JP2002258014A - Light scattering film, electrode substrate for liquid crystal display and liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light scattering film suppressed in backscattering and exhibiting no iridescent interference coloring, an electrode substrate for reflective and semitransmissive liquid crystal displays and the reflective and semitransmissive liquid crystal displays using such light scattering film. SOLUTION: The light scattering film is provided with a transparent resin having a first refractive index and a plurality of transparent particles dispersed in the transparent resin and having a second refractive index, and is characterized by having >1 and <=1.09 ratio of the one out of the first refractive index and the second refractive index to the other and having the transparent particles being a mixture of transparent particles with continuous distribution of particle diameters. The electrode substrate for the reflective and semiconductor liquid crystal displays and the reflective and semiconductor liquid crystal displays have such light scattering film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light scattering film used in a reflective or semi-transmissive liquid crystal display device, and an electrode substrate for a reflective or semi-transmissive liquid crystal display device using such a light scattering film. In addition, the present invention relates to a reflective or semi-transmissive liquid crystal display device, and more particularly to a light-scattering film which has little backscattering and suppresses iridescent interference color and yellowish coloring.

[0002]

2. Description of the Related Art In general, a liquid crystal display device comprises a pair of electrode substrates provided with a polarizing film and a transparent electrode for driving a liquid crystal and disposed opposite each other, and a liquid crystal sealed between the electrode substrates. It is mainly composed of substances. In a color liquid crystal display device that displays a color image, a color filter layer of red, green, blue, or the like is provided in a fine pattern on one of the pair of electrode substrates.

According to a liquid crystal display device using such a polarizing film, display is performed by switching light from a light source between transmission and non-transmission. That is, by applying a voltage between the opposing transparent electrodes, the alignment state of the liquid crystal material is changed, and the polarization plane of light transmitted through the liquid crystal layer made of the liquid crystal material is controlled. As described above, since a polarizing film is provided on each of these electrode substrates, light from a light source can be switched between transmitting and non-transmitting by controlling the polarizing plane.

[0004] Incidentally, the liquid crystal display device has the potential of low power consumption and light weight, and is expected to be used as a display device of a portable device or the like.

[0005] However, the liquid crystal display devices that are widely used at present have a rear electrode substrate (hereinafter, the observer-side electrode substrate of the pair of substrates is referred to as an observer-side electrode substrate, and a liquid crystal material). A light source (lamp) is disposed on the back surface or side surface of the electrode substrate located on the opposite side to the observer side with the liquid crystal layer interposed therebetween, and display is performed using light emitted from the light source. This is a backlight type or light guide type transmissive liquid crystal display device with a built-in lamp. In a transmissive liquid crystal display device with a built-in lamp, the power consumption of the built-in light source is extremely large. For example, the power consumed by a transmissive liquid crystal display device with a built-in lamp is less than the power consumption of a display device such as a CRT or a plasma display, but may reach almost the same level. Therefore, a large-capacity battery must be mounted, and as a result, the weight and size of the display device and the portable device increase.

That is, the transmissive liquid crystal display device with a built-in lamp cannot sufficiently exhibit the excellent characteristics that the liquid crystal display device has potentially. For this reason, a reflection type liquid crystal display device without a built-in light source has attracted attention.

The reflection type liquid crystal display device has a structure in which a reflection plate having a light reflection function or a reflection electrode having both a function of a liquid crystal driving electrode and a function of a light reflection plate is provided on a rear electrode substrate. ing. According to this reflective liquid crystal display device, external light such as room light or natural light is made to enter the liquid crystal layer from the observer-side electrode substrate side, and this incident light is reflected by the light reflector or the reflective electrode. Is emitted from the observer-side electrode substrate to perform display. As described above, since the reflection type liquid crystal display device does not have a built-in light source,
Low power consumption can be achieved. In addition, according to the reflection type liquid crystal display device, it is not necessary to mount a power supply for the light source, and the increase in size and weight due to mounting the light source is eliminated, so that the size and thickness of the device can be reduced. It becomes possible. That is, it can be said that the reflective liquid crystal display device is suitable as a display device of a portable device or the like.

In this reflection type liquid crystal display device, unlike a transmission type liquid crystal display device with a built-in lamp, display is performed using external light such as room light or natural light as described above. Must be assumed both when the external light enters the reflective liquid crystal display device from all directions and when it enters the reflective liquid crystal display device only from a specific direction. Therefore, in order to realize a display having a bright, clear, and appropriate viewing angle, light incident on the device must be efficiently incident on the liquid crystal layer, and light reflected on the back-side electrode substrate must be efficiently reflected by an observer. It is necessary to guide to the position. Therefore, in order to achieve such an object, it has been proposed to provide a reflective liquid crystal display device with a function of scattering incident light.

The transmissive liquid crystal display device has a remarkably reduced display effect under strong external light such as outdoors, whereas the reflective liquid crystal display device has a better display effect. Further, in a place where external light is scarce, the reflection type liquid crystal display device does not function at all, whereas in the transmission type liquid crystal display device, the visibility is further increased because the periphery is dark. That is, the transmissive liquid crystal display device and the reflective liquid crystal display device have a complementary relationship, and therefore, the transmissive liquid crystal display device having the functions of the transmissive liquid crystal display device and the reflective liquid crystal display device has significantly different external light. It is extremely useful for a portable terminal or the like which must be used in a place, and a transflective liquid crystal display device also needs to be provided with a function of scattering incident light.

FIGS. 1 to 3 are sectional views schematically showing a conventional reflection type liquid crystal display device having a light scattering function. In the reflection type liquid crystal display device 100a shown in FIG. 1, a liquid crystal layer 103 is sandwiched between a back side electrode substrate 101a and an observer side electrode substrate 102a, and a light scattering film 104 and a reflection plate 105 are provided on the back side of the back side electrode substrate 101a. Are sequentially provided. The back-side electrode substrate 101a includes a transparent substrate 106 and a transparent electrode 10 formed on one main surface thereof.
7a, and the observer-side electrode substrate 102a
It comprises a transparent substrate 108, a color filter layer 109 and a transparent electrode 110 formed sequentially on one main surface thereof.

The reflection type liquid crystal display device 100a is easy to manufacture. However, in the reflection type liquid crystal display device 100a, the incident light 111 incident on the liquid crystal layer 103 from the observer side electrode substrate 102a side
1a and the light-scattering film 104 sequentially, reflected by the reflection plate 105, and reflected by the light-scattering film 104 and the back-side electrode substrate 101a.
Are sequentially transmitted, and again incident on the liquid crystal layer 103 as scattered light 112. That is, the light scattering film 10 having a light scattering function
A transparent substrate 106 having a thickness of several hundred μm, which is much larger than the pixel size of several tens μm, is interposed between the liquid crystal layer 4 and the liquid crystal layer 103 for controlling transmission and non-transmission of light. Therefore, the reflection type liquid crystal display device 100 shown in FIG.
a is inferior in resolution.

