JP2886077B2 - Metal vapor discharge lamp with integrated front cover and reflector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-end type with a front cover and a reflecting mirror incorporated in a projector such as an OHP, a slide projector, a real projector, and a liquid crystal projector. The present invention relates to a metal vapor discharge lamp, particularly to a metal halide lamp.

[0002]

2. Description of the Related Art Conventionally, a halogen lamp has been widely used as a light source with a reflector as shown in the above-mentioned industrial application fields. However, the problem with halogen lamps is that lamp efficiency is low, sufficient illuminance cannot be obtained when projecting, or because there is a large amount of infrared light. In order to lower it, there were many cases where infrared absorption and reflection filters were installed. Also, in order to improve the color rendering properties even a little, the color temperature of the lamp is relatively high, for example, about 3
The breaking life of the filament is 35 due to the design at 200K.
It was as short as ~ 50 hours. To improve the service life,
If the color temperature of the lamp is designed to be low, the lamp efficiency will be further reduced.

On the other hand, the incorporation of a metal halide lamp in a reflecting mirror has conventionally existed as an existing technique, but most of the conventional techniques employ a metal halide lamp having a double tube structure with an outer tube as shown in FIG. It was used as general lighting, fixing it inside. In this case, the life of the lamp is ensured, but the size of the reflecting mirror itself is considerably large, and it is impossible to incorporate the lamp into a compact real machine as shown in the industrial application field. Further, as another example, as shown in FIG. 9, there is an example in which a double-ended metal halide lamp is mounted on a reflector as a lamp alone and used in an open state. In this example, since there is no outer tube, the reflector can be designed to be small, but the sealing portion of the lamp is still twice as long as the arc tube compared to the single-ended type. It protruded from the front opening, and I was able to write on the compactness.

[0004]

An object of the present invention is to overcome the following disadvantages of a halogen lamp as a light source with a reflecting mirror and the following disadvantages of a metal halide lamp. That is, the lamp efficiency is low as a disadvantage of the halogen lamp as the light source with the reflecting mirror,
When projected, sufficient illuminance could not be obtained, or the lamp was designed to have a relatively high color temperature (about 3200K), so that the filament breaking life was as short as 35 to 50 hours. If the color temperature of the lamp is designed to be low in order to improve the life, there is a problem that the lamp efficiency is further reduced. On the other hand, the current double-ended type metal halide lamp has a problem in compactness. In addition, with the recent trend of projectors, with the advent of metal halide lamps, the color temperature of the screen has become daylight (about 6000).
K) is often preferred, and as a light source for liquid crystal projectors in particular, metal halide lamps are becoming the mainstream. Therefore, conversely, the disadvantage that the halogen lamp has a low color temperature and is not a daylight color has been pointed out. However, there are, of course, fields where there is no problem with the light color of a halogen lamp such as illumination using an optical fiber or spot illumination. In summary, the problems that the inventors tried to solve in the present invention are compactness that enters the same reflector as a halogen lamp, and furthermore, the efficiency of the lamp is high, and the color temperature of the lamp is excellent in color rendering near daylight color,
Moreover, it is an object of the present invention to realize a light source having a longer lamp life than a halogen lamp and a relatively short stabilization time of the light color (color temperature and color rendering) of the lamp.

[0005]

