JP2000003614A - Discharge lamp fitted with reflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp fitted with a reflector, resistant to twisting moment at the time of nut fastening. SOLUTION: This lamp is equipped with a luminous tube 1 comprising a luminous part 4 and seal parts 5, 6 connected with continuity to both end parts of the luminous part 4. The seal parts 5, 6 are sealed up under a reduced pressure and each formed into a cylindrical shape. A base 13 comprises a tube part 14 and a screw part 17. The tube part 14 is formed into an elliptic shape. The seal part 6 of the luminous tube 1 is inserted in the tube part 14 of the base 13, and the luminous tube 1 and the base 13 are integrally fastened to each other by cement 18. The base 13 with the luminous tube 1 fastened thereto is inserted in an opening part 21 smaller in diameter in a reflector 20, and they are integrated with each other with the cement 18 packed in a gap between the opening part 21 in the reflector 20 and the base 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a discharge lamp with a reflector.

[0002]

2. Description of the Related Art As a light source for video equipment such as a liquid crystal projector, a discharge lamp with a reflector in which an arc tube is arranged at a focal position of a funnel-shaped reflector is known.

[0003] Such a discharge lamp with a reflecting mirror comprises a light emitting portion in which a pair of electrodes is provided with a distance between the electrodes of 1 to 3 mm, and sealing portions provided at both ends of the light emitting portion. An arc tube, a metal base including a tube portion and a screw portion, and a funnel-shaped reflecting mirror are provided. The sealed part of the arc tube is inserted into the cylinder of the base and fixed with cement. The base fixed to the arc tube is fixed to the reflector with cement, and the arc tube, the base and the reflector are integrated. Have been. The sealing portion has a cylindrical shape, and the cylindrical portion of the base has a cylindrical shape as shown in FIG. A ring-shaped metal terminal is fixed to the screw portion of the base with a nut, and a power supply line derived from a lighting device (not shown) is connected to the metal terminal.

[0004]

However, at the time of fixing with the nut, the base to which the arc tube is fixed comes off from the reflecting mirror even though the base and the reflecting mirror are fixed with cement. There was something.

[0005] The cylindrical portion of the base is formed in a cylindrical shape, and the adhesive strength between the base and the cement is weak due to the difference in material between the cement and the metal base. There is a problem that the base is rotated by the moment) and the base is removed together with the arc tube from the reflecting mirror.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a discharge lamp with a reflector which is resistant to a torsional moment when tightening a nut.

[0007]

According to the present invention, there is provided a discharge lamp with a reflector, comprising: a light emitting portion having a pair of electrodes therein; and a sealing portion connected to both ends of the light emitting portion; A cap comprising a tube portion and a screw portion, and a reflector are provided, and the sealing portion of the arc tube is inserted into the tube portion of the cap and fixed with cement, and the cap is cemented to the reflector. The arc tube, the base, and the reflecting mirror are fixedly integrated, and the sealing portion has a cylindrical shape, and the cylindrical portion of the base has a non-cylindrical shape.

Thus, even when a torsional moment is applied to the base, the base to which the arc tube is fixed does not come off from the reflecting mirror, and a discharge lamp with a reflecting mirror that is strong against the torsional moment can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A discharge lamp with a reflecting mirror according to a first embodiment of the present invention will be described.

As shown in FIG. 1, a discharge lamp with a reflector (hereinafter, referred to as a product A of the present invention), which is a light source for a liquid crystal projector comprising a 150 W ultra-high pressure mercury lamp and a reflector, has a pair of electrodes 2 inside. 3 is provided with a luminous tube 1 made of quartz comprising a luminous part 4 provided with a distance between the electrodes of 1.5 mm and sealing parts 5 and 6 provided at both ends of the luminous part 4. The sealing portions 5 and 6 include electrodes 2 and 3, electrode rods 7 and 8, metal foils 9 and 10, portions of the electrode rods 7 and 8 of the lead body to which external lead wires 11 and 12 are sequentially connected, metal The foils 9 and 10 and a part of the external lead wires 11 and 12 are sealed. The sealing portions 5 and 6 are sealed under reduced pressure and are formed in a cylindrical shape having a diameter of about 6 mm and a length of about 25 mm.

