JP2017183276A - Discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a film of fluorescent material, or the like, in a desired shape, in an excimer lamp.SOLUTION: A discharge lamp includes a bottomed outer pipe 20 having first and second introduction tubes formed at the opposite ends, an inner pipe 50 arranged in the outer pipe coaxially therewith, and having a convex face formed at the first introduction tube side end, a pair of electrodes 30, 40 opposed to each other while intervening the outer pipe and inner pipe, and a membrane formed on the inner surface of the outer pipe and the surface of the inner pipe including the convex face, where the first introduction tube is extending in the axial direction of the outer pipe. The second introduction tube may be configured to extend in the radial direction of the outer pipe.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a discharge lamp such as an excimer lamp or an external electrode type fluorescent lamp that emits light by dielectric barrier discharge or capacitively coupled high-frequency discharge, and in particular, a phosphor or the like is coated in a film shape on the inner surface of a small-diameter arc tube. Relates to a discharge lamp.

  As the excimer lamp, a double tube structure lamp is known in which an arc tube is constituted by an inner tube and an outer tube. For example, a foil electrode is embedded in the inner tube along the axial direction, and light is emitted by generating a dielectric barrier discharge with the outer electrode disposed on the outer surface of the outer tube. (See Patent Document 1).

  On the other hand, a discharge lamp that emits fluorescence by providing phosphors on the inner and outer tube surfaces in advance and exciting the phosphors with xenon excimer light is known (see Patent Document 2).

JP 2012-38658 A JP 08-228598 A

  In recent years, a small-diameter excimer lamp is also required for an excimer lamp having a double tube structure. In such a small-diameter lamp, it is difficult to apply a phosphor or the like in a film form. For example, in the method of heat sealing after applying the phosphor, the phosphor is easily peeled off, and it is difficult to uniformly apply the phosphor to the inner surface of the outer tube and the outer surface of the inner tube. In addition, when the phosphor coating material flows into and out of the arc tube through the introduction tube, starch and bubbles remain, and it is difficult to uniformly apply the phosphor.

  Therefore, it is required to form a film made of a phosphor or the like on the surface of the arc tube in a desired film state.

  The discharge lamp of the present invention has a bottomed outer tube formed with a first introduction tube and a second introduction tube at both ends, and is coaxially arranged in the outer tube, and has a convex surface at the first introduction tube side end. An inner tube formed, a pair of electrodes disposed opposite to each other with the outer tube and the inner tube interposed therebetween, and a film formed on the inner tube surface including the inner surface and the convex surface of the outer tube, The first introduction pipe extends along the axial direction of the outer pipe. The second introduction tube can be configured to extend along the radial direction of the outer tube.

  For example, the film can be formed of a phosphor film, and emits fluorescence when excited by ultraviolet rays radiated in the discharge space. There are various shapes and dimensions of the outer tube and the inner tube. For example, as a small-diameter discharge lamp, the outer tube has a wall thickness of 0.8 mm to 1.5 mm, the outer tube has an inner diameter of 6 mm to 25 mm, and the inner tube has a thickness. Can be determined to be in a range of 0.1 mm to 2 mm and a discharge distance of 3 mm to 12.5 mm.

  The membrane can be adjusted with respect to its axially formed length or thickness, or both length and thickness can be adjusted. For example, the film can be formed so as to be formed partway along the axial direction from the first introduction tube side. Further, the thickness of the film can be formed differently depending on the film formation location. In this case, a relatively thin film portion and a relatively thick film portion can be formed along the axial direction.

  According to another aspect of the present invention, there is provided a method for manufacturing a discharge lamp, comprising: forming a bottomed cylindrical outer tube, and forming a bottomed cylindrical inner tube with a convex surface that reduces the outer surface of the tip toward the tip side. A step of forming a tube, a step of providing a first introduction tube along the axial direction of the outer tube on the tip side of the outer tube, and a second introduction tube along the radial direction of the outer tube on the opening side of the outer tube The outer tube and the inner tube are arranged coaxially and are integrally welded at the rear end portions on the respective opening sides to form a discharge space, and the paint is allowed to flow in and out from the first introduction tube And forming a film on the inner peripheral surface of the outer tube, the outer peripheral surface of the inner tube, and the convex surface of the inner tube tip.

  For example, the step of removing the film from the inner surfaces of the first introduction tube and the second introduction tube, the step of exposing the inner surfaces of the first introduction tube and the second introduction tube to the discharge space, and evacuating the discharge space to discharge A step of sealing the gas and a step of hermetically sealing the first introduction tube and the second introduction tube by heating and melting may be included.

  According to another aspect of the present invention, there is provided a discharge lamp film generation (film formation) method comprising: a light-emitting tube having a bottomed first introduction tube and a second introduction tube at both ends, and an inner surface of the light-emitting tube. A discharge lamp film forming method, wherein the first introduction tube extends along the axial direction of the outer tube, and the second introduction tube extends along the radial direction of the outer tube. A suction period when the membrane material is sucked from the first introduction tube and / or the membrane material is adjusted so that the axial length and / or thickness of the membrane is a predetermined length and / or thickness. 1 Adjust the flow rate when flowing out from the inlet pipe.

  According to the present invention, in the discharge lamp, a film made of phosphor or the like can be formed on the surface of the arc tube in a desired film state.

It is a schematic sectional drawing of the discharge lamp which is 1st Embodiment. It is the figure which showed the manufacturing process of the discharge lamp. It is a schematic sectional drawing of the discharge lamp which is 2nd Embodiment. It is a schematic sectional drawing of the discharge lamp in 3rd Embodiment. It is a schematic sectional drawing of the discharge lamp which is 4th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of a discharge lamp according to the first embodiment.

  The discharge lamp 10, which is an excimer lamp, emits light that forms a discharge space S by integrally welding a bottomed cylindrical outer tube 20 made of a dielectric material such as quartz glass and an inner tube 50 at a sealing portion 53. A tube 11 is provided, and a phosphor film C (film) is applied to the inner surface of the arc tube 11.

  A distal end portion (hereinafter referred to as an outer tube distal end portion) 21 of the outer tube 20 that is the distal end of the arc tube 11 is placed at a position that is coaxial with the arc tube 11 (outer tube 20). 61 (referred to as a first introduction pipe) is disposed. In addition, a second introduction along the radial direction of the arc tube 11 (outer tube 20) is introduced into the rear end portion (hereinafter referred to as the outer tube rear end portion) 22 of the outer tube 20, which is the rear end of the arc tube 11. A tube (hereinafter referred to as a second introduction tube) 62 is provided.

  The outer surface of the distal end portion (hereinafter referred to as the inner tube distal end portion) 51 of the inner tube 50 is reduced in diameter toward the inner tube bottom surface (front end side) at a position facing the opening of the first introduction tube 61. Convex surface. That is, the inner tube distal end portion 51 has a hemispherical shape whose outer diameter decreases toward the distal end side (the side opposite to the sealing portion 53) of the discharge lamp 10. The inner tube tip 51 may have a bullet shape (elliptical shape), a tapered shape (triangle), or the like.

  By using the inner tube tip 51 having such a shape, no stagnation or bubbles are generated near the outer surface of the inner tube tip 51 when the paint flows into and out of the arc tube, and only the inner tube tip 51 is formed. However, it is possible to prevent a state where the film thickness is increased or a state where the film is not applied.

  The inner surface of the outer tube 20 (the inner peripheral surface of the cylindrical portion of the outer tube 20), the outer surface of the inner tube 50 (the outer peripheral surface of the cylindrical portion of the inner tube 50), and the convex surface of the inner tube tip 51 The phosphor film C is coated on the surface exposed to the discharge space S. On the other hand, the phosphor film C is not applied to the inner surfaces of the first introduction tube 61 and the second introduction tube 62 exposed to the discharge space S.

  In the discharge space S, a rare gas such as xenon gas or a mixed gas thereof is sealed as a discharge gas. The sealed pressure of the discharge gas is set to, for example, 5 kPa to 150 kPa.

  Inside the inner tube 50, a strip-shaped inner electrode 30 made of metal foil extending along the axial direction of the discharge lamp 10 is disposed. The inner electrode 30 is covered with an inner tube 50 that is a dielectric without being exposed to the discharge space S.

  The outer electrode 40 is formed of a net-like or spiral conductive member so as to transmit light radiated from the discharge space S, and the outer surface of the outer tube 20 that is a dielectric so as to face the inner electrode 30 in the radial direction. It is arranged along.

  A power supply line 70 connected to the end of the inner electrode 30 is connected to a power supply unit (not shown) installed outside, and power is supplied to the discharge lamp 10 via the power supply line 70.

  The polarities of the inner electrode 30 and the outer electrode 40 are determined as an anode and a cathode, respectively, and are opposed to each other with the arc tube 11 as a dielectric interposed therebetween. When a voltage of several kV is applied to the discharge lamp 10, a dielectric barrier discharge occurs between the inner electrode 30 and the outer electrode 40, and excimer light having a predetermined spectrum (for example, wavelength 172 nm) is emitted. The phosphor film C applied to the discharge lamp 10 is excited by excimer light (ultraviolet rays) radiated in the discharge space S and emits fluorescence. The discharge distance at this time is 3 mm to 12.5 mm (preferably 3 mm to 10 mm) in order to prevent the discharge distance from becoming narrow and insufficient illumination, while preventing the discharge distance from becoming long and unstable. It is better to set the range.

  The axial length of the outer tube 20 is set to 100 mm to 300 mm (preferably 100 mm to 250 mm). On the other hand, the thickness of the outer tube 20 is set to 0.8 mm to 1.5 mm in order to prevent the outer tube from being deteriorated by excimer light and to suppress the rise of the discharge start voltage. Further, the inner diameter of the outer tube 20 is set to 6 mm to 25 mm (preferably 8 mm to 20 mm) so as to prevent both unstable discharge due to a long discharge distance and insufficient illuminance due to a short discharge distance.

  The thickness of the inner electrode 30 is set to 20 μm to 50 μm in consideration of current capacity, ease of manufacture, prevention of peeling due to thermal expansion, and the like. In addition, the width of the foil is set to 1.2 mm to 10 mm in consideration of current capacity, ease of manufacture, and prevention of radiation light blocking due to enlargement of the electrode area. The material of the inner electrode 30 is molybdenum or an alloy containing the same.

The inner tube 50 is made of a dielectric material (such as SiO ₂ ) that approximates the thermal expansion coefficient of the inner electrode 30 as much as possible. The thickness of the inner tube 50 is set to 0.1 mm to 2 mm in consideration of the limit for maintaining insulation and prevention of increase in the discharge start voltage.

  FIG. 2 is a diagram illustrating a manufacturing process of the discharge lamp 10. Below, the manufacturing method of the discharge lamp 10 of this invention is demonstrated.

  The tip of the quartz tube that becomes the inner tube 50 is heat-sealed, and the bottomed cylindrical inner tube 50 is formed so that the outer surface of the inner tube tip becomes a convex surface that decreases in diameter toward the tip. Thus, the inner tube tip 51 is provided. Then, the feeder 70 is connected to the inner electrode 30 by resistance welding or the like, and inserted into the inner tube 50 (step (1)). At this time, after the inner electrode 30 is inserted, the inside of the inner tube 50 may be evacuated, heated from the outside, and welded to the inner electrode 30 to form a convex surface. Alternatively, the convex surface may be formed by performing a process of coating the inner electrode 30 with a dielectric film instead.

  A so-called abacus-shaped sealing portion 53 having a bowl shape is formed at the position of the inner tube 50 welded to the rear end portion 22 of the outer tube (step (2)).

  The outer tube tip 21 is provided by forming a bottomed cylindrical outer tube 20 by heating and reducing the diameter of one end of the quartz tube serving as the outer tube 20. The outer distal end portion 21 may have a cross-sectional shape other than the shape shown in FIG. 2, for example, may be formed in a tapered shape (funnel shape) whose diameter is reduced toward the first introduction tube 61. The outer tube rear end portion 22 to be welded to the sealing portion 53 of the inner tube 50 is opened. A first introduction tube 61 along the axial direction of the outer tube 20 is provided at the outer tube tip 21 that is the tip of the arc tube 11. A second introduction tube 62 is provided along the radial direction of the outer tube 20 on the outer tube rear end 22 side, which is the rear end of the arc tube 11 (step (3)).

  The second introduction pipe 62 is provided on the outer pipe rear end portion 22 side. However, when the outer pipe 20 and the inner pipe 50 are heat-welded, the opening of the second introduction pipe 62 may be heat-sealed. Therefore, the second introduction pipe 62 is oriented along the radial direction of the outer pipe 20 and does not interfere with the heat welding with the sealing portion 53 of the inner pipe 50 from the outer pipe rear end 22 to the outer pipe tip. It is better to be away from the part 21 side. Further, since the second introduction tube 62 may block light emitted from the discharge space S, an effective light emission range along the axial direction (a range in which the outer electrode 40 and the inner electrode 30 face each other in the radial direction). It is better to be provided on the rear end portion 52 side.

  The inner tube 50 is inserted into the outer tube 20 and arranged coaxially, and the outer tube rear end portion 22 and the sealing portion 53 on each opening side are integrally heat-welded to form the arc tube 11. (Step (4)).

  By sucking from the second introduction tube 62, the inside of the arc tube 11 is brought into a negative pressure state, and the phosphor paint is applied to the inner surface of the arc tube 11 by flowing in and out of the first introduction tube 61. A phosphor film is provided. Thereafter, the phosphor film is removed from the inner surfaces of the first introduction tube 61 and the second introduction tube 62, and the inner surfaces of the first introduction tube 61 and the second introduction tube 62 are exposed to the discharge space S (step (5). )).

  At this time, by providing the outer surface of the inner tube tip 51 at a position facing the first introduction tube 61, the phosphor film is homogeneous with respect to the circumferential direction of the inner surface of the outer tube 20 and the outer surface of the inner tube 50. Can be applied. Furthermore, the outer surface of the inner tube tip 51 is a convex surface that decreases in diameter toward the tip, so that the phosphor paint stagnates in the vicinity of the inner tube tip 51 when flowing into and out of the arc tube 11. And no bubbles remain, so that a locally thick portion is prevented from being provided at the inner tube tip 51, and the phosphor film is homogeneous in the axial direction, radial direction, and circumferential direction of the discharge lamp. C can be applied.

  By exposing the inner surfaces of the first introduction tube 61 and the second introduction tube 62 to the discharge space S, sealing is ensured in the subsequent step of hermetically sealing the first introduction tube 61 and the second introduction tube 62. It is possible to prevent the generation of cracks starting from the first introduction pipe 61 and the second introduction pipe 62.

  One of the first introduction tube 61 and the second introduction tube 62 is hermetically sealed by heating and melting, and the arc tube 11 (discharge space S) is evacuated from the other introduction tube to remove impurities. . At this time, vacuuming may be performed from both introduction pipes. Thereafter, a discharge gas is sealed inside the arc tube 11 through an inlet tube that is not hermetically sealed, and the inlet tube used for vacuuming and discharge gas sealing is hermetically sealed by heating and melting (step (6)). The outer electrode 40 is disposed on the outer surface of the arc tube 11 (step (7)).

  In the present embodiment, a first introduction pipe along the axial direction is provided at the front end of the outer pipe, and a second introduction pipe along the radial direction is provided at the rear end of the outer pipe. Further, the outer surface of the distal end portion of the inner tube is a convex surface that is opposed to the first introduction tube and has a diameter reduced toward the distal end side. As a result, when the phosphor paint is flowed into and out of the arc tube, no stagnation or bubbles remain, and the phosphor can be uniformly applied to the inner surface of the arc tube of the small-diameter discharge lamp. It is possible to provide a discharge lamp with good radiation efficiency by the phosphor.

  In addition, since the inner surfaces of the first introduction tube and the second introduction tube are exposed to the discharge space, sealing can be reliably performed in the subsequent heat sealing step of the introduction tube. Generation of cracks can be prevented, and the reliability of the discharge lamp coated with the phosphor can be improved.

  According to such a small-diameter excimer lamp, a discharge lamp that emits two ultraviolet rays can be configured. Hereinafter, a discharge lamp coated with a phosphor film will be described with reference to FIGS.

  The discharge lamp which is 2nd Embodiment is demonstrated using FIG. In the second discharge lamp, a phosphor film is provided so as to radiate two ultraviolet rays to the outside of the lamp. Below, the same code | symbol is used about the same component as 1st Embodiment.

  FIG. 3 is a schematic cross-sectional view of a discharge lamp according to the second embodiment.

  Here, the discharge lamp 10 'is an excimer lamp including an arc tube (discharge tube) 11, an inner electrode 30, and an outer electrode 40, and can be used as a light source for sterilization, sterilization, and deodorization. The arc tube 11 is a double tube structure discharge tube including a bottomed cylindrical outer tube 20 and an inner tube 50 made of a dielectric material such as quartz glass, and is welded as a unit at a sealing portion 53. A discharge space S is formed. In the discharge space S, a rare gas such as xenon gas or a mixed gas thereof is sealed as a discharge gas. The sealed pressure of the discharge gas is set to, for example, 5 kPa to 150 kPa.

  On the surface of the arc tube 11, a phosphor film C (film) is applied over substantially the entire surface. More specifically, the inner surface of the outer tube 20 (the inner peripheral surface of the cylindrical portion of the outer tube 20) 20I and the outer surface of the inner tube 50 (the outer peripheral surface of the cylindrical portion of the inner tube 50) 50S are fluorescent. The body C is applied as a film. The phosphor C includes a phosphor C1 applied to the inner surface 20I of the outer tube 20 and a phosphor C2 applied to the outer surface 50S of the inner tube 50, and has a substantially uniform thickness.

  As for the application of the phosphor C, for example, a phosphor introduction tube is provided at both ends of the outer tube 20, one introduction tube is placed in a phosphor solution having viscosity, and sucked and discharged from the other introduction tube. Thereby, the phosphor C can be applied to the surface of the arc tube 11. Alternatively, the fluorescent tube C may be applied in advance to the inner surface 20I of the outer tube 20 and the outer surface 50S of the inner tube 50, and then the arc tube 11 having a double tube structure may be formed.

  Inside the inner tube 50, a strip-shaped inner electrode 30 made of a metal foil extending along the axial direction of the discharge lamp 10 'is disposed. The inner electrode 30 is covered with an inner tube 50 that is a dielectric without being exposed to the discharge space S. A power supply line 70 connected to the end of the inner electrode 30 is connected to a power supply unit (not shown) installed outside, and power is supplied to the discharge lamp 10 via the power supply line 70.

  The outer electrode 40 is formed of a net-like or spiral conductive member so as to transmit light radiated from the discharge space S, is not exposed to the discharge space S, and is a dielectric that faces the inner electrode 30 in the radial direction. It is arrange | positioned in the axial direction along the outer surface 20S of the outer side pipe | tube 20 which is.

  The polarities of the inner electrode 30 and the outer electrode 40 are determined as an anode and a cathode, respectively, and are opposed to each other with the arc tube 11 as a dielectric interposed therebetween. When a voltage of several kV is applied to the discharge lamp 10 ', a dielectric barrier discharge occurs between the inner electrode 30 and the outer electrode 40, and ultraviolet light having a wavelength of 172 nm is emitted as excimer light. The thickness of the phosphor C film is such that ultraviolet light having a wavelength of 172 nm can be transmitted, and at least part of the ultraviolet light having a wavelength of 172 nm is transmitted through the phosphor C and emitted outside the lamp.

Oxygen (O ₂ ) in the air has a light absorption spectrum in a wavelength region of 100 nm to 240 nm. Therefore, oxygen (O ₂ ) outside the lamp absorbs ultraviolet light (first ultraviolet light) having a wavelength of 172 nm emitted from the discharge lamp 10 ′, undergoes photolysis of two oxygen atoms (O), and ozone molecules (O _3). ) (First product) is produced.

On the other hand, when the phosphor C receives ultraviolet light having a wavelength of 172 nm, the phosphor C emits fluorescence having a wavelength of 250 nm (second ultraviolet light), whereby the ultraviolet light having a wavelength of 250 nm is emitted from the phosphor C to the outside of the lamp. Ozone molecules (O ₃ ) have a light absorption spectrum in the wavelength range of 200 to 300 nm. Therefore, ozone (O ₃ ) generated by ultraviolet irradiation with a wavelength of 172 nm absorbs ultraviolet light with a wavelength of 250 nm emitted to the outside of the lamp.

  As a result, outside the lamp, excited state oxygen (second product) such as excited singlet oxygen atoms and singlet oxygen molecules having higher energy than the ground state is generated. Excited-state oxygen is active oxygen in a very highly active state, and can perform actions such as deodorization, bleaching, sterilization, and surface oxidation on an object.

  As described above, in the present embodiment, in the discharge lamp 10 ′ having the arc tube 11 having the double tube structure, the surface of the arc tube 11 (the outer surface 50S of the inner tube 50 and the inner surface 20I of the outer tube 20) A phosphor C that emits fluorescence having a wavelength of 250 nm upon receiving ultraviolet light having a wavelength of 172 nm is thinly applied with a substantially uniform thickness over the entire surface. As a result, both ultraviolet rays having wavelengths of 172 nm and 250 nm are emitted from the entire outer surface 50S of the outer tube 20 serving as the emission surface of the arc tube 11. By emitting two ultraviolet rays from the same emission surface region, it is possible to generate both ozone and excited state oxygen as active oxygen.

Note that the discharge lamp may emit ultraviolet light having a wavelength other than 172 nm, and may be ultraviolet light that is in the range of the light absorption spectrum of oxygen (O ₂ ) (wavelength range of approximately 100 nm to 240 nm). The phosphor C is also excited by ultraviolet rays due to discharge, and emits ultraviolet rays having a wavelength longer than that of ultraviolet rays due to discharge and in the light absorption spectrum of ozone (O ₃ ) (wavelength range of approximately 200 to 300 nm). What is necessary is just to comprise. Further, it is possible to adopt a configuration in which the phosphor is not applied to either the inner surface 20I of the outer tube 20 or the outer surface 50S of the inner tube 50.

  Next, the discharge lamp which is 3rd Embodiment is demonstrated using FIG. In the third embodiment, ultraviolet light having a wavelength of 172 nm and ultraviolet light having a wavelength of 250 nm are emitted from different emission surface regions. The rest is substantially the same as in the second embodiment.

  FIG. 4 is a schematic cross-sectional view of a discharge lamp in the third embodiment.

  The phosphor C ′ of the discharge lamp 10 ″ is applied only to the surface area facing the outer surface (radiation surface area) 20A of the left half of the outer tube 20, and is opposed to the outer surface 20B of the right half of the outer tube 20. The phosphor C ′ is applied to the inner surface 20I of the outer tube 20 and the phosphor C′2 is applied to the outer surface 50S of the inner tube 50. Consists of

  Further, the phosphor C ′ is not in the form of a thin film as in the first embodiment, and has a thickness that does not transmit ultraviolet light having a wavelength of 172 nm. For this reason, ultraviolet light having a wavelength of 172 nm is emitted from the emitting surface region 20B to the outside of the lamp, while ultraviolet light having a wavelength of 250 nm is emitted from the emitting surface region 20A to the outside of the lamp.

  In this way, by selectively emitting ultraviolet light having a wavelength of 172 nm and ultraviolet light having a wavelength of 250 nm while separately dividing the radiation region, it is possible to adjust the balance between the generation amount of ozone and excited state oxygen. Here, the emission surface area of the arc tube 11 is substantially bisected along the axial direction, but the ratio can be adjusted by adjusting the axial length of the phosphor C ′ applied. it can. For example, in the method of sucking up from the surface of the phosphor liquid, the height along the axial direction of the phosphor C ′ is adjusted by adjusting the sucking period, and the coating range along the axial direction of the phosphor C ′ can be adjusted. it can.

  Next, the discharge lamp which is 4th Embodiment is demonstrated using FIG. In the fourth embodiment, a radiation surface area that emits ultraviolet light having a wavelength of 172 nm and a radiation surface area that emits ultraviolet light having a wavelength of 250 nm are divided into a plurality of parts.

  FIG. 5 is a schematic cross-sectional view of a discharge lamp according to the fourth embodiment.

  The phosphor C ″ of the discharge lamp 100 is applied as a whole in the arc tube 11 as in the first embodiment. On the other hand, the thickness of the phosphor C ″ is not constant and is a thin film-like portion. (Thin portions) CA, CB and thicker portions (thick portions) C1, C2, C3. The thin portions CA and CB and the thick portions C1, C2, and C3 are alternately formed along the axial direction.

  By coating the phosphor C ″ in the arc tube 11 in this way, it is possible to emit ultraviolet light having a wavelength of 172 nm and ultraviolet light having a wavelength of 250 nm from the radiation surface region alternately arranged. While UV light having a wavelength of 172 nm is emitted from the CB to the outside of the lamp, while UV light having a wavelength of 172 nm is not transmitted from the thick portions C1, C2, and C3, only the ultraviolet light having a wavelength of 250 nm is emitted from the phosphor C ″ to the outside of the lamp. The phosphor C ″ can be formed as shown in FIG. 5 by changing the rate of lowering the phosphor liquid level step by step, for example, in the suction method from the phosphor liquid level. When the speed is slow, the coating is thick, and when the speed is fast, the coating is thin.The speed adjustment is realized by opening and closing the inlet pipe by providing a valve.

10 discharge lamp 11 arc tube 20 outer tube 30 inner electrode 40 outer electrode 50 inner tube C phosphor film

Claims (11)

A bottomed outer tube formed with a first introduction tube and a second introduction tube at both ends,
An inner tube that is coaxially arranged in the outer tube and has a convex surface at the first introduction tube side end,
A pair of electrodes disposed opposite to each other with the outer tube and the inner tube interposed therebetween;
A film formed on the inner surface of the outer tube and the surface of the inner tube including the convex surface;
The discharge lamp, wherein the first introduction tube extends along an axial direction of the outer tube.   The discharge lamp according to claim 1, wherein the second introduction tube extends along a radial direction of the outer tube.   The discharge lamp according to claim 1, wherein the film is adjusted with respect to at least one of an axial formation length and a thickness thereof.   4. The discharge lamp according to claim 1, wherein the film is formed partway along the axial direction from the first introduction tube side. 5.   The discharge lamp according to any one of claims 1 to 4, wherein the thickness of the film varies depending on a position where the film is formed.   6. The discharge lamp according to claim 1, wherein a relatively thin film portion and a relatively thick film portion are formed along the axial direction. The film is a phosphor film,
The discharge lamp according to any one of claims 1 to 6, wherein the discharge lamp emits fluorescence when excited by ultraviolet rays radiated in the discharge space. The wall thickness of the outer tube is 0.8 mm to 1.5 mm,
The inner diameter of the outer tube is 6 mm to 25 mm,
The inner tube has a thickness of 0.1 mm to 2 mm;
The discharge lamp according to any one of claims 1 to 7, wherein a discharge distance is set in a range of 3 mm to 12.5 mm. Form a bottomed cylindrical outer tube,
A step of forming a bottomed cylindrical inner tube with a convex surface that reduces the outer surface of the tip toward the tip side;
A step of providing a first introduction pipe along the axial direction of the outer pipe on the tip side of the outer pipe, and a second introduction pipe along the radial direction of the outer pipe on the opening side of the outer pipe;
The outer tube and the inner tube are arranged coaxially, and are integrally welded at the rear end on the opening side to form a discharge space,
Forming a film on the inner peripheral surface of the outer tube, the outer peripheral surface of the inner tube, and the convex surface of the inner tube tip by causing the paint to flow in and out from the first introduction tube. A method of manufacturing a discharge lamp characterized by the above. In the manufacturing method of the discharge lamp of Claim 9,
Removing the membrane from the inner surfaces of the first introduction tube and the second introduction tube;
Exposing inner surfaces of the first introduction tube and the second introduction tube to the discharge space;
Evacuating the discharge space and enclosing a discharge gas;
A method of manufacturing a discharge lamp, comprising a step of hermetically sealing the first introduction tube and the second introduction tube by heating and melting. A light emitting tube having a bottomed first introduction tube and a second introduction tube formed at both ends, respectively, and a film formed on the inner surface of the arc tube, the first introduction tube being an axis of the outer tube A discharge lamp film forming method, wherein the second introduction tube extends along a direction of the outer tube and extends along a radial direction of the outer tube,
A suction period for sucking up the membrane material from the first inlet tube and / or the membrane material so that the axial length and / or thickness of the membrane is a predetermined length and / or thickness A method for producing a film of a discharge lamp, characterized in that an outflow speed at the time of flowing out the first discharge pipe from the first introduction pipe is adjusted.

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