The reflection type liquid crystal display device 100b shown in FIG.
Are the rear electrode substrate 101b and the observer electrode substrate 102
b has a structure in which the liquid crystal layer 103 is sandwiched. In this reflection type liquid crystal display device 100b, the rear electrode substrate 101b is composed of a transparent substrate 106 and a reflection electrode 107b formed on one main surface thereof. The observer-side electrode substrate 102b includes a transparent substrate 108 and a color filter layer 10 sequentially formed on the rear side of the transparent substrate 108.
9 and a transparent electrode 110, and a light scattering film 104 provided on the viewer side of the transparent substrate 108. In addition,
The reflective electrode 107b of the rear electrode substrate 101b has a flat surface and specularly reflects light incident on the liquid crystal layer 103. That is, the reflective electrode 107 has both a function as an electrode for driving a liquid crystal and a function as a reflector.

In the reflection type liquid crystal display device 100b shown in FIG. 2, the light 111 from the light source first enters the light scattering film 104 to cause light scattering. The scattered light includes incident light 111
Forward scattered light 11 which is scattered light emitted forward in the traveling direction of
3 and the backscattered light 114 which is the scattered light emitted backward in the traveling direction of the incident light 111.
In 00b, only a part of the forward scattered light 113 contributes to display. That is, the forward scattered light 113 sequentially transmits through the transparent substrate 108, the color filter layer 109, and the liquid crystal layer 103, is specularly reflected by the reflection electrode 107b, and
03, the light sequentially passes through the color filter layer 109 and the transparent substrate 108, and reenters the light scattering film 104. Of the reflected light 113 from the reflective electrode 107b incident on the light scattering film 104, only the forward scattered light 115 is emitted toward the observer and contributes to the display. On the other hand, the backscattered light 114 is light that returns to the viewer side without being incident on the liquid crystal layer 103, and not only does not contribute to display but also causes a reduction in display contrast. As described above, in the reflection type liquid crystal display device 100b shown in FIG. 2, the external light cannot be effectively used, and a high display contrast cannot be realized. Further, the reflection type liquid crystal display device 1 shown in FIG.
00b has a structure in which a relatively thick transparent substrate 108 is interposed between the light scattering film 104 and the liquid crystal layer 103, similarly to the reflection type liquid crystal display device 100a shown in FIG. Inferior.

The reflection type liquid crystal display device 100c shown in FIG.
Are the rear electrode substrate 101c and the observer electrode substrate 102
a and the liquid crystal layer 103 are sandwiched between them. In this reflection type liquid crystal display device 100c, the back electrode substrate 101c is composed of a transparent substrate 106 and a reflection electrode 107c formed on one main surface thereof. The reflection electrode 107c of the back-side electrode substrate 101c has a fine uneven pattern on its surface, and has a function as an electrode for driving liquid crystal, a function as a reflector, and a function as a light scattering film. It is.

In the reflection type liquid crystal display device 100c, the incident light 111 incident on the liquid crystal layer 103 from the observer side electrode substrate 102a is reflected by the reflection electrode 107c and transmitted again through the liquid crystal layer 103 as scattered light 116. In this light scattering method, no light loss occurs except that a part of the incident light 111 is absorbed by the reflective electrode 107c.
According to the reflective liquid crystal display device 100c, high light use efficiency and high contrast can be realized. In addition, in the reflective liquid crystal display device 100c, since the relatively thick transparent substrate 106 or the transparent substrate 108 is not interposed between the reflective electrode 107c having the function of a light scattering film and the liquid crystal layer 103, excellent resolution is achieved. Nature can be realized.

However, in order to obtain the reflective electrode 107c having an uneven pattern on the surface, application, exposure, development and baking of a photosensitive resin are performed to form an underlayer having an uneven pattern on the surface. A metal thin film must be formed thereon using a vacuum deposition method, a sputtering method, or the like. Therefore, when the structure shown in FIG. 3 is adopted,
An increase in the number of manufacturing steps and a decrease in manufacturing yield are inevitable, resulting in an increase in manufacturing costs.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a light scattering film which suppresses backscattering, has a high light utilization rate, and has no iridescent coloring, and An object of the present invention is to provide an electrode substrate for a reflective liquid crystal display device and a reflective liquid crystal display device using such a light scattering film.

The present invention also provides a light-scattering film and an electrode substrate for a reflective liquid crystal display capable of realizing a reflective liquid crystal display with excellent display performance, and a reflective liquid crystal display with excellent display performance. The purpose is to:

Furthermore, the present invention relates to a light-scattering film, a reflective liquid crystal display and a transflective liquid crystal display capable of realizing a reflective liquid crystal display and a transflective liquid crystal display which are excellent in display performance and can be manufactured at a relatively low cost. An object of the present invention is to provide an electrode substrate for a device, and a reflective liquid crystal display device and a transflective liquid crystal display device which are excellent in display performance and can be manufactured at relatively low cost.

[0020]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and have reached the present invention. That is, according to claim 1 of the present invention, a transparent resin having a first refractive index and a second resin dispersed in the transparent resin.
A plurality of transparent particles having a refractive index of: wherein the ratio of one of the first and second refractive indexes to the other is greater than 1 and 1.09 or less; Are mixed in a continuous distribution of particles having different particle sizes, and the average particle size of the particles is 1.5 μm or more and 3.0 or more.
μm or less, and the value of the standard deviation σ
The light scattering film is characterized in that the average particle diameter is 3 or more and 1/3 or less of the value of the average particle diameter.

Here, the reason that the average particle size of the transparent particles used for the light scattering film is 1.5 μm or more is that the difference in the refractive index is 1.
In the range of 09, in order to obtain a sufficient scattering effect,
This is because 1.5 μm or more is necessary. 3.0
The reason why the thickness is set to be not more than μm is that the scattering effect is not sufficient with too large particles, and the thickness of the light scattering film is not desired to be too large.

The value (μm) of the standard deviation σ of the particle size is
The reason that the average particle diameter is not less than 0.3 and not more than 1/3 of the value of the average particle diameter is that when the value of σ is less than 0.3, the variation in the particle size is not sufficient, and the particle diameter is uniform. This is because the particles become monodisperse particles, and a rainbow color or a yellowish color due to the interference effect is observed. On the other hand, when the value of σ is increased, particles having a large particle diameter are present,
It is not preferable because the thickness of the light-scattering film is increased and unevenness is generated on the surface of the light-scattering film. It is appropriate to set about 1/3 of the average particle diameter to the σ value (μm).

