JPH08201797A - Color liquid crystal display element - Google Patents

Abstract

(57) [Summary] [Purpose] The alignment film on the color filter is uniformly aligned, including the vicinity of the bulge corresponding to the overlapping part of the color filter, and the liquid crystal molecules are well aligned over the entire pixel area. Oriented to display high quality color image. A ratio t / d between the thickness t of each color filter 5R, 5G, 5B and the liquid crystal layer thickness d of the portion corresponding to the color filter of that color is 0.19 or less, and The alignment film 6 was subjected to an alignment treatment in a direction substantially along the length direction of the overlapping portion of the edges of the adjacent color filters.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device.

[0002]

2. Description of the Related Art In a color liquid crystal display device for displaying a multicolor image, color filters of a plurality of colors are alternately arranged on one of a pair of substrates facing each other across a liquid crystal layer. It is composed.

FIG. 4 is a sectional view of a part of a conventional color liquid crystal display device, and FIG. 5 is a plan view of a part of the color filter forming substrate. This liquid crystal display element is of a simple matrix type, and one of a pair of transparent substrates 1 and 2 made of glass or the like, for example, a lower substrate (hereinafter referred to as a lower substrate) 1 in FIG. A predetermined number of scanning electrodes 3 extending in one direction (left-right direction in the drawing) are provided in parallel with each other, and a signal electrode 4 extending in a direction orthogonal to the scanning electrodes 3 is provided on the other substrate (hereinafter referred to as an upper substrate) 2. A predetermined number of them are provided in parallel with each other. The scanning electrodes 3 and the signal electrodes 4 are both transparent electrodes made of ITO or the like.

In addition, one of the substrates, for example, the lower substrate 1 provided with the scanning electrodes 3, is laminated on the scanning electrodes 3 to have a plurality of colors, for example, three colors of red, green and blue. Filters 5R, 5G, and 5B are arranged alternately.

Each of these color filters 5R, 5G, 5B is slightly wider than the width of the pixel portion D where the scanning electrode 3 and the signal electrode 4 on the upper substrate 2 face each other, and the color electrode 5 It is formed in a stripe shape corresponding to each pixel column along the length direction.

The color filters 5R, 5G and 5B are
For example, it is formed by repeating a method in which a photosensitive color resist to which a pigment of one color of red, green and blue is added is applied onto the substrate 1, and the resist film is exposed and developed to be patterned. The edge portions of the adjacent color filters 5R, 5G, 5B are vertically overlapped with a slight margin.

The color filters 5R, 5G and 5B shown in FIGS. 4 and 5 are formed in the order of the red filter 5R, the green filter 5G and the blue filter 5B. Therefore, one of the green filters 5G is formed. The side edges overlap the side edges of the adjacent red filter 5R, and the side edges of the blue filter 5B overlap the side edges of the adjacent green filter 5G and red filter 5R, respectively.

Further, the pair of substrates 1 and 2 are provided with alignment films 6 and 7, respectively, and the alignment film 6 on the lower substrate 1 side.
Is formed on and covers the color filters 5R, 5G, 5B, and the alignment film 7 on the upper substrate 2 side is formed on and covers the signal electrodes 4.

The alignment films 6 and 7 are horizontal alignment films made of polyimide or the like, and the alignment films 6 and 7 are each subjected to alignment treatment by rubbing the film surface in a predetermined direction.

The pair of substrates 1 and 2 are bonded to each other with a frame-shaped sealing material (not shown) in such a manner that the surfaces on which the electrodes 3 and 4 and the alignment films 6 and 7 are formed face each other. A liquid crystal 8 is filled in a region surrounded by the sealing material between the substrates 1 and 2.

A nematic liquid crystal is used for the liquid crystal 8, and the liquid crystal molecules are aligned in the vicinity of the substrates 1 and 2 by the alignment films 6 and 7, and are aligned on the surfaces of the alignment films 6 and 7. With a certain pretilt angle (about several degrees), the two substrates 1 and 2 are twist-aligned at a predetermined twist angle.

In FIG. 5, A1 indicates the alignment treatment direction of the alignment film 6 on the lower substrate 1 side, and A2 indicates the alignment treatment direction of the alignment film 7 on the upper substrate 2 side. Alignment film 6 on the lower substrate 1 side with reference to the horizontal axis O of the device
Is oriented in a direction deviated by a predetermined angle θ with respect to the horizontal axis O, and the orientation film 7 on the upper substrate 2 side is deviated in the opposite direction with respect to the horizontal axis O by the same angle θ. Orientation is applied.

