JP2002150999A - Discharge lamp device - Google Patents

Abstract

[PROBLEMS] To provide a discharge lamp device capable of lowering the temperature of an arc tube, preventing devitrification of the arc tube, having a long lamp life, high luminance, and excellent color rendering properties. . SOLUTION: In a discharge lamp device including a discharge lamp 10 and a concave reflecting mirror 20, quartz is formed on an outer surface of a light emitting tube 11 outside an effective angle for utilizing light, which irradiates an effective reflecting surface of the concave reflecting mirror, and particularly on an upper half of the outer surface. Film 3 with higher infrared emissivity than glass
0 is formed. Further, a film 30 having a higher infrared emissivity than quartz glass is formed on the visible / infrared reflective film 31. Also, a visible / infrared reflective film is formed on the outer surface of the arc tube on the outer surface of the upper hemisphere within the effective light utilization angle for irradiating the effective reflecting surface 22 of the concave reflector. A film having a higher infrared emissivity than quartz glass is formed on the reflective film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp device used for a liquid crystal projector device, a fiber lighting device, and the like.

[0002]

2. Description of the Related Art As a light source device such as a liquid crystal projector device, a discharge lamp device combining a discharge lamp and a concave reflecting mirror is used. In order to obtain a high-quality image, the discharge lamp has a high luminance and a high color rendering property. A short arc type ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, and the like are used.

[0003] Ultra-high pressure mercury lamps and metal halide lamps need to control the vapor pressure of mercury or metal in order to obtain good color rendering properties. The coldest part temperature in the tube is maintained at a certain temperature or higher, but recently, in order to obtain light with higher luminance and excellent color rendering properties, the arc tube tends to be maintained at a higher temperature. On the other hand, in a xenon lamp, if the temperature difference in the arc tube becomes large, flicker may become a problem due to fluctuations of the arc due to convection, and therefore, it is necessary to make the arc tube temperature as uniform as possible. For this reason, Japanese Unexamined Patent Application Publication No.
As disclosed in Japanese Patent Application Laid-Open No. 83051 and Japanese Patent Application Laid-Open No. 6-252836, a method has been proposed in which cooling air is blown from a blower pipe to an upper portion of a light emitting tube having a remarkable rise in temperature to cool it.

[0004]

However, there is a great demand for miniaturization and weight reduction of a projector device or the like. Therefore, a concave reflecting mirror has a short focal point capable of increasing a light receiving angle even with a small aperture, and a lamp insertion hole. Also small ones are used. For this reason, the discharge lamp combined with such a concave reflecting mirror also needs to be small, and therefore, the load on the tube wall of the arc tube becomes large. For example, in the case of an ultra-high pressure mercury lamp, the discharge lamp is lit with a tube wall load of 50 W / cc or more. Therefore, the temperature of the arc tube becomes extremely high.

[0005] When the arc tube of the discharge lamp is enlarged, the tube wall load is reduced and the temperature rise of the arc tube can be suppressed. However, if the arc tube is large, the lamp insertion hole of the concave reflector is small, so that the light reflected by the effective reflection surface near the lamp insertion hole again strikes the arc tube, partially reflects, and irradiates in a direction other than the predetermined direction. The "vignetting" phenomenon of the generated light occurs. Also, if the arc tube is large, it becomes difficult to secure the temperature of the coldest part of the arc tube,
Luminance and color rendering are impaired.

As described above, in a liquid crystal projector or the like, cooling air is blown into a concave reflecting mirror by a blower pipe to cool the light emitting tube. Ventilation is desired. Further, in order to reduce the size of the apparatus, air is often blown from the side of the concave reflecting mirror, making it difficult to obtain a sufficient cooling effect.

Ultra-high pressure mercury lamps, metal halide lamps, and xenon lamps used as light source lamps operate at a high pressure in which the internal pressure of the arc tube exceeds 4 MPa at the time of lighting, and the arc tube may be broken. For this reason, a transparent front glass is arranged near the opening of the concave reflecting mirror to make it a substantially sealed structure and an explosion-proof / sound-proof structure is often adopted, but in such a case, the cooling air blown from the blower pipe is used. Has a large pressure loss, and a good cooling effect cannot be expected.

