JPH06337442A - Liquid crystal panel having memory performance - Google Patents

Abstract

PURPOSE:To provide a liquid crystal panel having intial and long-term reliability and memory peroformance. CONSTITUTION:At least two kinds of layer structures are formed in ferroelectric liquid crystal or antiferroelectric liquid crystal, and the layer structures are characterized by being put in an energetically lowest condition, and thereby, they are charactrized in that (1) there exists a layer structure of which a component in parallel with a substrate of a (c) director has at least a single minimum value in a parameter to describe the layer structure and (2) there exists a layer structure of which a component in the cell thickness direction of an (a) director has at least a single maximum value in the parameter to describe the layer structure. A liquid crystal panel is stabilized structurally by such layer structures, and resistance is increased against mechanical and electric stress, and operational reliability and memory performance are improved significantly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal optical element, and more particularly to a liquid crystal panel using a liquid crystal such as a ferroelectric liquid crystal or an antiferroelectric liquid crystal having a memory property and characterized by a high speed response.

[0002]

2. Description of the Related Art Ferroelectric liquid crystals used in optical elements of display devices, or tristable liquid crystals having an antiferroelectric phase and a ferroelectric phase as described in, for example, JP-A-2-173724 (hereinafter referred to as "tristable liquid crystal"). A panel using "antiferroelectric liquid crystal") has a memory property because it utilizes the spontaneous polarization of the liquid crystal molecules, and has excellent responsiveness, so it has been practically used with a liquid crystal having an SmC ^* phase etc. Many attempts have been made to realize this. However, although such a liquid crystal has spontaneous polarization at the molecular level, it tends to be oriented in a spiral structure in which the long axis direction of the molecule is twisted, and this cancels the spontaneous polarization. Therefore, in order to leave the spontaneous polarization, it is necessary to realize a layer structure in which the orientation is regulated by an orientation treatment or the like.

From such a point of view, since a panel using a ferroelectric liquid crystal was proposed by Clark, Lagabal, etc., a forceful research was conducted, and besides the bookshelf structure originally proposed as a layer structure having spontaneous polarization, The twist structure, chevron structure, and the like have become known, and it has become clear that the optical characteristics of the panel deeply reflect the structure.

Regarding the well-known bookshelf structure, it is difficult to form the bookshelf structure in the cell from the beginning, and the layer structure is formed by the electric field induced phase deformation mode. However, even the phase structure once formed cannot secure structural stability under long-term driving, which impedes practical application of the ferroelectric liquid crystal panel and the antiferroelectric liquid crystal panel.

In addition, there has been a problem that there is a limit to the material used to improve the characteristics of the ferroelectric liquid crystal panel or the antiferroelectric liquid crystal panel, particularly the response characteristics, that is, the upper limit of the spontaneous polarization amount of the liquid crystal that can be used. . The material of the ferroelectric phase in the ferroelectric liquid crystal or the anti-ferroelectric liquid crystal is characterized by coupling with the electric field in a first-order relationship.
000 times faster response becomes possible. It is clear that the main body that plays this major role is spontaneous polarization, but when a material with a higher spontaneous polarization amount is used to improve this response characteristic, it is called the burn-in phenomenon in the case of ferroelectric liquid crystals. The display cannot be erased due to the excess memory effect. On the other hand, in such a case, the antiferroelectric liquid crystal facilitates the layer deformation due to the coupling effect between the liquid crystal at the interface and the alignment film, which makes it easier to have a bookshelf structure, but it is a fine pattern formed in the initial display state. The focal conic structure was maintained as it was, and the transmitted light characteristics of the panel could not be maintained with high quality. Therefore, as the spontaneous polarization amount of the liquid crystal material used to avoid these problems, the upper limit is 10 nC / cm ² for the ferroelectric liquid crystal and less than 200 nC / cm ² for the antiferroelectric liquid crystal. There was a restriction that it wouldn't be. Therefore, there has been a long-awaited demand for a technique that makes full use of a material having a high spontaneous polarization amount.

