JP2007134086A - High-pressure discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp capable of lowering a lamp current even if mercury is not used, and of optimizing a light emission spectrum of the discharge lamp to match the balance of light after passing through a liquid crystal device. <P>SOLUTION: The high-pressure lamp is provided with a fire-resistant and transparent airtight vessel and electrodes sealed to the airtight vessel, and is filled with light-emitting materials and a rare gas. The high-pressure discharge lamp is structured such that one or more kinds of halides selected from dysprosium halide, thulium halide, yttrium halide, holmium halide, ruthenium halide, erbium halide and terbium halide, and a second halide having vapor pressure higher than that of the first halide are added as the light-emitting materials; and the rare gas is filled at a pressure of 15 to 30 atmospheres. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a high-pressure discharge lamp such as a metal halide lamp that is mounted on a liquid crystal projector, an automobile illumination lamp, or the like.

  High-pressure discharge lamps are widely used because of their relatively high efficiency and high color rendering. Further, the high-pressure discharge lamp can be classified into several types such as a metal halide lamp and a mercury lamp depending on the difference in the enclosed material.

Metal halide lamps use different light emitting materials for discharge lamps depending mainly on applications such as liquid crystal projectors or automobile headlamps.
The luminescent material of the discharge lamp for a projector, mercury iodide dysprosium (DyI _3), or, mercury iodide neodymium (NdI ₃₎ is mainly used.
Mercury and sodium iodide (NaI) or mercury and scandium iodide (ScI ₃ ) are mainly used as light emitting materials for discharge lamps for automobile headlamps.

The use of mercury in conventional metal halide lamps is mainly used for the purpose of increasing the lamp voltage, although there is the purpose of utilizing the emission spectrum of mercury.
The reason why the lamp voltage is increased is that when the lamp voltage is low, the lamp current required to obtain a desired lamp input increases.
When the lamp current is large, there is a problem that the current capacity of the lighting circuit is increased and the amount of heat generation is increased, and further, the luminous efficiency of the metal halide lamp is lowered. In addition, there is a problem that the electrode of the metal halide lamp is consumed and the life of the lamp is shortened.

The only luminescent material used in ultra high pressure mercury lamps (UHP) is mercury.
The reason why mercury is used is that by using mercury, the emission spectrum of mercury can be used and the lamp voltage can be increased.
The reason why the lamp voltage is increased is that, as in the case of the metal halide lamp, if the lamp voltage is low, the lamp current required to obtain a desired lamp input increases.
When the lamp current is large, there is a problem that the current capacity of the lighting circuit increases and the amount of heat generation increases, and the luminous efficiency of the mercury lamp decreases. In addition, there is a problem that the consumption of the electrode of the mercury lamp increases and the life of the lamp is shortened.

However, mercury used as a light-emitting material in the above-described metal halide lamp and UHP is an environmentally hazardous substance that adversely affects the environment, and is therefore required to be eliminated.
In particular, according to the RoHS Directive, it is required to completely abolish mercury such that electronic and electrical equipment containing target substances such as mercury cannot be put on the market in EU member countries.

  Moreover, since the above-mentioned metal halide lamp and UHP use mercury, the temperature and density of mercury atoms in the lamp are very high during lighting. For this reason, in the above discharge lamp, the temperature inside the arc tube rises after the switch is turned on, and it takes several minutes for the inside of the arc tube to reach a predetermined pressure due to the evaporation of mercury, and the rise of the luminous flux at the start is delayed. End up.

  Further, the above-described metal halide lamp and UHP are vaporized during the lighting and are all vaporized, and therefore the inside of the arc tube has a high pressure of 50 to 200 atmospheres. For this reason, in order to restart after turning off the light, it is necessary to apply a very high pulse voltage, and therefore it is difficult to turn it on again instantaneously.

Therefore, a metal halide lamp that uses a first halide for obtaining an emission spectrum and further uses a second halide having a high vapor pressure as a material for increasing the lamp voltage instead of mercury has been proposed.
For example, a first halide made of a light-emitting metal such as Na, Li, Sc, or a rare earth as a light-emitting metal, and a metal that has a relatively high vapor pressure and is less likely to emit light in the visible region than the metal of the first halide. There has been proposed a discharge lamp using a second halide comprising: (For example, see Patent Document 1)

JP 11-238488 A

In the discharge lamp having the configuration described in Patent Document 1 described above, a rare gas such as argon is enclosed as a starting and buffering gas.
However, if this rare gas filling pressure is small, the lamp current cannot be reduced sufficiently.
In Patent Document 1, in many specific examples, the filling pressure of the rare gas is 5 atm at the maximum, and at this level of pressure, the lamp current needs to be increased to some extent.

