JP3895059B2 - Reflective liquid crystal display device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reflective liquid crystal display device provided with an uneven diffusion layer.
[0002]
[Prior art]
In recent years, OA devices such as personal computers and AV devices such as video cameras have become smaller and lighter, and portable information devices and portable AV devices have been put to practical use. As a display device mounted there, there is an increasing demand for smaller, lighter and lower power consumption, and development of a reflective liquid crystal display device has been actively conducted. The conventional reflective liquid crystal display device is a multi-color display that uses color change due to polarization retardation, while the currently developed one can display a paper white display without coloring that can be used for full-color display. The display quality is high.
[0003]
As a reflection means installed in the reflection type liquid crystal display device, a metal thin film having a high reflectance is generally used. However, although the incident light is reflected only by the reflecting means, the face and surroundings are reflected and paper white display cannot be performed. Therefore, paper white display has become possible by using a diffusion layer that diffuses reflected light. There are two types of installation methods for this diffusion layer: (1) a method of installing on the inner side (liquid crystal layer side) of the substrate and (2) a method of installing on the outer side of the substrate. The method (1) is difficult to manufacture as compared with (2) because the diffusion layer is placed inside the substrate, but since the diffusion layer is in contact with the liquid crystal layer, blurring of the display is reduced, and the method is fine. High contrast display is possible.
[0004]
Method (2) is an installation method in which the diffusion layer is attached to the surface of the substrate opposite to the liquid crystal layer, so it can be installed easily, but light diffuses after passing through the thickness of the substrate such as glass. As a result, the display is blurred and display with high contrast is impossible. For this reason, the method of (1) was often adopted, but when the uneven diffusion layer was installed, a problem of cell gap failure occurred. As a major factor in controlling the cell gap, the spraying density of the spacer can be considered. In Japanese Patent Application Laid-Open No. 6-281941, the scattering density of spacers is 201 / mm.²800 pieces / mm or more²Thus, a technique for keeping the cell gap uniform is disclosed.
[0005]
[Problems to be solved by the invention]
In a normal liquid crystal display device, a spacer exists between both side substrates in order to maintain a cell gap of the liquid crystal layer.
[0006]
In the case of a transmissive liquid crystal display device, only a specific polarization component of light emitted from the backlight is transmitted through the first polarizing plate. While being transmitted through the liquid crystal material, the polarization component undergoes a change in retardation, and display is performed by light transmitted through the second polarizing plate. That is, the light incident on the transmissive liquid crystal display device always travels linearly. Therefore, if there are too many scattering spacers locally in the display device instead of the liquid crystal material (aggregation), light leakage occurs or light is blocked more than necessary. In the transmissive liquid crystal display device, the aggregation of the spacers causes the deterioration of the display quality as described above.
[0007]
On the other hand, in the case of a reflective liquid crystal display device provided with an aluminum reflector having a concavo-convex shape, only a specific polarization component is transmitted through the polarizing plate for light irradiated from the panel surface (front light or natural light). While being transmitted through the liquid crystal material, the polarization component undergoes a retardation change and is diffusely reflected by the aluminum reflector having an uneven shape. The diffusely reflected light is again subjected to the retardation change in the liquid crystal material, and then displayed by the light passing through the polarizing plate. Since the light incident on the reflective liquid crystal display device is randomly reflected on the reflection plate, even if there are many scattering spacers locally due to the aggregation of the spacers, the light intensity is lower than that of the transmissive liquid crystal display device. Difficult to confirm the difference in light blocking state.
[0008]
On the other hand, in the reflection type liquid crystal display device in which the uneven diffusion layer is formed on the substrate in contact with the liquid crystal layer, the spacers 5 are scattered between the protrusions of the uneven diffusion layer 3 and the substrate 1 as shown in FIG. In some cases, the spacer 5 may be dispersed between the concave portion of the uneven diffusion layer 3 and the substrate 1, and the spacer 5 distributed between the concave portion of the uneven diffusion layer 3 and the substrate 1 is in a floating state. In the liquid crystal injection step after the bonding step, the spacer 5 may move from the liquid crystal injection port side toward the peripheral portion of the substrate, and the spacer 5 aggregates in the peripheral portion of the display surface, and the periphery of the display surface A cell gap difference occurs between the central portion and the central portion, and is visually recognized as a display defect. As an example, FIG. 9 shows a case where display unevenness occurs due to a cell gap difference between the peripheral portion and the central portion of the display surface.
