JP2003100253A - High-pressure metal vapor discharge lamp and lighting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-pressure metal vapor discharge lamp and a lighting apparatus, utilizing the discharge lamp to improve in a light-emission properties of the lamp by retaining heat of a light-emitting tube, and to prevent dispersion of glass pieces, even in the case of breakage of a light-emitting tube bulb, by covering the light-emitting tube with a shroud (translucent hollow tube) in an outer bulb. SOLUTION: The high-pressure metal vapor discharge lamp L and the lighting apparatus 9 utilizing the discharge lamp L, the high-pressure metal vapor discharge lamp L provided with the light emission tube 4 equipped with at least one pair of electrodes 5a, 5b facing each other on each end of the light-emitting tube bulb 40 of translucent high silica glass or translucent ceramic, injected with a discharge medium and sealed, and the heat-resistant translucent shroud 6 surrounding the light emission tube 4, in the outer bulb 1. The glass wall thickness t of the shroud 6 is not more than 2.0 mm, and the relation between a maximum outer diameter Bd of the light-emitting tube bulb 40 and an inner diameter Sd of the shroud 6 Bd/Sd is 0.68-0.83, in the airtight sealed high pressure metal vapor discharge lamp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure metal vapor discharge lamp in which an arc tube is enclosed in an outer bulb so as to improve the efficiency and color rendering of the lamp, and a lighting fixture equipped with this discharge lamp.

[0002]

2. Description of the Related Art High-pressure metal vapor discharge lamps, such as metal halide lamps, are compact and provide high efficiency and high color rendering, and are widely used as light sources for lighting in stores, shopping streets, halls and sports facilities.

This high-pressure metal vapor discharge lamp has high efficiency,
In order to obtain a high color rendering, the arc tube is downsized to raise the temperature and to prevent oxidation, this arc tube is enclosed in an outer bulb that is filled with an inert gas, nitrogen gas or vacuum atmosphere, and has a double glass tube structure. .

In the high-pressure metal vapor discharge lamp having such a structure, the vapor pressure of the luminescent metal in the discharge space is affected by the temperature of the coldest part of the arc tube during lighting, which greatly affects characteristics such as luminous efficiency. It is known. The coldest part of the arc tube is generated in the vicinity of the end part of the sealing part, which is the base of the electrode at the end part apart from the discharge path between the electrodes in the arc tube.

Therefore, the high-pressure metal vapor discharge lamp is designed to raise the temperature of the coldest part of the arc tube at the time of lighting, for example, by forming a heat insulating film on the outer surface near the sealing part at the end of the arc tube, or The arc tube is being made thinner and its shape is being changed.

The former heat insulating film is formed by using a metal oxide material containing alumina, silica, zirconia, titania or the like as a main component, which has excellent heat resistance and resistance to reaction with the glass of the arc tube. .

This heat insulating film is formed by applying a suspension obtained by suspending the above-mentioned metal oxide powder in an aqueous solution or the like to the outer surface near the sealing portion at the end of the arc tube, followed by drying and firing. . However, this heat-insulating film blocks light emission at the time of lighting and reduces the luminous efficiency, and cannot cope with thermal shock (repetition of temperature change) due to lighting / extinguishing, and thus peels off from the outer surface of the arc tube. Sometimes.

In the latter case, if the arc tube bulb is made thin, the temperature of the arc tube as a whole rises, so that the temperature of the tube wall rises excessively and the quartz glass reacts with the halogenated luminescent metal. As a result, there is a risk that the arc tube bulb may cause a phenomenon such as clouding or devitrification, or deformation such as squeezing only the end portion of the arc tube bulb into a thin shape requires time and labor for processing.

[0009]

DISCLOSURE OF THE INVENTION The present inventors have sought to improve the efficiency and color rendering of high-pressure metal vapor discharge lamps.
The present invention has been completed as a result of various investigations and investigations on the heat insulating means of the arc tube with a simple structure.

That is, according to the present invention, when the arc tube is further covered with a shroud (translucent hollow tube) inside the outer tube bulb, the efficiency is improved by regulating the relational ratio of the arc tube bulb diameter and the shroud diameter. It is intended to keep the arc tube warm.

In the case where the arc tube is covered with a shroud (translucent hollow tube) inside the outer tube bulb, and the glass piece of the bulb forming the arc tube scatters if the arc tube is damaged, A technique in which a shroud prevents a glass piece from directly flying to an outer bulb to soften an impact is disclosed in Japanese Patent Laid-Open No. 5-1201047 or 2000-
This is known from Japanese Patent No. 90879.

