JPH0284619A - Liquid crystal electrooptic element - Google Patents

Abstract

PURPOSE:To stabilize the oriented state of a ferroelectric liquid crystal by subjecting substrates to an orientation treatment and sealing the liquid crystal therebetween, then impressing a voltage to the liquid crystal to regulate the oriented state thereof. CONSTITUTION:This element has the substrates 11, transparent electrodes 12, insulating layers 15, diagonally vapor deposited layers 13A, the ferroelectric liquid crystal 14 and polarizing plates 17. At least one of the substrate 11 is subjected to the orientation treatment and after the ferroelectric liquid crystal 14 is sealed between the substrates, the voltage is impressed to the liquid crystal, by which the oriented state is regulated. The reforming of the substrate surfaces may be executed by subjecting at least one of the substrates to the orientation treatment and applying a coupling agent thereof or by subjecting the one substrate to the orientation treatment and applying the coupling agent to the other substrate. The liquid crystal attains the uniform state in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a liquid crystal electro-optic device, particularly a liquid crystal electro-optic device using ferroelectric liquid crystal.

[Prior art] As a conventional liquid crystal element using ferroelectric liquid crystal, C1ar
K. and Lagerwal) (Japanese Unexamined Patent Publication No. 107216/1983, U.S. Patent No. 436792)
Here, we will briefly explain the operation of a liquid crystal element using ferroelectric liquid crystal. FIG. 5 shows the alignment state of liquid crystal molecules. 26 is a locus (cone) in which the liquid crystal molecules appearing in the ferroelectric liquid crystal phase can move. Normally, the liquid crystal molecules 2 are sandwiched between the upper and lower electrically bridged substrates 25, so that they are not in the state 23 or the state in the figure. jl! It is most stable when it is at 24. The instability of states 821 and 22 is thought to be due to the interaction between the liquid crystal molecules and the alignment film. When a zero-order electric field is applied, the spontaneous polarization 27 points in the direction of the electric field. In other words, when an electric field in the opposite direction to the 0th order is applied, which is state 22 in the figure, the spontaneous polarization is reversed, and state 21 in the figure is obtained.
occupies When this state is observed under crossed Nicol conditions, depending on how the polarizing plates are arranged, for example, the state 22 appears dark and the state 21 appears bright. The best display condition in this case is that in a dark condition almost no light passes through, and in a bright condition the transmittance is almost equal to that when the polarization directions of the two polarizing plates are parallel and the liquid crystal element is excluded. In order to realize this, it is sufficient that the angle formed by the molecules of the shape 821 and the shape MM22 is 45°. Ordinary LCDs meet this condition. After the electric field is removed, the liquid crystal retains the state it was in when the electric field was applied. This is called memory property.

Conventional alignment control methods for liquid crystal electro-optical elements using ferroelectric liquid crystals include forming an organic polymer layer such as polyimide on the substrate surface and performing a rubbing treatment, and growing a liquid crystal layer from a spacer edge using a temperature gradient method. method, magnetic field rationing method,
There are methods such as slow cooling while applying a direct current electric field. However, when a normal alignment treatment (for example, rubbing with cloth) is performed, the liquid crystal molecules do not remain in states 21 and 22 of FIG. 5, but become stable in states 23 and 24. Condition 23 and condition! The angle between Q24 is usually less than 20 degrees, so when using the memory state for display, sufficient brightness cannot be obtained, and in the memory state, the position of the liquid crystal molecules in the cone is the same from the upper substrate to the lower substrate. light leaks in dark conditions. For this reason, multiplex driving methods using memory properties are essential for displays using ferroelectric liquid crystals, which reduce contrast, and these issues must be overcome. Therefore, as a method to improve contrast and transmittance, The oblique evaporation method and the energized orientation method are being considered.

When using the SiO oblique evaporation method as the liquid crystal alignment method (
12th LCD Symposium Proceedings 1 Series F12 (p, 32) or Japan Display 86 Proceedings 12
．． 3 (p, 464)), the contrast ratio is several tens of times higher and the light transmittance is several times higher than the optical properties obtained using the rubbing method, in which resins such as polyimide are rubbed with a cloth. can get. Moreover, if this method is used, the slow cooling process when aligning the liquid crystal is also easy. Other methods include the energizing orientation method disclosed in Japanese Patent Application Laid-open No. 62-92918 and Japanese Patent Application Laid-open No. 62-79427. According to this method,
Even in the memory state, the positions of the liquid crystal molecules are in states 21 and 22 in FIG. 5, and a bright and high-contrast display can be obtained.

(The first problem to be solved by the invention is the electric field response characteristics of ferroelectric liquid crystals, especially the memory effect.
It is thought that this is largely influenced by the chemical interaction between the liquid crystal molecules and the substrate surface. Chiral smectic C phase (hereinafter referred to as
According to the switching principle of SmC* phase),
In order to obtain a good memory effect, it is desirable that the liquid crystal molecules be aligned parallel to the substrate surface and in one direction. However, if conventional orientation control such as rubbing the polymer film surface is used, SmC* The orientation in the phase is in a twisted state, that is, the liquid crystal molecule director rotates on the side surface of a cone from the surface of one substrate to the surface of the opposite substrate, and the spontaneous polarization tends to exhibit a state in which it points inward or outward at both the upper and lower interfaces, which is therefore favorable. It was difficult to obtain a good memory effect.

Liquid crystal electro-optical devices manufactured using conventional techniques such as the above-mentioned rubbing method and temperature gradient method are manufactured by Ferroelectrics.
, 1984, Vol. 59, P69-116, zigzag wall δ-Φ defects are likely to occur. This defect is said to occur due to interaction between the substrate surface and the polarization of liquid crystal molecules. Furthermore, our experiments have shown that many occurrences occur when stress is applied to the liquid crystal layer in addition to the above. When this defect occurs in the element, light leakage causes a significant decrease in contrast.

Further, the conventional technique of oblique vapor deposition described above has problems with display unevenness and reliability, and has the disadvantage that it is difficult to increase the screen size. A strong memory state to obtain a high contrast ratio must depend on the cell thickness.The value varies depending on the type of liquid crystal, but only when the cell thickness of the device is below a certain value, bistable state of two uniform states. If the cell thickness exceeds a certain value (hereinafter referred to as critical cell thickness), the twisted L! i
The twisted state, in which the bent state becomes stable, is not very desirable for obtaining a high contrast ratio (National Technical Rep.
ort Vol. 33 No. 1, 1987).

Here, the uniform state refers to a state in which the director of the liquid crystal molecules is uniformly tilted with respect to the layer normal, and the spontaneous polarization at the interface between the upper and lower substrates points in the same direction, and the twisted state refers to a state in which the director is on the top surface. It rotates on the side surface of the cone from the top to the bottom surface, and the spontaneous polarization points inward or outward at both the upper and lower interfaces, and is in a state of spray deformation inside.

In addition, the optimal cell thickness of a liquid crystal optical element to obtain sufficient light transmittance depends on the birefringence Δn of the liquid crystal material used. Balancing both conditions is difficult.

In addition, in the conventional energization alignment method described above, an alternating current electric field is applied using display electrodes formed on the substrate of a liquid crystal element to perform energization alignment processing, so no electric field is applied between pixels and energization alignment is not performed. In the memory state, there is a difference in the orientation of liquid crystal molecules between pixels by the angle formed by states 22 and 24 in Figure 5, and when the polarizing plates are aligned so that the contrast of the pixels is maximized, light is generated between the pixels. There was a problem with leakage. Furthermore, since the effect of the energization orientation disappears within a few days, it is necessary to re-orient the energization when the display device starts operating or even while it continues to operate, which has the disadvantage of requiring special electrodes and circuits. .

