EP3461227B1

EP3461227B1 - Heater and method for manufacturing heater

Info

Publication number: EP3461227B1
Application number: EP18160259.0A
Authority: EP
Inventors: Hiroki Nakano; Masaaki TAKATSUKA; Shinjiro Aono; Yoshitaka Fujita; Syuhei Abe; Tsuyoshi Ohashi; Soichi Shibusawa
Original assignee: Toshiba Lighting and Technology Corp
Current assignee: Toshiba Lighting and Technology Corp
Priority date: 2017-09-22
Filing date: 2018-03-06
Publication date: 2019-10-30
Anticipated expiration: 2038-03-06
Also published as: EP3461227A1; JP2019057456A; JP6943109B2

Description

FIELD

Exemplary embodiments described herein relate to a heater and a method for manufacturing a heater.

BACKGROUND

A heater used for the purpose of heating an object to be irradiated by radiant heat is known. Since the heater is required to have an antiglare property in applications such as space heating and coating drying, a multilayer film having a high visible light blocking effect is formed on an outer surface of a light emitting tube. The multilayer film is formed by alternately laminating a high refractive index film and a low refractive index film in order to transmit infrared rays and block visible light.
In such a heater, a waterproof property corresponding to the application may be required. If the waterproof property is required in the heater, for example, a clasp for accommodating an end portion of the light emitting tube is filled with a filler and a conductive portion such as a lead wire is covered. Therefore, measures are taken to improve insulation performance and to impart the waterproof property following a predetermined standard.
The filler includes, for example, a solvent such as water or an organic solvent, and an insulating base material such as alumina, and is formed by drying or curing a filling material, which is imparted with an appropriate flowability, by light radiation or the like. In this case, most of the solvent is volatilized and removed, but if the filling material contains water as the solvent, there is a concern that the waterproof property is lowered due to influence of water slightly remaining in the filler.
Gas such as siloxane may be generated from the filler due to influence of heat when a heater is used depending on the selection of the base material. If gas generated as described above adheres to a surface of the multilayer film, there is a concern that the multilayer film is deteriorated and the antiglare property is lowered.
Document EP 0 848 575 A1 discloses a heater according to the state of the art.
An object of the exemplary embodiments is to provide a heater and a method for manufacturing a heater capable of suppressing deterioration of a multilayer film while maintaining a waterproof property.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating a heater according to Embodiment 1.
FIG. 2 is a sectional view that is taken along line A-A of FIG. 1 illustrating the heater according to Embodiment 1.
FIG. 3 is a sectional view illustrating a heater according to Embodiment 2.
FIG. 4 is a plan view illustrating a heater according to Embodiment 3.
FIG. 5 is a sectional view that is taken along line B-B of FIG. 4 illustrating the heater according to Embodiment 3.

DETAILED DESCRIPTION

A heater according to embodiments described hereinafter includes a light emitting tube, a multilayer film, a metal foil, a lead wire, an external lead-in wire, a sealing portion, a covering tube, a clasp, and a filler. The light emitting tube is provided with a heating body on an inside thereof. The multilayer film is formed on an outer peripheral surface of the light emitting tube. The metal foil is electrically connected to the heating body. The lead wire is electrically connected to the metal foil. The external lead-in wire has a connecting portion electrically connected to the lead wire. The sealing portion, in which the metal foil and a part of the lead wire are embedded, is formed in the light emitting tube so as to seal the inside of the light emitting tube. In addition, the sealing portion includes a lead-out portion with which the lead wire is drawn out to an outside of the light emitting tube. The covering tube covers the external lead-in wire and the lead wire that is drawn out from the lead-out portion. The clasp includes an opening portion through which the sealing portion is inserted, an accommodating portion that accommodates the sealing portion, and a through-hole through which the external lead-in wire passes from an inside of the accommodating portion to the outside. A portion between the sealing portion and the accommodating portion, and a portion between the external lead-in wire and the through-hole are filled with the filler so as to close the opening portion and the through-hole of the clasp. In addition, the filler contains 85% by mass or more of alumina.
In addition, the heater according to the embodiments described hereinafter further includes an annular member that is provided between the external lead-in wire and the covering tube.
In addition, the clasp according to the embodiments described hereinafter further includes a filling port which is opened so as to communicate the accommodating portion and an outside of the clasp.
Hereinafter, exemplary embodiments will be described with reference to the drawings. Each embodiment described below does not limit the technique in which the exemplary embodiments are disclosed. In addition, each of the following embodiments and modification examples can be appropriately combined within a scope not inconsistent. In the description of each embodiment, the same reference numerals are given to the same configurations and the later description thereof will be appropriately omitted.

