JP3399463B2 - Color liquid crystal display device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a color liquid crystal display device.

[0002]

2. Description of the Related Art A conventional color liquid crystal display device capable of providing a colored display comprises a liquid crystal cell having a color filter and a pair of polarizing films arranged with the liquid crystal cell interposed therebetween. The color filter is provided on one substrate of the liquid crystal cell, and the color filter is formed on the substrate and the transparent electrode is formed thereon. By applying a voltage to the liquid crystal cell, the alignment state of the liquid crystal molecules is changed to change the light transmittance of each color filter to perform color display.

Further, a color liquid crystal display device (Japanese Patent Laid-Open No. 6-308481) for performing color display by birefringence of a twist-oriented nematic liquid crystal layer of a liquid crystal cell without using a color filter and a polarizing film, and a liquid crystal layer. A color liquid crystal display device (JP-A-6-175125 and JP-A-6-301006) that also utilizes the birefringence of the retardation film has been proposed.

[0004]

A color liquid crystal display panel using a color filter is intended to obtain colored light by absorbing light of a specific wavelength by the color filter. Is low, which causes the display to be dark.

Further, a color liquid crystal display device which performs a color display by birefringence of a liquid crystal layer and a polarizing film (Japanese Patent Laid-Open No. 6-3
No. 08481), coloring occurs in white, it is difficult to display achromatic black, and the number of colors that can be displayed is small and the color purity is low.

Further, in a color liquid crystal display device using the birefringence of a liquid crystal layer and a retardation film (JP-A-6-175125 and JP-A-6-301006), it is difficult to display black and white close to an achromatic color.

In this color liquid crystal display element, it is required that white display is bright, achromatic black and white display with high contrast is possible, and beautiful red display is possible.

The present invention provides a color liquid crystal display device which can perform color display without using a color filter, and can realize bright white, achromatic black and white for high contrast display, and beautiful red display. With the goal.

[0009]

In order to solve the above problems, the color liquid crystal display device of the present invention is provided with a color filter.
Stripe drive that is duty-driven and has no
In a simple matrix color liquid crystal device with bright electrodes
Te, a liquid crystal cell filled with nematic liquid crystal between a pair of transparent substrates is a transparent electrode on the inner side are formed, two polycarbonate arranged on one of the liquid crystal cell - and the polymer film of Bo Nate, and the liquid crystal cell The nematic liquid crystal has a twist angle of 220 ° to 260 °, and the birefringence Δn _{LC of the} nematic liquid crystal is multiplied by the liquid crystal layer thickness d _LC. When Δn _LC · d _{LC is set} to 1.2 μm to 1.7 μm and the two polymer films are numbered 1 and 2 from the side close to the liquid crystal cell, the in-plane extraordinary refractive index of each film is n. _x
(I) (I = 1, 2), the ordinary refractive index is n _y (i) (I = 1,
2), when the film thickness is d _Film (i) (I = 1, 2), the film letter R is R _film (i) = (n
_{x (i) -n y (i} )) · d Film (i) (i = 1,2) birefringence difference, which is defined by using the _{Δ (R) = (R Film} (1) +
R _Film (2))-Δn _LC · d _LC from -0.1 μm-
A 0.2 [mu] m, further, the two above-mentioned polycarbonate - watching side of arranging the polymer film borate Ney <br/> bets from above believe above, based on the horizontal direction the twist direction of the liquid crystal as a positive The angle is measured as φ _P1 , the direction of the absorption axis of the lower polarizing film is φ _P1 , the direction of the liquid crystal molecules on the lower transparent substrate is φ _LC1 , the direction of the liquid crystal molecules on the upper transparent substrate is φ _LC2 , and the liquid crystal cell side height is The direction of the slow axis of the molecular film, that is, the direction of the extraordinary refractive index is φ _F1 , the direction of the slow axis of the polymer film on the upper polarizing film side, that is, the direction of the extraordinary refractive index is φ _F2 , and the absorption axis direction of the upper polarizing film is When φ _P2 , φ _LC1 −φ _P1 is ± 45 ° ± 10 ° and φ _F1 −φ _LC2 is 90 ° ± 10
And φ _F2 −φ _F1 is 0 ° ± 25 °, φ _P2 −φ
_F2 is ± 45 ° ± 10 °, and further, a Z coefficient Q _z = (n _x −n _z ) / (n defined by using nz as a refractive index in a direction perpendicular to the plane of the polymer film. _x -n _y) is,
0.1 Ri 0.8 der, the voltage applied is to the liquid crystal cell
Is, color display at low the voltage to the white or black, et al.
The color display changes with the voltage, white, black,
It is characterized by changing from green to red .

