JP2002214619A - Liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display which can use spherical spacers to facilitate the working process steps as spacing holding means between a pair of substrates while having an excellent visual angle characteristic by forming the surface of liquid crystal boundaries in a curved surface shape. SOLUTION: The array substrate 1 and the color filter substrate 8 are maintained at a prescribed spacing by interposing the spherical spacers 7 between both substrates 1 and 8. The color filters 10 of the color filter substrate 8 are so formed that the entire part of the surface within one pixel has a projecting shape for every pixel. The spherical spacers 7 are portioned into recessed 14 segments between the color filters 10 of the mutually adjacent pixels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device having a wide viewing angle.

[0002]

2. Description of the Related Art As a liquid crystal display device, a TN mode has been put to practical use, but the TN mode has a problem that a viewing angle is narrow. Therefore, those having excellent viewing angle characteristics, such as the ECB method and the VA method, have been studied. Further, a method has been proposed in which one pixel is aligned and divided so that the viewing angle characteristics are mutually compensated by liquid crystal molecules in each region. For example, a method in which a projection or a slit is formed on a pixel electrode or a counter electrode to perform alignment division is disclosed in Japanese Patent No. 2978.
No. 47350, and Japanese Patent No. 3005418. However, in the case of forming projections and slits, the aperture ratio is reduced by that part, so fine processing is required as much as possible, but a certain width is required to keep the production yield low, and the aperture ratio decreases. Resulting in. For example, Japanese Patent Application Laid-Open No. 2000-75275 discloses a structure in which a projection or a slit is not formed partially but the entire insulating film on a pixel electrode is curved for each pixel. This embodiment will be described with reference to FIG.
FIG. 8 is a cross-sectional view showing one pixel of this conventional liquid crystal display device. FIG. 8A shows a form in which the surface on the array substrate 102 side is concave, and FIG. This is a convex shape.

In FIG. 8A, a gate electrode and a gate wiring are formed on a transparent array substrate 102 such as glass, and a gate insulating film is formed thereon. A semiconductor layer made of amorphous silicon is formed over the gate electrode, and then a drain electrode, a source electrode, and a drain wiring are formed. Next, a pixel electrode 103 made of a transparent conductive film such as ITO is formed so as to be connected to the source electrode, and a concave shape is formed thereover by a transparent insulating film 104. This is done by using a thermoplastic material such as acrylic or polyimide for the insulating film 104, forming a relatively thick portion by a photoresist process, and then using thermoplasticity to remove the inclined surface and bottom of the concave portion. Form. An alignment film 105 having vertical alignment is formed on the insulating film 104, and a columnar spacer 112 made of an insulating film is formed substantially at the center of the concave portion. Array substrate 1
A CF substrate 110 (color filter substrate) is arranged on the side opposite to the surface 02. In this method, a color filter 109, a counter electrode 108 made of ITO, and an alignment film 107 having vertical alignment are sequentially stacked on a transparent CF substrate 110 made of glass or the like. A liquid crystal 106 having a negative dielectric anisotropy is sealed between the substrates 102 and 110. When no voltage is applied, the liquid crystal molecules 106 are vertically arranged. When a voltage is applied, the liquid crystal molecules 106 are arranged along the concave shape of the insulating film 104. Arrange in an inclined manner in a plurality of directions. Orthogonal Nicol polarizing plates 101 and 111 are attached to the outside of the substrates 102 and 110, and a normally black mode in which black display is performed when no voltage is applied is provided. FIG. 8B shows a configuration in which the insulating film 104 in the upper layer of the pixel electrode 103 is formed in a convex shape, and the other configuration is the same as that in FIG.

Japanese Patent Application Laid-Open No. 9-258208 discloses that
A structure in which the surface on the CF substrate 131 side is a curved surface is disclosed. FIG. 9 is a cross-sectional view of this conventional liquid crystal display device. FIG. 9A shows a form in which the surface on the CF substrate 131 side is concave, and FIG. 9B shows a form in which the surface on the CF substrate 131 side is convex. It is a form.

