JP6135740B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device having a surface protected and excellent impact characteristics as well as impact resistance.

  In general, a liquid crystal display device has a liquid crystal sandwiched between two thin substrates on which an alignment film, electrodes, etc. are formed, and a light guide plate, a polarizing plate, and a functional film such as an antiglare film or an antireflection film Has a structure in which the periphery of a liquid crystal panel in which layers are stacked is protected by a casing. Since the thin functional film is exposed on the display surface of the liquid crystal panel, it is vulnerable to external impact. When an impact is applied to the liquid crystal panel, the liquid crystal panel is damaged, or the alignment of the liquid crystal is disturbed to cause an alignment defect and display characteristics are deteriorated. Therefore, when the liquid crystal display device is transported, transported, or stored, and when the liquid crystal display device is used, the liquid crystal display device is required to have impact resistance.

In order to deal with such problems, a technique has been proposed in which a front substrate for protecting the liquid crystal panel from an external impact is disposed on the front surface of the liquid crystal panel. In this case, if an air layer is interposed between the liquid crystal panel and the front substrate, light is reflected at the interface with the air layer, particularly in a bright outdoors, and visibility is lowered.
Therefore, a protective member having a reinforced substrate such as tempered glass and a low reflective layer formed on the reinforced substrate on the front surface of the liquid crystal panel has a refractive index similar to that of the polarizing plate of the liquid crystal panel and the reinforced substrate of the protective member. There has been proposed a technique for simultaneously improving reliability against external impact and outdoor visibility by interposing an adhesive layer therebetween (see, for example, Patent Document 1).

JP 2009-265593 A

  In the technique described in Patent Document 1, an ultraviolet curable adhesive, a thermosetting adhesive, or OCA (Optical Clear Adhesive) is applied to an adhesive layer having a refractive index similar to that of a polarizing plate of a liquid crystal panel and a reinforced substrate of a protective member. A transparent adhesive tape is used, an adhesive is placed on a reinforced substrate or a liquid crystal panel, the reinforced substrate and the liquid crystal panel are overlapped, and the adhesive is cured or pressed by ultraviolet irradiation and heating, thereby reinforcing the substrate and the liquid crystal panel Are joined. However, when a curable pressure-sensitive adhesive is used, there are problems such as color unevenness due to deformation of the polarizing plate due to curing strain of the pressure-sensitive adhesive, and protrusion of the pressure-sensitive adhesive from the edge portion. Moreover, when using a transparent adhesive tape, there exist problems, such as the difficulty of alignment of a reinforced board | substrate and a liquid crystal panel, the bubble smear at the time of tape sticking, and the poor productivity by passing through an autoclave process.

  The present invention has been made in view of the above problems, and has as its main object to provide a liquid crystal display device having high impact resistance and good display characteristics.

  In order to solve the above-mentioned problems, the present invention provides a liquid crystal display characterized in that a rigid transparent substrate is bonded to an observation side surface of a liquid crystal panel via a fusion layer containing a thermoplastic resin. Providing equipment.

  According to the present invention, since the transparent base material having rigidity is bonded to the observation side surface of the liquid crystal panel via the fusion layer, the liquid crystal panel can be protected from external impact, and the impact resistance is increased and the reliability is improved. It is possible to improve. Further, according to the present invention, since the fusion layer contains a thermoplastic resin, the thermoplastic resin is formed into a sheet or film, and the liquid crystal panel, the sheet or film fusion layer, the transparent substrate, Can be integrated by thermocompression bonding, and the liquid crystal panel and the transparent substrate can be bonded to each other without degrading the image quality.

  In the said invention, it is preferable that the said transparent base material is a glass base material. This is because not only impact resistance but also scratch resistance can be enhanced.

  Moreover, in this invention, it is preferable that the thickness of the said transparent base material exists in the range of 0.5 mm-4 mm. This is because, if the thickness of the transparent substrate is within the above range, both the rigidity and strength of the transparent substrate and the weight reduction and thickness reduction of the liquid crystal display device can be achieved.

  Furthermore, in this invention, it is preferable that the thickness of the said melt | fusion layer exists in the range of 0.05 mm-0.5 mm. If the thickness of the fusion layer is within the above range, the thermoplastic resin can be formed into a sheet or film, and the liquid crystal panel and the transparent substrate are pasted using the sheet or film fusion layer. It becomes possible to match. In addition, when the thickness of the fusion layer is within the above range, it is possible to achieve both the adhesion between the liquid crystal panel and the transparent substrate and the weight reduction and thickness reduction of the liquid crystal display device.

  Moreover, in this invention, it is preferable that the said melt | fusion layer contains a crosslinking agent. This is because the heat resistance of the fusion layer after heat fusion can be improved.

  Furthermore, in the present invention, it is preferable to use a sheet-like or film-like fusion layer having a concavo-convex shape on the surface as the fusion layer. This is because, if the surface of the sheet-like or film-like fusion layer has an uneven shape, bubbles that are embraced when the liquid crystal panel and the transparent substrate are bonded together can be released.

  In the present invention, it is preferable that a light diffusion layer is disposed on the observation side of the liquid crystal panel. By sticking a transparent base material to the liquid crystal panel through the fusion layer, display defects due to the liquid crystal panel or the backlight unit may be easily recognized, but a light diffusion layer is disposed on the observation side of the liquid crystal panel. This is because it is possible to make it difficult to visually recognize display defects.

  In the said invention, it is preferable that the said light-diffusion layer contains a light-diffusion particle and a binder. This is because when the light diffusion layer contains light diffusion particles, it is possible to prevent the occurrence of glare (scintillation).

In the above case, the refractive index ratio between the light diffusing particles and the binder is preferably in the range of more than 1.000 and less than 1.020. If the refractive index ratio between the light diffusing particles and the binder is large, the contrast may decrease due to whitening. Therefore, the difference in the refractive index between the light diffusing particles and the binder is not zero, but the refractive index between the light diffusing particles and the binder. The ratio is preferably as small as possible. In particular, when the light diffusing layer contains light diffusing particles and has irregularities on the surface, the refractive index ratio between the light diffusing particles and the binder is as small as possible, thereby preventing glare and reducing contrast. Can be reduced.
The refractive index ratio between the light diffusing particles and the binder refers to the ratio of the light diffusing particles and the binder having a large refractive index to those having a small refractive index.

  Moreover, in the said invention, it is also preferable that the said light-diffusion layer has an unevenness | corrugation on the surface. This is because, when the light diffusing layer has irregularities on the surface, compared to the case where the light diffusing layer contains light diffusing particles, the contrast due to whitening hardly occurs even if the refractive index ratio at the irregularity interface is large.

  Furthermore, in the above invention, a second fusion layer containing a thermoplastic resin and the light diffusion layer may be sequentially disposed between the liquid crystal panel and the fusion layer. In this case, a commercially available sheet-like or film-like light diffusion layer can be used, and a liquid crystal display device can be produced at a low cost.

In the above invention, the light diffusion layer and the second fusion layer are in contact with each other, the light diffusion layer has irregularities on the surface on the second fusion layer side, and constitutes the light diffusion layer. The refractive index ratio between the material and the thermoplastic resin contained in the second fusion layer is preferably in the range of 1.010 or more and less than 1.300. If the refractive index ratio is less than the above range, the diffusion due to the unevenness of the interface between the light diffusion layer and the second fusion layer may be reduced, which may cause uneven spots. This is because the contrast may decrease due to the reflection of external light at the interface irregularities between the diffusion layer and the second fusion layer.
The refractive index ratio between the material constituting the light diffusion layer and the thermoplastic resin contained in the second fusion layer is the thermoplastic resin contained in the material constituting the light diffusion layer and the second fusion layer. Of these, the ratio of those having a large refractive index to those having a small refractive index.

  Furthermore, in the said invention, it is also preferable that the said light-diffusion layer contains a high refractive ultrafine particle or a low refractive ultrafine particle. This is because when the light diffusion layer contains high-refractive ultrafine particles or low-refractive ultrafine particles, the refractive index of the constituent material of the light diffusion layer can be adjusted.

  In the above invention, it is also preferable that the second fusion layer contains high refractive ultrafine particles or low refractive ultrafine particles. This is because the refractive index of the thermoplastic resin can be adjusted when the thermoplastic resin of the second fusion layer contains high refractive ultrafine particles or low refractive ultrafine particles.

  Furthermore, in the said invention, the said melt | fusion layer may contain the said light-diffusion particle, and may serve as the said light-diffusion layer. In the case where the fusion layer is disposed immediately above the liquid crystal panel, the occurrence of double images can be reduced by the fusion layer also serving as the light diffusion layer. Further, the layer configuration can be simplified.

  Moreover, in the said invention, in the projection surface from the normal line direction of the observation side surface of the said liquid crystal panel, the sum total of the in-plane projection area of the said light-diffusion particle | grains contained in the said light-diffusion layer is 8 to 63% of the whole. It is preferable to be within. With such a configuration, it is possible to achieve both suppression of display unevenness and improvement of contrast.

Further, in the above invention, when the normal transmission intensity of the light diffusion layer is Q, and the transmission intensity obtained by extrapolating a straight line connecting the transmission intensity at normal transmission ± 2 degrees and normal transmission ± 1 degree to the normal transmission angle is U ,
2 <Q / U <22
It is preferable to satisfy. This is because if Q / U is smaller than the above range, the blackness may deteriorate, and if Q / U is larger than the above range, display spots may occur. Therefore, by setting Q / U within the above range, it is possible to achieve both suppression of display unevenness and improvement of blackness.
Note that blackness is a performance that is required for moving images and has the contrast, three-dimensionality, and dynamism (for example, in the case of a youth scene under a blue sky, the hair displayed on the screen is smooth. It is a black with a feeling, its eyes are moist black, and the skin has a gloss that is unique to the youth and looks vibrant.

Moreover, in the said invention, when the pixel pitch of the horizontal direction of the said liquid crystal panel is set to P and the thickness of the said light-diffusion layer is set to T,
T <P / 2
It is preferable to satisfy. This is because, when the thickness of the light diffusing layer satisfies the above formula, the occurrence of double images in the normal viewing area can be reduced.

Further, in the present invention, when the vertical and horizontal lengths of the liquid crystal panel are L ₁ and W ₁ , and the vertical and horizontal lengths of the transparent substrate are L ₂ and W ₂ , respectively.
L ₁ ≦ L ₂ and / or W ₁ ≦ W ₂
It is preferable to satisfy. This is because it is possible to prevent the display quality of the image from being deteriorated due to stress applied to the liquid crystal panel and bending or distortion.

