JPH0456058A - Electrodeless discharge lamp device - Google Patents

Abstract

PURPOSE:To provide a high output spot-form light source, facilitate manufacture, prolong the lifetime, and easure easy restarting by lighting up through feeding of a high frequency current to either of two coils, and feeding current to the other coil at restarting after extinction. CONSTITUTION:Induction coils 2 are installed in two places such that each coil is situated the most remotely, and a high frequency current is fed to either of the coils for lighting up. When restarting is made after an extinction, current is fed to the other coil. The configuration shall be such, instead of installing only one of the two induction coils 2, that a light emission tube concerned 1 or either of the induction coils 2 is movable in the axial direction of the light emission tube 1, and thereby the induction coil concerned 2 is located at the other end of the light emission tube 1 at restarting after extinction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrodeless discharge lamp device that does not have an electric power source inside the lamp and excites discharge gas inside the lamp to emit light using a high-frequency electromagnetic field from the outside.

[Prior Art] Electrodeless discharge lamps have been researched and developed in various places since they have characteristics such as small size, high output, and long life. Although their uses are various, for example, the use as a high-output point light source is considered.Among such electrodeless discharge lamps, for example, the lamp disclosed in Japanese Patent Application Laid-Open No. 57-78766, As shown in FIG. 4, a bulb 6 is formed to cover the air-core coil 5, and the mercury vapor inside the bulb 6 is discharged by the tm field generated by passing a high-frequency wave through the air-core coil 5. The magnetic field generated by the cylindrical coil used here is strongest inside the cylindrical coil, but in this example, there is no discharge space in that part, and the bulb 6 is formed by exclusively using the magnetic field outside the coil. has been done.

In addition, the shape of high-output electrodeless discharge lamps that emit light using electromagnetic waves, which have recently been developed in various places, is spherical as shown in Figure 5, and a rare gas and a luminescent material are placed inside a bulb 7 made of transparent quartz or the like. is enclosed, and an induction coil 8 is wound around the valve 7. If a point light source with such a shape is required, the diameter of the bulb 7 must be made small, but the bulb 7 should be spherical, for example, with a low diameter and filled with discharge gas. is very difficult. Moreover, even if such a small spherical tube is made, the tube wall load, that is, (input/surface 1) increases, and the lamp life is shortened. moreover,
When using metal vapor discharge, the disadvantage is that the vapor pressure increases significantly during discharge, making instantaneous restart difficult.

[Till to be solved by the invention] The present invention was made in view of the above-mentioned drawbacks, and its purpose is to provide a point light source with high output, which has a long lifespan and is easy to restart. To provide an electrodeless discharge lamp device.

[Means for Solving the Problems] In order to solve the above problems, the present invention includes winding an induction coil around a part of a light-transmitting elongated tubular arc tube, and passing a high-frequency current through the induction coil. According to
In the electrodeless discharge lamp device in which only the coil winding portion in the interior space of the arc tube emits light, the induction coil is disposed at two locations so that the respective coils are located at the farthest positions; A high-frequency current is applied to one of the coils to turn on the light, and when restarting after the light goes out,
It is characterized by energizing a coil different from the coil that was energized during the previous lighting, and also according to the above-mentioned 2.
Instead of disposing only one of the two induction coils, either the arc tube or the induction coil is configured to be movable in the axial direction of the arc tube, so that when restarting after the light is turned off, the induction coil is moved. It is characterized in that it is located at the other end of the arc tube.

[Example 1] Figure 1 shows the first example of the present invention, where l is a long arc tube that is airtight and translucent, and contains xenon as a discharge gas inside. (Xe) gas at 100 Torr and several mg of mercury (Hg) are sealed. Note that the inner diameter of the arc tube 1 is 5 mm. Reference numeral 2 denotes an induction coil, which is wound several turns, for example, 3 turns, around each end of the arc tube in the shape of a solenoid, and both ends of each coil 2 are connected to a high frequency generation circuit 3 through a matching circuit (not shown). It is connected to the.