As described above, since the discharge lamp used as the light source lamp of the liquid crystal projector is required to have high luminance, excellent color rendering properties, and to be miniaturized, the temperature of the arc tube tends to be extremely high. . However, in general, the inner surface of a quartz glass arc tube becomes devitrified when its outer surface becomes 1100 ° C. or higher, and the luminous bulb swells to greatly reduce the amount of light, thereby significantly shortening the lamp life.

Accordingly, the present invention can reduce the temperature of the arc tube without increasing the size of the arc tube, can prevent the devitrification of the quartz glass constituting the arc tube, prolong the lamp life, and achieve high brightness. Accordingly, it is an object of the present invention to provide a discharge lamp device having excellent color rendering properties.

[0010]

In order to achieve the above object, an object of the present invention is to provide a luminous tube made of quartz glass and a sealing tube portion provided on both sides of the luminous tube. A discharge lamp in which a pair of electrodes held in the stop tube portion are disposed opposite to each other in the arc tube, and fixed on one sealing tube side of the discharge lamp,
In a discharge lamp device comprising a concave reflecting mirror which is opened on the other sealing tube side, an infrared emissivity of quartz glass is higher than that of quartz glass on an outer surface of a light emitting tube which is out of an effective angle of light utilization for irradiating an effective reflecting surface of the concave reflecting mirror. Form a high film.

Here, the average emissivity of quartz glass is ε, and the average emissivity of a film having a higher infrared emissivity than quartz glass is ε ′.
When (ε ′> ε), the cooling capacity by radiation is ε ′ /
Since it can be improved by a factor of ε, forming a film with a higher infrared emissivity than quartz glass with a large ε 'on the surface of the arc tube can suppress the temperature rise of the arc tube even with a small arc tube. Lamp life can be prolonged. In addition, the range in which a film having an infrared emissivity higher than that of quartz glass is formed is outside the effective angle at which light is applied to the effective reflection surface of the concave reflecting mirror, so that visible light that can be effectively used emits infrared light more than quartz glass. There is no interruption by the film with high efficiency, and the light use efficiency does not decrease.

When the discharge lamp is turned on in a horizontal position, the upper hemisphere of the arc tube becomes hotter, so that the concave reflector is effective on the outer surface of the upper hemisphere of the arc tube. When a film with a higher infrared emissivity than quartz glass is formed on the outer surface of the arc tube outside the effective angle of light utilization to irradiate the reflecting surface, the film formation area with a higher infrared emissivity than quartz glass is small,
The temperature of the arc tube can be efficiently controlled.

According to a third aspect of the present invention, a visible / infrared reflecting film is formed on the outer surface of the arc tube outside the effective light use angle for irradiating the effective reflecting surface of the concave reflecting mirror. When a film having a higher infrared emissivity than quartz glass is formed thereon, the amount of heat absorbed by the arc tube can be reduced and the amount of heat radiation can be increased even when radiation from an arc or an electrode is received.

Next, when the discharge lamp is turned on in a horizontal position, the effective light utilization angle for irradiating the outer surface of the upper hemisphere of the arc tube and the effective reflecting surface of the concave reflecting mirror is provided. When a visible / infrared reflective film is formed on the outer surface of the inner arc tube and a film with a higher infrared emissivity than quartz glass is formed on this visible / infrared reflective film, the infrared emissivity is higher than quartz glass. The area where the film is formed is enlarged, and the temperature of the portion of the arc tube where the temperature is desired to be lowered can be efficiently suppressed. In addition, the visible light reflected by the visible / infrared reflective film within the effective light use angle passes through the arc tube of the lower hemisphere and is reflected by the effective reflection surface of the concave reflector, so that the light use efficiency is almost reduced. Nothing.

[0015]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. In FIG. 1, a discharge lamp 10 is an ultra-high pressure discharge lamp having a lamp input of 150 W AC.
A sealing tube section 12 is provided at both ends of an arc tube 11 made of quartz glass.
Are connected continuously. A pair of electrodes 13 and 13 are arranged inside the arc tube 11 at a predetermined interval, and a predetermined amount of mercury is sealed therein. A molybdenum foil 14 is embedded in the sealing tube 12, and the ends of the electrodes 13, 13 are welded to the molybdenum foil 14. The end of the external lead rod 15 is also welded to the molybdenum foil 14 and extends from the end of the sealing tube 12. A base 16 is attached to one of the sealing tube portions 12.