This liquid crystal display element is of STN type in which the twist angle of liquid crystal molecules is 180 ° to 270 °. For example, in the STN type liquid crystal display element in which the twist angle is 240 °, both substrates 1 are used. The deviation angles θ between the alignment treatment directions A1 and A2 of the alignment films 6 and 7 on the first and second sides and the horizontal axis O are set to 30 °, respectively, and the liquid crystal molecules move from the lower substrate 1 side to the upper substrate 2 side. 5 is twisted in the direction indicated by the broken line arrow at a twist angle of 240 °.

The thickness d of the liquid crystal layer of the portion corresponding to the color filters 5R, 5G, and 5B of each color of the STN type liquid crystal display element (excluding the overlapping portion between the edge portions of the adjacent color filters) is usually 5. The color filters 5R, 5G, 5B for each color are set to have a thickness of about 1.3 μm, and therefore the thickness t of the color filters 5R, 5G, 5B for each color is set to 8 μm ± 0.35 μm. The ratio t / d between the liquid crystal layer thickness d of the portion corresponding to the color filter of that color is about 0.283 to 0.211.

Although not shown in FIG. 4, polarizing plates are arranged on both surfaces of the liquid crystal display element, that is, on the outer surfaces of the pair of substrates 1 and 2, respectively. The (transmission axis or absorption axis) is provided in a state of being oriented in a predetermined direction with respect to the alignment direction of liquid crystal molecules in the vicinity of both substrates 1 and 2 of the liquid crystal display element.

[0016]

In the color liquid crystal display element described above, since the edges of the color filters 5R, 5G and 5B provided on one of the substrates 1 are vertically overlapped with each other, the color filter 5R is not formed. , 5G, 5B, the alignment film 6 formed on the color filters 5R, 5B.
The portion corresponding to the overlapping portion of G and 5B is highly raised as shown in FIG.

In the conventional color liquid crystal display device in which the color filters 5R, 5G, 5B for the respective colors are formed to have a thickness of about 1.3 μm as described above, the overlapping portions of the edges of the adjacent color filters are overlapped. Height (the thickness of the portion of the green filter 5G and the blue filter 5B that overlaps the side edges of the adjacent color filters 5R and 5G)
t ′ is about 1.0 μm, and therefore the height of the protrusion of the alignment film 6 is about 1.0 μm.

In the conventional liquid crystal display device, the alignment films 6 and 7 provided on the pair of substrates 1 and 2 are subjected to the alignment treatment in the directions A1 and A2 shown in FIG. 5, respectively. If the alignment film 6 on the substrate 1 side provided with the color filters 5R, 5G, 5B is partially raised, the film surface of the alignment film 6 is rubbed in a predetermined direction by a rubbing roller in the manufacturing process of the liquid crystal display device. When the alignment treatment is performed by the above-described method, the vicinity of the raised portion of the alignment film 6 is not sufficiently rubbed, so that the alignment treatment failure occurs at that portion.

The defective alignment treatment of the alignment film 6 is mainly caused by the side face of the raised portion which is the side on which the rubbing roller descends when it moves, that is, the alignment treatment of the alignment film 6 shown in FIG. When rubbing from the left side to the right side in the figure as in the direction A1, it occurs near the side surface W on the right side of the raised portion.

Therefore, in the above-mentioned conventional liquid crystal display element, the initial alignment state of the liquid crystal molecules in each pixel portion D is disturbed in the portions corresponding to the overlapping portions of the color filters 5R, 5G and 5B, and therefore, The brightness and color quality of the side edges of the pixels of each color to be displayed are uneven, thus deteriorating the image quality.

Also in the conventional liquid crystal display element, if the flattening agent is overcoated on the color filters 5R, 5G and 5B and the alignment film 6 is formed thereon, the film surface of the alignment film 6 is removed. Almost flattening and uniform alignment treatment can be performed.

However, in the so-called bottom electrode type liquid crystal display device in which the electrode 3 is provided below the color filters 5R, 5G and 5B as described above, a flattening agent is provided on the color filters 5R, 5G and 5B. Overcoating, the voltage applied between the electrodes 3 and 4 of both substrates 1 and 2 greatly drops not only in the color filters 5R, 5G and 5B and the alignment films 6 and 7, but also in the overcoat film, resulting in display characteristics. In addition, since the flattening agent has to be applied in a considerably large thickness in order to form an overcoat film having a substantially flat film surface, it takes time to form the overcoat film, resulting in high cost. I will end up.

