JP2002341331A - Translucent color liquid crystal display device and back electrode substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a translucent color liquid crystal display device wherein the resolution when the translucent color liquid crystal display device is used a reflection color liquid crystal display is enhanced and which is manufactured at lower cost and to provide a back electrode substrate. SOLUTION: The back electrode substrate 108 formed by providing a light scattering film layer 109 and a back transparent electrode layer 105 on a pixel divided into a light reflection part and a light transmission part by a reflection mirror 115 and an observer side electrode substrate 107 provided with a color filter 102 and an observer side transparent electrode layer 101 are disposed opposite to each other and a liquid crystal material 104 is encapsulated between the electrode substrates. The light scattering film layer and the back transparent electrode layer are provided on the pixel of the back electrode substrate, which is divided into the light reflection part and the light transmission part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transflective color liquid crystal display device, and more particularly to a transflective color liquid crystal display device when an external light source is sufficiently bright, and when the external light source is absent or insufficient. Relates to a transflective color liquid crystal display functioning as a transmissive color liquid crystal display.

[0002]

2. Description of the Related Art FIG. 2A shows a main part of a transmission type liquid crystal display device. The transmission type liquid crystal display device has a polarizing film (omitted in FIG. 2A) and a pair of electrodes for driving the liquid crystal, that is, a pair of opposing electrodes on which an observer-side transparent electrode layer 203 and a back-side transparent electrode layer 205 are respectively disposed. The main part is constituted by the electrode substrates of the above, that is, the observer-side electrode substrate 207 and the back-side electrode substrate 208, and the liquid crystal material 204 sealed between these electrode substrates. In a transmissive liquid crystal display device that displays a color image, a color filter 202 is provided on one of the pair of electrode substrates to form a transmissive color liquid crystal display device.

When displaying a screen, a voltage is applied between opposing electrodes to change the orientation of a liquid crystal material sealed between electrode substrates, thereby controlling the plane of polarization of light transmitted through the liquid crystal material. At the same time, transmission and non-transmission are controlled by a polarizing film.

A transmission type liquid crystal display device is an electrode substrate located on the back side (of the paired electrode substrates, an electrode substrate located on the opposite side to the viewer with a liquid crystal substance interposed therebetween. A light source (light) 217 is disposed on the back surface or side surface of the substrate (hereinafter referred to as a substrate), and a screen display is performed with incident light 223 emitted from the light source 217. Are widely spread.

Conventionally, a liquid crystal display device is expected to be used for a portable display device such as a mobile device, taking advantage of a feature that it can be reduced in weight with low power consumption. However, the built-in lamp type transmissive liquid crystal display device has a built-in light source (light).
As a result, the power consumption is large, so that the transmissive liquid crystal display device with a built-in lamp has a short use time of the battery, and the ratio of the battery is large, so that the device is heavy and bulky. In other words, it cannot be said that the transmissive liquid crystal display device with a built-in lamp can take full advantage of the inherent advantages of the liquid crystal display device. Reference numeral 201 denotes a viewer-side transparent substrate, 206 denotes a rear-side transparent substrate, and 212 denotes a sealing material.

For this reason, a reflection type liquid crystal display device without a built-in light source (light) has been put to practical use. 2B and 2C show an example of a reflection type color liquid crystal display device. FIG.
In (b), a light-scattering film layer 209 having a light-scattering function is provided on the front surface of the observer-side electrode substrate 207, and the back-side electrode substrate 2
08, a reflective electrode layer 215 is provided. The light-scattering film layer 2 outside the observer-side electrode substrate 207 (of the pair of substrates sandwiching the liquid crystal substance, which is located on the observer side)
External light (incident light for reflection) 2 such as room light or natural light from the 09 side
21 is made incident on the liquid crystal display device, the incident light for reflection is reflected by the reflective electrode layer 215, and the scattered reflected light 22
2 is emitted from the light scattering film layer 209 to display a screen.

In FIG. 2C, a scattering / reflection electrode layer 225 having a light scattering function is provided on the back electrode substrate 208, and has two functions of reflection and light scattering. External light (reflecting incident light) 221 such as room light or natural light is incident on the liquid crystal display device from the observer-side electrode substrate 207 side, and the reflecting incident light is scattered and reflected by the scattering / reflecting electrode layer 225. The screen display is performed by emitting the scattered reflected light 222 from the observer side electrode substrate 207.

As described above, a reflection type liquid crystal display device without a built-in light source (light) can realize low power consumption.
Since the light source (light) is not built in, the device can be made smaller, lighter and thinner, and is suitable as a portable display device. However, since the reflection type liquid crystal display device does not function well in a dark place where external light is scarce, the portable liquid crystal display device having both the transmission type and the reflection type slightly sacrifices the portable performance, but is extremely useful in practical use. is there.

The transmission type liquid crystal display device has a remarkably reduced display effect under strong external light such as outdoors, whereas the reflection type liquid crystal display device has a much 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. Under such circumstances, the transmissive liquid crystal display device and the reflective liquid crystal display device have a complementary relationship. Therefore, the transflective liquid crystal display device having the functions of the transmissive liquid crystal display device and the reflective liquid crystal display device is not suitable for outdoor use. This is extremely useful for a portable terminal or the like that is used under strong external light or in a place where external light is scarce such as a room.
When a transflective liquid crystal display device performs color display, a color filter is required as described above.

There are several functional differences between the transmissive color liquid crystal display and the reflective color liquid crystal display. That is, the light source of the transmission type color liquid crystal display device is extremely high quality scattered light incorporated in the device, whereas the light source used in the reflection type color liquid crystal display device is various, and usually a point light source or a fluorescent light source is used. It is a limited surface light source such as a lamp, and is a light source that cannot be said to be scattered light.

For this reason, in a reflection type color liquid crystal display device, it is necessary to convert incident light into scattered light by some means.
For example, 1) as shown in FIG. 2B, fine particles having a refractive index different from that of the resin are dispersed in a transparent resin or the like, and incident light is scattered by refraction and diffraction of light. 2) As shown in FIG. 2 (c), the surface of the reflecting mirror is made uneven to reflect the incident light irregularly. The light is converted into scattered light by such a method.

The light path of the transmission type color liquid crystal display device shown in FIG. 2A is such that the incident light for transmission 223 from the light source 217 is transmitted from the rear transparent substrate 206 to the rear transparent electrode layer 205, the liquid crystal material 204, and the viewer side transparent. Electrode layer 203, color filter 2
02, the light passes through the observer-side transparent substrate 201 and is emitted toward the observer. In the reflection type color liquid crystal display device shown in FIG. 2B, the incident light for reflection 221 is reflected by the light scattering film layer 20.
9. Observer side transparent substrate 201, color filter 202,
After passing through the viewer-side transparent electrode layer 203 and the liquid crystal material 204,
It is folded back by the reflective electrode layer 215 also serving as a reflective plate, and again passes through the liquid crystal material 204, the observer-side transparent electrode layer 203, the color filter 202, the observer-side transparent substrate 201, and the light scattering film layer 209 to the outside. Reach.

In the reflection type color liquid crystal display device shown in FIG. 2C, the incident light for reflection 221 is applied to the transparent substrate 20 on the observer side.
1. Color filter 202, observer-side transparent electrode layer 20
3. After passing through the liquid crystal material 204, it is turned back at the scattering / reflection electrode layer 225, and again, the liquid crystal material 204, the observer-side transparent electrode layer 203, the color filter 202, and the observer-side transparent substrate 20
1 to the outside.

In the transflective color liquid crystal display device, there are two methods of selectively using the transmissive type and the reflective type: 1) a half-mirror type in which the transmitted light and the reflected light are each used by half using a half mirror, and 2). There is a pixel division method in which a pixel portion on a substrate is divided into two portions, one of which is transparent, a transmitted light is provided, and the other is provided with a metal reflection plate, and a reflected light is used for each half.

In the half-mirror system, a transflective color liquid crystal display device can be relatively easily realized by disposing a half mirror and a light scattering film layer outside the transmissive color liquid crystal display device. However, it is quite difficult to accurately control the transmittance and the reflectance of the half mirror on a mass production scale. On the other hand, in the pixel division method, it is possible to completely separate the light path for transmission and for reflection, and it is possible to accurately control the amount of transmission and the amount of reflection in the pixel area.

FIG. 3 is a sectional view of a typical transflective color liquid crystal display device. The transflective color liquid crystal display device shown in FIG. 3 is a half-mirror system in which a light-scattering film layer 309 and a half-mirror / electrode layer 305 are combined. The observer-side electrode substrate 307 and the back-side electrode substrate 308 are attached to each other with a sealant 312, and a liquid crystal material 304 is sealed therein. The back side electrode substrate 308 may be any of a simple matrix substrate and an active matrix substrate such as a TFT.

The transflective color liquid crystal display device shown in FIG. 3 includes the rear transparent electrode layer 205 of the transmissive color liquid crystal display device shown in FIG. 2A and the reflective color liquid crystal display device shown in FIG. By replacing the reflective electrode layer 215 with a half mirror / electrode layer 305 as shown in FIG. 3, a transflective color liquid crystal display device is realized. When the transflective color liquid crystal display device shown in FIG. 3 is used as a transmissive type, 50% of the incident light for transmission 323 is the half mirror / electrode layer 305 provided on the back side electrode substrate 308 and 50% of the incident light is the liquid crystal material 30.
4 to the observer-side electrode substrate 307.

When the transflective color liquid crystal display device shown in FIG. 3 is used as a reflective color liquid crystal display device, the incident light for reflection 321 is applied to the light scattering film layer 309 and the observer side electrode substrate 30.
7, half of the incident light is turned back by the liquid crystal material 304 and the half mirror / electrode layer 305, and the scattered reflected light 322 reaches the outside through the liquid crystal material 304, the observer side electrode substrate 307, and the light scattering film layer 309 again.

The case where the light scattering film layer 309 is arranged outside the observer side electrode substrate 307 as shown in FIG. 3 or the case where the light scattering film layer 309 is arranged outside the back side electrode substrate 308 as shown in FIG. The image displayed on the liquid crystal material 304 is the viewer-side transparent substrate 301 or the rear-side transparent substrate 3 respectively.
06, which has the disadvantage that the resolution of the image is significantly reduced. 318 is a polarizer / analyzer, 319 is a polarizer, 303 is a viewer-side transparent electrode, and 302 is a color filter.

The transflective color liquid crystal display device shown in FIG. 4 is an example in which a pixel is divided into two using a scattering / reflection electrode layer 415 to selectively use a transmissive type and a reflective type. When the transflective color liquid crystal display device shown in FIG. 4 is used as a transmissive type, about 透過 of the incident light for transmission 423 passes through the back side transparent electrode layer 405 provided on the back side electrode substrate 408 and the liquid crystal substance 40
4. Observer-side transparent electrode layer 403, color filter 40
2. The light passes through the observer-side transparent substrate 401 and exits outside. When the transflective color liquid crystal display device of FIG. 4 is used as a reflective color liquid crystal display device, the incident light for reflection 421 is used.
は of the incident light is turned back by the observer-side electrode substrate 407, the liquid crystal substance 404, and the scattering / reflecting electrode layer 415, and again passes through the liquid crystal substance 404 and the observer-side electrode substrate 407, and the scattered / reflected light 422 goes to the outside. Get out.

In the transflective color liquid crystal display device shown in FIG. 4, the light scattering function is performed by the scattering / reflecting electrode layer 415 having unevenness. That is, since the light scattering function is in contact with the liquid crystal substance, the resolution is excellent. In addition, this light scattering method is excellent in light use efficiency because there is no light loss except that the reflection incident light is partially absorbed by the scattering reflection electrode layer. However, in order to form the unevenness on the surface of the scattering / reflecting electrode layer, it is necessary to go through a processing step such as a photolithography method, so that the manufacturing steps are complicated and the manufacturing cost is increased. 418, a polarizer and analyzer; 419, a polarizer; and 406, a rear transparent substrate.

[0022]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems. The problem is to improve the resolution when used as a reflective color liquid crystal display in a transflective color liquid crystal display,
It is an object of the present invention to provide a transflective color liquid crystal display device at lower cost and a back electrode substrate used in the transflective color liquid crystal display device.

[0023]

SUMMARY OF THE INVENTION According to the present invention, a pixel is divided into a light-reflecting portion and a light-transmitting portion by dividing one pixel depending on the presence or absence of a reflecting mirror, and a transparent resin and a different refractive index dispersed therein are provided. A light-scattering film layer containing amorphous fine particles as a main component is provided, a back-side electrode substrate provided with a back-side transparent electrode layer on the light-scattering film layer, a color filter and an observer-side transparent electrode layer are sequentially formed. The provided observer-side electrode substrates are arranged to face each other, a liquid crystal material is sealed between these electrode substrates, and a screen is displayed by applying a voltage to each pixel for the liquid crystal material. This is a transflective color liquid crystal display device.

The present invention also provides a back electrode substrate having a back transparent electrode layer provided on a pixel which is divided into a light reflecting portion and a light transmitting portion by dividing one pixel by the presence or absence of a reflecting mirror; An observer-side electrode substrate provided with an observer-side transparent electrode layer disposed opposite to the side electrode substrate, and a liquid crystal material sealed between these electrode substrates. In a rear electrode substrate used for a transflective liquid crystal display device that applies a voltage to display a screen, a transparent resin and amorphous fine particles dispersed in the transparent resin and having different refractive indices are disposed on the pixels of the rear electrode substrate. A light-scattering film layer and a back-side transparent electrode layer each comprising, as main components, are sequentially provided.

The present invention also provides a back electrode substrate according to the above invention, wherein a color filter is provided on the light scattering film layer.

According to the present invention, in the back electrode substrate according to the present invention, a color filter is provided on the pixel.
A rear electrode substrate, wherein the light scattering film layer and the rear transparent electrode layer are sequentially provided on the color filter.

According to the present invention, there is provided the back electrode substrate according to the above invention, wherein the light scattering film layer is provided only on the reflecting mirror.

The present invention also provides a back electrode substrate according to the present invention, wherein a color filter is provided on a pixel provided with the light scattering film layer only on the reflecting mirror. is there.

[0029]

Embodiments of the present invention will be described below in detail. FIG. 1 is a sectional view of an embodiment of a transflective color liquid crystal display device according to the present invention. As shown in FIG. 1, a transflective color liquid crystal display device 100 according to the present invention.
Are polarizer 119, rear electrode substrate 108, liquid crystal substance 1
04, observer side electrode substrate 107, polarizer and analyzer 11
8 and a sealing material 112. The pixels are divided as indicated by a dashed line, and R
(Red), G (green), and B (blue) represent the pixel area.

The back-side electrode substrate 108 is composed of a reflecting mirror 115, a light-scattering film layer 109 composed mainly of a transparent resin and amorphous fine particles having a different refractive index dispersed therein and formed on a back-side transparent substrate 106; The side transparent electrode layer 105 is formed, and the pixel is divided into two parts by a light reflection part where the reflection mirror 115 is formed and a light transmission part where the reflection mirror 115 is not formed.

On the other hand, the observer-side electrode substrate 107 is formed by forming a color filter 102 and an observer-side transparent electrode layer 103 on an observer-side transparent substrate 101. The back side electrode substrate 108 and the observer side electrode substrate 107 are
2 and a liquid crystal material 104 is further sealed.
Then, the rear transparent electrode layer 10 of the rear electrode substrate 108 is formed.
5, and between the observer-side transparent electrode layer 103 of the observer-side electrode substrate 107, an electric signal is applied.

The transparent substrate 101 on the observer side and the transparent substrate 106 on the rear side are most preferably low expansion glass having the same coefficient of thermal expansion, but are made of a material which does not disturb the orientation of the liquid crystal substance 104.
Any substrate may be used as long as it does not elute ions that inhibit electrical operation. Specifically, non-alkali glass such as borosilicate,
Low expansion glass, soda glass whose surface is covered with silicon oxide or the like, a transparent resin plate, a resin film, or the like can be used.

The light scattering film layer 109 is a film layer in which amorphous fine particles 110 are dispersed in transparent resins 111 having different refractive indexes, and the thickness of the light scattering film layer 109 is preferably in a range of 2 μm to 5 μm. Examples of the amorphous fine particles 110 of the light scattering film layer 109 include fine particles made of an inorganic material and fine particles made of an organic polymer. In particular, organic polymer fine particles are mainly cited because they are amorphous, but inorganic fine particles can be used as long as they are amorphous. In the present invention, the fine particles are characterized by being amorphous fine particles, and it is considered that the fine particles are crystalline and have optical anisotropy, which is not preferable for light scattering. .

For example, inorganic fine particles are spherical amorphous fine particles such as oxides of silica and alumina, and organic polymer fine particles are acrylic fine particles and styrene acrylic fine particles and cross-linked products thereof, melamine-formalin condensate,
(Polytetrafluoroethylene), PFA (perfluoroalkoxy resin), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PVDF (polyfluorovinylidene), ETFE (ethylene-tetrafluoroethylene copolymer), etc. Polymers, silicone resin fine particles and the like can be exemplified. Among them, crosslinked acrylic resin fine particles have a refractive index of less than 1.5, and silica particles or silicon resin fine particles have a refractive index of 1.42 to 1.45 (halogen). Lamp D line 589nm)
Is particularly preferable because it is small.

Further, these fine particles are subjected to an appropriate surface treatment to improve the solvent dispersibility and compatibility with the transparent resin.
It is also possible to apply as the fine particles. Examples of such a surface treatment include, for example, SiO2, ZrO
2, a coating treatment of Al2O3, ZnO, a transparent resin, a coupling agent, a surfactant, or the like. In addition, a treatment for causing a surface reaction with an alcohol, an amine, an organic acid, or the like can be exemplified.

Further, these fine particles may be mainly contained as fine particles in the light scattering film layer. For example, it is sufficient that about 70% or more of the fine particles is contained. In addition to these fine particles, non-spherical fine particles such as irregular shaped fine particles and crystalline fine particles in a small amount of about 30% or less for the purpose of dispersion stability of the fine particles in the coating liquid and fine adjustment of light scattering characteristics. May be added.

The shape of the amorphous fine particles 110 is not particularly limited, but is preferably spherical or similar to spherical. The spherical fine particles can easily control the size, the particle size distribution, and the like, and thus easily control the optical characteristics of the light scattering film layer 109. The allowable range of the particle size of the fine particles is not particularly limited, depending on the intended thickness of the light scattering film layer and the presence or absence of coloring. However, when fine particles larger than the thickness of the light-scattering film layer are used, the surface of the light-scattering film layer becomes extremely rough, which is not preferable. The particle size of the fine particles is not particularly limited, but a preferable particle size range is about 0.7 μm to 3.5 μm, preferably 1.5 μm to 3.0 μm.

Although the specific gravity of the fine particles does not directly affect the optical characteristics of the light-scattering film layer, it has a great effect on the coating characteristics when forming the light-scattering film layer 109, and hence the light-scattering film layer 109 itself. It also relates to characteristics. It is desirable for the value to be close to the specific gravity of the transparent resin 111 solution for the stability of the coating liquid.

As the transparent resin 111 for dispersing the fine particles, a resin having high visible light transmittance and sufficient resistance to heat treatment or chemical treatment during the manufacturing process of the liquid crystal display device is desirable. Epoxy-modified acrylic resin, floren resin, and polyimide resin can be used as the high resin, and fluorine-modified acrylic resin and silicon-modified acrylic resin can be used as the low refractive index resin. In addition, an acrylic resin, an epoxy resin, a polyester resin, a urethane resin, a silicone resin, or the like can be appropriately used. When the light scattering film layer is provided in a pattern by a photolithography process, an acrylic resin or an epoxy resin having photosensitivity and developability can be used. It is also possible to use a thermosetting resin or an ultraviolet curable resin.

For example, when the crosslinked acrylic fine particles have a refractive index of 1.49 (a value obtained by using a halogen lamp D line at 589 nm), the transparent resin has a refractive index of 1.55 to 1.
Preferably it is 65. In addition, the refractive index is 1.42 to 1.
In the case of 45 silica particles or silicon resin fine particles, the transparent resin preferably has a refractive index of 1.50 to 1.60.

The light scattering film layer 109 is made of the amorphous fine particles 1
10 is mixed and dispersed in a transparent resin 111, applied on a transparent substrate, dried, and formed into an arbitrary shape through a photolithography process. In addition, as a coating method, spin coating, flow coating, roll coating, or the like can be applied, and as an exposure method, projection exposure or proximity exposure can be applied. Further, the light scattering film layer 109 can be formed by a conventional means such as a photolithography method, an electrodeposition method, a printing method, and an ink jet method as a pattern forming means.

The observer-side transparent electrode layer 103 provided on the observer-side transparent substrate 101 and the back-side transparent substrate 106
The transparent electrode layer 105 provided on the back side is made of ITO.
A thin film, a thin film obtained by adding titanium oxide, lead oxide, antimony oxide, bismuth oxide, hafnium oxide or yttrium oxide to indium oxide, a thin film obtained by adding aluminum oxide to zinc oxide, or a laminate of many of these thin films Multilayer films can be used.

As the reflecting mirror 115 provided on the rear electrode substrate 108, a metal thin film having a smooth surface can be used. As the base material, a thin film of a metal having high visible light reflectance such as silver, aluminum, an aluminum alloy, magnesium, nickel, titanium, and chromium, or a multilayer metal thin film formed by laminating a number of these thin films can be applied. . The reflecting mirror 115 made of a metal film having a high light reflectance is processed by a photolithography process so as to divide the pixel into two. Further, the uppermost surfaces of the viewer-side transparent electrode layer 103 and the back-side transparent electrode layer 105,
That is, an alignment film is formed at the interface with the liquid crystal material 104. (Omitted in FIG. 1)

Further, in the transflective color liquid crystal display device 100 of the present invention, a color screen can be displayed by providing the color filter 102. A well-known color filter can be used as the color filter 102. For example, a color filter formed by printing a printing ink containing a colorant by a printing method, a photosensitive resin is applied, and exposed and developed in a pattern according to a photolithography method. After that, a color filter obtained by dyeing the remaining photosensitive resin with a dye, a pigment dispersion obtained by applying a photosensitive resin in which a coloring agent is dispersed and exposing and developing it in a pattern according to a photolithography method. For example, a color filter or the like can be used. It is also possible to use a color filter by an electrodeposition method.

When the driving method of the liquid crystal substance changes, the structure of the rear electrode substrate 108 also changes. The point is that the rear transparent electrode layer 105 is provided above the reflecting mirror 115 which substantially divides the pixel into two parts. As long as the liquid crystal material between the side electrode substrate 107 and the viewer-side transparent electrode layer 103 can be driven, a simple matrix system or an active matrix system using an active element such as a TFT may be used.

Finally, an alignment film, a polarizing plate and a retardation plate are assembled, the back side electrode substrate and the observer side electrode substrate are overlapped, and the outer periphery is sealed with a sealing material 112. Then, a well-known liquid crystal material such as a nematic liquid crystal is used. The transflective color liquid crystal display device 100 is completed by enclosing the liquid crystal display 104.

When the transflective color liquid crystal display device of the present invention is used as a reflection type color liquid crystal display device in a place where much external light is present, the incident light 121 for reflection shown in FIG.
18 and enters the observer-side electrode substrate 107. Color filter 102, liquid crystal substance 104, light scattering film layer 109
Is reflected by the reflecting mirror 115, passes through the light scattering film layer 109, the liquid crystal substance 104, the color filter 102, and the polarizer / analyzer 118 again, and the scattered reflected light 122 reaches the outside.

In a place where external light is small, it is used as a transmission type color liquid crystal display device. The incident light for transmission 123 passes through the light transmitting portion of the rear transparent substrate 106 on which the reflecting mirror 115 is not formed on the polarizer 119 and substantially half the amount of incident light, and the light scattering film layer 109 and the rear transparent electrode layer 105 are formed. , Liquid crystal substance 104, observer-side transparent electrode layer 103, color filter 102, observer-side transparent substrate 101, polarizer and analyzer 1
Go outside through 18.

The transflective color liquid crystal display device 10 of the present invention
0 is excellent in image resolution because the light scattering film layer 109 for reflection and the observer side transparent electrode layer 103 are opposed to each other with the liquid crystal material 104 interposed therebetween. Since the scattering / reflection electrode layer 415 shown in FIG. 4 is not used, the load at the time of manufacturing the back electrode substrate 108 is small.

FIGS. 5, 6, 7, and 8 show a transflective color liquid crystal using one example of the back electrode substrate according to claims 3, 4, 5, and 6, respectively. It is sectional drawing of a display apparatus. Since the back electrode substrate 508 according to claim 3 shown in FIG. 5 is a back electrode substrate in which the color filter 102 is provided on the light scattering film layer 109, the back electrode substrate is used as a transflective liquid crystal display device. In this case, the resolution can be improved, and a lower-cost transflective color liquid crystal display device can be obtained.

In the transflective liquid crystal display device shown in FIG. 7, since the color filter 102 and the light-scattering film layer 109 are provided on different substrates, the rate of defective production is reduced. Further, since the light-scattering film layer 109 is composed of the amorphous fine particles 110 and the transparent resin 111, fine irregularities of about 0.1 μm are easily generated on the surface of the film layer. Since the color filter 102 is provided on the light-scattering film layer 109 in the electrode substrate 508 and the back-side electrode substrate 808 shown in FIG. 8, the occurrence of minute unevenness can be prevented. Further, a photolithography step is required to pattern the light scattering film layer 109 with high accuracy, which is disadvantageous in terms of cost. However, in the rear electrode substrate 808 shown in FIG.
2 can be made thinner in the reflection part and thicker in the transmission part.

[0052]

FIG. 1 is a sectional view of an embodiment of a transflective color liquid crystal display device according to the present invention. Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG.

<Embodiment 1> A transflective color liquid crystal display device according to Embodiment 1 is provided with a rear electrode substrate 108 and an opposing surface of the rear electrode substrate 108 as shown in FIG. Observer-side electrode substrate 107 and these electrode substrates 1
The main part is composed of the liquid crystal substance 104, the sealant 112, the polarizer / analyzer 118, and the polarizer 119 which are sealed between the electrodes 08 and 107.

The rear electrode substrate 108 has a pitch of 300 μm and a width of 14 μm in a screen area on the rear transparent substrate 106.
A reflective mirror 115 made of aluminum having a thickness of 0.2 μm is provided in a total of 480 stripe patterns of 5 μm, and a light scattering film layer 109 and a back side transparent electrode layer are provided on a pixel provided with the reflective mirror 115. 105 is formed. The portion provided with the reflecting mirror 115 is a light reflecting portion that divides one pixel into a light reflecting portion and a light transmitting portion. Further, the rear transparent electrode layer 105 is formed on the light scattering film layer 109 at the same position above the reflecting mirror 115 and on the light scattering film layer 109 where the reflecting mirror 115 is not provided.

Hereinafter, the manufacturing process of the back electrode substrate 108 will be described step by step. A 1737 (product number) glass substrate manufactured by Corning Incorporated was prepared as the rear transparent substrate 106. An aluminum thin film having a thickness of 0.2 μm was formed on this glass substrate, and the reflecting mirror 115 was formed in the above-mentioned stripe pattern shape by a photolithography process according to a conventional method. After washing this glass substrate, a coating solution 1 having the following composition was dropped on the glass substrate, and then spin-coated at 1000 rpm for 5 seconds.

FIG. 1 shows the positional relationship and the shape between the light scattering film layer 109 and the reflecting mirror 115. In order to process the light scattering film layer into such a shape, the coating film was dried at 90 ° C. for 5 minutes after coating.
Using active light mainly composed of ultraviolet rays, the amount of light is 200 mJ / cm.
2 was subjected to pattern exposure. Immediately thereafter, the film was developed with weakly alkaline water having a pH of 10.1 to which a surfactant was added to remove unexposed portions, and further heated at 230 ° C. for 60 minutes to obtain a film thickness of 3.2.
A light scattering film layer 109 having a thickness of μm was formed.

The composition of the coating liquid 1 is shown below. The coating liquid 1 is prepared by first adding E) cyclohexanone as a solvent and B)
An alkali-soluble resin, C) an acrylic monomer, and D) a photopolymerization initiator are added and sufficiently stirred and dissolved. Next, A) amorphous fine particles were added, the mixture was treated with a medialess disperser, and further treated with an ultrasonic disperser.

<Composition of the coating liquid 1> A) Amorphous fine particles 5 parts by weight (trade name: Seahoster P150; manufactured by Nippon Shokubai Co., Ltd.) 24 parts by weight (Acrylic copolymer resin solution, monomer composition wt ratio: methacrylic acid / methyl methacrylate / butyl methacrylate / cyclohexyl methacrylate = 15/20/35/30, nonvolatile content: 25%, acid value (mg-KOH / g) ): 24, Mw: 39000, Mn: 14900) C) Acrylic monomer 4 parts by weight (Aronix M-400; Toagosei Co., Ltd.) D) Photopolymerization initiator 0.4 parts by weight (trade name Irgacure-369; Ciba Specialty Chemicals Co., Ltd.) E) Cyclohexanone 13.6 parts by weight

Next, 0.1 μm is applied on the light scattering film layer 109.
After the formation of the m-thick ITO film, the rear-side transparent electrode layer 105 was provided in a 960 stripe pattern with a pitch of 150 μm and a width of 145 μm by a conventional photolithography process to obtain a rear-side electrode substrate.

On the other hand, the observer-side electrode substrate 107 is provided on the observer-side transparent substrate 101 with the color filters 102 of three colors.
Was formed in a stripe pattern of a total of 480 stripes of three colors with a pitch of 300 μm and a width of 290 μm, and further, an observer-side transparent electrode layer 103 was sequentially formed on the color filter 102.

First, a colored photosensitive resin liquid in which a red pigment is dispersed (coating liquid R), a colored photosensitive resin liquid in which a green pigment is dispersed (coating liquid G), and a colored photosensitive resin liquid in which a blue pigment is dispersed (coating liquid R) The coating, pre-baking, exposure, development, and post-baking steps of B) were sequentially repeated under the following process conditions to form a color filter 102 of three colors. Thereafter, a viewer-side transparent electrode layer 103 was formed, and an alignment film (omitted in FIG. 1) treatment was performed. The compositions of the coating liquid R, the coating liquid G, and the coating liquid B are shown below.

<Colored photosensitive resin composition> <Coating liquid R> Pigment: C.I. Pigment Red 177.2.42 parts by weight C.I. Pigment Yellow 139.0.31 part by weight Polymer : Anionic acrylic polymer ··· 6.47 parts by weight · Monomer: ARONIX M-400 ··· 3.88 parts by weight (manufactured by Toagosei Co., Ltd.) · Photopolymerization initiator: Irgacure -369 ... 0.97 parts by weight-Organic solvent ... 85.93 parts by weight <Coating liquid G> -Pigment: C.I. Pigment.Green 36..2.90 parts by weight C.I. Pigment Yellow 139 0.71 parts by weight Polymer: anionic acrylic polymer 6.53 parts by weight Monomer: Aronix M-400 3.92 parts by weight Photopolymerization Initiator: Irugaki 0.98 parts by weight ・ Organic solvent ・ ・ ・ ・ 84.96 parts by weight <Coating liquid B> ・ Pigment: C.I. Pigment.Blue 15: 6..2.27 parts by weight C.I. Pigment Violet 23 0.12 parts by weight Polymer: anionic acrylic polymer 5.56 parts by weight Monomer: Aronix M-400 3.34 parts by weight -Photopolymerization initiator: Irgacure-369-0.84 parts by weight-Organic solvent-87.87 parts by weight

<Process conditions><Coating liquid R>-Coating: 650 rpm for 15 seconds, pre-baking: hot plate at 90 ° C for 3 minutes,-Exposure: 120 mJ / cm2, post-baking: oven at 230 ° C for 60 minutes <Coating liquid G>-Coating: Exposure: 150 mJ / cm 2, Post-bake: Oven 230 ° C. for 60 minutes <Coating solution B> Coating: 700 rpm for 15 seconds, Pre-bake: Hot plate 90 ° C. for 3 minutes, Exposure: 100mJ / cm2, post bake: oven 230 ° C for 60 minutes

The rear transparent electrode layer 105 and the observer transparent electrode 103 of the rear electrode substrate 108 are provided in a stripe pattern in a direction orthogonal to each other. An alignment film was applied to the surface of the electrode 103. (Omitted in FIG. 1) The back side transparent electrode layer 105 is used as a scanning line, and the observer side transparent electrode layer 103 is used as a signal line. It was configured so that

A rear electrode substrate 108 having a reflecting mirror 115, a light scattering film layer 109, and a rear transparent electrode layer 105 formed on a rear transparent substrate (glass substrate) 106, and a viewer-side transparent substrate (glass substrate) ) Color filter 1 on 101
02 and the observer-side electrode substrate 107 on which the observer-side transparent electrode layer 103 is formed.
After sealing with 2, a well-known liquid crystal 104 such as a nematic liquid crystal.
And a transflective color liquid crystal display device 100 was assembled by incorporating an alignment film, a polarizing plate and a retardation plate.

<Second Embodiment> A transflective color liquid crystal display device according to a second embodiment includes a rear electrode substrate 508 and an observer provided opposite to the rear electrode substrate 508 as shown in FIG. The main part is constituted by the side electrode substrate 507, the liquid crystal substance 104 sealed between these electrode substrates, the sealant 112, the polarizer / analyzer 118, and the polarizer 119. The second embodiment has a structure in which the color filter 102 is provided in contact with the light scattering film layer 109 on the rear transparent substrate 106, and a structure in which only the observer transparent electrode layer 103 is provided on the observer transparent substrate 101. It is.

