JP3200964B2 - Manufacturing method of metal vapor discharge 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 manufacturing a metal vapor discharge lamp.

[0002]

2. Description of the Related Art In order to improve the luminous efficiency and the color rendering, a metal vapor discharge lamp in which a metal halide is sealed as a luminescent material together with mercury and a rare gas in a luminous tube formed of quartz has already been developed.

[0003] A metal halide undergoes a halogen cycle in which it is decomposed into a metal atom and a halogen atom by thermal dissociation in a high-temperature portion, and recombined into a metal halide in a low-temperature portion.

[0004] A metal vapor discharge lamp utilizes this phenomenon, and exists in a stable metal halide form near the tube wall of an arc tube in a low temperature portion in an arc tube during operation.
It does not react with the quartz arc tube. However, in the arc discharge space, which is a high-temperature portion, the metal atoms and the halogen atoms are thermally dissociated, and the metal atoms are excited to generate a spectrum unique to the metal. What uses the generated spectrum as light is a metal vapor discharge lamp.

[0005] The above-described halogen cycle is ideal. In practice, there are metal atoms that cannot be recombined with halogen atoms even near the tube wall of the arc tube in the low temperature part. That is, metal atoms and metal ions generated in the arc discharge space react with the quartz as the arc tube. In particular, alkali metals and alkaline earth metals easily dissolve in quartz, discolor the quartz, reduce the light transmittance, and lead to a decrease in the luminous flux maintenance rate.

[0006] Further, the reduction of the metal due to the reaction between the metal and the quartz leads to the reduction of the luminous substance, which leads to the reduction of the luminescence amount and the change of the luminescent color accompanying the change of the filling ratio of the filling. Furthermore, the free halogen generated by the disappearance of the metal has a strong electron adhesion, so that the lamp voltage increases and the starting voltage increases, thereby shortening the life of the lamp.

When a rare earth metal halide is used as the light emitting substance, the efficiency and the color rendering can be improved.
There is a problem that a rare-earth metal reacts with quartz to cause a devitrification phenomenon in which quartz is crystallized or the like, and the luminous flux maintenance ratio is lowered.

In order to solve these problems, a coating method for forming a metal oxide film having a light-transmitting property on the inner surface of an arc tube has been devised. Tokiko 46-21
No. 432, Japanese Patent Publication No. 50-27677, and Japanese Patent Publication No. 53-35392, it is difficult to form a film having excellent denseness by using these coating methods and coating materials. It is difficult to prevent the reaction between the halide and quartz as the arc tube, and the life of the lamp cannot be significantly improved.

In order to solve this drawback, a method of forming a metal oxide film by a CVD method using a gas of a metal chelate compound has been proposed (see Japanese Patent Application Laid-Open No. 3-238747). FIG. 2 is a schematic view of a low pressure CVD apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 3-238747.

In FIG. 1, reference numeral 1 denotes an arc tube;
, A gas introduction pipe for flowing a reaction gas, 4 a gas exhaust pipe, 5 a vaporizer for generating a source gas, 6 a carrier gas inlet, and 7 an arc tube. 1 is a pump for evacuating and depressurizing 1.

In the actual process, the inside of the arc tube 1 is evacuated to a reduced pressure by a pump 7, the arc tube 1 is heated by a heater 3 at a predetermined temperature, and a metal chelate compound is put in a vaporizer 5 and heated at a predetermined temperature. Then, the vapor is introduced into the arc tube 1 through the gas inlet tube 3 at a predetermined flow rate for a predetermined time together with the carrier gas flowing through the inlet 6 to form a metal oxide film on the inner surface of the arc tube 1. Although not shown, a gas flow device is connected to the carrier gas inlet 6 for flowing a predetermined amount of carrier gas.

[0012]

However, the CVD method using the above-mentioned metal chelate compound, that is, MOC
The VD (Metal Organic Chemical Vapor Deposition) method can form a dense film, but requires a complicated apparatus for CVD, and has a problem that it is not suitable for manufacturing a large number of arc tubes.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a metal vapor capable of easily forming a film of the same quality as a film formed by a CVD method on the inner surface of an arc tube. An object of the present invention is to provide a method for manufacturing a discharge lamp.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method for manufacturing a metal vapor discharge lamp in which a metal halide as a luminescent substance is sealed in a luminous tube formed of quartz. A predetermined amount of a metal chelate compound and an oxidizing reaction gas (for example, oxygen, ozone, nitrous oxide, carbon dioxide, etc.) are filled in, and the sealed arc tube is heated in an electric furnace or the like, so that the inner surface of the arc tube is heated. In which a dense metal oxide film is formed.

[0015]

According to the above method, the metal chelate compound which is solid at normal temperature is evaporated by heating, and the gas of the evaporated metal chelate compound and the reaction gas are deposited on the inner surface of the high-temperature arc tube in the same manner as in the CVD method. Is formed.

[0016]

An embodiment of the present invention will be described below with reference to FIG. FIG. 1A is a view schematically showing a manufacturing apparatus used in the present invention. In FIG. 1A, 11 is an arc tube formed of quartz, 12 is an exhaust tube, 13 is a vacuum exhaust device,
Reference numeral 15 denotes a valve, 16 denotes a metal chelate compound, 17 denotes a reaction gas container, and 18 denotes a vacuum pump.

A metal chelate compound which is solid at ordinary temperature (in this embodiment, acetylacetone (C ₅ H
A metal chelate compound using ₈ O ₂ ) is almost a metal and is a solid). A light emitting tube 11 in which a predetermined amount of 16 is sealed is connected to a vacuum exhaust device 13 via an exhaust tube 12.
With the gas filling valve 15 closed, the valve 14 for the vacuum pump 18 is opened, and the inside of the arc tube 11 in which the metal chelate compound 16 is sealed is evacuated. After the evacuation, the valve 14 is closed, the valve 15 for introducing the reaction gas is opened,
A predetermined amount of a reaction gas is sealed in the arc tube 11 (a pressure gauge for sealing the reaction gas is not shown). Thereafter, the exhaust pipe 12 is sealed off with a burner or the like (not shown). Sealed arc tube 21
Is heated at a predetermined temperature using an electric furnace 22 as shown in FIG. During this heating process, the metal chelate compound evaporated in the arc tube 21 reacts with the reaction gas to form a metal oxide film on the inner surface of the high-temperature arc tube 21. Further, since the electric furnace 22 is used, a large amount of arc tubes can be processed at the same time.

Here, an example using Zr (C ₅ H ₇ O ₂ ) ₄ as a metal chelate compound and oxygen as a reaction gas will be described as a specific example.

As shown in FIG. 1 (a), Zr (C ₅ H ₇ O ₂ ) _{4 is} added to an arc tube 11 having an inner diameter of 15 mm and a distance between electrodes of 32 mm.
Is sealed in an electric furnace 22 at 450 ° C. for 30 minutes to form a ZrO film having a thickness of about 1 μm on the inner surface of the arc tube 21 as shown in FIG.
_Two films could be formed.

Using this arc tube, a lamp for 250 W in which predetermined amounts of ScI ₃ , NaI, mercury and Ar gas were sealed as an enclosure in the arc tube was prototyped, and a lighting test was performed.

As a result of lighting for 6000 hours, the luminous flux maintenance ratio (the luminous flux value after aging lighting for 100 hours is 100%
Was 80%. In addition, it was 60% in the lamp of the same enclosure without applying the present invention.

Regarding the increase in lamp voltage, the lamp manufactured according to the present invention has an increase of 8 hours after lighting for 6000 hours.
V voltage rise. Incidentally, in the lamp of the same enclosure without applying the present invention, a voltage rise of about 30 V occurred.

As for the color temperature, a lamp designed to be about 4000 K was experimentally manufactured. In the lamp according to the present invention, the change in color temperature was within 100K, but in some lamps not according to the present invention, a change of 200K or more occurred.

[0024]

According to the present invention, as described above, a predetermined amount of a metal chelate compound and an oxidizing reaction gas are sealed in an arc tube, and the sealed arc tube is heated to form a dense metal on the inner surface of the arc tube. By forming an oxide film, C
A film of the same quality as the film generated by the VD method can be generated. Therefore, according to the present invention, it is possible to greatly improve the life characteristics of the metal vapor discharge lamp.

[Brief description of the drawings]

FIG. 1 is a schematic view of a manufacturing apparatus used in the present invention.

FIG. 2 is a schematic view of a reduced pressure CVD apparatus showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Arc tube 12 Exhaust tube 13 Vacuum exhaust device 14 Valve 15 Valve 16 Metal chelate compound 17 Reactor gas container 18 Vacuum pump

Continuing from the front page (72) Inventor Shingo Higashikawa 1048 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside (72) Inventor Miki Kotani 1048 Kadoma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd. (56) References Special JP-A-3-238747 (JP, A) JP-A-59-148229 (JP, A) JP-A-59-40436 (JP, A) JP-A-56-123651 (JP, A) JP-A-1-252779 ( JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01J 9/20 H01J 61/35

Claims (1)

(57) [Claims] 1. A method for manufacturing a metal vapor discharge lamp in which a metal halide as a luminescent substance is sealed in an arc tube formed of quartz, a predetermined amount of a metal chelate compound and an oxidizing reaction gas are sealed in the arc tube. A method for manufacturing a metal vapor discharge lamp, wherein a dense metal oxide film is formed on the inner surface of the arc tube by heating the sealed arc tube.