TWI423234B - Liquid crystal display apparatus and driving module thereof - Google Patents

Description

Liquid crystal display device and driving module thereof

The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device and a driving module thereof.

With the development of Flat Panel Display (FPD) technology, liquid crystal display devices have gradually replaced the traditional cathode ray tube (CRT) display due to their superior characteristics such as slimness, low power consumption and no radiation. Devices and applications to a wide range of electronic products. The liquid crystal display device mainly comprises a liquid crystal display panel, a driving module and a backlight module, wherein the driving module is used for driving the liquid crystal display panel.

Referring to FIG. 1 , a conventional liquid crystal display device 1 includes a liquid crystal display panel 11 and a driving module 12 . The liquid crystal display panel 11 includes a thin film transistor substrate (TFT substrate) and a color filter substrate (CF substrate), and has a plurality of pixels.

The driving module 12 has a scan driving circuit 121, a data driving circuit 122, a timing control circuit 123, and a gamma voltage generating circuit 124. The scan driving circuit 121 is electrically connected to the liquid crystal display panel 11 by a plurality of scanning lines S _N , and the data driving circuit 122 is electrically connected to the liquid crystal display panel 11 by a plurality of data lines D _N . The gamma voltage generating circuit 124 includes a voltage dividing circuit, such as a resistor string, which provides a gamma voltage to the data driving circuit 122 as a reference voltage for its voltage division, and provides a common voltage to the common electrode of the color filter substrate.

The timing control circuit 123 transmits the vertical clock signal and the vertical synchronization signal to the scan driving circuit 121, and converts the video signal received from the external interface into the data signal used by the data driving circuit 122, and transmits the data signal and the horizontal clock. The signal and the horizontal synchronization signal are sent to the data driving circuit 122. The scan driving circuit 121 sequentially turns on the scan line S _N according to the vertical clock signal and the vertical sync signal. When the scan line S _{N is} turned on, the data driving circuit 122 divides the data signal corresponding to each row of pixels, and divides the voltage according to the gamma voltage to obtain a voltage signal for driving the pixel, and the voltage signal is transmitted through the data line D _{N .} The pixel electrode that is sent to the pixel.

In addition, the gamma voltage generating circuit 124 also transmits a common voltage to the common electrode of the color filter substrate, so that the liquid crystal is actuated by the electric field formed by the common voltage of the common electrode and the voltage signal of the pixel electrode.

Recently, the technology of 3D stereoscopic display devices has also been developed. The left eye and the right eye are alternately displayed by the 3D display panel, and the left and right eyes are switched by the 3D glasses to view the left and right eyes. The eye synthesizes 3D images. When the 3D display panel displays the left eye image, the plurality of scan lines are turned on one by one, and after all the scan lines are turned on, the 3D glasses switch the left eye lens to receive the left eye picture; the right eye picture is also the same. Since the scanning line that is turned on later is shorter, the liquid crystal reaction time is shorter, so it is conventional to use an overdrive method to accelerate the liquid crystal reaction. The overdrive mode refers to accelerating the liquid crystal actuation by driving beyond the original pixel voltage difference. However, when the gray level of the pixel has reached a high point (for example, from 0 to 255 or from 255 to 0), there is no extra space to use the overdrive mode to accelerate the liquid crystal reaction, thus affecting the display quality.

Therefore, how to provide a driving module of a liquid crystal display panel, which can use the overdrive driving method to saturate the pixel charging, and improve the display quality is one of the current important topics.

In view of the above problems, an object of the present invention is to provide a driving module of a liquid crystal display panel capable of saturating a pixel by using an overdrive driving method to improve display quality.

In order to achieve the above object, according to the driving module of the liquid crystal display panel of the present invention, the liquid crystal display panel can display a 3D picture, and the driving module comprises a scan driving circuit, a data driving circuit, a timing control circuit and a gamma voltage. Generate a circuit. The scan driving circuit is electrically connected to the plurality of scanning lines on the liquid crystal display panel. The data driving circuit is electrically connected to a plurality of data lines on the liquid crystal display panel. The timing control circuit is electrically connected to the scan driving circuit and the data driving circuit. The gamma voltage generating circuit is electrically connected to the data driving circuit, and outputs a plurality of gamma voltages to the data driving circuit to cause the liquid crystal display panel to display a 3D picture, wherein the gamma voltage is one of the gamma voltage generating circuits A resistor string and a second resistor string are provided.

