JPH11162406A - High pressure discharge lamp, projecting device, and projector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the fusion of metal foil and the leak or break of a sealed tube part by arranging a translucent container made of quartz glass having a swelled part for forming a luminescent space and a sealing tube part extending to both ends from the swelled part, and metal foil, a lead rod, and a metal piece airtightly sealed on the inside. SOLUTION: A lead-in conductor within a sealed tube part 12 has metal foil 3M made of ribbon-shaped molybdenum, an inner lead rod 3A serving as an electrode rod, made of tungsten welded or crimped to one end of the metal foil 3M, and an outer lead rod 3B similar to the inner lead rod 3A at the other end. A metal piece 5 made of a ribbon-shaped molybdenum is flatly bent in the crossing direction to the outer lead rod 3B and connected to the portion near to the connecting part to the metal foil 3M of each of the outer lead rods 3B, 3B. Heat capacity of the outer lead rods 3B, 3B is increased, heat storage amount is increased, heat is radiated even from the wing-like enlarged metal pieces 5, 5 to the glass side, and the heat radiating amount is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an introduction conductor which uses quartz glass as a light-transmitting container, and particularly is located at a sealing tube portion of a high pressure discharge lamp having a high tube wall load, and a projection using the discharge lamp. The present invention relates to an optical device and a projector device equipped with the light projecting device.

[0002]

2. Description of the Related Art Short arc metal halide lamps,
2. Description of the Related Art High-pressure discharge lamps such as ultra-high pressure mercury lamps and xenon lamps are widely used in various fields such as photochemistry, semiconductor manufacturing, and imaging, as compact light sources having only an arc tube without an outer tube.

In these high-pressure discharge lamps, quartz glass is used in a light-transmitting container in consideration of heat resistance, pressure resistance and corrosion resistance. The lamp is sealed in a sealing tube portion for maintaining airtightness with quartz glass, and an introduction body using a metal foil made of a ribbon-like molybdenum foil having a thickness of 20 to 30 μm is sealed. . Also, an internal lead rod (electrode rod) made of molybdenum Mo or tungsten W is provided at one end of the metal foil.
However, an external lead rod made of molybdenum Mo is connected to the other end by means such as welding or caulking.
The internal conductor (electrode bar) and the external conductor are composed of the lead conductor. Further, a discharge electrode is provided at the tip of the inner lead rod, and the outer lead rod is connected to a lead wire, a base, and a terminal pin after exhausting the inside of the translucent container.

[0004] Then, a metal foil portion in the sealing tube portion,
The tips of the internal lead rod (electrode rod) and the external lead rod connected to this metal foil are buried in the glass, but the internal lead rod (electrode rod) and the external lead rod excluding the thin metal foil part Very small but voids are formed around the buried part of the surface of the inner lead rod (electrode rod) and the outer lead rod from the end of the sealing tube to the metal foil, The air enters the gap. This is due to the difference in thermal expansion coefficient between the quartz glass and the inner lead rod (electrode rod) and the outer lead rod.
The gap also progresses due to expansion and contraction due to the thermal shock of the blinking of the lamp, and it is practically impossible to prevent the formation of this gap.

When the high-pressure discharge lamp such as the metal halide lamp is turned on, most of the external lead rod connected to the discharge electrode which has the highest temperature faces the atmosphere and conducts and radiates heat and flows. It is in a high temperature state of about 350 to 400 ° C. depending on the electric current.

For this reason, the outer lead rods, although made of molybdenum, are gradually oxidized by oxygen in the atmosphere from the portion led out of the sealing tube portion, and this oxidation is embedded in the sealing tube portion. To the metal foil portion to which the external lead bar is connected.

When the oxidation reaches the inside of the external lead rod or the metal foil, the electric resistance increases, the temperature of this portion rises, stress is applied, or the lamp peels off from the glass. Eventually, the external lead rods and metal foil will be melted or the sealing tube will be broken and the airtightness of the container will not be maintained. was there.

Recently, in liquid crystal projectors and the like, there has been a demand for an increase in the light output from the device and a reduction in the size thereof. However, when the lamp is miniaturized, there is a problem that the wall load increases and the temperature of the lamp further increases.