[0009]
On the other hand, in the transmissive liquid crystal display device, since the uneven diffusion layer 3 normally used in the reflective liquid crystal display device is not formed, the opposing surfaces of the substrate 1 and the substrate 2 have a structure close to a plane as shown in FIG. It has become. Therefore, there is little movement of the spacer that occurred during the liquid crystal injection of the reflective liquid crystal display device having the uneven diffusion layer 3, and the change in the cell gap due to the aggregation of the spacer is small.
[0010]
As can be seen from this, in the transmissive liquid crystal display device and the reflective liquid crystal display device having the uneven diffusion layer, even if the spacers are scattered at the same spraying density, the mechanism of the spacer aggregation occurrence and the influence on the display quality are affected. Completely different.
[0011]
  That is, in a display device in which the uneven diffusion layer 3 is not formed, the dispersion density of the spacer is described as disclosed in JP-A-6-281194, but the uneven diffusion layer is formed on the substrate in contact with the liquid crystal layer. The reflection type liquid crystal display device is completely different from the conventional liquid crystal display device because the interaction between the spacer and the uneven surface of the uneven diffusion layer and the influence on the display characteristics are completely different from the conventional liquid crystal display device. It was. For this reason, it has been necessary to study a cell gap control technique for a reflective liquid crystal display device capable of high-contrast paper white display. Therefore, the present invention provides a reflective liquid crystal display device in which the uneven diffusion layer is on the inner side of the substrate, and by optimizing the distribution density of the spacers, the cell gap is made uniform, and there is no display defect.And manufacturing method thereofIt aims to realize.
[0012]
[Means for Solving the Problems]
  This applicationInventionReflective liquid crystal displayIs a pair of substrates, a liquid crystal layer interposed between the pair of substrates, an uneven diffusion layer formed on the inner surface of one substrate, and a thickness for adjusting the thickness of the liquid crystal layerspacerIn the reflective liquid crystal display device provided with the above, the spacer is 200 pieces / mm²More than 400 pieces / mm²With the following spray densityOn the uneven diffusion layerIt is arranged.
[0013]
  This applicationInventionIn addition to the above configuration, the reflective liquid crystal display deviceThe spacer is a spherical particle, and the uneven diffusion layer has an average value of the difference between the top of the convex portion and the bottom of the concave portion that is 1/10 or more and 1/3 or less of the particle size of the spacer, and the adjacent convex portion. The average value of the distance between the vertices is equal to or more than 10 times the particle size of the spacer.
[0014]
  This applicationInventionIn addition to the above configuration, the reflective liquid crystal display deviceThe uneven diffusion layer is a reflective electrode that applies a voltage to the liquid crystal layer.
  Further, the manufacturing method of the reflection type liquid crystal display device of the present invention includes a pair of substrates, a liquid crystal layer interposed between the pair of substrates, an uneven diffusion layer formed on the liquid crystal layer side of one substrate, and the liquid crystal layer. In the manufacturing method of a reflective liquid crystal display device provided with a spherical spacer for adjusting the thickness of the projection, the average value of the difference between the apex of the convex portion and the bottom point of the concave portion is 1/10 of the particle size of the spherical spacer. An uneven diffusion layer is formed on the one substrate, the average value of the interval between the vertices of adjacent convex portions being set to be equal to or more than 10 times and less than the particle size of the spherical spacer. 200 mm / mm on the uneven diffusion layer ² More than 400 pieces / mm ² The spherical spacers are arranged at the following distribution density, and after arranging the spherical spacers, the other substrate is bonded to the one substrate, and liquid crystal is injected between the one substrate and the other substrate. Features.
