JP2003149631A - Method for manufacturing transmission and reflection- combined type liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the chromaticity difference between transmitted light and reflected light in a transmission and reflection-combined type liquid crystal display device, wherein at least on of transparent substrates 1 and 2 is provided with a color filter, and in a part of each pixel area, transmission areas for transmitting light from a backlight and emitting the light and reflection areas for reflecting external light with a reflection plate and emitting the external light are formed. SOLUTION: This display device is characterized in that it is constituted of a first color filter part 10 in which a color filter is provided on the transparent substrate 1 and a second color filter part 20 in which a color filter is provided on the transparent substrate 2, and as the first color filter part 10, a color filter is formed which comprises clear parts 12 being substantially colorless provided in reflection areas and color parts 11 colored with prescribed colors provided in a transmission area, and as the second color filter part 20, a color filter, in which both a transmission area and reflection areas in each pixel area are colored with prescribed colors, is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal display device in combination with transmission and reflection, and more particularly to a method of manufacturing a liquid crystal display device in combination with transmission and reflection having a novel color filter structure. is there.

[0002]

2. Description of the Related Art In a liquid crystal display used in a portable device or the like, in order to extend battery life, a transmissive liquid crystal display that uses a backlight is changed to a reflective type that does not use a backlight. A liquid crystal display, or a liquid crystal display called a semi-transmissive type in which a backlight is turned on only when necessary or a combined transflective type is in progress.

The reflection type liquid crystal display has a problem that it can be visually recognized well in a bright place such as outdoors, but is difficult to see in a dark place such as an interior or at night. As a solution to such a problem, attention has been paid to the above-described transmission / reflection combined type liquid crystal display.

As a color filter used in such a transflective liquid crystal display, a conventional color filter used in a transmissive liquid crystal display or a reflective liquid crystal display is used, but the chromaticity difference between transmitted light and reflected light is used. There was a problem that was large. That is, since the transmitted light passes through the color filter once, the reflected light passes through the color filter twice, so that the chromaticity of the transmitted light is low and the chromaticity of the reflected light is high.

It is an object of the present invention to provide a method of manufacturing a liquid crystal display device of the combined transmission and reflection type which can reduce the chromaticity difference between transmitted light and reflected light.

[0006]

According to the manufacturing method of the first aspect of the present invention, a color filter is provided on at least one of a pair of transparent substrates sandwiching a liquid crystal layer, and external light is exposed to a part of each pixel region. By providing the reflecting plate that reflects light, a transmissive region that transmits the light from the backlight and emits the light to the outside and a reflective region that reflects the external light by the reflector and emits the light to the outside are provided in each pixel region. A method of manufacturing a formed transmissive / reflection type liquid crystal display device, comprising: a color filter having a first color filter portion provided on an inner transparent substrate which is a backlight side and a first color filter portion provided on an outer transparent substrate. 2 color filter sections, and as a first color filter section, a substantially colorless clear section provided in a reflection area on a reflection plate provided on the transparent substrate, and a transparent section on the transparent substrate. A color filter including a color portion colored in a predetermined color, which is provided in a transmissive area where the projection plate is not provided, is formed. The feature is that a color filter colored in a predetermined color is formed.

In the manufacturing method according to the second aspect of the present invention, a color filter is provided on at least one of a pair of transparent substrates sandwiching a liquid crystal layer, and a reflection plate for reflecting external light is provided in a part of each pixel region. Accordingly, a transmissive area is formed in each pixel area in which a transmissive area that transmits the light from the backlight and emits to the outside and a reflective area that reflects the external light by the reflector and emits this to the outside are used together. Color liquid crystal display device manufacturing method, wherein the color filter has a first color filter portion provided on an inner transparent substrate which is a backlight side, and a second color filter provided on the first color filter portion. And a substantially colorless clear portion provided in the reflection area on the reflection plate provided on the transparent substrate as a first color filter portion.
A color filter including a color portion colored in a predetermined color, which is provided in a transmissive region on the transparent substrate where the reflection plate is not provided, is formed, and as a second color filter portion, a transmissive region in each pixel region is formed. It is characterized in that a color filter is formed in which both the reflection areas are colored in a predetermined color.

Items common to the first aspect and the second aspect according to the present invention will be described below as the "present invention". In the present invention, as the first color filter portion, a color filter including a substantially colorless clear portion provided in the reflective region and a color portion colored in a predetermined color provided in the transparent region is formed. Also, the second
As the color filter portion, a color filter in which the transmissive area and the reflective area in each pixel area are colored with a predetermined color is formed. Therefore, the light that passes through the transmissive region, that is, the transmitted light, is transmitted to the color portion of the first color filter portion,
It passes through the second color filter section. That is, the transmitted light passes twice through the colored filter portion. On the other hand, the light passing through the reflection area, that is, the reflected light, is
It passes through the clear section of the first color filter section and the second color filter section when it is incident and when it is reflected. Since the clear portion is substantially colorless, the reflected light also passes through the colored color filter portion twice like the transmitted light. Therefore, according to the present invention, both the transmitted light and the reflected light pass through the colored filter portion twice, so that the chromaticity difference between the transmitted light and the reflected light can be made substantially equal.

In the present invention, the colorlessness of the clear portion in the first color filter portion means that it is relatively colorless with respect to the color portion, and may be slightly colored. That is, it means that the clear portion should be lighter in color than the color portion to the extent that the difference in chromaticity between transmitted light and reflected light can be reduced.

The first color filter portion and / or the second color filter portion in the present invention can be formed by, for example, a resist electrodeposition method. The resist electrodeposition method is a method of forming a color filter by depositing a colored resin layer by an electrodeposition method using a resist film as a mask. However, the formation of the first color filter portion and the second color filter portion of the present invention is not limited to the resist electrodeposition method, and may be formed by other methods such as a photolithography method.

The resin used in the resist electrodeposition method may be either cationic, anionic or amphoteric, and various conventionally known resins such as acrylic resin, epoxy resin, urethane resin, polybutadiene resin and polyamide resin. , Carboxyl group-introduced polybutadiene, carboxyl group-introduced alkyd resin and the like. Colored coatings composed of these resins are a kind of colloidal dispersion in which pigments and resin particles are dispersed in a solvent such as water, for example,
Anion type paint using a salt in which anions such as carboxy groups are neutralized with amine or ammonium as resin particles,
A cationic coating composition is known which uses a salt obtained by neutralizing an amino group with an organic acid such as acetic acid. When forming the clear portion, a clear electrodeposition paint is used. As the clear electrodeposition coating composition, a coating composition containing no pigment or a small pigment content, or an electrodeposition coating composition containing a transparent pigment and / or a fine particle pigment capable of providing a substantially transparent coating film can be used. .

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments according to the present invention will be described. However, the present invention is not limited to the following embodiments, and various modifications may be made without departing from the scope of the present invention. It is possible.

FIG. 1 is a schematic sectional view showing a transflective liquid crystal display device manufactured according to an embodiment of the first aspect of the present invention. In the liquid crystal display device shown in FIG. 1, a pair of transparent substrates 1 and 2 are provided so as to sandwich the liquid crystal layer 3. As the transparent substrates 1 and 2, transparent substrates such as glass substrates and plastic substrates are generally used. Although not shown, a backlight is provided below the transparent substrate 1.

On the surface of the transparent substrate 1 on the liquid crystal layer 3 side, the first
The color filter unit 10 is provided. On the transparent substrate 1, there is provided a reflection plate 4 for reflecting external light incident from the outside through the liquid crystal layer 3. Reflector 4
Is formed of a metal such as aluminum or silver. The surface of the reflection plate 4 is diffused and diffused to widen the viewing angle, so that fine irregularities are generally formed on the surface. Such fine irregularities on the surface of the reflector 4 are
It may be formed by forming irregularities on the base layer of the reflection plate 4.

The reflector 4 is provided in a part of the pixel area, and is not provided in other parts of the pixel area.
Therefore, as shown in FIG.
A reflective region that reflects external light and a transmissive region that directly transmits light from the backlight and emits the light to the outside are formed. Such a reflection plate 4 can be formed by patterning after forming the reflection plate on the entire surface and then removing the portion corresponding to the transmission region by etching or the like.

The first color filter section 10 is provided on the transparent substrate 1 provided with the reflection plate 4 as described above, and the clear section 12 is formed in the reflection area where the reflection plate 4 is provided. , And a collar portion 11 provided in the transmissive region where the reflection plate 4 is not provided. In FIG. 1, "C" indicates a clear layer, "R" indicates a color portion colored red, "G" indicates a color portion colored green, and "B" is colored blue. The colored portion is shown.

In the first color filter section 10, the black matrix section 1 is provided at the boundary of the pixel area.
3 is formed. Second color filter section 20
Are provided on the liquid crystal layer 3 side of the transparent substrate 2. In the second color filter section 20, the color section 21 in which the entire pixel region is colored with a predetermined color (R, G, or B) is formed. Therefore, both the transmissive area and the reflective area in each pixel area are colored with a predetermined color (R, G, or B). Also in the second color filter section 20, the black matrix section 22 is formed at the boundary portion of the pixel area.

Although not shown in FIG. 1, electrodes and the like for driving the liquid crystal layer 3 are formed on the first color filter section 10 and the second color filter 20.

FIG. 2 is a schematic sectional view showing the transmitted light in the transmissive region and the reflected light in the reflective region in the embodiment shown in FIG. As shown in FIG. 2, the transmitted light 30 from the backlight passes through the color portion 11 of the first color filter portion 10 and further to the second color filter portion 20.
The light is emitted to the outside through the color portion 21 of. Further, the light 40 incident from the outside passes through the color portion 21 of the first color filter portion 20, and then the second color filter portion 1
The clear plate 12 of 0 reaches the reflector 4 and the reflector 4
Is reflected by the first color filter unit 10 again.
The second color filter section 20 through the clear section 12 of
The light passes through the color portion 21 and is emitted to the outside as reflected light.
Since the clear portion 12 is a colorless layer that is not substantially colored, the reflected light 40, like the transmitted light 20, passes through the two color portions and then is emitted to the outside.

Therefore, in the liquid crystal display device manufactured according to the present invention, since the transmitted light and the reflected light both pass through the two color portions and are emitted to the outside, the chromaticity of the transmitted light and the reflected light is almost the same. It can be adjusted to be equivalent. Fine adjustment of the chromaticity difference between transmitted light and reflected light can be controlled by adjusting the thickness and color density of each color portion.

3 to 5 are schematic cross-sectional views for explaining an example of the process of manufacturing the first color filter portion shown in FIG. As shown in FIG. 3A, a reflective plate 4 is formed on the transparent substrate 1 so as to be patterned so that the reflective region is left except the transmissive region. After forming the insulating film 5 made of SiO ₂ on the reflection plate 4, the transparent conductive film 6 made of ITO or the like is formed thereon. A photoresist film 7 having a thickness of, for example, 1.5 is formed on the transparent conductive film 6.
It is formed by uniformly coating so as to have a thickness of μm. As the photoresist film 7, a positive type photoresist film is formed.

Next, as shown in FIG. 3B, ultraviolet rays are selectively exposed to a portion where the clear layer is to be formed using a mask or the like to form an exposed portion 7a on the photoresist film 7. Next, as shown in FIG. 3C, a developing process is performed using an alkaline solution to remove the exposed portion 7a and form an opening 7b.

Next, as shown in FIG. 3D, a clear electrodeposition coating is used to deposit a clear electrodeposition film on the opening 7b to form a clear portion 12. At this time, the transparent conductive film 6 is used as an electrode.

Next, as shown in FIG. 4 (e), the exposed area 7c is formed by selectively exposing the area forming the color area with ultraviolet rays. Next, as shown in FIG. 4 (f), a development process is performed using an alkaline solution to remove the exposed portion 7c and form an opening 7d.

Next, as shown in FIG. 4G, a colored electrodeposition film is deposited by using an electrodeposition coating material containing a pigment of a predetermined color to form the color portion 11. The color portions of other colors are also formed by repeating the steps of FIGS. 4E to 4G in the same manner as above.

Next, as shown in FIG. 5 (h), the exposed portion 7e is formed by selectively exposing the region forming the black matrix portion with ultraviolet rays, and as shown in FIG. 5 (h). The exposed portion 7e is developed with an alkaline solution and removed to form the opening 7f.

Next, as shown in FIG. 5 (j), the opening 7
An electrodeposition film containing a black pigment is deposited on f to form the black matrix portion 13. As described above, FIG.
The color filter portion 10 in the embodiment shown in can be formed. The second color filter section 20 has the same structure as a conventional color filter, and thus can be formed by a method similar to the conventional method. For example, in FIG.
In the formation of the first color filter portion shown in FIG. 5, it can be manufactured by a manufacturing method excluding the step of forming the clear portion.

In order to confirm the effect of the present invention, a glass substrate having an ITO film formed thereon is subjected to the method shown in FIGS.
The first color filter part is formed, and the second color filter part is formed on the glass substrate on which the ITO film is formed, and these color filters are overlapped, and the chromaticity in the transmissive region and the reflective region is determined by the C2 light source. It was measured using.
In the measurement of the reflection area, a silver vapor deposition plate having a reflectance of 95% was placed under the two overlapping filters. The measurement results are shown in Table 1.

[0029]

[Table 1]

As is apparent from Table 1, according to the present invention,
It can be seen that the chromaticity of the transmitted light and the chromaticity of the reflected light can be made substantially equal by using the first color filter part and the second color filter part in combination.

For comparison, the chromaticity of transmitted light and reflected light was measured in the same manner as above using only the second color filter section. The results are shown in Table 2.

[0032]

[Table 2]

Further, a color filter of the second color filter having a double thickness was prepared and the chromaticity of transmitted light and reflected light was measured in the same manner as above. The results are shown in Table 3.

[0034]

[Table 3]

As is clear from the results of Tables 2 and 3,
It can be seen that when a conventional color filter is used, the chromaticity of transmitted light is smaller than that of reflected light. Figure 6
FIG. 7 is a schematic cross-sectional view showing a color filter of a liquid crystal display device manufactured in an example according to the second aspect of the present invention.
As shown in FIG. 6, in this embodiment, the second color filter section 20 is provided on the first color filter section 10. Therefore, in this liquid crystal display device, the color filter is provided only on the transparent substrate 1 on the backlight side. Although not shown, a transparent conductive film made of ITO or the like is formed on the first color filter portion 10, and the transparent conductive film is used to form the color portion of the second color filter portion 20 by an electrodeposition method. Is forming.

With the structure of the color filter as shown in FIG. 6, the chromaticity of the transmitted light and the reflected light can be adjusted to be substantially equal to each other, as in the embodiment shown in FIG. In each of the above-mentioned embodiments, an example in which the color filter of the present invention is formed by the resist electrodeposition method is shown, but the present invention is not limited to this, and the color filter may be formed by other methods.

[0037]

According to the present invention, it is possible to manufacture a transmission / reflection combined liquid crystal display device capable of reducing the chromaticity difference between transmitted light and reflected light.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a liquid crystal display device manufactured according to an example according to a first aspect of the present invention.

FIG. 2 is a schematic cross-sectional view showing transmitted light passing through a transmissive region and reflected light passing through a reflective region in the embodiment of FIG.

