WO2007091594A1

WO2007091594A1 - High-pressure discharge lamp and image projection device using the same

Info

Publication number: WO2007091594A1
Application number: PCT/JP2007/052121
Authority: WO
Inventors: Ichiro Tanaka; Aki Shindo; Syuhei Kobayashi
Original assignee: Harison Toshiba Lighting Corp.
Priority date: 2006-02-08
Filing date: 2007-02-07
Publication date: 2007-08-16

Abstract

This invention provides a high-pressure discharge lamp comprising a light transparent bulb having a hermetically sealed discharge space, opposed electrodes provided in the discharge space, and a discharge medium sealed in the discharge space. The discharge medium comprises at least one first halide selected from Sc and/or rare earth metals other than Sc, a second halide of at least one of Fe, Zn, and Al, which has relatively high vapor pressure, and a rare gas, and is substantially free from mercury. The high-pressure discharge lamp is characterized in that not less than 30% by weight of the first and second halides is accounted for by a bromide.

Description

Specification

High pressure discharge lamp and image projection apparatus using the same

Technical field

[0001] The present invention requires high efficiency, high output, high light collection efficiency, and a compact design. For example, it is essentially sealed with mercury used as a light source for image projection of a liquid crystal projector. The present invention relates to an environment-friendly high-pressure discharge lamp and an image projection apparatus using the same.

Background art

Conventionally, a high pressure discharge lamp mounted as a light source for a projector has an electrode facing a discharge space formed inside a translucent airtight container, and this electrode is joined to one end of a metal foil. The other end of the metal foil is joined with an electrical lead-in wire, and has a pair of opposed sealing parts sealed with a reduced pressure seal so as to maintain hermeticity at the metal foil part. The space was filled with a discharge medium containing mercury, halogen, noble gas, etc., and the mercury vapor pressure in the discharge space became a high pressure of lOMPa or higher when it was turned on (for example, Patent Document 1).

[0003] From the viewpoint of environmental problems in recent years, there is a discharge lamp that does not contain mercury and has a greatly reduced Na content (for example, Patent Document 2).

Patent Document 1: Japanese Patent Laid-Open No. 2-98984

Patent Document 2: Japanese Patent Laid-Open No. 2001-76670

Disclosure of the invention

[0004] The technology of Patent Document 1 described above is a problem with respect to environmental problems that are becoming increasingly conscious today, because a large amount of mercury is enclosed so that the mercury vapor pressure exceeds 10 MPa when the ultra-high pressure mercury lamp is lit. It was a great effort to resolve the situation. Due to environmental issues in recent years, regulations on harmful substances have become stricter, and there has been a problem with the point of containing mercury. The technology of Patent Document 2 mentioned above is not suitable for image projection because it does not contain mercury and has a low color temperature of 2,700 to 3,500 K, which is environmentally friendly. there were.

[0005] Therefore, Zn (zinc) as a metal instead of mercury, and other luminescent metals as metal halides The metal iodide is mainly enclosed among the metal halides. In this case, if the lamp power is 80W or more and the distance between the electrodes is required to be 5mm or less so as to approach the point light source, the lamp becomes very heavy and the color temperature is less than 5, OOO (K). There is a problem that it becomes a characteristic of color temperature and is not suitable as a light source for a projector.

The object of the present invention is to use a high-pressure discharge lamp excellent in color reproducibility at a high color temperature of 5 ° C. or higher, which is required as a projector light source without essentially enclosing mercury, and to use this high-pressure discharge lamp. Another object of the present invention is to provide an image projection apparatus.

In order to solve the above-described problems, a high-pressure discharge lamp according to an aspect of the present invention includes a light-transmitting quartz glass bulb in which a sealed discharge space is formed, and a facing distance in the discharge space. And at least one first halide selected from Sc and soot or a rare earth metal other than Sc enclosed in the discharge space, Fe having a relatively high vapor pressure. , Zn, A1, at least one second halide, and a discharge medium that also contains noble gas power and essentially does not contain mercury, and the bromide ratio contained in the first and second halides Is characterized by 30 (wt%) or more.

[0008] Further, a high pressure discharge lamp according to another aspect of the present invention includes a translucent bulb in which a sealed discharge space is formed, an electrode disposed at a facing distance in the discharge space, and the discharge space. And a discharge medium which is essentially free of mercury, which is a light-emitting metal, a halogen, and a rare gas power, and the halogen is a halogen other than bromine in the number of moles of bromine (Br). The ratio with respect to the number of moles is 0.4 or more.