  In order to solve the above-described problems, in the present invention, the lamp current can be reduced without using mercury, and the discharge lamp can be adjusted so as to match the light balance after passing through the liquid crystal device. The present invention provides a high pressure discharge lamp capable of optimizing the emission spectrum.

  In order to solve the above problems and achieve the object of the present invention, a high-pressure discharge lamp of the present invention includes a fire-resistant and transparent hermetic container, an electrode sealed in the hermetic container, a luminescent material and a rare gas. A high-pressure discharge lamp having at least one kind selected from dysprosium halide, thulium halide, yttrium halide, holmium halide, lutetium halide, erbium halide, and terbium halide as a luminescent material. And a second halide composed of a metal halide having a vapor pressure higher than that of the first halide, and a rare gas is sealed at a pressure of 15 to 30 atmospheres. And

According to the configuration of the high-pressure discharge lamp of the present invention described above, the halide of the luminescent material is dysprosium halide, thulium halide, yttrium halide, holmium halide, lutetium halide, erbium halide, terbium halide. A second halide composed of a metal halide having a vapor pressure higher than that of the first halide is added to one or more types of first halide selected from the group consisting of 15 to 30 atmospheres of a rare gas. It is sealed at the following pressure.
With only the first halide, the emission spectrum of the discharge lamp is biased toward the short wavelength side of the visible light region (purple region or blue region), but it consists of a metal halide having a higher vapor pressure than the first halide. By adding the second halide, the spectral distribution of the light of the discharge lamp can be shifted to the long wavelength side (red region).
Moreover, since the lamp voltage can be increased by sealing the rare gas at a pressure of 15 atm or more and 30 atm or less, the lamp current can be sufficiently reduced.

According to the present invention described above, since mercury is not used, the environment is not greatly affected.
Further, according to the present invention, since the spectral distribution of the light of the discharge lamp can be shifted to the long wavelength side (red region) by adding the second halide, the balance of the light after passing through the liquid crystal device is achieved. It is possible to optimize the light balance of the discharge lamp to suit.
Thereby, it is possible to improve the light utilization efficiency and obtain high luminance after passing through the liquid crystal device.
Furthermore, according to the present invention, since the lamp current can be sufficiently reduced, the luminous efficiency can be improved and the life of the discharge lamp can be extended.

First, an outline of the present invention will be described prior to description of specific embodiments of the present invention.
The discharge lamp of the present invention includes an airtight container, an electrode, a halide, and a rare gas. Then, the electrode is sealed in an airtight container, and a halide and a rare gas are sealed in the airtight container to constitute a discharge lamp.

The airtight container is configured to be fireproof and transparent. The material may be made of any material as long as it is a material that can sufficiently withstand the normal operating temperature of the discharge lamp and can emit visible light in a desired wavelength region generated by the discharge to the outside. For example, translucent ceramics such as quartz glass, translucent alumina, YAG (yttrium, aluminum, garnet), single crystals thereof, or the like can be used.
Further, the inner surface of the hermetic container may be modified such that a halogen-resistant or metal-resistant transparent film is formed on the inner surface of the hermetic container.

  The electrode may be configured to be lit with either alternating current or direct current, and when operated with alternating current, the anode and the cathode have the same structure, but when operated with direct current, the anode is generally Since the temperature rises rapidly, it is preferable to use one having a larger heat radiation area than the cathode.

The halide which is a luminescent substance becomes a discharge medium. The halide used is preferably dysprosium halide, thulium halide, yttrium halide, holmium halide, lutetium halide, erbium halide, terbium halide, and more preferably dysprosium iodide ( DyI _3), iodide thulium _(TmI 3), iodide yttrium _(YI 3), iodide holmium _(HoI 3), iodide lutetium _(LuI 3), iodide erbium _(ERI 3), iodide terbium (TBI ₃ ).

  The above-mentioned halide is a metal halide capable of causing desired light emission, for example, a metal halide that generates visible light or ultraviolet light.

In the present invention, a metal halide having a high vapor pressure (second halide) is added as a discharge medium in addition to the above-described halide (first halide).
By adding a metal halide having a high vapor pressure, the emission spectrum is shifted from the short wavelength side to the long wavelength side, so that the distribution of the emission spectrum can be adjusted to be uniform.

In the present invention, the pressure of the rare gas sealed in the airtight container is set to 15 atm or more and 30 atm or less.
By setting the pressure of the rare gas to 15 atm or more and 30 atm or less, the lamp current can be sufficiently reduced.
If the pressure of the rare gas is less than 15 atm, a relatively large lamp current is required, which is not preferable.
When the pressure of the rare gas exceeds 30 atm, the effect of reducing the lamp current with respect to the increase in pressure is saturated and the possibility of the airtight container bursting is increased, which is not preferable.

More preferably, the addition amount of the metal halide having a high vapor pressure (second halide) is 1 mg / cc or less, that is, 1 mg or less per 1 cc of the internal volume of the hermetic container.
When a large amount of the second halide having a high vapor pressure is added, there is an advantage that the lamp voltage can be increased, but the emission spectrum shifts to the longer wavelength side, and the color temperature of the lamp decreases. End up. That is, since the emission spectrum shifts to the Red side, the amount of light on the Blue side decreases.
Therefore, when a discharge lamp whose emission spectrum has shifted to the long wavelength side is used in the projector as described above, the amount of blue light is insufficient when setting a desired color temperature. Needs to be dimmed and adjusted according to the amount of blue light. For this reason, the amount of light after passing through the liquid crystal device is reduced, and the luminance projected on the screen is reduced.
By making the addition amount of the second halide as small as 1 mg / cc, the light quantity on the short wavelength side and the light quantity on the long wavelength side can be made uniform, and the light balance of the discharge lamp can be balanced. It is possible to approach the balance after passing through the light, thereby further improving the light utilization efficiency.

When comparing a metal halide lamp using the halide of the present invention with a conventionally used ultra-high pressure mercury lamp (UHP), the metal halide lamp using the halide of the present invention has a more uniform emission spectrum. Can be obtained.
Therefore, when the metal halide lamp using the halide of the present invention is used for a projector or the like, it is possible to emit light closer to the balance of light after passing through the liquid crystal device than a conventional lamp using mercury. .

In the present invention, the metal halide having a high vapor pressure (second halide) is a metal halide having a relatively high vapor pressure compared to the halide serving as a light-emitting substance.
The second halide is preferably gallium halide, indium halide, tin halide, thallium halide, zinc halide, aluminum halide, more preferably gallium iodide (GaI ₃ ), indium iodide. (InI, InI ₃ ), tin iodide (SnI ₂ , SnI ₄ ), thallium iodide (TlI), zinc iodide (ZnI ₂ ), and aluminum iodide (AlI ₃ ).

  As the halogen constituting the halide (first halide) as the light-emitting substance of the present invention and the metal halide (second halide) having a high vapor pressure, any halogen such as iodine, bromine and chlorine can be used. Can also be effective. However, fluorine has the strongest reactivity of fluorine, and the reactivity decreases in the order of chlorine, bromine and iodine. In the present invention, the reactivity of iodine is most suitable. In the present invention, different halogens can be used in combination. For example, different halides such as iodide and bromide can be used in combination.

In the present invention, the rare gas acts as a starting gas and a buffer gas, and is not particularly limited as long as it does not pass through the airtight container. Since neon easily transmits through quartz glass, argon, krypton, or xenon is preferable because the material of the hermetic container is not selected. More preferably, the lamp current can be suppressed by increasing the sealing pressure. Xenon is preferred.
The rising characteristic of the luminous flux of the metal halide lamp can be improved by increasing the enclosure pressure of the rare gas. The good rise characteristic of the luminous flux is convenient for any purpose of use, and is particularly useful for headlamps such as automobiles and liquid crystal projectors.