In addition, the problem of the breaking strength of the layer structure peculiar to the ferroelectric liquid crystal phase has been raised from the beginning. Clerk,
The layer formed in the Lagubar mode was fragile to stress, and it was necessary to leave the layer once collapsed at a temperature of the SmC ^* phase or higher, and then re-form the layer again while cooling it in order to recover the layer. This treatment is unavoidable as long as the ferroelectric liquid crystal layer is used, but a panel showing a certain strength against a certain amount of stress is a necessary technique for practical application of the ferroelectric liquid crystal panel. Was one of the.

[0007]

DISCLOSURE OF THE INVENTION The present invention eliminates the above-mentioned drawbacks caused by the layer structure of the conventional ferroelectric liquid crystal or antiferroelectric liquid crystal, and (1) improves stability under long-term driving. (2) To increase the response speed, to increase the upper limit of the amount of spontaneous polarization of the liquid crystal material used (3) To show a certain level of strength against mechanical stress A new layer capable of the above It is intended to provide a structure.

[0008]

In order to solve the above problems, the present invention is very easy to form a stable layer structure such as the chevron structure in a ferroelectric liquid crystal phase or an antiferroelectric liquid crystal phase. In view of the above, a layer that dramatically improves electro-optical characteristics, especially memory characteristics and response characteristics by using a ferroelectric liquid crystal or an anti-ferroelectric liquid crystal while having a stable structure such as a chevron layer structure. It is intended to specify the state of the structure and provide a method for forming such a layered structure.

That is, as a first means for solving the above-mentioned problems, the present invention makes two substrates, one surface of which an electrode film and an alignment film are sequentially laminated and attached, and face each other with the alignment film inside. In a ferroelectric liquid crystal panel sandwiching a ferroelectric liquid crystal, the layer structure of the ferroelectric liquid crystal is a structure in which at least two kinds of layer structures are mixed, and as will be described more specifically in Examples described later. It is characterized in that there is a layered structure configured to take the lowest state in terms of energy.

As a second means for solving the above-mentioned problems, the present invention makes two substrates, one surface of which an electrode film and an alignment film are sequentially laminated and attached, face each other with the alignment film inside. In an antiferroelectric liquid crystal panel sandwiching antiferroelectric liquid crystal, at least two layers of the antiferroelectric liquid crystal are used.
The present invention is characterized in that a layered structure of more than one kind is mixed, and that there is a layered structure configured to take the lowest state in terms of energy, as will be described more specifically in Examples described later.

The present invention is characterized in that the layer structure is formed by controlling the contact angle of the alignment film as described later.

[0012]

According to the first means, the ferroelectric liquid crystal panel according to the present invention has the lowest energetically stable layer in the stable layer structure formed in the ferroelectric liquid crystal panel, that is, described later. By mixing a plurality of layers having the values of the director components Ay and Cz, it is possible to stabilize the layer structure and provide reliability in both driving and long-term storage. This is because a stable structure such as a chevron structure is not easily mechanically deformed, and since it has the lowest energy structure, even if it is deformed by receiving a force due to the application of a voltage, the force may be removed. This is due to the property of easily returning to the state of.

Further, by adopting such a structure, it is possible to dramatically improve the electro-optical characteristics of the ferroelectric liquid crystal, especially the memory characteristics and the response characteristics. This is also because the stability and restoration of the above-mentioned layer structure can be improved, and by these, the polarization density of the liquid crystal material that can be used without causing so-called image sticking can be dramatically increased. Further, according to the present invention, since there are two or more types of layered structures, a highly reliable partial response is performed even at an intermediate voltage between the threshold voltages of the respective layers, and the level of reproducibility and reliability is high. Key display is possible.

According to the second means, the antiferroelectric liquid crystal panel according to the present invention has the lowest energetically stable layer in the stable layer structure formed in the antiferroelectric liquid crystal panel. Director components Ay and C as described below
By mixing a plurality of layers having the value of z, it becomes possible to stabilize the layer structure and to provide reliability in both driving and long-term storage. This is because the stable layer structure itself is reversible with respect to mechanical deformation and has the lowest energy structure, so even if it is deformed by receiving a force due to the application of a voltage, etc. This is due to the property of easily returning to the state of.