In the color liquid crystal display device of the present invention, the twist angle of the nematic liquid crystal is 240 ° to 260 °.
And Δn _LC · d _LC is 1.5 μm to 1.7 μm.

Further, the present invention is a color liquid crystal display device characterized in that a reflection plate is provided on the outside of either one of the polarizing films to make it a reflection type.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention and comparative examples will be described below with reference to the drawings.

(Comparative Example 1) FIG. 1 is a sectional view of a color liquid crystal display element of Comparative Example 1. 10 and 11 are polarizing films,
Reference numerals 12 and 13 are transparent substrates, 14 and 15 are transparent electrodes, 16 is a liquid crystal layer, 17 is a reflector, and 18 is a polymer film.

FIG. 2 is an optical configuration diagram of the color liquid crystal display element of Comparative Example 1. 21 is a reference line, 22 is an absorption axis direction of the lower polarizing film, 23 is an absorption axis direction of the upper polarizing film, 24 is an alignment direction of liquid crystal molecules on the lower transparent substrate, 25
Is the alignment direction of liquid crystal molecules on the upper transparent substrate, and 26 is the slow axis direction of the polymer film. Further, φ _P1 is the absorption axis direction 22 of the lower polarizing film, φ _P2 is the absorption axis direction 23 of the upper polarizing film, φ _{LC 1} is the alignment direction 24 of liquid crystal molecules on the lower transparent substrate, and φ _LC2 is Φ _F of the orientation direction 25 of the liquid crystal molecules on the upper transparent substrate indicates an angle measured from the reference line 21 with respect to the slow axis direction 26 of the polymer film, with the twist direction of the liquid crystal being positive. Ω _LC indicates the twist direction and twist angle of the liquid crystal.

A transparent substrate 1 having stripe-shaped transparent electrodes 14 and 15 made of indium, tin and oxide.
A 5 wt% solution of N-methyl-2-pyrrolidinone of polyimide was printed on Nos. 2 and 13 and cured at 200 ° C., followed by a rotary rubbing method using a rayon cloth so as to achieve a predetermined twist angle. Orientation processing was performed.

A thermosetting seal resin mixed with 1.0 wt% of glass fiber having a predetermined diameter is printed on the periphery of the transparent substrate 12, and a resin having a predetermined diameter is printed on the transparent substrate 13. After the beads were scattered at a rate of 150 pieces / mm, the transparent substrates 12 and 13 were attached to each other so that the stripe-shaped transparent electrodes 14 and 15 were in a matrix form, and the seal resin was cured at 150 ° C. , Δn _LC = 0.25, a liquid crystal in which a predetermined chiral liquid crystal was mixed with a tolan-based nematic liquid crystal was vacuum-injected, sealed with an ultraviolet curable resin, and then cured by ultraviolet light.

Finally, a polycarbonate film is attached as the polymer film 18, and the polarizing films 10 and 11 are further attached.
As a neutral gray polarizing film (NPF-F1025DU manufactured by Nitto Denko Corporation) is attached as a reflection plate 1
As No. 7, a diffusion type aluminum reflector was attached.

