JP2002341119A - Reflection body and color liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection body preventing its metal reflection film from being deteriorated or released and to provide a color liquid crystal display device with high reliability as a product by mounting the reflection body of this kind. SOLUTION: The reflection body 7 is constructed by forming, on a resin substrate 11 for the reflection body with a projecting and recessing face 11a formed on the surface, the metal reflection film 12 with a projecting and recessing face 12a engaging with the external shape of the projecting and recessing face 11a. Difference between a linear thermal expansion coefficient of the resin substrate 11 for the reflection body and that of a color filter layer 13 directly formed on the metal reflection film 12 is <=60 ppm/ deg.C. The reflective color liquid crystal display device 1 is provided with a liquid crystal cell 35 having the reflection body 7 built therein and the color filter layer 13 directly formed on the metal reflection film 12 of the reflection body 7 built in the liquid crystal cell 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector capable of preventing deterioration and peeling of a metal reflection film, and a color liquid crystal display device provided with such a reflector.

[0002]

2. Description of the Related Art Generally, display modes of a color liquid crystal display device include a transmissive type having a backlight, a transmissive type, and a reflective type. A reflection type liquid crystal display device is a liquid crystal display device that performs display without using a backlight using only external light such as sunlight and illumination light, and is, for example, a portable information terminal that is required to be thin, light, and low in power consumption. It is often used for such purposes. In this reflective liquid crystal display device,
A reflector for reflecting light incident from the display surface side to perform display is provided, and the reflector is formed on a resin substrate for a reflector made of a photosensitive resin having an uneven surface on the surface. There has been known a device using a reflector on which a metal reflective film made of Al or the like having an uneven surface conforming to the outer shape of the uneven surface is formed.

A reflective type color liquid crystal display device provided with such a reflector includes a reflector mounted inside a liquid crystal cell in which a liquid crystal layer is interposed between a pair of glass substrates. There is a reflector external type in which a reflector is provided outside the liquid crystal cell, and in the case of a reflector internal type, a color filter layer is provided on a glass substrate on which the reflector is not provided, Some types are provided directly on the reflector or via another layer. In a liquid crystal display device in which another layer is provided between the reflector and the color filter layer, the other layer is interposed between the reflector and the color filter layer. Although color mixing between pixels occurs and the contrast is reduced, in a liquid crystal display device in which a color filter layer is directly provided on a reflector, a parallax is formed between the reflector and the color filter layer. Since there is no intervening other layer which is affected by the above, there is no color mixing due to parallax and the contrast is high, so that it is increasingly used.

FIG. 6 is a diagram showing an example of a conventional reflection type color liquid crystal display device of a color filter direct attachment type. This reflection type color liquid crystal display device has a pair of glass substrates 5.
A liquid crystal layer 53 is provided between the upper and lower glass substrates (display-side glass substrate) 1, and a single retardation plate 54 made of polycarbonate resin, polyarylate resin, or the like is provided on the upper surface side of the upper glass substrate (display-side glass substrate) 1. A polarizing plate 55 is provided on the upper surface side of the phase difference plate 54. A transparent electrode layer 58 made of ITO (indium tin oxide) or the like is formed on the opposite surface side of the display side glass substrate 51, a top coat 57 is formed on the transparent electrode layer 58, and further a polyimide resin or the like is formed thereon. Is provided.

Lower glass substrate (rear glass substrate) 2
Is provided with a reflector 75 having a concave-convex surface 75a which is a reflective surface on the surface thereof.
A color filter layer 66 is formed on a. The reflector 75 is provided on the glass substrate 52 and is made of a photosensitive resin having a random uneven surface 68a formed on a surface thereof by a transfer mold. (Base material) 68 and a metal reflection film 64 made of Al or the like formed on the uneven surface 68 a of the reflector resin base material 68.
It consists of: The surface of the metal reflection film 64 has an uneven surface 75a having a shape similar to the outer shape of the random uneven surface 68a of the resin substrate 68 for a reflector, and the uneven surface 75a serves as a reflective surface.

The color filter layer 66 is composed of red, green and blue colored layers. The width of each colored layer constituting the color filter layer 66 is about 80 μm, and the gap between adjacent colored layers is about 10 μm.
On the color filter layer 66, the color filter layer 6
6 is provided with an overcoat 67 for protection. Further, a transparent electrode layer 59 made of ITO (indium tin oxide) or the like is formed on the overcoat 67, and an alignment film 61 made of a polyimide resin or the like is provided on the transparent electrode layer 59. These alignment films 60 and 6
The liquid crystal in the liquid crystal layer 53 is arranged to be twisted 240 degrees due to the relation of 1 or the like. The liquid crystal layer 53 is sealed between the glass substrates 51 and 52 by a sealing body (not shown).