In an embodiment of the invention, the common voltage provided by the first resistor string is different from the common voltage provided by the second resistor string.

In an embodiment of the present invention, the gamma voltage provided by the first resistor string is divided into a first voltage group and a second voltage group, and the gamma voltage provided by the second resistor string is divided into a first A three voltage group and a fourth voltage group. The first voltage group and the third voltage group are for causing the liquid crystal display panel to display a static picture, and the second voltage group and the fourth voltage group are for causing the liquid crystal display panel to display a dynamic picture.

In an embodiment of the invention, the driving module further includes a first determining unit and a first switching unit. The first determining unit determines whether it is a static picture according to an image data. The first switching unit is electrically connected to the first resistor string and the second resistor string, and outputs a first voltage group, or a second voltage group, or a third voltage group according to one of the first determination signals output by the determining unit. The fourth voltage group.

In an embodiment of the invention, the first voltage group and the second voltage group have at least one different voltage.

In an embodiment of the invention, the first voltage group and the second voltage group have completely different gamma voltages.

In an embodiment of the invention, the gamma voltage generating circuit further includes a third resistor string for causing the liquid crystal display panel to display a 2D picture.

In an embodiment of the invention, the driving module further includes a second determining unit and a second switching unit. The second determining unit determines that the liquid crystal display panel displays the 2D picture or the 3D picture according to a selection signal. The second switching unit is electrically connected to the first resistor string, the second resistor string and the third resistor string, and outputs a gamma voltage of the first resistor string according to a second determination signal output by the second determining unit, or The gamma voltage of the second resistor string or the gamma voltage of the third resistor string.

To achieve the above objective, a liquid crystal display device capable of displaying a 3D picture according to the present invention comprises a liquid crystal display panel and a driving module. The liquid crystal display panel includes a plurality of scanning lines and a plurality of data lines. The driving module comprises a scan driving circuit, a data driving circuit, a timing control circuit and a gamma voltage generating circuit. The scan driving circuit is electrically connected to the scan lines. The data driving circuit is electrically connected to the data lines. The timing control circuit is electrically connected to the scan driving circuit and the data driving circuit. The gamma voltage generating circuit is electrically connected to the data driving circuit, and outputs a plurality of gamma voltages to the data driving circuit to cause the liquid crystal display panel to display a 3D picture, wherein the gamma voltage is firstly formed by the gamma voltage generating circuit A string of resistors and a second string of resistors are provided.

As described above, since the present invention uses two resistor strings to provide the gamma voltage and the common voltage, it has a larger overdrive driving space to drive the pixel liquid crystal to compensate for the liquid crystal reaction when the latter scanning line is turned on. Problems, which in turn improve display quality.

Hereinafter, a liquid crystal display device and a driving module thereof according to a preferred embodiment of the present invention will be described with reference to the related drawings.

Referring to FIG. 2, a liquid crystal display device 2 capable of displaying a 3D picture according to a preferred embodiment of the present invention includes a liquid crystal display panel 21 and a driving module 22. The liquid crystal display panel can be, for example, a Twisted Nematic (TN) or a Super Twisted Nematic (STN) liquid crystal display panel. The liquid crystal display panel 21 may include a thin film transistor substrate disposed on a color filter substrate, and having a plurality of scan lines S _N and a plurality of data lines D _N and constituting a plurality of pixels. The liquid crystal of each pixel is driven by an electric field formed by a voltage difference between a pixel electrode of the thin film transistor substrate and a common electrode of the color filter substrate.

In this embodiment, the 3D display technology can display the left eye and the right eye image alternately by, for example, the liquid crystal display panel, and the left eye and the right eye are switched by the 3D glasses to receive the left eye and the right eye image, and are synthesized in the human eye. 3D image. When the liquid crystal display panel 21 displays the left eye image, the plurality of scan lines are turned on one by one, and after all the scan lines are turned on, the 3D glasses switch the left eyeglasses to receive the left eye picture; the right eye picture is also the same.