Subsequently, specific embodiments of the present invention will be described.
As an embodiment of the discharge lamp of the present invention, a schematic configuration diagram of a metal halide lamp is shown in FIG.
The metal halide lamp 220 is formed by sealing a pair of electrodes 201 and 202 in an airtight container 208 made of, for example, a quartz tube and sealing a halide and a rare gas in the airtight container 208.
The airtight container 208 includes a central light emitting portion 208a and sealing portions 208b and 208c on both sides thereof. The light emitting unit 208a has a spherical shape or a spheroid shape having a space inside, and a halide and a rare gas are enclosed in the space inside. The sealing portions 208b and 208c at both ends are configured to seal so that a substance sealed in the light emitting portion 208a does not leak to the outside. Further, a metal foil 209 is sealed in the sealing portions 208b and 208c.
The pair of electrodes 201 and 202 are respectively attached to the tips of the lead wires 203 and sealed in the light emitting portion 208a. The lead wire 203 is attached to one end of the metal foil 209, and the lead wire 204 is attached to the other end of the metal foil 209. The lead wire 204 is led out from the sealing portions 208 b and 208 c of the airtight container 208. The electrodes 201 and 202, the lead wire 203, the metal foil 209, and the lead wire 204 are assembled into an integrated electrode structure 214. A part of the metal foil 209 and the lead wires 203 and 204 connected to both ends thereof are sealed by the sealing portions 208 b and 208 c of the airtight container 208.

In the metal halide lamp 220 of the present embodiment, the halide sealed in the hermetic vessel 208 is particularly configured such that the second halide having a high vapor pressure is added to the first halide described above.
Further, the pressure of the rare gas sealed in the hermetic container 208 is configured to be 15 atm or more and 30 atm or less.
As the first halide, one or more selected from the above-mentioned dysprosium halide, thulium halide, yttrium halide, holmium halide, lutetium halide, erbium halide, terbium halide, more preferably One or more kinds selected from dysprosium iodide, thulium iodide, yttrium iodide, holmium iodide, lutetium iodide, erbium iodide, and terbium iodide are used.
As the second halide, one or more selected from the above-mentioned gallium halide, indium halide, tin halide, thallium halide, zinc halide, and aluminum halide, more preferably gallium iodide, iodine One or more selected from indium iodide, tin iodide, thallium iodide, zinc iodide, and aluminum iodide are used.
As the rare gas, a gas selected from argon, krypton, and xenon is preferably used, and xenon is particularly preferably used.

  Further, preferably, the amount of the second halide added is 1 mg / cc or less, that is, 1 mg or less per 1 cc of the internal volume of the airtight container 208 (internal volume of the light emitting unit 208a), and a small amount.

The metal halide lamp 220 of the present embodiment can be used as it is in the state shown in FIG. 1, but when used in a projector or the like, for example, as shown in FIG. A reflector (reflecting mirror) 221 may be attached.
In the configuration shown in FIG. 2, a reflector (reflecting mirror) 221 having a mirror surface 222 inside is attached to one sealing portion 208 b of an airtight container 208 of a metal halide lamp (arc tube) 220.
By attaching the reflector (reflecting mirror) 221, the light from the light emitting unit 208 a is reflected by the mirror surface 222 and can be efficiently radiated to the right side in the drawing.

The metal halide lamp 220 of the present embodiment can be manufactured as follows.
First, as shown in FIG. 3A, an electrode assembly 214 composed of an electrode 201, a lead wire 203, a metal foil 209, and a lead wire 204 is inserted from the lower sealing portion 208 b of the hermetic container 208.
Further, evacuation is performed from the sealing portion 208c side above the airtight container 208.
Next, as shown in FIG. 3B, the sealing portion 208b on the lower side of the hermetic container is softened by a heating means 215 such as a CO ₂ laser or an oxygen-hydrogen mixed gas burner, and a shrink seal or softened quartz is machined. It seals by the pinch seal etc. which seals automatically.
Next, as shown in FIG. 3C, a rare gas 216 is sealed as a starting gas or a buffer gas in an airtight container 208 whose lower side is sealed. At this time, the pressure of the rare gas 216 in the airtight container 208 is set to be 15 atm or more and 30 atm or less at room temperature after sealing the sealing portion 208c.
Subsequently, the first halide 217 and the metal halide (second halide) 218, which are light emitting substances, are placed in the light emitting portion 208 a of the hermetic container 208.
Next, an electrode assembly 214 including the electrode 202, the lead wire 203, the metal foil 209, and the lead wire 204 is inserted from the sealing portion 208 c on the upper side of the hermetic container 208. At this time, the interval 219 between the two electrodes 201 and 202 is adjusted to a desired interval such as 0.5 to 4.5 mm.
Thereafter, the upper sealing portion 208c of the hermetic container 208 is sealed with a shrink seal, a pinch seal, or the like. In this way, as shown in FIG. 3D, the metal halide lamp 220 of the present embodiment shown in FIG. 1 can be manufactured.

