JPH04332456A - Fluorescent lamp and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent a sealing edge part of a fluorescent lamp, which is formed by press-fitting a glass-tubular body, from disturbing a liquid crystal display device, into which this fluorescent lamp is integrated as a backlight, from being made into a thin type. CONSTITUTION:A thin wall part thinner than the central wall thickness part is formed in a glass tubular body 1. An electrode unit 13 is inserted from one edge part 2 of the glass tubular body 1, and air is evacuated. Afterwards, the thin wall thickness part is press-fitted and is cut and the electrode unit 13 is sealed up in the one edge part 2 of the glass tubular body 1 so as to form a sealing edge part 2a.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp used as a backlight for, for example, a liquid crystal display device, and a method for manufacturing the fluorescent lamp.

0003

2. Description of the Related Art In recent years, for example, as liquid crystal display devices have become thinner, there has been a tendency for fluorescent lamps used as backlights of the liquid crystal display devices to become smaller in diameter.

[0004] As the diameter of fluorescent lamps has become smaller, an open end of a glass tube body is used as an exhaust pipe. After exhausting the glass tube from this one end,
A method of manufacturing a fluorescent lamp has been adopted in which a rare gas of ~4 Torr and an appropriate amount of mercury are sealed and one end of the lamp is sealed.

Known methods for sealing the ends of the glass tube include a bead seal method and a mechanical chip pressure bonding method.

A method for sealing a glass tube using the bead seal method is to insert and fix a well 24 connected to an electrode 23 into a glass tube 21 from one end 22, as shown in FIGS. 10 to 12. Insert the glass bead 25. Next, the inside of the glass tube 21 is evacuated from this one end 22, and the glass tube 21 and the glass beads 25 are welded together by heating with a burner 26 or the like in a vacuum. The electrode 23 is sealed at one end of the electrode 23.

The method of sealing the glass tube 21 using the mechanical chip pressure bonding method is to insert a well 24 connected to an electrode 23 from one end 22 of the glass tube 21, as shown in FIGS. 13 to 15 in order. Then, the inside of the glass tube body 21 is evacuated from this one end portion 22. Then, the vicinity of one end 22 of the glass tube body 21 is softened by heating with a burner, and the glass tube body 21 is cut by pressure with a mechanical tip.
1. An electrode 23 is sealed in one end 22 of the electrode 1.

[0008]

[Problems to be Solved by the Invention] However, in the sealing method using the bead seal method described above, the glass beads 25 are prepared in advance, and the glass beads 2
The problem is that the work of inserting and fixing the well 24 into the tube 5 is required, and the number of manufacturing steps for the fluorescent lamp is large.

Furthermore, in order to prevent leakage from the contact surface with the well 24, the glass beads 25 must be formed so that the contact surface with the well 24 has a width of at least 2 to 3 mm.

Furthermore, since the glass tube body 21 has a wall thickness of usually 0.4 to 0.8 mm, the glass beads 2
5 and the glass tube body 21 using the burner 26, it was difficult to weld the glass tubes 5 and 21 to the same melting state because their respective wall thicknesses were different. Therefore, residual strain occurs on the bonding surface between the glass bead 25 and the glass tube body 21, and this residual strain may cause cracks to occur in the bonding surface, and slow leakage of the fluorescent lamp may occur from this crack. There is.

Furthermore, the glass tube body 21 and the glass beads 2
Even if 5 and 5 are sufficiently melted and welded, gas is generated from the molten glass, and this gas remains as an impurity inside the glass tube body 21, causing the fluorescent lamp to be defective. There is.

On the other hand, in the conventional sealing method using the mechanical chip pressure bonding method described above, one end 22 of the glass tube body 21 is
The vicinity is crimped and cut using a mechanical chip to seal the end 28.
As shown in FIGS. 15 and 16, the sealed end 28 has a flat shape in which softened glass is extruded in a direction perpendicular to the direction in which the mechanical chip is crimped. Therefore, the length L in the longitudinal direction of the sealed end 28 in the direction perpendicular to the axial direction of the glass tube 21 is
It becomes longer than the outer diameter d of.

Therefore, when this fluorescent lamp is incorporated into, for example, a liquid crystal display device, the fluorescent lamp has a glass tube body 2.
The length L in the longitudinal direction of the sealed end 28 of 1 is the length L of the glass tube 21
Since the sealing end portion 28 is longer than the outer diameter d of the sealing end portion 28, this sealing end portion 28 becomes a cause of hindering the reduction in thickness of the liquid crystal display device.