In order to solve the above-mentioned problems, in the present invention, the above-mentioned light source is constituted as follows. A single-end type metal vapor discharge lamp in which a pair of conductors are embedded in a sealing portion that is flatly crushed and sealed, and a front cover and a reflecting mirror including a front cover and a reflecting mirror arranged so as to surround the lamp In the integrated metal vapor discharge lamp, the thickness of the arc tube constituting the lamp is T (m
m), when the distance between the electrodes is L (mm) and the lamp voltage of the lamp is V (volt), it is defined as 10 <V / (L × T) <25. A single-end type metal vapor discharge lamp in which a pair of conductors are embedded in a sealing portion that is flatly crushed and sealed, and a front cover and a reflecting mirror including a front cover and a reflecting mirror arranged so as to surround the lamp In the integrated metal vapor discharge lamp, the front outer diameter of the arc tube constituting the lamp is D
0.07 < ₁ (mm), when the outer diameter of the side surface of the arc tube is D ₂ (mm), the length of the arc tube is D ₃ (mm), and the lamp power of the lamp is W (watt), 0.07 < W / (D ₁ × D ₂ × D ₃ ) <0.20. A single-end type metal vapor discharge lamp in which a pair of conductors are embedded in a flat crush-sealed sealing portion, and a front cover and a reflecting mirror comprising a front cover and a reflecting mirror arranged so as to surround the lamp In the integrated metal vapor discharge lamp, when the volume of the area surrounded by the front cover and the reflector is Q ₁ (cm ³ ) and the volume of the arc tube constituting the lamp is Q ₂ (cm ³ ), Q ₁ / It is specified in Q ₂ <15.

Specifically, the following configuration is preferable. A single-ended metal halide lamp in which a pair of conductors are embedded in a flattened crush-sealed sealing part, and a front cover / reflecting mirror integrated type consisting of a front cover and a reflecting mirror arranged to enclose the lamp In the metal vapor discharge lamp, the thickness of the arc tube constituting the lamp is T (m
m), the distance between the electrodes is L (mm), the lamp voltage of the lamp is V (volt), and the front outer diameter of the arc tube is D ₁ (m
m), when the outer diameter of the side surface of the arc tube is D ₂ (mm), the length of the arc tube is D ₃ (mm), and the lamp power of the lamp is W (watt), 10 <V / (L) × T) <25 0.07 <W / (D ₁ × D ₂ × D ₃ ) <0.20 Further, the following condition is added to the above configuration. The volume of the area surrounded by the front cover and the reflector is Q
₁ (cm ³ ), the volume of the arc tube that constitutes the lamp is Q
_{When it is set to 2} (cm ³ ), Q ₁ / Q ₂ <15, and the area is filled with air.

[0007]

In the meaning of 10 <V / (L × T) <25, the relationship between the operating pressure of the lamp in the reflector and the thickness of the arc tube is defined in an optimum range, and the metal halide lamp (hereinafter simply referred to as the lamp) is used. ) To ensure the reliability of burst resistance. First, there are two main causes of the burst of the lamp. One is the pressure resistance of the arc tube against the operating pressure of the lamp, and the other is the adhesion strength of the crushed sealing part. The arc potential gradient V / L is proportional to the operating pressure of the lamp. When V / L ≧ 25 × T, the lamp has a relatively small thickness, and the pressure resistance strength of the arc tube as a container is lower than the operating pressure of the lamp. Increases rapidly. On the other hand, in the case of V / L ≦ 10 × T, the thickness of the arc tube becomes excessively large and rupture from the arc tube disappears, but the thickness and the quartz tube of the crushed sealing portion also increase. The quartz tube of the sealing part is heated by a flame burner from the outside, but the inner surface is harder to heat than the outer surface due to the thick wall, and the metal foil is pressed and adhered in a state where the viscosity of quartz is sufficiently low on the inner surface This makes it difficult to perform, and as a result, the adhesion strength decreases. This increases the probability of the lamp exploding. FIG. 3 shows that the value of V / (L × T) is 5 to 5.
10 shows the rate of occurrence of lamp rupture when the test was performed by changing the lamp to 40.

