JPH04361234A - Method and apparatus for production liquid crystal panel - Google Patents

Abstract

PURPOSE:To rationalize the production of the liquid crystal panel by more surely executing the sealing of a liquid crystal injection port to be executed after injection of a liquid crystal into a liquid crystal sealing part and easily and rapidly executing the sealing. CONSTITUTION:The injection of the liquid crystal 11 from the liquid crystal injection port 6c of the liquid crystal panel 6 to the liquid crystal sealing part 6d is stopped in the existing state of a negative pressure part 6f where the liquid crystal is not packed to assure the volume into which the sealing agent 12 can advance. The liquid crystal injection port 6c is immersed into the sealing agent 12 while this negative pressure part 6f is made to remain, by which the sealing agent 12 is penetrated into the liquid crystal injection port 6c as the liquid crystal 11 moves so as to be packed into the negative pressure part 6f. The continuous execution of the liquid crystal injection and the sealing agent injection within one device are executed by providing a liquid crystal reservoir and a sealing agent reservoir in a vacuum chamber and providing a driving means for relatively and selectively bringing these reservoirs closer to the liquid crystal injection port.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for manufacturing a liquid crystal panel.

0002

[Prior Art] Conventionally, in a liquid crystal panel in which two substrates on which electrodes are formed face each other and a liquid crystal enclosing part surrounded by a sealing material is provided between the two substrates, a liquid crystal injection port of the liquid crystal enclosing part is A commonly used method for injecting liquid crystal is to supply liquid crystal to a liquid crystal injection port with the liquid crystal panel placed in a vacuum chamber, and then inject the liquid crystal using a pressure difference (for example, Japanese Patent Publication No. 58-49853). method disclosed in the official gazette).

[0003] When liquid crystal injection is completed using this method, the liquid crystal injection port is closed with a sealant to seal the liquid crystal. This method involves supplying an appropriate amount of sealant near the liquid crystal injection port, and then allowing the liquid crystal to cool and contract, allowing the sealant to enter the liquid crystal injection port when the volume decreases, or as shown in Figure 9. After pressing the sealant 14 on the outside of the liquid crystal injection port 13a in the direction of the arrow with the pressing plate 15 to press fit the sealant 14 into the liquid crystal injection port 13a, the sealant 14 is cured and the liquid crystal is sealed. Panel 13 has been completed. In this case, since the sealant 14 is further press-fitted with the liquid crystal 16 filling the entire volume of the liquid crystal panel 13, the liquid crystal panel 13 swells by the volume of the sealant 14. For this reason, the liquid crystal panel 13 is slightly bent at the center, but this bending is ignored.

0004

[Problems to be Solved by the Invention] When manufacturing a liquid crystal panel, in order to completely seal the liquid crystal, it is necessary to infiltrate a sufficient amount of sealant into the liquid crystal injection port, and the work for this purpose is necessary. The problem is that it is complicated and time consuming.

[0005] Particularly when using a highly viscous liquid crystal such as a ferroelectric liquid crystal, it is difficult to move the liquid crystal near the liquid crystal injection port, the work of penetrating the sealant is troublesome, and there is a risk that liquid crystal sealing may become uncertain. be. Therefore, it is necessary to heat the ferroelectric liquid crystal to cause a phase transition and to lower the viscosity, which further complicates the manufacturing process and increases manufacturing costs. As described above, it is difficult to easily and stably mass-produce high-quality ferroelectric liquid crystal panels.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus that can reliably seal even high-viscosity liquid crystals and easily and stably manufacture high-quality liquid crystal panels.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the method for manufacturing a liquid crystal panel according to the present invention is to apply a negative pressure to the liquid crystal filling part of the liquid crystal panel and inject the liquid crystal from the liquid crystal injection port into the liquid crystal filling part by a pressure difference. Inject the liquid crystal, and stop the liquid crystal injection before the entire volume of the liquid crystal enclosure is filled with the liquid crystal. Then, the sealant is supplied to the liquid crystal injection port while leaving the negative pressure part where the liquid crystal is not filled in the liquid crystal filling part, and as the liquid crystal moves and is filled into the negative pressure part, the sealant is supplied to the liquid crystal injection port. After entering the liquid crystal, the sealant is cured to seal the liquid crystal injection port.

Alternatively, after injecting the liquid crystal, a recess where the liquid crystal is not filled is formed near the liquid crystal injection port, a sealant is injected from the liquid crystal injection port to fill the recess, and then the sealant is cured to fill the liquid crystal. The injection port may also be sealed.

In these methods, a ferroelectric liquid crystal can be used as the liquid crystal. Further, in this case, it is desirable to heat the liquid crystal panel or liquid crystal when injecting the liquid crystal and the sealant.

[0010] The liquid crystal panel manufacturing apparatus according to the present invention also has a vacuum chamber capable of substantially evacuating the inside thereof, and the vacuum chamber includes a liquid crystal reservoir for storing liquid crystal and a sealant for storing therein. A sealant reservoir for holding the liquid crystal panel and a holding block for holding the liquid crystal panel are provided. Furthermore, driving means is provided for relatively and selectively bringing the liquid crystal reservoir and the sealant reservoir into close proximity to the liquid crystal panel held by the holding block.

When this device is used to inject and seal ferroelectric liquid crystal, it is desirable to provide a heating device in the holding block or liquid crystal reservoir.

0012

According to the first method of the present invention, a sealant is supplied to the liquid crystal injection port immediately after the liquid crystal is injected. Then, the liquid crystal gradually moves to fill the negative pressure section in the liquid crystal enclosure, and the sealant enters the liquid crystal injection port accordingly. in this way,
Liquid crystal injection and sealant injection can be performed continuously as a series of steps in one device.

According to the second method, after forming a meniscus-shaped recess that is not filled with liquid crystal and has the same pressure as the outside air near the liquid crystal injection port without leaving a negative pressure part in the liquid crystal injection port, the liquid crystal injection port is sealed. When the sealant is supplied, capillary action acts and the sealant can be easily injected.

[0014]

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

In FIG. 2, there is provided a vacuum chamber (bell jar) 1 consisting of a bowl-shaped vacuum lid 1a made of transparent glass and a pedestal 1b on which it is placed. A vacuum pump 2 is connected.

A liquid crystal panel holding block 3 is provided on the pedestal 1b. A liquid crystal panel holding fitting 5 is attached to the upper part of the holding block 3, and the liquid crystal panel 6 is held by the holding block 3 with one side of the liquid crystal panel 6 in close contact with the holding block 3. (Detailed configuration of the holding fitting 5 is omitted). and holding block 3
The lower part 3a of the holding block 3 is cut out, and the liquid crystal injection port of the liquid crystal panel 6 projects downward from the end surface 3b of the holding block 3.

The liquid crystal panel 6 has two glass plates 6a formed with electrodes and an alignment film facing each other, and a liquid crystal injection port 6.
A sealing material 6b formed into a rectangular shape except for the portion c is sandwiched between both glass plates, and the inside of this sealing material 6b becomes a liquid crystal enclosing portion 6d. A spacer 6e is provided at a position slightly inside the liquid crystal injection port 6c within the liquid crystal enclosure 6d (see FIG. 1).

FIG. 3 shows this device with the holding block 3 omitted. A connecting arm 7 is attached to the center of the base 1b. The connecting arm 7 is a shaft rod 7 that passes through the pedestal 1b.
It has a structure in which a bifurcated branch part 7b is fixed to the end of a, and can be rotated and moved forward and backward (movement in the axial direction) by a driving means (not shown).

A liquid crystal reservoir 8 and a sealant reservoir 9 are fixed to each end of the bifurcated branch portion 7b. The liquid crystal reservoir 8 and the encapsulant reservoir 9 have a recessed liquid crystal reservoir 8a and a recessed encapsulant reservoir 9a, respectively.
a, the liquid crystal 11 and the sealant 1 are placed in the sealant reservoir 9a, respectively.
2 is stored. In this embodiment, a high-viscosity ferroelectric liquid crystal is used as the liquid crystal 11, and a thermosetting resin is used as the sealant 12.

By rotating the connecting arm 7, the liquid crystal reservoir 8 and the sealant reservoir 9 rotate within the notch 3a of the holding block 3 provided at a predetermined position about the shaft rod 7a. Alternatively, by selectively positioning either the sealant reservoir 9 below the liquid crystal panel 6 held by the holding block 3 and then raising the connecting arm 7, the liquid crystal reservoir 8a or the sealant can be sealed. Either of the agent reservoirs 9a is placed close to the liquid crystal injection port 6c of the liquid crystal panel (
(see Figure 2).

A nichrome wire (not shown) is buried inside the holding block 3, and the holding block 3 is heated by passing current through the nichrome wire from a power source (not shown). This heats the liquid crystal panel 6 that is in close contact with the holding block 3. Further, a nichrome wire (not shown) is similarly buried inside the liquid crystal reservoir 8, and the liquid crystal reservoir 8 is heated by passing a current through the nichrome wire. This heats the liquid crystal stored in the liquid crystal storage section 8a.

Next, the steps of liquid crystal injection and sealing using the apparatus constructed as described above will be explained.

With the liquid crystal panel 6 held by the holding block 3 and the connecting arm 7 lowered, the liquid crystal storage section 8a
The ferroelectric liquid crystal 11 and the sealant 12 are stored in the sealant reservoir 9a and the holding block 3 and the liquid crystal reservoir 8 are heated by passing a current through the nichrome wire. Then, the vacuum lid 1a is placed on the pedestal 1b, and the vacuum pump 2 is operated to bring the inside of the vacuum chamber 1 into a vacuum state. This results in
The liquid crystal enclosure 6d is also brought into a vacuum state (see FIG. 2).

Next, in this state, as shown in FIG. 4, the connecting arm 7 is rotated and raised to bring the liquid crystal reservoir 8a close to the liquid crystal injection port 6c of the liquid crystal panel 6, and the liquid crystal injection port 6c is inserted into the liquid crystal 11. Soak. Then, the vacuum pump 2 is stopped to leak air. Then, as air enters the vacuum chamber 1, the liquid crystal 11 rises within the liquid crystal enclosure 6d due to the pressure difference. At this time, if the liquid crystal has a high viscosity, the resistance to the upward movement of the liquid crystal increases as the liquid crystal is filled into the liquid crystal enclosure, and the upward speed of the liquid crystal decreases. In addition, the ferroelectric liquid crystal 11 in the liquid crystal reservoir 8a is heated by the conduction of the heat from the liquid crystal reservoir 8, and as a result, the ferroelectric liquid crystal 11 changes into, for example, a chiral smectic C phase (Sc* )
The liquid crystal undergoes a phase transition from the isotopic phase (ISO) to the chiral nematic phase (N*), its viscosity decreases, and the liquid crystal easily enters the liquid crystal enclosure 6d.

Then, as shown in FIG. 4, the liquid crystal enclosure 6
When there is a portion 6f in the upper part of d where the liquid crystal 11 is not yet filled and is kept under negative pressure, lower the connecting arm 7 and remove the liquid crystal inlet 6c of the liquid crystal panel 6 from the liquid crystal reservoir 8. (See Figure 1(a)).

[0026] In order to reliably seal the liquid crystal 11 with the sealant 12, it is preferable that the sealant 12 penetrates to the position of the spacer 6e. The volume of the liquid crystal inlet 6c is
It is preferable that the volume be approximately equal to the volume from the position of the spacer 6e to the position of the spacer 6e.

Immediately thereafter, the connecting arm 7 is rotated and raised to open the sealant reservoir 9 of the sealant reservoir 9 as shown in FIG.
A is brought close to the liquid crystal injection port 6c, and the liquid crystal injection port 6c is immersed in the sealant 12. This part is shown enlarged in FIG. 1(b). From this state, the liquid crystal 11 gradually moves so as to fill the negative pressure section 6f within the liquid crystal enclosure section 6d. Therefore, the liquid crystal 11 near the liquid crystal injection port 6c enters into the liquid crystal enclosing portion 6d, and the sealant 12 accordingly enters into the liquid crystal injection port 6c (see FIG. 1(c)).

When a sufficient amount of the sealant 12 has entered the liquid crystal injection port 6c, the connecting arm 7 is lowered, the vacuum cover 1a is removed, the liquid crystal panel 6 is removed from the holding block 3, and the liquid crystal injection port 6c is removed. The sealant 12 is heated and cured. As a result, the liquid crystal injection port 6c is closed, and the liquid crystal 11 is sealed within the liquid crystal enclosure 6d.

Next, a second method according to the present invention will be explained. The ferroelectric liquid crystal 11 is injected using the same apparatus as in the previous embodiment (see FIGS. 2 and 3), and the liquid crystal enclosing part 6d is
Stop liquid crystal injection before filling the entire volume (see Figure 4).
, separate the liquid crystal inlet 6c from the liquid crystal reservoir 8. As shown in FIG. 1(a), from the state where the negative pressure part 6f remains, the liquid crystal 1
1 moves, and eventually the negative pressure section 6f is filled with the liquid crystal 11, and a meniscus-shaped depression 6g without liquid crystal is created near the liquid crystal injection port 6c (see FIGS. 6 and 8(a)).

This recessed portion 6g has the same volume as the negative pressure portion 6f.

In this state, the continuous arm 7 is rotated and raised to insert the liquid crystal injection port 6 into the sealant 12 as shown in FIG.
Soak c. Then, the sealant 12 enters the liquid crystal injection port 6c due to capillarity and fills the recess 6g. (See FIG. 8(b)).

Thereafter, the sealant 12 is heated and cured,
Sealing of the liquid crystal 11 is completed. Note that even if the sealant 12 is cured with some air in the recess 6g remaining in the liquid crystal injection port 6c, the ferroelectric liquid crystal 11 has a high viscosity that makes it difficult for air bubbles to penetrate. It remains near the spacer 6e and does not pose a practical problem.

According to the first method of the present invention, since the negative pressure section 6f is provided within the liquid crystal enclosure section 6d, the sealant 12 can be injected using the pressure difference. Furthermore, according to the second method, since the liquid crystal injection port 6c is provided with a meniscus-shaped depression 6g, the sealant 12 can be injected using capillary action. In either case, the sealant 12 can be injected efficiently, and this is particularly effective when using a high-viscosity liquid crystal such as a ferroelectric liquid crystal.

Furthermore, in the above embodiment, since the liquid crystal 11 is heated and has a low viscosity when the sealant is injected, the liquid crystal near the liquid crystal injection port 6c is easily moved, and the sealant 12 enters quickly. I can do it. Therefore, it is easy to enter a sufficient amount of the sealant 12 into the liquid crystal injection port 6c, and the liquid crystal 11 can be completely sealed. Since a reservoir 9 is provided and these are selectively brought close to the liquid crystal injection port 6c of the liquid crystal panel by the connecting arm 7, the connecting arm 7 is operated after filling the liquid crystal filling part 6d with the liquid crystal 11. By bringing the sealant reservoir 9 close to the liquid crystal injection port 6c, the sealant 12 can be injected immediately. It becomes possible to further shorten the time required to manufacture the panel 6.

[0035] In the present invention, liquid crystal is filled in a vacuum chamber,
It is also possible to perform the injection of the sealant outside the vacuum chamber. In this case as well, the sealant 12 easily penetrates into the liquid crystal injection port due to the pressure difference and capillary action.

[0036]

[Effects of the Invention] In the present invention, since the injection of liquid crystal into the liquid crystal panel is stopped before the entire volume of the liquid crystal sealing part is filled with liquid crystal, a portion not filled with liquid crystal remains in the liquid crystal sealing part. Therefore, a volume into which the sealant can enter is secured, and since the sealant is injected using a pressure difference and capillary action, the sealant can easily penetrate. Therefore, sufficient sealing of the liquid crystal becomes possible. In this way, liquid crystal injection and encapsulant injection can be performed continuously as a series of steps within one device.
Improves work efficiency.

Furthermore, the present invention makes it easier to inject the sealant by stopping the injection of liquid crystal into the liquid crystal panel earlier than before, so the device does not become complicated and the sealant can be easily injected. The time required for injection is reduced, making it possible to rationalize the manufacturing of liquid crystal panels.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the first method according to the present invention in the order of steps; (a) is the state after liquid crystal injection, (b) is the state when sealant is injected, and (c) is the sealing state. It is in a completed state.

FIG. 2 is a sectional view of the device according to the invention.

FIG. 3 is a perspective view of the device with the holding block removed.

FIG. 4 is a partially cross-sectional front view when liquid crystal is injected in the first method.

FIG. 5 is a partially sectional front view during injection of a sealant in the first method.

FIG. 6 is a partially sectional front view when liquid crystal injection is completed in the second method.

FIG. 7 is a partially sectional front view during injection of a sealant in a second method.

FIG. 8 is an explanatory diagram showing the second method in order of steps;
(a) shows the state after the liquid crystal injection is completed, and (b) shows the state after the sealing is completed.

FIG. 9 is an explanatory diagram showing a conventional sealant injection process.

[Explanation of symbols]

1 Vacuum chamber 3 Holding block 6.LCD panel 6a　Board 6b Seal material 6c Liquid crystal inlet 6d Liquid crystal sealing part 6f Negative pressure section 6g recessed part 8 Liquid crystal reservoir 9 Sealant reservoir 11 Liquid crystal 12 Sealant

Claims (6)

[Claims] 1. A pair of substrates are juxtaposed to face each other, and a liquid crystal enclosing section and a liquid crystal injection port provided in a part of the liquid crystal enclosing section are separated by a sealing material in the gap between the two substrates. In the formed liquid crystal panel, the liquid crystal enclosing part is made negative pressure, and liquid crystal is injected into the liquid crystal enclosing part from the liquid crystal injection port by the pressure difference, and before the liquid crystal fills the entire volume of the liquid crystal enclosing part. The injection of the liquid crystal is stopped, a negative pressure part where the liquid crystal is not filled is left in the liquid crystal filling part, a sealant is supplied to the liquid crystal injection port, and the liquid crystal is moved and filled into the negative pressure part. A method for manufacturing a liquid crystal panel, comprising: injecting the sealant into the liquid crystal injection port and curing the sealant to seal the liquid crystal injection port. 2. A pair of substrates are juxtaposed to face each other, and a liquid crystal enclosing section and a liquid crystal injection port provided in a part of the liquid crystal enclosing section are separated by a sealing material in the gap between the two substrates. In the formed liquid crystal panel, the liquid crystal enclosing part is made negative pressure, and liquid crystal is injected into the liquid crystal enclosing part from the liquid crystal injection port by the pressure difference, and before the liquid crystal fills the entire volume of the liquid crystal enclosing part. Stop the liquid crystal injection, and then form a recess where the liquid crystal is not filled in the vicinity of the liquid crystal injection port, inject the sealant through the liquid crystal injection port to fill the recess, and then fill the recess with the sealant. A method for manufacturing a liquid crystal panel, comprising curing and sealing the liquid crystal injection port. 3. The method of manufacturing a liquid crystal panel according to claim 1, wherein the liquid crystal is a ferroelectric liquid crystal. 4. The method of manufacturing a liquid crystal panel according to claim 3, wherein the liquid crystal panel or the liquid crystal is heated when the liquid crystal is injected. 5. A vacuum chamber capable of substantially evacuating the interior thereof, and a liquid crystal reservoir for storing liquid crystal;
A sealant reservoir for storing a sealant and a holding block for holding a liquid crystal panel are provided, and the liquid crystal reservoir, the sealant reservoir, and the liquid crystal panel held by the holding block are 1. An apparatus for manufacturing a liquid crystal panel, comprising a driving means for relatively and selectively approaching a liquid crystal injection port of a liquid crystal panel. 6. The liquid crystal panel manufacturing apparatus according to claim 5, wherein the holding block or the liquid crystal reservoir is provided with a heating device.