The metal base 13 is, as shown in FIG.
A ring-shaped metal terminal 15 is connected to the screw portion 17 by a nut 16.
The metal terminal 15 is connected to a power supply line 15a that supplies power from a lighting device (not shown) to the lamp. The cylindrical part 14 is formed in an elliptical shape. The rotational symmetry about the central axis of the cylindrical portion 14 as the rotation axis is broken from a perfect circle, thereby improving the strength against the torsional moment. In order to break this rotational symmetry, the major axis of the ellipse is desirably 1.2 times or more the minor axis.

One of the sealing portions 6 of the arc tube 1 is inserted into an elliptical cylindrical portion 14 of a base 13, and a gap between the sealing portion 6 and the cylindrical portion 14 is filled with cement 18. And base 1
3 are integrally fixed.

The external lead wire 12 extending to the side of the sealing portions 5 and 6 to which the base 13 is fixed passes through the base 13 and is connected by welding at the tip of a screw portion 17. The other external lead wire 11 is connected to one end of a wire 19 provided through a reflecting portion of a reflecting mirror.
The other end of the wire 19 is connected to the lighting device, so that power is supplied to the arc tube 1 through the wire 19 and the power supply line 15a.

The reflecting mirror 20 has a funnel shape, and a base 13 to which the arc tube 1 is fixed is inserted into an opening 21 having a smaller diameter, and a space between the opening 21 of the reflecting mirror 20 and the base 13 is provided. The gap is filled with cement 18 and integrated.

The entire sealing portion 6 does not need to be inserted into the cylindrical portion 14 of the base 13, as long as a part of the sealing portion 6 is inserted and fixed to the cylindrical portion 14.

An explosion-proof glass 22 is fixed to the front surface of the reflecting mirror 20 by a metal band 23, and the arc tube 1 is sealed in the reflecting mirror 20.

Next, a discharge lamp with a reflector (hereinafter, referred to as a product B of the present invention) according to a second embodiment of the present invention will be described.

The configuration of the present embodiment is the same as that of the product A of the present invention, except for the base 24.

That is, as shown in FIG.
Is composed of a cylindrical portion 25 and a screw portion 26, and the cylindrical portion 25
Is formed with a notch 27. Notch 27
For example, the dimension of the width (W) is 3 mm and the length (L) is 4 m
m.

When the sealing member 6 and the base 24 are fixed to each other, the cement 18 enters the notch portion 27, and a resistance force against rotation is generated between the cement 18 and the notch portion. The strength against Therefore, the wider the width of the cutout portion is, the more effective it is. For example, it is desirable that the width is 0.4 times or more the inner diameter of the base 24.

Next, a description will be given of a discharge lamp with a reflecting mirror according to a third embodiment of the present invention (hereinafter referred to as a product C of the present invention).

The structure of this embodiment is the same as that of the product A of the present invention, except for the base 28.

That is, as shown in FIG.
Is formed of a cylindrical portion 29 and a screw portion 30 and has a shape obtained by cutting off a part of the cylindrical portion 29, for example, the tip of the cylindrical portion on the side opposite to the screw portion is formed in an arc shape. In the present embodiment, for example, the shape of the portion having a length of 4 mm from the tip of the cylindrical portion 29 is a semicircular shape. With such a configuration, the cement 18 penetrates into the cut-out portion, thereby improving the strength against the torsional moment.

Next, a description will be given of a discharge lamp with a reflecting mirror according to a fourth embodiment of the present invention (hereinafter referred to as a product D of the present invention).

The structure of this embodiment is the same as that of the product A of the present invention, except for the base 31.

