JPH02306293A - Method for driving liquid crystal display device - Google Patents

Abstract

PURPOSE:To prevent a picture quality deterioration due to the dispersion of the composing elements of a sample holding circuit by alternately switching the sample and storage systems of the sample holding circuit of each line in one field for one field to several fields. CONSTITUTION:A signal L to switch a sample holding circuit 2 is phase-inverted for one field, and in a first field, the signal of a first line is stored by the (A) system of the sample holding circuit 2, the signal of a second line is stored by the (B) system, and in such a way, the storage is alternately executed. Next, in a second field, the signal of the first line is stored by the (B) system of the sample holding circuit 2, the signal of the second line is stored by the (A) system, and in such a way, the storage is alternately executed. In such a way, since, for the output of a drain line, the change due to the dispersion of the composing elements of the sample holding circuit 2 can be averaged, the picture is uniformed, and the picture quality can be maintained satisfactory.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for driving a liquid crystal display device, and more particularly to a method for driving an active matrix type liquid crystal display device.

[Conventional technology]

Conventionally, a method for driving this type of liquid crystal display device has been as shown in FIGS. 3 to 5.

FIG. 3 is a block diagram of the drain line driving portion of the liquid crystal display device, FIG. 4 is a circuit diagram of the sample hold circuit 2 and driver circuit 3, and FIG. 5 is a timing diagram of this liquid crystal display device.

Driving of the drain lines is performed by a line-sequential scanning method, and the video signal V is stored for one line in the sample-and-hold circuit 2, and the signal is then output when a line is stored.

Therefore, the sample and hold circuit 2 is required for two lines.

One line of sample and hold circuit 2 is shown in (A) in Figure 4.
In the lineage shown as Sl・L, S,・L,...Sn.

It is switched at the timing of L and is stored in the capacitor C. Similarly to when storing another line, when storing the next line (,A), the signal ((B) system) stored one line before is output.

In this way, for each field, the first line signal is the (A) system of the sample and hold circuit 2, the second line signal is the (B) system, and so on. The even-numbered lines were stored and output in the (B) system of the sample-and-hold circuit 2. .

[Problem to be solved by the invention]

In the conventional driving method of the liquid crystal display device described above, the signal for one field is always divided into the odd lines and even numbers, such as the (A) system of the sample and hold circuit 2 for odd lines and the (B) system for even lines. Since the system of the sample and hold circuit 2 that stores lines is fixed, the output voltage will vary depending on the odd and even lines due to variations in the switcher capacity of the sample and hold circuit 2. Even when input, the output voltage fluctuates from line to line, resulting in striped shading on the screen and a major deterioration in image quality.

An object of the present invention is to provide a method for driving a liquid crystal display device that can prevent deterioration in image quality due to variations in the constituent elements of a sample and hold circuit.

[Means to solve the problem]

The method for driving a liquid crystal display device of the present invention includes a driver circuit that sequentially drives the drain electrode of an active matrix liquid crystal display panel having a gate electrode, a drain electrode, and a common electrode line by line; In one field of a liquid crystal display device, the liquid crystal display device includes a sample/hold circuit that has a display data sampling/storage system and operates these systems alternately to drive the driver circuit, and a shift register circuit that drives the sample/hold circuit. The sample/storage system of the sample and hold circuit of each line is alternately switched every one field to several fields.

〔Example〕

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

FIG. 1 is a timing diagram of a liquid crystal display device for explaining a first embodiment of the present invention.

The difference between this embodiment and the conventional liquid crystal display driving method shown in FIGS. The key point is that the switching is done alternately.

In FIG. 1, the phase of the signal that switches the sample-and-hold circuit 2 is inverted every field, and in the first field, the signal for the first line is stored in the (A) system of the sample-and-hold circuit 2, and the second line Eye signal (B)
Memorize in sequence, or alternately. next,
In the second field, the signal on the first line is stored in the (B) system of the sample-and-hold circuit 2, and the signal on the second line is stored in the (A) system, and so on.

That is, the system of the sample-and-hold circuit 2 for sampling and storing each line is switched for each field.

In this way, by switching the sample/memory system of each line for each field, it is possible to average out changes in the output of the drain line due to variations in the components of the sample and hold circuit 2, so that the screen is uniform. , and can maintain good image quality.

FIG. 2 is a timing diagram of a liquid crystal display device for explaining the operation of a second embodiment of the present invention.

In this embodiment, the system of the sample and hold circuit 2 is switched every two fields.

Similarly, the same effect can be obtained even if the system of the sample and hold circuit 2 is switched every several fields.

〔Effect of the invention〕

As explained above, the present invention prevents deterioration of image quality due to variations in the constituent elements of the sample and hold circuit by configuring the sample and storage system of each line of the sample and hold circuit to be switched every one to several fields. It has the effect of

[Brief explanation of drawings]

1 is a timing diagram of a liquid crystal display device for explaining a first embodiment of the present invention, FIG. 72 is a timing diagram of a liquid crystal display device for explaining a second embodiment of the present invention, and FIG.
The figure is a block diagram of a liquid crystal display device applied to the present invention, FIG. 4 is a circuit diagram of a sample hold circuit of the liquid crystal display device shown in FIG. 3, and FIG. 5 is a circuit diagram of a conventional liquid crystal display driving method. FIG. 2 is a timing diagram of a liquid crystal display device for explaining an example. 1...Shift register, 2...Sample hold circuit, 3...Driver circuit, (A)
, (B)...Sample/memory system, C...
····capacity. Agent Patent Attorney Uchihara Sound ￥1 Figure 2 Seki 1f = 3 (A>, (B) -1 fan 7° le ishii nino) iA
:NoH 14th map

Claims (1)

[Claims] It has a driver circuit that sequentially drives the drain electrode of an active matrix liquid crystal display panel, which has a gate electrode, a drain electrode, and a common electrode, line by line, and two display data sample and storage systems for each line. Sample and storage of the sample and hold circuit of each line in one field of a liquid crystal display device including a sample and hold circuit that operates alternately to drive the driver circuit and a shift register circuit that drives the sample and hold circuit. A method for driving a liquid crystal display device, characterized in that the system is alternately switched every one field to several fields.