[0015]
  In the reflective liquid crystal display device having the above configuration,Spacer spray density of 200 / mm²More than 400 pieces / mm²The reason for the following is that, if it is within this range, the designed cell gap is realized in the display area, and uniform display without display defects can be achieved. The lower limit of the spraying density of spacers in the liquid crystal display device is 200 / mm.²It is 200 / mm²If the amount is smaller, most of the spacer falls into the concave portion on the glass substrate, becomes thinner than the designed cell gap, and the display characteristics differ.
[0016]
  An example of this phenomenon will be described with reference to FIGS. 6 to 8 showing display characteristics of a polarization mode reflective liquid crystal display device. 6 shows the change in saturation when the cell gap of the reflective liquid crystal display device is changed, FIG. 7 shows the change in chromaticity when the cell gap is changed, and FIG. 8 shows the case when the cell gap is changed. ofBrightnessRepresents each change. In both cases, when the refractive index anisotropy (Δn) of the liquid crystal is 0.08 and the cell gap is 3 μm, the color tone and brightness are designed to be optimal, and the change in the optical characteristics based on the change in retardation is converted into the cell gap. To express. Therefore, if Δn and the cell gap are adjusted so that the retardation of the design value is the same, the same phenomenon occurs even when the cell gap is other than 3 μm. 6 and 7, when the cell gap deviates from the design value in a direction in which the cell gap decreases, the retardation also decreases, and blue coloring occurs. The change in color tone at this time is smaller than that when the cell gap is shifted in the increasing direction. However, as can be seen from FIG. 8, the brightness decreases when the cell gap is shifted in the smaller direction. It is easy to feel the coloring phenomenon in terms of the brightness reduction and the visibility.
[0017]
Also, the upper limit of the dispersion density of spacers in the liquid crystal display device is 400 / mm.²Is 400 pieces / mm²Exceeding the upper and lower substrates is not preferable because excess (excess) spacers other than the pacer that contribute to support the upper and lower substrates move during liquid crystal injection, and the cell gap becomes thicker than the design value, causing color spots.
[0018]
6 and 7, generally, when the cell gap is increased from the design value, the retardation is also increased, so that yellow coloring occurs. The change in color tone at this time is larger than when the cell gap is shifted in the direction of decreasing, and the coloring phenomenon is easily recognized from the viewpoint of visibility.
[0019]
Therefore, if the spraying density becomes too small, most of the spacer falls into the recesses, and the cell gap of the entire display area becomes thin, and if the spraying density becomes too high, the spacers fall into the recesses that do not receive pressure from the substrate. A large amount of spacers are generated and move mainly at the time of liquid crystal injection to cause aggregation, thereby increasing the cell gap. In the example of the polarization mode, the display defect due to the cell gap defect was observed as a coloring phenomenon or a brightness defect, but the reflection mode was different in the mode (for example, absorption mode) or in the alignment state of the liquid crystal. In addition, the liquid crystal display device may be recognized as a defect such as darkness in darkness, response speed, threshold value, alignment state, and the like.
[0020]
  Also, the reflection type liquid crystal display device having the above-described configuration.Then, the size of the spherical spacer and the uneven shape of the uneven diffusion layer,The average value of the difference between the apex of the convex part and the bottom point of the concave part is 1/10 or more and 1/3 or less of the particle diameter of the spacer, and the average value of the distance between the apexes of adjacent convex parts is the particle diameter of the spacer. More than 10 timesIf there is a relationship, the spacer and the concavo-convex shape are aligned and the interaction becomes remarkable, so that the dispersion efficiency of the spacer is greatly improved. In addition, the adverse effect of the uneven shape on the alignment state of the liquid crystal is small, and furthermore, since efficient diffused light is obtained as reflected light of the reflective liquid crystal display device, even if local spacer aggregation exists, It cannot be recognized as an orientation abnormality, and bright and good paper white display can be performed.