Φ _P1 = 10 °, φ _LC1 = -35 °, φ _LC2 =
35 °, Ω _LC = 250 °, φ _F = 125 °, φ _P2 = 80
And Δ (R) = R _Film −Δn _LC · d _LC is 0.085.
When Δn _LC · d _LC was changed while satisfying the condition of μm, the optical characteristics were measured in the reflection mode. Good black and white display and red display were realized in the range of 1.2 μm to 2.2 μm. This is because the color display is changed by using the change of the birefringence of the liquid crystal layer, so that the color change of white, black, green, and red can be made with good color purity by the birefringence amount of the liquid crystal layer above a certain level.

Further, Δ (R) is 0.0 μm to 0.1 μm
It was confirmed that when m was satisfied, both white display and black display were achromatic, and the display color changed to white, black, green, and red by applying a voltage. This makes Δ (R) 0.
0 μm to 0.1 μm, φ _F −φ _LC2 90 ° ± 10
By setting the angle to °, it is possible to change from white to black in an achromatic state where the birefringence of the liquid crystal layer and the polymer film are canceled at a low voltage.

Further, φ _LC1 −φ _P1 and φ _P2 −φ _F are ± 45 °
Since it is set to ± 10 °, the use of birefringence can be used near the maximum, and the color purity and the light utilization rate can be increased.

The twist angle of the liquid crystal has an influence on the duty ratio, which is the number of selectable electrodes when it is considered that the liquid crystal is driven by a simple matrix. The larger the twist angle, the higher the duty ratio. The size can be reduced, the number of selected lines can be increased, and the number of pixels can be increased. First of the present invention
In the embodiment of the present invention, the color changes to white, black, green, and red with the voltage. However, by setting the twist angle from 220 ° to 260 °, it is possible to drive at a duty ratio of 1/64 or less. It was confirmed that even red display was possible.

Further, Δn _LC · d _LC is 1.5 μm to 2.
It was confirmed that when the twist angle was set to 0 μm and the twist angle was changed from 240 ° to 260 °, it was possible to drive at a duty ratio of 1/200 or less.

Here, in particular, Δn _LC · d _LC = 1.9 μm,
R _Film = 1.985 μm, φ _P1 = 10 °, φ _LC1 = -3
5 °, φ _LC2 = 35 °, Ω _LC = 250 °, φ _F = 125
The results of measuring the optical characteristics when φ and φ _{P 2} = 80 ° are shown.

At this time, Δ (R) = R _Film −Δn _LC · d
_LC = 0.085 μm, φ _F −φ _LC2 = 90 °, φ _LC1 −φ
_P1 = -45 °, a φ _P2 -φ _F = -45 ° meet the conditions identified above.

White, black, green with a 1/240 duty ratio
Red and changing colors were available. The change in color change is shown in FIG. Further, the reflectance and the xy chromaticity coordinate (CIE1931) values in each color display are shown in (Table 1).

[0026]

[Table 1]

As a result, it can be seen that a monochrome display with an achromatic color and a red display with high color purity can be realized with a contrast of 5 or more in the reflection mode.

When the Z-factor Q _z of the polymer film 18 of polycarbonate was changed from 0.1 to 0.8 at the same set value, the change in the viewing angle of the optical characteristics was measured. It was confirmed that compared with the normal type of _z = 1.0 ( _ny = _nz ), the change amount of contrast change, reflectance change, and color change was small and good.

In the above comparative examples, polycarbonate was used as the polymer film, but polyarylate or polysulfone may be used.

Further, in the above comparative example, the reflection type using the aluminum diffuse reflection plate as the reflection plate 17 is used, but a silver reflection plate or the like may be used as the reflection plate. Also,
Instead of the reflector 17, a transmissive type having a backlight module may be used.

Comparative Example 2 FIG. 4 is a sectional view of a color liquid crystal display element of Comparative Example 2. 40 and 41 are polarizing films,
42 and 43 are transparent substrates, 44 and 45 are transparent electrodes, 46 is a liquid crystal layer, 47 is a reflector, and 48 and 49 are polymer films.

