JP2002203515A - Discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp wherein discharge of impure gases such as carbon dioxide gas or the like generated at the time of decomposition of thermal electron radioactive substances to the outside of a bulb can be carried out by regulating a shape of a sealing part of a flare stem to support a filament electrode carrying the thermal electron radioactive substances. SOLUTION: The discharge lamp is equipped with a glass tube bulb 1, and a mount 2 wherein at least two lead wires 5, 5 and an exhaust pipe 4 are penetrated and hermetically sealed at one end side of the flare stem 3 sealed and fixed at an end part of this bulb 1 and wherein a coiled filament electrode 6 carrying the thermal electron radioactive substance 8 is successively joined to the lead wires 5, 5. In the discharge lamp L, the mount 2 has the exhaust pipe 4 and the filament electrode 6 orthogonally arranged and installed, and a guide wall to form an exhaust route in a successive installation with the exhaust pipe 4 is installed at the one end side of the stem 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp in which a flare stem having a coiled filament electrode is sealed at an end of a glass tube bulb.

[0002]

2. Description of the Related Art A low-pressure mercury vapor discharge lamp, such as a fluorescent lamp, has a flared stem of a mount sealed at an end of a glass tube bulb on which a phosphor coating is formed, and a coil-like shape is inserted between lead wires implanted in the stem. A filament electrode is provided, and an easy discharge gas such as mercury and argon is sealed therein as a discharge medium. Ultraviolet light having a wavelength of 254 nm or the like in the excitation spectrum of mercury atoms due to electric discharge is used as an excitation source for the phosphor film to emit light.

The coil-shaped filament electrode of this fluorescent lamp is formed with a thermionic emitting material (emitter) made of barium, strontium, calcium oxide or the like to facilitate discharge of the lamp. This thermionic emissive material evaporates and scatters with the progress of lighting of the lamp and is consumed. When the thermionic emissive material is used up, the discharge sustaining voltage increases and the discharge becomes difficult, and the lamp becomes inconsistent and has a long life .

[0004] This thermionic emissive substance is usually (Ba, S
A material mainly composed of r, Ca) O is used, and is applied to the filament electrode as a carbonate for safety in a ball milled suspension together with a binder such as nitrocellulose in a mount manufacturing process.

After the mount is hermetically sealed to the end of the glass tube bulb on which the phosphor film is formed, the interior of the bulb is evacuated via an exhaust pipe provided in the mount. The filament electrode is energized to activate thermionic emission material. Thereafter, mercury (in the case of amalgam or the like, previously disposed in a bulb) and an easily dischargeable gas such as argon are sealed, and the exhaust pipe is connected. Sealed. After the evacuation work has been completed, the fluorescent lamp is completed through a fitting process and an inspection process, and is shipped as a product.

Although this fluorescent lamp is a light source excellent in luminous efficiency and life, further improvement in quality is desired.
The inventor paid attention to activation of thermionic emission material applied to the filament electrode in the evacuation step.
At the time of this activation, a large amount of carbon dioxide gas CO ₂ was generated, and it was thought that this gas was sucked by the exhaust pump and removed outside the valve, but a considerable amount actually remained. I understood.

This is a mount M using a flare stem.
In FIG. 6, a flare portion F of a stem S is sealed to an end of a glass tube bulb B as shown in FIG. In the mount M, the lead wires L, L and the exhaust pipe H are hermetically sealed in a crushed sealing portion P formed on one end side of the stem S.
A coil-shaped filament electrode A carrying a thermoelectron-emitting substance E is connected to the lead wires L, L.

The opening K of the exhaust pipe H sealed by the crushed sealing portion P of the stem S of the mount M is compressed from the other end of the exhaust pipe H when forming the crushed sealing portion P. It is formed by blowing near the side wall of the sealing portion P which is in a softened state by blowing gas. Usually, the side near the left or right side wall of the sealing portion P has a high temperature and a high degree of softening, or the side where the thickness is thin. It is formed near one of the side walls, but may be formed on both left and right sides as shown by dotted lines when the gas blowing pressure is high.

The direction indicated by the opening K of the exhaust pipe H is obliquely upward in FIG.

The activation of thermionic emission substance E applied to the filament electrode A is performed by the filament electrode A
The electrode A is heated to about 1000 ° C. to activate the thermionic emissive substance E. The heating decomposes the thermionic emissive substance E composed of carbonate to form a carbon dioxide gas C.
The O ₂ release.

The released carbon dioxide gas CO ₂ is supplied to the valve B
If the residual gas remains inside the lamp, the lamp characteristics such as an insufficiency and a short life due to an increase in the discharge starting voltage are adversely affected. Therefore, the gas is exhausted to the outside of the bulb B via the exhaust pipe H of the mount M in this exhaust process.

According to the inventor's consideration, carbon dioxide CO ₂
Is generated in the form of an intermediate region between the viscous flow and the molecular flow, and immediately becomes a molecular flow. In the intermediate region between the viscous flow and the molecular flow, if there is an exhaust port in a portion of the carbon dioxide CO ₂ generating source close to the portion where the thermionic radioactive substance E is formed, it can be immediately sucked and discharged out of the valve B. In the case of molecular flow, carbon dioxide C
If there is no obstruction between the O ₂ generation source and the exhaust port, it can be smoothly sucked and discharged out of the valve B.

The opening K of the exhaust pipe H formed in the stem as described above does not face the direction of the electrode A carrying the thermionic emissive substance E, and the opening K and the filament electrode A Filament electrode A within the solid angle to be formed
Is present, but there is an obstacle such as turbulence caused by the crushed side wall of the sealing portion P.
Most of ₂ can be discharged together with the residual gas. However, part of the carbon dioxide gas CO ₂ diffuses to the vicinity of the sealing portion C between the valve B and the mount M.

The carbon dioxide gas CO _{2 which} has reached the vicinity of the sealing portion C can be reduced by continuously exhausting the gas for a long time, but is easily removed within an exhaust work time in which an index or the like is set in advance. can not, but the finished lamp exhaust work is a small amount remains is carbon dioxide CO _2.

[0015]

Therefore, the present inventor has proposed that carbon dioxide CO ₂ generated when the above-mentioned thermoelectron-emitting material carried on the filament electrode is decomposed is discharged early before diffusing into the bulb. Various investigations were made on the means.

The present invention regulates the shape of a sealing portion of a flare stem that supports a filament electrode carrying a thermionic emissive substance, so that an impure gas such as carbon dioxide gas CO ₂ generated when the thermionic emissive substance is decomposed is regulated. It is an object of the present invention to provide a discharge lamp capable of effectively discharging the outside of the bulb.

Incidentally, According to the experiment of the present inventor, if the opening of the exhaust pipe is arranged perpendicularly to the extending direction of the filament electrode A, the carbon dioxide C
It was found that O ₂ could be immediately discharged out of valve B.

As a mount satisfying such conditions, an exhaust pipe is pierced through the center of a disk-shaped glass plate, and a mount is provided at a position separated from the exhaust pipe by a predetermined distance.
There is a configuration in which a button stem formed by sealing through a lead wire is used, and a filament electrode is connected to the two lead wires.

However, the reason why the lamp using the button stem is not widely spread is that it is very difficult to seal the two lead wires on a glass plate having a disk shape, and it is difficult to seal many lead wires. There is a problem that the yield is very poor as compared with the case of stopping.

In this type of lamp, two lamps per stem
It is enough if there is only one lead wire, and it is uneconomical to use a large number of lead wires for the sealing operation, which increases the cost of the lamp. Therefore, the flare stem method is still widely used at present.

[0021]

According to a first aspect of the present invention, there is provided a discharge lamp comprising: a glass tube bulb; and at least two lead wires at one end of a flare stem sealed at an end of the bulb. A discharge lamp including a mount in which a coil-shaped filament electrode carrying a thermoelectron-emitting substance supported on a lead wire and hermetically sealed through an exhaust pipe, and a discharge medium sealed in the bulb is provided. The mount is characterized in that an exhaust pipe and a filament electrode are disposed orthogonally to each other, and a guide wall is formed at one end of the stem so as to be connected to the exhaust pipe to form a discharge path. And

Since a gas guide wall is provided on the stem portion of the mount toward the filament electrode and near the opening of the exhaust pipe, carbon dioxide gas CO2 generated when the thermoelectron-emitting substance applied to the electrode is decomposed is provided. Before the guide wall guides and diffuses the impurity gas, etc., in the middle area between the viscous flow and the molecular flow, it is sucked into the exhaust hole immediately and discharged out of the valve, and the amount of impurity gas remaining in the valve Can be reduced.