The driving module 22 includes a scan driving circuit 221, a data driving circuit 222, a timing control circuit 223, and a gamma voltage generating circuit 224. The scan driving circuit 221 is electrically connected to the scan line S _N on the liquid crystal display panel 21. The data driving circuit 222 is electrically connected to the data line D _N on the liquid crystal display panel 21. The timing control circuit 223 is electrically connected to the scan driving circuit 221 and the data driving circuit 222. The gamma voltage generating circuit 224 is electrically connected to the data driving circuit 222, and outputs a plurality of gamma voltages V _G to the data driving circuit 222 to cause the liquid crystal display panel 21 to display a 3D picture, wherein the gamma voltage V _G is caused by One of the voltage generating circuit 224 is provided by a first resistor string R1 and a second resistor string R2.

The driving process of this embodiment is substantially as follows: the timing control circuit 223 transmits the vertical clock signal and the vertical synchronization signal to the scan driving circuit 221, and converts the image signal received from the external interface into the data signal used by the data driving circuit 222. And transmitting the data signal, the horizontal clock signal and the horizontal synchronization signal to the data driving circuit 222. The scan driving circuit 221 sequentially turns on the scan line S _N according to the vertical clock signal and the vertical sync signal. When the scan line S _{N is} turned on, the data driving circuit 222 divides the data signal corresponding to each row of pixels, and divides the voltage according to the gamma voltage V _G to obtain a voltage signal for driving the pixel, and the data line D _N The voltage signal is transmitted to the pixel electrode of the pixel.

In addition, the gamma voltage generating circuit 224 also transmits the common voltage V _C to the common electrode of the color filter substrate, so that the liquid crystal is activated by the common voltage of the common electrode and the electric field formed by the voltage signal of the pixel electrode, thereby achieving the display of the screen. .

Please refer to FIG. 3A and FIG. 3B , which are schematic diagrams of the first resistor string R1 and the second resistor string R2 of the embodiment. In this embodiment, each pixel is driven by a frame inversion method. The so-called picture inversion method refers to driving all pixels with a positive polarity voltage and driving all the pictures with a negative polarity voltage in two adjacent screens. Prime.

In this embodiment, the gamma voltage V _G provided by the first resistor string R1 is used as a basis for voltage division by the data driving circuit 222 when the pixel is driven by the negative polarity voltage. The gamma voltage V _G provided by the second resistor string R2 is used to divide the voltage by the data driving circuit 222 when the pixel is driven by the positive polarity voltage. The gamma voltage (V _G1 ～V _G6 ) provided by the first resistor string R1 is smaller than the common voltage V _C1 provided by the first resistor string R1, and the gamma voltage provided by the second resistor string R2 (V _G7 ～ V _G12 ) is greater than the common voltage V _C2 provided by the second resistor string R2.

In addition, a first resistor R1 string provided by the common voltage V _C1 and the second resistor R2 string provided by the common voltage V _C2 is not the same system. For example, the common voltage V _C1 is 7V, and the common voltage V _C2 is 3V. Moreover, a part of the gamma voltage of the first resistor string R1 falls between the common voltage V _C1 of the first resistor string R1 and the common voltage V _C2 of the second resistor string R2; a partial gamma voltage system of the second resistor string R2 the common voltage V _C2 falls between the common voltage V R1 of the first resistor string _C1 and the second resistor R2 of the string. That is, the ohmic voltage of the two resistor strings has overlapping portions.

The two common resistor strings R1 and R2 provide different common voltages V _C1 and V _C2 , so that in the embodiment, when the overdrive driving mode is used, a larger overdrive driving space is provided to drive the pixel liquid crystal to compensate the rear scanning line. When it is turned on, the liquid crystal reacts too late, which improves the display quality.

Please refer to FIG. 4A and FIG. 4B , which are schematic diagrams of a first resistor string R1a and a second resistor string R2a according to another preferred embodiment of the present invention. In this embodiment, the voltage of the gamma provided by the first resistor string R1a is divided into a first voltage group (including V _G1 ～ V _G6 ) and a second voltage group (including at least V _OD1 ), and the second resistor string The gamma voltage provided by R2a is divided into a third voltage group (including V _G7 to V _G12 ) and a fourth voltage group (including at least V _OD2 ). The first voltage group and the third voltage group are such that the liquid crystal display panel 21 displays a static picture, and the second voltage group and the fourth voltage group are used to cause the liquid crystal display panel 21 to display a dynamic picture.