  As shown in FIG. 2, when the reflector 221 is provided, after that, the reflector 221 is attached to one sealing portion 208b of the metal halide lamp (arc tube) 220, and the arc tube 220 and the reflector 221 are attached. Align and stick.

According to the configuration of the metal halide lamp 220 of the present embodiment described above, since mercury is not used, the environment is not adversely affected.
Further, since the halide sealed in the hermetic container 208 has a configuration in which the second halide having a high vapor pressure is added to the first halide, the emission spectrum is obtained only with the first halide. Is biased toward the short wavelength side (purple region or blue region) of the visible light region, the spectral distribution can be shifted to the long wavelength side (red region).
This makes it possible to optimize the light balance of the discharge lamp so as to match the light balance after passing through the liquid crystal device, improving the light utilization efficiency, and high after passing through the liquid crystal device. Brightness can be obtained.

Further, according to the configuration of the metal halide lamp 220 of the present embodiment, the lamp current can be sufficiently reduced because the pressure of the rare gas sealed in the airtight container 208 is 15 atm or more and 30 atm or less. .
Thereby, luminous efficiency can be improved and the life of the metal halide lamp 220 can be extended.

  Further, in the metal halide lamp 220 of the present embodiment, the amount of the second halide added is set to 1 mg / cc, so that the amount of shift of the emission spectrum to the low wavelength side can be moderately suppressed, and the light amount on the short wavelength side. Thus, the amount of light on the long wavelength side can be made uniform, the balance of the light of the discharge lamp can be brought close to the balance after passing through the liquid crystal device, and the light utilization efficiency can be further improved.

(Example)
Hereinafter, the present invention will be described by way of examples.
A quartz tube was used as the airtight container 208 of the metal halide lamp 220. After the quartz tube was cleaned and annealed, the electrode assembly 214 was inserted into one sealing portion 208b of the quartz tube 208.
Next, while the inside of the tube was evacuated, the quartz was softened by an oxygen-hydrogen mixed gas burner to perform shrink sealing.
Next, xenon (Xe) was sealed as a rare gas 216 for the starting gas and buffer gas in a quartz tube sealed on one side. The pressure in the xenon container at this time was 15 atm.
Next, a halide 217 as a luminescent material and a metal halide (second halide) 218 having a high vapor pressure were sealed.
Next, the electrode assembly 214 was also inserted into the other sealing portion 208c of the quartz tube. The electrode spacing 219 at this time was adjusted to 1.0 to 2.5 mm. Further, a shrink seal was applied to the other sealing portion 208c of the quartz tube so that the inner volume of the light emitting portion 208a of the hermetic container 208 was 0.9 cm ^3, and a sample of the metal halide lamp 220 was produced.

(Measurement / Evaluation)
When the metal halide lamp of the present invention is used as a TV projector, it is necessary to adjust the light amounts of Red, Green, and Blue to adjust the white balance. In the case of a projector lamp, white light is split into red, green, and blue wavelengths with a dichroic mirror or the like, and after passing through a liquid crystal device or the like, the split light is returned to one again. At this time, by designing a dichroic mirror or the like, it is possible to select a range of wavelengths of light used as Red, Green, and Blue.
Therefore, the wavelength region of each color is set to 430 to 509 nm as the wavelength region used as Blue, 510 to 579 nm as the wavelength region used as Green, and 600 nm to 700 nm as the region used as Red. The emission spectrum of each sample at an input of 100 W of the metal halide lamp was measured, and the luminous flux (lm) and color temperature (K) were further measured.
In addition, the light of the metal halide lamp of each sample is matched to the color with the least amount of light in the obtained spectrum so that the color temperature after passing through the liquid crystal device is 10000K, and the color with the large amount of light is evenly distributed. The light utilization rate (%) of each color after passing through the liquid crystal device and the luminous flux (lm) after passing through the liquid crystal device were measured.

