JP2009031438A - Liquid crystal display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display panel having excellent display quality, wherein gradation inversion in an oblique direction is not generated. <P>SOLUTION: The liquid crystal display panel is provided with an array substrate 1, a counter substrate 2, a plurality of pixel regions R2 having a plurality of divided regions R3 and a liquid crystal layer 3. The liquid crystal layer 3 is in either one alignment state of a first state that a plurality of liquid crystal molecules 3m are aligned in a direction vertical to planes of the array substrate 1 and the counter substrate 2 and a second state that the plurality of liquid crystal molecules are aligned in the same direction for every divided region R3 and aligned in a plurality of directions for every pixel region R2 by existence of applied voltage. A multiplication value Δnd of a thickness d of the liquid crystal layer 3 and refractive index anisotropy Δn of a liquid crystal material of the liquid crystal layer is 240 nm or less to light having 550 nm wavelength. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display panel.

  In general, a liquid crystal display device is used as an image display device. The liquid crystal display device includes a liquid crystal display panel. The liquid crystal display panel includes an array substrate, a counter substrate disposed opposite to the array substrate with a predetermined gap, and a liquid crystal layer sandwiched between the two substrates.

  Since the liquid crystal display device has features such as thinness, light weight, and low power consumption, it is applied to various fields such as OA (office automation) devices, information terminals, watches, and televisions. In particular, since a liquid crystal display device has a thin film transistor (hereinafter referred to as “TFT”) as a switching element, high-speed response can be obtained. ing.

  In recent years, with an increase in the amount of information, there has been an increasing demand for higher definition of images and higher display speed. High definition of an image is realized, for example, by miniaturizing the array structure of the array substrate on which the above-described TFT is formed.

  On the other hand, in terms of increasing the display speed, instead of the conventional display mode, OCB (Optically Compensated Birefringence) mode, VAN (Vertically Aligned Nematic) mode, HAN (Hybrid Aligned Nematic) mode, and π-array mode are used. It has been studied to employ a surface stabilized ferroelectric liquid crystal (AF) mode and an anti-ferroelectric liquid crystal (AFLC) mode.

  Among these display modes, the VAN mode can obtain a faster response speed than the conventional TN (Twisted Nematic) mode, and further, because of the vertical alignment, rubbing processing that causes defects such as electrostatic breakdown is unnecessary. Among them, a multi-domain type VAN (Multi-domain Vertical Alignment Nematic) mode (hereinafter referred to as “MVA mode”) is particularly attracting attention because it is relatively easy to expand the viewing angle.

  The MVA mode is realized by mask rubbing, a device of the pixel electrode structure, and a protrusion in the pixel. As a result, when the voltage is applied to the liquid crystal layer, the orientation of the liquid crystal molecules is divided into four regions so that the alignment directions of the liquid crystal molecules are at an angle of 90 ° to improve the symmetry of the viewing angle characteristics and suppress the inversion phenomenon. (For example, refer to Patent Document 1).

Furthermore, the viewing angle dependence of the phase difference of the liquid crystal layer in the state where the liquid crystal molecules are aligned vertically, that is, in the black display state, is compensated by using a negative retardation plate, and the contrast (CR) viewing angle characteristic is improved. Liquid crystal display devices are known. In addition, by providing an in-plane retardation to a negative retardation plate to form a biaxial retardation plate, a liquid crystal display device that compensates for the viewing angle dependency of the polarizing plate and realizes superior CR viewing angle characteristics is provided. Are known.
JP-A-11-258606

  As described above, in the conventional MVA mode, the viewing angle compensation for halftone and white display is insufficient, and the gradation characteristics differ between when the display screen is viewed from the front and when viewed from the oblique direction. When the display screen is viewed obliquely in the case of multicolor display, there is a problem that the halftone display cannot be maintained and the halftone is crushed, so that the whole image looks white. Further, when the display screen is viewed obliquely when white display is performed, there is a problem that the brightness of the halftone is not different from the brightness of the white display, and the overall display looks white in the halftone display.

  In addition, the conventional MVA mode in which the number of alignment divisions is 4 has a panel transmittance that is significantly inferior to that in the case of no alignment division. The above is caused by the occurrence of schlieren alignment at the alignment boundary and the installation of protrusions and electrode slits for alignment division. However, this panel transmittance problem can be improved by reducing the number of orientation divisions. The CR viewing angle of the two-part orientation is almost the same as the CR viewing angle of the four-part orientation.

However, gradation inversion occurs in the halftone viewing angle characteristics of the two-part orientation. As described above, in the bi-partition alignment MVA, the direction of the alignment division is parallel to each other between the two alignment regions on the left and right, and the liquid crystal molecules are aligned in the opposite direction. This is to compensate each other. However, since the anisotropy of the phase difference acts uniformly in the left-right direction, the degree of change in the phase difference with respect to the applied voltage changes between the front and the left-right direction. Therefore, when the number of orientation divisions is 2, the panel transmittance is improved, but the halftone viewing angle characteristics are inferior.
The present invention has been made in view of the above points, and an object thereof is to provide a liquid crystal display panel excellent in display quality.

In order to solve the above-described problems, a liquid crystal display panel according to an aspect of the present invention includes:
An array substrate;
A counter substrate disposed opposite to the array substrate with a gap;
A plurality of pixel regions overlapping the array substrate and the counter substrate and having a plurality of divided regions;
A first liquid crystal molecule that is sandwiched between the array substrate and the counter substrate and has a plurality of liquid crystal molecules aligned in a direction perpendicular to the plane of the array substrate and the counter substrate, depending on the presence or absence of a voltage applied between the array substrate and the counter substrate. And a liquid crystal layer that takes one of the alignment states of the second state in which the plurality of liquid crystal molecules are aligned in the same direction for each of the divided regions and are aligned in a plurality of directions for each of the pixel regions. ,
A value Δnd obtained by multiplying the thickness d of the liquid crystal layer by the refractive index anisotropy Δn of the liquid crystal material of the liquid crystal layer is 240 nm or less for light having a wavelength of 550 nm.

In addition, a liquid crystal display panel according to another aspect of the present invention includes:
An array substrate;
A counter substrate disposed opposite to the array substrate with a gap;
A plurality of pixel regions overlapping the array substrate and the counter substrate and having a plurality of divided regions;
A first state that is sandwiched between the array substrate and the counter substrate, no voltage is applied between the array substrate and the counter substrate, and a plurality of liquid crystal molecules are aligned in a direction perpendicular to the plane of the array substrate and the counter substrate; And any one of a second state in which a voltage is applied between the array substrate and the counter substrate, and the plurality of liquid crystal molecules are aligned in the same direction for each of the divided regions and aligned in a plurality of directions for each of the pixel regions. A liquid crystal layer adopting the alignment state of
A controller that is electrically connected to the array substrate and the counter substrate, adjusts the voltage applied between the array substrate and the counter substrate, and controls the alignment state of the plurality of liquid crystal molecules;
An alignment controller provided on at least one of the array substrate and the counter substrate so as to overlap the plurality of pixel regions, and controlling the alignment state of the plurality of liquid crystal molecules;
A first optical film provided on the outer surface side of the array substrate;
A second optical film provided on the outer surface side of the counter substrate,
The array substrate has a plurality of pixel electrodes to which the voltage applied to the liquid crystal layer is applied,
The dielectric anisotropy of the liquid crystal material of the liquid crystal layer is positive,
The alignment control unit is provided on the counter substrate so as to overlap the plurality of pixel regions, and includes a plurality of protrusions protruding toward the array substrate and a plurality of missing portions formed on the plurality of pixel electrodes. And
A value Δnd obtained by multiplying the thickness d of the liquid crystal layer by the refractive index anisotropy Δn of the liquid crystal material of the liquid crystal layer is 240 nm or less for light having a wavelength of 550 nm.

In addition, a liquid crystal display panel according to another aspect of the present invention includes:
An array substrate;
A counter substrate disposed opposite to the array substrate with a gap;
A plurality of pixel regions overlapping the array substrate and the counter substrate and having a plurality of divided regions;
A first state that is sandwiched between the array substrate and the counter substrate, no voltage is applied between the array substrate and the counter substrate, and a plurality of liquid crystal molecules are aligned in a direction perpendicular to the plane of the array substrate and the counter substrate; And any one of a second state in which a voltage is applied between the array substrate and the counter substrate, and the plurality of liquid crystal molecules are aligned in the same direction for each of the divided regions and aligned in a plurality of directions for each of the pixel regions. A liquid crystal layer adopting the alignment state of
At least one first alignment portion provided on the array substrate and rubbed in a first direction that overlaps at least one of the divided regions and is parallel to the plane; and at least one of the divided regions out of the first alignment portion An alignment film having at least one second alignment portion that is rubbed in a second direction opposite to the first direction and overlapping in parallel with the first direction;
Provided on the counter substrate, at least one third alignment portion that is rubbed in the second direction overlapping the at least one first alignment portion, and rubbed in the first direction overlapping the at least one second alignment portion. Another alignment film having at least one fourth alignment portion formed for each of the pixel regions;
A controller that is electrically connected to the array substrate and the counter substrate, adjusts the voltage applied between the array substrate and the counter substrate, and controls the alignment state of the plurality of liquid crystal molecules;
A first optical film provided on the outer surface side of the array substrate;
A second optical film provided on the outer surface side of the counter substrate,
The dielectric anisotropy of the liquid crystal material of the liquid crystal layer is positive,
A value Δnd obtained by multiplying the thickness d of the liquid crystal layer by the refractive index anisotropy Δn of the liquid crystal material of the liquid crystal layer is 240 nm or less for light having a wavelength of 550 nm.

  According to the present invention, a liquid crystal display panel excellent in display quality can be provided.

Hereinafter, a liquid crystal display panel according to a first embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 1 to 5, the liquid crystal display panel is sandwiched between the array substrate 1, the counter substrate 2 disposed opposite to the array substrate with a predetermined gap, and the array substrate and the counter substrate. A liquid crystal layer 3, a color filter 4, a first optical film 5, a second optical film 6, and a control unit 7 are provided. The display mode of the liquid crystal display panel is the MVA mode.

  The liquid crystal display panel has a rectangular display region R1 that overlaps the array substrate 1 and the counter substrate 2. The liquid crystal display panel has a plurality of pixel regions R2 provided in a matrix in the display region R1. The plurality of pixel regions R2 are parallel to the planes of the array substrate 1 and the counter substrate 2, and are parallel to the first direction d1 and the second direction d2 pointing opposite to each other, and to the first direction d1 and the second direction. They are arranged in a third direction d3 orthogonal to the direction d2. Each pixel region R2 has a plurality of divided regions R3 arranged side by side.

  The array substrate 1 is an active matrix substrate. The array substrate 1 has a rectangular glass substrate 10 as a transparent insulating substrate. A plurality of signal lines 11 extending on the glass substrate 10 in the third direction d3 and arranged at intervals in the first direction d1, and extending in the first direction d1 intersecting the plurality of signal lines. A plurality of scanning lines 12 arranged at intervals in the third direction d3 are arranged in a lattice pattern.

  The signal line 11 and the scanning line 12 are formed of a material such as aluminum, molybdenum, or copper as a conductive material. Each pixel region R2 is provided so as to overlap an area surrounded by two adjacent signal lines 11 and two adjacent scanning lines 12.

  On the glass substrate 10, for example, a plurality of TFTs (thin film transistors) 13 are provided as a plurality of switching elements near the intersection of the signal lines 11 and the scanning lines 12. The TFT 13 includes a gate electrode 13a extending a part of the scanning line 12, a gate insulating film 13b provided on the gate electrode, a channel layer 13c facing the gate electrode through the gate insulating film, and a channel layer A source electrode 13d connected to one region and a drain electrode 13e connected to the other region of the channel layer are included.

  The source electrode 13d is connected to the signal line 11, and the drain electrode 13e is connected to a pixel electrode 15 described later. The TFT 13 is formed of a common gate insulating film 13b. The channel layer 13c is formed of amorphous silicon or polysilicon as a semiconductor material. The gate electrode 13a, the source electrode 13d, and the drain electrode 13e are formed of a metal material such as aluminum, molybdenum, chromium, copper, and tantalum as a conductive material. One TFT 13 is provided in the pixel region R2 to form a pixel.

  In the display region R1, the color filter 4 is formed on the glass substrate 10, the signal line 11, the scanning line 12, and the TFT 13. The color filter 4 has a plurality of red colored layers 4R, a plurality of green colored layers 4G, and a plurality of blue colored layers 4B.

  The colored layers 4R, 4G, and 4B are each formed in a stripe shape and extend in the third direction d3. The colored layers 4R, 4G, and 4B are alternately arranged adjacent to each other in the first direction d1. Each of the colored layers 4R, 4G, and 4B is formed by overlapping the peripheral edge with the signal line 11. A plurality of contact holes 4h are formed in the colored layers 4R, 4G, and 4B. One contact hole 4h is formed in the pixel region R2.

  Here, a rectangular frame-shaped light shielding layer 14 is formed on the glass substrate 10 outside the display region R1. The light shielding layer 14 surrounds the outer periphery of the color filter 4. The light shielding layer 14 contributes to shielding light leaking from the peripheral edge of the display region R1.

  A plurality of pixel electrodes 15 are provided in a matrix on the color filter 4. The pixel electrode 15 is formed of a transparent conductive material such as ITO (indium tin oxide). The pixel electrode 15 is formed in a rectangular shape.

  Each pixel electrode 15 is electrically connected to the drain electrode 13e of the corresponding TFT 13 through a contact hole 4h formed in the color filter 4. One pixel electrode 15 is formed in each pixel region R2 to form a pixel.

  A plurality of missing portions 15 a are formed in the pixel electrode 15. The plurality of missing portions 15a are parallel to the plane and extend in a fourth direction d4 and a fifth direction d5 that are inclined by 45 ° from the first direction d1 and the third direction d3. The fourth direction d4 and the fifth direction d5 are orthogonal to each other. The missing part 15a demarcates the divided region R3.

  The missing part 15a has a function of controlling the alignment state (inclining direction) of the liquid crystal molecules 3m of the liquid crystal layer 3 near the missing part. The above function is exhibited by adjusting the voltage applied between the pixel electrode 15 and the common electrode 21.

  A plurality of columnar spacers 16 are formed on the pixel electrode 15 as a plurality of spacers. The spacer is not limited to the columnar spacer 16 and may be another spacer such as a spherical spacer. An alignment film 17 is formed on the color filter 4 and the pixel electrode 15. In this embodiment, the alignment film 17 is a vertical alignment film.

  The counter substrate 2 has a rectangular glass substrate 20 as a transparent insulating substrate. A common electrode 21 is formed on the glass substrate 20 in the display region R1. The common electrode 21 is formed of a transparent conductive material such as ITO. A plurality of protrusions 22 are formed on the common electrode 21.

  The plurality of protrusions 22 protrude from the surface of the common electrode 21 to the array substrate 1 side. The plurality of protrusions 22 are formed in stripes, and convex portions having a substantially triangular cross section are formed extending in the fourth direction d4 and the fifth direction d5. The height of the protrusion 22 is 1 μm. The protrusions 22 are arranged at intervals in the fourth direction d4 and the fifth direction d5. The protrusions 22 overlap the pixel electrode 15 and are provided between the missing portions 15a adjacent in the fourth direction d4 and between the missing portions 15a adjacent in the fifth direction d5. The protrusion 22 divides the divided region R3 together with the missing portion 15a of the pixel electrode 15. The protrusion 22 and the missing part 15a form an orientation control part.

  The protrusion 22 has a function of controlling the alignment state (inclining direction) of the liquid crystal molecules 3m of the liquid crystal layer 3 near the protrusion. The above function is exhibited by applying a voltage between the pixel electrode 15 and the common electrode 21.

