JP2002279937A - Electrodeless discharge tube and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small electrodeless discharge tube with a prescribed quantity of luminescent substance sealed in the discharge tube, and to provide its manufacturing method. SOLUTION: This electrodeless discharge tube 1 comprises a transparent member 2 with a through-hole 3 having a smooth internal wall surface, and two members 4, 5 for sealing both end parts of the through-hole 3. A luminescent substance 7 is sealed inside or hollow hole 6 formed by the transparent member 2 and two members 4, 5. An OH base is formed at either the open end face of the transparent member 2 with the through-hole 3, or at two members 4, 5 sealing both end faces of the open ends to manufacture the electrodeless discharge tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an electrodeless discharge tube which discharges and emits light by a high-frequency electromagnetic field and a method of manufacturing the same.

[0002]

2. Description of the Related Art Electrodeless discharge lamps do not have electrodes in the light-emitting portion, and therefore, like electrode discharge lamps such as metal halide and xenon lamps, the electrodes are consumed by plasma during light emission and shorten the lamp life. It has the feature that there is no problem of extending the service life and the service life can be extended. Therefore, studies have been made to apply the light source to a light source such as a projection display device. However, when applied to a projection display device or the like, it is necessary to form the light emitting portion small in order to increase the light use efficiency, and a small discharge tube is required.

On the other hand, a conventional method for manufacturing a discharge tube such as an electrodeless discharge lamp is disclosed in Japanese Patent Application Laid-Open No. Hei 9-17393.
As disclosed in the publication, a predetermined amount of a luminescent substance is introduced into a quartz glass container having an exhaust pipe at one end and an introduction pipe at the other end, and the exhaust pipe is connected to an exhaust device to form a container. After evacuation, if necessary, a predetermined amount of gas such as argon is introduced, and predetermined portions of the exhaust pipe and the introduction pipe are heated to a temperature equal to or higher than the melting point of the container base by a burner or the like, and sealed and cut. Is what you do.

[0004]

However, when a discharge vessel having a small vessel is to be formed by the above-mentioned conventional method, a portion where the exhaust pipe and the inlet pipe are melt-sealed with a burner or the like is used to seal the luminescent material. Since the heat capacity of the discharge tube is reduced due to the proximity to the sealed container portion and the heat capacity of the discharge tube is reduced, the luminescent substance introduced into the container evaporates and the exhaust tube or the introduction tube is sealed. Previously, the gas was exhausted through the exhaust pipe or the introduction pipe, and it was difficult to seal a predetermined amount of the luminescent substance in the discharge tube.

[0005] In particular, when a light emitting substance having a high vapor pressure, such as mercury or metal halide, is encapsulated, the above-mentioned problem has occurred remarkably. Therefore, it was not possible to produce a small electrodeless discharge tube that emits light stably. The discharge tube has an outer shape of 10 mm, an inner diameter of 8 mm, and a length of 1 mm.
As large as 5 mm, it was not suitable for projection display devices.
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a small electrodeless discharge tube in which a predetermined amount of a luminescent substance is sealed in a discharge tube, and a method for manufacturing the same.

[0006]