Embodiment 1

FIG. 1 is a plan view illustrating a heater according to Embodiment 1. As illustrated in FIG. 1, a heater 1 according to Embodiment 1 includes a light emitting tube 2, a multilayer film 3, a first clasp 4, a second clasp 5, a first covering tube 6, a second covering tube 7, a first external lead-in wire 8, a second external lead-in wire 9, and a heating body 10.
For ease of description, FIG. 1 illustrates a three-dimensional orthogonal coordinate system including a Z-axis with a vertically upward direction as a positive direction and a vertically downward direction as a negative direction. Such an orthogonal coordinate system is also illustrated in the other drawings used for the description later.
The light emitting tube 2 is formed of a material that is transparent and colorless, and is formed in a cylindrical shape. As the material of the light emitting tube 2, for example, quartz glass having a high softening point is exemplified.
The multilayer film 3 is formed on an outer peripheral surface of the light emitting tube 2. The multilayer film 3 is provided with a plurality of layers of a low refractive index film and a high refractive index film. The low refractive index film contains silicon oxide as a main component and the high refractive index film contains iron oxide as a main component. The multilayer film 3 transmits infrared rays and blocks visible light among the light emitted from the light emitting tube 2.
The multilayer film 3 is formed by a dipping method, a vacuum evaporation method, a sputtering method, or the like, and ten layers of the low refractive index film and the high refractive index film are alternately laminated. More specifically, for example, an odd number layer starting from a first layer directly formed on a surface of the light emitting tube 2 is formed of the low refractive index film and an even number layer starting from a second layer is formed of the high refractive index film. Since silicon oxide which is a main component of the low refractive index film, specifically silicon dioxide (SiO₂) is close to a component of the light emitting tube 2, an adhesion force to a surface of the light emitting tube 2 is improved by adopting the first layer. In addition, since silicon dioxide has excellent chemical and thermal resistance and mechanical strength, there is a low possibility of peeling or damage occurring even if the first layer is directly formed on the surface of the light emitting tube 2 which becomes high temperature. It is also possible to form the odd number layer with the high refractive index film and the even number layer with the low refractive index film. The uppermost layer furthest from the light emitting tube 2 in the multilayer film 3 may be the high refractive index film or the low refractive index film.
Iron oxide which is a main component of the high refractive index film has higher antiglare property than that of silicon oxide. Therefore, the antiglare property of the heater 1 can be improved by using iron oxide for the high refractive index film. However, since iron oxide is different from the component of the light emitting tube 2 as compared with silicon oxide, it is desirable to provide the high refractive index film on the outside the light emitting tube 2 via the low refractive index film.
The low refractive index film is not limited to silicon dioxide but may be in any form as long as it is a silicon oxide such as silicon monoxide (SiO). In addition, the low refractive index film is not limited to silicon oxide, and a metal compound other than silicon oxide such as magnesium fluoride (MgF₂) may be used. In addition, the high refractive index film is not limited to iron oxide (FeO, Fe₂O₃, Fe₃O₄, or the like), but also metal oxide other than iron oxide such as titanium oxide (TiO₂), niobium oxide (Nb₂O₅), and tantalum oxide (Ta₂O₅) may be used.
Further, film thicknesses of each layer of the multilayer film 3 may be different from each other, or may be the same thickness for each low refractive index film and the high refractive index film. Further, the film thickness of the low refractive index film may be thicker than the film thickness of the high refractive index film. Specifically, for example, the film thickness of the low refractive index film is 80 nm and the film thickness of the high refractive index film is 57 nm, but it is not limited thereto.
The heating body 10 is disposed inside the light emitting tube 2 and is sealed together with an inert gas and a halide (not illustrated). The heating body 10 is supported by an anchor material (not illustrated). One end of the heating body 10 is formed so as to extend to a sealing portion (not illustrated in FIG. 1) accommodated on an inside of the first clasp 4 and is electrically connected to the first external lead-in wire 8. On the other hand, the other end of the heating body 10 is formed so as to extend to the sealing portion (not illustrated) provided inside the second clasp 5, and is electrically connected to the second external lead-in wire 9.
The heating body 10 is a filament made of tungsten formed in a coil shape. The heating body 10 generates heat and emits light when a voltage is applied from a power source (not illustrated) via the first external lead-in wire 8 and the second external lead-in wire 9. The sealing portion will be described later with reference to FIG. 2.
The first external lead-in wire 8 and the second external lead-in wire 9 are heat-resistant electric wires of which a core wire is covered with a covering layer, for example, made of fluorocarbon resin such as polytetrafluoroethylene (PTFE).
The first external lead-in wire 8 is covered with the first covering tube 6. The first covering tube 6 improves the insulation property of the first external lead-in wire 8 on the inside of the first clasp 4. Similarly, the second external lead-in wire 9 is covered with the second covering tube 7. The second covering tube 7 improves the insulation property of the second external lead-in wire 9 on the inside of the second clasp 5.
The first clasp 4 and the second clasp 5 are members for supporting and fixing the light emitting tube 2. Specifically, the first clasp 4 and the second clasp 5 respectively accommodate the sealing portions which are provided at both ends of the light emitting tube 2. The sealing portions are respectively fixed to the first clasp 4 and the second clasp 5.
Here, an internal configuration of the first clasp 4 and the second clasp 5 will be described further detail with reference to FIG. 2. FIG. 2 is a sectional view that is taken along line A-A of FIG. 1 illustrating the heater according to Embodiment 1. FIG. 2 corresponds to a sectional view of the first clasp 4 and the vicinity thereof. The configuration of the second clasp 5 and the vicinity thereof is the same as the configuration of the first clasp 4 and the vicinity thereof illustrated in FIG. 2. Therefore, the illustration and the description of the second clasp 5 will be omitted.
As illustrated in FIG. 2, the first clasp 4 accommodates a sealing portion 2a formed in the light emitting tube 2 so as to seal the inside of the light emitting tube 2. In addition, a metal foil 12 is embedded in an inside of the sealing portion 2a. The sealing portion 2a in Embodiment 1 is a so-called pinch seal portion formed in a plate shape.
The metal foil 12 is formed in a rectangular shape by molybdenum. The metal foil 12 is electrically connected to one end 13 of the heating body 10. In addition, the metal foil 12 is electrically connected to a lead wire 20. Furthermore, the lead wire 20 is electrically connected to a connecting portion 21 of the first external lead-in wire 8 by, for example, welding. That is, the heating body 10 and the first external lead-in wire 8 are electrically connected via the metal foil 12, the lead wire 20, and the connecting portion 21. The connecting portion 21 is a splice terminal that is provided so as to cover a core wire 8b by removing a covering layer 8a from an end portion of the first external lead-in wire 8 having, for example, the core wire 8b and the covering layer 8a which covers the core wire 8b. However, the connecting portion 21 is not limited to the splice terminal and, for example, may be a solder connected to the lead wire 20.
In addition, the sealing portion 2a includes a lead-out portion 11 that is an opening for drawing out the lead wire 20 connected to the metal foil 12 to the outside of the light emitting tube 2.
In addition, the first external lead-in wire 8 and the lead wire 20 which is drawn out from the lead-out portion 11 are covered with the first covering tube 6. The first covering tube 6 is a cylindrical member formed of silicone rubber having heat shrinkability. Entry of water from the outside along a surface of the first external lead-in wire 8 toward the lead wire 20 is suppressed by covering the lead wire 20 and the first external lead-in wire 8 with the first covering tube 6.
In addition, one end of the first covering tube 6 is in contact with the sealing portion 2a so as to surround the lead-out portion 11. As described above, an insulation property of the lead wire 20 and the connecting portion 21 is easily secured by covering the connecting portion 21 of the first external lead-in wire 8 and the lead wire 20 drawn out from the lead-out portion 11 with the first covering tube 6.
The first clasp 4 includes an opening portion 14, an accommodating portion 15, and a through-hole 16. The opening portion 14 is provided at an end portion on a light emitting tube 2 side of the first clasp 4, that is, on a side of an X-axis in a negative direction. The opening portion 14 is wider than a dimension of the sealing portion 2a in a direction of an YZ plane so that the sealing portion 2a is inserted. The accommodating portion 15 communicates with the opening portion 14 and has a space provided to accommodate the sealing portion 2a.
In addition, the through-hole 16 is provided on a side opposite to the light emitting tube 2 of the first clasp 4, that is, at an end portion on a side of the X-axis in a positive direction. The through-hole 16 communicates with the accommodating portion 15 and is opened to a dimension that allows the first covering tube 6 covering the first external lead-in wire 8 to pass therethrough. If the sealing portion 2a is appropriately fixed to the inside of the first clasp 4 via the opening portion 14, the sealing portion 2a is accommodated in the accommodating portion 15 and the first external lead-in wire 8 passes through the through-hole 16 from the inside of the accommodating portion 15 to the outside.
In addition, the first clasp 4 is filled with a filler 19 so as to close the opening portion 14. Specifically, a portion between the sealing portion 2a and the accommodating portion 15 is filled with the filler 19. Entry of water from the outside to the inside of the first clasp 4 via the opening portion 14 is suppressed and the insulation property of the lead wire 20 and the connecting portion 21 covered with the first covering tube 6 can be appropriately secured by being filled with the filler 19 so as to close the opening portion 14. A part of the sealing portion 2a may be in contact with the accommodating portion 15 without the filler 19.
In addition, a portion between the first external lead-in wire 8 and the through-hole 16, more specifically, a portion between the first covering tube 6 covering the first external lead-in wire 8 and the through-hole 16 is filled with the filler 19 so as to close the through-hole 16 of the first clasp 4. Entry of water from the outside to the inside of the first clasp 4 via the through-hole 16 is suppressed and the insulation property of the lead wire 20 and the connecting portion 21 covered with the first covering tube 6 can be appropriately secured by being filled with the filler 19 so as to close the through-hole 16. Moreover, the first external lead-in wire 8 or a part of the first covering tube 6 may be in contact with the through-hole 16 without the filler 19.
The inside of the first clasp 4 is filled with a filling material including an alcohol-based nonaqueous solvent and a base material having the insulation property and containing 85% by mass or more of alumina, and then the alcohol-based nonaqueous solvent is volatilized and removed from the filled filling material by heating or the like, so that the filler 19 is obtained.
The base material of the filling material, that is, the filler 19 is an insulating alumina cement containing 85% by mass or more of alumina, for example, containing 85% by mass or more and 95% by mass or less of alumina. As described above, the opening portion 14 and the through-hole 16 are closed by using the filler 19 in which 85% by mass or more of alumina is mixed, so that the insulation property is improved. In addition, the filler 19 contains 85% by mass or more of alumina which hardly absorbs moisture so that the waterproof property is also secured.
In addition, the alcohol-based nonaqueous solvent contained in the filling material includes, for example, methanol, 3-methyl-3-methoxybutanol, and the like, but the exemplary embodiments are not limited thereto, and a solvent, to which an appropriate flowability is given by evenly dispersing the base material without containing water, may be provided. If the inside of the first clasp 4 is filled with the filling material containing the alcohol-based nonaqueous solvent, even if the alcohol-based nonaqueous solvent remains in the obtained filler 19, moisture does not contain in the filler 19 so that it does not affect the waterproof property of the heater 1 according to Embodiment 1. A mixing ratio of the alcohol-based nonaqueous solvent to the base material can be arbitrary set according to the flowability required for the filling material.
As described above, the filling material including the base material containing 85% by mass or more of alumina and the alcohol-based nonaqueous solvent has a large amount of alumina, the flowability is improved, and filling is easily performed by a composite operation such as containing alcohol instead of water as a solvent.
Moreover, the base material of the filling material, that is, the filler 19 may contain a component that is a generating source of gas such as siloxane. For example, the filler 19 may contain 15% by mass or less, for example, 5% by mass or more and 10% by mass or less of organosiloxane. The organosiloxane appropriately contained in the filler 19 contributes to the flowability of the filling material in cooperation with the alcohol-based nonaqueous solvent.
In addition, in the example illustrated in FIG. 2, the entire space inside the first clasp 4 is filled with the filler 19, but the example is not limited to the configuration, and the inside of the first clasp 4 may have a void which is not filled with the filler 19. However, if the filler 19 contains a component to be a generating source of gas such as siloxane, it is preferable that the inside of the first clasp 4 is filled with the filler 19 without gaps. Gas such as siloxane generated from the filler 19 and retained inside the first clasp 4 is simultaneously discharged to the outside to reach the multilayer film 3 formed on the surface of the light emitting tube 2, and deterioration of the multilayer film 3 can be suppressed by filling the inside of the first clasp 4 with the filler 19.
As described above, the heater 1 according to Embodiment 1 includes the light emitting tube 2, the multilayer film 3, the metal foil 12, the lead wire 20, the external lead-in wires 8 and 9, the sealing portion 2a, the covering tubes 6 and 7, the clasps 4 and 5, and the filler 19. The light emitting tube 2 is provided with the heating body 10 on the inside thereof. The multilayer film 3 is formed on the outer peripheral surface of the light emitting tube 2. The metal foil 12 is electrically connected to the heating body 10. The lead wire 20 is electrically connected to the metal foil 12. The external lead-in wires 8 and 9 include the connecting portions 21 electrically connected to the lead wires 20. The metal foil 12 and a part of the lead wire 20 are embedded in the sealing portion 2a, and the sealing portion 2a is formed in the light emitting tube 2 so as to seal the inside of the light emitting tube 2. In addition, the sealing portion 2a includes the lead-out portion 11 by which the lead wire 20 is drawn out to the outside of the light emitting tube 2. The covering tubes 6 and 7 cover the external lead-in wires 8 and 9, and the lead wires 20 drawn out from the lead-out portions 11. The clasps 4 and 5 include the opening portions 14 through which the sealing portions 2a are inserted, the accommodating portions 15 in which the sealing portions 2a are accommodated, and the through-holes 16 which allow the external lead-in wires 8 and 9 to pass the external lead-in wires 8 and 9 from the inside of the accommodating portions 15 to the outside. The portions between the sealing portions 2a and the accommodating portions 15, and the portions between the external lead-in wires 8 and 9, and the through-holes 16 are filled with the fillers 19 so as to close the opening portion 14 and the through-hole 16 of the clasps 4 and 5. In addition, the filler 19 contains 85% by mass or more of alumina. Therefore, according to the heater 1 of Embodiment 1, deterioration of the multilayer film 3 due to generation of gas such as siloxane can be suppressed while maintaining the waterproof property.