In the second embodiment, the reflecting mirror 115 and the light scattering film layer 1
09, color filter 102, rear transparent electrode layer 10
5. The material composition and process conditions used for forming the observer-side transparent electrode layer 103 are the same as those in Example 1.

A reflecting mirror 115 and a light scattering film layer 109 were formed on the rear transparent substrate 106 in the same manner as in the first embodiment. Then, a pitch of 300 μm and a width of 29
A color filter 102 is formed in a stripe pattern of a total of 480 stripes of R, G, and B colors of 0 μm, and an ITO film of 0.1 μm is further formed. Thereafter, a pitch of 150 μm and a width of 290 μm are formed by a photolithography process according to a conventional method.
The rear-side transparent electrode layer 105 was formed in a total of 960 stripe patterns with m.

<Third Embodiment> A transflective color liquid crystal display device according to a third embodiment has a rear electrode substrate 608 and an observer provided opposite to the rear electrode substrate 608 as shown in FIG. The main part is composed of the side electrode substrate 607 and the liquid crystal substance 104, the sealant 112, the polarizer / analyzer 118, and the polarizer 119 sealed between these electrode substrates.

In Example 3, the reflecting mirror 115, the color filter 102, and the light scattering film layer 109 were formed on the rear transparent substrate 106. On the pixel on which the reflecting mirror 115 is formed, the color filter 1 is formed into a stripe pattern of a total of 480 stripes of R, G and B colors having a pitch of 300 μm and a width of 290 μm.
02, a light scattering film layer 109 is formed, an ITO film having a thickness of 0.1 μm is formed, and a pitch of 150 μm and a width of 290 μm are formed by a photolithography process according to a conventional method.
The rear-side transparent electrode layer 105 was formed in a total of 960 stripe patterns with m.

<Fourth Embodiment> A transflective color liquid crystal display device according to a fourth embodiment includes a rear electrode substrate 708 and an observer provided opposite to the rear electrode substrate 708 as shown in FIG. The main part is constituted by the side electrode substrate 707 and the liquid crystal substance 104, the sealant 112, the polarizer / analyzer 118, and the polarizer 119 sealed between these electrode substrates.

In Example 4, a reflecting mirror 115 and a light-scattering film layer 109 were formed on a rear transparent substrate 106. The scattering film layer 1
09 was formed only on the reflecting mirror 115 as shown in FIG. Further, on the pixel on which the light scattering film layer 109 is formed,
An ITO film having a thickness of 0.1 μm is formed, and then a pitch of 150 μm and a width of 145 μm are formed by a photolithography process according to a conventional method.
The rear-side transparent electrode layer 105 was formed in a total of 960 stripe patterns with m. On the other hand, the observer side transparent substrate 10
R, G, B3 with pitch 300μm, width 290μm on 1
The color filter 102 and then the observer-side transparent electrode layer 103 were formed in a stripe pattern of a total of 480 colors.

Fifth Embodiment A transflective color liquid crystal display device according to a fifth embodiment, as shown in FIG. 8, has a rear electrode substrate 808 and an observation device provided opposite to the rear electrode substrate 808. The main part is composed of the user-side electrode substrate 807 and the liquid crystal substance 104, the sealant 112, the polarizer / analyzer 118, and the polarizer 119 sealed between these electrode substrates.

In the same manner as in Example 4, a reflecting mirror 115 was formed on the rear transparent substrate 106, and a light scattering film layer 109 was formed only on the reflecting mirror 115. Next, the color filter 102,
A rear transparent electrode layer 105 was formed. On the other hand, the structure has an observer-side transparent electrode layer 103 formed on an observer-side electrode substrate.

Finally, an alignment film, a polarizing plate, and a retardation plate were incorporated using a combination of both the observer-side electrode substrate and the back-side electrode substrate prepared in Examples 2 to 5 above. After overlapping the observer-side electrode substrate and the back-side electrode substrate and sealing the outer periphery with a sealant 112, a well-known liquid crystal material 104 such as a nematic liquid crystal is sealed to assemble a transflective color liquid crystal display device. In total, 5 types of transflective color liquid crystal display devices were obtained.

A voltage is applied between the rear transparent electrode layer 105 located on the light transmitting portion provided on the rear transparent substrate 106 and the observation transparent electrode layer 103 provided on the observation transparent substrate 101. When displayed on the screen, the incident light for transmission 1
With No. 23, a display screen of a sufficiently bright color image could be recognized. A screen is displayed by applying a voltage between the back transparent electrode layer 105 located on the light reflecting portion also provided on the back transparent substrate 106 and the observation transparent electrode layer 103 provided on the observation transparent substrate 101. , Incident light for reflection 12
1, a sufficiently bright and clear display screen was obtained. In the above embodiment, the structure of the electrode plate is a simple matrix. However, the present invention is not limited to this, and various active matrix systems may be used.

[0077]

According to the present invention, there is provided a back electrode substrate having a light scattering film layer and a back transparent electrode layer provided on a pixel which is divided into a light reflecting portion and a light transmitting portion by a reflecting mirror, a color filter, and an observer. Since it is a transflective color liquid crystal display device with the observer side electrode substrate provided with the side transparent electrode layer facing each other, when used as a reflective color liquid crystal display, the light scattering film layer is mounted outside the liquid crystal cell. The image resolution is improved compared to the reflective type color liquid crystal display device, and the manufacturing process can be reduced compared to the reflective type color liquid crystal display device provided with the scattering reflective electrode layer, resulting in a low-cost transflective color liquid crystal display device. .

The present invention also relates to a back surface used in a transflective color liquid crystal display device in which a light scattering film layer and a back side transparent electrode layer are provided on a pixel divided into a light reflecting portion and a light transmitting portion by a reflecting mirror. Since the transflective color liquid crystal display device is used as a reflective color liquid crystal display because it is a side electrode substrate, the image resolution is higher than that of a reflective color liquid crystal display device in which a light scattering film layer is mounted outside the liquid crystal cell. The manufacturing cost can be reduced compared with the reflection type color liquid crystal display device provided with the scattering / reflection electrode layer.

Further, according to the present invention, by providing the color filter and the light-scattering film layer on another substrate, the incidence of defective products in manufacturing can be reduced. Further, since the light scattering film layer is composed of amorphous fine particles and a transparent resin, fine irregularities are likely to be generated on the surface of the film layer. The occurrence of unevenness can be prevented. Further, by accurately patterning the light scattering film layer, the thickness of the color filter can be made thinner in the reflection part and thicker in the transmission part.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a transflective color liquid crystal display device according to the present invention.

FIG. 2A is a sectional view of a transmission type color liquid crystal display device according to a conventional method. (B) It is sectional drawing of the reflection type color liquid crystal display device using the light-scattering film layer which concerns on a conventional method. (C) is a cross-sectional view of a reflective type color liquid crystal display device using a reflective electrode having a light scattering function according to a conventional method.

FIG. 3 is a cross-sectional view of a half mirror type transflective color liquid crystal display device according to a conventional method.

FIG. 4 is a cross-sectional view of a pixel-division type transflective color liquid crystal display device according to a conventional method.

FIG. 5 is a cross-sectional view of a transflective liquid crystal display device using the back electrode substrate according to claim 3;

FIG. 6 is a cross-sectional view of a transflective liquid crystal display device using the back electrode substrate according to claim 4;

FIG. 7 is a cross-sectional view of a transflective liquid crystal display device using the back electrode substrate according to claim 5;

FIG. 8 is a sectional view of a transflective liquid crystal display device using the back electrode substrate according to claim 6;

[Explanation of symbols]

100: transflective color liquid crystal display device according to the present invention 101, 201, 301, 401 ... observer side transparent substrate 102, 202, 302, 402 ... color filter 103, 203, 303, 403 ... -Observer side transparent electrode layer 104, 204, 304, 404 ... Liquid crystal material 105 205, 405 ... Back side transparent electrode layer 106, 206, 306, 406 ... Back side transparent substrate 107 , 207, 307, 407 ... Observer side electrode substrate 108, 208, 308, 408 ... Back side electrode substrate 109, 209, 309 ... Light scattering film layer 110 ... ········· Amorphous fine particles 111 ······ Transparent resin 112, 212, 312, 412 ··· Sealing material 115 ···· ... ... Reflecting mirrors 118, 318, 418... Polarizers and analyzers 119, 319, 419... Polarizers 121, 221, 321, 421. Incident light 122, 222, 322, 422 ... Scattered reflected light 123, 223, 323, 423 ... Incident light for transmission 215 ... Reflective electrode layer 217 ...・ ・ ・ Light sources 225, 415 ・ ・ ・ Scattering / reflection electrode layer 300 ・ ・ ・ Semi-transmissive color liquid crystal of half mirror type combining light scattering film layer Display device 305: Half mirror / electrode layer 400: Transflective color liquid crystal display device of pixel division type combining scattering / reflection electrode layer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G02F 1/1333 500 G02F 1/1333 500 (72) Inventor Takao Taguchi 1-5-1, Taito, Taito-ku, Tokyo Letterpress stamp F term (for reference) in Printing Co., Ltd. 2H042 BA02 BA15 BA20 2H048 BA45 BA48 BB02 BB08 BB10 BB44 2H090 JA03 JA05 JC03 LA01 LA10 LA20 2H091 FA02Y FA08X FA08Z FA15Y FA16Y FA31Y LA15 LA17 LA20

Claims (6)

[Claims] 1. A transparent resin and amorphous fine particles dispersed in the transparent resin and having different refractive indices, which are divided into a light reflecting portion and a light transmitting portion by dividing one pixel according to the presence or absence of a reflecting mirror. A light-scattering film layer to be provided, a back-side electrode substrate provided with a back-side transparent electrode layer on the light-scattering film layer, and an observer-side electrode substrate provided with a color filter and an observer-side transparent electrode layer in this order. A transflective color liquid crystal display device, which is disposed to face each other, has a liquid crystal material sealed between these electrode substrates, and applies a voltage to each pixel for each pixel to display a screen. 2. A back electrode substrate having a back transparent electrode layer provided on a pixel which is divided into a light reflecting portion and a light transmitting portion by dividing one pixel into a light reflecting portion and a light transmitting portion. An observer-side electrode substrate provided with an observer-side transparent electrode layer arranged in opposition, and a liquid crystal material sealed between these electrode substrates are provided, and a voltage is applied to the liquid crystal material for each pixel. In the rear electrode substrate used for the transflective liquid crystal display device for displaying a screen, a transparent resin and amorphous fine particles dispersed in the transparent resin and having different refractive indices are mainly contained on pixels of the rear electrode substrate. A light-scattering film layer and a back-side transparent electrode layer are sequentially provided. 3. The back electrode substrate according to claim 2, wherein a color filter is provided on the light scattering film layer. 4. The rear electrode substrate according to claim 2, wherein a color filter is provided on the pixel, and the light scattering film layer and the rear transparent electrode layer are sequentially provided on the color filter. 5. The back-side electrode substrate according to claim 2, wherein said light-scattering film layer is provided only on said reflecting mirror. 6. The rear electrode substrate according to claim 2, wherein a color filter is provided on a pixel provided with the light scattering film layer only on the reflecting mirror.