JPH06290755A - Ceramic discharge lamp and luminaire using this discharge lamp - Google Patents

Abstract

PURPOSE:To provide a ceramic discharge lamp and a luminaire using this discharge lamp wherein a blackening phenomenon of an outer tube can be surely prevented before occurrence by improving lamp efficiency with high color rendering, and on the other hand, by preventing passing through in a translucent ceramic tube. CONSTITUTION:In this ceramic discharge lamp 3, an arc tube 6 is housed in an outer tube 5, and this arc tube 6 is constituted by sealing an electric introducer 19, provided with an electrode 13, to both end parts of a translucent ceramic tube 8. In the ceramic discharge lamp 3 sealed with emitting metal containing Na, cushioning metal and starting rare gas in this translucent ceramic tube 8, operating lamp voltage is set to 80V or less with a wall load of the arc tube 6 20W/cm<2> or more, and also a starting assist conductor 20 is provided so that it is placed in a condition not closely attached to the translucent ceramic tube 8 of the arc tube 6.

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 such as a high color rendering type high pressure sodium lamp and a lighting fixture using this discharge lamp, and in particular, blackening of an outer tube is prevented to improve lamp efficiency. The present invention relates to a ceramic discharge lamp and a lighting fixture using this discharge lamp.

[0002]

2. Description of the Related Art There are various types of high pressure sodium lamps as ceramic discharge lamps, such as a general type in which efficiency is emphasized and a high color rendering type in which color appearance is emphasized. Among them, the high color rendering high pressure sodium lamp is a light source suitable for a lighting field in which color rendering, which is how colors are viewed, is important, and is widely used for lighting of entrance halls, lobbies, stores, offices, and the like.

The conventional high color rendering high pressure sodium lamp is
The light emitting tube is housed in the outer tube, and the light emitting tube is configured by sealing the electric introducing member to both ends of the translucent ceramic tube. Na luminescent metal in translucent ceramic tube,
A Hg buffer metal and a starting rare gas such as Xe are enclosed.

In order to increase the lamp efficiency of this high-pressure sodium lamp, there is a method of suppressing the heat conduction loss from the discharge space to the translucent ceramic tube by raising the filling pressure of the starting rare gas. This type of high pressure sodium lamp has a correlation temperature of 2500K and an average color rendering index of 80.
The lamp efficiency is 50 lm / W.

However, if the pressure of the rare gas for starting is increased in order to increase the lamp efficiency of the high-pressure sodium lamp, it becomes difficult to start the lamp. In order to improve the startability of the lamp, a starting auxiliary conductor was adhered to the translucent ceramic tube of the arc tube, or a bimetal unit was used for the auxiliary auxiliary conductor for starting when the lamp was started and mechanically floated during lighting. There is something. In this high-pressure sodium lamp, the starting of the lamp is improved and ensured by applying a potential by a starting auxiliary conductor at the time of starting the lamp.

[0006]

Conventional high color rendering type high pressure sodium lamps have a structure in which a starting auxiliary conductor is closely attached to a translucent ceramic tube of an arc tube. In this high pressure sodium lamp, blinking lighting is repeated. Then, even during the life of the lamp, Na that has reacted with the ceramic tube in the discharge space of the arc tube is drawn to the potential of the outer auxiliary starting conductor, permeates the tube cross section of the translucent ceramic tube, and goes out. It may lead to blackening of the outer tube.

Further, in the case where the bimetal unit is used as the starting auxiliary conductor, the operating deterioration of the bimetal unit occurs during the life of the lamp, and due to this operational deterioration, the opening ability for releasing the starting auxiliary conductor from the outer surface of the translucent ceramic tube. Could deteriorate and the lamp starting voltage would rise, resulting in defective lighting.

The present invention has been made in consideration of the above-mentioned circumstances, and while improving the lamp efficiency with a high color rendering property, it prevents the passage through the translucent ceramic tube to prevent the blackening phenomenon of the outer tube. It is an object of the present invention to provide a ceramic discharge lamp that can be reliably prevented and a lighting fixture that uses this discharge lamp.

