JP3205250B2 - Liquid crystal element and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device in which a separation region is provided between pixels to separate each pixel, and a method of manufacturing the same. Regarding the structure.

[0002]

2. Description of the Related Art A conventional liquid crystal element has an electrode or a driving element for driving a liquid crystal layer, and has a structure in which liquid crystal is sandwiched between a pair of substrates which have been subjected to some kind of alignment treatment. In such a liquid crystal element, a separation region is provided so that a display pixel (hereinafter, referred to as a pixel) related to information transmission display can independently perform information display, and the separation region includes a transparent electrode and a metal electrode. A region commonly referred to as "between pixels" for electrically separating pixels having no pixel, and an auxiliary metal electrode or the like provided to prevent delay in the display element caused by a large screen of the liquid crystal element are arranged. Region exists.

There are various driving methods for liquid crystal elements. Among them, a simple matrix method which has a simple element structure and is easy to enlarge the screen is widely used. For example, there is a ferroelectric liquid crystal. A display element of a type that controls transmitted light in combination with a polarizing element by utilizing the refractive index anisotropy of the ferroelectric liquid crystal molecules is Clark (Cla).
rk) and Lagerwall (JP-A-56-07216, U.S. Pat. No. 4,367,942, etc.).

The ferroelectric liquid crystal generally has a non-helical chiral smectic C phase (SmC *) or a chiral smectic H phase (SmH *) in a specific temperature range. Correspondingly, it takes one of the first optically stable state and the second optically stable state and maintains the state when no electric field is applied, that is, it has bistability. It responds quickly to changes in speed and is expected to be widely used as a high-speed and storage type display element.

Here, in order to obtain good switching characteristics, the ferroelectric liquid crystal generally needs to be smaller than the helical pitch of liquid crystal molecules generated in a cholesteric phase which is one of the liquid crystal phases. Here, this pitch is generally about several tens to sub-μm. However, as the screen size of the liquid crystal element is increased with this thickness, a uniform liquid crystal over the entire display element is required to uniformly display the entire display area. The importance of making the device in a layer thickness, i.e., a uniform gap, increases.

Therefore, in order to enable a uniform display in the plane of the liquid crystal element as described above, a method of spraying spacers 4 'having a uniform diameter as shown in FIG.
Note that it is difficult to keep the gap near the center of the element uniform only by holding the upper and lower substrates 30a and 30b around the element as the screen size of the liquid crystal element increases. Closely contact between 30a and 30b,
A method is employed in which the particulate adhesive resin 5 'is sprayed so as not to widen the gap beyond the spacer diameter to maintain a uniform gap.

[0007]

However, such a conventional liquid crystal device is provided for driving a pixel 50 for transmitting and displaying information as shown in a schematic XY sectional view of FIG. 8 shown in FIG. Boundary regions between the transparent electrodes 2a 'and 2b' provided and the auxiliary metal electrode 9 provided between pixels for electrically separating a large number of pixels 50 and for alleviating delay (in FIG. (Surrounding portion), a discontinuous portion having an uneven shape occurs.

[0008] The presence of such irregularities allows the alignment films 3a ', 3a' formed on the substrates 30a, 30b to be formed.
When performing a uniaxial alignment treatment on 3b ', the rubbing method currently generally used causes a difference in the pretilt angle generated in each region.

That is, as shown in FIG. 10, the alignment films 3a ',
When a uniaxial alignment process is performed on 3b ′ in the direction indicated by arrow A by a rubbing method or the like, rubbing is performed more strongly in the convex portion 50a than in the pixel portion, and weakly in the concave portion 50b. In this case, a pre-tilt distribution is generated, and the orientation is discontinuous.

Then, in order to drive and display the pixel 50 in such a state having the discontinuity of the orientation, the transparent electrodes 2a ',
When a drive signal is applied to 2b ', an electric field equal to or higher than the liquid crystal layer 7B in the pixel 50 is applied to the liquid crystal layer 7A on the auxiliary metal electrode 9, and the memory property is broken first. further,
The domain in the state opposite to the stable state selected in the pixel generated by this failure is indicated by an arrow B from the boundary between the pixel area and the non-display area (the part enclosed by an ellipse in the figure).
And the display of the pixel 50 is broken.

Further, even with an orientation control film obtained by a uniaxial orientation treatment other than the rubbing method, the electric field strength applied to the liquid crystal layer from the inside of the pixel becomes larger on the auxiliary metal electrode, so that the memory property is easily broken. Therefore, the displayable voltage width is narrowed, and the driving characteristics as a display element are reduced.

Therefore, as an example of a solution to the discontinuity of the shape, a method of forming a flattening layer below the alignment film to flatten a step is used. However, even when the shape is flattened in this way, since electrical discontinuity occurs between pixels, alignment defects and breakdown of memory properties are hastened, and display performance is reduced. In addition, there are factors such as heat resistance and electrical durability of the flattening resin used as a method of flattening, which lower the practicability as a display element. In addition, flattening by polishing has a problem of lowering the yield due to generation of dust and the like.

Here, in order to confirm the effect of suppressing alignment defects and driving defects described in the present specification, a supplementary explanation will be given next regarding the alignment and driving of the ferroelectric liquid crystal used in the present invention.

