characteristic difference of switching elements such as thin film transistors provided in the pixels corresponding to the gate lines to prevent driving failure of the liquid crystal display panel, and also from the data lines. The characteristics of the video signals supplied to the pixels may be minimized so as to prevent the luminance difference from occurring for each gate line of the liquid crystal display panel, thereby improving the image quality of the liquid crystal display panel. .

Claims (10)

In order to drive the liquid crystal display panel having the gate lines regularly spaced apart from each other and connected to the gate lines through the gate link lines, the gate lines being sequentially connected to the gate lines from the gate driver. A method of driving a liquid crystal display panel, wherein at least one of a pulse width and a pulse size of a shifted scan signal is changed and applied according to a delay and distortion amount of the scan signal according to a difference in length of a gate link line. The method of claim 1, wherein the pulse width of the scan signal is changed in synchronization with a gate output enable signal (GOE) applied to the gate driver. The method of claim 1, wherein the pulse size of the scan signal is changed by a voltage level of a gate high voltage signal (Vgh) applied to the gate driver. The driving method of claim 1, wherein a pulse width gradually increases toward both sides of the scan signal with respect to the center of the gate driver. The driving method of claim 1, wherein the scan signal gradually increases in magnitude toward both sides of the scan signal toward the center of the gate driver. Detecting a delay and distortion amount of the scan signal according to a length difference between link lines connecting the gate lines and the gate driver of the liquid crystal display panel; And changing at least one of a pulse width and a pulse size of the scan signal according to the delay and distortion amount of the scan signal and applying the same to the gate lines. 7. The method of claim 6, wherein the pulse width of the scan signal is changed in synchronization with a gate output enable signal (GOE) applied to the gate driver. 7. The method of claim 6, wherein the pulse size of the scan signal is changed by a voltage level of a gate high voltage signal (Vgh) applied to the gate driver. delete 7. The method of claim 6, wherein the scan signal gradually increases in magnitude toward both sides of the scan driver with respect to the center of the gate driver.

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