JPS6321889Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to ultra-high pressure discharge lamps such as short-arc xenon lamps, ultra-high pressure mercury lamps, and ultra-high pressure metal halide lamps.

It replaces the conventional short-arc xenon lamp, which is equipped with a transparent quartz glass bulb with pinch seals on both sides of the spherical part where the tips of the anode and cathode are housed, and is compact and has excellent impact resistance. A high-intensity discharge lamp that is easy to manufacture and can also achieve higher brightness characteristics when necessary.
The present applicant has developed and already filed an application as Japanese Patent Application No. 180621/1982 (Japanese Unexamined Patent Publication No. 82454/1983). This high-intensity discharge lamp has a bulb in which the gas is sealed, formed into a straight tube shape using translucent alumina such as single-crystal sapphire, and a base that supports electrodes at both ends of the bulb, which are sealed via joint tubes. However, it is characterized by having an exhaust pipe attached to one of the caps. This feature eliminates electrode-to-bulb contact, eliminating the effects of these differential thermal expansions, and the physical characteristics of the valve and the exhaust structure allow the bulb to be removed from the valve.

By the way, although this new ultra-high pressure discharge lamp is not yet publicly known, as a result of tests conducted by the present inventor, it was found that the light intensity attenuation characteristics and ignition characteristics are poor. The light quantity attenuation characteristic is shown by curve A in FIG. 7, and the ignition characteristic is shown by dotted line B and two-dot chain line C in FIG. In the light intensity attenuation test, an illuminance meter was placed at a horizontal distance of 1 m from an ultra-high pressure discharge lamp that was continuously lit, and changes in illuminance were measured over time. In addition, the ignition test was conducted by counting the number of high-voltage pulses required to ignite each time the light was turned off for one hour after an appropriate cumulative lighting time had elapsed and the light was re-ignited. However, the cumulative lighting time of the test product indicated by dotted line B is 0, 28, 36, 42, and 67 hours, and the cumulative lighting time of the test product indicated by two-dot chain line C is 0, 16, 39,
It was 62.85 hours.

As a result of various experiments, these undesirable characteristics were found to be due to the structure of the new ultra-high-pressure discharge lamp, in which the base and brazed parts come into contact with the gas inside the bulb, and the fact that the getter attached to the anode It is presumed that this is due to the inconvenience in its action. In other words, harmful gases (H ₂ , O ₂ , H ₂ O, CO, CO ₂ , N ₂
etc.), the amount of harmful gases emitted is much higher than in conventional discharge lamps whose bulbs have spherical parts. Since the anode temperature of Getsuta during lighting is approximately 800℃ to 1000℃, the _H2 component of the adsorbed harmful gas, that is, the adsorbed _H2 gas,
Re-releases above 700℃. Therefore, it was assumed that a large amount of H ₂ gas existed inside the bulb during lighting, which accelerated the attenuation of the light amount and worsened the ignition performance.

The present invention was devised under the above circumstances, and its purpose is to improve the light attenuation characteristics and ignition characteristics, and to make it easy to install the getter that achieves this improvement, and to keep the getter in a fixed position. To provide an ultra-high pressure discharge lamp that can be held securely.

That is, in the present invention, caps supporting electrodes are sealed at both ends of a straight tube-shaped bulb made of translucent alumina via joint tubes, and an exhaust pipe is attached to one cap, and the bulb is sealed inside the bulb. In ultra-high pressure discharge lamps that contain gas, the small diameter part of the geta is directly wound around either the anode or the cathode, and the large diameter part of the geta, which is integrally connected to the small diameter part, is attached to the inner peripheral surface of the bulb. It is characterized by being worn in contact with.

