JPS61140922A - Liquid crystal element - Google Patents

Abstract

PURPOSE:To minimize the spacing error of a liquid crystal element having a ferroelectric liquid crystal sealed in a cell body by satisfying specific relations among the modulus of elasticity, thickness and spacing. CONSTITUTION:The relations expressed by the equation are so determined as to hold among E, (t) and (a) where the modulus of elasticity of a flexible substrate is designated as Ekgf/mm<2>, thickness thereof is as (t)mm and the spacing between spacer members as (a)mm in the liquid crystal element having the cell body holding the spacing between a pair of the substrates by a spacer member and the ferroelectric liquid crystal sealed in the cell body. The ferroelectric liquid crystal element which has the extremely thin layer of 0.1-3mu at the spacing between the substrates of the cell body and minimizes the spacing error is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal element, and more particularly to a liquid crystal element using ferroelectric liquid crystal.

Conventionally, display devices using a passive matrix electrode structure or an active matrix electrode structure have been known as methods for forming high-density pixels, but many of these display devices are based on electricity using TN (Twisted Nematic) liquid crystals. It uses optical modulation.

However, in a display device with this passive matrix electrode structure, the duty ratio decreases as the number of scanning lines increases, and there are problems such as occurrence of crosstalk and decrease in contrast.
A method in which a switching element (for example, an IL film transistor) is connected to each pixel is known, but in display devices using this, the process of manufacturing the switching element is complicated, and it is difficult to form a large screen. The problem is that it is difficult.

As a solution to these problems, a ferroelectric liquid crystal element recently announced by Clark et al. in U.S. Pat. No. 4,367,924 has attracted attention. Thickness 0
．． It is known to form an extremely thin layer of about 1 louver.

However, according to experiments conducted by the present inventors, if the liquid crystal layer thickness of a ferroelectric liquid crystal element having the above-mentioned memory effect has an error within the element plane, the a! It was found that the threshold characteristics and response speed changed significantly depending on the difference. In particular, in the experiments conducted by the present inventors, the above-mentioned error tolerance range is, for example, l
It has been found that it is necessary to have an error of 10% or less in the thickness of the liquid crystal layer of IL.

On the other hand, in the cell assembly method in conventional liquid crystal technology, since the target liquid crystal mode was the above-mentioned TN liquid crystal mode, the distance between the substrates constituting the cell body was as thick as 6 to 10 mm. Even if there was a certain degree of error in the thickness, the response speed of the V@reflection characteristic of the TN liquid crystal mode did not change significantly, so it was found that the cell body is compatible with the ultra-thin layer and uniformity as described above. Currently, no consideration is given to the assembly method. In particular, the ferroelectric liquid crystal element with a memory effect announced by Clark et al. mentioned above can be applied to large screen displays (e.g. diagonal size, 12 inches or more); however, it is difficult to form such a large screen. For example, the cell body to be obtained is 1. The cell assembly method that keeps the error between the substrate spacing and the side spacing within 10% has a problem that cannot be solved by simply applying the conventional cell assembly method.

Therefore, an object of the present invention is to reduce the distance between the substrates of the cell body to 0.
The object of the present invention is to provide a ferroelectric liquid crystal element which has a pole S layer of 1#L to 3IL and has extremely small spacing error.

The object of the present invention is to provide a cell body in which a gap between a pair of substrates, at least one of which is a flexible substrate, is maintained by a plurality of spacer members; In the element, the elastic modulus of the flexible base is E (K g f / mm2), and its thickness is t (
mm), and the distance between the spacer members is a (m
m), this is achieved by a liquid crystal element having the relationship between E, L, and a.

The present invention will be explained below with reference to the drawings.

FIG. 1 shows an embodiment of a liquid crystal element according to the present invention.

The liquid crystal element shown in FIG. 1 has a cell 100 and a ferroelectric liquid crystal 113 sealed inside the cell 100.
00 has a gap formed between base bodies 101 and 102, and a plurality of spacer members 111 that hold the gap.

The gap formed by the base bodies 101 and 102 is.

The sealing member 110 forms a sealed state. The base body 101 is preferably transparent and has optical anisotropy, and has sufficient strength to hold the cell body 100 itself, and generally has a thickness of about 1 to 5 mm depending on its area. glass is suitable.

The base 101 includes tin oxide and indium oxide.

A transparent conductive film 103 made of ITO (Indlun Tin Oxide) or the like is formed in a stripe shape, and a spacer member 111 having a thickness of about 0.1 g to about 3 mm is further formed. This spacer member 111 is made of a film-forming material (resin such as polyimide, polyamide, polyvinyl alcohol, photosensitive resin, 5i02, etc.) on the base 101.
After forming an inorganic insulator such as TiO2 (which can be formed by vapor deposition) to a thickness of about 0.11L to 3cm, it is etched using a prescribed photolithography method to form a stripe shape, lattice shape, or dot shape. can do. In particular, when creating this spacer member 111,
When a photocurable resin is used as a film forming material, there is an advantage that the photocurable resin can be directly formed as the spacer member 111 without using a separate photoresist resin.

It is suitable that the distance between the spacer members ill is 2 mm or less, preferably 800 mm or less. That is,
In the case of striped shapes, the distance between adjacent stripes is 2m.
m or less, preferably 800 or less. In the case of a lattice shape, the length of the long side of the lattice is set to 2 mm or less, preferably 800 #L or less, and in the case of a dot shape, the interval between the dots is set to 2 mm or less, preferably 800 #L or less.

Further, the base body 101 is provided with a drive circuit section 105 that applies a drive signal to the electrode group 103 and a drive circuit section 106 that applies an information signal to the lower electrodes 104. The drive circuit sections 105 and 106 are made of semiconductor elements such as amorphous silicon, polycrystalline silicon, and cadmium selenide. It can be formed by a transistor. Respective drive circuit sections 105 and 106
The source line and gate line are connected to terminal groups 108 and 109 arranged centrally on the base 101.

After forming the electrode group 103 and spacer member 111 on the substrate 101, a film of polyimide or polyvinyl alcohol is formed, and the surface thereof is rubbed, or by forming an oblique evaporation layer of s to 2, v
An alignment control effect is imparted to the ferroelectric liquid crystal arranged at k. Further, this base 101 may be a non-flexible glass plate as described above, but it may also be a flexible base used as a downstream base 102.

The electrode group 104 wired on the flexible substrate 102 is made of an anisotropic conductive material (a thermoplastic resin that exhibits conductivity only in the vertical direction, such as Sony Chemical's CP-1030 and Hitachi Chemical's "
It is connected to the drive circuit section 10B formed on the substrate lot through the Hitaserum anisotropically conductive adhesive film) 107, and is further connected to the terminal 91 so that it can be connected to an external control circuit (not shown).
Connected up to 09.

Also, on the substrate 101, there is an electrode group 1 which is wired to this substrate.
A drive circuit unit 105 is provided to apply a drive signal to 03. Further, a terminal group 108 for connecting a control signal from an external control circuit (not shown) to the drive circuit section 105
is formed.

In the cell body filled with ferroelectric liquid crystal 113, the gap between the substrate 101 and the flexible substrate 102 is held by a spacer member 111, and the periphery of the substrates 101 and 102 is sealed with epoxy adhesive or the like. The 0-emphasis electric liquid crystal 113 sealed by the member 110 is given orientation so that a monodomain is formed.

This orientation can be obtained by using a polyimide film, a polyvinyl alcohol film, etc., which is rubbed on each of the substrates 101 and 102, or by using 5i02H, etc., which is obliquely deposited.

A polarizer 112 and an analyzer 114 in a crossed Nichols state are arranged on both sides of such a cell body, and the ferroelectric liquid crystal 11
The optical modulation caused by the orientational modulation of 3 is obtained.

As mentioned above, when creating a ferroelectric liquid crystal element with a memory effect, the layer thickness of the liquid crystal should be set to O, lJL ~ 3
It is necessary to make the layer very thin at the end, and the tolerance range for variation in the layer thickness is 10% or less, for example, for the layer thickness of tg,
, it is necessary to have a variation tolerance of 1 μ or less. The present invention was developed based on this viewpoint. Flexible glass or plastic film is applied as the base 102, and the elastic modulus of the base 102 is set to E( Kgf/mm2) Let its thickness be t (mm).

The distance between the previously formed spacer members 111 is a (m
m), by satisfying the relationships between E and E and a, it is possible to form a uniform layer thickness with the variation in layer thickness within 103.

