JPS60241092A - Driving of matrix type liquid crystal display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Description of the field to which the invention pertains This invention relates to a method for driving an IJ type liquid crystal display panel.

(2) Conventional technology When driving a double matrix liquid crystal display panel having 20 common electrodes, l/n data = 1/(f
+1) All AC conversion was performed in units of two frames using bias time-division drive.

FIG. 1 shows a configuration in which the number of common electrodes is 16. For example, when driving an IJ type liquid crystal display panel with 16 common electrodes, 1/8 duty, 1/4
It is time-divisionally driven using a bias. Each signal in that case becomes as shown in FIG.

1 is an alternating current signal, and 2 is a COM signal n1 of the common electrode n1 selected first in one frame. 3 is the COM signal n! of the common electrode n2 selected second in one frame.
It is.

In FIG. 2, the signal of the common electrode n1 selected first after the alternating current signal 1 is inverted, that is, COM (H No. n12) becomes a selection signal for 71 hours at the same time as the alternating current signal 1 is inverted.

In this way, when a common electrode is selected at the same time as the alternating current signal 1 is inverted, phenomena such as the waveform applied to the selected common electrode are distorted, resulting in uneven contrast.

Similarly, for the common electrode n8 that is selected last in one frame, the COM signal n84 is selected for the time T1, and since the alternating current signal 1 is inverted, the COM signal nl 2
As in the case of , contrast unevenness is caused by waveform sagging and the like. Therefore, in the display state of the common electrode selected before and after AC 100 1 is inverted, a phenomenon occurs in which contrast is uneven due to waveform distortion and the 1 display quality is degraded.

(3) Object and structure of the invention In order to solve all of these drawbacks, the present invention provides a dual matrix type liquid crystal display panel having 2n common electrodes and a matrix for driving the double matrix type liquid crystal display panel. I
In the method of driving a J-square type liquid crystal display device, (1/(n+
2)) Duty.

[1/(zn+3+l)) bias time-division drive, and is characterized by alternating the voltage applied to the liquid crystal every two frames.The drawings will be described in detail below.

(4) Embodiment of the Invention In the case where a double matrix type liquid crystal display panel having the configuration as shown in FIG. 1 is driven by gold, FIG. 3 shows an embodiment of the present invention. 5 is an alternating current signal.

6 is the common electrode nIVC selected first in one frame.
COMIg issue to join! , 7 is a COM signal n2 applied to the common electrode n2 selected second in one frame. 8 is a COM signal n8 applied to the common electrode n8 selected last in one frame.

In FIG. 3, when the alternating current signal 5 is inverted and the COM signal nl 6 is selected, after a period of T,
The selection time is set to 1. In this case, there is the relationship T=T1.

The same applies to the COM signal n118.

The COM signal ng 8 is selected for a time T, and the alternating current signal 5 is inverted at a time T. In this case too, T=T
1 There is a relationship.

In this way, before and after AC conversion 1H No. 5 is reversed.

During T, all common electrodes are in a non-selected state.

(5) Description of effect As explained above, T before and after the alternating current signal 5 is inverted.
By setting all the common terminals &' to a non-selected state for a period of time, the waveform distortion etc. added to the common terminal i for the alternating current signal 5 is eliminated, and a signal without waveform distortion etc. is input to the common electrode. can do. Therefore, unevenness in the contrast of the common electrode before and after the alternating current signal 5 is inverted is also eliminated, contributing to higher display quality.

[Brief explanation of the drawing]

Figure 1 is a common electrode connection configuration diagram when there are 16 common electrodes, Figure 2 is a conventional drive signal diagram for a liquid crystal display panel with the configuration shown in Figure 1, and Figure 3 is a liquid crystal display panel with the configuration shown in Figure 1. FIG. 3 is a diagram of driving signals of the present invention for a display panel; 5- 1.5... AC conversion signal, 2.6... River/COM double signal * 3+ 71-=C0M signal n2, 4.8...
-・-・C0M1m No. n8゜61 3rd Ward -686-

Claims (1)

[Claims] In a drive means for a matrix liquid crystal display panel that sequentially drives all n common electrode lines in a time division manner, the line sequential division i
(1/(n+z)) duty, and after approximately 1 scanning time after the entire scanning of the n-grain common electrode, the signals applied to each dot of the liquid crystal display panel are switched to alternating current. A method for driving a matrix type liquid crystal display panel characterized by: