JP2947207B2 - Liquid crystal device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device, and more particularly to a liquid crystal device.
The present invention relates to a part-isted nematic liquid crystal device. [0002] Conventional super twisted nematics
Type (hereinafter referred to as STN type) liquid crystal devices are disclosed in
The twist angle of liquid crystal molecules is 90
Degrees or more, a pair of polarizing plates is provided above and below the liquid crystal cell,
These polarization axes (absorption axes) and the liquid crystal adjacent to the electrode substrate
The included angle between the direction of the molecular axis of the molecule and the molecular axis ranges from 30 degrees to 60 degrees.
It was an enclosure. Therefore, liquid crystal is colored by birefringence.
The appearance hue of the cell when no voltage is applied is not white.
Color, generally from green to yellow-red
You. In addition, the hue of the external appearance with the selection voltage applied is black.
And generally blue. FIG. 17 is a schematic view of a conventional STN type liquid crystal device.
It is. In the figure, 171 is an upper polarizing plate, and 172 is a liquid.
A transparent cell such as an ITO electrode on a substrate 173
174 is formed, and an alignment film 175 is further applied.
Has been rubbed. Upper and lower substrates are spacers 17
6 and a liquid crystal 177 sandwiched therebetween.
I have. 178 is a lower polarizing plate. FIG. 19 shows a liquid crystal cell in the above liquid crystal device.
FIG. 4 is an explanatory diagram showing the relationship between the polarization axis of a polarizing plate (absorption axis).
In the figure, reference numeral 190 denotes a lattice of the upper electrode substrate of the liquid crystal cell.
Bing direction, 191 is the Rabin of the lower electrode substrate of the liquid crystal cell
Direction, 192 is the direction of the polarization axis (absorption axis) of the upper polarizer
193 is the direction of the polarization axis (absorption axis) of the lower polarizing plate,
94 is the magnitude of the twist angle of the liquid crystal molecules of the liquid crystal cell, 195
Is the rubbing direction 190 of the upper electrode substrate and the bias of the upper polarizer.
The angle 196 with the direction 192 of the optical axis (absorption axis) is the lower side
Rubbing direction 191 of electrode substrate and polarization axis of lower polarizer
(Absorption axis) represents the angle formed by the direction 193. In FIG. 19, the angle 194 is set to 200
Degrees and angles 195 and 196 are about 50 degrees each,
Δn · d of the refractive index anisotropy Δn of the crystal and the thickness d of the liquid crystal layer
FIG. 2 shows the optical characteristics of the liquid crystal device when is set to 0.9 μm.
0 is shown. FIG. 1 shows a driving method of this type of liquid crystal device.
By the multiplex driving method usually used,
Positive mode when the above liquid crystal device is driven (no electric field
Pixel in the ON state and the pixel in the OFF state
2 shows the spectrum of the light transmittance of the sample. Note that the off state does not mean the state where no electric field is applied.
And molecular orientation in almost no applied state even when an electric field is applied
Is the state that is maintained, and the ON state is
Changes in the molecular orientation of the liquid crystal are necessary for optical changes to occur.
It means a state that is necessary and sufficient. The curve I in FIG.
Curve II shows the spectrum of the pixel in the ON state.
Curve I is “bright” Curve II is “dark”
That is, curves I and II can be visually distinguished
You can see that. [0009] However, the above figure
When the spectrum shown in FIG. 20 is plotted on color coordinates,
As shown in FIG. 21, in the conventional liquid crystal device, the positive mode
Is colored yellow when off and blue when on
You can see that. Thus, in the prior art, the positive mode
Sometimes the appearance color of the liquid crystal device in the off state is green, yellow-green,
Colored yellow or yellow-red, and blue when on
Color or navy blue. Negative mode (no voltage applied)
Dark when turned off, and dark when turned off and on
Then it becomes yellow. These colors are the display colors of the liquid crystal device.
Not a commonly preferred color. After all, the display color of the liquid crystal device
Is a combination of white and black, that is,
If shown, the combination of flat spectra is psychological
Is most suitable physically and physically.
There is a need for a liquid crystal device that can. In particular, color fill
When color display is performed in combination with
Whether the spectrum is flat or not depends on the vividness of the color.
Had a significant effect and the spectrum is shown in FIG.
In the conventional method, the blue and red colors are bright, regardless of the green color.
It is difficult to display in degrees. By the way, a method for eliminating the above-mentioned coloring is described.
Twisted nematic type (hereinafter referred to as TN type)
In the liquid crystal device, a single-layer twisted nematic
Twist that does not have power supply means in the field effect type liquid crystal display cell
Liquid crystal of two-layer structure with superposed nematic liquid crystal layer
An apparatus is known (for example, Japanese Patent Application Laid-Open No. 57-96315).
Gazette). However, the liquid disclosed in the above publication is
The crystal unit is applied to the STN-type liquid crystal device as described above.
Not something you can do. That is, the liquid crystal described in the above publication
The device is of the so-called TN type. That is, the twist angle is 90
Polarizers are arranged parallel or perpendicular to the direction of the adjacent liquid crystal molecules.
The principle of operation uses optical rotation
Things. Therefore, actively use birefringence as the operating principle
It is very different from the STN type structure
It can simply be applied to STN type liquid crystal devices as it is.
Absent. The present invention solves the above problems.
Therefore, the purpose is to use a liquid crystal that can display black and white
Providing a device, and a liquid suitable for color display.
An object of the present invention is to provide a crystal apparatus. A liquid crystal device according to the present invention comprises:
Super twisted nematic liquid crystal is sandwiched between a pair of substrates.
Liquid crystal cell and at least one polymer
And the polymer film is the liquid
The polymer filter so as to perform a reverse conversion of the conversion performed by the crystal cell.
The optical axis direction of the film is the polymer film of the liquid crystal cell.
With respect to the rubbing direction applied to the substrate on the side where
Set to approximately 90 ° and the twist angle of the liquid crystal
And Δn · d of the polymer film are set.
It is characterized by becoming. FIG. 1 shows a typical example of a liquid crystal device according to the present invention.
It is shown in FIG. In the figure, 11 and 18 are linear polarizers,
Reference numeral 12 denotes a display liquid crystal cell, and reference numeral 19 denotes an optically anisotropic body. The structure of the liquid crystal cell 12 is transparent on the substrate 13.
An electrode 14 is formed, and an alignment film 15 is further formed.
Has been rubbed. Upper and lower substrates are spacers 16
And the liquid crystal 17 is interposed therebetween. The polarizing plate, the liquid crystal material and the liquid crystal used in the present invention are used.
The alignment method and the driving method of the liquid crystal element are the same as those of the conventional TN type.
Or STN-type liquid crystal devices.
The same ones are applicable. The details are described below.
Bell. The optical characteristics are large in the polarization characteristics of the polarizing plate used.
Affected. In a specific embodiment of the present invention described later,
In all, LLC2-82-18 manufactured by Sanritsu Electric Co. is used.
But it is not limited to this.
Absent. FIG. 15 shows the wavelength dependence of the light transmittance of the two polarizing plates.
showed that. In the figure, I indicates a pair of polarizing plates
When placed in rows, II is the space when placed perpendicular to each other.
It is a spectrum curve. Liquid crystal composition used in the present invention
Is a nematic liquid crystal having a positive dielectric anisotropy. preferable
As an example of a liquid crystal, Chisso's SS-4008 is cited.
It is. The following are examples of other preferred liquid crystal compositions.
Some are like. Embedded image In the liquid crystal composition, the twisted structure of the liquid crystal is reduced.
It is preferable to add a chiral dopant to keep the
Good. As the chiral dopant, for example,
To make a right-handed spiral structure, BDH
CB-15, left-handed spiral structure
S-811 manufactured by Luc Co. can be used. The display liquid crystal cell 12 used in the present invention
The structure is the same as that of the liquid crystal cell used in the prior art shown in FIG.
The same configuration as the console 172 can be used. In FIG. 1, for example, glass
A transparent substrate such as plastic is used. On the substrate
Transparent electrode 14 such as ITO and its transparent electrode
An alignment film layer 15 for determining the alignment of the liquid crystal is formed thereon. Preferred examples used as the alignment film layer
And polyimide and polyvinyl alcohol. This
Generally, these alignment film layers are rubbed by rubbing.
A certain orientation can be given to the liquid crystal. Another liquid crystal
Using oblique deposition method such as SiO as alignment method
Can also. An example of a method for driving the liquid crystal device of the present invention is shown in FIG.
