JPS5978394A - Display panel driving system - 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 The present invention is directed to a method for driving a μ-matrix display panel.

A matrix display panel is used to display characters, graphs, or images in which the electrodes are arranged in a rack in both the X and Y directions. 1
In the case of a liquid crystal display, it is composed of N data lines and M timing lines (N x M) 1
Area display is performed on fixed pixels. At this time, normally 1
A multiplex drive is used in which one timing line is selected and a data filter is applied to the pixels in that column, and the period during which data corresponding to one pixel is applied is 17M in total. This is usually called Oduty.

- Generally, in the case of an image or graphic display, 100 timing lines μ are required.

Figure 41 shows the drive electrode arrangement of the liquid crystal matrix panel. J: t) (n
x rn ) pixel trays.

FIG. 2μ is an example of the driving waveform of the pulse in FIG. 1, and the timing, 4c1. Since the scanning is performed as c2...Cm, the duty becomes m timing lines, and l:s1/m. In the case of image display, gradation is required, and gradation can be achieved by modulating the drive pulse pulses applied to the data lines, as shown in FIG. When using such a drive method and panel r to display television images using the raster scan method, the problem is that the scanning line corresponding to the display timing line of the coupled television signal is 1°7. The frame is composed of 525 lines, and the odd field and even field are each 262, 5 lines each, so if you display the image as it is, it will be 1/2 + S.
It is stated that the deworming υr is 2.5 duty.

Also, if the resolution is halved, it is 1/131.2.5.
Driving at high duty is a must, but with this driving duty, it is almost impossible to obtain sufficient contrast with the liquid crystal display. It is necessary to equivalently reduce the driving duty r of the liquid crystal and improve the display contrast l-'ffi by means of (2) to create a display that is easy to read.

Accordingly, an object of the present invention is to provide a method for driving a liquid crystal matrix panel in which the contrast can be improved.

In the present invention, there is a period r1 in which no information is included before and after the vertical erasing period in the video signal.When no voltage is applied to the liquid, the voltage applied to the liquid crystal body 7 O
The effective value ratio of FF is increased to increase the contrast)k, and the intermediate scanning dkr is increased to the extent that it does not interfere with image display.
In addition to omitting one line per book so that it does not contribute to the display, and during this omitted period, no voltage is applied to the liquid crystal like the vertical synchronization period, which improves the contrast significantly.

In order to explain the history of the present invention in detail, a video signal based on an NTSC video signal is commonly used as an example. Proceed. , Figure 3 shows the signal system, where signal (A) is the vertical synchronizing signal V-8, (J)) is the horizontal synchronizing signal H-8, (C)
The video signals v and Sr are shown in the enlarged view (2). Also, Figure 4 shows the horizontal synchronization signal t in Figure 83, and the time of one field is 1/60 second, or 16.667 seconds, and within this, the scanning lines equivalent to 262.5 IL. It is included. liquid crystal matrix
In the case of a panel, it is possible to recognize images even with half this number of scanning lines, that is, 131, so for example, one scan line per two scanning lines can be recognized.
If the real image is thinned out and displayed, the drive becomes equivalent to 1/131 duty, but actually the image information is f”I 26
It is sufficient to display 200 to 220 of the 2.5 lines; rather, the information signal is often not included in the time corresponding to 40 to 60 minutes, including the remaining vertical blanking period. , Therefore, for example, only the 20th to 240th running blue sections in FIG. 4 are displayed as images 'f: nothing 1 to 19. ．． 24
If 1 to 262.5 is a rest period, the number of timing lines on the panel will be 220.

In-selection synchronization rx with timing) 1/151
．． There are up to 25 cases, but in order to avoid the effective value of sword 1 on the rI liquid crystal display during the suspension period, it is important to keep the timing line and the data line at the same position.Even during the same selection period, the liquid crystal 1fC7+ - The effective value ratio r can be achieved as above, and therefore the contrast can be improved.

Furthermore, even if the scanning lines in this effective image range are not thinned out appropriately, the image will not be subject to heavy distortion, and will look no different from normal images. For example, No. 41:! ! , l, in the usable scanning range, one out of every r lines is omitted (in the drawing, one out of every three lines) and the actual scanning f-line V''L (r-1
)/r times, and the driving duty can be lowered by this amount.However, if the data line and timing line are kept at the same level during this period, the effective value of 0N10FF is 111. The ratio has been improved to improve contrast. That is, according to the present invention, the contrast can be greatly improved without lowering the apparent image resolution.

In general, is the voltage averaging method of V-NV method? For example, if the duty is i 1 /D, the effective value ratio when the liquid crystal is lit and when the liquid crystal is not lit, which is a measure of contrast, is 262.5 in the conventional system.

-Number of scanning lines allocated within the 10,000-body stopping period - M, and if one is assigned to the omitted scanning line 'zr, the stopping period and saving H + 6
When the effective value is driven to U during the period, the effective value ratio becomes as follows, and clearly the ratio of equations (1) and (2) becomes larger. For example, N=10. D=262.5. If M=/10°r=5, the ratio is 1111 as it is conventionally, but
With the driving method of the present invention, yl can be increased to 1.182, and the contrast can be improved by 2 to 3 times.

FIG. 5 illustrates the driving waveform of the present invention, and uses the horizontal synchronizing signal H-8 standard as the timing line. One screen consists of a Kiyomata field and an even number field.
It is composed of frames, 1 frame, 1 frame, 1/
It is 60 seconds. For simplification, it is assumed that the odd and even fields are the same signal, and of the 262.5 scanning lines within one field period, m scanning lines are used as the display period, and the vertical return is 9 near elimination stage 1 output
Books and q trees will be on hiatus. Furthermore, for m books, one e-book and r book will be omitted. timing line C
1 to cm' are scanned sequentially from 017+> within the display period, and end at Cm', which is r-1/r times m'l' There is a period.

At this time, amplitude-modulated display data is manually input to the data lines 81 to Sn. The amplitude of this data line is 2vO in the vQ-NVO voltage averaging method.

What is characteristic in this waveform is that the data line has pause periods p and q.
, VN[lD is set in odd frames, jJVFsx is set to the same potential as the non-selection level of the timing line in even frames, and no voltage is applied to the liquid crystal during the rest period.
That is, the purpose is to prevent the expiry value from increasing during this period. At the same time, one by one, the retator ik timing lines are set to the non-select level.

Also frame signal fL&'! , is a basic signal for current conversion inversion drive every am frame and every even frame.

FIG. 6 is a block diagram of a data line drive circuit for implementing the method shown in FIG.
v is configured. Voltage selection circuits 10 to 12rS, frame No. 16 fL#F-Eri, are circuits for reversing the polarity, and screw pressure selection circuits 13 to 14 are the first 9 lines during the full running period,
This circuit makes the idle period the same as the non-selection level of the data lines and the timing line by the idle period signal fD corresponding to the period r-1/r times among the four and m lines. Also, according to the voltage selection circuit 15-16μ display data input D1,
The driving chip data is a 1st circuit that is manually operated, and n blocks 17 are prepared.

FIG. 7 is a set meal circuit flJ of timing lines when one tree is thinned out in the running-m-2r tree. The shift register 70 is started by a clock pulse YcL and a start pulse Ysp, and a gate 71 which changes the selection state to a non-line selection state from the signal generator NHK during the thinning period, and a driver 7 which selects the first driving tray.
Consisting of 2.

(b) is the operating waveform of (a). This waveform is one in three
This is an example of omission, and it can be seen that one selection period is omitted between selection manpower W2 and w3. Naturally, during this omitted period, one effective shift is applied to each pixel, so that the data line becomes qtA, as shown in FIG.

As described above, the present invention provides a period in which the display remains in the vicinity of the drooping imperial line erasure period and a period in which the display is omitted to the extent that it does not interfere with the effective display period klliji image display. By keeping the phase difference at 0, it improves the display contrast of the liquid crystal, and not only the above-mentioned fit indication, but also e, l! If it is an S-matrix panel, it can be applied to all scanning methods such as an upper and lower divided electrode method, a double matrix method, and two timing line and quadruple timing lines.

[Brief explanation of the drawing]

Fig. 1 shows an example of the configuration of a liquid crystal matrix panel, Fig. 2 shows its driving waveform, and Figs. 3 and 4 show examples of signals of the rask scan method, including the V-Sμ vertical synchronization signal and the H-sμ horizontal synchronization signal. It is. FIG. 5 is an example of drive waveforms according to the present invention, showing p and qμ rest periods, mO, and display periods, and 81 of the timing lines 01 to Cm' is the signal waveform of the data line. Also the 6th
FIG. 5 is a block diagram illustrating the formation of drive waveforms for the data lines in FIG. 5, and is constituted by pressure selection circuits 10 to 16. FIG. 7 shows a timing trace scan circuit used in the present invention and its operating waveforms. Applicant: Suwa Glass Co., Ltd.

Claims (1)

[Claims] (1) Provide display data in the data line area for the selected pixel column by J on the timing line.In the matrix display panel, provide a display pause period near the vertical blanking period of bidet number 1g, and Within the effective display period, there is a period in which the scanning line is omitted to the extent that it does not significantly affect the displayed image, and during the 611th period suspension period and the omission period, a voltage signal is set that does not cause a magnetic potential difference between the timing 1 and the data line. A method of driving a display panel depending on the applied voltage.