Next, according to claim 2, a reflective liquid crystal display comprising a transparent substrate, a light scattering film provided on one main surface of the transparent substrate, and a transparent electrode provided on the light scattering film. An electrode substrate for a device, wherein the light-scattering film includes a transparent resin having a first refractive index and a plurality of transparent particles having a second refractive index dispersed in the transparent resin. The ratio of the other of the second refractive indices to one is greater than 1 and less than or equal to 1.09, wherein the transparent particles are a mixture of particles having different particle sizes in a continuous distribution, and the average particle size of the particles is Is 1.5 μm or more and 3.0 μm or less, and the value of the standard deviation σ of the particle diameter is 0.3 or more and 1/3 or less of the value of the average particle diameter. This is a device electrode substrate.

Next, according to claim 3, a transflective liquid crystal comprising a transparent substrate, a light scattering film provided on one main surface of the transparent substrate, and a transparent electrode provided on the light scattering film. An electrode substrate for a display device, wherein the light-scattering film is
A transparent resin having a first refractive index and a plurality of transparent particles dispersed in the transparent resin and having a second refractive index, wherein the ratio of one of the first and second refractive indexes to the other is greater than 1. Large and not more than 1.09, wherein the transparent particles are obtained by mixing particles having different particle diameters in a continuous distribution, and the average particle diameter of the particles is not less than 1.5 μm and not more than 3.0 μm; and The electrode substrate for a transflective liquid crystal display device, wherein the value of the standard deviation σ of the particle size is 0.3 or more and 1/3 or less of the value of the average particle size.

Next, in claim 4, a back electrode substrate having a metal reflection layer provided on one main surface, and a surface arranged opposite to the back electrode substrate and opposed to the back electrode substrate. A reflective liquid crystal display device comprising a viewer-side electrode substrate provided with a transparent electrode layer, and a liquid crystal layer sandwiched between the back-side electrode substrate and the viewer-side electrode substrate, At least one of the back-side electrode substrate and the observer-side electrode substrate has a light scattering comprising a transparent resin having a first refractive index and a plurality of transparent particles dispersed in the transparent resin and having a second refractive index. A ratio of the other to one of the first and second refractive indices is greater than 1 and less than or equal to 1.09, wherein the transparent particles mix particles having different particle sizes in a continuous distribution. The average particle size of the particles is 1.5μ Not less than 3.0 μm and a value of the standard deviation σ of the particle diameter is not less than 0.3 and not more than ３ of the value of the average particle diameter. It is.

Next, in claim 5, a back electrode substrate provided with a semi-transparent metal mirror on one main surface or a back electrode substrate in which the inside of a pixel is divided by a reflective electrode and a transparent electrode at an arbitrary ratio; An observer-side electrode substrate, which is disposed to face the back-side electrode substrate and has a transparent electrode layer provided on a surface facing the back-side electrode substrate; and A transflective liquid crystal display device comprising a liquid crystal layer interposed therebetween, wherein at least one of the back-side electrode substrate and the observer-side electrode substrate has a first shape.
A light-scattering film comprising a transparent resin having a refractive index of and a plurality of transparent particles dispersed in the transparent resin and having a second refractive index, the other being one of the first and second refractive indexes Is greater than 1 and equal to or less than 1.09, wherein the transparent particles are obtained by mixing particles having different particle sizes in a continuous distribution, and the average particle size of the particles is 1.5 μm or more.
0 μm or less, and the value of the standard deviation σ of the particle size is
The transflective liquid crystal display device is characterized in that it is 0.3 or more and 1/3 or less of the value of the average particle size.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. In each of the drawings, the same components are denoted by the same reference numerals, and redundant description will be omitted.

First, the principle of the present invention and the light scattering film of the present invention will be sequentially described. FIG. 4 is a sectional view schematically showing a conventional light scattering film. Light scattering film 10 shown in FIG.
4 is composed of a transparent resin 121 and transparent particles 122 dispersed in the transparent resin 121. The shape of these transparent particles 122 is not constant but irregular. That is, these particles have an irregular surface shape and are not smooth, and have concave portions and convex portions. In order to obtain excellent light scattering properties, the transparent resin 121 and the transparent particles 1 are generally used.
For 22, materials having different refractive indexes are used.

As described above, the light 11 is applied to the light scattering film 104.
When 1 is irradiated, forward scattered light 113 that is scattered light emitted forward in the traveling direction of light 111 and back scattered light 114 that is scattered light emitted backward in the traveling direction of light 111 are generated. In addition, reference numeral 117 indicates straight traveling light. Further, the backscattered light 114 is formed by the transparent resin 121 and the transparent particles 1.
The reflected light returning to the incident side due to reflection generated at the interface with the transparent particles 122 and the light entering the transparent particles 122
2 is composed of the sum of light returning to the incident side after repeating total reflection inside 2.

It is inevitable that a part of the light 111 incident on the light scattering film 104 causes back scattering. However, the present inventor has conducted intensive studies on the assumption that it is possible to reduce backscattered light, and as a result, has found that the shape of the transparent particles 122 has a great effect on the generation of backscattered light. . That is, if the shape of the transparent particles 122 dispersed in the transparent resin 121 is irregular, the incident light 111
The number of times of collision with the interface of the transparent particles 122 increases, and a reflected light component is generated each time the collision occurs, so that backscattering increases.

When the transparent particles 122 are amorphous and the refractive index of the transparent particles 122 is larger than the refractive index of the transparent resin 121, the light incident on the transparent particles 122 is totally reflected inside the transparent particles 122. The opportunity to return to the back by repeating is increased. In this case, if the ratio of the refractive index of the transparent particles 122 to the refractive index of the transparent resin 121 is increased in order to enhance the light scattering property, the reflectance at the interface of the transparent particles 122 increases, and the total inside of the transparent particles 122 increases. Backscatter will increase further as more light returns backward due to reflection.

On the other hand, when the transparent particles 122 are indefinite and the refractive index of the transparent resin 121 is larger than the refractive index of the transparent particles 122, total reflection inside the transparent particles 122 does not occur. However, when the incident angle of the light on the transparent particles 122 is greater than or equal to the critical angle when the light is incident on the transparent particles 122 from the transparent resin 121, the light is totally reflected on the surface of the transparent particles 122. When the refractive index of the transparent resin 121 is larger than the refractive index of the transparent particles 122, such total reflection is repeated two or more times by the other transparent particles 122, thereby causing backscattering.