There is also a color liquid crystal display element called a top electrode type in which an electrode on the side of a substrate on which a color filter is provided is provided on the color filter. In this liquid crystal display element, the color filter By overcoating the top with a flattening agent and forming the electrode and the alignment film on it, it is possible to make the film surface of the alignment film almost flat without greatly reducing the voltage applied between the electrodes. However, even in that case, it takes a long time to form the overcoat film, resulting in a high cost.

According to the present invention, the alignment film can be formed in the vicinity of the raised portion corresponding to the overlapping portion of the color filters without overcoating and flattening the color filters of a plurality of colors provided on one substrate. An object of the present invention is to provide a color liquid crystal display device capable of displaying a high-quality color image by performing almost uniform alignment treatment including the liquid crystal molecules and orienting liquid crystal molecules in a good alignment state over the entire pixel portion.

[0025]

In a color liquid crystal display device of the present invention, an electrode and an alignment film are provided on a pair of substrates facing each other across a liquid crystal layer, and liquid crystal molecules of the liquid crystal layer are arranged in the pair of substrates. The substrates are twist-oriented between the substrates, and the color filters of a plurality of colors are alternately arranged on the inner surface of one of the substrates, and the thickness t of each color filter and the color filter of that color are The ratio t / d with respect to the liquid crystal layer thickness d of the corresponding portion is 0.19 or less.

In this color liquid crystal display element, the alignment film on the substrate side provided with the color filters is subjected to alignment treatment in a direction substantially along the length direction of the overlapping portion of the edges of the adjacent color filters. Is desirable.

Further, in another color liquid crystal display element of the present invention, an electrode and an alignment film are respectively provided on a pair of substrates which face each other across a liquid crystal layer, and the molecules of the liquid crystal are twisted between the pair of substrates. Along with the orientation, color filters of a plurality of colors are alternately arranged on the inner surface of one of the substrates, and the orientation film on the side of the substrate on which the color filters are provided has an edge of an adjacent color filter. It is characterized in that the alignment treatment is performed in a direction substantially along the length direction of the overlapping portion of the portions.

In this color liquid crystal display element, it is most preferable that the alignment treatment direction of the alignment film on the substrate side provided with the color filter is substantially parallel to the length direction of the overlapping portion of the edges of the adjacent color filters. desirable.

Even if the alignment treatment direction of the alignment film on the side of the substrate provided with the color filter is deviated obliquely with respect to the length direction of the overlapping portion of the edges of the adjacent color filters, the deviation angle is Should be 45 ° or less.

In this color liquid crystal display device,
The ratio t / d of the thickness t of the color filter of each color and the liquid crystal layer thickness d of the portion corresponding to the color filter of that color is 0.19.
The following is desirable.

The present invention also applies to a bottom electrode type color liquid crystal display element in which an electrode on the substrate side provided with a color filter is provided below the color filter, and a top electrode in which the electrode is provided above the color filter. Although it can be applied to a type of color liquid crystal display element, it is particularly advantageous to apply to a bottom electrode type.

[0032]

In the color liquid crystal display element of the present invention, the ratio t / d between the thickness t of the color filter of each color and the liquid crystal layer thickness d of the portion corresponding to the color filter of that color is 0.19 or less. Compared with the conventional liquid crystal display device in which the value of t / d is about 0.283 to 0.211, the thickness t of the color filter is small even if the liquid crystal layer thickness d is the same, and therefore the edge of the adjacent color filter is small. Since the height of the overlap between the parts is small, the height of the alignment film provided on the color filter is small.

When the bulging of the alignment film in the portion corresponding to the overlapping portion of the color filter is small as described above, when the alignment film is rubbed in a predetermined direction and subjected to the alignment treatment, the vicinity of the bulging portion is also sufficient. To be rubbed by.

Therefore, according to this color liquid crystal display element, even if the alignment film is provided on the color filter without overcoating and flattening the color filter, the alignment film is formed on the color filter. , It is possible to display a high quality color image by uniformly orienting the liquid crystal molecules in a good orientation state over the entire pixel portion including the vicinity of the bulge portion corresponding to the overlapping portion of the color filter. .

