JPH11160506A - Reflecting plate, translucent reflecting plate, and optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the reflecting plate and translucent reflecting plate which are light and free of a feeling of metallic reflection and gives a feeling of white like an ordinary diffusing plate and shows excellent display performance when used for a display device. SOLUTION: Granular bodies 11d are mixed with a surface type medium 11c which has thickness (t), a refractive index nF, and total weight WF and a mirror surface reflecting layer 11b is arranged on the reverse-surface side of the medium 11c; and a group of granular bodies A having a refractive index nPA, an external diameter dPA (μm), and total weight WPA is used and conditions represented as 0.5 μm<=dPA20 μm, 5 μm<=t<=200 μm, 10 wt.%<=WPA/(WPA+ WF)<=70 wt.%, and 0<|nPA-nF|>=0.362 are met.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector used for a display device, a semi-transmissive reflector, and an optical device having the same.

[0002]

2. Description of the Related Art Conventionally, when a reflecting plate or a semi-transmissive reflecting plate is installed on the back side of a display element, the reflecting surface may actually act as a mirror surface, so that an external image is not reflected on the reflecting surface. Or, in order to eliminate parallax of an image to be displayed, irregularities are often provided on the surface of the reflection surface (conventional example 1).

[0003] Further, there has been known a conventional example in which a scattering optical film utilizing a refractive index difference between a transparent granular material or beads and a surrounding medium is used as a reflecting plate instead of a simple metal reflecting surface. FIG. 2 shows a schematic diagram of the cross section. This is one in which a resin layer and beads are provided on a base (conventional example 2).

[0004] Further, a granular material having a diameter of 0.05 to 10 µm is mixed with a transparent binder made of a methacrylate copolymer, and applied to a polymer film at a thickness of 10 to 100 µm to form a back of a liquid crystal display device. A reflective sheet used for a light is also known (conventional example 3).

[0005] However, in the first conventional example, if unevenness is provided on the reflection surface made of metal or the like, a shadow due to the unevenness is generated, and light and dark may be visually recognized. In addition, there is a problem that the surface becomes rough and the display quality deteriorates. In addition, there is a problem that the metal reflection occurs on the unevenness of the metal surface, which causes a glaring feeling and lowers the display quality.

In the conventional example 2, it is difficult to form a reflector, it is mechanically weak, and it is difficult to mount it in close contact with a display device, it is also susceptible to dirt, and the position of beads is easily controlled. In addition, the bead layer is substantially a single layer, uniformity in the planar direction is likely to be uneven, and an appropriate scattering ability cannot be obtained, and furthermore, refraction of the material adhered to the upper surface of the bead layer The problem is that the scattering power changes depending on the rate.

The technique of the prior art 3 is for improving the reflection efficiency of a so-called backlight, and does not have a configuration in which external light is used effectively.

In addition, when combined with a polarizing plate type display element, the conventional polarizing plate and reflector, or a combination of a polarizing plate and semi-transmissive reflector, have a high degree of polarization of the polarizing plate and an insufficient amount of reflected light. There were problems such as the performance required for the display device was not sufficiently obtained.

[0009]

As described above, in the conventional example, since the metal reflector or the semi-transmissive reflector is provided with irregularities, the amount of reflected light is insufficient and the image becomes dark.
The visibility of the display element itself was reduced.

[0010] Alternatively, it is not suitable for mass production and is generally difficult to widely use due to manufacturing problems. Further, it is inferior in moldability, and it is difficult to produce a flat, thin and durable product.

In addition, a profile when assembled into a display device, that is, a desired viewing angle can be freely obtained.
In addition, it has been demanded that the display light amount can be appropriately set. According to the present invention, when a reflector or a semi-transmissive reflector is used in a display device, the reflector exhibits a bright white appearance without a metallic reflection, like a normal diffusion plate, and exhibits good display performance. Further, it is an object of the present invention to develop a high-performance optical device combining a polarizing plate and a reflecting plate and a polarizing plate and a semi-transmissive reflecting plate.

[0012]

Means for Solving the Problems That is, claim 1 is as follows.
Thickness t ([mu] m), the refractive index n _F, the reflector total weight is provided with and the granules planar medium is W _F, granules are placed in a medium, specular reflection on the back side of the medium A reflector having a layer disposed thereon, a particle group A having a refractive index n _PA , an outer diameter d _PA (μm), and a total weight of W _PA being used, and satisfying the expressions (1) to (5); I will provide a.