The results are shown in FIG. Multiplex drive method shown in the figure
Is a method commonly used at present, and
However, in the present invention, another driving method is used.
It can also be used. Optically anisotropic material used in the present invention
19, for example, a liquid crystal composition, a uniaxially stretched film, a liquid crystal
Polymer film, made of a mixture of liquid crystal and polymer compound
Film or the like is used. When using a liquid crystal composition
Include smectic liquid crystal, cholesteric liquid crystal, nematic
Liquid crystal or the like can be used. Specifically, the nematic
Liquid crystal, and even nematic liquid crystal, the same as the display cell.
It is also a desirable method to use. For uniaxially stretched film
For example, polyvinyl alcohol, polyester
, Polyetheramide, polyethylene, etc.
A treated film can be used. Liquid crystalline polymer
In the film, for example, polypeptide-polymethacrylate
A related mixed film can be used. Also poly
Not only peptides but also other liquid crystalline polymers can be used.
But specifically, a liquid crystalline polymer with a cholesteric phase
It is desirable to be a child. The structural formula is shown below as an example.
You. Embedded image A film composed of a mixture of a liquid crystal and a polymer is
When used as an optically anisotropic body, for example, P
For low molecular liquid crystal such as CH, CCH and biphenyl
Liquid crystal composition with a helical structure
The substance is converted to a polymer such as polymethyl methacrylate,
Use a mixture of vinyl acetate, polyamide, etc.
be able to. Preferred liquid crystal composition mixed in polymer
An example was given. Embedded image The novel feature of the present invention is that a conventional STN type liquid crystal device is used.
Provided with an optically anisotropic body to prevent coloring
And there. The effect of this optically anisotropic body
This will be described in detail below. FIG. 18 shows a conventional STN shown in FIG.
Is an explanatory diagram of optical characteristics of an off state of the liquid crystal device, and FIG.
181 is an incident light. The incident light 181 is one
Generally, it is natural light and includes light of all wavelengths in the visible region,
The direction is also random. The incident light 181 is applied to the linear polarizer 1
Linear polarized light 1831
1832, 1833, etc. Here 1831
1832 and 1833 have wavelengths of 450 nm and 550, respectively.
nm, 650 nm. Of course other wavelengths
Includes linearly polarized light, but here the three colors of blue, green, and red
Only these three wavelengths are shown as representative wavelengths. These
The linearly polarized light 1831, 1832, 1833
Pass through the file 184. The liquid crystal layer in the liquid crystal cell is optically
Is a twist of nematic liquid crystal showing uniaxial refractive index anisotropy
The structure is taken. In a liquid crystal layer with such a structure
Pass through the linearly polarized light 1831, 1832, 1833, etc.
The polarization state changes when
Can be predicted by a method described later. For example, the figure above
The spectrum of the conventional liquid crystal device whose spectrum is shown in FIG.
The results for the cases are shown as 1851, 1852, 185, respectively.
The polarization state is as shown in FIG. Pass through the liquid crystal layer in this way
This causes wavelength dispersion in the polarization state. this
Finally, the polarizations 1851, 1852, and 1853 are linearly polarized.
The light passes through the light plate 186. Polarized light of each wavelength is a linear polarizer
Only the component corresponding to the direction of 186 passes. example
For example, the above-described conventional liquid crystal device whose spectrum is shown in FIG.
For example, in the case of 1871/1872/1873
You. The light amount at a wavelength of 550 nm is larger than that at a wavelength of 450 nm.
It can be seen that the amount of light at 650 nm and 650 nm is small. these
FIG. 20 shows a spectrum of the result of
FIG. 21 is a plot of this on the color coordinates.
I. Thus, the conventional STN-type liquid crystal device has a birefringence.
Inevitably become colored due to wavelength dispersion
Was. Next, the light in the off state of the liquid crystal device according to the present invention.
An explanatory diagram of the chemical characteristics is shown in FIG. Compare FIG. 18 with FIG.
Then, the optically anisotropic body 28 is added as a constituent element in FIG.
18 is different from FIG. For explanation
In other words, the constituent elements except for the optically anisotropic body 28 and the polarizing plate 26
The case is the conventional example shown in FIG.
Is the same as the liquid crystal device whose spectrum is shown in
You. Accordingly, in FIG.
State 251, 25 after passing through the light source 24
2 · 253 is 1851/1852/1853 in FIG.
Is exactly the same as The difference is that
It is light that each polarized light 251, 252, 253 passes next.
The point is that it is a geometrically anisotropic body 28. In the present invention
Is that the optically anisotropic body 28 is polarized light 231,232,2.
33 corresponds to the wavelength generated by passing through the liquid crystal cell 24.
The optical anisotropy acts to cancel the scattering
It is. In order to explain this operation clearly,
The optical function of the liquid crystal cell 24 is defined as M. Further 231
The polarization state of 232 · 233 is P, 251,252 · 2
Assuming that the polarization state of 53 is P ′, P ′ is expressed by the following equation from P and M.
Is required. P ′ = M * P ‥‥ (1) Here, the optical function of the optically anisotropic member 28 is inversely transformed by M.
Function M ^-1 Suppose that 291,292,293
Is the polarization state of P ′, P ″ is P ′ and M ^-1 From
Is required. P ″ = M ^-1 * P '‥‥ (2) The following equation is obtained from the above equations (1) and (2). P ″ = M ^-1 * M * P ‥‥ (3) Clearly, M ^-1 * M = 1 ‥‥ (4) Therefore, P ″ = P ‥‥ (5) The above equation (5) is the polarization state of 291,292,293.
(P ″) is the polarization state of 231,232,233 respectively
It is shown that it is the same as the state (P). 231/23
2 · 233 is a value obtained when the natural light 21 passes through the linear polarizer 22.
Since it is the latter polarized light, all the wavelengths
It is linearly polarized light having a corresponding vibration direction. Therefore 291
・ 292 ・ 293 also has the same orientation as 231 ・ 232 ・ 233
Is linearly polarized light having a vibration direction. Polarization of linear polarizing plate 26
The direction of the optical axis is the same as the vibration direction of the polarized lights 291, 292, 293
If they match, this linearly polarized light is directly linearly polarized.
The light passes through the light plate 26 and becomes 271, 272, and 273. The spectrum of the emitted light at this time is as shown in FIG.
This is consistent with the spectrum of the polarizer shown in I of 15 (only
Neglects light absorption in liquid crystal cells and optically anisotropic bodies
). Polarizer spectrum is almost flat and colorless
It is. Thus, in the liquid crystal device of the present invention, the off state
The coloring phenomenon of the state can be eliminated. Although the gist of the present invention is as described above, the problem is shown in FIG.
Of the linearly polarized light 231,232 incident on the liquid crystal cell 24
Inverse conversion of the conversion performed by the liquid crystal cell 24 on 233 etc.
Optical anisotropy that can be performed over all wavelengths
Is it possible to exist in In conclusion
A bright person may have such an optically anisotropic condition.
I found that. Moreover, such a condition is satisfied by the liquid crystal cell 2
Regardless of condition 4, found that it can exist
did. FIG. 1 is used to explain this condition.
Optical differences between the liquid crystal cell and the polarizing plate in the liquid crystal device of the present invention.
FIG. 3 shows the relationship with the cube. In FIG.
Rubbing direction of lower electrode substrate of crystal cell, 32 is liquid crystal cell
The rubbing direction of the upper electrode substrate of the
The optical axis direction of the surface facing the liquid crystal cell, 34 is optically anisotropic
The direction of the optical axis of the surface facing the polarizer of the body, 35 is the lower polarized light
The direction of the polarizing axis (absorption axis) of the plate, 36 is the polarization of the upper polarizing plate
Axis (absorption axis) direction, 37 is the direction of the polarization axis of the upper polarizer
Angle between the optical axis direction 34 of the optically anisotropic body and
Is the angle between the optical axis directions 33 and 34 of the optically anisotropic body, 39
Is the angle between 33 and 32, 40 is the liquid crystal layer in the liquid crystal cell
Of the twist angle of the liquid crystal cell, 30 is the rubbing direction of the liquid crystal cell 3
1 and the direction 35 of the polarization axis of the lower polarizer.
You. Here, for example, the conditions of the liquid crystal cell are shown in FIG.
The conventional positive mode liquid crystal device whose spectrum is shown in
Exactly the same conditions as the placement, ie the screw of the liquid crystal layer in the liquid crystal cell
The angle of the angle 40 is 200 degrees and Δn · d is 0.9 μm.
