JPH08102299A - Ceramic discharge lamp with reflecting mirror, discharge lamp lighting device and lighting system - Google Patents

Abstract

PURPOSE: To provide a ceramic discharge lamp with a reflecting mirror, which can prevent the generation of malfunction such as the oxidation of an electrical conducting body, which is led from a light emitting tube, due to the heating thereof at the time of sealing a reflecting mirror or the like, and to provide the lighting device thereof, and the lighting system using it. CONSTITUTION: In electrical introducing bodies 33a, 33b of a light emitting tube 30, heat insulating shielding bodies 34, 34 are arranged as heat shielding body in a part projected outside. These heat shielding body 34 is made of silica, alumina, zirconia or the like. The ceramic discharge lamp with a reflecting mirror is formed of this light emitting tube 1 and a reflecting mirror 10 obtained by airtightly bonding a front surface glass 13 to the front surface opening part of a mirror main body 11, in which the light emitting tube 1 is housed.

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 light sources for outdoor lighting such as in parks and roads, have excellent luminous efficiency. Attempts are being made to use it as an illumination light source. 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.

For this reason, the inventor has constructed a ceramic discharge lamp with a reflector as shown in FIG. 4, in which the arc tube is housed in a reflector and integrated. That is, the ceramic discharge lamp with a reflecting mirror will be described with reference to FIG. 4. In FIG. 4, reference numeral 10 is a reflecting mirror and 30 is an arc tube.

Describing the structure of the reflecting mirror 10, reference numeral 11 denotes a mirror body made of hard glass or the like. The mirror body 11 has an ellipse having a front surface that is widened and opened and has a first focal point inside the reflecting mirror 10. It has a curved surface, and the reflecting surface 1 is on this inner surface.
2 is formed. The reflecting surface 12 is formed of, for example, a vapor deposited film of aluminum. A front glass 13 made of transparent glass is hermetically sealed at the front opening of the mirror body 11. Further, the rear surface of the mirror body 11 is sealed by the sealing portion 14. Therefore, the reflector 1
The interior of 0 forms an airtight space, and this 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 airtightly 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 constructed by hermetically sealing electrodes 32a and 32b in openings at both ends of a ceramic tube 31 made of alumina or the like. The ceramic tube 31 has a straight tube shape. Electric guides 33a and 33b made of niobium tubes are hermetically penetrated through both ends of the straight-tube type ceramic tube 31, and inner ends of the electric guides 33a and 33b facing the inside of the ceramic tube 31. The electrodes 32a, 32
b is connected, and these electric introduction bodies 33
The outer ends of a and 33b are hermetically sealed. The discharge space inside the ceramic tube 31 contains sodium Na and mercury.
It encloses amalgam with Hg, and also encloses noble gas.

The arc tube 30 as described above 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 conductive holder 20 is attached to the electric introduction bodies 33a and 33b protruding from both ends of the arc tube 30.
a and 20b are connected in an electrically conductive state,
The conductive holders 20a and 20b are welded to the conductive supports 21a and 21b, and the conductive supports 21a and 21b are connected to the power supply terminals 15a and 15b. Therefore, the arc tube 30 includes the conductive holders 20a and 20b and the conductive supports 21a and 21b.
Is mechanically supported via.

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, this type of ceramic discharge lamp with a reflecting mirror has a double tube structure.

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.

[0012]

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 body 11, the front glass 13 is covered by the burner 38. The peripheral portion and the opening of the mirror body 11 are heated and melted, and the front glass 13 is melted by welding them.
Is hermetically welded to the mirror body 11.

However, at the time of such heating, the one electric introduction body 33a and the one electroconductive holder 20a near the heating point are heated by the heat from the burner 38.
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 introducing member 3 made of a 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, there occurs a problem that the temperature of the electricity introducing body 33a during lighting varies for each lamp. That is, the electric introduction body 33a is
When a ceramic discharge lamp with a reflecting mirror of this type is used as a downlight, the lamp is turned on by reversing the posture shown in FIG. Therefore, it becomes the coldest part of the arc tube 30.

Excessive luminescent metal aggregates in such a coldest portion, which has the function of controlling the vapor pressure of the luminescent metal. However, when the electric introducing member 33a oxidizes and causes temperature variations,
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.

The present invention has been made under such circumstances, and an object of the present invention is to oxidize an electric introduction body, which is led out from an arc tube during a sealing operation of a reflecting mirror, by being excessively heated. It is intended to provide a ceramic discharge lamp with a reflecting mirror, a discharge lamp lighting device, and a lighting device, which can prevent problems such as occurrence of light emission, prevent variations and fluctuations in lamp characteristics, and prevent deterioration of life characteristics. .

[0020]

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 electric introduction bodies connected to these electrodes are provided at both ends of the ceramic tube. Of the arc tube, the mirror body having a reflecting surface, and the windshield that is hermetically welded to the front opening edge of the mirror body. And a heat shield arranged between the electric introduction body on the front opening side in the envelope and the straight edge of the front opening edge in the envelope. It is a ceramic discharge lamp with a mirror.

According to a second 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 directly led out from both ends of the ceramic tube. A tube-shaped arc tube, a mirror body having a reflecting surface, and a front glass that is hermetically welded to the front opening edge of the mirror body constitute an airtight envelope, and the arc tube is placed inside the front tube. It is provided with a reflecting mirror housed in a positional relationship orthogonal to the glass, and a heat shield disposed between the electric introduction body on the front opening side in the envelope and a straight line distance between the front opening edge portion. It is a ceramic discharge lamp with a reflecting mirror.

A third aspect of the present invention is the ceramic discharge lamp with a reflecting mirror according to the first or second aspect, characterized in that the electric introduction body is formed of a niobium tube.

A fourth aspect of the present invention comprises the ceramic discharge lamp with a reflecting mirror according to any one of the first to third aspects, and a lighting circuit for stably lighting the discharge lamp. Discharge lamp lighting device.

According to a fifth aspect of the present invention, there is provided an illuminating device comprising the lighting device for the ceramic discharge lamp with a reflecting mirror according to the fourth aspect and a lighting fixture provided with the lighting device.

A sixth aspect of the invention is characterized by comprising the ceramic discharge lamp with a reflecting mirror according to any one of the first to third aspects, and an illuminator containing the ceramic discharge lamp with a reflecting mirror. It is a lighting device.

[0026]

According to the first and second aspects of the present invention, the heat shield is disposed between the electric introduction body on the front opening side and the edge of the front opening in the envelope, so that the front glass is It does not receive heat when the mirror body is heat-welded, and the temperature rise of the electric 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. It is preferable that the heat shield forms a gap between itself and the electric introduction body, that is, a gas layer is interposed.

Further, a cylindrical heat shield is provided at the end of the arc tube so that the light distribution by the reflecting mirror is not obstructed, and the electricity introducing body is positioned in the cylindrical heat shield. It is preferable.

According to the third 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 invention of claim 4, a discharge lamp lighting device having stable lamp characteristics can be obtained.

According to the invention of claim 5 or 6, it is possible to obtain an illuminating device having stable lamp characteristics.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in FIGS. For this reason, this type of lamp constitutes a ceramic discharge lamp with a reflecting mirror in which the arc tube is housed in a reflecting mirror and integrated as shown in FIG. That is, a ceramic discharge lamp with a reflecting mirror will be described with reference to FIG.
Is a reflecting mirror, 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 mirror body 1
The diameter of the front opening of No. 1 is about 121 mm.

Describing the structure of the reflecting mirror 10, reference numeral 11 denotes a mirror body made of hard glass or the like. The mirror body 11 has an open front surface with an opening and an ellipse having a first focal point inside the reflecting mirror 10. It has a curved surface, and the reflecting surface 1 is on this inner surface.
2 is formed. The reflecting surface 12 is formed of, for example, a vapor deposited film of aluminum. A front glass 13 made of transparent glass is hermetically sealed at the front opening of the mirror body 11. Further, the rear surface of the mirror body 11 is sealed by the sealing portion 14. Therefore, the reflector 1
The interior of 0 forms an airtight space, and this 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 airtightly 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 that constitutes a high-pressure sodium lamp is housed in such a reflecting mirror 10.

The inner diameter of the arc tube 30 is made of alumina or the like 5.
The ceramic tube 31 having a thickness of 5 mm and a thickness of 0.5 mm is formed by hermetically sealing the electrodes 32a and 32b in the openings at both ends so that the distance between the electrodes is 20 mm. The ceramic tube 31 has a straight tube shape. Electric guides 33a, 33b made of niobium tubes are hermetically penetrated through both ends of such a straight tube-shaped ceramic tube 31, respectively, and inner ends of the electric guides 33a, 33b facing the ceramic tube 31 are formed. The electrodes 32a, 3
2b are connected, and these electric introduction bodies 3
The outer ends of 3a and 33b are hermetically sealed. The discharge space in the ceramic tube 31 is filled with sodium Na and mercury Hg in the form of amalgam of 25 mg in a ratio of Nawt%: Hgwt% = 25: 75, and xenon gas of 6.7 kPa is filled as a rare gas. Has been done.

The arc tube 30 as described above is attached to the power supply terminals 15a and 15b through the conductive holders 20a and 20b and the conductive supports 21a and 21b. That is, the conductive holder 20 is attached to the electric introduction bodies 33a and 33b protruding from both ends of the arc tube 30.
a and 20b are connected in an electrically conductive state,
The conductive holders 20a and 20b are welded to the conductive supports 21a and 21b, and the conductive supports 21a and 21b are connected to the power supply terminals 15a and 15b. Therefore, the arc tube 30 includes the conductive holders 20a and 20b and the conductive supports 21a and 21b.
Is mechanically supported via.

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, this type of ceramic discharge lamp with a reflecting mirror has a double tube structure.

Then, the electric introduction body 33a of the arc tube 30,
In the portion 33b, heat insulating heat-resistant coatings 34, 34 are formed as heat shields on the portion protruding to the outside. The heat resistant coating 34 is formed of, for example, silica, alumina, zirconia or the like.

As for the structure of the heat shield, as shown in FIG. 2 showing the partial details of the arc tube, it is attached to the end of the arc tube 30 and extends so as to surround the periphery of the electric introduction body 33a. It may be a cylindrical heat shield 34b. In this case, since the gas layer is present between the electricity introducing body, the heat shielding property is improved. Further, since it is provided at the end of the arc tube, it hardly interferes with the light distribution of the reflecting mirror. The heat shield is not limited to the above configuration.
That is, it is sufficient that the heat shield is present between the edge of the opening of the reflecting mirror and the electric introduction body.

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.

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, reference numeral 50 denotes 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. . The socket 51 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, 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 with stable lamp characteristics can be obtained.

In the case of the above-described embodiment, the case where 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-mentioned 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. However, the light emitting metal may be a metal halide, that is, it emits light. It suffices if the tube is a ceramic discharge lamp with a reflecting mirror made of ceramics.

[0047]

As described above, according to the inventions of claims 1 and 2, the heat shield is arranged between the electric introduction body on the front opening side and the front opening edge portion in the envelope. Therefore, the heat generated when the front glass and the mirror body are heat-welded is not received, and the temperature rise of the electric 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 third 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 invention of claim 4, a ceramic discharge lamp lighting device having stable lamp characteristics can be obtained.

According to the fifth and sixth aspects of the present invention, 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 a main part of an arc tube according to another embodiment.

FIG. 3 is a cross-sectional view showing a schematic configuration of the lighting device of the 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 ... Closure member, 4 ... Electric introduction body, 10 ... Reflecting mirror, 11 ... Mirror body, 12 ... Reflecting surface, 13 ... Front glass, 14 ... Sealing part, 15a, 15b … Power supply terminal, 18… Base, 3
4 ... Heat shield.

 ─────────────────────────────────────────────────── ─── 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 main body having a reflecting surface and a front glass that is airtightly welded to the front opening edge of the mirror main body constitute an airtight envelope, and a reflection mirror housing the arc tube therein, and an outer envelope. A ceramic discharge lamp with a reflecting mirror, comprising: an electric introduction body on the front opening side in the chamber; and a heat shield disposed between the front opening edge portion and a straight line. 2. A ceramic tube encapsulating a luminescent metal is sealed with electrodes at both ends, and an electric introduction body connected to these electrodes is of a straight tube shape led out from both ends of the ceramic tube. The arc tube, the mirror body having the reflecting surface, and the front glass that is hermetically welded to the front opening edge of the mirror body constitute an airtight envelope, and the arc tube is orthogonal to the front glass inside the envelope. And a heat shield disposed between the electric introduction body on the front opening side in the envelope and the front opening edge portion in the envelope in a linear distance. A ceramic discharge lamp with a reflector. 3. The ceramic discharge lamp with a reflecting mirror according to claim 1, wherein the electric introduction body is formed of a niobium tube. 4. A discharge lamp comprising the ceramic discharge lamp with a reflecting mirror according to any one of claims 1 to 3, and a lighting circuit for stably lighting the discharge lamp. Lighting device. 5. A lighting device comprising: the lighting device for the ceramic discharge lamp with a reflecting mirror according to claim 4; and a lighting fixture provided with the lighting device. 6. A lighting device comprising: the ceramic discharge lamp with a reflecting mirror according to claim 1; and a lighting fixture containing the ceramic discharge lamp with a reflecting mirror.