In order to prevent the external lead rod from being oxidized in the sealing tube, various means have been tried.
Has been implemented. For example, it is known that a portion of an end face of a sealing tube from which an external lead rod is led out is covered with frit glass. However, this means not only requires time and effort to coat the frit glass, but in the case of low-melting glass, the molten glass may flow into the socket and cause poor conduction.

Further, as another means, for example, as described in Japanese Patent Publication No. 2-267850, performing a treatment for preventing oxidation on the metal foil itself or the external lead rod itself is disclosed. That is, this is achieved by embedding a substance made of chromium, aluminum, silicon, titanium, tantalum, palladium or the like by ion implantation into the metal foil itself made of molybdenum Mo or the external lead rod itself. In this case, the oxidation is performed by preventing the dissolution of the foil surface, but the antioxidant layer is formed by a method that requires labor such as PECVD.

[0011]

SUMMARY OF THE INVENTION The inventor of the present invention covers the end of the above-mentioned sealing tube portion where the external lead rod is led out with frit glass, or forms an antioxidant layer on the metal foil or the external lead rod itself. In such a case, there is a risk that the formation thereof takes time or the function may be deteriorated such as peeling during lighting, and therefore, an oxidation preventing means from another viewpoint was studied.

[0012] Fundamentally, it has been found that by lowering the temperature of the external lead rod itself exposed to the atmosphere, the oxidation of the external lead rod and metal foil such as molybdenum foil is prevented, and as a result of various studies. Thus, the present invention has been completed.

As a known example similar to the present invention, there is Japanese Utility Model Laid-Open No. 3-24250. In this publication, a plurality of molybdenum foil disks extending in a direction perpendicular to this axis are fitted and connected to the axis of a rod-shaped electrode (inner conductor) connected to a metal foil. The disk dissipates thermal energy due to the temperature rise of the electrodes, thereby suppressing distortion of the sealing tube portion and preventing cracks in the sealing tube portion. That is, the thermal distortion of the sealing tube portion is absorbed by bending the molybdenum foil disk.

Further, although a molybdenum foil disk is also used for the conductive metal body forming the external lead rod, it is described that it has nothing to do with the rod-shaped electrode (inner conductor) side.

In view of the above circumstances, the present invention has been made in response to recent demands for higher output and smaller lamps. Then, the mechanism to prevent the oxidation of the external lead rod of the high-load lamp by a mechanism different from that described above,
A high-pressure discharge lamp capable of preventing fusing of the external lead bar or metal foil or leakage or destruction of the sealing tube portion due to oxidation of the external lead bar constituting the introducing conductor, a floodlight device using the discharge lamp, and It is an object to provide a projector device equipped with the light projecting device.

[0016]

According to a first aspect of the present invention, there is provided a high-pressure discharge lamp made of quartz glass having a bulging portion forming a light emitting space and sealing tube portions extending to both ends thereof. A container and a metal foil hermetically sealed in a sealing tube portion,
An internal lead rod connected to one end of the metal foil and provided with an electrode at the tip of the side protruding into the bulging portion; and an external lead rod connected to the other end of the metal foil and led out of the sealing tube. And a metal piece connected to the external lead rod and embedded in the sealing tube portion, and a discharge medium sealed in the translucent container.

When the high-pressure discharge lamp is energized, a discharge is generated between the two electrodes to emit light, and the temperature of the external lead rod also rises due to conduction heat from the electrodes, radiant heat of the discharge, and flowing current. However, a metal piece is connected and buried in the sealing tube portion near the connection portion of the external lead rod with the metal foil, and the external lead rod has a large heat storage capacity and a large heat storage amount, and has a wing shape. The heat can be dissipated from the expanded metal piece to the glass side, and the amount of heat dissipated is large, and the temperature rise of the external lead rod can be reduced as compared with the conventional case.

Since the above-mentioned metal pieces are buried in quartz glass, the material is not air-tightly bonded to quartz glass but is familiar, but it is molybdenum Mo, tungsten W, platinum P
t, tantalum Ta, etc. are good, and are used in a foil plate shape or a linear shape.

Since the temperature of the electrode may be higher at the anode electrode than at the cathode electrode, a metal piece may be provided only at the anode electrode.

The present invention is also applicable to high-pressure discharge lamps such as short arc metal halide lamps, ultra-high pressure mercury lamps and xenon lamps, and ultra-high pressure discharge lamps using a translucent vessel made of quartz glass.

In the present invention, the end of the quartz glass translucent container is referred to as a sealing tube. However, this sealing tube may be formed integrally with the bulging portion. It may be integrated afterwards by bonding.

A high pressure discharge lamp according to a second aspect of the present invention is characterized in that the tube wall load (lamp power / surface area of the bulging portion of the light-transmitting container) is 25 to 200 W / cm ² .

The present invention is applied to a high-output, miniaturized lamp having a high tube wall load W / cm ² , and has the same effect as that of the first aspect.

According to a third aspect of the present invention, there is provided the light projecting device according to the first or second aspect, wherein the reflecting device is disposed so as to face the reflecting mirror.
And a high-pressure discharge lamp according to (1).

A light projecting device in which the high-pressure discharge lamp is incorporated in a reflecting mirror has the same effect as that of the first or second aspect.

The light projecting device of the present invention can be applied to a spotlight for illumination and the like. Further, the emitted light can emit light in a wide wavelength range from the ultraviolet region to the infrared region as well as the visible light region. Further, a lens, a protective cover, and the like may be provided on the front surface of the reflecting mirror.

According to a fourth aspect of the present invention, there is provided a projector device according to the third aspect, an optical system lens disposed in front of a reflecting mirror of the light projecting device, and a light emitting device. A display screen is provided between the reflecting mirror and the optical system lens.

[0028] The projector device provided with the light projecting device having the function of the third aspect of the present invention has high reliability as a device.

Further, the projector device of the present invention is applicable not only to a liquid crystal display screen but also to light irradiation in many fields such as photochemistry, semiconductor production, and imaging.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a short metal halide lamp L as a high-pressure discharge lamp according to the present invention, FIG. 1 is a partially sectional front view, FIG. 2 is an enlarged sectional front view of a sealed tube portion at a lamp end in FIG. FIG. 3 is a view taken along arrow A- in FIG.
It is a cross-sectional view of the part cut | disconnected along the A line.

In the figure, reference numeral 1 denotes a substantially elliptical light-transmitting container made of quartz glass, and a bulging portion 1 forming a light emitting space in the center.
1 and sealing tube portions 12 extending from both ends thereof. Into the sealing tube portions 12, lead-in conductors 2 and 2 are sealed.

Each of the introduction conductors 2 and 2 is made of a metal foil 3M made of ribbon-shaped molybdenum Mo and a tungsten W welded or crimped to one end of the metal foil 3M.
And an external lead rod 3B made of tungsten W or molybdenum Mo welded or crimped to the other end side. And the metal foils 3M, 3
The M portion is inside the sealing tube portions 12 and 12 and the sealing tube portion 1
A hermetically sealed structure is buried by crushing 2,12.

An electrode 4A constituting the anode is provided at the tip of one internal lead bar 3A, and an electrode 4C constituting the cathode is provided at the tip of the other internal lead bar 3A (in this case, the internal lead bar 3A). Also serves as an electrode.)
They are arranged facing each other at a predetermined discharge interval.
Also, at a portion near the connection of the external lead rods 3B, 3B to the metal foil 3M, a metal piece 5 made of, for example, molybdenum Mo in a ribbon shape is folded flat in a direction intersecting with the external lead rod 3B. It is bent and connected by means such as welding.

A predetermined amount of mercury, a metal halide and an inert gas such as argon are sealed as a discharge medium in the bulging portion 2 forming the light emitting space. Examples of the metal halide include halogens such as iodine and bromine, dysprosium Dy, holmium Ho, and thulium T.
A rare earth metal such as m is encapsulated to improve characteristics such as luminous efficiency and color temperature.

When the short metal halide lamp L having the above configuration is energized via a lighting circuit, both electrodes 4A,
Discharge occurs between 4C and emits light. The temperature of the external lead rods 3B, 3B also increases due to the conduction heat from the electrodes 4A, 4C, the radiation heat of the discharge, and the flowing current.