The present invention solves the above problems by modifying the substrate surface and controlling the orientation by electric field treatment.The purpose of the present invention is to achieve bistable uniform orientation even when the cell thickness is greater than the critical cell thickness. It is an object of the present invention to provide a liquid crystal electro-optical element that eliminates light leakage outside the pixel, has a good memory effect, and has excellent optical properties with little reduction in contrast due to alignment defects, and a method for manufacturing the same.

[Means to solve the problem]

The present invention provides a liquid crystal electro-optical element comprising a ferroelectric liquid crystal sandwiched between a pair of substrates having transparent electrodes, in which one substrate is subjected to an alignment treatment, and the ferroelectric liquid crystal is This is a liquid crystal electro-optical element characterized in that the alignment state is regulated by applying a The quality is one in which at least one substrate has been subjected to alignment treatment and a coupling agent is applied thereto, or one in which one substrate has been subjected to alignment treatment and the other substrate is coated with a coupling agent. The coupling agent may have at least one of an amino group, an epoxy group, a mercapto group as a functional organ, or a mixture thereof. When applying a voltage in the current alignment process, a pair of substrates may be Orientation treatment,
After assembling with a distance of 1 to 10 μm and sealing the liquid crystal, an alternating current electric field of ±5000 V/m to ±100.0 OOV/■ and 1 to 2007 is applied from the outside of the liquid crystal element.

〔Example〕

Example 1 FIG. 1 is a sectional view of an electro-optical element in an example in which orientation treatment was performed by oblique evaporation. 11 is a substrate, 12
is a transparent electrode made of ITO (Indium Tin).
0xide) etc. 15 is Sin,
13A is an oblique evaporation layer, 1
4 is a ferroelectric liquid crystal, and 17 is a polarizing plate. Oblique deposition li
t3A is S from the direction tilted by 5° with respect to the surface of the substrate 11.
An alignment film is formed by obliquely depositing iO, and the layer thickness is about 100 OA. The insulating layer 15 may be formed only on one of the pair of substrates 11, and the material to be deposited does not need to be SiO as long as it is an insulator. 11 and the deposition direction is 18
It was assembled to form 0@.

The cell thickness was 2.8 μm. A ferroelectric liquid crystal 14 was heated and sealed between the substrates, and slowly cooled from an isotropic phase to room temperature at a rate of 1'C/min.

As the ferroelectric liquid crystal 14, C5-1011 manufactured by Chisso Corporation was used. For this C5-1011, the uniform/twist critical cell thickness was 2.2-2.4 μm. Therefore, in the device of this example, the liquid crystal exhibited a twisted state after being slowly cooled. When an alternating waveform of ±15V and 2007 was applied for about 30 seconds between the electrodes of this device, the liquid crystal exhibited a --like uniform state. Here, the electric field applied to obtain uniform orientation has an alternating waveform such as a square wave, a triangular wave, or a sine wave, and its frequency depends on the response speed of the liquid crystal used, as long as it is below the frequency at which the liquid crystal molecules are sufficiently inverted. It is valid. The above liquid crystal electro-optical element was sandwiched between polarizing plates 17 whose polarization axes were orthogonal to each other, and the driving waveform shown in FIG. 2(A) was applied to the electrodes 12 to evaluate the optical characteristics at that time. FIG. 2(B) is an example of the corresponding optical response. The quality of the memory effect is determined by the amount of transmitted light when an electric field is applied (1 in Figure 2 (B)).
．． ) and the amount of light after removing the electric field (■t in Figure 2 (B)): 1
! /I+ is considered to be better as it is larger.0 In this example, I! /I, -0.99, the contrast ratio was good at 1:30 or more, and the amount of transmitted light was 90%, which was sufficient. Here, the amount of transmitted light is calculated by taking as 100% the amount of transmitted light when a cell not containing liquid crystal is sandwiched between two polarizing plates whose polarization axes are parallel to each other.

Example 2 ZLI-377 manufactured by Merck & Co. was used as the ferroelectric liquid crystal 14 in FIG.
4 was used. In this case, the uniform/twist critical cell thickness was 1.8 μm. In addition, when considering the amount of transmitted light, the amount of transmitted light ■(%) -5yCλ)・C(λ)−P(λ)・sin4θ・enter1sin” (gd・Δn/λ) y(λ): Visual Sensitivity C (λ): light source, P (λ); wavelength characteristic θ of polarizing plate: Sw
rC'' tilt angle λ1.λ,: From the upper and lower limits of the visible region, the cell thickness d to obtain the maximum amount of transmitted light is ZLl-
When calculated for 3774, d=2.4 μm. In order to obtain the maximum amount of transmitted light, the cell thickness was set to 2.degree. 4 .mu.m, and an electro-optical element similar to that of Example 1 was constructed.

After the liquid crystal was heated and sealed and slowly cooled, an alternating waveform of ±IOV and 500 Hz was applied for 30 seconds to obtain a uniform orientation. When the thus obtained element was evaluated using the drive waveform shown in FIG. 2 in the same manner as in Example 1, a contrast ratio of 1:40 and a transmitted light amount of 90 to 95% were obtained.

Example 3 FIG. 3 is a cross-sectional view of an electro-optical element in which a coupling agent coated on a substrate is rubbed.

The same numbers as in Figure 1 are the same as those explained in Figure 1.0
As the ferroelectric liquid crystal 14, ZLI-3775 manufactured by Merck & Co., Ltd. was used. A silane coupling agent film 13B was formed on the substrate provided with the insulating layer 15, and the surface thereof was subjected to a rubbing treatment. The silane coupling agent used here was T-aminopropylmethyldiethoxysilane (Cm Hs O) x Si (CHs) Cs H, which is a compound containing an amino group.
hNHt. To form the film 13B, a 0.2% ethanol solution of the above compound was spun onto the substrate and baked at 80° C. for about 60 minutes. The thus obtained substrates were assembled so that the rubbing direction of the upper and lower substrates was 180@. The cell thickness was approximately 2 μm. In this embodiment, the Sin insulating layer 15 is provided on both the upper and lower substrates 11, but it is also possible to provide only one of them.
The rubbing treatment may also be applied to only one side of the substrate.

A ferroelectric liquid crystal is heat-sealed between the above substrates and room temperature (approximately 25
℃). Next, apply ±25V between the electrodes of this element.
When an alternating waveform of 15 Hz was applied for about 30 seconds, the alignment state of the liquid crystal exhibited a uniform state with dense striped dislocations in a direction substantially perpendicular to the layer direction. The zigzag walls and δ-Φ defects formed during cooling the encapsulation are removed by the electric field treatment.The liquid crystal electro-optical element obtained by the method of 0 or more' is sandwiched between polarizing plates whose polarization axes are orthogonal to each other, The driving waveform shown in FIG. 2(A) was applied, and the optical response shown in FIG. 2(B) at that time was evaluated. In the liquid crystal electro-optical element of this example, when measured at V-10V, it was good as /[, -0.97, and a contrast ratio of 1:38 was obtained.

Note that the coupling agent is thought to have the effect of changing the interaction between the liquid crystal molecules and the substrate surface, and in this example, T-aminopropyltriethoxysilane (Cm Hs O) s Si Cs was used as the coupling agent.
Hh NHtN, -β(aminoethyl)T-aminopropyltrimethoxysilane Hz NOx H4NHt C++ Hh Si
(OCHi)N-β(aminoethyl)T-aminopropylmethyldimethoxysilaneHz NOx Ha NHCs Hb (CH3)S
Similar results could be obtained using i(OCHs)t, etc.

