JP2002122870A - Liquid crystal display device, manufacturing method thereof, and liquid crystal dropping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure and control a liquid crystal drop amount by a drop injection method, and to reduce a liquid crystal viscosity by using a liquid crystal material most suitable for the drop injection method. A liquid crystal display device is manufactured easily with good yield by suppressing the response speed, especially the speed of the halftone. SOLUTION: A sealant 21 is applied to a peripheral portion of an image display area provided on one of a pair of substrates (substrate 22) to form a frame pattern, and liquid crystal is dropped into the frame pattern to bond the substrates. By curing the sealant 21, the sealant 21 is applied to the liquid crystal display device such that the start point 31a and the end point 31b of the sealant application are located outside the frame pattern.
Is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal obtained by dropping liquid crystal in a frame pattern formed by forming an ultraviolet-curable resin or an ultraviolet + thermosetting resin on a substrate, bonding the upper and lower substrates, and curing the resin. The present invention relates to a display device and a manufacturing method thereof, and a liquid crystal dropping device for performing the above-described dropping method.

[0002]

2. Description of the Related Art Conventionally, when a liquid crystal display panel is manufactured, a method of injecting liquid crystal into a panel from an injection port provided in a sealed cell has been used in a liquid crystal injection step. In recent years, there is a high demand for a large screen of a liquid crystal display panel, and it is becoming difficult to obtain sufficient display characteristics by this method.

[0003] Therefore, a sealing agent made of an ultraviolet curable resin or a resin cured by (ultraviolet light + heat) is applied to the periphery of the image display area of the cell substrate to form a frame pattern, and liquid crystal is dropped into the frame pattern. Attention has been focused on a drop-injection method in which substrates are bonded together. This dripping and injection method realizes a drastic time reduction and simplification of a paneling process including a liquid crystal injecting step, and enables production of a low-cost and highly reliable liquid crystal display panel. The liquid crystal display panel manufactured using this method has the advantages of an extremely high contrast ratio from the front, excellent visual characteristics, and good black-and-white responsiveness. It is suitable for application.

[0004]

As described above, the liquid crystal injection by the drop injection method has an extremely excellent effect on the manufacturing process and the display characteristics of the product, but has the following problems to be improved. There is a point.

[0005]-Problems relating to sealant-(1): See Fig. 23 In the drop-injection method, since the cell (substrate 101) does not require an injection port, the main seal 102 has a closed frame pattern, but using a dispenser. When a closed frame pattern is formed, the start point and the end point of the seal application overlap, and the seal width at the portion 103 increases. A light shielding film 1 is provided around the display area.
When the seal width is increased, a part of the sealant is shielded from light and poor curing occurs (FIG. 23).
(A)). For this reason, in the prior art, a method is used in which the main seal 102 is sufficiently separated from the light-shielding film so that the sealant is not shielded from light, or the start point and the end point of the seal application are set to a corner portion having a large margin (see JP-A-8-240807). ) Has been proposed (FIG. 23B).

However, if the main seal 102 is formed sufficiently away from the light-shielding film so that the sealant is not shielded from light, the ratio of the outer dimensions to the image display area 104 increases. In addition, if the start point and the end point of the seal application are set at the corners, the sealant is less likely to be applied to the light shielding film than the linear portions. However, this is because the distance between the light-shielding film and the sealant is about 1.4 times as large as the linear portion. If the bulge of the overlapping portion 103 becomes larger than that distance, the light-shielding film is applied to the light-shielding film, which also causes poor curing. Will be.

(2): See FIG. 24 The transfer seal 106 is formed at a position sandwiched between the upper and lower transparent electrodes 107 by mixing conductive particles 108 in a sealant to establish conduction between the upper and lower substrates. Conventionally, as the conductive particles 108, resin particles whose surfaces are coated with low resistance nickel or gold are used.

When resin particles 108 whose surfaces are coated with nickel or gold are mixed into the transfer seal 106, ultraviolet rays are absorbed or reflected, so that the ultraviolet rays hardly reach the inside of the seal. In addition, since the transfer seal 102 is sandwiched between the transparent electrodes 107, ultraviolet rays are attenuated by the transparent electrodes 107. When the light amount for curing the sealant and the light amount for deteriorating the liquid crystal are close to each other, the main seal 102 and the transfer seal 106 are collectively irradiated with ultraviolet rays in consideration of attenuation by the transparent electrode 107.
The liquid crystal adjacent to the main seal 102 without the transparent electrode 107 is deteriorated, and the holding ratio is reduced.

(3): See FIG. 25 In the case where the sealant is an ultraviolet curable resin, the curable resin is cured by (ultraviolet light + heat) in order to improve the curing rate. Heat treatment is performed. In the dropping injection, the process up to irradiation with ultraviolet rays is a single-wafer process, and the heat treatment process that requires time is performed by a batch process. For this reason, the substrates are stored in a transfer cassette 108 and placed in a thermosetting furnace for heat treatment.

The transfer cassette 108 has a substrate 101 at the substrate end so that the transfer arm can take the substrate 101 in and out.
It is the structure which supports. For this reason, in the transfer cassette 108, the substrate 101 cannot be held in parallel.
Substrate 101 is cut off. There is no problem if the sealant is completely cured only by irradiation with ultraviolet light, but in many cases it is completely cured by heat treatment, so the substrate holding force is still weak at the beginning of heat treatment, and displacement occurs due to the influence of bleeding .

(4): See FIG. 26 to FIG. 28 When the ultraviolet curable resin or the curable resin by (ultraviolet light + heat) is cured, a portion other than the resin is covered with the light shielding mask 112.
In general, ultraviolet irradiation is performed from the UV lamp 113 (FIG. 26A). At this time, in order to prevent the liquid crystal from being exposed to ultraviolet rays through the substrate, the alignment is performed so that the resin and the mask edge are substantially flush (FIG. 26B). However, unless the application width of the resin is considerably strictly controlled, the resin has a variation of about ± 0.2 mm. In order to prevent the resin and the light-shielding mask from overlapping with each other, such a dimensional margin is required between the resin end and the mask end. It is necessary to have When the margin region is irradiated with ultraviolet rays, the liquid crystal undergoes photolysis and the voltage holding ratio is reduced. Further, in the case of a diffused light source, the ultraviolet light is also emitted from an oblique direction, so that the ultraviolet light also reaches the inside of the mask edge, and the voltage holding ratio near the mask edge is reduced.

To cope with this problem, Japanese Patent Laid-Open No. 2-30 / 1990
Japanese Unexamined Patent Publication No. 8221 discloses a method in which an ultraviolet ray shielding layer is formed on the surface of a substrate excluding a sealing portion and ultraviolet rays are irradiated.
Japanese Patent Application Publication No. 01395 discloses a method of irradiating ultraviolet rays through a mask having a predetermined pattern and a filter for cutting ultraviolet rays of a specific wavelength or less (FIG. 27).
Japanese Patent Publication No. 700 proposes a method of forming a band-pass filter for cutting ultraviolet rays outside a display area and irradiating the ultraviolet rays.

Since the photolysis of the liquid crystal occurs at a short wavelength of less than about 320 nm, the photolysis of the liquid crystal can be minimized if the resin is cured by irradiating a longer wavelength. However, 300n is required for curing the ultraviolet curable resin.
A wavelength of not less than m and less than 320 nm is also required, and if the resin is cured at a longer wavelength, the reaction rate decreases. When the reaction rate is lowered, uncured components of the resin are eluted into the liquid crystal during the heat treatment and contaminate the liquid crystal.

It is also possible to select an ultraviolet curable resin in which the same polymerization reaction proceeds only at a wavelength at which photolysis of the liquid crystal does not occur, that is, at a long wavelength of 320 nm or more, but the choice of resin material is rather narrow. In consideration of the contamination of the resin material to the liquid crystal, the application stability, and the cured physical properties, the reliability is lower than that of the conventional resin.

The ultraviolet shielding layer disclosed in Japanese Patent Application Laid-Open No. 2-308221 is a filter that almost blocks ultraviolet light in order to prevent photodecomposition of liquid crystal.
The transmittance for wavelengths below nm is kept very low (several%
About 10%). Accordingly, when the sealing portion and the ultraviolet shielding layer overlap, the reaction rate of the resin is reduced in that portion, and the uncured component of the resin is eluted into the liquid crystal during the heat treatment, thereby contaminating the liquid crystal.

The filter disclosed in Japanese Patent Application Laid-Open No. H8-101395 is a filter that cuts ultraviolet rays having a specific wavelength or less that are harmful to the liquid crystal in order to prevent the photolysis of the liquid crystal.
The transmittance at wavelengths of 300 nm or more and less than 320 nm is considerably reduced (FIG. 28). Therefore, when the resin is cured through the filter, the reaction rate of the resin decreases, and the uncured component of the resin elutes into the liquid crystal during the heat treatment, thereby contaminating the liquid crystal.

The bandpass filter disclosed in Japanese Patent Application Laid-Open No. 10-221700 is a filter that cuts short wavelengths harmful to liquid crystals and long wavelengths that are heat sources to prevent photodecomposition of liquid crystals. The transmittance for wavelengths less than 10 nm is kept low (about 10 to 20%). Therefore, when the resin is cured through the filter, the reaction rate of the resin decreases, and the uncured component of the resin elutes into the liquid crystal during the heat treatment, thereby contaminating the liquid crystal.

-Problems relating to control of liquid crystal drop amount-In the drop injection method, when dropping using a dispenser means, the accuracy of the cell thickness of the substrate is determined by the amount of dropped liquid crystal, so that the drop amount is accurately measured. There is a need. However, in the conventional method, no matter how much control is performed, it is inevitable that the liquid remains in the needle of the dispenser means, and it is not clear whether the actual drop amount matches the assumed drop amount. Often they are different. In this case, there is a method in which the amount of liquid crystal is measured by measuring the weight of the liquid crystal dropped on the substrate for each substrate, but it is very difficult to use the liquid crystal panel in recent years when a large screen is required.

-Problems with Liquid Crystal Materials-At present, the display characteristics of liquid crystal display devices are improved,
The cost reduction is also required. As described above, the drop injection method is effective for reducing the cost, and thus the panel forming process can be greatly simplified. However, in the drop-injection method, the method of injecting a liquid crystal material and the method of bonding a pair of substrates are significantly different from the conventional method, so that a strong resistance is required for the liquid crystal material, and a liquid crystal material suitable for the drop-injection method is required. It has been.

In the drop-injection method, since ultraviolet (UV) light is used for curing the sealant, a liquid crystal material having high resistance to UV is required. The liquid crystal material must be resistant to contamination of the seal because the liquid crystal material may come into contact with the insufficiently cured seal.

Incidentally, a liquid crystal material having a negative dielectric anisotropy is used for a vertical alignment type liquid crystal display device. In general,
A liquid crystal material having a negative dielectric anisotropy is limited in a liquid crystal compound constituting the liquid crystal material, and currently widely used materials are roughly classified into three types. By selecting and manufacturing a liquid crystal material that is at least as good as possible from these liquid crystal compounds, the non-defective product rate is increased, display unevenness, image sticking, and the like are suppressed, which contributes to a longer product life.