In FIG. 9A, an array substrate 121 and a CF
A substrate 131 (color filter substrate) is disposed to face, and a liquid crystal 125 is sealed between the pair of substrates 121 and 131. A polymer wall 124 is formed on a transparent array substrate 121 such as glass so as to surround each pixel region, and a pixel electrode 122 is arranged in each pixel. Pixel electrode 12
An alignment film 123 having a vertical alignment property is formed on the upper layer 2. A projection 130 is formed on the CF substrate 131 at a portion facing the polymer wall 124 to make the color filter 129 of each pixel region concave. This projection 130
Has a lower layer 130a having a high affinity for the material forming the color filter 129 and an upper layer 130b having a low affinity for the material forming the color filter 129, and the lower layer 130a and the upper layer 130b are sequentially arranged at predetermined positions. It is formed by a lithography method. Ink is deposited between the projections 130 by a bubble jet (registered trademark) method or an ink-jet method to form a color filter 129.
Since the material of 30a has a high affinity for the ink, the lower layer 130a
The ink adheres to the side surface of a, and the surface of the ink becomes concave due to the meniscus. After drying the ink to form the color filter 129, the overcoat layer 128, the IT
A counter electrode 127 and a vertical alignment film 126 made of a transparent conductive material such as O are sequentially formed. Since a liquid crystal 125 having a negative dielectric anisotropy is used, when no voltage is applied, the liquid crystal molecules 1
25 are arranged vertically, and when a voltage is applied, the liquid crystal molecules 125
The substrate 131 is inclined and arranged in a plurality of directions along a concave shape on the surface of the substrate 131. Orthogonal Nicol polarizing plates 120 and 132 are attached to the outside of the substrates 121 and 131, and a normally black mode in which black display is performed when no voltage is applied is provided.

FIG. 9B shows a color filter 129 formed in a convex shape. In the case of FIG.
The materials of the lower layer 133a and the upper layer 133b that form are opposite to those in the case of FIG. That is, the protrusion 133 has
A lower layer 133a having a low affinity for the material forming the color filter 129 and an upper layer 133b having a high affinity for the material forming the color filter 129 are used. At this time, if the ink is arranged between the protrusions 133 by the inkjet method, the lower layer 133a repels the ink, so that the surface of the color filter 129 becomes convex due to the meniscus.

[0007]

However, in the above liquid crystal display device, a spherical spacer is scattered so that
It is not suitable for a method of maintaining a predetermined distance from the F substrate, and it is necessary to form a columnar spacer or a polymer wall corresponding to each pixel. For example, when a spherical spacer is used in the above-described conventional example, the distance between the pair of substrates is not constant, so that the distance between the substrates may not be constant depending on the state of dispersion of the spherical spacer. In addition, when the spherical spacer is interposed at the portion where the distance between the substrates is narrowest, the spherical spacer existing at the portion where the distance is wide floats in the liquid crystal, and does not play a role as a spacer. Further, when the spherical spacer exists in the pixel region, the alignment state of the liquid crystal is adversely affected. Therefore, instead of spherical spacers, columnar spacers or polymer walls are formed, but this manufacturing process is more complicated than the process of dispersing spherical spacers, and precision is required for the height and arrangement of the columnar spacers. Was not good in terms of yield.

Accordingly, an object of the present invention is to provide a liquid crystal display device having a wide viewing angle in which a spherical spacer can be used as a means for maintaining a distance between a pair of substrates.

[0009]

According to the present invention, there is provided a liquid crystal display device comprising: a first substrate on which a pixel electrode is formed for each pixel; and a counter electrode for generating an electric field between the pixel electrode and the first substrate. A second substrate, a spherical spacer interposed between the first substrate and the second substrate to maintain the two substrates at a predetermined distance, and sealed between the two substrates and according to an electric field between the two electrodes. In a liquid crystal display device having a liquid crystal whose arrangement state changes, a color filter in which the entire surface of one pixel is formed in a convex shape is provided for each pixel on the second substrate, and a color filter between adjacent pixels is provided. Is characterized in that the spherical spacer is located in the recess.