Another object of the present invention is to provide a ceramic discharge lamp capable of reliably preventing the lamp starting voltage from rising during the life of the lamp, and a lighting fixture using this discharge lamp.

[0010]

In order to solve the above-mentioned problems, a ceramic discharge lamp according to the present invention has an arc tube housed in an outer tube, and the arc tube transmits light. Discharge lamp having electrodes formed at both ends of a transparent ceramic tube and sealed, and a light emitting metal containing Na, a buffer metal and a rare gas for starting are sealed in the transparent ceramic tube. In the above arc tube, the tube wall load is 20 W / cm ² or more and the operating lamp voltage is 8
It is set to 0 V or less, and a starting auxiliary conductor is provided so as to be in a non-adhered state on the outer surface of the translucent ceramic tube of the arc tube.

In order to solve the above-mentioned problems, in the ceramic discharge lamp according to the present invention, as described in claim 2 in addition to the contents of claim 1, the starting auxiliary conductor is a translucent ceramic tube. Is set at a position of 0 <l ≦ 5 mm, where l is the distance from the outer surface, and as described in claim 3, the starting auxiliary conductor is a heat-resistant support member for supporting the electric introduction body. A cantilevered beam-shaped support is formed of a refractory metal material, and the starting auxiliary conductor has a heat-resistant support member for supporting the electric lead-in member and a translucent ceramic tube. It is configured to be recessed so as to approach.

Further, in order to solve the above-mentioned problems, the luminaire according to the present invention has the following features.
A translucent cover is attached to the front surface of a reflection mirror having a concave reflection surface, and a ceramic discharge lamp is provided in the center of the reflection mirror.The ceramic discharge lamp is a non-transparent ceramic tube outer surface of an arc tube. A starting auxiliary conductor is provided so as to be in a close contact state.

[0013]

In the ceramic discharge lamp according to the present invention, the wall load of the arc tube is 20 W / cm ² or more and the operating lamp voltage is set to 80 V or less, while the starting auxiliary conductor is the translucent ceramic of the arc tube. Since it is installed in a non-contact state with the tube, even if the ceramic discharge lamp is used with a tube wall load of 20 W / cm ² or more, a high-insulation vacuum is interposed between the translucent ceramic tube and the starting auxiliary conductor. Na that has reacted with the ceramic tube in the discharge space of the arc tube can be effectively prevented from passing through the translucent ceramic tube,
The blackening phenomenon of the outer tube can be prevented, and the lamp efficiency can be improved even with a high color rendering property.

Further, the starting auxiliary conductor is installed at a required distance from the outer surface of the translucent ceramic tube, and the potential difference between the plasma in the arc tube and the starting auxiliary conductor is limited to 80 V or less so that the translucent ceramic tube can be formed. Na can be prevented from penetrating the tube cross section, and within the range of the above potential difference, the deterioration of the starting auxiliary conductor is small, the increase of the starting voltage during the life of the lamp can be suppressed, and the startability of the lamp can be improved, It is possible to reliably prevent defective lighting.

In addition, since the luminaire equipped with this ceramic discharge lamp can prevent the blackening phenomenon of the outer tube in advance and effectively, the life of the lamp can be extended.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view showing a lighting fixture equipped with the ceramic discharge lamp of the present invention. This luminaire has a reflection mirror 1 having a concave reflection surface.
A transparent or semi-transparent translucent cover 2 is attached to the front opening of the. The ceramic discharge lamp 3 is detachably mounted on the optical center of the reflection mirror 1. Reference numeral 4 is a socket that supports the ceramic discharge lamp 3.

The ceramic discharge lamp 3 is, for example, a high color rendering high pressure sodium lamp constructed as shown in FIG. This high pressure sodium lamp 3 has an outer tube 5 and an arc tube 6 inside.
While the outer tube 5 is housed, a screw mold type base 7 is sealed at the mouth of the outer tube 5.