0.07 <W / (D ₁ × D ₂ × D ₃ )
The meaning of <0.20 is to ensure good initial characteristics and life characteristics of the lamp by defining the size of the arc tube in the reflector and the range of the lamp power.
Here, W / (D ₁ × D ₂ × D ₃ ) is a substitute value for the lamp wall load of the lamp. That is, although the lamp wall load of the lamp is generally obtained by dividing the lamp power by the inner surface area of the lamp, it is difficult to accurately determine the inner surface area of the lamp with a structure such as the present invention. /
(D ₁ × D ₂ × D ₃ ) was used. W / (D ₁ × D ₂ × D
_{If 3} ) is larger than the above range, the tube wall load of the lamp becomes too high in the reflecting mirror, and the reaction of the quartz on the inner surface of the arc tube with the rare earth metal as the filling material proceeds rapidly, and the inner surface of the quartz becomes cloudy. However, the luminous flux maintenance ratio on the surface to be illuminated in front of the light source rapidly decreases. FIG. 4 shows W / (D ₁ × D ₂ × D
₃ ) The luminous flux maintenance rate on the irradiated surface when the lamp is turned on for 100 hours in the reflecting mirror when the value of ₃ ) is changed from 0.03 to 0.25 and examined. From this, W / (D ₁
When (D ₂ × D ₃ ) is 0.2 or more, the luminous flux maintenance ratio becomes 50% or less, and it is confirmed that remarkable deterioration is exhibited.
On the other hand, when W / (D ₁ × D ₂ × D ₃ ) is smaller than this range, the load on the tube wall of the lamp becomes too small in the reflecting mirror, and the luminous flux on the surface to be illuminated due to the reduction in lamp efficiency is reduced. In addition, the color rendering of the lamp is reduced. FIG.
The average color rendering index (hereinafter referred to as Ra) on the irradiated surface when the value of / (D ₁ × D ₂ × D ₃ ) is changed from 0.03 to 0.25 is shown. From this, W / (D ₁ ×
When the value of (D ₂ × D ₃ ) is 0.07 or less, Ra becomes 80 or less, and it cannot be said that the color rendering properties are good.

In a state where gas is present in a region surrounded by the front cover and the reflecting mirror, Q ₁ / Q ₂ <15
Has the following meaning: First, the inventors turn on a metal halide lamp with a reflecting mirror in a state where the arc is horizontal and determine the irradiation distance 1 m ahead in order to determine what should be taken as an index indicating the stability of the light color of the lamp. The color temperature and Ra value on the surface were examined. FIG. 6 is an explanatory diagram of data obtained by examining how the color temperature and the value of Ra change after turning on the lamp. As a result, the color temperature and Ra were stable for almost the same time, and the color temperature was determined to be a representative characteristic for ease of measurement.

Therefore, when the relationship between the color temperature and the value of Q ₁ / Q ₂ was examined, data as shown in FIG. 7 was obtained. According to this, it was found that when the value of Q ₁ / Q ₂ was less than 15, the color temperature was stabilized within 3 minutes and there was no problem in practical use. This result can be explained as follows. That is, when the value of Q ₁ / Q ₂ is small, the lamp can quickly reach thermal equilibrium in a closed atmosphere in the reflector. In a closed atmosphere, convection loss is suppressed, so that the temperature of the coldest part of the lamp rises and good color rendering can be realized. On the other hand, when the value of Q ₁ / Q ₂ is large, on the other hand, it takes a long time for thermal equilibrium, and since the atmosphere is relatively large with respect to the lamp although it is sealed, convection loss also increases, and color rendering Is reduced. On the other hand, it was examined the color temperature stability during Ra, Q ₁ / Q
Ra tends to decrease as the value of ₂ increases,
When the value was small, sufficient color rendering properties were obtained.