FIG. 5 is an optical configuration diagram of a color liquid crystal display element of Comparative Example 2. Reference numeral 51 is a reference line, 52 is an absorption axis direction of the lower polarizing film, 53 is an absorption axis direction of the upper polarizing film, 54 is an alignment direction of liquid crystal molecules on the lower transparent substrate, and 55.
Is the alignment direction of the liquid crystal molecules on the upper transparent substrate, 56 is the slow axis direction of the polymer film (1) on the liquid crystal cell side, and 57 is the slow axis direction of the polymer film (2) on the upper polarizing film side. .

Φ _P1 is the absorption axis direction 52 of the lower polarizing film, and φ _P2 is the absorption axis direction 53 of the upper polarizing film.
, Φ _LC1 is the alignment direction 54 of the liquid crystal molecules on the lower transparent substrate.
, Φ _{L C2} is the alignment direction 55 of the liquid crystal molecules on the upper transparent substrate.
, Φ _F1 is in the slow axis direction 56 of the polymer film (1),
φ _F2 represents an angle in the slow axis direction 57 of the polymer film (2) measured from the reference line 51 with the twist direction of the liquid crystal being positive. Ω _LC indicates the twist direction and twist angle of the liquid crystal.

A transparent substrate 4 having stripe-shaped transparent electrodes 44 and 45 made of indium, tin and oxide.
A 5 wt% solution of N-methyl-2-pyrrolidinone of polyimide was printed on Nos. 2 and 43, cured at 200 ° C., and then subjected to a rotary rubbing method using a rayon cloth so as to achieve a predetermined twist angle. Orientation processing was performed.

A thermosetting seal resin mixed with 1.0 wt% of glass fiber having a predetermined diameter is printed on the periphery of the transparent substrate 42, and a resin having a predetermined diameter is printed on the transparent substrate 43. After the beads were scattered at a rate of 150 pieces / mm, the transparent substrates 42 and 43 were adhered to each other so that the stripe-shaped transparent electrodes 44 and 45 were in a matrix, and the seal resin was cured at 150 ° C. , Δn _LC = 0.25, a liquid crystal in which a predetermined chiral liquid crystal was mixed with a tolan-based nematic liquid crystal was vacuum-injected, sealed with an ultraviolet curable resin, and then cured by ultraviolet light.

Finally, polycarbonate is attached as the polymer films 48 and 49, and the polarizing film 4
A neutral gray polarizing film (NPF-F1025DU manufactured by Nitto Denko Corporation) was attached as Nos. 0 and 41, and a diffusion type aluminum reflector was attached as the reflector 47.

Φ_P1= 10 °, φ_LC1= -35 °, φ_LC2=
35 °, Ω_LC= 250 °, φ_F1= 124.5 °, φ_F2=
136 °, φ_P2= 93 °, Δ (R) = (R
_Film(1) + R_Film(2))-Δn_LC・ D_LCTo 0.08
Δn while satisfying 6 μm _LC・ D_LCChanged
Then, when the optical characteristics are measured in the reflection mode, it is 1.2 μm.
From 2.2 to 2.2 μm, good black and white display and red display can be realized.
Came. This is a color display using the birefringence change of the liquid crystal layer.
To change the birefringence of the liquid crystal layer above a certain level.
Therefore, the color purity from white to black, green, red is good.
It depends on what you can do.

Further, Δ (R) is 0.0 μm to 0.1 μ
It was confirmed that when m was satisfied, both white display and black display were achromatic, and the display color changed to white, black, green, and red by applying a voltage. This makes Δ (R) 0.
From 0 μm to 0.1 μm, φ _F1 −φ _LC2 90 ° ± 1
By setting 0 ° and φ _F2 −φ _F1 to 0 ° ± 25 °, it is possible to change from white to black in an achromatic state in which the birefringence of the liquid crystal layer and the polymer film are canceled at a low voltage. It depends on what you can do.

Further, φ _LC1 −φ _P1 and φ _P2 −φ _F2 are ± 45
Since the angle is ± 10 °, it is possible to use the birefringence near the maximum, and it is possible to increase the color purity and the light utilization rate.

