JPH0336525A - Liquid crystal display cell and negative type liquid crystal display element - Google Patents

Abstract

PURPOSE:To obviate the degradation in look by a differences in color tones by providing a transfer material adjusted in color tones so as to have nearly the same color as the color of a sealing material in a sealing material region or the region adjacent thereto. CONSTITUTION:The black sealing material 2 contg. spacers is sceen-printed in the peripheral part of, for example, a segment electrode substrate 3 and the transfer material 4 which is formed by incorporating a black dye into silver paste and is so adjusted as to have nearly the same color as the color of the sealing material is printed on a common electrode substrate 5. The spacers are sprayed over the entire surface of the substrates and two sheets each of the substrates 1A, 1B are disposed and press welded in such a manner that the orientated film surfaces face each other to form an empty cell. A nematic liquid crystal 7 is then injected into the cell from an injection port. This liquid crystal display element is a display of a negative type and has a white display part changing in the display by driving on the black background. The liquid crystal display element which obviates the drop-out of light near the transfer material and the degradation in the look by the differences in the color tones is obtd. in this way.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a liquid crystal display cell.

[Conventional technology]

In recent years, liquid crystal display elements have been increasingly used as display devices because they are capable of displaying large areas with low power. These devices usually have a structure in which a liquid crystal is sandwiched between substrates provided with electrodes, and a driving device that applies a voltage to the electrodes is installed on a liquid crystal display cell in which the periphery of the liquid crystal is sealed with adhesive. The display pattern i is usually formed by applying a voltage to a desired electrode through an electrode terminal. Common and segment electrode terminals are often used as voltage application terminals, but most cells have common electrode terminals and segment electrode terminals using a transfer material to expand the effective display area, simplify terminal connections, and stabilize manufacturing conditions. Segment electrode terminals are gathered on one substrate such as a segment substrate. Silver paste, which has good conductivity, is often used as a material for forming the transfer material for this purpose.

[Problems to be Solved by the Invention] The above-mentioned transfer has been developed in consideration of the stability of the transfer and the size of the display area.
It is often provided inside or in contact with the peripheral seal of a tFi crystal display cell.

At this time, in conventionally used liquid crystal display cells, an organic adhesive or frit glass is often used as the sealing material close to the transfer material, as described above.

Since the color tone of these sealants greatly affects the appearance of the display element, a color tone as close as possible to the background color of the display is often used.

For example, in a negative type liquid crystal display element, the color is black, and in a positive type liquid crystal display element, the background color is white or another color.

However, in such a case, if conventional silver paste or the like is used as the transfer material, not only will the color tone not match the sealing material, but in the case of a negative type liquid crystal display element, light will pass through the transfer material. There were cases where so-called light leakage occurred, which significantly impaired the appearance. Further, there are black transfer materials such as carbon paste, but since the material is different from that of the sealing material, the colors are different even though they are black, and the appearance is not good.

[Means for Solving the Problems] The present invention has been made to solve these problems, and provides a liquid crystal layer formed by sandwiching a liquid crystal layer between substrates having a pair of electrodes and sealing the periphery with a sealing material. In the cell, a transfer material whose color tone is adjusted to have substantially the same color as the sealing material is provided in the sealing material area or an area adjacent thereto, and conduction is established between the electrodes of the pair of substrates. The present invention provides a liquid crystal display cell. 2. The liquid crystal display cell according to claim 1, further comprising a polarizing plate on at least one side of the liquid crystal display cell, wherein the sealing organic adhesive has a black color and the transfer material has a color tone that is adjusted to have substantially the same color as the sealing material. The present invention provides a negative type liquid crystal display element characterized in that a voltage is applied to the electrodes.

The present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are cross-sectional views showing one example of a cell of a liquid crystal display element of the present invention. In the figure, IA and IB are substrates, 2 is a sealing material, 3 is an electrode on the segment side, 4 is a transfer, 5 is an electrode on the common side, 6 is an alignment film, and 7 is an electrode on the common side. is the liquid crystal layer, and 9A
, 9B are polarizing plates.

Transparent substrates such as glass and plastic can be used as the substrates IA and IB, and I TO (I
An electrode 3.5 made of a transparent conductive film such as n10B-SnO, ) or Snow is formed. Of course, a low-resistance metal lead may be attached to this transparent electrode, or a color filter, a light-shielding film, an insulating film, etc. may be formed above or below the transparent electrode.

An alignment film is usually formed on the surface of this substrate with electrodes. When a light shielding film is provided on the electrode, an alignment film is formed thereon. Examples of this orientation control method include polyimide and polyamide.

Known orientation control methods such as a method in which an organic polymer film such as polyvinyl alcohol is formed by a printing method or a spinner method and then rubbed, and an oblique vapor deposition method can be used.

The sealing material is made of ordinary organic adhesive such as epoxy resin or silicone resin, and usually an opening is formed in a part of the sealing material, and after forming a cell, liquid crystal is injected through the opening, and then the liquid crystal is injected into the opening. If necessary, pigments, dyes, etc. may be mixed in to adjust the color tone to be close to the background color of the liquid crystal display cell. Specifically, in the case of a negative type liquid crystal display element using a normal polarizing plate, it is sufficient to make the color black to match the background color, and in the case of a negative type liquid crystal display element using a color polarizing plate or dye, the background color should be made black to match the background color. It may be colored blue, red, green, etc. to match the color. In the case of a positive type liquid crystal display element, it may be colored in a light color to match the background color.

The polarizing plates 9A and 9B are provided on one or both sides of the cell as necessary depending on the nature of the liquid crystal sealed in the cell.

