JP2000047236A - Liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to prevent the degradation in a display grade as if images appear to be dimly displayed in spite of a non-display state by forming dummy electrodes for impression of non-display voltage in peripheral regions. SOLUTION: X electrode X0, X(m+1) and Y electrodes, Y0 Y(m+1) are added. The X electrodes or Y electrodes at the intersection points of the X electrode X0 to X(m+1) and the Y electrodes Y0, Y(n+1) and the intersection points of the X electrode X0, X(m+1) and the Y electrodes, Y0 to Y(n+1) are formed as the dummy electrodes 9, which are normally impressed with the non-display voltage. The peripheral regions 3 are provided with the dummy electrodes 9 to be impressed with the non-display voltage, by which display infeasible regions heretofore is made to the same regions as the non-display state portions 4b within the display electrode existence regions 4. If the element is formed in the manner described above, the peripheral portions of the transmittance higher than the transmittance of the non-display state portions 4b do not exist at all and, therefore, such sensation that the non-display state portions 4b dimly display something is eliminated and the display grade is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display (LCD) in which a non-display area where no display electrode is present and a display electrode existence area are provided in an effective display area, and more particularly to improvement of display quality.

[0002]

2. Description of the Related Art (1) Conventional Example 1 A liquid crystal display element has a frame portion covered with a frame-shaped cover so that a glass substrate cannot be seen, and an effective display area surrounded by the frame portion and having a visible glass substrate. I do. As shown in the example of the XY matrix display LCD in FIG. 3, in the effective display area 2, a peripheral area where display electrodes (referred to as X electrodes or Y electrodes existing at intersections of X electrodes and Y electrodes) do not exist (display is impossible) region)
3 and a display electrode existing area 4 inside the element 3. In FIG. 3, the electrodes are represented by lines, and the electrode spacing is drawn much larger than the thickness of the line. However, in practice, the electrodes are strip-shaped, and the electrode spacing is considerably smaller than the electrode width.

In the display electrode existing region 4, a transparent X electrode exists on one inner surface of two glass substrates opposed to each other with a liquid crystal interposed therebetween, and a transparent Y electrode exists on the other inner surface. The distance from the electrode, that is, the cell thickness is the smallest. Further, in the peripheral region 2, since the electrode exists only on one of the two glass substrates, the cell thickness is larger than that of the display electrode existing region.

In the display electrode existing region 4, a display state portion 4a where a display voltage is applied to the liquid crystal and a non-display voltage (non-selection voltage;
(Non-zero) applied non-display state portion 4b. Now, considering the transmittance in the effective display area 2,
Due to the difference in the number of layers (1 or 2) and the cell thickness of the overlapping electrodes and the difference in the voltage applied to the liquid crystal, for example, the transmittance of the peripheral region 3 where no voltage is applied to the liquid crystal becomes 10%.
0%, that of the non-display state part 4b is 80%, and that of the display state part 4a is 0%. As described above, when the peripheral region 3 having a higher transmittance than the non-display state portion 4b exists,
Although it is a non-display state part, it is felt that some image is blurred, which causes a deterioration in display quality.

(2) Conventional Example 2 As shown in FIG. 4, there is a type of liquid crystal display element in which a transparent display electrode 7 having a character, symbol or graphic shape is provided in the effective display area 2. The area around the display electrode 7 is a non-displayable area 8 where no display electrode exists. When the display potential (selection potential) is applied to the display electrode 7, the display state (lighting state) is set, and when the non-display potential (not zero) is applied, the display state is set to the non-display state. In the portion where the display electrode 7 is present, the transparent electrode is formed on the inner surface of the two glass substrates. In the non-displayable area 8, only one of the inner surfaces of the two glass substrates is provided with the transparent electrode. Alternatively, the cell thickness is different between the portion where the display electrode 7 exists and the non-displayable region 8.

Considering the transmittance of each part, for example, 0% when the display electrode 7 is in the display state, and 8% when the display electrode 7 is in the non-display state.
0%, and the non-displayable area 8 is 100%. When the display electrode 7 is in the display state, there is no particular problem.
Since there is a slight difference such as 80% with respect to 100% of the image, it appears as though the image is displayed dimly in the non-display state, which causes the display quality to deteriorate.