Here, the definition of the static picture is continuous if the two pictures are similar in gray scale (for example, the average gray level is less than a specific value), that is, a static picture, where the continuous two pictures refer to the continuous two pictures of the left eye or the continuous of the right eye. Two pictures. The definition of the dynamic picture is two consecutive pictures. If the gray levels are not similar (for example, the average gray level is greater than a specific value), it is a dynamic picture. The two consecutive pictures here refer to two consecutive pictures of the left eye or two consecutive pictures of the right eye. . Of course, the definition of static and dynamic pictures can be designed according to actual needs.

Since the dynamic picture indicates that the amount of change of the gray level is large, and there is a need for excessive driving, in this case, the data driving circuit 222 uses the second voltage group (when negative driving) or the fourth voltage group (positive driving). Time). For the second voltage group, the voltage difference between the gamma voltage V _OD1 and the common voltage V _C1 is larger than the voltage difference between the gamma voltage V _G1 and the common voltage V _C1 , so that a larger overdrive range can be obtained. Similarly, for the fourth voltage group, the voltage difference between the gamma voltage V _OD2 and the common voltage V _C2 is larger than the voltage difference between the gamma voltage V _G12 and the common voltage V _C2 , so that a larger overdrive range can be obtained. .

The first voltage group and the second voltage group have at least one different voltage, such as the gamma voltage V _OD1 , and the second voltage group may include at least one of the gamma voltages V _G1 ～ V _G6 ; of course, the second voltage group The gamma voltage can also be completely different from the gamma voltage of the first voltage group. In this case, the resistance of the first resistor string R1a is also relatively increased. Similarly, the third voltage group and the fourth voltage group have at least one different voltage, such as the gamma voltage V _OD2 , and the fourth voltage group may include at least one of the gamma voltages V _G7 ～ V _G12 ; The gamma voltage of the voltage group can also be completely different from the gamma voltage of the third voltage group. In this case, the resistance of the second resistor string R2a is also relatively increased.

As shown in FIG. 5, the driving module 22a of the embodiment further includes a first determining unit 225 and a first switching unit 226. The first determining unit 225 determines whether it is a static picture according to an image data S _I (of course, it can also determine whether it is a dynamic picture). The first switching unit 226 is electrically connected to the first resistor string R1a and the second resistor string R2a. Here, the first switching unit 226 is electrically connected to the gamma voltage generating circuit 224a. The first switching unit 226 outputs a first voltage group, or a second voltage group, or a third voltage group or a fourth voltage group according to one of the first determination signals S _J1 output by the first determining unit 225.

When the static picture is negatively driven, the first switching unit 226 outputs the first voltage group to the data driving circuit 222, and outputs the common voltage V _C1 to the common electrode; when the dynamic picture is negative driving, the first switching unit 226 output the second voltage group to the data driving circuit 222, and output the common voltage V _C1 to the common electrode; when the static picture is positive driving, the first switching unit 226 outputs the third voltage group to the data driving circuit 222, and outputs The common voltage V _C2 to the common electrode; when the dynamic picture is positively driven, the first switching unit 226 outputs the fourth voltage group to the data driving circuit 222 and outputs the common voltage V _C2 to the common electrode.

Referring to FIG. 6, the gamma voltage generating circuit 224 further includes a third resistor string R3 for causing the liquid crystal display panel 21 to display a 2D picture. In this embodiment, when a 2D picture is displayed, a column inversion or a dot inversion may be used. The third resistor string R3 can provide, for example, 12 gamma voltages V _G21 to V _G32 and a common voltage V _C3 . The liquid crystal display panel 21 of the present embodiment can display 2D and 3D pictures by the resistor strings R1, R2, and R3.

Referring to FIG. 7 , the driving module 22 of the embodiment further includes a second determining unit 227 and a second switching unit 228 . The second determining unit 227 determines that the liquid crystal display panel displays a 2D picture or a 3D picture according to a selection signal S _C . In this embodiment, the selection signal S _C can be generated by the user selection or generated by the liquid crystal display device 2 itself.