The arc tube 6 is composed of a sleeve-shaped translucent ceramic tube 8 and an electric introduction body 9 sealed at both ends thereof. The electric introduction body 9 is supported by the arc tube supports 10 and 11, respectively.

As shown in FIG. 3, the electric introducing member 9 includes a glass solder 12 containing alumina (Al ₂ O ₃ ) or calcia (CaO) as a main component as a sealing agent in the end cap 8a of the translucent ceramic tube 8. It is hermetically sealed via.
The electric introduction body 9 is provided with an electrode 13, while the inside of the translucent ceramic tube 8 is formed in a discharge space 14, and inside thereof, a luminescent metal of Na, a buffer metal of Hg and Xe, A.
A starting rare gas such as r or Ne is sealed at room temperature, for example, about 100 Torr.

When the electric introducing body 9 is sealed to the translucent ceramic tube 8, the sealing outer surface 9a of the electric introducing body 9 is roughened in order to improve the airtightness, and the electric connecting body 9 and the glass solder 12 are joined together. Improves adhesion. Reference numeral 16 is Na as a surplus light emitting metal and Hg as a buffer metal.

The arc tube 6 housed in the outer tube 5 is supported by arc tube supports 10 and 11. Arc tube support 11
Is fixed and held by a heat resistant support member 18 arranged along the inner surface of the outer tube 5. The heat resistant support member 18 is composed of, for example, a support wire made of stainless steel.

On the other hand, the heat-resistant support wire member 18 is provided with a rod-shaped starting auxiliary conductor 20 made of a refractory metal material such as Mo, Nb, Ti, and Ta in a cantilever shape. The starting auxiliary conductor 20 faces the translucent ceramic tube 8 of the arc tube 6 and is closely arranged in a non-contact state. The starting auxiliary conductor 20 is provided at a distance l, 0 <l ≦ 5 mm, from the outer surface of the translucent ceramic tube 8. Preferably, they are provided at intervals of 0.5 ≦ l ≦ 2 mm. If the distance 1 is larger than 5 mm, the lamp startability deteriorates.

Reference numeral 21 is a ring getter for maintaining a high vacuum inside the outer tube 5, and reference numeral 22 is a similar getter.

Now, as a high color rendering type high pressure sodium lamp, 10 mg of Na as a luminescent metal and Hg as a buffer metal in the form of Na or 25 weight percent (wt%) of amalgam in the arc tube 6 and a rare gas for starting. Xe is filled as a gas at room temperature at 75 Torr. And, the inner diameter of the translucent ceramic tube 8 is 4.5 mm, the distance between the electrodes is 9.5 mm, and the rated output is 5
0 watt type, a conventional type in which a starting auxiliary conductor 20 made of Nb is closely attached to a translucent ceramic tube,
Each of the types of the present invention separated by 1 mm from the translucent ceramic tube 8 was prototyped, and an experiment was conducted using 20 pieces of each type under the same conditions.

In an experiment, a high color rendering high-pressure sodium lamp of the present invention type and a conventional high-pressure sodium lamp of 0.5H (hour) ON-0.5H at 110% overload.
Repeated turning on and off of off. The results of the experiment show that, in the conventional high color rendering type high pressure sodium lamp, all 20 Nas enclosed in the discharge space penetrated to the outer surface of the translucent ceramic tube by repeating blinking and lighting up to 200 times. , 5 out of 20 by turning on and off 1000 times
A blackening phenomenon containing Na as a main component occurred in the outer tube of each high pressure sodium lamp.

On the other hand, in the high-pressure sodium lamp in which the starting auxiliary conductor 20 is provided in a non-adhered state with a distance of 1 mm from the translucent ceramic tube 8 of the arc tube 6, even if the lighting / extinction is repeated 1000 times, Na is emitted. Outer tube 5 as the main component
The blackening phenomenon of No. 1 did not occur, and none of the 20 in which Na penetrated to the outer surface of the translucent ceramic tube 8 existed.

In the high color rendering high pressure sodium lamp, the inner diameter φ of the translucent ceramic tube 8 of the arc tube 6 is
Is 4.0 mm to 6.0 mm, and the distance between electrodes is 8.5 mm to 15 mm
Within the range of 1, the color characteristics of the high color rendering type correlated color temperature Tc ≧ 2500K and the average color rendering index Ra ≧ 80 are changed while maintaining the color characteristics, and the tube wall load of the arc tube 6 is 17.6 W / cm ^{2 to} 49.8.
A test was conducted in which the same blinking and lighting as the above-mentioned method was repeated 1000 times by shaking in the range of W / cm ² .

Here, the tube wall load means the inner surface area S (cm ² ) of the lamp power (W) for controlling the electrodes of the arc tube 6 (the inner diameter of the discharge tube is d, and the effective length of the discharge space is l). When S = π
(represented by d · l).

From the test results, in the conventional type high-pressure sodium lamp, Na and the tube on the inner surface of the translucent ceramic tube 8 were observed in the sodium lamp having a load of 20 W / cm ² or more at the boundary of the tube wall load of 20 W / cm ^2. Reaction was large and the blackening phenomenon occurred on the outer tube, whereas 20W / cm
^{When it was 2} or less, the reaction between Na and the ceramic tube was small, and the blackening phenomenon did not occur in the outer tube.

Further, in a high pressure sodium lamp having a tube wall load of 20 W / cm ² or more, a similar experiment was conducted by separating the starting auxiliary conductor 20 from the translucent ceramic tube 8 of the arc tube 6 and conducting a translucent ceramic. N inside tube 8
Despite the large reaction between a and the tube, Na penetrated into the outer surface of the translucent ceramic tube 8 was very small, and the blackening phenomenon of the outer tube 5 did not occur.

On the other hand, it is considered that the Na permeation phenomenon is caused by the potential difference (operating lamp voltage) between the plasma potential in the discharge space of the arc tube 6 and the starting auxiliary conductor 20.
That is, when the potential difference is large, it is estimated that the movement of Na through the tube cross section of the translucent ceramic tube 8 is promoted, the tube wall load of the arc tube 6 is set to 20 W / cm ² or more, and the starting auxiliary conductor 20 Is separated from the translucent ceramic tube 8 by the required distance.
When a high-pressure sodium lamp shaken in the range of 0 V to 100 V was prototyped and Na intrusion in the tube cross section of the translucent ceramic tube 8 was observed, the operating lamp voltage was 80%.
It was confirmed that in the high-pressure sodium lamp of V or less, Na penetrates little to the outer surface of the translucent ceramic tube 8. As a result of an experiment based on the above estimation, it was found that 80 V was the boundary.

Further, in the conventional high-pressure sodium lamp in which the starting auxiliary conductor 20 is in close contact with the translucent ceramic tube 8 of the arc tube 6, the inner surface of the ceramic tube reacts with Al ₂ O ₃ which is ceramic. Na
Are attracted toward the outer surface side of the ceramic tube through the crystal grain boundaries of the tube cross section.
It was found that when was not in close contact with the translucent ceramic tube 8, a vacuum, which was in a highly insulated state, was interposed between the two, and an electric attraction force for attracting Na was not generated.

Therefore, even when the lamp wall load of the arc tube 6 is set to 20 W / cm ² or more in the high color rendering type high pressure sodium lamp to improve the lamp efficiency, the starting auxiliary conductor 20 is not in close contact with the translucent ceramic tube 8. By providing it, Na can be effectively prevented from passing through the tube cross section of the translucent ceramic tube 8, the blackening phenomenon of the outer tube 5 can be prevented, and the starting voltage rise during the life of the lamp can also be prevented.

