JP2738330B2 - Method and apparatus for manufacturing liquid crystal panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an industrial OA (Office)
The present invention relates to a manufacturing method and a manufacturing apparatus for a liquid crystal panel body used for a liquid crystal display for use in automation or home use. More particularly, the present invention relates to a liquid crystal alignment control method for a liquid crystal panel using a ferroelectric liquid crystal or an antiferroelectric liquid crystal.

[0002]

2. Description of the Related Art Liquid crystal displays (Liquid Crystal Dis)
Play: LCD) is lightweight and thin and can be used to display figures and characters on a flat surface for displays for small calculators, displays for measuring instruments such as testers, decorations, POPs, etc. It is widely used as various display bodies such as a display body. Recently, thin film transistors (TF
It is also used as a large-capacity thin terminal display for televisions and personal computers and workstations that display moving images in full color using T).

[0003] The above-mentioned various display devices mainly use the shutter property of the liquid crystal. A typical example of the liquid crystal exhibiting the shutter property is a twisted nematic (TN) using a nematic phase. Liquid crystal and super twisted nematic (STN) liquid crystal. There are also ferroelectric liquid crystals and antiferroelectric liquid crystals using a chiral smectic phase. Regarding each of these liquid crystals, (1) “Liquid Crystal” edited by Kobayashi and Okano: Baifukan, 1985 (2) “Structure and physical properties of ferroelectric liquid crystal” Fukuda and Takezoe: Corona Co., Ltd., 1990 (3 ) "Next-generation liquid crystal displays and liquid crystal materials" Supervised by Fukuda: CMC Corporation, 1992, etc.

[0004] Ferroelectric liquid crystal (FLC: Ferro-Electric)
Liquid Crystal) is Clark et al.
No. 16, U.S. Pat. No. 4,367,924). In addition, antiferroelectric liquid crystal (AFLC:
Anti-Ferro-Electric LiquidCrystal is available from Chandani et al. (ADLChandani et al, Japanese Journal.
Of Applied Physics, 28, L125
6 (1989)). Since both liquid crystals have a so-called memory effect, TF
It is expected that large-capacity display can be performed by simple matrix driving without using an active element such as T (Thin Film Transistor).

[0005] As these crystals are lowered in temperature from the liquid phase (ie, isotropic phase) on the high temperature side, for example, a chiral nematic phase (N ^* phase) → smectic A
(SmA phase) → Chiral smectic Cα phase (SmCα
^* Phase) → SmCβ ^* phase → SmCγ ^* phase → SmC _A ^* phase shows a complicated phase change. Some phases do not appear depending on the liquid crystal. For example, a chiral nematic phase has not been found in an antiferroelectric liquid crystal. In addition, the phase that responds to the electric field required for the liquid crystal display is a chiral smectic phase which is located on a lower temperature side than the chiral nematic phase and has low symmetry, and is close to a crystalline state.
In ferroelectric liquid crystal, chiral smectic C phase (SmC ^*
Phase in the antiferroelectric liquid crystal, a chiral smectic C _A phase (SmC _A ^* phase), a chiral smectic Cα phase (SmCα ^* phase), and a chiral smectic Cβ phase (Sm
Cβ ^* phase), chiral smectic Cγ phase (SmCγ
^* Phase).

However, in order to put a display using a ferroelectric liquid crystal or an antiferroelectric liquid crystal into practical use, it is necessary to simultaneously overcome two problems as described in the above-mentioned reference (3). . One is that a manufacturing method capable of mass-producing a large-area thin film composed of a defect-free chiral smectic phase, in particular, an orientation control technique must be established. Another is that a large area defect-free chiral smectic phase is stored in a liquid crystal panel frame having excellent shock resistance and impact resistance.

Conventionally, as a method of manufacturing a liquid crystal display (LCD), for example, a method using a liquid crystal panel as shown in FIG. 3 is known. In this method, first, a pair of glass substrates 102, 1 having transparent electrodes 104, 105 are provided.
03 are adhered to each other with a minute gap therebetween to form a panel frame for enclosing liquid crystal. Then, a desired liquid crystal 101 is sealed in the minute gap to form a liquid crystal panel. Further, a polarizing plate 106 is attached to the liquid crystal panel body, and a driving printed circuit board and an additional element such as a backlight are mounted to manufacture a liquid crystal display.

When producing a panel frame for enclosing a liquid crystal,
A large number of spherical or cylindrical spacers 107 are arranged on one of the pair of glass substrates 102 and 103, and a seal portion 108 is printed in a frame shape around the spacers 107 by screen printing or the like. Then, the other glass substrate is pressed against the glass substrate with an appropriate pressure with the spacer 107 and the seal portion 108 interposed therebetween, and the pair of glass substrates is entirely heated in this pressed state to heat and cure the seal portion 108. The two glass substrates are bonded to each other.

On the opposing glass substrates 102 and 103, transparent electrodes 104 and 105, an insulating film,
A color filter and the like are laminated as necessary, and furthermore, polyimide films 109 and 110 that have been subjected to a uniaxial orientation treatment, for example, a rubbing treatment, for orienting the liquid crystal are formed on the uppermost portion in contact with the liquid crystal 101. The width of the minute gap,
That is, the cell gap ranges from 1 to depending on the liquid crystal to be sealed.
It is set to a desired value between 10 μm. For a ferroelectric liquid crystal or an antiferroelectric liquid crystal, 1 to 3 μm, preferably 1.
It is set to 5-2 μm.

[0010] The encapsulation of liquid crystal in the panel frame for enclosing liquid crystal is as follows.
For example, it is performed as follows. First, the panel frame is set in an exhaust device, the inside of the panel frame is exhausted through an opening formed in the panel frame, and then the opening is closed with liquid crystal to be sealed. Thereafter, air is introduced into the exhaust device to apply a pressure difference to the liquid crystal in the opening, and the liquid crystal permeates into the panel frame. The penetration rate can be controlled by the pressure difference. The slowest is to penetrate only by surface tension without applying a differential pressure. In addition, the inside of the liquid crystal panel frame shown in FIG. 3 forms a continuous single space without a partition, and when the liquid crystal permeates the internal space, it can permeate anywhere in the internal space. It is.

The permeation temperature is a temperature corresponding to the liquid phase of the enclosed liquid crystal, and is about 80 ° C. to 120 ° C. for a ferroelectric liquid crystal or an antiferroelectric liquid crystal. After that, the opening is sealed and cooled again from a high temperature in an oven with a temperature control function. Is obtained.

In this structure, the upper and lower substrates 102 and 103 are not bonded to each other except for the seal portion 108.
When pressed locally, the substrates 102 and 103 have gentle irregularities, and the liquid crystal 101 in the liquid crystal panel flows. If the liquid crystal is in the nematic phase state, the nematic phase state is close to the liquid state. Therefore, even if such a liquid crystal flow occurs, if the pressing is released, the alignment state returns to the original state and no problem occurs. When carrying a liquid crystal display with a built-in liquid crystal panel as a portable type, or when using it daily in an office, when a certain impact or physical stress is applied to the substrate, the substrate is slightly deformed. There is no problem because it is reversibly restored when it is released.

On the other hand, when a ferroelectric liquid crystal or an antiferroelectric liquid crystal is sealed in a liquid crystal panel frame having this kind of structure, when the substrate is similarly deformed by local pressing or impact, the liquid crystal panel is deformed. Flow occurs in the internal liquid crystal. A ferroelectric liquid crystal or the like usually has a unique smectic layer structure as shown in FIG. 7. However, once a fluid flows in the smectic, a zigzag defect or a disorder occurs in the unique layer structure. The disturbance does not return. In such a case, it is necessary to heat the liquid crystal layer again to the isotropic phase, and further cool and reorient the liquid crystal layer, but such an operation is practically impossible. In order to prevent disturbance of the liquid crystal layer, it is necessary to carefully handle liquid crystal panels so that vibrations and shocks are not applied to the liquid crystal panel body even during the mounting process of the auxiliary equipment after alignment control, and it is also necessary for the liquid crystal display Special measures such as an absorber and a panel surface protection member are required. These cause a decrease in productivity and an increase in cost, and narrow the range of use as a liquid crystal display.

Therefore, especially when a liquid crystal such as a ferroelectric liquid crystal is used, even when the substrate is pressed or subjected to an impact, the internal liquid crystal does not undergo excessive flow so that the liquid crystal does not flow excessively. An excellent panel frame is required. As a method of realizing such a panel structure, a method of firmly bonding a pair of substrates to each other is known. If the display unit area is about A4 or larger, if the spacer member is not adhered, no matter what shape the spacer member is used, floating occurs between the substrates during the alignment control, the mounting process, and the use, so that it is not practical at all.

In the conventional structure shown in FIG. 3, a technique is known in which adhesive beads (that is, spherical bodies) are sprayed between the two substrates to fix the two substrates together.
No. 6,086,045. Japanese Patent Application Laid-Open No. Sho 63-163 discloses a technique in which a dot-shaped (that is, a columnar) adhesive member is formed on one substrate by photolithography, and the two substrates are more flexibly and firmly adhered to each other by the adhesive member. 50817, JP-A-62-96925, JP-A-62-118323, and JP-A-4-118.
No. 255826. Further, a technique using a striped adhesive member is disclosed in Japanese Patent Laid-Open No. 63-5 / 1988.
No. 0817 and JP-A-63-135917.

The purpose of bonding in each of the above prior arts is as follows.
Maintaining the distance between the upper and lower substrates constant and arranging the spacers corresponding to the non-pixel portions are particularly important items in the present invention, that is, (1) the process of penetrating the liquid crystal into the liquid crystal panel frame. This does not take into account the control of (2) the direction of volume shrinkage of the liquid crystal due to cooling, and (3) the control of the growth direction of the chiral smectic phase layer. As will be described later, a defect-free chiral smectic phase cannot be obtained with respect to those bonded in a dot shape and those bonded using beads. With respect to those bonded in a striped manner, there is a possibility that a defect-free chiral smectic phase may be obtained, but this is not sufficient.

Next, a liquid crystal panel body in which both substrates are bonded by an adhesive member, and a liquid crystal panel body in which a distance between the two substrates is simply maintained by beads or the like without using the adhesive member, is used. That is, the distance between the substrates is set to about 2 μm or less, and a liquid crystal panel body is formed by infiltrating a ferroelectric liquid crystal into a substance subjected to a normal rubbing treatment, and then the liquid crystal panel body is placed in an oven or a liquid. The initial alignment state of the ferroelectric liquid crystal when cooled will be briefly described.

In the SmC ^* phase layer obtained by cooling the ferroelectric liquid crystal from the high temperature state phase, an alignment abnormality inherent to the crystalline body is always found. This alignment abnormality includes a loop-shaped zigzag defect (reference numeral 113 in FIG. 4), a tree-like defect generated at a portion where adjacent crystal layer domains meet each other (reference numeral 114 in FIG. 5), and a defect of a nearly linear type. (Reference numeral 115 in FIG. 6). In many cases, tree-like defects cannot be clearly distinguished from near-linear defects. Also, dendritic defects are found only in one domain of the loop-shaped zigzag defect.

When non-adhesive spacers are scattered between the two substrates and when the dot substrates are randomly arranged and the two substrates are adhered to each other, many loop-shaped zigzag defects are observed, and rarely a tree is formed. Defects are seen. further,
As shown in FIG. 27, the dot-shaped fine spacer 107
Are regularly arranged and the two substrates are bonded to each other,
A zigzag defect 116 synchronized with the regularity period of the spacer 107 occurred. Many similar zigzag defects occur when non-adhesive striped spacers are used.

When both substrates are bonded by the stripe-shaped spacer, large zigzag defects which divide the panel surface into two or three parts are found, and many linear and tree-like alignment defects are found therein. In other words, when the two substrates are bonded by the stripe-shaped spacer, the amount of zigzag defects is reduced, but such bonding alone is not sufficient to completely eliminate the defects. In this case, when the liquid crystal panel body is rapidly cooled, narrow gaps formed by contraction of the liquid crystal layer in opposite directions are found in gaps between adjacent stripe-shaped spacers.