The whitening conditions in the case of this will be described. Optically anisotropic
In this case, the spectrum naturally becomes as shown in FIG.
It becomes a colored state. However, for example, liquid
Crystal cell, twist angle 38 of the liquid crystal layer is minus
200 degrees (that is, twisting the display liquid crystal cell
Δn · d is 0.9 μm
When used, as shown in FIG.
Spectrum becomes almost flat. However,
The other conditions are as follows. In FIG. 3, 37 is 45 degrees and 30 is the same.
45 degrees and 39 degrees are 90 degrees. The spectrum shown in FIG.
5 is plotted on the color coordinates. FIG. 2
It can be seen that it is almost white compared to the conventional method shown in FIG.
You. As shown in the above example, how the wavelength
However, as shown in FIG.
The condition of the chemical anisotropic body 28 exists. Show this correspondence
And the following. (1) Δn · d of the liquid crystal cell and Δn · d of the optically anisotropic body
Have the same absolute value. (2) Assuming that the twist angle of the liquid crystal cell is θ
The twist angle of the optically anisotropic body is minus θ (twist
Is reversed). (3) Opposite to the optically anisotropic liquid crystal cell
Optical axis direction 33 on the surface and Rabin on the upper electrode substrate of the liquid crystal cell
The angle 39 with the ganging direction 32 is 90 degrees. When the above three conditions hold, Δn · d
Of the liquid crystal device regardless of the value of the twist angle θ
The complete elimination of coloring in the
Wear. The above description is all about the coloring of the off state.
It was about the mechanism of dissolution. The present invention
In addition, coloring in the ON state is also eliminated at the same time.
Strictly explain the reason for the elimination of on-state coloring.
Is not impossible, but complicated. Invent anyway
The experimenter showed many examples in the examples described later.
No coloring in the ON state even under various conditions, or
Confirmed that there is almost no. As described above, coloring in the off state of the positive mode
In order to completely eliminate the above, the above three conditions must be satisfied.
Is necessary. However, in reality, it is not always shown in FIG.
As described above, the optically anisotropic material is a complete inverse of the liquid crystal cell conversion.
It is often sufficient for practical use. this child
Are conceptually shown in FIG. FIG. 6 corresponds to FIG.
You. 2 is different from FIG. 2 after passing through the optically anisotropic member 68.
The states 691, 692, and 693 of each polarized light correspond to the states 291 and 691 in FIG.
It is not perfect linearly polarized light like 292 and 293, but slightly
It is elliptically polarized light. As a result, the polarizing plate 6
6, the polarized light 671, 672, 673 after passing through
A slight degree of wavelength dependence occurs. example
For example, when a condition such as the condition shown in Example 20 described later is satisfied,
Fig. 8 shows the spectrum and Fig. 9 shows the spectrum on the color coordinates.
Are plotted. In the case of the conditions shown in Example 20, FIG.
After passing through an optically anisotropic body like 691, 692, 693 of 6
Is in an elliptically polarized state. Anyway
However, the coloring was almost completely eliminated as shown in FIG.
You. FIG. 7 shows an optically anisotropic body in this case and a liquid crystal cell.
And the relationship between each axis of the polarizing plate. As described above, the above three conditions are not satisfied.
Even practically, optical
An anisotropic condition exists. Alternatively, for other reasons,
It is better to use an optically anisotropic body other than the above three conditions
It may be desirable. One of the reasons is that the characteristics of the polarizing plate
In general, there is a wavelength dependency. The example is
This is shown in FIG. Optical characteristics such as these
By appropriately selecting the conditions of the anisotropic body, the liquid crystal device
Coloring can be improved. This is off state
Of course, the same applies to the ON state. Other reasons
In consideration of the wide viewing angle, the optical anisotropic
The matter may change. The optical anisotropy in the configuration shown in FIG.
Various conditions of the body have been described. Configuration shown in FIG.
In the drawing, the optically anisotropic body is above the liquid crystal cell in the drawing.
You. However, this hierarchical relationship has nothing to do with the essence of the present invention.
It is clear that This is shown in FIGS. 2 and 6.
This also applies to the positional relationship between the crystal cell and the optically anisotropic body. FIG. 10 shows another configuration example of the liquid crystal device of the present invention.
Indicated. FIG. 10 differs from the structure of FIG.
Exist both above and below the liquid crystal cell. Like this
Even in a simple configuration, complete coloring is effective as shown in FIG.
Can be eliminated. Naturally, as shown in FIG.
It is also possible to completely eliminate coloring. The above description is based on the state where the transmittance in the off state is high.
State, that is, the description of the positive mode. Off state
The following describes the state of low transmittance, that is, the negative mode.
You. The orientation of the polarization axis of the polarizing plate 26 in FIG.
If they are set to be orthogonal to the optical axis, the polarization 29
1, 292, 293 etc. all pass through the polarizing plate 26
Can not do. Therefore, the transmitted light
In the crossed Nicols state shown in FIG.
Matches the spectrum of the optical plate (except liquid crystal cell and optical
(Ignore light absorption etc. in a target anisotropic body). This state is
The darkest that can be obtained using the polarizer shown in FIG.
State. Thus, in the present invention, an optically anisotropic body is
By using it, even in the negative mode state,
The best flat spectral characteristics can be obtained. sand
That is, coloring can be eliminated in any case. Note that
The following description is for the positive mode. Next, the light passes through an optically anisotropic body such as a liquid crystal cell.
About the specific method of calculating the polarization state change of the light
The outline will be described below. Light incident on an optically anisotropic object is generally elliptical.
Polarization. Reference surface trace of elliptically polarized light now traveling in the positive direction of the Z axis
Is a column vector having xy components as elements, as follows:
be able to. [Equation 1] Here, ax and ay are the amplitudes of the xy components, respectively.
Width, ω is the angular frequency, ψx · ψy is the phase angle of the xy component
You. But in this case, the absolute phase of the wave does not matter
Then, the terms of the optical frequency and the absolute phase in the equation (6) are omitted.
The amplitude of each component is also normalized.
The state of polarization is described by the vector. [Mathematical formula-see original document] Now, the polarization E in the equation (7) is an optically anisotropic substance.
, And changes the polarization state to become the polarization E ′. Optical
The anisotropy is described by a 2 × 2 Jones matrix that performs this transformation.
Is expressed. For example, this optically anisotropic material is
When the linear phase retarder is uniaxial like a molecule,
The Jones matrix R can be expressed by the following equation. [Mathematical formula-see original document] Here, θ indicates that the fast axis of the linear phase shifter is the X axis.
The angle to be formed, Δ indicates retardation. In addition, Rita
Is the linear phase shifter Δn · d and the light wavelength λ.
Is defined as Δ≡2πΔn · d / λ. Polarization of light passing through this film-like polymer
From the left side of the incident light vector E, the state of the equation (8)
With the action of the Moon's matrix R
You. (Equation 4) Further, the optically anisotropic substance forms a film polymer.
If it is assumed that two or more sheets are stacked, the incident light vector
From the left side of Le E, according to the order of passing light
Apply the Jones matrix of equation (8) to obtain
Can be [Mathematical formula-see original document] When the optically anisotropic body is a liquid crystal cell,
Because the liquid crystal molecules are twisted,
It is complicated. However, as shown in FIG.
If the layer is divided into a sufficiently large number of layers, it will be shown in FIG.
Approximate by stacking liquid crystal layers that are not twisted.
Can be The liquid crystal layer that is not twisted
Since it is the same uniaxial linear retarder as the lumped polymer,
In the same way as when a plurality of
The polarization state of light that has passed through the liquid crystal cell.
Wear. Using the method described above, the angle 4 in FIG.
0 is 200 degrees, angle 38 is minus 200 degrees, angle 30
45 degrees, angle 37 45 degrees, angle 39 90 degrees
Liquid crystal cell and Δn · d of optically anisotropic body
Under the above-mentioned conditions of 0.9 μm, each of the liquid crystal layers was
The transition of the polarization state of light calculated by dividing into 20 is shown in FIG.
FIG. Figures 12, 13 and 14 are respectively
Polarization of light with wavelengths of 450 nm, 550 nm, and 650 nm.
The light state transition is shown. For example, in the case of FIG.
(A) The linearly polarized light 12 incident on the display liquid crystal cell in FIG.
1 is polarized as 122, 123, and 124 every 5 layers
The state changes and the cell exits with 125 elliptically polarized light. This
The elliptically polarized light 125 of FIG.
It is incident on the anisotropic body, and also after every five layers, 126.12
The polarization state changes to 7.128, and 129 linearly polarized light
Emit an optically anisotropic object. In each of the above steps,
The conversion of the polarization state by the optically anisotropic body in FIG.
Just the reverse of the conversion by the display liquid crystal cell in (a)
Light incident on the display liquid crystal cell,
An optically anisotropic body is emitted in exactly the same polarization state. This effect
As is clear from FIG. 13 and FIG.
Irrespective of the liquid crystal display device having the configuration of the present invention.
Coloration in the off state is completely eliminated and whitening
It becomes possible. As described above, when the above three conditions are not satisfied,
There is an optically anisotropic condition that can sufficiently eliminate
Exist. The condition is that light incident on one polarizing plate
Is the liquid crystal cell and the optical difference adjacent to the liquid crystal cell.
Elliptically polarized light with a different major axis for each wavelength
After that, when the light enters the other polarizer,
The optic so that the elliptically polarized light is substantially aligned in the major axis direction.
What is necessary is just to arrange a target anisotropic body. Specifically, the liquid crystal display
Of the optically anisotropic body according to the twist angle of the
Conditions may be set as appropriate, and the conditions will be described below based on the examples.
And will be described specifically. FIG. 22 shows a liquid crystal device according to the present invention.
Of the liquid crystal device when liquid crystal is used as the optically anisotropic
It is sectional drawing which showed the structure modelly. In the figure,
2201 is an upper polarizer, 2202 is an optically anisotropic body
Liquid crystal cell (hereinafter referred to as A cell)
2203 is the upper substrate of the A cell, 2204 is the A cell
The lower substrate 2205 is a liquid used as an optically anisotropic body.
Crystal 2206 is a liquid crystal cell (hereinafter referred to as a liquid crystal cell) which performs display by applying a voltage.
2207 is the upper electrode base of the B cell.
Plate, 2208 is the lower electrode substrate of the B cell, and 2209 is the B cell
Reference numeral 2210 denotes a lower polarizing plate.
FIG. 23 is a diagram showing the relationship between each axis of the liquid crystal device of the present invention.
You. In the figure, reference numeral 2311 denotes a lower electrode substrate of the B cell.
The rubbing direction 2312 is the rubbing direction of the upper electrode substrate of the B cell.
Bubbling direction, 2313 is rubbing direction of lower substrate of A cell
Direction 2314 is the rubbing direction of the upper substrate of the A cell, 23
15 is the direction of the polarization axis (absorption axis) of the lower polarizing plate;
Is the direction of the polarization axis (absorption axis) of the upper polarizer, and 2317 is the upper direction
The direction 2316 of the polarization axis (absorption axis) of the side polarizer and the
Angle formed by rubbing direction 2314 of upper substrate, 231
8 is the size of the liquid crystal twist angle in the A cell, and 2319 is the A cell.
Rubbing direction 2313 of the lower substrate of the
Angle between the rubbing direction 2312 of the polar substrate and 2320
Is the magnitude of the twist angle of the liquid crystal in the B cell, and 2321 is the B cell.
Rubbing direction 2311 of lower electrode substrate and lower polarizing plate
Of the polarization axis (absorption axis) of the
You. After that, the twist direction of the liquid crystal molecules in each cell
It is shown in the twisting direction from below to below. [Example 1] In FIG.
Crystal twist angle 2320 is about 200 degrees left twist, Δn ·
d is about 0.9 μm, angle 2319 is about 90 degrees, angle 23
17 from 30 to 60 degrees, angle 2321 to 30 degrees
To 60 degrees, the twist angle of the liquid crystal of cell A
2318 and Δn · d are the hatched portions in FIG.
Occasionally, it is almost white in the off state and almost black in the on state
A color liquid crystal device is obtained. The above conditions use the above equations (6) to (8).
Can be obtained by calculation.
An example will be described. That is, Δn · d twisted to the left by 200 °
= 0.9 μm B cell in the thickness direction of the cell
It is divided into 0, and 1 of Δnd · 0.0045 μm per layer
The axial phaser has a structure twisted by 1 ° to the left
The calculation is performed according to the above formula. At this time
The wavelength of the light is between 400 nm and 700 nm.
You. The polarization state of light incident on the liquid crystal of the B cell is
It differs depending on the type of polarizing plate used and the direction of the axis.
Imaginary polarizing plate (Transmissivity 50% when parallel Nicols, Cross Nicol
(Transmittance at the time of 0%). And on the polarizing plate
Rubbing direction of the adjacent substrate (the direction of the liquid crystal molecules on the substrate surface
Direction) and the direction of the polarization axis of the polarizing plate are 45 °.
You. Then, the linearly polarized light that has passed through the polarizing plate enters the B cell.
And the ellipse of light of each wavelength that has passed through the B cell
The state of polarization is determined. Next, the elliptically polarized light enters the A cell and passes therethrough.
The state of the elliptically polarized light after the calculation is obtained. Ellipse incident on cell A
Circularly polarized light is obtained by the same calculation as above, and the A cell and B cell
The angle between the rubbing directions of adjacent substrates should be 90 degrees.
You. Also, the liquid crystal of A cell is divided into 200 cells in the cell thickness direction.
Then, the uniaxial phase shifter is twisted to the right by 0.7 degrees and the whole
And then it has a structure that is twisted 140 degrees to the right
Assuming that Δn · d of the liquid crystal layer is an appropriate value, the above formula can be used.
Then, the state of the elliptically polarized light that has passed through the A cell can be obtained. further,
Here, the rubbing direction of the substrate adjacent to the polarizing plate and the
Pass through the polarizing plate at an angle of 45 degrees with the direction of the polarization axis
To determine the Y value after visibility correction
You. In the above calculation, Δn of the liquid crystal of the A cell
・ The value of d is set from 0 μm to 1.5 μm,
The relationship between Δn · d and the Y value after the visibility correction is obtained. This and
When Δn · d of the A cell is taken on the horizontal axis and the Y value is taken on the vertical axis, FIG.
As shown in (b), the Y value has a maximum value and a minimum value, and changes periodically.
Become The angle between the polarization axis and the rubbing direction is 45 degrees.
24B, there are two directions.
Curves are drawn. The display mode is negative mode.
(Dark when no voltage is applied) and positive mode (no voltage applied)
Condition is bright). No voltage applied in negative mode
It is desirable that the state is darker.
It is desirable that the non-application state be brighter. Therefore, FIG.
The part where the Y value is maximum in 4 (b) is in the positive mode, and the Y value is
Where the minimum is suitable for the negative mode. The Y value in the conventional negative mode voltage application state is
About 5% high, and clearly visible and on color coordinates
It is recognized that it is colored blue. On the other hand, the minimum Y in FIG.
The value is half of the Y value in the negative mode of the conventional STN type liquid crystal device.
It is as follows. The color at this time is slightly worn on the color coordinates
Although it is colored, it is sufficiently close to black visually when the Y value is small.
Recognized as a color. White when voltage is applied
It is recognized as. Therefore, in the negative mode, the Y value
At this time, Δn ·
d is the desired value. The part where the Y value is maximum is
Visual comparison with the color without voltage applied in the mode
However, the color coordinates are close to white. However, the Y value is maximal
It is almost white before and after the part. for that reason
In the positive mode, the area where black-and-white display can be obtained is quite wide.
And it is very difficult to determine the boundary.
Also, since the angle between the polarization axis and the rubbing direction is 45 degrees,
The direction of the polarization axis at one curve in FIG.
When shifted by a degree, it coincides with the polarization axis that is the other curve.
Accordingly, the maximum and minimum Δn · d in FIG.
The values are the same. From the above, the monochrome value means that the Y value is minimal.
Δn · d. In other words, the B cell has a left twist of 2
At 00 °, Δn · d = 0.9 μm, which is adjacent to the polarizing plate.
Direction of rubbing direction of substrate of B cell and direction of polarization axis of polarizing plate
Is 45 degrees, and the B cell and the A cell are adjacent to each other.
The angle between the rubbing directions of the substrates is 90 degrees, and A
The cell has a right-hand twist of 140 degrees, and the A cell adjacent to the polarizing plate
Between the rubbing direction of the substrate and the direction of the polarization axis of the polarizing plate.
When the angle of inclination is 45 degrees, Δn · d of the A cell is 0.
33 μm, 0.7 μm, 1.0 μm, 1.3 μm (A
Black and white when Δn · d is less than 1.5 μm)
Is obtained (see FIG. 24B). Next, the lamination of the substrate of each cell adjacent to the polarizing plate
Bing direction and direction of polarization axis of polarizing plate are other than 45 degrees
Or the rubbing method of each of the substrates adjacent to the B cell and the A cell
The same procedure is applied to the case where the direction angle is other than 90 degrees.
Perform calculations with. Then, the value of cell A where the Y value becomes
Δn · d is calculated as a range that has a certain width and appears periodically.
Round (in FIG. 24 (a), the twist angle is fixed to 140 degrees to the right.
Distribution of Δn · d when it is determined). However, at this time
As for the angle between the directions of the axes, the minimum value of the Y value is 3% or less.
Or, it is a range that does not cause extreme coloring. The condition of the B cell is kept as it is, and
The above also applies when only the magnitude of the cell twist angle is changed.
As described above, the range of Δn · d of the A cell in which the Y value is minimal is
Appears periodically. The A-cell I found in this way
FIG. 2 shows the relationship between the magnitude of the twist angle and Δn · d.
4 (a). That is, from FIG. 24A, the B cell is
When Δn · d is 0.9 μm with a left twist of 200 degrees
Is the magnitude of the torsion angle of the A cell and the Δ
There is not only one condition of n · d.
It can be seen that a fan-shaped range exists periodically. Further, the magnitude of the twist angle of the B cell and Δn
・ When d is changed, the black and white table
The magnitude of the twist angle and Δn · d of the A cell from which the
Can be Also in this case, the magnitude of the twist angle of the A cell and Δ
The relationship of n · d is fan-shaped and appears periodically. Thus, the torsion angle of an arbitrary B cell is
A cell screw for black and white display for Δn · d
Angle and Δn · d can be obtained.
Angle and Δn · d are not unique, and there are many
Things. [Embodiment 2] In Embodiment 1, the configuration shown in FIG.
The angle 2317 is about 40 degrees, and the twist angle 23 of the liquid crystal of the A cell is 23.
18 to about 140 degrees right twist, angle 2319 to about 90
Degrees, the twist angle 2320 of the liquid crystal of the B cell is about 200 degrees to the left.
Twist, angle 2321 about 40 degrees, Δ of liquid crystal layer of A cell
n · d is about 0.7 μm, and Δn · d of the liquid crystal layer of the B cell is about 0.7 μm.
0.9 μm. The appearance of the liquid crystal device at this time
The torque is shown in FIG. In the figure, curve I is off
The curve II shows the ON state. Conventional as shown in FIG.
The spectrum of the appearance of liquid crystal devices by technology is off (car
Yellow) when on (curve II)
Is blue. However, as shown in FIG.
As described above, in the liquid crystal device of the present invention, almost white is obtained in the off state.
And is almost black in the on state. [Embodiment 3] In the embodiment 1, in FIG.
The angle 2317 is about 40 degrees, and the twist angle 23 of the liquid crystal of the A cell is 23.
18 to the right about 200 degrees, angle 2319 to about 90
Degrees, the twist angle 2320 of the liquid crystal of the B cell is about 200 degrees to the left.
Twist, angle 2321 is about 50 degrees, Δ of liquid crystal layer of A cell
n · d is about 0.9 μm, and Δn · d of the liquid crystal layer of the B cell is about 0.9 μm.
0.9 μm. The appearance of the liquid crystal device at this time
The torque is shown in FIG. In the figure, curve I is off
The curve II shows the ON state. Also in this case, the second embodiment
As in the above, it is almost white in the off state and almost white in the on state.
It is black. [Fourth Embodiment] In the first embodiment, the configuration shown in FIG.
The angle 2317 is about 40 degrees, and the twist angle 23 of the liquid crystal of the A cell is 23.
18 to the right of about 260 degrees, angle 2319 to about 90
Degrees, the twist angle 2320 of the liquid crystal of the B cell is about 200 degrees to the left.
Twist, angle 2321 about 40 degrees, Δ of liquid crystal layer of A cell
n · d is about 0.8 μm and Δn · d of the liquid crystal layer of the B cell is about
0.9 μm. The appearance of the liquid crystal device at this time
The torque is shown in FIG. In the figure, curve I is off
The curve II shows the ON state. In this case, too,
2. Similar to the third embodiment, almost white in the off state,
It is almost black in the on state. [Embodiment 5] In FIG.
Angle of twist of crystal is about 250 degrees left twist, Δn ·
d is about 0.9 μm, angle 2319 is about 90 degrees, angle 23
17 from 30 to 60 degrees, angle 2321 to 30 degrees
To 60 degrees, the twist angle of the liquid crystal of cell A
When 2318 and Δn · d are shaded in FIG.
Almost white in off state, almost black in on state
A liquid crystal device is obtained. [Sixth Embodiment] In the fifth embodiment, the structure shown in FIG.
The angle 2317 is about 40 degrees, and the twist angle 23 of the liquid crystal of the A cell is 23.
18 to the right about 160 degrees, angle 2319 to about 90
Degrees, the twist angle 2320 of the liquid crystal of the B cell is about 250 degrees to the left.
Twist, angle 2321 about 40 degrees, Δ of liquid crystal layer of A cell
n · d is about 0.8 μm and Δn · d of the liquid crystal layer of the B cell is about
0.9 μm. The appearance of the liquid crystal device at this time
The torr is shown in FIG. In the figure, curve I is off
The curve II shows the ON state. Also in this case, the second embodiment
As in the above, it is almost white in the off state and almost white in the on state.
It is black. [Embodiment 7] In FIG.
7 is about 40 degrees, and the twist angle 2318 of the liquid crystal of A cell is about 3
60 degree right twist, angle 2319 about 90 degree, B cell
Liquid crystal twist angle 2320 left twist about 250 degrees, angle
2321 is set to about 40 degrees, and Δn of the liquid crystal layer of the A cell is further increased.
D is about 1.0 μm, and Δn · d of the liquid crystal layer of the B cell is about
0.9 μm. Also in this case, it is white in the off state.
Thus, the liquid crystal device becomes blacker in the on state. [Embodiment 8] In FIG.
7 is about 50 degrees, and the twist angle 2318 of the liquid crystal of A cell is about 1
70 degree right twist, angle 2319 about 90 degree, B cell
Liquid crystal twist angle 2320 is about 170 degrees left twist, angle
2321 is set to about 40 degrees, and Δn of the liquid crystal layer of the A cell is further increased.
D is about 0.7 μm, and Δn · d of the liquid crystal layer of the B cell is about
0.7 μm. Also in this case, it is white in the off state.
In the on state, the liquid crystal device becomes blacker. [Embodiment 9] In FIG.
Crystal twist angle 2320 to about 120 degrees left twist, Δn
d is about 0.9 μm, angle 2319 is about 90 degrees, angle 23
17 from 30 to 60 degrees, angle 2321 to 30 degrees
To 60 degrees, the twist angle of the liquid crystal of cell A
Assuming that 2318 and Δn · d are shaded portions in FIG. 30,
Almost white in off state, almost black in on state
A liquid crystal device is obtained. [Embodiment 10] Referring to FIG.
The twist angle 2320 of the liquid crystal is about 200 degrees left twist, Δn
D is about 0.6 μm, angle 2319 is about 90 degrees, angle 2
317 from 30 degrees to 60 degrees, angle 2321 to 30 degrees
To 60 degrees, the twist of the liquid crystal of A cell
When the angle 2318 and Δn · d are defined as the hatched portions in FIG.
When it is off, it is almost white, and when it is on, it is almost black.
Is obtained. [Embodiment 11] Referring to FIG.
The twist angle 2320 of the liquid crystal is about 200 degrees left twist, Δn
D is about 1.5 μm, angle 2319 is about 90 degrees, angle 2
317 from 30 degrees to 60 degrees, angle 2321 to 30 degrees
To 60 degrees, the twist of the liquid crystal of A cell
When the angle 2318 and Δn · d are defined by the hatched portions in FIG.
When it is off, it is almost white, and when it is on, it is almost black.
Is obtained. [Embodiment 12] Referring to FIG.
Liquid crystal twist angle 2320 is about 350 degrees left twist, Δn
D is about 0.9 μm, angle 2319 is about 90 degrees, angle 2
317 from 30 degrees to 60 degrees, angle 2321 to 30 degrees
To 60 degrees, the twist of the liquid crystal of A cell
If the angle 2318 and Δn · d are the shaded portions in FIG.