In addition, a first substrate on which a pixel electrode is formed for each pixel, a second substrate on which a counter electrode for generating an electric field between the pixel electrode is formed, and a first substrate and a second substrate A liquid crystal display device comprising: a spherical spacer interposed between the two substrates to maintain a predetermined distance between the two substrates; and a liquid crystal sealed between the two substrates and having a liquid crystal whose alignment state changes according to an electric field between the two electrodes. The two substrates are provided with a color filter formed in accordance with each pixel, and an insulating film laminated on the color filter and having an entire surface in one pixel formed in a convex shape, and the insulating film of an adjacent pixel is provided. And a spherical spacer is located in a recess between the two.

Therefore, the spherical spacer can be held between the pixels, and the inclination direction of the liquid crystal is restricted by the convex shape of the color filter and the insulating film, but the spherical spacer is easy to assemble as the means for maintaining the distance between the substrates. Can be used.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of the liquid crystal display device according to the first embodiment.

Reference numeral 1 denotes a transparent array substrate corresponding to a first substrate, in which a plurality of scanning lines and a plurality of signal lines 2 are arranged in a matrix, and a switching element is provided at an intersection of the scanning lines and the signal lines 2. A pixel electrode 4 is formed in one pixel in which a TFT (thin film transistor) is surrounded by a scanning line and a signal line 2. The TFT has a gate electrode connected to the scanning line, a source electrode connected to the signal line 2, and a drain electrode connected to the pixel electrode 4. The pixel electrode 4 is a signal line 2 or a TFT
The drain electrode of the TFT and the pixel electrode 4 are connected via a contact hole formed in the insulating film 3. Insulating film 3 and pixel electrode 4
An alignment film 5 having a vertical alignment property is laminated thereon. Numeral 8 denotes a transparent CF substrate (color filter substrate) corresponding to the second substrate, in which a lattice-shaped black matrix 9 is formed so as to surround each pixel, and one pixel as a whole corresponds to each pixel. A filter 10 is formed. A counter electrode 11, which is a transparent conductive material such as ITO, is formed on the color filter 10, and an alignment film 12 having a vertical alignment property is laminated thereon. A spherical spacer 7 is interposed between the two substrates 1 and 8, and the periphery of the display area is fixed with a sealing material to hold the two substrates 1 and 8 at a predetermined interval. A liquid crystal 6 having a negative dielectric anisotropy is sealed between the two substrates 1 and 8,
When no voltage is applied, the liquid crystal molecules 6 are vertically aligned by the action of the alignment films 5 and 12. When a voltage is applied, the liquid crystal molecules 6 are inclined in a plurality of directions within one pixel along the surface shape of the color filter 10. When the orthogonal Nicol polarizing plates 13a and 13b are attached to the outside of the substrates 1 and 8, a normally black mode in which black is displayed when no voltage is applied is provided.

In the first embodiment, the color filter 10 is made convex for each pixel, and the inclination direction of the liquid crystal molecules 6 is regulated by the shape. At this time, the color filter 10 is formed not by the ink jet method as shown in FIG. 9 but by photolithography, and the projections 130 and 1 shown in FIG.
33 does not exist. Therefore, a depression 14 is formed between the color filters 10, and the spherical spacer 7 is
Held in between. The manufacturing process of the color filter 10 will be described with reference to FIG. As a material of the color filter 10, a negative type color resist 15 is used. For example, the color resist 15 is obtained by dispersing a pigment in an acrylic / epoxy UV curable resin or the like and dissolving it in a solvent.

