JP2001117537A - Color liquid crystal display device and driving circuit therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the difference in transmittance on a driving circuit side even when color filter differs in transmittance for every color. SOLUTION: Three gate lines for every color are arranged in one horizontal line, and a gate driver 1 outputs such gate voltages 10R, 10G, 10B and 11R, 11G, 11B that sequentially turn on TFTs 5 connected with pixel 3 for every color via the gate lines. And, since a common voltage generation circuit (unshown in the figure) generates a common voltage 20 according to transmittance of each color to correct difference among the transmittance for every color and applies it to each pixel 3, it is possible to correct the difference even when the color filters differ in transmittance for every color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of pixels and a thin film transistor (TFT) at each intersection of a plurality of gate lines and a plurality of source lines arranged in a matrix.
and a driving circuit for driving the color liquid crystal display device.

[0002]

2. Description of the Related Art A conventional color liquid crystal display (LCD (L)
FIG. 3 shows an liquid crystal display (equivalent crystal display) matrix circuit.

[0003] In this LCD matrix circuit, the gate line and the source line ₆₁ through ₃ is configured for a matrix,
At each intersection, the switching element TFT5 and pixel 3
Are provided respectively.

In general, a color liquid crystal display device is provided with a large number of TFTs and pixels, but FIG. 3 shows only six TFTs 5 and pixels 3 for simplicity.

A driving circuit for driving a color liquid crystal display device has a gate driver 31, a data driver 2, and a common voltage generation circuit (not shown). data·
Driver 2 outputs the display data through the source line ₆₁ through _3.

[0006] The gate driver 31 applies a gate voltage 40, 42 to each one horizontal line via the gate line.
It is output only during the horizontal line period. Here, one horizontal line refers to one row of pixels 3 and TFTs 5 in a color liquid crystal display device arranged in a matrix.
One horizontal line period is a period for switching display of the pixel 3 in one horizontal line. Further, a common voltage 42 is applied to the pixel 3 via the common electrode 4 from the common voltage generation circuit.

Next, the operation of the conventional color liquid crystal display device will be described with reference to FIG. FIG. 4 is a timing chart of driving waveforms in the conventional color liquid crystal display device.

The gate driver 31 first sets the gate voltage 40 to a high level, and sets the three TFTs 5 in the upper part of FIG.
Is turned on. In this state, a common voltage 42 is output from the common voltage generation circuit via the common electrode 4. Then, from the data driver 2, the source line 6 ₁
Display data through 6 ₃ are output. Therefore, the voltage of the difference between the display data voltage and the common voltage 42 is applied to each pixel 3 connected to the upper three TFTs 5. Then, the gate driver 31 sets the gate voltage 40 to the low level next, and sets the gate voltage 41 to the high level in order to display the next row, and repeats the above operation.

In general, in a color liquid crystal display device, light from a backlight is turned on / off in accordance with on / off of display of each pixel, and the light is passed through a color filter to form red, green, and blue light. Three primary colors are generated. However, the transmittance of this color filter may be different for each of the three primary colors. If the transmittance greatly differs for each color, the reproducibility of the displayed color will be degraded. For this reason, the color filter is designed so that the transmittance is the same for each color.

However, in some cases, it is difficult to completely eliminate the difference between the transmittances of the color filters for each color, and even when the transmittance of the color filters has a difference for each color, the difference can be corrected. There is a demand for such a color liquid crystal display device.

[0011]

In the above-mentioned conventional color liquid crystal display device, a color filter must be constructed so that the difference in transmittance between colors is as small as possible. If the difference between the transmittances cannot be completely eliminated, there is a problem that the reproducibility of the display color is deteriorated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color liquid crystal display device and a drive circuit for the color liquid crystal display device which can correct the difference even if there is a difference in transmittance of each color in the color liquid crystal display device. is there.

[0013]

According to the present invention, a plurality of pixels and a plurality of switching elements are respectively formed at intersections of a plurality of gate lines and a plurality of source lines arranged in a matrix. The above-described color liquid crystal display device is characterized in that a plurality of gate lines for each color for each pixel to display are provided for one horizontal line.

A driving circuit for driving the color liquid crystal display device according to the present invention includes a data driver outputting display data via the source line, and one horizontal line via each gate line. A gate driver that outputs a gate voltage so that the pixels for each color are sequentially turned on in the line period, and a common voltage of a voltage corresponding to the transmittance of each color in the color filter is generated for each color. And an output common voltage generation circuit.

In the color liquid crystal display device of the present invention, three gate lines for each color are provided for one horizontal line, and the gate driver controls the switching element connected to the pixel for each color via the gate line. A gate voltage is output so as to turn on sequentially, and a common voltage generation circuit generates a common voltage corresponding to the transmittance of each color and applies it to each pixel in order to correct a difference in transmittance for each color. Thus, even if there is a difference in the transmittance of each color of the color filter, the difference can be corrected.

[0016]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an LCD matrix circuit in a color liquid crystal display device according to one embodiment of the present invention.
FIG. 2 is a timing chart showing driving waveforms in the color liquid crystal display device of the present embodiment. 1, the same components as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

The driving circuit of the color liquid crystal display device of the present embodiment has a gate driver 1 and a data driver 2.

