JP2000106140A - High-pressure discharge lamp and high-pressure discharge lamp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp having superior starting ability and restarting ability and capable of restraining turning to white turbidity and devitrification of the discharge container, and to provide a high-pressure discharge lamp device using this lamp. SOLUTION: This high-pressure discharge lamp has a light transmissive discharge container 1 formed with a spherical discharge space 1a, a pair of electrodes 2, 3 sealed in the light transmissive discharge container, and the discharge medium including at least mercury and the rare gas and sealed inside of the discharge space of the light transmissive discharge container. This high- pressure discharge lamp also has a starting conductor 7 having the same electrical potential as with one electrode, to which mercury is adhered after extinguishing the lamp, and extended from the electrode along the discharge container so that the end thereof is positioned between a position opposite the electrode and a position opposite to the side surface of an opposite side electrode and provided in the discharge space, separated by a distance of 0.5-3 mm from the outer surface of the discharge container.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-pressure discharge lamp containing mercury as a discharge medium and a high-pressure discharge lamp device using the same.

[0002]

2. Description of the Related Art In recent years, floodlights, image display devices, and the like have become widespread, and high-pressure discharge lamps are often used as light sources. Among them, short arc type high pressure discharge lamps, such as metal halide discharge lamps, which are particularly close to point light sources and have easy light distribution control, are being diversified as light sources for liquid crystal projectors, which have been spreading remarkably recently. In addition, small metal halide discharge lamps are becoming popular as light sources for automobile headlights. Further, small and short arc type high pressure discharge lamps are also used as spotlights in store lighting and the like.

First, a conventional high-pressure discharge lamp for a liquid crystal projector will be described.

FIG. 12 is a front view showing a first conventional high-pressure discharge lamp for a liquid crystal projector.

In the figure, 101 is a discharge vessel, 102 is an anode, 103 is a cathode, 104 and 104 are molybdenum foils for sealing, 105 is an external lead wire, and 106 is a base. The discharge vessel 101 includes a discharge space portion 101a and a pair of sealing portions 101b and 101c extending from both ends thereof.
A sealing molybdenum foil 104 is hermetically embedded in each of the sealing portions 101b and 101c. And the discharge vessel 10
An appropriate amount of a discharge medium made of mercury, a rare gas, and a halide of a luminescent metal is sealed in the inside of one discharge space 101a. The anode 102 has its electrode shaft 102a inserted into the sealing portion 101b and is welded to one end of the sealing molybdenum foil 104. An external lead wire 105a is welded to the other end of the sealing molybdenum foil 104. The cathode 103 has its electrode shaft 103a similarly inserted into the other sealing portion 101c, and is welded to one end of the sealing molybdenum foil 104. The other end of the sealing molybdenum foil 104 has an external lead wire (not shown). Are welded,
Further, it is connected to the cathode terminal 106a of the base 106. The base 106 includes a cylindrical body 106 b made of stainless steel, and the cylindrical body 106 b is connected to the sealing portion 1 on the cathode side of the discharge vessel 101.
01c.

Next, a liquid crystal projector will be described. A liquid crystal projector is a device that projects an image formed on a liquid crystal screen, and can project both a still image and a moving image. Since a variety of images can be projected by inputting a video signal or an image signal of a personal computer, it can be used as a presentation tool, a simple theater or a large-screen TV. And are used in various fields. Particularly recently, rear projection TVs have been positioned as large-screen TVs. When a liquid crystal projector is used in the position of a TV, the same performance as that of a CRT TV is required. For example, life 1
After 0000 hours or more, it is required that the device be operated reliably after the switch is turned on, that an image be seen instantaneously, and that the device be restarted immediately after the switch is turned off by mistake.

