JPH10188913A - Halogen lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly efficient halogen lamp with the maximum luminous efficiency by tensely mounting a filament on the center axis of a rotary ellipsoid formed in a silica bulb to make efficient use of the infrared reflecting coat applied rotary ellipsoid in the bulb without causing slippage throughout its life period. SOLUTION: This lamp has a sealed part 10 formed at least at one end of a silica glass tube 1, where a tungsten filament 4 and outside guide wires 8a, 8b are integrally embedded via metal foils 9a, 9b, and an exhaust tube sealed to the other end of the silica glass tube 1. Metal foils 9a, 9b, metal wires or metal coils slightly smaller than the inner diameter of the exhaust tube are fixed to one ends on the exhaust tube sides of inside guide wires 2a, 2b to hold the filament 4 and put in contact within the exhaust tube and a glass bridge rod 3 in which the inside guide wires 2a, 2b to hold both ends of the filament 4 are integrally embedded and held is put in contact with the inner face of the silica glass tube 1. Part of the silica glass tube 1 is a ellipsoid of revolution with a focal point near both ends of the filament 4 and an axis in the longitudinal direction of the filament 4, an infrared reflecting coat 7 being applied on the surface of the ellipsoid 6.

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 halogen lamp, and more particularly to an improvement in a filament support structure of a high efficiency halogen lamp.

[0002]

2. Description of the Related Art A tungsten filament and an external lead wire are integrally embedded at least at one end of a quartz glass tube via a metal foil, and an elliptical sphere is formed in a part of the quartz glass tube. A halogen bulb in which the filament is disposed between a primary focal point and a secondary focal point and an infrared reflecting film is formed on the surface of an ellipsoidal sphere is disclosed in JP-A-7-4525.
It is known as described in No. 4. Such a halogen bulb has an advantage that the luminous efficiency is better than that of a general halogen bulb in which the quartz glass tube has a straight shape.

[0003] An end-type halogen bulb has a structure as shown in FIG. A sealing portion 6 is provided at one end of the quartz glass 55.
0 is formed, and a pair of metal foils 59a and 59b such as molybdenum and internal introduction wires 52a and 52b connected to the filament 54 are fixed to the sealing portion 60 with a glass bridge 53, and then physically fixed. It is buried. The end of the quartz glass 55 is formed with an exhaust pipe 61 which is sealed after a halogen gas such as a bromide compound is sealed together with an inert gas inside the pipe. Further, a porcelain body 62 which is an insulator having a base 63 at a tip end is fixed to the sealing portion 60 via an inorganic adhesive (not shown). Here, the bulb is made of quartz glass or hard glass. In the figure, reference numeral 56 denotes a spheroid, and an infrared reflecting film 57 is attached to the surface of the spheroid.

[0004]

However, when a filament which is a luminous body is on the rotation axis of the ellipsoidal sphere, the maximum rise of the luminous flux can be expected, but when the filament is displaced from the rotation axis of the ellipsoidal sphere. In this case, the feedback rate of the infrared light returned to the filament from the infrared reflective film is reduced. The cause of such a deviation of the filaments is that the metal foils 59a and 59b are embedded in the quartz glass 55 in a pinch seal process due to fluctuations in the temperature distribution of the heated quartz glass or fluctuations in the pressure of the pinch seal.
This is because b moves inside the sealing portion 60, and for this reason, the position of the filament in the quartz glass tube is shifted from the rotation axis of the ellipsoidal sphere and fixed.

[0005] Table 1 shows the rate of decrease in bulb efficiency due to displacement of the filament from the axis of rotation. The efficiency of the bulb is about 17 (lm / W) without the infrared reflective film.
It is. As shown in Table 1, when the deviation of the filament from the rotation axis is 0 (mm), the efficiency of the bulb can be maximized, and when the deviation is 1 mm, the increase in the efficiency decreases to 50%.

[0006]

[Table 1]

[0007] This means that the positional relationship between the filament, which is a light emitting body, and the elliptical sphere, which is a reflector for returning infrared light, is as follows. Although the efficiency can be expected to be improved best, the efficiency cannot be expected when the filament is shifted from the center position.

[0008] The present invention has been made in view of the above,
The filament is stretched on the central axis of the spheroid formed on the quartz tube, and its displacement does not occur throughout the life of the spheroid. It is an object of the present invention to provide a high-efficiency halogen bulb capable of obtaining a high luminous efficiency.

[0009]

According to the present invention, a sealing portion in which a tungsten filament and an external lead wire are integrally embedded at least at one end of a quartz glass tube via a metal foil is formed. At the other end, an exhaust pipe is sealed, and a metal foil, a metal wire or a metal coil slightly smaller than the inside diameter of the exhaust pipe is fixed to one end of the internal introduction line holding the filament on the exhaust pipe side, and the inside of the exhaust pipe is fixed. A glass bridge rod that embeds and holds an internal introduction line that integrally holds and holds both ends of the filament is brought into contact with the inner surface of the quartz glass tube, and a part of the quartz glass tube is connected to both ends of the filament. A spheroidal sphere having a focal point near the axis and the longitudinal direction of the filament as an axis, and an infrared reflective film is applied to the surface of the spheroidal sphere.

According to the above construction, a glass bridge rod which embeds and holds an internal introduction line holding both ends of a filament stretched along a tube axis integrally with the inner surface of the quartz glass tube is brought into contact with the inner surface of the quartz glass tube. It is possible to minimize the displacement of the lamp filament from the rotation axis of the elliptical sphere due to the pinch seal processing, and efficiently return the infrared light from the filament to the filament via the infrared reflection film attached to the quartz glass tube. And a highly efficient luminous flux can be exhibited.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. FIG. 1 is a schematic side sectional view of an end-shaped halogen lamp according to an embodiment of the present invention, in which a sealing portion 10 is formed at one end of a quartz glass tube 1 and a pair of molybdenum or the like is provided on the sealing portion 10. , The internal lead wires 2a, 2b connected to the filament 4 and the external lead wires 8a, 8b are integrally embedded. The other end of the quartz glass tube 1 is provided with an exhaust tube 11 which is sealed after sealing a halogen gas such as a bromide compound together with an inert gas inside the tube.

A spheroid 6 is formed at the center of the quartz glass tube 1, and an infrared reflecting film 7 is applied to the surface of the spheroid 6. Further, a porcelain body 12 which is an insulator having a base 13 at a tip portion is fixed to the sealing portion 10 via an inorganic adhesive 17.

FIG. 2 is a sectional view taken along line AB of FIG. 1, and FIG. 3 is a sectional view taken along line CD of FIG. As shown in FIGS. 1 and 2, a metal foil 15 as a platinum clad molybdenum foil plated with platinum is fixed to one end 5 b of the internal introduction wire 2 b obtained by connecting one end of the filament 4 by welding.
The width, length and thickness of this metal foil are 1.5 mm, 3 mm,
30 μm. This metal foil 15 has the inner diameter 2 of the exhaust pipe 11.
However, the center deviation of the filament is suppressed to a maximum of 0.25 mm. Instead of the molybdenum foil, a tantalum foil plated with platinum or a molybdenum foil or a tantalum foil obtained by pressing a platinum foil may be used.

Also, as shown in FIGS. 1 and 3, the shape of the glass bridge rod 3 is processed into a shape approximating the inner diameter of the diameter portion of the quartz glass tube 1 to have a length substantially equal to the inner diameter. By making contact with the inner surface, displacement of the filament 4 can be prevented. This means that one end of the filament stretched along the tube axis is supported by an internal introduction line whose tip is in contact with the inner surface of the exhaust pipe, and the other end of the filament is held by one internal introduction line. This is because the glass bridge rod which embeds and holds the internal introduction wire integrally is brought into contact with the inner surface of the quartz glass tube. Then, the displacement of the elliptical sphere of the bulb filament from the rotation axis due to the pinch seal processing of the bulb can be minimized.

FIGS. 4 and 5 are a plan view and a sectional view of a principal part showing another embodiment according to the present invention. FIG. 4 is a plan view of the embodiment shown in FIG. A tantalum wire 18 having a diameter of 0.3 mm and a length of 2 mm is welded to the end 14 of the wire, and is fixed by abutting the inner surface of the exhaust pipe. FIG. 5 shows that the filament 4 is centered by fixing the coil-shaped tantalum wire 19 inscribed in the exhaust pipe 14.

[0016]

As described above, in the halogen lamp according to the present invention, the filament is stretched on the central axis of the bulb, and the displacement does not occur. Efficiently return to the filament and raise the temperature of the filament, the luminous efficiency of visible light can be increased, and it is possible to emit the same luminous flux as before with less power consumption, and high efficiency with low power consumption There is an advantage that a halogen bulb of the present invention can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a partial cross section of a halogen lamp according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view taken along line AB of FIG. 1;

FIG. 3 is a schematic sectional view taken along line CD of FIG. 1;

FIG. 4 is a partial schematic sectional view and a schematic plan view of a halogen lamp according to another embodiment of the present invention.

FIG. 5 is a partial schematic cross-sectional view and a schematic plan view of a halogen lamp according to another embodiment.

FIG. 6 is a schematic front view of a conventional halogen bulb.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Quartz glass tube 2a, 2b Internal introduction line 3 Bridge glass rod 4 Filament 5a, 5b Internal introduction line 6 Elliptical sphere 7 Infrared reflective film 8a, 8b External introduction line 9a, 9b Metal foil 10 Sealing part 11 Exhaust pipe sealing part REFERENCE SIGNS LIST 12 porcelain body 13 cap 14 tip of internal introduction wire 15 metal foil 17 inorganic adhesive 18 metal wire 19 metal coil

Claims (4)

[Claims] 1. A sealing portion in which a tungsten filament and an external lead wire are embedded integrally with at least one end of a quartz glass tube via a metal foil, and the other end of the quartz glass tube is sealed with an exhaust tube. In the halogen lamp, a metal foil, a metal wire, or a metal coil slightly smaller than the inner diameter of the exhaust pipe is fixed to the end of the internal introduction wire holding the filament on the exhaust pipe side, and is abutted inside the exhaust pipe. And, a glass bridge rod that embeds and holds an internal lead wire that holds both ends of the filament integrally is brought into contact with the inner surface of the quartz glass tube. A halogen bulb having a focal point and a spheroidal sphere centered on the longitudinal direction of the filament, wherein an infrared reflective film is applied to the surface of the spheroidal sphere. 2. The halogen lamp according to claim 1, wherein the metal foil inscribed in the exhaust pipe is formed by plating or crimping platinum on molybdenum foil or tantalum foil. 3. The metal wire or metal coil is tantalum,
2. The halogen bulb according to claim 1, wherein platinum is plated or pressed on molybdenum. 4. The infrared reflecting film is an interference film comprising alternating layers of a low refractive material and a high refractive material, wherein the low refractive material is silica dioxide, and the high refractive material is titanium dioxide or tantalum pentoxide. 4. The halogen bulb according to claim 1, wherein the halogen bulb comprises a body.