  In the present invention, a louver layer in which strip-like transmission parts and light-shielding parts are alternately arranged may be arranged on the observation side of the liquid crystal panel. This is because the contrast can be improved by the louver layer.

  In the said invention, it is preferable that the said permeation | transmission part and the said light-shielding part are alternately arranged in the left-right direction of the said liquid crystal panel. When the louver layer does not have a diffusing function, it is preferable that the transmissive portions and the light shielding portions are alternately arranged in the left-right direction of the liquid crystal panel as described above. This is because the contrast can be improved by the louver layer without narrowing the angle of view in the horizontal direction of the liquid crystal display device.

  Moreover, in the said invention, it is also preferable that the said permeation | transmission part and the said light-shielding part are alternately arranged in the up-down direction of the said liquid crystal panel. When the louver layer has a diffusing function, it is also preferable that the transmissive portions and the light shielding portions are alternately arranged in the vertical direction of the liquid crystal panel as described above. This is because the angle of view in the left-right direction of the liquid crystal display device can be increased while improving the contrast.

  In the above case, the maximum angle of light that can be emitted from the transmission part of the louver layer with respect to the normal direction of the observation side surface of the louver layer is preferably 45 degrees or more. This is because external light can be absorbed and a normal viewing area in the vertical direction of the liquid crystal display device can be secured.

  In the above case, the louver layer is preferably disposed on the observation side of the light diffusion layer. This is because the external light incident on the light diffusion layer can be reduced, and reflection of external light from the light diffusion layer can be absorbed to improve the contrast. Further, in order to suppress the generation of double images, it is preferable that the light diffusion layer is disposed in the vicinity of the liquid crystal panel.

  Furthermore, in the above case, it is preferable that the second fusion layer containing a thermoplastic resin and the louver layer are sequentially disposed between the liquid crystal panel and the fusion layer. This is because the liquid crystal panel, the louver layer, and the transparent substrate can be bonded with good adhesion by the fusion layer and the second fusion layer.

  In the present invention, a light absorption layer having an average light absorptance within a range of 1% to 30% within a wavelength range of 400 nm to 750 nm may be disposed on the observation side of the liquid crystal panel. This is because the contrast can be improved by the light absorption layer.

  In the said invention, it is preferable that the said light absorption layer has the selective absorption property which absorbs wavelengths other than the predetermined wavelength which image light itself has. Since the outside light has all wavelengths and the image light has only specific wavelengths (that is, it is common to use red, green, and blue which are the three primary colors of light), the light absorption layer has a selective absorption property. This is because the contrast can be further improved by suppressing the attenuation of the image light by the light absorption layer and increasing the absorption of the external light.

  In addition, when the light absorption layer has selective absorption, the liquid crystal display device of the present invention is a field sequential device in which the backlight is an LED light source having a different wavelength and the liquid crystal display device is driven in synchronization with the emission wavelength of the LED light source. A liquid crystal display device of the type is preferable. In the case of a field sequential method using LEDs, since it is not necessary to use a color filter, the image light itself has a predetermined wavelength, so that the wavelength range of selective absorption by the light absorption layer can be expanded. is there. Thereby, contrast can be further improved.

  In the said invention, it is preferable that the said light absorption layer is arrange | positioned at the observation side of the said light-diffusion layer. This is because the light diffusing layer is preferably disposed in the vicinity of the liquid crystal panel in order to suppress the generation of double images. In addition, by adopting such an arrangement, the light absorption layer is effective for both absorption of external light incident on the light diffusion layer and absorption of external light reflected by the light diffusion layer, and is preferable for improving contrast. . Furthermore, since the stray light of the image light incident on the light absorption layer from the liquid crystal panel passes through the light absorption layer obliquely, the image is clearer because the absorption is larger than the image light and the flare is reduced. is there.

  Moreover, in the said invention, it is also preferable that the said melt | fusion layer serves as the said light absorption layer. This is because the contrast can be improved as described above.

  Furthermore, in the said invention, it is preferable that the 2nd melt | fusion layer containing a thermoplastic resin and the said light absorption layer are arrange | positioned in order between the said liquid crystal panel and the said melt | fusion layer. This is because the liquid crystal panel, the light absorption layer, and the transparent substrate can be bonded with good adhesion by the fusion layer and the second fusion layer.

  In the present invention, the second fusion layer preferably contains the light diffusing particles and also serves as the light diffusing layer. This is because the second fused layer that also serves as the light diffusion layer can be disposed in the vicinity of the liquid crystal panel to suppress the generation of double images.

  In the said invention, it is preferable that a said 2nd melt | fusion layer contains a crosslinking agent. This is because the heat resistance after heat fusion of the second fusion layer can be improved.

  Moreover, in the said invention, it is preferable to use the sheet-like or film-like 2nd fusion | melting layer which has an uneven | corrugated shape on the surface as said 2nd fusion | melting layer. This is because, if the surface of the sheet-like or film-like second fusion layer has an uneven shape, bubbles that are embraced when the liquid crystal panel and the transparent substrate are bonded together can be released.

  In the present invention, since a rigid transparent substrate is bonded to the observation side of the liquid crystal panel via a fusion layer, the impact resistance is improved and the reliability is improved, and the liquid crystal is interposed via the fusion layer. There is an effect that it is possible to suppress a decrease in display quality caused by joining the panel and the transparent substrate. Furthermore, in the present invention, by providing functional layers such as a light diffusion layer, a louver layer, and a light absorption layer, display defects such as spots can be reduced, contrast can be improved, and display quality can be improved. There is an effect.

It is a schematic sectional drawing which shows an example of the liquid crystal display device of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display device of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display device of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display device of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display device of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display device of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display device of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display device of this invention. It is a schematic sectional drawing for demonstrating the light-diffusion layer in this invention.

Hereinafter, the liquid crystal display device of the present invention will be described in detail.
The liquid crystal display device of the present invention is characterized in that a transparent substrate having rigidity is bonded to an observation side surface of a liquid crystal panel via a fusion layer containing a thermoplastic resin.

The liquid crystal display device of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic sectional view showing an example of the liquid crystal display device of the present invention. The liquid crystal display device 1 illustrated in FIG. 1 includes a liquid crystal panel 20, a backlight unit 31 disposed on the back surface of the liquid crystal panel 20, and a casing 32 that protects the liquid crystal panel 20 and the backlight unit 31. Yes. In the liquid crystal display device 1, a rigid transparent substrate 2 is bonded to the surface of the observation side 10 of the liquid crystal panel 20 via a fusion layer 3 containing a thermoplastic resin. The liquid crystal panel 20 includes a liquid crystal cell 21, an observation side polarizing plate 22a disposed on the observation side 10 of the liquid crystal cell 21, a back polarizing plate 22b disposed on the back surface of the liquid crystal cell 21, and an observation side polarizing plate 22a. And a functional film 23 such as an antiglare film or an antireflection film disposed on the side 10. Although not shown, the liquid crystal cell 21 includes a pair of support plates, a liquid crystal sandwiched between the support plates, an alignment film that aligns liquid crystal molecules, an electrode that controls the alignment of liquid crystal molecules by an electric field, and a color filter. Have.

  According to the present invention, since the rigid transparent base material is bonded to the observation side surface of the liquid crystal panel via the fusion layer, the impact resistance of the liquid crystal display device can be improved and transported, transported or stored. It is possible to increase the reliability of the product when it is used. Further, according to the present invention, since the fusion layer contains a thermoplastic resin, the thermoplastic resin is formed into a sheet or film, and the liquid crystal panel, the sheet or film fusion layer, the transparent substrate, A liquid crystal display device can be manufactured by using a lamination method or the like in which layers are sequentially laminated and heat-pressed, and a liquid crystal display device excellent in impact resistance is obtained by a simple method without causing deterioration in display quality. It is possible.

2 to 4 are schematic cross-sectional views showing other examples of the liquid crystal display device of the present invention.
In the liquid crystal display device 1 illustrated in FIG. 2, a rigid transparent substrate 2 is bonded to the surface of the observation side 10 of the liquid crystal panel 20 via the fusion layer 3. The fusion layer 3 is obtained by dispersing light diffusion particles in a thermoplastic resin, and also serves as the light diffusion layer 5.
In the liquid crystal display device 1 illustrated in FIG. 3, a second fusion layer 6 containing a thermoplastic resin on the surface of the observation side 10 of the liquid crystal panel 20 and a light diffusion layer 5 in which light diffusion particles are dispersed in the resin. And the melt | fusion layer 3 containing a thermoplastic resin and the transparent base material 2 which has rigidity are laminated | stacked one by one.
In the liquid crystal display device 1 illustrated in FIG. 4, a rigid transparent substrate 2 is bonded to the surface of the observation side 10 of the liquid crystal panel 20 via a fusion layer 3 containing a thermoplastic resin. The transparent substrate 2 contains light diffusing particles and also serves as the light diffusing layer 5.

Thus, in this invention, it is preferable that the light-diffusion layer is arrange | positioned at the observation side of a liquid crystal panel. For example, in the liquid crystal display device 1 shown in FIGS. 2 to 4, when the functional film 23 that forms the surface of the observation side 10 of the liquid crystal panel 20 has irregularities on the surface of the observation side 10, the observation side 10 of the functional film 23. When the transparent substrate 2 is affixed to the surface of the functional film 23 via the fusion layer 3 or the fusion layer 3 and the second fusion layer 6, the unevenness of the functional film 23 becomes the fusion layer 3 or the second fusion layer 6. Will be filled with. Generally, the refractive index ratio between the material constituting the functional film and the thermoplastic resin constituting the fusion layer or the second fusion layer is higher than the refractive index ratio between the material constituting the functional film and air. Since it is small, there exists a possibility that the light diffusibility by the unevenness | corrugation of a functional film may be impaired by a melt | fusion layer or a 2nd melt | fusion layer. When the light diffusibility is impaired, display defects such as color unevenness and luminance unevenness due to the liquid crystal panel and the backlight unit are easily visually recognized. For example, in the technique described in Patent Document 1, since an adhesive layer having a refractive index similar to that of a polarizing plate and a reinforced substrate of a liquid crystal panel is used, light diffusion on the uneven surface existing on the surface of the liquid crystal display panel is eliminated. There is a problem that defects such as spots due to the liquid crystal display device itself are easily seen and the yield is lowered.
On the other hand, in this invention, it is possible to make it difficult to visually recognize a display defect by arranging the light diffusion layer on the observation side of the liquid crystal panel. That is, by providing an internal diffusion function, display defects such as spots superimposed on video light can be reduced.