[0009] According to the present invention, it is possible to realize a high color temperature of 5, OOO (K) or more required as a light source for image projection such as a projector, and a high pressure discharge lamp as a light source excellent in color reproducibility. It can be obtained.

Brief Description of Drawings

FIG. 1 is a diagram showing a configuration for explaining a high-pressure discharge lamp according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining an example of a temperature at which a second halogenated material effective for a high-pressure discharge lamp according to an embodiment of the present invention becomes latm.

FIG. 3 is a configuration for explaining an example of a high-pressure discharge lamp according to an embodiment of the present invention. FIG.

1—

[1-4] FIG. 4 is a diagram for explaining specifications of encapsulated metals A to E in the high-pressure discharge lamp according to one embodiment of the present invention.

FIG. 5 is a diagram for explaining the relationship between a metal bromide in a metal halide and a color temperature. FIG. 6 is a diagram showing a system configuration for explaining an image projection apparatus according to an embodiment of the present invention.

圆 7] A diagram for explaining the specifications of the sample A ′ to the enclosed metal in the high-pressure discharge lamp according to another embodiment of the present invention.

[Fig. 8] Diagram for explaining the relationship between metal bromide in metal halide and color temperature

Explanation of symbols

'Valve ゝ

12 ...- arc tube section,

131, 132 ... -sealing part,

14 ...-Discharge sky: Between,

151:, 152

161:, 162

171, 172

181:, 182 ... Metal foil,

191:, 192

20 ...- lighting device,

61 ·· -LCD projector,

62 · 'Body,

65-High pressure discharge lamp,

69 ··-Screeny.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. explain.

FIG. 1 is a configuration diagram for explaining a high-pressure discharge lamp according to an embodiment of the present invention. In FIG. 1, reference numeral 11 is a transparent quartz glass noble, and a bulb 11 made of the same material as the arc tube 12 at both ends in the longitudinal direction of the arc tube 12 with a substantially elliptical rotating body. It consists of sealing parts 131 and 132 which make the inside airtight. The arc tube portion 12 is formed with a substantially cylindrical discharge space 14 in the longitudinal direction thereof. For example, a doping material added from the inside of the sealing portions 131 and 132 is added to the discharge space 14. Electrodes 151 and 152 made of pure tungsten material that has not been disposed are arranged so that their tips are opposed to each other with a gap therebetween. The shaft diameter of the electrodes 151, 152 is Φ θ. 5 mm, and a coiler 1 61, 162 of φ 0.2 mm is wound around one end of the electrode 151, 152 for several turns. The same effect can be obtained even if doped tungsten or thorium tungsten is used as the electrode material.

[0014] It should be noted that protrusions 171, 172 are formed at the tip portions of the electrodes 151, 152, respectively, so as to be solidified into a substantially hemispherical shape by melting with a plasma heat source and integrated into an arc. The The electrodes 151 and 152 may be formed by cutting.

The sealing portions 131 and 132 are formed by crushing, and metal foils 181 and 182 made of molybdenum (Mo) are sealed therein. One end of each of the metal foils 181, 182 is welded to the electrodes 151, 152, and the other end is connected to, for example, a nickel wire 191, 192 force S. Wires 191, 192 are lead wires for receiving power from the lighting device 20 outside the lamp.

Here, the discharge space 14 is essentially filled with the first and second halogenated substances, and Xe (xenon) as the starting auxiliary gas.

[0017] The first halide is a metal halide that generates desired light emission such as visible light or ultraviolet light. For example, Scl (scandium iodide), Dyl (dysprosium iodide)

3 3

), DyBr (dysprosium bromide), NdBr (niobium bromide), InBr (indium bromide),

3 3 3

Csl (cesium iodide) is mentioned. In order to use visible light, when a metal halide that generates visible light efficiently is used as the first halogenide, generally, the metal halide does not necessarily have a high vapor pressure during lighting. .

[0018] The second halogenated material has a relatively high vapor pressure during lighting, and the first halogenated material. The metal is not limited to a specific metal as long as it is a metal that does not easily emit light in the visible region as compared with a compound metal. Examples of the metal include Fe (iron), Zn, and A1 (aluminum). Specific examples include Znl (zinc iodide) and ZnBr (zinc bromide).

twenty two

“The vapor pressure is high” means that it is not necessary to be too high like mercury, and preferably the pressure in the airtight container during lighting is about 5 atm or less. For example, the pressure in the airtight container during lighting is about 0. latm or more.

[0020] "It is difficult to emit light in the visible region compared to the metal of the first halide" has a relative meaning in the absolute sense that it does not emit visible light. Fe and Ni (nickel) emit more in the ultraviolet region than in the visible region, but Ti (titanium), A1 and Zn emit more in the visible region. Therefore, when these metals that emit a large amount of light in the visible range are caused to emit light alone, energy is concentrated on the metal, and light emission in the visible range increases. However, if the metal of the second halide is higher in energy level than the metal of the first halide and is difficult to emit light, the energy in the state where the first and second halides coexist. Is concentrated on the light emission of the first halide, so that the light emission of the metal of the second halide is reduced.

[0021] As shown in FIG. 2, the second halogenated material effective in this embodiment is illustrated together with the temperature at which it becomes latm. Note that these values vary somewhat depending on the literature, etc. Therefore, the temperature values in Fig. 2 are approximate values.

[0022] Most of the halogenated materials shown in Fig. 2 have a vapor pressure lower than that of mercury and the adjustment range of the lamp voltage is narrower than that of mercury. Thus, the adjustment range of the lamp voltage can be expanded. For example, All (aluminum iodide

Three

If the desired lamp voltage is not obtained, the lamp voltage will not change even if All is added.

Three

[0023] In contrast, if Znl is added instead of the addition of All,

3 2 2

Thus, the lamp voltage can be increased. Furthermore, if another second halide is added, a higher lamp voltage can be obtained.

[0024] Next, the second halogenated material is allowed if the ratio to the total visible light emitted by the discharge lamp is small and the influence is small, which is not prohibited from the emission of visible light. [0025] Mercury is essentially not enclosed in the discharge medium in the mercury-free high-pressure discharge lamp. `` Essentially no mercury is contained '' means that there is less than 2 mg, preferably less than 1 mg of mercury per lcc of the inner volume of the hermetic container, not just that no mercury is enclosed It means that. However, it is environmentally desirable not to enclose mercury at all. When maintaining the electrical characteristics of the discharge lamp with mercury vapor as in the past, in a small high-pressure metal vapor discharge lamp with a relatively small distance between the electrodes, 200 to 400 mg per lcc of the internal volume of the hermetic container, Depending on the case, it may be said that the amount of mercury is practically small!

[0026] The rare gas is sealed at a pressure of 2 to 15 atm. The rare gas is preferably Xe. The reason why the rare gas sealing pressure is set to 2 to 15 atm is that, within this range, the rise of the luminous flux up to several seconds immediately after lighting can be accelerated, and a desired luminous intensity can be obtained in a short time. If there is not much inconvenience in the time it takes to obtain the desired light intensity immediately after lighting, it is possible to reduce the sealing pressure.

Next, specific dimension examples of the high-pressure discharge lamp that is turned on by the high-pressure discharge lamp according to the embodiment of the present invention are shown in (1) to (4), and will be described with reference to FIG.

[0028] (1) The arc tube 12 has an outer diameter L1 at the center of 11.4 mm, a wall thickness L2 of 2.2 mm, and an inner diameter L3.

5. 6mm, sphere length L4 9.8mm, arc tube 12 inner surface area 195mm ² , inner volume 25

And 0mm ^3.

[0029] (2) Electrodes 151 and 152 have electrode axis L5 of φθ.5mm, coils 161 and 162 diameter L6 of φθ.15 mm, protrusions 171, 172 maximum diameter L7 of 1. Omm, distance between electrodes Set L8 to 2. Omm.

[0030] (3) The metal foils 181, 182 have a thickness of 0.028 mm, a width of 2. Omm, and a length of 15 mm.

[0031] (4) In the discharge space 14, Znl: 0.25 mg, ZnBr: 1.5 mg, Scl: 0

2 2 3

15mg, Dyl: 0. 05mg, DyBr: 0. 18mg, NdBr: 0. 33mg, InBr: 0. lOmg,

3 3 3 3

Csl: 0.07mg is enclosed, and the metal bromide ratio in these inclusions is 80 (wt%). In addition, Xe gas is enclosed at 9atm as a starting auxiliary gas.

