JPS5835339B2 - Hodentous Oyobisono Seizou Hohou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a discharge lamp in which a pair of electrodes are sealed within an arc tube.

Discharge lamps such as mercury lamps and metal halide lamps generally have a structure in which a pair of electrodes are sealed within an arc tube made of quartz.

In manufacturing this discharge lamp, there is a step of melting (chip-off) the exhaust pipe connected to the arc tube.

The exhaust pipe has traditionally been cut using an oxyhydrogen burner.

The light emitting element 8 formed of quartz has an irregular network structure of silicon dioxide, and hydrogen atoms generated by the oxyhydrogen burner easily pass therethrough.

Further, some hydrogen atoms enter and dissolve into the network structure of silicon dioxide.

Hydrogen in a quartz tube treated at high temperature is 5i02 + 1/2 H2Si"+0"-0H
- causes a reaction.

If a large amount of hydroxyl groups accumulate in the quartz tube in this way, hydrogen and water are released when the discharge lamp is lit, resulting in a disadvantage that the discharge starting voltage Vs increases significantly or the life of the discharge lamp decreases.

For example, an exhaust pipe connected to an emitting pipe with an internal capacity of 201 rLl is melted (chip-off) in about 10 to 15 seconds using an oxyhydrogen burner with a flow rate ratio of 6117 m of hydrogen and 21/min of oxygen, and then the emitted light is emitted. Temperature when lighting the tube 600~9
(The amount of hydrogen released into the arc tube within 1000 seconds after heating to 70°C was measured.

As a result, the amount of hydrogen in the issuing tube was approximately Q, Q 5 tor.
It was confirmed that it reached about r.

By the way, most of the hydrogen dissolved in the form of hydroxyl groups in the issuing tube can be released outside the issuing tube by treating it in vacuum at high temperature for a long time.

Figure 1 shows a 25i thick quartz arc tube in a vacuum with a 1050mm
FIG. 3 is a characteristic diagram showing the relationship between the wavelength of the emission spectrum and its transmittance at each heating time when heated at .degree.

From this characteristic diagram, it can be seen that if the arc tube is heated for 85 hours or more, absorption in the emission spectrum due to the presence of hydroxyl groups will almost disappear.

By the way, heating the arc tube for a long time of 85 hours or more as described above requires a long time to manufacture the discharge lamp, reduces work efficiency, and becomes a practical problem.

If you turn on a discharge lamp without heat treatment for a long time, the temperature will reach 600℃.
Hydrogen or water is gradually released into the arc tube at a temperature of ~700°C, increasing the starting voltage Vs of the discharge lamp and shortening its life.

In addition, the oxyhydrogen burner used for tip-off of exhaust pipes is dangerous because hydrogen is a substance that is easily explosive, and therefore requires a skilled person to cut it. was there.

The present invention has been made to eliminate the above-mentioned drawbacks, and its purpose is to provide a method for manufacturing a discharge lamp that has a low discharge starting voltage and an improved lifespan.

Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 2 shows a specific example of the arc tube according to the present invention.

Inside the arc tube 1 made of quartz, there are a pair of main electrodes 2 and 3.
A pair of auxiliary electrodes 4 and 5 are also provided.

The main electrodes 2, 3 are connected to lead wires 10.degree. 11 via metal foils 8, 9 sealed to pinch seals 6.7.

The auxiliary electrodes 4, 5 are connected to a lead-out line 14.15 via a metal foil 12.13 sealed to the pinch seal 6.7.

On the wall of the arc tube 1, there is a tip-off portion 16 formed by cutting (tip-off) an exhaust pipe (not shown).

The total amount of hydroxyl groups present inside the arc tube 1 is 1
000ppI11 or less.

Therefore, compared to conventional arc tubes, the discharge starting voltage Vs can be reduced by about 2
0% lower and the lifespan can be improved.

Next, a method for manufacturing a discharge lamp according to the present invention will be explained.

FIG. 3 shows an embodiment of the apparatus used in this method of manufacturing a discharge lamp.

Fusing the exhaust pipe 20 connected to the arc tube 1 (chip-off)
In the step of sealing the arc tube 1, the interior of the arc tube 1 is evacuated with the exhaust pipe 20 fixed.

Then, while rotating the arc tube 1 about its axis and pulling it downward in the figure, the base of the exhaust pipe 20 is irradiated with a focused beam from a xenon lamp of 800 watts to 30 kilowatts.

In FIG. 3, light rays generated from a pair of xenon lamps 22 and 23 placed on the left and right sides of the arc tube 1 are reflected by reflecting mirrors 24 and 25 having reflective surfaces in the shape of a column or a parabola in the column. , a high-density light beam is condensed into the exhaust pipe 20.
is irradiated.

The angle between the irradiation direction of the beam bundle 12 and a plane perpendicular to the axis of the exhaust pipe 20 is preferably 0 degrees to 10 degrees, as shown in FIG.

This is to sufficiently warm the meat in the tip-off section 16.

The reflective mirrors 24 and 25 used have reflective surfaces coated with a substance that easily reflects light, such as aluminum, silver, and magnesia.

In FIG. 3, the xenon lamps 22, 23 and the reflecting mirrors 24, 25 are desirably movable in order to align the focal point of the light beam with the exhaust pipe 20.

FIGS. 5 to 8 show the process in which the exhaust pipe 20 is melted down by the focused beam of the xenon lamp.

The exhaust pipe 20 (FIG. 5), which was cylindrical before being fused, is melted by the high-density light beam and becomes a shape protruding toward the center of the exhaust pipe 20 (FIG. 6), and eventually the exhaust pipe 20 is sealed with molten quartz glass (FIG. 7) and cut into two parts (FIG. 8).

When the density of the focused light beam obtained from the xenon lamps 22 and 23 is relatively small, the exhaust pipe 20 as shown in FIG.
A high melting point metal member 26 is coated on the outer peripheral surface of the member 2.
By irradiating the wall of the exhaust pipe 20 with light through the pipe 6, the wall of the exhaust pipe 20 can be easily fused.

As the high melting point metal member 26, a metal such as titanium, nickel, molybdenum, iridium, etc. is used, and it is 1 m thick.
The exhaust pipe 20 is coated or vapor-deposited with a foil having a size of m1 or less.

In this way, if the exhaust pipe 20 is cut by using the high-density focused beam of the xenon lamp instead of the conventional oxyhydrogen burner, there is no possibility that hydrogen will dissolve in the arc tube 11 and hydroxyl groups will be formed.

In addition, although the above-mentioned example shows the case where quartz is used as the arc tube, other glasses having properties similar to quartz,
The present invention can be applied even when ceramics or the like is used.

In the discharge lamp according to the present invention described in detail above, the total amount of hydroxyl groups present in the arc tube is 100 OPP or less.
Compared to conventional discharge lamps, the increase in discharge starting voltage can be sufficiently suppressed and the lamp can have a long life.

Further, in the method for manufacturing a discharge lamp according to the present invention, in the step of sealing the arc tube by fusing the exhaust pipe connected to the arc tube, while rotating the arc tube about its axis, The exhaust pipe is fused by irradiating it with a focused beam from a xenon lamp tilted 10 degrees from zero with respect to a plane perpendicular to the axis of the exhaust pipe.

Therefore, compared to fusing using a conventional oxy-hydrogen burner, the total amount of hydroxyl groups in the arc tube can be reduced to 0.4 - i, opp 11 degrees, and hydrogen into the arc tube when lit,
The amount of water etc. released can be reduced.

Then, the discharge starting voltage Vs can be suppressed to be lower by io~20%.

In addition, since the exhaust pipe and the xenon lamp that serves as the heat source for fusing it are not in contact, the heat source is an oxyhydrogen burner,
Unlike when a plasma arc is used, impurities do not get mixed into the arc tube when the exhaust pipe is fused.

The xenon lamp used has the advantage that it is easy to set the intensity of the condensed light and does not require a skilled person.

Furthermore, since the shape of the tip-off portion of the arc tube can be made uniform, it is easy to incorporate it into a mass production process.

Furthermore, unlike conventional oxyhydrogen burners, the exhaust pipe can be cut in a vacuum.

However, if the exhaust pipe is melted in an atmosphere with a pressure equal to or higher than the pressure inside the arc tube, it is possible to reduce the suction of impurities into the arc tube.

[Brief explanation of the drawing]

Fig. 1 is a characteristic diagram showing the relationship between the spectral wavelength and its transmittance when the heating time of the arc tube is changed, Fig. 2 is a front view showing a specific example of the discharge lamp according to the present invention, and Fig. 3 is A layout diagram showing an embodiment of the apparatus used in the method for manufacturing a discharge lamp according to the present invention, FIG. 4 is a side view showing an enlarged side view of the discharge lamp in FIG. is a process diagram showing the process of melting down the exhaust pipe by the method for manufacturing a discharge lamp according to the present invention,
FIG. 9 is a longitudinal sectional view showing an example of the treatment performed on the exhaust pipe in the method for manufacturing a discharge lamp according to the present invention. 1... Arc tube, 2, 3... Main electrode, 2
0...exhaust pipe, 22,23...xenon lamp, 24°25...reflector.

Claims (1)

[Claims] 1. In the step of sealing the arc tube by melting the exhaust pipe connected to the emission tube, while rotating the arc tube about its axis, the exhaust pipe is cut in a plane perpendicular to the axis of the exhaust tube. A method for manufacturing a discharge lamp, in which the exhaust pipe is fused by irradiating a focused beam of a xenon lamp tilted 10 degrees from zero.