This feature allows the small diameter part of the getter that is directly wound around the electrode to be used in a temperature range that is active against harmful gases other than _H2 gas, and also allows the small diameter part of the getter that is directly wound around the electrode to be used in a temperature range that is active against harmful gases other than H2 gas. The large diameter part
It can be used in the temperature range where it is active against _H2 gas due to heat conduction with the valve. This allows the getter to adsorb a large amount of harmful gas emitted from the cap or the like when the bulb is turned on, thereby increasing the purity of the gas sealed in the bulb and improving the light attenuation characteristics and ignition characteristics. Since the large diameter part and the small diameter part of the getter are connected as one, it is easy to install, as it only needs to be installed once. can be held in a fixed position relative to the valve by the small diameter part and the valve,
Therefore, there is no risk of the large diameter portion being moved inadvertently due to vibration or the like.

Hereinafter, the present invention will be described with reference to embodiments shown in the drawings.

FIG. 1 shows a short arc xenon lamp according to an embodiment of the present invention, and in the figure, reference numeral 1 denotes a straight tube-shaped bulb with both ends open. The bulb 1 is made of a translucent alumina such as alumina, single crystal sapphire, or polycrystalline sapphire. In this example, the outer diameter is 8 mm.
This is the case of single crystal sapphire with a diameter of 30.5 mm and a wall thickness of 0.85 mm. The characteristics of single crystal sapphire are superior to those of conventional transparent quartz glass as follows. Note that the values in parentheses are for transparent quartz glass. Density at room temperature 3.98gr/cm ³ (2.20gr/cm ³ ), Mohs hardness at room temperature 9(6), compressive strength at room temperature 21000Kg/cm ²
(11500Kg/cm ² ), Young's modulus at room temperature (35-42)×
10 ⁵ Kg/cm ² (7.4×10 ⁵ Kg/cm ² ), tensile strength at 20℃, 500℃ and 1000℃ 4060Kg/cm ² (1130Kg/cm ² ),
2800Kg/cm ² (1160Kg/cm ² ) and 3640Kg/cm ²
(1310Kg/cm ² ), rigidity at room temperature 21×10 ⁵ Kg/cm ²
(3.4×10 ⁵ Kg/cm ² ), Poisson's ratio 0.254 at room temperature
(0.14) etc.

Cylindrical joint pipes 2 are brazed to both metallized ends of the valve 1, respectively. The joint pipes 2, 2 are made of a metal material such as titanium or an iron-based alloy such as Kovar (trade name). A Ni-plated cap 3 or 4 is brazed or welded to the joint tubes 2, 2, respectively. The caps 3 and 4 are both made of a metal material such as pure iron or an iron-based alloy. One of the caps 3 supports an anode 5 which is press-fitted and brazed, and which is disposed within the bulb 1 along the axial direction of the bulb 1 . The other cap 4 is press-fitted and brazed, and this valve 1 is inserted into the valve 1.
A cathode 6 is supported, which is disposed along the axial direction of the anode 5 and faces the anode 5. The anode 5 and cathode 6, which are electrodes, are each made of a heat-resistant metal such as tungsten or tritated tungsten. The electrode gap g between the anode 5 and the cathode 6 is appropriately determined, and in this embodiment, the short arc electrode gap g is, for example, 2 cm or less. In addition, 3
a and 4a are air vent passages. Further, one of the caps, for example the cap 4, is formed with a communication passage 7 that communicates the inside and outside of the valve 1, and connected to this passage 7, an exhaust pipe 8 made of nickel, copper, etc. is attached to the cap 4 by brazing. It is being