However, metal pieces 5, 5 are connected and buried in the sealing tube portions 12, 12 near the connecting portions of the external lead rods 3B, 3B with the metal foils 3M, 3M. 3B, 3B has an increased heat capacity and a large amount of heat storage, and can also radiate heat from the metal pieces 5 and 5 spread in a wing shape to the glass side, thereby increasing the amount of heat radiation.

Therefore, according to the product of the present invention, the external lead rods 3B, 3B have a larger heat capacity and a larger heat radiation area than the conventional product, and can reduce the temperature that rises as compared with the conventional product. Oxidization of the surface can be prevented or reduced even when the external lead rods 3B, 3B
Of the introduction conductor 2 and destruction of the sealing tube portion 12 caused by oxidation of the sealing tube 12 can be prevented from being short-lived.

The shape and connection method of the metal piece 5 to be connected to the external lead bar 3B are not limited to the above-described embodiment, and various forms are possible. You can do that.

FIGS. 4A to 4C show external lead rods 3B.
The other form of the metal piece 5 connected to FIG. FIG. 4 (a)
A plurality of linear tantalum Ta wires are welded to the external lead rod 3B as metal pieces 5 so as to intersect with the lead rod 3B. In FIG. 4B, a flat molybdenum Mo foil is welded to the external lead rod 3B as a metal piece 5 so as to intersect with the lead rod 3B. In FIG. 4C, a plurality of (2 to 10) flat molybdenum Mo foils are intersected with the external lead rod 3B and welded as a metal piece 5 by stacking a plurality of (2 to 10) flat molybdenum Mo foils.

In Table 1, the emission characteristics and the temperature of the end surface of the sealed tube portion 12 where the external lead rod 3B is located when the various metal pieces 5 were connected to the external lead rod 3B were measured with a thermocouple. The results are shown in correspondence with the conventional product.

As a measurement sample, a short metal halide lamp of the same type except for the metal piece 5 was used.

[0042]

[Table 1] As is clear from Table 1, the product of the present invention in which the metal piece 5 is connected to the external lead rod 3B can lower the temperature of the external lead rod 3B by 231 to 64 ° C. as compared with the conventional product (one without the metal piece 5). It was confirmed that it was effective.

Further, there is a difference in temperature reduction depending on the form of the metal piece 5, and the metal piece 5 may be appropriately selected in consideration of the type and size of the lamp.

FIG. 5 is a partial sectional front view showing an embodiment of a light projecting device D of the present invention incorporating the short metal halide lamp L. In FIG. 5, the same parts as those in FIGS. The same reference numerals are given and the description is omitted.

In FIG. 5, reference numeral 6 denotes an external lead rod 3B attached to one sealing tube 12 of the translucent container 1 of the lamp L.
A base provided with a terminal portion 61 connected to the power supply device 62, a lead wire 62 connected to the other external lead bar 3 </ b> B, and the terminal portion 61 and the lead wire 62 connected to the lighting power supply device 8 via feed lines 63 and 64. I have.

Reference numeral 7 denotes a reflecting mirror formed of a material such as glass or metal, and has a light reflecting curved surface 71 that forms a quadratic curved surface such as a paraboloid of revolution or an ellipsoid of revolution. A base cylindrical portion 72 for fixing the base 6 of the short metal halide lamp L is integrally provided with a projection. The base 6 of the lamp L and the sealing tube 12 are inserted into the base cylindrical portion 72, and are fixedly joined with a heat-resistant adhesive 73 mainly composed of silica and alumina.

Further, 74 is an optical interference film or a chromium dichroic film or the like formed on the light reflective curved surface 71, aluminum, the total light reflection film such as silver, wherein the titanium oxide TiO ₂
This is a visible light transmitting infrared reflection film in which a high refractive index layer made of and a low refractive index layer made of silicon oxide SiO ₂ are alternately formed in multiple layers.