The second switching unit 228 is electrically connected to the first resistor string R1, the second resistor string R2, and the third resistor string R3. Here, the second switching unit 228 is electrically connected to the gamma voltage generating circuit 224. The second switching unit 228 outputs the gamma voltage of the first resistor string R1, or the gamma voltage of the second resistor string R2, or the third resistor string according to one of the second determination signals S _J2 output by the second determining unit 227. R3's gamma voltage.

When the picture is 2D, the second switching unit 228 outputs the gamma voltage of the third resistor string R3 to the data driving circuit 222, and outputs the common voltage V _C3 to the common electrode; when the 3D picture is negatively driven, the second switching unit 228 outputs the gamma voltage of the first resistor string R1 to the data driving circuit 222, and outputs the common voltage V _C1 to the common electrode; when the 3D picture is positively driven, the second switching unit 228 outputs the second resistor string R2 The voltage is applied to the data driving circuit 222, and the common voltage V _{C2 is} outputted to the common electrode.

In addition, in the present embodiment, in addition to the determination of the display of the 2D or 3D picture, the technical features of the voltage group of the above embodiment may be used in combination. In this case, the first determining unit 225 and the second determining unit 227 can be integrated in design, and the first switching unit 226 and the second switching unit 228 can also be integrated in design.

In summary, since the present invention uses two resistor strings to provide the gamma voltage and the common voltage, it has a larger overdrive driving space to drive the pixel liquid crystal to compensate for the liquid crystal reaction when the latter scanning line is turned on. Problems, which in turn improve display quality.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

1, 2, 2a. . . Liquid crystal display device

11, 21. . . LCD panel

12, 22, 22a. . . Drive module

121, 221. . . Scan drive circuit

122, 222. . . Data drive circuit

123, 223. . . Timing control circuit

124, 224, 224a. . . Karma voltage generating circuit

225. . . First judgment unit

226. . . First switching unit

227. . . Second judgment unit

228. . . Second switching unit

D _N . . . Data line

R1, R1a. . . First resistor string

R2, R2a. . . Second resistor string

R3. . . Third resistor string

S _C . . . Select signal

S _I . . . video material

S _J1 . . . First judgment signal

S _J2 . . . Second judgment signal

S _N . . . Sweep line

V _C , V _C1 , V _C2 , V _C3 . . . Common voltage

V _G , V _G1 ～ V _G12 , V _OD1 , V _OD2 , V _G21 ～ V _G32 . . . Karma voltage

1 is a schematic view of a conventional liquid crystal display device;

2 is a schematic view of a liquid crystal display device according to a preferred embodiment of the present invention;

3A and 3B are schematic diagrams showing a first resistor string and a second resistor string according to a preferred embodiment of the present invention;

4A and 4B are schematic diagrams showing a first resistor string and a second resistor string according to another preferred embodiment of the present invention;

FIG. 5 is a schematic diagram of a liquid crystal display device having a first determining unit and a first switching unit according to a preferred embodiment of the present invention; FIG.

6 is a schematic diagram of a third resistor string in accordance with a preferred embodiment of the present invention;

FIG. 7 is a schematic diagram of a liquid crystal display device having a second determining unit and a second switching unit according to a preferred embodiment of the present invention.

2. . . Liquid crystal display device

twenty one. . . LCD panel

twenty two. . . Drive module

221. . . Scan drive circuit

222. . . Data drive circuit

223. . . Timing control circuit

224. . . Karma voltage generating circuit

D _N . . . Data line

R1. . . First resistor string

R2. . . Second resistor string

S _N . . . Sweep line

V _C . . . Common voltage

V _G . . . Karma voltage

Claims (16)