In the embodiment of the present invention, the starting auxiliary conductor is fixed to the heat resistant support member, but the starting auxiliary conductor 25 of the high color rendering type high pressure sodium lamp 3A is as shown in FIG. A part of the heat resistant support member 18 may be recessed so as to be close to the translucent ceramic tube 8, and a part of the heat resistant support member 18 may be configured as the starting auxiliary conductor 25. In this case, the heat resistant support member 1
Instead of using a stainless steel wire, a wire made of a refractory metal material such as Mo, Ta, or Nb is used for at least a part of 8.

Further, it is desirable that the starting auxiliary conductor is arranged over more than half of the effective discharge space length of the arc tube.
In order to further improve the startability, it may be wound around the arc tube in a non-contact state in the circumferential direction.

[0037]

As described above, in the ceramic discharge lamp according to the present invention, the wall load of the arc tube is 20 W /
When the operating lamp voltage is set to 80 V or less at cm ² or more, the starting auxiliary conductor is provided in a non-adhesive state on the outer surface of the translucent ceramic tube of the arc tube, so that the ceramic discharge lamp has a wall load of 20 W / Even when used at cm ² or more, a highly insulating vacuum is interposed between the translucent ceramic tube and the starting auxiliary conductor, and Na that has reacted with the ceramic tube in the discharge space of the arc tube is translucent ceramic tube. It is possible to prevent the blackening phenomenon of the outer tube effectively and in advance, and it is possible to improve the lamp efficiency even with a high color rendering property.

Furthermore, since the starting auxiliary conductor is fixed, there is no deterioration of operation as in the case of using a bimetal unit, the rise of the starting voltage during the life of the lamp can be suppressed, and the startability of the lamp is improved to prevent lighting failure. It can be surely prevented.

Further, when this ceramic discharge lamp is adopted in a lighting fixture, the blackening phenomenon of the outer tube can be prevented in advance and effectively, so that the life of the lamp can be extended.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a lighting fixture including a ceramic discharge lamp of the present invention.

FIG. 2 is a diagram showing an embodiment of a ceramic discharge lamp according to the present invention.

FIG. 3 is a sectional view showing an electric introduction body provided in the ceramic discharge lamp shown in FIG.

FIG. 4 is a diagram showing another embodiment of the ceramic discharge lamp according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Reflection mirror 3 Ceramic discharge lamp (high color rendering high-pressure sodium lamp) 5 Outer tube 6 Light emitting tube 7 Base 8 Translucent ceramic tube 9 Electric introduction body 10,11 Light emitting tube support 12 Glass solder 13 Electrode 14 Discharge space 18 Heat resistance Support member (support wire) 20,25 Starting auxiliary conductor

Claims (5)

[Claims] 1. An arc tube is housed in an outer tube, and the arc tube is constituted by sealing an electric introduction body having electrodes at both ends of a translucent ceramic tube. In a ceramic discharge lamp in which a luminescent metal containing Na, a buffer metal, and a rare gas for starting are sealed, the arc tube has a wall load of 20 W / cm ² or more and an operating lamp voltage of 8
A ceramic discharge lamp which is set to 0 V or less and which is provided with a starting auxiliary conductor so as to be in a non-adhered state on the outer surface of the translucent ceramic tube of the arc tube. 2. The ceramic discharge lamp according to claim 1, wherein the starting auxiliary conductor is provided at a position of 0 <l ≦ 5 mm, where l is a distance from the outer surface of the translucent ceramic tube. 3. The ceramic discharge lamp according to claim 1, wherein the starting auxiliary conductor is supported in a cantilever shape by a heat-resistant support member that supports the electric introduction body, and is made of a refractory metal material. 4. The ceramic discharge lamp according to claim 1, wherein the starting auxiliary conductor is formed by recessing a heat-resistant support member that supports the electric lead-in member so as to approach the translucent ceramic tube. 5. A translucent cover is attached to the front surface of a reflection mirror having a concave reflection surface, and a ceramic discharge lamp is provided in the optical center of the reflection mirror.
A lighting fixture, wherein a starting auxiliary conductor is provided so as to be in a non-adhered state on the outer surface of a translucent ceramic tube of an arc tube.