(Sample 1)
A metal halide lamp 220 was manufactured by the above-described manufacturing method, and sample 1 was prepared by enclosing 3 mg of dysprosium iodide (DyI ₃ ) as a light-emitting substance and 15 atm of xenon (Xe) as a rare gas. FIG. 4 shows the spectral distribution at 100 W input of the metal halide lamp 220 of Sample 1.
The spectral distribution of FIG. 4 shows strong emission intensity from 400 to 450 nm. Further, gentle continuous light emission is seen from 450 to 700 nm. However, the intensity tends to decrease as the wavelength becomes longer. Further, the above-mentioned metal halide lamp has a luminous flux of 4200 (lm) and a color temperature of 36000K, which is very blue light.
Next, in order to achieve a color temperature of 10000 K after passing through the liquid crystal device, the light intensity when the color with a large amount of light is uniformly reduced is matched to the color with the smallest amount of light in the obtained spectrum. The utilization ratio was 70% for Blue, 80% for Green, and 100% for Red, and the luminous flux after passing through the liquid crystal device was 2900 (lm).

(Sample 2)
A metal halide lamp 220 was produced as Sample 2 in the same manner as Sample 1 except that ₃ mg of holmium iodide (HoI ₃ ) was encapsulated as a luminescent material. FIG. 5 shows the spectral distribution of the metal halide lamp 220 of Sample 2 at an input of 100 W.
The spectral distribution of FIG. 5 shows strong emission intensity from 400 to 450 nm. Further, gentle continuous light emission is seen from 450 to 700 nm. However, the intensity tends to decrease as the wavelength becomes longer. That is, the tendency was similar to that of Sample 1. Further, the above-mentioned metal halide lamp has a luminous flux of 2900 (lm) and a color temperature of 14000 K, which is very blue light.
Next, in order to achieve a color temperature of 10000 K after passing through the liquid crystal device, the light intensity when the color with a large amount of light is uniformly reduced is matched to the color with the smallest amount of light in the obtained spectrum. The utilization ratio was 80% for Blue, 80% for Green, and 100% for Red, and the luminous flux after passing through the liquid crystal device was 2100 (lm).

(Sample 3)
A metal halide lamp 220 was prepared as Sample 3 in the same manner as Sample 1 except that ₃ mg of thulium iodide (TmI ₃ ) was encapsulated as a luminescent material. FIG. 6 shows the spectral distribution of the metal halide lamp 220 of Sample 3 at an input of 100 W.
In the spectrum distribution of FIG. 6, although there are some characteristic bright lines from 400 to 600 nm, the spectrum is uniform overall. Moreover, strong luminescence intensity is shown from 400 to 430 nm. However, the intensity tends to decrease as the wavelength becomes longer. That is, the tendency was similar to that of Sample 1. The luminous flux of the metal halide lamp is 4900 (lm) and the color temperature is 8600K.
Next, in order to achieve a color temperature of 10000 K after passing through the liquid crystal device, the light intensity when the color with a large amount of light is uniformly reduced is matched to the color with the smallest amount of light in the obtained spectrum. The utilization ratio was 80% for Blue, 60% for Green, and 100% for Red, and the luminous flux after passing through the liquid crystal device was 2800 (lm).

(Sample 4; Example 1)
As a luminescent substance, ₃ mg of dysprosium iodide (DyI ₃ ), as a metal halide (second halide) having a high vapor pressure, 0.5 mg of indium iodide (InI), and as a rare gas, xenon (Xe) The metal halide lamp 220 was manufactured by the above-described manufacturing method by enclosing 15 atm. FIG. 7 shows the spectral distribution of the metal halide lamp 220 of Sample 4 at an input of 100 W.
In the spectrum distribution of FIG. 7, strong light emission from 400 to 450 nm in the sample 1 is suppressed. Conversely, the continuous spectrum increases from 450 nm to 700 nm. These are the effects of encapsulating indium iodide as the second halide. The above-mentioned metal halide lamp has a luminous flux of 6800 (lm) and a color temperature of 5400K.
Next, in order to achieve a color temperature of 10000 K after passing through the liquid crystal device, the light intensity when the color with a large amount of light is uniformly reduced is matched to the color with the smallest amount of light in the obtained spectrum. The utilization ratio was 100% for Blue, 80% for Green, and 70% for Red, and the luminous flux after passing through the liquid crystal device was 4500 (lm).