Further, within the bulb 1, for example, a getter 9 having the structure shown in FIGS. 3 and 4 or a getter 9 having the structure shown in FIGS. 5 and 6 is provided on the anode 5 side. That is, the getter 9 illustrated in FIGS. 3 and 4 uses a getter material as a wire, and this wire is formed into a coiled small diameter section 10 and a coiled large diameter section 11 that is integrally connected to the small diameter section 10. It is obtained by rolling it. Note that 12 is a short-circuiting member wrapped around the large diameter portion 11. Also, Figures 5 and 6
The getter 9 illustrated in the figure uses a getter material as a plate material, and as shown in the developed view of FIG.
A cut line 9c is provided along the longitudinal direction. Next, this plate material is wound so that the concave portion 9a and the convex portion 9b engage with each other, and the engaging portions are connected by spot welding to form the large diameter portion 11, and the narrow portion 9d is wound. It is obtained by processing to form a small diameter part 10 which is integrally connected to a large diameter part 11. The small diameter portion 10 of the getter 9 is wound so that its inner diameter is slightly smaller than the diameter of the electrode, and the large diameter portion 11 is wound so that its outer diameter is approximately equal to the inside diameter of the bulb 1. This getter 9 has a small diameter portion 10.
is installed by directly winding it around the anode 5, and the large diameter part 1
1 is mounted in contact with the inner circumferential surface of the valve 1, thereby being fixed within the valve 1. Of course, Getsuta 9
is for the plane perpendicular to bulb 1 and passing through the cathode point.
It is arranged at a position outside the range of light projection angle θ of less than 45°. To install the getter 9, insert the jig from the open end of the valve 1 on the side opposite to the anode 5 while the valve 1, the cap 3, the anode 5, one of the joint pipes 2, and the ring (described later) are assembled. In this case, the brazed portion of the valve 1 and the joint pipe 2 and the small diameter portion 10 are positioned with a distance l apart from each other using a jig. Above dimensions l
is provided to prevent the brazed portion from being heated when the getter 9 is vented by high-frequency heating. Further, as shown in FIG. 2, the getter 9 may have its small diameter portion 10 wrapped directly around the cathode 6 and mounted thereon, and its large diameter portion 11 may be provided in contact with the inner circumferential surface of the bulb 1. Additionally, getter materials include e.g.
The case is shown in which Ti, Zr, an alloy containing these as main components, a Ti-Zr alloy, or the like is used, and both getters 9 are made of Zr.

Enclosed gas is sealed at a predetermined pressure within the valve 1 whose both ends are sealed with the above structure. The sealed gas is an inert gas such as xenon, argon, or krypton, or a selected inert gas containing metal vapor such as mercury, cesium, sodium, potassium, lithium, or rubidium. An example is xenon gas.
This is the case when sealed at 10 to 20 atmospheres. Also, the first
In FIGS. 1 and 2, 13 is a ring that is inserted between the valve 1 and the caps 3 and 4 as required, and is made of, for example, a ceramic material, and 13a is an annular brazing material storage groove. Furthermore, 14 is an annular brazing material storage groove of the caps 3 and 4, 15 is a metal exhaust pipe cover,
16 is an adhesive that fixes the cover 15 in the adjusted position.

The ultra-high pressure discharge lamp having the above structure is lit and used in an air-cooled state by supplying electricity to the electrodes (that is, the anode 5 and the cathode 6) through the cap 3, the exhaust pipe cover 15, and the cap 4.

According to this ultra-high pressure discharge lamp, the light intensity attenuation characteristics can be improved. In other words, if the air cooling capacity of the ultra-high pressure discharge lamp is adjusted so that the surface temperature of the part of bulb 1 closest to the cathode spot is approximately 600°C, the temperature at both ends of bulb 1 will be approximately 300 to 400°C, but this low-temperature part Zr for
The large diameter portion 11 of the getter 9 is inscribed and installed. Therefore, due to heat conduction with the bulb 1, the temperature of the large diameter portion 11 becomes a temperature range showing high activity toward H ₂ gas, and the large diameter portion 11 mainly adsorbs the H ₂ gas inside the bulb 1. In addition, the anode 5 is heated to 800 to 1000℃ during lighting.
Therefore, the temperature of the small diameter portion 10 of the getter 9 becomes a high temperature range showing high activity against harmful gases,
In addition to adsorbing harmful gases other than H ₂ gas in valve 1, H ₂ gas that is once adsorbed during the temperature rising process (including H ₂ gas separated from H ₂ O gas)
emit. However, the release temperature of H ₂ O gas is 700℃
As mentioned above, H ₂ gas is adsorbed at about 870°C.
Of course, this released H ₂ gas is transferred to the large diameter portion 11.
Needless to say, it is attracted to. Note that even when the small diameter portion 10 is wound directly around the cathode 6, the temperature at the middle portion of the cathode 6 is 600 to 900°C, so that a similar harmful gas adsorption effect is performed.

As a result of the test, it was confirmed that by adsorption of H ₂ gas, the light intensity attenuation characteristic was improved as shown by curve D in FIG. 7 compared to curve A.

Furthermore, since the getter 9 can adsorb all harmful gases as described above, electron emission from the cathode 6 is not hindered by the harmful gases. This also improves ignition performance. By the way, the results of a test in which the lights were turned on for 23 hours, then turned off for 1 hour, and then turned on again for about 21 days, as shown by the dotted line E in the middle of Figure 8, showed that regardless of the size of the cumulative lighting time, high-voltage pulses were not applied. It was confirmed that ignition occurred every time with just one application.

Furthermore, according to the ultra-high pressure discharge lamp having the above structure, the getter 9 is directly wound around the electrode 5 or 6.
In other words, the small diameter part 10 is provided in a state where the electrode 5 or 6 is wound tightly by its elastic force, and in addition, the large diameter part 1
1 is inscribed in the valve 1, the getter 9 can be held in a fixed position without requiring any special holding means.

In implementing the present invention, the specific structures, shapes, etc. of valves, joint pipes, caps, anodes, cathodes, exhaust pipes, getters, small diameter parts, large diameter parts, It goes without saying that the position, material, and components of the filled gas are not limited to the above embodiments, and can be implemented in various configurations.

The gist of the present invention described above is the structure described in the scope of the above-mentioned utility model registration claims. Therefore, there is a large-diameter part that is inscribed in the bulb and used in a temperature range where _H2 gas is active, and a large-diameter part that is directly wound around the electrode and used in a temperature range where _H2 gas is active.
By providing a getter consisting of a small diameter portion that is used in a temperature range that is active against harmful gases other than gases, there is an effect that light attenuation characteristics and ignition characteristics can be improved. Since the above getter has an integral structure in which the small diameter part and the large diameter part are connected, it is easy to install it inside the valve, and the small diameter part is directly wound around the electrode and the large diameter part is inscribed in the valve. This structure has the effect of reliably holding the getter in place without requiring any special fixing and holding means.

[Brief description of the drawings]

FIG. 1 is an enlarged longitudinal sectional side view of a short arc xenon lamp according to an embodiment of the present invention, FIG. Fig. 4 shows an example of the getter used in the above lamp, Fig. 3 is a side view, Fig. 4 is a view seen from the direction of the arrow in Fig. 3, Figs.
The figures illustrate other getters. Figure 5 is a developed view, and Figure 6 is a developed view.
The figure is a perspective view, FIG. 7 is a characteristic diagram showing the attenuation tendency of the amount of light, and FIG. 8 is a characteristic diagram showing ignition performance. 1... Valve, 2... Joint pipe, 3, 4... Base, 5... Anode, 6... Cathode, 8... Exhaust pipe, 9
...Getta, 10...Small diameter part, 11...Large diameter part.

Claims (1)

[Scope of utility model registration request] Joint pipes are brazed to both ends of a straight bulb made of translucent alumina, and caps are brazed or welded to each of these coupling pipes, and one of the caps has this fitting inside the bulb. supports an anode disposed along the axial direction of the valve;
The other base supports a cathode that is arranged along the axial direction of the valve and faces the anode, and one of the bases is attached with an exhaust pipe that communicates with the inside of the valve, and the anode and cathode are connected to each other. The small diameter part of the getter is directly wrapped around either side and attached, and the large diameter part of the getter that is integrally connected to this small diameter part is attached in contact with the inner peripheral surface of the valve, and the sealed gas is sealed inside the valve. An ultra-high pressure discharge lamp characterized by: