JP3341410B2 - Electrodeless discharge lamp and its device - 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 in which a discharge gas is excited and emits light by applying a high-frequency electromagnetic field to a discharge gas sealed in the discharge tube without an electrode inside the discharge tube. And a device therefor.

[0002]

2. Description of the Related Art Hitherto, a high-frequency current has been applied to an induction coil wound around an arc tube, thereby causing a high-frequency electromagnetic field generated around the induction coil to be discharged from a discharge gas sealed in the arc tube. There has been proposed an electrodeless discharge lamp in which a so-called electrodeless discharge is generated in an arc tube to excite and discharge a discharge gas to emit light. This type of electrodeless discharge lamp has features such as small size, high efficiency, and long life, and is being researched and developed in various places.

Further, an electrodeless discharge lamp having a so-called double tube structure in which an arc tube is arranged in an outer tube with the aim of further increasing the efficiency and a device designed to increase the operating temperature is disclosed in, for example, US Pat. No. 5,150. , 015 and the like. In such an electrodeless discharge lamp, the support of the arc tube is made of a nonmetallic material, and in the embodiment described in the specification, the arc tube is held by a quartz tube called a gas probe.

[0004]

However, in such an electrodeless discharge lamp, the number of evacuation steps is increased, the welding of a quartz tube is required, and the manufacturing process is complicated. In addition, the startability of the lamp also employs a two-step method in which a discharge is first generated in the gas probe and the discharge is used to start the electrodeless discharge lamp. Difficulty remains.

The present invention has been made in view of the above problems, and has as its object to provide an electrodeless discharge lamp having a simple structure for holding an arc tube in an outer tube and having excellent startability, and an apparatus therefor. Is to provide.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a light-emitting tube having a light-transmitting property filled with a discharge gas, and a light-transmitting tube arranged to secure a closed space around the light-emitting tube. In an electrodeless discharge lamp including an outer tube having optical properties and an induction coil that excites and emits a discharge gas by applying a high-frequency electromagnetic field from outside the outer tube, the arc tube is supported via a metal supporting means. Fixed to the outer tube, and
An auxiliary electrode is provided on an outer surface portion where the step comes into contact with the outer tube .

[0007]

According to the present invention, the arc tube is fixed in the outer tube by:
Since this is performed via the metal supporting means, the configuration is simpler than in the related art. Further, the supporting means is an outer tube
When an auxiliary electrode is provided on the outer surface at a position where the discharge gas contacts the discharge gas in the arc tube via the support means, a pulse voltage or a high-frequency voltage is externally applied to the auxiliary electrode.
Is given, and a minute discharge is generated in the arc tube, and this minute discharge lowers a discharge starting voltage and facilitates starting.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS ( Basic Configuration Example 1 ) As shown in FIG. 1 having a basic configuration of the present invention , an arc tube 1 is formed of a translucent material such as quartz glass into a cylindrical shape. A rare gas and a metal halide are sealed inside as a discharge gas. For example, as a discharge gas, 100 Torr of xenon gas and 12 mg of NaI-TaI
-InI (a mixture of sodium iodide, thallium iodide, and indium iodide) was used. The shape of the arc tube 1 does not have to be cylindrical, and may be another shape such as a sphere.

The outer tube 2 is formed of a translucent material such as quartz glass so as to secure a closed space around the arc tube 1. The exhaust is performed through an exhaust pipe (not shown) provided on the upper surface (on the drawing) of the outer tube 2, and a closed space between the arc tube 1 and the outer tube 2 is filled with a vacuum or low-pressure gas. And
During lamp operation, the cooling effect of the lamp due to convection of the atmosphere and the like is limited.

The arc tube 1 is fixed in the outer tube 2 by contacting the upper surface (in the drawing) of the arc tube 1 with a plurality of projections 3 provided on the inner wall of the outer tube 2 and formed of tungsten. This is performed by pressing the lower surface of the arc tube 1 with a supporting pipe 4 as a supporting means. At this time, by heating the bottom surface of the outer tube 2 when the outer tube 2 is evacuated, the arc tube 1 can be firmly and easily fixed together with the projections 3.

In this embodiment , the support means 4 for supporting the arc tube 1 in the outer tube 2 is a support pipe made of tungsten. However, the present invention is not limited to this, and the shape is also limited to this. Not something. Further, it can be similarly fixed by using a metal having a spring characteristic for the support means 4. Furthermore, the position of the exhaust pipe of the outer pipe 2 may be a side surface of the outer pipe 2.

The induction coil 5 is disposed at the side of the arc tube 1 so as to be wound around the outer wall surface of the outer tube 2, and both ends thereof are connected to a high frequency power supply 6. This structure
In the example , the induction coil 5 is wound three turns,
The number of turns is not particularly limited as long as it is wound one or more turns.

In the electrodeless discharge lamp thus configured, when the high-frequency power supply 6 is operated, a high-frequency current flows through the induction coil 5 and an electromagnetic field is generated around the induction coil 5. The discharge gas in the arc tube 1 is sustained by this electromagnetic field. During discharge maintenance, electrons inside the arc tube 1 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.

[0014] In FIG 2 having a basic structure of a (basic configuration example 2) present invention, the basic
The point different from the typical configuration example 1 is that a zirconium-based getter material 7 is disposed on the support pipe 4, and the other configuration is the same as that of the first embodiment. Omitted. The position of the getter material 7 is such that the support pipe 4 is warmed by heat conduction when the lamp is turned on.

With this configuration, generation of impurities in the outer tube 2 can be suppressed to a very small amount. As a result, discharge by the impure gas does not occur between the outer tube 2 and the arc tube 1, electromagnetic field energy is added to the arc without waste, and a decrease in efficiency can be prevented.

In this configuration example , the getter material 7 is a zirconium-based getter, but it is a matter of course that the getter material 7 is not limited to a zirconium-based getter.

[0017] (Embodiment 1) FIG. 3 shows a first embodiment of the present invention, the basic
The difference from the first configuration example is that an auxiliary electrode 8 is provided on the outer surface of the support pipe 4 at a position where the support pipe 4 contacts the outer pipe 2.
The other configuration is basically
Since the configuration is the same as that of the configuration example 1, the description is omitted by assigning the same reference numerals to the same components. In this embodiment, the power supply 9
Is a pulse power supply, but a high frequency power supply may be used.

With such a configuration, the pulse voltage applied to the auxiliary electrode 8 gives energy to the discharge gas in the arc tube 1 via the support pipe 4 and generates a slight discharge in the arc tube 1. Let it. This small discharge lowers the firing voltage and facilitates starting.

( Embodiment 2 ) FIGS. 4 to 6 show a second embodiment of the present invention.
4 is a perspective view of the support means 4, FIG. 5 is a side view of a partial cross section showing the entire configuration including the high-frequency power supply, and FIG. 6 is a simplified perspective view.

As shown in FIG. 4, the support means 4 comprises four support rods 4a, 4b, 4c and 4d and a connecting plate 4e crossing in a cross shape. Are fixed to respective ends of the connection plate 4e.
A pair of support means 4 having such a configuration is prepared, and as shown in FIGS. 5 and 6, the connection plate 4 e side of each support means 4 abuts on the upper surface and the bottom surface of the outer tube 2.
The arc tube 1 is fixed in the outer tube 2 by pressing both sides of the arc tube 1 with the open ends of the support rods 4a, 4b, 4c, 4d.

In the present embodiment configured as above, since the arc tube 1 is more firmly fixed in the outer tube 2,
Particularly suitable when used in places with a lot of vibration.

[0022]

According to the first aspect of the present invention, it is possible to provide an electrodeless discharge lamp in which the arc tube can be fixed in the outer tube with a simpler structure. Also applied to the auxiliary electrode
The applied pulse voltage is discharged into the arc tube through the support pipe.
It gives energy to the electric gas and generates a slight discharge in the arc tube.
At the same time, this small discharge lowers the firing voltage,
An electrodeless discharge lamp that facilitates starting can be provided. Further, according to the second aspect of the present invention, energy is given to the discharge gas in the arc tube through the support means, and a minute discharge occurs in the arc tube, and this minute discharge lowers a discharge starting voltage,
An electrodeless discharge lamp device that can be easily started can be provided.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing an entire configuration including a high-frequency power supply according to a first configuration example having a basic configuration of the present invention.

FIG. 2 is a partial cross-sectional side view showing an entire configuration including a high-frequency power supply according to a second configuration example having a basic configuration of the present invention.

FIG. 3 is a partial cross-sectional side view showing the entire configuration including the high-frequency power supply according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a supporting means according to a second embodiment of the present invention.

FIG. 5 is a partial cross-sectional side view showing an entire configuration including a high-frequency power supply according to a second embodiment of the present invention.

FIG. 6 is a simplified perspective view showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arc tube 2 Outer tube 3 Projection part 4 Support means 5 Induction coil 6 High frequency power supply 7 Getter material 8 Auxiliary electrode 9 Pulse power supply

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shin Nobukawa, 1048 Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Works, Ltd. Inventor Shigeki Matsuo 1048 Kadoma Kadoma, Kadoma City, Osaka Pref. (72) Inventor Motohiro Saimi 1048 Kadoma Kadoma, Kadoma City, Osaka Pref.Matsushita Electric Works, Ltd. 1048 Kadoma, Ichidai-shi, Matsushita Electric Works, Ltd. (56) References JP-A-3-102703 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 65/04

Claims (2)

(57) [Claims] 1. A light-transmitting arc tube filled with a discharge gas, a light-transmitting outer tube arranged so as to secure a closed space around the light-emitting tube, and a high-frequency wave from outside the outer tube. An electrodeless discharge lamp including an induction coil for exciting and emitting a discharge gas by applying an electromagnetic field, wherein the arc tube is fixed to an outer tube via metal support means, and
An electrodeless discharge lamp, characterized in that an auxiliary electrode is provided on an outer surface of a position where the means contacts the outer tube . 2. An electrodeless discharge lamp according to claim 1,
A high frequency power supply connected to the induction coil;
With a pulsed or high-frequency power supply connected to the poles
Electrodeless discharge lamp device.