JPH10302612A - Short arc metal halide lamp, light source device and optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sufficient adhesive strength between a reflector and a lamp by knurling the circumferential surface of a base to increase the frictional resistance of the base surface, and letting an adhesive enter the knurling. SOLUTION: An electrode (positive electrode) 2a and an electrode (negative electrode) 2b are buried and fixed to sealing parts on both ends of an arc tube 1, and the circumference of a base 3 is knurled. The arc tube 1 is fixed to the bottom part of a reflecting mirror with cold mirror through the base 3 by use of an inorganic heat resisting adhesive 8 mainly composed of alumina or silica, and an external lead wire is connected to a thread part 9 provided on the base bottom part. As the knurling 4, crisscross pattern can provide the higher strength than plain pattern as adhesive strength. The base is knurled in the miniaturization of the base, whereby a sufficient adhesive strength between a reflector and a lamp can be provided even with a small adhesive area because the adhesive is penetrated into the knurling, and the screw fastening strength can be also sufficiently ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a base of a short arc metal halide lamp, and to an optical device using the lamp as a light source.

[0002]

2. Description of the Related Art Conventionally, a short arc metal halide lamp used only by an arc tube without using an outer tube has been mainly used as a light source of an optical device in a color liquid crystal projector. Projectors using the short arc metal halide lamp are becoming widespread as substitutes for televisions (CRTs). The projector device can project an image on a large screen in addition to being smaller in size than a television (CRT), but with the demand for further miniaturization of the projector device,
There is a demand for making the light source device incorporated in the projector device more compact.

[0003]

In order to reduce the size of the light source device, it is conceivable to reduce the size of the lamp. However, the size of the lamp is limited by the input power of the lamp. Because the length of the hermetic sealing part is limited by the temperature of the welding point between the outer lead wire of the hermetic sealing part of the arc tube and the molybdenum foil, etc. Is extremely low. As a result, it goes without saying that the size reduction of the reflector also results in a very low degree of design freedom.

In order to reduce the size of the light source device, the part having the highest degree of freedom in design can be said to be the base. The function of the base is to electrically connect the lamp power supply line and the external lead wire. In the case of a lamp used in combination with a reflector in a projector device, it is important to fix the reflector and the lamp integrally. There is also a role.

Usually, an inorganic heat-resistant adhesive is used for fixing the reflector and the lamp, and a metal or ceramic material is often used for the base. Metal bases are the mainstream, because the unit price is high, the heat retention effect is large, and problems such as excessive rise in temperature of the portion buried in the hermetically sealed external power supply line are likely to occur.

The base and the external lead wires are electrically connected by crimp terminals or screws, but are often electrically connected by screws for ease of work. However, downsizing the base reduces the bonding area of the base, making it impossible to provide sufficient bonding strength.When connecting with screws, the torque strength when tightening the screws directly affects the base. Therefore, there has been a problem that the lamp falls out without being able to withstand the torque strength, the lamp is damaged by the fall of the lamp, and the reflector is damaged.

In addition, the strength of the screw tightening torque is reduced,
Although there are measures to prevent damage, the shorter arc length of the arc tube causes a larger current to be supplied to the base from the screw part. It is necessary to make the connection between the base and the base more firmly, so that the screw tightening torque strength cannot be loosened.

The present invention has been made to solve the above-mentioned problems of the conventional light source device, and when the size of the base is reduced, a notch is provided in the base to increase the frictional resistance of the base surface. Since the adhesive penetrates into the notch, a metal halide lamp having a sufficient bonding strength between the reflector and the lamp even with a small bonding area, and having a sufficient screw tightening torque strength, a light source device thereof, and an optical device thereof can be used. The purpose is to provide.

[0009]

In order to solve the above-mentioned problems, a first aspect of the present invention is a quartz arc tube, a pair of electrodes provided at both ends of the arc tube, and at least a metal halide therein. A short arc metal halide lamp comprising a base provided on at least one end of the arc tube, wherein a notch is provided on a peripheral surface of the base.

According to a second aspect of the present invention, the arc tube wall load is 30
It is characterized by being lit at 150 W / cm ² . The invention according to claim 3 is characterized in that the notches on the peripheral surface of the base are knurls.

A fourth aspect of the present invention is characterized in that the pair of electrodes comprises an anode and a cathode, and is lit by direct current. According to a fifth aspect of the present invention, there is provided a short arc metal halide lamp according to any one of the first to fourth aspects,
An optical device characterized by using a light source device in combination with a reflector that reflects light emitted from the lamp in a projector device.

