JPH08329901A - Metal halide lamp, metal halide lamp device, metal halide lamp lighting device, light projecting device, and liquid crystal projector - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To stabilize an arc and bring it closer to a point light source. SOLUTION: 1 is a metal halide lamp, 2 is a translucent airtight container, the inner surface is approximately 4.3 cm ² , and the inner volume is 1.
It is 5 cc or less, for example, 0.82 cc. Reference numerals 3 and 4 denote a pair of electrodes arranged in the airtight container 2 so as to be separated from each other so that the distance between the electrodes is 6 mm or less, and the distance between the electrodes is, for example, 3.0 mm. The airtight container 2 contains mercury, rare gas, cesium, rare earth metal and halogen, and the amount of cesium enclosed is 5.1 × 10 ⁻³ mg / cc or more, 10.
A discharge medium of 2 × 10 ⁻² mg / cc or less is enclosed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short arc type metal halide lamp containing cesium, a metal halide lamp device, a metal halide lamp lighting device, a light projecting device, and a liquid crystal projector.

[0002]

2. Description of the Related Art In Japanese Patent Publication No. 65977/1993, in addition to rare gas and mercury, a cesium halide and a rare earth metal halide are filled in a discharge tube at a molecular mixing ratio of 10:90 to 50:50. Then, there is a description of the high pressure discharge lamp. Conventional lamps are intended to be suitable for indoor lighting, food lighting and show window lighting by enclosing cesium halide in a discharge tube in order to obtain the same light color as daylight corresponding to a color temperature of 5000K. is there. It should be noted that this publication describes a conventional lamp having an electrode distance of 7 mm or 18 mm.

[0003]

When the distance between the electrodes of the metal halide lamp is set to 6 mm or less, that is, a so-called short arc type, the arc becomes short, so that light control by a reflector or the like becomes easy and it can be suitable as a light source for a liquid crystal projector. However, the above-described conventional lamp is suitable as a light source for a liquid crystal projector, for example, where the light control by the reflector is difficult because the arc becomes long because the distance between the electrodes is as long as 7 mm or 18 mm and the light control is strict. Absent. In addition, if it is a liquid crystal projector, C
In order to obtain the screen illuminance comparable to that of an RT television, the color temperature of the light source needs to be 6000K or higher. However, the conventional lamp has a too low color temperature to be put to practical use.

Therefore, although the present invention relates to a metal halide lamp containing cesium, it solves a completely different problem from the conventional lamp, and is a metal halide lamp which is a stable arc but close to a point light source,
An object of the present invention is to provide a metal halide lamp device, a metal halide lamp lighting device, a light projecting device, and a liquid crystal projector.

[0005]

According to the invention of a metal halide lamp of claim 1, there is provided a translucent airtight container; a pair of metallized lamps which are arranged in the airtight container so as to have an interelectrode distance of 6 mm or less. Electrode; sealed in an airtight container, containing at least mercury, rare gas, cesium, rare earth metal and halogen, and the amount of cesium enclosed is 5.1 × 10 ⁻³ mg / cc or more, 10.2 × 10 ⁻² mg / and a discharge medium of cc or less.

In the present and following claims, the translucent airtight container may be any one that has sufficient fire resistance and airtightness to form a metal halide lamp, such as quartz and alumina. Ceramic materials of can be used.

For the pair of electrodes, well-known electrode materials used for metal halide lamps such as tungsten and thoriated tungsten can be used. As the electrode structure, in addition to the rod-shaped electrode, a structure in which the vicinity of the tip of the rod-shaped electrode is formed into a coil or a structure in which a coil is wound near the end of the electrode shaft is allowed.

Further, the pair of electrodes can be constructed such that one operates as an anode and the other operates as a cathode. The distance between electrodes is preferably 1 mm or more and 4 mm or less, but 6 m
The distance may be equal to or less than m and may be a distance at which an arc can be formed. If the distance between the electrodes exceeds 6 mm, the arc becomes too long, and the point light source moves away from it, making it difficult to control the light emission from the lamp.

