JPH10311989A - Liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the liquid crystal display element having field angle characteristics improved. SOLUTION: Dots 40 which constitute respective pixels are provided in matrix. Each dot 4O is divided into two subdots 42 and 44. A pixel electrode 30 of each dot 40 is divided into two pixel electrodes 32 and 34. An MIN(metal insulator metal) element 10 is connected between the pixel electrode 32 and a signal line 50 and an MIM electrode 20 is connected between the pixel electrode 34 and signal line 50. The driving voltages of the two subdots 42 and 44 constituting the dot 40 are made different from each other by making the element size of the MIM element 10 different from that of the MIM element 20 to delaying the inversion of one subdot to black behind that of the other subdot, thereby widening the field angle.

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 device, and more particularly to a metal-insulator-metal.
The present invention relates to an active matrix type liquid crystal display device using a (MIM) type nonlinear element as a switching element.

[0002]

2. Description of the Related Art A liquid crystal display element has a viewing angle characteristic in which the brightness varies depending on the viewing direction due to the refractive index anisotropy of the liquid crystal. It is required for a liquid crystal display element to eliminate this characteristic and increase the viewing angle.

[0003]

Accordingly, an object of the present invention is to provide a liquid crystal display device having improved viewing angle characteristics.

[0004]

The principle of the present invention devised by the present inventor to achieve the above object is as follows.

[0005] The liquid crystal panel has a normally white mode in which white appears when no charge is applied, and a normally black mode in which black appears. In Normal White mode,
In the direction in which the contrast ratio can be increased (this direction is referred to as the clear viewing direction), the image reverses to black. In the normally black mode, the image becomes white in the clear viewing direction and reverses to black in the reverse clear viewing direction. For this reason, the viewing angle of the liquid crystal display element is narrow. Therefore, the present inventor divides each dot forming the liquid crystal display element into a plurality of sub-dots, and changes the driving voltage of at least one of the plurality of sub-dots forming each dot to the driving voltage of another sub-dot. By making the driving voltage higher than that of the sub-dots, it was found that the inversion of black was delayed by that much in the sub-dots in which the driving voltage was increased, and as a result, the viewing angle could be widened.

Now, a further description will be given of a case where a MIM element is used as a non-linear element for driving each dot and one dot is divided into two sub-dots.

FIG. 1 is a diagram for explaining the transmission characteristics of the dot portion of the liquid crystal display device of the present invention, and FIG. 2 is a schematic plan view for explaining the configuration of the dot portion of the liquid crystal display device of the present invention. FIG.

As shown in FIG. 2, one dot 4 is divided into two sub-dots A and B, and the sub-dot A has a pixel electrode 3A.
And the MIM element 1 are provided.
And the MIM element 2 are provided, and the MIM elements 1 and 2 are connected to the signal line (column electrode) 5. If the driving voltage of the sub-dot A is made higher than the driving voltage of the sub-dot B as shown in FIG. 1, the sub-dot A is less likely to invert black than the sub-dot B, and as a result, the viewing angle is reduced. spread.

In FIG. 2, the arrows indicate the clear viewing direction in the normally white mode, and the arrangement of the sub-dots A and B is as shown in FIG. A may be arranged on the clear viewing direction side, and FIG.
As shown in FIG. 2C, the sub-dot A having a high driving voltage may be arranged on the opposite side to the clear viewing direction, and the sub-dot A and the sub-dot B may be arranged in a direction perpendicular to the clear viewing direction as shown in FIG. May be arranged horizontally. The same applies to the normally black mode.

When an MIM element is used as a non-linear element, the driving voltage of the sub-dot can be easily changed by utilizing the characteristics of the MIM element. That is, as a characteristic of the MIM element, the resistance value of the MIM element can be changed by changing the dimensions of the MIM element,
For example, if the resistance value is increased, the driving voltage can be increased, and as a result, the viewing angle can be widened by giving a difference in transmittance between the sub dots. When MIM elements are used as the non-linear elements, the capacitance can be changed by changing the size of the pixel electrode of the sub-dot to which each MIM element is connected. As a result, the driving voltage of the sub-dot is changed. You can also widen the viewing angle.

As described above, in the case of the normally white mode, the image reverses to black in the clear viewing direction, and in the normally black mode, the image reverses to white in the clear viewing direction and reverses to black in the reverse clear viewing direction. In the case of the mari-white mode, if the driving voltage of at least one sub-dot is made higher than the driving voltage of the other sub-dots, the inversion of the at least one sub-dot to black is delayed, and the viewing angle may be widened. In the normally black mode, if the driving voltage of at least one sub-dot is made lower than the driving voltage of the other sub-dots, the at least one sub-dot is less likely to be inverted to black and the viewing angle is reduced. Can be spread.

The present invention has been made based on such a principle and knowledge. According to the first aspect, in a liquid crystal display device in which each dot is driven by a non-linear element, each dot is divided into a plurality of sub-dots. At least one non-linear element is provided for each of the plurality of sub-dots that respectively divide the respective dots, and the driving characteristics of at least one of the plurality of sub-dots that respectively configure the respective dots. Is different from the driving characteristics of the other sub-dots.

According to a second aspect of the present invention, there is provided the liquid crystal display element according to the first aspect, wherein one of the non-linear elements is provided for each of the plurality of sub-dots constituting each of the dots. Is done.

According to a third aspect of the present invention, there is provided the liquid crystal display device according to the first or second aspect, wherein each of the dots is divided into two sub-dots.

According to a fourth aspect of the present invention, the driving characteristics of the non-linear element provided in the at least one sub-dot are made different from the driving characteristics of the non-linear element provided in the other sub-dot. A liquid crystal display device according to any one of claims 1 to 3 is provided.

According to a fifth aspect of the present invention, there is provided the liquid crystal display device according to any one of the first to fourth aspects, wherein the nonlinear element is an MIM element.

According to claim 6, the element size of the MIM element provided on the at least one sub-dot is made different from the element size of the MIM element provided on the other sub-dot. A liquid crystal display device according to claim 5 is provided.

According to a seventh aspect of the present invention, the area of the pixel electrode of the at least one sub-dot is made different from the area of the pixel electrode of the other sub-dot.
There is provided a liquid crystal display device as described above.

According to claim 8, the liquid crystal display element is a normally white mode element, and the driving voltage of the at least one sub-dot is higher than the driving voltage of the other sub-dots. A liquid crystal display device according to any one of claims 1 to 7 is provided.

According to a ninth aspect, the liquid crystal display element is a normally black mode element, and the driving voltage of the at least one sub-dot is lower than the driving voltage of the other sub-dots. A liquid crystal display device according to any one of claims 1 to 7 is provided.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be described with reference to the drawings.

(First Embodiment) FIG. 3 is a plan view for explaining a liquid crystal display device according to a first embodiment of the present invention.

The liquid crystal display element 100 of the present embodiment includes a glass substrate (not shown), a glass substrate on the opposite side (not shown) provided to face the glass substrate, and these two.
And a liquid crystal (not shown) held between two glass substrates.

On the glass substrate, a plurality of dots 40 constituting each pixel are provided in a matrix. In addition, a signal line 50 serving as a column electrode is provided on the glass substrate.
Is provided. The opposite glass substrate is provided with a stripe-shaped counter electrode (not shown) corresponding to the dot 40.

Each dot 40 has two sub-dots 42, 44
Is divided into The pixel electrode 30 of each dot 40 is also divided into two pixel electrodes 32 and 34. Secondary dot 42
In the example, the MIM element 10 is connected between the pixel electrode 32 and the signal line 50, and the MIM element 20 is connected between the pixel electrode 34 and the signal line 50 in the sub-dot 44.

