JP2004309532A - Outer surface diffusion semitransmission reflection plate and outer surface diffusion semitransmission color liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an outer surface diffusion semitransmission reflection plate used for an outer surface diffusion semitransmission color liquid crystal display having excellent color reproducibility of a color filter and to provide the outer surface diffusion semitransmission color liquid crystal display having the characteristic. <P>SOLUTION: In the outer surface diffusion semitransmission reflection plate, a transparent resist resin film is formed on a metal film to form a laminated film after the metal film is formed on one surface of a glass plate, a through hole to be a light guide path is formed by performing a photolithography step and an etching step to the laminated film so that light of a backlight as a light source made incident from the surface opposite to the surface of the glass plate on which the laminated film is formed passes through. The outer surface diffusion semitransmission reflection plate is used in the state that the transparent resist resin film remains without being peeled from the surface of the metal film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an external diffused transflective reflector used in an external diffused transflective color liquid crystal display device having excellent color reproducibility of a color filter, and to an external diffused transflective color liquid crystal display device having the above characteristics.
[0002]
[Prior art]
In recent years, an external diffusion semi-transmissive color liquid crystal display device that uses a backlight as a light source together with external light, has high reflection efficiency over a wide angle in a bright or dark place, and has a wide viewing angle in any direction. In addition, attention has been paid to a semi-transmissive color liquid crystal display device having an internal diffusion. For example, in Patent Literature 1 below, the surface of a transparent plate such as a glass plate through which light passes is made uniform and finely rough by sandblasting, and a metal film such as aluminum is formed thereon as a reflective film by a vacuum deposition method or the like. An internal diffusion semi-transmissive reflection plate is disclosed which is formed and patterned by performing a photolithography process and an etching process on a light guide path through which light passes through the reflection film at a constant uniform interval. A transparent protective film is formed on the reflective film of the plate to prevent oxidation of the reflective film and the surface is flattened. A color filter layer and a transparent electrode layer are formed on the transparent protective film. An internal diffusion semi-transmissive color liquid crystal display device as a substrate is disclosed. According to the inner surface diffusion semi-transmissive color liquid crystal display device, light incident from the outside is diffusely reflected on the surface of the reflection film and diffused uniformly, and light from the backlight as a light source passes through the light guide path and is directed to the front side. It is possible to efficiently use external light and light from a light source because it has high reflection efficiency over a wide angle in bright and dark places, and has a wide viewing angle in any direction. The effect is obtained.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-19507
[Problems to be solved by the invention]
Although the internal diffusion semi-transmissive color liquid crystal display device described in Patent Document 1 has excellent characteristics, the color reproducibility of the color filter is not always satisfactory. In addition, by performing a photolithography process and an etching process, a light guide path is formed in the metal film to form an inner surface diffusion semi-transmissive reflection plate, and a transparent protective film is formed thereon. A step of removing the formed resist is required. Therefore, there is a problem that the number of manufacturing steps increases and the manufacturing cost increases. Also, when the metal film is deteriorated by a resist stripper during the step of stripping the resist on the surface of the metal film, or when resist residue remains on the surface of the metal film due to insufficient peeling of the resist. May adversely affect the characteristics of the metal film as the reflective film. The resist residue on the surface of the metal film can be removed by sintering the surface of the metal film, but this leads to an increase in the number of manufacturing steps and an increase in cost.
At present, there is no external diffusion semi-transmissive color liquid crystal display device having excellent color reproducibility of color filters.
Accordingly, the present invention provides an external diffusion semi-transmissive color liquid crystal display device used in an external diffusion semi-transmissive color liquid crystal display device having excellent color reproducibility of a color filter, and an external diffuse semi-transmissive color liquid crystal display device having the above characteristics. The purpose is to do.
[0005]
[Means for Solving the Problems]
According to the outer surface diffusion semi-transmissive reflection plate of the present invention based on the above points, as described in claim 1, after forming a metal film on one surface of a glass plate, a transparent resist resin film is formed thereon. A photolithography process is performed on the laminated film so that light having a backlight as a light source that enters from a surface opposite to the surface of the glass plate on which the laminated film is formed passes. It is characterized in that a through hole serving as a light guide path is formed by performing an etching step, and the transparent resist resin film is used without being separated from the surface of the metal film.