As the rare earth metal, it is preferable to use dysprosium, neodymium, holmium, and thulium, which emit light having a continuous spectrum over the entire visible light region, but not limited thereto.

The discharge medium contains, in addition to the rare earth metal, at least one luminescent metal selected from indium, thallium, gallium, zinc and cadmium, which have peak wavelengths at three wavelengths of R, G and B at the time of light emission. To allow that.

As the halogen, iodine and / or bromine can be used, but the halogen is not limited thereto. Further, halogen is in the form of a compound with a rare earth metal or mercury,
It is allowed to be enclosed in the form of halogen alone. As the rare gas, besides argon, neon, krypton, and xenon can be used.

5.1 × 10 ^-3 mg / cc or more, 10.2
The enclosed amount of cesium of × 10 ^-2 mg / cc or less refers to the enclosed amount per 1 cc of the volume of the airtight container. The enclosed amount is
It can be calculated by measuring the volume of the airtight container and the amount of cesium enclosed in the airtight container and converting the amount enclosed per cc of the volume of the airtight container. Since rare earth metals have a high vapor pressure, if the rare earth metals are made to emit light as desired, the temperature of the airtight container becomes high, and the arc tends to become unstable due to the action of thermal convection in the airtight container. It acts to thicken and stabilize the arc formed between the middle electrodes. However, the amount of cesium enclosed is 5.1 × 10 ^-3
If it is less than mg / cc, the arc becomes unstable and the arc easily fluctuates even if the distance between the electrodes is extremely shortened, and the lamp flickers. 10.2 × 10 ^-2 m
If it exceeds g / cc, the arc becomes too thick, and the surface area of the arc becomes large. Therefore, the arc tends to move away from the point light source, and it becomes difficult to control the light emission from the lamp. Therefore, the enclosed amount of cesium is 5.1 × 10 ^-3.
The range of mg / cc or more and 10.2 × 10 ⁻² mg / cc or less is a general range in which the arc can be brought close to the point light source while the arc is stable when the distance between the electrodes is 6 mm or less.

A second aspect of the present invention is the metal halide lamp according to the first aspect, wherein the cesium is 5.1 × 10 ⁻³ m 2.
It is characterized in that it is not less than g / cc and not more than 9.2 × 10 ^-2 mg / cc. 5.1 × 10 ⁻³ mg / cc or more, 9.
2 × 10 ⁻² mg / cc or less is a desirable range in which the arc can be brought close to the point light source while being stable.

A third aspect of the present invention is the metal halide lamp according to the first aspect, wherein cesium is 5.1 × 10 ⁻³ m 2.
It is characterized in that it is not less than g / cc and not more than 4.6 × 10 ⁻² mg / cc.

5.1 × 10 ^-3 mg / cc or more, 4.6 ×
10 ⁻² mg / cc or less is the optimum range in which the arc can be brought close to the point light source while being stable. The invention according to claim 4 is the metal halide lamp according to any one of claims 1 to 3, wherein the color temperature is 6000 K or more and
It is characterized in that it can be turned on at 5000 K or less.

According to a fourth aspect of the present invention, when the amount of cesium is regulated within a predetermined range and the lamp is lit, the color temperature is 6000K or more and
Since it can be set to 5000 K or less, the emission spectrum amount of cesium in the red or infrared region is reduced, so that it becomes inconspicuous, so that the emission color is blue or white, and the emission is efficiently performed at a high color temperature.

The discharge medium can be constituted by encapsulating an appropriate amount of at least one of dysprosium, neodymium, holmium and thulium as a rare earth metal or at least one of indium, thallium, gallium, zinc and cadmium. It is not limited to this.

A fifth aspect of the present invention is the metal halide lamp according to any one of the first to third aspects, wherein the rare earth metal is at least one of dysprosium, neodymium, holmium, and thulium.

The invention according to claim 6 is the metal halide lamp according to any one of claims 1 to 4, characterized in that the distance between the electrodes is 1 mm or more and 4 mm or less. The distance between the electrodes is 1 mm or more and 4 mm or less is a desirable range in which the arc approaches the point light source. During the life of the metal halide lamp, the discharge medium or the electrode material in the airtight container may adhere to the electrode tips, and the distance between the electrodes is 1
If it is less than mm, the distance between the electrodes may be lost due to the deposits, and the service life may be shortened.

The invention according to claim 7 is the metal halide lamp according to any one of claims 1 to 6.
It is characterized in that it can be turned on when the wall load is 30 W / cm ² or more.

In the present invention, the tube wall load means a value obtained by dividing the lamp input power W by the inner surface area of the airtight container. According to the invention of claim 7, since it is possible to light at a wall load of 30 W / cm ² or more, the light output per unit surface area of the airtight container becomes high.

The invention according to claim 8 is the metal halide lamp according to any one of claims 1 to 7.
Each of the pair of electrodes is composed of an anode and a cathode, and is characterized by being lit by direct current.

Since the anode has a higher temperature than the cathode, the anode is generally larger than the cathode, but is not limited thereto. That is, the cathode and the anode are allowed to have the same shape.

The invention of a metal halide lamp device according to a ninth aspect comprises the metal halide lamp according to any one of the first to eighth aspects, and a reflector that reflects light emitted from the metal halide lamp.

The reflector may have a structure that reflects the light emitted from the metal halide lamp as desired, and a reflector having a quadratic curved surface having an elliptical or parabolic cross section can be used, but the reflector is not limited to this. .

The invention of a metal halide lamp lighting device according to a tenth aspect comprises the metal halide lamp according to any one of the first to eighth aspects, and a lighting means for stably lighting the metal halide lamp. And

The lighting means needs to have a ballast component that can maintain the arc in a stable manner. However, in addition to a ballast using a choke coil, an electronic ballast such as an inverter using a semiconductor switching device can be used. it can.

The invention of the projection device according to claim 11 is the invention according to claim 1.
A metal halide lamp according to any one of claims 1 to 8; a lighting means for stably lighting the metal halide lamp; a reflector for reflecting light emitted from the metal halide lamp; and a housing for housing the metal halide lamp, the lighting means, and the reflector; It is characterized by having.

As the light projecting device, a liquid crystal projector or an overhead projector is preferable, but a Dow light,
Allows lighting equipment such as spotlights. The invention of a liquid crystal projector according to claim 12 is the metal halide lamp according to any one of claims 1 to 8, a lighting means for stably lighting the metal halide lamp, and a reflector for reflecting light emitted from the metal halide lamp; A liquid crystal panel projected by the light emitted from the reflector; a liquid crystal driver for driving the liquid crystal panel; an optical system for projecting the transmitted light of the liquid crystal panel; a metal halide lamp, a lighting means, a reflector, a liquid crystal panel, a liquid crystal driver, and And a housing for accommodating the optical system.

As the optical system, known optical systems such as a condenser lens for image projection and an optical filter are allowed. The liquid crystal panel is preferably a color liquid crystal panel, but is not limited to this.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of a metal halide lamp device constituted by combining a metal halide lamp and a reflector according to the present invention will be described below with reference to FIG. FIG. 1 is a side view showing a partial cross section of a metal halide lamp device. In the figure, 1 is the rated input 2
It is a 50W metal halide lamp. 2 is a translucent airtight container made of, for example, quartz and having a wall thickness of 1.2 m.
m, the major axis is approximately 13.5 mm, and the minor axis is approximately 13 mm in an elliptical discharge space, the inner surface of which is approximately 4.3 cm ² ,
The internal volume is 1.5 cc or less, for example 0.82 cc. In 3 and 4, the distance L between the electrodes is 6 mm in the airtight container 2.
The distance L between the electrodes is set to, for example, 3.0 mm for a pair of electrodes that are spaced apart from each other as described below. One of the electrodes 3 is an anode, for example, a tip of a tungsten rod having a diameter of 0.9 mm has a substantially hemispherical shape having an outer diameter of 2.2 mm. The other electrode 4 is a cathode, and is, for example, a tungsten rod having a semispherical tip and a diameter of 0.7 mm.

