JP2012130964A - Device and method for pressurization for removal of air bubble - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for pressurization for removal of air bubbles.SOLUTION: This pressurization device includes: an input valve controlling pressure of air provided from outside; a plurality of nozzle parts jetting air provided from the input valve to panels; and a plurality of nozzle valves individually opening/closing the plurality of nozzle parts. Air is jetted toward opened one face of the panels for pressurization, so as to remove air bubbles between the two bonded panels. The plurality of nozzle valves pressurize the panels to the direction in which the air jetted to the panels is made to pass from the centers of the panels to edges, and open/close the plurality of nozzle parts repeatedly in a fixed cycle.

Description

  The present invention relates to an air pressure removing apparatus and method for removing air bubbles existing between substrates using an air pressing.

  An organic light emitting diode (OLED) is a “self-emitting organic substance” that emits light by using an electroluminescence phenomenon that emits light when a current is passed through a fluorescent organic compound. A display device that emits light by arranging an organic substance between them and applying an electric field. It can be driven at a low voltage and can be manufactured to be thin and thin, and it is widely used as a display means by having a wide viewing angle and a fast response speed.

  The OLED display panel 100 is divided into an OLED panel 10 and a cover glass 20. The OLED panel 10 includes an anode, a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, and an electron on a substrate. After being formed by laminating an injection layer (cathode), etc. in this order, it is encapsulated in a metal can or glass cap to protect organic materials that are extremely vulnerable to moisture or oxygen It is.

The cover glass 20 is bonded onto the OLED panel 10. As a conventional method of bonding the cover glass 20 and the OLED panel 10, an ultraviolet curable resin is mainly used. After applying an ultraviolet curable resin (UV resin) on the OLED panel 10, the OLED panel 10 is placed in a vacuum pressurizing chamber and pressed and bonded for a predetermined time. While the cover glass 20 is in close contact with the OLED panel 10 by the pressurizing process in the chamber, the ultraviolet curable resin pushed out of the bonding surface of the cover glass 20 and the OLED panel 10 is removed, and finally the ultraviolet curable resin is irradiated with ultraviolet light. Is completed by irradiating and curing.
Since such a process is performed in a separate vacuum pressurization chamber, there is a limit to increasing the size of the OLED display panel, and additional manpower and time are required to clean the cured resin extruded after the pressurization process. There is a problem that is required.

On the other hand, glass and glass may generally be bonded to an OCA film. What is important in bonding with an OCA film is to remove bubbles remaining between the glass and the film after bonding. A conventionally known bubble removal method is a method in which two glasses bonded to an OCA film are placed in a vacuum pressurization chamber such as an autoclave and a considerable pressure is applied to remove them.
The removal of bubbles by such a method may cause various problems due to having a chamber configuration, and not only has certain limitations in terms of its efficiency, but also has additional problems especially for OLED panels. To do.

As described above, the OLED panel 10 has a hermetically sealed structure to protect it from moisture or oxygen. Therefore, the OLED panel 10 has a certain limit in the pressure that can be withstand according to the type of the sealing structure, and is about 1.5 to 3.5 bar level. However, even when the OLED panel 10 and the cover glass 20 bonded to the OCA film are pressurized to such an allowable pressure, the bubbles are not removed, and the tendency is stronger as the panel becomes larger.
Therefore, an OCA film cannot be used for bonding the OLED panel 10 and the cover glass 20 conventionally.

An object of the present invention is to provide a bubble removing pressure device and method for removing bubbles existing between substrates using an air press.
Another object of the present invention is to provide a pressure removing apparatus and method for removing bubbles using an air press to remove bubbles existing between an organic light emitting diode panel bonded to an OCA (Optical Clear Adhesive) film and a cover glass. It is to provide.

In order to achieve the above object, a pressure removing device for removing bubbles between two panels bonded according to the present invention includes an input valve for controlling the pressure of air provided from the outside, and the input. A plurality of nozzle parts for injecting air provided from the valves to the panel, and a plurality of nozzle valves for individually opening and closing each of the plurality of nozzle parts, and injecting air toward one open surface of the panel An air press unit for pressurizing is provided.
The plurality of nozzle valves may open and close the plurality of nozzle portions so that air jetted onto the panel pressurizes the panel in a direction from the center of the panel toward the edge.
According to an embodiment of the present invention, the plurality of nozzle portions are formed on a nozzle plate facing one open surface of the panel, and are arranged at the center of the nozzle plate, and the first nozzle portion. 2nd nozzle part arrange | positioned in the area | region which surrounds, and the 3rd nozzle part arrange | positioned in the area | region surrounding the said 2nd nozzle part. Here, the first nozzle portion, the second nozzle portion, and the third nozzle portion are sequentially opened repeatedly in a certain cycle and simultaneously closed. In this way, by repeatedly pressurizing in a certain cycle and setting the pressurization speed to a certain level or more, the effect of removing bubbles can be obtained while limiting the pressure during one pressurization to a certain range. Can do.
According to an embodiment of the present invention, the plurality of nozzle valves may be realized in a form including a cover plate coupled to the input valve, a nozzle gate, and a rotation gate.
The nozzle gate is connected to at least one first through hole connected to the first nozzle part, at least one second through hole connected to the second nozzle part, and the third nozzle part. At least one third through hole is formed and fixed to the nozzle plate.
Each of the nozzle portions may include a plurality of nozzles, and upper end portions of the plurality of nozzles may be connected to a single groove whose upper side is open, and the through hole is formed at one point on the groove. The plurality of nozzles connected to the groove may be opened and closed simultaneously.
Further, the rotary gate is formed therein with an air space for receiving air provided from the input valve, and is rotatably coupled between the cover plate and the nozzle gate. The rotation gate opens the first through hole, the second through hole, and the third through hole, and simultaneously closes the first through hole, the second through hole, and the third through hole. A first slot, a second slot, and a third slot may be formed. Further, a plurality of remaining slots may be formed except for the first slot, and a gear or pulley structure for transmitting a rotational force from an external motor may be formed on the outer peripheral surface of the rotary gate. Good.
Further, the first through hole, the second through hole, and the third through hole are disposed on a center line passing through the center of the nozzle gate, and the remaining slots excluding the first slot are circles of a predetermined angle. Each may have an arc shape and be arranged on a concentric circle. It is preferable that the tip in the direction opposite to the rotation among the tips is located on the same center line passing through the center of the rotation gate, and the angle becomes smaller as the distance from the center of the rotation gate increases.

  According to another embodiment of the present invention, there is provided a pressure removing method for removing bubbles between two bonded panels, wherein a first nozzle portion is disposed at a central portion of the panel, and the first nozzle A second nozzle portion is disposed in a region surrounding the second nozzle portion, a third nozzle portion is disposed in a region surrounding the second nozzle portion, and the second nozzle portion is disposed while the first nozzle portion injects air. A step in which the third nozzle portion injects air while the first nozzle portion and the second nozzle portion inject air; and the first nozzle portion and the second nozzle in between the air injection. And a step of simultaneously closing the third nozzle portion and a step of repeating the spraying step and the closing step at regular intervals.

The pressure removing apparatus for removing bubbles according to the present invention can pressurize a panel for removing bubbles to air and remove bubbles between the panels. At this time, pressurization with air is performed from the center of the panel toward the edge, thereby reducing the space between the bonded panels from the center of the panel toward the edge (space of the adhesive substance) to the maximum. Bubbles existing in the meantime can be pushed out to the edge side.
In addition, since the air injection of the pressure removing device for removing bubbles of the present invention is repeatedly performed at an extremely high speed, even if the pressure applied to one pressurization is a low pressure, the effect of removing bubbles sufficiently. Can be earned. Therefore, even when a pressure higher than a certain pressure cannot be applied as in the OLED panel, the pressure removing device for removing bubbles can be applied.

It is sectional drawing which shows the structure of an OLED display panel. It is a figure which shows notionally the pressurization apparatus for bubble removal of this invention. It is a figure which shows the nozzle plate which concerns on one Embodiment of this invention. It is a disassembled perspective view of the air press unit which concerns on one Embodiment of this invention. It is sectional drawing of the air press unit shown in FIG. It is a top view of the nozzle plate applied to the air press unit shown in FIG. It is a top view of the nozzle gate applied to the air press unit shown in FIG. It is a top view of the rotation gate applied to the air press unit shown in FIG. It is a figure which shows the open state of the nozzle by operation | movement of a rotation gate. 6 is a graph provided for explaining an open state of a nozzle due to rotation of a rotary gate.

Hereinafter, the present invention will be described in more detail with reference to the drawings.
The present invention may be applied to remove air bubbles that exist between two first panels (or substrates) and a second panel that are generally bonded to each other, and in particular, OCA (Optical Clear Adhesive). It can be used to remove bubbles present between the organic light emitting diode (OLED) panel (simply OLED panel) adhered to the film and the cover glass using an air press. The following description also exemplifies the removal of air bubbles existing between the OLED panel 10 bonded to the OCA film and the cover glass 20.

  As shown in FIG. 2, an OLED display panel 100 in which an OCA film 30 is laminated between the OLED panel 10 and the cover glass 20 is shown, and the bubble removing device of the present invention is shown on the upper side thereof.

The bubble removing apparatus of the present invention includes an air press unit 200 and an air pump (not shown) that supplies high-pressure air to the air press unit 200.
The air press unit 200 removes bubbles between the cover glass 20 and the OLED panel 10 by spraying air toward the upper surface of the cover glass 20. To this end, the air press unit 200 is provided with an input valve 230, a nozzle plate 211 that is open to face the cover glass 20, and a nozzle plate 211 that is provided between the input valve 230 and the nozzle plate 211. And a nozzle valve device 213 for controlling air injection into the nozzle.

The input valve 230 maintains the pressure in the air press unit 200 at a constant pressure Ps by controlling the pressure of air supplied to the air press unit 200 from an air pump (not shown).
A plurality of nozzle portions 211 a, 211 b, and 211 c for injecting air are formed on the nozzle plate 211, and each nozzle portion 211 a, 211 b, 211 c includes a plurality of nozzles 301.

  The range of the allowable pressure of air ejected by the air press unit 200 is a slightly low value as clarified in the description of the prior art, and is determined according to the sealing structure of the OLED panel 10. Therefore, simply providing uniform air over the entire surface of the cover glass 20 using the plurality of nozzle portions 211a, 211b, and 211c may not remove bubbles as in the prior art. In order to eliminate this, the plurality of nozzle portions 211a, 211b, and 211c of the air press unit 200 of the present invention perform other operations.

  The plurality of nozzle portions 211 a, 211 b, and 211 c arranged to face the cover glass 20 may be sequentially arranged from the center of the nozzle plate 211 toward the edge. The nozzle valve device 213 connects the nozzle portions 211a, 211b, and 211c and the input valve 230 via different discharge pipes, and the nozzle valves 213a provided in the discharge pipes to open and close the corresponding nozzle portions. To 213c.

  FIG. 2 is an example conceptually showing an air press unit 200 including a nozzle plate 211 and a nozzle valve device 213. The nozzle plate 211 includes a first nozzle portion 211a, a second nozzle portion 211b, and a third nozzle portion 211c. The nozzle valve device 213 includes a first nozzle valve 213a for opening and closing the first nozzle portion 211a, a second nozzle valve 213b for opening and closing the second nozzle portion 211b, and a third nozzle valve 213c for opening and closing the third nozzle portion 211c. It is an example provided with. Although FIG. 2 illustrates that each of the second nozzle valve 213b and the third nozzle valve 213c is provided, two valves may be provided.

  As shown in FIG. 3, the first nozzle portion 211 a, the second nozzle portion 211 b, and the third nozzle portion 211 c are arranged concentrically (not limited to a circle) from the center of the nozzle plate 211. The air injection of the nozzle portion is a form that is applied sequentially starting from the center of the nozzle plate 211. For example, air is jetted in the order of [first nozzle portion 211a jet] → [first and second nozzle portions 211a, 211b jet] → [first to third nozzle portions 211a, 211b, 211c jet]. When the second nozzle portion 211b ejects, the first nozzle portion 211a maintains the air injection as it is, and when the third nozzle portion 211c ejects, the first and second nozzle portions 211b maintain the air injection as it is.

Thereby, the air provided to the cover glass 20 pressurizes the cover glass 20 from the center and expands the pressure toward the edge. Such pressurization reduces the volume between the cover glass 20 and the OLED panel 10, in other words, the volume of the space occupied by the OCA film 30 and air bubbles. It plays the role of pushing out bubbles in the direction of the edge by moving from the edge to the edge. As a result, even if the pressure is increased to a limited allowable pressure, the bubbles can be removed.
Pressing the air from the center of the cover glass 20 toward the edge has the effect of sweeping out the bubbles with a palm. The first to third nozzle valves 213a to 213c can maximize the effect of removing bubbles by repeatedly performing such air injection at a constant period. In other words, [first nozzle portion 211a injection] → [first and second nozzle portions 211a, 211b injection] → [first to third nozzle portions 211a, 211b, 211c injection] are repeated at a constant cycle (T). Done.

  Here, the higher the repetition speed of the sweeping operation (that is, the frequency f = 1 / T), the better, and the first to third nozzle valves 213c perform the role. However, when the repetition speed of the sweeping operation has a frequency of a certain level or more, a general valve may not be able to match the speed. Therefore, the present invention proposes a nozzle valve structure of a different form presented as follows.

The air press unit 400 shown in FIGS. 4 to 9 is an example including six nozzle portions and nozzle valves.
An air press unit 400 shown in FIG. 4 includes a nozzle plate 410, a cover plate 430 to which air is supplied from an input valve 490, a nozzle gate 450 provided between the nozzle plate 410 and the cover plate 430, and the nozzle gate 450 A rotation gate 470 provided between the cover plate 430 and rotating (or rotating) is provided. Here, the nozzle plate 410 may be the same as the nozzle plate 211 shown in FIG. 2, and the cover plate 430, the nozzle gate 450, and the rotation gate 470 serve as the nozzle valve device 213.

  As shown in FIG. 6, the nozzle plate 410 has a first nozzle part 410a, a second nozzle part 410b, a third nozzle part 410c, a fourth nozzle part 410d, and a fifth nozzle part concentrically from the center toward the edge. 410e and a sixth nozzle portion 410f are formed. The first to sixth nozzle portions 410a to 410f are first to sixth grooves that connect a plurality of nozzles 411 formed at regular intervals with respect to a virtual concentric circle and nozzles 411 arranged on the same concentric circle. 413 (groove) 413a to 413f. However, the first nozzle portion 410a is not only located at the center and arranged concentrically, but may not include another groove. The nozzle gate 450 is tightly coupled and fixed to the upper surface of the nozzle plate 410, so that the groove 413 is sealed by the nozzle gate 450.

As shown in FIG. 7, at least one through hole 451 connected to at least one point on each groove 413 of the nozzle plate 410 is formed in the nozzle gate 450, whereby each nozzle 411 of the nozzle plate 410 is formed. Is connected to the through hole 451 through the groove 413. However, in order to function as a valve together with the rotary gate 470, the through hole 451 is preferably provided on the center line passing through the center of the nozzle gate 450. FIG. 7 shows that the through hole 451 connected to each groove 413 is 90 °. An example in which four pieces are arranged at intervals is shown.
Accordingly, each nozzle 411 serves as an outlet of the groove 413, and the through hole 451 serves as an inlet of the groove 413. For example, the air that has passed through the sixth through hole 451f of the nozzle gate 450 supplies air to the sixth groove 413f connected to the sixth through hole 451f, and passes through the plurality of nozzles 411 formed in the sixth groove 413f. Air is injected.

The rotary gate 470 forms a cylindrical internal space (air space) to receive air supplied from the cover plate 430, and is rotatably attached between the cover plate 430 and the nozzle gate 450.
In order to rotatably receive the rotation gate 470, a circular track 431 is formed on the lower surface 430a of the cover plate 430 so as to sandwich the upper circular edge of the rotation gate 470, and the upper surface of the nozzle gate 450 has a circular shape for receiving the rotation gate 470. The receiving groove 453 is formed. The rotating gate 470 is rotated by receiving a rotational force from the outside. For example, a gear (pulley) structure is formed along the outer peripheral surface of the rotating gate 470 and an external motor (not shown) is formed. The rotational force may be transmitted.

  A space between the circular track 431 and the receiving groove 453 is sealed by a rotating gate 470. The rotation gate 470 is provided in a cylinder shape whose upper side is opened, and the lower surface of the rotation gate 470 is in close contact with the upper surface of the nozzle gate 450 to seal or open the through hole 451 on the nozzle gate 450. The opened upper side of the rotation gate 470 is sealed by a cover plate 430. Air supplied from the outside via the cover plate 430 is filled in an internal space (hereinafter referred to as “air space portion”) 471 of the sealed cylinder formed by the rotary gate 470 and the cover plate 430.

  As shown in FIG. 8, the first to sixth slots 473 (slots) 473 a to 473 f are formed in the rotary gate 470. Each slot 473 is formed such that the rotation gate 470 passes over the corresponding through hole 451 during a certain part of one rotation period, so that the first to sixth penetrations of the nozzle gate 450 by the rotation of the rotation gate 470. The holes 451 must be opened sequentially and repeatedly at a constant period (T). Here, since the rotation gate 470 rotates, the opening speed (per rotation / second) is the number of rotations per second of the rotation gate 470.

  The shape of the slot 473 may be variously provided, and is not limited to the shape shown in FIG.

  Depending on the shape of the slot 473, the continuous partial nozzle portions may be opened and closed at the same time, and the section of each nozzle portion may be changed accordingly. However, during one rotation of the rotary gate 470, [first through hole 451a] → [first and second through holes 451a, 451b] → [first to third through holes 451a, 451b, 451c] →. . . → The shape of the slot 473 must be provided so that the opening is performed in the order of [first to sixth through holes 451a to 451f]. In addition, two or more through holes can be opened and closed simultaneously, thereby changing the shape of the slot.

  The rotation gate 470 shown in FIG. 8 is an example assumed to rotate counterclockwise. Since the through holes 451 are arranged in a line on the center line, the slots 473 are also arranged in an arc shape on a concentric circle having the common center of the rotary gate 470, and the first to first nozzle gates 450 are rotated by the rotation of the rotary gate 470. The sixth through holes 451 are opened sequentially and repeatedly at a constant period (T).

  The first slot 473 a is provided at the center of the rotation gate 470. The right side tips (tips on the opposite side of the rotation direction) of the remaining second slot to sixth slots 473b to 47f are located on the first center line L1 that passes through the central portion of the rotation gate 470, thereby rotating. The through hole 451 is simultaneously closed by the rotation of the gate 470.

  The left end of the second slot to the sixth slot 473b to 47f (the end in the rotation direction) has a smaller arc angle as the slot 473 is located farther from the center of the rotation gate 470, and the rotation of the rotation gate 470 becomes smaller. Thus, the through holes 451 are opened in the order from the second slot 473b to the sixth slot 473f. Accordingly, as the slot 473 is located farther from the center of the rotation gate 470, the angle formed by the second center lines L2 to L6 and the first center line L1 connecting the corresponding left end and the center portion of the rotation gate 470 gradually increases. Provided to be smaller.

Hereinafter, the operation of the bubble removing device of the present invention will be described with reference to FIG. 9, focusing on the operation of the rotary gate 470 having the shape of the slot 473.
First, if the air compressed by an external air pump (not shown) is filled into the air space 471 via the cover plate 430, the air passes through the first slot 473a, the first through hole 451a, and the first nozzle 410a. Then, spraying is started on the cover glass 20 (S901).

Thereafter, when the rotation gate 470 rotates counterclockwise, the second slot 473b reaches the second through hole 451b first and is connected to the second through hole 451b and the second nozzle portion 410b. The second nozzle part 410b injects air (S903).
While the rotation continues, the third slot 473c, the fourth slot 473d, the fifth slot 473e, and the sixth slot 473f are connected to the through hole 451 and the nozzle portion 410 in this order, and air is injected (S905 to S911).

  Therefore, pressurization with air applied to the cover glass 20 is performed from the center of the cover glass 20 toward the edge, and such pressurization reduces the volume between the cover glass 20 and the OLED panel 10, It plays the role of pushing out bubbles that exist in the meantime to the edge side.

  Steps S901 to S911 are performed by one rotation of the rotary gate 470, and if the rotary gate 470 repeats rotation at a predetermined speed, sequential air injection by the first nozzle unit 410a to the sixth nozzle unit 410f is repeated. Air injection like the graph shown in FIG. 10 is performed. Further, the speed of the rotary gate 470 can be increased freely, and the repetition period or speed can be increased to a certain level. As described above, air injection or pressurization of the air press unit 400 is repeatedly performed at a constant cycle or speed, so that even if the pressure applied to one pressurization is a low pressure, the bubbles are sufficiently removed. This is applicable even when the pressure cannot be applied above a certain pressure as in the OLED panel 10.

The structure shown in FIGS. 4 to 9 described above has been described with respect to an example in which the number of nozzle portions and nozzle valves shown in FIG. 2 is six, but can be applied to the same form even when the numbers are different.
Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the present invention is not deviated from the gist of the present invention claimed in the claims. It should be understood that various modifications may be made by those having ordinary knowledge in the technical field to which the invention belongs, and such modifications may not be individually understood from the technical idea and perspective of the present invention. .

DESCRIPTION OF SYMBOLS 10 OLED panel 20 Cover glass 30 OCA film 100 OLED display panel 200, 400 Air press unit 211, 410 Nozzle plate 211a-211c, 410a-410f Nozzle part 213 Nozzle valve apparatus 213a-213c Nozzle valve 230, 490 Input valve 301, 411 Nozzle 413 Groove 430 Cover plate 431 Circular track 450 Nozzle gate 451 Through hole 470 Rotating gate 471 Air space 473 Slot

Claims (8)

A pressure removing device for removing bubbles between two bonded panels,
An input valve for controlling the pressure of air provided from the outside;
A plurality of nozzle portions for injecting air provided from the input valve to the panel;
A plurality of nozzle valves for individually opening and closing each of the plurality of nozzle portions, and pressurizing by injecting air toward the open surface of the panel,
The plurality of nozzle valves open and close the plurality of nozzle portions so that air sprayed onto the panel pressurizes the panel in a direction from the center of the panel toward the edge. . The plurality of nozzle portions are
Formed on a nozzle plate facing the open side of the panel;
A first nozzle portion disposed in the center of the nozzle plate;
A second nozzle portion disposed in a region surrounding the first nozzle portion;
A third nozzle portion disposed in a region surrounding the second nozzle portion,
2. The pressure removing device for removing bubbles according to claim 1, wherein the first nozzle unit, the second nozzle unit, and the third nozzle unit are sequentially opened and closed simultaneously at a predetermined cycle. . The plurality of nozzle valves are:
A cover plate coupled to the input valve;
At least one first through hole connected to the first nozzle part, at least one second through hole connected to the second nozzle part, and at least one third through hole connected to the third nozzle part. A nozzle gate formed and fixed to the nozzle plate;
An air space part for receiving air provided from the input valve is formed therein, and a rotary gate coupled rotatably between the cover plate and the nozzle gate,
The rotation gate opens the first through hole, the second through hole, and the third through hole, and simultaneously closes the first through hole, the second through hole, and the third through hole. The pressure removing device for removing bubbles according to claim 2, wherein a first slot, a second slot, and a third slot are formed. The first through hole, the second through hole, and the third through hole are disposed on a center line passing through a center of the nozzle gate;
The remaining slots excluding the first slot have arc shapes of a predetermined angle and are arranged on concentric circles, and the tip in the direction opposite to the rotation among the tips is the same passing through the center of the rotation gate. 4. The pressure removing device for removing bubbles according to claim 3, wherein the angle decreases as the distance from the center of the rotary gate is increased.   The pressure removing device for removing bubbles according to claim 3, wherein a gear or pulley structure for transmitting a rotational force from an external motor is formed on an outer peripheral surface of the rotating gate.   5. The bubble removing pressure device according to claim 3, wherein a plurality of remaining slots excluding the first slot are formed in the rotary gate. Each of the nozzle portions includes a plurality of nozzles, and upper end portions of the plurality of nozzles are connected to one groove opened on the upper side,
5. The pressure removing device for removing bubbles according to claim 3, wherein the through hole is formed at one point on the groove to simultaneously open and close a plurality of nozzles connected to the groove. 6. A pressure removing method for removing bubbles between two bonded panels,
Disposing a first nozzle portion in a central portion of the panel, disposing a second nozzle portion in a region surrounding the first nozzle portion, and disposing a third nozzle portion in a region surrounding the second nozzle portion; ,
The second nozzle portion injects air while the first nozzle portion injects air, and the third nozzle portion injects air while the first nozzle portion and the second nozzle portion inject air. Steps,
Simultaneously closing the first nozzle portion, the second nozzle portion, and the third nozzle portion while injecting air;
Repeating the steps of injecting and closing at regular intervals;
A pressure removing method for removing bubbles, comprising:

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