5 and 6 are schematic cross-sectional views showing other examples of the liquid crystal display device of the present invention.
In the liquid crystal display device 1 illustrated in FIG. 5, a second fusion layer 6 and a louver layer 7 in which strip-shaped transmission portions 7 a and light shielding portions 7 b are alternately arranged on the surface of the observation side 10 of the liquid crystal panel 20. The fusing layer 3 and the transparent substrate 2 are sequentially laminated. The second fusion layer 6 is obtained by dispersing light diffusion particles in a thermoplastic resin, and also serves as the light diffusion layer 5.
In the liquid crystal display device 1 illustrated in FIG. 6, the second fusion layer 6, the light diffusion layer 5, the band-shaped transmission part 7 a and the light shielding part 7 b are alternately arranged on the surface of the observation side 10 of the liquid crystal panel 20. The louver layer 7, the fusion layer 3, and the transparent substrate 2 are sequentially laminated.

  Thus, in the present invention, the louver layer may be disposed on the observation side of the liquid crystal panel. When the louver layer is arranged on the viewing side of the liquid crystal panel, oblique external light is blocked by the light shielding part of the louver layer, and the amount of external light reflected on the display surface is reduced. Can be improved. That is, the contrast can be improved by providing the function of absorbing external light.

7 and 8 are schematic cross-sectional views showing other examples of the liquid crystal display device of the present invention.
In the liquid crystal display device 1 illustrated in FIG. 7, the second fusion layer 6, the light absorption layer 8, the fusion layer 3, and the transparent base material 2 are sequentially formed on the surface of the observation side 10 of the liquid crystal panel 20. Are stacked. The second fusion layer 6 is obtained by dispersing light diffusion particles in a thermoplastic resin, and also serves as the light diffusion layer 5.
In the liquid crystal display device 1 illustrated in FIG. 8, the second fusion layer 6, the light diffusion layer 5, the light absorption layer 8, the fusion layer 3, and the transparent are formed on the surface of the observation side 10 of the liquid crystal panel 20. The substrate 2 is sequentially laminated.
7 and 8, the light absorption layer 8 has an average light absorption rate in the range of 1% to 30% within a wavelength range of 400 nm to 750 nm.

  Thus, in this invention, the light absorption layer may be arrange | positioned at the observation side of the liquid crystal panel. When the light absorption layer is disposed on the observation side of the liquid crystal panel, contrast and image sharpness can be improved. That is, the contrast can be improved by providing the function of absorbing external light.

  Hereinafter, each structure in the liquid crystal display device of this invention is demonstrated.

1. Transparent substrate The transparent substrate in the present invention has rigidity and is bonded to the observation side surface of the liquid crystal panel via a fusion layer.

The transparent substrate is not particularly limited as long as it has rigidity, and for example, a glass substrate or a resin substrate can be used.
The material of the resin base material is not particularly limited as long as a resin base material having rigidity can be obtained. Examples thereof include a polycarbonate resin, an acrylic resin, an organic glass resin, and an acrylic styrene resin. It is done.
Among these, the transparent substrate is preferably a glass substrate. Resistance to bending and impact resistance can be further increased. Further, in the conventional liquid crystal display device, the display surface of the liquid crystal panel is particularly easily scratched because the thin functional film is exposed. However, since the transparent substrate is a glass substrate, Can increase the sex. Furthermore, since the glass substrate absorbs ultraviolet rays, deterioration of the constituent members of the liquid crystal display device due to the ultraviolet rays can be suppressed. Further, the glass substrate is superior in water resistance and chemical resistance as compared with the resin substrate, and has an advantage that it is inexpensive.

  The thickness of the transparent substrate is not particularly limited as long as the desired rigidity can be obtained. For example, it may be about 0.5 mm to 4 mm, and particularly within the range of 0.7 mm to 3.5 mm. It is preferable that it is in the range of 1 mm-3 mm especially. This is because if the transparent substrate is thin, desired rigidity and strength may not be obtained, and if the transparent substrate is thick, it is difficult to reduce the weight and thickness of the liquid crystal display device.

As the size of the transparent substrate, when the vertical and horizontal lengths of the liquid crystal panel are respectively L ₁ and W ₁ , and the vertical and horizontal lengths of the transparent substrate are respectively L ₂ and W ₂ ,
L ₁ ≦ L ₂ and / or W ₁ ≦ W ₂
It is preferable to satisfy. This is because if the transparent base material is smaller than the liquid crystal panel, stress is applied to the liquid crystal panel, and the display characteristics may be deteriorated due to bending or distortion. For at least one of the vertical and horizontal lengths, the transparent substrate only needs to be the same as the liquid crystal panel or larger than the liquid crystal panel. More preferably, it is equal to or larger than the liquid crystal panel. For example, when the horizontal length is longer than the vertical length, W ₁ ≦ W ₂ is preferable. In particular, it is preferable that the transparent base material is equal to or larger than the liquid crystal panel for both the vertical and horizontal lengths. That is, it is preferable that L ₁ ≦ L ₂ and W ₁ ≦ W ₂ .

  The transparent substrate may also serve as a light diffusion layer described later. As illustrated in FIG. 4, since the transparent base material 2 also serves as the light diffusion layer 5, it is possible to make it difficult to visually recognize display defects due to the liquid crystal panel or the backlight unit. When the transparent substrate also serves as the light diffusion layer, the transparent substrate may contain light diffusing particles and may have irregularities on the surface on the observation side and / or the liquid crystal panel side.

  As a transparent base material which has an unevenness | corrugation on the surface, for example, a ground glass or a glass substrate on which an unevenness made of resin is formed can be used. As a method for producing frosted glass, for example, sandblasting, frosting, embossing, or the like can be applied. Moreover, as a method of forming the unevenness | corrugation which consists of resin on a glass base material, the coating method of uneven | corrugated shaping | molding resin, the method of bonding the film which has an unevenness | corrugation on the surface, etc. are applicable, for example.

  In addition, when a transparent base material serves also as a light-diffusion layer, since a light-diffusion layer is mentioned later, description here is abbreviate | omitted.

The transparent base material may be one in which strip-shaped transmission portions and light shielding portions are alternately arranged. That is, the transparent substrate may also serve as a louver layer described later.
In addition, since a louver layer is mentioned later when a transparent base material serves as a louver layer, description here is abbreviate | omitted.

The transparent substrate may have an average light absorption rate within a range of 1% to 30% within a wavelength range of 400 nm to 750 nm. That is, the transparent substrate may also serve as a light absorption layer described later.
In addition, since a light absorption layer is mentioned later when a transparent base material serves as a light absorption layer, description here is abbreviate | omitted.

2. Fusing Layer The fusing layer in the present invention contains a thermoplastic resin and adheres a liquid crystal panel and a transparent substrate.

  The thermoplastic resin contained in the fusing layer is not particularly limited as long as it is a resin that melts at a desired temperature. Among these, the melting point of the thermoplastic resin is preferably in the range of 50 ° C to 130 ° C, more preferably in the range of 60 ° C to 120 ° C, and still more preferably in the range of 60 ° C to 100 ° C. If the melting point exceeds the above range, the polarizing plate of the liquid crystal panel may deteriorate at the time of heat fusion, and if the melting point is less than the above range, depending on the surrounding environment when using the completed liquid crystal display device There is a possibility that the fused layer may be softened.

  Examples of such a thermoplastic resin include polyolefins such as polyethylene, polypropylene, polyisobutylene, polystyrene, and ethylene-propylene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethyl cellulose, cellulose triacetate, and the like. Cellulose derivatives, copolymers of poly (meth) acrylic acid and esters thereof, polyvinyl acetals such as polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyacetals, polyamides, polyimides, nylons, polyester resins, urethane resins, epoxy resins, A silicone resin, a fluororesin, etc. can be mentioned. Among these, polyvinyl acetal, polyolefin, ethylene-vinyl acetate copolymer, urethane resin, epoxy resin, silane-modified resin, and acid-modified resin are preferable from the viewpoint of adhesiveness and light transmittance. In particular, polyvinyl butyral and ethylene-vinyl acetate copolymer are suitable. This is because the ethylene-vinyl acetate copolymer is excellent in adhesiveness, and the polyvinyl butyral is excellent in transparency.

  In particular, when the fusion layer is in contact with the transparent substrate, the thermoplastic resin preferably has a small refractive index ratio with respect to the material constituting the transparent substrate. Similarly, when the fusion layer is in contact with the liquid crystal panel, the thermoplastic resin preferably has a small refractive index ratio with respect to the material constituting the outermost member (for example, a functional film) of the liquid crystal panel. .

The fusing layer may contain additives such as a light stabilizer, an ultraviolet absorber, a heat stabilizer, and an antioxidant. By including these additives, it is possible to obtain stable mechanical strength over a long period of time, prevention of yellowing, prevention of cracking, and excellent processability.
The fusing layer may further contain a crosslinking agent, a dispersing agent, a leveling agent, a plasticizer, an antifoaming agent, and the like. When the fusion layer contains a crosslinking agent, the heat resistance after heat fusion can be improved. As the crosslinking agent, for example, a silane coupling agent can be used.

The fusion layer may contain light diffusing particles. That is, the fusion layer may be one in which light diffusion particles are dispersed in a thermoplastic resin. In this case, the fusion layer can also serve as a light diffusion layer described later. As illustrated in FIG. 2, since the fusion layer 3 also serves as the light diffusion layer 5, it is possible to make it difficult to visually recognize display defects due to the liquid crystal panel or the backlight unit. When the fusion layer is disposed immediately above the liquid crystal panel, the fusion layer preferably contains light diffusion particles and also serves as the light diffusion layer.
In the case where the fusion layer also serves as the light diffusion layer, the light diffusion layer will be described later, and a description thereof will be omitted here.

The fusion layer may be one in which strip-shaped transmission portions and light shielding portions are alternately arranged. That is, the fusion layer may also serve as a louver layer described later.
In the case where the fusion layer also serves as the louver layer, the louver layer will be described later, and a description thereof will be omitted here.