The MIM element 10 has a lower electrode 1 made of Ta.
2 and Cr, upper electrode 14, lower electrode 12 and upper electrode 1
4 and an anodic oxide film of Ta (not shown).
It is composed of The MIM element 20 includes a lower electrode 22 made of Ta, an upper electrode 24 made of Cr, and a lower electrode 22 made of Cr.
And an anodic oxide film of Ta (not shown) provided between the upper electrode 24 and the upper electrode 24. The upper electrode 14 is composed of two sub upper electrodes 141 and 142. Even if one of the electrodes 141 and 142 is disconnected, the connection is secured from the other.
Reference numeral 4 includes two sub-upper electrodes 241 and 242, so that even if one of the sub-upper electrodes 241 and 242 is disconnected, the connection is secured from the other.

In the present embodiment, by making the element size of the MIM element 10 different from the element size of the MIM element 20, two sub-dots 4 forming one dot 40 are formed.
By changing the drive voltage between the sub-dots 2 and 44, the inversion of one sub-dot to black is made slower than the other sub-dot to widen the viewing angle.

(Second Embodiment) FIG. 4 is a plan view for explaining a liquid crystal display device according to a second embodiment of the present invention.

In the first embodiment, the MIM
Although the element size of the element 10 and the element size of the MIM element 20 are made different to make the drive voltage between the two sub-dots 42 and 44 different, in the liquid crystal display element 200 of the present embodiment, The element size is the same as the element size of the MIM element 20, but one dot 40 is formed by dividing the pixel electrode 30 of each dot 40 into two pixel electrodes 32 'and 34' having different areas. The first embodiment differs from the first embodiment in that the drive voltage between the two sub-dots 42 and 44 is made different, so that one of the sub-dots is turned black more slowly than the other sub-dot to increase the viewing angle. The difference is the same in other respects.

[0030]

According to the present invention, a liquid crystal display device having improved viewing angle characteristics is provided.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining transmission characteristics of a dot portion of a liquid crystal display device of the present invention.

FIG. 2 is a schematic plan view for explaining a configuration of a dot portion of the liquid crystal display element of the present invention.

FIG. 3 is a plan view for explaining the liquid crystal display device according to the first embodiment of the present invention.

FIG. 4 is a plan view illustrating a liquid crystal display device according to a second embodiment of the present invention.

[Explanation of symbols]

 1, 2, 10, 20 ... MIM elements 3A, 3B, 30, 32, 34 ... pixel electrodes 4, 40 ... dots 5, 50 ... signal lines (column electrodes) 12, 22 ... lower electrodes (Ta) 14, 24 ... Upper electrodes (Cr) 100, 200: Liquid crystal display elements 141, 142, 241, 242: Sub upper electrodes A, B, 42, 44: Sub dots

Claims (9)

[Claims] 1. A liquid crystal display device in which each dot is driven by a non-linear element, wherein each of the dots is divided into a plurality of sub-dots, and at least one non-linear is provided for each of the plurality of sub-dots constituting each of the dots. A liquid crystal display device comprising: an element; and a driving characteristic of at least one of the plurality of sub-dots constituting each of the dots is different from a driving characteristic of another sub-dot. 2. The liquid crystal display device according to claim 1, wherein one non-linear element is provided for each of the plurality of sub-dots constituting each of the dots. 3. The liquid crystal display device according to claim 1, wherein each of said dots is divided into two sub-dots. 4. The driving characteristic of the non-linear element provided on the at least one sub-dot is different from the driving characteristic of the non-linear element provided on the other sub-dot. 4. The liquid crystal display device according to any one of 3. 5. The liquid crystal display device according to claim 1, wherein said non-linear element is an MIM element. 6. An element size of said MIM element provided in said at least one sub-dot is different from an element size of said MIM element provided in said another sub-dot. Liquid crystal display element. 7. The liquid crystal display device according to claim 5, wherein the area of the pixel electrode of the at least one sub-dot is different from the area of the pixel electrode of the other sub-dot. 8. The liquid crystal display device according to claim 1, wherein the driving voltage of the at least one sub-dot is higher than the driving voltage of the other sub-dots. 8. The liquid crystal display device according to any one of items 7. 9. The liquid crystal display device according to claim 1, wherein a driving voltage of the at least one sub-dot is lower than a driving voltage of another sub-dot. 8. The liquid crystal display device according to any one of items 7.