These electrodes 3 and 4 are connected to metal foil conductors 7 and 8 sealed in pinch seal portions 5 and 6 formed at both ends of the airtight container 2, for example. Metal foil conductor 7, 8
Is made of molybdenum foil having a thickness of 30 μm and a width of about 3 mm, and one metal foil conductor 7 is electrically connected to a base 8 attached to an end through an external lead wire (not shown), and the other metal is The foil conductor 7 is connected to the external lead wire 9.

The airtight container 2 contains mercury, a rare gas, cesium, a rare earth metal and a halogen, and the amount of cesium enclosed is 5.1 × 10 ⁻³ mg / cc or more, 10.2 × 10 ^−2.
A discharge medium of mg / cc or less is enclosed.

The discharge medium is enclosed in the form of a metal halide, mercury as a buffer metal, and a rare gas such as argon.
The metal halide is a halide of at least one rare earth metal selected from dysprosium Dy, neodymium Nd, holmium Ho, and thulium Tm, and indium In, thallium Tl, gallium Ga, zinc Zn, and cadmium Cd. It contains at least one selected halide and a cesium Cs halide. The halide of at least one rare earth metal selected from Dy, Nd, Ho and Tm is iodide and bromide, for example, DyBr ₃ is 0.8 mg and NdBr is NdBr.
₃ is 0.2 mg.

It is at least one halide iodide and bromide selected from In, Tl, Ga, Zn and Cd, for example, TlBr is 0.4 mg. Further, the halide of cesium Cs is CsI, and the enclosed amount is regulated to 0.01 mg / cc or more and 0.2 mg / cc or less. For example, CsI is 0.15 mg, and therefore 0.16 mg / cc is enclosed. There is. When CsI is converted into the number of moles, it is 5.8 × 10 ⁻⁷ mole. The amount of Cs is 7.7 × 10 ⁻² mg / cc.

The total amount of metal halide enclosed is 3.0 × 1.
It is 0 ^-6 mol / cc or more and 3.0 × 10 ^-5 mol / cc or less, and the total amount of the metal halide enclosed is 1.55 mg. When converted into the number of moles, it is 5.3 × 10 ^-6 mol. is there.

Therefore, the relationship between the enclosed amount of cesium iodide CsI and the total enclosed amount of metal halides is 0.11: 1.
(Molar ratio). 30 mg of mercury Hg is sealed, and argon Ar is sealed at a sealing pressure of 53 kPa.

The metal halide lamp 1 comprises In, Tl,
At least one iodide and bromide selected from Ga, Zn, and Cd, specifically, TlBr of 0.4 m
Since it is enclosed by g, this TlBr has a peak wavelength in the wavelength range of RGB, which is the three primary colors of light, and efficiently radiates these RGB lights. The discharge medium is enclosed as described above, and the color temperature at the time of light emission is 6000K or more and 15000.
Below K, for example, 7500K is set.

The metal halide lamp 1 includes a reflector 1
1 attached to the metal halide lamp device 10
Is composed. The base body of the reflector 11 is made of glass or metal, and the inner surface of the rotating curved surface is made of Ti having excellent reflection characteristics.
It has a reflecting surface 12 made of a vapor deposition film such as O ₂ —SiO ₂ . The front surface of the reflector 11 has an opening diameter of, for example, 90 to 1.
The light projecting portion 13 having a size of about 30 mm is formed. A support tube portion 14 is provided on the top of the reflector 11, and a base 8 of the lamp 1 is fixed to the support tube portion 14 with an adhesive 15 such as insulating cement. The lamp shaft 0 ₁ -0 ₁ is the reflector 11
Is attached to the reflector 3 so as to substantially coincide with the central axis of the optical axis, that is, the optical axis 0 ₂ -0 ₂ . In addition, the reflector 11
An introduction hole 16 is formed in the hole, and an external lead wire 9 of the metal halide lamp 1 penetrates through the introduction hole 16 and is guided to the back side.

The metal halide lamp 1 constitutes a metal halide lamp lighting device in which the base 8 and the external lead wire 9 are connected to the lighting means 17 composed of, for example, an AC / DC converter. This lighting means 17 is a lamp
By inputting DC power of W to 250 W, the metal halide lamp 1 is lit under the condition that the wall load is 30 W / cm ² or more. The tube wall load is, for example, 56 because the inner surface area of the airtight container is 4.5 cm ^2.
It becomes W / cm ² .