Furthermore, in order to make the longitudinal length L of the sealed end 28 shorter than the outer diameter d of the glass tube, a method is adopted in which the sealed end 28 is shaped during crimping and cutting. However, in order to extend the shaped sealed end 28 in the axial direction of the glass tube body 21, the lamp length of the fluorescent lamp becomes long, and the effective light emission length relative to the total length of the fluorescent lamp is shortened.

The object of the present invention was made in view of the above-mentioned problems, and the sealed end portion formed by pressing and cutting the glass tube hinders the reduction in thickness of a device such as a liquid crystal display device in which it is incorporated. The object of the present invention is to provide an unprecedented fluorescent lamp and a method for manufacturing the same.

[Configuration of the invention]

[0017]

[Means for Solving the Problems] In the fluorescent lamp according to claim 1, an electrode portion is inserted into an end portion of a glass tube body, exhaust is exhausted from this end portion, and the end portion is crimped. In the fluorescent lamp in which the electrode portion is sealed, the sealed end portion sealed by pressure bonding has a flat cross section in a direction perpendicular to the axial direction of the glass tube, and the length in the longitudinal direction of this cross section is as follows. It is shorter than the outer diameter of the glass tube.

The method for manufacturing a fluorescent lamp according to claim 2 comprises:
A thin-walled part is formed in the glass tubular body, the thickness of which is thinner than that of the central part of the glass tubular body, an electrode part is inserted into one end of the glass tubular body, and exhaust is exhausted from the one end. The electrode portion is sealed by crimping the electrode portion.

[0019]

[Function] In the fluorescent lamp according to claim 1, the sealed end of the glass tube to which the electrode portion is crimped has a flat cross section in the direction perpendicular to the axial direction of the glass tube, and the longitudinal direction of this cross section is flat. Since the length of is shorter than the outer diameter of the glass tube, the sealed end of the crimped glass tube is located inward from the extended surface of the outer surface of the glass tube. .

The method for manufacturing a fluorescent lamp according to claim 2 comprises:
A thin-walled portion is formed in the glass tube, the thickness of which is thinner than that of the central portion of the glass tube, an electrode portion is inserted into one end of the glass tube, exhaust is exhausted from the one end, and the thin-walled portion is thinned. Since the electrode portion is sealed by crimping the thin wall portion, the sealed end portion with the thin wall portion crimped has a flat cross section in the direction perpendicular to the axial direction of the glass tube, and a flat cross section in the longitudinal direction of this cross section. The length is formed to be shorter than the outer diameter of this glass tube.

[0021]

[Embodiment] An embodiment of the fluorescent lamp of the present invention and its manufacturing method will be explained based on FIGS. 1 to 9.

In FIG. 1, reference numeral 1 denotes a glass tube, and this glass tube has an outer diameter d1 of 4 to 6 mm and a wall thickness t1 of 0.5 mm.
It is formed into a straight tube shape of 8mm.

As shown in FIG. 3, this glass tube body 1 has the following features:
The axial direction of the glass tube body 1 is held vertically, a vacuum pump (not shown) is connected to the upper end portion of the glass tube body 1 as one end portion 2, and the lower end portion of the glass tube body 1 as the other end portion 3 is made of alumina (Al
2 O3 ), titanium oxide (TiO3), or zinc oxide (ZnO). Then, when the ultraviolet absorber 4 is sucked up and applied to a predetermined height on the inner surface, which is lowered, for example, by 80 mm from the upper end of the glass tube 1, an ultraviolet absorbing film 5 as an ultraviolet blocking film is formed. Furthermore, as shown in FIG. 4, the ultraviolet absorbing film 5 near the other end 3 of the glass tube 1 is peeled off to form a sealing margin 6.

Next, as shown in FIG.
Holding the axial direction vertically, one end 2 of this glass tube 1
A vacuum pump (not shown) is connected to the upper end of the phosphor liquid 8 made of phosphor particles, and the lower end of the other end 3 is connected to a phosphor liquid 8 made of phosphor particles.
Soak in. Then, when the phosphor liquid 8 is sucked up and applied from the lower end of the glass tube 1 to a predetermined height slightly above the upper edge of the ultraviolet absorbing film 5 on the inner surface, a phosphor film 9 is formed. Further, as shown in FIG. 6, the fluorescent film 9 formed on the sealing margin 6 is peeled off so that the lower end of the ultraviolet absorbing film 5 is not exposed.

Next, as shown in FIG. 7, the glass tube 1 is turned upside down, and a Dumet wire is connected to the wedge-shaped electrode 11 made of nickel as a well 12 from the other end 3 of the glass tube 1. The connected electrode section 13 is inserted and brought into contact with the inner surface of the glass tube body 1. Then, the sealing margin 6 near the other end 3 is melted and sintered by heating with a burner 15, etc., and the electrode part 13 is sealed to the other end 3 of the glass tube 1, as shown in FIG. .

Furthermore, as shown in FIG. 9, the glass tube 1 is turned upside down again, and from one end 2 of the glass tube 1,
The electrode portion 13 is inserted into a portion below the upper edge of the fluorescent film 9 where the ultraviolet absorbing film 5 and the fluorescent film 9 are formed, and brought into contact with the inner surface of the glass tube 1 .

Then, one end 2 of the glass tube body 1 is fixed with a jig 1.
The portion of the glass tube 1 to be sealed, which is supported by the electrode portion 4 and sealed with the electrode portion 13, is softened by heating with a burner 15 or the like. Next, the softened portion to be sealed is stretched in the axial direction so that the outer diameter d2 is smaller than the outer diameter d1 of the glass tube 1.
The wall thickness t2 (
0.4≦t2≦0.6 mm).

Then, while the glass tube 1 is kept supported by the jig 14, the inside of the glass tube 1 is evacuated from the one end 2. After the glass tube body 1 is evacuated, a rare gas of 30 to 100 Torr and an appropriate amount of mercury are sealed inside the glass tube body 1, and the thin wall portion 16 is crimped and cut using a mechanical tip, and the well 12 is attached to the thin wall portion 16. It is sealed to form a sealed end 2a.

Furthermore, conductive pieces (not shown) for connection are connected to the wells 12 led out of the glass tube 1, respectively.

Next, the operation of this embodiment will be explained.

[0031] Thin wall portion 1 crimped with mechanical chip
6, since the outer diameter d2 and the wall thickness t2 are both smaller than the outer diameter d1 and the wall thickness t1 of the glass tube, the amount of glass to be crimped is large enough to crimp other parts of the glass tube 1. This is less than in the case. Therefore, the glass tube body 1 of the sealed end portion 2a where the thin wall portion 16 is crimped and sealed.
The length L in the longitudinal direction of the cross section in the direction perpendicular to the axial direction can be made shorter than the outer diameter d1 of the glass tube 1, and this sealed end 2a It is possible to prevent it from protruding outward from the extension surface.

Therefore, when the fluorescent lamp is used as a backlight of a liquid crystal display device, for example, since the sealed end 2a of the fluorescent lamp is located inward from the extended surface of the outer peripheral surface of the glass tube 1, The sealed end portion 2a can be prevented from becoming a cause of hindering the reduction in thickness of the liquid crystal display device.

[0033] Furthermore, this sealed end 2a is connected to the glass tube body 1.
Since the glass of the thin wall portion 16 is softened and then cut by pressure, the occurrence of cracks can be suppressed compared to the case where the glass is formed by welding. Therefore, slow leakage from the sealed end 2a can be prevented. Further, since the glass is not melted, generation of gas from the glass can be prevented, and impurity gas can be prevented from remaining inside the glass tube body 1.

Furthermore, when sealing the end of the glass tube body 1, a separate member such as glass beads is not required, and the process for manufacturing this separate member is eliminated, so that the number of steps for manufacturing the fluorescent lamp can be reduced.

In the above embodiment, the thin wall portion 16 is formed after the one end 2 of the glass tube 1 is supported by the jig 14, and then the one end 2 of the glass tube 1 is supported with the jig 14. Although the glass tube 1 was evacuated, the present invention is not limited to this, and after forming the thin wall portion 16 of the glass tube 1, one end 2 of the glass tube 1 is held with a jig 14, and the glass tube 1 is evacuated. The inside of the body 1 may be evacuated and the electrode section 13 may be sealed in the glass tube body 1.

[0036]

According to the fluorescent lamp according to claim 1, the crimped sealed end has a flat cross section in the direction perpendicular to the axial direction of the glass tube, and has a flat cross section in the longitudinal direction of the sealed end. Since the length is formed to be shorter than the outer diameter of the glass tube, this sealed end can be prevented from protruding outward beyond the extended surface of the outer peripheral surface of the glass tube. Therefore, when the fluorescent lamp is incorporated into, for example, a liquid crystal display device, the sealed end of the fluorescent lamp does not protrude outward beyond the extended surface of the outer circumferential surface of the glass tube, so that the sealed end is attached to the liquid crystal display. It is possible to prevent the display device from becoming a cause that hinders the reduction in thickness of the display device.

According to the method for manufacturing a fluorescent lamp according to claim 2, a thin wall portion having a thickness thinner than that of the central portion of the glass tube body is formed in the glass tube body, and this thin wall portion is crimped. By doing so, the amount of glass to be crimped can be reduced compared to the case where other parts of the glass tube are crimped. The cross section in the direction perpendicular to the axial direction of the glass tube can be formed flat, and the length of this cross section in the longitudinal direction can be formed to be shorter than the outer diameter of the glass tube. Therefore, the sealed end can be prevented from protruding outward beyond the extended surface of the outer peripheral surface of the glass tube, and the device incorporating this fluorescent lamp can be made thinner. Furthermore, since the thin wall portion of the sealed end portion is softened and crimped, cracks are prevented from occurring and slow leakage of the fluorescent lamp is suppressed. Furthermore, since the glass is not melted, gas generation from the glass can be prevented, and impurity gases from the fluorescent lamp can be prevented from remaining. Further, when sealing, a separate member such as glass beads is not required, and the manufacturing process for this separate member is eliminated, so the number of manufacturing steps for the fluorescent lamp can be reduced.

[Brief explanation of drawings]

FIG. 1 is a front view of a fluorescent lamp showing an embodiment of the present invention.

FIG. 2 is a front view of the sealed end of the fluorescent lamp.

FIG. 3 is an explanatory diagram illustrating a step of forming an ultraviolet absorbing film in a method of manufacturing a fluorescent lamp according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating a step of removing the ultraviolet absorbing film and forming a sealing margin.

FIG. 5 is an explanatory diagram illustrating a process of forming the same fluorescent film as above.

FIG. 6 is an explanatory diagram illustrating a step of removing the fluorescent film and forming a sealing margin.

FIG. 7 is an explanatory diagram illustrating a step of sealing the other end of the glass tube body.

FIG. 8 is a longitudinal sectional view of the glass tube with the other end sealed.

FIG. 9 is an explanatory diagram illustrating a process of forming a thin portion same as the above.

FIG. 10 is an explanatory diagram illustrating a sealing process using a bead seal method for a conventional fluorescent lamp.

FIG. 11 is an explanatory diagram illustrating a sealing process using a bead seal method following FIG. 10 of the same.

FIG. 12 is a longitudinal cross-sectional view of the fluorescent lamp sealed by the bead seal method.

FIG. 13 is an explanatory diagram illustrating a sealing process using a mechanical chip compression method for a conventional fluorescent lamp.

FIG. 14 is an explanatory diagram illustrating a sealing process using a mechanical chip pressure bonding method following FIG. 13 of the same.

FIG. 15 is a side view of the fluorescent lamp sealed by the mechanical chip pressure bonding method.

FIG. 16 is a front view of the sealed end portion of the same.

[Explanation of symbols]

1 Glass tube body 2a Sealed end 13　　　Electrode part 16 Thin wall part

Claims (2)

[Claims] 1. A fluorescent lamp in which an electrode part is inserted into an end of a glass tube body, exhaust is evacuated from this end, and the electrode part is sealed in this end by crimping. The sealed end portion is characterized in that a cross section in a direction perpendicular to the axial direction of the glass tube is flat, and the length of this cross section in the longitudinal direction is shorter than the outer diameter of the glass tube. fluorescent lamp. 2. A thin wall portion is formed in the glass tube body, the thickness of which is thinner than that of the central portion of the glass tube body, an electrode portion is inserted into one end portion of the glass tube body, and an exhaust gas is discharged from the one end portion. A method for manufacturing a fluorescent lamp, characterized in that the thin wall portion is crimped to seal the electrode portion.