The twist angle of the liquid crystal has an effect on the duty ratio, which is the number of selectable electrodes that can be considered when driving with a simple matrix. The larger the twist angle, the higher the duty ratio. The size can be reduced, the number of selected lines can be increased, and the number of pixels can be increased. In the present embodiment, the color changes with voltage, such as white, black, green, and red, but by setting the twist angle from 220 ° to 260 °,
It was confirmed that red display was possible even when driven at a duty ratio of 1/64 or less.

Further, Δn _LC · d _LC is from 1.5 μm to 2.
It was confirmed that when the twist angle was set to 0 μm and the twist angle was changed from 240 ° to 260 °, it was possible to drive at a duty ratio of 1/200 or less.

Here, in particular, Δn_LC・ D_LC= 1.6 μm,
R_Film(1) = 0.392 μm, R _Film(2) = 1.2
94 μm, φ_P1= 10 °, φ_LC1= -35 °, φ_LC2= 3
5 °, Ω_LC= 250 °, φ_F1= 124.5 °, φ_F1= 1
36 °, φ_P2= 93 ° was measured for optical characteristics
I will show the results.

At this time, Δ (R) = (R _Film (1) + R
_Film (2))-Δn _LC · d _LC = 0.086 μm, φ _F1 −
φ _LC2 = 89.5 °, φ _F2 −φ _F1 = 11.5 °, φ _LC1 −
φ _P1 = −45 °, φ _P2 −φ _F2 = −43 °, which satisfies the conditions confirmed above.

White, black, green, with a 1/240 duty ratio,
Red and changing colors were available. The change in color change is shown in FIG. Further, the reflectance and the values of XY chromaticity coordinates (CIE1931) in each color display are shown in (Table 2).

[0045]

[Table 2]

From this, it can be seen that a monochrome display with an achromatic color and a red display with high color purity can be realized with a contrast of 5 or more in the reflection mode.

When the Z value Q _z of the polycarbonate polymer films 48 and 49 was changed from 0.1 to 0.8 at the same set value, the change in the viewing angle of the optical characteristics was measured. , Q _z = 1.0 normal type ( _ny = _nz )
It was confirmed that the amount of change in contrast, the change in reflectance, and the change in color were all smaller and better than those of No.

In the above comparative examples, polycarbonate was used as the polymer film, but polyarylate or polysulfone may be used.

Further, in the above comparative example, the reflection type using the aluminum diffuse reflection plate as the reflection plate 47 is used, but a silver reflection plate or the like may be used as the reflection plate. Also,
Instead of the reflection plate 47, a transmissive type having a backlight module may be used.

(Embodiment 1) Since the color liquid crystal display element of Embodiment 1 has the same fabrication and structure as those of Comparative Example 2, the cross section of the color liquid crystal display element of Comparative Example 2 shown in FIG. This will be described with reference to the drawings and the optical configuration diagram of the color liquid crystal display element of FIG.

Φ _P1 = 10 °, φ _LC1 = -35 °, φ _LC2 =
35 °, Ω _LC = 250 °, φ _F1 = 133.5 °, φ _F2 =
120.5 °, φ _P2 = 174 °, and Δ (R) = (R
_Film (1) + R _Film (2))-Δn _LC · d _LC is -0.1
When Δn _LC · d _LC was changed while satisfying 5 μm and the optical characteristics were measured by the reflection mode, good black and white display and red display were realized in the range of 1.2 μm to 2.2 μm. This is because the color display is changed by using the change of the birefringence of the liquid crystal layer, so that the color change of white, black, green, and red can be made with good color purity by a certain amount or more of the birefringence of the liquid crystal layer.

Further, Δ (R) is changed from −0.1 μm to −0.
It was confirmed that when 2 μm was satisfied, the white display and the black display were both achromatic, and the display colors were changed to white, black, green, and red by applying a voltage. This is because Δ (R) is changed from −0.1 μm to −0.2 μm and φ _F1 −φ _{LC2 is set} to 9
By changing 0 ° ± 10 ° and φ _F2 −φ _F1 to 0 ° ± 25 °, it changes from white to black in the achromatic state where the birefringence of the liquid crystal layer and the polymer film are canceled at a low voltage. It depends on what you can do.