[0007] Further, regarding the liquid crystal projector, a metal halide type ultra-high pressure discharge lamp is used because brightness and low cost are currently considered with priority. Furthermore, in order to obtain a high brightness, the ultra-high pressure discharge lamp reduces the internal pressure of the discharge vessel during lighting to, for example, 3
It is designed to be at least 0 atm. That is, although the thickness of the discharge vessel made of quartz glass is increased in thickness and safety design is performed by devising its shape, the discharge vessel may rupture during its life due to use conditions and deterioration over time. . If the discharge vessel ruptures, it may damage other optical components. Therefore, in the event that the high-pressure discharge lamp ruptures, a structure in which a reflector is integrated has been adopted in order to prevent fragments from scattering as much as possible or to facilitate maintenance such as optical position adjustment. I have. Further, a structure in which the opening surface of the reflecting mirror is covered with a glass protection plate is also employed.

Next, a metal halide discharge lamp for an automobile headlight will be described. In a metal halide high-pressure discharge lamp for an automobile headlight, it is first required that an instant start and an instant restart can be performed earlier than in a metal halide high-pressure discharge lamp for a liquid crystal projector. For this reason, about 5 atm of xenon is sealed at room temperature, and the vapor pressure of mercury sealed as a buffer medium during lighting becomes 20 atm or more.

As a high-pressure discharge lamp containing mercury in a discharge medium as a luminescent substance or a buffer medium, there is a mercury lamp in addition to the above-mentioned metal halide discharge lamp.
The former uses mercury as a buffer medium, while the latter uses it as a luminescent medium.

In any case, in these high-pressure discharge lamps, when turned off, the electrodes cool down faster than the inner surface of the discharge vessel, so that mercury condenses and adheres to the surfaces of the electrodes.

[0011] In a DC lighting type high pressure discharge lamp,
Since the cathode is smaller than the anode, it cools faster and therefore the mercury adheres intensively to the cathode. When mercury adheres to the electrode surface, the electron emission at the cathode is inhibited by the mercury, so that the startability and the restartability are reduced.

Further, when the high-pressure discharge lamp is surrounded by a reflector and a glass protective plate, or is disposed in an outer tube, the high-pressure discharge lamp is difficult to cool even when the lamp is turned off. In order to perform a restart under a high pressure, it is necessary to apply a starting voltage having a considerably large pulse energy between the electrodes.

[0013] However, if the pulse energy of the starting voltage is increased, not only is it difficult to insulate the lighting components and it becomes expensive, but also the radiation noise increases. A problem of malfunction occurs.

In order to improve the startability, Japanese Patent Laid-Open Publication No.
A configuration described in JP-A-61957 has been proposed. FIG. 13 is a front view showing a second conventional high-pressure discharge lamp having a structure similar to that described in JP-A-2-61957.

In the figure, the same parts as those in FIG.

In the second prior art, a starting conductor 107 having the same potential as that of the cathode 103 is attached to the sealing portion 101b on the cathode side, and once at the boundary between the discharge space portion 101a and the sealing portion 101c. After being wound, it is characterized by a structure in which it is wound along the discharge space 101a and the terminal is wound once at the boundary between the sealing portion 101b on the opposite side of the anode and the discharge space 101a.

FIG. 14 is a front view showing a third conventional high-pressure discharge lamp. In the figure, the same parts as those in FIG. In the third prior art, a conductor 108 having the same potential as the cathode 103 is attached to the sealing portion 101c on the cathode side, and the terminal is terminated at the discharge space 101a.
And a sealing portion 101c.

[0018]

According to the second and third prior arts, the starting voltage can be reduced as compared with the first prior art. However, none of them has been reduced to the desired degree.

Further, the second prior art and the third prior art are not significantly different from each other. In each of the prior arts described above, it is necessary to apply a large energy pulse voltage in order to restart for several tens of seconds after turning off the light. Thereafter, the required pulse energy gradually decreases. Furthermore, there is a region that requires a large pulse energy again for 3 to 5 minutes after the light is turned off.

In the second and third embodiments, since the starting conductor is in close contact with the discharge vessel, there is an inconvenience that, for example, a quartz bulb or the like constituting the discharge vessel is easily clouded or devitrified.