(Sample 5; Example 2)
A metal halide lamp 220 was fabricated in the same manner as in Sample 4, except that ₃ mg of dysprosium iodide (DyI ₃ ) as the luminescent material and 0.5 mg of thallium iodide (TlI) as the second halide were encapsulated. Sample 5 was obtained. FIG. 8 shows the spectral distribution of the metal halide lamp 220 of Sample 5 at an input of 100 W.
In the spectrum distribution of FIG. 8, strong light emission from 400 to 450 nm in the sample 1 is suppressed. Conversely, the continuous spectrum increases from 450 nm to 700 nm. These are the effects of encapsulating thallium iodide as the second halide. The luminous flux of the metal halide lamp is 6700 (lm) and the color temperature is 7100K.
Next, in order to achieve a color temperature of 10000 K after passing through the liquid crystal device, the light intensity when the color with a large amount of light is uniformly reduced is matched to the color with the smallest amount of light in the obtained spectrum. The utilization ratio was 100% for Blue, 65% for Green, and 90% for Red, and the luminous flux after passing through the liquid crystal device was 4300 (lm).

(Sample 6; Example 3)
A metal halide lamp 220 was fabricated in the same manner as Sample 4, except that ₃ mg of dysprosium iodide (DyI ₃ ) as the luminescent material and 0.5 mg of zinc iodide (ZnI ₂ ) as the second halide were encapsulated. Sample 6 was obtained. FIG. 9 shows a spectral distribution of the metal halide lamp 220 of the sample 6 at an input of 100 W.
In the spectrum distribution of FIG. 9, strong light emission from 400 to 450 nm in the sample 1 is suppressed. Conversely, the continuous spectrum increases from 450 nm to 700 nm. These are the effects of enclosing zinc iodide as the second halide. The above-mentioned metal halide lamp has a luminous flux of 5200 (lm) and a color temperature of 7100K.
Next, in order to achieve a color temperature of 10000 K after passing through the liquid crystal device, the light intensity when the color with a large amount of light is uniformly reduced is matched to the color with the smallest amount of light in the obtained spectrum. The utilization ratio was 100% for Blue, 100% for Green, and 80% for Red, and the luminous flux after passing through the liquid crystal device was 4100 (lm).

(Sample 7; Example 4)
A metal halide lamp 220 is formed in the same manner as in the sample 4 except that ₃ mg of thulium iodide (TmI ₃ ) is used as a light emitting substance and 0.5 mg of gallium iodide (GaI ₃ ) is used as a second halide. A sample 7 was prepared. FIG. 10 shows the spectral distribution of the sample 7 metal halide lamp 220 metal halide lamp at an input of 100 W.
In the spectrum distribution of FIG. 10, strong light emission from 400 to 450 nm in the sample 1 is suppressed. Conversely, the continuous spectrum increases from 450 nm to 700 nm. These are the effects of encapsulating gallium iodide as the second halide. The above-mentioned metal halide lamp has a luminous flux of 6500 (lm) and a color temperature of 6800K.
Next, in order to achieve a color temperature of 10000 K after passing through the liquid crystal device, the light intensity when the color with a large amount of light is uniformly reduced is matched to the color with the smallest amount of light in the obtained spectrum. The utilization ratio was 100% for Blue, 70% for Green, and 90% for Red, and the luminous flux after passing through the liquid crystal device was 4200 (lm).

(Comparative example)
FIG. 12 shows the emission spectrum distribution of a 100 W ultra-high pressure mercury lamp conventionally used in TV projectors.
The emission spectrum of FIG. 12 has several large peaks from 350 to 450 nm, several large peaks from 550 to 600 nm, and no large peaks are seen above 600 nm. The luminous flux of the ultra high pressure mercury lamp is 7100 (lm) and the color temperature is 8700K.
Next, in order to achieve a color temperature of 10000 K after passing through the liquid crystal device, the light intensity when the color with a large amount of light is uniformly reduced is matched to the color with the smallest amount of light in the obtained spectrum. The utilization ratio was 70% for Blue, 60% for Green, and 100% for Red. The luminous flux after passing through the liquid crystal device was 4000 (lm).

  From the above results, the light after passing through the liquid crystal device of the super high pressure mercury lamp of the comparative example has a good balance of emission spectrum compared to the fact that only 56% of the light of the super high pressure mercury lamp can actually be used. Therefore, it can be seen that both the utilization factor of light after passing through the liquid crystal device and the luminous flux have improved.

  Furthermore, the metal halide lamps of Examples 1 to 4 (Samples 4 to 7), which use a halide as the luminescent material and add a metal halide (second halide) with a high vapor pressure, emits much light on the short wavelength side. Can be shifted to the long wavelength side. Therefore, by adding the second halide, the light of the metal halide lamp can be made uniform, and the light use efficiency after passing through the liquid crystal device can be increased.

