JP3243838B2 - 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 metal vapor discharge lamp such as a mercury lamp, a metal halide lamp or a sodium lamp.

[0002]

2. Description of the Related Art A mercury lamp utilizing the excitation light emission of mercury at the anode column of a hot cathode arc discharge, a metal halide is vaporized by heat from the mercury hot cathode arc discharge to dissociate into a metal and a halogen, and a color peculiar to the metal. Metal vapor discharge lamps such as a metal halide lamp that emits light that exhibits luminescence or a sodium lamp that emits yellow-orange D-line (589.0 nm, 589.9 nm) by hot cathode arc of sodium vapor have been used. Lighting of gyms and factories, OHP
And light sources for color liquid crystal projectors, fog lamps for automobiles, and the like.

The general structure of the above-mentioned metal vapor discharge lamp is as follows.
JP-A-63-136456 and JP-A-63-16
As disclosed in Japanese Patent Publication No. 0148, a structure in which openings are provided at both ends of a light-transmitting valve, a cap provided with an electrode is inserted into this opening, and the space between the cap and the opening is hermetically sealed with a sealing material. It has become.

In order to manufacture the above-mentioned metal vapor discharge lamp, first, one end opening of the light-transmitting bulb is sealed with a cap, and then mercury or a metal halide in Ar or N ₂ is placed in the light-transmitting bulb. , And then evacuate to about 10 ^-5 torr.In this state, insert a cap into the other end of the translucent bulb, set a sealing material in this other end, and use infrared or laser light. Thus, the sealing material is heated and melted to hermetically seal the other end opening.

[0005]

As described above, in a state where mercury or a metal halide is put in a light-transmitting bulb,
When the end of the light-transmitting bulb is heated for sealing, the pressure is reduced, so that mercury and metal halide in the light-transmitting bulb easily become vapor and escape outside the bulb.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 64-84564, a ceramic base tube is provided at both ends of a light-transmitting bulb, and a base for holding an electrode is attached to the outer end of the ceramic base tube. Thus, it is conceivable to shut off the valve from heat when brazing the base. However, since the joining between the valve and the ceramic base tube is performed by attaching a glass solder to the joint portion in advance and heating the valve and the ceramic base tube to a high temperature in a heating furnace in this state, the above-described problem is solved. It cannot be solved. Also, if mercury or a metal halide is charged into the bulb after the ceramic base tube is attached to the bulb, the number of steps and the number of parts increase.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, a metal vapor discharge lamp according to the present invention has an opening for inserting a cap through which an electrode penetrates is formed at a position facing a light-transmitting bulb. The length of the opening formed at the corresponding position was made longer for one of the openings.

[0008]

After inserting a cap through which an electrode penetrates into a short cylindrical opening of a light-transmitting bulb and sealing the opening with a sealing material, mercury or a metal halide is put into the light-transmitting bulb,
Next, the inside of the light-transmitting valve is evacuated to about 10 ^-5 torr, and in this state, a cap is inserted into the long cylindrical opening of the light-transmitting valve, a sealing material is set, and the sealing material is heated. It is melted to hermetically seal the long cylindrical opening.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a cross-sectional view of a metal vapor discharge lamp according to the present invention, and shows a short arc type metal halide lamp having a short distance between electrodes.

In this metal halide lamp, the shape of a light-transmitting bulb 1 made of polycrystalline alumina is substantially spherical, and mercury 2 and a metal halide 3 are sealed in the light-transmitting bulb 1. A short cylindrical opening 4 and a long cylindrical opening 5 are integrally formed at opposing positions. The light emitting surface 1a of the light-transmitting bulb 1 is formed to be thinner than other portions, so that the start-up at the time of starting is hastened.

A step is formed on the inner peripheral surface of the short cylindrical opening 4, and an alumina cap 6 having a step corresponding to the step is inserted.
₂ wire 7 penetrates, the cap 6 and the inner end penetrating portion of the W-ThO ₂ wire 7 are provided with Ti brazing 8,
_{2 The end of the} wire 7 facing the light-transmitting bulb 1 has W-ThO ₂
An electrode 9 is attached, and the end of the W-ThO ₂ wire 7 protruding from the cap 6 is connected to a Kovar (F) through a buffer layer 10.
The lead member 11 made of e-Ni-Co) is press-fitted, and the space between the lead member 11 and the outer end of the cylindrical opening 4 is sealed with a sealing material 12.

On the other hand, a cap 13 having a step is also inserted into the long cylindrical opening 5.
W-ThO ₂ wire 14 brazed 15 penetrates, is W-ThO ₂ electrode 16 opposed to the electrode 9 attached to the inner end of the W-ThO ₂ wires 14, the W-ThO ₂ wire 14 An end protruding from the cap 13 is press-fitted into a Kovar lead member 18 via a buffer layer 17, and a gap between the lead member 18 and the outer end of the cylindrical opening 5 is used as a sealing material 1.
9 is sealed.

The length of the long cylindrical opening 5 is such that mercury 2 and metal halide 3 placed in the light-transmitting bulb 1 do not evaporate due to heat when the sealing material 19 is melted. Length.

As the buffer layers 10 and 17, Au, A
Noble metals such as g and Pt are used. Thus, the buffer layer 1 is provided between the W-ThO ₂ wires 7 and 14 and the lead members 11 and 18.
With the interposition of 0 and 17, the difference in thermal expansion is alleviated to achieve conduction. That is, the lead members 11, 18
Although the thermal expansion coefficient of constituting a Kovar (Fe-Ni-Co) is substantially the same as alumina, quite different from the W-ThO ₂ and Kovar, W-ThO ₂ wires 7 becomes a high temperature,
The connection between the lead 14 and the lead members 11 and 18 becomes insufficient.
Therefore, by interposing the buffer layers 10 and 17 made of a noble metal such as Au, Ag, and Pt between them, conduction at high temperatures can be ensured.

Further, whiskers such as alumina are contained in the sealing materials 12 and 19. By including the whiskers in this way, even if cracks enter the cured sealing material, the cracks can be prevented from further developing.

A manufacturing procedure of the metal halide lamp having the above structure will be described with reference to FIG. First, as shown in FIG. 3 (a), a cap 6 and a lead member 11 are integrally inserted into a short cylindrical opening 4 in a container 20 having a gas introduction pipe and an exhaust pipe, and a seal is placed thereon. The sealing material 12 is set, and then the inside of the container 20 is evacuated to about 10 ⁻⁵ torr. In this state, the sealing material 12 is irradiated with a laser beam or the like from the outside through the transparent window 21 of the container 20, and the After the adhesive 12 is heated and melted, it is cured and the cylindrical opening 4 is sealed.

Next, as shown in FIG. 3 (b), the light-transmitting bulb 1 is turned upside down so that the long cylindrical opening 5 faces upward, and the gas in the container 20 is changed to nitrogen or argon. The mercury 2 and the metal halide 3 are introduced into the translucent bulb 1 in place of the active gas.

Thereafter, as shown in FIG.
The inside of the chamber is evacuated again to about 10 ^-5 torr, the cap 13 and the lead member 18 are integrally inserted into the long cylindrical opening 5, a sealing material 19 is set thereon, and sealing is performed from the outside. Lumber 1
The sealing material 19 is heated and melted by irradiating the sealing material 19 with laser light or the like, and then cured to seal the cylindrical opening 5. Thus, a metal halide lamp is manufactured.

FIG. 4 is a sectional view showing another embodiment. In this embodiment, a long arc type lamp having a large distance between electrodes is shown. In the case of the long arc type, when the cylindrical opening is sealed, that is, in the step corresponding to FIG. 3 (c), the mercury 2 and the metal halide 3 accumulate below and from the sealed end. Because of the distance, the thermal effect is relatively small as compared with the shot arc, but it is still effective by applying the structure of the present invention.

[0020]

As described above, in the metal vapor discharge lamp according to the present invention, one of the cylindrical openings for inserting the caps formed at the opposite positions of the translucent bulb is elongated, After sealing the short cylindrical opening of the light-transmitting valve, put mercury or metal halide into the light-transmitting valve, and then seal the long cylindrical opening with the pressure inside the light-transmitting valve reduced. In this case, the heat of the sealing does not affect the inside of the light-transmitting bulb, so that the mercury and the metal halide in the light-transmitting bulb can be prevented from leaking out of the bulb as vapor.

Further, since only one of the cylindrical openings formed in the light-transmitting bulb is long, the size of the entire lamp does not increase when the light-transmitting bulb is housed in the outer tube.
Furthermore, since the long cylindrical opening is formed integrally with the translucent bulb, the number of steps and the number of parts can be reduced as compared with a case where another member is added.

[Brief description of the drawings]

FIG. 1 is a sectional view of a metal vapor discharge lamp according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the metal vapor discharge lamp.

FIG. 3 is a view showing a manufacturing process of the metal vapor discharge lamp.

FIG. 4 is a sectional view showing another embodiment.

[Explanation of symbols]

1: Translucent bulb, 2: Mercury, 3: Metal halide,
4: short cylindrical opening, 5: long cylindrical opening, 6, 13 ...
Cap, 7, 17 ... wire, 9, 16 ... electrode, 10,
17: buffer layer, 11, 18: lead member, 12, 19 ...
Sealing material.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 61/30-61/48 H01J 9/24-9/50

Claims (2)

(57) [Claims] 1. A metal vapor discharge lamp in which a metal or a metal compound is sealed in a light-transmitting bulb, wherein the light-transmitting bulb is provided with a short cylindrical opening and a long cylindrical opening at positions opposed to each other. A cap provided with an electrode is inserted into each of the cylindrical openings, and a lead member connected to the electrode is disposed at an outer end of the cap. The lead member and the outer end of the cylindrical opening are A metal vapor discharge lamp, which is sealed with a sealing material that is melted by heating. 2. The metal vapor discharge lamp according to claim 1, wherein the light-transmitting bulb is made of polycrystalline alumina, the metal is mercury, and the metal compound is a metal halide. .