The orientation state of the ferroelectric liquid crystal is roughly classified into Cl,
There are two types of C2, which will be described with reference to the difference in the structure of the chevron layer of the smectic phase shown in FIG. In the figure,
Reference numeral 31 denotes a smectic phase chevron layer; 32, a Cl-oriented region; and 33, a C2-oriented region.
The smectic liquid crystal generally has a layered structure, but the transition from the SmA phase to the SmC phase or the SmC * phase shortens the layer interval. Therefore, as shown in FIG.
Takes a bent structure (chevron structure) near the center of the.

Here, the bending direction (orientation state) is as follows.
As shown in the figure, there can be two of Cl and C2, but as is well known, the liquid crystal molecules at the interface of the substrate form an angle (pretilt) with respect to the substrate due to the uniaxial orientation, and the direction is the rubbing direction. The liquid crystal molecules are leaning toward the head (the tip is floating). Because of this pretilt, the Cl orientation and the C2 orientation are not equivalent in elastic energy, and transition may occur at a certain temperature.

In addition, transition may occur in the liquid crystal molecules due to mechanical strain. When the layer structure shown in FIG. 3 is viewed in a plan view, a boundary 34 at the time of shifting from the Cl orientation to C2 in the rubbing direction A is called a lightning defect in a zigzag lightning shape, and a boundary 35 at the time of shifting from the C2 orientation to the Cl orientation is It is called a hairpin defect with a wide gentle curve.

Here, a pair of substrates 30 which have been subjected to a uniaxial alignment treatment in order to align such a ferroelectric liquid crystal.
a, 30b, and a pair of substrates 30a, 30b are disposed so as to face each other so that the uniaxial alignment directions are substantially parallel to each other and in the same direction, and the pretilt angle of the ferroelectric liquid crystal is α, and the tilt angle is α. (1/2 of cone angle) is 0,
If the layer tilt angle of the SmC * phase is δ and the ferroelectric liquid crystal has an alignment state represented by the following equation, there are four states having a chevron structure in the Cl alignment state.

Θ <α + δ... Equation 1 The four Cl orientation states are different from the conventional Cl orientation state, and two of the four Cl orientation states are: , Forming a bistable state (uniform state). Here, assuming that the apparent tilt angle in the absence of an electric field is θa, a state showing the following relationship among the four states of the Cl orientation state is called a uniform state.

Θ>θa> Θ / 2 Equation 2 In the uniform state, it is considered that the liquid crystal molecules (directors) are not twisted between the upper and lower substrates in view of the optical properties. .

Here, FIG. 12A is a schematic diagram showing the director arrangement in each state of the Cl orientation. In the figure, reference numerals 51 to 54 denote projections of the director in each state on the bottom surface of the cone, as viewed from the bottom surface direction, and are referred to as C directors. In addition, 51 and 52 are arrangements of C directors which are considered to be in a spray state and 53 and 54 are considered to be in a uniform state. And, as can be seen from the figure, in the two states 53 and 54 of the uniform,
The position of the liquid crystal molecules at the upper or lower substrate interface is replaced with the position in the splay state.

On the other hand, FIG. 12B shows the C2 orientation, and there are two states 55 and 56 by internal switching without interface switching. This uniform state of the Cl orientation produces a larger apparent tilt angle θa than the conventionally used bistable state in the C2 orientation, resulting in high luminance and high contrast.

By the way, as a driving characteristic of the ferroelectric liquid crystal element using the uniform states 53 and 54 exhibiting the bistable state, the first stable state and the other stable state can be achieved by applying a certain or more electric field. You. Further, to return to the original stable state, the polarity of the applied electric field may be reversed.

However, when the applied electric field is increased from the lowest electric field strength that moves between these two states, when the electric field strength exceeds a certain electric field strength, the phenomenon that the molecule position to be written returns to the original stable state position is caused by the present invention. The driving conditions under which information can be transmitted as a display element are the electric field width between the two electric field intensities described above. In other words, it has been confirmed by the present inventors that the phenomenon of returning from the molecular position to be written to the original stable state position strongly depends on the applied electric field strength and the orientation state.

Here, when this confirmed fact is compared with the structure of the liquid crystal element, the electric field strength is reduced with respect to the metal auxiliary electrode 9.
Since the upper liquid crystal layer thickness 7A is smaller than the liquid crystal layer thickness 7B in the pixel 50, even in the display voltage range within the pixel 50, the original stable state is maintained from the position of the molecule to be written. The position returns to the position where the electric field is applied (hereinafter referred to as “memory failure”). The failure of the memory property on the metal auxiliary electrode 9 affects the memory property of the pixel 50, and gradually deteriorates the memory property of the pixel 50.

As described above, when the alignment films 3a 'and 3b' formed in an uneven shape are subjected to a uniaxial alignment treatment,
The unevenness of the rubbing strength causes a pretilt distribution, and discontinuity of the orientation occurs. The present inventors and others have found that the minimum electric field strength (threshold characteristic) for switching between the two stable states described above and the electric field strength at which the memory property fails are reduced by the regulating force of the alignment films 3a 'and 3b'. It has been confirmed that the distribution depends on the shape, and the occurrence of the distribution of the pretilt derived from the shape, that is, the distribution of the alignment regulating force has been a factor of reducing the drive voltage width for uniformly driving the display element.

Therefore, the present invention has been made to solve such problems, and can improve the alignment generated in the separation region and the alignment and the driving characteristics in the electrically discontinuous portion. It is an object to provide a liquid crystal element.

[0027]

According to the present invention, a liquid crystal is sandwiched between a pair of substrates having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, and a driving signal is applied to the transparent electrode corresponding to each pixel. And driving the liquid crystal, and in a liquid crystal element that separates the pixels with a region where the transparent electrode is not present between pixels as a separation region, when a drive signal is applied to the transparent electrode, A horizontal alignment film or a vertical alignment film in a portion corresponding to the separation region of the substrate so that the liquid crystal present in the separation region is not driven by the drive signal, a solution containing a horizontal alignment agent or a vertical alignment agent, a solution injection unit, An alignment agent injection device having an injection unit moving unit that moves the solution injection unit, and a control unit that controls the injection unit moving unit to move the solution injection unit along the separation region. It is characterized in that to form out.

Further, the present invention is characterized in that the solution injection section has a nozzle, and the horizontal alignment film or the vertical alignment film is formed by a solution injected from the nozzle.

Further, in the present invention, the solution injection section includes a highly integrated nozzle, and a heating section for heating a tip of each of the nozzles to expand or foam the solution in the nozzle. Alternatively, the vertical alignment film is formed by the expanded or foamed solution injected from the nozzle.

Further, according to the present invention, while a liquid crystal is sandwiched between a pair of substrates having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, a drive signal is applied to the transparent electrode corresponding to each pixel, thereby In a liquid crystal element that drives the liquid crystal and separates the pixels by using a region where the transparent electrode is not present between pixels as a separation region, when a driving signal is applied to the transparent electrode, the pixel exists in the separation region. A horizontal alignment film or a vertical alignment film in a portion corresponding to the separation region of the substrate so that the liquid crystal is not driven by the drive signal,
Horizontal or vertical alignment agent, an alignment agent injection unit, a charging unit for charging the alignment agent, a deflection electrode unit for generating an electric field to deflect the injected charged alignment agent, and deflects the charged alignment agent And a voltage controller for controlling a voltage applied to the deflection electrode section so as to spray the charged alignment agent to the separation region. .

Further, the present invention is characterized in that the liquid crystal is a ferroelectric liquid crystal.

Further, according to the present invention, when the pretilt angle of the ferroelectric liquid crystal is α, the cone angle 2Θ and the apparent tilt angle satisfying the relationship of Θ <α + δ and Θ>θa> Θ / 2. θ
a and an orientation state in which the angle of inclination of the smectic layer is δ.

Further, according to the present invention, while a liquid crystal is sandwiched between a pair of substrates having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, a drive signal is applied to the transparent electrode corresponding to each pixel, thereby In a liquid crystal element that drives liquid crystal and separates the pixels by using a region where the transparent electrode is not present between pixels as a separation region, an auxiliary metal electrode extending from an edge of the transparent electrode to between the pixels is formed. A first alignment film is provided between the auxiliary metal electrode and the pixel, while a second alignment film is provided on a portion of the one transparent electrode where the auxiliary metal electrode is not provided. Is provided, the first alignment film and the second alignment film is one of vertical alignment and horizontal alignment,
It is characterized by different orientations.

Further, according to the present invention, among the auxiliary metal electrodes,
A portion provided on the one transparent electrode has a step higher than that between the transparent electrode and the pixel with respect to the substrate.

Further, in the present invention, the pair of substrates is one substrate having the auxiliary metal electrode and the other substrate having another transparent electrode so as to be opposed to the one transparent electrode. The distance between the auxiliary metal electrode provided on the edge and the another transparent electrode is determined by the distance between the one transparent electrode not provided with the auxiliary metal electrode and the another transparent electrode and the distance between the auxiliary metal electrode and the auxiliary metal. It is characterized in that the distance between the pair of substrates is smaller than the distance between the pixels where no electrode is provided.

Further, according to the present invention, while a liquid crystal is sandwiched between a pair of substrates having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, a driving signal is applied to the transparent electrode corresponding to each pixel. In a method for manufacturing a liquid crystal element, which drives a liquid crystal and separates the pixels by setting a region where the transparent electrode does not exist between pixels as a separation region, when a driving signal is applied to the transparent electrode, the separation region The liquid crystal present in the horizontal alignment film or the vertical alignment film in a portion corresponding to the separation region of the substrate so as not to be driven by the drive signal, a solution ejection unit, an ejection unit moving unit that moves the solution ejection unit, A solution containing a horizontal alignment agent or a vertical alignment agent is injected by an alignment agent injection device having a control unit that controls the injection unit moving unit to move the solution injection unit along the separation region. It is characterized in that in order to form a Rukoto.

Further, according to the present invention, the liquid crystal is sandwiched between a pair of substrates each having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, and a driving signal is applied to the transparent electrode corresponding to each pixel by applying a driving signal. In a method for manufacturing a liquid crystal element, which drives a liquid crystal and separates the pixels by setting a region where the transparent electrode does not exist between pixels as a separation region, when a driving signal is applied to the transparent electrode, the separation region The liquid crystal present in the horizontal alignment film or the vertical alignment film in a portion corresponding to the separation region of the substrate so as not to be driven by the drive signal, an alignment agent emitting unit, a charging unit for charging the alignment agent, and A deflection electrode section for generating an electric field for deflecting the charged alignment agent, and a voltage applied to the deflection electrode section for deflecting the charged alignment agent and dispersing the charged alignment agent to the separation region. It is characterized in that so as to form by spraying a horizontal orientation, or vertical alignment agent at the alignment agent diffusing device having a voltage control unit that Gosuru.

Further, with this configuration, when a drive signal is applied to the transparent electrode corresponding to each pixel, the pixels are separated and the liquid crystal present in the separation region where the transparent electrode does not exist is driven by the drive signal. This prevents the growth of the alignment defect and the breakdown of the memory property in the pixel.

Further, a horizontal or vertical alignment film is formed by injecting a solution containing a horizontal or vertical alignment agent with an alignment agent injection device, thereby performing a horizontal or vertical alignment process on the separation region. To do.

The horizontal or vertical alignment agent charged by the alignment agent spraying device is sprayed on the separation region to form a horizontal alignment film or a vertical alignment film. Perform processing.

[0041]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic plan view of a liquid crystal device according to a first reference example of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

In FIG. 1, reference numerals 1a and 1b denote a pair of opposed substrates, and these substrates 1a and 1b are provided with, for example, a stripe-shaped ITO transparent electrode (hereinafter referred to as a transparent electrode) having a thickness of about 400.degree. 2a and 2b are formed. On the transparent electrodes 2a and 2b, an alignment control film (hereinafter, referred to as an alignment film) 3 formed of a polymer organic film (for example, polyimide, polyamide, PVA resin, etc.) having a thickness of about 10 to 1000 mm.
a, 3b are formed. The alignment films 3a, 3
b: 1% NMP of polyamic acid LQ802 manufactured by Hitachi Chemical
The solution was formed by applying the solution with a spinner and firing at 270 ° C. for 60 minutes.

Further, in this embodiment, the transparent electrode 2
An insulating film such as SiO ₂ having a thickness of about 100 to 2000 °, for example, shown in FIG. 4 to be described later is formed between the insulating films a and 2b. This insulating film is made of PZT-6 (catalyst). And the substrate 1a,
It is formed by printing on 1b, preliminary drying at 80 ° C. for 3 minutes, and then performing main firing at 300 ° C.

The gap (liquid crystal cell gap) between the substrates 1a and 1b is generally kept constant by spacer particles 4 made of silica beads or the like of 0.1 μm to 10 μm. Particle members 5 are dispersedly arranged. The particle member 5 according to the present reference example
Preferably, a particulate resin used to prevent a change in the distance between the upper and lower substrates due to an external stress is used. For example, an epoxy resin or the like is used.

On the other hand, 6 is an epoxy-based adhesive (sealant) for sealing the outer periphery of the substrates 1a and 1b, for example.
The liquid crystal 7 is injected from the injection port 8 and then sealed with an epoxy resin or the like. 9 is an auxiliary metal electrode for alleviating delay,
After the AI electrode is formed by a sputtering method, it is formed by patterning using a photoresist.

Incidentally, in the liquid crystal device having such a configuration, the size of the pixel is 200 μm × 200 μm, the distance between the pixels is 10 μm, and the width of the auxiliary metal electrode is 10 μm. First, a uniaxial alignment control process is performed by a rubbing method so that when the substrates 1a and 1b formed up to the alignment films 3a and 3b are combined vertically, the substrates 1a and 1b are substantially balanced. In this rubbing method, a nylon 66 material having a bristle length of 4 mm was wrapped around a stealth roller having a diameter of 5 cm, and was rotated at 1000 rpm.
The uniaxial alignment control process is performed under the following conditions.

Then, ultraviolet light (hereinafter referred to as UV light) having a light diameter of 10 μmφ is applied to the rubbed substrates 1a and 1b by an ultraviolet irradiation device 10 as shown in FIG. L is scanned while the center between the pixels is the center of the UV light L. Here, by irradiating the UV light L in this manner, the alignment films 3a and 3b in the region corresponding to the region between the pixels on the substrates 1a and 1b and where the auxiliary metal electrode 9 is formed, ie, the separation region.
Is destroyed and a film exhibiting vertical alignment is formed. In this reference example, the scanning of the ultraviolet irradiation device 10 is performed by setting the UV light output to 20 mW / c.
m ² , 8 cm / min.

After treating the alignment films 3a and 3b in this manner, the spacer particles 4 for maintaining the gap and the adhesive particle members 5 are dispersed, the pressure is applied between the substrates 1a and 1b,
A liquid crystal element is formed by sealing the periphery of a and 1b with a sealant 6 and finally injecting a liquid crystal 7 from an injection port 8 and then sealing the injection port 9.

The liquid crystal injected into the device fabricated in this embodiment is a ferroelectric liquid crystal (pyrimidine-based mixed liquid crystal A). The phase transition temperature and physical properties of the ferroelectric liquid crystal are shown below. Pyrimidine-based mixed liquid crystal A -3 ° C 59 ° C 80 ° C 85 ° C Cryst. → SmC * → SmA → Ch → Iso ← ← ← 57 ° 79 ° 85 ° C. Tilt angle Θ = 4 ° (30 ° C.) Tilt angle of layer δ = 11 ° (30 ° C.) Apparent tilt angle θa = 11 ° (30 °) C.) By the way, in such a pyrimidine-based mixed liquid crystal A, the alignment film 3 having a pretilt angle on a pixel of, for example, 7 ° is used.
The drive evaluation and the alignment state of the device having a and 3b were observed, and the drive characteristics were compared with those of the device in which the treatment with the UV light L was omitted from the above-described preparation process.

As a result, the threshold value of the pixel was the same irrespective of the presence or absence of the UV light irradiation processing, but the electric field strength at which the memory property was broken was lower when the UV light irradiation processing was not performed. And the displayable electric field width is 10 to 2
Spread more than 0%.

Further, regarding the switching state,
If the light irradiation treatment is not performed, the element
While the breakdown of the memory property starts from the area surrounded by the ellipse that hits the most convex area in 0 (see FIG. 10), the one subjected to the UV light irradiation processing is surrounded by the ellipse shown in FIG. No memory failure is observed at the boundary between the separated region 50A and the pixel 50, and the memory failure occurs in the pixel 50 where the electric field strength is higher. In the figure, the arrow A indicates the rubbing direction, and 9a,
9b is an insulating film.

As described above, the UV is applied to the separation area 50A.
By irradiating the light L and performing the vertical alignment processing, the liquid crystal 7A present in the separation region 50A is
It can be prevented from being driven by the drive signals applied to the pixels a and 2b, and the growth of alignment defects and breakdown of the memory property in the pixel 50 can be suppressed.

Further, the present invention has been described with reference to the phenomenon of a display element using a ferroelectric liquid crystal having a thin liquid crystal layer. The display quality can be improved even in a liquid crystal element in which a display pixel group and a display pixel group are separated over the entire liquid crystal element including the driving method.

Further, by adopting such a structure, the method of fabricating the element which has been established conventionally is not drastically changed.
In addition, it is possible to improve the driving characteristics and the durability characteristics of the display element while securing the yield achieved by the conventional technology.

Next, a vertical alignment agent or a horizontal alignment agent is sprayed to form a vertical or horizontal alignment film, so that a horizontal alignment process or a vertical alignment process is applied to the separation region. The form will be described.

FIG. 5 shows an alignment agent injection for injecting, for example, an alignment agent for a vertical alignment film (hereinafter referred to as a vertical alignment agent) onto a substrate so as to form the liquid crystal element according to the first embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the apparatus, in which FIG.
Reference numeral denotes an alignment agent injection device, and reference numeral 21 denotes an ultrasonic vibrator which is a solution injection unit which is provided in the alignment agent injection device 20 and injects a solution containing a vertical alignment agent between pixels as separation regions and on auxiliary metal electrodes. In this embodiment, the ultrasonic transducer 2
The solution injected by No. 1 was prepared by mixing a polyamic acid LQl802 manufactured by Hitachi Chemical Co., Ltd., which is an example of a vertical alignment agent, with NMP at a ratio of 1% by weight.
Is dispersed in a solvent having a main component.

Then, the substrates 1a and 1b are separated by injecting a solution onto the substrates 1a and 1b, which are fixed on a stainless steel horizontal stage (not shown) by the ultrasonic vibrator 21 and printed with an alignment film and formed by firing. A vertical alignment film is formed at a portion corresponding to the region.

In the figure, reference numeral 22 denotes a micro-moving device for fixing the ultrasonic vibrator 21 and for moving the ultrasonic vibrator 21 to a predetermined position by rotating horizontally, vertically and rotationally;
Reference numeral denotes an XY stage that moves horizontally and vertically on the substrates 1a and 1b and holds the fine moving device 22, and the fine moving device 22 and the XY stage 23 constitute an emission unit moving unit. Further, reference numeral 24 denotes a nozzle provided on the ultrasonic vibrator 21 for injecting a solution, and reference numeral 25 denotes a solution storage section for storing the solution.

In order to align the positions of the nozzles 24 with the substrates 1a and 1b, alignment marks (not shown) formed by depositing a metal such as aluminum or chromium are formed on the substrates 1a and 1b. The moving device 22 is provided with a laser (not shown) that emits a laser beam to the alignment marker and three detection elements (not shown) that detect reflected light from the alignment mark.

Here, this laser is controlled by a control computer 26 as a control section so as to emit a laser beam to the marker before ejecting the solution, and the detecting element reflects the reflected light from the marker. Is detected, the detection signal is input to the control computer 26. Then, the control computer 26 checks the positions of the substrates 1a and 1b in the horizontal direction, the vertical direction, and the rotation direction according to the detection signal from the detection element, and moves the fine movement device 22 so that the nozzle 24 moves along the separation region.
Is corrected.

The control computer 26 starts the injection after the positioning of the nozzle 24 with respect to the substrates 1a and 1b in this manner, while moving the nozzle 24 by the fine moving device 22 with the fine movement. Scanning is performed along the separation region, and the frequency of the ultrasonic transducer 21 is controlled to control the emission speed from the nozzle 24.

Thus, the solution can be periodically ejected onto the substrates 1a and 1b, and by controlling the emission speed from the nozzle 24, the nozzle position scanning amount and the solution emission cycle can be controlled. Thus, a solution containing an alignment agent can be injected into portions corresponding to the separation regions periodically patterned on the substrates 1a and 1b. After the solution is injected in this way, it is baked to form a vertical alignment film.

Here, for the device thus formed, rubbing conditions such that the pretilt angle of the alignment film in the pixel is, for example, 17 ° are used, and the alignment state of the isolation region of the obtained device is determined by the uniformity of the pixel. When the polarizing plate position was set to cross Nicol at the molecular position in one of the stable states of the alignment state and observed under a polarizing microscope, the darkest state was confirmed even when the polarizing plate was rotated in any direction, and the vertical state was confirmed. It was confirmed that they exhibited orientation.

When the vertical alignment is used, the direction of the PS of the liquid crystal in the liquid crystal layer in the vertical alignment region does not respond to the electric field applied from the upper and lower electrodes. There is no influence on the voltage width.

Further, as a result of driving evaluation of this device, as compared with the case where the orientation of the separation region is uniform orientation,
The breakdown of the memory property is determined by the driving condition in the display pixel,
It is not governed by the orientation of the isolation region and the discontinuous characteristics of the electric field.
A drive voltage width capable of displaying equivalent to that of the first reference example described above was obtained.

In general, a black matrix for the purpose of shielding light is formed under the alignment film between the pixels. However, as in the present embodiment, the uniform alignment of the pixels is achieved by vertically separating the separation regions. When the polarizing plate is set in accordance with, a black state is exhibited, and it can also play a role of light shielding.

Next, instead of injecting the solution containing the vertical aligning agent with a nozzle, the aligning agent is charged and the charged aligning agent is deflected by an electric field and sprayed on the separation region, thereby separating. A second embodiment of the present invention in which a vertical or horizontal alignment film is formed in a region will be described.

FIG. 6 is a configuration diagram of an alignment agent spraying apparatus for spraying, for example, a vertical alignment film on a substrate so as to form the liquid crystal element according to the second embodiment.
Numeral 0 denotes an orienting agent dispersing device, and 41 denotes an ultrasonic vibrator which is a charging unit for charging the alignment agent and an injection unit for injecting a solution containing the charged alignment agent to the substrates 1a and 1b fixed to the stainless steel base. is there. The ultrasonic transducer 41 is provided with the same nozzle as in the first embodiment described above.

On the other hand, reference numerals 42 and 43 denote two pairs of opposed deflecting electrodes which are deflecting electrode portions for generating an electric field for deflecting the charged aligning agent contained in the solution. The voltage control unit 44 changes the magnitude of the voltage to be applied in synchronism with the injection cycle, so that the alignment agent is sprayed on the portion corresponding to the separation region of the substrates 1a and 1b. In the figure,
Reference numeral 45 denotes a particle accelerating electrode for accelerating the solution. The particle accelerating electrode has a slit 4a through which particles pass. Reference numeral 46 denotes an accelerating power supply for applying an accelerating voltage to the particle accelerating electrode, and 47 denotes an aligning agent container.

In this embodiment, since it is difficult to spray the alignment agent over the entire substrate 1a, 1b with only the two pairs of deflection electrodes 42, 43, the ultrasonic vibrator 41 has the above-described first electrode. A laser and a detector similar to those of the first embodiment are provided, so that horizontal and vertical movement and rotation of the nozzle can be performed.

Then, as a result of driving evaluation of the element formed by the device having the above-described configuration, the breakdown of the memory property is determined by the driving conditions in the pixel as compared with the case where the orientation of the isolation region is set to the uniform orientation. As a result, a display voltage range equivalent to that of the above-described reference example was obtained without being governed by the orientation of the separation region and the discontinuous characteristics of the electric field.

Next, a description will be given of a third embodiment of the present invention in which an expanded or foamed solution is ejected by a group of nozzles having a high density instead of a nozzle to form a vertical alignment agent in a separation region. .

FIG. 7 is a diagram showing a configuration of an alignment agent injection device that injects, for example, a vertical alignment agent onto a substrate so as to form a liquid crystal element according to the third embodiment of the present invention. In the figure, 70 is a vertical alignment agent injection device, 71 is provided with a large number of nozzles 72 integrated at a high density, and a heating device 73 as a heating unit for heating or expanding or foaming the solution in these nozzles 72. The solution expanding section is expanded and foamed by the solution ejecting section 71 and injected by a nozzle 72 having a high density to arrange the vertical alignment agent on the alignment film in the separation region. The solution injection unit 71 is provided with the same mechanism for positioning the element substrate and the nozzle 72 as in the first and second embodiments described above. In the same figure, reference numeral 74 denotes an alignment agent storage section.

After positioning between the nozzle 72 and the substrates 1a and 1b in the vertical alignment agent disposing apparatus 70 having such a configuration, injection spraying was performed. The control computer (see FIG. 5) sends a signal indicating which nozzle 72 of the nozzle group is to be heated and applied according to the scanning speed of the solution injection unit 71 and the period between pixels of the substrates 1a and 1b. This was performed by applying a voltage to the heating device 73.

Then, the orientation of the device obtained as a result,
The drive characteristics were equivalent to those of the first embodiment. Even if the nozzles 72 are highly integrated in this manner, the operation frequency of the ejection of each nozzle 72 does not change, so that the time for spraying the nozzles 72 to the same size element substrates 1a and 1b can be reduced.

In the above description, the arrangement of the alignment agent by the nozzle 72 has been described. However, the present invention is not limited to this, and the resist is coated on the alignment film in the separation region before performing the rubbing treatment. Patterning,
Thereafter, a rubbing process may be performed on the substrate including the pixels 50.

As a result, the portion where the rubbing treatment is not performed has a vertical orientation, and the portion where the rubbing treatment is performed has a uniform orientation. Thereafter, by stripping the resist, a vertical alignment film can be obtained in the separation region that has not been rubbed. In the display element according to the second reference example created as described above, the same improvement in drive characteristics as in the other embodiments was confirmed. This method has a high resolution, and is a promising method for an ultra-high-resolution display element, for which a finer display pixel is desired in the future.

In the first, second, and third embodiments described above, the case where a vertical alignment agent is used as an alignment agent has been described. However, the present invention is not limited to this, and the present invention is not limited thereto. An agent can also be used, and even when the horizontal alignment agent is used in this way, the same improvement in driving characteristics as in the first embodiment can be obtained.

Further, as in the first and second reference examples, the first, second, and third embodiments described above, continuous driving of a display element in which alignment defects are reduced and driving characteristics are improved is performed. Then, the presence or absence of a change in the element gap due to the movement of the liquid crystal was evaluated.

As a result, in the liquid crystal devices fabricated in any of the embodiments, the gap change due to the continuous driving was higher than that of the conventional liquid crystal device using the uniform orientation in which the pretilt distribution and the electric field discontinuity were inherent. Was 10% or less, and it was confirmed that the liquid crystal hardly moved when the measurement error was included.

This effect is attributable to the fact that when the separation region is horizontally oriented, the existence of the horizontal orientation acts between the pixels receiving the torque for moving the liquid crystal and acts as a wall, thereby suppressing the liquid crystal movement in the entire device. it is conceivable that.

When the vertical alignment exists, the liquid crystal molecules in the vertical alignment are much easier to move than the liquid crystal molecules in the uniform alignment, and the moving torque generated in the display pixel surrounds the display pixel. It is considered that the function of relaxing the vertical alignment region is that there is no place where the torque is locally concentrated in the entire display element, and as a result, the gap does not change.

[0084]

As described above, according to the present invention, the horizontal alignment process or the vertical alignment process is performed on the separation region so that the liquid crystal in the separation region is not driven within the driving conditions in which the display pixels can be driven. Therefore, it is possible to suppress the growth of the alignment defect and the breakdown of the memory property in the pixel. Then, by suppressing the growth of the alignment defect and the breakdown of the memory property in the pixel in this manner, the alignment generated in the separation region and the alignment and the driving characteristics in the electrically discontinuous portion can be improved. .

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a liquid crystal element according to a first reference example of the present invention.

FIG. 2 is a sectional view taken along line AA of the schematic plan view.

FIG. 3 is a diagram showing a state in which a portion corresponding to a separation region of a substrate of the liquid crystal element is irradiated with ultraviolet rays by an ultraviolet irradiation device.

FIG. 4 is a schematic diagram of the shape and orientation in a pixel region and a separation region of the liquid crystal element.

FIG. 5 is a diagram illustrating a configuration of an alignment agent injection device that injects an alignment agent onto a substrate of a liquid crystal element according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of an alignment agent spraying apparatus for spraying an alignment agent on a substrate of a liquid crystal element according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating a configuration of an alignment agent injection device that injects an alignment agent onto a substrate of a liquid crystal element according to a third embodiment of the present invention.

FIG. 8 is a plan view showing a configuration of a pixel of a conventional liquid crystal element.

FIG. 9 is an XY cross-sectional view of the above plan view.

FIG. 10 is a schematic diagram showing discontinuity in shape and orientation in a pixel region and a separation region of a conventional liquid crystal element.

FIG. 11 is a diagram showing an orientation model of a smectic layer of a ferroelectric liquid crystal used in a conventional liquid crystal element.

FIG. 12 shows each state of Cl orientation of the ferroelectric liquid crystal and C
FIG. 4 is a schematic diagram showing the arrangement of directors at each position between substrates in two orientations.

[Explanation of symbols]

1a, 1b, 30a, 30b Glass substrate 2a, 2b, 2a ', 2b' Transparent electrode 3a, 3b, 3a ', 3b Alignment control film 7, 7A, 7B Liquid crystal layer 9, 9' Auxiliary metal electrode 10 Ultraviolet irradiation device 20 , 70 Alignment Injector 21, 41 Ultrasonic Vibrator 22 Micro Movement Device 23 XY Stage 24, 72 Nozzle 26 Control Computer 40 Alignment Sprayer 42, 43 Deflection Electrode 44 Voltage Controller 50 Pixel 50A Separation Area 71 Solution injection unit 73 Heating device L Ultraviolet

Claims (11)

