JPS63104021A - Color liquid crystal display element and its manufacture - Google Patents

Abstract

PURPOSE:To keep a gap between substrates constant so that a good contrast can be obtained by sticking a spacer to only a part corresponding to a color filter of a specific color in a color liquid crystal display element in which film thickness of a color filter is different in accordance with each color. CONSTITUTION:On the inside surface of a transparent opposed substrate 14 consisting of a glass plate, etc., color filters 15(R), 15(G) and 15(B) of three primary colors are formed, and for instance, 15(B) is the thickest, 15(G)is of the next thickness, and 15(B) is the thinnest. A spacer 18 is stuck to only the color filter of a specific color, for instance, the part of 15(B), therefore, without being influenced by a step difference of each color filter 15(R), 15(G) and 15(B), a gap between both substrates 11, 14 becomes constant, and a cell gap which is set in advance can be exactly realized. In this way, deterioration of the display quality caused by unevnenness of the cell gap can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a color liquid crystal display element having a plurality of pixel electrodes and provided with color filters of different colors corresponding to these pixel electrodes.

"Prior Art" In recent years, color liquid crystal display elements used in liquid crystal color televisions and the like have a large number of pixel electrodes, and color filters of three primary colors are provided corresponding to each pixel electrode. Then, by applying a selection voltage to any pixel electrode, a color corresponding to that pixel electrode is displayed, making it possible to display a free pattern of color by combining dots of the three primary colors.

Incidentally, the intensity of transmitted light when no voltage is applied to the liquid crystal depends on the thickness of the liquid crystal layer and the wavelength of the transmitted light.

Conventionally, even in the case of color liquid crystals, the thickness was designed so that the intensity of transmitted light was minimum at the center wavelength of visible light (G, near green). Therefore, the transmitted light intensity of R (red) and B (blue) was not minimized, and the contrast was not improved.

When a liquid crystal cell with a twist angle of 90 degrees is sandwiched between two polarizing plates having the same polarization direction, the transmitted light intensity T is given by the following equation (2).

T (d, in) = sin (”, /T'i)/(1
・u ) −■ (However, n−d/λ, Δ to u=2
n: refractive index anisotropy of liquid crystal, d: thickness of wave crystal layer, and: transmission wavelength. ) Therefore, a color liquid crystal display element as shown in FIG. 4 has been proposed.

That is, in FIG. 4, 1 is a display substrate, and a large number of pixel electrodes 2 and an alignment film 3 are formed on the inner surface.

Reference numeral 4 denotes a counter substrate, on the inner surface of which are formed a large number of color filters 5 corresponding to the pixel electrodes 2, a counter electrode 6 covering the inner surface, and an alignment film 7 covering the inner surface. The color filter 5 is 5(R): red, 5(G).
): Green, 5 (8): Blue. The display substrate 1 and the counter substrate 4 are arranged facing each other with the electrode forming surfaces facing inside, and liquid crystal 8 is injected inside. In this color liquid crystal display element, each color filter 5(R)
, 5(G), and 5(8) depending on the film thickness or color, and the cell caps dr, d corresponding to each color are accordingly different.
q and db are different from each other. and,
Each color filter 5(R), 5(G) in voltage off state,
The transmitted light intensity T in 5(B) is set to 0 in each of the above equations. Therefore, it is necessary to obtain good contrast.

"Problems to be Solved by the Invention" However, in the above-mentioned liquid crystal display element, when bonding the display substrate 1 and the counter substrate 4, there is a problem mainly in the arrangement of the spacers to keep the gap between the substrates constant. Usually, this type of spacer consists of various beads with a constant particle size, and is interposed between the two substrates 1.4 to maintain a constant gap between the substrates. However, in the above liquid crystal display element, the spacer When the color filter 5 (8) is sandwiched, the gap becomes large, and when the color filter 5 (R) is sandwiched, the gap becomes small. Therefore, the substrate gap remains constant,
The cell cap was uneven and I was unable to obtain the desired good contrast.

Therefore, an object of the present invention is to provide a liquid crystal display element and a method for manufacturing the same, in which the gap between the substrates can be kept constant and good contrast can be obtained when the thickness of the color filter is changed depending on the color.

"Means for Solving the Problems" The present invention has a plurality of pixel electrodes, and color filters of three primary colors are provided on the inner surface of at least one substrate corresponding to each pixel electrode, and the films of these color filters A color liquid crystal display element having different thicknesses for each color is characterized in that a spacer is attached only to a portion corresponding to a color filter of a specific color.