An object of the present invention is to provide a high-pressure discharge lamp having a simple structure, excellent in startability and re-startability, and capable of suppressing clouding or devitrification of a discharge vessel, and a high-pressure discharge lamp device using the same. With the goal.

[0022]

A high-pressure discharge lamp according to claim 1 comprises: a light-transmitting discharge vessel having a spherical discharge space; a pair of electrodes sealed inside the light-transmitting discharge vessel; A discharge medium containing at least mercury and a rare gas and sealed in the discharge space of the translucent discharge vessel; and having the same potential as one electrode to which mercury adheres after the light is turned off, and substantially along the discharge vessel from the electrode side Extending between the position facing the electrode or the position facing the side surface of the electrode on the opposite side, and the outer end of the discharge space between the electrode and the outer surface of the discharge vessel in the discharge space.
A starting conductor disposed at a distance of 5 to 3 mm.

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

The translucent discharge vessel is capable of extracting visible light in a desired wavelength range generated by discharge to the outside, and has fire resistance and airtightness enough to withstand a normal operating temperature of a high pressure discharge lamp. Made of any suitable material. For example, quartz glass, translucent alumina, ceramics such as YAG, or a single crystal thereof can be used. If necessary, it is permissible to form a halogen-resistant or metal-resistant transparent film on the inner surface of the translucent discharge vessel or to modify the inner surface.

The high-pressure discharge lamp of the present invention may be configured to be operated by either AC or DC. Therefore, the pair of electrodes have the same structure when operated by an alternating current, but generally have a larger mass and surface area than a cathode when operated by a direct current because the temperature of the anode is generally large.

The present invention may be of a short arc type or a long arc type. The short arc type refers to a so-called electrode stable type in which the arc discharge is stabilized by the electrodes by reducing the distance between the electrodes formed in the translucent discharge vessel. For this reason, the light emission of the high-pressure discharge lamp can be made as close as possible to the point light source,
Light collection by an optical system such as a reflecting mirror or a lens can be performed efficiently.

In the case of a high-pressure discharge lamp for projection such as a liquid crystal projector or a headlight of an automobile, a small, short arc-type metal halide high-pressure discharge lamp is used, but the distance between the electrodes is actually 6 mm or less. It is suitable.
That is, if the distance between the electrodes exceeds 6 mm, the distance from the point light source is increased, and the focus characteristic of the optical system is deteriorated. For example, when used for a liquid crystal projector, the screen illuminance is reduced. Therefore, in the present invention, the short arc type high pressure discharge lamp refers to a lamp having a distance between electrodes of 6 mm or less. Further, the thickness is preferably 4 mm or less, and most preferably 1 to 3 mm for projection of a liquid crystal projector or the like or for automobile headlights. The distance between the electrodes is measured between the tips of the electrodes.

On the other hand, a long arc type high pressure discharge lamp is
It is a so-called tube wall stable type in which an arc formed between the electrodes in the translucent discharge vessel is stabilized on the inner surface of the translucent discharge vessel.

The long arc type high pressure discharge lamp is widely used for general lighting and the like.

In the present invention, the discharge medium contains at least mercury. As described above, mercury adheres to the surface of the electrode after the light is turned off by condensation, thereby deteriorating startability and restartability. The present invention aims to solve such a problem. As a discharge medium, a rare gas is actually filled in addition to mercury. The noble gas acts as a starting gas and a buffer gas. Xenon, argon, krypton, or the like can be used as the rare gas. In the case of a metal halide discharge lamp, a metal halide of a luminescent metal is added to the discharge medium.

The starting conductor has the same potential as one of the electrodes as in the second and third prior arts, and has a configuration extending substantially along the translucent discharge vessel from the electrode side. But the end positions are different. That is, in the present invention, the end of the starting conductor faces the discharge space, and is located between the electrode and a position facing the side surface of the electrode or the opposite electrode. 0.5
It is a characteristic configuration to be separated by 3 mm or less.

Further, since the starting conductor functions to generate a glow discharge at the time of starting, the current flowing through the starting conductor is small, so that a thin metal wire can be used. Using a thin metal wire makes it difficult to absorb the visible light generated by the discharge, so that the effective light amount can be reduced and the light distribution can be prevented from being disturbed.

The operation of the present invention is as follows. When a starting voltage is applied between the pair of electrodes at the time of starting and restarting the high-pressure discharge lamp, first, a glow discharge occurs between the terminal portion of the starting conductor and the electrode on the opposite side. Since this glow discharge occurs at a position close to one of the pair of electrodes, the glow discharge is likely to shift to arc discharge between the pair of electrodes as the glow discharge spreads. Then, the high pressure discharge lamp is turned on.

Therefore, in the present invention, since the starting conductor effectively contributes to starting, startability and restartability are remarkably improved.

On the other hand, in the second prior art, the terminal end of the starting conductor extends to a position facing the electrode axis portion of the opposite electrode, and the terminal between the terminal end and the electrode axis. Is the shortest distance, a glow discharge first occurs between the terminal end of the starting conductor and the electrode axis. However, since the glow discharge region is separated from the pair of electrodes, it is difficult to shift to arc discharge between the electrodes. That is,
The start-up acceleration effect is surprisingly not sufficient.

In the third prior art, since the end of the conductor faces around the electrode axis of the electrode having the same potential, glow discharge hardly occurs. That is, the effect as the starting conductor is small. Furthermore, in these prior arts, since the discharge space in which the discharge medium is sealed is in close contact with the outer surface of the vessel, cloudiness or devitrification of the discharge vessel is easily induced.

According to a second aspect of the present invention, in the high-pressure discharge lamp according to the first aspect, the starting conductor has a terminal located at a position facing the space between the pair of electrodes.

According to the present invention, since the end of the starting conductor faces between the electrodes, the glow discharge generated between the end of the conductor and the electrode on the opposite side easily transitions to arc discharge between the electrodes. .

The end of the starting conductor may be located at any position between the electrodes.

A high pressure discharge lamp according to a third aspect of the present invention is the high pressure discharge lamp according to the first or second aspect, wherein the electrodes are:
The starting conductor is at the same potential as the cathode.

The present invention specifies a DC lighting high pressure discharge lamp. As described above, when mercury adheres to the surface of the cathode, the electron emissivity of the cathode decreases.However, a glow discharge occurs first between the starting conductor and the anode, and then a DC arc discharge between the cathode and the anode. , The startability and restartability are improved.

According to a fourth aspect of the present invention, there is provided a high-pressure discharge lamp device comprising:
A high-pressure discharge lamp according to any one of claims 1 to 3, further comprising: a concave reflector fixed integrally with the high-pressure discharge lamp and surrounding at least a light emitting portion of the high-pressure discharge lamp.

It is appropriate that the high-pressure discharge lamp and the concave reflecting mirror are fixed in a predetermined positional relationship by a fixing means such as an adhesive such as a die cement. However, if necessary, both can be integrally fixed in a detachable form. Further, the sealing portion of the discharge vessel can be used to fix the high-pressure discharge lamp to the concave reflecting mirror. Furthermore, the high-pressure discharge lamp does not have to be entirely surrounded by a concave reflector, for example, the sealing part of one electrode may project outside from the concave reflector. Furthermore, as the concave reflecting mirror, a mirror having glass or metal as a base can be used. In any configuration, for example, by employing a dichroic mirror having visible light reflection / heat ray transmission performance on the reflection surface, it is possible to reduce the projection of heat rays on the illuminated surface. A translucent front cover may be attached to close the opening of the concave reflecting mirror. In this case, the space between the translucent front cover and the concave reflecting mirror may be airtight, but may not be airtight. In order to fix the translucent front cover to the concave reflecting mirror, the translucent front cover may be adhered with a silicone adhesive or mechanically fixed with a metal frame. further,
By forming the visible light transmitting / heat ray reflecting film on the inner surface or the outer surface of the translucent front cover, the heat ray projected on the illuminated surface can be blocked. Furthermore, if necessary, a function of a color filter that transmits light in a specific wavelength range with respect to visible light satisfactorily can be provided. Thus, if the opening surface of the concave reflector is closed with the translucent front cover, even if the high-pressure discharge lamp ruptures, the translucent front cover can prevent the fragments from being scattered around. it can.
On the other hand, since the reflection mirror is closed by the translucent front cover, even if the high-pressure discharge lamp is turned off, it is difficult to cool down the lamp, so that it is generally difficult to restart the lamp. , It is possible to reliably restart with a lower restart voltage than before.

Thus, the high-pressure discharge lamp device of the present invention is suitable as a light source for a projection device such as a liquid crystal projector. However, it can also be adapted as a light source for spotlights and downlights.

[0045]

Embodiments of the present invention will be described below with reference to the drawings.

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

FIG. 2 is an enlarged front view, partly cut away and partly in section.

In the figure, 1 is a discharge vessel, 2 is an anode, 3
Is a cathode, 4a and 4b are a pair of sealing metal foils, 5a and 5b are external lead wires, 6 is a base, and 7 is a conductor. Discharge vessel 1
Is made of quartz glass, and comprises a discharge space 1a and a pair of sealing portions 1b, 1c. The discharge space 1a has a spherical shape.
More specifically, it has a spindle shape. One sealing part 1
b has a length of 23 mm and is integrally connected to both ends of the discharge space 1a. The other sealing portion 1c is 13 mm.

As a discharge medium, 40 kPa of argon and mercury are sealed in the discharge vessel 1.

The anode 2 is made of tungsten and has an anode main part 2a and an electrode shaft 2b. Anode main part 2a
Has a diameter of 2.6 mm and is supported at the tip of the electrode shaft 2b. The anode 2 is supported by the discharge vessel 1 with the base end of the electrode shaft 2b loosely inserted into the sealing portion 1b.

The cathode 3 is made of tungsten and has a cathode main portion 3a and an electrode shaft 3b. Cathode main part 3a
Is formed by shaping the tip of an electrode shaft 3b having a diameter of 0.7 mm into a pointed shape and winding a tungsten coil 3a1. Further, the cathode 3 is supported by the sealing portion 1c, like the anode 2.

The sealing metal foil 4a has a width of 3 mm and a length of 13 m.
m of molybdenum foil, one end of which has an electrode shaft 2b,
External lead wires 5a are welded to the other ends, respectively, and are hermetically buried inside the sealing portions 1b at both ends of the discharge vessel 1. Similarly, the sealing metal foil 4b has a width of 3 mm and a length of 10 mm
The electrode shaft 3b at one end and the external lead wire 5b at the other end.
Each is connected and buried in the sealing portion 1c.

The external lead wires 5a and 5b are led out from the sealing portions 1b and 1c of the discharge vessel 1. And
The external lead wire 5 b on the cathode side is connected to the base 6. The base 6 includes a cylindrical body 6a and a cathode terminal 6b. The cylindrical body 6a is made of stainless steel, and has one end fixed to the end of the sealing portion 1c with a base cement 8. The cathode terminal 6b protrudes from the other end of the cylindrical body 6a, and is connected to the external lead wire 5b via the stranded wire 9 in the cylindrical body 6a.

The starting conductor 7 is made of a metal wire of an aluminum-chromium alloy, and the base end 7a is wound around the welded portion of the external lead wire 5b and the stranded wire 9 on the cathode side, so that the starting conductor 7 Connected to make same potential as cathode.

The intermediate portion of the starting conductor 7 is the sealing portion 1
c, is fixed to the light-transmitting discharge vessel 1 by being wound once at the boundary between the sealing portion 1c and the discharge space 1a, and then along the discharge space 1a. It is curved. Then, the terminal end 7 b of the starting conductor 7 reaches between the cathode 3 and the anode 2. Further, as shown by the symbol L in the drawing, the outer surface of the container of the spherical discharge space 1a and the starting conductor 7 are arranged so as to be separated by about 2 mm.

FIG. 3 is a front view showing a second embodiment of the high-pressure discharge lamp of the present invention.

FIG. 4 is a front view showing the third embodiment.

In each figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The second embodiment shown in FIG. 3 is different in that the end 7 b of the starting conductor 7 is located at a position facing the cathode 3.

The third embodiment shown in FIG. 4 differs from the third embodiment in that the terminal 7 b of the conductor 7 is located at a position facing the anode 2.

FIG. 5 is a partial sectional front view showing a first embodiment of the high-pressure discharge lamp device of the present invention. In the figure, the same parts as those in FIG. DL is a high-pressure discharge lamp, and 11 is a reflecting mirror.

In the high-pressure discharge lamp DL, the shape of the discharge space of the discharge vessel 1 is elliptical sphere, but the other structure is shown in FIG.
This is almost the same as shown in FIG. The concave reflecting mirror 11 includes a glass base 11a having a concave inner surface, a visible light reflecting / heat ray transmitting film 11b, and a cylindrical portion 11c. Glass substrate 11a
Is formed such that a concave portion on the inner surface is formed into a curved surface based on a paraboloid of revolution, and a cylindrical portion 11c is integrally protruded outside the top. The visible light reflection / heat ray transmission film 11b is formed of a dichroic reflection film.

To attach the high-pressure discharge lamp DL to the concave reflecting mirror 11, the base 6 is inserted into the cylindrical portion 11 c, and the emission center of the high-pressure discharge lamp DL is made to coincide with the focal point of the concave reflecting mirror 11. Between the base and the cylindrical portion 11c
To fix both. The conducting wire 13 is welded to the external lead wire 5a on the anode 2 side of the high-pressure discharge lamp DL and led out from the opening end of the concave reflecting mirror 11. Therefore, if the DC output terminal of the lighting device (not shown) is connected between the starting conductor 13 and the cathode terminal 6b, the high-pressure discharge lamp D
L can be turned on. The light beam generated from the high-pressure discharge lamp DL is incident on the visible light reflection / heat ray reflection film 11 of the reflecting mirror 11, and the visible light is reflected and emitted parallel to the optical axis. On the other hand, the heat rays pass through the visible light reflection / heat ray transmitting film 11b, further pass through the glass substrate 11a, and are radiated to the back side of the reflecting mirror 11.

FIG. 6 is a partially sectional front view showing a second embodiment of the high-pressure discharge lamp device of the present invention. In the figure, the same parts as those in FIG. This embodiment is different in that a translucent front cover 14 is provided at the opening end of the concave reflecting mirror 11. The translucent front cover 14 is made of glass, and is adhered to the open end of the concave reflecting mirror 11 with a silicone adhesive 15. The conductive wire 13 on the anode side is led out from between the open end of the concave reflecting mirror 11 and the translucent front cover 14.

FIG. 7 is a graph showing restart characteristics of the high-pressure discharge lamp device according to the second embodiment of the present invention together with those of the comparative example. In the figure, the horizontal axis indicates the restart time (second), and the vertical axis indicates the restart voltage (kV). The comparative example is a high-pressure discharge lamp device having the same specifications as the present embodiment except that the conductor 108 of the high-pressure discharge lamp has the same structure as that of the third conventional technique shown in FIG. Curve A
Indicates the restart characteristic of the present embodiment. Curve B shows the restart characteristic of the comparative example. As is clear from the figure, in the present embodiment, the restart voltage is less than half of the third conventional technique. It is 20 kV or less even at the highest. In addition,
The reason why the curve is divided in the comparative example of the curve B is that there is a time zone in which the restart voltage becomes 30 kV or more, but the measurement is not performed because the starting power supply can output only up to 30 kV.

FIG. 8 is a graph connecting each embodiment of the high-pressure discharge lamp of the present invention and the restart voltage in the prior art. In the figure, the horizontal axis represents each embodiment and the related art, and the vertical axis represents the restart voltage (kV). That is, 1 on the horizontal axis is the first prior art shown in FIG. 12, 2 is the third prior art shown in FIG. 14, 3 is the second embodiment of the present invention, 4 is the third embodiment, and 5 is the same. Also shows the third embodiment, and 6 shows the second prior art shown in FIG. 13, respectively, and the vertical axis shows these in the high-pressure discharge lamp device shown in FIG. is there. The restart voltage was measured by fixing each high-pressure discharge lamp in the concave reflecting mirror and the translucent front cover shown in FIG.

As is apparent from the figure, each embodiment of the present invention has a significantly lower restart voltage as compared with each prior art.

FIG. 9 is a conceptual diagram showing an optical system of a liquid crystal projector to which the high-pressure discharge lamp device of the present invention is applied.
In the figure, 21 is a high-pressure discharge lamp device, 22 is a reflecting mirror for changing the optical path, 23 is a UV-IR filter, 24 and 25 are polarizing plates, 26 is a liquid crystal display plate, 27 is a Fresnel lens, 2
8 is a projection lens and 29 is a screen. The high-pressure discharge lamp device 23 has substantially the same configuration as that shown in FIG.

FIG. 10 shows a fourth embodiment of the high-pressure discharge lamp according to the present invention.
1 is a front view showing a high-pressure discharge lamp for a vehicle headlight as an embodiment of the present invention. In the figure, 31 is an arc tube,
32 is an outer tube and 33 is a base. The arc tube 31 includes a discharge vessel 31a, a pair of electrodes 31b, 31b, a sealing metal foil 31.
c, 31c, conductor 31d, external lead wires 31e, 31f
And an insulating tube 31g. Discharge vessel 31
a is a spherical discharge space portion 31a1 and a pair of sealing portions 3;
1a2 and 31a3 are provided. A pair of electrodes 31b, 3
1b has the same structure and corresponds to AC lighting. The electrodes 31b and the external lead wires 31e and 31f are connected to both ends of the sealing metal foil 31c, and are hermetically embedded in the sealing portion 31a2. The conductor 31d has the same structure as that of FIG. External lead wire 3 led out to the base
1 e is directly introduced into the base 33. The external lead wire 31f led out to the opposite side of the base 33 is folded, covered with an insulating tube 31g, and introduced into the base 33.

The outer tube 32 has a cylindrical portion 32a in the middle and reduced diameter portions 32b, 32b at both ends. Cylindrical part 32
a mainly surrounds the discharge space portion 31a1. The reduced diameter portion 32b is bonded to the sealing portions 31a2, 31a3 with a silicone adhesive. The base 33 is connected to the discharge vessel 31a.
Is supported by one sealing portion 31a1, and the external lead wire 31
e and 31f are connected to a base terminal (not shown) and can be attached to an automobile headlight (not shown).

FIG. 11 is a perspective view showing an automobile headlight to which the high-pressure discharge lamp of the present invention is applied. In the figure, 41 is a reflecting mirror and 42 is a front lens. Reflector 4
1 is configured such that the high-pressure discharge lamp shown in FIG.

[0071]

According to the first to third aspects of the present invention, the starting conductor having the same potential as one of the electrodes to which mercury adheres after the light is turned off extends along the discharge vessel, and the terminal having the same potential as the terminal ends. Glow discharge generated between the starting conductor and the electrode on the opposite side shifts to arc discharge between the pair of electrodes by being located between the position facing the electrode and the position facing the side surface of the opposite electrode. Therefore, it is possible to provide a high-pressure discharge lamp having improved startability and restartability. Furthermore, since the starting conductor is arranged so as to be separated from the spherical portion of the discharge vessel forming the discharge space within a small range of 0.5 to 3 mm, it is possible to improve the startability and to make the discharge vessel white or cloudy. Devitrification can be suppressed.