According to a second aspect of the present invention, there is provided an outer surface diffusion semi-transmissive reflection plate, wherein the transparent resist resin film is formed using a negative type resist. .
According to a third aspect of the present invention, there is provided an outer surface diffusion semi-transmissive color liquid crystal display device including the outer surface diffusion semi-transmission type reflection plate according to the first aspect.
According to a fourth aspect of the present invention, there is provided an external diffusion semi-transmissive color liquid crystal display device according to the third aspect, wherein a color is provided on the external diffusion semi-transmissive reflection plate according to the first aspect. A filter layer is directly formed, and a transparent electrode layer and an alignment film are formed on the color filter layer via a flattening film to form one substrate for a liquid crystal display, and is opposed to the substrate via the liquid crystal layer. An external diffusion semi-transmissive color liquid crystal display device provided with a color liquid crystal display mechanism by disposing the other substrate for liquid crystal display provided with a light diffusion film, wherein a single color is provided in the through hole. The color filter layer is formed so as to be filled with a filter material.
According to a fifth aspect of the present invention, there is provided an outer surface diffusion semi-transmissive color liquid crystal display device, wherein a black layer is formed on the transparent resist resin film. It is characterized by.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
The outer surface diffusion semi-transmissive reflection plate of the present invention is formed as a laminated film by forming a metal film on one surface of a glass plate and then forming a transparent resist resin film thereon, and the laminated film is formed. A through-hole serving as a light guide path is formed by performing a photolithography process and an etching process on the laminated film so that light having a backlight as a light source incident from a surface opposite to the surface of the glass plate passes therethrough. It is characterized in that the transparent resist resin film is used without being peeled off from the surface of the metal film.
The internal diffusion semi-transmissive color liquid crystal display device described in Patent Document 1 described above has a transparent protective film formed on a reflective film formed on a glass plate having a uniform and fine rough surface. Since the surface is flattened and the color filter layer is formed thereon, the light guide path formed in the reflection film is filled with the protective film material, and the individual color filters, red (R), green (G) ) And blue (B) are formed on the protective film.
On the other hand, an external diffusion semi-transmissive color liquid crystal display device including the external diffusion semi-transmissive reflection plate of the present invention is, for example, a color filter layer is directly formed on the external diffusion semi-transmissive reflection plate, and A single collar is formed in the through hole that becomes the light guide path formed by performing a photolithography process and an etching process on a laminated film of a metal film that is a reflective film and a transparent resist resin film formed thereon. The filter material is formed to be filled. Therefore, in such an outer surface diffusion semi-transmissive color liquid crystal display device, the thickness of the color filter layer is increased, and particularly, light is incident from the surface opposite to the surface of the glass plate on which the laminated film is formed. This is effective in improving the color reproducibility of the color filter when light passes through the light guide path. In addition, the transparent resist resin film formed on the metal film is not peeled off, and is used as a component of the external diffusion semi-transmissive reflection plate, so that the number of manufacturing steps can be reduced and the cost can be reduced. There is an advantage that there are no various problems that may occur when the resist is stripped, and the characteristics of the metal film as the reflection film can be maintained.
[0007]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description.
[0008]
1. FIG. 1 shows an embodiment of an external diffusion transflective reflector according to the present invention. The outer surface diffusion semi-transmissive reflection plate A is manufactured, for example, through the steps shown in FIG.
[0009]
That is, first, as shown in FIG. 2A, the metal film 11 is formed on the glass plate 2 which is a transparent substrate. The metal film 11 is preferably made of aluminum, silver, or an alloy thereof, and has a thickness of 0.1 μm to 0.5 μm. Such a metal film 11 can be easily formed by, for example, a vacuum evaporation method or a sputtering method.
[0010]
Subsequently, as shown in FIG. 2B, a transparent resist resin film 12 is formed on the metal film 11 to form a laminated film. The transparent resist resin film 12 is not particularly limited as long as it is made of a material that does not adversely affect the reflectance when light incident from the outside is reflected on the metal film 11 located therebelow. However, the material of the transparent resist resin film 12 is a negative resist (acrylic resist) that has excellent transparency and can form a light guide path with excellent dimensional accuracy by performing a photolithography process in the next process. Etc.) are preferably used.