First, a color resist 15 is applied to the CF substrate 8 (FIG. 2A), and then the color resist 15 is irradiated with ultraviolet rays through a mask 16 (FIG. 2B). At this time, the portions of the color resist 15 irradiated with the ultraviolet rays are cured to become the color filters 10 corresponding to the respective pixels. However, patterns having different transmittances are applied to the pattern portions of the mask 16 that transmits the ultraviolet rays. For example, in order to make the surface of the color filter 10 convex, the pattern portion of the mask 16 has a transmittance of 100%, 80%, 60% from the central portion to the peripheral portion of the color filter 10.
% Are sequentially provided in three stages. When the developing process is performed after the exposure, a step-shaped color filter 10 is formed from the central portion to the peripheral portion [FIG. 2 (c)]. Thereafter, when heat treatment is performed, each step is rounded, and the entire surface of the color filter 10 becomes a smooth convex shape [FIG.
(D)]. 3A and 3B are diagrams showing the arrangement relationship between the color filter 10 and the pixel electrode 4. FIG. 3A shows the shape of the color filter 10 before the heat treatment, and FIG. 3B shows the shape of the color filter 10 after the heat treatment. Is shown. In FIG. 3, in order to make the arrangement of the pixel electrode 4 and the color filter 10 easy to understand, the pixel electrode 4 is simplified to a substantially rectangular shape, and the scanning lines and the signal lines 2 are omitted. Dotted lines in the color filter 10 indicate boundaries between regions where the transmittance of the mask during the exposure processing is different. The color filter 10 after the development processing is formed in an octagon in which the peripheral portion is located outside the pixel electrode 4 and the four corners of the rectangle are cut out, and after the heat treatment, the corners of the color filter 10 are rounded. It becomes slightly elliptical. By making the shape of the color filter 10 before the heat treatment octagonal and increasing the number of corners, the curved surface portion of the surface of the color filter 10 after the heat treatment can be increased. The color filter 10 is not particularly limited to an octagon as long as it is larger than the pixel electrode 4 as shown in FIG. 3, and may be formed into an ellipse before the heat treatment, for example.

A color filter of, for example, an R layer is formed by the process shown in FIG. 2. Thereafter, the same process is repeated for the G and B layers, and the color filter 1 corresponding to each pixel is formed.
0 is formed. Since the counter electrode 11 and the alignment film 12 having a substantially uniform thickness are laminated on the color filter 10, the surface shape of the color filter 10 becomes substantially the shape of the interface of the alignment film 12, and the tilt direction of the liquid crystal 6 can be regulated. it can. Since the color filter 10 has a convex shape in which the central portion of each pixel protrudes, a depression 14 is formed between adjacent pixels, and most of the spherical spacers 7 are dispersed by dispersing the spherical spacers 7 on the CF substrate 8 side. It is located in the recess 14 between them. Further, the spherical spacers 7 located in the pixels when being scattered are pressed by the array substrate 1 when the array substrate 1 is arranged to face the CF substrate 8, so that the spherical spacers 7 roll over the convex color filters 10 and To the depression 14 of FIG. Further, since the distance between the substrates 1 and 8 is gradually narrowed from the depression 14 to the center of the color filter 8, the spherical spacer 7 is held between the pixels by bonding the CF substrate 8 and the array substrate 1. This can prevent the spherical spacer 7 from adversely affecting the liquid crystal alignment. It is not necessary that all of the spherical spacers 7 be held in the recesses 14 between the pixels.
What is necessary is just to hold in four parts. Since the spherical spacers 7 are deformed when pressed, the spherical spacers 7 located in the pixels at the time of spraying may be deformed and held in the pixels when pressed by the array substrate 1.

Although the case where the color filter 10 is formed by the color resist method has been described above, it can be formed by the etching method. This will be described with reference to FIG. First, a colored resin 17 in which the R pigment is dispersed in a resin such as polyimide is applied to the CF substrate 8 (FIG. 4A).
A positive resist 18 is applied on the coloring resin 17. An exposure process is performed on the positive resist 18 through a mask having a predetermined pattern, and a portion of the positive resist 18 corresponding to the color filter 10 of the R layer is left by a developing process [FIG.
(B)]. Then, the first etching is performed to remove the colored resin 17 not covered with the positive resist 18 [FIG.
(C)] is the colored resin 1 left on the CF substrate 8 at this time.
8 has a size substantially equal to that of the finally formed color filter 10. Next, the positive resist 18 remaining on the colored resin 17 is subjected to exposure processing and development processing,
7 is partially removed [FIG. 4 (d)]. Then, the second etching process removes the colored resin 17 in the portion without the positive resist 18 (FIG. 4E). At this time, all the colored resin 17 in the portion without the positive resist 18 is removed. Instead, for example, about 20% in the thickness direction is removed. After that, mask exposure again,
A developing process is performed to remove a part of the outer peripheral portion of the positive resist 18 remaining on the colored resin 17 (FIG. 4F). Thereafter, a third etching process is performed [FIG. 4 (g)].
The portion of the colored resin 17 where the positive resist 18 does not exist is removed. Also in this case, as in the second etching, a part of the colored resin 17 is removed. For example, the portion subjected to the second etching has a thickness of about 60%, and the portion subjected to the third etching has a thickness of about 80%. Respectively, and the remaining colored resin 17 becomes thinner stepwise from the central portion to the peripheral portion. The positive resist 18 is peeled off with an organic solvent [FIG. 4 (h)], and a color filter before heat treatment is formed. The same processing is repeated for the G layer and the B layer to form the colored resin 17 of each color layer at a predetermined position, and thereafter, heat treatment is performed [FIG. 4 (i)]. Colored resin 17 by heat treatment
Are rounded, and a convex color filter 10 is formed for each pixel.

