JP3124367B2 - Liquid crystal optical element alignment method and apparatus therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for orienting a liquid crystal optical element used for manufacturing a liquid crystal element used for a liquid crystal display device of an electronic apparatus and the like, and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal material is formed on a substrate provided with electrodes, in particular,
As an alignment method in a liquid crystal element sandwiched between flexible substrates, there can be mentioned “alignment method of liquid crystal material” disclosed in JP-A-3-5727. In this method, a liquid crystal element is sandwiched between two liquid crystal element sandwiching plastic plates. Then, the front and back sides of the liquid crystal holding plastic plate are alternately brought into close contact with a roller unit consisting of two rolls,
Shearing due to bending deformation is applied. In this case, an electric field is applied by connecting an electric wire to the electrode of the substrate with electrodes.

[0003] Further, in Japanese Patent Application Laid-Open No. Hei 3-163525, "Method and Apparatus for Aligning Liquid Crystal Optical Element", a power supply is previously connected to two conductive rolls made of a conductive material to apply a voltage. The electric field and the shearing are simultaneously applied by exposing the electrodes facing each other of the liquid crystal element sandwiching the liquid crystal material, and bringing the electrodes into close contact with the roller surface.

FIG. 5 shows a schematic configuration of an orientation processing apparatus using a conventional conductive roll. In FIG. 5, the alignment processing device is configured to apply a sheet-like liquid crystal element 2 to a biaxially-stretched PET mirror 4 and to wind the liquid crystal element 2 and the biaxially-stretched PET mirror 4. Device 8 and a roll electric field applying unit 10. In this orientation processing apparatus, a roll electric field applying unit 1 is used by using a feeding device 6 and a winding device 8.
At 0, the positive and negative voltages are applied to bring the outer periphery of the roll into contact with the extraction electrode of the liquid crystal element 2, whereby an electric field and shear are applied to perform alignment.

[0005]

However, JP-A-3-5727 and JP-A-3-1635, which are shown in the prior art,
The alignment method of No. 25 is effective for a roll-shaped long liquid crystal element, but cannot be applied to a sheet-shaped liquid crystal element. In addition, when alignment disorder occurs in a part, a long liquid crystal element is taken out of the apparatus, and further processing is performed a plurality of times.
There was an improvement that the production was troublesome.

Further, the alignment processing apparatus shown in FIG. 5 is effective for a roll-like long liquid crystal element, but for a sheet-like liquid crystal element 2, it is attached to a biaxially stretched PET mirror 4 and
It is necessary to pay out and wind up. In this case, if the alignment becomes uneven, it is necessary to move the liquid crystal element 2 to the feeding device 6 again, and the operation and operation are complicated. Further, in the case of a roll-shaped long liquid crystal element, if the alignment becomes uneven, it is necessary to move the roll-shaped long liquid crystal element to the feeding device 6 side again, and the work and operation become complicated. Further, in the case of a long liquid crystal element, it is necessary to cut out the portion where the alignment unevenness has occurred and move it to the feeding device 6 side again, and the work and operation are complicated. Therefore, in these cases, there is a problem that the production yield is eventually deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and enables the liquid crystal element to be continuously subjected to alignment treatment any number of times irrespective of the shape of a long or sheet liquid crystal, thereby improving the production yield. An object of the present invention is to provide a liquid crystal optical element alignment method and a device thereof.

[0008]

According to the present invention, there is provided a liquid crystal device having a ferroelectric liquid crystal material sandwiched between two flexible substrates, provided with an electrode for applying a positive voltage. A voltage is applied between the electrodes of the positive voltage applying belt and the negative voltage applying belt while being conveyed using the positive voltage applying belt and the negative voltage applying belt provided with the electrodes for applying the negative voltage. A liquid crystal optical element characterized in that the ferroelectric liquid crystal material is aligned while applying a voltage to the liquid crystal element and applying a voltage between the electrodes by applying shear by bending deformation using an alignment roller. An orientation method is provided. Further, in performing the liquid crystal optical element alignment method of the present invention, a voltage may be applied between the electrodes of the positive voltage applying belt and the negative voltage applying belt using a positive voltage applying roller and a negative voltage applying roller, respectively. preferable. In another aspect of the present invention, a positive voltage is applied to a liquid crystal element having a ferroelectric liquid crystal material sandwiched between two flexible substrates and provided with electrodes for applying a positive and negative voltage while being transported. An endless positive voltage applying belt provided with an electrode to be provided, and an electrode for applying a negative voltage during transport of the liquid crystal element are provided, and this electrode faces an electrode provided on the positive voltage applying belt. And a plurality of rollers for rotating the positive voltage applying belt and the negative voltage applying belt, and performing at least bending and shear alignment on the liquid crystal element. A liquid crystal optical element alignment device, comprising: an alignment roller unit.

Hereinafter, a method and an apparatus for aligning a liquid crystal optical element according to the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a liquid crystal optical element alignment device that performs an alignment process by applying an electric field and shear. FIG. 1A is a side view of the configuration, and FIG.
Shows a front configuration diagram. 1A and 1B schematically includes a positive electric field application unit 2, an orientation roller unit 6, a negative electric field application unit 4, and a voltage source E. The positive electric field applying unit 2 is an upper belt for applying a positive voltage with an endless electrode (hereinafter, may be referred to as a positive voltage applying belt) 2.
a, guide rollers 2b and 2c and positive voltage applying roller 2d
have. The negative electric field applying unit 4 includes a lower belt for applying a negative voltage with an electrode (hereinafter, may be referred to as a belt for applying a negative voltage) 4a, guide rollers 4b and 4c, and a negative voltage applying roller 4d. The orienting roller section 6 is composed of eight rollers which are joined to the upper belt 2a for applying a positive voltage with electrodes and the lower belt 4a for applying a negative voltage with electrodes.

Here, the liquid crystal element will be described. The liquid crystal element 10 is configured by sandwiching a ferroelectric liquid crystal material between two flexible substrates with electrodes. The ferroelectric liquid crystal material in this case is preferably a chiral smectic C phase exhibiting a ferroelectric phase such as a low molecular weight, a high molecular weight, or a mixture. Examples of the ferroelectric liquid crystal state include a ferroelectric low-molecular liquid crystal, a ferroelectric polymer liquid crystal, and a mixture thereof. Here, the ferroelectric low-molecular liquid crystal includes, for example, one or more ferroelectric low-molecular liquid crystals, and a mixture of one or more ferroelectric low-molecular liquid crystals and other low-molecular liquid crystals. Ferroelectric low-molecular liquid crystals can be used. Also,
As the ferroelectric polymer liquid crystal, for example, one or more ferroelectric polymer liquid crystal, one or more ferroelectric low-molecular liquid crystal and one or more ferroelectric polymer liquid crystal And a ferroelectric polymer liquid crystal composed of one or more ferroelectric low-molecular liquid crystals and one or more other polymer liquid crystals.
That is, as the ferroelectric polymer liquid crystal, a ferroelectric polymer liquid crystal (a homopolymer or a copolymer or a mixture thereof), in which the polymer molecule itself exhibits ferroelectric liquid crystal properties, a ferroelectric polymer liquid crystal, and A mixture of a polymer liquid crystal and / or a normal polymer, a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low-molecular liquid crystal, a ferroelectric polymer liquid crystal and a ferroelectric low-molecular liquid crystal and a polymer liquid crystal, and / or Polymer liquid crystals exhibiting all ferroelectricity, such as mixtures with ordinary polymers or mixtures of these with ordinary low-molecular liquid crystals, can be used. Among the ferroelectric polymer liquid crystals, for example, a side chain type ferroelectric polymer liquid crystal having a chiral smectic C phase is preferably used.

Examples of the ferroelectric liquid crystal compound include desyloxybenzylidene-P'-amino-2-methylbutylcinnamate (DOBAMBC) and hexyloxybenzylidene-P'-amino-2-chloropropylcinnamate (HOBACPC). And 4-o- (2-methyl)-
Butylresorcylidene-4'-octylaniline (MB
RA8) and the like. When a device is formed using these materials, the liquid crystal compound is formed of SmC * phase or SmH
* The element can be supported by a copper block or the like in which a heater is embedded, if necessary, for maintaining the temperature in a phase. In the present invention, the aforementioned SmC *, S
In addition to mH *, the chiral smectic F phase and the ferroelectric liquid crystal composition may contain an adhesive, a viscosity reducing agent, a non-liquid crystal chiral compound, a dye, and the like, if necessary. I phase, J phase, G
It is also possible to use a ferroelectric liquid crystal that appears in a phase or K phase.

FIG. 2 is an exploded configuration diagram of the liquid crystal element 10. In FIG. 2, a flexible data electrode substrate 1 with electrodes
1 has an ITO electrode group 12 formed by patterning in the form of a stripe, and an extraction electrode 13 for electric field orientation.
The flexible common electrode substrate with electrodes 21 includes an ITO electrode group 22 orthogonal to the ITO electrode group 12 formed on the flexible data electrode substrate with electrodes 11, and an extraction electrode 2 for electric field alignment.
And 3. Examples of the flexible data electrode substrate with electrodes 11 and the flexible common electrode substrate with electrodes 21 include crystalline polymers such as uniaxially or biaxially stretched polyethylene terephthalate, amorphous polymers such as polysulfone and polyethersulfone, and polyethylene. , Polyolefins such as polypropylene, polycarbonates, polyamides such as nylon, and the like. Among these, uniaxially or biaxially stretched polyethylene terephthalate, polyether sulfone, and the like are particularly preferable. In the present invention, the two flexible substrates may be made of the same material or may be made of different materials, but usually, at least one of the two substrates described above. The substrate is made optically transparent and provided with transparent electrodes.

The material for forming the liquid crystal driving electrode group formed on the flexible substrate is not particularly limited as long as it is a material having conductivity. At least one of the electrodes has both conductivity and transparency. It is preferable to use a material having properties. Specifically, for example, ITO (IndiumTin) made of indium oxide or a mixture of indium oxide and tin oxide
Oxide) A transparent electrode such as a film is preferably used. The method for forming the liquid crystal driving electrode on the flexible substrate is not particularly limited, and is formed by a conventionally known method such as evaporation or sputtering. The ITO electrode groups 12 and 22 and the extraction electrodes 13 and 23 for electric field alignment do not require an alignment control film.
If necessary, an insulating film for preventing conduction and a color filter may be provided. The method of sandwiching the ferroelectric liquid crystal material is not particularly limited, and the ferroelectric liquid crystal material may not be oriented depending on the sandwiching method. On the other hand, in consideration of productivity of high-speed production, it is necessary to form a liquid crystal material and laminate it with a substrate. In this case, it is manufactured using a conventional film forming method, a coating method, or the like.

Next, the operation and function of the alignment method and the liquid crystal optical element alignment apparatus having the above-described configuration for performing alignment by applying an electric field and shear will be described. As the alignment method, the electric field and the shearing are performed at a temperature at which the liquid crystal material sandwiched between the flexible data electrode substrate with electrodes 11 and the flexible common electrode substrate with electrodes 21 shows some liquid crystal phase other than the isotropic phase. At the same time, uniaxial horizontal orientation is performed. The temperature at this time is lower than the temperature at which the liquid crystal material shows an isotropic phase or a mixed phase of the isotropic phase and the liquid crystal phase, specifically, a nematic phase (N phase), a cholesteric phase (Ch phase), A temperature at which a smectic phase (Sm phase) or a mixed phase thereof is shown. When the temperature is high and the isotropic phase (Iso phase) is used, the liquid crystal material has too high a fluidity to be aligned, and when the temperature is low and the glass phase or the crystalline phase is not sufficiently sheared, the liquid crystal material is not sufficiently sheared. do not do. Preferably, the orientation treatment is performed at a temperature at which various smectic phases are exhibited.

Next, in the orientation treatment by electric field and shear,
At least three guide rollers 4b, 4c and a negative voltage applying roller 4d are used for the guide rollers 2b, 2c, the positive voltage applying roller 2d, and the negative electric field applying unit 4 in the positive electric field applying unit 2. The material is not limited, and the three rollers cause the liquid crystal element 10 to shear due to bending.
Add to The voltage is applied by contacting the outer periphery of the positive voltage applying roller 2d in the positive electric field applying unit 2 with the outer periphery of the negative voltage applying roller 4d in the negative electric field applying unit 4, and facing the voltage applying electrodes 2e, 4e shown in FIG. The upper belt 2a for applying a positive voltage with two electrodes and the lower belt 4a for applying a negative voltage with electrodes
It is performed by an endless belt. The upper belt 2a for applying a positive voltage with electrodes and the lower belt 4a for applying a negative voltage with electrodes
Uses an electrically insulating member such as a plastic film (PC, PIT, etc.) polyester belt.

The upper belt 2a for applying a positive voltage with electrodes
The voltage application electrodes 2e and 4e provided on the electrode-attached lower voltage application lower belt 4a are respectively provided with an aluminum adhesive tape, a conductive anisotropic rubber, or the like on the outer periphery of the belt. A voltage is applied to the liquid crystal element 10 by providing two positive voltage applying rollers 2d and a negative voltage applying roller 4d provided separately from the rollers of the alignment roll section 6 so as to be provided at intervals not in contact with the electrodes 2e, 4e). . The positive voltage applying roller 2d and the negative voltage applying roller 4d
Is preferably φ10 to φ1000 (mm).
20 to 200 (mm) are more preferable. The diameter of each roller of the orientation roll unit 6 is preferably φ10 to 1000 (mm), and more preferably φ20 to φ200 (mm).
In this case, if the diameter is too large, the shearing becomes insufficient, and if the diameter is too small, the liquid crystal element 10 may peel off.

Next, the voltage (voltage source E in FIG. 1A) applied to the positive voltage applying roller 2d and the negative voltage applying roller 4d may be either AC or DC, and is applied continuously or intermittently. . The preferred electric field is 0.1 to 150 MV /
m, particularly preferably 5 to 150 MV / m. In this case, if the applied voltage is too low, the orientation becomes insufficient, and if the voltage is too high, dielectric breakdown in the liquid crystal element 10 may occur.

According to the liquid crystal optical element aligning apparatus having the above-described configuration, a positive voltage applying belt and a negative voltage applying belt are used for a liquid crystal element in which a ferroelectric liquid crystal material is sandwiched between two flexible substrates. While applying a voltage between the electrodes of the positive voltage application belt and the negative voltage application belt,
The orientation is performed by applying shear due to bending deformation using an orientation roller.

[0019]

EXAMPLES Hereinafter, the method and apparatus for aligning a liquid crystal optical element of the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. Example 1 CS-10 manufactured by Chisso Corporation was used as a ferroelectric liquid crystal material.
26 was used. As the alignment device, a liquid crystal optical element alignment device shown in FIGS. 1A and 1B was used. This liquid crystal optical element alignment device had the following configuration. Each roller of the orientation roll section 6 has an outer diameter of φ100 [mm] × 8, and is made of stainless steel (SUS304) and has a length of 350 [mm].
The orientation temperature was between room temperature and 120 ° C. The upper belt 2a for applying a positive voltage with an electrode and the lower belt 4a for applying a negative voltage with an electrode had a width of 350 [mm]. The positive voltage applying roller 2d in the positive electric field applying unit 2 and the negative voltage applying roller 4d in the negative electric field applying unit 4 use an aluminum outer diameter φ80 [mm], and the processing speed is 1.0 m / min. did. The production of the liquid crystal element 10 was performed using a PES having the size shown in FIG.
As shown in FIG. 4, a flexible data electrode substrate 11 with electrodes (polyether sulfone) and a flexible common electrode substrate 21 with electrodes are used.
A liquid crystal material was applied to the hatched portions on the ITO electrode group 12 side and the ITO electrode group 22 side using a microgravure coater to form a film. At this time, the film thickness after evaporation of the solvent was 2.2 μm.

Then, the laminate was shifted by 1.5 cm in the direction of the electrode-provided flexible common electrode substrate 21 on which nothing was applied, and the liquid crystal element 10 before the alignment treatment was manufactured. The PES substrate here is shown in Table 1 below. Fig. 1
(A) The processing speed was set to 1.0 m / min by the liquid crystal optical element alignment apparatus shown in (b). [Table 1 PES substrate used] ────────────────────────────────── Thickness Width Length Draw out for orientation Electrode width コ モ ン Common electrode 100μm 150mm 30cm 10mm PES300Ω / port ───── ───────────────────────────── Data electrode 100μm 150mm 27cm 10mm PES300Ω / port ──────────── ────────────────────── Next, the orientation conditions were as follows: the substrate used was 300 Ω / port of PES, and the line transfer speed was 1.0 m / min. The orientation temperature was room temperature, and the applied voltage was DC-60V. After the alignment treatment, a part of the liquid crystal element 10 was cut out, arranged between crossed Nicols, and the transmittance ratio when applying a voltage of plus or minus 5 V, that is, the contrast (Cr) was measured. The result shown in FIG. 2 was obtained. [Table 2] ───────────────── Voltage application ± 5V 72 Trust Bistable 68 ( Room temperature)

Embodiment 2

[0022]