[0013]

0.5 μm ≦ d _PA ≦ 20 μm (1) 5 μm ≦ t ≦ 200 μm (2) 1.0 wt% ≦ W _PA / (W _PA + W _F ) ≦ 70 wt% ( 3) 0 <| n _PA −n _F | ≦ 0.362 (4) d _PA ≦ t (5)

When the second and third optically active substances are further added to the medium and used, when they have a substantially effective weight and effective volume as compared with the particulate A group, , And the added weight thereof is added to W _X to obtain (W _PA + W _F
+ W _X ).

Further, claim 2 is based on the formulas (1A) to (3A).
3. The reflector according to claim 1, wherein

[0016]

0.5 μm ≦ d _PA ≦ 2 μm (1A) 5 μm ≦ t ≦ 45 μm (2A) 1.0 wt% ≦ W _PA / (W _PA + W _F ) ≦ 20 wt% ( 3A)

[0017] Claim 3 is based on the formulas (1B) to (3B).
3. The reflector according to claim 1, wherein

[0018]

2 μm ≦ d _PA ≦ 4 μm (1B) 10 μm ≦ t ≦ 60 μm (2B) 7 wt% ≦ W _PA / (W _PA + W _F ) ≦ 45 wt% (3B)

Further, claim 4 is obtained by formulas (1C) to (3C).
3. The reflector according to claim 1, wherein

[0020]

## EQU9 ## 4 μm ≦ d _PA ≦ 10 μm (1C) 15 μm ≦ t ≦ 70 μm (2C) 13 wt% ≦ W _PA / (W _PA + W _F ) ≦ 60 wt% (3C)

Further, according to claim 5, the thickness t ([mu] m), the refractive index n _F, the reflector total weight is provided with and the granules planar medium is W _F, granules in medium Placed,
A reflective layer is disposed on the back side of the medium, and has a refractive index n _PA and an outer diameter d.
_PA (μm), a granular material group A having a total weight of W _PA is used, a plurality of through holes are provided in the reflective layer from the front side to the back side, and the total effective cross-sectional area on the front side of the through holes is Provided is a semi-transmissive reflection plate characterized by satisfying the expressions (1) to (5), which is 5 to 40% with respect to the effective total area on the surface side of the reflection layer.

[0022]

0.5 μm ≦ d _PA ≦ 20 μm (1) 5 μm ≦ t ≦ 200 μm (2) 1.0 wt% ≦ W _PA / (W _PA + W _F ) ≦ 70 wt% ( 3) 0 <| n _PA −n _F | ≦ 0.362 (4) d _PA ≦ t (5)

According to a sixth aspect of the present invention, the reflector according to the first, second, third or fourth aspect or the semi-transmissive reflector according to the fifth aspect is combined with a polarizing plate having a single transmittance of 50 to 65%. An optical unit is provided.

In the above-mentioned reflecting plate and semi-transmissive reflecting plate of the present invention, the specular reflecting layer is preferably an aluminum specular reflecting layer or a silver specular reflecting layer. This is because the light reflection efficiency is improved and the overall light use efficiency is improved. 84% for specular reflective layer, 91.2% for aluminum specular reflective layer
Can be achieved. Specifically, a substrate formed by depositing aluminum or silver on a flat PET substrate or a glass substrate can be used.

Further, as the constituent members of the reflection plate and the transflective reflection plate described in the above claims and embodiments, a material having a refractive index of 1.338 to 1.7 can be used. Further, a preferred embodiment 1 of the present invention provides a method in which 1.4 ≦ n _F
≦ 1.6 and 1.4 ≦ n _PA ≦ 1.6.

The granular material A group may have substantially the same refractive index, or may have a refractive index of 0.001-0.
About 005 may be dispersed. Further, equation (3),
Satisfies (4) and has a large dispersion in the granular material A group (>
0.005).

In a preferred embodiment 2 of the present invention, in the reflector according to any one of the above-mentioned claims or embodiments, the granular material is a polymer bead and the medium is a polymer. According to a fourth aspect of the present invention, in the reflector according to any one of the above-mentioned claims or each aspect, the granular material is spherical, elliptical, or polyhedral. This is because the light quantity distribution in the minute area becomes more uniform and can be adapted to high-density display.

In order to appropriately disperse the group of particles A in the medium, a group of particles B having substantially the same refractive index as that of the medium is further added, so that the entire display surface and the uniform area in a minute area unit at the pixel level are added. Performance can be improved. The basic condition in this case is shown by Expression 11.