The first embodiment is more excellent than the conventional example shown in FIG. In the conventional example of FIG.
In order to form a concave or convex shape by the insulating film 104,
The thickness of the insulating film 104 varies depending on the location of the pixel electrode 103, and the electric field intensity between the pixel electrode 103 and the counter electrode 108 is not uniform. However, in the first embodiment, the pixel electrode 4
Since there is no need to provide an insulating film having a different thickness on the upper side, the intensity of the electric field between the pixel electrode 4 and the counter electrode 11 can be kept substantially uniform. In addition, as an example of the conventional example in FIG. 8, a pixel electrode is formed on a concave or convex insulating film 104. In this case, the insulating film 103 between the drain electrode of the TFT and the pixel electrode is formed. Since the thickness is increased, the drain electrode and the pixel electrode 4 can be more reliably connected in the first embodiment.

Next, a second embodiment will be described with reference to FIG. In the second embodiment, the surface of the color filter 19 is made substantially flat, and a convex insulating film 20 is formed thereon. The other portions are the same as in the first embodiment, and the same portions are denoted by the same reference numerals as in the first embodiment, and description thereof is omitted.

Any one of RGB color filters 19 is formed on the CF substrate 8 in accordance with each pixel, and the surface of the color filter 19 is substantially flat in each pixel. Then, a transparent insulating film 20 is laminated on the color filter 19, and the surface thereof is formed in a convex shape in which the central portion of one pixel projects like the color filter 10 of the first embodiment.
This insulating film 20 can also be formed by a photolithography method as shown in FIGS. For example, as the insulating film 20, a transparent resin having photosensitivity (Optomer PC)
300, 400 series (positive), NN500, 600
When a series (negative: manufactured by JSR Corporation) is used, the convex insulating film 20 can be formed in the same process as in FIG. In other words, after a photosensitive transparent resin is applied to the CF substrate 8, an exposure process is performed through a mask having a pattern having a partially different transmittance in order to form a convex shape. It is formed. In the second embodiment, the insulating film 20 is made convex by a process similar to that of FIG. 2, but in the first embodiment, the process of FIG. 2 is repeated for each of RGB colors in order to form the color filter 10 in a convex shape. On the other hand, in the second embodiment, since the insulating film 20 is formed in a convex shape, the insulating film 20 can be formed simultaneously for all the pixels, and the mask pattern and the number of steps are slightly different from those in the first embodiment. different. Further, the pattern of the mask is different when the positive type and the negative type are used as the photosensitive transparent resin, but the insulating film 20 is formed in a convex shape with one mask by using a mask having a pattern partially different in transmittance. It becomes possible.

Next, when a non-photosensitive transparent resin is used as the insulating film 20, the convex insulating film 2 is formed in the same process as in FIG.
0 can be formed. In other words, after applying a non-photosensitive transparent resin to the CF substrate 8, a resist is applied on the transparent resin, mask exposure processing and development processing are performed to leave the resist corresponding to the convex portion, and unnecessary transparent resin is removed by etching. Remove. Thereafter, mask exposure processing, development processing, and etching are repeated on the remaining resist several times to form a transparent resin that becomes thinner stepwise from the central portion to the peripheral portion of the pixel. Then, the corner portions of the transparent resin are rounded by the heat treatment, and the convex insulating film 20 having a smooth surface is formed.