As one of the causes of various display irregularities and defective products, the electrical characteristics of the liquid crystal panel are strongly related, and it is necessary to increase the voltage holding ratio of the liquid crystal cell, reduce the ion density, and reduce the residual DC voltage. is there. As the liquid crystal material, it is necessary to use a material having high purity and high specific resistance of bulk liquid crystal.

As a result of examining a large number of negative liquid crystals, it was found that some liquid crystals could maintain a high bulk resistivity and some deteriorated, and it was found that they depended on a negative liquid crystal compound. It should be noted that liquid crystal having a negative dielectric anisotropy has only a few material types, and it is not always possible to use only one of the three types. In order to satisfy electro-optical characteristics as a liquid crystal display device, it is necessary to have a liquid crystal physical property value, and it is necessary to use the above three types in combination.

Further, even if the resistance of the liquid crystal can be increased,
If the viscosity of the liquid crystal increases, the response speed of the liquid crystal display device decreases. According to the response theory of liquid crystal,
Since the response speed is considered to be proportional to the viscosity of the liquid crystal,
It has been desired to use a lower viscosity liquid crystal material.

As described above, the drop-injection method is a technique that contributes to the efficient manufacture of liquid crystal display panels and the realization of excellent display characteristics, but has various problems that need to be improved, and a solution is awaited. It is in the present situation.

The present invention has been made in view of the above problems, and has as its object to provide a liquid crystal display device, a method of manufacturing the same, and a liquid crystal dropping device which achieve the following objects.

(1) A liquid crystal display device is easily manufactured with a high yield by using a drop injection method by suppressing display unevenness due to a decrease in the holding ratio, which is likely to be caused by a sealant, and providing a highly reliable liquid crystal display device. To achieve.

(2) It is possible to precisely measure and control the amount of liquid crystal to be dropped by the drop-injection method, to adjust the amount of dropping appropriately for each dropping portion, to make the cell thickness uniform, and to improve the yield and the reliability. A liquid crystal dropping device for dropping and injecting liquid crystal is realized.

(3) By using a liquid crystal material most suitable for the drop-injection method, the liquid crystal viscosity can be reduced, the response speed, especially the halftone speed can be increased, and the display characteristics can be further improved. Implement a display device.

[0030]

Means for Solving the Problems As a result of intensive studies, the present inventors have reached the following aspects of the invention.

In the liquid crystal display device and the method of manufacturing the same according to the present invention, a sealing agent is applied to the periphery of the image display area provided on one of the pair of substrates to form a frame pattern, and liquid crystal is dropped into the frame pattern. Then, the respective substrates are attached to each other, and the sealant is cured so that the sealant is cured so that at least one of a start point and an end point of the sealant application is located outside the frame pattern. It is characterized by being applied. As a result, the starting point and the ending point do not overlap on the frame pattern, so that the seal width on the frame pattern is prevented from increasing and overlapping with the light shielding film.

In this case, it is preferable to apply the sealant such that at least one of the start point and the end point is located on the non-mounting side of the substrate. If the point is formed so as to be located outside the frame pattern, a connecting pattern that is connected to the frame pattern is required. Since the cutting position of the substrate is different between the upper and lower sides on the mounting side, when the point is located on the mounting side, the substrates of the cut portion are bonded to each other by a connecting pattern, and it is difficult to cut. On the non-mounting side, the cutting positions of the substrates are the same at the top and bottom, so that the substrates at the cut portions are not bonded by the connecting pattern, and the substrates can be easily cut.

Further, it is preferable that at least one of the start point and the end point is connected to the frame pattern so as to cross the non-mounting side. By forming the connection pattern diagonally, it is possible to connect the point and the frame pattern without crossing the non-mounting side, but it is difficult to apply the seal in the diagonal direction because of the control of the dispenser means, which is not practical. . If the point and the frame pattern are connected in such a manner as to cross the non-mounting side, the connection pattern can be formed in a straight line, so that the seal application becomes easy.

It is preferable that the start point and the end point are matched on the substrate, and a seal pattern formed by the sealant is formed continuously. If the seal pattern is formed continuously in the manner of a single stroke, the start point and the end point can be eliminated from the frame pattern, and the seal can be easily applied even on a multi-faced substrate.

In the liquid crystal display device and the method of manufacturing the same according to the present invention, a frame pattern is formed by applying a sealant to the periphery of the image display area provided on one of the pair of substrates, and liquid crystal is dropped into the frame pattern. Bonding the respective substrates and curing the sealant to conduct the liquid crystal display device between the pair of substrates by a transfer seal formed by mixing particles coated on the surface with a transparent conductive film. It is characterized by.

Of the transparent conductive films, for example, an ITO film has a higher resistance than nickel or gold which has been conventionally used as a conductive film, but is widely used as a transparent electrode in a liquid crystal display panel. It is not a problem for taking. Ultraviolet rays are partially absorbed and attenuated by the ITO film, but the highest transmittance of the metal film. By mixing this into the transfer seal, the ultraviolet rays can easily reach the inside of the seal, thereby facilitating the curing of the transfer seal. Becomes

In the liquid crystal display device and the method of manufacturing the same according to the present invention, a frame pattern is formed by applying a sealant to the periphery of the image display area provided on one of the pair of substrates, and liquid crystal is dropped into the frame pattern. Then, the respective substrates are bonded together, and the liquid crystal display device is targeted by curing the sealant. In order to make the pair of substrates conductive, an electrode under a transfer seal formed by mixing conductive particles into a resin is applied to the electrodes. And forming a film that reflects ultraviolet rays irradiated to cure the resin.

[0038] This makes it possible to reuse a part of the ultraviolet rays applied to the transfer seal by the reflection film, so that the amount of light for curing the transfer seal can be suppressed to be smaller than before.

In this case, it is preferable to use an aluminum film or a silver film as the film for reflecting the ultraviolet rays and form the film on the substrate on the thin film transistor side. An aluminum film or a silver film reflects ultraviolet light and is a metal film widely used in a TFT process, so that a reflective film can be formed without increasing the number of processes.

In the method for manufacturing a liquid crystal display device according to the present invention, a frame pattern is formed by applying a sealant to a peripheral portion of an image display area provided on one of the pair of substrates, and liquid crystal is dropped into the frame pattern. The liquid crystal display device is intended by bonding the respective substrates and curing the sealant, and in order to conduct between the pair of substrates, the resin is transferred to a transfer seal formed by mixing conductive particles in the resin. For curing, spot irradiation of ultraviolet light composed of parallel light is performed from a vertical direction or an oblique direction of the substrate.

For the spot irradiation, a parallel light having high linearity can be irradiated by using a light guide made of quartz fiber or the like. Since conductive particles that absorb or reflect a part or all of the ultraviolet light are mixed in the transfer seal, the ultraviolet light that reaches the transfer seal is attenuated by the particles. In addition, the transfer seal is sandwiched between transparent electrodes, which also attenuates ultraviolet rays.
By irradiating the transfer seal with spots of ultraviolet light composed of parallel light from the vertical direction or the oblique direction of the substrate, it is possible to additionally irradiate only the transfer seal with ultraviolet light corresponding to the attenuation. In addition, since parallel light can be emitted, deterioration of the liquid crystal due to light wraparound can be minimized.

In the method of manufacturing a liquid crystal display device according to the present invention, a frame pattern is formed by applying a sealant to a peripheral portion of an image display area provided on one of a pair of substrates, and liquid crystal is dropped into the frame pattern. Attaching each of the substrates and curing the sealant, the liquid crystal display device is targeted, and in order to conduct between the pair of substrates, a transfer seal formed by mixing conductive particles into a resin is applied. In order to cure the resin, the substrate is heat-treated while being cured in a state where the substrate is held in parallel by a supporting housing after the resin is cured by irradiating the ultraviolet ray and then irradiating with the ultraviolet ray.

Instead of the conventional transport cassette supporting the substrate at the edge of the substrate, the substrate is held in parallel by a transport cassette having a structure in which the substrate is held in parallel by supporting the substrate at multiple points or a parallel flat plate, and the substrate is thermally cured. The occurrence of displacement during the curing process is suppressed.

In the method of manufacturing a liquid crystal display device according to the present invention, a frame pattern is formed by applying a sealant to a peripheral portion of an image display area provided on one of the pair of substrates, and liquid crystal is dropped into the frame pattern. By bonding the respective substrates and curing the sealant, the liquid crystal display device is targeted, and an alignment film of liquid crystal is formed in a region where an end portion thereof is located inside and outside the periphery of the sealant and inside the outside periphery, Almost 300 nm or more 50
The method is characterized in that the sealant is cured by irradiating light having a wavelength of less than 0 nm.

The photolysis of the liquid crystal occurs at a short wavelength of less than about 320 nm, and the curing of the resin is at least 300 nm.
Since a wavelength of less than 20 nm is required, it is necessary to devise a method of irradiating the resin with the wavelength without irradiating the liquid crystal with the wavelength. However, in reality it is difficult,
Even if the position of each liquid crystal display panel is aligned using a cut filter as a mask, the above-described problem occurs, which is not preferable. In view of this, wavelengths of 300 nm or more and less than 320 nm are attenuated within a range that does not significantly reduce the reaction rate of the resin, and a device is devised to minimize the photolysis of the liquid crystal.

The resin was irradiated with ultraviolet light of a curing amount using edge filters having different transmittances at wavelengths of 300 nm or more and less than 320 nm, and the reaction rate of the resin was measured. As a result, there is a slight difference depending on the resin used,
In the case of the 313 nm emission line peak of a high-pressure mercury lamp, it was found that the reaction rate hardly decreased when the transmittance at that wavelength was about 30%. This is because the curing light amount is an ultraviolet light amount at which the reaction rate of the resin almost reaches saturation, but the curing reaction of the resin rapidly rises at about 30% of the curing light amount, and the reaction rate does not fluctuate greatly thereafter. .

However, when the liquid crystal was irradiated with the same amount of ultraviolet rays using this filter, the photolysis of the liquid crystal was still large, and a display defect occurred due to a decrease in the holding ratio. Accordingly, the liquid crystal was irradiated with the same amount of ultraviolet rays by cutting long wavelengths of 500 nm or more, which hardly affect the curing of the resin. As a result, the photodecomposition of the liquid crystal was reduced, and the display failure due to the decrease in the holding ratio did not occur. This is because photodecomposition of liquid crystal does not occur with a long wavelength of 500 nm or more alone, but when combined with a wavelength of 300 nm or more and less than 320 nm, a long wavelength of 500 nm or more becomes a heat source and photodecomposition of liquid crystal is promoted. It is.

The edge of the alignment film is formed in a region inside and outside the resin and inside the outer periphery of the resin. The alignment film has a function of adsorbing uncured components of the resin and suppressing diffusion into the liquid crystal. In addition, when the edge of the alignment film is formed flush with the inner periphery of the resin, a gap is generated between the alignment film end and the resin due to misalignment, and the edge of the alignment film is positioned outside the outer periphery of the resin. This is because, when formed, the resin and the substrate are bonded via an alignment film having low moisture resistance, and thus the bonding strength is significantly reduced under high temperature and high humidity. In addition, since the alignment film attenuates the wavelength of the 313 nm emission line peak by about 15%, it can be used as a filter for alleviating photolysis of liquid crystal. Accordingly, the wavelength transmittance of the filter used as the irradiation light source can be increased, and thus, the resin on the outer side of the alignment film can be more firmly cured.

Therefore, by combining the above methods, the photodecomposition of the liquid crystal can be minimized without significantly lowering the reaction rate of the resin, so that a display defect due to a decrease in the retention rate does not occur.

In this case, at least an end of the alignment film on the substrate on which the color filter is formed is formed in a region inside and outside the periphery of the sealant and inside the outside periphery. To cure the sealant.

The color filter functions as a mask for the image display area. If the edge of the alignment film on the substrate is formed in the region and light is irradiated from the substrate side, it is not necessary to mask the region other than the resin region.

In addition, at least the transparent electrode and the alignment film on the substrate on which the color filter is formed are formed such that each end is located in a region inside and outside the periphery of the sealant and inside the outside periphery. It is preferable that the sealing agent is cured by irradiating light of the wavelength from the side.

The transparent electrode film attenuates the wavelength of the 313 nm emission line peak by about 35%, and when used in combination with an alignment film, attenuates the wavelength by about 45%, so that it is used as a filter for alleviating the photolysis of liquid crystal. As a result, the wavelength transmittance of the filter used for the irradiation light source can be further increased, so that the transparent electrode and the resin on the outer edge of the alignment film can be hardened more firmly.

Further, as a means for irradiating light having a wavelength of approximately 300 nm or more and less than 500 nm, it is preferable to arrange a filter for substantially cutting light other than the wavelength on the irradiation light source side.

In the above-mentioned known example, a filter for cutting off ultraviolet rays having a specific wavelength or less harmful to the liquid crystal is arranged between the mask and the liquid crystal display panel. When the filter of the present invention is arranged in such an arrangement, the long wavelength cut filter becomes 500
Heat is absorbed by absorbing long wavelengths of nm or more, and the liquid crystal display panel is also heated. When a wavelength of 300 nm or more and less than 320 nm is irradiated while the liquid crystal display panel is heated, the photolysis reaction of the liquid crystal is promoted as described above.
Therefore, by disposing the long wavelength cut filter on the irradiation light source side, heat transfer to the liquid crystal display panel is prevented. In addition, the short-wavelength cut filter often absorbs light not only on the short-wavelength side but also on the long-wavelength side, and is arranged on the irradiation light source side to suppress the transfer of heat to the liquid crystal display panel.

Further, it is preferable that the curing light amount of the sealant is about 3000 mJ / cm ² or less based on I-line.

The curing light amount of the resin is set based on the integrated light amount in a wavelength band (about 350 nm ± 30 nm) near the 365 nm bright line (I line) peak where the irradiation intensity of the high-pressure mercury lamp becomes maximum. If the intensity of the I-line peak is 100,
The peak of the 313 nm emission line is about 60 for the high-pressure mercury lamp and about 30 for the metal halide lamp. However, the intensity of the high-pressure mercury lamp is strong only at the emission line peak, whereas the intensity of the metal halide lamp is broad near the emission line peak.
There is no significant difference between the two lamps at the integrated light amount at a wavelength of 0 nm or more and less than 320 nm.

The liquid crystal was irradiated with light having a wavelength of about 300 nm or more and less than 500 nm, and the amount of ultraviolet light that activates the photolysis of the liquid crystal was determined from the decrease in the retention. The transmittance of the cut filter used was 50% at the peak of the 313 nm emission line,
The peak at the 365 nm emission line is 90%. As a result, although there is a slight difference depending on the liquid crystal, the integrated light amount in the wavelength band (about 310 nm ± 20 nm) near the 313 nm emission line peak is 10%.
It was about 00 mJ / cm ² . However, in this case, it is difficult to compare with the curing light amount of the resin, so that it is about 3000 mJ / cm ² when converted into an I-line reference ultraviolet light amount. In the present invention, the wavelength of 300 nm or more and less than 320 nm can be attenuated by about 15% by the alignment film. However, the guaranteed value of the illuminance variation when a large substrate is irradiated with ultraviolet light is usually about ± 15%, Curing light amount is 3 based on I-line
At 000 mJ / cm ² or more, the maximum value of the variation exceeds this value, and the liquid crystal is irradiated with ultraviolet rays, so that the photodecomposition of the liquid crystal is activated and the retention is reduced. To activate the reaction, a certain amount of energy or more is required, and the reaction proceeds at an accelerated rate when energy exceeding the amount is given. Does not progress as far as difference.

The liquid crystal dropping device of the present invention includes dispenser means for discharging a predetermined amount of liquid crystal, and measuring means for measuring the amount of liquid crystal discharged by the dispenser means, wherein the measuring means has an optical sensor, It is characterized in that a signal fluctuation of the optical sensor generated when the liquid crystal discharged from the dispenser means passes through the optical sensor is integrated, and a discharge amount of the liquid crystal is measured.

The amount of liquid crystal discharged from the dispenser means is
Since the self-control of the dispenser means alone lacks accuracy, the measuring means is provided, and the amount (volume) of the liquid crystal discharged from the dispenser means is measured by scanning an optical sensor. In this case, the output of the optical sensor measures the width of the discharged liquid crystal droplets. If measured continuously, the time change of the discharged amount is measured, and if the measurement result is integrated, a value corresponding to the total discharged amount is obtained. can get. This value and the actual ejection amount are measured and compared to determine a correlation in advance, and the actual ejection amount can be estimated in real time based on the correlation. This makes it possible to accurately control the total discharge amount dropped onto a desired portion, and to make the cell thickness uniform even when a large-screen liquid crystal panel is manufactured.

In this case, as a specific example of the measuring means, a laser beam is scanned in a direction substantially perpendicular to the liquid crystal to be discharged,
It is preferable that the output of the laser beam fluctuates when the discharged liquid crystal traverses the laser beam, and the output of the laser beam is detected by the optical sensor to measure the discharge amount of the liquid crystal. In this way, by using a laser as the irradiation light source, the discharge amount of the liquid crystal can be measured more quickly and accurately.

It is preferable to measure the discharge amount of the liquid crystal from at least two directions, or to measure the discharge amount from two directions substantially orthogonal to each other, since it is possible to ensure the accuracy of the discharge amount measurement.

Further, it is preferable that the optical sensor is installed at a position within 2 cm from the liquid crystal discharge port of the dispenser means.

An optical sensor was provided at the liquid crystal discharge port of the needle of the dispenser means, and when the amount of liquid crystal actually dropped was measured, the liquid drop was continuously dropped to about 2 cm from the liquid crystal discharge port, and about 1 cm. It turned out to be most suitable. This is because if the discharge distance becomes longer than about 2 cm due to the pressure difference between the inside and the outside of the needle or the generation of bubbles, the liquid crystal that has been continuously discharged first becomes discontinuous, and the measurement accuracy decreases.

The liquid crystal dropping device of the present invention recognizes a dispenser means for discharging a predetermined amount of liquid crystal, and the shape of the liquid crystal droplet discharged by the dispenser means, and estimates the actual discharge amount of the liquid crystal from the shape. And a measuring means.

The amount of liquid crystal discharged from the dispenser means is
Since the accuracy is not sufficient only by the self-control of the dispenser means, the measuring means is provided, the shape of the liquid crystal droplet discharged from the dispenser means is recognized, and the actual discharge amount of the liquid crystal is estimated from the shape. In this case, the correlation between the liquid crystal droplet shape and the amount (volume) thereof is obtained in advance, and the actual ejection amount is estimated based on the knowledge. Thereby, it is possible to accurately control the total discharge amount dropped to a desired portion,
Even when a large-screen liquid crystal panel is manufactured, the cell thickness can be made uniform.

In this case, as a specific example of the measuring means, it is assumed that the shape of the liquid crystal droplet is optically recognized, and the actual discharge amount of the liquid crystal is estimated from an image of the shape.

Also, an optical sensor is provided near the liquid crystal discharge port of the dispenser means, and a signal of the optical sensor generated when the discharged liquid crystal passes through the optical sensor is used as a trigger signal to generate an image of a liquid crystal droplet shape. It is also preferable to estimate the actual liquid crystal discharge amount from the following equation.

Further, the dispenser means discharges the liquid crystal by moving a piston in a syringe, and controls the discharge amount according to the stroke amount of the piston. It is also preferable that the stroke amount is automatically changed.

Thus, the estimated value of the discharge amount from the dispenser means measured by the measuring means is fed back to the dispenser means, and accurate control of the discharge amount of the liquid crystal becomes possible.

The liquid crystal dropping device of the present invention has a plurality of thin tubes, discharge means for discharging a predetermined amount of liquid crystal from each of the thin tubes, and a tray corresponding to each of the thin tubes of the discharge means.
Measuring means for measuring the weight of the liquid crystal droplets received by each of the trays, and supplying the liquid crystal droplets whose weight is measured by the measuring means and the discharge amount is specified, from each of the trays. Features.

Since the amount of liquid crystal discharged from the discharge means is not accurate only by the self-control of the discharge means, the measuring means is provided, and the droplet discharged from each capillary is received by a plate, and the weight of the droplet is measured. After the measurement, a droplet is supplied from the pan. At this time, the amount of the liquid crystal remaining in the pan is measured in advance, and the supply amount is controlled based on this knowledge. This makes it possible to accurately control the total discharge amount dropped onto a desired portion, and to make the cell thickness uniform even when a large-screen liquid crystal panel is manufactured.

In this case, it is preferable that a water-repellent treatment for repelling the liquid crystal is applied to a portion of the measuring means which comes into contact with the liquid crystal. Thereby, the remaining of the liquid crystal is prevented as much as possible, and the liquid crystal amount can be supplied more accurately.

According to the liquid crystal display device and the method of manufacturing the same of the present invention, at least one of the substrates has a pair of transparent substrates, and a frame pattern is formed around the image display area by applying a sealant. A liquid crystal compound represented by the following general formula is intended for a vertical alignment type liquid crystal display device in which a liquid crystal having a negative dielectric anisotropy is dropped and the substrates are bonded together and the sealing agent is cured. And a liquid crystal material whose terminal alkyl group has a carbon number m of 2 or more.

[0075]

Embedded image

When a liquid crystal material containing a liquid crystal compound of the above general formula having a negative dielectric anisotropy and having an even number of carbon atoms m in the terminal alkyl group is used, the specific resistance of the bulk liquid crystal can be kept high. It is. A liquid crystal containing a neutral component having no polar group and containing an even-numbered m in the above general formula has an initial ratio higher than that of a liquid crystal containing a similar component and an odd-numbered m-number. Resistance, specific resistance after standing at high temperature, and specific resistance after exposure to ultraviolet (UV) light, m
Better results are obtained with an even number of liquid crystals.