According to the present invention, the luminous tube is covered with a shroud (translucent hollow tube) in the outer bulb, and the luminous tube is kept warm to improve the luminous characteristics such as high efficiency and high color rendering of the lamp. Another object of the present invention is to provide a high-pressure metal vapor discharge lamp that can prevent glass fragments from scattering even if the arc tube bulb is damaged, and a lighting fixture that uses this discharge lamp.

[0013]

A high pressure metal vapor discharge lamp according to claim 1 of the present invention has at least a pair of electrodes in an end portion of an arc tube bulb made of translucent high silica glass or translucent ceramic. A shroud that is provided facing each other and that contains a discharge medium inside and a heat-resistant translucent member that surrounds the arc tube is disposed along the tube axis inside a sealed portion formed at one end. In a high pressure discharge lamp equipped with an airtightly sealed outer bulb,
The glass thickness t of the shroud is 2.0 mm or less, and the relationship Bd / Sd between the maximum outer diameter Bd of the arc tube bulb and the inner diameter Sd of the shroud is 0.68 to 0.83.

When the high-pressure metal vapor discharge lamp continues to be lit, heat (infrared) rays are emitted from the arc tube along with visible light in all directions, and the discharge tube heats up the arc tube.
Further, in the case of this configuration, since the heat radiation is shielded by the shroud (translucent hollow tube) which is arranged close to and surrounding the arc tube, the temperature of the arc tube bulb further rises.

That is, since the temperature rise reaches the entire bulb of the arc tube and also the root portion of the electrode at the inner end of the bulb, which is the coldest part, is heated, the luminous metal sealed in the bulb is heated to vaporize. The pressure can be increased to improve the luminous efficiency and color rendering.

The relationship Bd / Sd between the maximum outer diameter Bd of the arc tube bulb and the inner diameter Sd of the shroud (hollow tube) is 0.6.
If it is less than 8, the temperature of the coldest part cannot be increased as described above, and there is a problem that the luminous efficiency is reduced.

If the above relationship Bd / Sd exceeds 0.83, the space between the arc tube bulb and the shroud (hollow tube) is too narrow, so that the temperature of the arc tube bulb rises excessively and devitrification or blackening occurs. There is a problem that the lamp life is shortened and the lamp life is shortened.

Also, by providing a shroud (hollow tube) surrounding the arc tube, even if the arc tube bulb is damaged and glass fragments scatter, the shroud (hollow tube) prevents this. Or, the shock can be mitigated to reduce the stress exerted on the outer pipe valve, and the outer pipe valve can be prevented from being damaged, which can greatly contribute to safety.

In the present invention and the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified.

The high-pressure metal vapor discharge lamp to which the present invention can be applied is a metal halide lamp, a short arc metal halide lamp, a mercury lamp, etc., and has a multi-tube structure such as a double tube in which an arc tube is sealed in an outer bulb. There is.

In this high-pressure metal vapor discharge lamp, the inside of the outer bulb is in an inert gas or nitrogen gas atmosphere or a vacuum atmosphere. That is, by injecting an inert gas or nitrogen gas into the outer bulb at a low pressure or creating a vacuum atmosphere, it is possible to prevent the arc tube constituent members, the support member, and the stem constituent member, which become hot at the time of lighting, from oxidizing and the like. The restart time can be shortened, and it can be prevented from bursting should the outer tube valve break.

As the discharge medium sealed in the arc tube bulb, mercury, a halide of a luminescent metal, a rare gas, or the like is appropriately selected and used according to the application and characteristics.

Further, as a material for forming the arc tube bulb, in the case where a transparent high silica glass containing silicon oxide as a main component such as quartz glass, borosilicate glass or aluminosilicate glass or sodium halide is not enclosed, By using a translucent ceramic made of alumina, yttria, magnesia, ruby, sapphire, or the like, light emission characteristics, heat resistance, corrosion resistance, electric insulation, etc. can be satisfied.

The shroud (light-transmitting hollow tube) can be made of the same heat-resistant light-transmitting material as that of the arc tube bulb, and has a cylindrical shape. The shroud (hollow tube) has a wall thickness of 2 mm or less, which is thinner than usual, and preferably has an advantage that the weight can be reduced in the range of 1.5 to 2.0 mm. In addition, a phosphor film, a light diffusing film, a coating film such as an ultraviolet ray reflecting film or a blocking film, or an uneven surface for light diffusing may be formed on the surface of the shroud (hollow tube).

Further, the introduction conductor sealed in the sealing portion of the arc tube bulb is not limited to the metal foil, and may be a metal wire. Furthermore, at least one pair of electrodes is provided inside the arc tube, and it does not matter whether or not the auxiliary electrode is provided.

Further, even if the lighting position of the discharge lamp is not only horizontal but also vertical, it is possible to achieve the same effect as long as the end portion of the arc tube can be kept warm.

A high pressure metal vapor discharge lamp according to a second aspect of the present invention is characterized in that the shroud has a length that covers at least the inner end portion of the arc tube bulb.

If the shroud (translucent hollow tube) covers the inner end of the arc tube bulb, the inner end forming the coldest portion is kept warm and a predetermined action is achieved. It also protects glass fragments from scattering when the bulb bulb ruptures. The total length is not limited, but may be any length as long as it covers a part of the sealing portion at both ends of the arc tube bulb.

A high pressure metal vapor discharge lamp according to a third aspect of the present invention is characterized in that a reinforcing member is wound around the outer periphery of the shroud.

As means for increasing the strength of the shroud (translucent hollow tube), a linear or mesh reinforcement made of inorganic fibers such as heat-resistant ceramics is wound around the outer circumference of the shroud (hollow tube). This can be dealt with. Therefore, the wall thickness of the shroud (hollow tube) can be reduced to reduce the weight of the lamp.

A high pressure metal vapor discharge lamp according to a fourth aspect of the present invention is characterized in that the arc tube bulb and the support member of the shroud are not applied with an electric potential during lighting.

By supporting the arc tube and the shroud (hollow tube) on a support member to which no electric potential is applied,
It is possible to prevent sodium ions, etc. from escaping from the bulb of the arc tube due to photoelectron action during lighting, which can prevent the luminous efficiency of the discharge lamp from decreasing and the lamp voltage to rise to shorten the life. it can.

That is, in a metal halide lamp containing sodium halide or the like, photoelectrons are emitted from the conductor when the conductor is irradiated with the ultraviolet rays emitted from the arc tube at the time of lighting, and the photoelectrons are diffused to the bulb of the arc tube. It adheres to the outer surface and negatively charges the arc tube. The arc tube bulb of this metal halide lamp is usually made of high silica glass (quartz glass), and the interstitial distance of silicon oxide that composes quartz glass is larger than the sodium ion in the arc tube. It is drawn to the potential by the negative photoelectrons on the outer surface of the arc tube, passes through the arc tube bulb, and disappears outside the arc tube. For this reason, the amount of sodium in the arc tube is reduced, and the luminous efficiency of the lamp is reduced, and excess free halogen is increased in the arc tube, which increases the lamp voltage and causes a short life. Can be prevented.

The high pressure metal vapor discharge lamp according to claim 5 of the present invention is characterized in that a halide is enclosed as a discharge medium.

In a lamp containing a halide,
The same operation as described in claim 4 is achieved.

A lighting fixture according to claim 6 of the present invention is a fixture main body, the high pressure metal vapor discharge lamp according to any one of claims 1 to 5 which is disposed in the fixture main body, And a lighting circuit device connected to the discharge lamp.

Since the high-pressure metal vapor discharge lamp having the above-mentioned actions 1 to 5 is incorporated, the temperature of the coldest part can be raised when the lamp is turned on, and the emission characteristics can be improved. Further, even if the arc tube bulb is damaged, the glass pieces will not be scattered and the safety will be improved. Therefore, a protective structure such as a front glass on the side of the lighting equipment is not essential.

This lighting device may be provided with a lighting circuit device inside the device or may be provided outside the device with a lighting circuit device connected to the lamp. This luminaire can exhibit high light emission characteristics for lighting in stores, halls, underground malls, offices, sports facilities, and the like.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view schematically showing a metal halide lamp as a high pressure metal vapor discharge lamp according to the present invention.

The metal halide lamp L shown in FIG.
Consists of a stem 2 sealed at one end of an outer tube valve 1,
The stem 2 has a structure in which an arc tube 4 and a shroud (translucent hollow tube) surrounding the arc tube 4 are supported via support members 7a, 7b and the like.

Explaining each of these parts in detail, the outer pipe valve 1
Is a so-called BT type which is made of translucent hard glass such as borosilicate glass and has a bulged portion 11 in the center and a closed top portion 12 on the lower side in the drawing and a small diameter portion on the neck portion 13 on the upper side. Is formed in. The neck portion 13 side has a sealing portion (not shown) in which the stem 2 is sealed, and the E-shaped cap 3 covers the sealing portion.
Is installed.

The arc tube 4 sealed in the outer bulb 1 is a straight tube (T) type high silica glass (quartz glass) bulb tube 40 which forms a translucent airtight container.
Has crushed and sealed portions 4a and 4b at both ends thereof.
A pair of main electrodes 5a and 5b made of tungsten W or molybdenum Mo and an auxiliary electrode 5s are provided in the vicinity of 0 in the vicinity of one main electrode 5a.

