JPH06283144A - Reflection type discharge lamp - Google Patents

Abstract

PURPOSE:To improve the starting property of a lamp and prevent the oxidation of a cap by electrically connecting bent support members to a pair of external lead wires of a light emitting tube, and arranging the support members at the bottom section of a glass outer tube via an insulating plate having an electric insulation property and a heat insulation property. CONSTITUTION:The insulating plate 32 of a reflection type discharge lamp 11 is formed with ceramic into nearly the same shape as a bottom section 31, and through holes 33a, 33b are bored smaller than the diameter of holes 34a, 34b of the bottom section 31. When support members 21a, 21b welded to external lead wires 20a, 20b of a light emitting tube 14 are inserted into the holes 34a, 34b via the through holes 33a, 33b, the tube 14 is erected without falling, and the arc position of the tube 14 can be precisely fitted at the focal position of a glass outer tube 16. The plate 32 prevents the wires 20a, 20b from being brought into contact with the metal film 15 of the bottom section 31 to avoid loss of the starting pulse, and the heat generated on the tube 14 is hardly transferred to a cap 18 eliminating its oxidation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a HID lamp, and more particularly to a reflection type discharge lamp using a metal halide lamp.

[0002]

2. Description of the Related Art A metal halide lamp, which is a type of HID lamp, is a lamp that achieves high output and high efficiency by enclosing a metal halide inside an arc tube, but recently, it is a single-sealed metal halide lamp. A compact reflective discharge lamp has also been developed, which is integrated with a glass outer tube having a mirror surface formed by evaporating a metal such as aluminum on the internal parabolic surface, and it has become widely used indoors. It was

In such a reflection type discharge lamp, the metal halide lamp is arranged such that the arc position of the arc tube of the metal halide lamp is near the focal point of the mirror surface and the sealing portion faces the bottom portion of the glass outer tube. The electrodes inside the arc tube and the base provided outside the bottom of the glass outer tube are electrically connected.
With this configuration, electric power can be supplied to the arc tube from the outside through the base.

[0004]

Here, in the conventional metal halide lamp, a pair of external lead wires led out from the sealing portion of the arc tube are bent in opposite directions at the outlet of the sealing portion,
We welded a pair of support members to the bent tip and inserted this into the hole at the bottom of the glass outer tube to bond it, but when inserting it, the arc tube fell to one side and the arc of the arc tube There was a problem that the position and the focus were out of alignment.

Further, there has been a problem that the external lead wire is damaged or a part of the sealing portion formed of glass is broken during the bending process of the external lead wire.

Further, there is also a problem that the starting pulse is blown off at a portion other than the electrodes due to the contact between the external lead wire and the metal film, which deteriorates the starting performance.

Further, since the output of the metal halide lamp is large and the distance between the arc tube and the base is relatively short, there is a problem that the base portion is likely to be heated by the heat from the arc tube and the base is easily oxidized. .

Further, as shown in FIG. 4, in the conventional metal halide lamp 1, a pair of electrodes 4a and 4b are sealed in the arc tube 2 and a coil portion 3 formed at the tips of the electrodes 4a and 4b.
a and 3b are opposed to each other with a discharge space in between.

When the metal halide lamp 1 is operated, an arc 5 as shown in FIG. 5 (a) is formed between the coil portions 3a and 3b.

Here, although the coil portions 3a and 3b are eroded as the life of the metal halide lamp progresses, the distances between the coil axis lines of the coil portions 3a and 3b and the electrode sealing ends are substantially the same. The shortest distance between the coils is not fixed,
Therefore, the formed arc changes into a shape as shown in FIG. 5 (b) or FIG. 5 (c), and becomes extremely unstable.

In such a situation, there has been a problem that the change of the lamp voltage and the change of the light output are caused.

The present invention has been made in consideration of the above-mentioned circumstances, and provides a reflection type discharge lamp capable of improving the mounting accuracy of the arc tube, improving the startability of the lamp, and preventing the oxidation of the base. The purpose is to provide.

It is another object of the present invention to provide a metal halide lamp capable of reducing the variation width of the lamp voltage which changes during the life of the lamp.