[0007]

The color filter layer 66 of a conventional reflection type color liquid crystal display device of the type directly attached with a color filter as shown in FIG. 6 is usually a color filter in which a pigment is dispersed in a photosensitive resin. After applying the filter layer forming material on the uneven surface 75 of the reflector 75, pre-baking is performed at about 80 ° C. to form a color filter layer material layer,
Next, a photomask is arranged on the color filter layer material layer, exposed, developed, then post-baked at about 200 ° C., and cooled to room temperature. However, when the color filter layer 66 is formed by such a method, the metal reflective film 64 is cooled after post-baking in the color filter layer forming step.
In addition, there is a problem that the wrinkles and the like are deteriorated, and the metal reflection film 64 is separated from the resin substrate 68 for the reflector, thereby lowering the reliability of the liquid crystal display device. Such a problem is not limited to the reflection type color liquid crystal display device, but the transflector is a transflector, and a color filter layer is directly attached to the transflector. This is also a problem that arises.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a reflector which can prevent deterioration and peeling of a metal reflection film. Another object of the present invention is to provide a color liquid crystal display device having high reliability as a product by providing a reflector that does not deteriorate or peel off the metal reflective film.

[0009]

SUMMARY OF THE INVENTION The present inventor has proposed a reflective color liquid crystal display device of the type directly attached with a color filter. Focusing on the linear thermal expansion coefficients of the resin base material and the color filter layer and the materials of the resin base material for these reflectors and the color filter layer, as a result of repeated studies and experiments,
The above problems occur because the difference in linear thermal expansion coefficient between the metal reflection film and the color filter layer is large, and the thickness of the metal reflection film is small and the adhesion is not large. It was clarified that when the post-bake cooling was performed, stress was applied to the metal reflection film, and the metal reflection film was degraded and peeled off. The inventor of the present invention has made the difference in linear thermal expansion coefficient between the color filter layer and the color filter layer directly formed on the metal reflection film as small as possible. Specifically, the difference in linear thermal expansion coefficient is 60 ppm / ° C. or less. That is, when the color filter layer is composed of a pigment and an acrylic photosensitive resin, it is determined that the above problem can be solved by constituting the reflector resin base material from an acrylic photosensitive resin. Thus, the present invention has been completed.

According to the present invention, a metal reflective film having an uneven surface conforming to the outer shape of the uneven surface is formed on a resin substrate for a reflector having an uneven surface formed on the surface thereof. As a means for solving the above-mentioned problem, the substrate is characterized in that the difference in linear thermal expansion coefficient between the substrate and the color filter layer formed directly on the metal reflection film is 60 ppm / ° C. or less. According to the reflector according to the present invention, the difference in linear thermal expansion coefficient between the resin substrate for the reflector and the color filter layer formed directly on the metal reflective film is 60 ppm.
/ ° C. or less, the stress applied to the metal reflection film can be reduced even when cooling after post-baking in the step of forming a color filter layer on the metal reflection film of the reflector, It is possible to prevent wrinkles and the like from deteriorating and peeling. As described above, when the liquid crystal display device is provided with the reflector of the present invention having no deterioration or peeling of wrinkles or the like in the metal reflective film, the liquid crystal cell caused by the deterioration or peeling of wrinkles or the like of the metal reflective film can be provided. It is possible to prevent occurrence of bubbles, display unevenness, and the like in the vicinity of the sealing material, and to provide a highly reliable liquid crystal display device.

As the resin substrate for a reflector having an uneven surface on the surface, for example, the photosensitive resin layer is irradiated with a light beam while a mold having an uneven portion on the mold surface is pressed against the photosensitive resin layer. The one prepared by curing the layer to form a cured resin layer, and then peeling the mold from the cured resin layer and transferring the irregularities to the surface is preferably used. By forming a metal reflective film on the surface of the resin substrate for a reflector having the uneven surface, a metal reflective film having an uneven surface conforming to the shape of the uneven surface of the resin substrate for the reflector is formed. The uneven surface of the metal reflection film becomes the uneven surface of the reflector. By changing the mold having the concave and convex portions pressed against the photosensitive resin layer, a desired concave and convex surface can be formed on the surface of the resin substrate for a reflector. Therefore, the metal reflective film formed on the concave and convex surface Thus, a desired uneven surface can be formed, and a reflector having desired reflection characteristics can be provided.

The concave and convex surface of the resin substrate for a reflector is formed with a plurality of long convex portions each having a top portion which is continuous at substantially the same height along one direction of the base material. A concave portion may be formed between them, and the height and width of the adjacent long convex portion may be formed at random. The uneven surface of the resin substrate for the reflector has the same curved cross-sectional shape R (curvature radius).
A large number of stripe grooves extending in the same direction may be provided in series, and the widths of these grooves may be irregularly changed so that interference fringes are not generated by light reflected from these grooves. In addition, the uneven surface of the resin substrate for a reflector has a plurality of stripe grooves having the same curved cross-sectional shape and the same R and extending in the same direction, and is formed in a direction in which the stripe grooves intersect. The width of each of the intersecting stripe grooves extending in the same direction may be irregularly changed so that interference fringes are not generated by reflected light from the light source. The intersecting directions of the intersecting stripe grooves may be orthogonal or may intersect at a predetermined angle. Stripe grooves or intersecting stripe grooves on the uneven surface of the reflector resin base material may have a linear planar shape of each groove,
It may be curved with a predetermined curvature. Further, each of the concave portions of the resin substrate for a reflector has a maximum inclination angle (absolute value of an angle between a tangent plane at an arbitrary point on a curved surface and the substrate surface) at one side of the concave portion. Wherein the depth of the recesses is irregularly formed in a range of 0.1 μm to 3 μm, and the plurality of recesses are irregularly arranged in a pitch of adjacent recesses in a range of 5 μm to 50 μm. It may be.