In the color liquid crystal display device of the present embodiment, three gate lines are provided for each horizontal line, and the gate lines are for R (red), G (green), and B, respectively.
(Blue) gate line.

The gate driver 1 has a gate voltage of 10 _R and a gate voltage of 10 _R through three gate lines so that the pixels for each color are sequentially turned on within one horizontal line period.
10 _G and 10 _B or gate voltages 11 _R , 11 _G and 11 _B are output.

Further, the common voltage generation circuit (not shown) in this embodiment generates and outputs a common voltage for each color, which corrects the difference in transmittance of each color in the color filter. For example, if the green transmittance is lower than the red transmittance, the common voltage applied to the red pixels is set to be higher than the common voltage applied to the green pixels.

Next, the operation of the present embodiment will be described with reference to the timing chart of FIG.

The gate driver 1 first has a gate voltage 1
0 _{R is set} to a high level, and the three TFTs 5 in the upper part of FIG.
The TFT 5 connected to the pixel 3 for R is turned on. In this state, the common voltage 2 corresponding to the red transmittance is transmitted from the common voltage generation circuit via the common electrode 4.
0 is output. Then, from the data driver 2, the display data is output via the source line 6 _1.

Next, the gate driver 1 sets the gate voltage 10 _R to a low level and sets the gate voltage 10 _G to a high level, and is connected to the G pixel 3 of the three TFTs 5 in the upper stage in FIG. The turned on TFT 5 is turned on.
In this state, a common voltage 20 corresponding to the green transmittance is output from the common voltage generation circuit via the common electrode 4. Then, from the data driver 2, the source line 6
Display data is output via ₂ .

Finally, the gate driver 1 sets the gate voltage 10 _G to a low level and sets the gate voltage 10 _B to a high level, and is connected to the B pixel 3 of the three TFTs 5 in the upper part of FIG. The turned on TFT 5 is turned on. In this state, a common voltage 20 corresponding to the blue transmittance is output from the common voltage generation circuit via the common electrode 4. Then, from the data driver 2, the display data is output via the source line 6 _3.

The gate driver 1 performs the above processing within one horizontal line period. And the gate driver 1
Next, the gate voltage 10 _{B is set} to the low level, and the gate voltages 11 _{R to} 11 _B are sequentially set to the high level in order to display the next row, and the above operation is repeated.

In the color liquid crystal display of this embodiment, 1
Three gate lines for each color are provided for the horizontal line, and the gate driver 1 outputs a gate voltage that sequentially turns on TFTs connected to pixels for each color via the gate lines. . The common voltage generation circuit generates a common voltage corresponding to the transmittance of each color and applies it to each pixel in order to correct the difference in transmittance of each color. Even if there is a difference in the rates, the difference can be corrected.

Further, in the present embodiment, the value of the common voltage 20 is different for each color of RGB, but the present invention is not limited to such a case, and one of the RGB is used.
Only the color may be set so that the value of the common voltage 20 is different from the other two colors.

[0029]

As described above, according to the present invention, three gates are provided for each horizontal line, and each pixel of RGB is sequentially turned on so as to respond to the respective transmittances of R, G and B. Since the common voltage can be set, even if there is a difference between the transmittances of the color filters for each color, the difference can be corrected.

[Brief description of the drawings]

FIG. 1 is a diagram showing an LCD matrix circuit in a color liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a timing chart showing driving waveforms in the color liquid crystal display device of FIG.

FIG. 3 is a diagram showing an LCD matrix circuit in a conventional color liquid crystal display device.

FIG. 4 is a timing chart showing driving waveforms in the color liquid crystal display device of FIG.

[Explanation of symbols]

1 gate driver 2 data driver 3 pixel 4 common electrode 5 TFT 6 ₁ to 6 ₃ source lines 10 _R, 10 _G, 10 _B gate voltage 11 _R, 11 _G, 11 _B gate voltage 20 common voltage 31 Gate driver 40 , 41 Gate voltage 42 Common voltage

Claims (6)

[Claims] 1. A color liquid crystal display device in which a plurality of pixels and a plurality of switching elements are respectively formed at intersections of a plurality of gate lines and a plurality of source lines arranged in a matrix, wherein: A color liquid crystal display device, comprising a plurality of gate lines for each color in which each pixel performs display. 2. The color liquid crystal display device according to claim 1, wherein said switching element is a TFT. 3. The color liquid crystal display device according to claim 1, wherein three gate lines are provided for one horizontal line. 4. A plurality of pixels and switching elements are respectively formed at intersections of a plurality of gate lines and a plurality of source lines arranged in a matrix, and each color in which each pixel performs display on one horizontal line. A drive circuit for a color liquid crystal display device for driving a color liquid crystal display device provided with a plurality of gate lines for each, a data driver outputting display data via the source line, and A gate driver that outputs a gate voltage through which the pixels for each color are sequentially turned on within one horizontal line period, and a transmittance corresponding to each color in a color filter. A driving circuit for a color liquid crystal display device, comprising: a common voltage generation circuit that generates and outputs a common voltage of each color for each color. 5. The driving circuit according to claim 4, wherein said switching element is a TFT. 6. The driving circuit according to claim 4, wherein three gate lines are provided for one horizontal line.