  An alignment film 23 is formed on the common electrode 21 and the protrusion 22. In this embodiment, the alignment film 23 is a vertical alignment film. For this reason, as shown in FIGS. 3 and 6, in a state where no voltage is applied between the pixel electrode 15 and the common electrode 21, the alignment film 23, together with the alignment film 17, causes the liquid crystal molecules 3m to be perpendicular to the plane. In the sixth direction d6.

  As shown in FIGS. 1 to 5, the array substrate 1 and the counter substrate 2 are arranged to face each other with a predetermined gap by a plurality of columnar spacers 16. The array substrate 1 and the counter substrate 2 are joined to each other by a sealing material 31 disposed outside the display region R1.

  The liquid crystal layer 3 is sandwiched between the array substrate 1 and the counter substrate 2. A liquid crystal injection port 32 is formed in a part of the sealing material 31, and the liquid crystal injection port is sealed with a sealing material 33. The liquid crystal layer 3 is made of a liquid crystal material having a positive dielectric anisotropy Δε. The liquid crystal layer 3 is a vertical alignment type.

  The liquid crystal layer 3 includes a first state in which a plurality of liquid crystal molecules 3m are aligned in the sixth direction d6 and a plurality of liquid crystal molecules 3m in each divided region R3 depending on the presence or absence of a voltage applied between the pixel electrode 15 and the common electrode 21. Any one of the second alignment states that are aligned in the same direction and aligned in a plurality of directions for each pixel region R2 is adopted. In this embodiment, a voltage is not applied between the pixel electrode 15 and the common electrode 21 to enter the first state, and a voltage is applied between the pixel electrode 15 and the common electrode 21 to enter the second state.

  In this embodiment, the dielectric anisotropy Δε of the liquid crystal material of the liquid crystal layer 3 is 4.6. A value Δnd obtained by multiplying the thickness d of the liquid crystal layer 3 by the refractive index anisotropy Δn of the liquid crystal material of the liquid crystal layer is 240 nm with respect to light having a wavelength of 550 nm. More specifically, the thickness d is 2.9 μm and the refractive index anisotropy Δn is 0.083.

  The first optical film 5 is provided on the outer surface side of the array substrate 1. More specifically, the first optical film 5 is disposed on the outer surface of the glass substrate 10. The second optical film 6 is provided on the outer surface side of the counter substrate 2. More specifically, the second optical film 6 is disposed on the outer surface of the glass substrate 20.

  In this embodiment, the first optical film 5 is formed of a polarizing plate 5a facing the outer surface of the glass substrate 10 and a retardation plate 5b positioned between the glass substrate 10 and the polarizing plate 5a. The polarizing plate 5a has an absorption axis a1 in the first direction d1. The phase difference plate 5b has a slow axis a2 in the third direction d3.

  The second optical film 6 is formed of a polarizing plate 6a facing the outer surface of the glass substrate 20, and a retardation plate 6b positioned between the glass substrate 20 and the polarizing plate. The polarizing plate 6a has an absorption axis a1 in the third direction d3. The phase difference plate 6b has a slow axis a2 in the first direction d1.

  The control unit 7 is electrically connected to the array substrate 1 and the counter substrate 2. More specifically, the control unit 7 is electrically connected to the plurality of pixel electrodes 15 and the common electrode 21. The controller 7 adjusts the voltage applied between the plurality of pixel electrodes 15 and the common electrode 21 to control the alignment state of the plurality of liquid crystal molecules 3m.

As shown in FIGS. 3, 5, and 7, in a state where a voltage is applied between the pixel electrode 15 and the common electrode 21, the missing portion 15 a and the protrusion 22 cause the plurality of liquid crystal molecules 3 m to move in the fourth direction d 4 and the fourth direction. Oriented in five directions d5. Here, the average value of the inclination angles of the plurality of liquid crystal molecules 3m is 20 ° or less with respect to the plane.
As described above, the MVA mode liquid crystal display panel is completed.

Next, the first optical film 5 and the second optical film 6 will be described in detail.
As shown in FIG. 2, FIG. 3, and FIG. 8, here, the phase difference plate 5b includes an x-axis parallel to the third direction d3, a y-axis parallel to the first direction d1 and the second direction d2, A z-axis parallel to the six directions d6. The phase difference plate 6b has an x-axis parallel to the first direction d1 and the second direction d2, a y-axis parallel to the third direction d3, and a z-axis parallel to the sixth direction d6.

  The phase difference plate 5b and the phase difference plate 6b are each formed by laminating two films. Each film is a liquid crystal material, for example, a discotic liquid crystal polymerized and hybridly arranged. In this embodiment, each film is formed using WVF manufactured by Fuji Film Co., Ltd. The plurality of liquid crystal molecules of the liquid crystal material is a polymer.

Retardation plate 5b, in 6b, the refractive index of the x-axis direction _n x, the refractive index in the y-axis direction _n y, the refractive index of the z-axis direction and _{n z.} The refractive index ellipsoid of the liquid crystal molecules of each of the phase difference plates 5b and 6b has a disk shape ( _nx = _ny > _nz ).

Due to the hybrid alignment, the tilt angle of the liquid crystal molecules continuously changes in the z-axis direction. In each phase difference plate, the direction in which the liquid crystal molecules of one film incline and the direction in which the liquid crystal molecules of the other film incline are parallel to the x-axis direction, and are opposite to each other in the x-axis direction. Therefore, according to the average tilt angle of the liquid crystal molecules, the anisotropy of the mean refractive index of the entire film becomes n _x> n _y. Further, if less 45 ° Average inclination angle of the liquid crystal molecules relative to the film plane (the plane), retardation plate 5b, a total of _{n x> n y> n z,} respectively 6b is realized.

For every two laminated films, there are a pair of liquid crystal molecules whose inclination angle is positive with respect to the film plane and liquid crystal molecules whose negative value is negative. Therefore, the total refractive index ellipsoid of the two films is not inclined with respect to the film plane. For this reason, the two films are biaxially stretched and have a function equivalent to that of a film in which the refractive index ellipsoid is _nx > _ny > _nz (for example, a biaxial arton film manufactured by JSR Corporation). Have. The two films become a retardation plate having a slow axis in the x-axis direction in total.

The phase difference plate 5b and the phase difference plate 6b are arranged such that these slow axes a2 are orthogonal to each other. Therefore, the phase difference plate 5b and the retarder 6b the average refractive index of the total anisotropy (refractive index ellipsoid IEa) is _n x _{= n} y> _{n z} next retardation plate 5b and the retarder 6b is Functions as a negative uniaxial flum in total.

  Therefore, as shown in FIGS. 6 and 11, the liquid crystal layer 3 and the retardation plate are in a state where the liquid crystal molecules 3m are aligned in the sixth direction d6, that is, the state where the liquid crystal layer 3 can be regarded as a positive uniaxial film. 5b and 6b compensate for each refractive index anisotropy. From the above, the problem of the viewing angle dependency of the black display state is solved.

  The phase difference plate 5b and the polarizing plate 5a are disposed so that the slow axis a2 and the absorption axis a1 are orthogonal to each other. The retardation plate 6b and the polarizing plate 6a are arranged so that the slow axis a2 and the absorption axis a1 are orthogonal to each other. Thereby, the phase difference plates 5b and 6b can also compensate the viewing angle dependency of the polarizing plates 5a and 6a. The effect described above can also be obtained when the polarizing plates 5a and 6a are arranged so that the absorption axes a1 are parallel to each other.

  Needless to say, the effect of eliminating the viewing angle dependency problem in the black display state can be obtained if the liquid crystal molecules 3m are aligned in the sixth direction d6, and a voltage is applied to the liquid crystal layer 3. Even if it is in a state, it may be in a state where it is not applied.

Here, as shown in FIGS. 8 to 12, the refractive index ellipsoid IEb is a refractive index ellipsoid of the liquid crystal molecules 3m, and the refractive index ellipsoid IEc is the entire refractive index ellipsoid IEa and refractive index ellipsoid IEb. It is a refractive index ellipsoid. Refractive index anisotropy of the liquid crystal molecules 3m becomes _{n a = n b <n c} .

Next, the phase difference plates 5b and 6b and the liquid crystal layer 3 will be described in detail.
In the MVA mode, which is a liquid crystal display mode, white display in the configuration in which the liquid crystal layer 3 is disposed between the reverse polar circular polarizers, in the case of white display in the case of the halftone and orthogonal polarizer configuration, in the black display of the parallel polarizer configuration Liquid crystal molecules (nematic liquid crystal molecules) whose inclination angle is a positive value with respect to the liquid crystal layer plane, and a negative value at the time of black display when the liquid crystal layer 3 is arranged between the circular polar polarizers of the same polarity Liquid crystal molecules (nematic liquid crystal molecules) exist in pairs, and the tilt angles of these liquid crystal molecules continuously change in the sixth direction d6.

  Here, in the liquid crystal display mode, an electric field is applied to the liquid crystal layer 3 in the sixth direction d6 to control the phase difference and optical rotation of the liquid crystal layer. As the liquid crystal display mode, the same applies to the TN mode, VA mode, homogeneous mode, hybrid aligned mode, optical compensated bend mode, and STN mode.

  The phase difference plate and the liquid crystal layer so that the inclination angle and the phase difference amount of the liquid crystal molecules of the phase difference plates 5b and 6b cancel each other and the inclination angle and the phase difference amount of the liquid crystal molecules 3m of the liquid crystal layer 3. Form. As a result, when white is displayed in the case of halftone and crossed polarizing plates, when black is displayed in the case of parallel polarizing plates, when white is displayed in the case where the liquid crystal layer 3 is arranged between the reverse polarity circularly polarizing plates, and the same polarity circle The viewing angle dependency of the entire liquid crystal display panel during black display in the configuration in which the liquid crystal layer 3 is disposed between the polarizing plates is compensated.

Next, the relationship between the phase difference plates 5b and 6b and the liquid crystal layer 3 will be described.
In this embodiment, the phase difference plate 5b, the thickness of 6b and t, the value of the phase difference of the phase difference _{plate, (n x -n y) t} = 50nm, (n x -n z) t = 120nm It is. This is a design value when Δnd is 290 nm.

The MVA mode is an ECB (Electrically Controlled Birefringence) mode that controls the electric field of the phase difference of the liquid crystal layer 3, and the polarizing plates 5a and 6a are arranged in a crossed Nicols arrangement. In this case, the parallel transmittance of the polarizing plate is I ₀ , the angle between the slow axis of the liquid crystal layer 3 and the optical axis of the polarizing plate is θ, the voltage applied to the liquid crystal layer is V, the layer thickness of the liquid crystal layer is d, and incident When the light wavelength is λ, the transmittance T (LC) of the liquid crystal layer 3 is expressed by the following equation.

In the above formula, the refractive index anisotropy Δn (λ, V) depends on the effective applied voltage in the region and the tilt angle of each of the liquid crystal molecules 3m. In order to change the transmittance T (LC) from 0 to I ₀ , it is necessary to change Δn (λ, V) · d / λ in the range of 0 to λ / 2. In the case of the MVA mode, the liquid crystal molecules 3m in the vicinity of the alignment films 17 and 23 hardly tilt even when a voltage is applied. Therefore, in order to set the range of Δn (λ, V) · d / λ to 0 to λ / 2, Δnd is a value sufficiently larger than half of the wavelength of 550 nm with high visibility, specifically 270 nm or more. It is necessary to. However, if Δnd is too large, the electro-optical characteristics become too steep, so the upper limit of Δnd is about 350 nm.

  The liquid crystal molecules 3m of the liquid crystal layer 3 having Δnd in the above range are in a substantially vertical state, and in order to compensate for the positive phase difference of the liquid crystal layer 3, a negative phase difference of −350 nm to −270 nm is required.

  Here, each of the polarizing plates 5a and 6a uses a TAC (tri-acetyl-cellulose) film as a base film. Each TAC film has a substantially uniaxial negative retardation, and generally has a negative retardation of -70 nm. Since two TAC films exist between the two polarizing plates 5a and 6a, a negative retardation layer of −140 nm exists between the two polarizing plates.

Therefore, in order to compensate for the positive retardation of the liquid crystal layer 3 in which the liquid crystal molecules 3m are substantially vertical, it is necessary to separately provide a negative retardation plate of −280 nm to −200 nm between the polarizing plates 5a and 6a. Retardation plate 5b the phase difference of the liquid crystal layer 3, to compensate for the 6b, the phase difference plate 5b, 6b of the orthogonal arrangement, each retardation plate 5b, is _(n x _-n z) t of 6b, 100 nm ≦ ( n _x -n _z) may if they meet the t ≦ 140nm. At the same time, polarizing plates 5a, to compensate the viewing angle dependence of 6a _may satisfy the _{(n x -n z) t- (} n x -n y) t = 70nm. _Therefore, (n x _-n y) t may be any _{30nm ≦ (n x -n y)} t ≦ 70nm.

Next, the case where the alignment state of the liquid crystal layer 3 is in the first state and the case in the second state will be described.
As shown in FIGS. 2, 6, 8, 9, and 11, in the first state, as described above, the plurality of liquid crystal molecules 3m are aligned in a direction perpendicular to the plane. In the liquid crystal layer 3, the retardation is increased in the vertical direction. In the entire phase difference plates 5b and 6b, the phase difference increases in the horizontal direction. In the entire liquid crystal layer 3 and the phase difference plates 5b and 6b, the phase difference is 0 and constant.

  Since the refractive index anisotropy of the liquid crystal layer 3 and the retardation plates 5b and 6b are compensated for each other, even when the display screen of the liquid crystal display panel is viewed from the vertical direction (sixth direction d6), the horizontal direction (sixth direction d6) The black display was good even when viewed from the direction inclined from the side. It can be seen that, in the first state, the problem of the viewing angle dependency of the black display state can be solved.

  As shown in FIGS. 2, 5, 7, 8, 10 and 12, in the second state, the plurality of liquid crystal molecules 3m are in the same direction (parallel to the fourth direction d4 and opposite to each other) for each divided region R3. It is oriented in any one of four directions (two directions that are parallel to the two directions and the fifth direction d5 and opposite to each other) and is oriented in a plurality of directions (the above four directions) for each pixel region R2. . For this reason, the number of alignment divisions is 4 in the second state. The average value of the inclination angles of the plurality of liquid crystal molecules 3m is 20 ° or less with respect to the plane. In the liquid crystal layer 3, the retardation is constant. In the liquid crystal layer 3 and the retardation films 5b and 6b as a whole, the retardation is substantially constant although it slightly decreases in the horizontal direction.

In the pixel region R2, the angle formed by the four directions is 90 °. Further, the polarizing plates 5a and 6a are arranged so that the four directions (direction in which the liquid crystal molecules 3m are inclined) and the angle formed by the absorption axes a1 of the polarizing plates 5a and 6a are 45 °. Thereby, the transmittance T (LC) of the liquid crystal layer 3 can be changed from ₀ to I ₀ .

  Here, as a result of investigation by the inventor of the present application, as shown in FIGS. 13 and 14, in the second state, Δnd is 240 nm, and the voltage applied to the liquid crystal layer 3 (between the pixel electrode 15 and the common electrode 21) is 56. It can be seen that it can be realized by setting it to / Δε [V] or more. In this embodiment, since Δε is 4.6, a voltage of about 12.2 [V] or more may be applied to the liquid crystal layer 3. In this embodiment, a voltage of 15 [V] is applied to the liquid crystal layer 3. The V (voltage) -T (transmittance) characteristic (R) of the red pixel region R2, the VT characteristic (G) of the green pixel region, and the VT characteristic (B) of the blue pixel region are shown in the figure. Street.

  Note that the second state may be realized by applying a voltage of −12.2 [V] or less to the liquid crystal layer 3. Therefore, the second state can be realized if the absolute value of the voltage applied to the liquid crystal layer 3 is equal to or greater than | 56 / Δε | [V].

  As described above, by applying a voltage to the liquid crystal layer 3, the plurality of liquid crystal molecules 3 m can be laid down, and the average value of the inclination angles of the plurality of liquid crystal molecules 3 m is 20 ° with respect to the plane of the liquid crystal layer 3. It can be as follows.

Here, the inventor of the present application investigated various display characteristics in the second state.
As shown in FIG. 15, it can be seen that the color reproduction range is wide at a wide viewing angle. Thereby, favorable white display (image display) can be performed at a wide viewing angle. Further, as shown in FIGS. 16 and 17, it can be seen that a high contrast ratio is obtained at a wide viewing angle.

  As shown in FIG. 18, when a total of eight types of voltages from 0 [V] to 15 [V] (in white display) are applied to the liquid crystal layer 3, the transmittance is in the horizontal direction (first It was almost uniform in the first direction d1 and the second direction d2). In particular, the transmittance was almost unchanged in the range of the viewing angle from 0 ° to 50 ° in the left-right direction.

  As described above, since the liquid crystal display panel suppresses the variation in the transmittance with respect to the viewing angle, the liquid crystal display panel is superior in luminance viewing angle characteristics to the conventional MVA mode liquid crystal display panel.

As shown in FIG. 19, the transmittance shown in FIG. 18 was converted into a relative luminance L ^* . When a total of eight kinds of voltages from 0 [V] to 15 [V] (in white display) are applied to the liquid crystal layer 3, the relative luminance L ^* is the left-right direction (the first direction d1 and the first direction) as shown in the figure. It was almost uniform in the two directions d2). In the halftone, ΔL ^* is less than 10%.

  As described above, since the liquid crystal display panel suppresses the variation in luminance with respect to the viewing angle, when the display screen is viewed from an oblique direction during multicolor display, the liquid crystal display panel is displayed on the display screen with the conventional MVA mode liquid crystal display panel. The phenomenon of whitening that has occurred can be eliminated. It can also be seen that the liquid crystal display panel is excellent in halftone viewing angle characteristics.

  According to the liquid crystal display panel configured as described above, the liquid crystal layer 3 takes one of the alignment states of the first state and the second state, and Δnd is 240 nm with respect to light having a wavelength of 550 nm. For this reason, a state in which white display is obtained is obtained by an arrangement in which liquid crystal molecules are aligned substantially horizontally over the entire thickness direction of the liquid crystal layer. Therefore, as in the IPS system, white display has a wide viewing angle regardless of the viewing angle compensation means for black display.

  A first optical film 5 is provided on the outer surface side of the array substrate 1, and a second optical film 6 is provided on the outer surface side of the counter substrate 2. The first optical film 5 is formed of a polarizing plate 5a and a retardation plate 5b. The second optical film 6 is formed of a polarizing plate 6a and a retardation plate 6b. For this reason, a wide viewing angle characteristic is obtained for black display, and as a result, a wide viewing angle characteristic is obtained for both black display and white display.

  In the case of white display, the absolute value of the voltage applied to the liquid crystal layer 3 is | 56 / Δε | [V] or more, and the average value of the inclination angles of the plurality of liquid crystal molecules 3m is 20 ° or less with respect to the plane. It is. Thereby, in a wide viewing angle, it is excellent in color reproducibility, a high contrast can be obtained, variation in transmittance can be suppressed, and thus variation in luminance level can be suppressed. For this reason, good white display becomes possible.

  The missing part 15a and the protrusion 22 form an orientation control part. Therefore, the alignment of the plurality of liquid crystal molecules 3m can be controlled so that the missing portion 15a and the protrusion 22 are in the alignment state of either the first state or the second state under the control of the control unit 7. .

In addition, by forming the liquid crystal display panel as described above, it is possible to improve the luminance viewing angle characteristics during white display without using an independent γ correction or a multi-gap structure technique.
As described above, a liquid crystal display panel excellent in display quality can be obtained.

Next, a liquid crystal display panel according to a second embodiment of the present invention will be described in detail.
The liquid crystal display panel includes an array substrate 1, a counter substrate 2, a liquid crystal layer 3, a color filter 4, a first optical film 5, a second optical film 6, and a control unit 7. The display mode of the liquid crystal display panel is the MVA mode. As in the first embodiment, the liquid crystal layer 3 takes one of the alignment states of the first state and the second state, and Δnd is 240 nm with respect to light having a wavelength of 550 nm.

  As shown in FIGS. 20, 21, and 22, the missing portion 15 a is not formed in the pixel electrode 15. Further, the protrusion 22 is not formed on the counter substrate 2. In this embodiment, the alignment film 17 and the alignment film 23 form an alignment control unit.

  The alignment film 17 overlaps at least one divided region R3, overlaps at least one first alignment portion 17a rubbed in the first direction d1, and overlaps at least one divided region R3 out of the first alignment portion. Each pixel region R2 has at least one second alignment portion 17b rubbed in the direction d2.

  The alignment film 23 overlaps at least one first alignment portion 17a and overlaps at least one third alignment portion 23a rubbed in the second direction d2 and at least one second alignment portion 17b and rubs in the first direction d1. The at least one fourth alignment portion 23b is provided for each pixel region R2.

  In this embodiment, the alignment film 17 includes one first alignment portion 17a that overlaps one division region R3 and one second alignment portion 17b that overlaps one division region R3 for each pixel region R2. Have. The alignment film 23 has, for each pixel region R2, one third alignment portion 23a that overlaps one first alignment portion 17a and one fourth alignment portion 23b that overlaps one second alignment portion 17b. is doing.

  When the alignment film 17 is rubbed, the first alignment portion 17a and the second alignment portion 17b are rubbed using a mask rubbing method. Similarly, when the alignment film 23 is rubbed, the third alignment portion 23a and the fourth alignment portion 23b are rubbed using a mask rubbing method.

  By the rubbing, each pixel region R2 has two divided regions R3 obtained by dividing the pixel region into two equal parts in the first direction d1. In the second state, the plurality of liquid crystal molecules 3m are inclined in a direction that is symmetric with respect to the boundary of the divided region R3. Accordingly, the liquid crystal molecules 3m between the adjacent divided regions R3 are inclined with the angle formed between them being 180 °. For this reason, the number of orientation divisions is 2 in the second state.

If the polarizing plates 5a and 6a are arranged so that the direction in which the liquid crystal molecules 3m are inclined and the angle between the absorption axes a1 of the polarizing plates 5a and 6a are 45 °, the transmittance T (LC) of the liquid crystal layer 3 is obtained. Can be changed from ₀ to I ₀ .

  In this embodiment, other configurations are the same as those of the above-described embodiment, and the same portions are denoted by the same reference numerals and detailed description thereof is omitted.

  Here, as a result of investigation by the inventor of the present application, as shown in FIGS. 13 and 14, in the second state, as in the first embodiment, Δnd is 240 nm and the liquid crystal layer 3 (the pixel electrode 15 and the common) It can be seen that this can be realized by setting the voltage applied between the electrodes 21) to 56 / Δε [V] or more. In this embodiment, a voltage of 15 [V] is applied to the liquid crystal layer 3. The V (voltage) -T (transmittance) characteristic (R) of the red pixel region R2, the VT characteristic (G) of the green pixel region, and the VT characteristic (B) of the blue pixel region are as described above. As in the first embodiment, it is as shown in the figure.

  As described above, by applying a voltage to the liquid crystal layer 3, the plurality of liquid crystal molecules 3 m can be laid down, and the average value of the inclination angles of the plurality of liquid crystal molecules 3 m is 20 ° with respect to the plane of the liquid crystal layer 3. It can be as follows.

Here, the inventor of the present application investigated various display characteristics in the second state.
As in the first embodiment, as shown in FIG. 15, it can be seen that the color reproduction range is wide at a wide viewing angle. Thereby, a favorable white display can be performed in a wide viewing angle. Further, as in the first embodiment, as shown in FIGS. 16 and 17, it can be seen that a high contrast ratio is obtained at a wide viewing angle.

As in the first embodiment, it can be seen that the transmittance characteristics shown in FIG. 18 are obtained.
As described above, since the liquid crystal display panel suppresses the variation in the transmittance with respect to the viewing angle, when the display screen is viewed obliquely during multicolor display, the display screen is a conventional MVA mode liquid crystal display panel. It is possible to eliminate the phenomenon of whitening that has occurred in the past.

As with the first embodiment, it can be seen that the luminance characteristics shown in FIG. 19 are obtained.
From the above, since the liquid crystal display panel suppresses the variation in luminance with respect to the viewing angle, the liquid crystal display panel has excellent viewing angle characteristics as well as the conventional MVA mode liquid crystal display panel.

  According to the liquid crystal display panel configured as described above, the liquid crystal layer 3 takes one of the alignment states of the first state and the second state, and Δnd is 240 nm with respect to light having a wavelength of 550 nm. The first optical film 5 is formed of a polarizing plate 5a and a retardation plate 5b. The second optical film 6 is formed of a polarizing plate 6a and a retardation plate 6b.

  In the case of white display, the absolute value of the voltage applied to the liquid crystal layer 3 is | 56 / Δε | [V] or more, and the average value of the inclination angles of the plurality of liquid crystal molecules 3m is 20 with respect to the plane. ° or less. For this reason, the liquid crystal display panel of this embodiment can obtain the same effects as those of the first embodiment described above.

  The alignment film 17 and the alignment film 23 form an alignment control unit. Therefore, under the control of the control unit 7, the alignment film 17 and the alignment film 23 can control the alignment of the plurality of liquid crystal molecules 3m so as to be in either the first state or the second state. it can.

Each pixel region R2 has two divided regions R3, and the number of orientation divisions is two. Therefore, the liquid crystal display panel of this embodiment can eliminate a substantial decrease in aperture ratio due to the number of alignment divisions as compared with the liquid crystal display panel of the first embodiment. In addition, the liquid crystal display panel of this embodiment can have an absolute luminance higher than that of the first embodiment. By forming a liquid crystal display panel as described above, even if the number of alignment divisions is 2, gradation inversion does not occur in an oblique direction, and excellent viewing angle characteristics can be obtained.
As described above, a liquid crystal display panel excellent in display quality can be obtained.

Next, a comparative example of the liquid crystal display panel of the present invention will be described.
(Comparative Example 1)
In Comparative Example 1, the liquid crystal layer 3 takes one of the alignment states of the first state and the second state, and Δnd is 320 nm with respect to light having a wavelength of 550 nm. In the case of white display, the absolute value of the voltage applied to the liquid crystal layer 3 is 4.7 [V], and the average value of the inclination angles of the plurality of liquid crystal molecules 3m is 20 ° or more with respect to the plane.

  The liquid crystal display panel of Comparative Example 1 has an alignment division number of 4 as in the liquid crystal display panel of the first embodiment. In Comparative Example 1, other configurations are the same as those of the first embodiment described above, and detailed description of the same portions is omitted.

Next, the case where the alignment state of the liquid crystal layer 3 is in the first state and the case in the second state will be described.
As in the first embodiment described above, as shown in FIGS. 9 and 11, in the first state, as described above, the plurality of liquid crystal molecules 3m are aligned in a direction perpendicular to the plane. For this reason, it can be seen that, similarly to the first embodiment, the problem of the viewing angle dependency in the black display state can be solved in the first state.

  As shown in FIGS. 23, 24, 25 and 26, in the second state, the average value of the inclination angles of the plurality of liquid crystal molecules 3m is 20 ° or more with respect to the plane. In the halftone, the phase difference in the vertical direction slightly increases in the liquid crystal layer 3. In the entire liquid crystal layer 3 and the phase difference plates 5b and 6b, the phase difference is substantially constant although it slightly decreases in the horizontal direction. Since the liquid crystal layer 3 and the retardation plates 5b and 6b do not completely compensate for the anisotropy of their respective refractive indexes, the display image is gray.

  In white display, the liquid crystal layer 3 has a constant phase difference in the vertical direction. This is because the pixel regions R2 and the divided regions R3 compensate each other. In the entire liquid crystal layer 3 and the retardation plates 5b and 6b, the retardation is reduced in the horizontal direction. For this reason, gradation inversion occurs in an oblique direction.

  Here, as a result of investigation by the inventor of the present application, as shown in FIG. 27, in the second state, Δnd is 320 nm, and the voltage applied to the liquid crystal layer 3 (between the pixel electrode 15 and the common electrode 21) is 4.7 [ V]. As described above, the liquid crystal molecules 3m cannot be laid down in the second state. Further, when the applied voltage is 4.7 [V], the transmittance of the blue pixel region R2 exceeds the peak.

  The VT characteristics (R) of the red pixel area R2, the VT characteristics (G) of the green pixel area, and the VT characteristics (B) of the blue pixel area are as shown in the figure.

Further, the inventor of the present application investigated various display characteristics in the second state.
As shown in FIG. 28, the contrast is 10 or more in all directions. It can be seen that high contrast is obtained at a wide viewing angle. For this reason, the liquid crystal display panel of Comparative Example 1 is excellent in viewing angle characteristics as in the first embodiment.

  As shown in FIGS. 29, 30 and 31, the liquid crystal layer 3 has 4.700 [V], 4.200 [V], 3.900 [V], 3.500 [V], 3.200 [V], A total of eight voltages of 3.100 [V], 2.900 [V], and 0.000 [V] were applied to measure the luminance. The luminance is as shown in the figure.

  In the front direction (0 °) of the display screen, the brightness of the eight gradations of the liquid crystal display panel is equally divided, but the left and right directions (first and second directions d1, d2) and diagonal directions (first 4, in the fifth direction d4, d5) and in the up-down direction (third direction d3), the brightness L of the eight gradations of the liquid crystal display panel is divided unevenly and is much lower than the front direction.

  As shown in FIG. 32, a total of six kinds of voltages were applied to the liquid crystal layer 3 to measure the luminance. The luminance is as shown in the figure. Similarly to the luminance characteristics shown in FIGS. 29 to 31, the luminance in the direction inclined from the front direction is much lower than that in the front direction.

  From the above, since the liquid crystal display panel of Comparative Example 1 has a variation in luminance with respect to the viewing angle, the luminance viewing angle characteristic is inferior to that of the liquid crystal display panel of the first embodiment.

As shown in FIG. 33, the luminance shown in FIG. 32 was normalized. The normalized luminance (relative luminance) L ^* is as shown in the figure. In the direction inclined from the front direction of the display screen, the brightness is much higher than that in the front direction.

  As described above, the liquid crystal display panel of Comparative Example 1 cannot suppress the variation in luminance with respect to the viewing angle, and when the display screen is viewed from an oblique direction during multicolor display, a phenomenon in which the display screen is faded occurs. That is, the liquid crystal display panel of Comparative Example 1 is inferior in luminance viewing angle characteristics than the liquid crystal display panel of the first embodiment.

(Comparative Example 2)
In Comparative Example 2, the liquid crystal layer 3 takes one of the alignment states of the first state and the second state, and Δnd is 320 nm with respect to light having a wavelength of 550 nm. In the case of white display, the absolute value of the voltage applied to the liquid crystal layer 3 is 4.7 [V], and the average value of the inclination angles of the plurality of liquid crystal molecules 3m is 20 ° or more with respect to the plane.

  The liquid crystal display panel of Comparative Example 2 has an alignment division number of 2 as in the liquid crystal display panel of the second embodiment. In Comparative Example 2, other configurations are the same as those of the second embodiment described above, and detailed description of the same portions is omitted.

Further, the inventor of the present application investigated various display characteristics in the second state.
As shown in FIG. 34, the contrast is 10 or more in all directions. It can be seen that high contrast is obtained at a wide viewing angle. For this reason, the liquid crystal display panel of Comparative Example 2 is excellent in viewing angle characteristics as in the second embodiment.

  As shown in FIGS. 35, 36, and 37, the liquid crystal layer 3 has 4.700 [V], 4.200 [V], 3.900 [V], 3.500 [V], 3.200 [V], A total of eight voltages of 3.100 [V], 2.900 [V], and 0.000 [V] were applied to measure the luminance. The luminance is as shown in the figure.

  In the front direction (0 °) of the display screen, the brightness of the eight gradations of the liquid crystal display panel is equally divided, but the left and right directions (first and second directions d1, d2) and diagonal directions (first 4, in the fifth direction d4, d5) and in the up-down direction (third direction d3), the brightness L of the eight gradations of the liquid crystal display panel is divided unevenly and is much lower than the front direction.

  In addition, the liquid crystal display panel of Comparative Example 2 obtained the luminance viewing angle characteristics shown in FIGS. 32 and 33, as with the liquid crystal display panel of Comparative Example 1. For this reason, the liquid crystal display panel of Comparative Example 2 is inferior in luminance viewing angle characteristics to the liquid crystal display panel of the second embodiment.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  The Δnd is 240 nm with respect to light having a wavelength of 550 nm. However, the present invention is not limited thereto, and the above-described effects can be obtained as long as Δnd is 240 nm or less with respect to light having a wavelength of 550 nm. The pixel region R2 only needs to have a plurality of divided regions R3. The value of the dielectric anisotropy Δε may be negative. When no voltage is applied to the liquid crystal layer 3, the alignment state of the plurality of liquid crystal molecules 3m is the first state.

  The alignment control unit is formed of at least one of the missing portion 15a, the protrusion 22, and the alignment films 17 and 23, but is not limited to this, and the array substrate 1 and the counter substrate 2 are stacked on the plurality of pixel regions R2. As long as it controls the alignment state of the plurality of liquid crystal molecules 3m. The alignment state of the liquid crystal layer 3 may be a first state when a voltage is applied to the liquid crystal layer, and may be a second state without applying a voltage.

1 is a perspective view of a liquid crystal display panel according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the liquid crystal display panel shown in FIG. 1. FIG. 3 is a cross-sectional view showing a part of the liquid crystal display panel shown in FIGS. 1 and 2. FIG. 4 is a schematic configuration diagram showing a part of the array substrate shown in FIGS. 1 to 3. The top view which shows roughly the structure of the wiring of the said liquid crystal display panel, and a pixel electrode. FIG. 6 is a cross-sectional view of the liquid crystal display panel taken along line AA in FIG. 5, and in particular, a schematic diagram illustrating an alignment state of liquid crystal molecules when no voltage is applied to the liquid crystal layer. FIG. 6 is a cross-sectional view of the liquid crystal display panel taken along line AA in FIG. 5, and in particular, a schematic diagram illustrating an alignment state of liquid crystal molecules when a voltage is applied to the liquid crystal layer. FIG. 4 is a perspective view showing an average refractive index ellipsoid of two retardation plates shown in FIGS. 2 and 3 in total. It is a perspective view which shows the refractive index ellipsoid of the liquid crystal molecule | numerator of the liquid-crystal layer shown in FIG. 3 and FIG. 6, and the figure when the voltage is not applied to a liquid-crystal layer. FIG. 8 is a perspective view showing a refractive index ellipsoid of liquid crystal molecules in the liquid crystal layer shown in FIG. 3 and FIG. 7 when white voltage is displayed by applying a voltage to the liquid crystal layer. The total refractive index ellipsoid of the two retardation plates when the eye point is changed from the vertical direction to the horizontal direction with respect to the display screen of the liquid crystal display panel, the refractive index ellipsoid of the liquid crystal molecules of the liquid crystal layer, and the above 2 It is the figure which showed the change of the refractive index ellipsoid in the whole two refractive index ellipsoids planarly, and is a figure when the voltage is not applied to the liquid crystal layer. The total refractive index ellipsoid of the two retardation plates when the eye point is changed from the vertical direction to the horizontal direction with respect to the display screen of the liquid crystal display panel, the refractive index ellipsoid of the liquid crystal molecules of the liquid crystal layer, and the above 2 It is the figure which showed the change of the refractive index ellipsoid in the whole two refractive index ellipsoids planarly, and is a figure in case the voltage is applied to the liquid crystal layer. The figure which showed the change of the transmittance | permeability with respect to the applied voltage of the said liquid crystal display panel with the graph. The graph which showed the relationship between the dielectric anisotropy and drive voltage for satisfying (DELTA) L * <10% in the relative-luminance characteristic of the said liquid crystal display panel. The omnidirectional total xy chromaticity diagram of the said liquid crystal display panel. FIG. 7 is an ISO contrast curve showing the viewing angle characteristics of the contrast ratio of the liquid crystal display panel shown in FIG. 6. FIG. 8 is an ISO contrast curve showing the viewing angle characteristics of the contrast ratio of the liquid crystal display panel shown in FIG. 7. The figure which showed the change of the transmittance | permeability of 8 gradations with respect to the viewing angle of the said liquid crystal display panel with the graph. The figure which showed the change of the relative luminance of 8 gradations with respect to the viewing angle of the said liquid crystal display panel with the graph. The top view which shows roughly the structure of the wiring of the liquid crystal display panel which concerns on the 2nd Embodiment of this invention, and a pixel electrode. FIG. 21 is a cross-sectional view of the liquid crystal display panel taken along line BB in FIG. 20, and in particular, a schematic diagram illustrating an alignment state of liquid crystal molecules when no voltage is applied to the liquid crystal layer. FIG. 21 is a cross-sectional view of the liquid crystal display panel taken along the line BB in FIG. 20, and in particular, a schematic diagram illustrating an alignment state of liquid crystal molecules when a voltage is applied to the liquid crystal layer. It is a perspective view which shows the refractive index ellipsoid of the liquid crystal molecule | numerator of the liquid crystal layer of the liquid crystal display panel of the comparative example 1 of this invention, and is a figure in case a voltage is applied to a liquid crystal layer and it becomes a halftone display. It is a perspective view which shows the refractive index ellipsoid of the liquid crystal molecule of the liquid-crystal layer of the liquid crystal display panel of the said comparative example 1, and is a figure in case a voltage is applied to a liquid-crystal layer and white display is carried out. The total refractive index ellipsoid of the two retardation plates when the eye point is changed from the vertical direction to the horizontal direction with respect to the display screen of the liquid crystal display panel of Comparative Example 1, and the refractive index ellipse of the liquid crystal molecules in the liquid crystal layer FIG. 6 is a diagram illustrating a plan change of the refractive index ellipsoid in the entire body and the two refractive index ellipsoids, and a case where a voltage is applied to the liquid crystal layer and halftone display is performed. The total refractive index ellipsoid of the two retardation plates when the eye point is changed from the vertical direction to the horizontal direction with respect to the display screen of the liquid crystal front panel of Comparative Example 1, and the refractive index ellipse of the liquid crystal molecules in the liquid crystal layer FIG. 6 is a plan view showing a change in the refractive index ellipsoid in the entire body and the two refractive index ellipsoids, and a voltage is applied to the liquid crystal layer to display white. The figure which showed the change of the transmittance | permeability with respect to the applied voltage of the liquid crystal display panel of the said comparative example 1 with the graph. FIG. 5 is an ISO contrast curve diagram showing the viewing angle characteristics of contrast of the liquid crystal display panel of Comparative Example 1; The figure which showed the change of the brightness | luminance of 8 gradations with respect to the left-right viewing angle of the liquid crystal display panel of the said comparative example 1 with the graph. The figure which showed the change of the brightness | luminance of 8 gradations with respect to the diagonal viewing angle of the liquid crystal display panel of the said comparative example 1 with the graph. The figure which showed the change of the brightness | luminance of 8 gradation with respect to the vertical viewing angle of the liquid crystal display panel of the said comparative example 1 with the graph. The figure which showed the change of the brightness | luminance of 6 gradations with respect to the viewing angle of the liquid crystal display panel of the said comparative example 1 with the graph. The figure which showed the change of the 6-gradation normalization brightness | luminance with respect to the viewing angle of the liquid crystal display panel of the said comparative example 1 with the graph. The ISO contrast curve figure which shows the viewing angle characteristic of the contrast of the liquid crystal display panel of the comparative example 2 of this invention. The figure which showed the change of the brightness | luminance of 8 gradations with respect to the left-right viewing angle of the liquid crystal display panel of the said comparative example 2 with the graph. The figure which showed the change of the brightness | luminance of 8 gradations with respect to the diagonal viewing angle of the liquid crystal display panel of the said comparative example 2 with the graph. The figure which showed the change of the brightness | luminance of 8 gradations with respect to the vertical viewing angle of the liquid crystal display panel of the said comparative example 2 with the graph.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Array substrate, 2 ... Opposite substrate, 3 ... Liquid crystal layer, 3m ... Liquid crystal molecule, 4 ... Color filter, 5 ... 1st optical film, 6 ... 2nd optical film, 5a, 6a ... Polarizing plate, 5b, 6b ... Phase plate, 7 ... control unit, 10 ... glass substrate, 13 ... TFT, 15 ... pixel electrode, 15a ... missing part, 17 ... alignment film, 17a ... first orientation part, 17b ... second orientation part, 20 ... glass Substrate, 21 ... common electrode, 22 ... projection, 23 ... alignment film, 23a ... third alignment portion, 23b ... fourth alignment portion, a1 ... absorption axis, a2 ... slow axis, d ... liquid crystal layer thickness, d1, d2 , D3, d4, d5, d6 ... direction, R1 ... display region, R2 ... pixel region, R3 ... divided region, Δn ... refractive index anisotropy, Δε ... dielectric constant anisotropy.

Claims (13)

An array substrate;
A counter substrate disposed opposite to the array substrate with a gap;
A plurality of pixel regions overlapping the array substrate and the counter substrate and having a plurality of divided regions;
A first liquid crystal molecule that is sandwiched between the array substrate and the counter substrate and has a plurality of liquid crystal molecules aligned in a direction perpendicular to the plane of the array substrate and the counter substrate, depending on the presence or absence of a voltage applied between the array substrate and the counter substrate. And a liquid crystal layer that takes one of the alignment states of the second state in which the plurality of liquid crystal molecules are aligned in the same direction for each of the divided regions and are aligned in a plurality of directions for each of the pixel regions. ,
A value Δnd obtained by multiplying the thickness d of the liquid crystal layer and the refractive index anisotropy Δn of the liquid crystal material of the liquid crystal layer is 240 nm or less for light having a wavelength of 550 nm. A first optical film provided on the outer surface side of the array substrate;
The liquid crystal display panel according to claim 1, further comprising: a second optical film provided on an outer surface side of the counter substrate.   2. The liquid crystal display panel according to claim 1, wherein, when white display is performed with the alignment of the plurality of liquid crystal molecules as the second state, an average value of inclination angles of the plurality of liquid crystal molecules is 20 ° or less with respect to the plane. .   In the case of white display, if the dielectric anisotropy of the liquid crystal material of the liquid crystal layer is set to Δε, the absolute value of the voltage applied between the array substrate and the counter substrate is | 56 / Δε | V or more. Item 2. A liquid crystal display panel according to item 1.   The liquid crystal display panel according to claim 1, wherein each of the plurality of pixel regions has two divided regions. The dielectric anisotropy of the liquid crystal material of the liquid crystal layer is negative,
The liquid crystal display panel according to claim 1, wherein when the voltage is not applied between the array substrate and the counter substrate, the alignment state of the plurality of liquid crystal molecules is the first state.   The liquid crystal display panel according to claim 1, wherein the array substrate is an active matrix substrate.   The apparatus further comprises a control unit that is electrically connected to the array substrate and the counter substrate, adjusts the voltage applied between the array substrate and the counter substrate, and controls the alignment state of the plurality of liquid crystal molecules. 2. A liquid crystal display panel according to 1.   The liquid crystal according to claim 1, further comprising an alignment control unit that is provided on at least one of the array substrate and the counter substrate so as to overlap the plurality of pixel regions, and controls the alignment state of the plurality of liquid crystal molecules. Display panel.   The liquid crystal display panel according to claim 9, wherein the alignment control unit is provided with a plurality of protrusions that are provided on the counter substrate so as to overlap the plurality of pixel regions and protrude toward the array substrate. The array substrate includes a plurality of pixel electrodes to which the voltage applied to the liquid crystal layer is applied,
The liquid crystal display panel according to claim 9, wherein the alignment control unit is formed of a plurality of missing portions formed in the plurality of pixel electrodes. An array substrate;
A counter substrate disposed opposite to the array substrate with a gap;
A plurality of pixel regions overlapping the array substrate and the counter substrate and having a plurality of divided regions;
A first state that is sandwiched between the array substrate and the counter substrate, no voltage is applied between the array substrate and the counter substrate, and a plurality of liquid crystal molecules are aligned in a direction perpendicular to the plane of the array substrate and the counter substrate; And any one of a second state in which a voltage is applied between the array substrate and the counter substrate, and the plurality of liquid crystal molecules are aligned in the same direction for each of the divided regions and aligned in a plurality of directions for each of the pixel regions. A liquid crystal layer adopting the alignment state of
A controller that is electrically connected to the array substrate and the counter substrate, adjusts the voltage applied between the array substrate and the counter substrate, and controls the alignment state of the plurality of liquid crystal molecules;
An alignment controller provided on at least one of the array substrate and the counter substrate so as to overlap the plurality of pixel regions, and controlling the alignment state of the plurality of liquid crystal molecules;
A first optical film provided on the outer surface side of the array substrate;
A second optical film provided on the outer surface side of the counter substrate,
The array substrate has a plurality of pixel electrodes to which the voltage applied to the liquid crystal layer is applied,
The dielectric anisotropy of the liquid crystal material of the liquid crystal layer is positive,
The alignment control unit is provided on the counter substrate so as to overlap the plurality of pixel regions, and includes a plurality of protrusions protruding toward the array substrate and a plurality of missing portions formed on the plurality of pixel electrodes. And
A value Δnd obtained by multiplying the thickness d of the liquid crystal layer and the refractive index anisotropy Δn of the liquid crystal material of the liquid crystal layer is 240 nm or less for light having a wavelength of 550 nm. An array substrate;
A counter substrate disposed opposite to the array substrate with a gap;
A plurality of pixel regions overlapping the array substrate and the counter substrate and having a plurality of divided regions;
A first state that is sandwiched between the array substrate and the counter substrate, no voltage is applied between the array substrate and the counter substrate, and a plurality of liquid crystal molecules are aligned in a direction perpendicular to the plane of the array substrate and the counter substrate; And any one of a second state in which a voltage is applied between the array substrate and the counter substrate, and the plurality of liquid crystal molecules are aligned in the same direction for each of the divided regions and aligned in a plurality of directions for each of the pixel regions. A liquid crystal layer adopting the alignment state of
At least one first alignment portion provided on the array substrate and rubbed in a first direction that overlaps at least one of the divided regions and is parallel to the plane; and at least one of the divided regions out of the first alignment portion An alignment film having at least one second alignment portion that is rubbed in a second direction opposite to the first direction and overlapping in parallel with the first direction;
Provided on the counter substrate, at least one third alignment portion that is rubbed in the second direction overlapping the at least one first alignment portion, and rubbed in the first direction overlapping the at least one second alignment portion. Another alignment film having at least one fourth alignment portion formed for each of the pixel regions;
A controller that is electrically connected to the array substrate and the counter substrate, adjusts the voltage applied between the array substrate and the counter substrate, and controls the alignment state of the plurality of liquid crystal molecules;
A first optical film provided on the outer surface side of the array substrate;
A second optical film provided on the outer surface side of the counter substrate,
The dielectric anisotropy of the liquid crystal material of the liquid crystal layer is positive,
A value Δnd obtained by multiplying the thickness d of the liquid crystal layer and the refractive index anisotropy Δn of the liquid crystal material of the liquid crystal layer is 240 nm or less for light having a wavelength of 550 nm.

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