[0021]
  Also, the reflection type liquid crystal display device having the above-described configuration.Then, since the uneven diffusion layer also serves as a reflective electrode, the number of production steps can be reduced, resulting in cost reduction.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view showing a reflective liquid crystal display device according to an embodiment of the present invention. As shown in FIG. 1, glass with a conductive film having a thickness of 0.7 mm is used as a substrate 1, and a sealing material 4 is printed on the substrate 1. Spacers 5 were dispersed on the substrate 2 having the uneven diffusion layer 3 made of an aluminum reflector. The uneven diffusion layer 3 diffuses and reflects light incident from the substrate 1 side. The uneven diffusion layer 3 has an average interval between the apexes of adjacent convex portions of 12 μm and the height of the apexes of the convex portions. Are randomly arranged, and the average difference between the apex of the convex portion and the bottom point of the concave portion is defined to be about 0.5 μm. The spacer 5 is sprayed onto the substrate 2 by a thin tube air flow type spacer spraying method, 300 pieces / mm.²The spacer 5 of spherical particles having a diameter of 3 μm was sprayed at a spraying density of The thin tube air flow type spacer spraying method is used when a thin metal pipe is blown with high pressure gas for a long time and the pipe wall and the P.P. B. (Plastic beads dispersion spacer) caused impact charging and obtained the same charge. This is a method of improving the dispersion efficiency by repelling B.
[0023]
Next, the substrate 1 and the substrate 2 were bonded together with the sealing material 4, and a liquid crystal 6 with Δn = 0.08 was injected between the substrate 1 and the substrate 2 to produce a reflective liquid crystal display device. The reflective liquid crystal display device of this embodiment was provided with a polarizing plate and a front light on the outside of the substrate 1 to observe the display characteristics, but no display characteristic unevenness occurred.
[0024]
Observe whether display defects due to cell gap unevenness in the panel surface occur when the dispersion density of spherical spacers with a diameter of 3 μm dispersed in the reflective liquid crystal display device having the uneven diffusion layer 3 shown in FIG. 1 is changed. did. A polarizing plate was placed outside the substrate 1, and the light of the front light was irradiated on the polarizing plate, and the unevenness of display characteristics in the display surface was visually observed. Since the alignment of the liquid crystal is different from the others in the place where the cell gap unevenness occurs, it is observed as a state (color spot) having a different coloring state. Spacer spray density is 200 / mm²More than 400 pieces / mm²There were almost no color spots in the following range, but 500 / mm²From around, the occurrence of color spots was observed around the panel.
[0025]
Next, the result of measuring the cell gap by the rotational analyzer method is shown in FIG. In the reflective liquid crystal display device of the present embodiment, since the reflective plate that is the uneven diffusion layer is a reflective electrode that applies a voltage to the liquid crystal layer, the picture element portion normally does not pass light. For this reason, the measurement was performed by allowing light to pass through a minute region between the picture element portions. In FIG. 5, the horizontal axis represents the amount of spacer sprayed and the vertical axis represents the cell gap. The cell gap at the center of the panel is indicated by a solid line, and the cell gap at the periphery of the panel is indicated by a dotted line. As shown in FIG. 5, the cell gap at the center of the panel has a spacer application rate of 200 / mm.²It saturates in the vicinity and is constant at about 3 μm when sprayed further. That is, the spread rate is 200 pieces / mm²When it is smaller, the spacer falls into the concave portion of the concave and convex portion as shown in FIG. 2, and the cell gap becomes smaller than the design value. If the spacers are dispersed too much, the spacers aggregate as shown in FIG. 3, and the cell gap in the peripheral portion of the panel becomes thick. In particular, the difference from the cell gap at the center of the panel is that the spread rate is 500 pieces / mm.²When it exceeded, it became large, causing color spots. When the cell gap of the color spot area generated around the panel was examined, it was about 0.5 to 0.6 μm thicker than the panel center.
[0026]
The relationship between the cell gap and the display characteristics of the reflective liquid crystal display device will be described below.
[0027]
(1) About coloring state
In order to show the change of the coloring state when the cell gap is changed, FIG. 6 shows the relationship between the cell gap and the saturation, and FIG. 7 shows the chromaticity coordinates. A region that is not recognized as a color difference is determined to be a region of 6 or less in saturation and x ≦ 0.33 and y ≦ 0.36 in chromaticity from a visibility experiment. It was found that color spots were clearly observed when the cell gap exceeded 3.4 μm.
[0028]
(2) About brightness
FIG. 8 shows the relationship between the cell gap and the brightness. As shown in FIG. 8, the brightness is constant when the cell gap is 2.8 to 3.7 μm.
[0029]
Therefore, when spherical spacers having a diameter of 3 μm are dispersed, good display characteristics can be obtained by setting the cell gap to 2.9 to 3.4 μm in consideration of blue coloring. Therefore, as shown in FIG. 5, the dispersion density of the spacers is 200 pieces / mm.²More than 400 pieces / mm²By setting the following range, it is possible to reduce the variation in the cell gap, so that display defects do not occur.
[0030]
In the present embodiment, a case where spherical spacers having a diameter of 3 μm are dispersed has been described. However, the relationship between the diameter of the spherical spacer used in the reflective liquid crystal display device and the unevenness of the uneven diffusion layer 3 is The average value of the difference between the bottom point of the recesses is 1/10 or more and 1/3 or less of the particle size of the spacer, and the average value of the interval between the vertices of adjacent convex portions is equal to or more than 10 times and less than the particle size of the spacer For example, for a spacer with a diameter of 2 to 10 μm, the interaction between the spacer and the concavo-convex shape is the same.²More than 400 pieces / mm²By setting the following range, the same effect can be obtained.
[0031]
In this embodiment, since the uneven diffusion layer 3 also serves as a reflective electrode, the number of production steps can be reduced and the cost can be reduced. However, an electrode for applying a voltage to the liquid crystal can be provided separately. For example, the reflecting means may be formed on the lower substrate, and the uneven diffusion layer may be installed on the upper substrate. Further, the reflection means may be formed on the lower substrate, and the uneven diffusion layer may be formed thereon.
[0032]
FIG. 10 is a plan view of a reflective liquid crystal display device according to another embodiment of the present invention, and FIG. 11 is a cross-sectional configuration view taken along the line AA. As shown in FIGS. 10 and 11, a thin film transistor 24 is formed on the lower substrate 2, and the reflective electrode 10 is connected to the source bus wiring and the gate bus wiring through the scattering layer 19 which is an interlayer insulating film. The transparent electrode 41 and the color filter 40 which are formed so as to overlap with a part thereof, the substrate 1 supporting them, the liquid crystal 6 sandwiched between these substrates 1 and 2, and above the substrate 1 ( The phase difference plate 42 and the polarizing plate 43 are disposed on the side not facing the liquid crystal 6.
[0033]
As shown in FIG. 11, on the insulating substrate 2 made of glass or the like, Ta as the gate electrode 12a branched from the gate wiring 12, SiNx as the insulating layer 13, a-Si as the semiconductor layer 14, n The thin film transistor 24 is composed of n-type a-Si as the type semiconductor layer 15, SiNx as the etch stopper 16, Ti as the source electrode 17a branched from the source bus wiring 17, Ti as the drain electrode 18, and the like. The thin film transistor 24 has a function as a switching element.
[0034]
A scattering layer 19 made of a photosensitive resin is formed on the entire surface of the substrate 1 so as to cover the thin film transistor 24. In the region where the reflective electrode 10 of the scattering layer 19 is formed, a plurality of irregularities are irregularly formed except for the region on the thin film transistor 24 and the region of the contact hole 11 formed on the drain electrode 18. . A reflective electrode 10 made of aluminum, silver, or the like is formed in the picture element region on the scattering layer 19, and the reflective electrode 10 is connected to the drain electrode 18 in the contact hole 11.
[0035]
Therefore, the aperture ratio of the reflective electrode 10 is also improved, the light incident on the liquid crystal layer 6 can be diffusely reflected, and a bright display is possible.
[0036]
On the other hand, a color filter 40 is formed on the substrate 1, and a transparent electrode 41 made of ITO or the like is formed on the entire surface of the color filter 40.
[0037]
FIG. 12 is a process cross-sectional view illustrating a manufacturing process of a reflective liquid crystal display device according to another embodiment of the present invention, in particular, a process of forming the reflective electrode 10 having an uneven shape.