In a preferred embodiment of the invention,! & Body 102 is made of flexible glass or plastic film, and cell 100
By forming a depressurized space shown in FIG.
Uniformity of liquid crystal layer thickness can be obtained. If the substrate 102 is not easy to bend, a decrease in layer thickness due to deformation at the intermediate point between the spacer members 111 becomes a problem, and if the rigidity is too large, deformation occurs in response to deviation of the substrate lot from the plane. becomes insufficient.

When a plastic film such as an isotropic vinyl chloride film formed by extrusion of a 1 m stretched polyester film is used as the substrate 102, the spacer member 111 is used.
Although deformation of the midpoint between the spacer members 1 and 1 poses a problem,
When the gap of 11M is 0.1 mm, even a film with a thickness of 25 microns has a variation of about 0.1 micron (when pressed at atmospheric pressure), which is within the practical range. Furthermore, when using a film with a thickness of about 100 microns, the amount of deformation is about 0.1 micron even if the distance between the spacer members 111 is 0.5 mm. If it is within mm, sufficient accuracy of the liquid crystal layer thickness can be obtained. When glass is used as the substrate 102, it needs to be thin enough to deform to match the flatness of the base 101. If normal unpolished glass is used as the base 101, the diameter is 100 mm.
There is a deviation from the plane of about 10 microns in the range of . If glass with a thickness of 0.1 mm is used as the substrate 102, the amount of deformation due to atmospheric pressure when it comes into contact with the spacer member 111 at a pitch of 100 mm is much larger than 10 microns, so at least the spacer member it
It can be seen that the range not touching t is less than that (100 mm). The distance between the spacer members 111 with a deformation amount of 0.1 micron is 1 to 2 mm, but this l1
11171! Since the flatness of the substrate 101 is better than 0.1 micron, sufficient precision in the thickness of the liquid crystal layer can be obtained.

In order to deform according to the base 101 within a range of 0.1 micron or less, the thickness of glass must be 0.3 m.
m or less, and considering variations in the flatness of the substrate 101 and variations in pressure during liquid crystal sealing, it is 0.2 m.
The thickness is desirably less than m.

FIG. 2 shows a circuit configuration in which drive circuit sections 105 and 106 are each formed of thin film transistors (polycrystalline silicon, amorphous zircon, cadmium selenide).

sw11 to 5Wn4 constituting the drive circuit section 105 are divided switching elements formed of S film transistors, and E(1) to E(n) are divided switching elements connected to the gates for controlling the divided switching elements. This is a block selection line. Note that since there are four common lines in this example, n is equal to N/4 in this case, Pi-PN is a discharge switching element formed by a thin film transistor, N is a discharge control line, and J is a discharge potential line. , 21 is a scanning line drive circuit which is an external control circuit for driving a shared scanning line, and 22 is a connection portion between the circuit board and the scanning line drive circuit 21.

When driving the display section 23, a common line A is connected to the source from the common scanning line drive circuit 21.

While giving repeated pulses to B, C, and D.

Divided block selection lines E (1) to E (n) sequentially 0N
Make it 10FF. In addition, PI to Pn have G when not selected.
(1) A pulse may be applied to the discharge control line I to control ~G (N) to -V (V).

In the above embodiment, the number of scanning lines is N and the number of common lines is 4. However, for example, there are 480 scanning lines and 2 common lines.
If there are 4 lines, the number of 1 divided block selection lines will be 20, and the number of connections with the external drive circuit will be 2, the discharge control line and the discharge potential line.
Including books, there are a total of 46 locations, which has the effect of reducing the number of connections by approximately 90%.

The drive circuit section 106 includes an S transistor formed of thin film transistors.
It has W1 to SWm. The video information signal is transferred from the external control circuit to the shift register 24, and when the transfer to the shift register 24 is completed, the SWI connected to the gate
The terminal 25 of ~S W m changes from the off state to the on state, and latches the state of the shift register 24 at this time.

Data line D1 connected to the source of the corresponding signal
~Dm is applied. The shift register 24 has a clock terminal 26 and a data input terminal 27, and the same signal as the OFF data level of the shift register 24 is supplied to the terminal 28.

FIG. 3 is a plan view schematically showing a liquid crystal cell used in the present invention. In this embodiment, a transparent conductive pattern for driving a 4-drive matrix is formed on the substrate, and is connected to an external drive circuit by bonding. The upper substrate 31 is a flexible substrate made of thin glass, and a seal is provided along its periphery to seal the other substrate (not shown) that faces the upper substrate 31. A portion 32 is formed. Further, a spacer member 33 is formed in the center portion of the substrate 31 surrounded by the seal portion 32.
It functions to regulate the thickness of the liquid crystal layer. The spacer member 33 is formed into a pattern by, for example, coating the substrate 31 with polyimide to a predetermined thickness and then photo-etching. Alternatively, the substrate 31 itself may be etched into a pattern using the spacer portions 33tvh.

Further, the surfaces of the two substrates are subjected to rubbing treatment to orient the liquid crystal, if necessary. Further, a liquid crystal layer region 34 is formed separated by a spacer member 33, and is adjacent to or in communication with a reduced pressure space 36 via an interface 35. Such a liquid crystal layer 34 is formed by reducing the pressure in the liquid crystal injection port 37. This depressurized space 36 is arranged so that after the inside of the empty cell is depressurized by evacuation, a liquid substance showing liquid crystal is sealed in the injection port 37 provided in the cell, and the vacuum container is returned to atmospheric pressure, and the liquid is This can be done by sealing the injection port before the cell is completely filled with the liquid material, and this reduced pressure space 36 allows the liquid crystal material to be injected into the cell. A reduced pressure state can be created. As a liquid crystal material, for example, ferroelectric liquid crystal DOBA
MBC is used, and its orientation state is from the one isotropic phase state,
It is obtained by slow cooling to a chiral smectic C phase state.

To explain in more detail how the liquid crystal is sealed, for example, a substrate 31 on which a spacer member 33 is formed and a flexible counter substrate such as a polyester film or thin glass are bonded together using an epoxy adhesive 32 or the like to form a cell. After forming the cell, the cell is held in a vacuum container, and after the air in the cell is sufficiently exhausted, the injection port 37 is immersed in the liquid crystal material. Thereafter, the pressure outside the cell is increased by introducing N2 gas or the like into the vacuum container, and the liquid crystal material is press-fitted into the cell. The liquid crystal material is applied to a predetermined area (for example, an image area) 39 (19
100mmXloomm), the injection operation is stopped and the injection port 37 is sealed. The liquid crystal cell formed in this manner is subjected to sufficient compressive force under atmospheric pressure due to the presence of the decompression space 36, so that the opposing substrate is in close contact with the spacer member 33, and the thickness Even extremely thin cells, such as those below, can be formed to have a uniform cell thickness over a large area. Also, the decompression space 36.

Thermal expansion of liquid crystal materials due to environmental changes during use of liquid crystal cells,
It also has the function of preventing the thickness of the cell from partially changing due to heat shrinkage.

In this example, thin glass was used as the flexible substrate,
Assuming that the thickness is t (mm) and the distance between the spacer stripes is a (mm), evaluate the variation W (maximum value - minimum value) in the thickness of the liquid crystal cell and the image quality when changing t and a. went.

However, the film thickness of the spacer is set to 2#L.

Unit (mm) In another preferred embodiment of the present invention, the spacer shape is lattice-like, and the lattice points are cylindrical with a diameter of 10i.
An experiment was conducted in the same manner as in Example I described above. The relationship between the parameters a, W, and image quality at this time was almost the same as in the previous example.

The amount of deformation at the center of the spacer is proportional to TTT, where E is the elastic constant of the flexible substrate. The elastic constant of glass is approximately 7000 Kgf/mm2, and the maximum deformation is o, i
In order to keep the value below IL, it is necessary that the length of the can be 0.32 or below, and the experimental results were consistent with this.

The ferroelectric liquid crystal used in the present invention is most preferably a chiral smectic liquid crystal, of which chiral smectic C phase (C3mC) is most preferable.

H phase (SmH), ■ phase (SmI), J phase (SmJ).

K phase (SmK), F phase (SmF), and G phase (SmG) liquid crystals are suitable.For this ferroelectric liquid crystal.

“LE JOυRNAI, DE PHYSIQUE
LETTER3″36(L-69)1975.rFe
rroelectric LiquidCrysta
lsJ ; “Applied Physics
Letters″36 (11) 1980. rsu
bm [cr.

5econd B15table Electro
opticSwitching in Liqui
d CrystalsJ ; “Solid State Physics” 16 (1
41) No. 19 No. 1 R Liquid Crystal", etc., and the ferroelectric liquid crystal disclosed therein can be used in the present invention.