[0032] When the high-pressure discharge lamp having the above configuration is driven at a rated lamp power of 100 W and a lamp voltage of 30 V, for example, the lamp efficiency is 45 (lmZW), the color temperature is 8,500 (K), and the average color rendering index Ra is With a high color temperature suitable as a projector light source, the color rendering index exceeds 80, A high pressure discharge lamp excellent in color reproducibility was obtained.

[0033] Verification of the above effect will be described with reference to Figs. Fig. 4 shows an example of trial manufacture of encapsulated metal with the specifications of samples A to E with the dimensions of the high-pressure discharge lamp explained in Fig. 3. Figure 5 evaluates the relationship between the weight percent of metal bromide in the halogenated metal and the initial properties.

As shown in FIG. 5, it can be seen that the color temperature increases as the bromide ratio increases. If the bromide ratio is 30 (wt%) or more near the broken line in the figure, the color temperature can be increased to 5,000 (K) or more. If the bromide ratio is 40 (wt%) or higher, the color temperature can be increased to 6,000 (K) or higher. Furthermore, if the bromide ratio is 60 (wt%) or higher, the color temperature can be increased to 7,000 (K) or higher, and if it is 80 (wt%) or higher, the color temperature is 8,500 ( K) can be higher. The upper limit of the bromide ratio is 99.9 (wt%).

[0035] For this reason, by setting the metal bromide content in the enclosed metal halide to 30 (wt%) or higher, the high color temperature of 5,000 (K) or higher required as a light source for projectors is achieved. This makes it possible to realize a high-pressure discharge lamp as a light source with excellent color reproducibility. In addition, since the enclosed gas does not contain mercury, environmental problems can be solved.

In the above-described embodiment, an example in which a Scl halogenated metal is used will be described.

Three

However, the present invention is not limited to this, and an iodide-based halogenated metal such as ScBr may be enclosed. Bromine

Three

Whether to use a halogenated metal of a halogen type or a halogenated metal of an iodide type is not limited to the metal species and halogen species constituting the halogenated metal. For example, different halogen compounds such as bromide and iodide can be mixed.

FIG. 6 is a system configuration diagram for describing an image capturing device according to an embodiment of the present invention when the high-pressure discharge lamp having the configuration shown in FIG. 1 is mounted on a liquid crystal projector.

In FIG. 6, 61 is a liquid crystal projector, and this liquid crystal projector 61 has a main body 62, and a projection opening 63 is formed on the front side of the main body 62. In addition, a light source 64 is disposed inside the main body 62, and the light source 64 is formed by a high-pressure discharge lamp 65 and a reflector 66 that is optically opposed to the high-pressure discharge lamp 65. And in front of the irradiation direction of the light source 64 A liquid crystal panel 67 as a display means is disposed, and a projection lens 68 as a projection means is disposed in correspondence with the projection opening 63 in front of the liquid crystal panel 67. A screen 69 is disposed in front of the projection opening 63.

Further, a lighting circuit 70 is connected to the high-pressure discharge lamp 65, a liquid crystal driving circuit 71 is connected to the liquid crystal panel 67, and a commercial AC power source 72 is connected to the lighting circuit 70 and the liquid crystal driving circuit 71. The lighting circuit 70 may be one that lights the high-pressure discharge lamp 65 with a direct current or one that lights with an alternating current.

The image capturing apparatus having the above-described configuration first lights up the high-pressure discharge lamp 65 of the light source 64 with the power supplied from the lighting circuit 70. The light from the high-pressure discharge lamp 65 is irradiated directly or reflected by the reflector 66 toward the liquid crystal panel 67. In the liquid crystal panel 67, the display is changed by the liquid crystal driving circuit 71, the light from the light source 64 is transmitted and projected by the projection lens 68, and an image is displayed on the screen 69.

[0041] It is also possible to dispose a transparent front glass that is open in the direction of radiation of the reflector 66, and to seal the high-pressure discharge lamp 65 disposed in the reflector 66 from the outside.

[0042] In this liquid crystal projector, since mercury is not contained and a high-pressure discharge lamp is used, a good color temperature characteristic can be obtained as a liquid crystal projector, and good lamp efficiency and lamp voltage can be obtained. In addition to improving the color reproducibility of the video, the optical design is easy to match.

Next, a high pressure discharge lamp according to another embodiment of the present invention will be described. In the description of the high pressure discharge lamp according to this embodiment, the description overlapping with the matter described in the previous embodiment is omitted.