According to a first aspect of the present invention, there is provided a transparent member having a hollow having a predetermined shape with a smooth inner wall surface, and a luminescent material sealed in the hollow.
The transparent member includes a plurality of members joined to each other, and provides an electrodeless discharge tube. The second invention comprises a transparent member having a smooth through hole having an inner wall surface, and a plurality of other members for sealing both ends of the through hole, wherein the transparent member and the plurality of other members are combined. Provided is an electrodeless discharge tube characterized in that at least a luminescent substance is sealed in a hollow hole configured. A third aspect of the present invention is a transparent member having a hollow hole formed by aligning and joining the concave portions of two transparent members having concave portions of the same shape with smooth inner wall surfaces. Provided is an electrodeless discharge tube characterized in that at least a luminescent substance is sealed therein. According to a fourth aspect of the present invention, there is provided a transparent member having a through-hole having one opening end face or a first member different from the transparent member.
Forming an OH group on at least one of the smooth joining end surfaces of the member, and pressing the first member against one of the opening end surfaces of the transparent member via the OH group to form a temporary joint. And a step of filling a light emitting substance and a discharge starting gas into a hollow formed by the first member and the through-hole, and placing a second member on the other open end face of the transparent member. Heat treating at a predetermined temperature to complete the bonding,
And a method of manufacturing an electrodeless discharge tube. According to a fifth aspect of the present invention, there is provided a method for forming an OH group on at least one concave surface of two transparent members having concave portions of the same shape with smooth inner wall surfaces, After sealing, the two transparent members are temporarily joined by pressing the concave portions through the OH groups so as to match with each other, and further heat-treated at a predetermined temperature to form the two transparent members. Completely joining the
And a method of manufacturing an electrodeless discharge tube.

[0007]

1 to 6 show an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a schematic diagram showing a main part configuration of a first embodiment of the electrodeless discharge tube of the present invention,
(A) is a top view thereof, and (b) is an AA sectional view. In FIG. 1, reference numeral 1 denotes an electrodeless discharge tube according to a first embodiment of the present invention, which is a columnar transparent member (for example, quartz glass or sapphire) having a through hole 3 with a smooth inner wall surface.
2 and first and second members 4, 5 joined to the transparent member 2 so as to close both open ends of the through hole 3 of the transparent member 2.
And a luminescent material 7 containing a discharge starting gas sealed in a hollow hole 6 obtained by sealing the opening end of the through hole 3 with the first and second members 4 and 5.

Here, the light emitting substance 7 is argon,
Noble gases such as neon, xenon, krypton, and gallium,
Metal halides such as indium and thallium, mercury, zinc, sulfur, selenium, tellurium and the like are appropriately selected and applied alone or in combination of a plurality of substances. In FIG. 1, the first and second members 4 and 5 are shown in a disk shape, but may be columnar or hemispherical.
Further, the first and second members 4, 5 are not necessarily required to be transparent, but are preferably transparent, and more preferably, the transparent member is adapted to adjust the thermal expansion of each component of the electrodeless discharge tube. It is preferable to use members of the same quality as 2.

The specific shape of the electrodeless discharge tube 1 according to the first embodiment of the present invention is approximately φ6 mm × 8 mm in outer shape, and the shape of the hollow hole 6 is approximately φ2 mm × 3 mm. The shape and dimensions are not limited to those described above. Depending on the application, a large one or a hollow one can be formed. An external high-frequency electromagnetic field (for example, approximately 8
(00 MHz), a discharge starting gas such as argon sealed in the electrodeless discharge tube 1 is excited to be in a plasma state. Then, the luminescent material 7 heated by the plasma is vaporized, and emits light having an emission spectrum unique to the luminescent material 7.

Next, a manufacturing method according to the first embodiment of the present invention will be described with reference to FIGS. The same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. FIG. 2 is a schematic cross-sectional view for explaining a first-half manufacturing process of the electrodeless discharge tube according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view for explaining the latter half of the manufacturing process.

(First OH Group Forming Step) First, FIG.
As shown in (a), an OH group is formed on at least one of the opening end face 2a of the transparent member 2 having the through hole 3 having a smooth inner wall surface or the end face 4a of the first member 4. At this time, the OH group is formed by the transparent member 2 and the first member 4.
This is because when bonding is performed in close contact with each other, room temperature bonding can be performed by utilizing a bonding phenomenon caused by hydrogen bonding between OH groups.

[0012] As a method of forming an OH group, there is a method of using an ion milling apparatus. In this method, vaporized H ₂ O is introduced into a vacuum chamber of an ion milling apparatus, and ionized using an ion gun to generate H ₂ O ⁺ , OH ⁺ , O ^{+ and the} like. Then, by irradiating this to the end face 2a of the opening of the transparent member 2 or the end face 4a of the first member 4, OH
A group is adsorbed. Plasma is generated by introducing vaporized H ₂ O into the inside of a sputtering device (not shown), and H ₂ O is ionized to similarly form the opening end face 2 a of the transparent member 2 disposed on the cathode portion, or 1 member 4
There is also a method in which OH groups are adsorbed on the end face 4a.

Alternatively, the opening end face 2a of the transparent member 2 and the end face 4a of the first member 4 may be polished with a chemical such as potassium hydroxide (KOH) using a chemical such as potassium hydroxide (KOH). Groups can be formed. The opening end face 2a of the transparent member 2 and the end face 4a of the first member 4 have a surface roughness of about 1 nm in Ra display.
In the following, it is desirable that the flatness should be approximately λ / 10 or less. This is to ensure that the transparent member 2 and the first member 4 are in close contact with each other.

(Temporary joining step) Next, as shown in FIG. 2 (b), the transparent member 2 and the first member 4 are pressed against each other with their opening end surfaces 2a and 4a facing each other. And closely joined together. Further, the temperature of both members is set to 800 ° C.
The discharge tube pot 20 is heat-treated at a temperature of about 1000 ° C. and diffusion bonded to form a completely bonded discharge tube pot 20. Thereby, necessary and sufficient bonding strength can be secured. Note that the above heat treatment temperature is a case where quartz glass is applied, and a crystalline material such as sapphire requires a higher temperature. If the transparent member 2 and the first member 4 are made of different materials, it is necessary to join the members having a low melting point at a temperature lower than the melting point. This is because the member is deformed and a predetermined dimensional accuracy cannot be secured.

(Second OH group formation step) Next, FIG.
As shown in (c), the other opening end face 2b or the second member 5 of the transparent member 2 constituting the discharge tube pot 20 is provided.
An OH group is formed on the end surface 5a by the same method as described with reference to FIG.

(Light-Emitting Substance and Discharge Initiating Gas Enclosing Step) In the light-emitting substance and discharge starting gas enclosing step, a gas sealing apparatus shown in FIG. 3A is used. The gas sealing device includes a vacuum chamber 30, a gas inlet 33 for introducing gas into the vacuum chamber 30, an exhaust port 34 for exhausting the inside of the vacuum chamber 30, and an infrared lamp 35 for heating. It has.
Further, the discharge tube pot 20 is provided at the bottom of the vacuum chamber 30.
And a vertically movable movable pressing means 32 disposed above and above the stage 31 so as to penetrate the vacuum chamber 30 from outside to inside.
In order to prevent an air leak that may occur when the pressing means 32 is moved up and down, an O-ring 36 is fitted around the fitting portion between the vacuum chamber 30 and the pressing means 32 by the pressing means 32. Have been.

First, as shown in FIG. 3A, a predetermined amount of the selected luminescent substance 7 is inserted into the hollow hole 6, and the discharge tube pot 20 is placed so that the opening end face 2b faces upward. It is installed at a predetermined position on a stage 31 provided inside the vacuum chamber 30. On the other hand, the second member 5 is installed at a predetermined position on the lower surface of the pressing means 32 so as to face the arc tube pot 20 with the end face 5a on which the OH group is formed facing downward. Thereafter, the air inside the vacuum chamber 30 is exhausted through the exhaust port 34 to make a vacuum state. At this time, the gas inlet 33 is closed.

Next, a discharge starting gas such as argon is supplied through a gas inlet 33 to a predetermined pressure (usually 0.1 Torr to 0.1 Torr).
(About 10 Torr). However, depending on the selected luminescent substance 7, it may not be necessary to introduce a discharge starting gas. The above-described operation of inserting the luminescent material 7 into the hollow hole 6 of the discharge tube pot 20 is desirably performed in an atmosphere of a replacement gas such as argon or nitrogen for the purpose of preventing the entry of moisture. Therefore, a series of operations from the step of inserting the luminescent substance 7 into the hollow hole 6 of the discharge tube pot 20 to the evacuation of the vacuum chamber 30 to a vacuum state may be all performed in a replacement gas atmosphere. desirable. This can be easily realized by configuring an in-line device.

(Temporary Joining Step) Next, as shown in FIG. 3B, the pressing means 32 is moved toward the stage 31 side, and the discharge tube pot 20 is press-contacted from above the second member 5. Since the joint between the discharge tube pot 20 and the second member 5 is based on hydrogen bonding, the jointless electrodeless discharge tube 1 having a low joint strength but in a temporarily joined state is formed, and the hollow hole 6 is formed.
The luminescent material 7 is sealed in the space. In this case, since the temporary bonding is performed at normal temperature, the evaporation of the luminescent material 7 is negligibly small. Therefore, the amount of the luminescent material 7 sealed in the hollow hole 6 is maintained at the predetermined amount at the time of insertion. It will be. In this case, the temporary bonding may be performed by heating to about 300 ° C. In this case, an oxygen bond is formed via oxygen O, and the bonding strength is higher than a hydrogen bond. Even in the above-described temporary bonding state, since the light-emitting substance 7 is completely sealed in the hollow hole 6 of the electrodeless discharge tube 1, it is said that the light-emitting substance 7 leaks from the temporary bonding part in a heat treatment step described later. there is no problem.

(Complete bonding step) Next, the infrared lamp 35 is turned on under pressure and the electrodeless discharge tube 1 is heated to 800 ° C.
A heat treatment is performed by heating to about 1000 ° C. to secure necessary and sufficient bonding strength based on diffusion bonding. The reason why the heat treatment is performed in a pressurized state is to prevent the internal pressure of the hollow hole 6 of the electrodeless discharge tube 1 from increasing due to the heating and to prevent the temporary joint from peeling off.

The above heat treatment temperature is also an example in the case where quartz glass is applied as described above. If the material of the joining member is different, the temperature of the member having a lower melting point is lower than that of the member having a lower melting point, and sapphire or the like is used. When a crystalline material is applied, it is necessary to process at a higher temperature. Heat treatment is
In order to suppress the occurrence of stress strain due to sudden temperature rise,
The temperature state may be divided into a plurality of stages and executed under a predetermined temperature profile. Further, when performing heat treatment at a temperature of about 1000 ° C. in the vacuum chamber 30, when the vacuum chamber 30 has various functional units such as a movable unit,
High-temperature heating may cause a problem in the functional unit. Therefore, the heat treatment may be stopped at about 300 ° C. in the vacuum chamber 30 and then the final heat treatment may be performed by another heat treatment apparatus.

According to the manufacturing method of the present invention, the step of enclosing the luminous substance in the electrodeless discharge tube does not involve heating, so that even if the shape of the electrodeless discharge tube is reduced, the amount of the luminous substance encapsulated is small. Initial values can be maintained throughout the manufacturing process.

Next, a second embodiment of the present invention will be described with reference to FIG. FIGS. 4A and 4B are schematic diagrams showing a configuration of a main part of an electrodeless discharge tube according to a second embodiment of the present invention, wherein FIG. 4A is a top view thereof, and FIG. The same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. FIG.
In the figure, reference numeral 40 denotes an electrodeless discharge tube according to the second embodiment of the present invention, which has a hollow hole 4 whose inner wall surface is smooth and whose one end is closed.
And a second member joined to the discharge tube pot 41 so as to close the opening end of the hollow hole 42 of the discharge tube pot 41. 5 (shown in a disk shape in FIG. 4), and a luminescent material 7 containing a discharge starting gas sealed in a hollow hole 6 obtained by sealing the open end of the hollow hole 42.

The electrodeless discharge tube 40 according to the second embodiment of the present invention can be manufactured through the same manufacturing steps as the method of manufacturing the electrodeless discharge tube 1 according to the first embodiment of the present invention. Specifically, the opening end face 41a of the discharge tube pot 41
Alternatively, O 2 may be formed on the end surface 5a of the second member 5 in the same manner as described above.
Form an H group. Then, the light-emitting substance 7 is
Is inserted into the hollow hole 42, and a discharge starting gas is introduced as necessary. Then, the opening end face 41a of the discharge tube pot 41 and the end face 5a of the second member 5 are closely contacted and pressurized, and furthermore, at a predetermined temperature. The electrodeless discharge tube 40
To manufacture. In the second embodiment of the present invention, similarly to the first embodiment, it is possible to stably manufacture a small electrodeless discharge tube in which a predetermined amount of a luminescent substance is sealed.

FIGS. 5A and 5B are schematic views showing the main parts of an electrodeless discharge tube according to a third embodiment of the present invention, wherein FIG. 5A is a top view thereof, and FIG. In FIG.
Reference numeral 50 denotes an electrodeless discharge tube according to the third embodiment of the present invention, which has smooth end surfaces 5 of cylindrical transparent members 51, 51.
1a and 51a are brought into close contact and have a columnar shape. Both end surfaces 51a, 51a of the transparent members 51, 51 are provided with substantially cylindrical concave portions 52, 52 having smooth inner wall surfaces at substantially central portions thereof, and the transparent members 51, 51 are brought into close contact with each other to form a cylindrical discharge tube. In this case, the concave portions 52 and 52 are combined to form a substantially cylindrical hollow hole 6 inside the electrodeless discharge tube 50. A light emitting substance 7 containing a discharge starting gas is sealed in the hollow hole 6. The hole 52
May be hemispherical. In this case, the shape of the hollow hole 6 is spherical.

The electrodeless discharge tube 50 according to the third embodiment of the present invention is manufactured by the same method as the method of manufacturing the electrodeless discharge tube 1 according to the first embodiment of the present invention.
1a, an OH group is formed, and a transparent member 5 is formed in a predetermined atmosphere.
One end surfaces 51a, 51a of the first and the first 51 are brought into close contact with each other via an OH group, and are temporarily joined at room temperature under appropriate pressure. Alternatively, the bonding may be performed at a temperature of about 300 ° C. as described above. The luminous substance 7 is sealed in advance in the hollow 6 inside the electrodeless discharge tube 50 formed by joining the transparent members 51, 51. Since the hermetically sealed state is maintained, the luminescent substance 7 does not leak through the joint.

FIGS. 6A and 6B are schematic views showing a main part of an electrodeless discharge tube according to a fourth embodiment of the present invention, wherein FIG. 6A is a top view thereof, and FIG. 6B is a DD sectional view thereof. In FIG.
Reference numeral 60 denotes an electrodeless discharge tube according to the fourth embodiment of the present invention, which is a semi-cylindrical transparent member 61 having a shape obtained by dividing a cylinder into two along a central axis thereof,
61a are closely arranged to form a cylindrical shape. Each of the inner side surfaces 61a, 61a of the transparent members 61, 61 is provided with a substantially semi-cylindrical concave portion 62, 62 having a central axis substantially coincident with the center axis and having a smooth inner wall surface.
In the case where a cylindrical electrodeless discharge tube 60 is formed by closely contacting each other, the concave portions 62 and 62 are combined to form a substantially cylindrical hollow hole 6 inside the electrodeless discharge tube 60. A light emitting substance 7 containing a discharge starting gas is sealed in the hollow hole 6. The hole 62 may be hemispherical. In this case, the shape of the hollow hole 6 is spherical.

The electrodeless discharge tube 60 according to the fourth embodiment of the present invention is manufactured by the same method as the method of manufacturing the electrodeless discharge tube 1 according to the first embodiment of the present invention.
1a, an OH group is formed on the transparent member 6 in a predetermined atmosphere.
The inner surfaces 61a, 61a of the members 1 and 61 are brought into close contact with each other via an OH group, and are temporarily joined at room temperature under appropriate pressure. Alternatively, the bonding may be performed at a temperature of about 300 ° C. as described above. The luminous substance 7 is sealed in advance in the hollow hole 6 inside the electrodeless discharge tube 60 formed by joining the transparent members 61, 61. Since the hermetically sealed state is maintained, the luminescent substance 7 does not leak through the joint.

As described above, in the fourth embodiment of the present invention, similarly to the first embodiment, it is possible to stably manufacture a small electrodeless discharge tube in which a predetermined amount of a luminescent substance is sealed. In the above-described first to fourth embodiments, the shape of the electrodeless discharge tubes 1, 40, 50, and 60 has been shown as a cylindrical shape. However, the outer shape is not limited to this. And so on.

[0030]

As is apparent from the above description, according to the present invention, when the luminous substance is sealed in the hollow of the electrodeless discharge tube, the container containing the luminous substance is heated to a high temperature. Since there is no light emitting substance, the light emitting substance does not evaporate and scatter at the time of encapsulation as in the prior art, and a small electrodeless discharge arc tube enclosing a predetermined amount of the light emitting substance can be stably manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a main part of a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view for explaining a first-half manufacturing process of the electrodeless discharge tube according to the first embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view for explaining a second-half manufacturing process of the electrodeless discharge tube according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating a configuration of a main part of a second embodiment of the present invention.

FIG. 5 is a schematic diagram showing a main part configuration of a third embodiment of the present invention.

FIG. 6 is a schematic diagram showing a configuration of a main part of a fourth embodiment of the present invention.

[Explanation of symbols]

1, 40, 50, 60 ... electrodeless discharge arc tube, 2, 51,
61: transparent member, 3, 42: hollow hole, 4: first member,
5: second member, 6: hollow hole, 7: luminescent substance, 20, 4
1 ... discharge tube pot, 2a, 2b, 4a, 5a, 41a,
51a: end face (joint end face), 52, 62 ... concave portion, 61
a ... Inner surface (joint end surface)

Claims (5)

[Claims] 1. A transparent member having a hollow having a predetermined shape with a smooth inner wall surface, and a luminescent substance sealed in the hollow. The transparent member is formed by joining a plurality of members. An electrodeless discharge tube characterized in that: 2. A transparent member having a through hole with a smooth inner wall surface, and a plurality of other members for sealing both ends of the through hole, wherein the transparent member and the plurality of other members are provided. An electrodeless discharge tube characterized in that at least a luminescent substance is sealed in a hollow hole to be formed. 3. A transparent member having a hollow hole formed by aligning and joining said concave portions of two transparent members having concave portions of the same shape with smooth inner wall surfaces, and light emission in said hollow hole. An electrodeless discharge tube wherein at least a substance is enclosed. 4. A step of forming an OH group on at least one of an open end face of a transparent member having a through-hole or a smooth joint end face of a first member different from the transparent member. A step of temporarily bonding the first member to one opening end surface of the transparent member via an OH group and temporarily bonding the first member; and a step of forming a luminescent material in a hollow formed by the first member and the through hole. Enclosing a discharge starting gas, and placing a second member on the other open end surface of the transparent member;
A method of performing a heat treatment at a predetermined temperature to perform complete bonding, and a method for producing an electrodeless discharge tube. 5. An at least one concave surface of two transparent members having concave portions of the same shape with smooth inner wall surfaces.
Forming a group, and after encapsulating a luminescent substance in a concave portion of one of the transparent members, pressing the concave portions through the OH group so that the concave portions coincide with each other, and temporarily joining the two transparent members. Performing a heat treatment at a predetermined temperature to completely join the two transparent members.