JP2781158B2 - Fluorescent tube firing device for backlight - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for firing a cold cathode fluorescent tube used for a backlight source of a liquid crystal display device, and more particularly, to a fluorescent lamp for a backlight in an upright state. TECHNICAL FIELD The present invention relates to a firing apparatus that eliminates uneven firing by blowing a gas through a furnace.

[0002]

2. Description of the Related Art A very thin fluorescent lamp having a diameter of about 2 to 3 mm is used as a backlight of a liquid crystal display device. The step of manufacturing such a fluorescent lamp includes a step of passing a fluorescent tube formed by applying a fluorescent material to the inner surface of a hollow glass tube through a furnace and heating and firing to remove impurities in the fluorescent material. .

As a conventional firing apparatus for performing such a fluorescent tube firing step, (a) as shown in FIG. 13A, a large number of rollers r are arranged in a rotatable and parallel manner. In this state, the fluorescent tube m is placed on a roller conveyor c attached to a chain t, and the fluorescent tube is passed under the heating furnace h while rotating the fluorescent tube in a substantially horizontal state by the rotation of the roller of the roller conveyor. Place a tube
As shown in FIG. 13 (B), by firing at a constant temperature, air is blown out from an air blowing nozzle n provided along the transfer direction of the roller conveyor c at the side of the roller conveyor c, and fired. A device for eliminating impurities released from the fluorescent material into the fluorescent tube, or
(B) As shown in FIGS. 14A and 14B, a number of shafts s are arranged in a rotatable and parallel manner, and a boss-equipped flange f is attached to each shaft s in the axial direction, and the flanges are provided. The fluorescent tube m is placed on the flange f of the conveyor c 'which is formed by forming an arc-shaped conveyance groove g at one location around the f.
While rotating the fluorescent tube in a substantially horizontal state by rotation of the shaft s and the flange f fixed to the shaft, sequentially pass under the heating furnace by the action of the transport groove formed in the flange, The fluorescent tube is heated and baked to a predetermined temperature, and air is blown out from an air blowing nozzle provided along the side of the roller conveyor c 'along the conveyor transfer direction to remove impurities released from the fluorescent material into the fluorescent tube by the baking. Devices and the like for elimination are known.

However, in the apparatus described in (a), since the roller r is deformed by heat as shown in FIG. 13C while the roller conveyor passes under the heating furnace, the diameter of the fluorescent tube is increased. If the diameter is too small, there is a disadvantage that the fluorescent tube m enters between the adjacent rollers r and the fluorescent tube is damaged. Further, since the diameter of the fluorescent tube is small, when firing a long fluorescent tube, there is a disadvantage that the air blown out from the air jet nozzle is not sufficiently supplied to the entire inside of the fluorescent tube.

In the apparatus described in (b), the fluorescent tubes are supported in a state of being floated from the shaft around the flange fixed to the shaft. If the length is L _{1 to} L ₃ , a flange must be provided correspondingly, and it is not possible to process a fluorescent tube of a length other than a predetermined type. Since the engagement occurs at the same position, the heating is delayed only by that portion, causing uneven firing.The fluorescent tube is bent by heat at a position not supported by the flange, and it is difficult to form the fluorescent tube in a straight line, and the tube is bent. In the case of a fluorescent tube of various lengths, in order to be able to treat the fluorescent tube of various lengths, it is not possible to rotate the tube, and in fact, unnecessary flanges come in contact in the middle of the fluorescent tube, causing uneven firing. Saruhara Also it becomes. Further, in the case where a long fluorescent tube is fired similarly to the apparatus described in (A), there is a problem that the air blown out from the air jet nozzle is not sufficiently supplied to the entire inside of the fluorescent tube.

[0006]

The problem to be solved by the present invention is that the fluorescent tube is heated and fired while holding one end of the fluorescent tube vertically while holding the tube vertically as described above. It is an object of the present invention to provide an apparatus for firing a fluorescent tube for a backlight, which eliminates the conventional drawbacks of transferring and firing in a substantially horizontal state when mounted on a plurality of flanges fixed to a shaft.

Another problem to be solved by the present invention is to supply a gas into the fluorescent tube through a holding head for holding an end of the fluorescent tube so that the gas can be reliably supplied into the fluorescent tube. It is another object of the present invention to provide an apparatus for firing a fluorescent tube for a backlight.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided a backlight fluorescent tube for heating and firing a fluorescent tube having a fluorescent material coated on its inner surface while transferring the fluorescent tube along a predetermined path. In the apparatus, a holding head for detachably holding an upper end of the fluorescent tube so as to hold the fluorescent tube in a vertical position and for sending gas from the held upper end of the fluorescent tube to the inside of the fluorescent tube; a holding head moving mechanism for moving the holding head to a Jo Tokoro transport path, a position of the lower side of the holding head, is disposed across the transfer path of the fluorescent tubes held by the holding head heating And a furnace.