If at least one alignment defect such as a zigzag defect exists on the electrode, when the refractive index for linearly polarized light differs on both sides of the alignment defect, a slight difference in shading occurs. There are problems such as the constant shining of itself, the loss of the memory effect in the surroundings, and the fact that it becomes a hotbed of the occurrence of new defects,
It is difficult to put into practical use. This is the same even when a gap is formed.

The structure of a zigzag defect and a measure for eliminating the zigzag defect are described in the above reference (3). According to this, the zigzag defect is considered to occur inevitably because the SmC ^* phase has a chevron structure shown in FIG. The chevron structure is a phenomenon in which a layer of a chiral smectic phase bends into a “≪” shape. The direction of this curvature is not uniquely determined, and there are two types, one that turns left in the figure and one that turns right, and each boundary is a zigzag defect 113. As shown in FIG. 8, if the layer A of the chiral smectic phase has an ideal bookshelf structure, it is considered that zigzag defects in the form of domains do not occur, but dendritic defects and linear defects appear. There is a possibility. Note that in FIGS. 7 and 8, the symbol K indicates an interface between the substrate and the liquid crystal layer.

In order to eliminate the zigzag defect, the bending direction of the liquid crystal layer in the chevron structure is fixed in one direction. (1) The liquid crystal molecular axis in the liquid crystal layer is not parallel to the substrate but in a certain direction. To form a large and finite angle in advance, that is, a method to increase the pretilt angle (“Next-generation liquid crystal displays and liquid crystal materials” supervised by Fukuda, 8
5 pages, CMC Corporation, 1992), (2)
To use an appropriate liquid crystal material and to make the combination of the alignment film and the rubbing direction appropriate (page 19 of the same magazine);
Alternatively, (3) a method using a ferroelectric liquid crystal having a small layer bending (that is, a decrease in the layer spacing of the smectic phase) at the time of the phase transition from the smectic A phase to the SmC ^* phase (see p. 37 of the same magazine). Have been.

However, in the method (1), the oblique vapor deposition method is adopted, and there is almost no effect when the display portion has a large area orientation of B5 size or more. Also, the methods (2) and (3) are effective only for specific materials, are not effective for material progress, and there is no clear guideline for obtaining such specific materials. In addition, even if the bending directions of the crystal layers are aligned in a certain direction by the above-described methods, defects caused by collision between domains in a liquid crystal cooling process and volume shrinkage of the liquid crystal are caused. It is not possible to eliminate defects that occur.

As a method different from the above-described zigzag defect eliminating method, after the SmC ^* phase layer is formed, while the generated zigzag defect is locally heated, the heated region is further moved. A method of removing a zigzag defect from a display effective area is disclosed by the present applicant in Japanese Patent Laid-Open No. 2-18 / 1990.
No., proposed by US Pat. This is an attempt to remove zigzag defects after a crystal layer is formed, but does not obtain a defect-free crystal layer from the beginning as in the present invention.

As yet another method, Japanese Patent Application Laid-Open No. 61-182017 discloses an example in which a liquid crystal panel body in which liquid crystal is sealed is cooled along a rubbing direction. This is for improving the alignment of the nematic phase of a hybrid type nematic liquid crystal subjected to a parallel alignment treatment on one side and a vertical alignment treatment on the other side,
This is different from the crystal growth of the chiral smectic phase layer targeted by the present invention.

JP-A-2-18 and JP-A-61-1
In each of the techniques disclosed in Japanese Patent Application Publication No. 82017, the inside of the panel frame for enclosing the liquid crystal is formed of a single space without partitions, and therefore, a desired defect-free oriented chiral smectic phase is inevitably obtained. Absent.

As still another method, a method is known in which a layer of a chiral smectic phase having few defects is induced on an electrode while moving a temperature gradient with a crystalline cross section of a PET (polyethylene terephthalate) film or the like as a starting point of crystal growth. (For example, "Structure and physical properties of ferroelectric liquid crystal"
Fukuda, Takezoe: Corona Co., Ltd., 234, 1990
page). However, this method has no idea that uniaxial processing, for example, rubbing treatment is performed using an alignment film. Therefore, a defect-free alignment chiral smectic for a liquid crystal panel body formed by performing rubbing treatment or the like. It is not helpful when trying to get a phase. Actually, it cannot be applied to the large-area liquid crystal panel body which is the object of the present invention.

On the other hand, since the antiferroelectric liquid crystal has no chiral nematic phase layer, the smectic A (S
It differs from ferroelectric liquid crystals in that the mA) phase directly precipitates, that is, undergoes nucleus growth. Defects are smectic A from isotropic phase
This is visually observed when the phase transitions to the (SmA) phase and when the phase transitions from the SmA phase to the antiferroelectric state, for example, the SmC _A ^* phase.
Defects seen in the case of transition from the SmA phase to the SmC _A ^* phase is the same as in the case of a ferroelectric liquid crystal.

The smectic A (SmA) phase is precipitated from the isotropic phase while first growing while growing parallel to the rubbing direction, but is generally perpendicular to the rubbing direction at the same or slightly lower speed. Precipitates while spreading in the direction. The alignment defects in this case include: (1) a defect generated in a portion where SmA phase domains grown in different places collide (reference X in FIG. 9); (2) a speed of growing in a certain angle direction with respect to the rubbing direction; (3) Liquid crystal is often generated in a meandering part, but the direction of the smectic phase layer is largely different from that of the surrounding area. (Z in FIG. 11). The defect (1) has a string shape extending substantially perpendicular to the rubbing direction, and is small but numerous. The reason for the occurrence of (2) is unknown, but the area is large.

Although the defects of (1) and (3) are similar, the size of the discrepancy is different. Regarding the defect (1), the layer direction of both domains bordering the defect is basically defined in the rubbing direction and is the same. This defect is also a slight discrepancy because the two domains are formed by growing from different directions.
These defects are also taken over by the antiferroelectric phase and remain as defects.

Regarding the defect (1) and the alignment defect of the ferroelectric liquid crystal, if the number of these defects is small, about 100
For example, Japanese Patent Application Laid-Open No. 63-303323 discloses that a rectangular wave of about Hz to 300 Hz can be removed by applying the same for several hours. Techniques that use such electric fields are not practical either. In general, there is no known technique for growing a layer (monodomain layer) of a large-area chiral smectic phase free of alignment defects, that is, defect-free based on a certain rule.

[0033]

As described above, when a liquid crystal panel body is manufactured by using the conventional alignment control method,
Zigzag defects in large area chiral smectic phase layer,
At least one of various alignment defects such as a tree-like alignment defect and a linear alignment defect necessarily occurs. Accordingly, it is an object of the present invention to provide a method of manufacturing a liquid crystal panel body that can completely remove the above-described various alignment defects which are inevitably generated according to a conventional method of manufacturing a liquid crystal panel body. It is another object of the present invention to provide a manufacturing apparatus for a liquid crystal panel body which can reliably realize the manufacturing method, has high productivity, and is industrially useful.

[0034]

In order to achieve the above object, a method of manufacturing a liquid crystal panel according to the present invention comprises the steps of: (1) forming an alignment film on at least one of a pair of substrates facing each other; (2) At least one of the alignment films is subjected to a uniaxial orientation treatment, and (3) at least one end between the pair of substrates so as to extend in a direction substantially parallel to the uniaxial orientation treatment. A plurality of linear spaces are formed continuously in parallel with each other and the portion other than the openings is sealed with respect to the liquid. (4) Ferroelectricity is formed inside these linear spaces. A liquid crystal or an antiferroelectric liquid crystal is sealed, (5) the sealed liquid crystal is maintained at a temperature exhibiting a high-temperature state phase, and (6) a temperature gradient is formed in the sealed liquid crystal in the direction of the uniaxial alignment treatment. While being held, one side of the linear space Toward the parts side to the other end side,
It is characterized in that cooling is performed sequentially from a temperature exhibiting a high-temperature state phase to a temperature exhibiting a low-temperature state phase.

The cross-sectional shape of the above-mentioned linear space is not limited to a specific shape and area, but is desirably a flattened quadrilateral having a cross-sectional area of 0.006 mm ² or less. Also, the length of the linear space is not limited to a specific length, but is desirably set to 10 cm or more.

The following method can be adopted as a more specific form of the above-mentioned method of manufacturing a liquid crystal panel body. That is, in the method, (1) a stripe-shaped electrode in which a plurality of linear electrodes are arranged at a predetermined pitch is formed on a pair of substrates;
(2) An alignment film is formed on one or both of the stripe electrodes on each substrate, (3) Uniaxial alignment treatment is performed on at least one of the alignment films, and (4) A stripe electrode on one substrate A linear partition member is formed between each of the linear electrodes at the same pitch or at a plurality of pitch intervals and substantially parallel to the uniaxial alignment treatment; After the substrates are opposed to each other so that the striped electrodes are orthogonal to each other, the partition member formed on one substrate is bonded to the other substrate, thereby forming a linear space sealed with respect to the liquid. Form.

In the method of manufacturing a liquid crystal panel using flat electrodes instead of stripe electrodes, (1) a flat electrode is formed on a pair of substrates, and (2) a flat electrode on each substrate is formed. An alignment film is formed on one or both of them, (3) at least one of the alignment films is subjected to a uniaxial alignment treatment, and (4) at an appropriate pitch on a planar electrode formed on one of the substrates, The partition member is formed so as to extend substantially parallel to the uniaxial orientation treatment, and (5) the partition member formed on one substrate is bonded to the other substrate, thereby sealing the liquid. Form a linear space.

The high-temperature state phase described in the above-mentioned method for manufacturing a liquid crystal panel body can be any one of an isotropic phase, a chiral nematic phase and a chiral smectic A phase. Further, the low-temperature phase can be a chiral smectic C phase or an antiferroelectric liquid crystal phase. The uniaxial alignment treatment is a treatment performed to align liquid crystal molecules in a certain direction. For example, a rubbing treatment, an oblique deposition treatment, or the like can be considered.

Further, the apparatus for manufacturing a liquid crystal panel according to the present invention has the following liquid crystal panel, namely: (1) an opening is provided at at least one end, and a portion other than the opening is provided for liquid. (2) forming an alignment film on at least one of the pair of substrates, wherein a plurality of closed linear spaces are formed between a pair of substrates facing each other and continuously arranged in parallel with each other; 3) uniaxially aligning at least one of the alignment films in a direction substantially parallel to the direction in which the linear space extends, and (4) ferroelectric liquid crystal in the linear space. The present invention also relates to a liquid crystal panel formed by enclosing an antiferroelectric liquid crystal, and more particularly, to forming a low-temperature phase monodomain layer in the liquid crystal enclosed in the liquid crystal panel.

This manufacturing apparatus comprises: (A) a high-temperature portion having a temperature at which the sealed liquid crystal exhibits a high-temperature state phase; (B) a low-temperature portion having a temperature at which the sealed liquid crystal exhibits a low-temperature state phase; (C) In a state where the temperature gradient is formed and held in the direction of the uniaxial alignment treatment, the temperature gradient is relatively set with respect to the liquid crystal panel body from one end side to the other end side of the linear space. And temperature gradient moving means for moving the temperature gradient.

In the above manufacturing apparatus, it is desirable to provide a heat insulating member between the high temperature part and the low temperature part in order to more effectively provide the temperature gradient to the liquid crystal panel body.
Further, the high-temperature portion and the low-temperature portion can be constituted by any of a gas atmosphere, a liquid atmosphere, and a solid. The solid means a Peltier element and other solid heating elements.

Further, as a more specific configuration of the apparatus for manufacturing a liquid crystal panel, a liquid region acting as a high-temperature portion, an air region acting as a low-temperature portion, and a liquid region immersed in the liquid region. Gas-liquid interface moving means for relatively moving the gas-liquid interface between the liquid region and the atmospheric region, and heat insulation provided with a slit movable along the liquid surface of the liquid region and capable of passing the liquid crystal panel body. A configuration having a member can also be adopted.

Further, as a more specific configuration of the apparatus for manufacturing a liquid crystal panel body, a tunnel type furnace having an opening which can function as a high temperature section and through which the liquid crystal panel body can pass, and an atmosphere region which functions as a low temperature section And a liquid crystal panel body moving means for relatively moving the liquid crystal panel body and the tunnel type furnace so that the liquid crystal panel body moves between the tunnel type furnace and the atmospheric region. Can also.

Further, as a more specific configuration of the apparatus for manufacturing a liquid crystal panel body, there are provided a high-temperature conveyance roller which functions as a high-temperature section and can convey the liquid-crystal panel body, and an atmospheric region or low-temperature conveyance roller which functions as a low-temperature section. A configuration can also be employed.

Further, as a more specific configuration of the apparatus for manufacturing a liquid crystal panel body, a sand bath functioning as a high-temperature portion;
It is also possible to adopt a configuration having an atmosphere region acting as a low-temperature portion and a liquid crystal panel body moving means for moving the liquid crystal panel body between the sand bath and the atmosphere region.

The present invention is realized by an inseparable constitutional requirement that a liquid crystal panel body in which liquid crystal is sealed is formed by a specific structure, and a specific cooling process is performed on the liquid crystal panel body having the specific structure. Therefore, the liquid crystal panel will be described first.

The liquid crystal panel to which the present invention is applied is, for example, a panel having a structure as shown in FIG. When the liquid crystal panel is viewed from above, it has a structure as shown in FIG. In FIG. 1, a linear partition member 8 having a thickness corresponding to the cell gap G is provided between transparent electrodes 5 in a stripe shape formed on one glass substrate 3.
Are formed. The other glass substrate 2 is adhered to the partition member 8 by appropriate means, whereby the pair of substrates is completely adhered, and the liquid crystal panel frame for enclosing the liquid crystal in which the cell gap G is accurately defined. Is configured.

Reference numerals 9 and 7 are polyimide alignment films. Reference numeral 4 denotes an opposing transparent electrode that faces one of the transparent electrodes 5 and extends in a stripe shape in a direction perpendicular to the transparent electrode 5. Reference numeral 6 denotes an insulating film. As the insulating film, a thin film of about 1000 ° of alumina or silica can be used. The color filter can be provided below one of the transparent electrodes. With this configuration, a linear space R is formed between the partition members 8. The liquid crystal panel 1 is manufactured by enclosing a ferroelectric liquid crystal or an antiferroelectric liquid crystal in these spaces R.

The linear spaces R above the stripe-shaped electrodes 5 are separated from each other by the partition wall members 8 and are completely closed spaces except for the opening at the front end portion 22 and the opening at the rear end portion 23 in FIG. Has formed. That is, portions other than the openings are sealed with respect to the liquid. The rear end portion 23
It can also be closed by bonding to the seal portion 21. The cross-sectional shape of the linear space R is a flat quadrilateral shape, that is, a rectangular shape. In this case, the minimum width of the long side L of the rectangle is substantially the same as the line width of the striped electrode 5, for example, about 50 to 500.
It is automatically set to μm. The short side S of the rectangle is set to be substantially equal to the cell gap G, for example, 1 to 3 μm. Strictly speaking, the cross-sectional shape of the linear space R is influenced by a step due to the thickness of the transparent electrode 5, some irregularities on the surface of the transparent electrode 5, bending of the side surface of the partition member 8, or roundness of the four corners. It is not a complete quadrilateral.

The width W of the partition member 8 serving as a partition partitioning the linear space R is set to be equal to or less than the length between the adjacent electrodes 5, for example, 10 to 100 μm. The length L _R (FIG. 2) of the linear space R is the length of the electrode exposed as the display portion H,
For example, it is set longer than 10 to 40 cm. The reason why the length of the linear space R is set to be longer than that of the display unit is as follows.
This is because the alignment abnormality E is observed at a length of about 5 to 10 mm at the entrance and exit of the liquid crystal in the linear space R. A specific method itself for continuously forming such a linear space R on a substrate is disclosed in Japanese Patent Application Laid-Open No. 62-96925 by the present applicant.

The uniaxial orientation treatment is applied to the inner wall of the space R substantially parallel to the direction in which the linear space R extends. As the uniaxial orientation treatment, for example, a rubbing treatment, an oblique deposition treatment, or the like is used, but when targeting a large-area panel body,
A rubbing treatment is desirable in view of productivity and alignment ability.
This rubbing treatment is applied without interruption to at least one of the two wide surfaces P1 and P2 (FIG. 1) among the surfaces forming the linear space serving as the liquid crystal passage, that is, the four surfaces in contact with the liquid crystal. Two surfaces P3 and P in the cell gap direction
The rubbing treatment is not impossible for No. 4, but sufficient orientation of crystal molecules cannot be obtained only by these surfaces.

When the two surfaces P1 and P2 facing each other are provided with an orientation, the rubbing directions can be aligned in either parallel or anti-parallel. Parallel means that the rubbing directions of the two surfaces P1 and P2 are aligned in the same direction (↑↑), and antiparallel means that the rubbing directions of the two surfaces P1 and P2 are reversed (↑ ↓). This is the case when setting. However, at some request, the rubbing directions may not be completely aligned between the two surfaces P1 and P2 but may be opposed to each other at a certain angle. In this case,
It is desirable that the center line of the angle formed by both rubbing directions coincides with the direction in which the partition extends. The angle difference at this time is desirably set within 12 °. In the case where one rubbing direction and the direction in which the partition wall extends are made to substantially coincide with each other, the angle difference between the two rubbing directions should be kept within 6 °. Two sides P1 and P2
When the rubbing directions are the same, the angle between the rubbing direction and the direction in which the partition extends does not necessarily have to be parallel. However, preferably, the angle between the rubbing direction and the partition wall is set within 12 °.

To describe these restrictions more precisely, it is desirable that the layer normal direction of the smectic phase determined by the upper and lower rubbing directions substantially coincides with the direction in which the partition walls extend. In the case of ferroelectric liquid crystal, the layer normal direction substantially coincides with the rubbing direction, but in the case of antiferroelectric liquid crystal, their directions may be different from each other. It is safe to keep the angle between the layer normal direction and the partition wall within 6 ° to 10 °.

Next, a method of cooling a liquid crystal panel, which is another important component of the present invention, will be described. In order to completely eliminate the alignment defect of the liquid crystal, it is important to (A) control the penetration of the liquid crystal, (B) control the growth form of the layer of the smectic phase, and (C) smooth the contraction of the liquid crystal upon cooling. . First, the advantage of the structure of the liquid crystal panel frame for enclosing the liquid crystal employed in the present invention will be described from the viewpoint of the liquid crystal permeation because the liquid crystal cannot be prevented from passing through the liquid crystal permeation control (A).

The main problems here are (1) the problem of the affinity between the liquid crystal and the alignment film, and (2) the residual bubbles generated by the liquid crystal meandering when the liquid crystal permeates into the panel frame. And the problem of accumulation of liquid crystal distortion. Regardless of the ferroelectric liquid crystal or the antiferroelectric liquid crystal, when it penetrates into the liquid crystal panel frame, it penetrates to the deep part of the panel frame in parallel to the rubbing direction and linearly in the rubbing direction. It is desirable to do. The reason is that, when the liquid crystal is permeated under the same conditions with respect to the differential pressure and the temperature, if the rubbing direction and the permeation direction are shifted, it is observed that the permeation speed is reduced accordingly, It shows that when an angle is formed between the liquid crystal and the permeation direction, the affinity between the alignment film surface and the liquid crystal decreases.

For example, if the liquid crystal penetrates only by the surface tension, the liquid crystal can be most naturally and stably arranged with respect to the alignment film. In this case, if the angle between the rubbing direction and the permeation direction is made orthogonal to each other. A speed difference of about 2 to 4 times occurs. The better the affinity between the alignment film and the liquid crystal, the more advantageous the liquid crystal is because it penetrates into the panel frame faster, the more stable the liquid crystal is arranged on the alignment film in a natural state, and the more the alignment film is stable. , The orientation to the inside of the liquid crystal becomes stronger.

Conversely, if the inclination between the rubbing direction and the liquid crystal permeation direction is increased, the liquid crystal is more likely to meander, and air pockets, that is, bubbles or voids are more likely to be generated. Also, since the liquid crystal is highly viscous, the meandering pattern of the liquid crystal is stored as an unstable conformation and accumulates distortion around it. This contributes to the occurrence of the alignment abnormality as it is, or the induction of the alignment abnormality with the change in the volume of the liquid crystal. In the case where the liquid crystal was penetrated in the direction perpendicular to the rubbing direction, it was actually found that the zigzag defects relatively increased even under the best conditions according to the present invention. This phenomenon occurred irrespective of whether the two substrates were bonded or not bonded by the partition member, and regardless of the shape of the partition member.

Next, the means for permeating the liquid crystal in the straight state along the rubbing direction will be described. To do this,
It is desirable to form a straight passage partitioned between the pair of substrates as narrowly as possible, and to allow the liquid crystal to permeate in the passage. Such passages are necessary the longer the distance to be penetrated, ie the larger the area.
If this is described in accordance with the liquid crystal panel frame for liquid crystal encapsulation, as shown in FIG. 1, the liquid crystal permeates in a linear space R having a narrow sectional area and extending in the rubbing direction.

Further, it is necessary to completely adhere the upper and lower substrates with a stripe-shaped partition member to maintain a uniform cell gap. If a stripe-shaped partition member is not used, the space between the upper and lower substrates becomes a single open space,
Liquid crystals can penetrate anywhere in principle. In general, although it tends to permeate easily in the rubbing direction, it actually permeates first in a narrow portion of the cell gap. this is,
The flow of the liquid crystal is disturbed and meanders. In the worst case, the unpermeated portion remains as air bubbles, or the meandering is stored and accumulates as distortion of the liquid crystal around. This tendency is remarkable in the case of a panel frame in which both substrates are not bonded, but even in a panel frame in which both substrates are bonded, if a dot-shaped spacer is used, the meandering of the liquid crystal is completely prevented. It cannot be prevented. In addition, when a dot-shaped spacer is used, the existence of the spacer itself causes disturbance of the flow of the liquid crystal, and accumulates distortion of the liquid crystal around the spacer.

In view of this, it is effective to form a linear space between the two substrates by the stripe-shaped partition member and to allow the liquid crystal to penetrate inside the liquid crystal in order to obtain a desirable liquid crystal permeation state. JP-A-61-205919 discloses a panel frame having a structure in which such a linear space is formed parallel to the rubbing direction, but does not adhere the partition member to the substrate, that is, a structure in which the linear space is not sealed. It is disclosed in JP-A-61-205921. However, when a large-area liquid crystal panel body is manufactured by using this structure, a floating is necessarily generated between the partition member and the substrate, and the flow of the liquid crystal is disturbed at the place, so that it is difficult to make the liquid crystal go straight. In order to solve this problem, it is conceivable that the two substrates are temporarily brought into close contact with each other when the liquid crystal is penetrated. In that case, however, a special device is required to bring the two substrates into close contact with each other. When a liquid crystal display is manufactured by mounting a driving transistor, a backlight or the like on a body, or when the manufactured liquid crystal display is used, the liquid crystal panel body has insufficient seismic shock resistance and is not practical.

Next, another reason why the constitution of the present invention is advantageous will be described in detail from the aspect of the growth of the layer of the chiral smectic phase. First, a ferroelectric liquid crystal is allowed to penetrate in a high-temperature phase parallel to the rubbing direction into a liquid crystal enclosing panel frame in which the area of the substrate on which the alignment film surface is properly formed is about the size of a B5 plate. Make a panel body. The panel frame is
Three types were compared: (1) those bonded with stripe-shaped partition members, (2) those bonded with dot-shaped members, and (3) non-bonded stripe members. A liquid crystal panel using each panel frame is immersed in a constant temperature water bath at a temperature at which the liquid crystal exhibits a liquid phase, and then cooled at a rate of about 0.5 ° C./min. The cooling in the liquid is for cooling the entire surface of the liquid crystal panel as uniformly as possible.

Then, in a liquid crystal panel body in which both substrates are bonded by a dot-shaped member and a liquid crystal panel body in which both substrates are not bonded only by sandwiching a stripe-shaped member, a space for liquid crystal sealing formed between the two substrates is formed. It is released, and as a result, a large number of large and small zigzag defects and tree-like defects are generated. On the other hand, for those bonded with stripe-shaped partition members,
An alignment state with extremely few defects was stably obtained. However, even in the case of bonding using a stripe-shaped partition wall member, as the size of the liquid crystal display section was increased from A4 size to B4 size, a good alignment state could not be obtained.

Regarding the tendency of the orientation defect, both large-sized and small-sized zigzag defects are observed in both those using the non-adhesive stripe-shaped member and those using the bonded or non-adhered dot-shaped member. It seems to add a little.
In the liquid crystal panel body of the type bonded by the stripe-shaped partition member, although the number of alignment defects is reduced, the liquid crystal panel is not used in the cooling method characterized by the present invention. There are zigzag defects, tree-like defects, and linear defects that divide the surface of the body into two or three.

Therefore, in the case of parallel rubbing in which a pair of upper and lower rubbing directions are combined to be the same, FIGS. 12 and 13 show how the SmC ^* phase is generated from the SmA phase and grows within a range observable with a microscope. It will be described using FIG. First, the entire surface of the liquid crystal is in the SmA phase (FIG. 12).
(A)), when the transition from the SmA phase to the SmC ^* phase starts, a distorted SmC ^* phase domain begins to appear (FIG. 12 (b)), which spreads over the whole. This is C1
Called orientation state (J. Kanebe et al., Ferroelectri
cs, 114, 3 (1991)). When the temperature drops slightly, zigzag defects begin to form (FIG. 12C). This indicates that at this point a domain has occurred in which the layer has flexed in the opposite direction, which is called the C2 orientation state. Thereafter, the zigzag domain further grows (FIG. 13D), and adjacent zigzag domains meet (FIG. 13E).

In this case, there are the following two cases in which the domains meet. One is when domains where the direction of deflection of the layers is the same, especially when the C2 state domain is encountered,
If the conformity at the meeting point is poor, it may remain inside as a tree-like defect or a linear defect (FIG. 13 (f)).
This is a defect that is very similar to one of the reasons for the occurrence of the alignment defect in the antiferroelectric liquid crystal described above, that is, the defect that occurs in the portion where the SmA phase domains grown in different places collide (FIG. 9). As for this defect, if the outermost boundary of the united domains comes out of the region used for display, only the domains in the same bending direction exist inside the display unit.

Another method of meeting the domains is that domains in which the bending directions of the liquid crystal layer are different from each other grow individually and finally meet. Then, the place where this is met becomes an intrinsic zigzag defect. These typically occur with antiparallel rubbing, described below. Therefore, the zigzag defect is based on this mechanism and C1 state.
It is considered to be due to the occurrence of a structural change such as a change to two states.

The following reasons can be considered as the reason why the zigzag defect grows. When the phase transitions from the SmA phase to the SmC ^* phase, the molecules in the SmA phase layer are inclined from the normal direction of the layer, so that the distance between the SmA phase layers is reduced. This narrowing distance is about 10% of the length of the molecule, that is, about 3 °. If the volume change is small near the transition point, somewhere in the liquid crystal should be slightly longer to compensate for this decrease in layer spacing. However, shrinkage due to a temperature drop is dominant in the liquid crystal as a whole.

One of the expansions of the liquid crystal extends in the cell gap direction. However, since this is restrained by a pair of glass substrates facing each other, the liquid crystal is curved by the amount of expansion. The other of the elongation is the elongation of a component perpendicular to this, that is, a component parallel to the glass substrate. Actually, they appear as a combination of these, but quantitatively, the extension in the cell gap direction is larger. T.P. Laker et al. (Physical Review, A37, 1053 (198
According to 8)), bending of the layer almost proportional to the amount of extension has been found, and this bending structure is called a chevron structure shown in FIG. In general, the direction in which the layer flexes is
There are two types, a direction indicated by reference numeral 111 and a direction indicated by reference numeral 112, and the boundary between domains having respective directions is a zigzag defect 113.

A tree-like defect is usually generated by collision of liquid crystal phase domains in the same bending direction. As in the present invention, a large number of linear spaces may be formed continuously and parallel to each other between a pair of glass substrates facing each other, and a liquid crystal may be sealed in those spaces to form a panel body. If a conventional cooling treatment is performed, for example, uniform cooling in an oven, this kind of dendritic defect occurs. However, the amount of generated defects is much smaller than that of a conventional liquid crystal panel body in which liquid crystal is sealed in a single open space. This is a difference caused by whether or not the liquid crystal is regulated in a narrow and narrow space. In the present invention, since the linear partition walls exist due to the function of the partition member, the liquid crystal phase domains grow in the horizontal direction indicated by the arrow ZZ in FIG. This is because collision is far less likely.
If the size of a region where one crystal nucleus is generated is defined as a unit area of 1, the number of collisions is approximately 2a ² -2a in a region where one side is a.
Is proportional to This cannot be ignored in large areas.

When dot-shaped spacers are used, whether the substrates are bonded by the spacers or not, even if the bending direction of the liquid crystal layer can be defined in a fixed direction, even if the substrates are not bonded to each other. The occurrence of defects due to collision cannot be avoided in a large area. Even if the structure of the liquid crystal panel body according to the present invention is adopted, there is no probability that a liquid crystal phase domain grows in parallel to the linear space to generate a tree-like defect. The problem can be solved by employing the cooling process of the liquid crystal panel body according to the present invention.

Next, means for regulating the bending direction of the chiral smectic phase layer, which is the most important element of the present invention,
Explain the legal facts that support it. The nucleus causing the alignment defect, that is, the generation cause of the minute liquid crystal phase domain is local temperature unevenness. When the size of the liquid crystal panel is increased, even if the liquid crystal panel is immersed in a medium having a large heat capacity, the occurrence of temperature unevenness cannot be prevented. Blocking requires a very large cooling system, which is not feasible in practice. Therefore, the inventors of the present invention have repeatedly studied experimentally what occurs in the liquid crystal layer when the temperature is locally lowered. As a result, the present inventor has found the following rules and empirical facts.

That is, it was presumed that the bending direction of the liquid crystal layer in the chevron structure was the direction in which the temperature was lowered earlier in time. This phenomenon did not depend on the combination of the alignment film and the liquid crystal.

As described above, almost simultaneously with the expansion of the liquid crystal layer at the transition point, there is always a large volume shrinkage from the periphery toward the center of the cooling point, which pulls the periphery toward the cooling point. This means that the center of the layer parallel to the substrate tends to shift in that direction. That is,
As schematically shown in FIGS. 14A and 14B, the liquid crystal layer A easily bends toward a portion Q that has been cooled earlier in time, and which portion is cooled first. That is, there is a high probability that the bending direction is determined. Note that, in FIG. 14, the symbol M indicates a liquid crystal molecule.

From the above, it is understood that the direction in which the liquid crystal layer bends can always be defined to be constant if the liquid crystal panel body is cooled from one direction. The layer normal direction of the layer of the chiral smectic phase due to the interaction between the alignment film and the liquid crystal is regulated so as to be substantially parallel to the rubbing direction, so that the bending direction is concentric around the cooling point. No. In order to limit the direction in which the layer of the smectic phase bends, the liquid crystal panel body is cooled while intentionally applying a temperature gradient parallel to the rubbing direction from one end so that the temperature gradient is not absolutely reversed. The direction in which the liquid crystal layer bends is defined. Thereby, the direction in which the liquid crystal layer bends can be defined in principle and in practice.

Needless to say, in order for the liquid crystal in the center of the smectic phase layer to move and bend sufficiently, the volume shrinkage of the liquid crystal must be concentrated in the rubbing direction, that is, in the layer normal direction. . For this purpose, it is necessary that the liquid crystal is sealed in a linear space having an appropriate cross section as in the liquid crystal panel of the present invention. If the width L of the space is too wide,
The contraction of the liquid crystal in the width direction increases, and the contribution to the layer normal direction decreases, so that the effect is lost. Another problem is that the length L _{R of the} space is too short.

In fact, no matter what the configuration of the liquid crystal panel body, if the liquid crystal panel body is intentionally cooled so that a temperature gradient is applied along the rubbing direction, the liquid crystal layer is bent in almost one direction. It is. As a preferable method for cooling while giving a temperature gradient, for example, a liquid crystal panel body is immersed in a liquid kept at a constant temperature, and then pulled up at a constant speed or drained to move a gas-liquid interface. Can be adopted. However, even if such a cooling method is used, zigzag defects or tree-like defects always occur when the object to be cooled is not the liquid crystal panel having the internal structure according to the present invention. This is because the liquid crystal panel frame is deformed due to the temperature gradient, and the volume contraction force is not concentrated in the layer normal direction but diffuses.

On the other hand, another advantage of employing the method for manufacturing a liquid crystal panel according to the present invention is that the generation of tree-like defects can be reliably prevented. That is, the liquid crystal panel body is sequentially cooled from one end side to the other end side of the linear space formed by the partition member,
The liquid crystal phase domains do not grow simultaneously at different places in the direction parallel to the partition member, and therefore, tree-like defects due to the collision of the domains hardly occur in the direction parallel to the partition member.

On the other hand, the liquid crystal phase domain generated in the liquid crystal grows in a direction perpendicular to the stripe-shaped partition member, that is, in the width direction L of the linear space R in FIG. There is a possibility that tree defects will occur due to collisions between domains. However, by reducing the distance L between the adjacent partition members, the occurrence of such a tree-like defect is surely eliminated. When the interval L is set equal to the width of the electrode, the probability of occurrence of a tree-like defect is minimized. In the case of a planar electrode, the interval L between the partition members can be set arbitrarily. However, if the interval L is set to 2 mm or less, this kind of tree-like defect did not occur at all.
In this way, two orientation abnormalities of a zigzag defect and a tree-like defect can be eliminated at the same time. Since it is desirable to set the interval L between the partition members, that is, the width L of the linear space R to 2 mm or less and the cell gap G to 3 μm or less, the cross-sectional area of the linear space R is 0.006 mm ^2. It is desirable that:

Next, the advantages obtained by using the liquid crystal panel having the structure according to the present invention and the specific cooling method for cooling the liquid crystal panel will be described from the viewpoint of facilitating the mass transfer accompanying the volume shrinkage of the liquid crystal. I do. It is considered that the defects that can be eliminated from this viewpoint are linear defects and voids generated due to the mechanism shown in FIG. This void usually occurs when the liquid crystal panel body is cooled unevenly. In order to limit the bending direction of the liquid crystal layer to one direction,
Even when cooling the liquid crystal panel body from one end of the liquid crystal panel body along the rubbing direction, the cooling direction may be in two opposing directions, one of which may cause a linear defect. . Even in such a case,
All linear defects disappear completely when the temperature is lowered slowly along the rubbing direction from another properly selected direction.

The appearance of the SmC ^* phase from the liquid phase is schematically shown in FIGS. 15 (a) to 15 (c). In (a), the entire liquid crystal 1 sealed in a glass substrate 2 is placed in a high temperature state and exhibits a liquid phase. In (b), when the liquid crystal is gradually cooled from the upper side of the figure, the liquid crystal undergoes a phase transition in the order of liquid phase → chiral nematic (N ^* ) phase → SmA phase → SmC ^* phase. At this time, most of the liquid crystal except for the vicinity of the alignment film is:
The shrinkage as a whole proceeds in the direction of arrow C while moving in the direction of arrow B. For this reason, the layer of the SmA phase or the like is always deformed upward in the figure and does not bend downward. In (c), the area of the SmC ^* phase increases as the cooling progresses. If the phase change and the movement of the liquid crystal do not proceed smoothly, it is presumed that a linear defect occurs. In the worst case, a void is generated in a direction perpendicular to the direction of the phase movement. In rare cases, voids may be generated perpendicular to the rubbing direction.

Another cause of the linear defect is that when the direction in which the stripe-shaped partition member extends and the layer normal direction determined by the rubbing direction largely differ from each other, the contraction of the liquid crystal due to the cooling impinges on the partition member and is hindered. Is to be done. Liquid crystal distortion is accumulated in the portion where the shrinkage is stopped, even if no clear defect appears.

The reason that the occurrence of linear defects is related to the direction of cooling the liquid crystal panel body is that there is a direction in which the liquid crystal layer moves easily due to the relationship between the alignment film and the liquid crystal (FIG. 14A). This is because the liquid crystal layer does not move smoothly in the reverse direction (FIG. 14B). In other words, it can be said that there is a preferred bending direction of the liquid crystal layer, and a defect easily occurs because a conflict occurs between the direction defined by cooling and the preferred direction. The volume contraction of the liquid crystal also occurs in a direction perpendicular to the direction in which the cooling proceeds, but this is regulated by the partitioning function of the partition member, and the propagation is prevented.

On the other hand, in the structure of the conventional liquid crystal panel body, the liquid crystal undergoes non-uniform contraction in all directions other than the direction along the rubbing direction, and the substrate gap changes correspondingly. As a result, distortion accumulates in the liquid crystal plane. The distortion mainly appears as large and small zigzag defects. In the case of a conventional liquid crystal panel body in which dot-shaped spacer members are regularly arranged, it can be seen from the fact that zigzag defects occur regularly, and that liquid crystal distortion is regularly distributed. In such a conventional liquid crystal panel, even if the liquid crystal panel is cooled from one end, the non-uniform shrinkage of the liquid crystal cannot be controlled, so that a defect-free orientation in a low-temperature state phase cannot be obtained. This occurs similarly even when the stripe-shaped member is used without bonding.

As is particularly important for antiferroelectric liquid crystals, in general, volume contraction occurs with cooling even in the SmA phase. However, according to the present invention, the volume shrinkage is also limited in the direction in which the partition member extends in the linear space partitioned by the partition member, so that potential accumulation of liquid crystal distortion is small. Without such partitions, volume shrinkage of the liquid crystal occurs in all directions, accumulating distortion of the liquid crystal, which induces defects.

Next, a device for giving a temperature gradient to a liquid crystal panel body in which liquid crystal is sealed will be described. In the present invention, two atmospheres, a high-temperature atmosphere and a low-temperature atmosphere, are prepared. First, the liquid crystal panel body is placed in a high-temperature atmosphere to hold the liquid crystal in a high-temperature state phase at a constant temperature. It is not necessary that the entire liquid crystal panel body be in a high-temperature atmosphere, but a high-temperature atmosphere is prepared so that at least a width of 5 cm or more including a portion where the temperature first decreases, more preferably, the entire liquid crystal is in a high-temperature state phase. It is meaningless that the distance between the high temperature atmosphere and the low temperature atmosphere is longer than the length of the liquid crystal panel body. Also, there may be a continuous temperature gradient between the two atmospheres, or
The temperature gradient may be limited by interposing a heat insulating member having poor heat conduction. The distance itself between the two atmospheres is appropriately set in accordance with the size of the liquid crystal panel body, the temperature range of each phase that the liquid crystal can take, the phase state of the liquid crystal in a high temperature state, and the like.

The advantage of interposing the heat insulating member is that the temperature gradient of the atmosphere surrounding the liquid crystal panel body can always be kept constant. Radiation heat, heat conduction, convection, etc. between the heat sources fluctuates the temperature gradient around the liquid crystal panel body, and this fluctuation has a high probability of inducing defects in the panel body. Can be suppressed. The temperature gradient only needs to occur with respect to the liquid crystal panel body, and there is no need for a thermal gradient to exist in the atmosphere between the high temperature part and the low temperature part. As a mode of generation of the temperature gradient, it is preferable that the temperature gradient is generated by heat conduction of the liquid crystal panel itself from one end where cooling starts. Further, it is desirable to provide a heat insulating portion in order to prevent the liquid crystal panel from being externally affected, and to configure the liquid crystal panel so as to move through the heat insulating portion. In particular, when the high temperature part is a liquid, for example, water, it has been effective to provide a heat insulating part with respect to eliminating various adverse effects caused by water vapor and also with respect to preventing the liquid surface from swaying.

Regarding the angle between the direction of the temperature gradient between the two heat sources of the high temperature part and the low temperature part and the rubbing direction, that is, the direction in which the partition member extends, if the largest component of the temperature gradient is not necessarily parallel to the rubbing direction. You don't have to. For example, when a temperature gradient is generated in the liquid crystal panel body by pulling up the liquid crystal panel body from a liquid acting as a high temperature part or a low temperature part, the rubbing direction of the liquid crystal panel body is appropriately changed from a direction perpendicular to the gas-liquid interface by an angle θ. That is, the liquid crystal panel body can be pulled up in the vertical direction while only tilting.

When the inclination angle θ is 90 °, a temperature gradient does not occur in the rubbing direction, so that many defects occur.
However, when θ was set to 70 ° or less, more preferably 60 ° or less, no defect occurred. If θ is large, the direction in which the liquid crystal layer bends tends to greatly deviate from the layer direction of the liquid crystal layer determined by the rubbing treatment.

The high temperature atmosphere can be selected from various atmospheres such as an atmosphere in an oven, an atmosphere in a water tank having a large heat capacity, a hot plate, a solid heating element such as a Peltier element, and the like. The low temperature atmosphere is determined by the temperature of the SmC ^* phase, but may be, for example, an oven or ordinary air.

In order to move the temperature gradient formed in the liquid crystal panel between the high temperature part and the low temperature part in parallel on the surface of the liquid crystal panel, the high temperature part and the low temperature part are moved with respect to the liquid crystal panel. Either the movement or the movement of the liquid crystal panel body with respect to the high temperature part or the like may be selected. However, in view of productivity and cost, it is more advantageous to move the liquid crystal panel.

In the case of a liquid crystal panel having a short partition member and thus a short linear space, that is, a small liquid crystal panel, the phase change as shown in FIG. 15 did not appear properly, and therefore, defect-free alignment was difficult to obtain. . In order to obtain defect-free orientation, a length of at least 10 cm was required.

[0092]

In the method of manufacturing a liquid crystal panel according to the present invention, the direction of permeation of liquid crystal is regulated by a linear space which is a narrow passage, and the direction is defined in a uniaxial alignment direction, for example, parallel to a rubbing direction, and furthermore, in a uniaxial alignment direction. The liquid crystal panel body is sequentially cooled so that a temperature gradient is generated in the direction, and while the layer is naturally deformed in the direction of volume contraction, the liquid crystal therein changes to a low temperature state phase, for example, an SmC ^* phase. With such a synergistic configuration, it is possible to obtain a defect-free liquid crystal that does not generate any defects such as zigzag defects, tree-like defects, and linear defects that could not be achieved conventionally. .

[0093]

Example 1 Example 1 in FIG.
1mm glass substrate is optically polished and the flatness of the plane is 2μ.
One set of transparent substrates 2 and 3 processed within m is prepared. A 1500 ° ITO film is formed on each of the transparent substrates 2 and 3 by sputtering, and a stripe-shaped IT having a line width of 270 μm and a pitch of 300 μm is formed by conventional photolithography.
O electrodes 4 and 5 were formed except for each 1 cm on both sides of the substrates 2 and 3. The length of the electrode 4 on the substrate 2 is the same as the length of the substrate 2 in the longitudinal direction, and the length of the electrode 5 on the substrate 3 is the same as the length of the substrate 3 in the lateral direction.

Next, a 2% solution of a polyimide resin (HL1110; manufactured by Hitachi Chemical Co., Ltd.) was spin-coated on one of the substrates 3 at 1000 rpm for 20 seconds.
After drying in an oven at a temperature of about 1 hour to form an alignment film 9, rubbing treatment was performed at room temperature in a direction parallel to the electrode 5 in order to perform rubbing on both sides. Further, a viscosity of 25 cp of a resist MP-S1400 (manufactured by Shipley Co., Ltd.) is formed on the substrate 3.
The solution was spin coated at 1000 rpm for 20 seconds. Thereafter, the adhesive partition wall members 8 having the pattern shown in FIG. 2 were formed evenly at positions not overlapping with the respective ITO electrodes 5 by conventional photolithography. Then, at 140 ° C, 1
Dried for hours. The partition member 8 has a thickness of 2 μm and a width of 30 μm.
m and the length were 20 cm. The number of partition members 8 is 900
It is a book.

In FIG. 2, a wide line portion 21 surrounding the display portion H is used for bonding the peripheral portions of the glass substrates 2 and 3, and is a seal for preventing excessive diffusion of the enclosed liquid crystal and contact with the atmosphere. Also serves as a department. The liquid crystal inlet 10 is a partition member 8
On one end side. 2% of a polyimide resin (HL1110; manufactured by Hitachi Chemical Co., Ltd.)
After spin coating the solution at 1000 rpm for 20 seconds,
After drying in an oven at 180 ° C. for about 1 hour, an alignment film 7 was formed. Further, a rubbing treatment was performed.

After the rubbing, parallel rubbing is performed so that the rubbing direction is substantially parallel to the partition member 8.
That is, so that the upper and lower rubbing directions are the same direction,
The two substrates 2 and 3 were superimposed and temporarily brought into close contact. Then, in this state, when the inside of the panel body, that is, the linear space R was evacuated by setting the jig (not shown) for atmospheric pressure pressurization, the substrates 2 and 3 were completely adhered to each other by the atmospheric pressure. Then, put the panel body into the oven while decompressing, 5 ° C
The temperature was raised to 180 ° C. at a rate of / minute, and the temperature was maintained for 1 hour. Thereafter, the temperature was gradually reduced to room temperature and returned to normal pressure. As a result, a liquid crystal panel frame for enclosing a liquid crystal having a cell gap of 1.8 μm, the upper and lower substrates 2 and 3 being completely adhered, and having a group of partitions by the partition member 8 was obtained. The area of the display section H is 27 cm × 20 cm.

Thereafter, the periphery of the obtained liquid crystal panel frame was fixed with an epoxy resin or the like to form a structure excellent in earthquake resistance, impact resistance, and sealing performance. The liquid crystal panel frame was set in a reduced pressure heating furnace to reduce the pressure to 10 ^-2 pa, then the temperature was increased to 90 ° C, and the liquid crystal panel was sealed in a liquid crystal container containing a ferroelectric liquid crystal CS1014 (manufactured by Chisso Corporation). The inlet 10 was immersed, and the sealing port 10 was closed with liquid crystal. When this state was maintained, the liquid crystal permeated into the panel at a speed of about 1.5 cm / hour. In addition, CS1014 is a liquid phase → 82 ° C. →
Chiral nematic phase → 71 ° C. → SmA phase → 64 ° C. → S
It undergoes a phase transition of the mC ^* phase.

After the liquid crystal completely enters the inside of the liquid crystal panel frame, it is returned to room temperature in about 3 hours, and the liquid crystal sealing port 10 is sealed with epoxy resin to obtain a liquid crystal panel body in which liquid crystal is completely sealed. . Separately, two types of liquid crystal panel bodies were prepared: a completely similar panel structure and liquid crystal in which the upper and lower rubbing directions are antiparallel, and a one-side rubbing type.
Observation of a chevron structure and alignment defects with changing the cooling direction for a total of three types of liquid crystal panel bodies gave the results shown in Table 1.

[0099]

[Table 1]

As a specific cooling method, first, the liquid crystal panel body was immersed in a water tank whose temperature was controlled at 85 ° C., and held for 3 minutes to make the entire liquid crystal a liquid phase which was a high-temperature state phase. afterwards,
The water in the water tank was drained such that the air-water interface of the water tank was lowered at a speed of 2.5 cm / min, or the liquid crystal panel was pulled out of the water. The cooling direction can be changed by reversing the direction in which the liquid crystal panel body is immersed in the liquid.

FIG. 22 shows the overall configuration of the manufacturing apparatus used in the embodiment. In this device, the warm water 33 stored in the water tank 34 is used as a high temperature part, and the atmosphere region Q as a low temperature part is used.
A 20-mm-thick styrofoam plate provided with a slit through which the liquid crystal panel body 1 can pass was used as the heat insulating member 32 for insulating the space between the liquid crystal panel body 1 and the high-temperature portion. This heat insulating member 32 floats on the liquid surface so as to prevent the liquid surface from swaying,
When draining, it is made to move simultaneously with the water surface. The arrow D indicates the direction of movement of the liquid crystal panel body 1 relative to the air-water interface P. This movement direction is substantially parallel to the rubbing direction applied to the liquid crystal panel body 1 and therefore substantially parallel to the partition member 8. is there. At this time, the relationship between the way of the high temperature side and the low temperature side and the rubbing direction was as shown in FIGS.
In these figures, the thick line F indicates the tilt direction of the liquid crystal preferred by the alignment film, that is, the pretilt direction.