[0044] In this embodiment, the discharge space 14 of the high-pressure discharge lamp has Znl: 0.5 as the luminescent metal.

2 mg, ZnBr: 1.5 mg, Scl: 0.15 mg, Dyl: 0.05 mg, DyBr: 0.18 mg, NdBr

2 3 3 3 3

: 0. 33mg, InBr: 0. lOmg, Csl: 0.07mg enclosed, occupied in these inclusions

Three

The metal bromide ratio is 80 (wt%). In addition, Xe gas is sealed as a starting auxiliary gas at a room temperature of 9 atm.

[0045] The high-pressure discharge lamp having the above configuration is, for example, rated lamp power of 100W and lamp voltage of 30V. Driving

The lamp efficiency is 45 (lmZW), the color temperature is 8,500 (K), the average color rendering index Ra is 82, the color rendering index exceeds 80 at a high color temperature suitable as a projector light source, A high pressure discharge lamp excellent in color reproducibility was obtained.

[0046] Verification of the above effect will be described with reference to FIGS. Figure 7 was explained in Figure 3.

An example is shown in which the encapsulated metal is prototyped with the specifications of Samples ~ with the dimensions of a high-pressure discharge lamp. FIG. 8 is for explaining the ratio between the number of moles of bromine (Br) and the number of moles of iodine (I) in the metal halide, that is, the relationship between the number of Br moles, the number of ZI moles, and the color temperature.

[0047] As shown in FIG. 8, it can be seen that the color temperature increases as the Br mole number ZI mole number ratio increases. Br mole number ZI mole number ratio of 0.4 or higher near the broken line in the figure increases the color temperature, and the color temperature can be increased to 5,000 (K) or higher, which is required as a light source for projectors. High color temperature of 5,000 (K) or higher can be achieved. If the Br mole number Zl mole number ratio is 1.0 or more, the color temperature can be increased to 6,000 (K) or more. Furthermore, if the Br mole number ZI mole ratio is 2.0 or more, the color temperature can be increased to 7,000 (K) or more, and if the Br mole ZI mole ratio is 5.0 or more, the color temperature is increased. The temperature can be raised above 8,000 (K). The upper limit of the Br mole number Zl mole number ratio is 30.0.

[0048] For this reason, when the ratio of Br mole number Zl mole number in the enclosed metal halide is 0.4 or more, the color temperature increases, and the color temperature increases to 5,000 (K) or more. Therefore, we were able to obtain a light source with excellent color reproducibility at a high color temperature of 5,000 (K) or more, which is required as a light source for projectors.

[0049] Further, since the enclosed gas does not contain mercury, it is possible to solve environmental problems.

Industrial applicability

The present invention can realize a light source that essentially does not enclose mercury and has a high color temperature and color reproducibility, and can be applied to a high-pressure discharge lamp and an image projection apparatus using the high-pressure discharge lamp.

Claims

The scope of the claims

[1] A translucent bulb in which a sealed discharge space is formed, an electrode disposed at a facing distance in the discharge space, and a rare earth metal other than Sc and Sc enclosed in the discharge space It contains essentially mercury, consisting of at least one first halide selected from the above, at least one second halide of Fe, Zn, Al having a relatively high vapor pressure, and a rare gas. No discharge medium, and

A high-pressure discharge lamp characterized in that a bromide ratio contained in the first and second halides is 30 (wt%) or more.

[2] A translucent bulb in which a sealed discharge space is formed, an electrode disposed at a facing distance in the discharge space, and a rare earth metal other than Sc or Sc enclosed in the discharge space. It contains essentially mercury, consisting of at least one first halide selected from the above, at least one second halide of Fe, Zn, Al having a relatively high vapor pressure, and a rare gas. No discharge medium, and

[3] A translucent bulb in which a sealed discharge space is formed, an electrode disposed at a facing distance in the discharge space, and a luminescent metal, a halogen, and a rare gas ska encapsulated in the discharge space A discharge medium essentially free of mercury,

The halogen is a high pressure discharge lamp characterized in that the ratio of the number of moles of bromine to the number of moles of halogens other than bromine is 0.4 or more.

[4] The high pressure discharge lamp according to any one of claims 1 and 3, and

An image projection apparatus comprising: the high-pressure discharge lamp as a light source; and an image projection apparatus main body that projects an image based on light emitted from the light source.