In the above-described apparatus for firing a fluorescent tube for a backlight, the holding head transfer mechanism includes a rotating table that rotates about a rotation axis that extends substantially vertically, and the plurality of holding heads are attached to a peripheral portion of the rotating table. It may be. Further, the holding head has a hollow rotary shaft rotatably supported by the rotary table and a chuck attached to the rotary shaft to grip the fluorescent tube, and the gas sent to the fluorescent tube is Even if the baking device is provided with a large gear that is fixed to the rotary table adjacent to the rotary table and is fixed to the rotary table, the firing device meshes with a pinion fixed to the rotary shaft. Good. Furthermore,
A rotary valve having a rotary valve disk concentrically fixed to the rotary table and a fixed valve disk in contact with the rotary valve disk and disposed concentrically with the rotary valve disk; A port of a disk may be in fluid communication with the interior of the rotating shaft to control the supply of gas from the holding head via the rotary valve. Further, a nozzle head having a nozzle hole formed with a conical inner surface is attached to the lower end of the rotating shaft, and the fluorescent tube is held by the chuck with the upper end of the fluorescent tube in contact with the conical inner surface. Is also good. Also,
The heating furnace may be divided into a plurality of heater blocks in a circumferential direction, and an electric heater may be disposed on a surface of each of the heater blocks facing the transfer path.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a fluorescent tube firing apparatus according to the present invention. The baking apparatus 1 according to this embodiment is roughly divided into a holding head 4 that holds the fluorescent tubes in a vertical state, a holding head transfer mechanism 2 that supports the holding head 4 and moves along a predetermined transfer path, A gas supply device 6 for controlling the supply of gas, for example, clean air, to the holding head, and a chuck rotating mechanism 7 for rotating a chuck attached to the holding head
And a heating furnace 8 for heating and firing the fluorescent tubes held and transported by the holding head 4, which are arranged in a positional relationship as shown in FIG.

1 and 2, a holding head transfer mechanism (hereinafter simply referred to as a transfer mechanism) 2 includes a hollow inner support 15 fixed vertically to a lower frame 11 by a known method.
A rotary support shaft 21 disposed outside the inner support 15 and concentric with the inner support 15 and disposed between the hollow outer support 16 fixed to the middle frame 12 in a known manner;
A rotary table 23 fixed to the upper part of the rotary support shaft 21; The rotation support shaft 21 is rotatably supported on the columns 15 and 16 by a plurality of bearings 22a to 22d. A gear 25 is fixed to the lower end of the rotation support shaft 21, and the gear 25 meshes with a gear 27 attached to an output shaft 26a of a speed reducer 26 attached to the lower frame. The speed reducer 26 is driven by a motor 28. Therefore, the rotary table 23
Is continuously rotated by a motor via a speed reducer 26, gears 27 and 25 and a rotation support shaft 21.

2 to 4, a plurality of fluorescent tube holding heads 4 are arranged at equal intervals around the turntable 23. As shown in FIG. The holding head 4 includes a bracket 41,
A rotating shaft 43 rotatably mounted in a through hole 41a of the bracket 41 via a bearing 42;
3 has a nozzle head 44 attached to the lower end thereof, and a chuck 50 attached to the rotating shaft 43 below the bracket 41. A through hole 43a penetrating in the axial direction is formed in the rotating shaft. The nozzle head 44, the nozzle hole 44a of Jo Tokoro diameter as shown in FIG. 5
Is formed at the lower open end of the nozzle hole 44a. The inner surface 44a of the cone receives the upper edge of the fluorescent tube m to be fired.

3, 4 and 7 to 9, the chuck 50 has a mounting member 51 fixed to a lower portion of the rotating shaft 43, and is rotatably mounted to one end of the mounting member 51. Lever member 52 and mounting member 51
Lever member 5 rotatably attached to the other end of the lever
3 and a link 54 connecting both lever members 52 and 53
And The lever member 52 is provided by a spring 58a provided between the lever member and a spring receiver attached to the mounting portion 51, and the lever member 53 is provided by a spring 58b provided between the lever member and the spring receiver.
, Respectively, are deflected in the counterclockwise direction in FIG. As is clear from FIG. 7, the rotation center of the lever member 52 and the rotation center of the lever member 53 with respect to the mounting member 51 are on a line OO passing through an axis of the rotation shaft 43 to which the mounting member 51 is mounted. Are located in
A cam follower 57 that engages with an external cam to rotate the lever member is rotatably attached to the second end of the lever member 52.

As shown in FIG. 9, the claw members 55 and 56 receive the fluorescent tube m in the V-shaped groove 55b of the claw 55a and hold the fluorescent tube m with the other claw 56a to hold the end of the fluorescent tube. . As shown in FIG. 8, the center of the V-shaped groove 55 b of the claw 55 a is located away from the center of rotation of the lever member 53 so that the axis of the fluorescent tube m held by both claws coincides with the axis of the rotating shaft 43. separated by a distance of L _1, also the center of the claw 56a is spaced from the center of rotation of the lever member 52 by a distance of L _2.

In the holding head, the lever member 52
Cam follower 57 attached to the second end 52b of the
Is pushed by an external cam (not shown) to
Is moved to the open position Po against the action of the spring, the other lever members 53 are also moved to the open position via the link 54, and the pawl members 55 attached to those lever members are moved.
And 56 are spaced apart from each other in the open position of the chuck. Under these conditions, when the fluorescent tube m is supplied from below by a supply device (not shown) in a state where its axis is aligned with the axis of the rotating shaft 43 (at this time, the outer edge of the upper end of the fluorescent tube is a nozzle. The cam follower 57 separates from the cam, and the lever member 52 is turned clockwise in FIG. 8 by the action of the spring to the closed position Pc. In this state, the lever member 53 is also in the closed position, and the fluorescent tubes are held by the claw members 55 and 56 of the chuck attached to the lever members. At this time, the axis of the fluorescent tube is aligned with the axis of the rotating shaft 43.

2 and 5, a gas supply device 6 for supplying a gas such as clean air into the rotating shaft 43 of the holding head is passed through the inner support 15 and connected to a gas supply source (not shown). A plurality of gas supply pipes 61, a rotary valve 65 provided between the disk-shaped upper frame 13 attached to the upper end of the inner support 15 via the cylindrical spacer 14 and the rotary table 23, A plurality of piping groups 64 are provided for communicating the rotary valve with the through hole 43a of the rotating shaft 43 of each holding head. The rotary valve 65 includes a ring-shaped fixed valve disk 66 fixed to the upper frame 14 concentrically with the rotation axis of the rotation support shaft 21,
A ring-shaped rotary valve disk 67 is concentrically fixed on the rotary table 23 via a support member 68. The lower surface of the fixed valve disk 66 and the upper surface of the rotary valve disk 67 are in contact. Fixed valve disk 66
A groove 66a extending a predetermined distance in the circumferential direction and a plurality of supply passages (the same number as the number of gas supply pipes 61, but only one gas supply pipe 61 is shown in FIG. 66b, and the supply passage 66b communicates with the corresponding gas supply pipe 61 via the conduit 62. A plurality of ports 6 (equal to the number of holding heads attached to the rotary table) of which one end is open on the upper surface of the valve disk 67 and the other end is open on the outer peripheral surface of the rotary valve disk 67.
7a are formed. An open end on the upper surface side of the port 67a communicates with the groove 66a of the fixed valve disc. Each port 67a communicates with a corresponding through hole 43a of the rotating shaft 43 of the holding head 4 via a corresponding piping group 64. Each tubing group 64 includes a conduit 64a having one end connected to a port 67a of the rotary valve disc.
A connector 64b connected to the other end of the conduit 64a and fixed to the bracket 41 of the holding head; a rotary connector 64c of a known structure mounted on the upper end of the rotating shaft 43; and the connector 64b and the rotary connector 64d and a conduit 64d for connection with the conduit 64d.

In the gas supply device 6, when the firing device is operating, gas such as clean air is supplied into the groove 66a of the fixed valve disk 66 via the gas supply pipe 61 and the conduit 62. And the rotary table 23
When the holding head attached to the rotary table comes to a predetermined position by the rotation of the port, the port 67a corresponding to the holding head starts communicating with the groove 66a, and is inserted into the through hole of the rotating shaft of the holding head. Start gas supply.

2 to 4, a chuck rotating mechanism 7 includes a ring-shaped large gear 72 mounted on a mounting ring 71 fixed to the upper frame 13 outside the rotary valve 65, and a rotating shaft of the holding head 4. A pinion 73 is attached to the upper portion of the wheel 43 and meshes with the gear 72. This chuck rotating mechanism 7
Is the rotary table 23 because the large gear 72 is fixed.
When the holding head moves along the outer periphery of the large gear due to the rotation of the pinion 73, the pinion 73 revolves around the large gear while rotating, thereby rotating the rotation shaft 43, thereby rotating the chuck. I have. As the chuck rotates, the fluorescent tube held by the chuck also rotates.

In FIGS. 10 to 12, the heating furnace 8 for heating and firing the fluorescent tube is moved from the position U in FIG. 10 along an arc centered on the rotation axis O _t of the rotation support shaft 21 of the transfer device 2. V extends in the circumferential direction. The heating furnace 8 is divided into a plurality (four in this embodiment) of parts 80a to 80d along the circumferential direction.
0d constitutes an end portion, and portions 80b and 80c constitute an intermediate portion. Each of the portions 80a to 80d has an inner portion 81 arranged radially inward with respect to the arcuate transfer path P of the fluorescent tube m held by the chuck 50 of the holding head 4, and an outer portion arranged radially outward. And a portion 82.

One divided inner heater block 81
Is provided with an outer wall 810, both end walls 811 and a heat insulating block 812 surrounded and held by the walls, and an electric heater tube 83 having a known structure is arranged on a surface of the heat insulating block on the transfer path P side. I have. Similarly, the outer heater block 82 includes an outer wall 820, both end walls 821, and a heat insulating block 822 held and surrounded by the walls.
An electric heater tube 84 having a known structure is arranged on the surface of the heat insulating block on the transfer path P side. Cover plates 85 and 86 are disposed and fixed above the inner heater block 83 and the outer heater block 84, respectively, leaving a narrow gap between them to allow a fluorescent tube to pass. At the inlet end 87 of the heating furnace section 80a and at the outlet end 88 of the section 80d, the heat insulating block of the inner heater block and the heat insulating block of the outer heater block have a narrow gap between them so that the fluorescent tube can pass therethrough. Separated by. These are to minimize the heat in the heating furnace from leaking outside through the upper part, the inlet and the outlet of the heating furnace.

[0021] In the firing device having the above structure, during operation is supplied clean air to the position of the rotary valve of the gas supply apparatus, the speed of the rotary table 23 of the transfer device 2 is Jo Tokoro counterclockwise direction in FIG. 10 by a motor Is rotated continuously. When the holding head 4 reaches the position W due to the rotation of the rotary table, the fluorescent tube is sent to the position of the chuck 50 of the holding head in a vertical state by a fluorescent tube supply mechanism of a known structure (not shown).
The second open end is biased to the open position Po in FIG. 8 by an external cam (not shown) by an external cam (not shown). Hold. At this time, the outer edge of the upper end of the fluorescent tube abuts on the conical inner surface 44b of the nozzle head 44 to prepare for the supply of clean air via the nozzle head.

As the rotary table 23 of the transfer device 2 still rotates, the fluorescent tube m moves along the transfer passage P in the counterclockwise direction in FIG. The inside of the heating furnace is advanced from the entrance end of the furnace 8. Simultaneously with or before or after the fluorescent tube enters the heating furnace, clean air is supplied to the port connected to the holding head holding the fluorescent tube via the rotary valve 65 of the gas supply device 6. Then, the clean air starts to be supplied into the fluorescent tube via the through hole 43a of the rotating shaft 43 and the nozzle hole 44a of the nozzle head 44. Heating and firing of the fluorescent tube is performed until the fluorescent tube moves along the transfer path P and reaches the outlet end of the heating furnace. While the fluorescent tube is being fired, the clean air supplied from the upper end of the fluorescent tube is discharged into the heating furnace from the lower end. Impurities generated from the fluorescent material by heating of the fluorescent tube while the clean air passes through the inside of the fluorescent tube is discharged to the outside by the air flow.

When the fluorescent tube exits from the exit end of the heating furnace, the supply of clean air to the holding head via the rotary valve is stopped, the chuck is opened by a cam (not shown), and a take-out device having a known structure (not shown) As a result, the fluorescent tube is received from the chuck of the holding head. Hereinafter, the same operation is repeated, and the heating and firing of the fluorescent tubes is sequentially performed while the holding head moves along the transfer path P by the rotation of the rotary table.

[0024]

According to the present invention, the following effects can be obtained. (A) Since the gas can be reliably supplied to the inside of the fluorescent tube by bringing the nozzle head close to the end of the fluorescent tube, a high-quality fluorescent tube can be manufactured. (B) Since the fluorescent tube is held and rotated in a vertical state, the fluorescent tube does not bend or warp. (C) Since the fluorescent tube can be reliably rotated, uneven firing is eliminated. (D) Due to continuous driving, unnecessary impact on the fluorescent tube during firing can be reduced. (E) Since the fluorescent tube is held by the chuck, damage to the fluorescent tube during the firing step can be reduced as compared with the conventional method .

[Brief description of the drawings]

FIG. 1 is an elevational view showing one embodiment of a baking apparatus for a fluorescent tube for a backlight according to the present invention, and is a view showing a part in a cross section.

FIG. 2 is an enlarged cross-sectional view of an upper portion of the firing device of FIG.

FIG. 3 is an enlarged vertical sectional view of a holding head.

FIG. 4 is an elevational view of the holding head of FIG. 3 as viewed along arrow AA.

FIG. 5 is an enlarged sectional view of a nozzle head.

FIG. 6 is a top view of the holding head of FIG. 3;

FIG. 7 is a cross-sectional view of the holding head of FIG. 4 as viewed along arrow BB.

FIG. 8 is a bottom view as viewed along arrow CC in FIG. 4;

FIG. 9 is a perspective view showing a state where the fluorescent tube is held by a claw member.

FIG. 10 is a plan sectional view of a heating furnace.

11 is a cross-sectional view of the heating furnace of FIG. 14 taken along line EE.

12 is a cross-sectional view of the heating furnace of FIG. 14 taken along line FF.

13A to 13C are diagrams illustrating an example of a conventional firing method.

14A and 14B are diagrams illustrating another example of a conventional firing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluorescent tube baking apparatus 2 Holding head transfer mechanism 21 Rotation support shaft 23 Rotary table 4 Holding head 41 Bracket 43 Rotation shaft 43a Through hole 44 Nozzle head 50 Chuck 6 Gas supply device 7 Chuck rotation mechanism 72 Large gear 73 Pinion 8 Heating furnace

Claims (6)

(57) [Claims] 1. A backlight fluorescent tube firing apparatus for heating and firing a fluorescent tube coated with a fluorescent material on its inner surface along a predetermined route while heating the fluorescent tube, wherein the fluorescent tube is vertically inside the holding head to send the gas transport path of the holding head Jo Tokoro of the fluorescent tube from the upper end portion of the fluorescent tube which is held together to hold the upper end of the fluorescent tube to hold a posture of detachably For a backlight, comprising: a holding head transfer mechanism that moves along the holding head; and a heating furnace that is located below the holding head and that is arranged across a transfer path of the fluorescent tube held by the holding head. Fluorescent tube firing device. 2. The apparatus for firing a fluorescent tube for a backlight according to claim 1, wherein the holding head transfer mechanism includes a rotating table that rotates about a vertically extending rotation axis, and the plurality of holding heads are provided. An apparatus for firing a fluorescent tube for a backlight, which is attached to a periphery of the rotary table. 3. The apparatus for firing a fluorescent tube for a backlight according to claim 2, wherein said holding head is attached to said hollow rotary shaft rotatably supported by said rotary table and said rotary shaft. And a chuck for gripping the fluorescent tube. Gas sent to the fluorescent tube is passed through the rotating shaft, and the baking device is disposed adjacent to the rotating table and concentrically with the rotating table. A baking device for a fluorescent tube for a backlight, comprising: a set gear wheel, the gear wheel meshing with a pinion fixed to the rotating shaft. 4. The apparatus for firing a fluorescent tube for a backlight according to claim 3, further comprising: a rotary valve disk concentrically fixed to said rotary table and said rotary valve disk being in contact with said rotary valve disk. A rotary valve having a valve disk and a fixed valve disk disposed concentrically, wherein a port of the rotary valve disk is in fluid communication with the interior of the rotary shaft and is separated from the holding head via the rotary valve. Baking device for a fluorescent tube for backlight, which controls the supply of gas. 5. The apparatus for firing a fluorescent tube for a backlight according to claim 3, wherein a nozzle head having a nozzle hole formed with a conical inner surface is attached to a lower end of the rotating shaft, An apparatus for firing a fluorescent tube for a backlight which is held by the chuck in a state where the upper end of the fluorescent tube is in contact with the inner surface. 6. The apparatus for firing a fluorescent tube for a backlight according to claim 1, wherein said heating furnace includes a plurality of heater blocks divided in a circumferential direction. A baking device for a fluorescent tube for a backlight, wherein an electric heater is provided on a surface facing the transfer path.