JP2586582B2 - Driving method of liquid crystal display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a liquid crystal display device, and more particularly to an alternating current driving method for a matrix liquid crystal display device.

[Conventional technology]

The configuration of the matrix type liquid crystal display device includes a liquid crystal display panel in which two glass substrates having a plurality of strips and transparent electrodes are bonded together via a liquid crystal layer so that the transparent electrodes are orthogonal to each other, and a drive circuit for supplying a signal to the transparent electrodes. And a control circuit for controlling the driving circuit.

A driving method of the matrix type liquid crystal display device will be described with reference to FIGS. A video signal to be displayed on the matrix type liquid crystal display device is input to a control circuit 12 through a video signal line 11, a synchronizing signal synchronized with the video signal is generated by the control circuit 12, and an X side driving circuit is passed through the synchronizing signal lines 15 and 16. 1
3, input to the Y-side drive circuit 14. As shown in FIG.
Output Y ₁ output X ₁ and Y-side driving circuit 14 of the X-side driving circuit 13 is inverted in units of fields into the AC signal in phase synchronized with the video signal, the liquid crystal display panel 10 is driven AC.

[Problems to be solved by the invention]

In the above-described conventional driving method, alternating-current driving in which the video signal is inverted in units of one field is performed. Therefore, when the synchronization of one field becomes 30 Hz or less, flicker appears on the display of the liquid crystal display panel, and flickering is observed. However, there is a disadvantage that the image quality is deteriorated and the display becomes very difficult to see.

[Means for solving the problem]

A driving method of a liquid crystal display device according to the present invention is a liquid crystal display device having a matrix type liquid crystal display panel, a driving circuit for driving the liquid crystal panel, and a control circuit for controlling the driving circuit. AC drive is performed at a frequency that is a multiple of a positive number, and display lines at the inversion timing of the AC are thinned out.

〔Example〕

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

FIGS. 1A and 1B are diagrams showing an original display state and a display state according to an embodiment of the present invention. In the display state of the present invention, display is performed by thinning out one display line to four display lines. That is, the first to third lines of the video signal 1 are displayed, the fourth line is skipped, and the 4 × n line is similarly thinned out. FIG. 2 shows waveforms indicating the state. The AC signal is inverted and synchronized with the 4 × n-th unit for thinning out the video signal, and the X-side signal and the Y-side signal are also inverted to perform AC drive.

3 (a) and 3 (b) are diagrams showing an original display state and a display state of another embodiment of the present invention. That is, in this embodiment, the 5 × n-th video signal is skipped,
One line is displayed on five display lines for display. FIG. 4 shows waveforms indicating the state. The X-side signal and the Y-side signal are inverted every 5 × n-th unit to perform AC conversion.

[Effects of the Invention] As described above, the present invention reduces the alternating current of the liquid crystal drive to one.
This is performed not in units of fields, but in units of several lines, and by increasing the cycle and skipping the display lines at the timing of the inversion of the alternating current, there is an effect of eliminating flicker such as flicker which deteriorates the display quality. . Further, the present invention has a similar effect for an active matrix type liquid crystal display device. The AC frequency may be set to any frequency that does not cause flickering even if it is not 30 Hz.
Further, the number of display lines to be interposed may be any number. In addition, the present invention can be adopted without distinction between interlaced and non-interlaced scanning.

[Brief description of the drawings]

FIG. 1 is a diagram showing a display state according to an embodiment of the present invention. FIG. 1 (a) is a schematic view of a scanning line showing an original display state, and FIG. 1 (b) is a view of an embodiment of the present invention. FIG. 3 is a schematic diagram of a scanning line showing a display state. FIG. 2 is a waveform diagram of each signal for performing the display of FIG. 1 (b). FIG. 3 is a diagram showing a display state according to another embodiment of the present invention. FIG. 3 (a) is a schematic view of a scanning line showing an original display state, and FIG. 3 (b) is another embodiment of the present invention. It is a schematic diagram of the scanning line which shows the display state of an example. FIG. 4 is a waveform diagram of each signal for making the display of FIG. 3 (b). FIG. 5 is a configuration diagram of a conventional liquid crystal display device, and FIG. 6 is a waveform diagram of signals at various parts in FIG. 10 ... LCD panel, 11 ... Video signal line, 12 ... Control circuit, 13 ... X side drive circuit, 14 ... Y side drive circuit

Claims (1)

(57) [Claims] 1. A liquid crystal display device comprising a matrix type liquid crystal display panel, a driving circuit for driving the liquid crystal panel, and a control circuit for controlling the driving circuit, at a frequency which is a positive multiple of the frequency for displaying one display screen. A method for driving a liquid crystal display device, wherein AC driving is performed and display lines at the inversion timing of the AC switching are thinned out.