[0029]

0.5 μm ≦ d _PB ≦ 20 μm (1D) 5 μm ≦ t ≦ 200 μm (2) 1.0 wt% ≦ W _PB / (W _PB + W _F + W _PA ) ≦ 20 wt%・ (3) 0 ≒ n _PA −n _F (4) d _PB ≦ t (5)

Further, it is preferable to use a liquid crystal display element in combination as a display element of a display device employing the above-mentioned reflection plate, transflective plate or optical device, so that a bright and high display quality can be obtained.

[0031]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, K kinds of granules (K is a positive integer) are prepared, and they are mixed into a medium material having a refractive index different from that of the K kinds of granules. The medium material containing these particles is thinned into a layer to form a thin film exhibiting a high haze ratio. The thin film composed of the medium and the granular material is called a light control layer. Then, the light control layer is provided on the reflector or the semi-transmissive reflector. This makes it possible to manufacture a reflector or a semi-transmissive reflector that looks like high-quality paper with no irregularities on the surface.

The present invention also provides a light control reflector integrated with a polarizing plate, a light control reflector, and a light control, wherein the above-mentioned reflector or semi-transmissive reflector is further combined with a polarizer having a high single transmittance and a low degree of polarization. It is possible to configure a new optical device using a transflective plate to obtain a brighter display.

The present invention is not limited to the TN liquid crystal display device and the STN liquid crystal display device of the simple matrix drive system,
The present invention can also be applied to a ferroelectric liquid crystal display device, an antiferroelectric display device, an active matrix driving type liquid crystal display device, a screen device, and the like.

In the present invention, the granular material can be used as long as it has a predetermined size. The material of the granular material may be glass or a transparent inorganic material, but in practice, it is preferable to use beads made of a polymer having excellent optical characteristics and moldability. Further, it is preferable in terms of handling and optical characteristics that it is processed into a desired shape and dimensions such as a spherical shape and an elliptical shape.

The present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an example (Configuration Example A) of the reflector of the present invention. The reflection plate 11 includes a light control layer 11 a and a specular reflection layer 11.
b. The thickness t of the light control layer 11a is 5 to 200 μm.
Select and set from the range of m. Furthermore, a medium 11c made of a polymer, different refractive index granules 11d made of spherical or oval polymer with (hereinafter, also referred to as beads) and medium 0.5 [mu] m ≦ d ₁ ≦ 20 [mu] m diameter d ₁ of
And d ₁ ≦ t. When the shape of the granular material is elliptical, the length in the minor axis direction is adopted as the outer diameter. As described above, the outer diameter of the granular material obtained from various materials is defined as d _PA, and the diameter when it can be approximated to a substantially spherical shape is defined as d ₁ . It described below with reference to d _1.

In the present invention, the weight ratio of the polymer beads 11d in the light control layer 11a is set to 1 to 70 wt%.
Here, the weight ratio is a relative ratio to the total weight of the medium and all the beads.

Further, the refractive index of the medium 11c and n _F, the refractive index of the beads 11d are the refractive index n _PA different from the n _F.
If only the optical condition surface is considered, the refractive index of the polymer material may be set by selecting an appropriate combination from a range of approximately 1.338 to 1.7. At this time, 1.4
≦ n _F ≦ 1.6, 1.4 ≦ n _PA ≦ 1.6, 0.00 <|
It is set so as to satisfy n _F −n _PA | ≦ 0.362.

Here, the refractive index is 1.4 ≦ n _F ≦ 1.6,
1.4 ≦ n _PA ≦ 1.6, 0.00 <| n _F −n _PA | ≦
The reason for setting it to 0.362 is that when 0.00 = | n _F −n _PA |, the medium becomes a transparent medium, cannot scatter light, and does not function. | N _F −n _PA |> 0.362
In the case of (1), the haze ratio increases, and the intensity of the reflected light decreases. Another reason is that polymers that are advantageous in production fall within this range. A typical example is acrylic or polystyrene.

Next, the thickness t of the light control layer 11a is set to 5 μm
The reason for setting ≦ t ≦ 200 μm is that, in the case of t <5 μm, the light scattering ability is reduced and the haze ratio becomes low, so that metal reflection by a reflecting plate or a semi-transmissive reflecting plate provided below, or a mirror surface This is because the reflection of an external image and the parallax of the displayed image are visually recognized.

When t> 200 μm, the light control layer 11
This is because the haze ratio of the entire “a” increases and light is excessively scattered, so that the intensity of specularly reflected light is weakened. The outer diameter d ₁ of the beads 11d is set to 0.5 μm ≦ d ₁ ≦ 20 μm. The reason is that in the case of d ₁ <0.5 μm, the size of the beads 11 d becomes smaller than the size that can be correlated with the wavelength of visible light, so that the effect of reflection and refraction of visible light decreases,
Light scattering ability becomes poor. When d ₁ > 20 μm, the number of times of light reflection and refraction in the light control layer 11a is reduced, so that the light scattering ability becomes poor.

Accordingly, a bead 11d having an outer diameter d ₁ in a medium having a thickness t can be formed such that the relationship between the outer diameter of the granular material in the thickness direction and the effective cross-sectional area in the area direction satisfy certain conditions. Distribute as follows.

The outer diameter of the beads 11d is the same as that of the light control layer 11.
The thickness is set to be equal to or less than the thickness a. That is, beads 11d
T ₁ , the thickness of the light control layer, and the thickness of the medium substantially t
Then, d ₁ ≦ t is satisfied. The reason is d
_This is because when ₁ > t, unevenness occurs on the surface of the light control layer 11a, and when this is used for a display element, the visibility is reduced.

Further, under the above-mentioned conditions for forming the light control layer 11a, the weight ratio W _R = W _PA / (W _PA + W _F) of the beads 11d.
) Satisfies W _R <1 wt% or W _R > 70 wt%, the total area of interfaces having different refractive indices becomes smaller in the correlation with the medium, and therefore the number of times of refraction or reflection of light. Is generally reduced.

Therefore, W _R <1 wt% and W _R
If> 70 wt%, the light controllability is reduced. Therefore, in order to improve visibility by using the light control layer 11a is preferably set to _{1wt% ≦ W R ≦ 70wt%} .

As the semi-transmissive reflection plate 12a, a mirror reflection plate provided with a minute through-hole having an area ratio of 5 to 40% is used (abbreviated as a hole in the drawings). This is shown in FIG. 3 (configuration example B). This is because if the total area of the through holes is less than 5%, the brightness on the display surface of the display element is insufficient when the backlight is used under the transflective plate. Also, if the total area of the through holes is larger than 40%, the brightness becomes insufficient when the display surface of the display element is viewed using only external light.

The area of one through-hole is preferably about 100 μm × 100 μm and 10,000 μm ² or less assuming that the area is substantially square. This is because if the area of one through hole is 10,000 μm ² or less, it is difficult for human eyes to visually recognize the area. Further, it is preferable that the area of the through-holes per unit area of the semi-transmissive reflection plate and the number of the through-holes are substantially equal and uniformly dispersed.

This is to make the brightness uniform on the display surface of the display element when the backlight is used under the transflective plate 12a. Then, uniformity of display on the screen can be achieved.

FIGS. 4 to 7 (constitutional examples C to C) show the above-described reflector and semi-transmissive reflector provided with a polarizing plate.
E). In these figures, assuming that the individual transmittances of the reflection plate 11 of FIG. 4 and the polarizing plates provided on the semi-transmissive reflection plates of FIGS. 5 and 6 are T, respectively, 50% ≦ T ≦ 65%. . This is because when T <50%, the brightness becomes insufficient when the display surface of the display element is viewed using only external light. Further, when 65% <T, the degree of polarization of the polarizing plate is low, so that the contrast is reduced.

In the above-mentioned reflector, semi-transmissive reflector, first optical device (reflector with a polarizing plate) or second optical device (combination with a semi-transmissive reflector with a polarizer), bright metallic reflection is obtained. It is possible to realize a white luminous feeling like a diffusion plate without feeling.

The reflector 11 or the semi-transmissive reflector 1 of the present invention
2 is preferably provided between the rear glass substrate and the rear alignment film of the liquid crystal display device or below the rear glass substrate of the liquid crystal display device.

It is preferable that the reflectors 13 and 14 with a polarizing plate or the semi-transmissive reflectors 15 and 16 with a polarizing plate of the present invention be installed under the rear glass substrate of the liquid crystal display device.
Further, only the light control layer 11a of the present invention can be provided on the front polarizing plate, under the front polarizing plate, on the front glass substrate, and below the front glass substrate of the liquid crystal display device.

FIG. 8 shows a sectional view of an example of the liquid crystal display device of the present invention (Structural example F). An upper polarizer 1, an upper retarder 2, an upper retarder 3, an upper substrate 4, an upper electrode 5, an upper alignment film 6, a liquid crystal layer 7, a lower alignment film 8, a lower electrode 9, a lower substrate 10, FIG. 3 is a schematic diagram illustrating a cross-sectional state in which reflecting plates 11 are sequentially stacked.

FIG. 9 shows the granular material 1 in the light control layer 11a near one pixel of the liquid crystal display device employing the present invention.
1d, 11d _i, and shows the distribution of 11d _j schematically (example distribution A). Also, 11d, 11d in FIG.
_i, and 11d _j is equal refractive index, an example of using in the outer diameter dimension slightly dispersed respectively. The refractive index of these beads is set differently from that of the medium.

Also, the weight ratio of the granular material used was unchanged.
It can be approximated to be approximately the volume ratio, and the distribution density in the plane direction is also considered to substantially match the weight ratio. Therefore, the total area S _11d occupied by the beads 11d may be provided so as to be in a range of 1% ≦ S _11d ≦ 70% with respect to the pixel area. Preferably, the above formulas (3), (3A),
(3B) and (3C) can be similarly converted to an area and approximated.

FIG. 10 is a schematic plan view of another distribution example B. Two groups of beads having a different refractive index from the medium are dispersed in the medium. One group is (11d, 11d
_i , 11d _j ) group, all of which have the same refractive index, but differ in the outer diameter of the beads. Another group is (1
8D, 18D _i 18D _j ), which also have the same refractive index, but differ in the outer diameter of the beads. Furthermore, the refractive indices of these groups are different. That is, the maximum value and the minimum value of both the groups 11d and 18D are separated from each other, and the refractive index distribution does not overlap.

Next, a method for forming the light control layer of the present invention will be described. It can be broadly divided into the following two (a) and (b)
There are two methods. First, the technique (a) involves spraying beads made of a polymer, and there are cases (A), (B) and (C).

(A) K types (K is an integer of 1 or more) of polymer beads are sprayed on a liquid resin provided in a thin film form to form a layer which is naturally diffused. (B) K types (K is an integer of 1 or more) of polymer beads are scattered on a substrate, and then a liquid resin is formed so as to cover the polymer beads.
(C) A semi-solid or viscous resin is prepared, and K kinds (K is an integer of 1 or more) of polymer beads are sprinkled into the resin and external force is applied to uniformly stir the resin. These are the three. Thereafter, the liquid resin or the viscous resin is cured to form a light control layer.

In this case, in the methods (A) and (B), beads composed of K kinds of polymers (K is an integer of 1 or more) may be sprayed in a mixed state. In order to control the arrangement position of each type to a high degree, it is possible to change the order and amount of application for each type.

Next, in the method (b), a film and a curable compound are used in combination. (D) K types (K
(An integer of 1 or more) is applied to a liquid medium mixed with beads of a polymer, and the film thickness is controlled by adjusting the rotation speed of the roll and / or the amount of application to the film. (E) K types (K
Is an integer of 1 or more). The film thickness is controlled by adjusting the transport speed and / or the coating amount. (F) K types (K is an integer of 1 or more) of beads are sprayed on a film-like substrate which is continuously conveyed,
Thereafter, a liquid medium is arranged, and the distribution density of the polymer beads is controlled by adjusting the transport speed and / or the spray amount.

In the above method (b), if a curable compound is used as the liquid medium, the light control layer can be completed by curing. When a curable compound is used, after the film is formed into a film, the film is cured by applying ultraviolet light or applying heat.

At this time, utilizing the difference in physical properties between the material constituting the granular material and the medium material, for example, the difference in melting point and solubility, mixing, stirring, dispersion, and curing of the medium are performed in each process. Should be performed. In addition, the above (a), (b)
The light control layer can also be formed by further combining the above methods.

Next, Tables 1 to 16 show a list of polymer materials that can be used in the present invention. In principle, those which have optically high transparency and can be molded into a granular material, or those which become liquid when dissolved in a solvent can be used. Above all,
Synthetic polymers are preferable because their compositions can be adjusted and used in combination with each other, and can be stably supplied in mass production. When the light control layer is formed, it is preferable to systematically select and use a combination of materials exhibiting substantially the same optical characteristics in a desired temperature range. For example, if the ambient temperature is -40 to +95
It is preferable to select so as to exhibit desired characteristics in a temperature range of ° C.

In Tables 1 to 16, the first column shows the total number of the substance, the second column shows the substance name, and the third column shows the application method in the present invention.
The fourth column shows the refractive index, and the fifth column shows the temperature at which the refractive index is obtained in the fourth column. Any polymer material can be used for the granular material and the medium of the present invention. However, in the context of ordinary manufacturing methods, when considering the melting point of the polymer material as a substance, the coefficient of linear expansion, moldability, and whether or not it has a liquid property, for example, a substance of ○ △ ▽ is used. Is preferred.

Further, a plurality of kinds of polymers can be mixed and the refractive index thereof can be adjusted to be used as a granular material and a medium material in advance. A plurality of types of polymers can be mixed and used for the medium.

The physical properties of polymers are described in “Polymer Handbook” (Polymer Handbook).
k, Wiley Interscience) and Handbook of New Polymers, edited by The Society of Polymer Science, Section 3.3 Optoelectronic Polymer Materials (FIG. 3.3 on pages 88 to 89)
9, Table 3.18, Table 3.19, etc.) and the like, a polymer material may be selected so as to obtain a desired structure.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

[0069]

[Table 4]

[0070]

[Table 5]

[0071]

[Table 6]

[0072]

[Table 7]

[0073]

[Table 8]

[0074]

[Table 9]

[0075]

[Table 10]

[0076]

[Table 11]

[0077]

[Table 12]

[0078]

[Table 13]

[0079]

[Table 14]

[0080]

[Table 15]

[0081]

[Table 16]

[0082]

(Example 1) The reflector of the present invention comprises a light control layer and a specular reflection layer. First, the light control layer of this example was made of polymethyl methacrylate (PMMA, the refractive index was 1.492), and the film thickness was 25 μm. This light control layer was an adhesive layer. Beads are polystyrene (PSt, refractive index is 1.
59), the diameter is 1 μm, and 3 wt.
% Was uniformly mixed. An aluminum mirror reflection layer was used as the mirror reflection layer.

FIG. 11 shows the results of measuring the luminance of the reflector of this example.
(A). In addition, the measurement results of a conventional aluminum reflector having an uneven surface are also shown. The measurement system is shown in FIG.
Shown in The incident light was set to a direction of -30 °, and the luminance of the emitted light was measured.

Although the specular reflection portion was brighter than the conventional aluminum reflector having an uneven surface, the reflected light luminance distribution at other outgoing angles was almost the same as that of the aluminum reflector having an uneven surface. That is, the regular reflection portion was brighter than the conventional product, and the other portions were able to achieve the same brightness as the conventional product.

Next, this reflector was used for a liquid crystal display device. The liquid crystal display element is a 240 ° twisted 7.5-inch size 1 / polarizer and two phase difference plate type.
A 240-duty simultaneous row selection method MLA (multi-line addressing drive) method with a liquid crystal layer retardation value of 0.585 μm, a glass substrate thickness of 0.7 mm, and a color filter pixel size of 306
μm × 102 μm in width, the width of the lattice black matrix was 20 to 25 μm, and the retardation values of the two retardation plates were 460 nm and 380 nm.

A comparison between a liquid crystal display device using a conventional aluminum reflector having a surface irregularity for a liquid crystal display device and a liquid crystal display device combining the reflector of the present invention with a conventional aluminum reflector having a surface irregularity. Although there was uneven brightness due to surface irregularities and glare due to metal reflection, the reflector using the new beads did not have the drawbacks of the conventional product, and was whiter. As a result, a liquid crystal display device having a good appearance such as a white diffuser plate has been made possible.

Example 2 The light control layer of this example was made of polyethyl alcohol (PEA, refractive index 1.4684) and had a thickness of 30 μm. The beads were polyphenyl methacrylate (PPhM, refractive index 1.5706), the diameter was 3 μm, and 30 wt% was uniformly mixed in the light control layer.

A transflective plate was constructed by employing a silver specular reflection layer as the specular reflection layer. The size of the through hole is 1000 on average
0 μm ² , and the ratio of the total surface area of the through holes to the effective total area of the reflection surface was 20%. This transflective plate was used in combination with the liquid crystal display element (MLA-STN) used in Example 1.

When this is compared visually with a conventional combination of an aluminum semi-transmissive reflector with a surface irregularity and a liquid crystal display element, the one using a conventional aluminum semi-transmissive reflector with a surface irregularity has reduced luminance unevenness due to surface irregularities. There was glare due to metal reflection. In contrast, the display device employing the transflective plate of the present example does not have the drawbacks of the conventional product,
Further, it was white. As a result, a liquid crystal display device with good appearance such as a white diffuser plate can be achieved.

Example 3 The light control layer of this example is made of polymethyl methacrylate (PMMA, refractive index 1.492).
The film thickness was 45 μm. Beads are made of polystyrene (PS
t, the refractive index was 1.59), the diameter was 3 μm, and 10 wt% was uniformly mixed in the light control layer. A silver mirror reflection plate was used as the mirror reflection layer. The single transmittance of the polarizing plate is 6
0% was used.

Next, this reflector was used in combination with a liquid crystal display device. The liquid crystal display element is a type using two polarizing plates and one retardation plate. The retardation of the liquid crystal layer is 1.27 μm and the retardation of the retardation plate is 1.40 μm.
m. Δn = 0.196 (25 ° C.)
Time), T _C is 99 ° C., and dielectric anisotropy is +15 (25 ° C.).
H) and a viscosity of 24 cSt (at 20 ° C.). A glass substrate having a thickness of 0.4 mm was used. Four gradation display was performed at 1/65 duty.

Each gradation is 0%, 41%, 65%, 100%
It is. Each gradation corresponds to white, orange, blue, and green colors. Color display using birefringence has become possible.

A visual comparison between this and a conventional combination of an aluminum reflector having a surface irregularity and a liquid crystal display element shows that a device using a conventional aluminum reflector having a surface irregularity has uneven brightness due to surface irregularities and glare due to metal reflection. In contrast, the display device using this example did not have the drawbacks of the conventional product and was whiter.

As a result, a liquid crystal display device having a good appearance such as a white diffuser plate has been made possible. Further, by using a polarizing plate having a high single transmittance, the background color became 1.2 times brighter than that of a liquid crystal display device having the same structure as that of a normal liquid crystal display device.

Example 4 The light control layer of this example is made of polyvinyl alcohol (PVA, refractive index is 1.49) and has a film thickness of 3
It was set to 0 μm. The beads were polysulfone (PSu, the refractive index was 1.633), the diameter was 1 μm, and 3 wt% was uniformly mixed in the light control layer.

A silver specular semi-transmissive reflection plate was used as the specular reflection layer. The size of the through-hole was 10,000 μm ² on average, and the total surface area of the through-hole was 20% of the whole. The polarizing plate used had a single transmittance of 60%.

This transflective plate was used in combination with a liquid crystal display device. The liquid crystal display device is a 240 ° twist type, 7.5 inch size, 1/240 duty, simultaneous row selection method M using two polarizing plates and two phase difference plates.
The LA (multi-line addressing drive) system has a liquid crystal layer retardation of 0.127 μm, a liquid crystal layer cell gap of 6.7 μm, and a glass substrate having a thickness of 0.1 μm.
7 mm, pixel size of color filter is 306 μm vertically
× 102 μm in width, the width of the lattice black matrix was 20 to 25 μm, and the retardation of each of the two retardation plates was 435 nm.

A display device using the transflective plate of this embodiment;
A visual comparison of a conventional aluminum-semi-transparent reflector with a surface irregularity combined with a liquid crystal display element shows that the conventional aluminum-semi-transmissive reflector with a surface irregularity shows uneven brightness due to surface irregularities and glare due to metal reflection. On the other hand, in the case of employing this example, there was no defect as in the conventional product, and it was whiter. As a result, a liquid crystal display device having a good appearance such as a white diffuser plate has been made possible.

Further, by using a polarizing plate having a high single transmittance, the brightness was 1.2 times higher than that of a liquid crystal display device having the same structure using a normal surface irregular semi-transmissive reflector.

[0100]

The present invention provides a personal computer, a word processor, a fish finder, a portable communication device, an information terminal, an in-vehicle instrument panel, and various dot matrix display devices for consumer use (audio devices, clocks,
It can be used as a functional element of a display device having a display function such as a game device, an amusement device, a car navigation system, a camera, a TV phone, and a calculator.

In particular, since the display device employing the present invention can be used with low power consumption, portable electronic devices such as a mobile phone, an electronic notebook, an electronic book, an electronic dictionary, a PDA (portable information terminal), and a pager ( When used for pagers, etc., it exhibits high functionality in conjunction with its high visibility and expressiveness. Also, because it is bright even in a dark environment,
High visibility.

According to the second aspect of the present invention, high uniformity can be achieved by using a very small-sized granular material. According to the third aspect of the present invention, it is possible to obtain a reflector that is particularly easy to manufacture and easy to design by using minute-sized particles.

According to the fourth aspect of the present invention, it is possible to manufacture a reflector suitable for a large screen or more easily manufactured by using a large-sized granular material. According to the fifth aspect of the present invention, it is possible to form a new semi-transmissive reflection plate capable of effectively utilizing both the light from the light source and the outside light.