Also, in the lamp of the present invention, the opening of the exhaust pipe faces the filament electrode and is not directed toward the bulb surface. There is no direct gas or mercury spray,
Problems such as unnecessary substances adhering to the bulb and peeling of the phosphor film when the phosphor film is formed can be prevented.

In the claims and the following claims, the technical meanings of the terms are as described below unless otherwise specified.

The glass tube bulb is one in which both ends are sealed with a flare stem having electrodes to form an airtight container, and the material, shape and dimensions are not limited. Generally, a glass tube of soda lime glass, lead glass, or the like is used for reasons such as environmental friendliness, economy, and workability.

The shape of the glass tube bulb may be one or a plurality of glass tubes such as a straight tube, ring, U-shaped, W-shaped, double U-shaped (saddle-shaped) and H-shaped. Can be formed.

The discharge lamp can be applied to a fluorescent lamp using a hot cathode composed of a coil-shaped filament, an ultraviolet radiation lamp having no phosphor film formed thereon, and the like. , OA equipment, etc.

The thermoelectron-emitting substance (emitter) carried on the coil-shaped filament electrode is a commonly used substance mainly composed of an oxide of barium Ba, strontium Sr and calcium Ca.

As the discharge medium, argon Ar,
A gas mainly composed of an easily dischargeable (rare) gas such as xenon Xe, krypton Kr, and neon Ne is sealed. Also, mercury Hg is encapsulated by being liquid or amalgamated and attached to pellets or plates, for example.
There is also a lamp in which only a rare gas is not filled.

Further, the phosphor film can use various known phosphors. For example, a halophosphate phosphor or a three-wavelength rare earth phosphor may be used for a fluorescent lamp for general illumination. it can. Other arbitrary phosphors can be used according to the purpose and grade of the fluorescent lamp.

[0031] The discharge lamp according to claim 2 of the present invention comprises:
The guide wall forming the discharge path of the mount is formed of an exhaust pipe facing the inside of the valve.

A guide wall forming an impurity gas discharge system is formed by extending an exhaust pipe, and an opening thereof is brought closer to the filament electrode.
Has the same effect as described in (1).

The gas can be more efficiently sucked if the opening at the tip of the exhaust pipe is opened in a truncated shape.

[0034] The discharge lamp according to claim 3 of the present invention comprises:
A guide wall forming a discharge path of the mount is provided by molding a central portion of a crushed sealing portion that hermetically seals a lead wire and an exhaust pipe into a curved shape avoiding a virtual extension of the exhaust pipe. It is characterized by the following.

A guide wall forming a discharge path for the impure gas is formed by forming a crushed sealing portion following the opening of the exhaust pipe into a substantially semicircular curved shape. It guides and guides the air to the opening of the exhaust pipe, and has the same effect as described in the first aspect.

Since the crushed sealing portion having a curved shape has a large volume, a lead wire for supporting a shield or the like for shielding an electrode can be implanted in the sealing portion.

A discharge lamp according to a fourth aspect of the present invention comprises:
A guide wall forming a discharge path of the mount is provided by cutting out a central portion of a crushed sealing portion that hermetically seals a lead wire and an exhaust pipe.

A guide wall forming an exhaust gas discharge path is formed by using opposing wall surfaces formed by bisecting a crush seal portion following the opening of the exhaust pipe. Thus, the air is guided to the opening of the exhaust pipe to be discharged, and has the same effect as described in the first aspect.

[0039] The discharge lamp according to claim 5 of the present invention comprises:
A phosphor film is formed on the inner surface of the glass tube bulb.

When applied to a fluorescent lamp in which a phosphor film is formed on the inner surface of the bulb, the same effects as those of the above-mentioned claims 1 to 4 can be obtained.

[0041]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a partial cross-sectional front view showing one end of a discharge lamp, for example, a straight tube fluorescent lamp L, FIG. 2 shows a mount used for the fluorescent lamp L of FIG. 1, FIG. The figure is a partially cutaway side view,
FIG. 3C is a top view of a section taken along line aa in FIG.

In the drawing, reference numeral 1 denotes a straight tube glass bulb made of soda lime glass or lead glass, and a mount 2A is provided at each end (since both ends are the same, only one end is shown in FIG. 1). The flare portion 31 of the flare stem 3 made of a glass tube made of lead glass or the like is sealed to form an airtight container. Reference numeral 11 denotes a sealing portion with the stem 3, and reference numeral 12 denotes a phosphor film. In the figure, reference numeral 43 denotes a sealed (chip-off) portion of the exhaust pipe 4.

Further, as shown in FIG. 2, the mount 2A passes through the center of a flare stem (a glass tube whose one end side is expanded in a flared shape) 3 and an exhaust pipe 4 and a straight exhaust pipe 4.
A pair of lead wires 5 and 5 are disposed on both sides of the slab, and a crushed sealing portion 32 formed by heating and softening the other end is provided.

The exhaust pipe 4 located inside the crushed sealing portion 32
The portions correspond by means such as interposing a heat-resistant member in the exhaust hole 41 so that the exhaust hole 41 is not crushed when the sealing portion 32 is crushed. In addition, sealing wires 51, 51 such as dumet wires are used for the lead wire portion located in the crush sealing portion 32 in order to maintain airtightness.

The leg portions 61 of the coil-shaped filament electrode 6 formed by doubly or triple winding a tungsten wire are connected to the tips of the lead wires 5 and 5 by means such as welding or crimping. The coil-shaped portion is coated with a thermionic emission material (emitter) 8 mainly composed of an oxide of barium Ba, strontium Sr and calcium Ca, and is carried.

The extending direction of the filament electrode 6 and the opening 42 of the exhaust pipe 4 are orthogonal to each other. That is, the exhaust pipe 4 is coaxial with the axis of the valve as shown in the figure, and its tip is located at the top of the crushed sealing portion 32 which is longer than the conventional one or protrudes from the sealing portion 32.
The peripheral wall of the exhaust pipe 4 forms a guide wall forming an exhaust gas discharge path.

The operation of evacuating the fluorescent lamp L can be performed by ordinary manufacturing equipment. That is, the exhaust pipe 4
Since the opening 42 of the exhaust pipe 4 is provided so as to face the coil-shaped filament electrode 6 and close to the coil electrode 6 without any shielding, the thermionic emission material 8 is formed by applying a current to the electrode 6 in the exhaust process. The impurity gas such as carbon dioxide gas CO2 in the intermediate region between the viscous flow and the molecular flow generated at the time of decomposition is immediately sucked into the exhaust hole 41 connected to the vacuum pump and discharged.

Then, the impurity gas remaining in the valve 1 can be reduced to a very small amount by suppressing the diffusion of the impurity gas to other portions in the valve 1.

When the temperature of the electrode 6 rises when the thermoelectron-emitting material 8 is decomposed, scattered matter such as evaporated matter and compounds of the adhered substance adhered to the electrode member are removed together with the carbon dioxide gas CO 2 and the like through the exhaust hole 41. Can be sucked and discharged.

If the opening 42 at the end of the exhaust pipe 4 is opened in a truncated shape, gas can be more efficiently sucked. The tip of the exhaust pipe 4 projects further from the top of the stem 3 as shown by a dotted line in FIGS.
Then, it may be made to approach the filament electrode 6.

Also, once the impurity gas released by the decomposition of the thermoelectron-emitting material 8 is adsorbed on the phosphor film 7 or the wall of the bulb 1, it cannot be removed by suction with a vacuum pump and remains in the bulb 1. If this occurs, it is released as an impure gas during the operation of the lamp L, combines with mercury and adheres to the bulb 1 wall near the electrodes 6a and 6b to cause blackening, but such a phenomenon can be prevented.

When the fluorescent lamp L having this configuration is turned on by a lighting device, ultraviolet light of 254 nm or the like is generated from the evaporated mercury in the bulb 1 of the lamp L, and the fluorescent film 7 is excited to have a predetermined emission characteristic. Is shown. In addition, even if there is no impurity gas such as carbon dioxide gas CO2 remaining in the bulb 1, it is extremely small, and it suppresses the occurrence of inconsistencies due to a rise in the discharge starting voltage and blackening of the bulb 1 wall of the lamp L. Light emission characteristics can be improved.

Further, the first embodiment (see FIG. 4) of the evacuation operation in which the decomposition of the thermoelectron-emitting substance 8 is performed in a vacuum atmosphere,
Embodiments 2 and 3 of exhaust work performed in a low-pressure inert atmosphere
(See FIG. 4), there was no significant difference in the emission characteristics of the completed fluorescent lamp L.

The opening 41 of the exhaust pipe 4 extends to the center of the stem 3 and faces the filament electrodes 6a and 6b. When the active gas is introduced, the sprayed gas is dispersed by hitting the filament electrodes 6a and 6b, so that it does not strongly collide with the phosphor film 7 formed on the inner surface of the bulb 1 and peels off the phosphor film 7. This can be suppressed.

Accordingly, with a simple structure in which the arrangement of the exhaust pipes 4a and 4b is slightly changed from that of the conventional product, the advantageous effect that the luminous characteristics and appearance of the discharge lamp L can be maintained well.

In the above-described embodiment, the fluorescent lamp L having the fluorescent film 12 formed on the inner surface of the glass tube bulb 1 has been described as a discharge lamp, but the present invention does not have a fluorescent film such as an ultraviolet radiation lamp. The same applies to lamps.

FIGS. 3 and 4 show another embodiment of the mount used in the lamp of the present invention. FIG. 3 (a) is a front view, FIG. 3 (b) is a partially cutaway side view, and FIG. (A) is a top view as seen from a section taken along the line of arrow in the figure. In the figure, the same parts as those in FIG.

In the mount 2B shown in FIG. 3, the exhaust pipe 4 at the center of the stem 3 is sealed at the distal end near the lower end of the crush sealing portion 32, and the exhaust pipe 4 is provided around the opening 42 of the exhaust pipe 4. The crush seal portion 32 is formed upright in a substantially semicircular or substantially triangular curved shape. The coil-shaped filament electrode 5 has a configuration in which it faces the opening 42.

The substantially semicircular crush sealing portion 32 provided around the opening portion 42 of the exhaust pipe 4 forms a side wall continuous with the exhaust hole 41 but not all around, and forms a discharge system. As a guide wall, a negative pressure flow path is formed at the time of evacuation, and an impure gas such as carbon dioxide gas CO ₂ generated by decomposition of thermionic emission material 8 applied to the filament electrode 5 is guided to the exhaust pipe 4. The gas is guided to the opening 42, acts as a guide for preventing diffusion into the valve 1, and the impurity gas and the like can be discharged to the outside of the valve 1 through the exhaust hole 41.

When the shape of the crushed sealing portion 32 is substantially semicircular or substantially triangular as described above, another lead wire 6 is implanted near the center as shown by a dotted line in the figure. It can be used, for example, when supporting a shield ring having a rectangular shape, an oval shape, a circular shape, or the like that covers the periphery of the filament electrode 6 as an electrode or a support of the mercury emission structure.

In the mount 2C shown in FIG. 4, the exhaust pipe 4 at the center of the stem 3 seals the distal end near the lower end of the crush seal 32, and the center of the crush seal 32 is notched. The notch 33 has an opening 42 of the exhaust pipe 4. The mount 2C also has a configuration in which the coil-shaped filament electrode 5 crosses and faces the opening 42.

In this case as well, the opening 42 of the exhaust pipe 4
Although not the entire circumference of the exhaust pipe 4, the guide walls forming the discharge path of the impure gas are connected to the crush sealing portions 32, 32 that follow the opening 42 of the exhaust pipe 4.
Is formed by utilizing the opposing wall surfaces formed by dividing into two. The sidewalls on both sides form a negative pressure flow path during exhaust, and serve as a guide for preventing diffusion of impurity gases such as carbon dioxide gas CO ₂ generated by decomposition of thermionic emission material 8 applied to the filament electrode 6. Thus, it is possible to guide the impurity gas or the like to the exhaust hole 41 and to help discharge it to the outside of the valve 1.

Then, the mount 2B having the crushable sealing portion 32 having the structure shown in the embodiment of FIG. 3 and FIG.
2C also exhibits the same operational effects as the mount 2A of the above-described embodiment. The formation of the crush sealing portion 32 shown in FIGS. 3 and 4 can be easily obtained by using a pincher (die).

Further, in the above-mentioned mounts 2A to 2C, the leg portions 61 of the coiled filament 6 connected to the tips of the lead wires 5 and 5 by welding or crimping are viewed from the side surfaces of the lead wires 5 and 5. The protruding part is shown in FIG.
May be melted as shown in FIG.

The wire-shaped or coiled leg portions 61, 61 projecting from the side surfaces of the lead wires 5, 5 are originally unnecessary portions in terms of characteristics, but secure connection when connecting. It is a necessary part for.

The leg portions 61, 61 are concentratedly heated and shrunk by using a plasma torch or a laser beam, and the fused portions 62, 62 are welded to the lead wire 5. However, even if there is an abnormality, the welded portions 62 can strengthen the connection between them, thereby eliminating problems such as defects.

The fluorescent lamp L using such mounts 2A to 2C is mounted on a socket such as a lighting fixture or a lighting device (neither is shown), and the filament electrodes 6 and 6 are connected via a lighting circuit device. It is lit by energizing to. The fluorescent lamp L is either no residual impurity gases such as carbon dioxide CO ₂ in the valve, a very small amount even, prevention of short-life Hakare also Habukeru luminaires and lighting time, such as lamp replacement An apparatus can be provided.

[0068]

In the invention according to claims 1 to 4, according to the present invention, efficiently impure gas such as carbon dioxide CO ₂ generated during the activity of the thermal electron emitting material coated formed filament electrode from the glass tube bulb emissions it can. As a result, there is no impurity gas remaining, or even a very small amount, and the emission characteristics are improved to prevent the occurrence of short life and the reduction of the luminous flux maintenance rate due to the inconvenience caused by the increase in the firing voltage. This has the advantage of providing an improved lamp.

According to the fifth aspect of the present invention, the effects described in the first to fourth aspects are achieved by applying the present invention to a fluorescent lamp in which a phosphor film is formed on the inner surface of a glass tube bulb.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view of a main part (one end) showing an embodiment of a discharge lamp of the present invention, for example, a straight tube fluorescent lamp.

2 (a) to 2 (c) show a mount used for the fluorescent lamp of FIG. 1, wherein FIG. 2 (a) is a front view, FIG. 2 (b) is a partially cutaway side view, and FIG. a) is a top view of a section taken along line aa in FIG.

3 (a) to 3 (c) show another embodiment of the mount, FIG. 3 (a) is a front view, FIG. 3 (b) is a partially cutaway side view, and FIG. 3 (c) is a view (a). FIG. 4 is a top view of a section taken along line bb in FIG.

4 (a) and 4 (c) show other embodiments of the mount, wherein FIG. 4 (a) is a front view, FIG. 4 (b) is a partially cutaway side view, and FIG. 4 (c) is a view (a). FIG. 7 is a top view of a section taken along line cc of arrow in FIG.

FIG. 5 is a front view showing a connection portion between a lead wire of a mount and a coil-shaped filament electrode.

FIG. 6 is a partially sectional front view showing one end of a conventional fluorescent lamp.

[Explanation of symbols]

 L: Discharge lamp (fluorescent lamp) 1: Glass tube bulb 2A-2C: Mount 3: Flare stem 4: Exhaust pipe 41: Opening 5: Lead wire 6: Filament electrode 8: Thermionic emission material

Claims (5)

[Claims] At least two lead wires and an exhaust pipe are hermetically sealed through one end of a glass tube bulb and a flare stem sealed to an end of the bulb, and the lead wire is provided with a thermionic radiation. In a discharge lamp including a mount in which a coil-shaped filament electrode carrying a substance is connected and a discharge medium sealed in the bulb, the mount has an exhaust pipe and a filament electrode arranged orthogonally. And a guide wall formed at one end of the stem so as to be connected to the exhaust pipe to form a discharge path. 2. The discharge lamp according to claim 1, wherein the guide wall forming the discharge passage of the mount comprises an exhaust pipe facing the inside of the bulb. 3. A guide wall forming a discharge passage of the mount forms a central portion of a crushed sealing portion which hermetically seals a lead wire and an exhaust pipe into a curved shape avoiding a virtual extension of the exhaust pipe. The discharge lamp according to claim 1, wherein the discharge lamp is provided. 4. A guide wall forming a discharge path of the mount is provided by forming a central portion of a crushed sealing portion which hermetically seals a lead wire and an exhaust pipe by notch molding. The discharge lamp according to claim 1. 5. The discharge lamp according to claim 1, wherein a phosphor film is formed on an inner surface of the glass tube bulb.