[0007]

The present invention relates to a non-display state portion 4 in which a non-display voltage (non-selection voltage) is applied to a liquid crystal.
b (FIG. 3) or the portion of the display electrode 7 (FIG. 4) has a lower transmittance than the peripheral region 3 or the non-displayable region 8 where no voltage is applied to the liquid crystal. Regardless, the image appears to be displayed dimly and the display quality is degraded. The purpose is to prevent this.

[0008]

According to a first aspect of the present invention, there is provided a liquid crystal display in which an effective display area includes a peripheral area where no display electrode exists and a display electrode existence area surrounded by the peripheral area. It relates to a display element. In the first aspect, a dummy electrode for applying a non-display voltage (non-selection voltage) to the liquid crystal is formed in the peripheral region.

(2) The invention according to claim 2 is the method according to (1), wherein the liquid crystal display element comprises X electrodes X0, X1, X2,.
m, X (m + 1) and Y electrodes Y0, Y1, Y2,.
It is an XY matrix display type provided with Y (n + 1), and the display electrode is made of an X electrode or a Y electrode present at the intersection of the X electrodes X1 to Xm and the Y electrodes Y1 to Yn, and the dummy electrode is an X electrode. X0 to X (m + 1) and Y electrodes Y0, Y (n + 1)
And the X electrodes X0, X (m + 1) and the Y electrodes Y0
It consists of an X electrode or a Y electrode located at the intersection with Y (n + 1).

(3) The invention according to claim 3 is characterized in that, in (2), the X electrodes X0 and X (m + 1) or the Y electrodes Y0 and Y (n
+1) are connected to each other. (4) The invention of claim 4 relates to a liquid crystal display element in which a display electrode having a shape of a character, a symbol or a figure is provided in an effective display area. In the present invention, in particular, a dummy electrode for applying a non-display voltage to the liquid crystal is formed around the display electrode.

(5) In a fifth aspect of the present invention, in the above (4), the dummy electrode is divided into a plurality.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Embodiment 1 A first embodiment of the present invention is shown in FIG. 1 and parts corresponding to those in FIG. The LCD of FIG. 1 is an improvement of the LCD of FIG. 3, in which a dummy electrode 9 for applying a non-display voltage (non-selection voltage) to the liquid crystal is formed in the peripheral region 3.

FIG. 1 is an example of an XY matrix display type LCD like FIG. 3, but X electrodes X0 and X (m + 1) and Y electrodes Y0 and Y (n + 1) are added to the example of FIG. X at the intersection of the X electrodes X1 to Xm and the Y electrodes Y1 to Yn
The point that the electrode or the Y electrode is the display electrode is the same as in FIG. However, the X electrodes X0 to X (m + 1) and the Y electrodes Y0, Y
The X electrode or the Y electrode at the intersection with (n + 1) and at the intersection between the X electrodes X0 and X (m + 1) and the Y electrodes Y0 to Y (n + 1) (shown by dots in FIG. The non-display voltage is always applied.

In the example of FIG. 1B, one end (X driver side) of the X electrode X0 is not connected to the X driver 5, and the other end is connected to the X electrode X (m) by a wiring (wire or wiring pattern) La.
+1). Similarly, one end (Y driver side) of the Y electrode Y0 is not connected to the Y driver 6, and the other end is connected to the terminal of the electrode Y (n + 1) by the wiring Lb.
By doing so, the X driver 5 can omit the drive circuit for the electrode X0, and the Y driver 6 can also omit the drive circuit for the electrode Y0, so that it is more economical than that of FIG.

FIG. 1 shows a case of an XY matrix type LCD, but the invention of claim 1 is not limited to this case, and may be a segment type display LCD. By providing a dummy electrode 9 for applying a non-display voltage in the peripheral region 3, a non-display region (for example, transmittance of 100%) in the related art is replaced with a non-display state portion (for example, transmission) in the display electrode existing region 4. (80%). In this manner, since there is no peripheral portion having a higher transmittance than the non-display state portion 4b, the sense that the non-display state portion 4b is blurryly displayed is lost, and the display quality is improved.

(2) Embodiment 2 An embodiment according to claim 4 is shown in FIG. 2 with parts corresponding to those in FIG. In FIG. 2, a dummy electrode 9 for constantly applying a non-display voltage to the liquid crystal is formed around the display electrode 7 (a portion which was conventionally a non-display area). In the example of FIG. 2, the dummy electrodes 9 are divided into a plurality of parts and are connected to each other by a wiring pattern (not shown).

In this manner, the display electrode 7 in the non-display state (for example, the transmittance is 80%) and the surrounding dummy electrode 9 have the same transmittance, and the display electrode 7 in the conventional non-display state is blurred. And the feeling that the image appears to be displayed is eliminated, and the display quality is improved. FIG. 2 shows a case where only one display electrode 7 for displaying F in the effective display area 2 exists for simplicity, but the present invention can of course be applied to a case where there are a plurality of display electrodes 7.

In the above description, the LCD is of a normally white mode in which the liquid crystal is transparent (light transmission) when no voltage is applied to the liquid crystal and the light is cut off when a display voltage is applied. The present invention is not limited to this case, and the present invention can be applied to a normally black mode LCD in which the light is blocked when the applied voltage is zero and the display is transparent when the display voltage is applied.

[0019]

As described above, in the present invention, the dummy electrode 9 is provided in the peripheral region 3 of the effective display region 2 which has been a non-displayable region in the past, and a non-display voltage is applied to the liquid crystal. Therefore, the transmittance of the non-display state portion 4b in the display electrode existing area becomes almost the same as that of the peripheral area 3, and it seems that the image is displayed dimly in spite of the conventional non-display state. Inconvenience has been resolved,
The display quality can be improved.

In the case of an LCD in which the display electrode 7 having the shape of a character, a symbol, or a figure is provided in the effective display area 2, in the present invention, the display area 7 around the display electrode 7 is conventionally a non-display area 8. The non-display voltage is always applied by providing a dummy electrode 9 at the place where the display electrode 7 to which the non-display voltage is applied has a transmittance substantially equal to the transmittance of the surrounding portion. The display quality can be improved in the same manner.

[Brief description of the drawings]

FIG. 1 is a diagram showing the principle configuration of an electrode pattern of an LCD according to the first to third embodiments.

FIG. 2 is a diagram showing the principle configuration of an electrode pattern of an LCD according to the fourth and fifth embodiments.

FIG. 3 is a principle configuration diagram showing an example of a conventional LCD electrode pattern.

FIG. 4 is a principle configuration diagram showing another example of an electrode pattern of a conventional LCD.

Continued on the front page F term (reference) 2H092 GA02 GA31 NA04 NA25 NA28 NA29 PA06 PA07 2H093 NA01 NC90 ND14 ND15 NE03 NE07 5C094 AA04 BA43 CA15 CA19 CA20 EA01

Claims (5)

[Claims] A liquid crystal display device in which a peripheral region where no display electrode is present and a display electrode existence region surrounded by the peripheral region are provided in an effective display region, wherein a non-display voltage (non-selection voltage) is applied to the liquid crystal. Wherein a dummy electrode for applying a voltage is formed in the peripheral region. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display element includes X electrodes X0, X1, X2, Xm, X (m + 1) and Y electrodes Y0, Y1, Y2, Yn, Y (n + 1). An XY matrix display type, wherein the display electrodes are the X electrodes X1 to Xm and the Y electrodes Y1 to Y1.
An X electrode or a Y electrode present at the intersection of Yn; and the dummy electrode comprises an intersection between the X electrodes X0 to X (m + 1) and the Y electrodes Y0, Y (n + 1) and the X electrodes X0, X
A liquid crystal display device comprising an X electrode or a Y electrode present at the intersection of (m + 1) and Y electrodes Y0 to Y (n + 1). 3. The method according to claim 2, wherein the X electrodes X0 and X
(m + 1) or the Y electrodes Y0 and Y (n + 1) are connected to each other. 4. A liquid crystal display device in which a display electrode having a shape of a character, a symbol or a figure is provided in an effective display area, wherein a dummy electrode for applying a non-display voltage to a liquid crystal is provided around the display electrode. A liquid crystal display device characterized by being formed in a liquid crystal display device. 5. The liquid crystal display device according to claim 4, wherein the dummy electrode is divided into a plurality of parts.