Example 4 In FIG. 3, the ferroelectric liquid crystal 14 is C5-1 manufactured by Chisso Corporation.
018, a 5% ethanol solution of T-glycidoxyprobyltrimethoxysilane, an epoxy-based silane coupling agent, was spin-coded onto the alignment film 13B, and 120"C6
An example is shown in which a product heat-treated for 0 minutes is used.
A device was constructed in the same manner as in Example 3, liquid crystal was heated and sealed, and after cooling, an alternating waveform of ±30 V and 15 Hz was applied. When the thus obtained element was evaluated using the driving waveform shown in FIG. 2 in the same manner as in Example 3, it was found that 1m/It-0.95,
A contrast ratio of 1:43 was obtained. Furthermore, similar effects were obtained when T-glycidoxypropylmethyljethoxysilane was used as the epoxy silane coupling agent.

Example 5 Same as in Example 3.4 using a titanate coupling agent such as isopropyl tri(N-aminoethyl-aminoethyl) titanate and an aluminum coupling agent such as acetalkoxyaluminum diisopropylate. When we constructed and evaluated a liquid crystal electro-optic element, it was +! /ll-0.95, contrast ratio 1:35, and amount of transmitted light 90%.

Example 6 This is a ferroelectric liquid crystal electro-optical element in which a substrate is subjected to a rubbing treatment and a coupling agent is further applied thereon. The cross-sectional view of the structure is the same as shown in FIG.
As the ferroelectric liquid crystal 14, ZLr-3775 manufactured by Merck & Co. was used. A rubbing treatment was performed on the substrate 11 provided with the ITO transparent electrode 12 and the 5-ins insulating layer 15, and a silane coupling agent 1113B was formed thereon. The silane coupling agent used here was T-aminopropylmethyljethoxysilane (C!HgO)2SiCCHs)CsH, which is a compound having an amino group.
It is 6MHz. The film was formed in the same manner as in Example 3. The substrates thus obtained were assembled so that the rubbing direction of the upper and lower substrates was 180 m. The cell thickness was approximately 2 μm. The insulating layer may be formed only on one of the upper and lower substrates. Furthermore, the rubbing treatment may be performed only on one side of the substrate.

A ferroelectric liquid crystal is heat-sealed between the above substrates and room temperature (approximately 25
After cooling to ``C'', there is a gap of ±2 between the electrodes of this element.
When 5V, 157 alternating waveform was applied for about 30 seconds,
The alignment state of the liquid crystal exhibited a uniform state with a dense striped structure substantially perpendicular to the layer direction. The above electric field treatment removes the zigzag walls and δ-Φ defects formed during cooling of the encapsulation. A driving waveform shown in FIG. 2 was applied, and the optical response at that time was evaluated. In the liquid crystal electro-optical element of this example, V
When measured as = lOV, it was 1, /1. -0.97, which was good, and a contrast ratio of 1:38 was obtained.

In this example, T-aminopropylmethyljethoxysilane was used as the amino-based silane coupling agent, but γ-aminopropyltriethoxysilane (Cz Hs
O) 3 Si Cs H5NH2N-β(aminoethyl)γ-aminopropyltrimethoxysilane Ht NCZ Ha NHt Cz HhS i (
OCH* )3N-β(aminoethyl)T-aminopropylmethyldimethoxysilane Hz NCz Ha NHCv Hh (CH3)
Similar results could be obtained using S 1 (OCR*)x and the like.

Example 7 C5-1018 manufactured by Chisso Corporation was used as the ferroelectric liquid crystal, and T-glycidoxyprobyltrimethoxysilane CH2CHCH20C, an epoxy-based silane coupling agent, was used as the alignment film.
A 5% ethanol solution of 3Hb Si (OCHs)ゝ・1 was spin-coded and 120'C6
An example is shown in which a product heat-treated for 0 minutes is used.
A device was constructed in the same manner as in Example 6, liquid crystal was heated and sealed, and after cooling, an alternating waveform of ±30 V and 15 Hz was applied. When the thus obtained element was evaluated using the driving waveform shown in FIG. 2 in the same manner as in Example 6, it was found that Iz/I+ =0.95 and contrast ratio l:43.

In addition, as an epoxy silane coupling agent, γ-glycidoxypropylmethyljethoxysilane A similar effect was obtained when using .

Example Day DOFOOO4 manufactured by Dainippon Ink Co., Ltd. was used as the ferroelectric liquid crystal, and the silane coupling agent T mercaptopropyltrimethoxysilane H3 (CHz
)3 S i (OCRl)! An example is shown in which a 0.2% ethanol solution of Subinko-1-L, 80"C was heat-treated for 60 minutes.A device was constructed in the same manner as in Example 6, and liquid crystal was sealed and aligned. ±3 after
An alternating current waveform of 0 V and 15 Hz was applied. When the device thus obtained was evaluated in the same manner as in Example 6, it was found that L/
1,=0.91. A contrast ratio of 1:40 was obtained.

Other mercapto group-based silane coupling agents have similar effects.

The method of treating the camping agent is not limited to that shown here.

Example 9 In Example 6.7.8, isopropyltri(N~ruaminoethyl7minoethyl) is used as the coupling agent.
A liquid crystal electro-optical device was constructed using titanate. Both It
/1. = 0.99, contrast ratio 1:45, and amount of transmitted light 90%.

Example 10 In Example 6.7.8, a liquid crystal electro-optical element was constructed using acetalkoxyaluminum diisopropylate as a coupling agent. Both It
/1. -0.90, contrast ratio l:30, and amount of transmitted light 80%.

Example 11 This is a ferroelectric liquid crystal electro-optical element in which a substrate is subjected to orientation treatment by oblique evaporation, and a coupling agent is further applied thereon. A sectional view thereof is shown in FIG. 4, in which the reference numerals are the same as in FIGS. 1 and 3. 13C is a vapor-deposited alignment layer, 16 is a coupling agent film, and 17 is a polarizing plate.As the ferroelectric liquid crystal 14, ZLI-3775 manufactured by Merck & Co., Ltd. was used.

On the substrate provided with the ITO transparent electrode 12 and the SiO□ insulating layer 15, approximately 1000 A of Si0 is vapor-deposited from a direction 60' with respect to the normal line of the substrate to form a vapor deposition alignment layer 13C, and a silane coupling agent is further applied to the surface thereof. A film 16 was formed. The silane coupling agent used here was T-aminopropylmethyljethoxysilane (C, Hs O)□S i (CH3), which is a compound having an amino group.
C2HANHl. In forming 11a,
A 0° 2% ethanol solution of the above compound was spin-coded onto the substrate and baked at 80° C. for about 60 minutes. The substrates thus obtained were assembled so that the vapor deposition direction of the upper and lower substrates was 180°. The cell thickness was approximately 2 μm.

The insulating layer 15 may be provided only on one of the upper and lower substrates.
Furthermore, the vapor deposition process may be performed only on one side of the substrate.

A ferroelectric liquid crystal 14 is heat-sealed between the substrates and cooled to room temperature (approximately 25°C).
When an alternating waveform of 25 V and 157 V was applied for about 30 seconds, the alignment state of the liquid crystal exhibited a uniform state with dense striped dislocation in a direction substantially perpendicular to the layer direction. The above-mentioned electric field treatment removes the zigzag walls and δ-Φ defects formed during the cooling process. , the optical response was evaluated by applying the drive waveform shown in FIG. -0.9 g, which was good, and a contrast ratio of 1:48 was obtained.

In this example, T-aminopropylmethyljethoxysilane was used as the amino-based silane coupling agent, but T-7minopropyltriethoxysilane (Ct Hs
O) s S i Cx Hh NHlN-β(aminoethyl)T-aminopropyltrimethoxysilane Hz NC! H-NHz Cs Hh Si (O
CH3) 3N-β(aminoethyl)T-aminopropylmethyldimethoxysilane H! NC! Ha NHCs Hh (CHs)
Similar results were also obtained using Si(OCH3)z and the like.

Example 12 C5-1018 manufactured by Chisso Corporation was used as the ferroelectric liquid crystal, a 5% ethanol solution of r-glycidoxyprobyltrimethoxysilane, an epoxy-based silane coupling agent, was spin-coded on the alignment film, and the film was heated at 120°C at 60°C. The device was constructed in the same manner as in Example 11, and the liquid crystal was heated and sealed, and after cooling, ±30V,
A 15 Hz alternating waveform was applied. When the thus obtained element was evaluated using the drive waveform shown in FIG. 2 in the same manner as in Example 11, Is /II =0.93 and contrast ratio of 1:35 were obtained. Furthermore, similar effects were obtained when T-glycidoxypropylmethyljethoxysilane (QC!Is)* was used as the epoxy silane coupling agent.

Example 13 DOF-0004 manufactured by Dainippon Ink Co., Ltd. was used as the liquid crystal composition, and 0, 2
An example is shown in which a % ethanol solution was spin-coded and heat-treated at 80° C. for 60 minutes. A device was constructed in the same manner as in Example 11, liquid crystal was encapsulated, and after slow cooling, an alternating waveform of ±30 V and 157 was applied. When this device was evaluated in the same manner as in Example 11, L/i, -0,
90, and a contrast ratio l:38 was obtained. Other silane coupling agents having mercapto groups also have similar effects. Furthermore, the method for treating the coupling agent is not limited to that shown here.

Example 14 An example of a method for manufacturing a liquid crystal element by energizing alignment treatment will be described.

FIG. 6 is a cross-sectional view of a liquid crystal element manufactured according to this example. The same reference numerals as in FIG. 1 indicate the same parts as in the same figure.A comb-shaped electric scraper 12 for multiplex driving is provided on each of the two substrates 11, and an insulating layer 15 is further provided on the electrode 12. An alignment film 13 is provided thereon. T-ruaminopropyltriethoxysilane is used as the alignment film 13. After the alignment film 13 was applied and dried, a rubbing treatment was performed. The rubbing process may be performed only on one side of the substrate.

In addition, the rubbing process can be used to improve the orientation [! It may be performed before forming 13. The insulation l115 may be provided only on one side.

The two substrates subjected to the above treatment were combined so that the comb-shaped electric scrapers 12 were perpendicular to each other. The distance between the substrates is 2 μm.

Liquid crystal ZLI-3775 (manufactured by Merck & Co., Ltd.) is filled in this gap and sealed. 1st is a spacer. This element
The device was slowly cooled from 100°C to 50°C, and then the device was sandwiched between two electrodes 1 and heated to -5000V/am~f.
: 100. 000■/ll111.1) (Z~20
An alternating electric field of 0.07 was applied to carry out an energization orientation treatment. At this time, if the electric field is less than ±5,000 V/ffl1l or the frequency is more than 200 Hz, the current will not be oriented, and if the electric field is more than ±100.0 OOV/111++ or the frequency is less than 17. If you do so, the liquid crystal will decompose.

Unlike the case where a voltage is applied between the transparent electrodes 12, the thus obtained liquid crystal element can be energized and aligned in the same way between the pixels, so that no light leaks between the pixels.

The liquid crystal used here may have a ferroelectric phase within the operating temperature range. For orientation 1913, in addition to organic polymers such as polyimide, polyvinyl alcohol, polymethyl methacrylate, and polyester, silane-based force/mumbling agents, titanium-based coupling agents, aluminum-based coupling agents, and chromium-based coupling agents can be used. .

〔Effect of the invention〕

The present invention modifies the substrate surface and controls power distribution with the above configuration, eliminates the drawbacks of the prior art, makes it possible to stabilize the orientation state of the ferroelectric liquid crystal, and achieves a good memory effect. It is possible to obtain an excellent liquid crystal electro-optical element that has excellent durability and an excellent amount of transmitted light, and has little reduction in contrast caused by alignment defects and color leakage between pixels and non-pixels. In addition, the orientation state, contrast ratio, and amount of transmitted light are 2 after voltage application.
It is a stable element that does not change even after more than a month has passed.