Further, the present invention provides a color filter having a plurality of pixel electrodes, and color filters of three primary colors are provided on the inner surface of at least one substrate corresponding to each pixel electrode, and the film thicknesses of these color filters are different for each color. In a method for manufacturing a liquid crystal display element, a photosensitive resin containing a spacer is applied to the inner surface of at least one substrate, and light is irradiated to cure only the portion of the photosensitive resin that corresponds to a color filter of a specific color. A feature is that the spacer is attached by developing.

"Function" In this way, in the color liquid crystal display element of the present invention, since the spacer is attached only to the part corresponding to the color filter of a specific color, even if the film thickness of the color filter is different depending on each color, The gap can be kept constant, thereby providing the expected good contrast.

In addition, in the method for manufacturing a liquid crystal display element of the present invention, the spacer is formed into a portion corresponding to a color filter of a specific color by a simple process of applying a photosensitive resin containing a spacer, irradiating it with light, and developing it. can only be attached.

Embodiment J of the Invention FIG. 1 shows an embodiment of a color liquid crystal display element according to the invention.

The inner surface of the transparent display substrate 11 made of a glass plate or the like has I
A large number of pixel electrodes 12 are formed by patterning transparent electrodes such as TO films, and alignment films 13 made of polyimide resin or the like are formed on their rough inner surfaces.

Further, on the inner surface of the transparent counter substrate 14, which is also made of a glass plate or the like, color filters of three primary colors +5(R), +
5 (G) and +5 (B) are formed. In this case, +5CB) is the thickest, +5(G) is the next thickest, and 15
(R) is the thinnest. These color filters +5(R), +5(G), and +5(B) can be produced by, for example, applying a photosensitive gelatin-based resin by photolithographic printing, photoetching, and dyeing, or using a resin containing pigments or dyes. Each color is sequentially formed using an ink offset printing method or the like. In addition, color filter +5 (R
), +5(G), and +5(B) are formed corresponding to each pixel electrode 12 of the display substrate 11.

These color filters +5(R), +5CG)
, +5(B), an opposing electric fence 16 made of ITO film or the like is formed. Roughly speaking, an alignment film 17 made of polyimide resin or the like is formed inside the counter electrode 16.

The display substrate 11 and the counter substrate 14 are arranged facing each other with the electrode forming surfaces facing inside, and their peripheral portions are adhered with epoxy resin or the like to form a cell. In this case, both substrates 11.
A spacer 18 is interposed between the holes 14. In this example, for the spacer 1, synthetic resin beads "Micro Pearl" (trade name, manufactured by Building Blocks Fine Chemicals) with an F1 diameter of 9 um were used, or other synthetic resin beads, alumina beads, glass fiber, etc. were used. You may. In the present invention, the spacer 18 is connected to a color filter of a specific color through the resin 19.
It is attached only to the part 5(B). In this embodiment, the alignment film 17 is attached after the spacer 18 is attached.
Therefore, the alignment film 17 is coated on the spacer 18 and the resin 19. Liquid crystal 20 is injected into the cell thus obtained and sealed.

This color liquid crystal display element can perform display by disposing polarizing plates (not shown) in parallel Nicols on the vertical surface of the display substrate 11 and the outer surface of the counter substrate 14, respectively, and disposing a backlight on the back side.

That is, when the voltage is off, the light from the backlight passes through the polarizing plate, the opposing substrate 14, and each color filter +5 (
R), +5 (G), and +5 (B), respectively, or rotated by the TN liquid crystal 20, the display substrate 11
The light passes through the polarizer on the side, forming a dark background. In this case, each color filter +5 (R), +5 (G),
By changing the thickness of +5(B), the cell cap is adjusted so that the transmitted light intensity T of the above-mentioned 0 formula is minimized for each color, so a good light blocking effect by the liquid crystal 20 can be obtained. It will be done.

In addition, when the voltage is on, the liquid crystal 20 of that part
Since the optical rotation makeup disappears, the light that has passed through the polarizing plate, the opposing substrate 14, and the color filters +5(R), +5(G), and +5(B) passes through the display substrate 11 and the polarizing plate as it is, and then passes through the color filter. 15(R), 15(G),
It can be visually recognized as the original colored by 15(8). In this case, of course, the pixel electrode 1 to which a voltage is applied
Color filters corresponding to 2 +5 (R), +5 (G
), +5 (8) colors are visible. Therefore, by selecting the pixel electrode 12 to which a voltage is applied, it is possible to display color in a free pattern consisting of dots of the three primary colors.