The sealing material may contain spacers such as glass beads, glass fibers, plastic fibers, alumina powder, etc. mixed therein as required, and the spacer determines the distance between the substrates. A spacer is similarly interposed between the two substrates as required, thereby improving the uniformity of the distance between the two substrates within the substrate plane.

The spacer placed within the substrate surface may be the same as the spacer mixed in the sealing material described above, but as mentioned above, an alignment film, a light shielding film, etc. are usually provided on the substrate surface, or Since strong pressure is applied to the sealing portion during cell manufacturing, it may be possible to make the spacing between the substrates more uniform if the spacers are not of the same size, so they can be adjusted as appropriate depending on the conditions.

The present invention is characterized in that the transfer material 4 for transferring the electrodes of the upper and lower substrates is made of substantially the same color as the sealing material.

Methods for coloring the transfer material include, for example, mixing a colored dye into the silver paste mentioned above, or mixing a colored dye or pigment and conductive particles into an organic adhesive. . Regarding the amount of dye or pigment to be mixed, it is preferable to mix the dye or pigment while adjusting the amount of at least one type of dye or pigment so that the color of the transfer material becomes approximately the same color as the color of the sealing material. In particular, when the sealing material is black, a dye or pigment of a complementary color to the color originally contained in the transfer material may be mixed therein.

As a method for forming the transfer material according to the present application, a method commonly used for forming a transfer in a peripheral sealing material may be adopted.

That is, a sealing material is formed around the electrodes on one substrate by a printing method or the like, and a transfer material is applied to a predetermined position on that substrate or the other substrate using a printing method such as screen printing or a dispenser. The two substrates are bonded together, and the sealing material is cured by thermocompression bonding, ultraviolet irradiation, or the like.

[Example] (Example 1) As shown in Fig. 1, ITO on a glass substrate with ITO was patterned by photoetching, and 50 nm
An overcoat layer for an alignment film of polyimide (m) was formed, and alignment treatment was performed by rubbing a pair of substrates so that they were perpendicular to each other. Next, a black sealing material containing spacers is screen printed on the peripheral part of the segment electrode substrate, and a transfer material adjusted to have almost the same color as the sealing material is printed on the common electrode substrate by mixing silver paste with black dye. Then, spacers were spread over the entire surface of the substrates, and the two substrates were arranged and pressure-bonded so that the alignment film surfaces faced each other to form empty cells.

Next, nematic liquid crystal was injected through the injection port, and the injection port was sealed to produce a liquid crystal cell. A pair of polarizing plates are installed on both sides of this liquid crystal cell, so that the polarization axis of one substrate is perpendicular to the alignment direction of adjacent liquid crystal molecules, and the polarization axis of the other substrate is parallel to the alignment direction of adjacent liquid crystal molecules. (so that the polarization axes were parallel to each other).

This liquid crystal display element was a negative type display, and had a white display portion on a black background whose display changed when driven.

As a result, a liquid crystal display element was obtained in which the appearance did not deteriorate due to light leakage near the transfer material or difference in color tone from the sealing material.

(Example 2) ITO of a glass substrate with ITO was patterned by photoetching, and a 50 nm overcoat layer for an alignment film of polyimide was formed on it, and a pair of substrates were patterned so that they were perpendicular to each other. Orientation treatment was performed by rubbing. Next, a blue sealing material containing spacers is screen printed on the peripheral part of the segment electrode substrate, a transfer material containing silver paste and blue coloring material is printed on the common electrode substrate, and spacers are sprinkled over the entire surface of the substrate. Two substrates were arranged and pressed together so that the alignment film surfaces faced each other, and empty cells were formed.

Next, nematic liquid crystal mixed with blue dye was injected through the injection port, the injection port was sealed, and a liquid crystal cell was manufactured. A pair of polarizing plates were placed on both sides of this liquid crystal cell so that the polarizing axes of both substrates were parallel to the alignment direction of adjacent liquid crystal molecules (the polarizing axes were orthogonal to each other).

This liquid crystal display element had a positive type display, and had a black display part on a bright blue background whose display changed when driven.

As a result, a liquid crystal display element was obtained in which the appearance does not deteriorate due to differences in color tone between the transfer material and the sealing material or the background color.

[Effects of the Invention] According to the liquid crystal display cell according to the present invention, a liquid crystal display cell that does not have deterioration in appearance due to differences in color tone between the transfer material and the sealing material or the background color can be obtained. Furthermore, claim 2
According to the liquid crystal display element according to the above, in addition, a negative type liquid crystal display element with an extremely good appearance without light leakage from the peripheral sealing material or the vicinity of the transfer material adjacent thereto can be obtained.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing an example of a liquid crystal display cell of the present invention. LA and 1B are substrates, 2 is a sealing material, 3 is a segment electrode, 4 is a transfer material, 5 is a common electrode, 7 is a liquid crystal layer, and 9A and 9B are polarizing plates. ','ili'nee,'',1

Claims (2)

[Claims] (1) In a liquid crystal cell in which a liquid crystal layer is sandwiched between substrates having a pair of electrodes and the periphery is sealed with a sealing material, a transfer material whose color tone is adjusted so as to exhibit almost the same color as the sealing material is used. A liquid crystal display cell characterized in that the liquid crystal display cell is provided in a sealing material area or an area adjacent thereto to provide electrical continuity between the electrodes of the pair of substrates. (2) Polarized light is applied to at least one side of the liquid crystal display cell according to claim 1, wherein the sealing organic adhesive exhibits a black color, and the transfer material has a color tone adjusted so as to exhibit approximately the same color as the sealing material. A negative type liquid crystal display element characterized by having a plate and applying a voltage to an electrode.