[0012]

Next, examples will be described. FIG. 1 is a sectional view showing a main part of an embodiment of a light source device using a metal halide lamp according to the present invention. In the figure, reference numeral 1 denotes a quartz glass arc tube tare. At both ends of the arc tube 1, an electrode (anode) 2a and an electrode (cathode) 2b are embedded and fixed in a sealing portion. The distance between the electrodes 2a and 2b, that is, the arc length is 1.5 mm. 3 is φ7mm, length 2
It is a base of 0 mm, and knurls 4 are provided on its peripheral surface.

The maximum outer diameter of the arc tube 1 is D = 10.0 mm
In the arc tube 1, 0.6 mg of a metal halide containing dysprosium iodide, neodymium iodide, and cesium iodide in a weight ratio of (8: 2: 5) as an encapsulating additive.
33250 Pa of argon for starting and mercury as a buffer gas are enclosed. Note that reference numerals 5a and 5b denote molybdenum foils connected to the electrodes 2a and 2b, which connect an external lead wire and an internal lead wire to supply power. A heat-insulating and heat-reflective film 6 made of white alumina or silica is applied near the reflector buried portion of the electrode 2b. The arc tube 1 is fixed to the bottom of a reflector 7 with a cold mirror via a base with an inorganic heat-resistant adhesive 8 containing alumina and silica as main components, and an external lead wire is provided on a thread 9 provided at the base of the base. It has a structure to be connected.

The above-mentioned light source device is horizontally lit using a dedicated electronic ballast so that the power is 150 W at DC and the tube axis is horizontal. FIG. 2 shows an embodiment of this lamp base, and FIG.
Shows a mouthpiece of another embodiment. The base of FIG. 2 is provided with knurls 4 throughout the base.

A lamp was manufactured using the base shown in FIG. 2 and the conventional base, and an M4 screw was attached to the M4 thread provided on the base of the base, and the lamp was broken to confirm the adhesive strength between the base and the reflector. Table 1 shows the results of the torque strength test. The samples used were knurled base lamps and conventional knurled baseless lamps, each having 10 lamps. The bases were all knurled or the same except for none, and the bonding conditions were the same.

[0016]

[Table 1]

As shown in Table 1, it can be seen that the provision of knurls increases the adhesive strength.

Further, the present invention provides a light emitting tube having a wall load of 30 to 30.
It is defined as 150 W / cm ² for the following reason. The practical lamp output from the use of this lamp is 100 W class or more, but it is difficult to reduce the arc without deteriorating the luminous characteristics in the design with a wall load of 30 W / cm ² or more in this class or more. From the standpoint of further miniaturization, the wall load naturally increases, and the miniaturization of the base is also required. In a lamp having a low wall surface load and a relatively large design tolerance, the deterioration in characteristics due to the size of the base is small, and it is relatively easy to secure the bonding area between the reflector and the lamp. INDUSTRIAL APPLICABILITY The present invention is effective for a lamp having a high wall load and requiring a smaller size.

Although the knurls have been described as the notches, the knurls have a higher adhesive strength than the plain knurls. Further, the lamp has been described as a DC lighting lamp, but may be an AC lighting lamp. Although the case where the knurls are formed on the entire peripheral surface of the base as shown in FIG. 2 has been described, it may be formed on a part of the peripheral surface as shown in FIG.

[0020]

According to the present invention, in the light source device which is reduced in size, the notch is provided on the peripheral surface of the base, so that the frictional resistance of the surface of the base increases, and the adhesive enters the notch. The adhesive strength between the reflector and the lamp can be sufficiently provided without causing a decrease in the adhesive strength due to a decrease in the adhesive area of the base. Further, even in a metal die having a low frictional resistance on a surface plated with nickel or the like, a decrease in adhesive strength can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of a light source device according to the present invention.

FIG. 2 is a side view showing one embodiment of a base of the short arc metal halide lamp according to the present invention.

FIG. 3 is a side view showing another embodiment of the base of the short arc metal halide lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arc tube 2a, 2b Electrode 3 Base 4 Knurl 5a, 5b Molybdenum foil 6 Heat insulation and reflection film 7 Reflector 8 Adhesive 9 Thread

Claims (5)

[Claims] A short circuit comprising: a quartz arc tube; a pair of electrodes provided at both ends of the arc tube; and a metal halide sealed at least inside the arc tube, and a base provided at at least one end of the arc tube. An arc metal halide lamp, wherein a notch is provided on a peripheral surface of the base. 2. An arc tube wall load of 30 to 150 W / cm ^2.
The short arc metal halide lamp according to claim 1, wherein the short arc metal halide lamp is turned on. 3. The short arc metal halide lamp according to claim 1, wherein the notches on the peripheral surface of the base are knurls. 4. The short arc metal halide lamp according to claim 1, wherein said pair of electrodes comprises an anode and a cathode, and is lit by direct current. 5. A light source device comprising a combination of the short arc metal halide lamp according to claim 1 and a reflector for reflecting light emitted from the lamp, in a projector device. An optical device characterized by being used.