According to the second aspect of the present invention, in addition, since the end of the conductor is located at a position facing between the pair of electrodes, it is possible to provide a high-pressure discharge lamp having optimum starting and restarting properties. .

According to the third aspect of the present invention, in addition, the electrode is composed of a cathode and an anode, and the starting conductor is set to the same potential as the cathode, so that it is possible to provide a DC lighting high pressure discharge lamp.

According to the fourth aspect of the present invention, it is possible to provide a high-pressure discharge lamp device having the concave reflecting mirror fixed integrally with the high-pressure discharge lamp and having the effects of the first to third aspects.

[Brief description of the drawings]

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

FIG. 2 is an enlarged front view, partially cut away and partially sectioned,

FIG. 3 is a front view showing a second embodiment of the high-pressure discharge lamp of the present invention.

FIG. 4 is a front view showing a third embodiment of the high-pressure discharge lamp of the present invention.

FIG. 5 is a partially sectional front view showing a first embodiment of the high-pressure discharge lamp device of the present invention.

FIG. 6 is a partial sectional front view showing a second embodiment of the high-pressure discharge lamp device of the present invention.

FIG. 7 is a graph showing restart characteristics of the high-pressure discharge lamp device according to the second embodiment of the present invention together with those of the comparative example.

FIG. 8 is a graph connecting the embodiments of the high-pressure discharge lamp of the present invention and the restart voltage in the prior art.

FIG. 9 is a conceptual diagram showing an optical system of a liquid crystal projector to which the high-pressure discharge lamp device of the present invention is applied.

FIG. 10 is a front view showing a high-pressure discharge lamp for an automobile headlight to which the high-pressure discharge lamp of the present invention is applied.

FIG. 11 is a perspective view showing an automobile headlight to which the high-pressure discharge lamp device of the present invention is applied.

FIG. 12 is a front view showing a first conventional high-pressure discharge lamp for a liquid crystal projector.

FIG. 13 is a front view showing a second conventional high-pressure discharge lamp having a structure similar to that described in JP-A-2-61957.

FIG. 14 is a front view showing a third conventional high-pressure discharge lamp.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Discharge container 1a ... Discharge space part 1b ... Sealing part 1c ... Sealing part 2 ... Anode 2a ... Anode main part 2b ... Electrode axis 3 ... Cathode 3a ... Cathode main part 3b ... Electrode axis 4a ... Sealing metal foil 4b ... Seal metal foil 5 ... External lead wire 6 ... Base 6a ... Insulating cylinder 6b ... Cathode terminal 7 ... Starting conductor

Claims (4)

[Claims] 1. A translucent discharge vessel having a spherical discharge space formed therein; a pair of electrodes sealed inside the translucent discharge vessel; and a translucent discharge containing at least mercury and a rare gas. A discharge medium sealed in the discharge space of the container; a position which has the same potential as one of the electrodes to which mercury adheres after the light is turned off, extends substantially along the discharge container from the electrode side, and has a terminal end facing the electrode Or a starting conductor disposed between the position facing the side surface of the opposite electrode and spaced from the outer surface of the discharge vessel in the discharge space by 0.5 to 3 mm. High pressure discharge lamp. 2. The high-pressure discharge lamp according to claim 1, wherein the starting end of the starting conductor is located at a position facing between the pair of electrodes. 3. The high-pressure discharge lamp according to claim 1, wherein the electrode comprises a cathode and an anode; and the starting conductor has the same potential as the cathode. 4. A high-pressure discharge lamp according to claim 1, further comprising a concave reflector fixed integrally with the high-pressure discharge lamp and surrounding at least a light-emitting portion of the high-pressure discharge lamp. A high-pressure discharge lamp device characterized by the above-mentioned.