From the above findings, the present inventors have found that, in order to suppress the occurrence of backscattering when light is incident on the light scattering film, (1) the shape of the transparent particles and (2) the transparent resin It is particularly important to control the ratio of the refractive index of the transparent particles to the refractive index of the transparent particles, and (3) it is also important to give the distribution of the particle size of the transparent particles a certain spread.

Therefore, the present inventors first studied the shape of transparent particles that can suppress the occurrence of backscattering. As a result, they found that if the shape of the transparent particles was basically spherical, the backscattering was significantly reduced.

When the transparent particles have such a shape and the refractive index of the transparent particles is higher than the refractive index of the transparent resin, the transparent particles function as a convex lens, and the light incident from behind the transparent particles is reflected by the transparent particles. Focus forward. On the other hand, when the transparent particles have the above-described shape and the refractive index of the transparent particles is lower than the refractive index of the transparent resin, the transparent particles function as concave lenses, and emit light as if there is a focus behind the transparent particles. Scatter forward of the transparent particles. That is, in each case, backscattering can be significantly reduced as compared with the case where amorphous transparent particles are used.

When the light-scattering film is provided on the observer-side electrode substrate as shown in FIG. 2, external light is incident on the light-scattering film and causes first scattering. Next, the light transmitted through the light scattering film is reflected by a reflection plate or a reflection electrode provided on the rear electrode substrate. Thereafter, the reflected light is incident on the light scattering film, causes second scattering, and is emitted outside the device.

As described above, light scattering occurs twice before external light is incident on the reflective liquid crystal display device and is emitted as display light. Light scattering occurs in both of the two light scatterings. When the angle is 45 ° or more, the scattering angle of light emitted from the device with respect to light incident on the device is 90 ° or more. Since such scattered light hardly contributes to display, it is important for the light scattering film used in the reflection type liquid crystal display device that the scattering angle is 45 ° or less in each of the two light scatterings. .

The light scattering angle changes according to the ratio between the refractive index of the transparent particles and the refractive index of the transparent resin. In the present invention, in order to reduce the scattering angle to 45 ° or less, the ratio of the refractive index of the transparent particles and the refractive index of the transparent resin to the lower refractive index of the higher refractive index is set to 1.09 or less. Hereinafter, this will be described in detail.

FIG. 5 is a diagram schematically showing a sectional structure of the light scattering film according to the first embodiment of the present invention. The light scattering film 14 shown in FIG. 5 is composed of a transparent resin 21 and true spherical transparent particles 22 dispersed in the transparent resin 21. Further, in the light scattering film 14 shown in FIG. 5, if the refractive index of the transparent particles 22 is n1 and the refractive index of the transparent resin 21 is n2, the relationship represented by the inequality n1> n2 is satisfied. Although only one transparent particle 22 is illustrated in FIG. 5, the light scattering film 14 actually includes a large number of transparent particles 22. In FIG. 5, each broken line is a line drawn for the following description.
2 is a straight line that passes through the center 23 and is orthogonal to the incident lights 31a to 31c.

As shown in FIG. 5, of the incident lights 31a to 31c incident on the transparent resin 21, the incident light 31a traveling on the center line of the transparent particles 22 is transmitted through the transparent particles 22 without being scattered. It is emitted as straight light 32.

On the other hand, incident light that travels away from and parallel to the center line of the transparent particles 22, for example, a part of the incident light 31 b enters the transparent particles 22 and is emitted as forward scattered light 33 b, and the rest is the transparent particles 22 b. The light is reflected at the interface and travels as forward or backward scattered light 34. At this time, if the scattering angle (outgoing angle) of the forward scattered light 33b is θ, the incident angle of the incident light 31b with respect to the transparent particles 22 is x, and the refraction angle of the incident light 31b incident on the transparent particles 22 is y, Equation (1)
The following relationship holds. θ = 2 × (xy) (1)

Here, the maximum scattering angle θ is obtained when the incident angle x = (90−0) ° = 90 °. That is, as shown by reference numeral 31c in FIG. 5, when the incident light is incident on the transparent particles 22 so as to be in contact with the surface thereof, the scattering angle θ becomes the maximum. In other words, the broken line 25
When the incident light 31c enters from the intersection of the light and the surface of the transparent particle 22, the scattering angle θ becomes maximum.

As described above, in order to effectively use scattered light for display, it is important that the scattering angle θ be 45 ° or less. Therefore, as shown in the following equation (2), by substituting 45 ° which is the boundary value as the scattering angle θ and 90 ° at which the scattering angle θ becomes the maximum as the incident angle x into the above equation (1), , The boundary value of the refraction angle y can be obtained. 45 = 2 × (90−y) (2)

The boundary value of the refraction angle y obtained from the equation (2) is 67.5 ° and the boundary value of the scattering angle θ is 45 °.
The boundary value of the ratio between the refractive index n1 and the refractive index n2 can be obtained by performing the calculation shown in the following equation (3) using n1 / n2 = 1 / sin 67.5 ° = 1.0824 (3)

From the above, when the transparent particles 22 are truly spherical and the refractive indices n1 and n2 satisfy the relationship represented by the inequality n1> n2, the ratio n1 / n2 may be set to 1.0824 or less. I understand. Actually, the refractive index may be set to 1.09 or less, including an error, as defined in claim 1.

Next, the case where the transparent particles 22 are truly spherical and the refractive indices n1 and n2 satisfy the relationship represented by the inequality n2> n1 will be described.

FIG. 6 is a diagram schematically showing a sectional structure of a light scattering film according to the second embodiment of the present invention. The light scattering film 14 shown in FIG. 6 is different from the light scattering film 14 shown in FIG.
2 and the refractive index n2 of the transparent resin 21 are inequality n
2> n1 only in satisfying the relationship shown in n1. In FIG. 6, a broken line 26 is a straight line orthogonal to the broken line 25.

