JPH0660810A - Manufacture of electrodeless discharge lamp - Google Patents

Abstract

PURPOSE:To further enhance an improvement level of an optical flux maintaining ratio due to the reduction of a blackening phenomenon by the use of a getter. CONSTITUTION:A getter 10 is disposed in a relatively lower portion (on a base side) inside a lamp 4 via a metal wire 9 fixed to the upper portion of a stem 6, so as to exhaust the inside of the lamp 4 and chip it off. The getter 10 to be used is of a non-deposition type or a Zr-Al alloy type. The getter 10 has previously included an Hg-Ti alloy, and serves as a mercury dispenser capable of supplying mercury necessary for electric discharge. The getter 10 is heated up to a temperature exceeding an upper limit of a primary activating process temperature outside of the lamp 4 by an induction heating method or the like. The getter can be vaporized and scattered in the superheating process so that a coating film 11 can be formed inside on the base side facing the getter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrodeless discharge lamp which has no electrode inside the lamp and discharges and emits a discharge gas inside the lamp by an external high frequency electric field.

[0002]

2. Description of the Related Art Various discharge lamps that have been put to practical use for lighting have been mainly incandescent lamps, fluorescent lamps, and HI.
It is classified into D etc.

Among them, the fluorescent lamp is for emitting the fluorescent substance coated on the inner surface of the tube by ultraviolet rays generated by the discharge of mercury vapor or a rare gas enclosed in the tube.
This type of lamp is widely used because it has features such as high efficiency, long life, and low cost. Initially, it was limited to the straight pipe type or the ring type, but recently, a compact type with a smaller size and higher output has been developed and put into practical use.

Particularly in recent years, an electrodeless fluorescent lamp which eliminates the electrodes of the original fluorescent lamp and emits light by a high frequency electromagnetic field has been developed and put into practical use. Since this type of lamp does not have an electrode, it has achieved dramatically smaller size, higher output, and longer life than a conventional electrode type fluorescent lamp.

For example, according to the electrodeless discharge lamp disclosed in Japanese Patent Application Laid-Open No. 61-71957, the lamp 1 has a coil 3 on the outer circumference of a substantially spherical bulb 2, as shown in FIG.
The light emitting area of the lamp 1 is small, that is, a small-sized and high-brightness light source is possible.
In addition to being able to provide a lighting fixture with a relatively free optical design, it also has the features of long life and high efficiency.

FIG. 4 shows a concrete example of actual manufacturing of such a lamp. The lamp 4 is formed by a glass bulb 5 for a general electric bulb and a glass stem 6, and a predetermined amount of mercury and a rare gas are enclosed in an internal airtight space 7 formed of these. Further, a phosphor coating 8 is provided on the inner surface of the bulb 5.

By the way, it is known that when mercury is used as the discharge gas as described above, a blackening phenomenon occurs inside the lamp as the lighting time elapses, and the luminous flux decreases. It is considered that this is due to the deposition of a compound mainly composed of mercury oxide (HgO) due to the reaction between the mercury and the residual impure gas (O ₂ , CO ₂ , H ₂ O, etc.) in the lamp.

In the electrodeless fluorescent lamp, since there is no defect due to electrode breakage, the luminous flux is effectively reduced, and therefore the blackening phenomenon is particularly important to prevent. As a countermeasure against this, it is known that disposing the getter in the lamp is effective for removing the residual impure gas. For this purpose, a vapor deposition type typified by a Ba-based (for example, Ba-Al alloy) and a non-vapor deposition type typified by a Zr-based (for example, Zr-Al alloy) have been put into practical use. In a fluorescent lamp utilizing mercury discharge, mercury and barium are highly reactive, so that the latter Zr system is generally used rather than the former Ba system.

FIG. 5 is an example of a getter arrangement in an electrodeless fluorescent lamp, in which a metal ring-shaped container is filled with a Zr-Al alloy through a metal wire (for example, nickel-plated iron wire) 9 previously provided on the stem 6. Getter (eg SA
St101) 10 manufactured by ES company is arranged by spot welding. The getter 10 exerts an effect by performing an activation treatment by induction heating or the like from the outside after the lamp is chipped off.

[0010]

By thus disposing the getter in the lamp, it is possible to suppress the occurrence of the blackening phenomenon and improve the reduction of the luminous flux. However, such a conventional activation treatment method may be insufficient depending on the application.

The present invention has been made in view of the above points, and an object thereof is to manufacture an electrodeless discharge lamp capable of further improving the improvement level of the luminous flux maintenance factor by reducing the blackening phenomenon using a getter. To provide a method.

[0012]

In order to solve the above-mentioned problems, the present invention provides a method of manufacturing an electrodeless discharge lamp in which at least mercury is enclosed in a lamp and a getter for adsorbing residual impure gas is arranged. , The getter is a non-evaporation type, and after the lamp is chipped off, the getter is forcibly evaporated by heating it at the original activation temperature or higher, and it is scattered to the non-light emitting part in the lamp to form a film. It is characterized by being formed.

[0013]

According to the present invention, an originally non-deposition type getter is overheated to forcefully evaporate and scatter, and the scattered film of the getter material is spread over a wide range on the non-light-emission part in the lamp. Due to the formation, the impure gas remaining in the lamp is adsorbed at this portion, and the blackening phenomenon is suppressed.

[0014]

FIG. 1 is a simplified diagram showing an embodiment of the present invention.
(A) shows the state after evacuation and chip off, and (b) shows the state after getter overheat treatment.

First, the getter 10 is placed in a relatively lower portion (on the base side) in the lamp 4 through the metal wire 9 provided on the stem 6.
The lamp 4 is evacuated and the inside of the lamp 4 is exhausted and the chip is turned off (see FIG. 1A). Here, the getter 10 used is a non-deposition type getter, and is a Zr—Al alloy type S getter.
AES (product number St101-505 / O / 5-0.
5). The getter 10 also contains a Hg—Ti alloy in advance and also serves as a mercury dispenser that can supply mercury necessary for discharge.

Next, heating is performed from the outside of the lamp 4 by a method such as induction heating to a temperature above the upper limit of the original activation temperature of the getter 10 (900 ° C. in this embodiment). By such overheat treatment, the getter material is evaporated and scattered to form the coating film 11 on the inner surface of the base side facing the surface of the getter material (see FIG. 1B).

The following table shows the comparison data of the luminous flux maintenance factor by the life test of the lamp prototyped according to this embodiment and the lamp according to the conventional example. The lamp size used was an outer diameter of 35 mm and the lamp input was about 6 W. The phosphor applied to the inner surface of the lamp is a rare earth three-wavelength white product.

[0018]

[Table 1] As is apparent from the above table, the luminous flux maintenance factor of the example product is significantly improved as compared with the conventional product.

Next, FIG. 2 shows a different embodiment of the present invention, which is basically the same as the above embodiment, except that a shielding plate 12 made of stainless steel or the like is provided above the stem 6. The getter 10 is fixed via the shield plate 12. The state of forming the film of the getter material on the inner surface of the lamp 4 is the same as that in the above-mentioned embodiment, and is not shown.

With this structure, it is possible to prevent evaporation and scattering of the getter material due to overheat treatment from reaching the light emitting surface above the lamp 4. Therefore, according to the present embodiment, in addition to the effects of the above-described embodiment, there is an effect that vapor deposition can be surely performed only on the non-light emitting portion on the base side.

[0021]

As described above, according to the present invention, in the production of an electrodeless discharge lamp in which at least mercury is enclosed in the lamp and a getter for adsorbing residual impure gas is arranged, the getter is not vapor-deposited. With the mold, after tipping off the lamp, by forcibly evaporating by heating the getter at the original activation temperature or higher, by forming a coating by scattering to the non-light emitting portion in the lamp,
We were able to significantly improve the luminous flux maintenance factor.

The reason for this is not clear at present, but it is presumed that by coating the getter over a wide area, the specific area becomes large, and the impure gas adsorption capacity of the getter is improved.

[Brief description of drawings]

FIG. 1 is a simplified diagram showing an embodiment of the present invention, in which (a) shows a state after exhaust and chip-off, and (b) shows a state after getter overheat treatment.

FIG. 2 is a simplified diagram showing a different embodiment of the present invention.

FIG. 3 is a simplified diagram showing a basic configuration of a conventional electrodeless discharge lamp.

FIG. 4 is a partial cross-sectional front view showing an example of a conventional electrodeless fluorescent lamp.

FIG. 5 is a simplified diagram showing a conventional example.

[Explanation of symbols]

 4 Lamp 5 Glass Bulb 6 Glass Stem 7 Internal Airtight Space 8 Phosphor Coating 9 Metal Wire 10 Getter 11 Coating 12 Shielding Plate

Claims (1)

[Claims] 1. In the production of an electrodeless discharge lamp in which at least mercury is enclosed in a lamp and a getter for adsorbing residual impure gas is provided, the getter is a non-deposition type and the lamp is a chip. After turning off
A method for manufacturing an electrodeless discharge lamp, characterized in that the getter is forcibly evaporated by heating at a temperature above the original activation temperature and scattered to a non-light emitting part in the lamp to form a film.