3 is a schematic cross-sectional view showing an example of a manufacturing process of a first color filter section in the embodiment shown in FIG.

FIG. 4 is a schematic cross-sectional view showing an example of a manufacturing process of a first color filter section in the embodiment shown in FIG.

FIG. 5 is a schematic cross-sectional view showing an example of a manufacturing process of the first color filter section in the embodiment shown in FIG.

FIG. 6 is a schematic cross-sectional view showing a liquid crystal display device manufactured by an example according to the second aspect of the present invention.

[Explanation of symbols] 1, 2 ... Transparent substrate 3 ... Liquid crystal layer 4 ... Reflector 5 ... Insulating film 6 ... Transparent conductive film 7 ... Photoresist film 7a, 7c, 7e ... Exposure unit 7b, 7d, 7f ... Opening 10 ... First color filter section 11 ... Color part 12 ... Clear section 13 ... Black matrix part 20 ... Second color filter section 21 ... Color part 22 ... Black matrix part 30 ... transmitted light 40 ... Reflected light

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/13357 G02F 1/13357 (72) Inventor Hiroyuki Hashiguchi 19-17 Ikedanaka-cho, Neyagawa-shi, Osaka Japan Int Co., Ltd. (72) Inventor Masafumi Ohata 19-17 Ikedanaka-cho, Neyagawa, Osaka Japan Paint Co., Ltd. F-term (reference) 2H042 BA03 BA15 BA20 DA02 DA04 DA11 DA12 DC08 DE04 2H048 BA02 BA11 BA54 BA62 BB02 BB03 BB07 BB14 BB15 BB42 2H091 FA02Y FA14Y FC06 FD04 FD05 GA02 LA13

Claims (3)

[Claims] 1. A color filter is provided on at least one of a pair of transparent substrates sandwiching a liquid crystal layer, and a reflection plate for reflecting external light is provided in a part of each pixel region, so that light from a backlight is transmitted. A method of manufacturing a transflective / combined liquid crystal display device, wherein a transmissive area that transmits and emits to the outside and a reflective area that reflects external light by the reflector and emits the external light to each pixel area are formed in each pixel area. The color filter includes a first color filter section provided on the transparent substrate on the inner side which is the backlight side, and a second color filter section provided on the transparent substrate on the outer side, As the first color filter portion, a substantially colorless clear portion provided in a reflection area on the reflection plate provided on the transparent substrate and the reflection plate on the transparent substrate are provided. Forming a color filter comprising a color portion colored in a predetermined color provided in a non-transmissive area, and as the second color filter section, the transmissive area and the reflective area in each pixel area are both of a predetermined color. 1. A method for manufacturing a combined transflective liquid crystal display device, which comprises forming a color filter colored in the above. 2. A color filter is provided on at least one of a pair of transparent substrates sandwiching a liquid crystal layer, and a reflection plate for reflecting external light is provided in a part of each pixel region, so that light from a backlight is shielded. A method of manufacturing a transflective / combined liquid crystal display device, wherein a transmissive area that transmits and emits to the outside and a reflective area that reflects external light by the reflector and emits the external light to each pixel area are formed in each pixel area. The color filter is composed of a first color filter section provided on the transparent substrate on the inner side which is the backlight side, and a second color filter section provided on the first color filter section. As the first color filter portion, a substantially colorless clear portion provided in a reflection area on the reflection plate provided on the transparent substrate, and the reflection on the transparent substrate. Forming a color filter comprising a color portion colored in a predetermined color provided in a transmissive region not provided with the transmissive region and the reflective region in each pixel region as the second color filter unit. A method for manufacturing a combined transflective liquid crystal display device, which comprises forming a color filter in which both regions are colored in a predetermined color. 3. The transflective / combined liquid crystal display according to claim 1, wherein the first color filter portion and / or the second color filter portion is formed by a resist electrodeposition method. Device manufacturing method.