JP2001264765A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device having excellent viewing angle characteristics. SOLUTION: In the liquid crystal display device having a liquid crystal layer 3 inserted between a pair of substrates 1, 2 and having a pair of polarizing plates 5, 6, on and under the pair of substrates 1, 2, the alignment film 1c on one substrate 1 is subjected to horizontal aligning treatment while the alignment film 2c on the other substrate 2 is subjected to perpendicular aligning treatment so that the liquid crystal layer 3 has a region 12a where the liquid crystal molecules 4 are arranged horizontal and a region 12b where the molecules 4 are arranged perpendicular both influenced by the alignment films. The gap widths dh, dv of the region 12a of the horizontal arrangement and the region 12b of the perpendicular arrangement, respectively, are determined in such a manner that the retardation of the liquid crystal layer 3 is controlled to almost constant when the polarizing plate 6 is observed in at least two different inclined directions a, b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device excellent in high-speed response and viewing angle characteristics.

[0002]

2. Description of the Related Art Liquid crystal display devices are characterized by being thin and light and having low power consumption, and are widely used from portable terminals to personal computers and televisions. Such a liquid crystal display device is required to have a high-speed response and a wide viewing angle as its performance, and various devices have been devised to satisfy the demand. As a liquid crystal display device capable of high-speed response, for example, JP-A-9-146086 and JP-A-9-19739
7, HAN alignment (hybrid aligned ne) disclosed in JP-A-10-123505.
liquid crystal display device).

[0003] This conventional liquid crystal display device will be described with reference to FIGS. 7 and 8. Here, a description will be given of a case of a normally white mode in which white display is performed when the display is off. FIG. 7 is a schematic configuration diagram of the liquid crystal display device in a white display (when off), and FIG.
FIG. 3 is a schematic diagram showing a positional relationship between a transmission axis of a polarizing plate and an alignment state of liquid crystal molecules in a white display (when off).

In this liquid crystal display device, one substrate 100b is subjected to a horizontal alignment treatment, and the other substrate 100a is subjected to a vertical alignment treatment.
Reference numeral 02 denotes a horizontal arrangement on the horizontal alignment substrate 100b side, a vertical alignment on the vertical alignment substrate 100a side, and the liquid crystal layer 101 therebetween gradually changes the alignment state from the horizontal alignment to the vertical alignment. In the on state, the liquid crystal molecules 102b near the substrate 100b are arranged horizontally, but the other liquid crystal molecules are arranged vertically.

[0005] Polarizing plates 103 are arranged above and below the substrate 100 with the liquid crystal layer 101 interposed therebetween.
The angle between the transmission axes 107 of both polarizing plates 103 is 90 degrees, and the transmission axis 107b of the polarizing plate 103b corresponding to the horizontally oriented substrate 100b is set at 45 degrees with the horizontally oriented direction. Note that the transmission axis may be replaced with the absorption axis. In FIG. 8, the liquid crystal molecules 102b on the substrate 100b side and the transmission axis 107b of the polarizing plate 103b are indicated by dotted lines, and
The liquid crystal molecules 102a on the 0a side and the transmission axis 107a of the polarizing plate 103a are shown by solid lines.

An optical compensation sheet 108 is provided between the substrate 100a and the polarizing plate 103a. The optical compensatory sheet 108 is composed of the liquid crystal layer 101 and the optical compensatory sheet 10 in the ON state.
8 has a refractive index ellipsoid such that the composite refractive index ellipsoid becomes a sphere. For example, a uniaxial or biaxial optical anisotropic element is used.

The incident light (linearly polarized light) passing through the transmission axis 107b passes through the liquid crystal molecules 102 of the liquid crystal layer 101 and the optical compensation sheet 108, and reaches the polarizing plate 103a. At this time, since the combined refractive index ellipsoid of the liquid crystal layer 101 and the optical compensation sheet 108 becomes an ellipsoid, the light reaching the polarizing plate 103a becomes elliptically polarized light due to the birefringence effect of the liquid crystal layer 101 and the optical compensation sheet 108, and is transmitted. After passing through the axis 107a, white display is performed.

When a predetermined voltage is applied to the liquid crystal layer 101, the alignment state of the liquid crystal molecules changes to a vertical alignment, and the liquid crystal layer 1
The composite refractive index ellipsoid of 01 and the optical compensation sheet 108 becomes a sphere. Therefore, when the incident light (linearly polarized light) that has passed through the transmission axis 107b reaches the polarizing plate 103a, the amplitude direction maintains linear polarization in the same direction as the transmission axis 107b, and a black display is made without passing through the transmission axis 107a. Become.

[0009]

However, the HAN-aligned liquid crystal display device can realize good white display when viewed from the normal direction of the surface of the polarizing plate 103a, but has a certain angle with respect to the normal direction. When viewed from the direction, the light transmittance and the like vary depending on the direction, and good display cannot be obtained.
When viewed obliquely from the direction 109 of the transmission axis 107, there is not much change. However, when viewed obliquely from the directions 110 and 111 that form an angle of 45 degrees with the transmission axis 107, the difference increases. In particular, when viewed from the long axis direction 110 of the horizontally aligned liquid crystal molecules 102a, the retardation of the liquid crystal layer 101 increases, so that the liquid crystal molecules 102a appear to be colored compared to when viewed from the front of the polarizing plate 103a. When viewed from the short-axis direction 111, the retardation of the liquid crystal layer 101 is small, so that it becomes darker than when viewed from the front of the polarizing plate 103a.

In order to reduce such viewing angle dependence,
Regardless of the direction in which the polarizing plate 103a is viewed obliquely, various attempts have been made in the optical compensation sheet so that the combined refractive index ellipsoid of the liquid crystal layer 101 and the optical compensation sheet 108 becomes a sphere.

Therefore, the present invention provides a liquid crystal layer having a viewing angle compensating function by compensating for the retardation of liquid crystal molecules in a liquid crystal layer and liquid crystal molecules in a horizontal alignment, thereby enabling a wide viewing angle and high-speed response. It is an object to provide a liquid crystal display device.

[0012]

According to a first aspect of the present invention, there is provided a liquid crystal display having a liquid crystal layer sandwiched between a pair of substrates and a pair of polarizing plates disposed above and below the pair of substrates. In the liquid crystal layer, there are a region in which liquid crystal molecules are vertically aligned and a region in which liquid crystal molecules are horizontally aligned along the normal direction of the polarizing plate surface, and the retardation of the liquid crystal layer when the polarizing plate is viewed obliquely from at least two different directions. Is set so that the gap width is substantially constant.

According to a second aspect of the present invention, in a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates and a pair of polarizing plates are disposed above and below the pair of substrates, the liquid crystal layer has a normal to the surface of the polarizing plate. There is a region in which liquid crystal molecules are vertically aligned and a region in which liquid crystal molecules are horizontally aligned along the direction, and the retardation of the liquid crystal layer when the polarizing plate is viewed obliquely from at least one direction and when the polarizing plate is viewed from the normal direction. The gap width of both regions is set so that the retardation of the liquid crystal layer is substantially the same.

According to a third aspect of the present invention, in a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates and a pair of polarizing plates are arranged above and below the pair of substrates, the liquid crystal layer has a normal to the surface of the polarizing plate. There are a region where liquid crystal molecules are vertically aligned and a region where horizontal alignment occurs along the direction.When the polarizing plate surface is viewed from an oblique direction, the retardation of the region where the liquid crystal molecules are horizontally aligned and the region where the liquid crystal molecules are vertically aligned The gap width of both regions is set so that the retardation of the liquid crystal layer when viewed from a range having the same angle with respect to the normal direction of the polarizing plate is compensated for each other and is substantially constant. I do.

According to a fourth aspect of the present invention, in the pair of substrates, a vertical alignment process is performed on an alignment film of one substrate and a horizontal alignment process is performed on an alignment film of the other substrate, so that a gap width between the two regions is increased. Is characterized in that the alignment anchoring of the alignment film is adjusted so that is equal to a set value.

According to a fifth aspect of the present invention, the pair of polarizing plates have a transmission axis or an absorption axis of about 90 degrees with each other, and
The transmission axis or the absorption axis is arranged so as to form an angle of about 45 degrees with the horizontal alignment direction of the alignment film.

According to a sixth aspect of the present invention, the direction in which the polarizing plate is viewed obliquely forms an angle of 40 ° to 50 ° with the transmission axis or the absorption axis of the polarizing plate, and is perpendicular to the surface of the polarizing plate. It is characterized by being included in a range forming an angle of 10 degrees to 70 degrees.

According to a seventh aspect of the present invention, the retardation of the horizontal alignment region when the liquid crystal layer is viewed from the normal direction of the surface of the polarizing plate is set to be in a range of about 200 nm to about 300 nm. Features.

The invention according to claim 8 is characterized in that a nematic liquid crystal having a positive dielectric anisotropy is interposed between the substrates.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. This liquid crystal display device is in a normally white mode. FIG. 1 is a schematic configuration diagram showing an arrangement state of liquid crystal molecules in a white display (at the time of off), and FIG. 2 shows an arrangement state of liquid crystal molecules in a black display (at the time of on). 3 is a schematic side view of the liquid crystal display device in an off state, and FIG. 4 is a diagram showing a relationship between a transmission axis of a polarizing plate and an arrangement direction of liquid crystal molecules.

The first substrate 1 has a pixel electrode 1b and an alignment film 1c laminated on a glass substrate 1a, and the second substrate 2 has a glass substrate 2a.
a, a transparent electrode 2b and an alignment film 2c are laminated. First
After the spacers are scattered on the substrate 1, the first substrate 1 and the second
The substrates 2 are arranged at predetermined positions so that the alignment films 1c and 2c face each other, and the periphery of the substrates 1 and 2 is fixed with a sealant. The alignment film 1c of the first substrate 1 is subjected to a horizontal alignment process, and the alignment film 2c of the second substrate 2 is subjected to a vertical alignment process. A nematic liquid crystal 3 having a positive dielectric anisotropy is sealed between the two substrates 1 and 2, and the liquid crystal molecules 4 maintain an alignment described later due to the influence of the alignment films 1c and 2c.

A lower polarizer 5 is disposed below the first substrate 1, and an upper polarizer 6 is disposed above the second substrate 2. The lower polarizing plate 5 and the upper polarizing plate 6 are arranged so that their transmission axes 8a and 8b are orthogonal to each other when viewed from the normal direction 9 of the surface thereof. They are arranged so as to form an angle of 45 degrees with one orientation direction 7. In this embodiment, the transmission axis will be described, but an absorption axis may be used instead of the transmission axis. Since the substrates 1 and 2 and the deflecting plates 5 and 6 are arranged in parallel, their normal directions 9 coincide with each other.

In the off state (FIG. 1), the liquid crystal molecules 4a on the first substrate 1 are horizontally arranged at an inclination of the pretilt angle θ due to the horizontal alignment of the alignment film 1c.
Are vertically affected by the vertical alignment of the alignment film 2c. Note that the liquid crystal molecules 4a affected by the alignment film 1c may be horizontally arranged in parallel with the first substrate 1 without having a pretilt angle.

The gap width of the horizontal alignment region 12a of the liquid crystal molecules 4 and the gap width of the vertical alignment region 12b are determined by the first substrate 1
When viewed from an oblique direction having an angle with respect to the normal direction 9, the retardation of the horizontal array region 12 a and the retardation of the vertical array region 12 b are compensated for so that the retardation of the liquid crystal layer 3 becomes substantially constant. Is done. In particular, as shown in FIGS. 1 and 4, when viewed from the same direction a (β1 = 45 °) as the long axis direction of the horizontally aligned liquid crystal molecules 4a, the same direction as the short axis direction of the liquid crystal molecules 4a b
If the retardation of the liquid crystal layer 3 when viewed from (β2 = 45 °) is set to be substantially the same, the change in the amount of light can be minimized and the viewing angle dependency can be reduced. At this time, the gap width between the two regions is determined by the orientation films 1c and 2c.
It can be set by adjusting the strength of the orientation anchoring of c.

In the off-state, the amplitude direction is the transmission axis 8a.
Then, linearly polarized light (incident light) 10 a having the same direction as above passes through the lower polarizing plate 5 and reaches the upper polarizing plate 6 via the liquid crystal molecules 4. At this time, the transmitted light 10b reaching the upper polarizing plate 6 is
The linearly polarized light 10c whose amplitude direction is the same as that of the transmission axis 8b of the upper polarizing plate 6 passes through the upper polarizing plate 6 and becomes white display.

The liquid crystal molecules 4a in the horizontal alignment region 12a
Compensates for the retardation given to the transmitted light 10b and the retardation given to the transmitted light 10b by the liquid crystal molecules 10a in the vertical alignment region 12b. For example, even when the liquid crystal is viewed obliquely from the directions a and b at 45 degrees with the transmission axis 8b. The retardation of the layer 3 becomes almost the same, and a white display with almost the same tuning is obtained from any direction, and the viewing angle characteristic is improved.

In the ON state (FIG. 2), the liquid crystal molecules 4a near the first substrate 1 are arranged horizontally, but the other liquid crystal molecules 4a are not aligned.
Are arranged vertically. The linearly polarized incident light 10a passing through the lower polarizing plate 5 passes through the liquid crystal molecules 4 while almost maintaining the state at the time of incidence, and linearly polarized light 10d whose amplitude direction is orthogonal to the transmission axis 8b reaches the upper polarizing plate 6. The transmitted light 10d
Are blocked by the upper polarizing plate 6 to display black.

Next, an example of the gap width of the horizontal arrangement area and the gap width of the vertical arrangement area will be described. FIG. 5 is a schematic side view illustrating the traveling path of light when the upper polarizing plate 6 is viewed from the direction a in FIGS. 1 and 4. FIG. 6 is a side view illustrating the upper polarizing plate 6 from the direction b in FIGS. FIG. 3 is a schematic side view for explaining a traveling path of light when viewing FIG. In order to simplify the description and calculation, the liquid crystal layer 3 is divided into two regions, a vertical alignment region 12b and a horizontal alignment region 12a, and the liquid crystal molecules 4 in the vertical alignment region 12b are divided.
b are all vertically aligned parallel to the normal direction 9 of the surface of the first substrate 1, and the liquid crystal molecules 4a in the horizontal alignment region 12a are all horizontally aligned in a direction orthogonal to the normal direction 9 of the surface of the first substrate 1. And In this example, the retardation when viewing the liquid crystal layer 3 from the direction of 70 degrees (α) with respect to the normal direction 9 of the first substrate 1 is set to be substantially constant.

The refractive index of the liquid crystal molecules 4 is n in the major axis direction._x= 1.
5575, short axis direction n_y= 1.4754 and the liquid crystal layer 3
The gap width of the vertical array region is d_v, The horizontal array area is d_h
And At this time, the retardation of the liquid crystal layer in the horizontal alignment region 12a is
Option Δn · d_h= (N_x-N _y) ・ D_hIs about 275 nm
Is set in advance so that This is the surface of the upper polarizing plate 6
The retardation of the liquid crystal layer 3 when viewed from the normal direction 9
Is the same as the retardation of the liquid crystal layer in the horizontal alignment region 12a.
Be one. And generally, the retardation of the liquid crystal layer
R, when the incident light wavelength is λ, the transmittance I is sin^Two(Rπ
/ Λ) is proportional to the wavelength of light
When the length is set to 550 nm, the transmittance of this light is the highest.
Is R = 275 nm. Therefore, the horizontal arrangement
Set the retardation of the liquid crystal layer in the area 12a to 275nm
A good white display when the upper polarizing plate 6 is viewed from the front.
Is obtained. Thus, Δn · d_h= 275nm
Is d_h= 3350 nm and d_hIs determined.

When viewed from the direction of α = 70 °, the light traveling direction α ′ in the liquid crystal layer 3 is about 38 ° (FIGS. 5 and 6).

Next, the retardation R _h (a, α) in the horizontal arrangement area 12a in the a direction, when α = 70 °, is calculated. The extraordinary light refractive index n _xh (a, α) in the horizontal alignment region 12a at this time is represented by the following equation. _{n xh (a, α) =} n x · n y / (n x 2 · sin 2 α '+ n y 2 · cos 2 α') 0.5 The ordinary refractive index n _yh (a, α) is n _yh (a, α) = n _y, optical path d _h (a in the horizontal arrangement region 12a, alpha) is d _h (a,
α) = d _h / cos α ′. Therefore, the retardation R _h (a, α) in the horizontal array region 12a can be expressed by the following equation. _{R h (a, α) =} {n xh (a, α) -n yh (a, α)} · d h (a, α) = [n x · n y / (n x 2 · sin 2 α ' ^{_{+ n y 2 · cos 2 α}} ') 0.5 -n y] · d h / cos α' = 209 then the b direction, the retardation in the horizontal arrangement region 12a in the case of _{α = 70 ° R h (b} , α) calculated I do. The extraordinary light refractive index n in the horizontal alignment region 12a at this time
_xh (b, _α) is _{n xh (b, α) =} n x, the ordinary refractive index n _yh (b,
alpha) is _{n yh (b, α) =} n y, optical path d _h (b in the horizontal arrangement region 12a, alpha) is expressed by _{d h (b, α) =} d h / cosα '. Therefore, the retardation R _h (b, α) in the horizontal array region 12a can be expressed by the following equation. _{R h (b, α) =} {n xh (b, α) -n yh (b, α)} · d h (b, α) = {n x -n y} · d h / cosα '= 350 primary Next, the retardation R _v (α) in the vertical array region 12b at this time is calculated. The vertical array region 12b
Retardation R _v (alpha) is also the same when viewed from b direction when viewed from a direction. First, the vertical alignment region 12b
The extraordinary light refractive index n _xv (a, α) at is expressed by the following equation. _{n xv (α) = n x} · n y / (n x 2 · cos 2 α '+ n y 2 · sin 2 α') 0.5 The ordinary refractive index n _yv (alpha) is _{n yv (α) = n y} , The optical path d _v (α) in the vertical array region 12b is d _v (α) = d _v / cos α ′
Can be represented by Therefore, the retardation R _v (α) in the vertical array region 12b can be expressed by the following equation. _{R v (α) = {n} xv (α) -n yv (α)} · d v (α) = [n x · n y / (n x 2 · cos 2 α '+ n y 2 · sin 2 α' ^{_{) 0.5 -n y] · d v}} / cosα '= 0.038d v then calculating the retardation of the entire liquid crystal layer 3.

First, when viewed from the direction a, the liquid crystal molecules 4a in the horizontal alignment region 12a are viewed from the long axis direction of the liquid crystal molecules 4a. Long axis direction and vertical array area 1
The major axis directions of the liquid crystal molecules 4b of 2b coincide. Therefore, the retardation R (a, α) of the entire liquid crystal layer 3 at this time can be expressed by the following equation. When viewed from the direction b, the liquid crystal molecules 4a are viewed from the short-axis direction of the horizontally aligned liquid crystal molecules 4a. The direction is perpendicular to the major axis direction of the liquid crystal molecules 4b in the vertical alignment region 12b. Therefore, the retardation R (b, α) of the entire liquid crystal layer 3 at this time can be expressed by the following equation. Here, if R (a, α) = R (b, α), the viewing angle dependency is reduced, and from the above equation, d _v = 1855 nm. At this time, R (a, α) = R (b, α) = 279n
m, which is almost equal to the retardation of 275 nm when viewed from the front of the substrate, and the viewing angle characteristics are improved. At this time, Δn · d _v = 152.

The alignment anchoring strength of the alignment films 1c and 2c is set so as to obtain the gap widths d _v and d _h thus obtained. Here determined gap width d _v, d _h is a value when the liquid crystal molecules 4 of the liquid crystal layer 5, are arranged as shown in FIG. However, the horizontally aligned liquid crystal molecules 4a are inclined at the pretilt angle θ, and the alignment state of the liquid crystal molecules 4 from the first substrate 1 to the second substrate 2 is gradually changed from horizontal alignment to vertical alignment. Thus obtained gap width d _v, by adjusting to a proper value each gap width by experiments or the like after setting the d _h, viewing angle dependence of retardation does not change much even when viewed from an oblique direction when the white display Liquid crystal display device.

[0034] The alignment anchoring strength obtained gap width d _v, if possible strong satisfying a condition of d _h, increases the range occupied by the horizontal arrangement region 12a and a vertical array region 12b, the horizontal arrangement it is possible to reduce the area of the liquid crystal molecules 4 to change the array state to the vertical arrangement, the gap width of the alignment state of the liquid crystal molecules 4 are both areas d _v, arrangement state (Fig. 5 and which is assumed when determining the d _h 6 ).

Further, if an optical compensation sheet is added to the liquid crystal display device in which the respective gap widths are set as described above, the viewing angle dependency can be further eliminated, and the viewing angle characteristics can be improved. Further, on the first substrate 1 side, a uniaxially stretched film having a stretching axis in a direction at 90 degrees to the alignment direction of the alignment film 1c is provided, and the uniaxially stretched film is used to maintain the liquid crystal molecules 4a which maintain a horizontal alignment state when turned on. By canceling the retardation, a good black display can be obtained at the time of ON, and the contrast is improved.

In this embodiment, a case was described in which the direction was 45 degrees with respect to the transmission axis of the upper polarizing plate and the direction was α = 70 °. However, the present invention is not limited to this direction. Alternatively, the retardation of the liquid crystal layer may be set to have substantially the same value when the polarizing plate 6 is viewed obliquely from another direction. However, since the retardation when viewed from the direction of the transmission axis of the upper polarizer 6 and the direction of 45 degrees is the most different, the transmission axis forms an angle of 40 to 50 degrees with respect to the transmission axis and α is included in the range of 0 to 70 degrees. If the retardation of the liquid crystal layer 3 is set to have substantially the same value when the upper polarizing plate 6 is viewed from a certain direction in the range, the viewing angle characteristics are improved.

In this embodiment, the retardation of the liquid crystal layer 3 in the horizontal alignment region 12a when the upper deflecting plate 6 is viewed from the normal direction 9 is set to about 275 nm, but the present invention is limited to this value. is not. However, when the retardation increases, the display becomes colored yellowish, and when the retardation decreases, the display becomes darker. Therefore, if the retardation of the liquid crystal layer 3 in the horizontal alignment region 12a is set to be in a range from about 200 nm to about 300 nm, an appropriate display can be obtained.

[0038]

According to the present invention, the region where the liquid crystal molecules present in the liquid crystal layer are horizontally aligned and the region where the liquid crystal molecules are vertically aligned compensate for each other's retardation. Since the gap width between the horizontal alignment region and the vertical alignment region of the liquid crystal layer is set so as to reduce the change in retardation, the viewing angle dependency is reduced and a liquid crystal display device with a wide viewing angle can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an arrangement state of liquid crystal molecules when a normally white mode liquid crystal display device according to an embodiment of the present invention is off.

FIG. 2 is a schematic view showing an arrangement state of liquid crystal molecules when a normally white mode liquid crystal display device according to an embodiment of the present invention is turned on.

FIG. 3 is a schematic view of a liquid crystal display device according to an embodiment of the present invention when viewed from a side.

FIG. 4 is a schematic view of a liquid crystal display device according to one embodiment of the present invention when viewed from a normal direction of a polarizing plate.

FIG. 5 is a diagram schematically illustrating an alignment state of liquid crystal molecules along the line A′-A ′ in FIG. 4 of the present invention.

FIG. 6 is a diagram schematically illustrating an alignment state of liquid crystal molecules along a line B′-B ′ in FIG. 4 of the present invention.

FIG. 7 is a schematic view of a conventional liquid crystal display device as viewed from the side.

FIG. 8 is a schematic diagram when a conventional liquid crystal display device is viewed from a normal direction of a polarizing plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st substrate 1c Alignment film 2 2nd substrate 2c Alignment film 4 Liquid crystal molecule 5 Lower polarizing plate 6 Upper polarizing plate 7a, 7b Orientation direction 8a, 8b Transmission axis

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Kase 3-201 Minamiyoshikata, Tottori-shi, Tottori Sanyo Electric Co., Ltd. (72) Inventor Yoshitaka Mori 3-201 Minamiyoshikata, Tottori-shi, Tottori Sanyo Tottori Inside Electric Co., Ltd. (72) Inventor Shinichiro Tanaka 3-201 Minamiyoshikata, Tottori City, Tottori Pref.

Claims (8)

[Claims] 1. A liquid crystal display device having a liquid crystal layer sandwiched between a pair of substrates and a pair of polarizing plates disposed above and below the pair of substrates, wherein the liquid crystal layer is disposed along a direction normal to a surface of the polarizing plate. There is a region in which liquid crystal molecules are vertically arranged and a region in which liquid crystal molecules are horizontally arranged, and the gap width between the two regions is set so that the retardation of the liquid crystal layer when the polarizing plate is viewed obliquely from at least two different directions is substantially constant. A liquid crystal display device characterized by being set. 2. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates and a pair of polarizing plates are arranged above and below the pair of substrates, wherein the liquid crystal layer is provided along a direction normal to a surface of the polarizing plate. There is a region in which liquid crystal molecules are vertically aligned and a region in which the liquid crystal molecules are horizontally arranged, and the retardation of the liquid crystal layer when the polarizing plate is viewed obliquely from at least one direction and the when the polarizing plate is viewed from a normal direction. A liquid crystal display device wherein the gap width of the two regions is set so that the retardation of the liquid crystal layer is substantially the same. 3. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates, and a pair of polarizing plates are disposed above and below the pair of substrates, wherein the liquid crystal layer is provided along a direction normal to a surface of the polarizing plate. There is a region in which liquid crystal molecules are vertically aligned and a region in which the liquid crystal molecules are horizontally arranged, and when the polarizing plate surface is viewed from an oblique direction,
The retardation of the region where the liquid crystal molecules are horizontally aligned and the retardation of the region where the liquid crystal molecules are vertically aligned compensate for each other, and the retardation of the liquid crystal layer when viewed from the range having the same angle with respect to the normal direction of the polarizing plate. A liquid crystal display device, wherein a gap width between the two regions is set so that retardation is substantially constant. 4. In the pair of substrates, a vertical alignment process is performed on an alignment film of one substrate and a horizontal alignment process is performed on an alignment film of the other substrate, so that a gap width of the two regions becomes a set value. 4. The liquid crystal display device according to claim 1, wherein the alignment anchoring of the alignment film is adjusted as described above. 5. The pair of polarizing plates are arranged such that the transmission axis or the absorption axis thereof is about 90 degrees and the transmission axis or the absorption axis is about 45 degrees with the horizontal alignment direction of the alignment film. The liquid crystal display device according to claim 1, wherein: 6. A direction in which the polarizing plate is viewed obliquely forms an angle of 40 ° to 50 ° with a transmission axis or an absorption axis of the polarizing plate, and is 10 ° with respect to a normal direction of the surface of the polarizing plate.
The liquid crystal display device according to claim 1, wherein the liquid crystal display device is included in a range forming an angle of from 70 degrees to 70 degrees. 7. When the liquid crystal layer is viewed from the direction normal to the surface of the polarizing plate, the retardation of the horizontal alignment region is about 2
7. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is set to be in a range from 00 nm to about 300 nm. 8. The liquid crystal display device according to claim 1, wherein a nematic liquid crystal having a positive dielectric anisotropy is interposed between said substrates.