In this color liquid crystal display element, as described above, since the spacer 18 or the color filter of a specific color (in this example, +5CB) is attached only to the portion of the spacer 18, each color filter +5(R) , +5(G) ,
Both substrates 11.
14 becomes constant, and a preset cell gap can be reliably realized. Therefore, deterioration in display quality due to uneven cell caps can be prevented.

Note that the spacer 18 is a color filter +5 (R), +
5(G).

Further, the spacer 18 is used as a color filter of a specific color on the inner surface of the display substrate 11 -15(R), +5(G), +5
It may be adhering to the part corresponding to (B).

FIGS. 2 and 3 show the process of attaching spacers 18 to color filters +5(R), +5(G), and +5(B) of specific colors when manufacturing the above color liquid crystal display element. ing.

That is, as shown in FIG. 2, color filters +5(R), +5(G), +5 are provided on the inner surface of the counter substrate 14.
(8) is formed by the method described above. Zarani, color filter +5 (R),! 5 (G), +5 (8)
A counter electrode 16 made of an ITO film or the like is formed thereon by means such as sputtering. Then, the spacer 18 made of the synthetic resin beads described above is mixed with the photosensitive resin I9, and this is applied to the inner surface of the counter substrate 14. As the photosensitive resin 19, various types can be used, such as acrylic, polyvinyl alcohol, ceratin, polyimide resins, and ultraviolet curing resins. In this example, acrylic photosensitive resin rRW-102J (5 product names,
(Made by Building Blocks Fine Chemical ■) was used. The amount of spacer 18 added to photosensitive resin 19 is 0.1 to 1.0.
Approximately % by weight is appropriate. In this state, the photomask 21
Cover it and irradiate light only to the part corresponding to the blue color filter +5 (B). Note that the photosensitive injection resin used here can be either a negative type or a positive type. In that case, cover the area where you want the spacer 18 to be attached with the photomask 21 and apply it to other areas. All you have to do is irradiate it with light.

As mentioned above, the photosensitive resin 1 containing the spacer 18
After applying 8 to 9 and exposing to light, by developing according to a conventional method, a photosensitive resin 19 is applied only to the area corresponding to the blue color filter + 5CB) as shown in FIG.
The spacer 19 is cured and the spacer 19 adheres thereto, while the photosensitive resin 19 remains uncured and removed by development in other parts.

Then, the alignment film 17 shown in FIG. 1 is formed over these. The color liquid crystal display element shown in FIG. 1 can then be manufactured by bonding the display substrate 11 and the counter substrate 14 together, and injecting and sealing the liquid crystal 20 inside according to a conventional method.

"Effects of the Invention" As explained above, according to the color liquid crystal display element of the present invention, the film thickness of the color filter is different for each color, and the spacer is attached only to the part corresponding to the color filter of a specific color. Therefore, the gap between the substrates can be kept constant without being affected by the difference in level between the color filters.

Therefore, it is possible to accurately create a cell gap that corresponds to the color of the color filter, and it is possible to obtain good display contrast. In addition, according to the manufacturing method of the present invention, the spacer is attached only to the part corresponding to the color filter of a specific color by a simple process of applying a photosensitive resin containing the spacer, irradiating it with light, and developing it. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view showing an embodiment of a color liquid crystal display element according to the present invention, and FIGS. 2 and 3 are partial cross-sectional views sequentially showing the steps of attaching spacers in the method for manufacturing a color liquid crystal display element according to the present invention. 4 are partial cross-sectional views showing an example of a conventional color liquid crystal display element. In the figure, 11 is a display substrate, 12 is a pixel electrode, 13 is an alignment film, 14 is a counter substrate, +5(R), +5(G), +
5(B) is a color filter, 16 is a counter electrode, 17 is an alignment film, 18 is a spacer, 19 is a resin, and 20 is a liquid crystal.

Claims (2)

[Claims] (1) A color liquid crystal display element that has a plurality of pixel electrodes, and color filters of three primary colors are provided on the inner surface of at least one substrate corresponding to each pixel electrode, and the film thickness of these color filters is different for each color. A color liquid crystal display element characterized in that a spacer is attached only to a portion corresponding to a color filter of a specific color. (2) A color liquid crystal display element having a plurality of pixel electrodes, in which color filters of three primary colors are provided on the inner surface of at least one substrate corresponding to each pixel electrode, and the film thicknesses of these color filters are different for each color. In the manufacturing method of
The spacer is attached by applying a photosensitive resin containing a spacer to the inner surface of at least one of the substrates, and developing it by irradiating light so that only the portion of the photosensitive resin that corresponds to the color filter of a specific color is cured. A method for manufacturing a color liquid crystal display element, characterized in that: