JP2004164996A - Metallic vapor discharge lamp and high pressure mercury-vapor discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive electrode and a high quality lamp by suppressing reduction in illuminance at an early time of lamp lighting, lamp bursting during lighting, and color unevenness. <P>SOLUTION: In a discharge lamp, mercury, halogen and rare gases of 0.1-0.3 mg/mm<SP>3</SP>are enclosed into a discharge vessel with a pair of electrodes, in each of which an electrode core bar 12 is doubly wound with a coil 13 of a single tungsten wire, and the start and the end of winding of the coil 13 are placed on the side at which main arc discharge is generated. The high quality lamp may be provided, in a metallic vapor discharge lamp and a high pressure mercury-vapor discharge lamp having an electrode of which the tip 14 is melted to be smaller than the width of the electrode coil by a method of the arc discharge or laser irradiation. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a metal vapor discharge lamp and a high-pressure mercury vapor discharge lamp mainly used as a backlight of a projector device.
[0002]
[Prior art]
In recent years, a light source device including a short arc discharge lamp combined with a reflector has been widely used as a light source for a projector device, a projector, and the like.
Generally, a projector device is required to have sufficient brightness on a screen, and therefore needs a light source close to a point light source. A metal halide lamp or a mercury lamp is used as the lamp, and a lamp with a shorter arc is desired. However, in the lamp, the short arc causes a decrease in the lamp voltage and an increase in the lamp current.
[0003]
FIG. 3 shows an example of a conventional electrode.
The electrode shown in the figure is usually composed of a core rod 17 made of tungsten and a coil 18 made of tungsten. Due to the fact that the coil is wound around the core rod, the relation between the thickness of the core rod and the coil is limited to a certain extent. As a result, extremely thick coils cannot be wound around the core rod.
In the electrode as shown in FIG. 3, if the electrode tip is excessively heated while the lamp is lit, the electrode is melted at an early stage, causing a decrease in brightness.
[0004]
In addition, measures such as enlarging the electrode to prevent melting are conceivable, but the larger the electrode, the larger the difference in the coefficient of thermal expansion between tungsten, which is the electrode material, and quartz, which is the material of the discharge vessel, during lighting. As a result, the pressure during lighting is high, which leads to rupture.
For this reason, as shown in FIG. 4, it is considered that the tip 19 of the electrode is melted and the heat capacity of the tip is increased to thereby reduce the consumption (for example, see Patent Documents 1, 2, and 3). Although it is possible to slow down the consumption of the electrodes by the method, since the heat radiation effect is small, it is necessary to increase the size of the electrodes, and the above-described problem occurs.
[0005]
Therefore, as shown in FIG. 5, it is conceivable to make the coil 20 double, make the core rod 21 thinner, make the coil part larger, melt the tip, and make the melted part larger. The movement amount of the middle arc becomes too large, causing problems such as color unevenness on the screen, and if too small, the above-described problem occurs.
[0006]
Therefore, as shown in FIG. 6, a coil portion 22 is simulated from a tungsten rod by mechanical cutting or the like (see, for example, Patent Document 4), and the tip portion 23 is made thin and the temperature is low during lighting. By increasing the thickness toward the end, a sufficient cooling effect can be obtained, so there is little wear during lighting.By making the core rod thin, during lighting, tungsten as the electrode material and quartz etc. as the discharge vessel material are used. Due to the difference in the coefficient of thermal expansion, it is possible to produce a problem-free electrode with a low probability of occurrence of a lamp leading to rupture due to high pressure during lighting, but it is expensive, and because it is cut from thick tungsten, Due to the properties of tungsten, the electrode is mechanically fragile and difficult to handle.
[0007]
[Patent Document 1]
Japanese Patent No. 3327895 (Claim 1 and FIG. 4 on page 13)
[Patent Document 2]
Japanese Patent No. 3327896 (FIG. 3 on page 8)
[Patent Document 3]
JP-A-10-92377 (FIG. 1 on page 6)
[Patent Document 4]
JP-A-10-92377 (FIG. 4 on page 6)
[0008]
[Problems to be solved by the invention]
The purpose is to provide a high-quality lamp at low cost by using an inexpensive electrode that is easy to handle by suppressing illuminance reduction due to electrode wear in the early stage of lamp lighting, rupture during lighting, color unevenness due to large arc movement during life, etc. And
[0009]
[Means for Solving the Problems]
In order to achieve the above object, in the discharge lamp according to the first aspect of the present invention, a pair of electrodes is formed by winding a coil of one tungsten wire around an electrode core rod twice, and starting and ending the winding of the coil. Is a metal vapor discharge lamp characterized by comprising an electrode located on the side where a main arc discharge occurs.
[0010]
In the invention according to claim 2, the core rod at the tip of the electrode is melted, and the width of the melted portion in the direction perpendicular to the opposing direction of the pair of electrodes is smaller than the electrode coil portion. The metal vapor discharge lamp described in No. 1 was used.
[0011]
In the invention according to claim 3, the core rod at the tip of the electrode and the inner coil are melted, and the width of the melted portion in the direction perpendicular to the facing direction of the pair of electrodes is smaller than the electrode coil portion. A metal vapor discharge lamp according to claim 1 is characterized.
[0012]
According to a fourth aspect of the present invention, in the metal vapor discharge lamp according to the first or second aspect, the electrode tip is melted by an arc discharge method or a laser irradiation method. This makes it possible to provide a metal vapor discharge lamp having stable characteristics using inexpensive electrodes.
[0013]
Further, in the discharge lamp according to the fifth aspect of the present invention, 0.1 to 0.3 mg / mm3 of mercury, halogen and a rare gas are sealed in a discharge vessel provided with a pair of electrodes, and the distance between the pair of electrodes is 2 mm. 0.0mm or less, and a coil made of one tungsten wire is wound twice around the electrode core rod, and the winding of the coil is provided with an electrode positioned on the side where the main arc discharge occurs at the end of winding. High-pressure mercury vapor discharge lamp.
[0014]
In the invention according to claim 6, the core rod at the tip of the electrode is melted, and the width of the melted portion in the direction perpendicular to the opposing direction of the pair of electrodes is smaller than the electrode coil portion. 5 is a high-pressure mercury vapor discharge lamp.
[0015]
Further, in the invention according to claim 7, the core rod at the tip of the electrode and the inner coil are melted, and the width of the melted portion in the direction perpendicular to the opposing direction of the pair of electrodes is smaller than the electrode coil portion. A high-pressure mercury vapor discharge lamp according to claim 5 is provided.
[0016]
The high pressure mercury vapor discharge lamp according to claim 6 or 7, wherein the electrode tip is melted by an arc discharge method or a laser irradiation method. By doing so, it is possible to provide a high-pressure mercury vapor discharge lamp using inexpensive electrodes and having stable characteristics.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples with reference to the drawings.
A coil 16 made of one tungsten wire is wound twice around the electrode core rod 15, and the winding and winding of the coil 16 are positioned on the side where the main arc discharge occurs, as shown in FIG. A part of the core rod and a part of the inner coil are melted to form an electrode shown in FIG. 1 and a metal vapor discharge lamp of the present invention using the electrode will be described.
[0018]
In a high-pressure mercury vapor discharge lamp in which 0.1 to 0.3 mg / mm3 of mercury, halogen and a rare gas are enclosed in a discharge vessel having a pair of electrodes shown in FIG. 1, the distance between the pair of electrodes is 2.0 mm or less. In this electrode, the coil is wound twice on the core rod, the winding start and end of the coil are located on the side where the main arc discharge occurs, and a part of the core rod and a part of the inner coil are melted. Have been.
[0019]
In the electrode of FIG. 2 according to the present invention, the width of the tip in the direction perpendicular to the opposing direction of the pair of electrodes is melted smaller than the electrode coil portion B, and the coil end having a lower operating temperature is made larger than the melted portion. By doing so, the electrode shown in FIG. 1 is formed, and the early illuminance reduction as a lamp due to the early consumption of the fused portion is suppressed. Compared to FIG. 5, color unevenness due to the amount of movement of the arc during the life is suppressed, and the core rod is suppressed to be thin, so that the possibility of lamp rupture is low, the mechanical strength is strong, the handling is easy, and mechanical processing and the like are performed. It is an inexpensive electrode because it is not performed.
By using this electrode, a high-quality lamp could be provided at low cost.
[0020]
FIG. 7 shows an embodiment of a high-pressure mercury vapor discharge lamp according to the present invention, and FIG. 1 shows an embodiment of an electrode used in the high-pressure mercury vapor discharge lamp of the present invention.
Referring to FIG. 7, this short arc discharge lamp rated at 220 W has a discharge vessel 1 made of quartz, in which argon gas, halogen, and mercury are sealed at a density of 0.2 mg / mm ^3. A pair of electrodes 2a and 2b made of tungsten are arranged at a distance of 1.3 mm, and are connected to a conducting wire 4 extending outside from the discharge vessel 1 via a metal foil 3 made of molybdenum.
[0021]
A discharge lamp having the same specifications as those of the electrode according to the present invention shown in FIG. 1 and the conventional electrode shown in FIG. 5 except for the electrode is assembled into a reflector having the same specifications as shown in FIG. When the evaluation was performed using the optical system shown in FIG. 9, the left and right illuminance balance causing color unevenness on the screen was 100% using the product of the present invention in FIG. In contrast, in the case of the conventional product shown in FIG. 11, there was a result that the variation exceeded 10%.
A similar result was obtained when the lamp of FIG. 7 was filled with a metal halide containing dysprosium (Dy) -neodymium (Nd) -cesium (Cs) as a main component.
As described above, it was clearly found that the characteristics of the high-pressure mercury vapor discharge lamp of the present invention were better.
[0022]
【The invention's effect】
As described above, in the high-pressure mercury vapor discharge lamp using the electrode of the present invention, color unevenness due to the amount of arc movement during the life is suppressed, and the core rod is suppressed to be thin, so that the possibility of lamp rupture is low, The mechanical strength was strong and easy to handle, and the electrode was inexpensive because no mechanical processing was performed. By using this electrode, a high-quality lamp could be provided at low cost.
[0023]
Similarly, in a metal vapor discharge lamp, a high-quality lamp could be provided at low cost by using the electrode of the present invention.
[0024]
[Brief description of the drawings]
FIG. 1 is a plan view showing an example of an electrode used in one embodiment of the present invention.
FIG. 2 is a plan view showing an example of an electrode used in one embodiment of the present invention before melting.
FIG. 3 is a plan view showing an example of a conventional electrode.
FIG. 4 is a plan view showing an example of a conventional electrode.
FIG. 5 is a plan view showing an example of a conventional electrode.
FIG. 6 is a plan view showing an example of a conventional electrode.
FIG. 7 is a schematic view of an arc tube using an electrode according to one embodiment of the present invention.
FIG. 8 is a schematic view of an embodiment in which a light-emitting tube of the present invention is incorporated in a reflector and evaluated.
FIG. 9 is a schematic diagram of an optical system for evaluating the lamp of the present invention.
FIG. 10 is an experimental result showing the illuminance balance of a discharge lamp showing one effect of the present invention.
FIG. 11 shows the results of the same experiment on a conventional discharge lamp.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 discharge vessel 2 electrode 3 metal foil 4 external conductor 5 short arc discharge lamp 6 reflecting mirror 7 cover glass 8 Embodiment 9 of the present invention lens 10 liquid crystal 11 screen 12 electrode core rod 13 coil 14 tip 15 tip 16 coil 17 Electrode core rod 18 Coil 19 Tip 20 Coil 21 Electrode core 22 Pseudo coil part 23 Tip

Claims (8)

In the discharge lamp, the pair of electrodes is provided with an electrode in which a coil made of one tungsten wire is wound twice around the electrode core rod, and the winding of the coil is located on the side where the main arc discharge occurs at the end of winding. A metal vapor discharge lamp characterized by the following. 2. The metal vapor discharge lamp according to claim 1, wherein the core rod at the tip of the electrode is melted, and the width of the melted portion in the direction perpendicular to the facing direction of the pair of electrodes is smaller than the electrode coil portion. 2. The metal vapor according to claim 1, wherein the core rod at the tip of the electrode and the inner coil are melted, and a width of the melted portion in a direction perpendicular to the facing direction of the pair of electrodes is smaller than that of the electrode coil portion. Discharge lamp. 3. The metal vapor discharge lamp according to claim 1, wherein the electrode tip is melted by an arc discharge method or a laser irradiation method. In a discharge lamp, 0.1 to 0.3 mg / mm3 of mercury, halogen and a rare gas are sealed in a discharge vessel having a pair of electrodes, the distance between the pair of electrodes is 2.0 mm or less, and an electrode core rod is provided. A high-pressure mercury vapor discharge lamp, comprising a double-wound coil of one tungsten wire, and an electrode positioned at the side where the main arc discharge occurs, at the beginning and end of winding of the coil. 6. The high-pressure mercury vapor discharge lamp according to claim 5, wherein the core rod at the tip of the electrode is melted, and the width of the melted portion in the direction perpendicular to the facing direction of the pair of electrodes is smaller than the electrode coil portion. 6. The high-pressure mercury according to claim 5, wherein the core rod at the tip of the electrode and the inner coil are melted, and the width of the melted portion in the direction perpendicular to the facing direction of the pair of electrodes is smaller than that of the electrode coil portion. Vapor discharge lamp. 8. The high-pressure mercury vapor discharge lamp according to claim 6, wherein the electrode tip is melted by an arc discharge method or a laser irradiation method.

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