JPH01193716A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To decrease the number of constitution dots of one display picture element and to make a half-tone display by dividing minimum display picture elements which constitute a picture plane into plural dots which differ in area ratio and turning on and off the dots. CONSTITUTION:An electrode of one display picture element of a liquid crystal panel is divided unequally into irregular electrodes 1a-1c. For an N-half-tone display, N combinations of the unequally divided electrodes 1a-1c are considered so that a total electrode area ratio of each combination to the total area of one display picture element electrode is an equal interval, i.e. an integral multiple. Therefore, N kinds of the area of one display picture element in the on state of the electrode are prepared by making the intervals of the area variation equal. Consequently, the on electrode area ratio of one display picture element is controlled to make the N-half-tone display.

Description

[Detailed Description of the Invention] [Field of industrial application] The present invention relates to a liquid crystal display device, and particularly relates to a liquid crystal display device suitable for displaying a monochrome tone display on a seven-frame display liquid crystal. Regarding display #C direct.

[Conventional technology]

For liquid crystal display devices currently in use, the relationship between the applied voltage and the display density is steep, as shown in Figure 2. It is necessary to control the applied voltage in the range of 10-"J' to 10-1V.

Furthermore, as shown in the aS diagram, -"applied voltage -display ISO I3F
Since the temperature dependence of +temperature is high, only intermediate g can be displayed unless detailed temperature compensation is performed.

To solve this problem, the conventional method was developed,
As described in No. 7, a method has been proposed in which a large and small image system in a display is divided into even smaller dots, and a halftone display is actually performed by the number of divided dots lit.

Figure 4 shows a waveform in which one display pixel is divided into seven dots in order to put into practice the method described in the above-mentioned Japanese Patent Application Laid-Open No. 58-123587. As shown in the figure, by changing the number of lit dots, the intermediate a14 display changes.

[Problem that the invention attempts to solve]

However, in the above-mentioned conventional Manshiki, the display 11 IIl line is simply divided into intermediate parts, and in order to realize a halftone display only by the number of lights, the display 1 is proportional to the halftone stage eiN.
1! The number M of divided dots of the Il system increases, and the connections/threads thereof become M≧N-1.

Accordingly, the screen size is 640 dots) x 400
In order to perform live viewing on a liquid crystal display device with dot intermediate A48 floor display, it is necessary to drive approximately 1.8 million dots (640 x 400 x (8-1)) at the very least.

As mentioned above, in the past, the intermediate AI1m display was expressed only by the number of lit dots that were obtained by further dividing one display pixel, so the number of intermediate tone levels, the corresponding number of dots, and the number of dots were determined. One consideration must be given to the deterioration in yield of the G-picture display device due to the large number of power intensifying ports. First of all, in the back-track stage of liquid crystal display devices, the greater the number of dots, the greater the probability that a defective product will occur.

Letting the defect rate of 1 dot be P, the relationship between =X number N (pieces) and defect-free probability Y (chi) is expressed as follows: Y= (1-P
)NX 100 (%).

For example, if P = 10-', the value of Y is determined by the sister of N, as shown in FIG.

Now, as an example, the total number of dots on a liquid crystal panel with a screen size of 640 x 400 dots and an 8-level halftone display is
640 x 400 x (8-1)=approximately 1.8 million pieces, the yield is nearly 20%, the manufacturing efficiency of the liquid crystal panel suffers, and the cost also increases.

In addition, as the number of dots increases, the number of drivers for driving each dot and the wiring area of signal lines for controlling each dot also become thicker (as the proportion of the area for the pattern pattern on the liquid crystal panel board increases). It's thick.

It has become a problem.

Therefore, in a multi-level vI4 display liquid crystal panel, it is necessary to reduce the number of constituent dots for one display pixel as much as possible.

An object of the present invention is to reduce the number of constituent dots for one display pixel and to provide a liquid crystal display 91i, ljl that can perform intermediate display.
: Our goal is to provide the following.

(Means for Solving Problem a!1) In order to achieve the above object, the first invention of this volume provides a liquid crystal display device that performs intermediate multi-gradation display, in which the minimum display I [l!i The dots are further divided into a plurality of dots with a lower area ratio, and the corresponding number of dots are controlled to be turned on or off, so that the above-mentioned intermediate multi-gradation display is performed by increasing the total number of lit dots. This is what I did.

