JPS6222061Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a discharge lamp equipped with a metal capsule for supplying the required amount of mercury to the space inside the bulb.

Generally, during the evacuation process of discharge lamps, a certain amount of mercury is sealed inside the bulb through the exhaust pipe from the exhaust head, but because the temperature of the bulb is high during the evacuation operation, a large amount of mercury is filled in the bulb immediately after it is filled into the bulb. of mercury evaporates. The mercury vapor then dissipates into the vacuum system (exhaust system), and most of it is condensed in the trap, but some of it is released from the vacuum pump to the outside and tends to contaminate the working environment.

In addition, the amount of mercury sealed in the bulb is about 3 to 5 times greater than the required amount, taking into account dissipation into the vacuum system, which is not preferable from the point of view of effective use of resources.

Therefore, as shown in FIGS. 1 and 2, the applicant previously connected an electrode D to the tips of two strut lines C and C extending from a stem B sealed at the end of a bulb A. A ring-shaped metal member F having a space E is disposed near this electrode D, and a metal capsule G is formed by incorporating a required amount of mercury in this metal member F and crushing and sealing the opening. proposed a discharge lamp in which the space E is positioned so as to be bridged, and one crushed part H is welded to a metal member F.

According to this discharge lamp, the mercury in the metal capsule G is supplied to the space inside the bulb by high-frequency heating of the metal member F and the metal capsule G after the exhaust operation is completed, so that mercury vapor is released from the exhaust system to the outside. The metal capsule G contains the minimum amount of mercury necessary for a discharge lamp, so resources can be used effectively. Furthermore, when the metal member F and the metal capsule G are heated with high frequency, the metal capsule G is smaller than the metal member F and is welded to bridge the space E. Since G is heated intensively, excellent effects such as being able to quickly supply mercury to the space inside the bulb can be obtained.

By the way, this discharge lamp uses 500
The mercury vapor pressure inside the metal capsule G becomes significantly high because the metal capsule G passes through an oven controlled at a temperature of about .degree. However, since this metal capsule G is extremely small, for example, with a width of 2 to 3 mm, a total length of 5 mm, and a length of the crushed part H of about 2 mm, it will collapse when its internal pressure becomes extremely high during the exhaust process. An opening is likely to be formed in portion H. For this reason, mercury leaks out of the metal capsule G and is dissipated into the vacuum system, which not only contaminates the working environment, but also causes the space inside the valve to be heated during high-frequency heating after sealing the exhaust pipe. The disadvantage is that a predetermined amount of mercury is no longer supplied to the device, resulting in a significant loss of life characteristics.

In view of these points, the present invention provides a discharge lamp that can completely eliminate leakage of mercury from a metal capsule during a high-temperature heat treatment step before high-frequency heating of the metal capsule.Examples will be described below.

In FIGS. 3 to 5, numeral 1 denotes a bulb, and a phosphor 2 is coated on the inner surface of the bulb. 3 is a stem sealed at the end of the valve 1; 4, 4 is a strut line implanted in the stem 3 and extending into the interior space of the valve;
Reference numeral 5 denotes an electrode such as a filament coil connected to the tips of the strut wires 4, 4. Reference numeral 6 denotes a ring-shaped metal member disposed near the electrode 5; in the illustrated example, it is disposed so as to surround the electrode 5;
It can also be arranged so as to be further away from the non-discharge space side. Reference numeral 7 denotes a non-volatile getter made of, for example, zirconium-aluminum, which is coated on the inner surface of the metal member 6, and can be coated on the outer surface of the metal member 6 and the support wire 4, or can be omitted. 8
is a space formed between the ends 6a and 6b of the metal member 6. Reference numeral 9 denotes a support wire that supports the metal member 6 while electrically insulating it from the support wires 4, 4, and is implanted in the stem 3. In addition, when the metal member 6 is disposed closer to the non-discharge space than the electrode 5, it can be supported by either one of the support wires 4, 4 instead of the support wire 9. Reference numeral 10 denotes a metal capsule fixed to the ends 6a and 6b of the metal member 6 by means such as welding so that the space 8 is bridged, and includes, for example, a bottomed cylindrical uncollapsed part 11 and an uncollapsed part. Crushed portion 1 wider than 11
2, the required amount of mercury 13 is accommodated in the uncollapsed portion 11, and the end of the crushed portion 12 is seam welded 10.
It is configured as follows. Furthermore, this metal capsule 1
0 is manufactured, for example, as shown in FIG.
That is, as shown in FIG. Stores 13. Next, as shown in FIGS. b and c, the bottomed cylindrical part 11
The cylindrical opening 12' formed with a larger diameter is crushed and sealed. Thereafter, the end portion of the crushed portion 12 is seam welded 10a to complete the manufacturing. 14 is the crushed portion 12 of the metal capsule 10 and the ends 6a, 6 of the metal member 6.
In the separation part formed between the metal capsule part and the metal member 6 excluding the welded part with b, the part of the crushed part 12 close to the uncrushed part 11 is It is bent at an inclination angle of 20 to 70 degrees.

Next, a method of fixing the metal capsule 10 to the metal member 6 and a method of supplying the mercury 13 to the interior space of the bulb in the metal capsule 10 will be explained. First, a non-volatile getter 7 is coated on the inner surface of an elliptical metal member 6 having a long diameter part and a short diameter part, and the electrode 5 is surrounded by this metal member 6, and the end of the support wire 9 is attached to a part of the metal member 6. Weld. Then, after bending the portion of the crushed portion 12 of the metal capsule 10 close to the uncrushed portion 11 with respect to the horizontal plane so that θ=20 to 70° (see FIG. 5), The end portion 6 of the metal member 6 is positioned so that the collapsed portion 12 faces the discharge space side and the crushed portion 12 faces the non-discharge space side.
The crushed portions 12 are overlapped and welded to a and 6b so that the space portion 8 is bridged. As a result, a separation part 14 is formed between the uncrushed part 11 of the metal capsule 10 and the metal member 6. Note that the separating portion 14 can also be formed by separating the unsquashed portion 11 from the metal member 6 after welding the metal capsule 10 to the metal member 6. The mount thus constructed is sealed to the end of a bulb 1 whose inner surface is coated with a phosphor 2.

Next, connect this discharge lamp to the exhaust system of the exhaust device,
While passing through an oven controlled at about 500℃, impurity gas in the space inside the valve is exhausted.
Then, the valve is filled with a certain amount of inert gas, such as argon gas, to a pressure of 1.5 to 3.5 mmHg, and the exhaust pipe is sealed with a burner or the like. Thereafter, a high-frequency heating coil is arranged around the outer circumference of the bulb 1 so that a loop current flows through a closed circuit consisting of the metal member 6 and the metal capsule 10, and high-frequency heating is performed. Then, a loop current flows through the metal member 6 and the metal capsule 10, but since the space 8 of the metal member 6 is bridged only by the crushed portion 12, the loop current is concentrated in the crushed portion 12. do. For this,
The crushed portion 12 is heated extremely rapidly and reaches a high temperature compared to the metal member 6. At the same time, the uncrushed part 11
The temperature also increases due to heat conduction from the crushed portion 12, and the vapor pressure of the built-in mercury 13 increases significantly. When the mercury vapor pressure exceeds the sealing force of the collapsed portion 12, an opening is formed in the collapsed portion 12 that substantially coincides with the axial direction of the bulb 1 and faces toward the non-discharge space, and Mercury 13 is discharged into the bulb interior space through this opening. This mercury release takes place in about 1 to 2 seconds after high-frequency heating. At this time, the crushed portion 12 of the metal capsule 10
If the structure is such that tension is applied to the opening of the capsule, the capsule can be opened more stably. Impure gas released during high-frequency heating of the metal member 6 and metal capsule 10 is quickly adsorbed by the nonvolatile getter 7, and the space inside the valve is kept clean.

In this way, the crushed portion 1 in the metal capsule 10
The ends of 2 are seam welded, so for example
Even if the mercury vapor pressure inside the metal capsule increases when passing through an oven of an exhaust device controlled at about 500° C., no opening is formed in the crushed portion 12. Therefore, leakage of mercury 13 into the bulb interior space before high frequency heating can be completely eliminated, and a predetermined amount can be reliably supplied to the bulb interior space during high frequency heating, which has a favorable effect on the characteristics, especially the life characteristics.

Further, the metal capsule 10 is attached to the end portion 6 of the metal member 6.
a, 6b, the crushed portion 12 is welded so as to bridge the space 8, and in particular, the unwelded portion to the metal member 6 (mainly the unpressed portion 1
Since the separation part 14 is formed in 1), the loop current concentrates on the crushing part 12 during high-frequency heating. For this reason, the crushed portion 12 is heated to a high temperature in an extremely short time compared to the metal member 6, and the uncrushed portion 11 is similarly heated by heat conduction or the like.
1, the vapor pressure of mercury 13 in the collapsed part 1 in a short time
The pressure is increased to sufficient to form an opening in 2. Therefore, the mercury 13 can be reliably supplied to the inner space of the bulb in approximately 1 to 2 seconds after high-frequency heating.

Moreover, since the time for supplying mercury 13 to the space inside the bulb can be reduced to less than half that of the discharge lamp shown in FIGS. You can achieve your goals. Therefore, for example, if the working index is 1 second/
The present invention can be easily applied to a discharge lamp manufacturing apparatus as high-speed as this without complicating the apparatus.

Furthermore, since the crushed portion 12 of the metal capsule 10 is formed wider than the un-squeezed portion 11, the metal member 6
Even if there is slight variation in the space 8, welding can be performed reliably, and damage to the unsquashed portion 11 can be significantly reduced.

Further, the end portion 6 of the metal member 6 adjacent to the space portion 8
Since the metal capsule 10 is welded to a and 6b, the metal member 6 is heated by the loop current during high frequency heating, but the metal capsule 10
Because the heating ends in a short time, it is not heated like the metal capsule 10. For this reason, the amount of impure gas generated is reduced, which not only improves the characteristics at the initial stage of lighting, but also effectively improves the luminous flux, appearance characteristics, etc. during the life of the lamp. In particular, if a member that releases less gas is used as the metal member 6, the non-volatile getter 7 can be omitted in addition to the above-mentioned effect of suppressing the release of impurity gas.

Furthermore, when welding the metal capsule 10 to the metal member 6, the crushed portion 12 close to the uncrushed portion 11 of the metal capsule 10 is
is bent in advance at an angle of θ=20 to 70° with respect to the horizontal plane, so that the uncrushed portion 11 is bent against the metal member 6.
The uncollapsed portion 11 is not damaged by the welding electrode and can be easily mounted on the stem. However,
If θ is less than 20°, the uncollapsed portion 11 will come into contact with the metal member 6, and the release of mercury 13 will be significantly impaired. It is not preferable to deviate from this range because the crushed portion 11 may be damaged and the mercury inside will leak, making it impossible to supply the required amount of mercury to the space inside the bulb, and the characteristics of the discharge lamp will be significantly impaired.

Note that the present invention is not limited to the above-mentioned embodiments; for example, the metal capsule may be constructed by crushing a metal pipe. In addition, when a bottomed cylindrical body is used for the crushing part, the opening of the bottomed cylindrical body before crushing is made wider (larger in diameter) than the cylindrical part, and the width is made wider by the crushing operation. You can also.
In addition to having the same thickness throughout, the cylindrical portion can also be made thicker than the collapsed portion. Furthermore, the direction in which the metal capsule is fixed to the metal member can be reversed by 180 degrees, and can be appropriately selected depending on the shape of the metal member.

As described above, according to the present invention, leakage of mercury into the space inside the bulb during the heat treatment process before high-frequency heating of the metal capsule can be completely eliminated, and a predetermined amount of mercury can be supplied to the space inside the bulb during high-frequency heating. can improve life characteristics etc.

[Brief explanation of the drawing]

Figure 1 is a cutaway side view of the main parts of a discharge lamp that is the premise of this proposal, Figure 2 is a cross-sectional view of Figure 1, Figure 3 is a cutaway side view of the main parts showing an embodiment of the proposal, and Figure 4. is a cross-sectional view of Fig. 3, and Fig. 5 is a - cross-sectional view of Fig. 4.
The cross-sectional view and FIG. 6 are a front cross-sectional view and a side cross-sectional view for explaining the method of manufacturing the metal capsule. In the figure, 1 is a valve, 3 is a stem, 4 is a strut line,
5 is an electrode, 6 is a metal member, 8 is a space, 10 is a metal capsule, 10a is a seam welded portion, 11 is an uncollapsed portion (cylindrical portion), 12 is a crushed portion, and 13 is mercury.

Claims (1)

[Scope of utility model registration request] Electrodes are connected to two strut wires extending from the stem at the end of the bulb, a ring-shaped metal member having a space is disposed near the electrodes, and a metal capsule containing mercury is placed in this metal member. In the case where the space is fixed so that the space is bridged, the opening of the metal capsule is crushed to be wider than the uncrumpled part, and the crushed end is seam welded, and the uncollapsed part of the metal capsule and the metal member are 1. A discharge lamp characterized in that a separation part is formed between the uncollapsed part and the metal member so that the inclination angle θ with respect to the metal member is 20 to 70°.