FIG. 2 is a conceptual diagram of the liquid crystal projector of the present invention. The liquid crystal projector drives the reflector 11 that reflects the light emitted from the metal halide lamp 1, the lighting means 17, the liquid crystal panel 21 projected by the light emitted from the reflector 11, for example, a color liquid crystal panel, and the liquid crystal panel 21. A liquid crystal driver 22 and a housing 23 for housing these are provided, and the housing 23 is, for example, the liquid crystal panel 2.
2 is a housing in which a light projecting portion is formed in a portion facing 2 and an optical system 24 such as a lens is disposed in the light projecting portion.

Lighting means 1 connected to commercial AC power supply 25
When the lamp 1 is turned on by the power supply from 7, the light emitted from the lamp 1 is reflected by the reflector 11 and illuminates the liquid crystal panel 21. The liquid crystal display panel 21 is provided with RGB color filters (not shown) corresponding to each pixel, and the color filters are controlled by the liquid crystal driver 22 which operates according to the color image signal. LCD panel 2
The light that has passed through 1 is colored in one of RGB by this color filter, and this colored light is condensed by the optical system 24 and projected on the screen 26. Therefore, a color image controlled by the liquid crystal display panel 21 is projected on the screen 26.

FIG. 3 is a characteristic diagram of the screen illuminance measured when the amount of cesium enclosed in the metal halide lamp of the above-described embodiment is changed. The vertical axis represents relative screen illuminance and the horizontal axis represents the amount of cesium enclosed.

From FIG. 3, the amount of cesium enclosed is 10.2 ×
10 ^-2 mg / cc or less, preferably 9.2 x 10 ^-2 mg
It was confirmed that the screen illuminance can be increased to a level of 80% or more by setting it to be / cc or less. Furthermore, it was confirmed that the screen illuminance can be increased to a level of 90% or more if the amount of cesium enclosed is set to 4.6 × 10 ^-2 mg / cc or less.

On the other hand, if the amount of cesium enclosed is too small, the arc becomes extremely unstable, and the arc bends or shakes, causing a problem such as flickering of the screen. Table 1 is a table showing the results of measuring the stabilization of the arc during the initial lighting.

[0046]

[Table 1]

From Table 1, the amount of cesium enclosed is 5.1 × 1.
It can be seen that when the amount is less than 0 ⁻³ mg / cc, the arc during initial lighting becomes remarkably unstable. Since the lamp 1 is operated by direct current, the metal halide and mercury are separated into the anode and the cathode during lighting due to the catalysis phenomenon, so that the halide is less likely to adhere to the inner wall of the airtight container. Therefore, devitrification can be prevented and the life characteristics are improved.

In the metal halide lamp device 10 of the above embodiment, since the metal halide lamp 1 as a light source is turned on with high brightness close to a point light source, the reflection control by the reflector 11 is facilitated and the light collection rate is increased. be able to.

Furthermore, according to the liquid crystal projector of this embodiment, the illuminance on the screen 26 surface can be increased. Further, according to the above-described embodiment, the amount of rare earth metal halides such as DyBr ₃ and NdBr ₃ filled with respect to the total amount of metal halides enclosed is 0.3 (molar ratio).
As described above, the amount of rare earth metal halide enclosed is relatively large relative to the total amount of metal halide enclosed. As a result, the amount of cesium halide enclosed becomes relatively small, so that the arc can be made thinner, and the light emitting area can be made smaller to approach the point light source.

[0050]

As described above, according to the first aspect of the invention, the arc can be made short and thin, and the arc can be stabilized, so that a stable point light source can be provided.

According to the second aspect of the invention, since the arc is further thinned, a more stable and desirable metal halide lamp can be provided. According to the invention of claim 3, the arc is further thinned, so that a more stable and optimal metal halide lamp can be provided.

According to the invention of claim 4, since the metal halide lamp has a high color temperature, it is possible to provide a metal halide lamp desirable for color image display. According to the invention of claim 5, it is possible to provide a light source which is desirable for displaying a color image, since it is possible to generate light over almost the entire visible wavelength range.

According to the invention of claim 6, it is possible to provide a metal halide lamp which has a long life and is closer to a point light source. According to the invention of claim 7, it is possible to provide a compact metal halide lamp having a high light output.

According to the eighth aspect of the invention, since the lamp is operated by direct current, the arc metal halide and mercury are separated into the anode and the cathode, and the metal halide hardly adheres to the bulb wall, resulting in devitrification. It can be prevented and the life characteristics are improved.

According to the ninth aspect of the invention, since the metal halide lamp as the light source has high brightness and is close to a point light source, the reflection control by the reflector can be facilitated and the light collection rate can be increased. According to the invention of claim 12, it is possible to provide a liquid crystal projector with high screen illuminance.

[Brief description of drawings]

FIG. 1 is a side view showing a partial cross-section of a first embodiment of a metal halide lamp device of the present invention.

FIG. 2 is a conceptual diagram showing a liquid crystal projector of the present invention.

FIG. 3 is a characteristic diagram showing the relationship between the amount of cesium enclosed in a discharge lamp and the screen illuminance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Metal halide lamp 2 ... Airtight container 3, 4 ... Electrode 11 ... Reflector 17 ... Lighting means 21 ... Liquid crystal display panel 22 ... Liquid crystal driver 23 ... Housing

Claims (12)

[Claims] 1. A translucent airtight container; a pair of electrodes which are sealed in the airtight container so that the distance between the electrodes is 6 mm or less; at least mercury, noble gas, which is sealed in the airtight container; Contains cesium, rare earth metals and halogens, and the encapsulation amount of cesium is 5.1 × 10 ⁻³ mg / cc or more, 1
A metal halide lamp comprising: a discharge medium having a concentration of 0.2 × 10 ^-2 mg / cc or less; 2. The metal halide lamp according to claim 1, wherein the cesium content is 5.1 × 10 ⁻³ mg / cc or more and 9.2 × 10 ⁻² mg / cc or less. 3. The metal halide lamp according to claim 1, wherein cesium is 5.1 × 10 ⁻³ mg / cc or more and 4.6 × 10 ⁻² mg / cc or less. 4. The metal halide lamp has a color temperature of 600.
The metal halide lamp according to any one of claims 1 to 3, wherein the metal halide lamp is configured to be capable of lighting at 0K or more and 15000K or less. 5. The metal halide lamp according to claim 1, wherein the rare earth metal is at least one of dysprosium, neodymium, holmium and thulium. 6. The metal halide lamp according to claim 1, wherein the distance between the electrodes is 1 mm or more and 4 mm or less. 7. The metal halide lamp according to any one of claims 1 to 6, wherein the metal halide lamp is configured to be capable of lighting at a wall load of 30 W / cm ² or more. 8. The metal halide lamp according to claim 1, wherein each of the pair of electrodes is composed of an anode and a cathode and is lit by direct current. 9. A metal halide lamp device comprising: the metal halide lamp according to claim 1; and a reflector that reflects light emitted from the metal halide lamp. 10. A metal halide lamp lighting device, comprising: the metal halide lamp according to any one of claims 1 to 8; and a lighting means for stably lighting the metal halide lamp. 11. A metal halide lamp according to claim 1, a lighting means for stably lighting the metal halide lamp, a reflector for reflecting light emitted from the metal halide lamp, a metal halide lamp, and a lighting means. And a housing that houses the reflector; 12. A metal halide lamp according to claim 1, a lighting means for stably lighting the metal halide lamp, a reflector for reflecting the light emitted from the metal halide lamp, and a light emitted from a reflector. A liquid crystal panel that is projected by light; a liquid crystal driver that drives the liquid crystal panel; an optical system that projects the transmitted light of the liquid crystal panel; a metal halide lamp, a lighting means, a reflector, a liquid crystal panel, a liquid crystal driver, and an optical system. A liquid crystal projector comprising: a housing;