The refractive index n1 and the refractive index n2 are inequality n2> n1
Is satisfied, the scattering angle θ can be calculated from the following equation (4). θ = 2 × (y−x) (4)

The refractive index n1 and the refractive index n2 are equal to the inequality n.
When the relationship of 2> n1 is satisfied, a part of the incident light is totally reflected at the interface of the transparent particles 22, as indicated by the incident light 31d and the scattered light 33d. Therefore, in order to obtain the boundary value of the ratio between the refractive index n1 and the refractive index n2, the incident light 31
The case where the incident angle x of b is the critical angle and the scattering angle θ is 45 ° may be considered. In this case, since the critical angle of the incident angle x obtained from the above equation (4) is 67.5 °,
By performing the calculation shown in the following equation (5), the refractive index n
The boundary value of the ratio between 1 and the refractive index n2 can be obtained. n2 / n1 = 1 / sin67.5 ° = 1.0824 (5)

From the above, when the transparent particles 22 are truly spherical and the refractive indices n1 and n2 satisfy the relationship represented by the inequality n2> n1, the ratio n2 / n1 may be set to 1.0824 or less. I understand. In this case, in practice, the refractive index may be set to 1.09 or less, as defined in claim 1.

When the diameter of the transparent particles 22 as viewed from the incident angle direction is uniform and the distance between the particles is equal, the scattered light is colored as a result of the diffraction phenomenon. To prevent this, it is preferable to broaden the particle size distribution of the transparent particles and randomize the distance between the particles. When the transparent particles are spherical particles and at least two or more monodisperse particles having different particle diameters are mixed, the ratio of the minimum particle diameter to the maximum particle diameter is 1.3 times or more. If the amount of particles existing in the range of 1/2 to 3/2 times the average particle diameter is at least 70% by weight of the total particle amount, coloring does not hinder practical use. That is, the remaining 30% by weight of the particles may be outside the above range.

Also in this case, the ratio of the small particle size to the large particle size is at least 1.3 times, and more preferably, the monodispersed particles occupying the maximum mixing ratio should exceed 70% by weight in the mixing ratio. I just need. Preferably, the particle size distribution is as continuous as possible, but the particle size distribution may be discontinuous.

The term “monodisperse particles” used herein means:
The lexical meaning is that the value of the particle size is aligned to only one value, but in reality this is not the case. In the case of a fine particle having a particle size of 1 to 3 μm, it is realistic to say that a particle having a particle size distribution having a certain degree of spread (variation) corresponds to the monodispersion. The inventors want to define the realistic variation in particle size seen in monodisperse particles by the standard deviation σ of the particle size. If the value of the standard deviation σ of the particle size is 0.25 (μm) or less, the particles are said to be monodisperse particles. Within this range, it can be said that the particles have a relatively uniform particle size, that is, monodisperse particles.

In order to efficiently scatter light with the light scattering film 14, it is necessary to fill the light scattering film 14 with the transparent particles 22 at high density. Further, as described above, it is desired that the light scattering film 14 has a sufficiently small thickness. Therefore, it is preferable to form the light scattering film 14 such that the transparent particles 22 form a single-layer structure, a two-layer structure, or a three-layer structure in the light scattering film 14.

As the transparent resin 21 of the light scattering film 14, for example, an acrylic transparent resin, a fluorine-based acrylic resin, a silicone-based acrylic resin, an epoxy acrylate resin,
And a fluorene resin.

The light scattering film needs to be patterned as required. That is, there is a case where it is desired to remove the scattering film at a portion other than the pixel, particularly at a seal portion on the outer periphery, or a case where the scattering film is desired to be formed only at a part of the pixel as in the transflective liquid crystal display device shown in FIG. . At this time, as a material of the transparent resin 21, an alkali-soluble resin having galvanic acid at a terminal such as methacrylic acid or an acrylic polymer composed of acrylic acid and various acrylic resins, a poimide precursor, a floren resin having a carboxylic acid at a terminal group, and the like Can be immersed in an alkaline solution to remove the scattering film. Further, the light scattering film 14 can be formed in a predetermined pattern by photolithography. That is, the above-mentioned anionic resin can be mixed with various monomers and a photopolymerization initiator to impart photosensitivity, and subjected to patterning through exposure and alkali development processes.

The transparent particles 22 of the light scattering film 14 are preferably made of an optically isotropic material. When the transparent particles 22 are made of an optically anisotropic material, that is, when the transparent particles 22 have a refractive index anisotropy, the respective polarization planes of the light rays traveling through the particles 22 , The transparent particles 22 have different refractive indices from each other. Therefore, the light incident on the transparent particles 22 is separated into two or more light components whose polarization planes are orthogonal to each other, and the respective light components are separated at different speeds from each other.
Go through 2. That is, the light components emitted from the transparent particles 22 have different phases from each other. Therefore, the polarization plane of the light obtained by combining the light components rotates. Therefore, when this light scattering film is used in a reflection type liquid crystal display device, it is difficult to control between light transmission and light shielding by the polarizing film, and display contrast may be reduced. Further, since the phase difference of the light component varies depending on the wavelength, the light intensity after passing through the polarizing film varies depending on the wavelength, and as a result,
Undesired coloring may occur in the displayed image.

On the other hand, when the transparent particles 22 are made of an optically isotropic material such as an equiaxed crystal or an amorphous material, such a material has a refractive index anisotropy. Therefore, it is possible to reliably prevent the above-described reduction in display contrast and undesired coloring of a display image.

As the material of the transparent particles 22 of the light scattering film 14, it is preferable to use an inorganic compound or resin in consideration of the refractive index, availability, control of the shape, and the like. In particular, when an inorganic oxide or a resin is used as the inorganic compound, it is easy to make the transparent particles 22 amorphous. In general, when a material that easily crystallizes is used, the obtained particles are likely to become amorphous due to the crystal structure. Therefore, it is difficult to obtain a transparent particle 22 having a smooth surface using a material that is easy to crystallize and having the smooth surface formed of one of a convex surface and a combination of a convex surface and a flat surface. On the other hand, when a material that easily becomes amorphous such as an inorganic oxide or a resin is used, the shape of the particles is determined by surface tension and the like, so the surface is smooth, and the smooth surface is convex and convex. The transparent particles 22 composed of any one of the combination of the transparent particles and the flat surface can be easily obtained. Note that the crystallinity of the transparent particles 22 was determined by X-ray diffraction analysis.
The determination can be made by examining the presence or absence of a peak due to diffraction on the crystal plane. When a mixture of amorphous transparent particles and crystalline transparent particles is used as the transparent particles 22, the ratio of the crystalline transparent particles to the total transparent particles is preferably 30% by mass or less.

The transparent particles 22 made of an inorganic oxide include, for example, particles made of silica, alumina and the like. The transparent particles 22 made of resin include acrylic particles and styrene acrylic particles and crosslinked products thereof; particles of melamine-formalin condensate; PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxy resin), and FEP (tetrafluoroethylene). -Hexafluoropropylene copolymer), fluorine-containing polymer particles such as PVDF (polyvinylidene), and ETFE (ethylene-tetrafluoroethylene copolymer); and silicone resin particles. Among such resins, silicone resins, melamine resins,
And a fluorine-based acrylate resin. In addition, since most of the transparent resin 21 has a relatively low refractive index, among these, silica particles and silicone resin particles are particularly preferable because the refractive index is as small as 1.40 to 1.45 (halogen lamp D line 589 nm). It is.