Further, in this color liquid crystal display element, the alignment film on the substrate side provided with the color filter is subjected to an alignment treatment in a direction substantially along the length direction of the overlapping portion of the edges of the adjacent color filters. Since the vicinity of the raised portion of the alignment film is more sufficiently rubbed, the alignment film is more uniformly aligned over the entire alignment film so that the liquid crystal molecules are aligned in a better alignment state over the entire pixel area. You can

Further, according to another color liquid crystal display element of the present invention, the alignment film on the substrate side provided with the color filters is aligned in a direction substantially along the length direction of the overlapping portion of the edge portions of the adjacent color filters. Since the treatment is performed, even if the portion of the alignment film corresponding to the overlapping portion of the color filter is swelled, when the alignment film is rubbed in a predetermined direction and subjected to the alignment treatment, the vicinity of the swell portion is also sufficiently rubbed. To be done.

Therefore, even in this color liquid crystal display element, even if the alignment film is provided on the color filter without overcoating and flattening the color filter, A high-quality color image can be displayed by uniformly aligning the liquid crystal molecules in the entire pixel portion including the vicinity of the raised portion corresponding to the overlapping portion of the color filters and aligning the liquid crystal molecules in a favorable alignment state.

In this case, if the alignment film on the substrate side provided with the color filters is subjected to the alignment treatment in a direction substantially parallel to the lengthwise direction of the overlapping portions of the edge portions of the adjacent color filters, the raised portion of the alignment film is formed. It is possible to rub near the area more sufficiently.

However, even if the alignment treatment direction of the alignment film is deviated obliquely with respect to the length direction of the overlapping portion of the color filter, if the deviation angle is 45 ° or less, the ridge portion of the alignment film is formed. It is possible to rub enough in the vicinity.

Further, in this color liquid crystal display device, the ratio t / d between the thickness t of the color filter of each color and the liquid crystal layer thickness d of the portion corresponding to the color filter of the color is 0.
If it is 19 or less, as described above, the swelling height of the overlapping portion between the edge portions of the adjacent color filters becomes small as compared with the conventional liquid crystal display element, and the swelling of the alignment film provided on the color filter also becomes small. Since the size becomes smaller, the alignment film can be more uniformly aligned over the entire surface, and the liquid crystal molecules can be aligned in a better alignment state over the entire pixel portion.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to. FIG. 1 is a sectional view of a part of the color liquid crystal display element of this embodiment, and FIG. 2 is a plan view of a part of the color filter forming substrate.

In FIGS. 1 and 2, those corresponding to the conventional color liquid crystal display elements shown in FIGS. 4 and 5 are designated by the same reference numerals, and the same elements as the conventional color liquid crystal display elements are designated by the same reference numerals. The description is omitted.

The color liquid crystal display element of this embodiment is an STN type liquid crystal display element of a simple matrix system, and is composed of color filters 5R of three colors, for example, three colors of red, green and blue.
5G and 5B are scanning electrodes 3 formed on the inner surface of the lower substrate 1.
Is provided above.

The color filters 5R, 5G and 5B are
For example, it is formed by repeating a method in which a photosensitive color resist to which a pigment of one color of red, green and blue is added is applied onto the substrate 1, and the resist film is exposed and developed to be patterned. The edge portions of the adjacent color filters 5R, 5G, 5B are vertically overlapped with a slight margin.

The color filters 5R, 5G,
5B has a width slightly wider than the width of the pixel portion D in which the scanning electrode 3 and the signal electrode 4 on the upper substrate 2 side face each other, and in each pixel column along the length direction of the signal electrode 4, respectively. It is formed in a corresponding stripe shape.

In this embodiment, each color (red, green,
Liquid crystal layer thickness d of the portion (excluding the overlapping portion between the edge portions of the adjacent color filters) corresponding to the thickness t of the blue) color filters 5R, 5G, 5B and the color filter of that color
The ratio t / d of the above is set to 0.19 or less.

That is, for example, the liquid crystal layer thickness d of the portion corresponding to the color filters 5R, 5G, and 5B of each color is d =
5.8 μm ± 0.35 μm, color filter 5 for each color
The thickness t of R, 5G, 5B is t = 0.9 μm ± 0.1 μ
m (preferably t = 0.9 μm ± 0.05 μm), and therefore, the color filters 5R, 5G, 5 for each color.
The ratio t / d between the thickness t of B and the liquid crystal layer thickness d of the portion corresponding to the color filter of that color is about 0.130 to 0.183.
(When t = 0.9 μm ± 0.05 μm, t / d = about 0.138 to 0.174).