When it is off, it is almost white, and when it is on, it is almost black.
Is obtained. [Embodiment 13] From Embodiment 1 to Embodiment 12
In this case, the same effect can be obtained even if the A cell and the B cell are arranged upside down.
Fruit is obtained. Further, the lower substrate 2 of the A cell shown in FIG.
204 and an upper electrode substrate 2207 of the B cell.
The same effect can be obtained by replacing the substrate with a single substrate. [Embodiment 14] In FIG. 34, 3422 is
The upper polarizer, 3423 is the upper A cell, 3424 is the B cell
, 3425 is a lower A cell, and 3426 is a lower polarizing plate.
You. In the liquid crystal device having the structure shown in FIG.
3. The liquid crystal molecules of both the lower A-cell 3425 are twisted to the right.
You. The liquid crystal molecules of the B cell 3424 are twisted left.
At this time, the twist angle of the liquid crystal molecules of the upper A cell 3423 is
Twist angle of liquid crystal molecules of lower A cell 3425
Is the torsion angle of the entire A cell, and the liquid of the upper A cell 3423 is
Δn · d of the crystal layer and Δn · d of the liquid crystal layer of the lower A-cell 3425.
The sum of d is defined as Δn · d of the entire A cell. This A
Example 1 The torsion angle of the entire cell and Δn · d of the entire A cell
Even when the conditions for the A cell from Example to Example 12 were used,
The same effects as in the first to twelfth embodiments can be obtained. Up
The order in which cells 3423, 3424, and 3425 are arranged is determined.
The same effect can be obtained even if it changes. A cell is
Under the same conditions as above, three or more layers can be provided. [Embodiment 15] In the structure of Embodiment 14
And the lower substrate 3429 of the upper A cell 3423 and the B cell 3
424 upper electrode substrates 3430 are combined into one base.
Replace with a board. Further, the lower electrode substrate of B cell 3424
3432 and the upper substrate 3433 of the lower A cell 3425
One substrate is replaced with one substrate. If you do this
The number of substrates is reduced, the structure is simplified, and the same as in Embodiment 14.
The same effects can be obtained. [Embodiment 16] From Embodiment 1 to Embodiment 15
The temperature T of the liquid crystal NI point of the A cell _A (K), B cell
The temperature at the NI point of the liquid crystal _B (K). At this time, 0.86 ≦ T _A / T _B When a liquid crystal satisfying ≦ 1.15 is used, the B cell and the A cell
Even when the Δn · d of the liquid crystal layer changes, the appearance color of the liquid crystal device is almost
Almost unchanged. [Embodiment 17] From Embodiment 1 to Embodiment 16
Here, as the liquid crystal of the A cell, the dielectric anisotropy Δε is positive.
When using a liquid crystal, A
Liquid crystal orientation is disturbed, and color unevenness appears on the appearance of the liquid crystal device.
Sometimes. Therefore, as the liquid crystal of A cell,
If a liquid crystal with a negative rate anisotropy Δε is used,
Liquid that does not cause uneven color appearance even if it is affected by static electricity
Crystal unit. [Embodiment 18] From Embodiment 1 to Embodiment 16
Then, attach electrodes inside the upper and lower substrates of the A cell,
A liquid crystal having a positive Δε is used as the liquid crystal. By doing so
Even if the temperature changes the color of the external appearance of the liquid crystal device.
Even if a voltage is applied between the electrodes attached to the upper and lower substrates of A cell
By doing so, it is possible to cancel the change in color. [Embodiment 19] Embodiments 13 and 15 are
In Examples 1 to 18 except for A cell and B
In order to prevent light reflection on the substrate surface where the cell contacts,
And the B cell are optically bonded. Embossed as an adhesive layer
Heat and pressure using a modified polyvinyl butyral film
To adhere. In addition, thermosetting epoxy as an adhesive
A system-based and urethane-based adhesive may be used. Further access
A lil-based UV adhesive may be used. As above
When cell A and cell B are bonded together, reflection occurs at the interface between both cells
Can be reduced. [Embodiment 20] FIG. 35 shows an optically anisotropic body.
Using a film-like polymer layer (hereinafter referred to as A film)
The following shows an example of the structure in the case where there is. In the figure, 3536 is
Upper polarizing plate, 3537 is upper A film, 3538 is B
Cell, 3539 is lower A film, 3540 is lower polarized light
It is a board. FIG. 36 shows a liquid crystal device using an A film.
FIG. 3 is a diagram showing a relationship between each axis of the arrangement. In FIG.
5 is the rubbing direction of the upper electrode substrate of the B cell, 3646 is
Rubbing direction of lower electrode substrate of B cell, 3647 is upper side
3648 is the light of the lower A film toward the optical axis of the A film.
Axis direction, 3649 is the polarization axis (absorption axis) of the upper polarizer
Direction, 3650 is toward the polarization axis (absorption axis) of the lower polarizer
Direction 3651 is the direction 3 of the polarization axis (absorption axis) of the upper polarizer.
649 and the direction 3647 of the optical axis of the upper A film.
Angle 3652 is the direction 3647 of the optical axis of the upper A film
And the rubbing direction 3645 of the upper electrode substrate of the B cell.
Angle, 3653 is the magnitude of the twist angle of the liquid crystal of the B cell,
Reference numeral 3654 denotes a rubbing direction 364 of the lower electrode substrate of the B cell.
6 and the angle formed by the optical axis direction 3648 of the lower A film
3655 is the optical axis direction 3648 of the lower A film and lower
Angle between the polarization axis (absorption axis) of the side polarizer and the direction 3650
Degrees. In the figure, the angle 3651 is set to about 40 degrees,
Degree 3652 is about 90 degrees, Angle 3653 is about 200 degrees left
Lower electrode substrate of B cell without inserting twisted lower A film
Rubbing direction 3646 and the polarization axis (absorption
The angle between the direction 3650 and the axis 3650 is about 40 degrees. Ma
In addition, the refractive index anisotropy Δn of the upper A film and the upper A film
The product Δn · d of the layer thickness d is about 0.55 μm,
n · d is about 0.9 μm. At this time, the LCD
When the color of the appearance of the device is off, it is almost white,
Will be almost black. This A film is made of DAC, PET, vinegar.
Acid cellulose, PVA, polyamide, polyether sal
Phone, acrylic, polysulfone, polyimide, poly
An olefin-based uniaxially stretched film is used. An example using the A film will be described below.
You. [Embodiment 21] In FIG.
51 at about 50 degrees, angle 3652 at about 90 degrees, B cell liquid
Crystal twist angle 3653 left twist about 200 degrees, angle 3
654 is about 90 degrees, and the angle 3655 is about 50 degrees. Ma
Further, Δn · d of the upper A film and Δn of the lower A film
・ Addition of d is about 0.6μm, Δn ・ d of B cell is
It is about 0.9 μm. In this case, the same effect as in the twentieth embodiment is obtained.
Fruit is obtained. [Embodiment 22] Referring to FIG.
When there is no film, Δn ·
d is about 0.55 μm, angle 3651 is about 50 degrees, angle 3
652 about 90 degrees, B cell liquid crystal twist angle 3653
Approximately 250 degrees left twist, Rabin B cell lower electrode substrate
Direction 3646 and the direction of the polarization axis (absorption axis) of the lower polarizer
The angle formed with 3650 is about 50 degrees, and Δn ·
Even when d is about 0.9 μm, the appearance color of the liquid crystal device is
It is almost white in the off state and almost black in the on state.
You. [Embodiment 23] Referring to FIG.
There is no film, and the upper A film is 1 from top to bottom.
11 fills with optical axis shifted in the direction of right twist by 5 degrees
And the sum of Δn · d is about 0.7 μm.
Furthermore, the polarization axis (absorption axis) of the upper polarizer and the upper A film
The angle between the uppermost film and the direction of the optical axis of the
Degree, the direction of the optical axis of the lowermost film of the upper A film and
Approximately the angle between the rubbing direction of the upper electrode substrate of B cell
90 °, rubbing direction of lower electrode substrate of B cell and lower deviation
The angle between the optical axis and the polarization axis (absorption axis) is about 40 degrees,
B-cell liquid crystal twist angle 3653 with left-handed screw of about 200 degrees
Then, the Δn · d of the liquid crystal of the B cell is set to about 0.9 μm. This
The color of the external appearance of the liquid crystal device is almost white in the off state
In the on state, the color becomes almost black. [Embodiment 24] Referring to FIG.