Therefore, the present invention can be applied to high multi-breeding displays, liquid crystal light valves, various electronic shutters, polarizers, etc.

[Brief explanation of the drawing]

Figure 1, 3rd r! ! Figure 4 is a cross-sectional view of the electro-optical element of the present invention, Figure 2 (A) is the driving waveform used in evaluating the electro-optical element of the present invention, and Figure 2 (B) is the corresponding optical response. Figure 5 is a conceptual diagram showing the operating principle of a ferroelectric liquid crystal element, and Figure 6 is a diagram illustrating a method of manufacturing a liquid crystal element of the present invention. 1... Electrode 11... Substrate 12... Transparent electrode 13... Alignment film 13A, 13C... Oblique vapor deposition layer 13B, 16
・・・・・・Coupling agent film 14−・・・・
- Ferroelectric liquid crystal 15 --- Insulating layer 17 --- Polarizing plate 18 --- Spacer 21 --- Most stable state of liquid crystal molecules when electric field is applied 22
・・・−・Most stable state of liquid crystal molecules when applying a reverse electric field 23・
...Most stable state when applying an electric field and setting the return electric field to zero 24 ... - Most stable state when applying a reverse electric field and setting the return electric field to zero 25 - ... Electro-scraped substrate 26 ... ...-Movable locus (cone) of liquid crystal molecules that appear in the ferroelectric liquid crystal phase 27...-Spontaneous scratching 2B...-Liquid crystal molecules

Claims (1)

[Claims] (1) In a liquid crystal electro-optical element comprising a ferroelectric liquid crystal sandwiched between a pair of substrates having transparent electrodes, at least one substrate is subjected to alignment treatment, and the ferroelectric liquid crystal is A liquid crystal electro-optical element characterized in that an alignment state is regulated by applying a voltage after being encapsulated. (2) The liquid crystal electro-optical element according to claim (1), wherein the alignment treatment is performed by oblique evaporation. (3) The liquid crystal electro-optical element according to claim (1), wherein the alignment treatment is performed by a rubbing method on a coupling agent applied on the substrate. (4) In a liquid crystal electro-optical element comprising a ferroelectric liquid crystal sandwiched between a pair of substrates having transparent electrodes, at least one substrate is subjected to an alignment treatment, a coupling agent is further applied thereon, and the A liquid crystal electro-optical element characterized in that the orientation state of the ferroelectric liquid crystal is regulated by applying a voltage after the ferroelectric liquid crystal is sealed. (5) In a liquid crystal electro-optical element consisting of a ferroelectric liquid crystal sandwiched between a pair of substrates having transparent electrodes, one substrate is subjected to alignment treatment, the other substrate is coated with a coupling agent, and the ferroelectric liquid crystal is A liquid crystal electro-optical element characterized in that the orientation state of the dielectric liquid crystal is regulated by applying a voltage after the dielectric liquid crystal is sealed. (6) The liquid crystal electro-optical element according to claim (4) or (5), wherein the alignment treatment is performed by oblique evaporation. (7) The liquid crystal electro-optical element according to claim (4) or (5), wherein the alignment treatment is performed by a rubbing method. (8) The coupling agent is a coupling agent having at least one of an amino group, an epoxy group, and a mercapto group as a functional organ, or a mixture thereof.
4), the liquid crystal electro-optical element described in (5), (6), or (7). (9) In a method for manufacturing a liquid crystal element in which a ferroelectric liquid crystal is sandwiched between a pair of substrates having transparent electrodes, at least one of the two substrates is subjected to alignment treatment, and assembled with a distance of 1 to 10 μm apart, After sealing the liquid crystal, ±5,000V
/mm~±100,000V/mm, 1Hz~200H
A method for manufacturing a liquid crystal element, characterized in that an alternating current electric field of z is applied from the outside of the liquid crystal element to carry out an energization alignment process.