JPH08203478A - Incandescent light bulb, reflective lighting device using the same, and vehicle headlight - Google Patents

Abstract

(57) [Abstract] [Purpose] In the case of a lamp with a light-shielding plate near the filament, infrared rays are effectively returned to the filament to improve efficiency, and an incandescent bulb and a lighting device and vehicle using the same. Provide headlights. [Structure] In an incandescent light bulb 1 in which a part of light emitted from a filament 6 is shielded by a light shielding plate 15 provided in the vicinity of this filament, and other light is emitted to the outside of a bulb, the light shielding plate 15 is used to shield this light. It has a curved reflecting surface 16 that reflects the light coming toward the plate and returns it to the filament. On the surface of the bulb 2, an infrared reflecting film 5 that reflects the light emitted from the filament and returns it to the filament is provided. It is characterized in that it is formed only in a region which is not shielded by the light shielding plate. The visible light and infrared rays coming from the filament toward the light shielding plate are reflected by the reflection surface of the light shielding plate and returned to the filament, so that the infrared ray return efficiency is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incandescent lamp having an infrared ray reflecting film formed on a bulb containing a filament, a reflection type illumination device using the same, and a vehicle headlamp.

[0002]

2. Description of the Related Art Generally, an incandescent light bulb including a halogen light bulb is a light source that utilizes the light emission due to the incandescence of a filament, so that it has a large amount of heat radiation and tends to have a lower lamp efficiency than a discharge lamp. In order to reduce the heat radiation of such an incandescent light bulb and improve the lamp efficiency, research has recently been conducted on forming a film that reflects infrared rays and transmits visible light, that is, an infrared reflection film, on the outer surface of the bulb.

If an infrared reflecting film is formed on the outer surface of the bulb, the infrared reflecting film reflects the infrared rays emitted from the filament, and the reflected infrared rays are returned to the filament to reheat the filament, and thus the filament. Since the incandescent is promoted, the electric power supplied from the outside can be saved and the luminous efficiency is improved. Also, because the amount of heat wasted wasted is reduced,
There is also an advantage that the heat effect on the equipment can be reduced.

If an incandescent light bulb having such an infrared reflection film, particularly a halogen light bulb, is used as a light source of a vehicle headlight, the lamp efficiency is improved and a large amount of light can be obtained, and thus far-distance irradiation is performed. Is effective for. by the way,
The headlight of the vehicle is a lamp that emits a passing beam,
There is a lamp for radiating a traveling beam, and there is also a lamp.
As shown in Japanese Patent Laid-Open No. 19956, there is a lamp in which a filament for a passing beam and a filament for a traveling beam are housed in the same lamp, and the traveling beam and the passing beam are selectively used by switching these lamps or filaments to light. It is like this.

In this case, since the passing beam emitted from the passing beam filament is required to have a light distribution characteristic so as not to give glare to an oncoming vehicle, a light shielding plate is provided in the vicinity of the passing beam filament, and this light shielding is performed. The plate limits light irradiation in an undesired direction.

[0006]

However, when the above shading plate is installed near the filament, neither visible light nor infrared ray reaches the bulb surface on the back side of the area shielded by this shading plate. . Therefore, even if an infrared reflecting film is formed on the bulb surface on the back side of the light shielding plate, the infrared reflecting film in this region cannot sufficiently exhibit its function.

Moreover, it is noted that the conventional light-shielding plate does not irradiate the light emitted from the filament to an undesired region. Therefore, the shape of the light-shielding plate is a flat plate made of molybdenum or a shallow plate. It was shaped like a dish. The light-shielding plate having such a shape has a function of blocking light directed to a specific area, but does not have a sufficient function of reflecting the light emitted from the filament and returning it to the filament. Therefore, the infrared ray emitted from the filament is reflected. The function of returning it to the filament is also insufficient.

Therefore, the infrared rays emitted from the filament toward the light shield plate are not reflected by the light shield plate, and the infrared ray reflection formed on the surface of the bulb corresponding to the back region of the light shield plate. Since it does not reach the film, it is not reflected even by this infrared reflecting film, and therefore infrared rays are not effectively returned to the filament, and therefore there is a problem that efficiency improvement cannot be expected to a great extent.

Therefore, it is an object of the present invention to use an incandescent lamp which can effectively return infrared rays to the filament and improve the efficiency in the case of a lamp provided with a light shielding plate in the vicinity of the filament. An object of the present invention is to provide a reflective lighting device and a vehicle headlight.