Further, among the liquid crystal compounds of the above general formula, m
It is desirable to use only those having a number of 2,4. In general, when the terminal alkyl chain of the liquid crystal compound becomes longer, the liquid crystal viscosity becomes larger, which is an undesirable direction for a liquid crystal display device. The liquid crystal compound of the above general formula also has a function of maintaining the nematic phase by widening the temperature range of the mixed liquid crystal to a low temperature side. In this case, it is preferable to include two or more kinds of compounds having different m numbers. Therefore, it is preferable to use a compound having an m number of 2, 4 in order to suppress an increase in liquid crystal viscosity.

In the liquid crystal display device and the method of manufacturing the same according to the present invention, at least one of the substrates has a pair of transparent substrates, and a frame pattern is formed around the image display area by applying a sealant. A liquid crystal having a negative dielectric anisotropy is dropped, and the substrates are attached to each other, and the sealant is cured. The liquid crystal material is a neutral liquid crystal material having no polarity. The liquid crystal containing the neutral liquid crystal compound has a high volatility in which the weight ratio decreases by 1% or more when left in a vacuum when the liquid crystal is dropped, and rotates in comparison with the non-volatile neutral liquid crystal compound. It is characterized in that the viscosity is lower by 15% or more.

By introducing a low-viscosity material, the viscosity of the liquid crystal can be reduced by 15% or more from the state before the introduction, and the volatility of the liquid crystal at this time is 1% by weight.
% Decrease (volatilization). Thus, the response speed of the liquid crystal display device can be improved by reducing the viscosity of the liquid crystal material.

In this case, the liquid crystal material has a transparent point of 70 ° C. or more and a dielectric anisotropy Δε of −4.0 ≦
Δε <0, and the refractive index anisotropy Δn is 0.100
It is preferable to set it to 0 or more. By satisfying these conditions, display characteristics such as luminance (transmittance) and response speed and mass productivity can be improved.

Further, it is preferable that these liquid crystal display devices have a multi-domain structure in which the liquid crystal molecules fall in two or more directions. As a result, the viewing angle characteristics can be improved, which is convenient for application to a liquid crystal monitor or the like.

[0082]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments to which the present invention is applied will be described below in detail with reference to the drawings.

-General Structure of Liquid Crystal Display Device- FIG. 1 is a schematic sectional view showing a general main structure of a liquid crystal display device. This liquid crystal display device includes a pair of transparent glass substrates 1 and 2 facing each other at a predetermined interval, and a liquid crystal layer 3 sandwiched between the transparent glass substrates 1 and 2.

On one transparent glass substrate 1, an insulating layer 4
A plurality of pixel electrodes 15 are formed via a transparent glass substrate, and a transparent alignment film 6 a is formed so as to cover the pixel electrodes 5. On the other transparent glass substrate 2, a color filter 7, a common electrode 8 and an alignment film are formed. 6b are sequentially stacked. Then, the alignment films 6a and 6b are abutted to sandwich the liquid crystal layer 3, the glass substrates 1 and 2 are fixed, and polarizers 9 and 10 are provided outside the substrates 1 and 2. The pixel electrode 5 is formed together with the active matrix. In the illustrated example, the data bus line 11 of the active matrix is shown.
Note that the electrode may be provided only on one substrate (for example, in the case of the IPS mode).

Here, in forming the liquid crystal layer 3 using the drop-injection method, various embodiments will be described below in which various improvements are made to the structure, the manufacturing process, and the liquid crystal dropping apparatus used in the manufacturing. It is disclosed as.

As a method of manufacturing a liquid crystal display device commonly used in each of the embodiments, a UV curable resin or a (UV + heat) curable resin is used as a material for a main seal, and a TFT is used.
(Thin Film Transistor) Glass substrate A serving as a substrate, CF
(Color filter) Prepare a glass substrate B as a substrate,
For example, a frame pattern of a main seal is formed in an image display area of a glass substrate B by a dispenser, and liquid crystal is dropped into the frame pattern by a drop-injection method. Then, the substrates A and B are bonded to each other to cure the main seal. Thereafter, the bonded substrates A and B are cut out into a state of a TFT substrate + CF substrate, and a liquid crystal display device is completed through various post-processes.

(First Embodiment) FIG. 2 is a schematic plan view showing a state of a glass substrate on which a frame pattern is formed before a liquid crystal injection step is performed by a drop injection method in the present embodiment. In this example, the main seal 21 is made of an ultraviolet resin (for example, product name 30Y-363, manufactured by ThreeBond).
By using a dispenser, a connection pattern and a frame pattern are formed around the display area 23 on the glass substrate 22 side serving as a CF substrate. Start point 31a and end point 3 of overlapping portion 31
1b is provided at the non-mounting side and outside the frame pattern, and the joining patterns are formed so as to be adjacent to each other after bonding.

The main seal 21 has a seal width of 1 m.
m, the radius of the corner is 1 so that the line width is equivalent to that of the straight line.
mm. The frame pattern is formed such that the gap between the inner periphery thereof and the light shielding film 23 after bonding is 0.5 mm.

Next, a required amount of liquid crystal is dropped into the frame pattern by a liquid crystal dropping method, and the glass substrate 22 and the TF are placed in a vacuum.
A glass substrate serving as a T substrate is attached, and liquid crystal is injected by opening to the atmosphere.

After collectively irradiating ultraviolet rays from the glass substrate 22 side, seal hardening is performed by heat treatment, and this is cut into predetermined dimensions to obtain a liquid crystal display panel. In addition, regarding the cutting of the substrate, the glass substrate 22 serving as the CF substrate is cut along the cutting line 32.
A glass substrate serving as a TFT substrate is executed along the cutting line 33.

Here, for comparison with the liquid crystal display device of this example, a liquid crystal display device shown in FIG. 23 is manufactured as a comparative example.

In Comparative Example 1, a frame pattern is formed by the main seal 102 as shown in FIG. The start point and the end point are provided at positions on the frame pattern, and the frame pattern is connected at the start point and the end point (the overlapping portion 103 is formed). Otherwise, a liquid crystal display panel is obtained in the same manner as in this example.

In Comparative Example 2, a frame pattern is formed on the main seal 102 as shown in FIG. The start point and the end point are formed at positions on the frame pattern and the corners, and the frame pattern is connected at the start point and the end point (the overlapping portion 103 is formed). The corners are not formed in an arc shape. Otherwise, a liquid crystal display panel is obtained in the same manner as in this example.

In this example, since the start point 31a and the end point 31b are outside the frame pattern, no overlap between the start point 31a and the end point 31b is formed on the frame pattern, and the main seal 21 of the frame pattern connecting portion overlaps the light shielding film 23. No. On the other hand, in Comparative Examples 1 and 2, since the overlapping portion 103 of the start point and the end point is formed on the frame pattern, the main seal 102 of the frame pattern connecting portion overlaps the light shielding film 105. Comparative Example 1,
The seal width of the frame pattern connection part of No. 2 is 2.6 mm, and the seal width when the main seal 102 is applied twice is 2.0 m.
m. This is because the dispenser moves up and down at the start point and the end point, so that the seal application amount is larger than that of the linear portion. In the connection part of the frame pattern of Comparative Example 1, the main seal 102 protrudes 0.8 mm toward the inner periphery and the gap between the inner periphery and the light shielding film 105 is 0.5 mm. In the frame pattern connecting portion of Conventional Example 2, the protrusion amount is the same as 0.8 mm, but the gap between the inner periphery and the light shielding film 105 is expanded by 1.4 times, so that the overlap between the main seal 102 and the light shielding film 105 is small. , 0.
1 mm. If the gap between the inner periphery and the light-shielding film is further widened, the overlap between the main seal 102 and the light-shielding film 105 can be eliminated.

Further, even if the start point and the end point are formed apart from each other on the frame pattern, the overlap between the main seal and the light-shielding can be eliminated. It is not appropriate because strength cannot be maintained.

The liquid crystal display panels of this example and Comparative Examples 1 and 2 were subjected to a lighting test. As a result, no display unevenness occurred in this example, but in Comparative Examples 1 and 2, display unevenness occurred due to poor curing of the main seal 102 at the frame pattern connection portion.

As described above, according to the first embodiment, display unevenness due to a decrease in holding force, which is likely to be caused by a sealant, is suppressed, and a liquid crystal display can be easily formed with a good yield by using a drop injection method. By manufacturing the device, a highly reliable liquid crystal display device can be realized.

-Modifications- Here, various modifications of the first embodiment will be described.

(Modification 1) In Modification 1, a two-chamfered seal pattern and a main seal as shown in FIG. 3 are formed around the image display area on the glass substrate 22 side serving as a CF substrate by a main seal 41 using a dispenser. FIG.
The four chamfered seal patterns shown in FIG.

In the case of the two chamfers shown in FIG.
3b are connected on the substrate 22 to form a seal pattern continuously as one overlapping portion 43 so that the main seal 41 does not cross at the frame pattern connecting portion. On the other hand, in the four chamfering of FIG. 4, the start point 44a and the end point 44b are
The seal pattern is continuously formed as one overlapping portion 44 by being connected above, so that the main seal 42 intersects at the frame pattern connecting portion. Otherwise, a liquid crystal display panel is obtained in the same manner as in the first embodiment.

In the case of the two chamfers shown in FIG.
Since 3b is outside the frame pattern and the main seal 41 does not intersect at the frame pattern connection portion, the main seal 41 at the frame pattern connection portion does not overlap the light shielding film 23. In the case of the four chamfers shown in FIG. 4, the main seal 42 intersects at the frame pattern connecting portion, and the seal width becomes as large as 2.0 mm.
The main seal 42 of the frame pattern connecting portion does not overlap with the light shielding film 23 because the overlapping portion 44 is thinner than the overlapping portion 44 between the a and the end point 44b and the connecting portion is a corner portion.

Each of the liquid crystal display panels manufactured using the two chamfers shown in FIG. 3 and the four chamfers shown in FIG. 4 was subjected to a lighting test. As a result, display unevenness did not occur in both cases.

(Modification 2) The main steps of Modification 2 are shown in FIG. Here, (a) is a schematic plan view of the substrate 22a, (b)
Is a schematic sectional view near the transfer seal of the substrate 22a, and (c) is a schematic sectional view showing the transfer seal in an enlarged manner.

Here, an ITO film is formed on the surface of a resin spacer (for example, Micropearl SP manufactured by Sekisui Fine Chemical Co., Ltd.) by vapor deposition to obtain conductive particles 45. The transfer seal 24 is made of the ultraviolet curable resin used in the first embodiment, and is mixed with conductive particles 45 at 1 wt%. When the attenuation rate of the ultraviolet light by the conductive particles 45 and the transparent electrode 46 was measured, the transfer seal 24 was measured.
The amount of light irradiated to the main seal 21 is 1
It was found to be 0% less.

A reflection film 47 serving as an electrode is formed at the position where the transfer seal 24 is formed on the TFT substrate side using an aluminum film. The formation of the aluminum film is performed simultaneously with the film formation process of the TFT. The ultraviolet irradiation was performed by irradiating the substrate seal 22 with a light amount for curing the main seal 21 with ultraviolet light, and then irradiating the transfer seal 24 with spot light from a vertical direction of the substrate using a light guide 48 in the vertical direction of the substrate. The light amount of the spot irradiation is almost equal to the amount of ultraviolet light attenuation by the conductive particles 45 and the transparent electrode 46 (Modification 2
A) and 2/3 of this attenuation (Modification 2B). Otherwise, a liquid crystal display panel is obtained in the same manner as in the first embodiment.

Here, for comparison with the liquid crystal display device of this embodiment, a liquid crystal display device shown in FIG. 24 is manufactured as a comparative example. In this comparative example, 1 wt% is mixed into the transfer seal 106 using conductive particles (for example, Micropearl NI manufactured by Sekisui Fine Chemical Co., Ltd.) in which the surface of the resin spacer is coated with nickel. Otherwise, a liquid crystal display panel is obtained in the same manner as in Comparative Example 1 of the first embodiment.

The liquid crystal display panels according to Modifications 2A and 2B and Comparative Example were subjected to lighting tests. As a result, in the modified examples 2A and 2B, no display unevenness occurred, but in the comparative example, display unevenness due to poor curing occurred in the frame pattern connecting portion (the overlapping portion 103) and the transfer seal 106. In the modified example 2B, the amount of light applied to the transfer seal 24 is insufficient, but the ultraviolet light is reflected by the reflective film 47 to compensate for the insufficient amount, so that display unevenness due to poor curing does not occur.

If there is some margin between the amount of light that degrades the liquid crystal and the amount of light that cures the sealant with ultraviolet light, a reflective film can be formed under the transfer seal 24 without irradiating the transfer seal 24 with a spot. It is also possible to harden the transfer seal 24 by slightly increasing the amount of light.

(Modification 3) In Modification 3, as shown in FIG. 6, after the substrates 22a and 22b are bonded to each other by curing of the sealing material to form the substrate 51, the transfer of the structure supporting the substrate 51 at multiple points is performed. The heat treatment after the irradiation of the ultraviolet rays is performed by using the substrate transfer cassette 52 provided with the spacer 53 for arm access.

On the other hand, as a comparative example, a heat treatment after ultraviolet irradiation is performed using a conventional substrate transfer cassette 108 having a structure for supporting the substrate 110 at the substrate end as shown in FIG.

Otherwise, both the modified example 3 and the comparative example are the first.
A liquid crystal display panel is obtained in the same manner as in the embodiment.

Each of the liquid crystal display panels according to Modification Example 3 and Comparative Example was subjected to a lighting test. As a result, no displacement occurred during the heat treatment in Modification Example 3, but a displacement occurred in Comparative Example. In the third modified example, the substrate 51 can be held in parallel because the surface of the substrate 51 is supported at multiple points. Deviation occurs.

(Second Embodiment) FIG. 7 shows that a liquid crystal injection step is performed by a drop injection method in this embodiment.
FIG. 8 is a schematic perspective view showing a state when irradiating ultraviolet rays.
FIG. 4 is a schematic cross-sectional view showing a state of a glass substrate by enlarging a circle C in FIG.

In this example, an ultraviolet-curing resin (trade name: 30Y-363 / manufactured by Three Bond Co./curing light amount: 2500 mJ / cm ^{2 based on} I-line) was used for the main seal. A glass substrate 61 serving as a substrate and a glass substrate 62 serving as a TFT substrate are attached to each other and cut out to manufacture a liquid crystal display panel. This embodiment is to improve an ultraviolet irradiation step performed when bonding the glass substrates 61 and 62.

The end of the alignment film 63 on the glass substrate 61 was formed in a region inside and outside of the resin and inside of the outside.

For comparison, as shown in FIG. 9, an alignment film 63 on a glass substrate 61 serving as a CF substrate is a conventional example.
An edge is formed inside the inner periphery of the resin, and a liquid crystal display panel provided with a light shielding mask 64 is also manufactured.

For the ultraviolet irradiation, a high-pressure mercury lamp is used as a light source. As shown in FIG. 7, a cut filter 64 that does not substantially transmit a short wavelength of less than 300 nm and a cut filter 65 that does not substantially transmit a long wavelength of 500 nm or more are provided on the irradiation light source side. Place and do.

As shown in FIG. 10, when both filters are combined, the transmittance at the 313 nm bright line peak is 50%, and the transmittance is 36%.
The peak at the 5-nm emission line is 90%. The amount of ultraviolet light was 2700 mJ / cm ^{2 on the} basis of the I-ray. However, when the variation of the irradiation area was examined, the minimum value of the variation was 230 mJ / cm ^2.
0 mJ / cm ^2, was 3100mJ / cm ² at the maximum value portion.

When the transmittance of each of the glass substrate and the glass substrate to which the alignment film was added was measured, the glass substrate (trade name: NA35 / manufactured by NH Techno Glass Co., Ltd./0.7 mm thick) had an emission line peak of 313 nm, and the alignment film was 84%. (Product name JA
(LS-684 / manufactured by JSR Corporation / film thickness 80 nm) was 71%, and it was found that the wavelength was attenuated by about 15% by the alignment film.

The liquid crystal (trade name: MJ96213 / Merck) is irradiated with ultraviolet light using the long and short wavelength cut filters 64 and 65, and the threshold value of the amount of ultraviolet light at which the photolysis of the liquid crystal is activated is maintained. It was determined from the drop. As a result, FIG.
As shown in FIG. 1, when ultraviolet light was irradiated through the glass substrate, the wavelength band near the 313 nm bright line peak (310 ± 20
1000 mJ / cm ² about an accumulated light quantity of nm), retention decreased at 3000 mJ / cm ² about the I line reference is increased, was small retention decreases at this below. Similarly, using only the short-wavelength cut filter 64, the threshold value of the amount of ultraviolet light at which the photolysis of the liquid crystal is activated is determined from the decrease in the holding ratio.
It was found to be about 0 mJ / cm ^2, which is less than half that of the long and short wavelength cut filters. This is 500nm
The liquid crystal is heated by irradiating the above long wavelength,
This is because the photolysis reaction of the liquid crystal with a wavelength of 300 nm or more and less than 320 nm is promoted. Therefore, it was found that the photolysis of the liquid crystal was activated because the amount of ultraviolet light transmitted through the alignment film exceeded this value in any part of the irradiation area.

In this example, the long and short wavelength cut filters 6 are used.
4, 65 is applied to cure the main seal. On the other hand,
In the conventional example, only the short-wavelength cut filter is applied (conventional example 1), and the long / short wavelength cut filter is applied (conventional example 2).
Then, a mask other than the resin is masked with a light shielding mask to cure the main seal. When the liquid crystal display panel manufactured in this manner was subjected to a lighting display test, display unevenness due to a decrease in the holding ratio in the entire circumference near the main seal in Conventional Example 1 corresponded to the maximum value portion of the irradiation area in Conventional Example 2. In the vicinity of the main seal, display unevenness occurred due to a decrease in the holding ratio. This is considered to be due to the photolysis of the liquid crystal by irradiation with ultraviolet rays.

In the conventional examples 1 and 2, the retention decreased at some corners. The corners are provided with an R (arc) so that the seal width does not increase when applying the seal, so that the distance between the display area and the resin is shorter than the peripheral area. In the conventional example, since an alignment film is provided inside the inner periphery of the resin, even if a small amount of uncured component remains in the resin, the uncured component is diffused into the liquid crystal by the heat treatment and reaches the very end of the display area. As a result, it is considered that the retention decreased in some corners.

On the other hand, in the present example, there was no display unevenness caused by the decrease in the holding ratio which occurred in Conventional Examples 1 and 2. This is because the filter and the alignment film suppressed the photodecomposition of the liquid crystal, and the alignment film suppressed the elution of the uncured component of the resin.

As described above, according to the second embodiment, display unevenness due to a decrease in the holding ratio, which is likely to be caused by the sealant, is suppressed, and the liquid crystal display is easily performed with a good yield by using the drop injection method. By manufacturing the device, a highly reliable liquid crystal display device can be realized.

-Modification- Here, a modification of the second embodiment will be described.

In this modification, the edge of the transparent electrode and the edge of the alignment film on the glass substrate 61 are formed in a region inside and outside of the resin and inside and outside of the resin, and the liquid crystal display is formed in the same manner as in the second embodiment. Make a panel. The irradiation condition of the ultraviolet rays is the same as that of the second embodiment except that the amount of the ultraviolet rays is 3200 mJ / cm ^{2 on the} basis of the I-ray. When the variation of the irradiation area was examined, the minimum value of the variation was 2700 m.
J / cm ² , and the maximum value was 3700 mJ / cm ² .

When the transmittance of the glass substrate to which the transparent electrode and the alignment film were added was measured, 84% of the glass substrate had a 313 nm bright line peak, and the transparent electrode (ITO / film thickness 13
00A) and the orientation film was 46%, and it was found that the wavelength was attenuated by about 45% by the transparent electrode and the orientation film.

Therefore, even at the maximum value portion of the irradiation area, the amount of ultraviolet light passing through the transparent electrode and the alignment film is attenuated by the transparent electrode and the alignment film, and thus does not exceed the above threshold value. Turned out not to be.

When the liquid crystal display panel manufactured as described above was subjected to a lighting display test, no display unevenness due to a decrease in the holding ratio occurred in the conventional example. In addition, since the amount of ultraviolet light applied to the transparent electrode and the resin on the outer side of the alignment abdomen is increased, the amount of curing light is applied even at the minimum value of the variation. Strength improved by 10%.

Comparative Examples 1 and 2 A liquid crystal display panel is manufactured in the same manner as in the second embodiment. The irradiation conditions of the ultraviolet light are the same as those in the second embodiment. However, as shown in FIG. 12, a high-pressure mercury lamp is used as the irradiation light source of the ultraviolet light, and the cut filter 65 that does not substantially transmit a short wavelength of less than 320 nm is attached to the glass substrate 61. Place on the side.

Using the short-wavelength cut filter 65,
The threshold of the amount of ultraviolet light that activates the photolysis of the liquid crystal is maintained.
It was 3000 mJ /
cm ^TwoIrradiation may not activate liquid crystal photolysis
Do you get it. Therefore, the inner and outer periphery of the resin and the inner and outer periphery
In the region to be formed, 300 like the transparent electrode film or the alignment film of this example is used.
A filter that attenuates wavelengths between nm and 320 nm
It turns out that photolysis of liquid crystal is not activated even without
Was.

When the thus manufactured liquid crystal display panel (Comparative Example 1) was subjected to a lighting display test, display unevenness due to a decrease in the holding ratio occurred in all stations near the main seal. When this panel was disassembled and the liquid crystal near the main seal was analyzed by gas chromatography, a resin component derived from the main seal was detected.

Further, a UV-curable resin was prepared using a photoinitiator having an absorption band on the long wavelength side of 320 nm or more as in the known example, and this was used as a main seal for the same comparison. When the thus prepared liquid crystal display panel (Comparative Example 2) was subjected to a lighting display test, display unevenness occurred due to a decrease in retention in a part near the main seal. When this panel was disassembled and the liquid crystal near the main seal was analyzed by gas chromatography, a resin component derived from the main seal was detected to a lesser extent than in Comparative Example 1.

This is because when the resin is cured on the long wavelength side of 320 nm or more, the reaction rate of the resin is reduced by the amount of energy that is insufficient compared with the case where the wavelength of 300 nm or more and less than 320 nm is used. This shows that even if the absorption band of the photoinitiator is shifted to the longer wavelength side of 320 nm or more, only the energy absorption efficiency is improved, but the reaction rate of the resin is not the same.

(Third Embodiment) FIG. 13 is a schematic configuration diagram of a liquid crystal dropping device of the present embodiment. This liquid crystal dropping device includes a dispenser 71 that discharges a predetermined amount of liquid crystal, and a measuring unit 72 that measures the amount of liquid crystal discharged by the dispenser.

[0136] The dispenser 71 discharges a predetermined amount of liquid crystal from a needle-shaped discharge portion and drops the liquid crystal into a frame pattern formed on a glass substrate.

The measuring means 72 includes a laser device 73 as an irradiation light source, an optical sensor 74 for sensing the laser beam emitted from the laser device 73, and a data logger 75 for recording the output of the optical sensor 74 with respect to time. And a computer 76 for analyzing and displaying the result of recording by the data logger 75.

In this liquid crystal dropping device, the dispenser 71
The laser device 73 irradiates a laser beam to the liquid crystal discharged from the liquid crystal, and records a result of detecting the laser beam crossing the liquid crystal to be dropped by the optical sensor 74 with a data logger 75. At this time, the data logger 75 records a time-dependent output fluctuation as shown in FIG. 14, for example. The output of the liquid crystal is measured by integrating the output with the computer 76 over time. The computer 76 estimates the weight based on the correlation between the output of the optical sensor 74 and the weight of the liquid crystal that has been created in advance.

In the illustrated example, only one optical sensor is shown. However, two optical sensors are provided, and the discharge amount of the liquid crystal is measured from two directions substantially orthogonal to each other.
Further, it is also preferable to provide an optical sensor to perform measurement from multiple angles.

Further, the dispenser 71 discharges liquid crystal by moving a piston in a syringe, and controls the discharge amount by the stroke amount of the piston. The stroke amount of the piston is determined based on the result of image processing. It is also suitable to be configured to change automatically.

The positional relationship between the dispenser 71 and the optical sensor 74 is most preferably about 1 cm, as shown in FIG. 15, since the liquid drops continuously drop down to about 2 cm from the liquid crystal discharge port. I understood that. This is because if the discharge distance becomes longer than about 2 cm due to the pressure difference between the inside and the outside of the needle or the generation of bubbles, the liquid crystal that has been continuously discharged first becomes discontinuous, and the measurement accuracy decreases.

The discharge amount was actually measured using this liquid crystal dropping apparatus. At this time, the number of scans is 100, 0 per second.
The liquid crystal to be dropped is set to 00 times, and the total amount of the liquid crystal to be dropped is 250 mg. The dispenser 71 was set to discharge this amount.

After the dropping, the total dropping amount was estimated to be 245 mg from the output of the optical sensor 74 48 times. Therefore, 5 mg was added using a micro syringe. When the variation of the cell thickness of the liquid crystal display panel manufactured as described above was measured, the variation was within about 1%. In this example, the number of times of scanning the ejected liquid crystal can be made extremely large, so that a dispenser having a function of repeating ejection in a short time can sufficiently cope with it.

As described above, according to the liquid crystal dropping device of the third embodiment, it is possible to precisely measure and control the amount of liquid crystal dropped by the drop injection method, and to appropriately control the amount of drop for each dropping portion. By adjusting the cell thickness, the cell thickness can be made uniform, and highly reliable dropping of liquid crystal can be performed with good yield.

-Modifications- Here, various modifications of the third embodiment will be described.

(Modification 1) In Modification 1, FIG.
As shown in (1), the measuring means 77 is configured to measure the discharge amount from the shape of the liquid crystal dropped from the dispenser 71 into the frame pattern of the glass substrate.

The measuring means 77 is provided with a CCD 78 for picking up an image of the dropped liquid crystal and an output of the CCD 78, as shown in FIG.
As shown in (b), the area of the hatched portion of the liquid crystal 79 is calculated, and the area and the weight (volume) of the liquid crystal which have been created in advance
And a computer 76 for estimating the weight based on the correlation with

In the illustrated example, only one CCD is shown. However, in order to further improve measurement accuracy, a plurality of CCDs are required.
D may be provided to capture the liquid crystal shape from different directions.

(Modification 2) In Modification 2, FIG.
As shown in (1), the measuring means 81 is configured to measure the discharge amount from the shape of liquid droplets of the liquid crystal discharged from the dispenser 71 in the air.

The measuring means 81 includes a laser device 73 as an irradiation light source, an optical sensor 74 for sensing the laser beam emitted from the laser device 73, and a timing at which the optical sensor 74 recognizes the passage of the liquid crystal by the laser beam. Then, the CCD 78 for imaging the dropped liquid crystal in the air, and the CCD 7
As shown in FIG. 17B, the area of the hatched portion of the liquid crystal 79 is calculated from the output of FIG. 8, and based on the previously created correlation between the area and the weight (volume) of the liquid crystal, the weight is calculated. And a computer 76 for estimating.

In this case, since the shape of the liquid crystal can be reliably grasped in the air by the CCD 78, high-precision measurement can be performed without being affected by the surface shape of the glass substrate. Although only one CCD is shown in the illustrated example,
In order to further improve the measurement accuracy, it is preferable to provide a plurality of CCDs so as to capture the liquid crystal shape from different directions.

(Modification 3) The liquid crystal dropping device of Modification 3 is as follows.
As shown in FIG. 18A, a measuring dropping jig 83 which has a plurality of thin glass tubes 82 and discharges a predetermined amount of liquid crystal from each of the thin tubes 82, and each of the measuring dropping jigs 83 It has a receiving tray 84 corresponding to the thin tube 82, and a measuring means 85 for measuring the weight of the liquid crystal droplet received by the receiving tray 84, respectively.
The liquid crystal droplets whose weight is measured and whose discharge amount is specified by the above-described method are supplied dropwise into the frame pattern of the glass substrate by rotating each tray 84.

As shown in FIG. 18B, each thin tube 82 is coated with a highly water-repellent Teflon (registered trademark) on the inner surface in contact with the liquid crystal, and the liquid crystal is extruded by the pressing of the inert gas. It is configured to discharge. When the liquid crystal is dropped on the glass substrate, the liquid crystal often remains in each of the thin tubes 82, and it is preferable to use an inert gas to promote the discharge, and to coat the inner surface of each of the thin tubes 82 with Teflon. Thus, more effective ejection can be performed.

(Fourth Embodiment) In the present embodiment, a liquid crystal material suitable for the liquid crystal dropping method will be disclosed. The liquid crystal material of this example contains a liquid crystal compound represented by the following general formula, and the number of carbon atoms m of the terminal alkyl group is an even number of 2 or more.

[0155]

Embedded image

When a liquid crystal material containing a liquid crystal compound of the above general formula having a negative dielectric anisotropy and having a terminal alkyl group having an even number of carbon atoms m is used, the specific resistance of the bulk liquid crystal can be kept high. It becomes possible.

In the present example, a liquid crystal a containing a neutral component having no polarity as a common base, and a liquid crystal a containing an odd-numbered m in the general formula, and a liquid crystal a containing an even-numbered m in the general formula Was prepared, and the specific resistance of the bulk liquid crystal was compared between the two liquid crystal materials under the following conditions.

In all of the initial specific resistance, the specific resistance after standing at high temperature, and the specific resistance after exposure to ultraviolet (UV) light, a ′ (m:
(Even number) gave better results. In particular, UV
After exposure, the resistivity value can be kept high by about an order of magnitude, which is very advantageous during curing of the UV seal in the dropping process. FIG. 19 shows these relationships. Here, a liquid crystal A (n = 1,
In 3), a liquid crystal B and a liquid crystal C were used as the liquid crystal a '.

Further, among the liquid crystal compounds of the above general formula, m
It is desirable to use only those having a number of 2,4. In general, when the end of the liquid crystal compound becomes longer, the viscosity of the liquid crystal increases, and the response speed decreases, so that the direction is not preferable for the liquid crystal display device. The liquid crystal compound of the above general formula also has an effect of maintaining the nematic phase by widening the temperature range of the mixed liquid crystal to a low temperature side. In this case, the compound preferably has the m number of 2 or more. Therefore, in order to suppress an increase in the viscosity of the liquid crystal, it is desirable to use a compound having the m number of 2,4.

It is also necessary to lower the viscosity of the liquid crystal material and improve the response speed of the liquid crystal display. In the drop-injection method, a vacuum standing state (including an evacuation time) when bonding is extremely short. Evacuation time, which conventionally required several hours, can be reduced to several minutes. In the past, liquid crystal volatilized in a vacuum, so it was necessary to adjust the liquid crystal with a liquid crystal compound whose volatility was suppressed.However, in the drop injection method, even a material having volatility could be used for mass production. became.

When a low-viscosity material for lowering the viscosity of the liquid crystal is introduced, the viscosity of the liquid crystal can be reduced by 15% or more as compared with that before the introduction (FIG. 21: liquid crystal E → liquid crystal D). It was found that the volatility of the liquid crystal at that time showed a decrease (volatilization) of 1% or more in weight ratio.

When the TV characteristics were measured, no significant difference was observed between before and after the introduction of the low-viscosity material. On the other hand, with regard to the response characteristics, it was confirmed that it was possible to increase the speed including the halftone, and it was effective.

Also, from the relationship with the specifications of the liquid crystal display device,
The clearing point of the liquid crystal material is 70 ° C. or higher, and the dielectric anisotropy Δε
Is set to −4.0 ≦ ０ε <0, and the refractive index anisotropy △ n is 0.1.
When a liquid crystal material of 000 or more is used, the luminance (transmittance)
-It is good in that display characteristics such as response speed and mass productivity are improved.

Further, in this liquid crystal display device, if the liquid crystal molecules have a multi-domain structure in which the direction in which the liquid crystal molecules fall is two or more, the viewing angle characteristics are excellent, which is convenient for a liquid crystal monitor or the like.

-Experimental Example- Hereinafter, an experimental example in which the liquid crystal display device according to the fourth embodiment is manufactured and various display characteristics are examined will be described.

(Experimental Example 1) Using a substrate having an ITO electrode, JALS-684 (manufactured by JSR Corporation) was formed as an alignment film by a spinner, and predetermined spacers (cell thickness: 4.0 μm) were sprayed. Using a thermosetting sealing material, a blank cell was produced.

With respect to these empty cells, the m number = 1,
3 and liquid crystals B and C where m = 2,4
Was injected into each empty cell, sealed, and a polarizing plate was attached with crossed Nicols to produce a VA cell.

As shown in FIG. 20, the voltage holding ratio, the ion density, and the residual DC voltage were measured for each cell, and the difference in the electrical characteristics was examined. Liquid crystal A, liquid crystal B,
The liquid crystal C has physical properties shown in Table 1 below. (A) and (b) show the voltage holding ratio, (c) shows the ion density, and (d) shows the residual DC voltage. As a result of the experiment, liquid crystals B and C (m number = 2, 2) were better than liquid crystal A (m number = 1, 3)
In 4), the electrical characteristics were improved, and dependence on the accumulated components was confirmed.

[0169]

[Table 1]

(Experimental Example 2) The specific resistances of the liquid crystals A, B and C were measured. Initial value of bulk liquid crystal, after UV exposure (100
mW / cm ² , 60 seconds) and after heating (120 ° C., 60
Min) and after dripping of the UV-curable resin (contamination dependency), four conditions were examined. Liquid crystal B, C (m = 2, 4)
Shows that under all conditions, a result higher than that of the liquid crystal A (m number = 1, 3) was obtained. In particular, the data after UV exposure showed that there was a significant improvement effect that the specific resistance value was one digit higher. It could be confirmed.

(Experimental Example 3) The difference between the liquid crystal D before the introduction of the low-viscosity material and the liquid crystal E after the introduction was examined.
The introduced liquid crystal D is a liquid crystal having no problem even if the conventional vacuum dip injection is used. On the other hand, the liquid crystal E has volatility when left in vacuum because a low-viscosity material is introduced.

As a result of the experiment, as shown in FIG. 21, the liquid crystal E showed a little more than 1% weight change (decrease) when left for 1 hour.
It was confirmed that the liquid crystal D had sufficiently higher volatility.

A VA cell was manufactured in the same procedure as in the third embodiment except that the spacers were changed (cell thickness: 3.5 μm) using liquid crystals D and E. The TV characteristics are equivalent. As shown in FIG. 22, as a result of examining the response speed, the liquid crystal E with the introduction of the low-viscosity material is faster than the liquid crystal D without the introduction for all the applied voltages, and especially the intermediate liquid crystal corresponding to the low gradation side. It was confirmed that the effect of increasing the speed was great in the tone control region.

As described above, according to the fourth embodiment, it is possible to provide a liquid crystal material most suitable for the drop injection method, whereby the viscosity of the liquid crystal can be suppressed to a small value, and the response speed, particularly, the intermediate speed A liquid crystal display device that achieves high-speed key adjustment and further improves display characteristics is realized.

Hereinafter, various aspects of the present invention will be collectively described as supplementary notes.

(Supplementary Note 1) A sealant is applied to the periphery of the image display area provided on one of the pair of substrates to form a frame pattern, and liquid crystal is dropped into the frame pattern to bond the substrates. A method of manufacturing a liquid crystal display device by curing the sealant, wherein the sealant is applied so that at least one of a start point and an end point of the sealant application is located outside the frame pattern. A method for manufacturing a liquid crystal display device characterized by the above-mentioned.

(Supplementary Note 2) The liquid crystal display device according to Supplementary Note 1, wherein the sealant is applied so that at least one of the start point and the end point is located on a non-mounting side of the substrate. Production method.

(Supplementary note 3) The method of manufacturing a liquid crystal display device according to supplementary note 2, wherein at least one of the start point and the end point is connected to the frame pattern so as to cross the non-mounting side.

(Supplementary Note 4) The method for manufacturing a liquid crystal display device according to Supplementary Note 1, wherein the start point and the end point are made coincident with each other on the substrate, and a seal pattern using the sealant is continuously formed.

(Supplementary Note 5) A sealant is applied to the periphery of the image display area provided on one of the pair of substrates to form a frame pattern, and liquid crystal is dropped into the frame pattern to bond the substrates. A method of manufacturing a liquid crystal display device by curing the sealing agent, wherein the resin is cured into a transfer seal formed by mixing conductive particles into a resin in order to conduct between the pair of substrates. And a method of irradiating spots of ultraviolet light composed of parallel light from a vertical direction or an oblique direction of the substrate.

(Supplementary Note 6) A sealant is applied to the periphery of the image display area provided on one of the pair of substrates to form a frame pattern, and liquid crystal is dropped into the frame pattern to bond the substrates. A method for manufacturing a liquid crystal display device by curing the sealing agent, wherein a transfer seal formed by mixing conductive particles in a resin is applied to make the pair of substrates conductive, and the resin is cured. Liquid crystal display device, wherein after the substrate is cured by ultraviolet irradiation, and after the ultraviolet irradiation, the substrate is heat-treated while holding the substrate in parallel by a support housing. Manufacturing method.

(Supplementary Note 7) A frame pattern is formed by applying a sealant around the image display area provided on one of the pair of substrates, and liquid crystal is dropped into the frame pattern to bond the substrates. A liquid crystal display device obtained by curing the sealant, wherein the pair of substrates are electrically connected by a transfer seal formed by mixing particles having a surface coated with a transparent conductive film. apparatus.

(Supplementary Note 8) A frame pattern is formed by applying a sealant around the image display area provided on one of the pair of substrates, and liquid crystal is dropped into the frame pattern to bond the substrates. A liquid crystal display device obtained by curing the sealant, wherein conductive particles are mixed into a resin, and irradiation is performed as an electrode under a transfer seal for conducting between the pair of substrates to cure the resin. A liquid crystal display device, wherein a film that reflects ultraviolet light is formed.

(Supplementary note 9) The method for producing a liquid crystal display device according to supplementary note 8, wherein an aluminum film or a silver film is used as the film for reflecting ultraviolet light, and the film is formed on the substrate on the thin film transistor side.

(Supplementary Note 10) A sealant is applied to the periphery of the image display area provided on one of the pair of substrates to form a frame pattern, and liquid crystal is dropped into the frame pattern to bond the substrates. A method of manufacturing a liquid crystal display device by curing the sealant, wherein an alignment film of liquid crystal is formed in a region where an end thereof is located inside and outside the periphery of the sealant and inside and outside the periphery of the sealant, and is approximately 300 nm or more. A method for manufacturing a liquid crystal display device, comprising irradiating light having a wavelength of less than 500 nm to cure the sealant.

(Supplementary Note 11) At least an end of the alignment film on the substrate on which the color filter is formed is formed in a region inside and outside the periphery of the sealant and inside the outside periphery.
The method for manufacturing a liquid crystal display device according to claim 10, wherein the sealing agent is cured by irradiating the light having the wavelength from the substrate side.

(Supplementary Note 12) Almost 300 nm or more and 500
12. The method for manufacturing a liquid crystal display device according to appendix 10 or 11, wherein a filter that substantially cuts light other than the wavelength is disposed on the irradiation light source side as means for irradiating light having a wavelength of less than nm.

(Supplementary Note 13) The curing light amount of the sealant was
Almost 3000 mJ / cm based on I-line ^TwoTo do
13. The liquid crystal according to any one of supplementary notes 10 to 12, wherein
A method for manufacturing a display device.

(Supplementary Note 14) Dispenser means for discharging a predetermined amount of liquid crystal, and measuring means for measuring the amount of liquid crystal discharged by the dispenser means, the measuring means comprising:
A liquid crystal dropping device comprising an optical sensor, wherein a signal fluctuation of the optical sensor generated when the liquid crystal discharged from the dispenser means passes through the optical sensor is integrated to measure a discharge amount of the liquid crystal.

(Supplementary Note 15) The measuring means scans the laser light in a direction substantially perpendicular to the liquid crystal to be ejected, and the ejected liquid crystal traverses the laser light so that the output of the laser light is changed and detected by the optical sensor. 15. The liquid crystal dropping device according to supplementary note 14, wherein the liquid crystal discharge amount is measured.

(Supplementary Note 16) The liquid crystal dropping device according to Supplementary note 14 or 15, wherein the measuring means measures a discharge amount of the liquid crystal from at least two directions.

(Supplementary Note 17) The liquid crystal dropping device according to Supplementary Note 16, wherein the measuring means measures the discharge amount of the liquid crystal from two directions substantially orthogonal to each other.

(Supplementary note 18) The optical sensor according to any one of Supplementary notes 14 to 17, wherein the optical sensor is installed at a position within 2 cm from the liquid crystal discharge port of the dispenser means.
Item 6. A liquid crystal dropping device according to item 1.

(Supplementary Note 19) Dispenser means for discharging a predetermined amount of liquid crystal, and liquid crystal measuring means for recognizing the shape of the liquid crystal discharged by the dispenser means and estimating the actual discharge amount of the liquid crystal based on this. And a liquid crystal dropping device.

(Supplementary note 20) The liquid crystal according to supplementary note 19, wherein the measuring unit optically recognizes the liquid droplet shape of the liquid crystal and estimates an actual discharge amount of the liquid crystal from an image of the shape. Dropping device.

(Supplementary Note 21) An optical sensor is provided near the liquid crystal discharge port of the dispenser means, and a signal of the optical sensor generated when the discharged liquid crystal passes through the optical sensor is used as a trigger signal to form a liquid crystal droplet. 21. The liquid crystal dropping device according to supplementary note 20, wherein the actual discharge amount of the liquid crystal is estimated from the image of (1).

(Supplementary Note 22) The dispenser means includes:
The liquid crystal is discharged by moving a piston in a syringe, and the control of the discharge amount is adjusted by the stroke amount of the piston, and the stroke amount of the piston is automatically changed based on the result of image processing. The liquid crystal dropping device according to any one of supplementary notes 19 to 21, which is characterized by the following.

(Supplementary Note 23) A discharge means for discharging a predetermined amount of liquid crystal from each of the thin tubes, and a receiving tray corresponding to each of the thin tubes of the discharging means. Measuring means for measuring the weight of each liquid crystal droplet, and supplying liquid crystal droplets whose weight has been measured by the measuring means and whose discharge amount has been specified, from each of the trays. .

(Supplementary note 24) The liquid crystal dropping apparatus according to supplementary note 23, wherein a water-repellent process for repelling the liquid crystal is applied to a portion of the measuring means that comes into contact with the liquid crystal.

(Supplementary Note 25) A pair of substrates, at least one of which is transparent, has a frame pattern formed by applying a sealant around the image display area, and the frame pattern has a negative dielectric anisotropy. A liquid crystal display device of a vertical alignment type in which the liquid crystal is dropped and the respective substrates are adhered to each other, and the sealing agent is cured. The liquid crystal display device includes a liquid crystal compound represented by the following general formula, and has a terminal alkyl group. A liquid crystal display device using a liquid crystal material having an even number of carbon atoms m of 2 or more.

Embedded image

(Supplementary Note 26) The liquid crystal display device according to Supplementary Note 25, wherein the liquid crystal compound has a terminal alkyl group having 2 or 4 carbon atoms m.

(Supplementary Note 27) A pair of substrates, at least one of which is transparent, has a frame pattern formed by applying a sealant around the image display area, and the frame pattern has a negative dielectric anisotropy. A liquid crystal display device of a vertical alignment type obtained by dropping liquid crystal and bonding the substrates and curing the sealant, wherein the liquid crystal material includes a neutral liquid crystal compound having no polarity, and the neutral liquid crystal compound Is highly volatile, whose weight ratio is reduced by 1% or more under vacuum when dropped, and has a rotational viscosity of 15% or more lower than that of a non-volatile neutral liquid crystal compound. A liquid crystal display device characterized by the above-mentioned.

(Supplementary Note 28) The liquid crystal material has a clearing point of 70 ° C. or higher and a dielectric anisotropy Δε of −4.
0 ≦ Δε <0, and the refractive index anisotropy Δn is 0.1
28. The liquid crystal display device according to supplementary note 27, wherein the liquid crystal display device has a size of 000 or more.

[0204]

According to the present invention, it is possible to suppress the display unevenness due to the decrease in the holding ratio, which is likely to be caused by the sealant, to easily manufacture the liquid crystal display device with a high yield by using the drop injection method, and to improve the reliability. It is possible to realize a liquid crystal display device with high performance.

Further, it is possible to precisely measure and control the amount of the liquid crystal dropped by the drop injection method, to adjust the amount of dropping at each dropping portion appropriately to make the cell thickness uniform, and to obtain a liquid crystal with high yield and high reliability. It is possible to realize a liquid crystal dropping apparatus for dropping and injecting liquid crystal.

Further, by using a liquid crystal material most suitable for the drop injection method, the liquid crystal display device is capable of suppressing the liquid crystal viscosity, increasing the response speed, particularly the halftone, and further improving the display characteristics. The device can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a general main configuration of a liquid crystal display device.

FIG. 2 is a schematic plan view illustrating a state of a glass substrate on which a frame pattern is formed before a liquid crystal injection step is performed by a drop injection method in the first embodiment.

FIG. 3 is a schematic plan view showing a main configuration (two chamfers) of Modification Example 1 of the first embodiment.

FIG. 4 is a schematic plan view showing a main configuration (four chamfers) of Modification Example 1 of the first embodiment.

FIG. 5 is a schematic view showing main steps of a modified example 2 of the first embodiment.

FIG. 6 is a schematic perspective view showing a substrate transport cassette of Modification 3 of the first embodiment.

FIG. 7 is a schematic perspective view showing a state when irradiating ultraviolet rays after performing a liquid crystal injection step by a drop injection method in the second embodiment.

FIG. 8 is a schematic sectional view showing a state of a glass substrate by enlarging a circle C in FIG. 7;

FIG. 9 is a schematic sectional view showing a comparative example of the second embodiment.

FIG. 10 is a characteristic diagram showing wavelength dependence of transmittance.

FIG. 11 is a characteristic diagram showing a photolysis reaction of a liquid crystal.

FIG. 12 is a schematic sectional view showing Comparative Examples 1 and 2 of the second embodiment.

FIG. 13 is a schematic configuration diagram of a liquid crystal dropping device according to a third embodiment.

FIG. 14 is a characteristic diagram showing a time-dependent output fluctuation of the optical sensor.

FIG. 15 is a schematic configuration diagram showing a positional relationship between a dispenser and an optical sensor.

FIG. 16 is a schematic configuration diagram showing Modification Example 1 of the liquid crystal dropping device of the third embodiment.

FIG. 17 is a schematic configuration diagram showing Modified Example 2 of the liquid crystal dropping device according to the third embodiment.

FIG. 18 is a schematic configuration diagram illustrating a third modification of the liquid crystal dropping device according to the third embodiment.

FIG. 19 is a characteristic diagram showing an initial specific resistance of a liquid crystal material, a specific resistance after being left at a high temperature, and a specific resistance after exposure to ultraviolet light (UV) in the fourth embodiment.

FIG. 20 is a characteristic diagram showing the results of measuring the voltage holding ratio, ion density, and residual DC voltage of each cell in Experimental Example 1.

FIG. 21 is a characteristic diagram showing a result of examining a difference in volatility between a liquid crystal before introducing a low-viscosity material and a liquid crystal after introducing the material in Experimental Example 3.

FIG. 22 is a characteristic diagram showing a result of examining a difference in speeding-up between a liquid crystal before introducing a low-viscosity material and a liquid crystal after introduction in Experimental Example 3.

FIG. 23 is a schematic view for explaining a problem with a conventional sealant.

FIG. 24 is a schematic view for explaining a problem with a conventional sealant.

FIG. 25 is a schematic view for explaining a problem with a conventional sealant.

FIG. 26 is a schematic view for explaining a problem with a conventional sealant.

FIG. 27 is a schematic view for explaining a problem with a conventional sealant.

FIG. 28 is a characteristic diagram for explaining a problem with a conventional sealant.

[Explanation of symbols]

 1, 2, 22 Glass substrate 21, 41, 42 Main seal 23 Light shielding film 24 Transfer seal 31, 44 Overlapping part 31a Start point 31b End point 45 Conductive particles 46 Transparent electrode 47 Reflective film 52 Substrate transport cassette 64 Short wavelength less than 300 nm Cut filter 65 Long wavelength cut filter of 500 nm or less 71 Dispenser 72, 77, 85 Measuring means 73 Laser device 74 Optical sensor 75 Data logger 76 Computer 78 CCD 82 Thin glass tube 83 Weighing jig 84 Receiving tray

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Hideaki Tsuda, Inventor 4-1-1, Kamidadanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Kimiaki Nakamura 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa No. 1 Fujitsu Limited F term (reference) 2H089 LA03 LA07 LA41 NA22 NA35 NA44 NA45 PA04 TA02 TA09 TA13 2H092 GA36 GA39 HA04 JA24 NA01 NA29 PA04 PA09 4H027 BD03 BD08 CM05

Claims (11)

[Claims] 1. A frame pattern is formed by applying a sealant to a peripheral portion of an image display area provided on one of a pair of substrates, a liquid crystal is dropped in the frame pattern, and the substrates are bonded to each other. A method of manufacturing a liquid crystal display device by curing a sealant, wherein the sealant is applied such that at least one of a start point and an end point of the sealant application is located outside the frame pattern. Of manufacturing a liquid crystal display device. 2. A frame pattern is formed by applying a sealant to a peripheral portion of an image display area provided on one of a pair of substrates, a liquid crystal is dropped in the frame pattern, and the substrates are bonded to each other. A method for manufacturing a liquid crystal display device by curing a sealant, comprising: a transfer seal formed by mixing conductive particles in a resin; a transfer seal formed by mixing conductive particles in the resin; A method of manufacturing a liquid crystal display device, comprising irradiating spots of ultraviolet light composed of light from a vertical direction or an oblique direction of a substrate. 3. A frame pattern is formed by applying a sealant to a peripheral portion of an image display area provided on one of the pair of substrates to form a frame pattern, and liquid crystal is dropped into the frame pattern, and the substrates are bonded to each other. A method for manufacturing a liquid crystal display device by curing a sealant, in order to conduct between the pair of substrates, applying a transfer seal formed by mixing conductive particles in a resin, and curing the resin Manufacturing the liquid crystal display device, wherein the substrates are cured by irradiation with ultraviolet light to bond the substrates together, and after the irradiation with the ultraviolet light, the substrates are heat-treated while the substrates are held in parallel by a support housing. Method. 4. A frame pattern is formed by applying a sealant around an image display area provided on one of the pair of substrates, and a liquid crystal is dropped into the frame pattern to bond the respective substrates together. What is claimed is: 1. A liquid crystal display device obtained by curing a sealant, wherein said pair of substrates are electrically connected by a transfer seal formed by mixing particles having a surface coated with a transparent conductive film. 5. A frame pattern formed by applying a sealant around a periphery of an image display area provided on one of the pair of substrates, and liquid crystal is dropped into the frame pattern to bond the respective substrates together. A liquid crystal display device obtained by curing a sealant, comprising conductive particles mixed in a resin, and irradiating ultraviolet rays for curing the resin as an electrode under a transfer seal for conducting between the pair of substrates. A liquid crystal display device comprising a film that reflects light. 6. A frame pattern is formed by applying a sealant to a peripheral portion of an image display area provided on one of a pair of substrates, a liquid crystal is dropped in the frame pattern, and the substrates are bonded to each other. A method for manufacturing a liquid crystal display device by curing a sealant, comprising: forming an alignment film of liquid crystal in a region where an end thereof is inside and outside the periphery of the sealant and inside and outside the periphery of the sealant; A method of manufacturing a liquid crystal display device, wherein the sealing agent is cured by irradiating light having a wavelength of: 7. Dispenser means for discharging a predetermined amount of liquid crystal, and measuring means for measuring the amount of liquid crystal discharged by the dispenser means, wherein the measuring means has an optical sensor and discharges from the dispenser means. A liquid crystal dropping device, which integrates a signal fluctuation of the optical sensor generated when the liquid crystal passes through the optical sensor, and measures a discharge amount of the liquid crystal. 8. Dispenser means for discharging a predetermined amount of liquid crystal, and liquid crystal measuring means for recognizing the shape of the liquid crystal discharged by the dispenser means and estimating the actual liquid crystal discharge amount based on the shape. A liquid crystal dropping device, comprising: 9. A discharge means having a plurality of thin tubes, for discharging a predetermined amount of liquid crystal from each of the thin tubes, and a saucer corresponding to each of the thin tubes of the discharge means. A liquid crystal dropping device, comprising: measuring means for measuring the weight of each liquid drop; and supplying liquid crystal liquid drops whose weight has been measured by the measuring means and whose discharge amount has been specified, from each of the trays. 10. A liquid crystal having a pair of substrates at least one of which is transparent, a frame pattern formed by applying a sealant around the image display area, and a negative dielectric anisotropy in the frame pattern. Is a liquid crystal display device of a vertical alignment type wherein the substrates are bonded together and the sealant is cured, the liquid crystal display device including a liquid crystal compound represented by the following general formula, and the number of carbon atoms in a terminal alkyl group thereof. A liquid crystal display device using a liquid crystal material in which m is an even number of 2 or more. Embedded image 11. A liquid crystal having a pair of substrates at least one of which is transparent, a frame pattern formed by applying a sealant around the image display area, and a negative dielectric anisotropy in the frame pattern. A liquid crystal display device of a vertical alignment type wherein the substrates are bonded together by dropping, and the sealant is cured, wherein the liquid crystal material includes a neutral liquid crystal compound having no polarity, and includes the neutral liquid crystal compound. The liquid crystal has a high volatility, the weight ratio of which is reduced by 1% or more when left in a vacuum when dropped, and has a rotational viscosity of 15% or more lower than the non-volatile neutral liquid crystal compound. Characteristic liquid crystal display device.