The fusion layer may have an average light absorption rate within a range of 1% to 30% within a wavelength range of 400 nm to 750 nm. That is, the fusion layer may also serve as a light absorption layer described later.
In the case where the fusion layer also serves as the light absorption layer, the light absorption layer will be described later, and a description thereof will be omitted here.

  The thickness of the fusion layer is not particularly limited as long as a desired adhesive force can be expressed, and is appropriately adjusted according to the type of the thermoplastic resin. Specifically, the thickness of the fusion layer is preferably within a range of 0.05 mm to 0.5 mm, more preferably within a range of 0.05 mm to 0.3 mm, and even more preferably 0.1 mm to 0 mm. Within the range of 3 mm. If the thickness of the fusion layer is thin, the desired adhesive strength may not be obtained, and if the thickness of the fusion layer is large, excessive heating is required to sufficiently express the interlayer adhesion strength by the fusion layer, This is because thermal damage to the liquid crystal panel and the transparent substrate may increase.

  As a method of bonding the liquid crystal panel and the transparent substrate through the fusion layer, for example, a thermoplastic resin is formed into a sheet or film, and the liquid crystal panel and the transparent substrate are transparent through the sheet or film fusion layer. The method of laminating with a base material can be mentioned.

  The method for forming the thermoplastic resin into a sheet or film is not particularly limited as long as it is a method capable of producing a sheet-like or film-like fusion layer having a uniform thickness. A resin film forming method, for example, a solution film forming method or a melt film forming method may be employed.

Moreover, it is preferable that the sheet-like or film-like fusion layer before bonding has an uneven shape on the surface. That is, it is preferable to use a sheet-like or film-like fusion layer having a concavo-convex shape on the surface as the fusion layer. This is because, if the surface of the sheet-like or film-like fusion layer has an uneven shape, bubbles that are embraced when the liquid crystal panel and the transparent substrate are bonded together can be released.
The concavo-convex shape is not particularly limited as long as it can escape the bubbles to be held when the liquid crystal panel and the transparent substrate are bonded together, but the ten-point average roughness Rz is preferably 0.2 μm or more. This is because if the ten-point average roughness Rz is within the above range, it is possible to easily remove bubbles when the liquid crystal panel and the transparent substrate are bonded. The cut-off value is preferably 0.8 mm.

3. Second Fusion Layer In the present invention, when functional layers such as a light diffusion layer, a louver layer, and a light absorption layer, which will be described later, are disposed on the observation side of the liquid crystal panel, the second fusion layer is provided between the liquid crystal panel and the fusion layer. Moreover, the 2nd melt | fusion layer containing a thermoplastic resin and said functional layer may be arrange | positioned in order.
For example, as shown in FIG. 3, when the light diffusion layer 5 is disposed on the observation side 10 of the liquid crystal panel 20, the second fusion layer 6, the light diffusion layer 5, and the like are formed on the surface of the observation side 10 of the liquid crystal panel 20. The fusion layer 3 and the transparent substrate 2 are laminated in order, the liquid crystal panel 20 and the light diffusion layer 5 are bonded together via the second fusion layer 6, and the light diffusion layer 5 and the transparent substrate 2 are fused. It may be bonded via the layer 3.
Further, as shown in FIG. 5, when the louver layer 7 is disposed on the observation side 10 of the liquid crystal panel 20, the second fusion layer 6 and the louver layer 7 are fused on the surface of the observation side 10 of the liquid crystal panel 20. The adhesion layer 3 and the transparent substrate 2 are laminated in order, the liquid crystal panel 20 and the louver layer 7 are bonded together via the second fusion layer 6, and the louver layer 7 and the transparent substrate 2 attach the fusion layer 3. It may be pasted together.
As shown in FIG. 7, when the light absorption layer 8 is disposed on the observation side 10 of the liquid crystal panel 20, the second fusion layer 6, the light absorption layer 8, and the fusion layer are formed on the surface of the observation side 10 of the liquid crystal panel 20. The adhesion layer 3 and the transparent substrate 2 are laminated in order, the liquid crystal panel 20 and the light absorption layer 8 are bonded together via the second fusion layer 6, and the light absorption layer 8 and the transparent substrate 2 are fused. 3 may be pasted together.
The thermoplastic resin constituting the fusion layer and the second fusion layer can be formed into a sheet or film, and the display quality can be improved by using the sheet or film fusion layer and the second fusion layer. The liquid crystal panel, the functional layer, and the transparent substrate can be bonded together by a simple method without lowering.

  The thermoplastic resin contained in the second fusion layer can be the same as the thermoplastic resin contained in the fusion layer.

In particular, as illustrated in FIGS. 3, 6, and 8, the second fusion layer 6 is in contact with the light diffusion layer 5, and the light diffusion layer 5 is a surface on the second fusion layer 6 side. In the case where the surface has irregularities, the refractive index of the thermoplastic resin contained in the second fusion layer is preferably different from the refractive index of the material constituting the light diffusion layer. It is more preferable that the refractive index ratio between the contained thermoplastic resin and the material constituting the light diffusion layer is large. This is because the larger the refractive index ratio between the thermoplastic resin contained in the second fusion layer and the material constituting the light diffusion layer, the higher the light diffusibility due to the uneven surface of the light diffusion layer.
The refractive index ratio will be described in the section of the light diffusion layer described later, and will not be described here.

When the second fusion layer is in contact with the light diffusion layer and the light diffusion layer has irregularities on the surface on the second fusion layer side, the thermoplastic resin has a refractive index. In order to adjust the refractive index, it is also preferable that high refractive index ultrafine particles or low refractive index ultrafine particles having an average particle diameter in the range of 1 nm to 300 nm are contained. By adjusting the refractive index of the thermoplastic resin, it is possible to increase the refractive index ratio between the thermoplastic resin contained in the second fusion layer and the material constituting the light diffusion layer. This is because light can be more effectively diffused by the surface irregularities.
Note that the high refractive index ultrafine particles and the low refractive index ultrafine particles are described in the section of the light diffusion layer described later, and thus the description thereof is omitted here.

  Further, when the second fusion layer is in contact with the liquid crystal panel, the thermoplastic resin may have a small refractive index ratio with respect to the material constituting the outermost member (for example, a functional film) of the liquid crystal panel. preferable.

The second fusion layer may contain light diffusing particles. That is, the second fusion layer may be one in which light diffusion particles are dispersed in a thermoplastic resin. In this case, the second fusion layer can also serve as a light diffusion layer described later. As illustrated in FIGS. 5 and 7, since the second fusion layer 6 also serves as the light diffusion layer 5, it is possible to make it difficult to visually recognize display defects due to the liquid crystal panel or the backlight unit. When the second fusion layer is disposed immediately above the liquid crystal panel, the second fusion layer preferably contains light diffusing particles and also serves as the light diffusion layer.
In the case where the second fusion layer also serves as the light diffusion layer, the light diffusion layer will be described later and the description thereof is omitted here.

  The second fusion layer is disposed between the liquid crystal panel and the fusion layer, and is usually disposed immediately above the liquid crystal panel. Functional layers such as a light diffusion layer, a louver layer, and a light absorption layer are disposed between the second fusion layer and the fusion layer.

The thickness of the second fusion layer can be the same as the thickness of the fusion layer.
In particular, as illustrated in FIGS. 3, 6, and 8, the second fusion layer 6 is in contact with the light diffusion layer 5, and the light diffusion layer 5 contains light diffusion particles. When the surface has irregularities due to particles, the thickness of the second fusion layer is thicker than the irregularities on the surface of the light diffusion layer caused by the light diffusion particles in order to prevent the diffusion due to the irregularities on the surface of the light diffusion layer from being impaired. Is preferred.

  In addition, since it is the same as that of the said melt | fusion layer about the formation method of a 2nd melt | fusion layer and another point, description here is abbreviate | omitted.

4). Light Diffusion Layer In the present invention, it is preferable that a light diffusion layer is disposed on the observation side of the liquid crystal panel. By sticking a transparent substrate to the liquid crystal panel via a fusing layer, display defects such as color unevenness and brightness unevenness due to the liquid crystal panel and backlight unit may be easily seen, but on the observation side of the liquid crystal panel By arranging the light diffusion layer, it is possible to make it difficult to visually recognize display defects.

As the light diffusion layer, a layer in which light diffusion particles are dispersed in a binder (hereinafter referred to as particle diffusion) or a layer having irregularities on the layer surface (hereinafter referred to as interface diffusion) can be used. Among these, the light diffusion layer preferably has an internal diffusion function by particle diffusion and / or interface diffusion, and more preferably has an internal diffusion function by both particle diffusion and interface diffusion. The light diffusion layer having an internal diffusion function by both particle diffusion and interface diffusion is a light diffusion layer 5 in which the light diffusion particles 5b are dispersed in the binder 5a and the surface has irregularities, as illustrated in FIG. In FIG. 9, reference numeral 15 denotes an arbitrary layer in contact with the light diffusion layer 5.
Particle diffusion is effective in preventing glare (scintillation), but the light diffusivity sufficient to prevent display defects depends only on particle diffusion. The contrast may decrease due to the above.
On the other hand, in the interfacial diffusion, the inclination angle of the irregularities can be made smaller than that of the particles (the particles have an inclination angle of 0 to 90 degrees), so the refractive index ratio at the irregular interface (the light diffusion layer and the light diffusion layer Even if the refractive index ratio with the layer in contact is large, whitening is not a problem. However, glare (scintillation) may occur only by interfacial diffusion.
Therefore, by separating the functions of both the particle diffusion and the interface diffusion, the display defect is prevented by the interface diffusion, and the glare is prevented by the particle diffusion, whereby a good image quality can be realized.

In the case of particle diffusion, the refractive index ratio between the light diffusing particles and the binder is not particularly limited as long as the refractive indexes of the light diffusing particles and the binder are different. Among them, as described above, since the particles have an inclination angle of 0 degree to 90 degrees, if the refractive index ratio between the light diffusing particles and the binder is large, a decrease in contrast due to whitening may occur. The difference in the refractive index of the binder is not zero, but the refractive index ratio between the light diffusing particles and the binder is preferably as small as possible. In particular, when the light diffusion layer has an internal diffusion function by both particle diffusion and interface diffusion, the refractive index ratio between the light diffusion particles and the binder is as small as possible, thereby preventing glare and preventing contrast. Reduction can be reduced. Specifically, the ratio of the light diffusing particles and the binder having a high refractive index to those having a low refractive index is preferably more than 1.000 and less than 1.020, and more than 1.000 and less than 1.010. More preferably, it is more than 1.000 and less than 1.005.
In addition, the refractive index of a light-diffusion particle and a binder shall refer to the literature value of the material to be used, respectively.

  The refractive indexes of the light diffusing particles and the binder are not particularly limited as long as the above refractive index ratio is satisfied. The refractive index of the light diffusing particles may be higher or lower than the refractive index of the binder.

On the other hand, in the case of interfacial diffusion, the refractive index ratio between the material constituting the light diffusion layer and the material constituting the layer in contact with the light diffusion layer is the material constituting the light diffusion layer and the layer in contact with the light diffusion layer. If the refractive index of material differs, it will not specifically limit. Especially, it is preferable that the refractive index ratio of the material which comprises the light-diffusion layer and the material which comprises the layer which touches a light-diffusion layer is large. This is because the larger the refractive index ratio between the material constituting the light diffusion layer and the material constituting the layer in contact with the light diffusion layer, the higher the light diffusibility due to the irregularities on the surface of the light diffusion layer. In particular, when the light diffusion layer has an internal diffusion function by both particle diffusion and interface diffusion, the refractive index ratio between the material constituting the light diffusion layer and the material constituting the layer in contact with the light diffusion layer should be increased. Thus, it is possible to prevent the display defect from being visually recognized. Specifically, a ratio of a material having a large refractive index to a material having a small refractive index among materials constituting the light diffusing layer and a material constituting the layer in contact with the light diffusing layer is in a range of 1.010 or more and less than 1.300. It is preferably within the range, more preferably within the range of 1.020 or more and less than 1.250, and even more preferably within the range of 1.030 or more and less than 1.200. If the refractive index ratio is less than the above range, unevenness due to unevenness is small, so that there is a risk of spot defects, and if it is above the above range, contrast may decrease due to reflection of external light on the uneven surface.
In addition, each said refractive index shall refer to the literature value of the material to be used.
The refractive index of the material constituting the light diffusion layer refers to the refractive index of the binder when the light diffusion layer contains light diffusion particles and a binder, and light when the light diffusion layer does not contain light diffusion particles. The refractive index of the constituent material of the diffusion layer.

  Here, in the case of interface diffusion, the layers in contact with the light diffusion layer 5 are the fusion layer 3 (FIG. 3), the second fusion layer 6 (FIGS. 3, 6, and 8), and the light absorption layer 8 (FIG. 3). 7 and FIG. 8). The refractive index of the material constituting the fusion layer refers to the refractive index of the thermoplastic resin contained in the fusion layer. Similarly, the refractive index of the material constituting the second fusion layer refers to the refractive index of the thermoplastic resin contained in the second fusion layer.

  In the case of interfacial diffusion, as will be described later, since the light diffusion layer is preferably disposed in the vicinity of the liquid crystal panel in order to suppress the generation of double images, an arbitrary layer is provided on both sides of the light diffusion layer. When in contact, it is preferable that the refractive index ratio between the material constituting the light diffusion layer and the material constituting the layer in contact with the liquid crystal panel side of the light diffusion layer satisfies the above-described refractive index ratio. For example, as shown in FIG. 3, when the light diffusion layer 5 is in contact with the fusion layer 3 and the second fusion layer 6, the second fusion layer 6 is in contact with the liquid crystal panel 20 side of the light diffusion layer 5. Therefore, the refractive index ratio between the material constituting the light diffusion layer and the thermoplastic resin contained in the second fusion layer preferably satisfies the above-described refractive index ratio. Further, as illustrated in FIG. 8, when the light diffusion layer 5 is in contact with the light absorption layer 8 and the second fusion layer 6, the material constituting the light diffusion layer and the second fusion layer contain it. It is preferable that the refractive index ratio with the thermoplastic resin satisfies the above-described refractive index ratio.

  Each refractive index of the material constituting the light diffusion layer and the material constituting the layer in contact with the light diffusion layer is not particularly limited as long as the above refractive index ratio is satisfied. The refractive index of the material constituting the light diffusion layer may be higher or lower than the refractive index of the material constituting the layer in contact with the light diffusion layer.

In the present invention, the transparent substrate may also serve as the light diffusion layer, the fusion layer may also serve as the light diffusion layer, and the second fusion layer may also serve as the light diffusion layer. Further, a light diffusion layer may be provided separately from the transparent substrate, the fusion layer, and the second fusion layer. For example, when a fusion layer is disposed immediately above the liquid crystal panel, the fusion layer 3 may also serve as the light diffusion layer 5 as illustrated in FIG. 2, and transparent as illustrated in FIG. The substrate 2 may also serve as the light diffusion layer 5. In addition, when the second fusion layer is disposed immediately above the liquid crystal panel, the second fusion layer 6 may also serve as the light diffusion layer 5 as illustrated in FIGS. 5 and 7. 6 and FIG. 8, the light diffusion layer 5 may be provided separately. Although not shown, the fusion layer may also serve as the light diffusion layer, and the transparent substrate also serves as the light diffusion layer. May be.
When the transparent substrate also serves as the light diffusion layer, both particle diffusion and interface diffusion can be applied. When the fusion layer or the second fusion layer also serves as the light diffusion layer, only the particle diffusion can be applied because the fusion layer and the second fusion layer melt when the liquid crystal panel and the transparent substrate are bonded together.

When the light diffusion layer is a binder in which light diffusion particles are dispersed, and the fusion layer or the second fusion layer also serves as the light diffusion layer, the binder is used as the fusion layer or the second fusion layer. It becomes the thermoplastic tree contained in the layer. Moreover, when a transparent base material serves as a light-diffusion layer, a binder becomes glass and resin contained in a transparent base material. Further, when the light diffusion layer is provided separately from the transparent base material, the fusion layer, the second fusion layer, and the like, the binder is a resin contained in the light diffusion layer.
For the thermoplastic resin contained in the fused layer and the second fused layer, and the glass and resin contained in the transparent substrate, see the above-mentioned fused layer, second fused layer, and transparent substrate. Since it described, description here is abbreviate | omitted.

When the light diffusion layer is provided separately from the transparent substrate, the fusion layer, the second fusion layer, etc., the resin contained in the light diffusion layer is particularly limited as long as it has transparency. For example, fluorine resin, silicon resin, acrylic resin, benzoguanamine resin, ethylene resin, styrene resin, phenol resin, imide resin, epoxy resin, amino resin, urethane resin, vinyl resin, cellulose resin and the above-mentioned resin Copolymers or the like can be used.
Even when the light diffusion layer does not contain light diffusion particles, these resins can be used for the light diffusion layer.

When the light diffusing layer contains light diffusing particles, the above-mentioned binder includes high refractive index ultrafine particles or low refractive index ultrafine particles having an average particle diameter in the range of 1 nm to 300 nm in order to adjust the refractive index. It is also preferable that it is contained. Further, when the light diffusing layer does not contain light diffusing particles, it is also preferable that the above-mentioned resin similarly contains the above-described high refractive index ultrafine particles or low refractive index ultrafine particles.
As ultra-high refractive index ultrafine particles, ZnO (refractive index 1.90), TiO ₂ (refractive index 2.3 to 2.7), CeO ₂ (refractive index 1.95), Sb ₂ O ₅ (refractive index 1. 71), SnO _2, ITO (refractive index 1.95), Y ₂ O ₃ (refractive index 1.87), La ₂ O ₃ (refractive index 1.95), ZrO ₂ (refractive index 2.05), Al ₂ O ₃ (refractive index 1.63) and the like. Examples of the low refractive index ultrafine particles include silica fine particles, hollow silica fine particles, fluoride fine particles such as magnesium fluoride, lithium fluoride, aluminum fluoride, calcium fluoride, and sodium fluoride.
In the case of interfacial diffusion, the refractive index ratio between the binder or resin contained in the light diffusion layer and the material constituting the layer in contact with the light diffusion layer can be increased by adjusting the refractive index of the binder or resin. This is because light can be diffused more effectively by the irregularities on the surface of the light diffusion layer. In both the case of particle diffusion and interface diffusion, the refractive index ratio between the binder and the light diffusing particles can be reduced by adjusting the refractive index of the binder, thereby preventing glare. This is because a decrease in contrast can be reduced.

  The light diffusing particles are not particularly limited as long as they have a refractive index different from that of the binder and have transparency, and are appropriately selected depending on the type of the binder. Specifically, inorganic particles such as silicon oxide and aluminum oxide, silicone resin, acrylic resin, divinylbenzene resin, benzoguanamine resin, styrene resin, melamine resin, acrylic-styrene resin, polycarbonate resin, Examples thereof include organic particles such as polyethylene resin, polyvinyl chloride resin, and polymethyl methacrylate resin, or particles of a mixture of two or more of these.

The average particle size of the light diffusing particles is the average particle size of the light diffusing particles when the light diffusing layer has an internal diffusion function by both particle diffusion and interface diffusion, and the thickness of the light diffusing layer is 1. The lower limit is preferably 0.3 or more, more preferably 0.6 or more, and particularly preferably 0.8 or more. This is because the uneven surface can be reliably formed on the surface of the light diffusion layer. On the other hand, when the thickness of the light diffusion layer is 1, the upper limit of the average particle diameter of the light diffusion particles is preferably 3 or less, and more preferably 2 or less. This is to prevent air bubbles from being mixed in the process of bonding the liquid crystal panel and the transparent substrate. Specifically, the average particle diameter of the light diffusing particles is preferably in the range of 0.5 μm to 15 μm, more preferably in the range of 1.0 μm to 10 μm, and particularly preferably in the range of 2 μm to 8 μm. This is because when the average particle size is smaller than the above range, particle diffusion is inferior, and when the average particle size is larger than the above range, the effect of preventing glare is reduced.
The average particle diameter means the primary particle diameter when the individual particles are dispersed, and the secondary particle diameter when the individual particles are aggregated.

  Here, the average particle diameter is generally used to indicate the particle size of the particles, and can be measured by a light scattering method or an electron micrograph. In the present invention, it is a value measured by a laser method. The laser method is a method of measuring an average particle size, a particle size distribution, and the like by dispersing particles in a solvent and thinning and calculating scattered light obtained by applying a laser beam to the dispersion solvent. The average particle size is a value measured using a particle size analyzer Microtrac UPA Model-9230 manufactured by Leeds & Northrup as a particle size measuring device by a laser method.

  The shape of the light diffusing particles is not particularly limited, but in the case of particles having a primary particle diameter of 0.5 μm or more, a spherical shape is preferable. If it is indefinite, external light reflection becomes strong and the contrast may decrease, and the sharpness may decrease due to generation of stray light.

In the present invention, the sum of the in-plane projected areas of the light diffusing particles contained in the light diffusing layer is within the range of 8% to 63% of the whole on the projection surface from the normal direction of the observation side surface of the liquid crystal panel. Among them, it is preferable to be in the range of 15% to 53%, particularly in the range of 23% to 42%. If the sum of the in-plane projected areas of the light diffusing particles contained in the light diffusing layer is too small, the probability that the light incident on the light diffusing layer will collide with the light diffusing particles becomes too low, so light diffusion sufficient to prevent glare The effect may not be obtained. On the other hand, if the sum of the in-plane projected areas of the light diffusing particles contained in the light diffusing layer is too large, the contrast may be reduced due to reflection of external light by the light diffusing particles.
The in-plane projected area of the light diffusing particles contained in the light diffusing layer can be measured by a transmission electron microscope (TEM) of the light diffusing layer.

  The content of the light diffusion particles in the light diffusion layer is not particularly limited as long as it is an amount capable of diffusing light. Since the probability that the incident light collides with the light diffusing particles depends on the thickness of the light diffusing layer, it is preferable to include the light diffusing particles to obtain the sum of the in-plane projected areas of the light diffusing particles contained in the light diffusing layer. The amount also depends on the thickness of the light diffusion layer. Therefore, the content of the light diffusing particles in the light diffusing layer is 32 / T parts by weight to 375 / T parts by weight per 100 parts by weight of the binder in the light diffusing layer when the thickness of the light diffusing layer is T (μm). In particular, it is preferably in the range of 63 / T parts by weight to 312 / T parts by weight, more preferably in the range of 94 / T parts by weight to 250 / T parts by weight.

Further, in the present invention, when the regular transmission intensity of the light diffusion layer is Q, and the transmission intensity obtained by extrapolating a straight line connecting transmission intensity at regular transmission ± 2 degrees and regular transmission ± 1 degree to the regular transmission angle is U,
2 <Q / U <22
It is preferable to satisfy. That is, the content of the light diffusing particles in the light diffusing layer, the particle size of the light diffusing particles, the refractive ratio of the light diffusing particles and the binder, the irregularities on the surface of the light diffusing layer, the material constituting the light diffusing layer and the light diffusing layer It is preferable that the refractive index ratio with the material of the layer in contact and the positional relationship between the light diffusing particles and the unevenness of the light diffusing surface are adjusted so as to satisfy the above formula. With such a configuration, it is possible to achieve both suppression of display unevenness and improvement of blackness.
When Q / U is in the above range, an excellent image with high contrast and less glare is obtained. The reason for this is to reduce stray light components generated by the light diffusing particles and the unevenness of the interface while appropriately imparting a small diffusion of the image light. That is, (a) the transmission diffusion is small (the regular transmission intensity is high), (b) the large diffusion is reduced, and (c) the diffusion is converted to the diffusion near the regular transmission. Here, the diffusion intensity near the regular transmission in the case of isotropic diffusion will be considered.
When the layers having different diffusion transmission intensity distributions are laminated, the reduction rate of the diffusion transmission intensity is larger as the diffusion intensity is closer to 0 degrees. Therefore, when the normal transmission intensity (Q) is decreased, the diffusion intensity near the normal transmission angle is increased. In addition, when the distribution of the light diffusing particles and the unevenness of the interface is sparse, the intensity distribution of the diffusion characteristics does not exist for both the diffusion intensity distribution by the diffusing element and the light diffusing particles and the unevenness of the interface. It is the sum of two intensity distributions with only intensity. In this intensity distribution, when the intensity obtained by extrapolating the intensity gradients of ± 1 degree and ± 2 degrees to the normal transmission angle is the virtual normal transmission intensity (U), U indicates the normal transmission of the diffusion characteristic by the diffusion element. Q / U is a ratio between the “part Q having no diffusion element” and the “regular transmission intensity U of the diffusion element part”, that is, a measure of the diffusion state in the vicinity of the regular transmission.
Note that, for example, the transmission intensity can be measured for each degree within a range of normal transmission ± 45 degrees by a minute declination luminance meter, and Q and U can be calculated.

As the thickness of the light diffusion layer, when the pixel pitch in the horizontal direction of the liquid crystal panel is P and the thickness of the light diffusion layer is T,
T <P / 2
It is preferable to satisfy. This is because if the thickness of the light diffusion layer is too thick, a double image is generated and the image quality may be deteriorated. When the thickness of the light diffusion layer satisfies the above formula, it is difficult to observe a double image at a viewing angle of ± 60 degrees. Specifically, in the 20-inch liquid crystal display device, the thickness of the light diffusion layer is preferably 500 μm or less.
In addition, the thickness of the said light-diffusion layer means the thickness of the light-diffusion layer arrange | positioned nearest to a liquid crystal panel, when there exist multiple light-diffusion layers.

The arrangement of the light diffusion layer may be selected as long as it is on the observation side of the liquid crystal panel. When the transparent substrate, the fusion layer, or the second fusion layer also serves as the light diffusion layer, the arrangement of the light diffusion layers is the arrangement of the respective layers. When the light diffusion layer is provided separately from the transparent substrate, the fusion layer, and the second fusion layer, the light diffusion layer is disposed between the fusion layer and the second fusion layer. Among these, as illustrated in FIGS. 2, 5, and 7, the light diffusion layer 5 is preferably disposed immediately above the liquid crystal panel 20. That is, it is preferable that the fusion layer 3 or the second fusion layer 6 also serves as the light diffusion layer 5. In general, a light diffusing film is often provided on the outermost surface of a liquid crystal panel. Therefore, if the distance between the liquid crystal panel and the light diffusing layer is long, the light diffusing layer and the light diffusing film included in the liquid crystal panel Double images may occur. If the light diffusing layer is disposed immediately above the liquid crystal panel, the distance between the liquid crystal panel and the light diffusing layer can be shortened, and the occurrence of double images can be suppressed.
The distance between the liquid crystal panel and the light diffusion layer refers to the distance between the observation side surface of the liquid crystal panel and the light diffusion layer disposed closest to the liquid crystal panel when there are a plurality of light diffusion layers.

5. Louver layer In the present invention, a louver layer in which strip-shaped transmission portions and light shielding portions are alternately arranged may be disposed on the observation side of the liquid crystal panel. In the louver layer, band-shaped transmission parts and light-shielding parts are alternately arranged at regular intervals, and incident light of a certain incident angle or more is incident on the light-shielding part and is absorbed and cannot be transmitted. The thickness of the louver layer Only light having a predetermined incident angle is transmitted according to the interval between the light shielding parts and the angle formed by the light shielding part with respect to the surface of the louver layer. Therefore, external light having a large incident angle can be limited by the louver layer without blocking display light. Therefore, oblique external light is blocked by the light shielding portion of the louver layer, and the amount of external light reflected on the display surface is reduced, so that the contrast in the front direction can be improved.

The louver layer may be any one in which strip-shaped transmission portions and light shielding portions are alternately arranged, and a general louver layer can be used.
The arrangement of the transmission part and the light shielding part of the louver layer with respect to the liquid crystal panel is preferably selected as appropriate in accordance with the characteristics of the louver layer to be used. In general, in the liquid crystal display device, it is preferable to make the diffusion in the left-right direction larger than the diffusion in the vertical direction.
For example, in the louver made by 3M, the transparent layer and the light shielding layer are arranged in parallel and do not have a light diffusion function. Therefore, the louver layer is arranged so that the transparent layer (light shielding layer) is in the horizontal direction of the liquid crystal panel. It is preferable that the transmissive portions and the light shielding portions are alternately arranged in the left-right direction of the liquid crystal panel. This is because the contrast can be improved by the louver layer without narrowing the angle of view in the horizontal direction of the liquid crystal display device.
In addition, in the louver made by Dai Nippon Printing Co., Ltd., a wedge-shaped or trapezoidal light-shielding layer is formed on a transparent film, and the space between the light-shielding portions is filled with a transparent resin, and has a light diffusion function by the wedge or trapezoid hypotenuse. Therefore, it is preferable that the transmission portions and the light shielding portions of the louver layer are alternately arranged in the vertical direction of the liquid crystal panel so that the light shielding layer is in the vertical direction of the liquid crystal panel. This is because the angle of view in the left-right direction of the liquid crystal display device can be increased while improving the contrast.
Furthermore, in a louver having a condensing function, it is preferable to dispose the transmissive portion and the light shielding portion of the louver layer so as to condense in the vertical direction and increase the front luminance.

  As another modified example, the light-shielding portion of the louver layer is arranged so as to be inclined, and the transmission (light-shielding) angle is varied up and down (left and right) to match the direction in which the viewing range is desired to be larger. (For example, in the case of a television, the viewing angle in the upward direction is wide and the viewing angle in the downward direction is narrowed).

  When the louver layer does not have a diffusion function, the maximum angle of light that can be emitted from the transmission part of the louver layer with respect to the normal direction of the observation side surface of the louver layer is preferably 45 degrees or more. That is, it is preferable that the thickness of the louver layer, the interval between the light shielding portions, and the angle formed by the light shielding portion with respect to the surface of the louver layer are adjusted so that the maximum angle is 45 degrees or more. This is because external light can be absorbed and a normal viewing area in the vertical direction of the liquid crystal display device can be secured. In addition, when the maximum angle is within the above range, it is possible to prevent light leakage due to the polarizing plate constituting the liquid crystal panel and to efficiently block external light and improve contrast.

  The thickness of the louver layer is not particularly limited as long as the maximum angle can be within a predetermined range.

  The louver layer may be arranged on the observation side of the liquid crystal panel, but in particular, when the light diffusion layer is formed, the louver layer is preferably arranged on the observation side of the light diffusion layer. This is because it is possible to suppress reflection by the light diffusion layer by reducing external light incident on the light diffusion layer, which is preferable for improving the contrast.

  In the present invention, the transparent base material may also serve as the louver layer, the fusion layer or the second fusion layer may also serve as the louver layer, and the transparent base material, the fusion layer, or the second fusion layer. A louver layer may be provided separately from the layer. Especially, it is preferable that the louver layer is provided separately from the transparent base material, the fusion layer, and the second fusion layer. This is because a transparent substrate having a louver function is expensive.

6). Light Absorbing Layer In the present invention, a light absorbing layer having an average light absorptance within a range of 1% to 30% within a wavelength range of 400 nm to 750 nm may be disposed on the viewing side of the liquid crystal panel. The contrast and the clearness of the image can be improved. Furthermore, by using a light-absorbing layer that uses dyes or pigments that selectively absorb external light of a specific wavelength that transmits the wavelength of the image light and absorbs wavelengths in other visible light regions, It is also possible to improve the contrast while maintaining the brightness of the light. Further, when the light absorption layer is disposed on the observation side of the light diffusion layer, external light is absorbed by the light absorption layer, and the amount of light incident on the light diffusion layer is reduced and reflected by the light diffusion layer. The external light is absorbed again by the light absorption layer, whereby the contrast can be improved more efficiently.

The light absorption layer may have an average light absorptivity within a range of 1% to 30% within a wavelength range of 400 nm to 750 nm, and more preferably within a range of 4% to 25%, particularly within a range of 5% to 20%. It is preferable to be within. This is because if the average light absorptance is smaller than the above range, the contrast improvement effect due to the absorption of external light is low, and if the average light absorptance is greater than the above range, the luminance reduction of the image due to the absorption of the image light is too large. When the average light absorptance is in the range of 4% to 25%, particularly in the range of 5% to 20%, the above-described effect can be further ensured.
In addition, the said average light absorptivity can be measured with a spectral transmittance meter, for example.

  In addition, the light absorption layer has low light absorptivity at a wavelength corresponding to the emission wavelength of image light projected from the liquid crystal display device (high transmittance), and high light absorptance at other wavelengths (transmittance). It is more preferable to have a so-called selective absorption function. That is, it is preferable that the light absorption layer has selective absorptivity that absorbs wavelengths other than the predetermined wavelength of the image light itself. Since external light has all wavelengths and image light has only specific wavelengths (that is, it is common to use red, green, and blue, which are the three primary colors of light), the light absorption layer has a selective absorption function. This is because the contrast can be further improved by suppressing the attenuation of the image light by the light absorption layer and increasing the absorption of the external light.

  When the light absorption layer has a selective absorption function, among others, the liquid crystal display device of the present invention is an LED light source with a different wavelength, and is a field sequential method that drives the liquid crystal display device in synchronization with the emission wavelength of the LED light source. A liquid crystal display device is preferred. That is, when the liquid crystal display device of the present invention is driven by a field sequential method using LEDs, it is preferable that a light absorption layer is formed. In the case of the field sequential method using LEDs, since it is not necessary to use a color filter, the image light itself has a predetermined wavelength, so that the wavelength range of selective absorption by the light absorption layer can be expanded. In this case, the contrast can be further improved.

The material of the light absorption layer is not particularly limited as long as it satisfies the above average light absorption rate; black dyes such as aniline black; black pigments such as carbon black, acetylene black, lamp black, and mineral black Is mentioned.
In addition, as a material having selective transparency, it exhibits high transmittance for light in the wavelength range of high luminance among the wavelengths of video light, and exhibits low transmittance for light of other wavelengths. Materials can be used. Examples of such materials include xanthene dyes, anthraquinone dyes, phthalocyanine dyes, triphenolmethane dyes, azo dyes, indigoid dyes, carbonium ion dyes, and metal chelates such as pigments and neodymium. It is done. These materials may be used as a mixture or may be used as a laminate.

  The thickness of the light absorption layer is not particularly limited as long as the average light absorption rate is satisfied.

  The arrangement of the light absorption layer may be on the observation side of the liquid crystal panel, but in particular, when the light diffusion layer is formed, the light absorption layer is preferably arranged on the observation side of the light diffusion layer. . As described above, the external light is absorbed by the light absorption layer, the amount of light incident on the light diffusion layer is reduced, and the external light reflected by the light diffusion layer is absorbed again by the light absorption layer. This is because the contrast can be improved efficiently.

  In the present invention, the transparent substrate may also serve as the light absorption layer, the fusion layer or the second fusion layer may also serve as the light absorption layer, and the transparent substrate, the fusion layer, or the second layer. A light absorption layer may be provided separately from the fusion layer.

7). Liquid crystal panel In the liquid crystal panel of the present invention, a transparent substrate is bonded to the observation side surface via a fusion layer.
As illustrated in FIG. 1, the liquid crystal panel 20 includes a liquid crystal cell 21, an observation side polarizing plate 22 a disposed on the observation side 10 of the liquid crystal cell 21, and a back polarizing plate 22 b disposed on the back surface of the liquid crystal cell 21. And a functional film 23 such as an antiglare film or an antireflection film disposed on the observation side 10 of the observation side polarizing plate 22a. Although not shown, the liquid crystal cell 21 includes a pair of support plates, a liquid crystal sandwiched between the support plates, an alignment film that aligns liquid crystal molecules, an electrode that controls the alignment of liquid crystal molecules by an electric field, and a color filter. Have.
Note that since a general liquid crystal panel can be used for the liquid crystal panel, description thereof is omitted here.

8). Other members In the present invention, in addition to the above-described functional layers such as the light diffusion layer, the louver layer, and the light absorption layer, a functional layer having an arbitrary function may be disposed on the observation side of the liquid crystal panel.

For example, between the liquid crystal panel and the transparent substrate, the dynamic storage elastic modulus under the conditions of 25 ° C. and 1000 Hz to 10,000 Hz is in the range of 9 × 10 ⁴ Pa to ⁴ × 10 ⁶ Pa for the purpose of improving impact resistance. An inner shock absorbing layer may be disposed.
The above-mentioned member may serve as the shock absorbing layer, or a newly provided layer may be used.

  When the above-mentioned member also serves as an impact absorbing layer, it is possible to absorb the impact by adding a compound that increases the dipole moment. Compounds that increase the dipole moment include N, N-dicyclohexylbenzothiazyl-2-sulfenamide (DCHBSA), 2-mercaptobenzothiazole (MBT), dibenzothiazyl sulfide (MBTS), N-cyclohexylbenzothia. Zir-2-sulfenamide (CBS), N-tert-butylbenzothiazyl-2-sulfenamide (BBS), N-oxydiethylenebenzothiazyl-2-sulfenamide (OBS), N, N- A compound containing a mercaptobenzothiazyl group such as diisopropylbenzothiazyl-2-sulfenamide (DPBS) or the like, a benzotriazole having an azole group bonded to a benzene ring as a parent nucleus, and 2- {2 having a phenyl group bonded thereto '-Hydroxy-3'-(3 ", 4", 5 ", 6" Torahydrophthalimidemethyl) -5′-methylphenyl} -benzotriazole (2HPMB), 2- {2′-hydroxy-5′-methylphenyl} -benzotriazole (2HMPB), 2- {2′-hydroxy- 3'-t-butyl-5'-methylphenyl} -5-chlorobenzotriazole (2HBMPCB), 2- {2'-hydroxy-3 ', 5'-di-t-butylphenyl} -5-chlorobenzotriazole Examples thereof include a compound having a benzotriazole group such as (2HDBPCB) or a compound having a diphenyl acrylate group such as ethyl-2-cyano-3,3-di-phenyl acrylate.

  In the present invention, the various functional layers described above may be combined in any manner.

9. Manufacturing Method of Liquid Crystal Display Device The liquid crystal display device of the present invention is preferably produced using a lamination method in which, for example, a liquid crystal panel, a sheet-like or film-like fusion layer and a transparent substrate are heat-pressed. This is because a liquid crystal display device excellent in impact resistance can be obtained by a simple method without causing deterioration in display quality.
For example, in the case of the liquid crystal display device 1 shown in FIGS. 2 and 4, the liquid crystal panel 20, the sheet-like or film-like fusion layer 3, and the transparent base material 2 are sequentially laminated, and these are heat-pressed to form a liquid crystal display device. Can be produced. In the case of the liquid crystal display device 1 illustrated in FIG. 3, the liquid crystal panel 20, the sheet-like or film-like second fusion layer 6, the light diffusion layer 5, the sheet-like or film-like fusion layer 3, and the transparent substrate 2 A liquid crystal display device can be manufactured by sequentially laminating and thermally bonding these layers.
In the case where the fusion layer and various functional layers are laminated, it is more preferable to use a laminated body of the fusion layer and various functional layers in advance. This is because by reducing the number of manufacturing steps of the liquid crystal display device, loss of the expensive liquid crystal display device due to damage or the like is reduced.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

Hereinafter, the present invention will be specifically described with reference to examples.
[Example 1]
(1) Preparation of thermoplastic resin 0.3 parts by weight of a silane coupling agent (methacryloxypropyltrimethoxysilane) was added to a vinyl acetate copolymer containing 28% by weight of vinyl acetate and 15 g / 10 min. Further, 0.2 parts by weight of an antioxidant was added and kneaded to obtain a thermoplastic resin.
(2) Manufacture of fused film Using the above thermoplastic resin, a film molding machine having a 150 mmφ extruder and a 1000 mm wide T die, resin temperature: 90 ° C., take-off speed: 5 m / min, and a thickness of 300 μm A fused layer was obtained.
(3) Bonding of Glass Substrate / Fusion Film / Liquid Crystal Panel The above fusion film is composed of a glass substrate (922 mm × 542 mm) and a liquid crystal panel (920 mm × 540 mm) having a lateral pixel pitch of 0.2 mm. In between, the liquid crystal panel was sandwiched so as to be inside the peripheral part of the glass substrate, and vacuum laminated to produce a liquid crystal display device. A specific manufacturing method is as follows.
That is, first, blue sheet glass (thickness: 3 mm), the fused film (thickness: 300 μm), the liquid crystal panel, and a release sheet were sequentially laminated on a release sheet provided on a laminator. Subsequently, the laminator was set to a set temperature of 90 ° C., the lid was lowered, the sample was evacuated, and the temperature was raised to 70 ° C. After the temperature was raised, the pressure in the upper chamber was set to 30 KPa, and the vacuum laminator The glass sheet / fused film / liquid crystal panel laminate has an inner dimension of 922 mm by pressing the diaphragm sheet between the upper / lower chambers and holding for 5 minutes, and finally releasing both the upper / lower chambers to the atmosphere. A liquid crystal display device was manufactured by fixing the peripheral portion to a frame of × 542 mm.

