JP3093641B2 - Exhaust device for fluorescent display tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust device for a fluorescent display tube, and more particularly to an exhaust device for a fluorescent display tube having no exhaust pipe for exhaust and having an exhaust hole sealed with a lid member.

[0002]

2. Description of the Related Art A fluorescent display tube having a structure in which there is no exhaust pipe for exhaust and an exhaust hole is sealed with a cover member is known. As a device for vacuum-evacuating and sealing such a fluorescent display tube, an exhaust device shown in FIG. 3 has been used. In this exhaust device, an exhaust head 3 connected to an exhaust path 13 has an O-ring 26 and a heat equalizing plate 5 on an upper end surface thereof, and a fluorescent display tube 2 has an exhaust hole 8 formed on the exhaust head 3. It is placed so that it becomes the center of 26. Inside the exhaust head 3, a sealing heater 6, which is a component having a heater mounted thereon, is disposed, and a lid member 60 is provided on an upper end surface.
Is placed. The sealing heater 6 is pressed against the lower end of the guide shaft 9 by the compression spring 11 so as not to be sucked up to the exhaust hole 8 side of the fluorescent display tube 2 even during vacuum evacuation. In addition, power is supplied from a circuit wired to the turntable 12. A plurality of exhaust heads 3 are fixed on the rotary table 12 and are rotated at a set index time. The sealing heater 6 can be raised only while raising the push-up portion 14 disposed at a fixed position outside the rotary table 12. In the process of evacuating and sealing the fluorescent display tube 2, a lid member 60 coated with a low-melting glass on the upper surface is placed on the upper end surface of the sealing heater 6, and the O-ring 26 is attached to the heat equalizing plate 5 on the exhaust head 3. Via the fluorescent display tube 2
And the inside of the exhaust head 3 is evacuated. Rotary table 1
By rotating 2 at the set index time, the fluorescent display tube 2 can obtain a constant process index time. By proceeding with the process, the fluorescent display tube 2 is sufficiently evacuated and heated to a predetermined temperature by the heating furnace 15.
The sealing heater 6 starts heating at a predetermined position after the start of evacuation, and is controlled to a temperature at which the low-melting glass of the lid member 60 melts. When the process proceeds and the fluorescent display tube 2 reaches the position of the push-up portion 14, heating by the sealing heater 6 is stopped, the push-up portion 14 is raised, the sealing heater 6 is pushed up, and the lid member 60 is moved to the fluorescent display tube 2. It is pressed against the exhaust hole 8 with a constant pressure and sealed. After being pushed up for a certain period of time, the push-up portion 14 is lowered and the sealing heater 6 is raised.
Is locked downward by the compression spring 11.

On the other hand, Japanese Patent Application Laid-Open No. 04-061727 discloses that, as shown in FIG. 4, the sealing heater 50 is installed in an exhaust head 24 and moves vertically through compression springs 30 and 51. An exhaust sealing device 1 for a fluorescent display tube provided with a transmission device 33 that provides the following. This is the transmission device 3
3, the pressing force of the cover member 60 is set by the compression springs 30, 51, and the transmission device 33 is raised by pressing means (not shown), and is fixed by the stopper plate 39 in this state. Further, the lowering of the transmission device 33 is performed by releasing the stopper plate 39, which is the exhaust sealing device 1 for a fluorescent display tube.

[0004]

The first problem is that, in the prior art, a process index is required to keep the state in which the sealing heater is pushed up and pressed for a certain period of time after the lid member is sealed. You have to make the time longer. The reason is that the sealing heater push-up is limited only when the rotary table is stopped, and the sealing heater is locked downward by the compression spring to lower the sealing heater push-up portion while the rotary table is moving. Because.

A second problem is that, in the prior art, in order to keep the sealing heater in contact with the lid member for more than a certain time in order to heat or cool the lid member even after sealing, the process index time must be lengthened. That is something that must be done.
The reason is the same as the case of the first problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and it is possible to maintain the sealing heater in a raised state without increasing the process index even after sealing, thereby reducing the pressing time of the lid member. In addition, the degree of freedom of temperature control including heating and cooling time is increased, and more stable temperature control including heating and cooling time, which is more stable than the conventional process index time, can be obtained. An object of the present invention is to provide an exhaust device for a fluorescent display tube.

[0007]

An exhaust device for a fluorescent display tube according to the present invention comprises a rotary table, an exhaust head disposed on the rotary table, connected to an exhaust path, and evacuating the fluorescent display tube through an exhaust hole. A sealing heater that is housed inside the exhaust head, seals the fluorescent display tube by mounting a lid member on the upper surface, and heating and fusing the lid to the exhaust hole; In a fluorescent display tube exhaust device having a push-up portion that raises the sealing heater at a position, a compression spring and a magnet are disposed below the sealing heater for locking downward during evacuation, Alternatively, the lower portion of the sealing heater may be provided with a downward locking during evacuation.
Magnet and the seal
A magnet for surely lowering the arrival heater is arranged.

In the conventional example, since the downward locking force of the sealing heater 6 is only the compression spring 11 force, when the push-up portion 14 is lowered during sealing, the sealing heater 6 is also lowered by the compression spring 11 force. . Therefore, the pressing force application time of the lid member 60 is
It is determined by the time during which the push-up unit 14 is raised.

In the present invention, the downward locking force of the sealing heater 6 is the force of the compression spring 11 or the attraction force of the magnet 47 and the magnet 16, and the force of the compression spring 11 is smaller than in the prior art. Even if the portion 14 is lowered, the sealing heater 6 is pressed and held in the exhaust hole 8 by the atmospheric pressure from the lower end of the sealing heater 6. Therefore, the pressing force application time of the lid member 60 does not need to be governed by the time during which the push-up portion 14 is raised. Therefore, from the elapse of the process index time, the rotation table 1
Even if the push-up portion 14 descends due to the movement of the sealing member 6, the sealing heater 6 is locked upward, so that an appropriate pressurizing time and temperature control are applied to the cover member 60.

[0010]

Next, an exhaust device for a fluorescent display tube according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of an exhaust device for a fluorescent display tube according to a first embodiment of the present invention. As shown in FIG. 1, in the exhaust device for a fluorescent display tube according to the first embodiment of the present invention, an exhaust head 3 connected to an exhaust path 13 has an exhaust head 3 and a fluorescent display tube 2 on its upper end surface. And a heat equalizing plate 5 for supporting and uniformly heating the fluorescent display tube 2 so that the fluorescent display tube 2 has the exhaust hole 8 at the center of the O-ring 26. Be placed. Inside the exhaust head 3, the sealing heater 6, which is a component having a heater attached to an upper portion sufficient to melt the low-melting glass applied to the lid member 60, is attached to the sealing heater support 18 via the O-ring 26. The lid member 60 is placed on the upper end surface. The sealing heater 6 has an elastic force of the compression spring 11 disposed between the heater bottom 19 and the sealing heater support 18 and a magnet 16 attached to the magnet 16 attached to the lower end of the guide shaft 9 and the heater bottom 19 and magnetized. The sealing heater 6 is locked downward by a magnetic force generated between the suction heater 17 and a suction plate 17 made of a metal having a certain shape. The elastic force of the compression spring 11 can lock the sealing heater 6 downward when the inside of the exhaust head 3 is at atmospheric pressure, and when the inside of the exhaust head 3 is vacuum, the sealing heater 6
The elastic force is set to such an extent that it cannot be locked downward. The magnetic force of the magnet 16 is sufficient to lock the sealing heater 6 downward even when the inside of the exhaust head 3 is vacuum. Further, the sealing heater 6 includes a rotating table 12.
The power is supplied from a circuit (not shown) wired to the power supply. A plurality of exhaust heads 3 are fixed on the rotary table 12, and are moved at a set index time by intermittently rotating the rotary table 12. This movement makes it possible to pass through the fixed heating furnace 15 and evacuate the exhaust head 3 via the exhaust path 13. The sealing heater 6 is pushed up by raising a push-up portion 14 disposed at a fixed position outside the rotary table 12,
The cover member 60 is pressed against the exhaust hole 8 of the fluorescent display tube 2. Even if the push-up portion 14 is lowered, the sealing heater 6 can be locked upward by atmospheric pressure in a state where the inside of the exhaust head 3 is evacuated. Further, when the inside of the exhaust head 3 is set to the atmospheric pressure at the outside air introducing portion disposed at a fixed position outside the rotary table 12, the sealing heater 6 can be lowered. The push-up force of the push-up portion 14 is set to be equal to or greater than the combined force of the magnetic force of the magnet 16, the elastic force of the compression spring 11, and the own weight of the sealing heater 6.

Next, the operation of the exhaust device for a fluorescent display tube according to the first embodiment of the present invention will be described in detail with reference to FIG. A lid member 60 coated with a low-melting glass on the upper surface is placed on the upper end surface of the sealing heater 6 locked downward by the force of the compression spring 11 and the attraction force of the magnet 16, and is placed on the heat equalizing plate 5 on the exhaust head 3. After the fluorescent display tube 2 is placed via the O-ring 26, the rotary table 12 is moved to evacuate the inside of the exhaust head 3 and the fluorescent display tube 2. By moving the turntable 12 at the set index time, the fluorescent display tube 2 obtains a constant process index time. By moving the rotary table 12 and proceeding with the process, the exhaust head 3
The degree of vacuum in the inside and the fluorescent display tube 2 gradually increases, but the sealing heater 6 remains locked downward by the force of the compression spring 11 and the attraction force of the magnet 16. The fluorescent display tube 2 is heated to a predetermined temperature by passing through the heating furnace 15. The sealing heater 6 is energized and heated at a predetermined position after the rotation table 12 is moved, and is controlled to a temperature at which the low-melting glass applied to the lid member 60 is melted.

When the degree of vacuum in the fluorescent display tube 2 is sufficiently increased to reach a predetermined temperature and the fluorescent display tube 2 reaches the position of the push-up portion 14, the push-up portion 14 is raised, and the force of the compression spring 11 and the magnet 16 The sealing heater 6 is pushed up with a constant pressing force equal to or more than the suction force of the above, and the lid member 60 in which the low-melting glass is sufficiently melted is pressed against the exhaust hole 8 to seal. After pushing up for a certain period of time, the push-up section 14 is lowered. The downward locking force of the sealing heater 6 is:
Since the force of the compression spring 11 and the attraction force of the magnet 16 and the force of the compression spring 11 are small, even if the push-up portion 14 descends, the sealing heater 6 is not affected by the atmospheric pressure from the lower end of the sealing heater 6. The exhaust hole 8 is pressed and held. As the process index time elapses, a constant pressing force and temperature control can be applied to the lid member 60 even when the rotary table 12 moves, so that the fusion force can be improved.

Further, when the fluorescent display tube 2 reaches the outside air introduction portion at a predetermined position due to the elapse of the process index time, the inside of the exhaust head 3 becomes atmospheric pressure and the compression spring 1 moves downward.
The sealing heater 6 is lowered by the force of 1, and is locked downward by the force of the compression spring 11 and the attraction force of the magnet 16, so that the fluorescent display tube 2 can be taken out.

FIG. 2 is a sectional view of an exhaust device for a fluorescent display tube according to a second embodiment of the present invention. As shown in FIG. 2, in the exhaust device for a fluorescent display tube according to the second embodiment of the present invention, the sealing heater 6 has a compression spring 11 between a heater bottom portion 19 and a sealing heater support portion 18. Instead, the sealing heater 6 is locked downward only by the magnetic force of the magnet 16 and the weight of the sealing heater 6. The push-up portion 14 is located at the same exhaust position as that of the first embodiment, but the second push-up portion 49 is located at the position of the outside air introduction portion.
have. A magnet 47 is attached to the upper end surface of the second push-up portion 49. When the fluorescent display tube 2 arrives at the outside air introduction portion , the inside of the exhaust head 3 becomes atmospheric pressure, and then the sealing head is closed.
To compensate for the instability of the descent of only the weight of
In order to lower the heater 6 reliably, the second push-up portion 49 is raised, and the magnet 47 is attracted to the suction plate 17, and the second push-up portion 49 is moved.
Is lowered, the sealing heater 6 can be lowered by the attraction force of the magnet 47. When the second push-up portion 49 is further lowered, the sealing heater 6 is locked downward by the attraction force of the magnet 16, and the magnet 47 and the attraction plate 17 are separated. In this embodiment, since the compression spring 11 is not provided, the structure can be simplified.

[0016]

The first effect is that an appropriate pressurizing time and a stable pressing force to the lid member can be obtained, and the fusing property of the lid member can be improved. The reason is that the sealing heater can be locked to the lid member side by the atmospheric pressure even after the sealing, so that the pressurizing time can be extended and the degree of freedom can be increased. This is because the pressure can be reduced and the pressing force can be stabilized.

The second effect is that an appropriate heating and cooling time for the lid member after sealing can be obtained, and the fusion property can be improved as in the first effect. The reason is that the sealing heater can be locked to the lid member side by the atmospheric pressure even after the sealing, so that the heating and the cooling time can be lengthened, the degree of freedom of the temperature control can be increased, and a marginal setting is possible. is there.

[Brief description of the drawings]

FIG. 1 is a sectional view of an exhaust device for a fluorescent display tube according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an exhaust device for a fluorescent display tube according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of an example of a conventional fluorescent display tube exhaust device.

FIG. 4 is a cross-sectional view of another example of a conventional exhaust device for a fluorescent display tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust sealing device 2 Fluorescent display tube 3, 24 Exhaust head 12 Rotary table 5 Heat equalizing plate 6 Sealing heater 8 Exhaust hole 9 Guide shaft 11, 30, 51 Compression spring 13 Exhaust path 14 Push-up part 15 Heating furnace 16, 47 Magnet 17 Adsorption plate 18 Sealed heater support 19 Heater bottom 33 Transmission device 50 Heater 60 Cover

Claims (2)

(57) [Claims] 1. A rotary table, an exhaust head disposed on the rotary table, connected to an exhaust path, and evacuating the fluorescent display tube through an exhaust hole, and a lid member housed inside the exhaust head and mounted on a top surface. A sealing heater that seals the fluorescent display tube by heating and fusing the lid member to the exhaust hole; and a push-up unit that raises the sealing heater at a predetermined position on the rotary table. In a vacuum exhaust device for a fluorescent display tube, a compression spring and a magnet are arranged below the sealing heater for locking downward during evacuation, and a magnet is arranged. 2. A rotary table, an exhaust head disposed on the rotary table, connected to an exhaust path, for evacuating the fluorescent display tube through an exhaust hole, and a lid member housed inside the exhaust head and mounted on an upper surface. A sealing heater that seals the fluorescent display tube by heating and fusing the lid member to the exhaust hole; and a push-up unit that raises the sealing heater at a predetermined position on the rotary table. In an exhaust device for a fluorescent display tube , a vacuum is exhausted below the sealing heater.
Magnet for locking down when
Magnetic force for securely lowering the sealing heater on the upper end surface
An exhaust device for a fluorescent display tube, wherein stones are arranged .