JPH09161731A - Tungsten halogen lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance utilization efficiency of the light by making a shape of an electric lamp smaller. SOLUTION: A lead-in wire 4 is connected to a sealing part on one end of a glass bulb through a pair of molybdenum foils 3, and a coil-shape filament 1 stretched in parallel along the tube axis is provided in the central vicinity of the bulb, and a light reflecting film 6 is applied to an inside surface or an outside surface of the bulb, and a part of the light reflecting film 6 has an opening part 7, and is constituted so that the reflected light by the light reflecting film 6 does not collide with the coil shaped filament 1, and that the central axis of the filament 1 is dislocated in the opposite side direction of the opening part 7 to the center of the tube axis of the bulb.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a halogen light bulb, and to an improvement in a light bulb structure for realizing a smaller light bulb having a high light utilization efficiency.

[0002]

2. Description of the Related Art Halogen bulbs containing a tungsten filament in a quartz glass tube and containing an inert gas and a halogen gas are more compact and have a longer life than ordinary incandescent bulbs, and maintain brightness until the end of their life. However, it has the advantage of high efficiency and is widely used as a light source for general lighting in stores, offices, and the like. In addition, this type of halogen bulb makes use of the feature that it is particularly small, and
It is widely used as a light source for optical devices such as optical fibers and liquid crystal projectors.

[0003]

For such a halogen bulb for optical equipment, a compact bulb having a high light utilization rate is required. In order to improve the light utilization rate, see FIG.
Like the halogen light bulb 30 with a reflecting mirror, the reflecting mirror 31 and the halogen light bulb 3 each having a reflecting surface formed in a substantially elliptic curved surface shape.
It is common to combine 2 and. The reflecting surface of the halogen bulb with a reflecting mirror is designed so that the primary focus of the substantially elliptic curved surface of the reflecting surface is disposed near the filament 33, and the secondary focus is disposed in front of the opening of the mirror. To be done. A mirror having a short focal length between the primary focus and the secondary focus is called a short focus type, and a mirror having a long focal length is called a long focus type. However, if a reflecting mirror is combined with a halogen light bulb, it may become undesirably large in size, which poses a problem.

Further, in order to improve the light utilization efficiency by taking advantage of its small size, a light reflecting film 6 is provided on an inner surface or an outer surface of a cylindrical glass bulb 2a shown in a sectional view of a main part of FIG. For example, it is conceivable to form the opening 7 in almost half of the entire circumference of the valve 2a. In this structure, the light emitted from the coil-shaped filament 35 arranged substantially in the center of the tube axis of the glass bulb is reflected on the inner surface of the bulb by the light reflecting film and is condensed at the opening of the light reflecting film. However, the light reflected by the light-reflecting film hits the filament and is not concentrated in the opening so much that it has no effect and has not been put to practical use.

The present invention has been made in view of the above problems, and an object thereof is to provide a halogen bulb of various shapes which is more compact and has high light utilization efficiency, and which is particularly suitable as a light source for optical equipment.

[0006]

In order to achieve the above object, the present invention relates to a halogen bulb in which a light reflecting film is applied to the inner surface or the outer surface of a glass bulb, wherein a part of the light reflecting film has an opening. The central axis of the filament is shifted in a direction opposite to the opening with respect to the center of the tube axis of the glass bulb so that the light reflected by the light reflection film does not collide with the coiled filament. Efficiency is improved and light utilization is improved.

Since the filament position is changed, most of the light emitted from the filament is collected in the opening without hitting the filament after being reflected by the light reflecting film. However, some light still hits the filament and may not reach the opening. If the deviation from the center is not more than the radius of the filament, the amount of light that hits the filament and does not reach the opening increases, so the effect is small, and the distance between the filament and the inner wall of the bulb is 2 mm.
In the following cases, the halogen cycle will be disturbed.

Although it is considered that the light utilization rate is reduced by performing a process for diffusing light on the opening of the light reflection film of the glass bulb, it has an effect of erasing the image of the filament. Such a process of diffusing light is performed by making unevenness on the valve surface. Also, JP-A-61-82660
It is also possible to implement the configuration as disclosed in Japanese Patent Laid-Open No. 61-80202.

The light reflecting film may be a metal thin film of aluminum, silver, gold, platinum or the like. However, since the metal thin film also reflects infrared rays, depending on the shape of the filament and the bulb, infrared rays may heat the filament to cause hot spots. It may occur and the life may be shortened. Also, depending on the purpose of use, it is often desirable to use only visible light among the light emitted from the filament.

As described above, when the filament shape and the bulb shape are likely to cause hot spots and have a short life, or when it is desired to eliminate infrared rays, an optical interference film that transmits infrared rays and reflects visible light is used. May be. When the light interference film is used, it may also serve the purpose of reflecting a part of visible light and adjusting the color.

When measuring the sugar content of fruit, the sugar content of fruit is 9
It is used to absorb infrared rays in the vicinity of 00 nm. When used for such a purpose, the light reflecting film may selectively reflect infrared rays in the vicinity of 900 nm. As such a technique, a technique using a laser beam has been published in the following paper. The halogen lamp is suitable as a light source used for such infrared spectroscopic analysis as well because it has a high infrared emissivity. Thus, for some purposes, infrared radiation in a certain wavelength range may be required. In this case, a desired wavelength can be selectively reflected by applying an infrared reflection film made of a light interference film.

Further, in order to further improve the light utilization rate, the bulb may have a substantially spherical shape. When a cylindrical valve is used, it is more effective to stretch a long filament along the central axis of the cylindrical valve, but when a spherical valve is used, it is effective regardless of the filament shape. Therefore, the effect of the present invention is greater when a spherical valve is used. Further, the same action and effect can be obtained also in a double-ended halogen light bulb using a cylindrical bulb having sealing parts at both ends.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention,
FIG. 3 is a front view of a halogen bulb in which a cylindrical glass bulb is used and a light reflecting film is applied to the rear surface of about half (180 degrees) of the entire circumference of the bulb. FIG. 2 shows the halogen bulb AA ′ of FIG.
It is a line expansion sectional view, and traces a radiant ray from a filament. In the figure, reference numeral 1 designates a coil-shaped tungsten filament, which is stretched in parallel along the tube axis of a cylindrical glass bulb 2a having a tip-off portion at one end and a sealing portion at the other end. It is hung. Further, an argon gas and a halogen compound such as bromine and chlorine (CH ₂ Br ₂ , CH ₃ Br, HBr, etc.) are enclosed inside.

A pair of molybdenum foils 3 are embedded in the sealing portion, and the ends of the internal lead-in wires 4 led out from both ends of the coil-shaped filament 4 are connected and the external lead-in wire 5 led out to the outside of the valve. The tip is connected. A light reflection film 6 made of a metal thin film such as aluminum is applied to the outer surface of the glass bulb 2a (the rear surface of about half of the entire circumference of the bulb). Further, the front surface of about half of the entire circumference of the glass bulb 2a is provided with the opening 7 without the light reflecting film being applied.
Is configured as The light reflection film 6 may be another metal that reflects light or a light interference film that selectively transmits light.

Next, description will be made with reference to FIG. The glass bulb 2a is ideally a cylindrical one. Although the glass bulb actually used cannot be said to be a perfect cylindrical shape, some errors can be ignored in the effect of the present invention, so ray tracing was performed for the case of using an ideal cylindrical glass bulb. Ray tracing was performed on the rays emitted in the left half of FIG. 2, and the ray 8 emitted from the filament 1 appears in the left half. Of the light reflected by the light reflecting film 6 (primary reflected light), the light 9b emitted to the front surface
Appears in the right half. We traced 19 rays, but the light 8 emitted directly to the front surface by shifting the filament 1 from the central axis to the light reflection film side is 7 out of 19 (solid line), and the primary reflected light is the front surface. It is recognized that the light 9b radiated to the lens is 9 out of 19 (two-dot chain line), and the light 9a on which the primary reflected light hits the filament is only 3 out of 19 (two-dot chain line), and this effect is large.

Of the light 8 emitted from the filament 1 of the halogen bulb, the light emitted to the opening 7 side is directly emitted to the front surface. Further, some of the light emitted to the light reflection film 6 side hits the filament 1 and is not emitted to the front surface, but most of the light is emitted to the front surface without hitting the filament 1 because the filament is displaced from the center by the dimension A.

FIG. 3 shows a second embodiment of the present invention, in which a spherical bulb 2b is used to form about half (18) of the entire circumference of the glass bulb.
It is a front view of a halogen bulb in which a light-reflecting film is applied to the rear surface (0 degree). FIG. 4 is a cross-sectional view of the halogen bulb of FIG. 3 taken along the line AA ', in which the radiation rays from the filament are traced. In the figure, the same members as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. The glass bulb 2b is ideally spherical, but the glass bulb actually used cannot be said to be perfectly spherical. However, since the effect of the present application can be ignored with some error, ray tracing was performed for the case where an ideal spherical glass bulb was used. Ray tracing was performed for the rays emitted in the left half of FIG.
The light ray 8 emitted from appears in the left half. Of the light reflected by the light reflection film 6 (primary reflected light), the light 9b emitted to the front surface appears in the right half. Although 19 rays were traced, 8 out of 19 rays 8 were directly emitted to the front surface by displacing the filament 1 from the central axis toward the light reflecting film side.
This is a book (solid line), and the primary reflected light is emitted to the front surface 9
b is 9 out of 19 (two-dot chain line), and the light 9a on which the primary reflected light hits the filament is only 2 out of 19 (two-dot chain line), and this effect is recognized to be large.

FIG. 5 is a sectional view of the halogen bulb of FIG. 3 taken along the line BB ', in which light rays from the filament are traced. The glass bulb 2b is ideally spherical, but the glass bulb actually used cannot be said to be perfectly spherical. However, ray tracing was performed for the case where an ideal spherical glass bulb was used as described above. However, the chip-off part and the sealing part were taken into consideration. Ray tracing was performed on the rays emitted in the upper half of FIG. 5, but the ray 8 emitted from the filament 1 appears in the upper half. Of the light (primary reflected light) reflected by the light reflection film 6, the light 9b emitted to the front surface appears in the lower half. Although 19 rays were traced, light 8 emitted directly to the front surface was obtained by displacing the filament 1 from the central axis toward the light reflecting film side.
Is 7 out of 19 (solid line), the light 9b in which the primary reflected light is emitted to the front surface is 6 out of 19 (two-dot chain line), and the light 9a in which the primary reflected light hits the filament is 4 out of 19 Book (two-dot chain line), or there are two lights that enter the chip-off part,
A temporary effect is recognized. The effect is smaller than that in the cross-sectional view taken along the line AA ′, but this is due to the influence of the tip-off portion at the tip of the glass bulb and the vertically stretched filament.

FIG. 6 shows a third embodiment of the present invention, in which a straight tube type glass bulb 2c is used and a light reflecting film is applied to the upper surface of about half (180 degrees) of the entire circumference of the bulb. It is a front view of a base halogen light bulb. FIG. 7 is an enlarged cross-sectional view of the halogen bulb of FIG. 6 taken along the line AA ′, in which the radiation rays from the filament are traced. Reference numeral 11 in the drawing denotes a tungsten filament formed in a coil shape, which is stretched in parallel with the longitudinal direction along the tube axis of the straight tube type glass bulb 2c having sealing portions at both ends. There is. Further, an argon gas and a halogen gas such as bromine are enclosed inside.

A pair of molybdenum foils 13 are embedded in the sealing portion, and the tips of the internal introducing wires 14 led out from both ends of the coiled filament 11 are connected and the external introducing wire 15 led out of the valve. The tip is connected. A light reflection film 16 made of a metal thin film such as aluminum is applied to the outer surface of the glass bulb 2a (upper surface of about half of the entire circumference of the bulb). Also, glass bulb 2
The lower surface of about half of the entire circumference of c is formed as an opening 17 without being coated with a light reflecting film. The light reflection film 16 may be another metal that reflects light or a light interference film that selectively transmits light.

Next, description will be given with reference to FIG. The glass bulb 2c is ideally a straight tube type, but the glass bulb actually used is not a perfect straight tube type.
However, since the effect of the present application can be ignored with some error, ray tracing was performed in the case of using an ideal straight tube type glass bulb. Ray tracing was performed for the rays emitted in the right half of FIG. 7, but the rays 18 emitted from the filament 11 appear in the right half. Of the light reflected by the light reflection film 16 (primary reflected light), the light 9b emitted to the front surface appears in the left half. Although 19 rays were traced, the light 18 emitted directly to the front surface by displacing the filament 11 from the central axis to the light reflection film side was 8 out of 19 (solid line).
The light 9b in which the primary reflected light is emitted to the front surface is 7 out of 19 (two-dot chain line), and the light 9a in which the primary reflected light hits the filament is four out of 19 (two-dot chain line), This effect is recognized to be great.

Here, a conventional halogen light bulb with a reflection film will be described from the same points as the above for comparison with the above-mentioned respective embodiments. FIG. 9 is a sectional view of a main part of a conventional example using a cylindrical glass bulb as shown in FIG.
Rays are traced in the same manner as in FIG. Of the light reflected by the light reflection film 6 (primary reflected light), the light emitted to the front surface appears in the left half. We traced 19 rays, but by displacing the filament from the central axis, 9 rays 8 were directly emitted to the front surface, and the primary reflected light was emitted to the front surface out of 19 rays. The number of 0, primary reflected light hitting the filament is 10 out of 19 (9a), and the difference from each of the above-mentioned examples is obvious.

As described above, in the ray tracing radiated from the filament described in each of the embodiments, the primary reflected light has been described, but in reality, the light reflected by the light reflecting film twice or more may be considered. It is considered that the incandescent filament also reflects light to some extent, but since it has no great influence, no simulation was performed.

FIG. 10 shows a modification of FIG. 1, in which the opening of the light reflecting film has a rectangular shape. In the figure, the same members as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. As shown in FIG. 10, a light reflection film 6a made of a metal thin film such as aluminum is applied to the outer surface of the glass bulb 2a. Further, one surface of the glass bulb 2a where the coiled filament 1 is located is formed as an opening 7a without being coated with a light reflecting film. As described above, by making the opening formed in the light reflection film of the glass bulb narrower than that of FIG. 1 and making it rectangular, the first-order reflected light is not concentrated much in the opening, but there is also secondary or more reflection. Therefore, light is collected in the narrow opening, and the luminous efficiency per surface area of the bulb is improved.

FIG. 11 shows a modification of FIG. 3, in which the opening of the light reflecting film has a rectangular shape. 1 and 3 in the figure
The same members as those described above are denoted by the same reference numerals, and description thereof will be omitted.
As shown in FIG. 11, a light reflection film 6b made of a metal thin film such as aluminum is applied to the outer surface of the glass bulb 2b. Further, one surface of the glass bulb 2b on which the coiled filament 1 is located is formed as an opening 7b without being coated with a light reflecting film. By forming the rectangular opening in the glass bulb in this way, the luminous efficiency per surface area of the bulb is improved as in the above case.

FIG. 12 shows the spectral transmittance curve of the optical interference film used in the present application, and the curve 20 is 720-83.
It is an infrared reflecting film that reflects near infrared rays near 0 nm.
The curve 21 is an infrared reflecting film that reflects 800 nm to 1100 nm, and although the transmittance in the visible region is low, the original purpose is to reflect infrared rays, so there is no problem. A curve 22 is a visible light reflection film that reflects 500 nm to 750 nm, and has a characteristic of transmitting infrared rays.

The present invention is not limited to the above-mentioned embodiments, and various modifications and applications can be carried out. The halogen bulb of the embodiment as shown in FIGS. 1 and 3 may be used in an optical device in which a lens or the like is arranged on the opening side of the halogen bulb, or may be used as a single bulb. It is also effective when used as a general lighting bulb. Furthermore, when a reflection mirror is used in combination on the opening side of the light reflection film, the light reflection film of the glass bulb also prevents glare.

In the halogen bulb of the embodiment as shown in FIG. 6, a gold film is used as a light reflecting film, and it can be used as a heat source for heating. Here, there are two reasons for using the gold film. Because gold has a higher reflectance than other metals,
This is because gold has very high heat resistance. In the currently commercialized double-ended type halogen bulb for heating, since the central axis of the filament and the central axis of the bulb are substantially aligned with each other, heat rays are not effectively radiated. In the present invention, as shown in FIG. 7, the heating wire is effectively used by displacing the central axis of the filament from the central axis of the valve.

Further, the halogen bulb of the embodiment shown in FIG. 6 can be used for general lighting. Furthermore, when a reflection mirror is used in combination on the opening side of the light reflection film, the light reflection film also prevents glare. The halogen bulb of the embodiment as shown in FIGS. 10 and 11 can be used as a microreader bulb by subjecting the bulb surface to unevenness so as to diffuse light toward the opening side of the bulb. it can.

[0030]

As is apparent from the above description, the halogen bulb according to the present invention has a relatively simple structure and is smaller in size, has higher light utilization efficiency, and has various shapes particularly suitable as a light source for optical equipment. You get a halogen bulb.

[Brief description of the drawings]

FIG. 1 is a front view of a halogen bulb according to a first embodiment of the present invention (cylindrical bulb).

2 is an enlarged cross-sectional view (cylindrical bulb) of a main part of the halogen bulb of FIG. 1 taken along the line AA ′.

FIG. 3 is a front view of a halogen bulb according to a second embodiment of the present invention (spherical bulb).

FIG. 4 is a sectional view of a main part of the halogen bulb of FIG. 3 taken along the line AA ′ (spherical bulb).