Embedded image

A flexible data electrode substrate 11 with electrodes and a flexible common electrode substrate 21 with electrodes are made of PES (polyether sulfone) using the above-mentioned ferroelectric polymer liquid crystal material.
Was used. A liquid crystal material was applied and formed into a film by a microgravure coater in the same manner as in the above-described embodiment. The film thickness after evaporation of the solvent was 2.1 μm. Next, the common electrode side PES substrate on which nothing was applied was shifted by 1.5 cm in the width direction and laminated in the same manner as in FIGS. 3 and 4 to prepare a liquid crystal element before the alignment treatment. [Table 3] ────────────────────────────── Thickness Width Length Electrode width for alignment ─────── ─────────────────────── Common electrode 100μm 150mm 20m 10mm PES50Ω / port ────────────────── ──────────── Data electrode 100μm 150mm 20m 10mm PES50Ω / port ───────────────────────────── ─ As the alignment device, a liquid crystal optical element alignment device shown in FIGS. 1A and 1B was used, and this configuration was provided with a winding device and an unwinding device corresponding to a long liquid crystal device.

In this liquid crystal optical element alignment apparatus, alignment processing was performed at a line speed of 2.0 m / min, an applied voltage of DC-60 V, and room temperature. The contrast after the alignment treatment was as shown in Table 4 below. [Table 4] ───────────────── Voltage application 75 to ± 5V Rust (room temperature) As described above, according to the first and second embodiments, the contrast at the time of applying the electrolysis and at the time of the bistable state are very good. In addition, a stable alignment treatment was possible even in a long rolled liquid crystal element as in Example 2.

As described above, according to the present invention, a liquid crystal device in which a ferroelectric liquid crystal material is sandwiched between two flexible substrates is provided by using a positive voltage applying belt and a negative voltage applying belt. While applying a voltage between the electrodes of the positive voltage application belt and the negative voltage application belt, the alignment roller is used to apply shear by bending deformation to perform alignment, so that the shape of the liquid crystal element is long. Even if it is in the form of a scale or sheet, the alignment treatment can be continuously performed as many times as possible, which has the effect of improving the production yield.

[Brief description of the drawings]

FIG. 1A is a side view showing a configuration of an embodiment of a liquid crystal optical element alignment method and apparatus according to the present invention. (B) It is a front view showing composition in an example of a liquid crystal optical element alignment method and its device of the present invention.

FIG. 2 is a plan view illustrating a configuration of a liquid crystal element in an example.

FIG. 3 is a perspective view showing a bonding state of a liquid crystal element, which is used for describing the embodiment.

FIG. 4 is a plan view for explaining the application of a liquid crystal material in an example.

FIG. 5 is a side view showing a schematic configuration of a conventional orientation processing apparatus.

[Explanation of symbols]

2 Positive electric field applying part 2a Upper belt for applying positive voltage with electrode (positive voltage applying belt) 2b, 2c, 4b, 4c Guide roller 2e Electrode for applying voltage 2d Positive voltage applying roller 4 Negative electric field applying part 4a Negative voltage with electrode Lower belt for applying voltage (belt for applying negative voltage) 4d Negative voltage applying roller 4e Voltage applying electrode 6 Alignment roller section 10 Liquid crystal element

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1337 G02F 1/1333 G02F 1/13 101 G02F 1/141 G09F 9/00-9/46

Claims (3)

(57) [Claims] 1. A liquid crystal device comprising a ferroelectric liquid crystal material sandwiched between two flexible substrates, a positive voltage applying belt provided with a positive voltage applying electrode, and a negative voltage applying electrode provided. While transporting using the applied negative voltage application belt,
A voltage is applied to the liquid crystal element by applying a voltage between the electrodes of the positive voltage applying belt and the negative voltage applying belt, and shearing due to bending deformation is applied between the electrodes by using an alignment roller. A method for aligning a liquid crystal optical element, comprising: aligning a ferroelectric liquid crystal material while applying a voltage. 2. The method according to claim 1, wherein a voltage is applied between the electrodes of the positive voltage applying belt and the negative voltage applying belt by using a positive voltage applying roller and a negative voltage applying roller, respectively. Liquid crystal optical element alignment method. 3. A liquid crystal element having a ferroelectric liquid crystal material sandwiched between two flexible substrates and provided with electrodes for applying a positive and negative voltage, and an electrode for applying a positive voltage while transporting the liquid crystal element. An endless positive voltage applying belt, and an electrode for applying a negative voltage during transport of the liquid crystal element, wherein the electrode is arranged to face an electrode provided on the positive voltage applying belt. A negative voltage application belt having a shape, an orientation roller unit having a plurality of rollers for rotating the positive voltage application belt and the negative voltage application belt, and performing at least bending and shear orientation on the liquid crystal element, A liquid crystal optical element alignment device, comprising: