JP3094952B2 - Liquid crystal injection method, liquid crystal specific resistance monitoring device and monitoring method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the specific resistance of a liquid crystal injected into a liquid crystal panel, and to a liquid crystal panel.

[0002]

2. Description of the Related Art In order to perform high-quality display on a liquid crystal panel, it is necessary to inject a liquid crystal having a large specific resistance. What lowers the specific resistance of the liquid crystal are ionic impurities and low-resistivity organic impurities. Judging by the process, these impurities are included in the liquid crystal itself and the liquid crystal used in the liquid crystal injector. It can be broadly classified into those that are mixed in from the dish of the dish and those that are caused by contamination of the liquid crystal panel substrate surface in the liquid crystal panel to be injected.

Heretofore, attention has been paid to the former two, and techniques for removing these impurities at the time of liquid crystal injection, particularly techniques for removing ionic impurities, have been developed. However, in these devices and methods for removing impurities, the measurement of the specific resistance at the time of injecting the liquid crystal after removing the impurities is ignored, and the value of the specific resistance of the liquid crystal actually injected cannot be known. .

However, a specific resistance monitoring device capable of monitoring the specific resistance of the injected liquid crystal is disclosed in Japanese Utility Model Laid-Open No. 5-75.
742. In this specific resistance monitoring device, a monitoring electrode for measuring the specific resistance of a liquid crystal is provided on a liquid crystal dish. Then, by constantly measuring the specific resistance of the liquid crystal dish using this conventional specific resistance monitor device, when something abnormal occurs in the liquid crystal and the specific resistance changes, the liquid crystal injection operation can be immediately stopped. Therefore, the number of defective products created can be minimized. However, this specific resistance monitor cannot measure the specific resistance of the liquid crystal in the liquid crystal panel after the injection, and therefore cannot detect this abnormality when impurities exist in the liquid crystal panel.

When the specific resistance of the liquid crystal in the liquid crystal dish is measured and the specific resistance is measured by exposing the electrode directly to the liquid crystal dish, the specific resistance of the liquid crystal in an actually used state is measured. Since measurement cannot be performed, accurate measurement of specific resistance cannot be performed.

[0006]

As described above, the conventional liquid crystal resistivity monitor and method have the following problems. (1) Although the specific resistance of the liquid crystal in the liquid crystal dish at the time of liquid crystal injection can be measured, the specific resistance of the liquid crystal in the liquid crystal panel cannot be monitored. Can not do. (2) Since the specific resistance is measured by exposing the electrodes directly to the liquid crystal dish, accurate measurement of specific resistance cannot be performed.

An object of the present invention is to provide a liquid crystal panel capable of monitoring the specific resistance of the liquid crystal in the liquid crystal panel simultaneously with the injection of the liquid crystal.

It is another object of the present invention to provide an apparatus and a method for monitoring the specific resistance of a liquid crystal which can accurately measure the specific resistance of the liquid crystal in a liquid crystal dish.

[0009]

In order to achieve the above object, a liquid crystal panel according to the present invention has two liquid crystal panel substrates, and a region sandwiched between the liquid crystal panel substrates is filled with liquid crystal. In the liquid crystal panel, one or more sets of monitoring electrodes for measuring the specific resistance of the liquid crystal are provided outside a display portion of the liquid crystal panel substrate.

According to the present invention, a monitor electrode for measuring the specific resistance of the liquid crystal is provided outside the display portion of the liquid crystal panel so that the specific resistance of the injected liquid crystal can be measured while the liquid crystal is being injected. It was done.

Therefore, if the specific resistance of the liquid crystal in the liquid crystal dish is measured before the injection, impurities in the injected liquid crystal and impurities caused by contamination in the panel can be separated.

According to an embodiment of the present invention, each of the sets of monitor electrodes is provided such that one monitor electrode is provided on the one liquid crystal panel substrate, and the other monitor electrode is provided on the one monitor electrode. The other liquid crystal panel substrate is provided so as to face the other liquid crystal panel substrate.

According to the present invention, two electrodes of a set of monitor electrodes are provided so as to face different liquid crystal panel substrates.

Therefore, since an electric field is applied perpendicularly to the liquid crystal surface to measure the specific resistance, the specific resistance of the liquid crystal of the liquid crystal panel for performing liquid crystal display by applying an electric field perpendicular to the liquid crystal surface is used. Can be measured.

According to another embodiment of the present invention, in each of the sets of monitor electrodes, both monitor electrodes are provided adjacent to the same liquid crystal panel substrate.

According to the present invention, two electrodes of a set of monitor electrodes are provided adjacent to the same liquid crystal panel substrate.

Therefore, since the specific resistance is measured by applying an electric field parallel to the liquid crystal surface, the specific resistance of the liquid crystal of the liquid crystal panel for performing the liquid crystal display by applying the electric field parallel to the liquid crystal surface is used. Can be measured.

Further, the liquid crystal resistivity monitor of the present invention is provided adjacent to a liquid crystal dish filled with liquid crystal to be injected into a liquid crystal panel, and has electrodes each having an insulating film applied on the surface. And a monitor cell configured by stacking two liquid crystal panel substrates.

According to the present invention, a monitor cell having the same structure as a liquid crystal panel is provided adjacent to a liquid crystal dish. Therefore, since the specific resistance of the liquid crystal of the liquid crystal dish can be measured in the same state as actually used, the specific resistance can be accurately measured.

Further, according to the method of monitoring the specific resistance of a liquid crystal of the present invention, the liquid crystal is filled with liquid crystal to be injected into a liquid crystal panel, and the liquid crystal is absorbed under reduced pressure by a liquid crystal injection tube.
Two liquid crystal panel substrates provided adjacent to the liquid crystal dish by discharging the liquid crystal absorbed under reduced pressure from the liquid crystal injection tube by positive pressure, and provided with electrodes each having a surface coated with an insulating film. Is injected into the superimposed monitoring cell, and 2 provided in the monitoring cell is provided.
The specific resistance of the liquid crystal is measured by measuring the value of a current flowing by applying a voltage between the two electrodes.

According to the present invention, there is provided a liquid crystal display provided adjacent to a liquid crystal dish.
The specific resistance of the liquid crystal on the liquid crystal dish is measured by a monitor cell having the same structure as the liquid crystal panel. Therefore, since the specific resistance of the liquid crystal of the liquid crystal dish can be measured in the same state as actually used, the specific resistance can be accurately measured.

[0022]

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

(First Embodiment) First, a device and method for monitoring the specific resistance of a liquid crystal according to a first embodiment of the present invention will be described. FIG. 1 is a diagram showing a structure of a specific resistance monitoring device for explaining a specific resistance monitoring method according to a first embodiment of the present invention.

The liquid crystal resistivity monitor according to the present embodiment comprises:
A liquid crystal dish 13 filled with liquid crystal 16 and a monitoring cell 1 for monitoring the specific resistance of the liquid crystal 16 in the liquid crystal dish 13
8 and a cell stopper 24 for fixing the monitor cell 18 to the edge of the liquid crystal dish 13 and connecting a conductor for measuring the specific resistance to the monitor cell 18.

A voltage is applied to the monitor cell 18 from the power supply 12 via a cell stopper 24. The voltage applied by the power supply 12 is measured by the voltmeter 14, and the current flowing at that time is measured by the ammeter 1.
5, the specific resistance of the liquid crystal 16 injected into the monitor cell 18 is measured from the voltage and the current.

The liquid crystal panel 17 is provided with six sets of monitoring electrodes 1 to 6 for measuring the specific resistance of each part. Each of the monitoring electrodes 1 to 6 is composed of two electrodes provided on the liquid crystal panel substrate facing each other. Then, the monitoring electrodes 1 to 6 are set to 100 μm outside the display unit.
It is manufactured in a size of mx3 cm.

The injection port 4 is provided below the liquid crystal panel 17.
The liquid crystal 16 in the liquid crystal dish 13 is injected from the injection port 46. A voltage is applied from a power supply 9 to each of the monitoring electrodes 1 to 6 provided opposite to each other, and an electric field is applied perpendicularly to the liquid crystal surface. Then, the voltage applied by the power supply 9 is measured by the voltmeter 7, the current flowing at that time is measured by the ammeter 8, and the specific resistance of the liquid crystal in the liquid crystal panel 17 is measured from the voltage and the current.

FIG. 1 shows a case where a voltage is applied to a set of monitoring electrodes 1. However, it is possible to switch which set of monitoring electrodes 1 to 6 is to be applied with a voltage. The specific resistance at an arbitrary site can be measured by the amount of the injected liquid crystal or the like. Therefore, there is no case where a voltage is simultaneously applied to two or more sets of the set of monitoring electrodes 1 to 6.

Next, the structure of the monitor cell 18 will be described.
This will be described with reference to FIG. FIG. 2A shows a monitoring cell 1.
8 is a top view, and FIG. 2B is a cross-sectional view taken along a line AB in FIG. 2A.

The monitoring cell 18 has a 1 cm × 1 cm I
Since two glass substrates 10 and 11 on which TO (indium / tin oxide) electrodes 19 and 20 are respectively formed are bonded, and two injection ports are provided on both sides of the glass substrate 11, the two Liquid crystal is uniformly injected into the interior at normal pressure by capillary action. In addition, ITO
The electrodes 19 and 20 are insulated and coated with a 100 nm thick polyimide.

Next, regarding the structure of the cell stopper 24,
This will be described with reference to FIG. FIG. 3A shows the cell stopper 2.
4 is a top view, and FIG. 3B is a cross-sectional view taken along line CD of FIG. 3A.

The cell stopper 24 connects the ammeter 15 for measuring the specific resistance, the voltmeter 14 and the power source 12 to a conducting wire 27.
Have terminals 22 and 23 for connection. Each of the terminals 22 and 23 has a metal ball 25 and a spring 26, and the metal balls 2 and
5, the monitor cell 18 is fixed. A lead 27 is connected to the metal ball 25, and the metal ball 25 is
By contacting the TO electrodes 19 and 20, the conducting wire 27 becomes I
It is configured to conduct with the TO electrodes 19 and 29.

In this embodiment, a power supply, a voltmeter and an ammeter are used to measure the specific resistance. However, a voltage waveform generator is used instead of the power supply, and the voltmeter and the ammeter are used instead. The specific resistance can be measured using an oscilloscope.

Next, a method of measuring the specific resistance in the present embodiment will be described with reference to the flowchart of FIG.

First, in FIG. 1, the liquid crystal 16 in the liquid crystal dish 13 is injected into the monitoring cell 11. FIG. 4 shows a method of injecting the liquid crystal 16 into the monitor cell 18. The liquid crystal 1 in the liquid crystal dish 13 is controlled by a liquid crystal injection tube 21 made of Teflon.
6 is collected by absorbing about 50 μl under reduced pressure, and the liquid crystal 16 is dropped on the inlet 28 of the monitor cell 18 by discharging the liquid crystal 16 under a positive pressure.

Then, the value of the specific resistance is measured from the response current value to the voltage application from the power supply 12 (step 30).
If the measured specific resistance value is not a normal value (step 31), the injection of the liquid crystal 16 into the liquid crystal panel 17 is stopped (step 32). In step 31,
When it is determined that the measured specific resistance is a normal value, the liquid crystal 16 is continuously injected into the liquid crystal panel 17 (step 33).

Then, while injecting the liquid crystal 16, the specific resistance of the liquid crystal 16 in the liquid crystal panel 17 is measured (step 3).
4) If the measured specific resistance is an abnormal value, the injection of the liquid crystal 16 is stopped (step 36). And step 3
If it is determined in step 5 that the measured specific resistance is a normal value, the liquid crystal 16 is continuously injected into the liquid crystal panel 17 (step 37). The above operation is performed until the liquid crystal panel 17 is filled with the liquid crystal 16.

In this embodiment, the liquid crystal panel 17 is
Before injecting the liquid crystal 6, the specific resistance of the liquid crystal 16 in the liquid crystal dish 13 is measured by the monitoring cell 18 to confirm that there is no abnormality. Is found, it can be determined that the contamination is caused by the contamination in the liquid crystal panel 17.

Next, a method of monitoring the specific resistance of the liquid crystal using the monitoring electrodes 1 to 6 will be described with reference to FIG.

In FIG. 6, the liquid crystal is injected into the liquid crystal panel 17 from the injection port 46 toward the upper side of the figure. At this time, the specific resistance of the liquid crystal is monitored by the monitoring electrodes 1 to 6.
Here, when the liquid crystal is injected to the liquid surface 54 in FIG. 6, there is no abnormality in the specific resistance measured at the electrodes 5 and 6, and when the liquid crystal is injected to the liquid surface 55, the specific resistance is measured at the electrodes 3 and 4. It is assumed that an abnormality is detected in the specific resistance. In this case, the abnormal cause of the specific resistance is between the monitoring electrodes 5 and 6 and the monitoring electrodes 3 and 4. This information is valuable information when taking measures against the cause of the abnormality.

In the liquid crystal panel 17 according to the present embodiment in which a plurality of sets of monitoring electrodes 1 to 6 are provided as described above, the specific resistance of the liquid crystal 16 when the liquid crystal 16 is injected is changed.
Can be monitored sequentially for each part of. for that reason,
When contamination is found somewhere in the liquid crystal panel 17 and a decrease in specific resistance is observed, the injection operation can be immediately stopped, and
By comparing the measured specific resistances between the electrode sets, it is possible to predict a portion that has caused an abnormality, and to obtain important information on countermeasures.

Next, the results of actual measurement of the specific resistance using the liquid crystal specific resistance monitor of the present embodiment will be described.

First, the specific resistance of the liquid crystal in the liquid crystal dish was measured using the liquid crystal dish that was kept clean and the liquid crystal dish that was intentionally contaminated. Here, 10 ml of a 10 mmol / l sodium benzoate methanol solution was added, and after methanol was evaporated, an experiment was performed using a liquid crystal dish containing clean liquid crystal as a deliberately contaminated liquid crystal dish. Table 1 shows the result of comparison between the specific resistance of the liquid crystal and the specific resistance of the liquid crystal in a normal operation.

[0044]

[Table 1] From this experimental result, it is understood that contamination of the liquid crystal dish can be detected by the device for monitoring the specific resistance of the liquid crystal of the present embodiment.

Next, the liquid crystal was intentionally contaminated, and the same experiment as above was performed. Aniline was mixed so that the concentration with respect to the liquid crystal was 0.1%, and the specific resistance was measured as a liquid crystal contaminating the liquid crystal. Table 2 shows the results of this experiment.

[0046]

[Table 2] From this experimental result, it can be seen that even when the liquid crystal is contaminated by the liquid crystal resistivity monitor of the present embodiment, the abnormality can be detected.

Further, Table 3 shows the results of the specific resistance monitored when each liquid crystal was injected into the liquid crystal panel 17 shown in FIG. 3 under the same conditions as when the experimental results in Table 1 were obtained.

The specific resistance was measured when each of the monitoring electrodes 1 to 6 was filled with the liquid crystal 16. Table 3 shows the results. However, in this experiment, for the sake of simplicity, only the specific resistance of the monitoring electrodes 1, 3, and 5 was measured.

[0049]

[Table 3] In the case of normal operation, the specific resistance tended to decrease slightly toward the upper part of the liquid crystal panel 17. This is considered to be due to slight contamination in the liquid crystal panel 17. The reason why the specific resistance does not decrease in the results of the contamination experiment is that the contamination in the liquid crystal panel 17 is much lower than the contamination level of the injected liquid crystal.

Further, each liquid crystal under the same conditions as when the experimental results in Table 2 were obtained was injected into the liquid crystal panel 17 in the same manner as in the above experiment, and the results of monitoring the specific resistance during the injection process are shown in Table 4.

[0051]

[Table 4] In this experimental result, the contamination of the liquid crystal panel shown in Table 3 was not detected. In this case, it can be understood that the liquid crystal or the liquid crystal dish injected without contamination has a cause of a decrease in specific resistance.

Next, an example in which partial contamination of the panel is detected will be described. Before bonding the panel substrate, as shown in FIG.
A 1 / l solution of sodium benzoate in methanol was dropped, and after evaporating the methanol, the substrates were attached to form a liquid crystal panel for experiments. Table 5 shows the results of monitoring the specific resistance when normal liquid crystal was injected into the liquid crystal panel.

[0053]

[Table 5] In the contamination experiment, the liquid crystal measured by the monitor electrode 1 did not reach the contaminated portion 41 and remained clean, so that the specific resistance was maintained at the same level as that of the normal panel. However, the monitor electrodes 3 and 4 and the liquid crystal that has reached the liquid level 55 are contaminated portions 41.
, It is contaminated by sodium benzoate, and its specific resistance is low. Thus, the contaminated portion can be predicted from the monitor of the specific resistance.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG.

In the first embodiment shown in FIG. 1, the monitor electrodes 1 to 6 are provided as a set on the liquid crystal panel substrates facing each other, but in the present embodiment, the monitor electrodes 61 to 7 are provided.
2 are provided side by side on the same liquid crystal panel substrate.

FIG. 8 shows a state where a voltage is applied between the monitoring electrodes 61 and 66.

The method for measuring the specific resistance of the liquid crystal panel of the present embodiment is the same as that of the liquid crystal panel of the first embodiment, and therefore will not be described.

In the liquid crystal panel of this embodiment, an electric field can be applied horizontally to the surface of the liquid crystal. Therefore, in a liquid crystal panel of the type in which an electric field is applied horizontally to the liquid crystal surface to perform liquid crystal display, the ratio can be reduced in a state close to the actual operation. Resistance measurements can be made.

[0059]

As described above, the present invention has the following effects. (1) Since the specific resistance of the liquid crystal inside the liquid crystal panel can be measured, not only can the number of defective products be reduced, but also whether the abnormality is caused by the liquid crystal plate, the liquid crystal itself, or the panel. Can be clarified. (2) When there is a cause in the liquid crystal panel, an approximate location can be estimated, so that subsequent measures can be taken efficiently. (3) Accurate specific resistance of the liquid crystal in the liquid crystal dish can be measured.

[Brief description of the drawings]

FIG. 1 is a diagram showing the structure of a specific resistance monitoring device and a liquid crystal panel for explaining a specific resistance monitoring method according to a first embodiment of the present invention.

2 is a top view of the monitoring cell 18 of FIG. 1 (FIG. 2);
(A)) and sectional drawing (FIG. 2 (b)).

FIG. 3 is a top view of the cell stopper 24 of FIG. 1 (FIG. 3);
(A)) and sectional drawing (FIG. 3 (b)).

FIG. 4 is a diagram showing a method of injecting a liquid crystal 16 into a monitor cell 18.

FIG. 5 is a flowchart showing a method of monitoring a specific resistance.

FIG. 6 is a diagram for explaining a method of monitoring a specific resistance during liquid crystal injection.

FIG. 7 is a diagram for explaining a method of monitoring a specific resistance at the time of injecting liquid crystal when there is a contaminated portion 41 in the liquid crystal panel 17.

FIG. 8 is a diagram illustrating a structure of a liquid crystal panel according to a second embodiment of the present invention.

[Explanation of symbols]

 1-6 Monitor electrode 7 Voltmeter 8 Ammeter 9 Power supply 10, 11 Glass substrate 12 Power supply 13 Liquid crystal dish 14 Voltmeter 15 Ammeter 16 Liquid crystal 17 Liquid crystal panel 18 Monitor cell 19 ITO electrode 20 ITO electrode 21 Liquid crystal injection tube 22 , 23 Terminal 24 Cell stopper 25 Metal ball 26 Spring 27 Conductor 28 Inlet 30-37 Step 41 Contaminated part 46 Inlet 54, 55 Liquid surface 61-72 Monitor electrode

Claims (5)

(57) [Claims] 1. A liquid crystal display device comprising: two liquid crystal panel substrates;
Area sandwiched between panel substratesLiquidLiquid crystal for crystal injection
In the injection method,Before injecting the liquid crystal into the liquid crystal panel, the liquid crystal is
Collecting from a filled liquid crystal dish; The collected liquid crystal was collected near the liquid crystal panel.
Measuring the specific resistance of the liquid crystal; A monitor electrode provided outside a display portion of the liquid crystal panel substrate
When, The specific resistance of the liquid crystal injected into the liquid crystal panel is
While measuring with the monitor electrode, the liquid
A method for injecting a liquid crystal, comprising injecting a crystal. 2. When the monitor electrode is provided outside a display portion of the liquid crystal panel substrate, the set of monitor electrodes is provided by one monitor electrode provided on the one liquid crystal panel substrate and the other monitor electrode provided on the other liquid crystal panel substrate. 2. The liquid crystal injection method according to claim 1, wherein a monitor electrode is provided on the other liquid crystal panel substrate so as to face the one monitor electrode. 3. When the monitor electrode is provided outside a display portion of the liquid crystal panel substrate, the set of each monitor electrode is provided adjacent to the same liquid crystal panel substrate in which two monitor electrodes are both provided. The liquid crystal injection method according to claim 1. 4. A liquid crystal panel substrate, which is provided adjacent to a liquid crystal dish filled with liquid crystal to be injected into a liquid crystal panel and provided with electrodes each having a surface coated with an insulating film, is superposed. A liquid crystal specific resistance monitoring device having a monitoring cell configured as described above. 5. A liquid crystal dish filled with liquid crystal to be injected into a liquid crystal panel, wherein the liquid crystal is decompressed and absorbed by a liquid crystal injection tube, and the decompressed liquid crystal is discharged from the liquid crystal injection tube by positive pressure. The liquid crystal panel is provided adjacent to the liquid crystal dish, and is injected into a monitor cell in which two liquid crystal panel substrates provided with electrodes each having a surface coated with an insulating film are superimposed, and provided in the monitor cell. 2
A method for monitoring a specific resistance of a liquid crystal, wherein a specific resistance of the liquid crystal is measured by measuring a current value flowing by applying a voltage between two electrodes.