Further, by adopting such a structure, it is possible to dramatically improve the electro-optical characteristics of the antiferroelectric liquid crystal, especially the memory characteristics and the response characteristics. This is also because the stability and restoration of the above-mentioned layer structure can be improved, and these can dramatically increase the polarization density of the liquid crystal material that can be used without increasing the so-called initial focal conic structure. Further according to the invention 2
Since there are more than one kind of layer structure, a highly reliable partial response is performed even at an intermediate voltage between the threshold voltages of the respective layers, and gray scale display with high reproducibility and reliability is possible.

[0016]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings. FIG. 12 is an explanatory view showing the structure of the ferroelectric liquid crystal panel. The cross section 1202 of the SmC ^* layer is the substrate 12
Immediately below 01, the layer normal a is sandwiched with respect to the substrate 1201 while showing a finite value. The layer 1202 contains molecules 1203, the molecular orientation of which is a (Ax, Ay, Az) indicating the layer normal and c (C) indicating the molecular direction.
x, Cy, Cz). This notation is known as the c-director notation.

The coordinate system follows the coordinate axis 1204. Note that the z direction at this time is substantially coincident with the alignment treatment direction, and the x axis is in the plane of the substrate 1201. At this time, the free energy F of the liquid crystal in the layer 1202 is expressed by the following equation (Nakagawa: Liquid).
Crystals 651 (8) 1990). F = A / 2 * (▽ .a) ^ 2 + {(▽ .c) ^ 2 + (▽ × c) ^ 2} -D. c. ▽ × c + D1. ν. ▽ × c-C (▽ .a) (▽ .c) + L / 2 (κ-κ0) ^ 2 (1) In the formula (1), capital letters A, C, D, D1 , L are elastic constants of layer deformation. The following relationships are established for each parameter. κ = a. ν-1 ・ ・ ・ ・ ・ ・ (2) κ0 = dA / dC ^*・ ・ ・ ・ ・ ・ ・ ・ (3) p = ν × c ・ ・ ・ ・ ・ ・ (4) a ‖ν (5) Here, dA represents the layer thickness of the smectic A layer, and dC ^* represents the layer thickness of the smectic C ^* layer. p is a polarization vector and has a relationship with other vectors a, c and ν as shown in FIG.

If the states of molecular orientation are variously determined for one layer with a and c as variables, the free energy F corresponding to each state can be calculated from the equation (1). Among these, the layer structure in a variable state in which F has a minimum value corresponds to the layer structure in the present invention and is a highly stable layer structure. A plurality of types of layer structures satisfying such conditions have been devised and confirmed as examples of the present invention.
The result is that the chevron structure is relatively easy to realize, whereas the bookshelf structure is extremely difficult to realize.

In this embodiment, first, with the aid of numerical calculation, a plurality of types of layer structures in which the free energy F has a minimum value are devised and designed, the designed layer structure is prototyped, and the prototyped layer structure is produced. Was determined using the ATR method described later, and the electro-optical characteristics of the panel were measured. These will be described in detail below.

In the numerical calculation of the free energy F, C
It was standardized as x ^ 2 + Cy ^ 2 + Cz ^ 2 = 1 and Az = 1 and used as the basis for confirming the minimum energy of the system. As described above as a parameter particularly focused on in the design of the layer structure in the present embodiment, it is the relationship between the direction of the cone axis defined by Cx, Cy and Cz and the layer normal Ay. According to the conventional model, a model in which the cone sticks to the layer surface has a constant Ay, whereas in the present embodiment, Ay, Cz.
Was designed by the model as an independent variable with a finite value.

Examples of several kinds of layer structures of the present invention designed in this way are shown below by using the above parameters.

FIG. 1 shows a structure in which the layer normal Ay has a maximum value and Cz has a minimum value. In the figure, the vertical line of Ay shows the value of the tangent of the layer normal, and the value of d shows the value normalized to 0 for the lower substrate and 1 for the upper substrate. The coordinate axes taken in the cells are as shown in FIG. The same applies to the examples shown below.

FIG. 2 shows a structure in which Ay has one maximum value, Cz has two minimum values and one maximum value.