A driving module of a liquid crystal display panel, wherein the liquid crystal display panel can display a 3D image, the driving module comprises: a scanning driving circuit electrically connected with a plurality of scanning lines on the liquid crystal display panel; and a data driving circuit, And a plurality of data lines on the liquid crystal display panel are electrically connected; a timing control circuit is electrically connected to the scan driving circuit and the data driving circuit; and a gamma voltage generating circuit is electrically connected to the data driving circuit Connecting, and outputting a plurality of gamma voltages to the data driving circuit to cause the liquid crystal display panel to display a 3D picture, wherein the gamma voltage is a first resistance string and a second resistance string of the gamma voltage generating circuit The gamma voltage provided by the first resistor string is divided into a first voltage group and a second voltage group, and the gamma voltage provided by the second resistor string is divided into a third voltage group and a fourth voltage group, the first voltage group and the third voltage group are for causing the liquid crystal display panel to display a static picture, and the second voltage group and the fourth voltage group are for displaying the liquid crystal The display panel displays the dynamic picture. The driving module of claim 1, wherein the first resistor string provides a gamma voltage that is less than a common voltage provided by the first resistor string, and the second resistor string provides a gamma voltage. The system is greater than the common voltage provided by the second resistor string. The driving module of claim 1, wherein the common voltage provided by the first resistor string is different from the common voltage provided by the second resistor string. The driving module of claim 1, further comprising: a first determining unit, determining whether the image is a static image according to an image data; and a first switching unit, the first resistor string and the first resistor string The second resistor string is electrically connected, and outputs the first voltage group, or the second voltage group, or the third voltage group or the fourth voltage group according to one of the first determination signals output by the first determining unit . The driving module of claim 1, wherein the first voltage group and the second voltage group have at least one different voltage. The driving module of claim 1, wherein the first voltage group and the second voltage group have completely different gamma voltages. The driving module of claim 1, wherein the gamma voltage generating circuit further comprises a third resistor string for causing the liquid crystal display panel to display a 2D picture. The driving module of claim 7, further comprising: a second determining unit, determining that the liquid crystal display panel displays a 2D picture or a 3D picture according to a selection signal; and a second switching unit The first resistor string, the second resistor string and the third resistor string are electrically connected, and output a threshold voltage of the first resistor string according to a second determination signal output by the second determining unit, or The gamma voltage of the second resistor string, or the third power The gamma voltage that blocks the string. A liquid crystal display device capable of displaying a 3D picture, comprising: a liquid crystal display panel comprising a plurality of scanning lines and a plurality of data lines; and a driving module comprising: a scanning driving circuit, and the scanning lines are electrically connected a data driving circuit electrically connected to the data lines; a timing control circuit electrically connected to the scan driving circuit and the data driving circuit; and a gamma voltage generating circuit and the data driving circuit Electrically connecting, and outputting a plurality of gamma voltages to the data driving circuit to cause the liquid crystal display panel to display a 3D picture, wherein the gamma voltage is a first resistance string and a second resistance of the gamma voltage generating circuit Provided by the string; wherein the voltage of the first resistor string is divided into a first voltage group and a second voltage group, and the voltage of the second resistor string is divided into a third voltage group And a fourth voltage group, wherein the first voltage group and the third voltage group are such that the liquid crystal display panel displays a static picture, and the second voltage group and the fourth voltage group are used to make the liquid crystal display surface The board displays a dynamic picture. The liquid crystal display device of claim 9, wherein the first resistor string provides a gamma voltage that is less than a common voltage provided by the first resistor string, and the second resistor string provides a gamma voltage. The system is greater than the common voltage provided by the second resistor string. The liquid crystal display device of claim 9, wherein the common voltage provided by the first resistor string is different from the common voltage provided by the second resistor string. The liquid crystal display device of claim 9, wherein the driving module further comprises: a first determining unit, determining whether the image is a static image according to an image data; and a first switching unit, a resistor string and the second resistor string are electrically connected, and output the first voltage group, the second voltage group, or the third voltage group or the first according to one of the first determination signals output by the determining unit Four voltage groups. The liquid crystal display device of claim 9, wherein the first voltage group and the second voltage group have at least one different voltage. The liquid crystal display device of claim 9, wherein the first voltage group and the second voltage group have completely different gamma voltages. The liquid crystal display device of claim 9, wherein the gamma voltage generating circuit further comprises a third resistor string for causing the liquid crystal display panel to display a 2D picture. The liquid crystal display device of claim 15, wherein the driving module further comprises: a second determining unit, determining, according to a selection signal, that the liquid crystal display panel displays a 2D picture or a 3D picture; and a second a switching unit, the first resistor string and the second resistor string And the third resistor string is electrically connected, and outputs a gamma voltage of the first resistor string or a gamma voltage of the second resistor string according to a second determination signal output by the second determining unit, or The gamma voltage of the third resistor string.