More specifically, an example of the ferroelectric liquid crystal compound used in the method of the present invention is decyloxybenzylidene-p-7 minnow 2-methylbutyl cinnamate (DOBAMBC).
, Negysyloxybenzylidene-p-amino-2-chloroprovir cinname) (HOBACPC) and 4
-o-(2-methyl)-butylresolsiliten-4'-
Examples include octylphniline (MBRA8).

When constructing an element using these materials, the liquid crystal compounds include SmC*, SmH, and Sm.

In order to maintain the temperature state such that the number of SmJ, SmK, SmF, and 3m0 units is maintained, the element can be supported by a copper block or the like in which a heater is embedded, if necessary.

FIG. 4 schematically depicts an example of a ferroelectric liquid crystal cell. 41 and 41' are In2O3, 5n02 and IT
It is a substrate (glass plate) coated with a transparent electrode such as O (Indium-Tin Oxide), between which a liquid crystal molecular layer 42 is oriented perpendicular to the glass surface.
The liquid crystal of the main phase is sealed.

A thick line 43 represents liquid crystal molecules.

This liquid crystal molecule 43 has a dipole moment (on P) 44 in the direction orthogonal to the molecule.

When a voltage higher than a certain threshold is applied between the electrodes on the substrates 41 and 41', the helical structure of the liquid crystal molecules 43 is unraveled, and the dipole moment The orientation direction can be changed. The liquid crystal molecules 43 have an elongated shape and exhibit refractive index anisotropy in the long axis direction and the short axis direction. Therefore, for example, if polarizers are placed above and below the glass surface in a crossed nicol positional relationship, It is easily understood that this is a liquid crystal optical element whose optical characteristics change depending on the polarity of applied voltage. Furthermore, if the thickness of the liquid crystal cell is made sufficiently thin (for example, lp
), as shown in Figure 2, the helical structure of the liquid crystal molecules unravels (non-helical structure) even when no electric field is applied, and its dipole moment) P or P' is directed upward (54) or downward (54'). ). When an electric field E with a different polarity above a certain threshold value E' is applied to such a cell as shown in FIG. 5, the dipole moment electric field E or E' will move upward 54 or downward!
! 54', and the liquid crystal molecules change direction accordingly.
stable state 53 (beak-like yts> or second stable state s
53' (dark state).

There are two advantages to using such a ferroelectric liquid crystal as an optical modulation element. First, the response speed is extremely fast.
The orientation of the second liquid crystal molecules has bistability.

The second point will be explained with reference to FIG. 5, for example. When the electric field E is applied, the liquid crystal molecules are aligned in the first stable state Jli53.

This first stable state 53 is maintained even when the electric field is cut off, and when an electric field E' in the opposite direction is applied, the liquid crystal molecules are aligned to the second stable state 53' and the orientation of the molecules is changed. However, it remains in this state even when the electric field is turned off, and has a memory function in each stable state. Further, each orientation state is maintained as long as the applied electric field E does not exceed a certain threshold value. Such fast response speed and
In order to effectively realize bistability, it is preferable that the cell be as thin as possible, and 0.1 #L to 3 IL is generally suitable. A liquid crystal-electro-optical device having a matrix electrode structure using ferroelectric liquid crystals of this kind has been proposed by Clark and Ragaval in US Pat. No. 4,367,924, for example.

FIG. 6 shows another embodiment of the display device of the present invention. The same reference numerals as in FIGS. 1 and 2 represent the same members.

The display device shown in FIG. 6 is the same device as that used in the display device shown in FIG. 1, except that the terminals of the electrode group 104 wired to the flexible substrate 102 are divided into terminal groups 109' and 109#, respectively. . Therefore, in the display device of this embodiment, each terminal group 1
Two anisotropic conductors lOγ and 107″ and respective drive circuit portions 106′ and 106″ are arranged to be electrically tangential to 09′ and 109″.

In this display device, the density of the number of terminals per unit length of the terminal groups 109' and 109'' can be reduced, and electrical connection with an external control circuit can be made without causing a short circuit between the terminals. can.

As explained above, by making one side of the substrate flexible and encapsulating the liquid crystal under reduced pressure through a spacer, it is possible to obtain the precision of the liquid crystal layer required to construct a ferroelectric liquid crystal cell over a large area. became. In addition, by forming only striped electrodes on the flexible substrate side and connecting them to drive elements made of thin film transistors formed on the other substrate, it is easy to connect a large number of electrodes, and it is possible to achieve high pixel density in a large area. display device has become possible.