In the second embodiment, as in the first embodiment, the surface of the CF substrate 8 is convex corresponding to the pixel, so that the inclination direction of the liquid crystal molecules 6 can be restricted and the spherical spacers 7 can be formed.
Can be held in the recess 14 between the pixels. Furthermore, according to the second embodiment, since the thickness of the color filter 19 in one pixel can be made uniform, it is also possible to reduce density unevenness in the pixel due to the variation in the thickness of the color filter.

Next, a third embodiment will be described with reference to FIG. In the third embodiment, a transparent insulating film 21 is formed on the array substrate 1, the surface of one pixel is formed in a concave shape by the insulating film 21, and the distance between the array substrate 1 and the CF substrate 8 is almost entirely reduced. It is constant. The other portions are the same as in the first embodiment, and the same portions are denoted by the same reference numerals as in the first embodiment, and description thereof is omitted.

By using the same material as the insulating film 20 of the second embodiment as the material of the insulating film 21 and performing the same steps as in FIG. 2 or FIG. 3, the surface of the insulating film 20 can be made concave. At this time, the pattern of the mask at the time of mask exposure differs depending on whether the material of the color filter 10 or the insulating film 21 is a positive type or a negative type. The color filter 6 of this embodiment is formed in a convex shape with a central portion protruding for each pixel similarly to the color filter 6 of the first embodiment, and the surface of the insulating film 21 of the array substrate 1 is formed in a convex shape of the color filter 10. Are formed in a concave shape so that the interval becomes substantially uniform. Then, by dispersing the spherical spacers 7 on the CF substrate 8 and then bonding the CF substrate 8 and the array substrate 1, most of the spherical spacers 7 can be located in the depressions 14 between adjacent pixels. The array substrate 1 and CF
Since the distance between the substrates 8 is substantially uniform, the spherical spacer 7 serves to maintain the distance between the substrates 1 and 8 even when the spherical spacer 7 exists in the pixel, and acts as the spherical spacer 7. In addition, by making the insulating film 21 concave, the inclination direction of the liquid crystal 6 can be restricted by the surface shapes of both the color filter 10 and the insulating film 21, and excellent viewing angle characteristics can be obtained. In this embodiment, the concave insulating film 21 is provided on the pixel electrode 4.
The pixel electrode 4 may be arranged on the concave insulating film 21, and in this case, the electric field between the pixel electrode 4 and the counter electrode 11 can be made substantially uniform.

Next, a fourth embodiment will be described with reference to FIG. In the fourth embodiment, the surface of the color filter 19 is made substantially flat, and a convex insulating film 20 which is formed over the entire pixel and whose central portion protrudes over the color filter 19 is disposed thereon. Further, a transparent insulating film 21 is formed on the array substrate 1, the surface of one pixel is formed in a concave shape by the insulating film 21, and the distance between the array substrate 1 and the CF substrate 8 is substantially uniform as a whole. . The CF substrate 8 of this embodiment has the same configuration as the CF substrate 8 of the second embodiment, and the array substrate 1 has the same configuration as the array substrate 1 of the third embodiment. By using the same material as the insulating film 20 of the second embodiment as the material of the insulating films 20 and 21 of the fourth embodiment, and performing the same process as in FIG. 2 or FIG. It can be convex or concave.

In this embodiment, as in the above-described embodiment, the spherical spacers 7 are scattered on the CF
By bonding the substrate and the array substrate 1, most of the spherical spacers 7 can be located in the recesses 14 between adjacent pixels. Further, since the thickness of the color filter 19 in one pixel can be made uniform, the density unevenness in the pixel due to the variation in the thickness of the color filter can be reduced. In addition, since the distance between the array substrate 1 and the CF substrate 8 is made substantially uniform, even when the spherical spacer 7 is present in the pixel, it serves to maintain the distance between the substrates 1 and 8 and acts as the spherical spacer 7. I do. In addition, by making the insulating film 21 concave, the inclination direction of the liquid crystal 6 can be restricted by the surface shapes of both the color filter 10 and the insulating film 21, and excellent viewing angle characteristics can be obtained.