In addition, φ _LC1 −φ _P1 and φ _P2 −φ _F2 are ± 45
Since the angle is ± 10 °, it is possible to use the birefringence near the maximum, and it is possible to increase the color purity and the light utilization rate.

The twist angle of the liquid crystal has an effect on the duty ratio, which is the number of selectable electrodes that can be considered when driving with a simple matrix. The larger the twist angle, the more the duty ratio. The size can be reduced, the number of selected lines can be increased, and the number of pixels can be increased. In the present embodiment, the color changes with voltage, such as white, black, green, and red, but by setting the twist angle from 220 ° to 260 °,
It was confirmed that red display was possible even when driven at a duty ratio of 1/64 or less.

Further, Δn _LC · d _LC is 1.5 μm to 2.
It was confirmed that when the twist angle was set to 0 μm and the twist angle was changed from 240 ° to 260 °, it was possible to drive at a duty ratio of 1/200 or less.

Here, in particular, Δn_LC・ D_LC= 1.7 μm,
R_Film(1) = 0.790 μm, R _Film(2) = 0.7
60 μm, φ_P1= 10 °, φ_LC1= -35 °, φ_LC2= 3
5 °, Ω_LC= 250 °, φ_F1= 133.5 °, φ_F1= 1
20.5 °, φ_P2Measure optical characteristics when = 174 °
I will show the fixed results.

At this time, Δ (R) = (R _Film (1) + R
_Film (2))-Δn _LC · d _LC = -0.15 μm, φ _F1 −
φ _LC2 = 98.5 °, φ _F2 −φ _F1 = −13 °, φ _LC1 −φ
_P1 = -45 °, a φ _P2 -φ _F2 = 53.5 ° satisfies the conditions identified above.

1/240 duty ratio of white, black, green,
Red and changing colors were available. The change in color change is shown in FIG. The values of reflectance and XY chromaticity coordinates (CIE1931) in each color display are shown in (Table 3).

[0059]

[Table 3]

As a result, it can be seen that a monochrome display with an achromatic color and a red display with high color purity can be realized with a contrast of 5 or more in the reflection mode.

When the Z-coefficient Q _z of the polycarbonate polymer films 48 and 49 was changed from 0.1 to 0.8 at the same set value, the change in the viewing angle of the optical characteristics was measured. , Q _z = 1.0 normal type ( _ny = _nz )
It was confirmed that the amount of change in contrast, the change in reflectance, and the change in color were all smaller and better than those of No.

In the above embodiments, polycarbonate is used as the polymer film, but polyarylate or polysulfone may be used.

Further, in the above embodiment, the reflection plate 47 is used.
As a reflection type using an aluminum diffuse reflection plate, a silver reflection plate or the like may be used as the reflection plate. Further, a transmissive type having a backlight module may be used instead of the reflection plate 47.

[0064] color (Comparative Example 3) Comparative Example 3 - liquid crystal display device, since the generation and structure is common to Comparative Example 2 and Embodiment 1, Comparative Example 2 and the actual
This will be described with reference to the sectional view of the color liquid crystal display element of FIG. 4 used in the first embodiment and the optical configuration diagram of the color liquid crystal display element of FIG.

Φ _P1 = 10 °, φ _LC1 = -35 °, φ _LC2 =
35 °, Ω _LC = 250 °, φ _F1 = 130.5 °, φ _F2 =
82.5 °, φ _P2 = 10 °, and Δ (R) = (R
_Film (1) + R _Film (2))-Δn _LC · d _LC is 0.59
When Δn _LC · d _LC was changed while satisfying 4 μm and the optical characteristics were measured by a reflection mode, good black and white display and red display were realized in the range of 1.2 μm to 2.2 μm. This is because the color display is changed by using the change of the birefringence of the liquid crystal layer, so that the color change of white, black, green, and red can be made with good color purity by a certain amount or more of the birefringence of the liquid crystal layer.