That is, as shown in FIG.
Is composed of a cylindrical portion 32 and a screw portion 33, and the shape of the cylindrical portion 32 is cylindrical.
4 are formed. By providing the protrusion 34,
By embedding the protrusions 34 in the cement 18, the rotational symmetry is broken, and the strength against the torsional moment is improved.

In this embodiment, the protrusion 34 of about 5 mm is formed. Further, a concave portion (not shown) may be formed on the outer surface instead of the projecting portion 34. In this case, the same effect can be obtained by filling the hollow with the cement 18.

Further, the projecting portion 34 and the concave portion may be formed on the outer surface of the cylindrical portion 31 in combination. For example, FIG.
As shown in (1), a mesh-like unevenness of about 0.5 mm square may be formed on the outer surface of the cylindrical portion 32. Alternatively, the irregular surface may be formed by making a linear scratch on the outer surface of the base completely at random. Further, as shown in FIG. 7, a protrusion 35 may be provided on the outer surface of the cylindrical portion 25 of the base 24 (see FIG. 3) used in the product B of the present invention.

Next, the torsional moment of each of the above-mentioned products of the present invention and the inner diameter 7 mm, outer diameter 8 mm, and length 1 shown in FIG.
A comparison was made with the torsional moment of a discharge lamp equipped with a reflecting mirror, which is a conventional liquid crystal projector light source having a 5 mm cylindrical base 38. The torsional moment was measured by tightening a nut on the screw portion of the base, and measuring the moment when the base began to rotate.

As a result, the torque strength of the conventional product was 0.2
While the torque strength is 0.35 to 0.55 kgfm in each of the present invention products, the strength against the torsional moment is improved by the present invention. .

[0031]

As described above, according to the present invention, even when a torsional moment is applied to the base, the base to which the arc tube is fixed does not come off from the reflecting mirror, and a discharge lamp with a reflecting mirror which is strong against the torsional moment is provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a discharge lamp with a reflecting mirror according to an embodiment of the present invention.

FIG. 2 is a perspective view of the same elliptical base.

FIG. 3 is a perspective view of a base having a notch.

FIG. 4 is a perspective view of a base in which a part of the cylindrical portion has an arc shape.

FIG. 5 is a perspective view of a base having a protrusion on the outer surface of the base.

FIG. 6 is a perspective view of a base having a mesh-like projection on the outer surface.

FIG. 7 is a perspective view of a base having a notch and a protrusion on the outer surface.

FIG. 8 is a perspective view showing a base of a conventional discharge lamp with a reflector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arc tube 5,6 Sealing part 13,24,28,31 Cap 14,25,29,32 Cylindrical part 17 Screw part 18 Cement 20 Reflecting mirror 27 Notch part 34,35 Projection part

Claims (6)

[Claims] 1. A light emitting tube comprising a light emitting portion having a pair of electrodes therein, sealing portions provided at both ends of the light emitting portion, a base comprising a cylindrical portion and a screw portion, and a reflecting mirror. The sealing portion of the arc tube is inserted into the cylindrical portion of the base and fixed with cement, and the base is fixed to the reflecting mirror with cement and the arc tube, the base, and the reflecting mirror are provided. Wherein the sealing portion has a cylindrical shape and the cylindrical portion of the base has a non-cylindrical shape. 2. The discharge lamp with a reflecting mirror according to claim 1, wherein the cylindrical portion of the base has an elliptical shape. 3. The discharge lamp with a reflector according to claim 1, wherein the base of the base has a notch. 4. The discharge lamp with a reflecting mirror according to claim 1, wherein the cylindrical portion of the base has a cylindrical shape and has a notch. 5. The discharge lamp with a reflecting mirror according to claim 1, wherein a projection is provided on the surface of the cylindrical portion of the base. 6. The discharge lamp with a reflecting mirror according to claim 1, wherein a concave portion is provided on a surface of the cylindrical portion of the base.