In the light projecting device D having such a configuration, when the short metal halide lamp L is turned on by supplying electricity from the lighting power supply device 8, light from the lamp L is partially direct and partially visible light. Visible light enters the transmitted infrared reflecting film 74 and becomes reflected light, which is emitted to the front of the reflecting mirror 7. In addition,
The infrared light incident on the visible light transmitting infrared reflecting film 74 passes through the reflecting film 74 and the reflecting mirror 7 and is emitted to the rear of the reflecting mirror 7, and visible light with less heat rays can be emitted in front of the reflecting mirror 7. Further, a lens, a protective cover, and the like may be provided on the front surface of the reflecting mirror.

The short metal halide lamp L attached to the reflecting mirror 7 also has the metal piece 5 connected to the external lead rod 3B, so that the external lead rod 3B
Temperature rise can be suppressed, so that even if oxidation does not occur, the temperature is light and short life can be prevented. Therefore, it is possible to provide the light emitting device D having the same operation and effect as described above.

FIGS. 6A and 6B show another embodiment of the base 6 attached to one sealing tube portion 12 of the translucent container 1 of the lamp L. FIG. 6A is an exploded view. The perspective view and FIG. (B) are taken along the line BB in FIG.
FIG. 7 is a cross-sectional view of a cut portion (showing a state after a cylindrical body 66 of a base 6 is put on a sealing tube portion 12). This FIG.
In the base 6 shown in FIGS. 7A and 7B, slits 67 are formed on a part of a metal cylindrical body 66, and a terminal portion 68 having a screw portion and a nut is provided on a cylindrical or cylindrical surface at an end portion. It is. The base 6 has the slits 67 of the cylindrical body 66 mounted so as to sandwich the upper and lower sealing surfaces of the sealing tube portion 12 and is fixed via an adhesive (not shown), and the terminals are fixed. The external lead rod 3B is connected to the portion 68.

In this embodiment, the diagonal length of the sealing tube 12 is substantially equal to the inner diameter of the cylindrical body 66 and the outer diameter of the cylindrical body 66 is reduced as shown in the bottom view of FIG. it can. In other words, the fact that the outer diameter of the base body 66 can be reduced means that the diameter of the hole passing through the base cylindrical portion 72 of the reflecting mirror 7 can be reduced, the effective area of the curved surface 71 for light reflection can be increased, and the light radiation efficiency can be improved. Can be improved.

The power supply line 63 is connected to the terminal 68 of the base 7.
The sealing tube 12 of the lamp L is in direct contact with the slits 67 when the tip of the lamp L (not shown) is wound or a ring-shaped terminal piece is fastened and fixed by rotating a nut. The rotational force is applied to the entire lamp L, and no excessive rotational force is applied to the external lead rod 3B and the adhesive layer, so that the external lead rod 3B and the adhesive layer can be prevented from being broken.

Although not shown, a slit is not formed in the cylindrical body of the base, and the corner of the sealing tube portion is brought into contact with the inner wall surface of the cylindrical body of the base or the cylindrical body of the base is sealed with the sealing tube. Even if it is made into a rectangular shape almost the same as the part, the sealing tube part abuts against the inner wall of the cylindrical body and serves as a stopper against rotational force,
When the nut for attaching the power supply line to the terminal portion is tightened, an excessive rotational force is not applied to the external lead rod and the adhesive layer, so that destruction of these portions can be prevented in the same manner as described above.

FIG. 7 is a schematic view showing an embodiment of a liquid crystal projector P of the present invention using the above-mentioned light projecting device D. In the drawing, the same parts as those in FIGS. The description is omitted here.

In FIG. 7, reference numeral 91 denotes an optical system lens;
Denotes a projection surface such as a screen, and a liquid crystal screen 93 is provided between the light projecting device D and the optical lens 91 as a display screen.

In this liquid crystal projector P, light emitted from a lamp L in a light projecting device D is condensed by a reflecting mirror 7 and projected on a projection surface 92 via an optical lens 91.
An image displayed on a liquid crystal screen 93 disposed between the light projecting device D and the optical system lens 91 is enlarged and projected on a projection surface 92.

Also, the lamp L in the light projecting device D mounted on the projector device P can suppress the temperature rise of the external lead rod 3B at the time of lighting. There is no possibility that the life will be short. Therefore, since the light projecting device D having the above-described operational effects is provided, it is possible to provide the liquid crystal projector device P that does not require the light projecting device D to be replaced in a short time.

The present invention is not limited to the above embodiment. For example, the high-pressure discharge lamp is not limited to a short metal halide lamp, but may be various metal halide lamps filled with halides, an ultra-high pressure mercury lamp, a xenon lamp filled with high-pressure xenon gas, or the like. The lamp is not limited to the shape, but may be an elliptical shape, a spherical shape, a straight tube shape, or the like, and the sealing may be a molding without using a mold.

The temperature of the external lead rod of the lamp is lowered by using a metal piece. However, if it is necessary to further lower the temperature, other means may be used in combination, for example, by adding alumina to the outer surface of the sealing tube. An Al ₂ O ₃ coating may be formed.

In the above embodiment, molybdenum foil is used as the metal foil for sealing, but metal foil made of other materials such as tungsten may be used.

Further, the lamp, light projecting device and projector device of the present invention are not limited to those shown in the embodiment,
The present invention can be applied to light irradiation in many fields such as photochemistry, semiconductor manufacturing, and imaging.

[0062]

According to the first aspect of the present invention, the heat capacity and the heat radiation area of the external lead rod are increased, and the temperature rise can be reduced. As a result, the occurrence of oxidation of the external lead rod is prevented or reduced, and It is possible to provide a high-quality discharge lamp of improved quality, which prevents a short life from occurring due to melting of the introduced conductor and destruction of the sealing tube portion due to.

According to the second aspect of the present invention, the same effect as described in the first aspect can be obtained by applying the present invention to a high-pressure discharge lamp having a high tube wall load.

According to the third aspect of the present invention, in the case where the high-pressure discharge lamp having the effects described in the first or second aspect is incorporated in a reflecting mirror, high reliability with high quality without short life is improved. It is possible to provide an improved light emitting device.

According to the fourth aspect of the present invention, there is provided a projector which is equipped with a light projecting device having the effects described in the third aspect and has high quality and high reliability without short life. .

[Brief description of the drawings]

FIG. 1 is a partial sectional front view showing an embodiment of a high-pressure discharge lamp of the present invention.

FIG. 2 is an enlarged cross-sectional front view of a sealing tube portion at a lamp end in FIG. 1;

FIG. 3 is a cross-sectional view of a portion cut along the line AA in FIG. 2;

FIGS. 4A to 4C are schematic diagrams showing various forms of metal pieces connected to external lead rods.

FIG. 5 is a partial sectional front view showing an embodiment of the light projecting device of the present invention.

6 (a) is an exploded perspective view, and FIG. 6 (b) is a portion cut along the line BB in FIG. 6 (a). FIG.

FIG. 7 is a schematic diagram showing an embodiment of the projector device of the present invention.

[Explanation of symbols]

 L: High pressure discharge lamp (short metal halide lamp) D: Light projecting device P: Projector device 1: Translucent container 12: Sealing tube 2: Introduced conductor 3M: Metal foil (molybdenum foil) 3A: Internal lead rod (electrode) Rod) 3B: external lead rod 4A: electrode (anode) 4B: electrode (cathode) 5: metal piece 7: reflecting mirror 91: optical lens 93: display screen

Claims (4)

[Claims] 1. A translucent container made of quartz glass having a bulging portion forming a light emitting space and sealing tube portions extending at both ends thereof; a metal foil hermetically sealed in the sealing tube portion; An internal lead rod connected to one end of the foil and provided with an electrode at the tip protruding into the bulging portion; an external lead rod connected to the other end of the metal foil and led out of the sealing tube;
A high-pressure discharge lamp comprising: a metal piece connected to an external lead rod and embedded in a sealing tube portion; and a discharge medium sealed in a translucent container. 2. The high-pressure discharge lamp according to claim 1, wherein a tube wall load (lamp power W / surface area of the bulging portion of the translucent container cm ² ) is 25 to 200 W / cm ² . 3. A light projecting device comprising: a reflecting mirror; and the high-pressure discharge lamp according to claim 1 disposed facing the reflecting mirror. 4. The light projecting device according to claim 3, an optical lens disposed in front of a reflecting mirror of the light projecting device, and a light projecting device disposed between the reflecting mirror and the optical lens of the light projecting device. And a display screen provided.