When there is no film 3539, the upper A-fill
The Δn · d of the memory 3537 is about 0.65 to 0.85 μm.
36 angle 3651 from 35 degrees to 55 degrees, angle 3652
From 80 degrees to 100 degrees, the twist angle 365 of the liquid crystal of the B cell.
3 with a left twist of about 200 degrees,
Bing direction 3646 and the polarization axis (absorption axis) of lower polarizing plate
The angle between direction 3650 and 35 degrees
The Δn · d of the liquid crystal was set to about 0.9 μm. The appearance color of this liquid crystal device is almost off in the off state.
It became slightly white and almost black in the on state. [Embodiment 25] Referring to FIG.
When there is no film 3539, the upper A-fill
Δn · d of the memory 3537 is about 0.25 to 0.45 μm.
36 angle 3651 from 35 degrees to 55 degrees, angle 3652
From 80 degrees to 100 degrees, the twist angle 365 of the liquid crystal of the B cell.
3 with a left twist of about 200 degrees,
Bing direction 3646 and the polarization axis (absorption axis) of lower polarizing plate
Angle between direction 3650 and 35 degrees, B cell
Of the liquid crystal was about 0.9 μm. This liquid crystal device
The appearance color is almost white in the off state and in the on state
It became almost black. [Embodiment 26] Referring to FIG.
When there is no film 3539, the upper A-fill
36 is about 0.4 to 0.6 μm, and FIG.
Angle 3651 from 35 degrees to 55 degrees, and angle 3652 to 8
0 to 100 degrees, the twist angle 3653 of the liquid crystal of B cell
180 degrees left twist, Rabin B cell lower electrode substrate
Direction 3646 and the direction of the polarization axis (absorption axis) of the lower polarizer
Angle between 3650 and 35 ° to 35 °, B cell liquid crystal
Was set to about 0.9 μm. The appearance color of this liquid crystal device is almost off in the off state.
It became slightly white and almost black in the on state. [Embodiment 27] Referring to FIG.
When there is no film 3539, the upper A-fill
Δn · d of the camera 3537 is about 0.5 to 0.7 μm, and the angle 3
651 from 35 degrees to 55 degrees, and the angle 3652 in FIG.
0 to 100 degrees, the twist angle 3653 of the liquid crystal of B cell
180 degrees left twist, Rabin B cell lower electrode substrate
Direction 3646 and the direction of the polarization axis (absorption axis) of the lower polarizer
Angle between 3650 and 35 ° to 35 °, B cell liquid crystal
Was set to about 1.0 μm. The appearance color of this liquid crystal device is almost off in the off state.
It became slightly white and almost black in the on state. [Embodiment 28] Referring to FIG.
When there is no film 3539, the upper A-fill
36 is about 0.5 to 0.6 μm, and FIG.
Angle 3651 from 35 degrees to 55 degrees, and angle 3652 to 8
0 to 100 degrees, the twist angle 3653 of the liquid crystal of B cell
230 degrees left twist, Rabin on the lower electrode substrate of B cell
Direction 3646 and the direction of the polarization axis (absorption axis) of the lower polarizer
Angle between 3650 and 35 ° to 35 °, B cell liquid crystal
Was set to about 0.9 μm. The appearance of the liquid crystal device is almost off in the off state.
It became slightly white and almost black in the on state. [Embodiment 29] Embodiments 20 to 28
In the above, the A film is integrated with the polarizing plate.
You. FIG. 37 shows the structure when the polarizing plate and the A film are integrated.
The structure is shown as a model. In the figure, reference numeral 3756 denotes a polarizing plate.
Protective film, 3775 is a polarizer, 3758 is an A film
And 3759, a protective film for the polarizing plate. See the same figure
A film integrated with a polarizing plate and used in a liquid crystal device
Has the same effect. [Embodiment 30] From Embodiment 1 to Embodiment 29
Then, place the reflector outside the upper or lower polarizer
Also, a reflection type liquid crystal device for monochrome display can be obtained. [Embodiment 31] The A filter shown in the embodiment 20 will be described.
Instead of using LUM as an optical anisotropic body, cholesteric
Liquid crystalline polymer film (hereinafter referred to as Ach film)
Example of the case of using “Lum” as an optically anisotropic body
Will be described in detail. FIG. 38 shows an Ach filter as an optically anisotropic body.
This shows a structure using a memory. 3861 in FIG.
Upper polarizer, 3862 Ach film, 3863 B
Cell, 3864: upper electrode substrate of B cell, 3865: B
The liquid crystal of the cell, 3866 is the lower electrode substrate of the B cell, 386
7 is a lower polarizing plate. FIG. 39 shows a liquid crystal using an Ach film.
FIG. 4 is a diagram illustrating a relationship between axes of the display device. In the figure
3968 is a rubbing direction of the lower electrode substrate of the B cell;
69 is a rubbing direction of the upper electrode substrate of the B cell, 3970
Is the major axis of the liquid crystal molecules adjacent to the B cell of the Ach film
Direction, 3971 is adjacent to the upper polarizer of the Ach film
Long axis direction of liquid crystal molecules, 3972 is polarization axis of lower polarizer
Direction (absorption axis), 3973 is the polarization axis (absorption axis) of the upper polarizer.
3974 is the large twist angle of the liquid crystal of the B cell.
3975 is the angle between 3970 and 3969
Degrees, 3976 is the angle between the 3973 and 3971
Degrees, 3977 is the angle between the 3968 and 3972
Degrees, 3978 is the angle between the 3971 and 3970
Degree shall be indicated. Here, a polarizing plate, an Ach film and a B cell
Are arranged as shown in FIG. 38, and the conditions of each axis are set as follows.
Specified. The twist angle 3974 of the liquid crystal of the B cell is set to about 20.
0 degree left twist, B so that Δn · d is 0.9 μm
The cell was assembled. On the other hand, Ach film
Angle 3978 twisted to the right about 330 degrees, Δn · d uniaxial
Adjusted to about 1.05 μm in terms of stretched film
Adjust the angle 3975 from 80 degrees to 100 degrees, angle 397
6 and 3977 range from 40 degrees to 50 degrees respectively
The liquid crystal device was manufactured by setting. At this time, the liquid crystal device
When the over-light spectrum is measured, the appearance color is off.
In this case, the color became almost white, and in the on state, the color became almost black. In this embodiment, the Ach film is made of poly
Peptide and polmethyl methacrylate [Example 32] In FIG.
Angle 3974 is twisted left about 200 degrees, Δn · d is 0.9
A B cell was assembled to have a thickness of μm. On the other hand, Ach
The film in advance and the angle 3978 to the right about 360 degrees.
And Δn · d is about 1.0 in terms of uniaxially stretched film.
and adjust the angle 3975 from 80 degrees to 1
00 degree range, angles 3976 and 3977 respectively
The liquid crystal device is manufactured by setting it in the range of 40 degrees to 50 degrees.
Was. At this time, almost white when the color of the external appearance is off.
The color became almost black in the ON state. [Embodiment 33] Referring to FIG.
The liquid crystal twist angle 3974 is about 200 degrees left twist, Δn
The B cell was assembled so that d was 0.9 μm. one
On the other hand, the Ach film is set in advance and the angle
10 ° right twist, Δn · d converted to uniaxially stretched film
And adjust the angle to about 0.95 μm.
Range from 80 to 100 degrees, angle 3976 to 40 degrees
Angle of 3977 in the range of 40 to 50 degrees.
The liquid crystal device was manufactured by setting to the box. At this time, the appearance is almost white when the color is off.
The color became almost black in the ON state. [Embodiment 34] Referring to FIG.
The twist angle of the liquid crystal 3974 is about 180 degrees left twist, Δn
The B cell was assembled so that d was 0.9 μm. one
On the other hand, Ach film in advance, angle 3978 about 1
80 ° right twist, Δn · d converted to uniaxially stretched film
And adjust it to be about 0.9 μm.
80 degrees to 100 degrees, angle 3976 from 40 degrees
50 degree range, angle 3977 range from 40 degree to 50 degree
And the liquid crystal device was manufactured. At this time, the appearance is almost white when the color of the appearance is off.
The color became almost black in the ON state. [Example 35] In Examples 31 to 34
Instead of liquid crystalline polymer films,
Even when a mixture of liquid crystals is used, the same results as in Examples 31 to 34 are obtained.
The fruit was obtained. [Embodiment 36] In Embodiments 31 to 34
TN liquid crystal ZLI3 manufactured by Merck as an Ach film
285 and a chiral dopant CB-15 manufactured by BDH
Consisting of a mixture of
The same as in Examples 31 to 34 when using a rimer film.
The effect was obtained. Example 37 In Examples 31 to 36
Use a reflector outside the upper or lower polarizer.
Is almost white in the off state,
Became almost black. According to the present invention, the conventional STN type liquid crystal device can be used.
The coloring phenomenon, which was a major drawback of the arrangement, was solved. I mean
The present invention has enabled perfect black and white display. If only that
However, the amount of light in the transmission state increased, and a bright display was obtained. Change
In addition, the amount of light leaking in the non-transmission state
Along with the increase in the amount of light in the state, the contrast ratio
Up. According to the above effects, the present invention provides a color display.
Good color display characteristics when applied to
Came. Especially when the twist angle is 180 degrees or more,
Is the front, and the area near the concentric circle is clearly visible, centered on the front
Area. For this reason, a full-color image display device is used.
Compared to those using conventional TN-type liquid crystal devices,
Angle width, viewing angle direction (TN type
Viewing direction), contrast ratio, etc. are greatly improved
Was. Naturally, color display (8 color display) without gradation display
The case is also improved compared to the TN type. In the present invention, the thickness of the liquid crystal layer of the display liquid crystal cell is controlled.
Regardless of the above effect, the above effects can be obtained.
High-speed response display device by reducing layer thickness
Can be easily realized. Because the response speed is
This is because it is proportional to the square of the thickness of the liquid crystal layer. Further, according to the present invention, as described above, the contrast
Multiplex drive.
It is also effective in increasing the number of drive lines.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a typical example of a liquid crystal device according to the present invention. FIG. 2 is a diagram showing optical characteristics of a liquid crystal device according to the present invention in an off state. FIG. 3 is a diagram showing a relationship among a liquid crystal cell, a polarizing plate, and an optically anisotropic body in the liquid crystal device of the present invention. FIG. 4 is a view showing a spectrum in an off state of the liquid crystal device according to the present invention. FIG. 5 is an xy chromaticity diagram in which the off-state spectrum of the liquid crystal device according to the present invention shown in FIG. 4 is put on color coordinates. FIG. 6 is a diagram conceptually showing a case where an optically anisotropic body does not completely reverse the conversion of a liquid crystal cell. FIG. 7 is a diagram showing a relationship in each axis direction when a film-like polymer is used as an optically anisotropic body in the liquid crystal device of the present invention. FIG. 8 is a diagram showing a spectrum curve under the conditions shown in Example 20. FIG. 9 is an xy chromaticity diagram showing the spectrum curve shown in FIG. 8 in color coordinates. FIG. 10 is a diagram showing another configuration example of the liquid crystal device of the present invention. FIG. 11A is a diagram schematically illustrating a cross section when a liquid crystal layer is divided into 10 parts. (B) is a diagram conceptually showing the relationship between the liquid crystal layer thickness and the twist angle in (a). FIG. 12 shows a wavelength 450 calculated by dividing a liquid crystal layer into 20 parts.
The figure which showed transition of the polarization state of light of nm. FIG. 13 shows a wavelength 550 calculated by dividing a liquid crystal layer into 20 parts.
The figure which showed transition of the polarization state of light of nm. FIG. 14 shows a wavelength 650 calculated by dividing a liquid crystal layer into 20 parts.
The figure which showed transition of the polarization state of light of nm. FIG. 15 shows a polarizing plate 2 used in a specific example of the present invention.
FIG. 7 is a diagram showing the wavelength dependence of the light transmittance of a sheet. FIG. 16 illustrates an example of a method for driving a liquid crystal device of the present invention. FIG. 17 is a schematic view of a conventional super twisted nematic liquid crystal device. FIG. 18 is a diagram showing optical characteristics of a conventional STN-LCD in an off state. FIG. 19 is a diagram showing a relationship between a liquid crystal cell of a conventional liquid crystal device and a polarization axis (absorption axis) of a polarizing plate. FIG. 20 is a diagram illustrating a spectrum of light transmittance of a pixel in an on state and a pixel in an off state during multiplex driving of a conventional liquid crystal device. 21 is an xy chromaticity diagram in which the spectrum curve shown in FIG. 20 is plotted in color coordinates. FIG. 22 is a diagram showing a structure of a liquid crystal device according to one embodiment of the present invention. FIG. 23 is a diagram showing a relationship between axes of the liquid crystal device of the present invention. FIG. 24 (a) is a graph showing the relationship between the twist angle of the liquid crystal of the A cell and Δ in the case where the conditions of the B cell are fixed in the first embodiment of the present invention.
The figure which showed the desirable range of nd. FIG. 6B is a diagram showing the relationship between the Y value and Δn · d when the range of FIG. FIG. 25 is a diagram showing the relationship between the wavelength and the transmittance characteristics of the appearance of the liquid crystal device according to the second embodiment of the present invention. FIG. 26 is a diagram showing the relationship between the wavelength and the transmittance characteristics of the appearance of a liquid crystal device according to a third embodiment of the present invention. FIG. 27 is a diagram showing the relationship between the wavelength and the transmittance characteristics of the appearance of a liquid crystal device according to a fourth embodiment of the present invention. FIG. 28 is a diagram showing a desirable range of the twist angle of the liquid crystal of A cell and Δnd when the condition of B cell is fixed in the example of the present invention. FIG. 29 is a view showing the relationship between the wavelength and the transmittance characteristics of the appearance of a liquid crystal device according to a sixth embodiment of the present invention. FIG. 30 is a diagram showing a desirable range of the twist angle of the liquid crystal of the A cell and Δn · d when the condition of the B cell is fixed in Example 9 of the present invention. FIG. 31 shows the twist angle and Δn · d of the liquid crystal of cell A when the conditions of cell B are fixed in Example 10 of the present invention.
FIG. FIG. 32 shows a relationship between the twist angle of the liquid crystal of the A cell and Δn · d when the condition of the B cell is fixed in Example 11 of the present invention.
FIG. FIG. 33 shows a relationship between the twist angle of the liquid crystal of the A cell and Δn · d when the condition of the B cell is fixed in the twelfth embodiment of the present invention.
FIG. FIG. 34 is a diagram showing a structure of a liquid crystal device according to Embodiment 14 of the present invention. FIG. 35 is a diagram showing a structure of a liquid crystal device according to Embodiment 20 of the present invention. FIG. 36 is a diagram illustrating a relationship between axes of a liquid crystal device according to Embodiment 21 of the present invention. FIG. 37 is a diagram showing a structure of a polarizing plate of a liquid crystal device according to Embodiment 29 of the present invention. FIG. 38 is a diagram showing a structure of a liquid crystal device according to Embodiment 31 of the present invention. FIG. 39 is a diagram illustrating a relationship between axes of a liquid crystal device according to a working example 31 of the invention. [Description of Signs] 11, 18, 3861, 3867 Polarizing Plate 12, 3863 Liquid Crystal Cell 19, 3862 Optically Anisotropic Body

──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application No. 61-172144 (32) Priority date July 22, 1986 (33) Priority claim country Japan (JP) (31) Priority Claim number Japanese Patent Application No. 61-303168 (32) Priority date December 19, 1986 (33) Priority country Japan (JP) (31) Priority claim number Japanese Patent Application No. 62-64828 (32) Priority (Showa 62 (1987) March 19, (33) Priority country Japan (JP) (72) Inventor Mitsuo Nagata 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (72) Inventor Kazuo Aoki 3-3-5 Yamato, Suwa City, Nagano Prefecture Inside Seiko Epson Corporation (56) References JP-A-64-519 (JP, A) JP-A-63-149624 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) G02F 1/133 500 G02F 1/1335 610

Claims (1)

(57) [Claims] A liquid crystal cell in which a super-twisted nematic liquid crystal is sandwiched between a pair of substrates, and at least one polymer film are arranged, and the polymer film performs a reverse conversion of a conversion performed by the liquid crystal cell. The direction of the optical axis of the polymer film is set to approximately 90 ° with respect to the rubbing direction applied to the substrate on the side of the liquid crystal cell where the polymer film is arranged, and the twist angle of the liquid crystal and △ n · d and Δn · d of the polymer film are set.