In the electrodeless discharge lamp configured in this way, when a high frequency voltage is applied to either end of the induction coil 2, an alternating magnetic field is generated around the coil 2, especially inside the arc tube 1, and the magnetic field causes light to be emitted. An induced electric field is generated along the inner wall of the tube l. Therefore, this induced electric field gives energy to the electrons, and the electrons ionize atoms in the arc tube 1 by impact, causing dielectric breakdown. Further, the discharge is similarly maintained by the induced electric field.

Incidentally, as the temperature of the arc tube 1 rises, the mercury vapor pressure in the light emitting section also rises, but excess mercury (Hg) collects at the coldest section of the tube wall. In this embodiment, it will adhere to the inner wall of the arc tube l of the coil 2 that is not lit. In other words, if the arc tube 1 has a distribution such that the temperature is highest on the discharge side and the lowest temperature on the non-discharge side when lit, and the length of the tube is sufficiently long, the temperature at the coldest point is It will be close to room temperature.

After stable operation in this manner, the light is turned off, and when the light is turned on next time, a high frequency current is applied to the coil 2 on the side that is not lit first. Then, since mercury is attached to the inner wall of the arc tube and the temperature is such that the mercury vapor pressure is not so high, restarting is easy. Thereafter, each time the light is turned on and off, the coil 2 through which the high frequency is energized is changed.

As described above, since the arc tube I in this embodiment is tubular, it is very cumbersome to manufacture, and since the discharge section is limited to the winding section of the coil 2, it is difficult to manufacture it even though it is a straight tube lamp. Nevertheless, a point-like light source is obtained. Furthermore, an additional effect is a long life. this is,
Blackening, which is a phenomenon peculiar to high pipe wall loads, is also significantly reduced because the burden is partially reduced.

Although xenon and mercury are used as the fillers in this embodiment, it is needless to say that the type and pressure are not limited as long as the discharge means can maintain the discharge.

[Embodiment 2] FIG. 2 shows a second embodiment of the present invention, in which an arc tube 1
is annular, and the two induction coils 2 are arranged at the farthest positions from each other. The other configurations are the same as those in the previous embodiment.

With this configuration, the overall size of the device can be made compact when arc tubes I of the same volume are used.

[Embodiment 3] FIG. 3 shows a third embodiment of the present invention, which differs from the first embodiment in that an induction coil 2 and a high frequency generation circuit 3 are provided.
Instead of 1&l, arc tube 1 or induction coil 2
The other structure is configured to be movable in the tube axis direction of the arc tube I, and the induction coil 2 is positioned at the other end of the arc tube I when the light is turned off and restarted. This is the same as in Example 1.

This embodiment also provides the same effects as the first embodiment.

[Effects of the Invention] The electrodeless discharge lamp device according to the present invention is configured as described above, so that when the lamp is restarted after being turned off, the part that was the coldest point when the lighting was stabilized is subjected to electrodeless discharge. Therefore, it is possible to provide an electrodeless discharge lamp device that is a high-output point light source, has a long life in a manufactured package, and is easy to restart.

[Brief explanation of drawings]

FIG. 1 is a simplified diagram showing a first embodiment of the invention, FIG. 2 is a simplified diagram showing a second embodiment of the invention, and FIG. 3 is a simplified diagram showing a third embodiment of the invention. , FIG. 4 is a partially sectional front view showing a conventional example, and FIG. 5 is a simplified diagram showing a different conventional example. ■... Arc tube, 2... Induction coil, 3... High frequency generation circuit.

Claims (2)

[Claims] (1) By winding an induction coil around a portion of a long, thin, translucent tubular arc tube and passing a high-frequency current through the induction coil, only the coil-wound portion of the space within the arc tube emits light. In the electrodeless discharge lamp device, the induction coils are arranged at two locations so that the respective coils are located at the farthest positions, and
An electrodeless discharge lamp device characterized in that the lamp is lit by passing a high-frequency current through either one of the coils, and when restarting after the lamp is turned off, electricity is energized to a coil different from the coil that was energized during the previous lighting. (2) Instead of arranging only one of the two induction coils according to claim 1, either the arc tube or the induction coil is configured to be movable in the tube axis direction of the arc tube, and the light is turned off. An electrodeless discharge lamp device, characterized in that the induction coil is located at the other end of the arc tube upon subsequent restart.