(Relationship between rare gas filling pressure and lamp current)
Using 3 mg of dysprosium iodide (DyI ₃ ) as the luminescent material, a metal halide lamp was produced by the same method as that for each of the above samples. At this time, the pressure inside the container of xenon was changed to 10 atmospheric pressure, 15 atmospheric pressure, 20 atmospheric pressure, 25 atmospheric pressure, and 30 atmospheric pressure to produce a metal halide lamp.
FIG. 9 shows the relationship between the pressure in the xenon container of the manufactured metal halide lamp and the lamp current.

As shown in FIG. 9, the lamp current can be lowered by increasing the xenon sealing pressure. In particular, by setting the pressure to 15 atm or more and 30 atm or less, the lamp current becomes as low as 3.5 A or less.
Therefore, when the lamp current is reduced, the current capacity of the lighting circuit and the amount of heat generation are not increased, and the light emission efficiency of the metal halide lamp is improved. Moreover, since the consumption of the electrodes of the metal halide lamp is reduced, the life of the lamp can be extended.

Further, from FIGS. 4 to 6, dysprosium iodide, holmium iodide, and thulium iodide have spectral distributions having the same tendency, and from FIGS. Even when any one of indium iodide, thallium iodide and zinc iodide is added, the spectrum distribution has the same tendency. Further, as shown in FIG. 10, even when gallium iodide is added to thulium iodide, the spectral distribution has the same tendency as in FIGS.
Therefore, even if the combination of the first halide and the second halide is any combination thereof, it is possible to make the light uniform and increase the light utilization rate.

  The present invention is not limited to the above-described embodiments, and various other configurations can be taken without departing from the gist of the present invention.

It is a block diagram of the metal halide lamp of this invention. It is a figure which shows the structure which attached the reflector to the metal halide lamp of FIG. AD is a manufacturing process diagram showing a manufacturing method of the metal halide lamp of the present invention. It is a spectrum distribution in the input 100W of the metal halide lamp of the sample 1. FIG. It is a spectrum distribution in the input 100W of the metal halide lamp of the sample 2. FIG. It is a spectrum distribution in the input 100W of the metal halide lamp of the sample 3. FIG. It is a spectrum distribution in the input 100W of the metal halide lamp of the sample 4. It is a spectrum distribution in the input 100W of the metal halide lamp of the sample 5. FIG. It is a spectrum distribution in the input 100W of the metal halide lamp of the sample 6. FIG. It is a spectrum distribution in the input 100W of the metal halide lamp of the sample 7. FIG. It is a figure which shows the relationship between the enclosure pressure of xenon, and a lamp current. It is a spectrum distribution of a 100 W super high pressure mercury lamp.

Explanation of symbols

  201, 202 Electrode, 203 Lead wire, 208 Airtight container, 208a Light emitting part, 208b, 208c Sealing part, 209 Metal foil, 214 Electrode assembly, 215 Heating means, 216 Noble gas, 217 Light emitting substance (first halide) 218 High vapor pressure metal halide (second halide), 219 Electrode spacing, 220 Metal halide lamp, 221 Reflector, 222 Mirror surface

Claims (5)

In a high-pressure discharge lamp having a fire-resistant and transparent hermetic container, an electrode sealed in the hermetic container, a luminescent material and a rare gas sealed in the hermetic container,
A halide is used as the luminescent material,
The halide is one or more first halides selected from dysprosium halide, thulium halide, yttrium halide, holmium halide, lutetium halide, erbium halide, terbium halide, A second halide comprising a metal halide having a higher vapor pressure than the first halide is added,
The high pressure discharge lamp is characterized in that the rare gas is sealed at a pressure of 15 to 30 atmospheres.   The high-pressure discharge lamp according to claim 1, wherein the amount of the second halide added is 1 mg / cc or less.   The high-pressure discharge lamp according to claim 1, wherein the rare gas is xenon.   The first halide is at least one selected from dysprosium iodide, thulium iodide, yttrium iodide, holmium iodide, lutetium iodide, erbium iodide, and terbium iodide. The high-pressure discharge lamp according to claim 1.   The said 2nd halide is 1 or more types chosen from a gallium halide, an indium halide, a tin halide, a thallium halide, a zinc halide, and an aluminum halide, The Claim 1 characterized by the above-mentioned. High pressure discharge lamp.

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