(57) [Claims] 1. A liquid crystal is sandwiched between a pair of substrates having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, and a drive signal is applied to the transparent electrode corresponding to each pixel to drive the liquid crystal. In addition, in a liquid crystal element that separates the pixels by using a region where the transparent electrode is not present between pixels as a separation region, when a driving signal is applied to the transparent electrode, the liquid crystal present in the separation region is A horizontal alignment film or a vertical alignment film in a portion corresponding to the separation region of the substrate so as not to be driven by the drive signal, a solution containing a horizontal alignment agent or a vertical alignment agent,
An alignment agent injection device having a solution injection unit, an injection unit moving unit that moves the solution injection unit, and a control unit that controls the injection unit movement unit to move the solution injection unit along the separation region. A liquid crystal element characterized by being formed by injection. 2. The liquid crystal device according to claim 1, wherein the solution emitting section has a nozzle, and the horizontal alignment film or the vertical alignment film is formed by a solution injected from the nozzle. 3. The solution injection unit includes a highly integrated nozzle and a heating unit that heats a tip of each of the nozzles to expand or foam the solution in the nozzle. The liquid crystal device according to claim 1, wherein a film is formed by the expanded or foamed solution ejected from the nozzle. 4. A liquid crystal is sandwiched between a pair of substrates having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, and a liquid crystal is driven by applying a drive signal to the transparent electrode corresponding to each pixel. In addition, in a liquid crystal element that separates the pixels by using a region where the transparent electrode is not present between pixels as a separation region, when a driving signal is applied to the transparent electrode, the liquid crystal present in the separation region is A horizontal alignment film or a vertical alignment film at a portion corresponding to the separation region of the substrate so as not to be driven by a drive signal, a horizontal alignment agent or a vertical alignment agent, an alignment agent emitting unit, and a charging unit that charges the alignment agent, A deflecting electrode unit for generating an electric field for deflecting the injected charged alignment agent, and applying the deflecting electrode unit to the deflection electrode unit so as to deflect the charged alignment agent and to spread the charged alignment agent to the separation region. A liquid crystal element, characterized in that formed by spraying at aligning agent spray device having a voltage control unit for controlling the pressure. 5. The liquid crystal device according to claim 1, wherein the liquid crystal is a ferroelectric liquid crystal. 6. The ferroelectric liquid crystal has a cone angle 2 角 and an apparent tilt angle θ satisfying the following relationships when the pretilt angle is α: Θ <α + δ and Θ>θa> Θ / 2.
6. The liquid crystal element according to claim 5, wherein the liquid crystal element has an alignment state of a and the inclination angle δ of the smectic layer. 7. A liquid crystal is sandwiched between a pair of substrates having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, and a drive signal is applied to the transparent electrode corresponding to each pixel to drive the liquid crystal. In addition, in a liquid crystal element that separates the pixels by using a region where the transparent electrode is not present between pixels as a separation region, an auxiliary metal electrode extending from an edge of the transparent electrode to between the pixels is formed, A first alignment film is provided between the auxiliary metal electrode and the pixel, and a second alignment film is provided on a portion of the one transparent electrode where the auxiliary metal electrode is not provided. A liquid crystal device, wherein the first alignment film and the second alignment film have one of a vertical alignment and a horizontal alignment, and have different alignments from each other. 8. A portion of the auxiliary metal electrode provided on the one transparent electrode has a step higher than that between the transparent electrode and the pixel with respect to the substrate. Liquid crystal element. 9. The pair of substrates refer to one substrate having the auxiliary metal electrode and the other substrate having another transparent electrode so as to face the one transparent electrode. The separation distance between the provided auxiliary metal electrode and the another transparent electrode is determined by the separation distance between the one transparent electrode where the auxiliary metal electrode is not provided and the another transparent electrode and the auxiliary metal electrode. 8. The liquid crystal device according to claim 7, wherein the distance between the pair of substrates is smaller than the distance between the pixels not provided. 10. A liquid crystal is sandwiched between a pair of substrates having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, and a drive signal is applied to the transparent electrode corresponding to each pixel to drive the liquid crystal. And a method of manufacturing a liquid crystal element in which a region where the transparent electrode is not present between pixels is used as a separation region to separate the pixels. When a driving signal is applied to the transparent electrode, the pixel is present in the separation region. A horizontal alignment film or a vertical alignment film in a portion corresponding to the separation region of the substrate so that the liquid crystal is not driven by the drive signal, a solution injection unit, an emission unit moving unit that moves the solution emission unit, and the solution injection unit And ejecting a solution containing a horizontal alignment agent or a vertical alignment agent with an alignment agent injection device having a control unit that controls the injection unit moving unit so as to move along the separation region. Method of manufacturing a liquid crystal element, characterized in that the the form Ri. 11. A liquid crystal is sandwiched between a pair of substrates having a transparent electrode and an alignment film subjected to a uniaxial alignment control process, and a liquid crystal is driven by applying a drive signal to the transparent electrode corresponding to each pixel. And a method of manufacturing a liquid crystal element in which a region where the transparent electrode is not present between pixels is used as a separation region to separate the pixels. When a driving signal is applied to the transparent electrode, the pixel is present in the separation region. A horizontal alignment film or a vertical alignment film in a portion corresponding to the separation region of the substrate so that the liquid crystal is not driven by the drive signal, an alignment agent emitting unit, a charging unit for charging the alignment agent, and an injected charged alignment agent A deflection electrode unit for generating an electric field for deflecting the charge, and an electrode for controlling a voltage applied to the deflection electrode unit so as to deflect the charged alignment agent and disperse the charged alignment agent to the separation region. Method of manufacturing a liquid crystal device characterized by by the control unit and the alignment agent spraying device having been so formed by spraying the horizontal alignment agent or vertical orientation agent.