Further, in this embodiment, as the liquid crystal (nematic liquid crystal) 8, the twist pitch (thickness of the liquid crystal layer necessary for twisting the liquid crystal molecule array by 360 °) P is P =
11.0 μm ± 0.2 μm is used, and therefore the liquid crystal layer thickness d (d = 5.8 μm) of this liquid crystal display element is used.
(m ± 0.35 μm) and the twist pitch P of the liquid crystal 8 are about 0.46 to 0.54.

Further, in this embodiment, the alignment film 6 on the lower substrate 1 side provided with the color filters 5R, 5G and 5B is arranged in the lengthwise direction of the overlapping portions of the edges of the adjacent color filters 5R, 5G and 5B. Alignment treatment (rubbing) is performed in a direction substantially along with the alignment treatment direction of the alignment film 6, and the alignment treatment direction of the alignment film 7 on the upper substrate 2 side is set according to the twist angle of the liquid crystal molecules. .

That is, in FIG. 2, A1 is the lower substrate 1
Side, the alignment treatment direction of the alignment film 6 and A2 indicate the alignment treatment direction of the alignment film 7 on the upper substrate 2 side. In this embodiment, the alignment film 6 on the lower substrate 1 side is changed to the color filters 5R, 5G ,. 5
The alignment treatment is performed in a direction substantially parallel to the lengthwise direction of the overlapping portion of B, and the alignment film 7 on the upper substrate 2 side is aligned with the alignment film 6 on the lower substrate 1 side.
The alignment treatment is performed in a direction deviated by a predetermined angle from the alignment treatment direction A1.

The alignment directions of the liquid crystal molecules of the liquid crystal layer in the vicinity of the substrates 1 and 2 are regulated by the alignment films 6 and 7, and a certain pretilt angle (about several degrees) with respect to the surfaces of the alignment films 6 and 7. The two substrates 1 and 2 are twist-aligned at a predetermined twist angle.

In this embodiment, the alignment films 6 and 7 described above are used.
The angle of deviation between the alignment treatment directions A1 and A2 is approximately 240 °, and the liquid crystal molecules are twist-aligned at a twist angle of approximately 240 °.

In the above color liquid crystal display element, the ratio t / d of the thickness t of the color filters 5R, 5G and 5B of each color to the liquid crystal layer thickness d of the portion corresponding to the color filter of that color is 0.
19 or less (in this embodiment, t / d = about 0.130-0.
183), the value of t / d is about 0.283 to
The thickness t of the color filters 5R, 5G, and 5B is smaller than that of the conventional liquid crystal display element of 0.211 even if the liquid crystal layer thickness d is the same.

That is, in the conventional color liquid crystal display element shown in FIGS. 4 and 5, the liquid crystal layer thickness d is d = 5.8 μm.
In the case of ± 0.35 μm, color filters 5R, 5G,
The thickness t of 5B is t = about 1.3 μm, but in the color liquid crystal display element of this embodiment, when the liquid crystal layer thickness d is the same as the conventional one (d = 5.8 μm ± 0.35 μm), The thickness t of the color filters 5R, 5G, 5B is t = 0.9 μm ±
It is 0.1 μm.

Therefore, according to the color liquid crystal display element of this embodiment, the adjacent color filters 5R, 5G and 5 are arranged.
Rising height of the overlapping portion between the edge portions of B (the thickness of the portion of the green filter 5G and the blue filter 5B that overlaps the side edges of the adjacent color filters 5R and 5G)
Since t'is t '= about 0.7 μm, which is smaller than that of the conventional liquid crystal display element (t' = about 1.0 μm), the protrusion of the alignment film provided on the color filters 5R, 5G, 5B is also increased. small.

Then, in this way, the color filter 5
If the protrusion of the alignment film 6 in the portion corresponding to the overlapping portion of R, 5G, and 5B is small, when the alignment film 6 is rubbed in a predetermined direction by a rubbing roller for alignment treatment, the vicinity of the protrusion is also sufficient. To be rubbed.

