JPH05343033A - Short arc metal halide lamp device - Google Patents

Abstract

PURPOSE:To provide an excellent screen picture plane even having the short arc length of clear emission tube, by preventing the occurrence of illumination nonuniformity on screens, and providing dielectric strength to high-voltage pulses. CONSTITUTION:A base 3, connected to an outside lead wire 2a, is provided on one end of a short arc methal halide lamp 1, having an arc length of 4mm and from which the outside lead wire 2a and an outside lead wire 2b are led out to both ends; and the base 3 of the lamp 1 is inserted in and fixedly mounted on the bottom part lamp supporting hole 6 of a reflecting mirror 5 to fix the lamp 1 to the reflecting mirror 5. A terminal assembly pedestal 8, having a wall thickness of 0.7-1.3 times that of the reflecting mirror and providing an insertion hole 9, is integrally formed on an outer side surface in the middle part between the supporting hole 6 of the reflecting mirror 5 and a front face flange to arrange a terminal assembly 10. The other end of an power supply wire 12, to which one end is connected to the other outside lead wire 2b of the lamp 1, is passed through the insertion hole 9 to be connected to the terminal assembly 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short arc metal halide lamp device for use as a light source of a video device, which is constructed by combining a short arc metal halide lamp with a reflecting mirror.

[0002]

2. Description of the Related Art In recent years, high-density TFTs have been used as video equipment.
A so-called liquid crystal projector is becoming popular in which a small liquid crystal plate is combined with an optical system and projected on a large screen to enjoy images such as video movies. The backlight is a short arc type in which a rare earth metal halide is enclosed. A short arc metal halide lamp device is used in which a reflector having a curved surface of a parabolic, elliptical or multifocal even-order function is combined with the above metal halide lamp.

The metal halide lamp used at that time is composed of only an arc tube without an outer tube, most of which is a double-ended type in which external lead wires are led out to both ends of the arc tube, and is integrated with a reflecting mirror. It is configured. When the lamp is integrated with the reflector, an optical axis arrangement is often adopted in which the optical axis of the reflector and the tube axis of the lamp are aligned. In this case, the lamp on the opening side of the reflector is used. It becomes difficult to pull out the power supply line connected to the external lead wire.

Conventionally, as a method of pulling out the power supply line, as shown in FIG. 5, a lamp mounting support hole 102 provided in a reflecting mirror 101 is used to make a metal halide lamp.
A method of drawing out both power supply lines 104a and 104b of 103 is known.

[0005]

By the way, the short arc metal halide lamp used in this kind of lamp device requires a high voltage pulse for the starting performance of the lamp, so that both power supply lines are provided in the central supporting hole of the reflecting mirror. When inserting and pulling out, the insulation distance between the two must be made large and the central support hole becomes large. Therefore, in consideration of the optical efficiency, the size of the reflecting mirror itself should be further increased or the efficiency should be sacrificed to reduce the illuminance.

Further, in this method of taking out the power supply line, it is possible to use a member made of ceramics in the taken-out portion in order to strengthen the insulation. Therefore, when an experiment was conducted, the temperature was kept by the ceramics. It was found that the temperature rise of the so-called lamp seal portion was large and caused a serious problem in life.

Further, conventionally, the structure shown in FIG. 6 is known in order to increase the insulation distance of the power supply line. That is, in FIG. 6, 201 is a short arc metal halide lamp, both ends of which are external lead wires connected to electrodes.
202a and 202b are provided. 203 is a heat ray transmissive cold mirror with a metal halide lamp at the bottom.
One end of 201 is fixed. 204 is a cold mirror 20
The lead fixing frame made of ceramic attached to the opening of 3 is used for the external lead wire 202a of the metal halide lamp 201.
A conductor 205 connected to is fixed, and an external lead-out terminal 206 is led out from the lead fixing frame 204. 207 is a mounting terminal fixing frame, which is a cold mirror 203.
It is fixed to the outside of the bottom of the metal halide lamp 20
Mounting terminal 208 with 1 external lead wire 202b connected
Is provided.