FIGS. 16 to 21 show the bending direction of the layer actually formed by the temperature gradient and the degree of bending of the chiral smectic phase layer obtained correspondingly. Here, the orientation states of (a) and (b) are called the C2 state and the C1 state, respectively, as described above. On the other hand, although the common names are not defined for the respective states shown in (c) to (f), in this specification, (c) and (d) are referred to as C1 / C2 hybrid states, abbreviated as C1 / C2.
2 state, (e) one side C2 state, and (f) one side C
Let's call it one state. Note that when the upper and lower uniaxial orientation settings are the same, the (c) state and the (d) state cannot be distinguished.

In each of the rubbing directions, the direction of bending of the liquid crystal layer in the liquid crystal chevron structure was directed to the end where cooling started. In the case of the parallel rubbing (a, b in Table 1: FIGS. 16 and 17), particularly when the cooling direction is set to the same direction as the rubbing direction (b in FIG. 17: FIG. 17), some linear defects and abnormal orientation are observed. It was observed. This is because a partial change from the C1 state to the C2 state has occurred as shown in FIGS. This change does not mean that the liquid crystal at the center of the layer is largely moved and the direction in which the layer bends changes by 180 °. Because there is deformation due to temperature gradient,
Such a change cannot occur. This is a change such that the C1 state can be read as the C2 state, as schematically shown in FIG. This means that a slight structural change causes a change from the C1 state to the C2 state. Whether such a change actually occurs depends on the properties of the liquid crystal itself, the amount of bending deformation in the C1 state, and the temperature.

When the cooling direction was set opposite to the rubbing direction (a in Table 1: FIG. 16), no alignment abnormality was found in the main part. This is because the curve in the direction of the C2 state suddenly occurs without passing through the C1 state, the interaction between the liquid crystal and the alignment film more favors the state of (Table 1a: FIG. 16), and 1a: In the state of FIG. 16), mass transfer is performed smoothly. Even in the case of (Table 1b: FIG. 17), if the moving direction of the air-water interface was reversed again, defect-free orientation was obtained. Incidentally, in any case of FIGS. 16 and 17, within about 5~10mm liquid crystal entrance of the partition member (in FIG. 2 L _E
And L _X ) had an alignment abnormality.

Further, one-side rubbing (e and f in Table 1: FIG. 2)
0, FIG. 21), similar results were obtained.

In the case of so-called antiparallel rubbing in which the rubbing directions are different between the upper and lower substrates (c and d in Table 1: FIGS. 18 and 1)
In 9), there should be no distinction in the bending direction of the liquid crystal layer.
However, defect-free orientation was obtained only when cooling from either one. However, even if there were defects, the amount was extremely small. This is presumably because the partition member was formed on the alignment film by photolithography, so that the function of the alignment film became vertically asymmetric. If the partition member is formed by a printing method and the symmetry of the operation of the alignment film is maintained, a defect-free alignment state will be obtained regardless of the cooling method. These results indicate that the direction in which the liquid crystal layer bends can be freely reversed by selecting the cooling direction.

If the bending direction of the liquid crystal layer, which is favored by the interaction between the liquid crystal and the alignment film, coincides with the bending direction determined by cooling, complete defect-free alignment can be obtained. In the reverse case, defect-free orientation can occur, but experimentally, linear defects and some orientation abnormalities have occurred. Regarding a liquid crystal panel body in which the direction of bending of the liquid crystal layer does not reverse at all due to the direction of cooling, or the liquid crystal panel body is full of alignment abnormalities in the entire liquid crystal, the bending of the liquid crystal layer does not depend on the cooling method. Since it is considered that the direction is determined, it is not necessary to adopt the cooling method as in the present invention, and cooling may be performed in an oven as in the related art. However, even in such a case, it is necessary that there is no collision between liquid crystal phase domains and no defect due to shrinkage. This probability can occur by chance if the panel size is small, but cannot occur with any panel structure over a large area.

The temperature at which the movement of the air-water interface is started is adjusted to a chiral nematic phase (75 ° C.) which is in a different phase state from the liquid phase.
Alternatively, a similar defect-free orientation was obtained even with the SmA phase (67 ° C.). These phase states change from isotropic to 0.1 in liquid.
Formed with slow cooling at a rate of 2 ° C / min. However,
When the moving speed of the air-water interface was increased to 5 cm / min or more, zigzag defects and tree-like defects occurred.

While the liquid crystal panel of the present embodiment was immersed in an oven or the water bath of the present embodiment, the liquid crystal panel was cooled at a rate of 0.2 ° C./min.
When cooled from 5 ° C. to room temperature, the entire liquid crystal inside the panel body is divided into two large domains in which the liquid crystal layer bends in different directions, and tree-like defects are scattered inside those domains. No orientation was obtained. Regarding this liquid crystal panel body, even if the method of immersing the panel body or the cooling temperature conditions were changed, the position of the alignment abnormality was slightly moved, and no improvement was observed.

(Comparative Example 1) A liquid crystal panel having the same configuration using the same material and the same substrate as in Example 1,
A device in which a stripe-shaped partition member was not bonded to an opposing substrate was manufactured. The stripe shape of the partition member 8 at the center in FIG. 2 was formed in the same manner as in Example 1. After drying for 1 hour, the seal portion 21 was formed of epoxy resin by a screen printing method.

The two substrates were superposed in the same procedure as in Example 1, and they were set in an atmospheric pressure jig, kept at 90 ° C., and in this state, the two substrates were bonded together at the seal portion. By this method, a liquid crystal panel body was obtained in which the partition member 8 and the substrate were not adhered but closely adhered in the vicinity of the seal portion, but were floating in the center. Liquid crystal was permeated into the liquid crystal panel so as to be substantially parallel to the rubbing direction. Then, it was immersed in a water bath at the same temperature as in Example 1 and cooled under the same conditions. However, large and small zigzag defects were scattered regardless of the cooling direction, and no defect-free initial orientation was obtained.

Comparative Example 2 A liquid crystal panel was obtained in the same procedure as in Example 1, except that the shape of the adhesive member was a column having a radius of 8 μm. The adhesive members were regularly arranged at a pitch of 5 mm on the line where the striped member of Example 1 was. Liquid crystal was permeated into this panel so as to be substantially parallel to the rubbing direction. Next, the liquid crystal panel was immersed in a water bath at the same temperature as in Example 1, and cooled under the same conditions. As a result, zigzag defects and tree-like defects were found regardless of the cooling direction, and no defect-free initial orientation was obtained.

(Comparative Example 3) A liquid crystal panel frame was obtained in the same procedure as in Example 1. However, dot-shaped glass beads having a diameter of 2 μm were used as spacers corresponding to the partition members.
The upper and lower substrates are not bonded. Liquid crystal was penetrated into the liquid crystal panel frame so as to be substantially parallel to the rubbing direction to form a liquid crystal panel body. Next, the liquid crystal panel was immersed in a water bath at the same temperature as in Example 1, and cooled under the same conditions. In this liquid crystal panel, the direction of contraction of the liquid crystal was not determined, and zigzag defects were generated around the glass beads used as the spacers, so that no defect-free initial alignment was obtained. Further, the panel gap was changed by heating and cooling.

(Embodiment 2) Four types of liquid crystal panel bodies having the same configuration and the same procedure as those in Embodiment 1, and the angles formed by the stripe-shaped partition member and the rubbing direction are 90 °, 40 °, 23 °, and 12 °. Was prepared. Cooling was performed in the same manner as in Example 1. However, in the case of 90 °, a large number of zigzag defects were generated in parallel to the partition member regardless of the angle at which the air-water interface was moved. Since the liquid crystal of the liquid crystal panel body in which the stripe-shaped partition member and the rubbing direction were substantially parallel was completely defect-free, the defect generation rate was continuous while the inclination angle of the partition member became almost parallel from 90 °. It can be seen that the number has increased.

Therefore, disposing the partition member in a direction not parallel to the rubbing direction only causes a risk of occurrence of a defect, and performing such an operation is practically meaningless. Incidentally, even when the inclination angle of the partition member was 23 °, a small number of linear defects parallel to the rubbing direction were generated. This is because the liquid crystal permeation direction deviates from the rubbing direction.
It is considered that the movement of the liquid crystal to move along the rubbing direction hits the partition member and is hindered.

When the inclination angle of the partition member was 40 °, a larger number of linear defects and some small zigzag defects were generated as compared with the case where the inclination angle was 23 °. When the partition member had an inclination angle of 12 °, a defect-free oriented liquid crystal was obtained.

Example 3 A liquid crystal panel body was manufactured by the same configuration and the same procedure as in Example 1, but as shown in FIG. 26, some of the plurality of partition members 8 were thinned out to form a partition member 8. Ten types of two linear spaces R1 and R2 each having a width L of about 1 mm and about 2 mm between the openings were formed. The method of infiltrating and cooling the liquid crystal was the same as in Example 1.
A small number of zigzag defects and linear defects occurred in the liquid crystal penetrated into the linear space R2 having a width L = 2 mm. As a result, it is understood that the opening of the stripe-shaped partition member is preferably narrow. However, the specific numerical value is selected according to the required volume shrinkage, panel size, pixel size, arrangement of color filters, adhesive strength, pressure resistance, and the like. Further, when the present liquid crystal panel body is used as a writing body for optical writing, it is selected according to a scanning pitch of a writing laser beam or the like.

Example 4 In FIG. 25, a pair of transparent substrates 2 and 3 were prepared by optically polishing a 45 cm square glass substrate having a thickness of 1.1 mm and processing the flatness of the flat surface to within 2 μm. Planar electrodes 4 and 5 were formed on the transparent substrates 2 and 3 by forming an ITO film of 2000 ° by sputtering.

Next, a 2% solution of a polyimide resin HL1110 was spin-coated on one substrate 3 at 1000 rpm for 20 seconds, dried in an oven at 180 ° C. for about 1 hour, and rubbed at room temperature in a direction parallel to one side. did. Further, a 30 cp viscosity solution of a rubber-based resist OMR-83 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) in which a spherical spacer was added at 1% by weight with respect to the resin content was added to the substrate at 3000 rpm.
Spin coated for 5 seconds.

Thereafter, an adhesive partition wall member 8 having the pattern shown in FIG. 2 was formed at the center of the substrate 2 in parallel with the rubbing direction by a conventional photolithography. The partition member 8 has a thickness of 2.2 μm and a length of 37 c.
m, and the number was 900. The main difference from the first embodiment is the length of the formed linear space R. The area H usable as the display unit is 37 cm × 30 cm.
The opposite substrate 2 was spin-coated with a 2% solution of a polyimide resin HL1110 at 1000 rpm for 20 seconds.
It was dried in an oven at 80 ° C. for about 1 hour.

In the same manner as in the first embodiment, the upper and lower substrates 2 and 3
A liquid crystal panel frame was obtained in which the rubbing directions were parallel and the same direction, there was no sinking at the center, the cell gap was about 2.0 μm, and there was a partition member group in which the upper and lower substrates were completely bonded. Then, a ferroelectric liquid crystal ZL13 is provided on this liquid crystal panel frame.
774 (Merck Co., Ltd.) was enclosed. This liquid crystal has a liquid phase → 86 ° C. → N ^* phase → 76 ° C. → SmA phase → 62 ° C. → S
It undergoes a phase transition of the mC ^* phase.

After the liquid crystal panel body is immersed in a water tank whose temperature is controlled at 88 ° C. and held for 3 minutes so that the entire liquid crystal becomes a liquid phase, the air-water interface of the water tank is lowered at a rate of 2.5 cm / min. The water in the aquarium was drained. No defect was found in the main part of the liquid crystal panel body in the cooling direction of FIG.
When the cooling direction was reversed, only a few linear defects were found. The combination of the alignment film and the liquid crystal layer in the liquid crystal panel body of this embodiment is such that the direction in which the liquid crystal layer bends in the opposite direction to the first embodiment is in a natural state. However, there were alignment abnormalities including zigzag defects up to about 10 mm at the beginning and end of the partition member.

With this liquid crystal panel immersed in liquid,
The panel was cooled to room temperature at a rate of 0.2 ° C./min while controlling the temperature so that the temperature difference across the panel was 0.1 ° C. In this case, a zigzag defect appeared across the adhesive member at a position where the entire surface of the panel was substantially vertically divided into 1: 2. Many linear defects were found inside two liquid crystal phase domains forming zigzag defects. When the liquid crystal panel body was cooled by changing the way of immersion, the position of the zigzag chip fluctuated, but did not disappear. This indicates that the distribution of cooling points and the mass transfer in volume shrinkage are the causes of the generation of defects.

Comparative Example 4 A liquid crystal panel frame was manufactured in the same procedure as in Example 3. However, the size of the glass substrate used is 10 cm square, and the area usable as the display unit is 8 cm × 8 cm. A ferroelectric liquid crystal ZL13774 (manufactured by Merck Ltd.) was sealed in the liquid crystal panel frame in the same manner as in Example 3. After the encapsulation, the same processing as in Example 3 was performed, but the temperature gradient was not sufficiently applied, and zigzag defects occurred.

Example 5 A liquid crystal panel frame for enclosing liquid crystal was manufactured in the same manner as in Example 1. The liquid crystal is ferroelectric liquid crystal CS1014 (manufactured by Chisso Corporation).
Was enclosed. FIG. 23 shows the entire configuration of the device actually used. In order to make the phase on the higher temperature side than the chiral smectic C phase a chiral nematic phase, the set temperature on the higher temperature side of the temperature gradient was 75 ° C. Regarding the atmosphere for temperature control, the atmosphere 42 at a temperature (high temperature part) corresponding to the higher temperature side than the chiral smectic C phase is dry air, while the atmosphere 43 at the temperature (low temperature part) corresponding to the chiral smectic C phase is used. Was also dry air. The moving speed of the temperature gradient was 1 cm / min. Reference numeral 32 denotes a heat insulating member having a length L _D of 10 cm in the temperature gradient direction.

When the liquid crystal panel 1 was moved in the direction of arrow D relative to the temperature gradient section formed by the high temperature section 42 and the low temperature section 43, the liquid crystal panel 1 having a completely defect-free chiral smectic C phase was obtained. I got

Example 6 A liquid crystal panel frame for enclosing liquid crystal was manufactured in the same manner as in Example 1. The liquid crystal is ferroelectric liquid crystal CS1014 (manufactured by Chisso Corporation).
Was enclosed. FIG. 24 shows the overall configuration of the apparatus used for the embodiment.

To set the phase on the higher temperature side than the chiral smectic C phase to the smectic A phase, the set temperature on the higher temperature side of the temperature gradient was set at 65 ° C. As the temperature control means, contact temperature control devices 52 and 53 using a Peltier element, that is, solid temperature control means were used. These temperature control devices 52 and 53 are capable of controlling the temperature within a temperature range corresponding to the chiral smectic C phase to the isotropic phase, a temperature corresponding to a higher temperature side than the chiral smectic C phase (high temperature portion), and Both the temperature (low temperature portion) corresponding to the chiral smectic C phase is determined by the temperature control device 52,
The temperature was controlled by 53. The moving speed of the temperature gradient is 1cm
/ Min. Reference numeral 32 denotes a heat insulating member.

The liquid crystal panel 1 is moved relative to the temperature gradient formed by the high temperature section 52 and the low temperature section 53 by an arrow D.
When the liquid crystal panel was moved in the direction, a perfectly perfect chiral smectic C phase was obtained.

Comparative Example 6 A liquid crystal panel frame for enclosing liquid crystal was produced in the same manner as in Example 1. Then, a ferroelectric liquid crystal CS1014 (manufactured by Chisso Corporation) was sealed as a liquid crystal. In order to make the phase on the higher temperature side than the chiral smectic C phase a chiral nematic phase, the set temperature on the higher temperature side of the temperature gradient was 75 ° C. Regarding the atmosphere for temperature control, the atmosphere having a temperature corresponding to the higher temperature side than the chiral smectic C phase was water, and the chiral smectic C phase was used.
The atmosphere at the temperature corresponding to the phase was the atmosphere. However, no heat insulating member was provided in the temperature gradient section. The moving speed of the temperature gradient was 2.5 cm / min.

As a result, the temperature gradient portion was not properly formed by the temperature rise due to the steam, the direction of contraction of the liquid crystal was not determined, and a zigzag defect was generated in a wavy shape in accordance with the movement of the temperature gradient portion.

Example 7 A liquid crystal panel frame for enclosing liquid crystal was manufactured in the same manner as in Example 1. As a liquid crystal, an antiferroelectric liquid crystal CS4000 (Chisso Corporation)
Manufactured). Other materials are the same as in the fifth embodiment. C
S4000 has an antiferroelectric phase, the phase transition, the isotropic phase → 101 ° C. → smectic A phase → 84 ° C. → chiral smectic C phase → 82 ° C. → chiral smectic C _A phase.

In order to make the phase higher in temperature than the chiral smectic C _A phase an isotropic phase, the set temperature on the high temperature side of the temperature gradient was set at 102 ° C. As the temperature control means, a contact-type temperature control apparatus using a Peltier element, which is a solid temperature control means, was used. The moving speed of the temperature gradient was 2.5 cm / min. As a result, a liquid crystal panel having a chiral smectic C _A ^* phase having extremely few zigzag defects was obtained.

In the same procedure as in Examples 1 and 3, the combination of the liquid crystal and the polyimide resin for alignment was obtained by obtaining the perfect defect-free alignment by appropriately selecting the high-temperature phase temperature and the cooling direction. The list is as follows. Ferroelectric liquid crystal: CS1013, CS1015, CS10
17, CS1019, (manufactured by Chisso Corporation), ZLI
3775 (manufactured by Merck Ltd.), SCE8, SCE9, S
CE10, SCE11 (BDH) polyimide resin: S610 (Nissan Chemical Co., Ltd.), PI
X1400, PIQ5200, (Hitachi Chemical Co., Ltd.
AL3046, AL1051, manufactured by Nippon Synthetic Rubber.

(Example 8) A ferroelectric liquid crystal SCE8 and SCE9 (both manufactured by BHD) were selected as liquid crystals to be used, and other conditions were the same as in Example 1, to produce a liquid crystal panel body. In any of the six types (a) shown in FIG. 16 to (f) shown in FIG. 21, no defect was observed.

(Embodiment 9) FIG. 29 shows another embodiment of the apparatus for manufacturing a liquid crystal panel according to the present invention. This apparatus includes a tunnel-type furnace 62 acting as a high-temperature part, a liquid crystal panel body moving device 65 including a transport roller 64, and heat insulation for insulating between the atmosphere region Q acting as a low-temperature part and the inside of the furnace 62. And a portion 63. The furnace 62 and the heat insulating section 63 have openings 66 through which the liquid crystal panel 1 can pass. In the furnace 62, appropriate heating means, for example, a heating device using heat generated when a current flows through a resistor, a heating device using an infrared heater, and the like are provided. In this device, the liquid crystal panel 1 conveyed by the moving device 65 moves in the order of the furnace 62, the heat insulating portion 63, and the atmosphere region Q as shown by the arrow J. During this movement, a temperature gradient is formed in the liquid crystal panel body 1, and the temperature gradient moves relatively to the liquid crystal panel body 1, particularly in a direction parallel to the linear space R.

According to the present embodiment, the temperature of the high-temperature portion constituted by the furnace 62 can be set to 100 ° C. or higher, which is higher than the liquid. Further, since the cooling process for the liquid crystal panel body 1 can be performed by a flow operation, the production efficiency of the liquid crystal panel body is improved.

(Embodiment 10) FIG. 30 shows still another embodiment of the apparatus for manufacturing a liquid crystal panel according to the present invention. This device has a plurality of high-temperature transport rollers 72 that can transport the liquid crystal panel body 1 in the direction of arrow J. These high-temperature transport rollers are formed of rubber rollers, ceramic rollers, or other rollers, and are maintained at a high temperature by being heated by a built-in heating device or a heating device provided outside. The liquid crystal panel body 1 includes a roller 72
While being conveyed by the rollers, it moves between the high-temperature portion constituted by the rollers 72 and the low-temperature portion constituted by the atmospheric region Q, and is cooled while being placed at a predetermined temperature gradient.

Also in this embodiment, the temperature of the high-temperature portion constituted by the high-temperature roller 72 is set to 100
It can be set above ℃. Further, since the cooling process for the liquid crystal panel body 1 can be performed by a flow operation, the production efficiency of the liquid crystal panel body is improved. The high-temperature transport roller 72 transports the liquid crystal panel body 1 with the pair of rollers sandwiching the liquid crystal panel body 1. Since the liquid crystal panel body 1 has a structure in which a pair of substrates are firmly adhered to each other by a large number of partition members, such a configuration is adopted. The liquid crystal panel body 1 itself is not damaged or the liquid crystal structure in the liquid crystal panel body 1 is not broken even when the sheet is transported while being pinched.

(Embodiment 11) FIG. 31 shows still another embodiment of the apparatus for manufacturing a liquid crystal panel according to the present invention. This device comprises a sand bath 82 acting as a high temperature part, an atmosphere region Q acting as a low temperature part, and a liquid crystal panel body moving device 85 for moving the liquid crystal panel body 1 between the sand bath 82 and the air region Q. And The moving device 85
The liquid crystal panel body 1 is constituted by an arbitrary mechanism capable of transporting the liquid crystal panel body 1 vertically. The sand in the sand bath 82 is heated by a built-in heating device or a heating device installed outside.

According to this embodiment, the temperature of the high-temperature portion constituted by the sand bath 82 can be set to 100 ° C. or higher, which is higher than the liquid. Further, since there is no steam, that is, steam as in the case of using a liquid, the temperature gradient applied to the liquid crystal panel 1 is stabilized.

[0142]

According to the present invention, since the partition member forming the linear space adheres the upper and lower substrates firmly and flexibly,
A liquid crystal panel having excellent shock resistance and shock resistance that does not destroy the liquid crystal alignment layer can be obtained. This liquid crystal panel body does not bend even when touched by hand and can be freely carried without being deformed. The performance is improved. Also, the shock resistance when used as a liquid crystal display is improved.

According to the present invention, (1) the liquid crystal permeation direction is regulated by a linear space which is a narrow passage, and (2) the direction is defined parallel to a uniaxial orientation direction, for example, a rubbing direction. (3) The liquid crystal panel body is sequentially cooled so that a temperature gradient is generated in the uniaxial orientation direction, and the liquid crystal in the liquid crystal molecule layer is naturally deformed in the direction of volume shrinkage, and the liquid crystal therein is changed to a low temperature state phase, for example, an SmC ^* phase. And change.
With such a synergistic configuration, a completely defect-free oriented chiral smectic phase can be reliably formed on a large-area liquid crystal panel body with good reproducibility, which could not be achieved conventionally. Further, a high-quality and large-sized liquid crystal display can be manufactured at low cost.

In addition, a liquid crystal phase can be sealed so that an unfilled portion does not occur inside a very large area liquid crystal panel frame for sealing liquid crystal.

In addition, as long as any ordinary ferroelectric liquid crystal or antiferroelectric liquid crystal on the market and an appropriate planar polyimide-based alignment film are used in any combination, special measures should be taken. Instead, if the liquid crystal is sealed inside the liquid crystal panel frame, a defect-free orientation is inevitably obtained.

For the first time, the applicability to an ultra-large liquid crystal display such as a high definition using a ferroelectric liquid crystal or an anti-ferroelectric liquid crystal was demonstrated.

Further, the method of the present invention does not require special equipment such as a vacuum apparatus, and can be easily introduced into mass production technology from an industrial point of view, whereby a ferroelectric liquid crystal and an antiferroelectric liquid crystal can be used. Liquid crystal panel can be manufactured at low cost.

[0148]

[Brief description of the drawings]

FIG. 1 is a perspective sectional view showing an internal structure of a liquid crystal panel frame or a liquid crystal panel body used in the method of the present invention.

FIG. 2 is a plan sectional view of the liquid crystal panel body.

FIG. 3 is a front sectional view showing an internal structure of an example of a conventional liquid crystal panel body.

FIG. 4 is a plan view schematically showing an example of a zigzag defect which is one of the orientation abnormalities.

FIG. 5 is a plan view schematically showing a tree-like defect which is another one of the orientation abnormalities.