Metallic foils 41, 41 and 41 made of molybdenum Mo in the form of ribbons are provided in the crushed sealing portions 4a, 4b.
s is hermetically sealed, the electrodes 5a, 5b and 5s are provided on the inner side of the metal foils 41, 41 and 41s, and the external lead-in wire 42 made of molybdenum Mo wire or the like is provided on the outer side of the valve 40. 42 and 42s are connected by means such as welding and caulking.

The arc tube bulb 40 is filled with a predetermined amount of mercury, a metal halide, and an inert gas such as argon as a discharge medium. As the metal halide, halogen such as iodine I and bromine Br and at least one luminescent metal such as sodium Na, scandium Sc, and cesium Cs are encapsulated to improve characteristics such as luminous efficiency, color rendering and color temperature. I am measuring.

The shroud (transparent hollow tube) 6 is
It is made of translucent high-silica glass (quartz glass) and has a cylindrical shape with open upper and lower ends, and is arranged at a predetermined distance from the internal arc tube 4.

The support member 7a on the neck portion 13 side
Is a support wire which is fixed to the band member 72 wound around the glass tube 21 of the stem 2 by means such as fastening, or which does not have an external introduction wire different from the introduction wires 21 and 22 implanted in the stem 2. It may be supported by being fixed to the.

Support of the arc tube 4 and the shroud (hollow tube) 6 in the outer bulb 1 is performed by the outer bulb 1
Wires 7, such as molybdenum Mo, which are disposed on the top portion 12 and the neck portion 13 side of the above, or support members 7a, 7b formed by shaping a plate-like body into a substantially U-shape, and sealing portions 4a, 4
Band member 7 made of a strip-shaped metal plate with b positioned
The arc tube 4 is fixed by sandwiching the sealing portions 4a and 4b with 1, 71 and connecting them by means such as welding.

Further, the shroud (hollow tube) 6 is punched into a ring shape having substantially the same shape as the end surface of the shroud (hollow tube) 6, and holding plates 60 having standing pieces 61, ... The standing pieces 61, ... Are erected so as to suppress the end portion of the shroud (hollow tube) 6 from the outside or sandwich it from both sides of the inner and outer surfaces, and part of the standing pieces 61 ,. The members 71, 71 are fixed by being connected by means such as welding.

In this state, the arc tube 4 and the shroud (hollow tube) 6 are not completely supported, and metallic blade-shaped elastic members 73, 73 are provided on the side surface of the support member 7b. , 73 may also be provided on the support member 7a on the neck portion 13 side.) This elastic member 73,
73 elastically abuts on the inner peripheral surface of the top portion 12 of the bulb 1, and the arc tube 4 itself also functions as a main pillar and is supported so as to be on the central axis of the outer bulb 1.

The electrical connection inside the outer tube valve 1 has the circuit configuration shown in FIG. That is, the one lead wire 21 of the stem 2 is the power feed wire 74 and the external lead wire 42.
And the other lead wire 22 of the stem 2 is connected to the main electrode 5a via the lead wire 22 and the other lead wire 5b via the external lead wire 42. Connected with. A starting auxiliary circuit is connected in parallel with the upper and lower main electrodes 5a and 5b of the arc tube 4.

This start-up assisting circuit includes a starting lamp (glow starter) 81 for starting, a bimetal switch 82, and a resistor 8.
3 are connected in series, and the lighting tube 81 and the bimetal switch 82 are connected.
It is connected to the auxiliary electrode 5s through the current limiting resistor 84 from the connection portion with. In the figure, 88 is an AC power supply, and 89
Is a lighting circuit device having a ballast and the like, and these parts constitute a lighting circuit. In addition, the parts within the dotted line are parts sealed in the outer bulb 1 of the discharge lamp L.

Therefore, in this embodiment, the arc tube 4
The shroud (hollow tube) 6 is supported by the support members 7a and 7b to which no electric potential is applied.

The high-pressure metal vapor discharge lamp L shown in FIG. 1 is a metal halide lamp L having a double tube structure in which a light emitting tube 4 is housed in a BT type outer tube bulb 1 and is in a vertical, horizontal or inclined state. It is lit.

When this metal halide lamp L is mounted in a socket and energized from a power source 88 through a lighting circuit device 89, a starting auxiliary circuit such as a lighting tube 81 provided in the outer bulb 1 operates to cause the arc tube. A discharge is generated between one of the main electrodes 5a of No. 4 and the auxiliary electrode 5s provided in parallel with and adjacent to the main electrode 5a, and this discharge is caused by the kick voltage when the contact of the bimetal in the lighting tube 81 is opened. Is the left and right main electrodes 5
The discharge occurs between a and 5b, and the lamp L lights up and emits light.

When the lamp L continues to be turned on, heat (infrared) rays are emitted from the arc tube 4 in all directions together with visible light, and the discharge tube heats up the arc tube 4. In the case of this configuration, since the heat radiation is shielded by the shroud (hollow tube) 6 which is arranged close to and surrounding the arc tube 4, the arc tube bulb 40 further rises in temperature.

That is, this temperature rise is caused by the arc tube bulb 4
0 and the roots of the electrodes 5a and 5b at the inner end of the bulb 40 are also heated, so that the luminescent metal enclosed in the bulb 40 evaporates well to increase the vapor pressure and luminous efficiency and color rendering. be able to.

Further, this high-pressure metal vapor discharge lamp L is
Since the support members 7a and 7b supporting the arc tube 4 and the shroud (hollow tube) 6 are not used for electrical connection, no electric potential is applied, and power is not supplied to the main electrode 5b on the other end side of the arc tube 4. The power supply line 74 is a fine wire that is far away from the discharge lamp L. It is possible to prevent sodium ions and the like from coming out of the arc tube bulb 40 due to photoelectron action during lighting.
It does not lower the luminous efficiency of the device or raise the lamp voltage to shorten the life.

In the above embodiment, the arc tube 4 and the shroud (hollow tube) 6 are supported by the support members 7a and 7b which are not applied with electric potential. In the discharge lamp having a structure that does not come out, it does not matter even if the structure is such that the support members 7a and 7b are also used as conductors and a potential is applied.

Further, since the shroud (hollow tube) 6 is provided so as to surround the arc tube 4, the arc tube bulb 40 should be provided.
Even if the glass is broken and the glass pieces scatter, the stress can be prevented or mitigated to reduce the stress exerted on the outer pipe valve 1, and the outer pipe valve 1 can be prevented from being broken, which greatly contributes to safety.

Further, in order to increase the impact strength of the shroud (hollow tube) 6, a wire or mesh reinforcement made of inorganic fiber such as heat resistant ceramics is wound around the outer circumference. be able to. If the shroud (hollow tube) 6 is made relatively thin, the weight of the lamp L can be reduced.

FIG. 3 shows light emission when a current metal halide lamp R of a mercury lamp ballast-compatible type and a lamp L according to the present invention in which a shroud (hollow tube) 6 is provided in the current lamp are rated to be lit. It is a graph which compared each part temperature of a tube.

Each of the lamps R and L used as the samples had a rated lamp power of 700 W, and the total length of the lamp (outer bulb + base portion) was about 370 mm.
The total length is about 130 mm, the space between inner spaces is about 88 mm, the maximum outer diameter is about 29 mm, the distance between the electrode tips is about 65 mm, and about 43 mg of a halide containing Sc-Na-I-Br as a discharge medium, mercury About 90 mg and Ar
The arc tube 4 in which gas is sealed at about 2 kPa is sealed together with nitrogen gas at about 53 kPa. Further, the lamp L according to the present invention encloses the arc tube 4 and has a total length of about 98 mm and a wall thickness t of about 2.0 mm. A shroud (hollow tube) 6 having an inner diameter of about 41 mm is provided.

When these lamps R (dotted line) and L (solid line) are lit in a vertical state in an atmosphere at an ambient temperature of 25 ° C., as is clear from the graph (horizontal axis ... each part, vertical axis ... temperature), The invention lamp L was able to improve the luminous efficiency by about 5% at the maximum because the temperature inside the end portion of the arc tube 4 was increased by about 60 ° C. as compared with the current product.

According to the consideration of the inventors, the temperature of the arc tube bulb 40 increases as the gap between the outer diameter of the arc tube bulb 40 and the inner diameter of the shroud (hollow tube) 6 becomes smaller. Also, as the difference is large and the interval is wide, the temperature rise of the arc tube bulb 40 is small, but when the interval is an absolute value, the temperature rises depending on the lamp power, the arc tube bulb 40 diameter and the shroud (hollow tube) 6 diameter. The degree of change was not uniform.

Then, as a result of various examinations by the present inventors,
Outer diameter Bd of arc tube bulb 40 and shroud (hollow tube) 6
Of the arc tube bulb 40 by taking the ratio with the inner diameter Sd of
We have found a value that is invariable even if the diameter or shroud (hollow tube) 6 diameter changes.

That is, FIG. 4 shows the discharge lamp L shown in FIG.
FIG. 4 is an end view in which substantially the center of is cut in a direction orthogonal to the tube axis. The outer diameter B of the arc tube bulb 40 shown in FIG.
Ratio of d to inner diameter Sd of shroud (hollow tube) Bd /
It has been found that by regulating Sd, the heat retention can be made substantially constant even if the lamp power and the absolute value of the arc tube diameter change.

The graph shown in FIG. 5A shows the ratio Bd / Sd (horizontal axis) of the outer diameter Bd of the arc tube bulb 40 to the inner diameter Sd of the shroud (hollow tube) 6 for each rated lamp power. The luminous efficiency Lm / W (vertical axis) is compared. The solid line in the graph indicates a lamp having a rated lamp power of 700 W, and the dotted line indicates a lamp having a rated lamp power of 1000 W.

In the graph shown in FIG. 5B, the above ratio Bd / Sd (horizontal axis) is compared with the luminous flux maintenance factor% (vertical axis) after 1000 hours of lighting for each rated lamp power. The solid and dotted lines in the graph are the same as above.

From the graphs of FIGS. 5A and 5B, the ratio Bd / Sd of the outer diameter Bd of the arc tube bulb 40 to the inner diameter Sd of the shroud (hollow tube) 6 is 0.68 to 0.83. It has been found that the discharge lamp L that satisfies the luminous efficiency and the luminous flux maintenance factor can be obtained within the range. Also, in the discharge lamps of other lamp powers, almost the same results were obtained within the above ratio range.

If this ratio Bd / Sd is less than 0.68, the space between the arc tube bulb 40 and the shroud (hollow tube) 6 is too wide, and therefore the temperature rise in the coldest part of the arc tube bulb 40. The temperature is low and heat retention is not sufficient, and the desired light emission characteristics cannot be obtained.

When the ratio Bd / Sd exceeds 0.83, the distance between the arc tube bulb 40 and the shroud (hollow tube) 6 becomes narrow, and the temperature of the arc tube bulb 40 becomes too high, so that the lamp is burned. There is a problem such as a short life.

The ratio Bd / Sd is 0.68.
A predetermined light emission characteristic was obtained in the range of 0.83 to 0.83, but a range of about 0.70 to 0.80 is preferable in consideration of variations and the like. Needless to say, the shroud (hollow tube) 6 is provided irrespective of the above range, so that the shroud 6 can be prevented from scattering when the arc tube bulb 40 is damaged.

Further, in this type of high-pressure metal vapor discharge lamp, the luminous flux is lowered with the progress of lighting, and one of the causes thereof is the blackening of the arc tube bulb due to the consumption of the electrodes. As a countermeasure against blackening caused by the electrodes, it is effective to lower the electrode temperature, and it is possible to deal with it by changing the diameter and the number of turns of the electrode coil, but it is still insufficient.

One of the consumption of the electrodes is that the arc generated in the discharge space in the arc tube and the shaft diameter of the electrodes influence. When the diameter of the arc and the electrode shaft is small, the temperature locally rises at the contact portion and the electrode wear becomes active. Also, when the arc and the electrode shaft diameter are large, the temperature at the electrode tip becomes uniform,
It is possible to prevent a local temperature rise.

Therefore, it has been found that the electrode wear level is balanced between the electrodes located above and below when the discharge lamp is vertically lit by setting conditions.

For example, a starter including a starting tube for starting is provided, and the rated voltage is 100V or 200V and the secondary voltage is 1V.
At 30 V, in a 1000 W type mercury lamp ballast-compatible metal halide lamp, the upper electrode shaft diameter is about 1.8 m.
m, the lower electrode shaft diameter is about 1.4 mm, the distance between both electrode tips is about 80 mm, and a lamp with vertically asymmetrical electrodes is arranged, and the upper and lower electrode shaft diameter is about 1.8 mm, the distance between both electrodes is about 80 mm.
Was compared with a lamp having vertically symmetrical electrodes.

In the former lamp having vertically asymmetric electrodes, the arc is in contact with the entire electrodes, whereas in the latter lamp having vertically symmetrical electrodes, the contact portion between the arc and the electrodes is This is a point and a local temperature rise has occurred. Further, the luminous flux maintenance factor after lighting for 1000 hours was about 90% in the former lamp provided with vertically asymmetric electrodes, whereas it was about 80% in the lamp provided with vertically symmetrical electrodes.

Then, a pair of electrodes are arranged in the arc tube bulb so as to face each other with a distance a between the electrode tips, and the electrode shaft diameter on the upper side during lighting is u and the electrode shaft diameter on the lower side is d. If d
<U, 0.7 <d / u <0.8 is satisfied, and 0.
Within the range of 017 <d / a <u / a <0.023, it is possible to suppress the blackening of the arc tube when the lamp is lit, to provide a high-pressure metal vapor discharge lamp with a high luminous flux maintenance rate and a long life. I found that I could do it.

FIG. 6 is a vertical cross-sectional view showing the outline of an embodiment of a lighting fixture 9 for road lighting or the like equipped with the high pressure metal vapor discharge lamp L according to the present invention. Are denoted by the same reference numerals and description thereof will be omitted.

FIG. 6 is a longitudinal sectional view showing the outline of an embodiment of a lighting fixture 9 for high ceilings for sports facility lighting or the like equipped with the high pressure metal vapor discharge lamp L according to the present invention.

In FIG. 6, in the lighting apparatus 9, a socket 92 is attached to a base 91 which is a mounting portion for a ceiling surface and the like, and a guard 93 is provided to surround the socket 92. Then, at the lower end of the guard 93, a reflector 94 having a conical shape made of a metal plate or enamel and having a reflecting surface formed on the inner surface is fixed, and the base 3 of the discharge lamp L is attached to the socket 92. Holding and electrical connection are made.

In this embodiment, the base 91,
The guard 93, the reflective shade 94, and the like make up the instrument body. Further, the lamp lighting circuit device and the power switch (not shown) are provided in a place different from the main body of the device.

Such a lighting fixture 9 is attached, for example, to the ceiling surface of a sports facility with the opening side of the reflection shade 94 facing downward, and when the power switch is turned on, the discharge lamp L is inserted through the lighting circuit device and the socket. Is energized.

When the lamp L in the vertical state with the base 3 side up (base up) is turned on in the reflection shade 94, visible light from the lamp L is reflected by the reflection surface or directly. A predetermined illuminance is obtained by passing through the opening and irradiating the coat or the ground surface, which is the irradiation target.

Therefore, the lighting fixture 9 according to the embodiment of the present invention using the above-mentioned high-pressure metal vapor discharge lamp L is
The efficiency of light emission such as high luminous efficiency and high color rendering can be improved according to the ability of the lamp L, and safety can be improved. Therefore, it is possible to omit the means for preventing scattering such as windshield at the opening of the equipment. Lighting equipment can be provided.

The present invention is not limited to the above embodiment. For example, the attachment of the shroud (hollow tube) to the support member is not limited to the ring-shaped metal plate on which the upright pieces are formed, but an axial notch is provided at the end of the shroud (hollow tube), and this notch emits light. It may be performed by mounting the pipe on a band member for fixing the pipe.

Further, the lighting equipment according to the present invention is not limited to lighting a discharge lamp in a vertical state, but can of course be applied to a lighting equipment that lights in a horizontal or inclined state.

[0088]

According to the first aspect of the present invention, since the shroud (light-transmitting hollow tube) arranged close to and surrounding the arc tube blocks heat radiation from the arc tube, the arc tube bulb is provided. Heats up. This temperature rise also raises the entire bulb of the arc tube and the root of the electrode at the inner end of the bulb, so that the luminescent metal enclosed in the bulb evaporates well, increasing the vapor pressure and increasing the luminous efficiency and color rendering. It is possible to improve the light emitting characteristics such as properties.

In this high-pressure metal vapor discharge lamp, no electric potential is applied to the support member supporting the arc tube or shroud (hollow tube), and sodium ions and the like escape from the bulb of the arc tube due to photoelectron action during lighting. This prevents the discharge lamp from lowering the luminous efficiency and increasing the lamp voltage to shorten the life.

Further, even if the arc tube bulb is damaged by the shroud (hollow tube) and the glass pieces scatter, the shroud (hollow tube) prevents this or relaxes the impact to form an outer bulb. It is possible to provide a high-pressure metal vapor discharge lamp having various advantages such as reducing stress exerted, preventing damage to the outer bulb, and greatly contributing to safety.

According to the invention of claim 2, since the shroud (hollow tube) covers the inner end portion of the arc tube bulb, the inner end portion forming the coldest portion is kept warm so that the above-mentioned claim is achieved. The same effect as described in 1 is obtained.

According to the third aspect of the invention, by winding the reinforcing body, the strength can be increased and the weight of the lamp can be reduced even if the wall thickness of the shroud (hollow tube) is reduced.

According to the fourth and fifth aspects of the present invention, the arc tube and the shroud (hollow tube) are supported by the support member having no electric potential, so that sodium ions and the like can be removed from the bulb of the arc tube by photoelectron action during lighting. It is possible to provide a high-pressure metal vapor discharge lamp that can be prevented from coming out, and that can prevent the discharge lamp from lowering the luminous efficiency and from increasing the lamp voltage to shorten the life.