Method for Manufacturing Heater

A method for manufacturing a heater 1 configured as described above will be described. The method for manufacturing a heater 1 includes a multilayer film forming step, a connecting step, a sealing step, a covering step, an inserting step, an accommodating step, a passing-through step, a filling step, and a drying step. In the multilayer film forming step, the multilayer film is formed on the outer peripheral surface of the light emitting tube where the heating body is provided on the inside thereof. In the connecting step, the heating body and the metal foil, the metal foil and the lead wire, and the lead wire and the connecting portion of the external lead-in wire are electrically connected respectively. In the sealing step, the metal foil and a part of the lead wire are embedded, and the sealing portion is formed by sealing the inside of the light emitting tube so as to draw out the lead wire to the outside of the light emitting tube. In the covering step, the external lead-in wire and the lead wire drawn out from the sealing portion are covered with a covering tube. In the inserting step, the sealing portion is inserted into the opening portion of the clasp. In the accommodating step, the sealing portion is accommodated in the accommodating portion of the clasp. In the passing-through step, the external lead-in wire passes from the inside of the accommodating portion to the outside of the through-hole of the clasp. In the filling step, the portion between the sealing portion and the accommodating portion, and the portion between the external lead-in wire and the through-hole are filled with the filling material including the alcohol-based nonaqueous solvent and the base material containing 85% by mass or more of alumina so as to close the opening portion of the clasp. In the drying step, drying is performed for removing the alcohol-based nonaqueous solvent from the filled filling material. According to the heater 1 manufactured as described above, deterioration of the multilayer film 3 due to generation of gas such as siloxane can be suppressed while maintaining the waterproof property. Moreover, the method for manufacturing the heater 1 is not limited to the order of the steps described above. For example, the multilayer film forming step and the connecting step may be interchanged.

Embodiment 2

FIG. 3 is a sectional view illustrating a heater according to Embodiment 2. A heater 1 according to Embodiment 2 is different from the heater 1 according to Embodiment 1 illustrated in FIG. 2 in that an annular member 22 is further provided. That is, the heater 1 includes the annular member 22 between a first external lead-in wire 8 and a first covering tube 6. Moreover, in FIG. 3, the same reference numerals are given to the same portions as those of the heater 1 according to Embodiment 1.
The annular member 22 is an O-ring made of silicone rubber having, for example, the waterproof property. In the heater 1 including the annular member 22 between the first external lead-in wire 8 and the first covering tube 6, entry of water from the portion between the first external lead-in wire 8 and the first covering tube 6 is further suppressed. Particularly, even if the first external lead-in wire 8 is bent, for example, by 180° when the heater 1 is installed in a lamp (not illustrated), the annular member 22 is installed in the first external lead-in wire 8 so that the annular member 22 and the first external lead-in wire 8 can be reliably in contact with each other. Therefore, it is suitable for securing the waterproof property.
As described above, the heater 1 according to Embodiment 2 further includes the annular members 22 provided between the external lead-in wires 8 and 9, and the covering tubes 6 and 7. Therefore, it is possible to further enhance the waterproof property.

Embodiment 3

FIG. 4 is a plan view illustrating a heater 1A according to Embodiment 3 and FIG. 5 is a sectional view that is taken along line B-B of FIG. 4 illustrating the heater 1A according to Embodiment 3. The heater 1A according to Embodiment 3 is different from the heater 1 according to Embodiment 1 in that a first clasp 4A and a second clasp 5A are provided instead of the first clasp 4 and the second clasp 5 included in the heater 1 according to Embodiment 1. Moreover, in FIGS. 4 and 5, the same reference numerals are given to the same portions as those of the heater 1 according to Embodiment 1.
As illustrated in FIG. 4, the first clasp 4A includes a first filling port 17. Similarly, the second clasp 5A includes a second filling port 18. Moreover, the configuration of the second clasp 5A and the vicinity thereof is the same as the configuration of the first clasp 4A and the vicinity thereof illustrated in FIG. 5. Therefore, in FIG. 5, the illustration and the description of the second clasp 5A will be omitted.
As illustrated in FIG. 5, the first filling port 17 is formed so as to communicate with an outside of the first clasp 4A. The first filling port 17 is used to fill the inside of the first clasp 4A with the filling material which is a basis of the filler 19. Since a sealing portion 2a is accommodated in the accommodating portion 15 and then the accommodating portion 15 is filled with the filling material, only a small gap is left between the opening portion 14 and the sealing portion 2a, and filling of the filling material from the opening portion 14 is difficult. Therefore, the first filling port 17 that is used exclusively for being filled with the filling material is separately provided from the opening portion 14. Therefore, it is possible to smoothly execute a filling operation of the filling material.
In addition, the first filling port 17 is provided to communicate with the sealing portion 2a as viewed from the Z-axis direction, and a side surface of the plate-like sealing portion 2a in the Y-axis direction (thickness direction) is disposed so as to overlap the first filling port 17. As described above, the filling material filled from the first filling port 17 in which the sealing portion 2a is disposed is moved so as to spread throughout the accommodating portion 15 while being distributed in both directions across the sealing portion 2a. Therefore, the first clasp 4A includes the first filling port 17 so that it is possible to smoothly execute a filling operation of the filling material. Here, it is preferable in terms of work that a width of the first filling port 17 in the Y-axis direction is larger than a thickness of the sealing portion 2a in the Y-axis direction. However, the exemplary embodiment is not limited to the configuration, and, for example, the width of the first filling port 17 in the Y-axis direction may be the thickness of the sealing portion 2a in the Y-axis direction or less.
In the example illustrated in FIG. 5, the first filling port 17 is provided so as to be integrated with the opening portion 14, but the configuration is not limited thereto, and for example, the first filling port 17 may be provided directly above the connecting portion 21. In the example illustrated in FIG. 5, the first filling port 17 is provided on the side of the Z-axis in the positive direction of the first clasp 4A, but the exemplary embodiment is not limited thereto. For example, the first filling port 17 may be provided on the side of the first clasp 4A of the Y-axis in the positive direction or the negative direction.
As described above, the clasps 4A and 5A according to Embodiment 3 further include the filling ports 17 and 18 which are opened to allow the accommodating portions 15 to communicate with the outside of the clasps 4A and 5A. Therefore, in a state where the sealing portion 2a is accommodated in the accommodating portion 15, appropriate filling of the accommodating portion 15 with the filling material is easily performed and deterioration of the multilayer film 3 can be suppressed while maintaining the waterproof property.

Claims

A heater (1) comprising:
a light emitting tube (2) where a heating body (10) is provided on an inside thereof;

a multilayer film (3) that is formed on an outer peripheral surface of the light emitting tube;

a metal foil (12) that is electrically connected to the heating body;

a lead wire (20) that is electrically connected to the metal foil;

an external lead-in wire (8) that has a connecting portion (21) electrically connected to the lead wire;

a sealing portion (2a) in which the metal foil and a part of the lead wire are embedded, which is formed in the light emitting tube so as to seal the inside of the light emitting tube, and includes a lead-out portion (11) with which the lead wire is drawn out to an outside of the light emitting tube; characterised by

a covering tube (6) that covers the external lead-in wire and the lead wire that is drawn out from the lead-out portion;

a clasp (4) that includes an opening portion (14) through which the sealing portion is inserted, an accommodating portion (15) that accommodates the sealing portion, and a through-hole (16) through which the external lead-in wire passes from an inside of the accommodating portion to the outside; and

a filler (19) with which a portion between the sealing portion and the accommodating portion, and a portion between the external lead-in wire and the through-hole are filled so as to close the opening portion and the through-hole of the clasp, and which contains 85% by mass or more of alumina.
The heater according to claim 1, further comprising:
an annular member (22) that is provided between the external lead-in wire and the covering tube.
The heater according to claim 1 or 2,
wherein the clasp further includes a filling port (17,18) which is opened so as to communicate the accommodating portion and an outside of the clasp.
A method for manufacturing a heater comprising:
forming a multilayer film on an outer peripheral surface of a light emitting tube where a heating body is provided on an inside thereof;

electrically connecting the heating body and a metal foil to each other, the metal foil and a lead wire to each other, and the lead wire and a connecting portion of an external lead-in wire to each other, respectively;

embedding the metal foil and a part of the lead wire, and forming a sealing portion by sealing the inside of the light emitting tube so as to draw out the lead wire to an outside of the light emitting tube;

covering the external lead-in wire and the lead wire drawn out from the sealing portion with a covering tube;

inserting the sealing portion into an opening portion of a clasp;

accommodating the sealing portion in an accommodating portion of the clasp;

causing the external lead-in wire to pass from an inside of the accommodating portion to an outside of a through-hole of the clasp;

filling a portion between the sealing portion and the accommodating portion, and a portion between the external lead-in wire and the through-hole with a filling material including an alcohol-based nonaqueous solvent and a base material containing 85% by mass or more of alumina so as to close the opening portion of the clasp; and

removing the alcohol-based nonaqueous solvent from the filled filling material.