Therefore, according to this liquid crystal display element, the color filters 5R, 5G, 5B are not over-coated with the flattening agent to flatten the color filters 5R, 5G, 5B.
Although the alignment film 6 is provided on the R, 5G, and 5B, the alignment film 6 is provided on the color filters 5R, 5G, and 5B.
It is possible to display a high-quality color image by uniformly aligning the liquid crystal molecules in the entire pixel portion including the vicinity of the raised portion corresponding to the overlapping portion of the liquid crystal molecules.

Further, in this liquid crystal display element, since the rising height t'of the overlapping portion between the edge portions of the adjacent color filters 5R, 5G and 5B is small, the portions corresponding to the color filters 5R, 5G and 5B of the respective colors. Liquid crystal layer thickness d (excluding the overlapping portion) and color filters 5R, 5G, 5B
The difference from the liquid crystal layer thickness d'of the corresponding overlapping portion is small.

That is, in the conventional liquid crystal display element shown in FIGS. 4 and 5, the swelling height t'of the overlapping portions of the color filters 5R, 5G and 5B is about 1.0 μm, and therefore the liquid crystal layer thickness is the same. The difference between d and d'is d-
d '= about 1.0 .mu.m, which is large, but in the liquid crystal display element of the above-mentioned embodiment, since the rising height t'of the overlapping portion of the color filters 5R, 5G, 5B is about 0.7 .mu.m, the liquid crystal layer thickness d The difference between d and d'is as small as d-d '= about 0.7 μm.

Therefore, the liquid crystal display element of the above-mentioned embodiment is
The ratio d / P between the liquid crystal layer thickness d and the twist pitch P of the liquid crystal 8 in the portion (excluding the overlapping portion) corresponding to the color filters 5R, 5G, and 5B of each color, and the color filter 5R,
The difference between the ratio d ′ / P of the liquid crystal layer thickness d ′ and the twist pitch P of the liquid crystal 8 in the corresponding portion of the overlapping portions of 5G and 5B is small, and therefore the color filters 5R, 5G and 5B
Even in the portion corresponding to the overlapping portion of, the liquid crystal molecules can be twist-aligned in a good state that is almost the same as the other portions, and the alignment state of the liquid crystal molecules can be made substantially uniform over the entire display region.

Further, in the liquid crystal display element of the above embodiment, the substrate 1 provided with the color filters 5R, 5G and 5B is provided.
The alignment film 6 on the side of the adjacent color filters 5R, 5G,
Since the alignment treatment is performed in the direction substantially along the length direction of the overlapping portion of the edge portions of 5B, the alignment film 6 can be rubbed in the vicinity of the raised portion in the same manner as the flat portion. The film 6 can be aligned almost uniformly over the entire surface, and the liquid crystal molecules can be aligned in a better alignment state over the entire pixel portion.

In the above liquid crystal display element, it is not necessary to overcoat the color filters 5R, 5G and 5B with a flattening agent, so that the color filters 5R, 5G and 5B are not flattened.
It is a bottom electrode type in which the electrode 3 on the substrate 1 side provided with 5G and 5B is provided below the color filters 5R, 5G and 5B, but it is applied between the electrodes 3 and 4 of both substrates 1 and 2. The voltage drop only occurs in the color filters 5R, 5G, 5B and the alignment films 6 and 7. Therefore, the voltage applied to the liquid crystal layer does not drop significantly and the display characteristics are not deteriorated. Since it is not necessary to form the overcoat film, the manufacturing cost of the liquid crystal display element can be reduced.

In the above embodiment, the color filter 5
The orientation film 6 on the substrate 1 side provided with R, 5G, 5B is subjected to orientation treatment in a direction substantially parallel to the length direction of the overlapping portion of the color filters 5R, 5G, 5B. The processing direction A1 corresponds to the color filters 5R, 5G, 5B.
If the direction is substantially along the length direction of the overlapping portion, the direction may be obliquely displaced with respect to the length direction of the overlapping portion, and the displacement angle is 45 ° or less (desirably 30 ° or less. In the case of (1), the vicinity of the raised portion of the alignment film 6 can be sufficiently rubbed.

FIG. 3 is a plan view of a part of a color filter forming substrate showing another embodiment of the present invention. In this embodiment, a lower substrate 1 provided with color filters 5R, 5G, 5B is shown.
The alignment film 6 on the side of the adjacent color filters 5R, 5G,
45 ° with respect to the length direction L of the overlapping portion of the edges of 5B
Alignment processing is performed in a direction that is obliquely displaced with the following displacement angle ψ, and the alignment processing direction A2 of the alignment film 7 on the upper substrate 2 side is set with reference to the alignment processing direction A1 of the alignment film 6.

In this embodiment also, the alignment films 6 and 7 described above are used.
The angle of deviation between the alignment treatment directions A1 and A2 is approximately 240 °, and the liquid crystal molecules are twist-aligned at a twist angle of approximately 240 °.

In the above embodiment, the ratio t / d between the thickness t of the color filters 5R, 5G and 5B of each color and the liquid crystal layer thickness d of the portion corresponding to the color filter of that color is 0.19.
The alignment film 6 on the side of the substrate 1 on which the color filters 5R, 5G, and 5B are provided is defined as follows.
Although the alignment treatment is performed in a direction substantially along the length direction of the overlapping portion of the edges of R, 5G, and 5B, if the value of t / d is 0.19 or less, the alignment of the alignment film 6 The treatment may be arbitrary.

That is, if the value of t / d is 0.19 or less, as described above, the color filters 5R, 5
Since the ridge of the alignment film 6 in the portion corresponding to the overlapping portion of G and 5B can be sufficiently rubbed in the vicinity of this ridge portion, the alignment film 6 is formed in the overlapping portion of the color filters 5R, 5G and 5B, for example. Even when the alignment treatment is performed in the direction of an angle larger than 45 ° with respect to the length direction, the rubbing failure hardly occurs in the vicinity of the raised portion.

However, rubbing in the vicinity of the raised portion of the alignment film 6 can be performed better as the deviation angle between the alignment processing direction A1 and the lengthwise direction of the overlapping portion of the color filters 5R, 5G and 5B becomes smaller. Even when the value of t / d is 0.19 or less, it is preferable that the alignment film 6 be subjected to the alignment treatment in a direction substantially along the length direction of the overlapping portions of the color filters 5R, 5G, and 5B.

On the other hand, the alignment film 6 is replaced by the color filter 5
When the alignment treatment is performed in a direction substantially along the length direction of the overlapping portion of R, 5G, 5B, even if the value of t / d is larger than 0.19, that is, the overlapping portion of the color filters 5R, 5G, 5B. Even if the alignment film 6 has a large swell in the portion corresponding to, the rubbing failure hardly occurs in the vicinity of the swell.

However, if the protrusion of the alignment film 6 is small, the vicinity of the protrusion can be rubbed better, so that the alignment film 6 is colored by the color filters 5R, 5G, 5 and 5.
Even when the alignment treatment is performed in a direction substantially along the length direction of the overlapping portion of B, it is desirable that the value of t / d is 0.19 or less.

The color liquid crystal display element is an STN type in which liquid crystal molecules are twist-aligned at a twist angle of 180 ° to 270 ° (240 ° in the above embodiment). It is not limited to
The present invention can be applied to a TN type color liquid crystal display element in which a twist orientation is made at a twist angle of 0 °, and is not limited to a simple matrix method, but an active matrix method using a two-terminal nonlinear element such as a thin film transistor or MIM as an active element. It can also be applied to color liquid crystal display devices.

Further, the color liquid crystal display device of the above embodiment is of a bottom electrode type in which the electrode 3 on the substrate 1 side provided with the color filters 5R, 5G and 5B is provided below the color filters 5R, 5G and 5B. However, this invention is
It can also be applied to a top electrode type color liquid crystal display element in which an electrode is provided on the color filter. Even in that case, it is not necessary to overcoat the color filter with a flattening agent. Manufacturing cost can be reduced.

[0073]

In the color liquid crystal display device of the present invention, the ratio t / d between the thickness t of the color filter of each color and the liquid crystal layer thickness d of the portion corresponding to the color filter of that color is set to 0.19 or less. Since the ridge height of the overlapping portion between the edges of the adjacent color filters is small, the alignment film can be applied to the overlapping portion of the color filter without overcoating and flattening the color filter. It is possible to display a high-quality color image by uniformly aligning the liquid crystal molecules in the entire pixel portion including the vicinity of the swelling portion and aligning the liquid crystal molecules in a good alignment state.

Further, in this color liquid crystal display device, the alignment film on the substrate side provided with the color filter is subjected to an alignment treatment in a direction substantially along the length direction of the overlapping portion of the edge portions of the adjacent color filters. The alignment film can be further uniformly aligned over the entire alignment film to align the liquid crystal molecules in a better alignment state over the entire pixel portion.

Further, in another color liquid crystal display element of the present invention, the orientation film on the substrate side provided with the color filters is oriented in a direction substantially along the length direction of the overlapping portion of the edges of the adjacent color filters. Since the liquid crystal molecules are processed, the alignment film is uniformly aligned even in the vicinity of the bulge corresponding to the overlapping portion of the color filter without overcoating and flattening the color filter. Can be oriented in a good orientation over the entire pixel portion, and a high quality color image can be displayed.

In the present invention, if the alignment film on the substrate side provided with the color filters is subjected to the alignment treatment in a direction substantially parallel to the length direction of the overlapping portion of the edges of the adjacent color filters, the alignment film is swelled. It is possible to rub the vicinity of the part more sufficiently.

However, even if the alignment treatment direction of the alignment film is deviated obliquely with respect to the length direction of the overlapping portion of the color filter, if the deviation angle is 45 ° or less, the ridge portion of the alignment film is It is possible to rub enough in the vicinity. Further, in this color liquid crystal display element, if the ratio t / d between the thickness t of the color filter of each color and the liquid crystal layer thickness d of the portion corresponding to the color filter of that color is 0.19 or less, as described above. In addition, since the swell height of the overlapping portion between the edges of the adjacent color filters is small, the alignment film provided on the color filters is more uniformly aligned over the entire area, and liquid crystal molecules are distributed over the entire pixel area. Can be oriented in a better orientation state.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a color liquid crystal display element showing an embodiment of the present invention.

FIG. 2 is a plan view of a part of a color filter forming substrate of the color liquid crystal display device.

FIG. 3 is a plan view of a part of a color filter forming substrate showing another embodiment of the present invention.

FIG. 4 is a partial sectional view of a conventional color liquid crystal display device.

FIG. 5 is a plan view of a part of a color filter forming substrate of a conventional color liquid crystal display device.

[Explanation of symbols]

 1, 2 ... Substrate 3 ... Scanning electrode 4 ... Signal electrode 5R, 5G, 5B ... Color filter 6, 7 ... Alignment film 8 ... Liquid crystal D ... Pixel part A1, A2 ... Alignment treatment direction

Claims (8)

[Claims] 1. An electrode and an alignment film are respectively provided on a pair of substrates facing each other across a liquid crystal layer, and liquid crystal molecules of the liquid crystal layer are twist-aligned between the pair of substrates, and either one of them is provided. Color filters of a plurality of colors are alternately arranged on the inner surface of the substrate, and the ratio of the thickness t of the color filters of the respective colors to the liquid crystal layer thickness d of the portion corresponding to the color filters of the colors is t / A color liquid crystal display device, wherein d is 0.19 or less. 2. The substrate-side alignment film provided with a color filter is subjected to an alignment treatment in a direction substantially along a length direction of an overlapping portion of edges of adjacent color filters. 1. The color liquid crystal display element according to 1. 3. The color liquid crystal display element according to claim 1, wherein the electrode on the substrate side provided with the color filter is provided under the color filter. 4. An electrode and an alignment film are provided on a pair of substrates facing each other across a liquid crystal layer, and the molecules of the liquid crystal are twist-aligned between the pair of substrates, and one of the substrates is provided. The color filters of a plurality of colors are alternately arranged on the inner surface of the, and the alignment film on the substrate side provided with the color filter is substantially in the longitudinal direction of the overlapping portion of the edges of the adjacent color filters. A color liquid crystal display device characterized by being subjected to an alignment treatment in a direction along the line. 5. The alignment treatment direction of an alignment film on a substrate side provided with a color filter is substantially parallel to a length direction of an overlapping portion of edges of adjacent color filters. The described color liquid crystal display device. 6. An alignment treatment direction of an alignment film on a substrate side provided with a color filter is obliquely displaced with respect to a length direction of an overlapping portion of edges of adjacent color filters, and the displacement angle is 45. 5. The color liquid crystal display device according to claim 4, wherein the color liquid crystal display device is at most °. 7. A ratio t / the thickness t of the color filter of each color and the liquid crystal layer thickness d of the portion corresponding to the color filter of the color.
d is 0.19 or less, The color liquid crystal display element as described in any one of Claims 4-6. 8. The color liquid crystal display device according to claim 4, wherein the electrode on the substrate side provided with the color filter is provided below the color filter.