JPH0896759A - Ceramic discharge lamp with reflecting mirror, its lighting device and lighting system using this ceramic discharge lamp with reflecting mirror - Google Patents

Abstract

PURPOSE: To provide a ceramic discharge lamp with reflecting mirror preventing a trouble such as heating an electric introducer, drawn out from an emitting tube, oxidized at sealing work time of the reflecting mirror, to provide a lighting device of this ceramic discharge lamp and to provide a lighting system using this ceramic discharge lamp. CONSTITUTION: A device comprises a ceramic-made arc tube 1 mounting an electrode 5 sealed in both ends further to draw out an electric introducer 4 and a reflecting mirror 10 air-tightly connecting a front glass 13 to a front face opening part of a mirror main unit 11 of receiving this arc tube 1, to form the arc tube 1 into a U shape. The electric introducer, drawn out from both end parts of this U-shaped arc tube, is guided to a back part of the reflecting mirror and connected to power feed members 15a, 15b in the outside. Since the electric introducer, drawn out from the end part of the U-shaped arc tube, is set up toward a back side of the reflecting mirror, the electric introducer is prevented from receiving heat when heated to be welded with the front glass and the mirror main unit, to suppress the temperature rise of the electric introducer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic discharge lamp with a reflecting mirror applied to a downlight such as a store lighting, a lighting device for the same, and a lighting device using the same.

[0002]

2. Description of the Related Art High-pressure sodium lamps, which are widely used as a light source for outdoor lighting such as in parks and roads, have excellent luminous efficiency. Therefore, recently, color rendering properties have been improved to make them large stores, factories, gymnasiums, and theaters. Attempts are being made to use it as an indoor illumination light source such as. When this type of high pressure thorium lamp is used as a light source for indoor lighting, it is effective to use it as a downlight. Therefore, in this type of lamp, as shown in FIG. 4, the arc tube is housed in a reflecting mirror. It is designed to form an integrated ceramic discharge lamp with a reflector.

That is, a conventional ceramic discharge lamp with a reflecting mirror will be described with reference to FIG.
Reference numeral 0 is a reflecting mirror, and 30 is an arc tube. Describing from the structure of the reflecting mirror 10, 11 is a mirror body made of hard glass or the like, and this mirror body 11 has a curved surface whose front surface is widened and opened, and a reflective surface 12 is formed on the inner surface thereof. There is. The reflecting surface 12 is formed of, for example, a vapor deposited film of aluminum. At the front opening of the mirror body 11,
A front glass 13 made of transparent glass is hermetically sealed. Further, the rear surface of the mirror body 11 is sealed by the sealing portion 14. Therefore, the inside of the reflecting mirror 10 forms an airtight space, and the airtight space is kept in a vacuum atmosphere or an inert gas atmosphere. Therefore, the reflecting mirror 10 constitutes an airtight envelope, that is, an outer tube.

A pair of power supply terminals 15a and 15b are hermetically embedded in the rear surface sealing portion 14 of the mirror body 11. A metal cover 16 is attached to the outer surface of the rear part of the mirror body 11, and a base 18 is attached to the metal cover 16 via a glass spacer 17. The pair of power supply terminals 15a and 15b hermetically embedded in the sealing portion 14 have one power supply terminal 15a electrically connected to the shell 18a of the base 18 via a lead wire 19a and the other power supply terminal 15a. The terminal 15b is electrically connected to the external terminal 18b of the base 18 via another lead wire 19b.

An arc tube 30 which constitutes a high pressure sodium lamp is housed in such a reflecting mirror 10. The arc tube 30 is configured by hermetically sealing electrodes 32a and 32b in openings at both ends of a ceramic tube 31 made of alumina or the like. In the conventional case, the ceramic tube 31 has a straight tube shape. Electric conductors 33a and 33b made of niobium tubes are hermetically penetrated through both ends of such a straight tube-shaped ceramic tube 31, and the ceramic tubes 3 of the electric conductors 33a and 33b are penetrated.
The electrodes 32a and 32b are connected to the inner ends facing the inside of 1, and the outer ends of these electric introduction bodies 33a and 33b are hermetically sealed. Ceramic tube 3
The discharge space in 1 is filled with a predetermined amount of mercury, sodium and a rare gas.

The arc tube 30 as described above is provided with the reflecting mirror 10 described above.
It is housed inside and is attached to the power supply terminals 15a and 15b through conductive holders 20a and 20b and conductive supports 21a and 21b. That is, the electric introduction body 33 protruding from both ends of the arc tube 30.
Conductive holders 20a and 20b are connected to a and 33b in an electrically conductive state, and these conductive holders 20a and 20b are welded to the conductive supports 21a and 21b. 21a,
21b is connected to the power supply terminals 15a and 15b. Therefore, the arc tube 30 has the conductive holders 20a and 20b.
And mechanically supported via the conductive supports 21a and 21b.

In this case, in order to equalize the light distribution characteristics of the reflected light, the bulb axis OO of the arc tube 30 is housed in the reflecting mirror 10 such that it coincides with the optical axes O1 -O1 of the reflecting mirror 10. In addition, the luminous center of the arc tube 30 is arranged so as to maintain a predetermined position with respect to the focal point of the reflecting mirror 10.

Therefore, a ceramic discharge lamp with a reflecting mirror of this type has a double tube structure. Further, heat insulating coatings 34, 34 having heat insulating properties are formed on the portions of the electric introduction bodies 33a, 33b of the arc tube 30 that project to the outside. The heat resistant coating 34 is formed of, for example, silica, alumina, zirconia or the like.

When such a ceramic discharge lamp with a reflecting mirror is used as a downlight, the position shown in FIG.
Lights up. Then, the light emitted from the arc tube 30 is reflected by the reflecting surface 12 of the reflecting mirror 10, so that the reflected light irradiates the lower side through the front glass 13 and thus downward illumination can be obtained.

[0010]

However, in the ceramic discharge lamp with a reflecting mirror of this type, the arc tube 30 is formed by a straight tube type ceramic tube, and the arc tube 30 is formed.
Is accommodated in the reflecting mirror 10 such that the valve axis OO of the same is aligned with the optical axes O1 -O1 of the reflecting mirror 10. Therefore, the one electric introduction body 33a protruding from the one end side of the arc tube 30 and the one conductive holder 20a connected to the electric introduction body 33a are located close to the front glass 13.

In the case of such an arrangement, by heating when the front glass 13 is bonded to the opening of the mirror body 11,
There is a problem that the one electric introduction body 33a and the one conductive holder 20a are heated and oxidized.

That is, since the reflecting mirror 10 of this type serves as an envelope and maintains an airtight space, when the front glass 13 is joined to the opening of the mirror main body 11, the front glass 13 of the front glass 13 is joined by the burner 38. The peripheral portion and the opening of the mirror body 11 are melted by heating, and the front glass 13
Is hermetically bonded to the mirror body 11.

However, during such heating, the heat from the burner 38 causes the one electric introducing member 33a and the one conductive holder 20a near the heating point.
Are heated, thus oxidizing them. When the electricity introducing body 33a and the conductive holder 20a are oxidized, the mechanical strength is reduced.

In particular, the electric lead 3 made of niobium tube
When 3a is oxidized, deterioration progresses in the middle of its life, leading to poor adhesion and airtight leakage. Further, when the electricity introducing body 33a is oxidized, the emissivity of the electricity introducing body 33a during lighting changes for each lamp, which causes a problem that the temperature varies. That is, when the ceramic discharge lamp with a reflecting mirror of this type is used as a downlight, the electricity introducing body 33a is turned on in a manner opposite to the posture shown in FIG.
3 is directed downwards, so that the electric introduction body 33a is also located on the lower side, and thus is the coldest part of the arc tube 30.

Excessive luminescent metal aggregates in such a coldest portion, which has the effect of controlling the vapor pressure of the luminescent metal. However, when the electric introducing member 33a is oxidized, temperature variations occur.
Since the vapor pressure varies from lamp to lamp, color temperature, color rendering,
This causes a problem that the lamp characteristics such as total luminous flux vary.

As a means for preventing this, conventionally, heat-resistant coatings 34, 34 have been formed on the protruding portions of the electric introduction bodies 33a, 33b. By doing so, even if the electric introducing member 33a receives heat during the sealing operation of the front glass 13, the temperature rise of the electric introducing member 33a is reduced because the heat insulating heat resistant coating 34 is formed, and Oxidation is suppressed because it also blocks contact with oxygen.

However, the formation of such a heat-resistant coating 34 is more effective than the case without the heat-resistant coating 34,
It is still not sufficient, and there is a problem that the electric introduction body 33a is oxidized and temperature variations occur.

The present invention has been made in view of the above circumstances. An object of the present invention is to oxidize an electric introduction body, which is led out from an arc tube when a reflecting mirror is sealed, by being excessively heated. (EN) Provided are a ceramic discharge lamp with a reflector, a lighting device using the same, and a lighting device using the same, which can prevent problems such as occurrence of light emission, and prevent variations and fluctuations in lamp characteristics and deterioration in life characteristics. It is a thing.

[0019]

According to a first aspect of the present invention, electrodes are sealed at both ends of a ceramic tube in which a luminescent metal is sealed, and an electric introduction body connected to these electrodes is made of the ceramic tube. Of the arc tube, a mirror main body having a reflecting surface, and a front glass hermetically bonded to the front opening of the mirror main body, thereby forming an airtight envelope. In a ceramic discharge lamp with a reflecting mirror comprising: a reflecting mirror, the arc tube is formed in a U shape, and the electric introducing body is led out from both ends of the U shape arc tube. The electric introduction body is guided to the back of the mirror body and connected to an external power feeding member.

The invention of claim 2 is characterized in that the electric introducing member is formed of a niobium tube. A third aspect of the present invention is characterized in that the pair of electrodes are arranged so as to face each other at both ends of the central straight line portion of the arc-shaped arc tube.

According to a fourth aspect of the present invention, there is provided a ceramic discharge lamp with a reflecting mirror according to any one of the first to third aspects,
A lighting device for a ceramic discharge lamp with a reflecting mirror, comprising: a lighting circuit for lighting the discharge lamp.

According to a fifth aspect of the present invention, there is provided a ceramic discharge lamp with a reflecting mirror according to any one of the first to third aspects,
A lighting device equipped with this discharge lamp, and a lighting device.

According to a sixth aspect of the present invention, there is provided a ceramic discharge lamp with a reflecting mirror according to any one of the first to third aspects,
A lighting device comprising: a lighting circuit for lighting the discharge lamp; and a lighting fixture provided with the discharge lamp and the lighting circuit.

[0024]

According to the invention of claim 1, an arc tube bent in a U-shape is used as the arc tube, and the electric introduction body led out from both ends of the arc tube is directed to the back side of the reflecting mirror. Since the electric introduction body is located far from the heat-welded portion between the front glass and the mirror body, the heat is not received when the front glass and the mirror body are heat-welded, and the temperature of the electric introduction body rises. Is suppressed. Therefore, it is possible to prevent the electric introduction body from being oxidized, and to prevent the electric introduction body from deteriorating in the middle of its life or from causing airtight leakage due to poor adhesion. In addition, variations in temperature of the electric introduction body can be suppressed, and variations and fluctuations in lamp characteristics and deterioration in life characteristics can be prevented.

According to the second aspect of the present invention, even when the electric introduction body is formed of a niobium tube, oxidation due to heating is suppressed. According to the third aspect of the present invention, since the pair of electrodes are arranged at both ends of the intermediate linear portion of the arc tube having the U-shape, the discharge is linearly generated in the intermediate linear portion of the arc tube. Therefore, the discharge is not bent, and the tube wall of the arc tube is not deteriorated by the heat of the discharge.

According to the invention of claim 4, a lighting device for a ceramic discharge lamp having stable lamp characteristics can be obtained. According to the inventions of claims 5 and 6, it is possible to obtain an illuminating device having stable lamp characteristics.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIGS. In this embodiment, the reflecting mirror 10
4 may be the same as the conventional structure shown in FIG. 4, so the same reference numerals are given and detailed description thereof is omitted, but 11 is a mirror body, 12 is a reflecting surface, 13 is a front glass, and 14 is a sealing. 15a and 15b are a pair of power supply terminals corresponding to the external power supply member of the present invention, 16 is a metal cover, 17 is a glass spacer, 18 is a base, and 19a and 19b are lead wires. When the rated power is 70 W, the diameter of the front opening of the mirror body 11 is about 121 mm.

The reflecting mirror 10 accommodates the arc tube 1 which constitutes a high pressure sodium lamp. The detailed structure of the arc tube 1 is shown in FIG. 2, and based on this, 2 is a ceramic tube made of alumina or the like having an inner diameter of 5.5 mm and a wall thickness of 0.5 mm, which is bent in a U shape. Is doing. That is, the ceramic tube 2 has a U-shape with straight line portions 2a, 2a at both ends and a central straight line portion 2b connected to these straight line portions 2a, 2a.

Both ends of the ceramic tube 2 are airtightly closed by a closing member 3 made of an alumina disk or a niobium disk. This blockage is performed by an adhesive agent (not shown). At the central portions of the closing members 3 and 3, an electric introducing member 4 is provided via an adhesive (not shown).
4 is airtightly penetrated. The electric introduction bodies 4 and 4 are made of niobium tubes, and the electrodes 5 and 5 are connected to the inner ends facing the inside of the ceramic tube 2, and the lead-out ends led out of the ceramic tube 2 are hermetically sealed. It has been stopped.

The electrodes 5 and 5 are constructed by winding electrode coils 5b around the tips of the electrode shafts 5a, and the roots of these electrode shafts 5a are connected to the electric introduction bodies 4 and 4, respectively. In addition, this coupling is performed in the middle of the electric introduction bodies 4 and 4 as shown in FIG.
It is held by being squeezed in the direction orthogonal to the paper surface.

The electrode shafts 5a, 5a are inserted through the linear portions 2a, 2a at both ends of the ceramic tube 2 and are guided to both ends of the central linear portion 2b.
The electrode coils 5b and 5b are provided at the tip of 5a. Therefore, the pair of electrode coils 5b, 5b are arranged at both ends of the central straight portion 2b of the ceramic tube 2, and the distance between these electrodes is, for example, 20 mm, and the discharge generated between these electrodes 5, 5 is Are generated linearly in the central straight line portion 2b. The discharge space of the ceramic tube 2 is filled with mercury, sodium and a rare gas. The mercury, sodium, and rare gas are introduced by using the electric introduction body 4 made of the niobium tube. That is, the discharge space in the ceramic tube 2 is exhausted through the electricity introducing body 4 made of this niobium tube, and then a predetermined amount of mercury, sodium and a rare gas are supplied to the discharge space through the electricity introducing body 4, and when this is completed, electricity is generated. The outer end of the introduction body 4 is hermetically sealed. In addition, mercury and sodium are
An amalgam containing 25% by weight of sodium is used, and for example, 25 mg is enclosed. Further, xenon is enclosed as 50 Torr as a rare gas.

The U-shaped arc tube 1 having such a structure is housed in the reflecting mirror 10. In this case, the U-shaped arc tube 1
Is a linear portion 2a at both ends and a sealing portion 14 of the mirror body 11
The central straight portion 2b faces the front glass 13.

Then, the linear portions 2a, 2a at both ends of the arc tube 1 are provided.
The electric introduction bodies 4 and 4 derived from are electrically and mechanically connected to the conductive holders 20a and 20b, and these conductive holders 20a and 20b are welded to the conductive supports 21a and 21b. . These conductive supports 21a and 21b are connected to the power supply terminals 15a and 15b. Therefore, the arc tube 1 has a conductive holder 2
It is mechanically supported via 0a, 20b and conductive supports 21a, 21b.

In this case, the line connecting the electrodes 5 and 5 of the arc tube 1 is orthogonal to the optical axis O1 -O1 of the reflecting mirror 10, and is located approximately in the middle of the central straight line portion 2b of the arc tube 1. The emitted light emission center X is arranged so as to maintain a predetermined position with respect to the focal point of the reflecting mirror 10.

With such a configuration, the arc tube 1 and the reflecting mirror 10 constitute a double-tube-structured ceramic discharge lamp with a reflecting mirror. The operation of the ceramic discharge lamp with a reflecting mirror having such a configuration will be described.

The front glass 13 is provided at the opening of the mirror body 11.
When welding the burner 38, as in the conventional case shown in FIG.
Then, the mirror body 11 and the front glass 13 are heated. However, in the case of the present embodiment, the arc tube 1 is U-shaped,
The electric introduction bodies 4 and 4 led out from both ends are the mirror body 1.
Since they are installed toward the back side of 1, i.e., the sealing portion 14 side, these electric introduction bodies 4 and 4 are located far from the heating points of the mirror body 11 and the front glass 13.

Therefore, the electric introduction bodies 4 and 4 do not receive heat when the front glass 13 and the mirror body 11 are heat-welded, and the electric introduction bodies 4 and 4 are prevented from rising in temperature and being oxidized. It Therefore, it is possible to prevent the electric introduction bodies 4 and 4 from deteriorating in the middle of their lifespan and from causing airtight leakage due to defective adhesion. In addition, it is possible to suppress variations in temperature of the electric introduction body, and variations and fluctuations in lamp characteristics,
And it is possible to prevent deterioration of life characteristics.

The arc tube 1 is formed in a U shape,
Since the pair of electrodes 5 and 5 are arranged at both ends of the central straight line portion 2b so as to face each other, discharge is performed in the central straight line portion 2b.
Occurs in. Therefore, the arc is straightened, and the arc does not approach the tube wall and thermally deteriorate the tube wall.

Such a ceramic discharge lamp with a reflecting mirror can be used, for example, in a lighting device and a lighting device shown in FIG. That is, in FIG. 3, 50 is a lighting fixture for a ceiling-embedded downlight, and a socket 51 is attached to the top of the lighting fixture 50. The base 18 of the ceramic discharge lamp with a reflecting mirror shown in FIG. 1 is screwed into this socket 51, whereby the ceramic discharge lamp with a reflecting mirror is housed in the lighting fixture 50 and attached in a downward posture. . Above socket 5
1 is connected to a power source 53 via a lighting circuit 52 including a ballast. Incidentally, 54 is the ceiling of the building.

In such an illuminating device, since the light emitted from the arc tube 1 is reflected by the reflecting surface 12 of the reflecting mirror 10,
This reflected light illuminates the lower side through the front glass 13, and thus downward illumination can be obtained.

With such a structure, a lighting device and a lighting device having stable lamp characteristics can be obtained. In the lighting device as described above, the lighting circuit 52 including a ballast may be installed at another location apart from the lighting fixture 50.

In the case of the above-mentioned embodiment, when the electric introduction bodies 4 and 4 projecting from both ends of the arc tube 1 are made of niobium tubes and the electric introduction bodies 4 and 4 also serve as exhaust pipes. However, the present invention is not limited to this, and the electric introduction body may be made of a niobium wire.

Further, in the above embodiment, the case of the high pressure sodium lamp using thorium Na as the light emitting substance housed in the light emitting tube 1 has been described, but the light emitting metal may be a metal halide, in short, it emits light. It suffices if the tube is a ceramic discharge lamp with a reflecting mirror made of ceramics.

[0044]

As described above, according to the invention of claim 1, an arc tube bent in a U-shape is used as the arc tube, and the electric introduction body led out from both ends of the arc tube is reflected. Since it is installed toward the back side of the mirror, the electric introducer is located far from the heat welding point between the windshield and the mirror body, and thus does not receive heat when heat welding the windshield and the mirror body. The temperature rise of the introduction body is suppressed. Therefore, it is possible to prevent the electric introduction body from being oxidized, and to prevent the electric introduction body from deteriorating in the middle of its life or from causing airtight leakage due to poor adhesion. In addition, variations in temperature of the electric introduction body can be suppressed, and variations and fluctuations in lamp characteristics and deterioration in life characteristics can be prevented.

According to the second aspect of the present invention, even when the electric introduction body is formed of a niobium tube, oxidation due to heating is suppressed. According to the third aspect of the present invention, since the pair of electrodes are arranged at both ends of the intermediate linear portion of the arc tube having the U-shape, the discharge is linearly generated in the intermediate linear portion of the arc tube. Therefore, the discharge is not bent, and the tube wall of the arc tube is not deteriorated by the heat of the discharge.

According to the invention of claim 4, a lighting device for a ceramic discharge lamp having stable lamp characteristics can be obtained. According to the inventions of claims 5 and 6, it is possible to obtain an illuminating device having stable lamp characteristics.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a ceramic discharge lamp with a reflector, showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an arc tube of the same embodiment.

FIG. 3 is a cross-sectional view showing a schematic configuration of a lighting device using the ceramic discharge lamp with a reflecting mirror of the same embodiment.

FIG. 4 is a sectional view of a conventional ceramic discharge lamp with a reflecting mirror.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Arc tube 2 ... Ceramic tube 3 ... Blocking member 4 ... Electric introduction body 5 ... Electrode 10 ... Reflecting mirror 11 ... Mirror body 12 ... Reflecting surface 13 ... Front glass 14 ... Sealing part 15a, 15b ... Power supply terminal 18 ... Base

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Aoki 4-3-1, Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Lighting & Technology Corporation

Claims (6)

[Claims] 1. An arc tube in which electrodes are sealed at both ends of a ceramic tube encapsulating a luminescent metal, and electric introduction bodies connected to these electrodes are led out from both ends of the ceramic tube, A mirror body having a reflecting surface and a front glass that is airtightly joined to the front opening of the mirror body constitute an airtight envelope, and a reflecting mirror that houses the arc tube therein,
In the ceramic discharge lamp with a reflecting mirror, the arc tube is formed in a U shape, and the electric introducing body is led out from both ends of the U shape arc tube, and the electric introducing body is the mirror body. A ceramic discharge lamp with a reflecting mirror, characterized in that it is guided to the back part of the and connected to an external power feeding member. 2. The ceramic discharge lamp with a reflecting mirror according to claim 1, wherein the electric introduction body is formed of a niobium tube. 3. The pair of electrodes are arranged so as to face each other at both ends of a central straight line portion of the arc tube having a U-shape.
A ceramic discharge lamp with a reflector as described in. 4. A reflector-equipped ceramic discharge lamp comprising: the reflector-equipped ceramic discharge lamp according to any one of claims 1 to 3; and a lighting circuit for lighting the discharge lamp. Lighting device for electric lights. 5. A lighting device comprising: the ceramic discharge lamp with a reflecting mirror according to any one of claims 1 to 3; and a lighting fixture to which the discharge lamp is mounted. 6. Any one of claims 1 to 3
2. A lighting device comprising: the ceramic discharge lamp with a reflecting mirror according to claim 1; a lighting circuit for lighting the discharge lamp; and a lighting fixture provided with the discharge lamp and the lighting circuit.