Further, according to the invention of claim 6, a high-performance optical device can be achieved by obtaining a reflector with a polarizing plate and a semi-reflector with a polarizing plate having desired optical characteristics. Further, according to the present invention, a display with a high contrast ratio can be obtained, and a bright display with a wide viewing angle can be obtained.

Further, the present invention can be applied to various applications as long as the effect is not impaired.

[Brief description of the drawings]

FIG. 1 is a schematic view of a cross section of a reflector (Structural Example A) of the present invention.

FIG. 2 is a schematic diagram of a cross section of Conventional Example 2.

FIG. 3 is a schematic diagram of a cross section of a semi-transmissive reflection plate (Configuration Example B) of the present invention.

FIG. 4 is a schematic view of a cross section of a reflective plate with a polarizing plate (Structural Example C) of the present invention.

FIG. 5 is a schematic view of a cross section of a reflective plate with a polarizing plate (Structural Example D) of the present invention.

FIG. 6 is a transflective plate with a polarizing plate of the present invention (Configuration Example D)
FIG.

FIG. 7 is a transflective plate with a polarizing plate of the present invention (Configuration Example E).
FIG.

FIG. 8 is a schematic view of a cross section of (Configuration Example F) of a liquid crystal display device using the present invention.

FIG. 9 is a schematic diagram of a cross section in a plane direction of a reflector (distribution example A) of the present invention.

FIG. 10 is a schematic diagram of a cross section in a plane direction of a reflector (distribution example B) of the present invention.

FIG. 11 is a graph showing the evaluation results (divided diagram a) and a measurement system (divided diagram b).

[Explanation of symbols]

 11a: light control layer 11b: specular reflection layer 11d: beads 11c: medium 11: reflection plate

Claims (6)

[Claims] 1. A thickness t (μm), a refractive index n _F , and a total weight W
_In a reflection plate provided with a planar medium and a granular material as _F , the granular material is disposed in the medium, the specular reflection layer is disposed on the back surface side of the medium, the refractive index n _PA , the outer diameter d _PA ( [mu] m), the total weight is used is granulate group a is W _PA, equation (1) to
(5) A reflecting plate satisfying (5). 0.5 μm ≦ d _PA ≦ 20 μm (1) 5 μm ≦ t ≦ 200 μm (2) 1.0 wt% ≦ W _PA / (W _PA + W _F ) ≦ 70 wt% ( 3) 0 <| n _PA −n _F | ≦ 0.362 (4) d _PA ≦ t (5) 2. The reflector according to claim 1, wherein the reflector satisfies the expressions (1A) to (3A). 0.5 μm ≦ d _PA ≦ 2 μm (1A) 5 μm ≦ t ≦ 45 μm (2A) 1.0 wt% ≦ W _PA / (W _PA + W _F ) ≦ 20 wt% ( 3A) 3. The reflecting plate according to claim 1, wherein the following formulas (1B) to (3B) are satisfied. 2 μm ≦ d _PA ≦ 4 μm (1B) 10 μm ≦ t ≦ 60 μm (2B) 7 wt% ≦ W _PA / (W _PA + W _F ) ≦ 45 wt% (3B) 4. The reflection plate according to claim 1, wherein the following formulas (1C) to (3C) are satisfied. 4 μm ≦ d _PA ≦ 10 μm (1C) 15 μm ≦ t ≦ 70 μm (2C) 13 wt% ≦ W _PA / (W _PA + W _F ) ≦ 60 wt% (3C) 5. A thickness t (μm), a refractive index n _F , and a total weight W
_In a reflection plate provided with a planar medium and a granular material as _F , the granular material is disposed in the medium, the specular reflection layer is disposed on the back surface side of the medium, the refractive index n _PA , the outer diameter d _PA ( [mu] m), the total weight is used is granulate group a is W _PA, provided more through holes extending to the back side from the front side to the reflective layer, total reflection layer of the effective cross-sectional area at the surface side of the through hole 5 to 40% of the total effective area on the surface side of
(5) A transflective reflector, characterized by satisfying (5). 0.5 μm ≦ d _PA ≦ 20 μm (1) 5 μm ≦ t ≦ 200 μm (2) 1.0 wt% ≦ W _PA / (W _PA + W _F ) ≦ 70 wt% ( 3) 0 <| n _PA −n _F | ≦ 0.362 (4) d _PA ≦ t (5) 6. The reflection plate according to claim 1, 2, 3, 4 or 5, or the transflective plate according to claim 5, 50 to 65%
An optical device characterized by being combined with a polarizing plate having a single transmittance as described above, and further combined with a display element.