It should be noted that embodiments other than the above-described embodiment are possible without departing from the gist of the present invention. For example, the convex shape may be set aside from the central portion of one pixel, and the convex shape may be formed asymmetrically. In this embodiment, the insulating film for protecting the signal lines and the like and the concave insulating film are separately provided. However, the concave portions may be formed by the insulating films for protecting the signal lines and the like.

[0028]

According to the present invention, the color filter or the insulating film of the second substrate is formed so that the entire surface in one pixel is convex for each pixel, so that a depression can be formed between adjacent pixels, and the spherical spacer can be used as a spacer. Positioned in the depression, the influence of the spherical spacer on the alignment state of the liquid crystal can be reduced. Therefore, although the surface shape at the interface with the liquid crystal layer is curved to restrict the tilt direction of the liquid crystal molecules and obtain an excellent viewing angle characteristic, the spherical shape of the work process is easy and the yield is good as a means for maintaining the distance between a pair of substrates. Spacers can be used, and manufacturing efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a process of forming a color filter in a convex shape using a color resist.

FIG. 3 is a diagram showing an arrangement relationship between a color filter and a pixel electrode.

FIG. 4 is a diagram illustrating a process of forming a color filter in a convex shape by an etching method.

FIG. 5 is a schematic sectional view of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 6 is a schematic sectional view of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 7 is a schematic sectional view of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 8 is a schematic sectional view of a conventional liquid crystal display device.

FIG. 9 is a schematic sectional view of a conventional liquid crystal display device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first substrate 4 pixel electrode 5, 12, 22 alignment film 7 spherical spacer 8 second substrate 10, 19 color filter 14 depression 20 insulating film 21 insulating film

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H089 LA07 LA12 NA09 QA12 QA14 SA16 TA05 TA09 TA12 TA13 2H091 FA02Y FA08X FA08Z FA35Y FB02 FC01 FC10 FC23 GA03 GA07 GA08 GA13 KA10 LA12 LA19 5C094 AA03 AA08 AA43 A43 A43 CA19 CA24 DA13 DB01 DB04 EA04 EA10 EB02 EC03 ED03 FA01 FA02 FB01 FB15 GB10

Claims (7)

[Claims] A first substrate on which a pixel electrode is formed for each pixel; a second substrate on which a counter electrode for generating an electric field between the pixel electrode; a first substrate and the second substrate A liquid crystal display comprising: a spherical spacer interposed between the two substrates to maintain the two substrates at a predetermined distance; and a liquid crystal sealed between the two substrates and having a state of arrangement that changes according to an electric field between the two electrodes. In the device, the second substrate is provided with a color filter in which the entire surface in one pixel is formed in a convex shape for each pixel,
The liquid crystal display device, wherein the spherical spacer is located in a concave portion between the color filters of adjacent pixels. 2. A first substrate on which a pixel electrode is formed for each pixel, a second substrate on which a counter electrode that generates an electric field between the pixel electrode, and the first substrate and the second substrate A liquid crystal display comprising: a spherical spacer interposed between the two substrates to maintain the two substrates at a predetermined distance; and a liquid crystal sealed between the two substrates and having a state of arrangement that changes according to an electric field between the two electrodes. In the device, the second substrate is provided with a color filter formed in accordance with each pixel, and an insulating film laminated on the color filter and having an entire surface in one pixel formed in a convex shape. A liquid crystal display device, wherein the spherical spacer is located in a concave portion between the pixel and the insulating film. 3. The liquid crystal display device according to claim 2, wherein the thickness of the color filter is substantially uniform within one pixel. 4. The liquid crystal display device according to claim 1, wherein the convex portion has the most protruding portion substantially at the center of one pixel. 5. The liquid crystal display device according to claim 1, wherein the first substrate is provided with an insulating film in which the entire surface in one pixel is formed in a concave shape for each pixel. 6. The liquid crystal display device according to claim 5, wherein the distance between the two substrates is substantially uniform due to the concave portion of the first substrate and the convex portion of the second substrate. 7. The liquid crystal display device according to claim 1, wherein an alignment film having a vertical alignment property is laminated on the first substrate and the second substrate, and liquid crystal having a negative dielectric anisotropy is sealed between the two substrates. The liquid crystal display device according to claim 1.