JPH08201792A - Liquid crystal display - Google Patents

Abstract

(57) [Abstract] [Purpose] To ensure wide viewing angle characteristics in all directions without reducing the light utilization efficiency of the backlight. [Structure] The wide viewing angle mode liquid crystal display element 1 itself has wide viewing angle characteristics. Further, when a microlens 10 is provided in such a liquid crystal display element 1, the viewing angle characteristics of the wide viewing angle mode (axisymmetric mode) are improved. It is possible to improve the viewing angle characteristics in a bad direction, for example, a direction of 45 ° from the polarization axis of the polarizing plate. Further, in this case, the wide viewing angle mode liquid crystal display element 1 has a wide viewing angle characteristic and therefore has a characteristic that the contrast change is small even if the viewing angle is slightly shifted. You can Also,
Since a scattered light source can be used, the incident angle of incident light is multidirectional, and the outgoing light is also multidirectional, so that a wider viewing angle characteristic can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can display in a liquid crystal display mode for wide viewing angles in which liquid crystal molecules are aligned in a plurality of directions in a liquid crystal cell, and the viewing angle characteristics are completely axisymmetric in all directions. Relates to a liquid crystal display device that is easy to see. For example, the present invention relates to a liquid crystal display device applicable not only to a personal display device such as a word processor or a personal computer but also to a personal digital assistant or the like which can be used by a large number of people by surrounding it on a desk.

[0002]

2. Description of the Related Art In a liquid crystal display device, in order to improve the viewing angle characteristics, it is necessary to orient the liquid crystal molecules in at least two or more directions within each picture element arranged in a matrix.

FIG. 9 shows a tilted state of the liquid crystal molecules 29 in a liquid crystal display device in which the liquid crystal molecules 29 are oriented in at least two or more directions within a picture element, due to voltage application. (B) is a halftone state, (c)
Is the case of applying a saturation voltage. In FIG. 9, 2
Reference numerals 1 and 22 are substrates, 27 is a polymer wall surrounding the liquid crystal droplet 28, and 30 is a central axis.

On the other hand, FIG. 10 shows the case of a liquid crystal display device of TN (twisted nematic) mode similarly to FIG.

In a liquid crystal display device in which liquid crystal molecules are oriented in at least two or more directions within a picture element, the liquid crystal molecules are seen in both directions A and B in the halftone state shown in FIG. 9B. The apparent refractive index of is averaged. Therefore, the contrast from both A and B directions becomes equal,
The viewing angle characteristics are improved as compared with the case of the TN mode in FIG.

In these two types of liquid crystal display devices, when the saturation voltage is applied, the liquid crystal molecules are aligned along the electric field, and the same alignment state is obtained regardless of the difference in initial alignment. In this saturated voltage applied state, the viewing angle characteristics are those of the polarizing plate and d.Δn (d is the liquid crystal layer thickness, Δ
n is a refractive index anisotropy of the liquid crystal) and a synergistic effect with light leakage due to elliptically polarized light at a specific angle, and the polarization axis of the polarizing plate is 45 degrees from the polarization axis on both sides of the liquid crystal cell with the polarization axes orthogonal to each other. A region having relatively weak viewing angle characteristics occurs in the ° direction.

[0007] Further, the liquid crystal molecules are separated by treating the substrate.
In a liquid crystal display device configured to be oriented in more than one direction,
The liquid crystal cell itself has anisotropy with respect to the viewing angle, and does not have the omnidirectional viewing angle characteristic.

By the way, the following are known as specific examples of the liquid crystal display device in the wide viewing angle mode described above.

One of the liquid crystal display devices has a liquid crystal drop surrounded by polymer walls in a liquid crystal cell and electrically controls a transparent state or a cloudy state by utilizing a birefringence of liquid crystal. It is a thing. The display by this liquid crystal display device basically displays the transparent state when the ordinary refractive index of the liquid crystal molecules and the refractive index of the polymer wall that is the supporting medium are matched, and the alignment of the liquid crystal is aligned by applying a voltage, When no voltage is applied, the light scattering state (white turbid state) due to the disordered orientation of the liquid crystal molecules is displayed. This liquid crystal display device is characterized in that it does not require a polarizing plate and does not require alignment treatment.

The following methods have been proposed as a method of manufacturing a liquid crystal display device of this type. Special table Sho 61-502
In No. 128, a mixture of light or thermosetting resin and liquid crystal is put between a pair of substrates constituting a liquid crystal cell, and then the resin is cured to precipitate the liquid crystal, and the wall of the resin A method of forming liquid crystal droplets therein is disclosed. Further, a wide viewing angle mode liquid crystal display device in which polarizing plates orthogonal to each other are provided on both sides of the liquid crystal cell manufactured in this way is disclosed in Japanese Patent Laid-Open No. 4-338923.
And Japanese Patent Laid-Open No. 4-212928.

Another liquid crystal display device is of a non-scattering type and uses a polarizing plate to improve the viewing angle characteristics of the liquid crystal cell. This liquid crystal display device is disclosed in JP-A-5-2724.
No. 2, proposed is a method of producing a composite material of a liquid crystal and a polymer material between a pair of substrates by phase-separating a mixture of liquid crystal and a photocurable resin. In this method, the orientation state of the liquid crystal domain becomes random due to the generated polymer, and the rising direction of the liquid crystal molecule is different in each liquid crystal domain when a voltage is applied, so the apparent refractive index seen from each direction is This is a method of equalizing and improving the viewing angle characteristics in the halftone state.

Furthermore, as another one of the liquid crystal display devices, there is a liquid crystal display device recently proposed by the present inventors (Japanese Patent Application No. Hei.
-199285). In this type of liquid crystal display device, by photocontrolling with a photomask or the like during photopolymerization, liquid crystal molecules are omnidirectionally aligned in a pixel region, for example, a spiral shape, and the liquid crystal molecules are controlled by voltage. As a result, the spiral orientation or the like causes the umbrella to open or close, thereby significantly improving the viewing angle characteristics.

Further, as another liquid crystal display device, a film made of a crystalline polymer and having a spherulite structure is formed on the surface of a substrate, and the film has a wide viewing angle which produces an axially symmetric alignment regulating force. A display mode has been proposed (Japanese Patent Application No. 5-96289).

Further, as another liquid crystal display device, there has been proposed a device in which an alignment film is applied on a substrate and liquid crystal molecules are aligned in a random direction without performing alignment treatment such as rubbing (Japanese Patent Laid-Open No. Hei 10 (1999) -264242). 6-194655).

[0015]

However, in each of the liquid crystal display devices described above, sufficient wide viewing angle characteristics have not been obtained, and there is room for improvement.

Therefore, in order to secure a further improved wide viewing angle characteristic, there has been proposed a liquid crystal display apparatus with a microlens or a liquid crystal display apparatus in which a viewing angle characteristic in the 45 ° direction is improved by a retardation plate. The former liquid crystal display device with a microlens has a configuration in which a microlens is installed in a TN type liquid crystal cell and the display characteristics in the front direction are expanded by the microlens to widen the viewing angle characteristics (Japanese Patent Laid-Open No. 5-1.
19308, JP-A-5-80207). In this liquid crystal display device, a parallel light source is required as a light source of the liquid crystal display device in order to bring out the characteristics of the front surface, and in order to use an ordinary scattered light source as this parallel light source, only the straight-ahead portion of the scattered light source is used. Need to do. For this reason, the light utilization efficiency is extremely reduced, and the intensity of the backlight must be increased, resulting in an increase in power consumption. Further, there is a problem that an optical means for obtaining the parallel light source is required, which causes an increase in cost.

A liquid crystal display device in which the viewing angle characteristics in the 45 ° direction are improved by the latter retardation plate has a structure in which a frisbee type negative retardation plate is arranged (Japanese Patent Laid-Open No. 5-2724).
No. 2). The reason for using a negative Frisbee type retarder is
It is as follows. That is, when a voltage is applied and the liquid crystal molecules are aligned vertically with respect to the cell substrate, the liquid crystal molecules have a refractive index anisotropy, so that they are 45 ° from the polarization axis of the polarizing plate.
In the direction, the traveling direction of the light beam obliquely crosses the index ellipsoid of the liquid crystal. Therefore, the main axis of the refractive index ellipsoid is deviated from the polarization axis direction, the incident light is separated and proceeds in the axial direction of the refractive index ellipsoid in the vertical plane of the incident light, and becomes elliptically polarized light.
The viewing angle characteristics in the direction of 45 ° from the polarization axis of the polarizing plate deteriorate. Therefore, in order to alleviate the birefringence of the liquid crystal molecules when a voltage is applied and improve the viewing angle characteristics in the 45 ° direction, a frisbee type negative retardation plate is provided.

However, in the liquid crystal display device having this retardation plate, when the refractive index difference between the z direction and the x and y directions is increased in order to reduce the birefringence of liquid crystal molecules, the voltage is turned off.
Coloring is seen in the viewing angle characteristics at the time, which is not practical.
Further, when the birefringence is reduced, there is a problem that the effect of improving the viewing angle characteristic is reduced.

The present invention has been made to solve the problems of the prior art, and a liquid crystal display capable of ensuring a wide viewing angle characteristic in all directions without lowering the utilization efficiency of the light of the backlight. The purpose is to provide a device.

[0020]

In a liquid crystal display device according to the present invention, a liquid crystal provided between a pair of substrates is provided on at least one substrate within each picture element arranged in a matrix.
A microlens is provided on the liquid crystal display element oriented in the direction or more, and thereby the above object is achieved.

In the liquid crystal display device of the present invention, the liquid crystal display element has a liquid crystal region surrounded by polymer walls, and in the liquid crystal region, the alignment direction of liquid crystal molecules on one substrate is at least two directions or more. It can be oriented.

In the liquid crystal display device of the present invention, an alignment film may be provided on the liquid crystal side of at least one of the pair of substrates, and the alignment film may align liquid crystal molecules in at least two directions. .

In the liquid crystal display device of the present invention, an alignment film is provided on at least one of the pair of substrates on the liquid crystal side, and the alignment film is made of a crystalline polymer and has a spherulite structure. be able to.

In the liquid crystal display device of the present invention, an alignment film is provided on the liquid crystal side of at least one of the pair of substrates, and the liquid crystal display element has a liquid crystal region surrounded by polymer walls. It is possible to adopt a structure in which the alignment film is not subjected to alignment treatment and the liquid crystal regions are randomly aligned.

In the liquid crystal display device of the present invention, the alignment state of the liquid crystal molecules in the liquid crystal region surrounded by the polymer wall can be axially symmetrical.

In the liquid crystal display device of the present invention, each of the picture elements may be provided with one lens.

In the liquid crystal display device of the present invention, each of the picture elements may be provided with a plurality of lenses.

[0028]

The liquid crystal display device of the present invention, as shown in FIG.
One lens unit 11 for each picture element 2 on the liquid crystal display element 1.
The microlens 10 is installed in the state of arranging.
This liquid crystal display element 1 is composed of picture elements 2 arranged in a matrix.
In the wide viewing angle mode, at least one of the substrates 3 is oriented in two or more directions.

FIG. 11 shows a TN mode liquid crystal display element 31.
2 shows a configuration of a conventional example in which the viewing angle characteristic in the front direction is enlarged by the microlens 32. In this conventional liquid crystal display device, the light from the light source 33 is converted into light close to parallel light by the parallel light producing unit 34, and the characteristics in the front direction in the TN mode liquid crystal display device are determined by the microlens 3
Expanded by 2.

On the other hand, in the above-described liquid crystal display device of the present invention, the wide viewing angle mode liquid crystal display element 1 itself has wide viewing angle characteristics, and further, such a liquid crystal display element 1 is provided with the microlens 10. If it is provided, a high-contrast area near the front is expressed with the same effect as if it was magnified by a lens, and the direction in which the viewing angle characteristic of the wide viewing angle mode (axial symmetry mode) is poor, for example, 45 ° from the polarization axis of the polarizing plate The viewing angle characteristics can be improved. Also, in this case,
The wide viewing angle mode liquid crystal display element 1 has a wide viewing angle characteristic, and therefore has a characteristic that the change in contrast is small even if the viewing angle is slightly shifted, and a scattering light source can be used for the backlight 12. Further, since the scattered light source can be used, the incident angle of the incident light is multidirectional, and thus the outgoing light is also multidirectional, so that a wider viewing angle characteristic can be obtained.

As described above, according to the present invention, the viewing angle characteristics in the direction of poor viewing angle characteristics in the wide viewing angle mode (axisymmetric mode) can be improved, and as a result, all of the light emitting element display elements such as CRT, plasma display and EL element can be obtained. It is possible to approach the azimuth characteristics. Further, according to the present invention, since a parallel light source is not required and the characteristics in the vicinity of the front, which have excellent viewing angle characteristics in the wide viewing angle mode, are enlarged by the microlens, the energy of the light source can be effectively used. (Wide-viewing-angle display mode that can be used in the present invention) As the wide-viewing-angle display mode liquid crystal display element that can be used in the present invention, the following liquid crystal display elements in which liquid crystal molecules are aligned in two or more directions are applicable.

A non-scattering type polarizing plate is used to improve the viewing angle characteristics, and a polymer protrusion is prepared in advance in the liquid crystal cell and injected into the liquid crystal cell. And a liquid crystal display device having a constitution in which the viewing angle characteristics are improved by disturbing the alignment of liquid crystal molecules by the protrusions (Japanese Patent Laid-Open No. 27242/1993), when the mixture is irradiated with light for phase separation, By controlling the light with a photomask, the liquid crystal molecules are oriented in all directions (spiral shape) in the pixel area, and by controlling the voltage of the liquid crystal molecules, the spiral orientation is as if the umbrella opens. A liquid crystal display device capable of remarkably improving the viewing angle characteristics by performing operations such as opening and closing (Japanese Patent Application No.
-199285) A liquid crystal display element in wide viewing angle display mode (Japanese Patent Application No. 5-96289) which is a crystalline polymer on the surface of the substrate and which has a spherulite structure and makes use of an axially symmetric alignment control force. A liquid crystal display device in which an alignment film is applied and liquid crystal molecules are randomly aligned without performing alignment treatment such as rubbing (Japanese Patent Application No. 6-194655, etc.) A pixel is divided into two regions, and each region is divided. A liquid crystal display device having a configuration in which regions having different viewing angle characteristics are mutually complemented by making the regions different alignment states. By the way, when the liquid crystal display device described above is sandwiched by a pair of crossed Nicols polarizing plates, When a saturation voltage is applied, liquid crystal molecules (when Δε> 0) are aligned in the direction of the electric field, and the viewing angle characteristic dependence of the black level is almost the same. Therefore, although the contrast is different for each display mode, the viewing angle characteristic dependence has a similar tendency.

The broken line in FIG. 2 shows the viewing angle characteristics of the liquid crystal display element shown in. From this figure, it can be seen that the viewing angle characteristics are relatively wide in the axial direction, but the viewing angle characteristics deteriorate in the 45 ° direction from the axial direction. This characteristic is almost the same for each of the other liquid crystal display elements of.

In particular, in a liquid crystal display element in which liquid crystal molecules are oriented in an axially symmetrical manner for each picture element, when the axis is deviated for each picture element, when the viewing angle is tilted, the area of the area which becomes a blind spot area is reduced. Since each picture element is different, it causes roughness.
That is, the axis of orientation must be accurately aligned for each picture element.

However, in the present invention, since only the characteristics near the front surface of the liquid crystal display element are used, there is a characteristic that the above-mentioned roughness is unlikely to occur, and the manufacturing allowable range is wide.

(Structure of Microlens Applicable to the Present Invention) It is preferable that the microlens has an effect of spreading incident light in all directions. That is, it has a spherical structure, a semi-cylindrical shape, a pyramid shape and the like. Each lens of the microlens does not necessarily have to correspond to 1: 1 with respect to the picture element, and it is preferable to arrange one or more lenses for each picture element. The microlens may be installed outside the cell or inside the cell.

The performance of the microlens can be expressed by the F value shown in FIG. In the present invention, the F value of the microlens is preferably 0.28 or less. When the F value is 0.28 or more, in the present invention, the light source of the backlight does not use a light beam close to parallel rays, so that the brightness of the available rays is lowered and the liquid crystal display device becomes dark. Further, the surface shape (curvature) of the microlens must be increased in order to increase the F value, resulting in a rough display state.

(Driving Method) In the present invention, a driving method such as simple matrix driving, active driving by a-si TFT, p-Si TFT, MIM or the like can be used and is not particularly limited.

(Substrate Material) As the substrate material, glass or polymer film which is a transparent solid can be used, and as the non-transparent solid, a substrate with a metal thin film aiming at a reflection type, a Si substrate and the like can be used. As the plastic substrate, a material that does not absorb visible light is preferable, and PET, acrylic polymer, styrene, polycarbonate, or the like can be used.

Further, two kinds of these substrates may be combined to form a cell on a different kind of substrate, and two kinds of substrates having the same kind and different kinds but different in substrate thickness may be used in combination.

Further, in the case of a plastic substrate, it is possible to manufacture a liquid crystal display element in which a polarizing plate is integrated by making the substrate itself have a polarizing ability.

[0042]

EXAMPLES Examples of the present invention will be specifically described below.
The present invention is not limited to the examples below.

(Embodiment 1) FIG. 4 is a sectional view schematically showing a liquid crystal display device of this embodiment. This liquid crystal display device includes a pair of substrates 3 facing each other, and a display medium in which a liquid crystal region 4 is surrounded by a polymer wall 5 between both substrates 3. The liquid crystal region 4 is composed of picture elements 2 formed by facing portions of transparent electrodes 6 formed on the display medium side of both substrates 3.
Exist for each. Further, a polarizing plate 7 is provided on the opposite side of both substrates 3 from the display medium to form the liquid crystal display element 1.

With respect to the liquid crystal display element 1 having the above structure, the microlens 10 having the lens portion 11 on each picture element 2 is provided.
Are formed. On the other hand, on the opposite side of the liquid crystal display element 1 from the microlens 10, the scattered light source 1 is used as a backlight.
Two are provided.

Next, a method of manufacturing the liquid crystal display device of this embodiment having the above structure will be described.

First, a transparent electrode 6 made of ITO (a mixture of indium oxide and tin oxide) and having a thickness of 500 Å is formed on two substrates 3 made of glass having a thickness of 1.1 mm, for example. In addition, you may use the board | substrate 3 in which the transparent electrode 6 was previously formed.

Next, a wall 5a having the structure shown in FIG. 5 was formed on the transparent electrode 6 of one of the substrates 3 and outside the picture element using, for example, OMR-83 (manufactured by Tokyo Ohka Co., Ltd.). . The wall 5a is to create a "trigger" for the phase separation between the liquid crystal and the polymer in the mixture described later.

Next, the two substrates 3 thus prepared were arranged so as to face each other, and a spacer having a diameter of, for example, 5 μm was interposed therebetween to secure the cell thickness, thereby forming a cell.

Next, 0.40 g of isobornyl acrylate, 0.40 g of R-684, 0.10 g of p-phenylstyrene, 0.10 g of the following compound A and 4 g
Liquid crystal material ZLI-4792 (manufactured by Merck & Co .: Δn = 0.
094) and 0.025 g of a photoinitiator (Irugacure651)
The homogeneous mixture of and was capillary-injected into the cell.

[0050]

Embedded image

Next, the temperature of the above mixture is maintained at 100 ° C., and then the temperature of the mixture is once cooled to room temperature.
Furthermore, it heated up to 50-60 degreeC. In this state, the voltage O
By repeating N-OFF, the voltage is turned off, and the temperature of the mixture is gradually cooled to 25 ° C. (the liquid crystal is in a nematic state), for example, at a cooling rate of 10 ° C./hr, and further 30 ° C.
UV light (3mW / cm ² : 3
(65 nm) to cure the resin.

When the cell manufactured as described above is observed with a polarization microscope, a liquid crystal region having a shape according to the resist pattern is formed as shown in FIG.
It was observed that the orientation state was axially symmetric with respect to. In addition, the hatched portion in the drawing is a portion having a light-extinguishing pattern.

Next, two polarizing plates having polarization axes orthogonal to each other were attached to both sides of the produced cell. Thereby, the liquid crystal display element 1 is manufactured. The process up to here is
The same applies to the production of the liquid crystal display element of Comparative Example 1 described later.

Next, the microlens (F value = 0.25) 10 shown in FIG. 7 is installed on the liquid crystal display element 20 to complete the liquid crystal display device of the first embodiment. In this case, the microlens 10 preferably has one or more lens portions 11 in one picture element. This also applies to Examples 2 and 3 below.

The solid line in FIG. 2 shows the results of measuring the viewing angle characteristics of the liquid crystal display device of the first embodiment. As shown in this figure, the isocontrast curve (CR> 10) was 60 ° or more, and the display characteristics were completely anisotropic.

(Comparative Example 1) As Comparative Example 1, the liquid crystal display element before the above-mentioned microlens was installed was prepared as in Example 1.
Was prepared in the same manner as in.

The viewing angle characteristics of the manufactured liquid crystal display device are shown in FIG.
It was confirmed that the viewing angle characteristics were excellent in the polarization axis direction of the polarizing plate, as indicated by the broken line in FIG. 45 ° from the polarization axis
In the direction, black level uplift was observed when a saturation voltage was applied, and display deterioration was observed at 40 ° or more from the vertical plane.

(Embodiment 2) The liquid crystal display device of the present embodiment 2 uses a substrate having a spherulite structure although the basic structure is almost the same as that of FIG.

The structure of the liquid crystal display device of the second embodiment will be described in the order of manufacturing steps.

First, ITO having a thickness of 500 Å is formed on two substrates made of glass having a thickness of 1.1 mm, for example.
A transparent electrode made of (a mixture of indium oxide and tin oxide) was formed. A substrate having this structure from the beginning may be used. Next, a film made of nylon 66 was coated on each of the two substrates having the transparent electrodes by a spin coating method to form a spherulite structure on the film. The spherulite structure may be formed only on one of the substrates.

Next, the two produced substrates are arranged so as to face each other,
A cell having a diameter of, for example, 5 μm was interposed between the two substrates to secure the cell thickness to form a cell.

Next, the liquid crystal material ZLI-47 was placed in the cell.
92 (manufactured by Merck & Co., Inc .: adjusted with a chiral agent S-811 so that the spiral pitch was 90 °) was injected. This allows
A liquid crystal display device is manufactured.

The obtained liquid crystal display element has liquid crystal molecules oriented in a spiral shape along the spherulite structure on the substrate, and has excellent viewing angle characteristics in a halftone. The steps up to here are the same in the production of the liquid crystal display element of Comparative Example 2 described later.

Next, the microlens 10 shown in FIG. 7 is placed on the liquid crystal display element manufactured as described above, and the liquid crystal display device of the second embodiment is finally manufactured.

The liquid crystal display device of Example 2 manufactured in this way was measured for viewing angle characteristics, and as a result, it was almost the same as the solid line in FIG. 2 and the isocontrast curve (CR> 10) was 60 ° or more. The display characteristics were completely anisotropic.

(Comparative Example 2) As Comparative Example 2, the liquid crystal display element before the above-mentioned microlens was installed was prepared as in Example 2.
Was prepared in the same manner as in.

The obtained liquid crystal display device was a display device having excellent viewing angle characteristics in the polarization axis direction as in Comparative Example 1.

(Third Embodiment) The liquid crystal display device according to the third embodiment is basically the same as that shown in FIG. 4, but the liquid crystal molecules are randomly aligned.

The structure of the liquid crystal display device of the third embodiment will be described in the order of manufacturing steps.

First, an IT of 500 angstrom thickness is formed on two substrates made of, for example, 1.1 mm thick glass.
A transparent electrode made of O (a mixture of indium oxide and tin oxide) was formed. The substrate having this configuration may be used from the beginning.

Next, a polyimide film was coated on both substrates by spin coating.

Next, without rubbing the polyimide film, both substrates were arranged opposite to each other, and a spacer having a diameter of, for example, 5 μm was interposed between the two substrates to secure a cell thickness, thereby forming a cell.

Next, the liquid crystal material ZLI-47 was placed in the cell.
92 (manufactured by Merck & Co., Inc .: adjusted with a chiral agent S-811 so that the spiral pitch was 90 °) was injected. A liquid crystal display device is obtained through the above steps.

The liquid crystal display device thus obtained has a liquid crystal molecule in a randomly aligned state because the alignment regulating force on the substrate is small, and thus it has an excellent viewing angle characteristic in a halftone. The steps up to here are the same in the production of the liquid crystal display element of Comparative Example 3 described later.

Next, the microlens 10 shown in FIG. 7 is installed on the liquid crystal display element, and finally the liquid crystal display device of the third embodiment is completed.

As a result of measuring the viewing angle characteristics of the completed liquid crystal display device, it was almost the same as the solid line in FIG. 2 and the isocontrast curve (CR> 10) was 60 ° or more and the display characteristics were completely anisotropic. It was

(Comparative Example 3) As Comparative Example 3, the liquid crystal display element before the above-mentioned microlens was installed was used in Example 3
Was prepared in the same manner as in.

The obtained liquid crystal display device was a display device having excellent viewing angle characteristics in the polarization axis direction, as in Comparative Example 1.

(Embodiment 4) The liquid crystal display device of the present embodiment 4 is basically the same in structure as that of FIG. 4, but a plurality of microlenses are provided in one picture element.

The liquid crystal display device of Example 4 was manufactured as follows. That is, as shown in FIG. 8, the liquid crystal display element manufactured in Comparative Example 3 was manufactured by installing the microlens 10 having four lens portions 11 per picture element.

When the viewing angle characteristics of the liquid crystal display device thus obtained were measured, the display characteristics almost equal to those of Example 3 were obtained.

[0082]

As described above in detail, according to the present invention, in the liquid crystal display device having the alignment directions of two or more directions, the viewing angle characteristics in the direction of 45 ° from the polarization axis having the poor viewing angle characteristics can be improved. As a result, it is possible to secure wide viewing angle characteristics in all directions without deteriorating the light utilization efficiency of the backlight. Therefore, it can be used as a flat panel display that can withstand a CRT.

Further, by making the most of the above characteristics, it can be used as a display device such as a large-sized high-definition liquid crystal display device or a portable information terminal device. In particular, it is effective and preferable in a liquid crystal display device used by 2 to 4 people at the same time.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a principle of improving a viewing angle characteristic in the present invention.

FIG. 2 is a diagram showing viewing angle characteristics (solid line) in the liquid crystal display device of the present invention, and also showing viewing angle characteristics (broken line) in the liquid crystal display element of Comparative Example 1 which is a conventional technique.

FIG. 3 is an explanatory diagram of an F value of a microlens preferably used in the present invention.

FIG. 4 is a sectional view schematically showing a liquid crystal display device of the present invention.

5 is a cross-sectional view showing the structure of the wall formed in Example 1. FIG.

FIG. 6 is a diagram showing a state in which the liquid crystal display elements of Example 1 and Comparative Example 1 are observed with a polarization microscope.

FIG. 7 is a sectional view showing a microlens used in the present invention.

FIG. 8 is a cross-sectional view schematically showing a liquid crystal display device of Example 4.

FIG. 9 is a diagram showing a cross-sectional structure of a conventional liquid crystal display device.

FIG. 10 is a diagram showing a cross-sectional structure of a conventional liquid crystal display device having another configuration.

FIG. 11 is a diagram schematically showing a configuration of a conventional example in which a viewing angle characteristic in the front direction is enlarged by a microlens in a TN mode liquid crystal display element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal display element 2 Picture element 3 Substrate 4 Liquid crystal region 5 Polymer wall 6 Transparent electrode 7 Polarizing plate 10 Microlens 11 Lens part 12 Scattering light source

Claims (8)

[Claims] 1. A microlens is provided on a liquid crystal display element in which liquid crystals provided between a pair of substrates are oriented in two or more directions on at least one substrate in each pixel arranged in a matrix. Liquid crystal display device provided. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device has a liquid crystal region surrounded by polymer walls, and in the liquid crystal region, the alignment directions of liquid crystal molecules on one substrate are at least two directions. The described liquid crystal display device. 3. An alignment film is provided on the liquid crystal side of at least one of the pair of substrates, and the alignment film aligns liquid crystal molecules in at least two directions.
The liquid crystal display device according to item 1. 4. The liquid crystal according to claim 1, wherein an alignment film is provided on the liquid crystal side of at least one of the pair of substrates, and the alignment film is made of a crystalline polymer and has a spherulite structure. Display device. 5. An alignment film is provided on the liquid crystal side of at least one of the pair of substrates, and the liquid crystal display element has a liquid crystal region surrounded by polymer walls, and the alignment film is aligned. The liquid crystal display device according to claim 1, wherein the liquid crystal region is not subjected to a treatment and the liquid crystal regions are randomly aligned. 6. The liquid crystal display device according to claim 2, wherein the alignment state of the liquid crystal molecules in the liquid crystal region surrounded by the polymer wall is axially symmetrical. 7. The liquid crystal display device according to claim 1, wherein each of the picture elements is provided with one lens. 8. The liquid crystal display device according to claim 1, wherein each of the picture elements is provided with a plurality of lenses.