FIG. 3 shows a structure in which Ay has two local maximum values, Cz has three local minimum values and two local maximum values. (Note that A
Even if the signs of the coordinate axes of y and Cz are changed at the same time, generality is not lost. )

FIG. 4 shows a structure in which y has two maximum values and one minimum value, and Cz has two maximum values and three minimum values. When Ay crosses 0, a kink occurs as a layered structure.

FIG. 5 shows a structure in which Ay has no extremum, while only Cz has an extremum (in this case, a minimal value).

FIG. 6 is almost the same as FIG. 5, but shows the structure when the layer structure formed in the cell is asymmetric.

FIG. 7 shows a structure in which Ay has two inflection points and Cz has one minimum value.

In FIG. 8, Ay is an extreme value (a minimum value in this case) on one side of the cell, and Cz has two extreme values (a maximum value in this case).
Shows a structure having

FIG. 9 shows a structure in which both Ay and Cz have local minimum values.

FIG. 10 shows a structure in which Ay has one minimum value and one maximum value, and Cz has two maximum values.

FIG. 11 shows the structure when Cz has two maximum values as in FIG. 10, while the positions in the cell that give the maximum value and the minimum value of Ay are reversed.

Next, a method for forming the layer structure described above will be described. That is, by giving the following properties to the alignment film and appropriately selecting the forming conditions by controlling the applied voltage, one kind or several kinds of the above-mentioned layered structures can be used alone or in combination. Can be formed. The properties to be imparted to the alignment film are that the contact angle of the alignment film is about 20 to 30 degrees when methylene iodide is used and 35 to 45 degrees when pure water is used. This explanation is currently unclear, but it has been found that it is very effective to at least give a treatment for inactivating OH groups among the constituent molecular groups exposed on the surface of the PVA or polyimide alignment film. did. The layer structure formed also depends on the contact angle.

A method for confirming the layer structure thus formed will be described. The layer structure actually formed in this example was confirmed by using the ATR method. This method is Sambl
Although detailed in the papers such as es, the outline is as follows.

A liquid crystal cell was prepared in which a film showing absorption (usually, a vapor deposition film of gold or silver having a thickness of 300 to 400 angstrom) was provided between the glass substrate and the alignment film, and P was formed in this cell.
Polarized light (that is, light with an electric field vector in the plane of incidence of light)
Let's make the incident. Light is mostly reflected by the metal film up to a certain incident angle, but it induces the phenomenon of giving and receiving light energy to and from the metal film in the range exceeding the total reflection angle defined by the dielectric tensor, and the metal film and the alignment film , It is known to exhibit a characteristic reflection intensity profile determined by the orientation of liquid crystals.

This reflection profile is particularly sensitive to the property (orientation) of the substance just below the metal film, and the property can be discussed in detail from the relationship between the absolute value of the reflection intensity and the reflection angle giving the intensity. As a result of confirming the layer structure of the ferroelectric liquid crystal prepared under various conditions as described above by using this ATR method, the layer structure shown in FIGS. 1 to 11 is selected from among many kinds of layer structures. Was found to exist.
In addition, it was confirmed that these layers can be prepared individually or in a mixed state by selecting the preparation conditions.

Next, FIG. 14 shows the experimental results on the memory characteristics, responsiveness, and durability of the panel using the ferroelectric liquid crystal of which the layer structure of this embodiment was confirmed in the above-described manner.
Shown in. The layer structure of the liquid crystal used in the experiment is a mixture of the structures shown in FIG. 5 and FIG. FIG. 14 shows the results of measuring the change in the light transmittance of the liquid crystal when driven by applying inversion voltages 51, 52, 55, 56 and intermediate voltages 53, 54, 57, 58 to the electrodes of the cells. According to these results, it is understood that the liquid crystal exhibits excellent reproducibility, optical stability, excellent memory characteristics, and fast response speed. Next, the same measurement was performed after driving for 30 days with the same driving waveform, but almost the same result as the initial result was obtained. From this, it is understood that this example is excellent in stability over time. The reason why the memory property and the responsiveness are improved is that the liquid crystal material having a high spontaneous polarization density (50 nC / cm ² for the ferroelectric liquid crystal) can be used because the stability of the layer structure is improved. The layer structure in which two types of layers are mixed is that in this case, the production conditions are rather gentler than in the case of producing purely one type, and by combining the characteristics of the individual layers, for example, This is because a new advantage such as gradation display is produced.

(Embodiment 2) Next, an antiferroelectric liquid crystal panel will be described as a second embodiment of the present invention with reference to the drawings.
FIG. 15 is an explanatory view showing the structure of the antiferroelectric liquid crystal panel of this embodiment. The cross section 1302 of the antiferroelectric layer is the substrate 120.
Immediately below 1, the layer normal a is sandwiched with respect to the substrate 1201 while showing a finite value. Antiferroelectric layer 1302
The molecule 1303 is included in the matrix, and its molecular orientation is represented by a (Ax, Ay, Az) indicating the layer normal and c (Cx, Cy, Cz) indicating the molecular direction. This notation is known as the c-director notation.

The coordinate system follows the coordinate axis 1204. Note that the z direction at this time is substantially coincident with the alignment treatment direction, and the x axis is in the plane of the substrate 1201. At this time, the free energy F of the liquid crystal in the layer 1302 is expressed by the following equation (Nakagawa: Liquid).
Crystals 651 (8) 1990). F = A1 / 2 * (▽ .a) ^ 2 + {(▽ .co) ^ 2 + (▽ × co) ^ 2 + (▽ .ce) ^ 2 + (▽ × ce) ^ 2} -D2. co. ▽ × co + D2. ce. ▽ × ce + D3. ν. ▽ × co + D3. ν. ▽ × ce-C1 (▽ .a) {(▽ .co) + (▽ .ce)} + L1 / 2 (κ-κ0) ^ 2 + K (6)

In the equation (6), capital letters A1, C1,
D2, D3 and L1 are elastic constants of the deformation of the antiferroelectric layer. Co and ce are c-directors showing the molecular directions of the odd-numbered layers and the even-numbered layers of the smectic layers forming the antiferroelectric layer. K is the coupling energy between the odd-numbered layer and the even-numbered layer. The following relationships of parameters are established. κ = a. ν-1 ・ ・ ・ ・ ・ ・ (2) κ0 = dA / dC ^*・ ・ ・ ・ ・ ・ ・ ・ (3) p = ν × c ・ ・ ・ ・ ・ ・ (4) a ‖ν (5) Here, dA represents the layer thickness of the smectic A layer, and dC ^* represents the layer thickness of the smectic C ^* layer. For c, co
Either c or ce may be treated as c. p is a polarization vector, and has a relationship as shown in FIG. 13 with other vectors a, c, and ν as in the first embodiment.

In the present embodiment, a is a for one layer.
If the states of molecular orientation are variously determined by using and and c (co or ce) as variables, the free energy F corresponding to each state can be calculated from the equation (6).
Among these, the layer structure in the state of a variable in which F has a minimum value corresponds to the layer structure in this embodiment, and is a layer structure having high stability. A plurality of types of layer structures satisfying such conditions have been devised and confirmed as examples of the present invention, but it is relatively easy to realize in the chevron structure, but extremely difficult to realize in the bookshelf structure. The result is.

In this embodiment, first, with the aid of numerical calculation, a plurality of types of layer structures in which the free energy F has a minimum value are devised and designed, and the designed layer structure is made the same as in the first embodiment. ATR described above with the prototype layer structure
Method, and the electro-optical characteristics of the panel were measured.

In the numerical calculation of the free energy F, as in the first embodiment, Cx ^ 2 + Cy ^ 2 + Cz ^ 2
= 1 and Az = 1 were standardized and used as the basis for confirming the minimum energy of the system. In the design of the layer structure in this embodiment, the particular attention is paid to the relationship between the direction of the cone axis defined by Cx, Cy and Cz as parameters and the layer normal Ay, as in the first embodiment. According to the conventional model, the model in which the cone sticks to the layer surface is a constant Ay model, but in the present embodiment, Ay and Cz are designed as independent variables having finite values.