[0014]

In order to achieve the above object, the reflection type discharge lamp of the present invention is, as described in claim 1, a single-sealed arc tube having a sealed portion at one end, A glass outer tube having a reflection part that accommodates the arc tube and has a metal film that reflects the light output from the arc tube and an optical opening that transmits the light reflected by the reflection part is provided. In the reflection type discharge lamp, wherein the arc tube is supported by a pair of supporting members that are inwardly projected from the bottom of the glass outer tube facing the sealing portion, the supporting member is provided in front of the sealing portion. Electrically insulating and adiabatic insulation having a pair of insulating plate through holes that are bent and electrically connect their tips to a pair of external lead wires led out from the sealing portion, respectively A plate through the insulating plate through hole and the support member. In which is arranged between the bottom portion and the sealing portion in a state of being.

Further, in the reflection type discharge lamp of the present invention, as described in claim 2, the insulating plate described in claim 1 is formed so as to have substantially the same shape as the bottom portion, and the insulating plate through hole is formed. Is smaller than the diameter of the hole formed in the bottom.

According to a third aspect of the present invention, there is provided a reflection type discharge lamp, which is located on the sealing portion side of the insulating plate according to the first aspect and has a predetermined space between the through holes of the insulating plate. It is provided with a protrusion.

The metal halide lamp of the present invention is
In a metal halide lamp in which a pair of electrodes are sealed in an arc tube and coil portions formed at the tips of the electrodes are opposed to each other across a discharge space, the distance between the axis of the coil portion and the sealing end of the electrodes is It is shifted.

[0018]

In the reflection type discharge lamp of the present invention described in claim 1, since the heat insulating insulating plate is provided between the sealing portion and the bottom, the heat generated in the arc tube is blocked by the insulating plate. , The temperature rise of the base part becomes small.

Further, since the electrically insulating plate is disposed between the sealing part and the bottom part in a state where the supporting member is penetrated through the insulating plate through hole, a portion other than the electrode, for example, an external lead wire is provided. The possibility that the starting pulse will break between the metal film on the bottom is reduced.

In the reflection type discharge lamp of the present invention as defined in claim 2, the insulating plate is formed to have a shape substantially equal to the shape of the bottom portion, and the diameter of the through hole of the insulating plate is the diameter of the hole provided in the bottom portion. When the support member welded to the outer lead wire of the arc tube is inserted into the hole through the through hole of the insulating plate, the arc tube stands upright without falling sideways.

In the reflection type discharge lamp of the present invention as defined in claim 3, since the predetermined protrusion is provided on the sealing plate side of the insulating plate and between the through holes of the insulating plate, the external lead wires are not connected to each other. There is no risk of the start-up pulse coming off due to contact.

In the metal halide lamp of the present invention, the distance between the axis of the coil portion and the sealing end of the electrode is offset from each other, so that the arc distance is constant even if the electrode is corroded as the life of the metal halide lamp is extended. The sudden change in the lamp voltage due to the spot movement disappears.

By arranging the electrodes as described above, the electrodes approach the chip side and the sealing portion side, respectively, and the temperature of the bulb rises without changing the arc position.

[0024]

Embodiments of the reflective discharge lamp of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is a sectional view showing a reflection type discharge lamp of this embodiment.

The reflection type discharge lamp 11 according to the present embodiment includes an arc tube 1.
2 and a metal halide lamp 14 having a sealing portion 13.
And a glass outer tube 16 which is a mirror surface by providing a predetermined metal film 15 on the parabolic surface inside so that the arc tube 12 is near the focal point of the mirror surface of the metal film 15 and the sealing portion 13 is outside the glass. Tube 1
It is arranged so as to face the bottom portion 31 of No. 6.

For the metal halide lamp 14, for example, a single-sealed 150 W type, and for the glass outer tube 16, for example, PAR 38 is preferably used.

The arc tube 12 is filled with a metal halide and has electrodes 17a and 17b sealed inside, and metal foil conductors 19a and 19b such as molybdenum foil, external lead wires 20a and 20b and supporting members. The bottom portion 31 of the glass outer tube 16 is provided via the supporting members 21a and 21b having a function.
Are electrically connected to the respective caps 18 provided on the outside of the.
Here, the support members 21a and 21b are bent in the facing direction before the sealing portion 13, and their tips are welded to the external lead wires 20a and 20b.

The reflection type discharge lamp 11 of the present embodiment includes a sealing portion 1.
An insulating plate 32 having electrical insulation and heat insulating properties is arranged between the base plate 3 and the bottom portion 31, and the supporting members 21a and 21b are penetrated into insulating plate through holes 33a and 33b provided in the insulating plate 32, respectively. .

The insulating plate 32 is preferably made of ceramic, for example.

The insulating plate 32 is formed so as to have substantially the same shape as the bottom portion 31, and the insulating plate through holes 33a, 33 are formed.
The diameter of b is smaller than the diameter of the holes 34a and 34b provided in the bottom portion 31.

The insulating plate 32 is provided with a predetermined projection 35 on the sealing portion side of the insulating plate 32 and between the insulating plate through holes 33a and 33b.

FIG. 2 is a plan view of the insulating plate 32.

In the reflective discharge lamp 11 of this embodiment,
The insulating plate 32 is formed to have substantially the same shape as the bottom portion 31, and the diameters of the insulating plate through holes 33a and 33b are
Since the diameter is made smaller than the diameter of the holes 34a, 34b provided in the bottom portion 31, the supporting members 21a, 21b welded to the external lead wires 20a, 20b of the arc tube 14 are connected to the insulating plate through holes 33.
When the arc tube 14 is inserted into the holes 34a and 34b through the holes a and 33b, the arc tube 14 is substantially upright without falling sideways.

Therefore, the arc tube 14 can be attached to the glass outer tube 16 with the arc position of the arc tube 14 accurately aligned with the focal position.

Further, the insulating plate 32 is replaced with an insulating plate through hole 33.
Since the support members 21a and 21b are penetrated through the a and 33b, the support members 21a and 21b are disposed between the sealing portion 13 and the bottom portion 31, so that the insulating plate 32 is provided between the external lead wires 20a and 20b and the metal film on the bottom portion 31. The external lead wires 20a, 2
0b and the metal film of the bottom portion 31 are not in contact with each other, and the starting pulse is not likely to be blown out.

Further, since the protrusion 35 is provided on the sealing portion side of the insulating plate 32 and between the insulating plate through holes 33a and 33b, the start pulse is blown between the external lead wires 20a and 20b. The risk is reduced.

Therefore, the starting characteristics of the metal halide lamp 14 can be greatly improved.

As a result of conducting trials for improving startability by making 100P prototypes for the case with and without the insulating plate 32, a start failure of 5% was obtained for the case without the insulating plate. As a result of the investigation, it was found that the external lead wire or the supporting member was brought into contact with the metal reflection film. However, no start-up failure was found in the case where the insulating plate was provided.

Further, since the insulating plate 32 is provided between the sealing portion 13 of the metal halide lamp 14 and the bottom portion 31 of the glass outer tube 16, the heat generated in the arc tube 12 is blocked by the insulating plate 32, and the base 18 It is possible to reduce the temperature rise of the above, and it is possible to avoid the oxidation of the die part.

Further, in the conventional reflection type discharge lamp, the external lead wires led out from the sealing portion are bent in opposite directions, and the bent tips are welded to the support member. At this time, there was a risk of damaging the external lead wires or damaging the sealing portion formed of glass, but in the present embodiment, the supporting member was bent in the opposite direction in front of the sealing portion, Since the bent tip is welded to the external lead wire, damage to the external lead wire and the sealing portion can be avoided.

Although the metal film 15 is provided on the entire inner surface of the glass outer tube 16 in the above-described embodiment, the metal film 15 may be omitted in the bottom portion 31.

That is, in the conventional reflection type discharge lamp having no insulating plate, the heat from the arc tube is directly radiated to the bottom to oxidize the base, so that it is necessary to provide a metal film for reflecting infrared rays. However, in the present invention, since the heat is blocked by the insulating plate, the metal film at the bottom can be omitted.

(Second Embodiment) FIG. 3 is a sectional view showing a metal halide lamp 41 according to this embodiment.
As can be seen in the figure, in the metal halide lamp 41, a pair of electrodes 43a and 43b are sealed in the arc tube 40, and coil portions 42a and 42b formed at their tips are opposed to each other across a discharge space. In addition, the electrodes 43a and 43b
Are electrically connected to external lead wires 45a and 45b through metal foil conductors 44a and 44b, respectively.

In the coil portions 42a and 42b, the distances La and Lb between the axes 46a and 46b and the sealing ends of the electrodes are offset from each other.

In the metal halide lamp of this embodiment, since the distance between the axis of the coil and the sealing end of the electrode is different from each other, the arc distance is constant even if the electrode is corroded as the life of the metal halide lamp progresses. Therefore, the sudden change of the lamp voltage due to the movement of the spot disappears.

Therefore, the lamp voltage is stable and the change in characteristics can be suppressed.

Further, by arranging the electrodes as described above, the electrodes approach the chip side and the sealing portion side, respectively, and the temperature of the bulb rises without changing the arc position.

Therefore, the temperature of the coldest part can be made uniform, and the lighting direction characteristics can be improved.

[0050]

As described above, the reflection type discharge lamp of the present invention has, as described in claim 1, a single-sealed arc tube having a sealing portion at one end, and the arc tube accommodated therein. And a glass outer tube having an optical opening that transmits a light reflected by the reflecting portion and a metal film that reflects the light output from the light emitting tube. In a reflective discharge lamp configured to be supported by a pair of supporting members that are inwardly projected from the bottom portion of the glass outer tube facing the sealing portion, the supporting member is bent before the sealing portion, and those While electrically connecting the tip to each of a pair of external lead wires led out from the sealing portion, an electrically insulating and heat insulating insulating plate having a pair of insulating plate through holes penetrating the supporting member is provided. The sealing is performed with the support member penetrating the plate through hole. Parts and so arranged between said bottom and improves the startability of the lamp, it is possible to further prevent the cap oxidation.

Further, in the reflection type discharge lamp of the present invention, as described in claim 2, the insulating plate described in claim 1 is formed to have substantially the same shape as the bottom portion, and the insulating plate through hole is formed. Since the diameter of the arc tube is smaller than the diameter of the hole formed in the bottom portion, in addition to the above-mentioned effect, the mounting accuracy of the arc tube can be further improved.

Further, as described in claim 3, the reflection type discharge lamp of the present invention has a predetermined structure on the side of the sealing portion of the insulating plate according to claim 1 and between the through holes of the insulating plate. Since the protrusion is provided, the startability of the lamp can be further improved and the oxidation of the base can be prevented.

Further, the metal halide lamp of the present invention is
In a metal halide lamp in which a pair of electrodes are sealed in an arc tube and coil portions formed at the tips of the electrodes are opposed to each other across a discharge space, the distance between the axis of the coil portion and the sealing end of the electrodes is Since the shifts are made, the change width of the lamp voltage that changes during the life can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a reflective discharge lamp according to a first embodiment.

FIG. 2 is a plan view of an insulating plate provided in the reflective discharge lamp of the first embodiment.

FIG. 3 is a sectional view of a metal halide lamp according to a second embodiment.

FIG. 4 is a sectional view of a conventional metal halide lamp.

FIG. 5 is a diagram showing an arc formed between electrodes of a conventional metal halide lamp.

[Explanation of symbols]

 11 Reflective Discharge Lamp 12 Arc Tube 13 Sealing Part 14 Metal Halide Lamp 15 Metal Film 16 Glass Outer Tube 17a, 17b Electrode 18 Caps 20a, 20b External Lead Wires 21a, 21b Supporting Member 31 Bottom 33a, 33b Insulating Plate Through Hole 34a, 34b hole 35 protrusion 41 metal halide lamp 42a, 42b coil portion 43a, 43b electrode 46a, 46b axis line of coil portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Makoto Nishizawa 1-48 Mita, Minato-ku, Tokyo TOSHIBA LIGHTEC CORPORATION (72) Hisanori Sano 1-428 Mita, Minato-ku, Tokyo Toshiba Within Lytec Co., Ltd.

Claims (3)

[Claims] 1. A single-sealed arc tube having a sealing part at one end, a reflecting part that houses the arc tube and has a metal film that reflects the light output from the arc tube, and the reflection part. A glass outer tube having an optical opening that allows reflected light to pass therethrough, the pair of supporting members projecting the arc tube inward from the bottom of the glass outer tube facing the sealing portion. In the reflective discharge lamp, the supporting member is bent in front of the sealing portion, and the ends thereof are electrically connected to a pair of external lead wires led out from the sealing portion, respectively. An electrically insulating and heat insulating insulating plate having a pair of insulating plate through holes that can penetrate a supporting member is provided between the sealing part and the bottom part in a state where the supporting member penetrates the insulating plate through hole. A reflective discharge lamp characterized by being placed in. 2. The insulating plate is formed to have substantially the same shape as the bottom portion, and the diameter of the through hole of the insulating plate is smaller than the diameter of the hole provided in the bottom portion.
The described reflective discharge lamp. 3. The reflection type discharge lamp according to claim 1, wherein a predetermined protrusion is provided on the side of the sealing portion of the insulating plate and between the through holes of the insulating plate.