In the metal halide lamp device having the structure shown in FIG. 6, although the insulation distance between both power supply lines can be secured, when the lamp device is mounted on a video device or the like, an external device provided on the lead fixing frame 204 is used. Output terminal 20
It becomes extremely difficult to insulate 6 in the video device, and the video device itself becomes large, which is a problem.

Furthermore, Japanese Utility Model Laid-Open No. 2-32602 discloses a metal halide lamp device having a structure as shown in FIG. In other words, 303 is a glass substrate with a thickness of 4.5 mm and a dielectric film applied to it.
13mm parabolic cold mirror, the cold mirror 303
External lead 3 of the metal halide lamp 301 on the bottom side of the
02a is connected to the base 304, and the base 304 is cold-mirrored.
Insert it into the mounting hole 305 on the bottom of 303 and fix it. Further, a protruding terminal board pedestal 306 having a maximum wall thickness of 9 mm formed integrally with the cold mirror 303 is provided substantially in the middle of the bottom mounting hole 305 of the cold mirror 303 and the opening flange end, and the terminal board attached to the pedestal 306 is provided. A power supply line 309 connected to the external lead wire 302b on the mirror opening side of the lamp 301 is also connected to 307 via a take-out insertion hole 308 having a diameter of 4.5 mm which is also formed in the pedestal 306.

The metal halide lamp device constructed as described above can achieve both the insulation distance and the temperature of the seal portion,
It has a good structure. However, the arc length of a short arc metal halide lamp used in combination with a reflector is 4
It has been found that when the surface area of the arc tube is as short as about mm and has a large clear arc tube without frosting, illuminance unevenness occurs on the screen when incorporated in an image device and projected on the screen.

Upon studying the cause of this occurrence, as shown in FIG. 8, by integrally providing a protruding terminal plate support 306 for mounting the terminal plate on a part of the cold mirror 303, as shown in FIG.
It was found that a concave portion 310, which is recessed as compared with the portion other than the periphery of the take-out insertion hole 308, is formed on the glass surface of the substrate inside the mirror around the take-out insertion hole 308 formed in the pedestal 306. For this reason, not only is the reflection from the portion corresponding to the area of the take-out insertion hole 308 not performed, but the shape of the recess 310 deviates largely from the desired reflection curved surface. It turned out that there was a bright part.

The present invention has been made to solve the above problems in the conventional metal halide lamp device.
Provided is a short arc metal halide lamp device which prevents occurrence of illuminance unevenness on a screen, has dielectric strength even when a high voltage pulse is applied, and can obtain a good screen screen even with a short arc length in a clear arc tube. The purpose is to

[0013]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a spherical surface, a parabolic surface, an ellipsoidal surface, an even-dimensional functional surface using glass as a substrate and a dielectric multilayer film as a reflecting material. Or a reflector with a reflective surface that combines them,
A short arc metal halide lamp with an arc length of 10 mm or less derived from external lead wires at both ends, in a short arc metal halide lamp device provided at approximately the focal position of the reflector, a power supply connected to one external lead wire of the lamp. The wire is taken out from a take-out hole provided at substantially the center of the reflector, and the power supply line connected to the other external lead wire is provided at the middle of the center take-out hole of the reflector and the front flange. Around the wall thickness of 0.7
It is constructed so that it can be taken out from the through hole in the center of the terminal board pedestal having a thickness of 1.3 times.

As described above, the terminal plate pedestal is formed integrally with the reflecting mirror by making the thickness of the terminal plate pedestal 0.7 to 1.3 times the peripheral thickness of the reflecting mirror base. The effect of sink marks on the inner surface of the reflecting mirror hardly appears, and therefore no concave portion is formed on the inner surface around the take-out insertion hole, and good screen illuminance with substantially no illuminance unevenness can be obtained. Also, a sufficient insulation distance can be maintained between the power supply lines, and since it is not necessary to provide ceramics or the like for insulation strengthening in the seal part, it is possible to reduce the temperature rise of the seal part and prolong the service life. it can.

[0015]

EXAMPLES Next, examples will be described. FIG. 1 is a perspective view showing an embodiment of a short arc metal halide lamp device according to the present invention. In the figure, reference numeral 1 is a short arc metal halide lamp, which has a maximum outer diameter of 10 mm, a maximum inner diameter of 8 mm, a substantially elliptical light emitting portion, and both end seal portions are connected to respective electrodes with an electrode distance of 4.0 mm. The arc tube is provided with external lead wires 2a and 2b, and DyI ₃ -NdI ₃ -CsI is contained in the arc tube in a weight ratio of 8:
In addition to 0.8 mg of 2: 5 and 0.2 mg of HgI ₂ ,
20.000 Pa of Ar as a starting auxiliary gas and 10 mg of Hg as a buffer gas are enclosed. A base 3 connected to the external lead wire 2a is provided at one end of the arc tube,
A heat-resistant Al ₂ O ₃ -Si is formed around the electrode on the other end side.
A mixture of O ₂ is applied and formed as the reflective and heat retaining film 4. The surface of the arc tube on which the heat insulating film 4 is not formed is
It is composed of a clear surface that has not been frosted.

5 has an opening with a diameter of 110 mm and has a focal length
A 13 mm glass-based parabolic reflector having a dielectric multilayer film on its inner surface as a reflective layer, and a lamp support hole 6 is formed at the bottom thereof, and the metal halide lamp 1 is provided in the support hole 6.
The metal halide lamp 1 is fixed to the reflecting mirror 5 by inserting the base 3 of the above and fixing it with an inorganic adhesive. On the outer surface intermediate between the bottom support hole 6 of the reflecting mirror 5 and the opening flange edge,
Two strip-shaped projections 7 with a height of 0.5 mm, a width of about 2 mm and a length of 13 mm
The terminals a and 7b are integrally provided with the reflecting mirror 5 at intervals of about 8 mm between the ends to form the terminal board pedestal 8. As shown in FIG. 2, an insertion hole 9 having a diameter of 3 mm for drawing out the power supply line is formed in the central portion of the terminal board pedestal 8, and the edge of the insertion hole 9 on the inner surface of the reflecting mirror is cut off. A tapered portion 9a having a maximum diameter of 4.2 mm for prevention is formed.

The terminal board pedestal 8 has a strip-shaped projection 7
A terminal plate 10 having a hole 10a is placed between a and 7b, and the terminal plate 10 is attached to the terminal plate cradle 8 by an eyelet 11 which is passed through the hole 10a.
The other end of the power supply line 12 fixed to the other end of the metal halide lamp 1 and connected to the other external lead wire 2b of the metal halide lamp 1 through the insertion hole 9 of the terminal board support 8 and the hole 10a of the terminal board 10 to the terminal board 10. Connected. The terminal board support 8 has a wall thickness of 4.5 mm
Since it is formed to project only 0.5 mm from the surface of the reflecting mirror 5, the maximum thickness of the strip-shaped projections 7a and 7b of the terminal board support 8 is 5.0 mm, which is equal to the thickness of the surrounding reflecting mirror 5. It is 1.11 times thicker.

Next, an experiment conducted for confirming the operation and effect of the short arc metal halide lamp device constructed as described above will be described. Figure 3 shows a 40-inch diagonal screen used to evaluate uneven illuminance.
20 shows the short arc metal halide lamp device having the above-mentioned structure incorporated in a liquid crystal projector using an optical system, turned on at a rating of 135 W, projected on the screen 20, and evaluated the illuminance unevenness on the screen. In order to evaluate the unevenness of illuminance, the position of the lamp device arranged in the liquid crystal projector should be set so that the shadow of the insertion hole for drawing out the power supply line formed on the reflecting mirror is most on the diagonal line AA ′ of the screen 20. The illuminance distributions of the conventional example having the configuration shown in FIG. 7 and the illuminance distribution of the present example were measured so that they would appear larger. In FIG. 3, O indicates the center position of the screen.

The measurement results are shown in FIG. In FIG. 4, the solid line shows the illuminance distribution along the screen AA 'of this embodiment, and the broken line shows the illuminance distribution of the conventional example. As can be seen from these illuminance distributions, it was confirmed that the illuminance distribution of the present example was significantly improved as compared with the illuminance distribution of the conventional example, and a uniform and good-quality screen without illuminance unevenness was obtained.
In FIG. 4, the hatched portion is a concave portion formed around the insertion hole 308 in the reflecting mirror 303 provided with the protruding terminal plate support 306 in the conventional metal halide lamp device.
310 indicates the shadow area where the illuminance has decreased.

Further, the same experiment was carried out on various projections of the terminal board pedestal provided on the reflecting mirror. As a result, the thickness of the terminal board pedestal was not formed. Within the range of 0.7 to 1.3 times the wall thickness of the reflecting mirror part, there is almost no influence of the sink of the base glass of the reflecting mirror by the terminal board pedestal, and the uneven illuminance may not occur substantially. confirmed. The lower limit is set to 0.7 times when the wall thickness of the terminal board pedestal is less than 0.7 times the wall thickness of the reflecting mirror portion, the substrate glass is not distorted, but the mechanical strength is reduced. This is because problems will occur.

Further, when an experiment was carried out by combining short arc metal halide lamps with various arc lengths with a reflecting mirror, when the arc length exceeds 10 mm, the illuminance of the entire screen is lowered and the screen becomes dark, and the meat of the terminal board pedestal is reduced. Almost no effect was obtained by reducing the thickness. Therefore, the arc length of the short arc metal halide lamp used in the present invention is specified to be 10 mm or less.

[0022]

As described above on the basis of the embodiments,
According to the present invention, the effect of sink marks and the like on the inner surface of the reflecting mirror due to the integral formation of the terminal board pedestal for inserting and connecting the power supply line with the reflecting mirror does not appear, and there is practically no unevenness in illuminance. The screen illuminance is obtained. In addition, a sufficient insulation distance can be maintained between the power supply lines, and the temperature rise of the seal portion can be reduced to prolong the service life.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a short arc metal halide lamp device according to the present invention.

FIG. 2 is an enlarged sectional view of a terminal board pedestal portion in the embodiment shown in FIG.

FIG. 3 is a diagram showing a screen used for evaluating illuminance unevenness of a short arc metal halide lamp device.

FIG. 4 is a diagram showing an evaluation result of uneven illuminance of the short arc metal halide lamp device of the present invention and the conventional example.

FIG. 5 is a diagram showing a configuration example of a conventional metal halide lamp device.

FIG. 6 is a diagram showing another configuration example of a conventional metal halide lamp device.

FIG. 7 is a diagram showing still another configuration example of the conventional metal halide lamp device.

FIG. 8 is an enlarged cross-sectional view of a conventional terminal plate pedestal portion shown in FIG.

[Explanation of symbols]

 1 Short arc metal halide lamp 2a, 2b External lead wire 3 Base 4 Reflective and heat-retaining film 5 Reflector 6 Lamp support hole 7a, 7b Strip-shaped protrusion 8 Terminal plate cradle 9 Insert hole 9a Taper part 10 Terminal plate 11 Eyelet 12 Power supply line

Claims (1)

[Claims] 1. A reflector having a spherical surface, a parabolic surface, an ellipsoidal surface, an even-dimensional function surface, or a combination of these surfaces, using glass as a substrate and a dielectric multilayer film as a reflecting material, and external lead wires at both ends. A short arc metal halide lamp having an arc length of 10 mm or less derived from the above, in a short arc metal halide lamp device provided at substantially the focal position of the reflecting mirror, a power supply line connected to one of the external lead wires of the lamp is the reflection The power supply line taken out from the take-out hole provided in the substantially central portion of the mirror and connected to the other external lead wire has a peripheral wall thickness of the reflecting mirror base provided between the central take-out hole of the reflecting mirror and the front flange. A short arc metal halide lamp device, characterized in that it is taken out from a through hole in the center of a terminal board pedestal having a thickness of 0.7 to 1.3 times.