[0011]

FIG. 1 is an explanatory view of a single embodiment of a metal halide lamp used in the present invention. In the figure, 1
Is an arc tube made of quartz glass, 2 is connected to the arc tube 1,
It is a sealing portion that is flatly crushed and sealed. 3 is a molybdenum metal foil buried in the sealing portion 2, 4 is an internal lead rod extending from the molybdenum metal foil 3 to the inside of the arc tube 1,
An electrode is attached to the tip 5 or formed so as to function as an electrode. 6 is an external lead rod.
The arc tube may be frosted. As an example of the dimension, the distance L between the electrodes is 3.5 mm and the outer diameter D
₁ and the D ₂ 12 mm, length D ₃ is 9 mm, the thickness T is 1.4 mm. The inner volume of the arc tube is about 0.3 cc. In this arc tube, dysprosium iodide, neodymium iodide and cesium iodide are enclosed in a total amount of about 0.6 mg,
Further, 14 mg of mercury and 7000 Pa of argon (25 ° C.)
Standard) Enclose. When the lighting is performed at a power consumption of about 150 watts, the operating pressure during the lighting is about 2.6 × 10 ⁶ Pa.

In the above-mentioned filling material, a rare earth metal is used because visible light can be obtained well. In addition to the above, scandium, holmium, thulium, erbium and praseodymium are preferable. Further, in order to correct and improve the light emission characteristics, sodium, aluminum, thallium, tin, indium, lithium, and the like may be added together with these rare earth metals. Naturally, the starting gas may be neon, xenon, krypton, or the like.

FIG. 2 is an explanatory view of a light source in which the lamp shown in FIG. 1 is integrally assembled together with a front cover and a reflector with an adhesive. In the figure, 7 is a front cover, and 8 is a reflecting mirror. The rear end of the reflecting mirror 8 is a cylindrical portion 9 and the sealing portion of the lamp is fixed with an adhesive or the like. The opening of the reflecting mirror 8 is 50 mm, the reflecting surface 10 is formed of a spheroid, and a reflecting film is formed.

In the above light source, the front cover is made of frosted glass or glass processed to have a lens function in order to adjust light distribution characteristics.
The reflecting surface 10 may be a rotating paraboloidal surface, a spherical surface, or, as is known, a plain surface processing, a dimple processing, or a combination surface of minute planes. The reflective film may be an aminium vapor-deposited film or a multilayer interference film composed of titanium dioxide / silicon dioxide. Here, an area S (shaded area) surrounded by the front cover and the reflection film is a value when no lamp is provided, and is 16 cc.
It is. The volume on the lamp side is about 1.4 cc. Therefore, the value of Q ₁ / Q ₂ is about 11.4. The opening may be approximately 40-50 mm.

After the above light source was turned on for 3 minutes so that the arc was horizontal, the characteristics of light on the surface to be irradiated about 1 m in front were measured. After 3 minutes, the lighting condition of the lamp is stabilized, the lamp voltage is 80 volts, and Ra is 8
5. The result was that the color temperature was 6000K. A continuous lighting test was performed as it was, and it took 500 hours for the illuminance on the irradiated surface to reach 50% of the initial value. For comparison, use the same single lamp as above, with an opening of 60 mm
And a 70 mm reflecting mirror, and the time until stabilization was examined. The value of Q ₁ / Q ₂ in both cases is
As shown in FIG. 7, the former 22 and the latter 33 have a stable time of less than 5 minutes for the former and slightly more than 7 minutes for the latter. Ra was the former 80 and the latter 78. Further, when the same single lamp as described above is turned on without being attached to the reflector, the color temperature is 7500K,
a73. In any case, it is understood that it is better to select Q ₁ / Q ₂ <15.

[0016]

As can be understood from the above description of the data and the description of the embodiments, while eliminating the drawbacks of a light source with a front cover and / or a reflecting mirror using a halogen lamp, the same size as the light source with a halogen lamp is used. Thus, a light source with a front cover and a reflecting mirror having the advantages of a metal halide lamp can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory view of one embodiment of a metal halide lamp used in the present invention.

FIG. 2 is an explanatory diagram of an embodiment of the present invention.

FIG. 3 is an explanatory diagram of data relating to a burst occurrence probability.

FIG. 4 is an explanatory diagram of data of a luminous flux maintenance factor on a surface to be irradiated.

FIG. 5 is an explanatory diagram of data relating to an average color rendering index.

FIG. 6 is an explanatory diagram of data relating to a color temperature and an average color rendering index.

FIG. 7 is an explanatory diagram of data relating to a color temperature stabilization time.

FIG. 8 is an explanatory diagram of a conventional light source.

FIG. 9 is an explanatory diagram of a conventional light source.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arc tube 2 Sealing part 3 Molybdenum metal foil 4 Internal lead rod 6 External lead rod 7 Front cover 8 Reflecting mirror 9 Tube part 10 Reflecting surface

Claims (7)

(57) [Claims] 1. A single-end type metal vapor discharge lamp in which a pair of conductors are embedded in a sealing portion which is flatly crushed and sealed, and a front cover and a reflector which are arranged so as to surround the lamp. In a metal vapor discharge lamp integrated with a front cover and a reflector, the thickness of the arc tube constituting the lamp is T (mm), the distance between the electrodes is L (mm), and the lamp voltage of the lamp is V
A metal vapor discharge lamp integrated with a front cover and a reflecting mirror, characterized in that 10 <V / (L × T) <25 when (volts). 2. A single-ended metal vapor discharge lamp in which a pair of conductors are embedded in a sealing portion which is flatly crushed and sealed, and a front cover and a reflector which are arranged so as to surround the lamp. In a metal vapor discharge lamp integrated with a front cover and a reflecting mirror, the front outer diameter of an arc tube constituting the lamp is D ₁ (m
m), when the side outer diameter of the arc tube is D ₂ (mm), the length of the arc tube is D ₃ (mm), and the lamp power of the lamp is W (watt), 0.07 <W / (D ₁ × D ₂ × D ₃ ) A metal vapor discharge lamp integrated with a front cover and a reflecting mirror, characterized in that it satisfies <0.20. 3. A single-end type metal vapor discharge lamp in which a pair of conductors are embedded in a sealing portion which is flatly crushed and sealed, and a front cover and a reflector which are arranged so as to surround the lamp. In a metal vapor discharge lamp integrated with a front cover and a reflector, the volume of the area surrounded by the front cover and the reflector is Q
₁ (cm ³ ), the volume of the arc tube constituting the lamp is Q
_A metal vapor discharge lamp integrated with a front cover and a reflector, characterized in that Q ₁ / Q ₂ <15 when ₂ (cm ³ ). 4. The front cover / reflector-integrated metal vapor discharge lamp according to claim 3, wherein a region surrounded by the front cover and the reflector is filled with air or an inert gas. 5. The front cover according to claim 1, wherein the metal vapor discharge lamp is a metal halide lamp in which a metal and a halogen participate in a discharge.
Metal vapor discharge lamp with integrated reflector. 6. A single-end type metal halide lamp in which a pair of conductors are embedded in a sealing portion which is flatly crushed and sealed, and a front cover including a front cover and a reflector arranged so as to surround the lamp. -In a reflector-integrated metal vapor discharge lamp, the thickness of the arc tube constituting the lamp is T (mm), the distance between the electrodes is L (mm), and the lamp voltage of the lamp is V
(Bolt), the front outer diameter of the arc tube is D ₁ (mm), the side outer diameter of the arc tube is D ₂ (mm), and the length of the arc tube is D ₃
(Mm), assuming that the lamp power of the lamp is W (watt), 10 <V / (L × T) <25 0.07 <W / (D ₁ × D ₂ × D ₃ ) <0.20 A metal vapor discharge lamp integrated with a front cover and a reflector, characterized in that it is specified. 7. When the volume of the region surrounded by the front cover and the reflecting mirror is Q ₁ (cm ³ ) and the volume of the arc tube constituting the lamp is Q ₂ (cm ³ ), Q ₁ / Q ₂ < The metal vapor discharge lamp with a front cover and a reflecting mirror according to claim 6, wherein the region is filled with air.