FIG. 5 is a sectional view of a main part of the halogen bulb of FIG. 3 taken along line BB ′ (spherical bulb).

FIG. 6 is a front view (double-ended type) of a halogen light bulb showing a third embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view of the main part of the halogen bulb of FIG.

FIG. 8 is a front view of a halogen bulb with a reflector as a conventional example.

FIG. 9 is an enlarged cross-sectional view of a main part taken along the line AA ′ similar to FIG. 2 when the filament of the conventional halogen bulb using the cylindrical glass bulb similar to that in FIG. 1 is arranged at the center.

FIG. 10 is a front view (cylindrical bulb) of a halogen bulb showing a modification of the first embodiment of the present invention.

FIG. 11 is a front view (spherical bulb) of a halogen light bulb showing a modification of the second embodiment of the present invention.

FIG. 12 is a spectral transmittance curve diagram of a light reflection film using the light interference film used in the present invention.

[Explanation of symbols]

1 Coiled filament 2a Cylindrical glass bulb 2b Spherical glass bulb 2c Straight tube glass bulb 3 Molybdenum foil 4 Internal lead-in line 5 External lead-in line 6 Light-reflecting film 7 Light-reflecting film opening 8 Light emitted from filament 9a Light Light reflected by the reflective film (primary reflected light) that strikes the inner filament 9b Light emitted to the front surface of the light (primary reflected light) reflected by the light reflective film 20 Light reflection film that reflects light of 720 to 830 nm ( Infrared reflective film 21 21 Light reflective film that reflects light of 800 to 1100 nm (infrared reflective film) 22 Light reflective film that reflects light of 500 to 750 nm (visible light reflective film) Dimension A Deviation from the central axis of the filament

Claims (7)

[Claims] 1. A chip-off portion is provided at one end side and a sealing portion is provided at the other end side, and an inert gas and a halogen or a halogen compound are sealed inside, and a pair of molybdenum foils are interposed in the sealing portion. Inside a cylindrical glass bulb formed by connecting an internal lead wire and an external lead wire, there is a coiled filament stretched in parallel along the tube axis near the center of the glass bulb, and the inner surface of the glass bulb. Alternatively, in a halogen bulb having a light-reflecting film applied on the outer surface, a part of the light-reflecting film has an opening, and the central axis of the filament is the glass so that the light reflected by the light-reflecting film does not hit the coiled filament. A halogen light bulb, wherein the halogen bulb is offset from the center of the bulb axis in a direction opposite to the opening. 2. A chip-off portion is provided on one end side and a sealing portion is provided on the other end side, and an inert gas and a halogen or a halogen compound are enclosed therein, and a pair of molybdenum foils are interposed in the sealing portion. Inside the glass bulb formed by connecting the internal introduction line and the external introduction line, having a coiled filament stretched in parallel along the tube axis near the center of the glass bulb,
In a halogen bulb in which a light-reflecting film is applied to the inner surface or the outer surface of the glass bulb, a part of the light-reflecting film has an opening, and the glass bulb is such that light emitted from a filament is condensed in the opening. It has a substantially spherical shape, and the central axis of the filament is displaced in the direction opposite to the opening with respect to the center of the tube axis of the glass bulb so that the light reflected by the light reflecting film does not hit the coiled filament. A halogen light bulb that is characterized. 3. A sealing portion is provided at each end, an inert gas and a halogen or a halogen compound are sealed inside, and an internal introducing wire and an external introducing wire are connected to the sealing portion via a pair of molybdenum foils. Inside the cylindrical glass bulb made by
In a halogen bulb having a coil-shaped filament stretched in parallel along the tube axis near the center of the glass bulb and applying a light-reflecting film on the inner or outer surface of the glass bulb, a part of the light-reflecting film is provided. Has an opening, and the central axis of the filament is offset from the center of the tube axis of the glass bulb in the direction opposite to the opening so that the light reflected by the light reflecting film does not hit the filament. Halogen bulbs featuring. 4. The center axis of the coiled filament is displaced from the center of the tube axis of the glass bulb by at least about the filament radius, and the distance between the filament and the inner wall of the bulb is at least 2 mm. Claim 1
A halogen bulb according to any one of 3 to 3. 5. The halogen bulb according to claim 1, wherein the glass surface of the opening of the glass bulb is treated to diffuse light emitted from the filament. 6. The halogen bulb according to claim 1, wherein the light reflecting film is transparent to infrared rays. 7. The halogen light bulb according to claim 1, wherein the light reflecting film reflects infrared rays and transmits visible light.