An example of several kinds of layer structures of the present embodiment designed in this way using the above parameters is the same as that shown in FIGS. 1 to 11 in the first embodiment. . Strictly speaking, Journal of Television Society 44
As shown on page 537 of Vol. 5, the directions of molecules in the odd-numbered layer and the even-numbered layer of each smectic layer constituting the antiferroelectric layer are symmetrical with respect to the boundary surface of the layers. Therefore, regarding the parameter Cy, the even-numbered layer and the odd-numbered layer are symmetrical with respect to the x-axis,
One of them is the same as that shown in FIG. 1 to FIG. 11, and the other is not the same, but shows the same tendency as to how the extreme value appears.

Next, with reference to the drawings, the experimental results on the memory characteristics, responsiveness, and durability of the panel using the antiferroelectric liquid crystal of which the layer structure of this embodiment was confirmed, which was produced in this way, were confirmed. explain. FIG. 16 is a diagram showing a hysteresis curve of light transmittance when a voltage is applied to the antiferroelectric liquid crystal panel used in the experiment, and FIG. 17 is a driving method and transmission of the antiferroelectric liquid crystal panel used in the experiment. It is a figure which shows the light quantity. The layer structure of the liquid crystal used in the experiment is a mixture of the structures shown in FIG. 5 and FIG. As shown in FIG. 16, when the voltage is increased from zero, the transmittance starts to change at V1, the transmittance saturates at V2, and conversely when the voltage is decreased, the transmittance decreases at V5. Start doing. When a voltage having a polarity opposite to that of the voltage is applied and its absolute value is increased, the transmittance starts to change at V3 and saturates at V4. On the contrary, when the absolute value of the voltage is reduced, the transmittance starts to change at V6.

From this, when a pulse wave is applied to the antiferroelectric liquid crystal panel, when the absolute value of the product value of the pulse width and the voltage exceeds the threshold value, the second or third stable state is obtained. (Ferroelectric liquid crystal state) is selected, and when the absolute value of the product value of the pulse width and the voltage is equal to or less than a certain threshold value, the first stable state (antiferroelectric liquid crystal state) is selected. You can see that.

In this experiment, the panel was driven by applying pulses as shown in FIG. That is, the second or third stable state is selected in the selection period, and this state is held in the non-selection period to turn the panel state to the ON state. In addition, the first stable state is selected during the selection period, and this state is maintained during the non-selection period, thereby turning the panel state to the OFF state. In this way, the ON-state driving and the OFF-state driving were alternately repeated.

From these results, it can be seen that the liquid crystal exhibits excellent reproducibility, optical stability, excellent memory characteristics, and fast response speed. Next, the same measurement was performed after driving for 30 days with the same driving waveform, but almost the same result as the initial result was obtained. From this, it is understood that this example is excellent in stability over time. The memory property and responsiveness are improved because the stability of the layer structure is improved and the spontaneous polarization density is high (250 nC / cm ² ).
This is because liquid crystal materials can now be used. The layer structure in which two types of layers are mixed is that in this case, the production conditions are rather gentler than in the case of producing purely one type, and by combining the characteristics of the individual layers, for example, This is because a new advantage such as gradation display is produced. In addition to the advantages described above, the panel of the present example has the advantages that it has a wide viewing angle and good multiplex characteristics because it uses an antiferroelectric liquid crystal. .

[0049]

As described above, according to the present invention, in a ferroelectric liquid crystal panel or an antiferroelectric liquid crystal panel, a plurality of layer structures are formed by a combination of the alignment film and the electric field treatment disclosed in the embodiments. As a result, the remarkable effects listed below were realized. (1) The layer structure formed in the cell exhibits the lowest free energy (including the local lowest). Therefore, the (2) layer structure exhibits very strong stability against changes with time under long-term driving. (3) This makes it possible to provide a liquid crystal cell having stable memory characteristics and response characteristics. (4) With this layer structure, the image sticking effect under long-term driving, which has been a problem so far, is reduced, and it is possible to use a material with a spontaneous polarization amount of 50 nC / cm ^{2 in} a ferroelectric liquid crystal. Up to now 1
It greatly breaks the wall of 0 nC / cm ² . Further, in the antiferroelectric liquid crystal, the spontaneous polarization amount is 250 nC /
A material of cm ² can be used, which greatly breaks the upper limit of 200 nC / cm ² that has hitherto been set. Therefore, this is a great technique for realizing the possibility of high-speed response originally possessed by the ferroelectric liquid crystal material and the antiferroelectric liquid crystal material. (5) Since the number of bending points of the chevron structure formed in the cell is plural, the strength against stress is higher than that of the conventional panel.