According to the invention of claim 6, since the high-pressure discharge lamp having the effects of claims 1 to 5 is incorporated, the temperature of the coldest part rises when the lamp is lit, and high emission characteristics are obtained. In addition, even if the arc tube bulb is damaged, it is possible to provide a highly safe lighting device that does not scatter glass fragments.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of a high-pressure metal vapor discharge lamp according to the present invention.

FIG. 2 is a schematic circuit diagram showing a lighting circuit of a high-pressure metal vapor discharge lamp according to the present invention.

FIG. 3 is a graph comparing the temperature of each part of the arc tube bulb when the high pressure metal vapor discharge lamp according to the present invention and the conventional high pressure metal vapor discharge lamp are lit.

FIG. 4 is an end view of the high-pressure metal vapor discharge lamp shown in FIG. 1, taken approximately in the center thereof in a direction orthogonal to the tube axis.

FIG. 5A is a ratio Bd / Sd (horizontal axis) of the outer diameter Bd of the arc tube bulb and the inner diameter Sd of the shroud (hollow tube).
And the luminous efficiency (vertical axis) in the same graph (b)
Is the ratio Bd / Sd (horizontal axis) of the outer diameter Bd of the arc tube bulb to the inner diameter Sd of the shroud (hollow tube), and lighting 1000
It is a graph which contrasted the luminous flux maintenance factor (vertical axis) after time.

FIG. 6 is a front view showing the outline of an embodiment of a lighting fixture according to the present invention.

[Explanation of symbols]

L: High-pressure metal vapor discharge lamp (metal halide lamp) 1: Outer tube valve 4: Arc tube 40: Arc tube bulb 4a, 4b: sealing part 5a, 5b: main electrode 6: Shroud (translucent hollow tube) 9: Lighting equipment

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 41/19 H05B 41/19 Y // F21Y 101: 00 F21Y 101: 00 (72) Inventor Hiroyuki Ogata Kanagawa 1-201 1-chome, Funakoshi-cho, Yokosuka-shi, Japan (72) Inventor, Satoshi Iwasawa 1-201 1-chome, Funakoshi-cho, Yokosuka-shi, Kanagawa Osram-Melco-Toshiba Lighting (72) ) Inventor Daisuke Takayama 4-3-1, Higashi-Shinagawa, Shinagawa-ku, Tokyo Inside Toshiba Litec Co., Ltd. (72) Inventor Takahito Kashiwagi 4-3-1, Higashi-Shinagawa, Shinagawa-ku, Tokyo Inside (72) Invention Makoto Hashimoto 4-3-1, Higashishinagawa, Shinagawa-ku, Tokyo Within Toshiba Litec Co., Ltd. (72) Inventor Toshihiko Kami 4-3-1, Higashi-Shinagawa, Shinagawa-ku, Tokyo F-term inside Toshiba Litec Co., Ltd. (reference) 3K014 AA01 CA00 DA05 3K083 AA07 AA15 AA45 BC03 BC34 BD09 BD16 BD25 CA31 CA32 CA33 5C015 QQ03 QQ06 QQ14 QQ34 QQ35 5C043 A03A02 A02 DD39

Claims (6)

[Claims] 1. An airtightly sealed outer tube bulb is provided with at least a pair of electrodes facing each other in an end portion of an arc tube bulb made of translucent high silica glass or translucent ceramic, and a discharge medium is internally provided. In a high-pressure metal vapor discharge lamp in which a cylindrical shroud made of a sealed arc tube and a heat-resistant translucent member surrounding the arc tube is supported by a support member that does not receive a potential during lighting, the glass wall thickness t of the shroud is A high pressure metal vapor discharge lamp having a relationship Bd / Sd of 0.68 to 0.83 between the maximum outer diameter Bd of the arc tube bulb and the inner diameter Sd of the shroud of 2.0 mm or less. 2. The high pressure metal vapor discharge lamp according to claim 1, wherein the shroud has a length that covers at least an inner end portion of the arc tube bulb. 3. The high pressure metal vapor discharge lamp according to claim 1, wherein a reinforcing body is wound around the outer periphery of the shroud. 4. The high-pressure metal vapor discharge lamp according to claim 1, wherein a halide is enclosed as a discharge medium. 5. A support circuit inside the outer bulb is provided with a starting circuit component connected to an electrode of the arc tube for energizing the arc tube with a high voltage at the time of starting. The high pressure metal vapor discharge lamp according to any one of 1. 6. A fixture main body; a high-pressure metal vapor discharge lamp according to any one of claims 1 to 5 disposed in the fixture main body; a lighting circuit device connected to the high-pressure metal vapor discharge lamp. And a light fixture.