The second invention of this volume is that in a liquid crystal display device 1tVc that performs an intermediate multi-gradation display, the smallest display pixel constituting the screen is further divided into a plurality of dots, and the surface of the plurality of dots has a true light transmittance. Installing a filter and controlling each dot included in the display pixel to turn on or off,
The above-mentioned intermediate multi-width WIa14 display is performed by the difference in the total light filtering of the above-mentioned filters on the lighting dots.

[Effect]

In the first invention, the electrode of one display pixel of the liquid crystal panel is
Divide into tuns with uneven area ratio. In the case where the plural a pieces of electrodes divided into non-uniform parts are represented by the middle N position g4,
The method of combining Nm is considered so that the ratio of each total electrical surface area in each combination to the display 11111I element 11L pole overall area area is at equal intervals, that is, the ratio is multiplied by the number of times. As a result, it is possible to prepare N different types of rounding when the display 11jllI wooden electrode is turned on, with the rounding rounding at intervals of →. As a result, by controlling the on-electronic ratio of the display 11[Ili system, it becomes possible to display an intermediate N level.

Furthermore, by dividing one display pixel electrode into areas with unequal ratios, the number of divided electrodes can be reduced compared to the conventional method of dividing the electrode.

In the second invention of this volume, the smallest pixel constituting a liquid crystal screen is decomposed into even smaller dots, and filters with different densities are placed on the surface of these dots in order to control the original transmittance. By turning on or turning off each of these fX dots constituting one display pixel to create N combinations, the total number of violets transmitted by the plurality of dots can be N. In other words, it is possible to control the 221i value of one display pixel back N times, resulting in N different contrast ratios and an intermediate display of 614 levels.

〔Example〕

An embodiment of the present invention will be described below.

The giA diagram shows a cross section of a multi-layer IJ liquid crystal panel for displaying intermediate 8 gray levels. The area ratio of electrodes for one display pixel is 4:2:
In the figure, it is divided into 5 parts, 1α and 1C91b, so that the number is 1.

One set of matαt tbI 1c is one pixel for each display, as shown in FIG. 6A.

Electrode 1α is connected to X driver 6α, electrode 1b is connected to X driver 6
b, the electrode 1C is driven by the X driver 6CVc, and the Y
The set meal is driven by the transparent dL pole 2 from the driver 7.

In addition, in the figure, 3 is a sublayer, 4 is glass, and 5 is a polarizing filter.

In order to display 1 pixel of each display in 8 gray scales, each display 1
'#L 1-α, 1+6.1c on/
Eight combinations of f (ON-OFF) are shown in FIG. 7A.

In FIG. 7, when electrodes 1α, 1b, and 1c are all ON, display 11! When the transmittance element ratio of the ll-based liquid crystal panel is O, and the 4 poles 1α, 1b, and 1c are all OFF, the display 11i
If we assume that the 111-element liquid crystal panel has a permissive element ratio of 1, then Tani' Naomari 1α, 1C, 1bO with a 4:2:1 ratio of 4:2:1.
) Due to the combination of ON and OFF, the display area ratio of the 11 display lines is 0, 1/7, 2/7 as shown in Figure 7.
゜577, 4/7, 5/7, 6/7, 117)
It is possible to make 8 pieces of porridge, and it is possible to display 8 pieces of porridge in the middle (b) 14 pieces per pixel of display.

Next, an embodiment of the second invention of the present application will be described with reference to FIG. 1B.

FIG. 1B shows a cross-sectional view of a monochrome matrix liquid crystal panel displaying 8 intermediate gray levels. 1 in the diagram! Elements that are the same as in FIG. 1A have the same reference numerals.

In this embodiment, one minimum display pixel constituting the liquid crystal screen is divided into pixel constituting electrodes 8α, 8b, and 8c. On the surface of these divided 11L poles 8α+ 8b@13c,
Filters 9α, 9b, and 9c having different light transmittances are installed.

Minute #111IL poles 8α, 8b, 8c are X driver 10α, X driver 10b, respectively, as shown in FIG. 6B.
X)" drive data is received from the driver 10c, and the liquid crystal between the electrodes is controlled ON-OFF by the set drive using the transparent electrode 2 from the Y driver 8, and the IJ display is performed.

In FIG. 7B, as an example of displaying 8 intermediate gradations, divided X pole 9
a, 9b, 9cノ0N-OF cD 岨AIb
It is shown that the transmission element ratio of the display 11 tree can be accommodated in 8 levels by this. In diagram g7B, filter 9α.

-am light rates of 9b and 9c are 25% and 50, respectively.
%, 100%.

shall be.

In this case, all electrodes 8α* 8h t 8 c are OFF.
When , the signal passes through all the filters 9α, 9b, and 9c.

Let the total transmitted light sound be 1. 8α, 96,8
When all of the filters 9a, 9b, and 9c are ON, there is no transmitted light, so the sum of the transmitted violets of the filters 9α, 9b, and 9c is set to 0. The total transmitted photoelectric ratio when the synthetic fibers are combined is o by the combination of 8 interruptions of ON and OFF of the divided electrodes 8α, 8b, and 8C.

1/7, 2/7, 5/7, 4/7, 5/7,
There will be 8 stages of 6/7 and 1. In other words, this is the transmission source ratio of one display pixel, that is, the contrast ratio, and the display 1
Enables intermediate swt tone display for round elements.

[Cut rice of invention]

According to the invention, when displaying one pixel in half tone, it is possible to increase the number of electrodes for composing one pixel of display, and to increase the rate of shift.

In a 640 x 400 dot 8 intermediate gradation matrix liquid crystal panel, the conventional method only has the total number of dots or 640 x 400 dots.
400 X (W-1) = approximately 1.8 million pieces, and from Figure 5, in the case of P = 10-', the number of steps was 20%, but according to the invention, one display stroke 31c is reduced to 3 dots. Therefore, 640 x 400 x 5 =
Approximately 770,000 pieces will be sold, and the Ayumu Mari will be renamed to the 5 Mutsumi.

Furthermore, by increasing the number of dots forming one display pixel, the number of X drivers for driving the dots can be reduced, thereby reducing costs.

[Brief explanation of the drawing]

Figures 1A and 1B represent books Mm1 and 2, respectively.
A cross-sectional view and a perspective view of a liquid crystal panel according to an embodiment of the invention, FIG. 2 is a graph showing the applied voltage-display characteristics of the liquid crystal, and FIG. 5 is the temperature dependence of the applied voltage-display characteristics of the liquid crystal. FIG. 4 is an explanatory diagram for explaining the conventional 8-gradation display; FIG. 5 is a graph showing the defect-free yield of liquid crystal arrays with respect to the number of pixels; FIGS. 6A and 6B.
The figures are block diagrams showing the configuration for driving the matrix liquid crystal in the embodiments of FIGS. IA and 1B, and FIG. 7A, respectively.
FIG. 1A and FIG. 7B are explanatory diagrams for explaining the intermediate 8-gradation display of the embodiment of FIG. 1A and FIG. 1B, respectively. 1α+ 1 ha I C* 9α, Bb, Bc...
I [! I-cord configuration: 2...transparent electrodes 3...
・Liquid crystal layer 4 A glass 5...Polarizing filter 6α, 6b, 6C, 7α, 7b, 7c・-X driver 8...Y driver IA diagram (b) ) e17 7If] a i (V) ton) NO
, l Otsu , 54 5 6 '7Y15 Figure Gozato Kan [Sword 9h array's attack #, from Shoru of Yoyo 〒6A figure R spear 68 figure t78 to item #) Otsu: Zl: 4th Figure 7B

Claims (1)

[Claims] 1. In a liquid crystal display device that performs intermediate multi-gradation display, the smallest display pixel constituting the screen is further divided into a plurality of dots with different area ratios, and the plurality of dots are lit. Alternatively, a liquid crystal display device characterized in that the lighting is controlled to be non-lit and the intermediate multi-gradation display is performed based on the difference in the total area of the lighting dots. 2. In a liquid crystal display device that performs intermediate multi-gradation display, the smallest display pixel constituting the screen is further divided into a plurality of dots, and filters with different light transmittances are installed on the surfaces of the plurality of dots, and A liquid crystal display device characterized in that each dot included in the display pixel is controlled to be turned on or off, and the intermediate multi-gradation display is performed based on a difference in the total amount of light transmitted through the filter on the lit dot.