The above-mentioned transparent particles 22 can be subjected to an appropriate surface treatment for the purpose of improving the dispersibility in a solvent or the transparent resin 21. As such a surface treatment, for example, the transparent particles 2
The surface of No. 2 is coated with SiO ₂ , ZrO ₂ , Al ₂ O ₃ , ZnO, a transparent resin, a coupling agent such as a silane coupling agent, a titanate coupling agent or an aluminate coupling agent, or a surfactant. Processing. Further, a treatment for causing a reaction on the surface of the transparent particles 22 using an alcohol, an amine, an organic acid, or the like can also be given.

These coating liquids can contain additives such as an organic solvent, a dispersing aid, a leveling agent, and a coupling agent.

The light scattering film 14 can contain a small amount of additives such as coloring materials. In this case, either the transparent resin 21 or the transparent particles 22 may contain an additive, or both the transparent resin 21 and the transparent particles 22 may contain an additive.

The light scattering film 14 described above may be used for any purpose, but is preferably used for a reflection type liquid crystal display device. Hereinafter, an electrode substrate for a reflection type liquid crystal display device and a reflection type liquid crystal display device using the light scattering film will be described.

FIG. 7 is a sectional view schematically showing a reflection type liquid crystal display device using the light scattering film 14 according to the first to fourth embodiments of the present invention. The reflection type liquid crystal display device 10 shown in FIG.
Has a structure in which a liquid crystal layer 13 containing a liquid crystal substance such as a nematic liquid crystal is sandwiched between a rear electrode substrate 11 and an observer electrode substrate 12.

The back-side electrode substrate 11 mainly includes a substrate 16 and a reflective electrode 17 formed on one main surface thereof. Generally, a glass substrate or the like is used as the substrate 16, and a mirror-reflective aluminum electrode or the like is used as the reflective electrode 17. On the rear electrode substrate 11, an alignment film (not shown) is usually formed on one main surface of the substrate 16 so as to cover the reflective electrode 17, and a polarizing film is formed on the other main surface of the substrate 16. (Not shown) is provided. When the reflection type liquid crystal display device 10 is driven by an active matrix system, usually, between the substrate 16 and the reflection electrode 17,
Various wirings, a first insulating layer, a switching element such as a TFT, and a second insulating layer (all not shown) are sequentially provided from the substrate 16 side. Although the reflective electrode 17 is used in the rear electrode substrate 11 shown in FIG. 9, a transparent substrate is used as the substrate 16, a transparent electrode is used instead of the reflective electrode 17, and a reflective plate is disposed on the rear side of the substrate 16. May be provided.

The observer side electrode substrate 12 is a transparent substrate 18
And a color filter layer 19 sequentially formed on one main surface thereof, a light scattering film 14 having a thickness of, for example, 2 μm, and a transparent electrode 20. Generally, the transparent substrate 18
As the transparent electrode 20, ITO (mixed oxide of indium oxide and tin oxide) is used.
A film or the like is used. The color filter layer 19 is for coloring transmitted light by a known pigment dispersion method or dyeing method, and has a structure in which red, green, and blue color regions are usually juxtaposed. In the reflection type liquid crystal display device 10 shown in FIG. 7, the color filter layer 19 is provided on the observer side electrode substrate 12, but may be provided on the back side electrode substrate 11. In some cases, the color filter layer 19 may not be provided in the reflective liquid crystal display device 10. This observer-side electrode substrate 12 is also similar to the back-side electrode substrate 11,
An alignment film (not shown) is formed on one main surface of the transparent substrate 18 so as to cover the transparent electrode 20.
A polarizing film (not shown) is provided on the other main surface of the.

Since the reflection type liquid crystal display device 10 shown in FIG. 7 uses the light scattering film 14, it is not necessary to form an uneven pattern on the surface of the reflection electrode 17. Therefore, the reflective liquid crystal display device 10 can be manufactured at a relatively low cost. Further, the reflection type liquid crystal display device 10 shown in FIG. 7 is excellent in display performance because the above-mentioned light scattering film 14 is provided on the surface of the observer side electrode substrate 12 facing the liquid crystal layer 13.

The transflective liquid crystal display device 10a shown in FIG.
In the figure, a part of the rear transparent electrode 105 is a metal reflective electrode 17, and a part where the reflective electrode 17 exists is a reflective liquid crystal display. In this liquid crystal display device 10a, the light scattering film 1
4 are provided. At the portion where the light scattering film 14 exists, the color filter 19 is thinner by the thickness of the light scattering film 14. This is convenient for a light reflection type liquid crystal display in which a high transmittance is desired as a color filter. FIG. 9 shows another example of a transflective liquid crystal display device. In this example, the light from the backlight is transmitted to some extent using a semi-transparent metal mirror 125, but incident light from the outside is also reflected to some extent. In this case, the scattering film 14
Generally, it is provided on the entire display surface.

Normally, in order to obtain a reflected light intensity profile satisfying the above relationship, the particle size of the transparent particles 22 should be 0.7 μm.
m or more and less than 3.5 μm, more preferably 1.0 μm or more and less than 3.0 μm, and more preferably 1.5 μm or more and 3.0 μm.
Most preferably, it is less than m. Here, the transparent particles 22
Can be prevented from being caused by diffraction by widening the particle size distribution of. It is preferable that the ratio of the minimum particle size to the maximum particle size is 1.5 to 3 times and the particle size is continuously distributed. Similarly, the effect can be further enhanced by mixing several types of transparent resins 22 having different refractive indices n1.

In order to obtain a reflected light intensity profile satisfying the above relationship, the ratio of the volume of the transparent particles 22 to the volume of the transparent resin 21 is 0.2 or more and 1.2 or more.
It is practically less than 0.6 and preferably 0.6 or more and less than 1.2.

The reflection type liquid crystal display device 10 shown in FIG.
In such a case, the light scattering film 14 needs to have sufficient adhesiveness to the color filter layer 19. In addition, the light scattering film 14 is generally required to have excellent properties for obtaining reliability, such as moisture resistance, solvent resistance, and chemical resistance. Generally, in order to obtain the light scattering film 14 having these excellent characteristics, the ratio of the bright particles 22 in the light scattering film 14 may be reduced. From such a viewpoint, the ratio of the volume of the transparent particles 22 to the volume of the transparent resin 21 is preferably less than 1.0, and more preferably less than 0.8.