FIG. 6 is a plan view schematically showing a linear defect which is still another one of the alignment abnormalities.

FIG. 7 is a perspective sectional view schematically showing a relationship between a chevron structure and a structure of a zigzag defect observed in a layer of an SmC ^* phase.

FIG. 8 is a perspective sectional view showing a bookshelf structure of an SmC ^* phase layer.

FIG. 9 is a diagram schematically showing a state of misalignment of layers, which is one of the orientation abnormalities of the antiferroelectric liquid crystal.

FIG. 10 is a diagram schematically showing a state in which two domains having different growth directions are present, which is one of the orientation abnormalities of the antiferroelectric liquid crystal.

FIG. 11 is a view schematically showing another state of the layer misalignment, which is another one of the orientation abnormalities of the antiferroelectric liquid crystal.

FIG. 12 is a diagram schematically showing a process of generating a tree-like defect.

FIG. 13 is a diagram schematically showing a tree-like defect generation process following FIG. 12;

FIG. 14 is a diagram schematically showing a situation where a liquid crystal layer bends toward a lower temperature. In particular, (a) shows a case where the temperature decreases first from the right side, and (b) shows a case where the temperature decreases sequentially from the center portion to the left and right sides.

FIG. 15 is a diagram schematically showing a state in which different phases are gradually generated toward lower temperatures inside the liquid crystal, and the SmC ^* phase layer is further bent.

FIG. 16 is a view schematically showing a bending direction of a liquid crystal layer and an inclined state of liquid crystal molecules corresponding to a relationship between a rubbing direction and a cooling direction, particularly a situation in which the cooling direction is opposite to the rubbing direction in parallel rubbing. is there.

FIG. 17 is a diagram schematically showing a bending direction of a liquid crystal layer and an inclined state of liquid crystal molecules corresponding to a relationship between a rubbing direction and a cooling direction, particularly a situation in which the cooling direction is the same as the rubbing direction in parallel rubbing. is there.

FIG. 18 schematically illustrates the bending direction of the liquid crystal layer and the tilt state of the liquid crystal molecules corresponding to the relationship between the rubbing direction and the cooling direction, particularly the situation where the cooling direction is the same as the lower rubbing direction in antiparallel rubbing. FIG.

FIG. 19 schematically shows the bending direction of the liquid crystal layer and the tilt state of the liquid crystal molecules corresponding to the relationship between the rubbing direction and the cooling direction, particularly the situation when the cooling direction is the same as the upper rubbing direction in antiparallel rubbing. FIG.

FIG. 20 is a view schematically showing a bending direction of a liquid crystal layer and an inclined state of liquid crystal molecules corresponding to a relationship between a rubbing direction and a cooling direction, particularly a situation in which the cooling direction is opposite to the rubbing direction in one-side rubbing. is there.

FIG. 21 is a diagram schematically showing a bending direction of a liquid crystal layer and an inclined state of liquid crystal molecules corresponding to a relationship between a rubbing direction and a cooling direction, particularly a situation in which the cooling direction is the same as the rubbing direction in one-side rubbing. is there.

FIG. 22 is a view schematically showing one embodiment of the apparatus for manufacturing a liquid crystal panel according to the present invention.

FIG. 23 is a view schematically showing another embodiment of the apparatus for manufacturing a liquid crystal panel according to the present invention.

FIG. 24 is a view schematically showing still another embodiment of the apparatus for manufacturing a liquid crystal panel according to the present invention.

FIG. 25 is a perspective sectional view showing another embodiment of the internal structure of the liquid crystal panel used in the method of the present invention.

FIG. 26 is a perspective sectional view showing still another embodiment of the internal structure of the liquid crystal panel used in the method of the present invention.

FIG. 27 is a diagram schematically showing an example of how zigzag defects appear in a liquid crystal panel bonded with regular dot-type members.

FIG. 28 is a diagram schematically showing how the liquid crystal molecular layer bends when the liquid crystal is cooled, and particularly showing how the layer bends when the liquid crystal is cooled from the direction in which rubbing started.

FIG. 29 is a perspective view showing still another embodiment of the apparatus for manufacturing a liquid crystal panel according to the present invention.

FIG. 30 is a perspective view showing still another embodiment of the apparatus for manufacturing a liquid crystal panel according to the present invention.

FIG. 31 is a perspective view showing still another embodiment of the apparatus for manufacturing a liquid crystal panel according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Liquid crystal panel body 2, 3 Glass transparent substrate 4, 5 Transparent ITO electrode 6 Insulating film 7, 9, Polyimide alignment film 8 Partition member 10 Liquid crystal sealing opening 21 Sealing part 22 Front end of linear space 23 Rear end of linear space 32 Insulation member 33 Hot water (high temperature part) 34 Water tank 42 Dry air (high temperature) 43 Dry air (low temperature) 52 Temperature controller (high temperature) 53 Temperature controller (low temperature) 62 Tunnel type furnace (high temperature part) 63 Thermal insulation part 65 Liquid crystal panel body moving device 66 Opening 72 High-temperature transport roller 82 Sand bath (high temperature part) 85 Liquid crystal panel body moving device A Liquid crystal layer D Moving direction of liquid crystal panel body with respect to temperature gradient G Cell gap H Display portion of liquid crystal display K Substrate and Interface with liquid crystal layer L Long side dimension of cross section of linear space R M Liquid crystal molecule Q Atmospheric region R Linear space S Short section of linear space R Side dimension W width P _1, P ₂ linear interstices R liquid crystal with wide surface P ₃ in contact of, P ₄ linear interstices narrow surface contacting the liquid crystal R of the partition member 8

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-203427 (JP, A) JP-A-61-204615 (JP, A) JP-A-61-205918 (JP, A) JP-A-61-205918 205919 (JP, A) JP-A-61-205920 (JP, A) JP-A-61-205921 (JP, A)

Claims (18)

(57) [Claims] 1. An alignment film is formed on at least one of a pair of substrates facing each other, (2) a uniaxial alignment process is performed on at least one of the alignment films, (3) A linear space in which at least one end has an opening between the pair of substrates so as to extend in a direction substantially parallel to the uniaxial alignment treatment, and a portion other than the opening is sealed with respect to the liquid. Are continuously formed in parallel with each other, (4) a ferroelectric liquid crystal or an antiferroelectric liquid crystal is sealed in the linear space, and (5) the sealed liquid crystal exhibits a high-temperature state phase. (6) The sealed liquid crystal is moved from one end to the other end of the linear space in a state where a temperature gradient is formed and held in the direction of the uniaxial alignment treatment. From low temperature phase to high temperature phase Method of manufacturing a liquid crystal panel member, characterized by successively cooled to a temperature. 2. The method for manufacturing a liquid crystal panel according to claim 1, wherein the cross-sectional shape of the linear space is a flat and substantially quadrangular shape and the cross-sectional area is 0.006 mm ² or less. A method for manufacturing a liquid crystal panel, wherein the length is 10 cm or more. 3. The method of manufacturing a liquid crystal panel according to claim 1, wherein: (1) forming a plurality of linear electrodes arranged at a predetermined pitch on a pair of substrates; Forming an alignment film on one or both of the stripe-shaped electrodes on the substrate; (3) performing a uniaxial alignment treatment on at least one of the alignment films; and (4) forming each linear shape of the stripe-shaped electrodes on one of the substrates. Forming a linear partition member between the electrodes at the same pitch or a plurality of pitches as the electrodes and substantially parallel to the uniaxial alignment treatment; and (5) stripe-shaped electrodes on a pair of substrates After the substrates are opposed to each other so as to be orthogonal to each other, a partition member formed on one substrate is bonded to the other substrate to form a linear space sealed with respect to the liquid. Characteristic LCD panel Manufacturing method Le body. 4. The method for manufacturing a liquid crystal panel according to claim 1, wherein: (1) a planar electrode is formed on a pair of substrates; and (2) an alignment film is formed on one or both of the planar electrodes on each substrate. (3) At least one of the alignment films is subjected to a uniaxial alignment treatment. (4) At an appropriate pitch on the planar electrode formed on one of the substrates, and (5) A partition member formed on one substrate is formed so as to extend substantially in parallel, and (5) a partition member formed on one substrate is bonded to the other substrate to form a linear space sealed with respect to a liquid. A method for manufacturing a liquid crystal panel, comprising: 5. The method for manufacturing a liquid crystal panel according to claim 1, wherein the high temperature state phase is any one of an isotropic phase, a chiral nematic phase, and a chiral smectic A phase. A method of manufacturing a liquid crystal panel, comprising: 6. The liquid crystal panel manufacturing method according to claim 1, wherein the low-temperature phase is a chiral smectic C phase or an antiferroelectric liquid crystal phase. Panel body manufacturing method. 7. The method of manufacturing a liquid crystal panel according to claim 1, wherein the uniaxial alignment treatment is a rubbing treatment or an oblique deposition treatment. Production method. 8. At least one end has an opening, and a portion other than the opening forms a linear space closed to a liquid between a pair of substrates facing each other. Forming an alignment film on at least one of the pair of substrates, in a direction substantially parallel to a direction in which the linear space extends,
With respect to a liquid crystal panel body formed by performing a uniaxial alignment treatment on at least one of the alignment films and enclosing a ferroelectric liquid crystal or an anti-ferroelectric liquid crystal in their linear spaces, In a manufacturing apparatus for a liquid crystal panel body for forming a low-temperature phase monodomain layer on a liquid crystal, a high-temperature portion having a temperature at which the enclosed liquid crystal exhibits a high-temperature state phase, and the enclosed liquid crystal exhibits a low-temperature state phase A low-temperature portion having a temperature, and a temperature gradient is formed and held in the direction of the uniaxial alignment treatment, and the temperature is raised with respect to the liquid crystal panel body from one end side to the other end side of the linear space. A temperature gradient moving means for relatively moving the gradient. 9. An apparatus for manufacturing a liquid crystal panel according to claim 8, wherein a heat insulating member is provided between the high temperature section and the low temperature section. 10. The apparatus for manufacturing a liquid crystal panel according to claim 8, wherein at least one of the high temperature part and the low temperature part is a gas atmosphere. 11. The apparatus for manufacturing a liquid crystal panel according to claim 8, wherein at least one of the high-temperature section and the low-temperature section is in a liquid atmosphere. 12. The apparatus for manufacturing a liquid crystal panel according to claim 8, wherein at least one of the high-temperature portion and the low-temperature portion is made of a solid. 13. The liquid crystal panel manufacturing apparatus according to claim 8, wherein the liquid region acts as a high temperature portion, the air region acts as a low temperature portion, and a liquid region. Gas-liquid interface moving means for relatively moving the gas-liquid interface between the liquid region and the atmospheric region with respect to the liquid crystal panel body immersed in the liquid crystal; A heat insulating member provided with a slit through which the panel body can pass. 14. An apparatus for manufacturing a liquid crystal panel according to any one of claims 8 to 12, wherein the tunnel type has an opening functioning as a high-temperature portion and through which the liquid crystal panel can pass. And a liquid crystal panel that moves the liquid crystal panel body and the tunnel furnace relatively so that the liquid crystal panel body moves between the tunnel furnace and the air area. An apparatus for manufacturing a liquid crystal panel, comprising: a body moving unit. 15. The apparatus for manufacturing a liquid crystal panel according to any one of claims 8 to 12, wherein: a high-temperature transport roller that functions as a high-temperature section and can transport the liquid-crystal panel body; A working atmospheric zone or cold transport roller;
An apparatus for manufacturing a liquid crystal panel, comprising: 16. The liquid crystal panel manufacturing apparatus according to claim 8, wherein: a sand bath acting as a high-temperature portion; an atmosphere region acting as a low-temperature portion; An apparatus for manufacturing a liquid crystal panel, comprising: a liquid crystal panel body moving means for moving the body between a sand bath and an atmospheric region. 17. The apparatus for manufacturing a liquid crystal panel according to claim 8, wherein the high temperature state phase is any one of an isotropic phase, a chiral nematic phase, and a chiral smectic A phase. An apparatus for manufacturing a liquid crystal panel body. 18. The liquid crystal panel manufacturing apparatus according to claim 8, wherein the low-temperature phase is a chiral smectic C phase or an antiferroelectric liquid crystal phase. Liquid crystal panel manufacturing equipment.