Further, Δ (R) is 0.5 μm to 1.0 μm
It was confirmed that when m was satisfied, both white display and black display were achromatic, and the display color changed to white, black, green, and red by applying a voltage. This makes Δ (R) 0.
5 μm to 1.0 μm, φ _F1 −φ _LC2 90 ° ± 1
By setting 0 ° and φ _F2 −φ _F1 to 45 ° ± 25 °, it is possible to change from white to black in an achromatic state in which the birefringence of the liquid crystal layer and the polymer film are canceled at a low voltage. It depends on what you can do.

Further, since φ _LC1 −φ _P1 is ± 45 ° ± 10 °, it is possible to use the birefringence near the maximum, and it is possible to improve the color purity and the light utilization rate. .

The twist angle of the liquid crystal has an influence on the duty ratio, which is the number of selectable electrodes that can be considered in the case of driving with a simple matrix. The larger the twist angle, the higher the duty ratio. The size can be reduced, the number of selected lines can be increased, and the number of pixels can be increased. In the present embodiment, the color changes with voltage, such as white, black, green, and red, but by setting the twist angle from 220 ° to 260 °,
It was confirmed that red display was possible even when driven at a duty ratio of 1/64 or less.

Further, Δn _LC · d _LC is 1.5 μm to 2.
It was confirmed that when the twist angle was set to 0 μm and the twist angle was changed from 240 ° to 260 °, it was possible to drive at a duty ratio of 1/200 or less.

Here, in particular, Δn_LC・ D_LC= 1.9 μm,
R_Film(1) = 1.734 μm, R _Film(2) = 0.7
60 μm, φ_P1= 10 °, φ_LC1= -35 °, φ_LC2= 3
5 °, Ω_LC= 250 °, φ_F1= 130.5 °, φ_F1= 8
2.5 °, φ_P2= 10 ° and measure the optical characteristics
I will show the results.

At this time, Δ (R) = (R _Film (1) + R
_Film (2))-Δn _LC · d _LC = 0.594 μm, φ _F1 −
φ _LC2 = 95.5 °, φ _F2 −φ _F1 = −48 °, φ _LC1 −φ
_P1 = −45 °, which satisfies the conditions confirmed above.

White, black, green with a 1/240 duty ratio,
Red and changing colors were available. The change in color change is shown in FIG. Table 4 shows the reflectance and xy chromaticity coordinate (CIE1931) values in each color display.

[0073]

[Table 4]

As a result, in the reflection mode, the contrast is increased.
5 or more is black and white display is achromatic and red with high color purity
It can be seen that In addition, with the same setting value,
Z coefficient of polymer films 48, 49 of polycarbonate
Q _zChange the viewing angle of the optical characteristics by changing the value from 0.1 to 0.8.
Was measured, Q_z= 1.0 normal
Ip (n_y= N_z), The contrast change,
Both the change in reflectance and the change in color are small and good.
I confirmed.

Although polycarbonate is used as the polymer film in the above embodiments, polyarylate or polysulfone may be used.

Further, in the above embodiment, the reflection plate 47 is used.
As a reflection type using an aluminum diffuse reflection plate, a silver reflection plate or the like may be used as the reflection plate. Further, a transmissive type having a backlight module may be used instead of the reflection plate 47.

[0077]

As described above, according to the present invention, color display can be performed without using a color filter, and bright white, black and white capable of high contrast display with achromatic color, and
A beautiful red display can be realized.

By using a polymer film having a Z coefficient Q _z of 0.1 to 0.8, a color liquid crystal display device having a wide viewing angle range can be obtained.

Further, by providing the reflection plate, a bright reflection type color liquid crystal display element can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a color liquid crystal display device of Comparative Example 1.

FIG. 2 is an optical configuration diagram of a color liquid crystal display device of Comparative Example 1.

FIG. 3 is a chromaticity diagram showing a color change of the color liquid crystal display element of Comparative Example 1.

FIG. 4 is a color chart of Comparative Example 2 , Embodiment 1 and Comparative Example 3 ;
Cross-sectional view of liquid crystal display element

[FIG. 5] Colors of Comparative Example 2 , Embodiment 1 and Comparative Example 3
Optical block diagram of liquid crystal display device

FIG. 6 is a chromaticity diagram showing a color change of a color liquid crystal display element of Comparative Example 2.

7 is a chromaticity diagram showing a color change of the color liquid crystal display element of Comparative Example 1. FIG.

FIG. 8 is a chromaticity diagram showing a color change of the color liquid crystal display element of Comparative Example 2.

[Explanation of symbols]

10,11 Polarizing film 12, 13 Transparent substrate 14,15 transparent electrodes 16 Liquid crystal layer 17 Reflector 18 Polymer film

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ogawa Tetsu 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References Patent 3292809 (JP, B2) International Publication 96/13752 (WO, A1) ) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/13363

Claims (3)

(57) [Claims] 1. A duty without a color filter
Simple matrix with driven transparent electrodes in stripes
In the color liquid crystal device box, a liquid crystal cell encapsulating nematic liquid crystal between a pair of transparent substrates is a transparent electrode on the inner side are formed, while on the arranged two polycarbonate of a liquid crystal cell - and the polymer film of Bo Nate ,
The liquid crystal cell and a pair of polarizing films disposed on both sides of the polymer film are sandwiched between the nematic liquid crystal and the twist angle of 220 ° to 2 °.
The product Δn _LC · d _LC of the birefringence Δn _{LC of the} nematic liquid crystal and the liquid crystal layer thickness d _LC is set to 60 ° and 1.2 μm to 1.7.
μm, and the extraordinary refractive index in the plane of each film when the above two polymer films are numbered 1 and 2 from the side close to the liquid crystal cell is n _x (i) (I = 1, 2), Refractive index n
_y (i) (I = 1, 2), the film thickness is d _Film (i) (I
= 1, 2), the film letter R
_{Film (i) = (n x} (i) -n y (i)) · d Film (i)
Birefringence difference Δ (R) = defined using (i = 1, 2)
(R _Film (1) + R _Film (2)) − Δn _LC · d _LC is −
A -0.2μm from 0.1 [mu] m, further, the two above-mentioned polycarbonate - as viewed from above consider upper side of arranging the polymer film Bo Nate, based on the horizontal direction the twist direction of the liquid crystal as a positive the angle is measured as, .phi.P1 the absorption axis direction of the lower polarizing film, _LC1 in the direction of liquid crystal molecules on the lower transparent substrate phi, the direction of liquid crystal molecules on the upper transparent substrate phi _LC2, the liquid crystal cell side polymer The direction of the slow axis of the film, that is, the direction of the extraordinary refractive index is φ _F1 , the direction of the slow axis of the polymer film on the upper polarizing film side, that is, the direction of the extraordinary refractive index is φ _F2 , and the absorption axis direction of the upper polarizing film is φ.
_{When P2} , φ _LC1 −φ _P1 is ± 45 ° ± 10 °, φ _F1 −φ _LC2 is 90 ° ± 10 °, and φ _F2 −φ _F1
Is 0 ° ± 25 °, and φ _P2- φ _F2 is ± 45 ° ± 10 °
And further, Z coefficient Q _z = (n _x −n defined by using nz as a refractive index in a direction perpendicular to the plane of the polymer film.
_{z) / (n x -n y} ) is a 0.8 to 0.1, the
When a voltage is applied to the liquid crystal cell,
The color display changes from white to black, and the color display above
A color liquid crystal display element characterized by changing to white, black, green, and red with a voltage. 2. The twist angle of the nematic liquid crystal is 24.
0 ° to 260 °, and Δn _LC · d _LC is 1.5 μm to 1. The color liquid crystal display element according to claim 1, wherein the color liquid crystal display element has a thickness of 7 μm. 3. The color liquid crystal display device according to claim 1, wherein a reflection plate is provided on the outside of either one of the polarizing films to provide a reflection type.