Further, the ratio of the volume of the transparent particles 22 to the volume of the transparent resin 21 also affects the film forming property of the light scattering film 14. The specific gravity of the transparent resin solution, which is the material of the transparent resin 21, and the specific gravity of the transparent particles 22 may be substantially the same. However, since the particle size of the transparent particles 22 is relatively large as a powder, when the specific gravity of the transparent particles 22 exceeds 1.5, sedimentation of the transparent particles 22 easily occurs in the transparent resin solution. Further, when the ratio of the transparent particles 22 in the transparent resin solution is increased, the flatness of the light scattering film 14 is reduced. Therefore, from the viewpoint of the film forming property of the light scattering film 14, the transparent resin 21
The ratio of the volume of the transparent particles 22 to the volume (volume of the solid content of the transparent resin solution) is preferably 1.2 or less. In summary, the ratio of the volume of the transparent particles 22 to the volume of the transparent resin 21 is preferably 0.2 or more and less than 0.8, more preferably 0.5 or more and 0.8
It is more desirable to make it less than.

[0074]

Next, an embodiment of the present invention will be described.

(Example 1) That is, the following coating liquid was prepared for a thermosetting light scattering film. A fine particles 6% by weight ・ Polymethacrylate crosslinked fine particles having an average particle size of 2.0 μm (trade name: Eposter MA1002; Nippon Shokubai Co., Ltd.)
): Standard deviation of particle size σ = 0.88 B binder resin 47% by weight ・ Fluorene resin having glycidyl group, solid content 40% by weight
Solution 40% by weight ・ Epoxy acrylate, solid content 25% by weight Solution 7% by weight C Thermosetting agent 22% by weight 12% by weight polyvalent carboxylic acid solution D Organic solvent 25% by weight Add the above A and B, mix and disperse medialessly The mixture was mixed and stirred for 3 hours with a machine, and C was further added to prepare a coating solution.

Subsequently, the above-mentioned coating solution was applied onto a glass substrate for forming a scattering film by a spin coating method of rotating at a rotation speed of 800 rotations for 5 seconds. Then, apply the coating liquid
It was 3 minutes at 200 ° C. Next, baking was performed at 230 ° C. for 60 minutes to obtain a scattering film layer. At this time, the thickness of the scattering film is about 3
μm.

Light scattering film 1 formed by such a method
4 is extremely flat and has a flatness of 0.1 μm.
m or less. Further, the light scattering film 14 had a structure in which a transparent resin 21 having a refractive index of 1.55 upon curing had a mixed distribution of transparent particles 22 having a refractive index of 1.45.

(Comparative Example) That is, the following coating liquid was prepared for a thermosetting light scattering film. A fine particles 6% by weight ・ Polymethacrylate crosslinked monodispersed fine particles having an average particle diameter of 1.8 μm (trade name: MX180; manufactured by Soken Chemical Co., Ltd.):
Standard deviation of particle size σ = 0.24 B binder resin 47% by weight ・ Fluorene resin having glycidyl group, solid content 40% by weight
Solution 40% by weight Epoxy acrylate, solid content 25% by weight Solution 7% by weight C Thermosetting agent 22% by weight ・ 12% by weight polyvalent carboxylic acid solution D Organic solvent 25% by weight

The above-mentioned A and B were added and mixed, and mixed and stirred by a medialess disperser for 3 hours. C was further added to prepare a coating solution.

Subsequently, the above-mentioned coating solution was applied on a glass substrate for forming a scattering film by a spin coating method in which the glass substrate was rotated at a rotation speed of 800 for 5 seconds. Then, apply the coating liquid
It was 3 minutes at 200 ° C. Next, baking was performed at 230 ° C. for 60 minutes to obtain a scattering film layer. At this time, the thickness of the scattering film is about 3
μm.

The examples and comparative examples prepared as described above were visually inspected for the presence or absence of iridescence due to the interference phenomenon and for yellowish coloring. The results are shown in Table 1 below.

[0082]

[Table 1]

From the results shown in Table 1, Example 1 is the best product in which neither rainbow nor yellowish coloring due to interference is observed in the light scattering film.
In the comparative example, some slight iridescent coloring was observed. In addition, yellowish coloring was also observed.

Example 2 A reflection type liquid crystal display device 10 shown in FIG. 9 was manufactured by the following method.

First, on one main surface of the glass substrate 18,
A color filter layer 19 in which red, green, and blue color regions are juxtaposed is formed by a known pigment dispersion method, and then a structure in which transparent fine particles 22 in a transparent resin 21 are dispersed on the color filter layer 19 is formed. Of the light scattering film 14 was formed.

That is, the same coating liquid as in Example 1 was prepared for a thermosetting scattering film. A fine particles 6% by weight ・ Polymethacrylate crosslinked fine particles having an average particle size of 2.0 μm (trade name: Eposter MA1002; Nippon Shokubai Co., Ltd.)
): Standard deviation of particle size σ = 0.88 B binder resin 47% by weight ・ Fluorene resin having glycidyl group, solid content 40% by weight
Solution 40% by weight ・ Epoxy acrylate, solid content 25% by weight Solution 7% by weight C Thermosetting agent 22% by weight 12% by weight polyvalent carboxylic acid solution D Organic solvent 25% by weight Add the above A and B, mix and disperse media The mixture was mixed and stirred for 3 hours with a machine, and C was further added to prepare a coating solution.

Next, the coating solution was applied to the color filter layer 19.
The glass substrate 18 was rotated at a rotation speed of 800 revolutions per minute for 5 seconds to form a coating film. Further, this coating film was dried and baked at 230 ° C. for 60 minutes to form a light scattering film 14 having a thickness of 3.0 μm.

Light scattering film 1 formed by such a method
4 is extremely flat and has a flatness of 0.1 μm.
m or less. Further, the light scattering film 14 had a structure in which a transparent resin 21 having a refractive index of 1.55 upon curing had a mixed distribution of transparent particles 22 having a refractive index of 1.45. Further, a transparent electrode 20 made of ITO was formed on the light scattering film 14 obtained by the above-described method by a sputtering method. As described above, the observer-side electrode substrate 12 was obtained.