Further, in the reflector according to the present invention,
When the color filter layer contains at least a pigment and an acrylic photosensitive resin, if the resin base for the reflector contains at least an acrylic photosensitive resin, the resin for the reflector The difference between the linear thermal expansion coefficient of the base material and the linear thermal expansion coefficient of the color filter layer can be reduced,
In some cases, the coefficient of linear thermal expansion can be substantially the same, so that even if cooling is performed after post-baking in the step of forming a color filter on the metal reflection film, the stress applied to the metal reflection film can be reduced, and the metal reflection film can be reduced. It is possible to prevent wrinkles and the like from deteriorating and peeling.

Further, in the reflector of the present invention, the acrylic photosensitive resin constituting the resin substrate for the reflector is one or more selected from polymers of acrylic acid, methacrylic acid, and derivatives thereof. Two or more photosensitive resins can be used. In the reflector of the present invention,
The acrylic photosensitive resin contained in the color filter layer may be one or two or more photosensitive resins selected from polymers of acrylic acid, methacrylic acid, and derivatives thereof.

According to the present invention, there is provided a liquid crystal cell incorporating the reflector of the present invention having any one of the above-mentioned constitutions, and a color filter layer is directly formed on a metal reflective film of the reflector incorporated in the liquid crystal cell. A color liquid crystal display device characterized in that it is formed is a means for solving the above problem. According to the color liquid crystal display device of the present invention, since the difference in linear thermal expansion coefficient between the reflector resin base material of the reflector and the color filter layer formed directly on the metal reflection film is small, the metal reflection Even if cooling is performed after post-baking in the step of forming a color filter layer on the film, or if heat history is applied to the color filter layer or the reflector in a step after the step of forming the color filter layer, the metal reflection film Can be reduced, and the metal reflective film can be prevented from being degraded or peeled, such as wrinkles, and a color liquid crystal display device having high reliability as a product can be provided. That is, in the color liquid crystal display device of the present invention, since the metal reflective film is provided with the reflector of the present invention that does not have deterioration or peeling of wrinkles or the like, it is caused by the deterioration or peeling of wrinkles or the like of the metal reflective film. It is possible to prevent the occurrence of bubbles and display unevenness in the vicinity of the sealing material of the liquid crystal cell, and to obtain a highly reliable liquid crystal cell. Furthermore, the color liquid crystal display device of the present invention does not include another layer that causes parallax between the reflector and the color filter layer. There is no color mixture due to parallax, and high contrast can be achieved. The present invention is applicable not only to a reflective color liquid crystal display device but also to a transflective color liquid crystal display device in which the reflector is a transflective reflector and a color filter layer is directly attached to the transflector. Is possible.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing a partial cross-sectional structure of a reflective color liquid crystal display device of an embodiment provided with a reflector according to the present invention. In FIG. 1, a reflective color liquid crystal display device 1 according to the present invention includes a liquid crystal layer 3.
The first substrate 10 and the second substrate 20 made of transparent glass and the like opposing each other with the
This is a configuration in which a seal member provided in a ring shape around the peripheral portions of 0 and 20 is bonded and integrated. Note that since FIG. 1 shows the central portion of the liquid crystal display device, the sealing material is not shown in FIG.

On the liquid crystal layer 30 side of the first substrate 10,
An undercoat 6 made of SiO ₂ or the like, a reflector 7,
The color filter layer 13 formed directly on the surface of the reflector 7 and the reflector 7
And an overcoat 14 made of acrylic resin or the like for flattening unevenness due to the color filter layer 13 and SiO 2.
₂ film 8 and transparent electrode layer 15 for driving liquid crystal layer 30
In addition, an alignment film 16 made of polyimide or the like for controlling the alignment of the liquid crystal molecules constituting the liquid crystal layer 30 is laminated. Also, turn on the liquid crystal layer 30 side of the second substrate 20, an undercoat 21 of SiO ₂ or the like, a transparent electrode layer 25, the top coat 24 made of SiO ₂ or the like,
An alignment film 26 made of polyimide or the like is formed by lamination.

The above-mentioned first substrate 10 and second substrate 20
And the components provided between these substrates,
A liquid crystal cell 35 of N (Super Twisted Nematic) mode is configured. The first retardation plate 2 is provided on the opposite side of the second substrate 20 to the liquid crystal layer 30 side (outer surface side of the second substrate 20).
7a, a second retardation plate 27b, and a polarizing plate 28 are stacked in this order.

The color filter layer 13 is made of red R,
It is composed of colored layers of three primary colors of green G and blue B. The colored layers of these three primary colors are arranged in a stripe pattern alternately arranged vertically and / or horizontally in the order of R, G, and B. Each colored layer contains a pigment and an acrylic photosensitive resin. The acrylic photosensitive resin contained in the color filter layer 13 includes acrylic acid,
One or more photosensitive resins selected from polymers of methacrylic acid and their derivatives are used. The color filter layer 13 may include other materials in addition to the above materials. The width of each colored layer constituting the color filter layer 13 is about 80 μm, and the gap between adjacent colored layers is about 10 μm. The color filter layer 13 is formed, for example, by applying an acrylic photosensitive resin in which a pigment is dispersed on the surface of the metal reflective film 12 of the reflector 7 and then pre-baking at a predetermined temperature to form a photosensitive resin layer. Then, a photomask is disposed on the photosensitive resin layer, exposed, exposed, developed, then post-baked at a predetermined temperature, and then cooled to room temperature.

The reflector 7 includes a resin substrate 11 for a reflector having an uneven surface 11a on the surface thereof, and a metal reflection film 12 formed on the resin substrate 11 for the reflector. The metal reflection film 12 has an uneven surface 12a that matches the outer shape of the uneven surface 11a of the base material 11. The reflector resin base material 11 has a metal reflection film 12 formed thereon.
This is provided in order to provide a concave and convex shape to efficiently scatter reflected light. Thus, the metal reflection film 12
By imparting a concave-convex shape, the light incident on the liquid crystal display device 1 can be efficiently reflected, and thus a bright display can be realized.

FIG. 2 is a perspective view showing a reflector 7 according to an embodiment of the present invention having a reflector resin base material 11 and a metal reflection film 12 formed thereon. This resin substrate 1 for a reflector
As shown in FIG. 2, the uneven surface 11 a of one is formed in a wavy shape having an indeterminate transverse cross section, and is formed in one direction of the substrate 10 (arrow a in FIG. 2).
), The tops of each of which are continuous at substantially the same height along the same direction), 151, 152, 153, 154, 155,.
And the long convex portions 151, 152, 153, 154, in the direction (the direction of the arrow b in FIG. 2) orthogonal to the one direction (the direction a).
155 are arranged side by side with an interval therebetween, and random recesses 171 and 17 having a depth and a width are provided between the long protrusions.
2, 173, 174, 175,... In addition, the recesses 171 to 175 in the uneven surface 11a are preferably formed to have a depth of 0.5 μm to 3 μm and a width of 5 μm to 30 μm. In addition, the height and width of the adjacent long convex portions are also randomly formed.

The tops of the long projections are formed at substantially the same height. Needless to say, each top may have some undulations. In the uneven portion of the uneven surface 11a, the inclination angle distribution is preferably in the range of -10 ° or more and + 10 ° or less. Here, the inclination angle distribution means that when the cross section of the long convex portion is viewed as shown in FIG.
It means an angle θ between a tangent S and a horizontal line H at an arbitrary point P of a sin curve waveform appearing in the cross section. Therefore, the range in which the inclination angle distribution is −10 ° or more and + 10 ° or less means that θ is in the range of −10 ° or more and + 10 ° or less in an arbitrary cross section of the long convex portion shown in FIG. means.

The resin base material 11 for the reflector has a difference between the linear thermal expansion coefficient of the color filter layer 13 and the linear thermal expansion coefficient of the color filter layer 13 formed directly on the metal reflective film 12. 60 ppm / ° C or less, preferably 50 p
It is made of a material having a pm / ° C or lower. In the case of the present embodiment, since each colored layer of the color filter layer 13 is made of a pigment and an acrylic photosensitive resin, the resin substrate 11 for the reflector is also made of an acrylic photosensitive resin. In addition, when the acrylic photosensitive resin used for the color filter layer 13 is a polymer of acrylic acid, methacrylic acid, or a derivative thereof, the acrylic photosensitive resin used for the reflector resin base material 11 is also acrylic acid, methacrylic acid. ,
And polymers of their derivatives. As long as the difference between the linear thermal expansion coefficient of the color filter layer 13 and the linear thermal expansion coefficient of the color filter layer 13 can be set to 60 ppm / ° C. or less, other materials other than the above-described materials may be included in the reflector resin substrate 11.

As a method of producing the resin substrate 11 for a reflector as described above, for example, the undercoat 6
Acrylic photosensitive resin layer formed via the mold, the mold having a concave and convex portion on the mold surface is pressed to irradiate light to cure the photosensitive resin layer to form a cured resin layer, and then the mold Is peeled from the cured resin layer and an uneven portion is transferred to the surface.

The metal reflecting film 12 is made of a metal material having a high reflectivity, such as Al or A1 alloy, or Ag or Ag alloy.
Can be formed by forming a film to a thickness of about 100 nm to 200 nm on the uneven surface 11a by a film forming method such as sputtering, vacuum deposition, chemical vapor deposition (CVD), ion plating, and electroless plating. According to the reflector 7, as the resin substrate 11 for the reflector, one having a difference in linear thermal expansion coefficient of 60 ppm / ° C. or less from the color filter layer 13 formed directly on the metal reflection film 12 was used. Thereby, even if cooling is performed after the post-baking in the step of forming the color filter layer on the metal reflection film 12 of the reflector 7, the stress applied to the metal reflection film 12 can be reduced, and the metal reflection film deteriorates such as wrinkles. And peeling can be prevented,
If such a reflector 7 is provided in a liquid crystal display device, a highly reliable liquid crystal display device can be manufactured. Further, the reflector 7 has the uneven surface 12a as described above.
Therefore, reflection of light from an unnecessary direction can be suppressed, and light incident from a specific direction can be efficiently reflected around a specific direction.

The transparent electrode layer 15 is made of ITO (Indium tin oxide).
A large number of strip-shaped planes made of a transparent conductive film such as xide) are aligned and formed, and individually connected to an external drive circuit (not shown) to drive the liquid crystal molecules constituting the liquid crystal layer 30. For this purpose, the SiO ₂
It is formed via the film 8. Similarly, the transparent electrode layer 25 is also formed by arranging a large number of strip-shaped planar members made of a transparent conductive film such as ITO on the substrate 20 via the undercoat 21 and individually connected to an external drive circuit. ing. The transparent electrode layer 15 and the transparent electrode layer 25 are arranged so as to be perpendicular to each other in a plan view, and the liquid crystal display device 1 is of a passive matrix type.

The reflection type color liquid crystal display device 1 of the present embodiment.
According to the method, the difference in the linear thermal expansion coefficient between the reflector resin base material 11 of the reflector 7 and the color filter layer 13 formed directly on the metal reflection film 12 is small. Since the coefficient of linear thermal expansion of the color filter layer 13 is uniformed), it is cooled after post-baking in the step of forming the color filter layer 13 on the metal reflection film 12, or in a step after the step of forming the color filter layer. Even if a heat history is applied to the color filter layer or the reflector, the stress applied to the metal reflection film can be reduced, and the metal reflection film can be prevented from being deteriorated or peeled, such as wrinkles. A color liquid crystal display device can be provided. That is, in the color liquid crystal display device 1 of the present embodiment, the reflector 7 of the present embodiment has no deterioration or peeling of wrinkles or the like in the metal reflection film 2.
Is provided, it is possible to prevent the occurrence of bubbles and display unevenness in the vicinity of the sealing material of the liquid crystal cell caused by the deterioration or peeling of wrinkles or the like of the metal reflection film, and has an advantage of high reliability. is there. Further, in the reflective color liquid crystal display device of the present embodiment, the reflector 7 and the color filter layer 1 are provided.
Since no other layer that causes parallax is interposed between the third layer and the third layer, in addition to the above-described advantages, there is no color mixing due to parallax and high contrast can be achieved.

In the reflection type color liquid crystal display device of the present embodiment, a plurality of long convex portions having the tops continuous at substantially the same height along one direction of the substrate 11 are formed as a reflector. A concave portion is formed between these elongated convex portions, and the height and width of the adjacent elongated convex portions are formed at random, and the concave and convex surface 11 of the reflective resin substrate 11 is formed.
Although the description has been given of the case where the one composed of the metal reflection film 12 formed on the substrate a is used, a reflector as shown in FIGS. 3 to 5 may be used.

The reflector 37 shown in FIG. 3 has an uneven surface 31a on the surface.
Metal reflection film 3 having an uneven surface 32a conforming to the outer shape of the uneven surface 31a on a reflector resin base material 31 on which is formed
2 are formed, and the uneven surface 32a becomes a reflection surface. Unevenness 31a of this resin body 31 for reflector
Means a number of stripe grooves 36 having the same curved cross-sectional shape (radius of curvature) and extending in the same direction as shown in FIG.
Are continuously formed, and the widths of these grooves are irregularly changed so that interference fringes are not generated by the reflected light from the stripe grooves 36. R is 100 μ
If it exceeds m, the stripe groove is visible, and the display quality of the liquid crystal display device is greatly reduced. On the other hand, when R is a value less than the order of visible light, that is, smaller than 0.4 μm, effective reflection characteristics cannot be obtained, so that R is preferably set to 0.4 μm or more.

The metal reflection film 32 formed on the uneven surface 32a of the resin substrate 31 for the reflector also has the stripe grooves 3
6 have stripe grooves of the same shape. The reflector resin base material 31 is made of the same material as the above-described reflector resin base material 11, and the difference in linear thermal expansion coefficient between the color filter layers 13 formed directly on the metal reflection film 32 is small. It is not more than 60 ppm / ° C. The metal reflection film 32
It is made of the same material as the metal reflection film 12 described above. In a liquid crystal display device provided with such a reflector 37, since the direction of reflection of incident light from a direction perpendicular to the direction of the stripe groove extends over a wide range, the reflection efficiency is good and the display becomes bright.

The reflector 47 shown in FIG. 4 has an uneven surface 41a on the surface.
Reflective metal film 4 having a concave-convex surface 42a conforming to the external shape of the concave-convex surface 41a on a reflector resin base material 41 on which
2 are formed, and the uneven surface 42a becomes a reflection surface. The reflector resin base material 41 has a plurality of stripe grooves 46 having the same curved cross-sectional shape extending in the same direction and extending in the same direction.
Are also formed in the direction in which they intersect, and the width of each of the intersecting stripe grooves 46... Extending in the same direction is irregularly changed so that interference fringes are not generated by reflected light from these grooves. It is.

The metal reflection film 42 formed on the uneven surface 41a of the resin substrate 41 for a reflector also has intersecting stripe grooves having the same shape as the intersecting stripe grooves 46. The reflector resin base material 41 is made of the same material as the above-described reflector resin base material 11, and the difference in linear thermal expansion coefficient between the color filter layers 13 formed directly on the metal reflection film 42 is small. It is not more than 60 ppm / ° C. In a liquid crystal display device provided with such a reflector 47, in particular, since the direction of reflection of light incident from a direction orthogonal to each direction of the intersecting stripe grooves extends over a wide range,
The reflection efficiency is improved, and the display becomes brighter.

The reflector 87 shown in FIG. 5 has an uneven surface 81a on the surface.
Metal reflection film 8 having an uneven surface 82a conforming to the outer shape of the uneven surface 81a on the reflector resin base material 81 on which is formed
2 are formed, and the uneven surface 82a becomes a reflection surface. The reflector resin base material 81 is made of the same material as that of the above-described reflector resin base material 11, and the difference in linear thermal expansion coefficient between the color filter layers 13 formed directly on the metal reflection film 82 is small. It is not more than 60 ppm / ° C. On the surface of the reflector resin base material 81, a large number of concave portions 83A whose inner surfaces form a part of a spherical surface are continuously formed so as to overlap left and right, and the metal reflective film 8 is formed on the surface.
2 are stacked.

The depth of the concave portion 83A is set to 0.1 μm to 3 μm.
m, the pitch of the adjacent concave portions 83A is randomly arranged in a range of 5 μm to 50 μm, and the inclination angle of the inner surface of the concave portion 83A is set in a range of −30 degrees to +30 degrees. In particular, it is particularly important that the inclination angle distribution of the inner surface of the concave portion 83A is set in the range of −30 degrees to +30 degrees, and that the pitch of the adjacent concave portions 83A is randomly arranged in all directions in the plane. This is because, if the pitch of the adjacent concave portions 83A has regularity, interference colors of light may appear and reflected light may be colored. Also,
If the inclination angle distribution of the inner surface of the concave portion 83A exceeds the range of −30 degrees to 30 degrees, the diffusion angle of the reflected light is too wide, the reflection intensity is reduced, and a bright display cannot be obtained. , The reflection intensity peak inside the liquid crystal display device decreases, and the total reflection loss increases.)

If the depth of the concave portion 83A exceeds 3 μm, the top of the convex portion cannot be filled with the flattening film (overcoat film 14), and the desired flatness cannot be obtained, causing display unevenness. . When the pitch between the adjacent concave portions 83A is less than 5 μm, there is a restriction on the production of the transfer die used to form the reflector resin base material 81, and the processing time becomes extremely long. However, there are problems such as the inability to form the shape of the light beam and the generation of interference light. Further, in practice, 30 μm to 100 μm which can be used for producing the transfer mold
When using a diamond indenter having a diameter of m,
It is desirable that the pitch of 3A be 5 μm to 50 μm.

In the above embodiment, the case where the present invention is applied to a reflective type color liquid crystal display device and a reflector provided therein has been described. However, a transflective type color liquid crystal display device and a transflective type provided therewith. In such a case, a second polarizing plate is provided outside the first substrate 10, and further below the second polarizing plate (opposite the first substrate 10). Is provided with a backlight as a light source for performing transmissive display. The thickness of the metal reflective film of the transflective body provided in such a transflective color liquid crystal display device is 8 nm to 50 nm (80 ° to 500 nm).
Å) is preferred, and more preferably 8 nm to 30 n
m (80 ° to 300 °) is preferable in that the display in the transmission mode can be brightened, and the difference in display brightness between the transmission mode and the reflection mode can be reduced.

[0037]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to only these Examples. (Example 1) 34 wt% of acrylic photosensitive resin and 66 wt% of 3-methoxybutyl acetate (CH ₃ COOC ₂ H ₄ CH (OCH ₃ ) CH ₃ ) on a glass substrate by spin coating.
% Was applied so as to have a thickness of 700 nm and prebaked at 80 ° C. to obtain a photosensitive resin layer. Then, a silicon transfer mold having an uneven portion on the mold surface was prepared, and the photosensitive resin layer was coated with 50 kg / cm ^2.
To transfer the irregularities of the transfer mold to the upper portion. Then, while the transfer mold was pressed against the photosensitive resin layer, the cured resin layer was irradiated by irradiating ultraviolet rays from the back side of the substrate, and the mold was released to obtain a resin substrate for a reflector as shown in FIG. After UV irradiation, an Al film having a thickness of 120 nm is deposited on the uneven surface on the upper surface of the resin substrate for the reflector, and the uneven surface (reflective surface) conforming to the outer shape of the uneven surface of the substrate as shown in FIG. ) Was obtained.

Then, 73 to 77 wt% of propylene glycol monomethyl ether acetate (CH ₃ OC ₃ H ₆ OCOCH ₃ ) and diethylene glycol diethyl ether ((C ₂ H ₅ OC
H ₃ was CH _{3) 2} O) 11 to 15% of an acrylic photosensitive resin 9～11Wt percent and pigments 0.5 to 2 wt% and a color filter layer material made of coated. Next, after pre-baking at 80 ° C. to form a material layer for a color filter layer, a photomask is arranged and exposed on this layer, developed, and then post-baked at 200 ° C. to form a reflector. A color filter layer was formed directly on the uneven surface. Next, an acrylic overcoat agent was applied on the color filter layer by a spin coater. Thereafter, the reflector was pre-baked at 80 ° C. and post-baked at 200 ° C. to form an overcoat.

Comparative Example 1 As a resin base material for a reflector, 30 wt% of a polyimide resin and 70% of N-methylpyrrolidone were used.
A reflector was formed on a glass substrate in the same manner as in Example 1, except that a color filter layer was formed on the uneven surface of the reflector. Formed.

Next, using the reflector obtained in Example 1, a color filter layer (CF) and an overcoat (OC), a reflection type liquid crystal display panel of a color filter direct attachment type (the liquid crystal display panel of Example). Were prepared and used as samples. Also, using the reflector obtained in Comparative Example 1, the color filter layer (CF), and the overcoat (OC), a large number of reflective liquid crystal display panels of a color filter direct attachment type (the liquid crystal display panel of Comparative Example) were manufactured. , As a sample.
PSI-2501 (trade name; manufactured by Chisso Corporation) was used as the upper and lower alignment films constituting the liquid crystal display panel, and alignment processing was performed so that the twist angle was 240 °. The upper and lower transparent electrode layers were made of ITO. AP-4132L as STN liquid crystal
A (trade name; manufactured by Chisso Corporation) was used. Only one retardation plate was used, and one made of polycarbonate was used. NPF-EG1225DU as a polarizing plate
(Trade name; manufactured by Nitto Denko Corporation) was used.

When the liquid crystal display panels of the manufactured examples and comparative examples were left at a high temperature, left at a low temperature, applied a thermal shock (thermal history), applied a thermal shock at a low temperature, The reliability of the liquid crystal cell was evaluated. The results are shown in Tables 1 and 2 below. The evaluation when left at high temperature here is
Evaluation was made based on the presence or absence of abnormalities when the sample liquid crystal display panel was left in an atmosphere of 70 ° C. for 120 hours and the presence or absence of abnormalities when the sample liquid crystal display panel was left in an atmosphere of 70 ° C. for 240 hours. In addition, the evaluation when left at low temperature,
The sample liquid crystal display panel was placed in a -20 ° C atmosphere for 120 minutes.
The evaluation was made based on the presence or absence of abnormality when left for a period of time and the presence or absence of abnormality when the sample liquid crystal display panel was left in a -20 ° C. atmosphere for 240 hours. Also, thermal shock (thermal history)
Was evaluated when the sample liquid crystal display panel was
After leaving in a 30 ° C atmosphere for 30 minutes,
Letting it stand for 0 minute is one cycle. After 10 cycles, check whether there is any abnormality, and leave the sample liquid crystal display panel in a -30 ° C atmosphere for 30 minutes, and then leave it in an 80 ° C atmosphere for 30 minutes. Is one cycle, and this is 2
The evaluation was made based on the presence or absence of an abnormality when the cycle was performed for 0 cycles. When a thermal shock was applied at a low temperature, the sample liquid crystal display panel was evaluated in the Z direction (vertical direction) in a -20 ° C atmosphere.
Was evaluated by the presence or absence of abnormality when three shocks equivalent to 200 G were applied.

[Table 1] Test items Number of samples Evaluation result High-temperature storage 5, no abnormalities Low-temperature storage 5, no abnormalities Thermal shock 5, no abnormalities Low-temperature shock 5 No abnormalities

The samples in Table 1 are the liquid crystal display panels of the embodiment (the reflectors of the embodiment 1 and those provided with CF and OC).

[Table 2] Test items Number of samples Evaluation result High-temperature storage 5 No co-abnormality Low-temperature storage 5 has abnormalities, bubbles are generated near the sealing material Thermal shock 5 is abnormal, bubbles are generated near the sealing materials Low-temperature shock 5 abnormalities Yes, bubbles are generated near the sealing material

The samples in Table 2 are liquid crystal display panels of comparative examples (those provided with the reflector of Comparative Example 1, CF and OC).

From the results shown in Tables 1 and 2, the liquid crystal display panel of Comparative Example 1 provided with the reflector, the color filter layer and the overcoat of Comparative Example 1 was left at low temperatures, when subjected to thermal shock, When a low-temperature impact was applied, bubbles were generated in the vicinity of the sealing material in each case, and it was found that defects were easily generated in the liquid crystal cell. On the other hand, the liquid crystal display panel of Example 1 provided with the reflector, the color filter layer, and the overcoat of Example 1 was exposed to high-temperature, low-temperature, thermal shock, and low-temperature shock. In any case, no abnormality occurred in the liquid crystal cell, indicating that the liquid crystal cell was highly reliable.

[0047]

As described above, the reflector of the present invention is
The difference in the coefficient of linear thermal expansion between the color filter layer formed directly on the metal reflective film and the color filter layer formed on the reflective material having a metal reflective film formed on the reflective resin substrate is 60 pp.
By using a material having a m / ° C. or lower, the stress applied to the metal reflection film can be reduced even if cooling is performed after post-baking in the step of forming a color filter layer on the metal reflection film of the reflector. Deterioration of wrinkles and the like and peeling of the film can be prevented. Further, the color liquid crystal display device of the present invention has a liquid crystal cell incorporating the reflector of the present invention, and the color filter layer is directly formed on the metal reflective film of the reflector incorporated in the liquid crystal cell. Forming a color filter layer on the metal reflection film because the difference in linear thermal expansion coefficient between the reflector resin base material of the reflector and the color filter layer formed directly on the metal reflection film is small. Even after cooling after post-baking, or if a thermal history is applied to the color filter layer or the reflector in a step after the step of forming the color filter layer, the stress applied to the metal reflection film can be reduced, and the metal reflection film can be reduced. It is possible to prevent wrinkles and the like from deteriorating and peeling, and to provide a color liquid crystal display device having high reliability as a product. Since the color liquid crystal display device of the present invention is provided with the reflector of the present invention without deterioration or peeling of wrinkles or the like in the metal reflective film as described above, it is caused by deterioration or peeling of wrinkles or the like of the metal reflective film. This can prevent the occurrence of bubbles, display irregularities, and the like near the sealing material of the liquid crystal cell, which results in high reliability. Furthermore, the color liquid crystal display device of the present invention does not include another layer that causes parallax between the reflector and the color filter layer. There is no color mixture due to parallax, and high contrast can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a partial cross-sectional structure of a reflective color liquid crystal display device according to an embodiment provided with a reflector according to the present invention.

FIG. 2 is an enlarged view showing an uneven surface of an acrylic photosensitive resin layer constituting a reflector according to the embodiment of the present invention.

FIG. 3 is a perspective view showing another embodiment of the reflector of the present invention.

FIG. 4 is a perspective view showing another embodiment of the reflector of the present invention.

FIG. 5 is a perspective view showing another embodiment of the reflector of the present invention.

FIG. 6 is a cross-sectional view showing a schematic configuration of a conventional reflection type color liquid crystal display device directly attached to a color filter.

[Explanation of symbols]

1 ... liquid crystal display device, 7, 37, 47, 87 ... reflector
10 1st substrate, 11, 31, 41, 81 ... resin base material for reflectors, 11a, 31a, 41a, 81a ... uneven surface, 12, 32, 42, 82 ... metal Reflective film, 12a,
32a, 42a, 82a: uneven surface, 13: color filter layer, 15, 25: transparent electrode layer, 16, 26: alignment film, 20: second substrate, 30 ...・ Liquid crystal layer, 35 ・ ・ ・ Liquid crystal cell, 36, 46 ・ ・ ・ Stripe groove, 83A ・ ・ ・ Recess, 1
51, 152, 153, 154, 155...
171, 172, 173, 174, 175...

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G02F 1/1335 520 G02F 1/1335 520 F term (Reference) 2H042 BA04 BA15 BA20 DA02 DA04 DA11 DB08 DC01 DC02 DC03 DC08 DD01 DE00 2H048 BA11 BA47 BA48 BB02 BB08 BB44 2H091 FA02Y FA08X FA08Z FA11X FA11Z FA14Z FA41Z FC02 FC03 FC06 GA01 LA17

Claims (5)

[Claims] 1. A resin substrate for a reflector having an uneven surface conforming to the outer shape of the uneven surface is formed on a resin substrate for a reflector having an uneven surface formed on the surface thereof. Wherein the difference in linear thermal expansion coefficient from the color filter layer formed directly on the metal reflective film is 60 ppm / ° C. or less. 2. The color filter layer comprises at least a pigment and an acrylic photosensitive resin, and the resin substrate for the reflector comprises at least an acrylic photosensitive resin. The reflector according to claim 1, wherein 3. An acrylic photosensitive resin constituting the resin substrate for a reflector is one or more photosensitive resins selected from polymers of acrylic acid, methacrylic acid, and derivatives thereof. The reflector according to claim 2, wherein the reflector is provided. 4. The method according to claim 1, wherein the acrylic photosensitive resin contained in the color filter layer is at least one photosensitive resin selected from polymers of acrylic acid, methacrylic acid, and derivatives thereof. The reflector according to claim 2 or 3, wherein the reflector is provided. 5. A liquid crystal cell incorporating the reflector according to claim 1, wherein a color filter layer is directly formed on a metal reflection film of the reflector incorporated in the liquid crystal cell. A color liquid crystal display device characterized by the following.