As a specific numerical example of the discharge lamp 10, the outer diameter D of the arc tube 11 is 10 mm and the wall thickness is 2.5 mm.
mm, the outer diameter d of the sealing tube 12 is φ6 mm, and the length SL is 2
5 mm, the amount of enclosed mercury is 0.15 mg / mm ² .

The concave reflecting mirror 20 is an F6 parabolic mirror formed of crystallized glass. A lamp insertion tube 21 is formed on the top of the back surface of the concave reflecting mirror 20, and one sealing tube 12 of the discharge lamp 10 is inserted into the lamp insertion tube 21 and held in a predetermined positional relationship. I have. Concave reflector 2
The effective reflection surface 22 is a surface that forms a paraboloid of the inner surface of the zero and irradiates the reflected light to the opening side of the concave reflection mirror 20, and a visible light reflection film is formed on the surface. Two cooling air passage holes 23 are provided in front of the effective reflection surface 22 so as to face each other.
An explosion-proof / sound-proof front glass 24 is attached to the front opening of the concave reflecting mirror 20.

A specific example of the concave reflecting mirror 20 is as follows.
The wall thickness is 2.5 mm, the diameter is 45 mm, the inner diameter of the lamp insertion tube 21 is 11 mm, and the area of the cooling air passage hole 23 is about 200 mm ² . The visible light reflecting film is made of TiO.
₂ and SiO ₂ thin films are alternately laminated in 37 layers.

The light radiated from the arc luminescent spot between the electrodes 13 of the discharge lamp 13 is applied to the effective reflecting surface 2 of the concave reflecting mirror 20.
2, the angle formed by the line connecting the end of the effective reflection surface 22 on the opening side and the end of the lamp insertion tube to the center between the electrodes 13 is light. The effective use angle, which is a range of 48 to 129 ° in this example. A film 30 having an infrared emissivity higher than that of quartz glass is formed in an annular shape on the outer surface of the arc tube 11 at an effective light use angle. The film 30 having a higher infrared emissivity than quartz glass is made of, for example, SiZrO ₄ .Mn ₂ O ₃ and Fe ₂ O
_3. CoO mixed fine powder is applied to a thickness of 5 to 20 μm and baked.

When the discharge lamp 10 is turned on, cooling air is blown from the cooling air passage hole 23 formed on the side surface of the concave reflecting mirror 20 at a wind speed of about several m / s.
After cooling, it was discharged from the other cooling air passage hole 23. When the temperature of the upper outer surface of the arc tube 11 was measured, it was 1070 ° C. In a conventional example in which the film 30 having a higher infrared emissivity than quartz glass is not formed, this temperature is 1
There was 100 ° C and the temperature dropped by 30 ° C. As a result, the devitrification speed of the arc tube 11 with respect to the lighting time becomes slow, and a good luminous flux maintenance ratio can be realized. However, the temperature of the lower outer surface of the arc tube 11 also dropped by about 30 ° C. from 870 ° C. in the conventional example. That is, the ratio of the temperature difference between the upper and lower portions of the arc tube 11 became large, and a white “cloud” was recognized at the lower portion of the arc tube 11. Then, the light output decreased by about 5%.

FIG. 2 shows an embodiment of the second aspect of the present invention. The discharge lamp 10 and the concave reflecting mirror 20 are the same as those shown in FIG. 1, and the discharge lamp 10 is turned on in a horizontal posture. A film 30 having a higher infrared emissivity than the same quartz glass as that shown in FIG. 1 is formed only on the upper surface of the arc tube 11 outside the effective light use angle.

When the discharge lamp 10 was turned on, the discharge lamp 10 was cooled under the same cooling conditions as described above, and the temperature of the outer surface of the upper part of the arc tube 11 was measured.
The temperature dropped from 070 ° C to 30 ° C. As a result, as in the case of FIG. 1, the devitrification speed of the arc tube 11 with respect to the lighting time becomes slow, and a good luminous flux maintenance ratio can be realized. On the other hand, the temperature of the outer surface of the lower part of the arc tube 11 is 870 like the conventional example.
° C and did not decrease. In other words, the temperature difference between the upper and lower portions of the arc tube 11 became small, no white “cloud” was recognized below the arc tube 11, and the light output hardly decreased.

FIG. 3 shows a main part of the third embodiment of the present invention. The discharge lamp 10 has a lamp input of DC 150
W is an ultra-high pressure discharge lamp having a cathode 13 in an arc tube 11.
A and the anode 13B are opposed to each other, but other specifications are the same as those of the discharge lamp 10 shown in FIG. Also, a concave reflecting mirror (not shown) is the same as that shown in FIG.
The discharge lamp 10 is turned on in a horizontal posture. A visible / infrared reflective film 31 is first formed only on the upper surface of the outer region of the effective light use angle of the arc tube 11, and the visible / infrared reflective film 31 is formed on the visible / infrared reflective film 31 as shown in FIG. A film 30 having a higher infrared emissivity than the same quartz glass is formed. As the visible / infrared reflective film 31, “water platinum” (manufactured by Daiken Chemical Co., Ltd., product name: 5611V, etc.), a dielectric multilayer film, or the like can be used. Water platinum is a liquid containing balsam platinum or balsam gold as a main component.
Although applied and baked with a thickness of about the same, these thin films have a property of reflecting visible and infrared light well and having high heat resistance. In FIG. 3, the visible / infrared reflective film 31 is illustrated as being partially exposed for easy understanding, but actually, the visible / infrared reflective film 31 has a higher infrared emissivity than quartz glass. It is completely covered by the high film 30.

After cooling under the same cooling conditions as described above,
When the temperature of the upper outer surface was measured, the temperature could be further lowered by 5 ° C. or more than when only the film 30 having a higher infrared emissivity than the quartz glass was formed. Therefore, a greater effect can be obtained than in the above example. this is,
The visible / infrared reflecting film 31 mainly emits visible / infrared light having a wavelength of 4 μm or less emitted from the anode 13B.
This is because the heat input to No. 1 can be reduced.

FIG. 4 shows a main part of an embodiment of the present invention. The discharge lamp 10 is a short arc xenon lamp with a lamp input of DC 1 kW. The arc tube 11 made of quartz glass has an outer diameter of 32 mm and a thickness of 2 mm.
, And a sealing tube portion 12 is integrally connected to both ends of the arc tube 11. Xenon gas is sealed in the arc tube 11. In the arc tube 11, the sealing tube portion 1 is provided.
A cathode 13A and an anode 13B whose ends are welded to the molybdenum foil 14 embedded in the second 2 are arranged facing each other at an interval of 3 mm.

When the discharge lamp 10 is turned on in a horizontal position, the visible reflection film 32, the visible / infrared reflection film 31, and infrared radiation from the quartz glass are formed on the surface of the arc tube 11 within the effective light use angle region on the upper surface. A film 30 having a high rate was formed in this order. The portion where these are formed is a region of about φ7 mm centered on the upper end of the tip of the anode 13B. Although the visible reflection film 32 is not always necessary, it is preferable to form the visible reflection film 32 under the visible / infrared reflection film 31 because visible light can be more reliably reflected. Also, as in the case of FIGS. 1 to 3, a film 30 having a higher infrared emissivity than quartz glass or the like may be formed on the outer surface of the arc tube 11 at an effective light use angle.

The visible reflection film 32 is made of, for example, (SiO ₂ + T
a ₂ O ₅ ), a visible / infrared reflective film 3
Reference numeral 1 denotes a dielectric multilayer film of (SiO ₂ + Ta ₂ O ₅ ) + “water platinum”, which is applied to a thickness of several tens μm and baked. The film 30 having a higher infrared emissivity than quartz glass is made of SiZrO ₄ .Mn ₂ O ₃ and F
It is obtained by applying and baking a mixed fine powder of e ₂ O ₃ .CoO to a thickness of several tens μm.

The discharge lamp 10 was turned on alone in an open natural air-cooled state without being combined with a concave reflecting mirror, and the temperature of the upper outer surface of the arc tube 11 was measured.
The temperature was reduced by about 80 ° C. as compared with the conventional example in which the film 30 having a higher infrared emissivity than quartz glass was not formed. Therefore, even when the discharge lamp device is used in combination with the concave reflecting mirror, the temperature of the upper outer surface of the arc tube 11 can be greatly reduced. Then, the light reflected by the visible reflection film 32 or the visible / infrared reflection film 31 passes through the lower part of the arc tube 11 and is reflected by the effective reflection surface of the concave reflecting mirror, so that the light output hardly decreases. Absent.

[0029]

As described above, according to the first to third aspects of the present invention, there is provided a discharge lamp apparatus including a discharge lamp and a concave reflecting mirror, wherein the light is applied to an effective reflecting surface of the concave reflecting mirror outside an effective angle. A film with a higher infrared emissivity than quartz glass is formed on the outer surface of the arc tube, especially the upper half of the outer surface, and a film with a higher infrared emissivity than quartz glass is formed on the visible / infrared reflective film Therefore, it is possible to lower the temperature of the arc tube without reducing the size of the arc tube, to prevent devitrification of the arc tube, to have a long lamp life, to provide a high-luminance and excellent color rendering property. can do. Further, as in the invention of claim 4, a visible reflection film or a visible / red light is formed on the outer surface of the arc tube within the effective angle of using light for irradiating the effective reflection surface of the concave reflector on the outer surface of the upper hemisphere of the arc tube. If an external reflection film is formed and a film having an infrared emissivity higher than that of quartz glass is formed on the visible / infrared reflection film, a better effect can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment according to claim 1;

FIG. 2 is an explanatory diagram of an embodiment according to claim 2;

FIG. 3 is an explanatory view of a main part of the third embodiment.

FIG. 4 is an explanatory diagram of a main part according to an embodiment of claim 4;

DESCRIPTION OF SYMBOLS 10 Discharge lamp 11 Arc tube 12 Seal tube portion 13 Electrode 13A Cathode 13B Anode 14 Molybdenum foil 15 External lead rod 16 Base 20 Concave reflecting mirror 21 Lamp insertion tube portion 22 Effective reflection surface 23 Cooling air passage hole 24 Front glass 30 Film with higher infrared emissivity than quartz glass 31 Visible / infrared reflective film 32 Visible reflective film

Claims (4)

[Claims] 1. An arc tube made of quartz glass and a sealing tube portion provided continuously on both sides of the arc tube, and a pair of electrodes held by the sealing tube portion are opposed to each other in the arc tube. A discharge lamp comprising a discharge lamp and a concave reflecting mirror fixed on one sealing tube side of the discharge lamp and opened on the other sealing tube side; A discharge lamp device characterized in that a film having an infrared emissivity higher than that of quartz glass is formed on the outer surface of an arc tube outside the effective angle for utilizing light for irradiation. 2. The discharge lamp is lit in a horizontal position,
A film having a higher infrared emissivity than quartz glass is formed on the outer surface of the arc tube on the outer surface of the upper hemisphere outside the effective light utilization angle for irradiating the effective reflection surface of the concave reflecting mirror. The discharge lamp device according to claim 1, wherein 3. A visible / infrared reflective film is formed on the outer surface of the arc tube outside the effective angle of light utilization for irradiating the effective reflective surface of the concave reflecting mirror, and quartz glass is applied on the visible / infrared reflective film. 3. The discharge lamp device according to claim 1, wherein a film having a high infrared emissivity is formed. 4. An arc tube made of quartz glass and a sealing tube portion provided on both sides of the arc tube, and a pair of electrodes held by the sealing tube portion are arranged to face each other in the arc tube. A discharge lamp that is fixed on one sealing tube side of the discharge lamp and has a concave reflecting mirror that opens on the other sealing tube side, wherein the discharge lamp is lit in a horizontal position. Forming a visible / infrared reflective film on the outer surface of the upper hemisphere of the arc tube and at the outer surface of the arc tube within an effective light utilization angle for irradiating the effective reflection surface of the concave reflector; A discharge lamp device comprising a film having a higher infrared emissivity than quartz glass formed on a reflective film.