By using this observer-side electrode substrate 12, the reflection-type liquid crystal display device 10 shown in FIG. 9 having a structure in which the liquid crystal layer 13 is sandwiched between the observer-side electrode substrate 12 and the separately formed rear-side electrode substrate 11 is shown. Was prepared. Note that an alignment film was provided on each of the opposing surfaces of the back electrode substrate 11 and the observer electrode substrate 12. The reflective liquid crystal display device 10 was provided with polarizing films on both surfaces. In the obtained liquid crystal display device, coloring of the screen due to the scattering film was not recognized, and the viewing angle was wide enough to be practically used.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating an example of a conventional reflective liquid crystal display device having a light scattering function.

FIG. 2 is a cross-sectional view schematically showing another example of a conventional reflection type liquid crystal display device having a light scattering function.

FIG. 3 is a cross-sectional view schematically showing still another example of a conventional reflective liquid crystal display device having a light scattering function.

FIG. 4 is a cross-sectional view schematically showing a conventional light scattering film.

FIG. 5 is an explanatory view schematically showing an optical path of a light scattering film using the transparent particles of the present invention.

FIG. 6 is an explanatory view schematically showing another optical path of a light scattering film using the transparent particles of the present invention.

FIG. 7 is a sectional view showing one embodiment of a reflection type liquid crystal display device using the light scattering film of the present invention.

FIG. 8 is a cross-sectional view showing one embodiment of a transflective liquid crystal display device using the light scattering film of the present invention.

FIG. 9 is a cross-sectional view showing another embodiment of the transflective liquid crystal display device using the light scattering film of the present invention.

[Explanation of symbols]

100a, 100b, 100c Reflective liquid crystal display device 10a, 10b Transflective liquid crystal display device 11, 101a, 101b, 101c Back side electrode substrate 12, 102a, 102b Observer side electrode substrate 13, 103 Liquid crystal 14, 104 Light scattering film 105 Reflecting plate 16, 106 Transparent substrate 17, 107a, 107b, 107c Reflecting electrode 18, 108 Transparent substrate 19, 109 Color filter layer 20, 110 Transparent electrode 21, 121 Transparent resin 22, 122 Transparent particle 31a, 31b, 31c Incident light 32 forward light 33, 33b, 33c, 113 forward scattered light 33d, 112 scattered light 34, 114 back scattered light 35 regular reflected light 36 display light 111 light 116 scattered light straight forward light 125 semi-transparent metal mirror

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takao Taguchi 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. F-term (reference) 2H042 BA02 BA15 BA20 2H091 FA15Y FA16Y FB02 FB08 FB12 FD23 GA02 LA03 LA20 2H092 HA05 JB08 NA01 PA12

Claims (5)

[The claims] 1. A light-scattering film comprising a transparent resin having a first refractive index and a plurality of transparent particles having a second refractive index dispersed in the transparent resin, wherein the first and second light-transmitting films are provided. The ratio of the other to the other is greater than 1 and 1.0
9, wherein the transparent particles are obtained by mixing particles having different particle diameters in a continuous distribution, and the average particle diameter of the particles is 1.5 μm or more and 3.0 μm or less, and a standard particle diameter The light scattering film, wherein the value of the deviation σ is 0.3 or more and 1/3 or less of the average particle size. 2. An electrode substrate for a reflective liquid crystal display device, comprising: a transparent substrate; a light scattering film provided on one main surface of the transparent substrate; and a transparent electrode provided on the light scattering film. The light scattering film includes a transparent resin having a first refractive index and a plurality of transparent particles dispersed in the transparent resin and having a second refractive index. The light scattering film has a first refractive index and a second refractive index. The ratio of one to the other is greater than 1 and less than or equal to 1.09, wherein the transparent particles are obtained by mixing particles having different particle sizes in a continuous distribution, and the average particle size of the particles is 1.5 μm.
An electrode substrate for a reflection-type liquid crystal display device, wherein the value is not less than 3.0 μm and the value of the standard deviation σ of the particle diameter is not less than 0.3 and not more than ３ of the value of the average particle diameter. . 3. An electrode for a transflective liquid crystal display device comprising: a transparent substrate; a light scattering film provided on one main surface of the transparent substrate; and a transparent electrode provided on the light scattering film. A substrate, wherein the light-scattering film includes a transparent resin having a first refractive index and a plurality of transparent particles having a second refractive index dispersed in the transparent resin; The ratio of the other to one of the refractive indices is greater than 1 and less than or equal to 1.09, and the transparent particles are obtained by mixing particles having different particle sizes in a continuous distribution, and the average particle size of the particles is 1.
For a semi-transmissive liquid crystal display device, having a value of not less than 5 μm and not more than 3.0 μm, and a value of a standard deviation σ of a particle diameter is not less than 0.3 and not more than ３ of a value of an average particle diameter. Electrode substrate. 4. A rear electrode substrate provided with a metal reflective layer on one main surface, and a transparent electrode layer disposed on a surface facing the rear electrode substrate and facing the rear electrode substrate. A reflection-type liquid crystal display device, comprising a viewer-side electrode substrate and a liquid crystal layer sandwiched between the back-side electrode substrate and the viewer-side electrode substrate, wherein the back-side electrode substrate and the At least one of the observer-side electrode substrates includes a light-scattering film including a transparent resin having a first refractive index and a plurality of transparent particles having a second refractive index dispersed in the transparent resin. The ratio of one of the first and second refractive indices to the other is greater than 1 and equal to or less than 1.09, and the transparent particles are obtained by mixing particles having different particle sizes in a continuous distribution, and Average particle size of 1.5 μm or more and 3.0
μm or less, and the value of the standard deviation σ
A reflection type liquid crystal display device characterized by having an average particle diameter of 3 or more and 1/3 or less of an average particle diameter. 5. A back-side electrode substrate having a semi-transparent metal mirror provided on one main surface or a back-side electrode substrate in which the inside of a pixel is divided by a reflective electrode and a transparent electrode at an arbitrary ratio; An observer-side electrode substrate in which a transparent electrode layer is provided on a surface facing the back-side electrode substrate, and
A transflective liquid crystal display device comprising a liquid crystal layer sandwiched between the rear electrode substrate and the observer electrode substrate, wherein at least one of the rear electrode substrate and the observer electrode substrate is provided. Comprises a light-scattering film including a transparent resin having a first refractive index and a plurality of transparent particles dispersed in the transparent resin and having a second refractive index;
The ratio of one of the refractive indexes to the other is greater than 1 and equal to or less than 1.09, and the transparent particles are obtained by mixing particles having different particle diameters in a continuous distribution, and the average particle diameter of the particles is 1 0.5 μm or more and 3.0 μm or less, and the value of the standard deviation σ of the particle diameter is 0.3 or more and 1 of the value of the average particle diameter.
/ 3 or less, wherein the transflective liquid crystal display device.