[Brief description of drawings]

FIG. 1 is a diagram showing parameters of a layer structure of a liquid crystal in one example of the present invention.

FIG. 2 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 3 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 4 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 5 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 6 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 7 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 8 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 9 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 10 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 11 is a diagram showing parameters of a layer structure of liquid crystal in one example of the present invention.

FIG. 12 is an explanatory diagram showing a cell structure of a ferroelectric liquid crystal panel of the present invention.

FIG. 13 is a diagram showing a relationship between spontaneous polarization p and another vector parameter in a ferroelectric liquid crystal or an antiferroelectric liquid crystal.

FIG. 14 is a diagram showing drive waveforms and optical characteristics of the ferroelectric liquid crystal panel of the present invention.

FIG. 15 is an explanatory diagram showing a cell structure of an antiferroelectric liquid crystal panel of the present invention.

FIG. 16 is a diagram showing a hysteresis curve of light transmittance of the antiferroelectric liquid crystal panel of the present invention.

FIG. 17 is a diagram showing a driving method and an amount of transmitted light of the antiferroelectric liquid crystal panel of the present invention.

[Explanation of symbols]

51 Inversion Driving Waveform 52 Inversion Driving Waveform 53 Intermediate Driving Waveform 54 Intermediate Driving Waveform 55 Inversion Driving Waveform 56 Inversion Driving Waveform 57 Intermediate Driving Waveform 58 Intermediate Driving Waveform 1201 Substrate 1202 SmC ^* Layer 1203 Ferroelectricity Liquid crystal molecule 1204 Coordinate axis 1302 Antiferroelectric layer 1303 Antiferroelectric liquid crystal molecule

Claims (6)

[Claims] 1. A ferroelectric liquid crystal panel comprising a ferroelectric liquid crystal sandwiched between two substrates, each having an electrode film and an alignment film sequentially laminated on one surface and attached with the alignment film facing inside. A ferroelectric liquid crystal panel characterized in that the layer structure of the ferroelectric liquid crystal is a structure in which at least two kinds of layer structures are mixed, and there is a layer structure configured to take the lowest state in terms of energy. . 2. An antiferroelectric liquid crystal in which an antiferroelectric liquid crystal is sandwiched between two substrates having electrode films and an alignment film sequentially laminated on one surface and made to face each other with the alignment film inside. In the panel, the antiferroelectric liquid crystal has a layered structure in which at least two types of layered structures are mixed, and an antiferroelectric liquid crystal has a layered structure configured to have the lowest energy state. Dielectric liquid crystal panel. 3. Among the parameters that describe the layer structure of the liquid crystal, at least one component parallel to the substrate of the c-director is included.
The ferroelectric liquid crystal panel according to claim 1 or the antiferroelectric liquid crystal panel according to claim 2, characterized in that there is a layered structure having a maximum value. 4. Among the parameters for describing the layer structure of liquid crystal, at least one component parallel to the substrate of the c-director is included.
The ferroelectric liquid crystal panel according to claim 1 or the antiferroelectric liquid crystal panel according to claim 2, characterized in that a layered structure having a minimum number of pieces exists. 5. Among the parameters for describing the layer structure of the liquid crystal, there is a layer structure in which a vertical component has at least one local maximum value on the substrate of the a director. The ferroelectric liquid crystal panel according to claim 2 or the antiferroelectric liquid crystal panel according to claim 2. 6. The layer structure according to claim 1, wherein among the parameters for describing the layer structure of the liquid crystal, a component of the a director in the vertical direction has at least one local minimum value. 3. A ferroelectric liquid crystal panel according to claim 2 or 3.
The anti-ferroelectric liquid crystal panel described in.