[0038]
As shown in FIG. 12A, a positive photosensitive resin 19 (product name: OFPR-800: Tokyo) is formed on one surface of an insulating substrate 1 on which a thin film transistor 24 as a liquid crystal driving element is formed. Applied to a thickness of 1 to 5 μm. In the second embodiment, the film was formed at 3 μm. Next, a photomask 21 as shown in FIG. 13 was placed, and the first exposure was performed at 40 mj. As shown in FIG. 13, the pattern of the photomask 21 at this time completely shields the portion 31 corresponding to the thin film transistor 24, and the portion 32 corresponding to the contact hole portion 11 is a completely transmissive portion. Also, a circular light shielding portion 33 is arranged. In addition, this circular transmission part 33 was arrange | positioned at random so that a diameter might be 5-10 micrometers and an adjacent center space | interval might be 8-20 micrometers. Then, the photomask 21 and the substrate 2 on which the thin film transistor 24 was formed were exposed after being aligned as shown in FIG.
[0039]
Next, in this state, as shown in FIG. 12B, another photomask 20 was arranged and second exposure was performed at 240 mj. At this time, the photomask pattern has a configuration in which only a portion corresponding to the contact hole portion 11 is a complete transmission portion, and the other regions are light shielding portions.
[0040]
Thereafter, as shown in FIG. 12C, the photosensitive resin 9 is developed with TMAH (tetramethylammonium hydroxide: manufactured by Tokyo Ohka Kogyo Co., Ltd.), so that the photosensitive region 9 irradiated with light by the first exposure is exposed. The photosensitive resin 19 is not completely removed by development, but is reduced by 50 to 90% from the initial film thickness, and the photosensitive resin 19 in the region of the contact hole portion 11 irradiated with light by the second exposure. Is completely removed, and only the contact hole portion 11 is opened on the substrate 2 and a photosensitive resin 19 having irregular circular irregularities is formed. Then, the unevenness on the substrate 2 is subjected to a heat treatment at 200 ° C. for 60 minutes, so that the region where the film is reduced due to the heat dripping phenomenon is deformed, and the unevenness having a smooth shape is formed.
[0041]
Thereafter, as shown in FIG. 12 (d), an Al thin film as the reflective electrode 10 is formed on the photosensitive resin 19 having the projections and depressions to a thickness of about 2000 mm by a sputtering method. Patterning is performed so that one reflective electrode 10 corresponds.
[0042]
In addition, the reflective electrode 10 is connected to the drain electrode 18 of the thin film transistor 24 through the contact hole 11 and is formed along the unevenness formed in the photosensitive resin 19. Also, the surface contributing to display has irregular circular irregularities corresponding to the irregularities of the photosensitive resin.
[0043]
  Figure like this12By the steps shown in (a) to (d), it is possible to form the reflective electrode 10 having a gentle and high-density concavo-convex shape, and to create an ideal reflector with less regular reflection components by reducing the flat portion. It is possible.
[0044]
As described above, a substrate on which the thin film transistor and the uneven reflective electrode were formed was completed. Subsequent bonding to the counter substrate on which the color filter 40 is formed, dispersion of spacers, and injection of liquid crystal were performed in the same manner as described above. Further, the retardation plate 42 and the polarizing plate 43 were installed outside the substrate to complete the reflection type liquid crystal display device.
[0045]
As described above, even when the uneven scattering layer is configured as the base film of the reflective pixel electrode connected to the thin film transistor, the dispersion density of the spacer is not affected by the interaction effect of the spacer and the unevenness. By setting the range, a higher display quality can be realized.
[0046]
【The invention's effect】
  This applicationAccording to the invention, it is possible to prevent the occurrence of display defects.
[0047]
  In addition, this applicationAccording to the invention, since the interaction between the size of the spacer and the concavo-convex shape of the concavo-convex diffusion layer becomes significant, the dispersion efficiency is greatly improved. In addition, efficient diffused light can be obtained as reflected light of a reflective liquid crystal display device without adversely affecting the alignment of the liquid crystal layer, so even if there is local aggregation of spacers, it is recognized as an alignment abnormality. The display quality can be kept good.
[0048]
  In addition, this applicationAccording to the invention, since the uneven diffusion layer also serves as an electrode, the number of production steps can be reduced, resulting in cost reduction.
[Brief description of the drawings]
FIG. 1 is a diagram showing a cross-sectional view of a reflective liquid crystal display device having an uneven diffusion layer.
FIG. 2 is a diagram showing a cross-sectional view of a reflective liquid crystal display device with a small amount of spacer spraying.
FIG. 3 is a cross-sectional view of a reflective liquid crystal display device with a large amount of spacer dispersion.
FIG. 4 is a cross-sectional view showing a conventional liquid crystal display device.
FIG. 5 is a diagram showing a result of measuring a cell gap of a reflective liquid crystal display device provided with an uneven diffusion layer by a rotating analyzer method.
FIG. 6 is a diagram illustrating a relationship between a cell gap and saturation.
FIG. 7 is a diagram showing chromaticity coordinates.
FIG. 8 is a diagram illustrating a relationship between a cell gap and brightness.
FIG. 9 is a diagram illustrating a display defect due to a cell gap difference between the peripheral portion and the central portion of the display surface.
FIG. 10 is a plan view of a reflective liquid crystal display device according to another embodiment of the present invention.
11 is a cross-sectional configuration diagram taken along a line AA in FIG. 10;
FIG. 12 is a process cross-sectional view illustrating a manufacturing process of a reflective liquid crystal display device in another embodiment of the invention.
FIG. 13 is a diagram showing the arrangement of photomasks.
[Explanation of symbols]
1, 2 substrate
3 Uneven diffusion layer
4 Sealing material
5 Spacer
6 Liquid crystal layer
7 Inlet
10 Reflective electrode
11 Contact hole
12 Gate bus wiring
12a Gate electrode
13 Insulating layer
14 Semiconductor layer
15 n-type semiconductor layer
16 Etch stopper
17 Source bus wiring
17a Source electrode
18 Drain electrode
19 Interlayer insulation film (uneven diffusion layer)
20 Photomask
21 Photomask
22 UV light
24 Thin film transistor
31, 33 Shading part
32, 34 Transmission part
40 color filters
41 Transparent electrode
42 phase difference plate
43 Polarizer

Claims (2)

A reflective type comprising a pair of substrates, a liquid crystal layer interposed between the pair of substrates, an uneven diffusion layer formed on the inner surface of one substrate, and a spherical spacer for adjusting the thickness of the liquid crystal layer In liquid crystal display devices,
The spherical spacer is disposed on the uneven diffusion layer at a spray density of 200 pieces / mm ² or more and 400 pieces / mm ² or less,
In the uneven diffusion layer, the average value of the difference between the peak of the convex part and the bottom point of the concave part is 1/10 or more and 1/3 or less of the particle diameter of the spacer, and the average value of the distance between the vertexes of adjacent convex parts is 10x der less equal or more times the diameter of the spacer is,
The uneven diffusion layer is formed on the scattering layer, a scattering layer formed by subjecting a photosensitive resin to exposure processing, development processing, and heating processing in which a photomask having a circular pattern is disposed, and the liquid crystal A reflective liquid crystal display device comprising a reflective electrode for applying a voltage to the layer . A reflective type comprising a pair of substrates, a liquid crystal layer interposed between the pair of substrates, an uneven diffusion layer formed on the liquid crystal layer side of one substrate, and a spherical spacer for adjusting the thickness of the liquid crystal layer In the manufacturing method of the liquid crystal display device,
A photosensitive resin is formed, and an exposure process, a development process, and a heating process in which a photomask having a circular pattern is arranged are applied to the photosensitive resin, and a reflective electrode for applying a voltage to the liquid crystal layer is formed thereon. By doing so, the average value of the difference between the apex of the convex portion and the bottom point of the concave portion is 1/10 or more and 1/3 or less of the particle size of the spherical spacer, and the average value of the interval between the apexes of adjacent convex portions Is formed on the one substrate a concave-convex diffusion layer set to be equal to or more than 10 times the particle size of the spherical spacer,
On the formed uneven diffusion layer, the spherical spacers are arranged at a spray density of 200 / mm ² or more and 400 / mm ² or less,
A method of manufacturing a reflective liquid crystal display device, wherein after the spherical spacer is arranged, the other substrate is bonded to the one substrate, and liquid crystal is injected between the one substrate and the other substrate.

Images