JP3022172B2 - Electrodeless lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a discharge gas by applying a high-frequency electromagnetic field to the discharge gas from outside the bulb without having electrodes inside the bulb made of a translucent material in which the discharge gas is sealed. The present invention relates to an electrodeless discharge lamp that emits excited light.

[0002]

2. Description of the Related Art Conventionally, an electrodeless lamp has been known which excites a discharge gas to emit light by applying a high-frequency electromagnetic field to a discharge gas sealed in a bulb. Since this kind of electrodeless discharge lamp has features such as small size, high output, and long life, research and development are conducted in various places, and various uses as a high output point light source are considered. . As shown in FIG. 4, the electrodeless discharge lamp includes a bulb-shaped bulb 1 surrounding an induction coil 2, a high-frequency current is applied to the induction coil 2, and a discharge sealed in the bulb 1. There is one in which a high-frequency electromagnetic field acts on a gas to excite and emit a discharge gas (Japanese Patent Application Laid-Open No. 57-78766). As the discharge gas, a gas containing mercury vapor is used. Ultraviolet rays are emitted by the excitation of mercury atoms, and are converted into visible light by a phosphor. By the way, since the coil used as the induction coil 2 is surrounded by the bulb 1, the temperature of the coil becomes extremely high during the operation of the lamp. There is a problem that efficiency becomes poor.

On the other hand, as shown in FIG. 5, a spherical valve 3 is provided, and an induction coil 4 having a winding wound around the outer periphery of the valve 3 is provided. Electrodeless discharge lamps have been considered. With this configuration, the heat of the induction coil 4 can be released to the outside air, and the strong portion of the electromagnetic field inside the induction coil 4 can effectively act on the discharge gas.

Further, there has been proposed an electrodeless discharge lamp having a double tube structure intended to keep the bulb warm and improve luminous efficiency.
For example, USP, 150,015 discloses an electrodeless discharge lamp shown in FIG. FIG. 6 is a sectional view of the electrodeless discharge lamp, 6 is an arc tube, 7 is an outer tube holding the arc tube 6 inside, 8 is an induction coil, and 9 is a high-frequency power supply.

[0005]

In the electrodeless discharge lamp shown in FIG. 6, a getter member 10 is sealed in order to maintain the degree of vacuum inside the outer tube 7. In general, encapsulation of the getter member 10 to maintain the degree of vacuum is a known technique. However, if fusion of a metal and a glass member is used as the holding means, the glass member may be damaged, and in particular, the electrodeless discharge may be performed. There is a problem that the advantage of improving the reliability due to the absence of a fused portion between glass and metal, which is one feature of the electric lamp, is lost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to avoid glass breakage due to fusion of a metal and a glass member, thereby providing a highly reliable electrodeless electrode with less impurity gas. An object of the present invention is to provide a structure of a discharge lamp.

[0007]

According to a first aspect of the present invention, there is provided an electrodeless discharge lamp including a high-frequency power supply connected to an induction coil disposed outside a light-transmitting material filled with a discharge gas. A non-electrode discharge lamp that energizes a higher frequency current and excites and emits the discharge gas by applying a high frequency electromagnetic field to the discharge gas sealed in the bulb has a getter member that adsorbs an impure gas,
The getter member is configured to be held by being surrounded by a glass member having an opening.

According to a second aspect of the present invention, in the electrodeless discharge lamp, a high-frequency current is supplied from a high-frequency power supply to an induction coil disposed outside the first bulb made of a light-transmissive material filled with a discharge gas. In an electrodeless discharge lamp that excites and emits the discharge gas by applying a high-frequency electromagnetic field to the discharge gas sealed in the first bulb, the first bulb includes:
The second is made of a glass member whose internal space has been evacuated to a high vacuum.
A getter member that is held inside the valve and adsorbs impure gas in a space between the second valve and the first valve, the getter member being held by a glass member having an opening; It is characterized in that it is configured as follows.