The transparent resist resin film 12 is formed, for example, by applying a resin liquid for forming the transparent resist resin film 12 onto the glass plate 2 by a coating method such as a spin coating method, and then applying a heating device such as a heating furnace. It can be formed by heating and baking for 40 seconds or more in a temperature range of ° C to 120 ° C. It is desirable that the film thickness be 0.5 μm to 3.0 μm. With such a film thickness, the balance between the transmitted color of light using the backlight as a light source and the reflected color of light incident from the outside becomes good, and excellent color reproducibility can be obtained.
[0011]
Finally, as shown in FIG. 2 (c), after performing a photolithography process on the transparent resist resin film 12, an etching process is performed on the metal film 11 to pass light using a backlight as a light source. Then, a through-hole 13 serving as a light guide path for emitting light to the front side is formed in the laminated film. Exposure / development by photolithography is performed, for example, by using a photomask on which a predetermined fine pattern (a pattern for forming a light guide path in the transparent resist resin film 12) is drawn with high precision according to a conventional method. After performing, developing using a predetermined developing solution to remove the resin other than the pattern portion, and finally baking by heating at about 240 ° C. for at least 30 minutes using a heating device such as a heating furnace. It should be done in. By the above operation, the pattern on the photomask is accurately transferred, and a light guide path is formed in the transparent resist resin film 12. The etching process for the metal film 11 may be performed according to a conventional method using an etchant corresponding to the material of the metal film.
There is no particular limitation on the pattern for forming the light guide path, but it is preferable that the pattern of the formed light guide path be smaller than the size of each color filter formed later, and It is desirable to make the pattern such that at least one or more light guide paths exist in the area of each color filter. In this case, it is desirable that the aperture ratio of the aperture formed as the light guide path in the area of each color filter is 10% to 50%. If the aperture ratio is smaller than 10%, the transmittance may decrease. On the other hand, if the aperture ratio exceeds 50%, the reflectance may decrease.
[0012]
FIG. 3 shows an embodiment of the color filter layer formed on the outer surface transflective reflector A. A color filter layer composed of three types of color filters, namely, red (R) 18R, green (G) 18G, and blue (B) 18B, is formed directly on the transparent resist resin film 12, It is formed so that a single color filter material is filled in the through-hole 13 formed in the laminated film with the transparent resist resin film 12. Therefore, the thickness of the color filter layer is increased. In particular, light incident from the surface opposite to the surface of the glass plate on which the laminated film of the metal film and the transparent resist resin film is formed passes through the light guide path. This is effective in improving the color reproducibility of the color filter when passing through.
In addition, it is desirable that a portion serving as a boundary between adjacent color filters is positioned on the transparent resist resin film 12 and the black layer 22 is formed on the portion in order to prevent light leakage and secure contrast. The black layer 22 may be formed according to a conventional method before or after forming the color filter layer.
[0013]
The formation of the color filter layer on the outer-surface diffusion semi-transmissive reflection plate A shown in FIG. 1 is not limited to the embodiment shown in FIG. Alternatively, an embodiment may be adopted in which two types of color filter materials are filled in the through-hole 13 with the black layer as a boundary.
[0014]
2. FIG. 4 shows an embodiment of an external diffusion semi-transmissive color liquid crystal display device having an external diffusion semi-transmissive reflection plate A. FIG.
In the external diffusion semi-transmissive color liquid crystal display device B, the color filter layers (18R, 18G, 18B) are directly formed on the external diffusion semi-transmissive reflection plate A in the mode shown in FIG. A transparent electrode layer 50 made of ITO and an alignment film 51 are formed on the layer with a flattening film 49 interposed therebetween to form one substrate for a liquid crystal display. The other substrate for liquid crystal display is arranged so as to face the substrate via a liquid crystal layer 34 sealed by a sealing agent 33. This substrate includes a light diffusing film 35, a polarizing plate 36, and retardation plates 37 and 38 provided in this order on the upper surface side of the glass substrate 31, and the lower surface side of the glass substrate 31. Is formed by laminating a transparent electrode layer 45 made of ITO, a planarizing film 46, and an alignment film 47.