[Brief explanation of drawings]

FIG. 1(A) is a plan view schematically representing the present invention;
Figure CB) is a sectional view taken along the line AA', and Figure 2 is an explanatory diagram showing the drive circuit used in the present invention. Figure 3 is 1
1 is a plan view of a liquid crystal cell used in the present invention. 4 and 5 are perspective views schematically showing a ferroelectric liquid crystal element used in the present invention. FIG. 6 is a plan view showing another embodiment of the present invention. 101, substrate 102; flexible substrate 103.104. Electrode group 105, 106, 106', 106'; Drive circuit section 1
07.107.107″; Anisotropic conductor 108.10
9; Terminal group 110.32; Seal member 111.33. Spacer member 112, 114; polarizing means (polarizer, analyzer) l13
; Ferroelectric liquid crystal procedure amendment ceremony) April 1985/Otsuto Manabu Shiga, Commissioner of the Patent Office1, Indication of the case 1982 Patent Application No. 2636632, Name of the invention Liquid crystal element3, Amendment Relationship with the case of a person who does
)Representative of Canon Co., Ltd. Ryu Kaki Part 4, Agent address: 3-30-25 Shimomaruko, Ota-ku, Tokyo 148, Date of amendment order: March 26, 1985 (shipment date) 6. Details subject to amendment Book 7, Contents of amendment (1) ““ on page 21, line 19 to page 22, line 4 of the specification
LE JOURNAL...4.1quid Cryst
als J;
E P) IYSIQUE LETTERS” >3
6 (L-69) 1975, r ferroelectric
``Liquid List'' (rFsrroe)
Electric Liquid Crystals J
) ; “Applied Physics Letters
s”) 3 6 (11) 1980r Submicro Second Meeting Bistiple ゝElectro-optic Switching in Liquid Crystals JCrSub intestinal icr. 5econd B15table !1electro
aptic Switching 1nLiqui
d CHstals”) ; Correct as J.

Claims (15)

[Claims] (1) In a liquid crystal element having a cell body in which a gap between a pair of substrates, at least one of which is a flexible substrate, is maintained by a plurality of spacer members, and a ferroelectric liquid crystal sealed inside the cell body, The elastic modulus of the flexible substrate is E (Kgf/m
m^2), whose thickness is t (mm), and the distance between the spacer members is a (mm), the above E, t and a
A liquid crystal element characterized by having a relationship of a^4/Et^3<0.32. (2) The liquid crystal element according to claim 1, wherein the flexible substrate is glass with a thickness of 0.2 mm or less. (3) The liquid crystal element according to claim 1, wherein the flexible substrate is a uniaxially stretched film having a thickness of 25 μm or more. (4) The liquid crystal device according to claim 3, wherein the uniaxially stretched film is a uniaxially stretched polyester film. (5) The liquid crystal element according to claim 1, wherein the spacer member has a thickness of 0.1 to 3 μm. (6) The liquid crystal element according to claim 1, wherein the spacer member has a parallel stripe shape, and the distance between adjacent stripes is 2 mm or less. (7) The liquid crystal element according to claim 1, wherein the spacer member has a parallel stripe shape, and the distance between adjacent stripes is 800 μm or less. (8) The liquid crystal element according to claim 1, wherein the spacer member has a lattice shape, and the length of the long side thereof is 2 mm or less. (9) The liquid crystal element according to claim 1, wherein the spacer member has a lattice shape, and the length of the long side thereof is 800 μm or less. (10) The liquid crystal element according to claim 1, wherein the spacer member has a dot shape, and the interval between the dots is 2 mm or less. (11) The spacer member has a dot shape,
2. The liquid crystal element according to claim 1, wherein the distance between the dots is 800 μm or less. (12) The liquid crystal element according to claim 1, wherein the inside of the cell body is in a reduced pressure state. (13) The liquid crystal device according to claim 1, wherein the ferroelectric liquid crystal is a chiral smectic liquid crystal. (14) The liquid crystal element according to claim 13, wherein the chiral smectic liquid crystal has a non-helical structure. (15) The chiral smectic liquid crystal has a C phase, an H phase,
14. The liquid crystal element according to claim 13, which is an I-phase, J-phase, K-phase, G-phase or F-phase.