[Example 2]
(1) Preparation of thermoplastic resin 0.3 parts by weight of a silane coupling agent (methacryloxypropyltrimethoxysilane) was added to a vinyl acetate copolymer having a vinyl acetate content of 10% by weight and an MFR of 25 g / 10 minutes. Further, 0.2 parts by weight of an antioxidant was added and kneaded to obtain a thermoplastic resin having a refractive index of 1.462.
(2) Manufacture of fused film Using the above thermoplastic resin, a film molding machine having a 150 mmφ extruder and a 1000 mm wide T die, resin temperature: 120 ° C., take-off speed: 30 m / min, and a thickness of 50 μm A fused layer was obtained.
(3) Production of Fusion Film / Film with Light Diffusing Layer / Fusion Film First, acrylic styrene beads having a particle size of 4 μm (refractive index) with respect to 100 parts by weight of UV curable resin (refractive index: 1.520). : 1.520) A resin composition for a light diffusion layer to which 27.5 parts by weight were added was applied to one side of a polyester film having a thickness of 80 μm so that the dry film thickness was 5 μm and cured. A light diffusion layer was formed. Next, on the both surfaces of the film with a light diffusing layer, using the dry laminate method, a two-component curable ester resin adhesive (refractive index: 1.462) is used. , 50 μm) was laminated to produce a laminate of fusion film / film with light diffusion layer / fusion film.
(4) Bonding of glass substrate / fusion sheet / liquid crystal panel According to the bonding method of (4) glass substrate / fusion film / liquid crystal panel in Example 1, instead of a fusion film, a fusion film / Using a laminate of a film with a light diffusion layer / a fusion film, the light diffusion layer of the film with a light diffusion layer was disposed on the liquid crystal panel side to produce a liquid crystal display device.

[Example 3]
A liquid crystal display device was produced in the same manner as in Example 2 except that acrylic styrene beads having a refractive index of 1.525 were used in the production of the film with a light diffusion layer of Example 2.

[Example 4]
A liquid crystal display device was produced in the same manner as in Example 2 except that acrylic styrene beads having a refractive index of 1.558 were used in the production of the film with a light diffusion layer of Example 2.

[Example 5]
In the production of the film with a light diffusing layer in Example 2, the refractive index of the resin is 1.462 by adding magnesium fluoride powder having a particle size of 4 nm to the UV curable resin, and the particle size is replaced with acrylic styrene beads. : A liquid crystal display device was produced in the same manner as in Example 2 except that silicon beads having a refractive index of 1.458 were used.

[Example 6]
In Example 2, a liquid crystal display device was produced in the same manner as in Example 2 except that a film with a light diffusion layer was produced as shown below.
First, by performing nickel electroforming twice on the transfer body having the surface unevenness for forming the light diffusion layer obtained by applying and curing the silicone mold forming agent, the mold having the reverse shape of the surface unevenness of Example 2 is obtained. Produced. Next, between this mold and the polyester film (thickness: 80 μm), 100 parts by weight of UV curable resin (refractive index: 1.520), particle size: 4 μm, refractive index: 1.525. The resin composition for light diffusion layer added with 3.2 parts by weight of acrylic styrene beads was interposed, irradiated with UV from the polyester film side, and then peeled off from the mold, so that the light diffusion layer had a thickness of 5 μm. A film with a diffusion layer was obtained.

[Example 7]
In Example 3, a liquid crystal display device was produced in the same manner as in Example 3 except that the amount of acrylic styrene beads added was 53 parts by weight.

[Example 8]
In Example 2, a liquid crystal display device was produced in the same manner as in Example 2 except that a film with a light diffusion layer was produced as shown below.
Thickness: 150 μm on each side of polyester film, 100 parts by weight of UV curable resin (refractive index: 1.520), particle size: 4 μm, refractive index: 1.525 acrylic styrene beads 13.75 wt. A resin composition for a light diffusing layer to which parts were added was applied, applied so that the dry film thickness was 5 μm, and cured to form a light diffusing layer.

[Example 9]
In Example 3, when producing a fusion film in contact with the light diffusion layer of the film with a light diffusion layer, except that the carbon pigment was added to the thermoplastic resin so that the average light absorption rate was 15%, A liquid crystal display device was produced in the same manner as in Example 3.

[Example 10]
In Example 3, when preparing a fusion film in contact with the light diffusion layer of the film with a light diffusion layer, except that a carbon pigment was added to the thermoplastic resin so that the average light absorption rate was 34%, A liquid crystal display device was produced in the same manner as in Example 3.

[Example 11]
A liquid crystal display device was produced in the same manner as in Example 1 except that the size of the glass substrate was 918 mm × 538 mm and that a frame having an inner dimension of 920 mm × 540 mm was used.

[Example 12]
In preparation of the film with a light diffusing layer of Example 3, instead of the polyester film, a louver film (having a diffusing function in a direction perpendicular to the light shielding layer, thickness: 80 μm) manufactured by Dai Nippon Printing Co., Ltd. was used. A liquid crystal display device was produced in the same manner as in Example 3 except that the liquid crystal panel was arranged so as to extend in the lateral direction.

[Example 13]
In preparation of the film with a light diffusing layer of Example 9, a louver film (having a diffusing function in a direction perpendicular to the light shielding layer, thickness: 80 μm) manufactured by Dai Nippon Printing Co., Ltd. was used instead of the polyester film. A liquid crystal display device was produced in the same manner as in Example 9 except that the liquid crystal panel was arranged so as to extend in the vertical direction.

[Example 14]
In Example 1, a liquid crystal display device was produced in the same manner as in Example 1 except that the periphery of the liquid crystal panel was fixed to a frame having an internal size of 920 mm × 540 mm.

[Evaluation]
The evaluation results of the liquid crystal display devices of Examples 1 to 14 are shown in Table 1 below.
The in-plane projected area of the light diffusion particles contained in the light diffusion layer was measured using a transmission electron microscope (TEM).
The average light absorptance was measured using a spectral transmittance meter.
For the regular transmission intensity Q of the light diffusion layer and the transmission intensity U obtained by extrapolating the straight line connecting the transmission intensity at regular transmission ± 2 degrees and regular transmission ± 1 degree to the regular transmission angle, a minute declination luminance meter is used. Thus, the transmission intensity was measured and calculated every degree within the range of normal transmission ± 45 degrees.
For spots, blackness, glare, double image, contrast, brightness, and angle of view, a liquid crystal display is installed in a room with an illuminance of approximately 1,000 Lx, “Phantom” was displayed, and the above video was viewed from a location about 1.5 m to 2.0 m away from the liquid crystal display device (liquid crystal television), and sensory evaluation was performed. In particular, “Excellent” was given as “Excellent”, “Excellent” as “Good”, “Do n’t be bothered by Δ”, “Bitter” as “C”.
Further, regarding image disturbance, sensory evaluation was performed as to whether or not the degree of coloring of the liquid crystal screen changes when the center of the liquid crystal display device is pressed.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device 2 ... Transparent base material 3 ... Fusion layer 5 ... Light-diffusion layer 6 ... 2nd fusion layer 7 ... Louver layer 7a ... Transmission part 7b ... Light-shielding part 8 ... Light absorption layer 10 ... Observation side 20 ... Liquid crystal panel 21 ... Liquid crystal cell 22a ... Observation side polarizing plate 22b ... Back polarizing plate 23 ... Functional film 31 ... Backlight unit 32 ... Housing

Claims (10)

A liquid crystal display device in which a rigid transparent substrate is bonded to an observation side surface of a liquid crystal panel via a fusion layer containing a thermoplastic resin,
When the vertical and horizontal lengths of the liquid crystal panel are L1 and W1, respectively, and the vertical and horizontal lengths of the transparent substrate are L2 and W2, respectively.
L1 ≦ L2 and / or W1 ≦ W2
Meet the,
On the observation side of the liquid crystal panel, a light diffusion layer is disposed between the liquid crystal panel and the fusion layer,
When the pixel pitch in the horizontal direction of the liquid crystal panel is P, and the thickness of the light diffusion layer is T,
T <P / 2
The filling,
The liquid crystal display device , wherein the transparent substrate is bonded to the observation side surface of the liquid crystal panel via the light diffusion layer and the fusion layer .   A liquid crystal display device in which a rigid transparent substrate is bonded to an observation side surface of a liquid crystal panel via a fusion layer containing a thermoplastic resin,
  When the vertical and horizontal lengths of the liquid crystal panel are L1 and W1, respectively, and the vertical and horizontal lengths of the transparent substrate are L2 and W2, respectively.
      L1 ≦ L2 and / or W1 ≦ W2
The filling,
  On the observation side of the liquid crystal panel, a light diffusion layer is disposed between the liquid crystal panel and the fusion layer,
  Between the light diffusion layer and the fusion layer, a light absorption layer having an average light absorption rate within a range of 1% to 30% within a wavelength range of 400 nm to 750 nm is disposed,
  The liquid crystal display device, wherein the transparent base material is bonded to the observation side surface of the liquid crystal panel via the light diffusion layer, the light absorption layer, and the fusion layer. The liquid crystal display device according to claim 1 or claim 2 wherein the transparent substrate is characterized in that it is a glass substrate. The thickness of the said transparent base material exists in the range of 0.5 mm-4 mm, The liquid crystal display device in any one of Claim 1 to 3 characterized by the above-mentioned. The liquid crystal display device according to any one of claims 1 to 4, wherein a thickness of the fusion layer is in a range of 0.05 mm to 0.5 mm. The liquid crystal display device according to claim 1, wherein the bonding layer contains a crosslinking agent to Claim 5. Examples fusion layer, the liquid crystal display device according to any one of the use of sheet-like or film-like bonding layer of having an irregular shape on a surface of claim 1, wherein up to claim 6. Oite the viewing side of the liquid crystal panel, between the liquid crystal panel and the bonding layer, and the light-shielding portion are disposed louver layers arranged alternately with the strip-shaped transparent portion,
The transparent substrate is bonded to the observation side surface of the liquid crystal panel through the light diffusion layer, the louver layer, and the fusion layer, according to any one of claims 1 to 7. A liquid crystal display device as described above. The liquid crystal display device according to claim 2 , wherein the light absorption layer has selective absorptivity for absorbing a wavelength other than a predetermined wavelength of the image light itself. In different LED light source backlight wavelengths, any of claims 1, wherein the synchronization with the emission wavelength of the LED light source is a liquid crystal display device of field sequential method for driving a liquid crystal display device to claim 9 A liquid crystal display device according to any one of the claims.

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