A backlight 60 such as a lamp is arranged on the back side of the outer surface transflective reflector A, whereby an outer surface transflective color liquid crystal display device B is formed. The backlight 60 has a lower power consumption than that used in the transmission type color liquid crystal display device, and it is desirable that the backlight 60 can evenly illuminate the outer surface diffusion semi-transmission type reflection plate A.
The transparent electrode layer 50 may be omitted by providing the metal film 42 with an electrode function to form a reflective electrode plate.
[0015]
The light diffusion film 35 may have a diffusivity due to surface irregularities, or may contain a diffusing agent inside the film, and have a diffusivity due to a difference in refractive index between the resin and the diffusing agent. Is also good. Further, a transparent protective film may be laminated or a hard coat layer may be provided to prevent the surface of the light diffusion film 35 from being damaged. In order to prevent the reflection of external light, an anti-glare layer that forms irregularities on the surface and irregularly reflects the external light, or an anti-reflection layer composed of a multilayer dielectric thin film may be formed. In the external diffusion semi-transmissive color liquid crystal display device B shown in FIG. 4, the light diffusion film 35 is provided on the upper surface of the polarizing plate 36, but the light diffusion film 35 is provided on the lower surface of the polarizing plate 36. It may be something.
[0016]
According to the outer surface transflective color liquid crystal display device B, light incident from the outside is reflected at the surface of the metal film 11 with excellent reflectance, and then diffused uniformly to the outside by the light diffusion film 35. Then, light using the backlight 60 disposed on the back side of the outer-surface diffusion semi-transmissive reflection plate A as a light source passes through the through-hole 13 and is emitted to the front side. At this time, since the through hole 13 is filled with a single color filter material to increase the thickness of the color filter layer, the color reproducibility of the color filter is improved.
[0017]
【The invention's effect】
According to the present invention, there is provided an external diffusion semi-transmissive color liquid crystal display device having excellent color reproducibility of a color filter, and an external diffusion semi-transmissive color liquid crystal display device having the above characteristics. Provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of an external diffusion semi-transmissive reflection plate of the present invention.
FIG. 2 is a view showing one manufacturing process of the outer surface diffusion semi-transmissive reflection plate shown in FIG. 1;
FIG. 3 is a view showing one embodiment of a color filter layer formed on the outer surface diffusion semi-transmissive reflection plate shown in FIG. 1;
FIG. 4 is a diagram showing an embodiment of an external diffusion transflective color liquid crystal display device including the external diffusion transflective reflector shown in FIG. 1;
[Explanation of symbols]
Reference Signs List A Outer diffusion semi-transmissive reflection plate B Outer diffusion semi-transmissive color liquid crystal display device 2, 31 Glass substrate 11 Metal film 12 Transparent resist resin film 13 Through hole (light guide path)
18R, 18G, 18B Color filter layer 22 Black layer 34 Liquid crystal 35 Light diffusion film

Claims (5)

After forming a metal film on one surface of the glass plate, a transparent resist resin film is formed thereon to form a laminated film, and light is incident from the surface opposite to the surface of the glass plate on which the laminated film is formed. By performing a photolithography process and an etching process on the laminated film so that light from a backlight as a light source passes, a through hole serving as a light guide path is formed, and the transparent resist resin film is separated from the surface of the metal film. An outer-surface diffusion semi-transmissive reflection plate used in a state where the reflection plate is not used. 2. The outer-surface diffusion transflective reflector according to claim 1, wherein the transparent resist resin film is formed using a negative resist. An external diffusion transflective color liquid crystal display device comprising the external diffusion transflective reflection plate according to claim 1. A color filter layer is directly formed on the outer surface diffusion semi-transmissive reflection plate according to claim 1, and a transparent electrode layer and an alignment film are formed on the color filter layer via a flattening film. An external diffusion semi-transmissive color liquid crystal having a color liquid crystal display mechanism by arranging another substrate for liquid crystal display provided with one substrate and a light diffusion film provided so as to face the substrate via a liquid crystal layer 4. The display device according to claim 3, wherein the color filter layer is formed so that a single color filter material is filled in the through hole. Display device. 5. The transflective color liquid crystal display device according to claim 4, wherein a black layer is formed on the transparent resist resin film.

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