According to a third aspect of the present invention, in the electrodeless discharge lamp, a high-frequency current is supplied from a high-frequency power supply to an induction coil disposed outside the first bulb made of a transparent material filled with a discharge gas, and the first bulb is supplied to the first bulb. In an electrodeless discharge lamp that excites and emits the discharge gas by applying a high-frequency electromagnetic field to the discharge gas sealed in the first bulb, the first bulb includes:
The second is made of a glass member whose internal space has been evacuated to a high vacuum.
The first valve is held inside the valve, and a valve wall of at least a portion of the first valve is in contact with a space outside the second valve via the light-transmitting material layer. A getter member for adsorbing impurity gas is provided in a space between the glass members, and the getter member is configured to be held in a form surrounded by a glass member having an opening.

[0010]

According to the electrodeless discharge lamp of the first aspect, since the getter member is held in a form surrounded by the glass member having the opening, the glass is formed by the bulb manufacturing process, the temperature cycle during lamp operation, and the like. There is no fear of breakage, and long-term reliability can be ensured by a getter member that adsorbs impurity gas.

According to the electrodeless discharge lamp of the second aspect, the first bulb is held inside the second bulb made of a glass member whose interior space is evacuated to a high vacuum, and the first bulb is connected to the first bulb.
In the space between the valves, a getter member for adsorbing the impure gas is provided, and the getter member is configured to be held in a form surrounded by a glass member having an opening. Is maintained in a high vacuum, and there is no fear of glass breakage due to the bulb manufacturing process or temperature cycling during lamp operation.

According to the electrodeless discharge lamp of the third aspect, the first bulb is held inside the second bulb made of a glass member whose internal space has been evacuated to a high vacuum, and at least a part of the first bulb. the valve wall is in contact with the outer space of the second valve through the translucent material one layer, and the second valve first
In the space between the valves, a getter member for adsorbing the impure gas is provided, and the getter member is configured to be held in a form surrounded by a glass member having an opening. Is maintained in a high vacuum, there is no risk of glass breakage due to the bulb manufacturing process, temperature cycling during lamp operation, and the like, and it is easy to apply an auxiliary voltage at the start of discharge of the first bulb.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the electrodeless discharge lamp of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of an electrodeless discharge lamp. As shown in the figure, a bulb 11 is formed in a spherical shape by a translucent material such as quartz glass, and a rare gas and mercury are sealed as a discharge gas. For example, 3 Torr of argon and 10 mg of mercury are used. Here, the shape of the valve 11 does not have to be spherical, and may be another shape such as a cylindrical shape. The induction coil 12 is formed so as to wind around the outer wall surface of the valve 11 and is wound three turns, but the number of turns is not particularly limited, and it is sufficient that the induction coil is wound one or more turns.

The induction coil 12 is connected to a high frequency power supply (not shown). When the high-frequency power supply is operated, a high-frequency current flows through the induction coil 12 and an electromagnetic field is generated around the induction coil 12. By this electromagnetic field, the discharge gas inside the bulb 11 is maintained for discharge. During the maintenance of the discharge, the electrons inside the bulb 11 receive the kinetic energy by the electromagnetic field and collide with the discharge gas atoms to give energy. The discharge gas atoms are ionized or excited. The excited atoms emit light when returning to the ground state. This light emission is used as light energy. In some cases,
The generated ultraviolet light may be converted into visible light by a phosphor and used. As a getter member 13 inside the valve 11,
For example, a compound of Zr and Al is held in a form surrounded by a glass member 14 having an opening 4a. During discharge maintenance,
That is, during the operation of the lamp, the temperature of the bulb 11 becomes high, and the impurity gas (for example, water,
Oxygen) is released. When such an impure gas is present in the bulb space, the discharge starting voltage is increased or the luminous efficiency is reduced. However, the getter member 13 adsorbs these impure gases, and the discharge start voltage is increased and the luminous efficiency is reduced. Prevent drop. As described above, in the electrodeless discharge lamp shown in FIG. 1, there is no metal penetrating the bulb member, so that the possibility of bulb breakage and leakage is extremely small.

Referring to FIGS. 2 and 3, different embodiments of the electrodeless discharge lamp of the present invention will be described. FIG. 2 is a sectional view of the electrodeless discharge lamp, and FIG. 3 is a perspective view. As shown in FIG. 2 and FIG. 3, the first bulb 15 is formed in a spherical shape by a translucent material such as quartz glass, and contains a rare gas and a metal halide as a discharge gas. For example, as discharge gas, 100 Torr of xenon gas and 12 mg of NaI-TlI-InI
(A mixture of sodium iodide, thallium iodide, and indium iodide). Here, the shape of the first valve 15 need not be spherical, but may be another shape such as a cylindrical shape. The second valve 16 is a sealed quartz valve, the inside of which is evacuated to a high vacuum, and configured to surround the first valve 15. In some cases, an infrared reflecting film may be formed on the wall surface of the second bulb 16 to further enhance the heat retaining effect of the first bulb 15. At the lower part of the second valve, a hollow internal protrusion 16a projecting inside the second valve, one end of which is opened outside the second valve.
Is formed, and the first valve 15 is provided with a valve wall 15a.
Is fused to the other end of the internal projection 16a, and the first bulb 15 is connected to the outer space of the second bulb 16 via one layer of quartz at this point.

A pulse applying electrode 17 is disposed in the hollow portion 16b of the internal protrusion 16a up to the vicinity of the valve wall 15a of the first valve 15. The pulse applying electrode 17 is connected to a pulse generator 18. ing. Inside the second valve 16, for example, Zr and Al
Is held in a form surrounded by a glass member 20 having an opening 20a. The induction coil 21 is wound at a position close to the first valve 15 outside the second valve 16. Here, the induction coil 21 is wound three turns, but the number of turns is not particularly limited, and is one.
It only needs to be wound for at least one turn.

The induction coil 21 is connected to a high frequency power supply (not shown). When the high-frequency power supply is operated, a high-frequency current flows through the induction coil 21, and an electromagnetic field is generated around the induction coil 21. The discharge gas in the first bulb 15 is maintained by the electromagnetic field. Induction coil 2
If it is difficult to start the discharge with only 1, the pulse generating electrode 17
Voltage. During discharge maintenance, electrons inside the first bulb 15 receive kinetic energy by an electromagnetic field and collide with discharge gas atoms to give energy. The discharge gas atoms are ionized or excited. The excited atoms emit light when returning to the ground state. This light emission is used as light energy. During discharge maintenance, that is, during lamp operation, the temperature of the first bulb 15 becomes extremely high. For example, the temperature of the outer wall of the first bulb 15 becomes about 800 ° C. When such a high-temperature operation is continued for a long time, an impurity gas such as water or oxygen is generated in the inner space of the second valve 16 from the inner surface of the quartz valve or the quartz material. When such an impure gas is present, the heat retention effect of the first valve 15 is reduced, or the discharge is started earlier than the discharge gas inside the first valve 15, resulting in wasteful power absorption. 15 prevents the start of discharge. In the present embodiment, the generated impure gas is immediately adsorbed by the getter member 19, and the above-described problem does not occur. The getter member 19 is surrounded by a glass member 20 (for example, quartz), and the glass member 20 is
It is configured to be fused to the valve 16 (quartz). Therefore, since there is no metal penetrating the valve member, the possibility of valve breakage and leakage is extremely small.

[0018]

According to the electrodeless discharge lamp of the first aspect,
Since the getter member is held in a form surrounded by a glass member having an opening, there is no need to worry about glass breakage during the bulb manufacturing process or temperature cycling during lamp operation. The effect is that the property can be secured.

According to the electrodeless discharge lamp of the second aspect, the first bulb is held inside the second bulb made of a glass member whose internal space has been evacuated to a high vacuum, and the first bulb is connected to the first bulb.
In the space between the valves, there is a getter member that adsorbs impure gas, and the getter member is configured to be held in a form surrounded by a glass member having an opening, so that the inside of the second valve is maintained for a long time. High vacuum is maintained, and there is an effect that there is no fear of glass breakage due to a bulb manufacturing process or a temperature cycle during lamp operation.

According to the electrodeless discharge lamp of the third aspect, the first bulb is held inside the second bulb made of a glass member whose internal space has been evacuated to a high vacuum, and at least a part of the first bulb. Of the second valve is in contact with the space outside the second valve via one layer of the transparent material.
In the space between the valves, a getter member for adsorbing the impure gas is provided, and the getter member is configured to be held in a form surrounded by a glass member having an opening. Is maintained in a high vacuum, there is no fear of glass breakage due to a bulb manufacturing process or a temperature cycle during lamp operation, and an auxiliary voltage is easily applied at the start of discharge of the first bulb.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of an electrodeless discharge lamp of the present invention.

FIG. 2 is a sectional view showing another embodiment of the electrodeless discharge lamp of the present invention.

FIG. 3 is a perspective view showing another embodiment of the electrodeless discharge lamp of the present invention.

FIG. 4 is a sectional view showing an example of a conventional electrodeless discharge lamp.

FIG. 5 is a configuration diagram showing another example of a conventional electrodeless discharge lamp.

FIG. 6 is a sectional view showing still another example of the conventional electrodeless discharge lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Valve 12, 21 Induction coil 13, 19 Getter material 14, 20 Glass member 14a, 20a Opening 15 First valve 15a Valve wall 16 Second valve

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeki Matsuo 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. inventor Shohei Yamamoto Osaka Prefecture Kadoma Oaza Kadoma 1048 address Matsushita Electric Works Co., Ltd. in the (56) reference Patent flat 5-182639 (JP, a) (58 ) investigated the field (Int.Cl. ^7, DB name) H01J 65/04

Claims (3)

(57) [Claims] 1. A high-frequency current is supplied from a high-frequency power supply to an induction coil disposed outside a bulb made of a light-transmitting material containing a discharge gas, and a high-frequency electromagnetic field is applied to the discharge gas enclosed in the bulb. In the electrodeless discharge lamp that excites and emits the discharge gas when actuated, the electrodeless discharge lamp has a getter member that adsorbs an impure gas, and the getter member is held in a form surrounded by a glass member having an opening. An electrodeless discharge lamp characterized in that: 2. A high-frequency current is supplied from a high-frequency power supply to an induction coil disposed outside a first valve made of a light-transmissive material in which a discharge gas is sealed, so that the discharge gas sealed in the first bulb is supplied to the induction coil. In the electrodeless discharge lamp that excites and emits the discharge gas by applying a high-frequency electromagnetic field, the first bulb is held inside a second bulb made of a glass member whose internal space is evacuated to a high vacuum, A structure in which a getter member for adsorbing impurity gas is provided in a space between the second valve and the first valve, and the getter member is held in a form surrounded by a glass member having an opening. An electrodeless discharge lamp characterized in that: 3. A high-frequency current is supplied from a high-frequency power supply to an induction coil disposed outside a first valve made of a light-transmitting material in which a discharge gas is sealed, so that the discharge gas sealed in the first bulb is supplied to the induction coil. In the electrodeless discharge lamp that excites and emits the discharge gas by applying a high-frequency electromagnetic field, the first bulb is held inside a second bulb made of a glass member whose internal space is evacuated to a high vacuum, A valve wall of at least a portion of the first valve is in contact with a space outside the second valve via the light-transmitting material layer, and a space between the second valve and the first valve is provided.
An electrodeless discharge lamp, comprising: a getter member that adsorbs an impure gas, wherein the getter member is held by being surrounded by a glass member having an opening.