[0010]

According to a first aspect of the present invention, there is provided a bulb having a light emitting portion having a spherical shape or a shape similar to a spherical shape, a filament contained in the light emitting portion of the bulb, and a filament in the vicinity of the filament. A light-shielding plate provided with a curved reflection surface that regulates the light emitted from the filament only in a predetermined direction and that reflects the light emitted from the filament and returns it to the filament. An incandescent light bulb, comprising: an infrared reflection film formed on the surface of the bulb in a region that is not shielded by the plate, and reflecting the light emitted from the filament and returning it to the filament.

The invention according to claim 2 is the incandescent lamp according to claim 1, wherein the reflection surface of the light shielding plate has an elliptical spherical shape surrounding the filament.

An invention according to claim 3 is the incandescent lamp according to claim 1 or 2, characterized in that the light shielding plate surrounds a region of 180 ° or less around the filament.

The invention of claim 4 is characterized in that the light shielding plate is formed of tungsten or a tungsten alloy.
The incandescent light bulb described in.

A fifth aspect of the present invention is a reflection type illumination comprising the incandescent lamp according to any one of the first to fourth aspects and a reflector incorporating the incandescent lamp. It is a device.

According to a sixth aspect of the present invention, there is provided a bulb in which a spherical portion having a spherical shape or a shape similar to the spherical shape and a cylindrical portion continuous with the spherical portion are formed, a filament for a low beam which is housed in each of the spherical portion and the cylindrical portion, and It is provided in the vicinity of the traveling beam filament and the low beam filament, and regulates the light emitted from the low beam filament only in a predetermined direction, and reflects the light emitted from the low beam filament. The infrared rays are formed on the surface of the bulb that has a curved reflecting surface that returns to this filament and the area of the bulb that is not shielded by this reflector, and reflects the light emitted from each filament and returns it to these filaments. An incandescent light bulb for a headlight, comprising: a reflection film.

An invention according to claim 7 is the incandescent light bulb according to any one of claims 1 to 4 or claim 6,
A vehicle headlight, comprising: a reflector incorporating the incandescent light bulb.

[0017]

According to the first aspect of the present invention, visible light and infrared rays emitted from the filament toward the light shielding plate are reflected by the reflection surface of the light shielding plate and returned to the filament. Therefore, the infrared return efficiency is improved and the lamp efficiency is improved. Moreover, in the bulb, since there is no infrared reflection film on the back surface of the light shielding plate, it is not necessary to form an extra coating.

According to the invention of claim 2, since the reflecting surface of the light shielding plate has an elliptical spherical shape surrounding the filament, the visible light and infrared rays reflected by the reflecting surface are favorably returned to the filament.

According to the invention of claim 3, since the light shielding plate surrounds a region of 180 ° or less around the filament,
It is effective for obtaining the passing beam light.

According to the fourth aspect of the invention, since the light shielding plate is made of tungsten or a tungsten alloy, the reaction with halogen is small and the durability is improved.

According to the invention of claim 5, the advantages of the incandescent lamp described in claim 1 can be utilized, and an efficient lighting device can be provided.

In the incandescent light bulb for headlights according to the sixth aspect of the invention, since the filament for the low beam which is frequently used is housed in the spherical portion, the spherical portion is excellent in returning infrared rays to the filament and has a high return efficiency. Moreover, also in this case, the visible light and infrared rays emitted from the low beam filament toward the light shielding plate are reflected by the light shielding plate and returned to the low beam filament. Therefore, the infrared return efficiency is improved and the lamp efficiency is improved. Moreover, in the bulb, since there is no infrared reflection film on the back surface of the light shielding plate, it is not necessary to form an extra coating.

According to the invention of claim 7, the advantages of the incandescent light bulb described in any one of claims 1 to 4 and claim 6 can be utilized, and an efficient vehicle headlamp can be provided. it can.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the first embodiment shown in FIGS.

This embodiment shows an example applied to a low beam floodlight illumination device in a four-lamp type vehicle headlight, FIGS. 1 to 4 show a halogen bulb used as a light source, and FIG. It is sectional drawing of the whole optical illuminating device.

The halogen bulb 1 shown in FIGS. 1 to 4 is
At one end of the arc tube bulb 2 made of quartz glass, a light emitting portion having a shape similar to a sphere or an ellipsoid,
In this example, the spherical portion 3 is formed, and the crush sealing portion 4 is formed at the other end.

On the outer surface (or inner surface) of the spherical portion 3,
The visible light transmitting infrared reflecting film 5 is formed over a predetermined region. As shown in FIG. 4, the infrared reflective film 5 is formed of, for example, titanium oxide (TiO ₂ ) or tantalum oxide (Ta).
₂ O ₅ ), zirconium oxide (ZrO ₂ ), zinc sulfide (ZnS) and other high refractive index layers 51, silicon oxide (silica = SiO ₂ ), magnesium fluoride (MgF)
₂ ) and other low refractive index layers 52 ... Are alternately formed as a multilayer film of, for example, a total of 9 to 35 layers. Such an infrared reflection film 5 reflects infrared rays by a multilayer interference action, however, It has the effect of transmitting visible light.

A filament 6 made of tungsten W is housed in the bulb 2. Filament 6
Consists of a single or double coil, and its coil axis is arranged so as to coincide with the center line of the valve, and the center of the coil is arranged so as to substantially coincide with the center point of the spherical portion 3. There is. This filament 6 is connected to a pair of internal lead wires 7 and 8, and these internal lead wires 7 and 8 are metal foil conductors 9 made of molybdenum Mo or the like, which are sealed in the crushing and sealing portion 4, respectively. Connected to 10. The Mo foils 9 and 10 are connected to the external lead wires 11 and 12, respectively. A halogen gas is enclosed in the bulb 2.

The light-shielding plate 1 is provided on one side of the filament 6.
5 are arranged close to each other. The light-shielding plate 15 has been conventionally made of molybdenum Mo, but in the case of Mo, it reacts with halogen at high temperatures and easily deteriorates, resulting in a short life. Therefore, in this embodiment, the light shielding plate 15 is made of tungsten W.
Alternatively, it is formed of an alloy of tungsten W and molybdenum Mo. This improves the durability of the light shield plate 15.

The light shielding plate 15 directs the light emitted from the filament 6 in an undesired direction so that the halogen light bulb 1 emits a passing beam having a predetermined light distribution when the halogen light bulb 1 is used as a headlight of a vehicle. In other words, when the beam becomes a low beam, it is regulated so as not to give glare to an oncoming vehicle, and its light blocking area is determined. Light-shielding plate 15 of this example
Shields the periphery of the filament 6 in an area of 180 ° or less, and has a curved surface such as an elliptic spherical surface in cross section. The surface facing the filament 6 reflects visible light and infrared rays. A surface 16 is formed.
The filament 6 is arranged at the center (focus) of the reflecting surface 16. Therefore, the light shielding plate 15 regulates the irradiation of the light emitted from the filament 6 in a direction other than the predetermined direction, and reflects the visible light and infrared rays that have traveled toward the light shielding plate 15 on the reflecting surface 16, thereby
The effect of returning to. Such a light shielding plate 15 is joined to a holder 17 made of a tungsten wire or the like by means such as welding, and the holder 17 is welded to one inner lead wire 7.

The infrared reflecting film 5 is not formed on the surface of the bulb 2 facing the back surface of the light shielding plate 15. That is, the light emitted from the filament 6
The projection area on the surface of the bulb 2 in the area blocked by the above, in other words, the surface of the bulb 2 surrounded by the line connecting the points where the extension line of the line connecting the filament 6 and the peripheral edge of the light shielding plate 15 intersects the bulb 2. The infrared reflective film 5 is not formed in the upper region.

The halogen bulb 1 having the above structure is housed in the reflector 20, as shown in FIG. The reflector 20 includes a reflector 22 having a reflecting surface 21 and a front lens 2 attached to a front opening of the reflector 22.
3 and a mounting hole 24 is formed at the top of the rear surface of the reflector 22. The halogen bulb 1 is inserted into the mounting hole 24, and the crushed sealing portion 4 of the halogen bulb 1 is joined to the mounting hole 24 with an adhesive 25 such as insulating cement. Thereby, the halogen bulb 1 is positioned and attached to the reflector 22 at a predetermined position. Reference numeral 26 is a closing plate that closes the open end of the mounting hole 24.

With respect to the first embodiment having such a structure,
The operation will be described. When a power supply voltage of, for example, DC 12V is applied through the external lead wires 11 and 12, a current flows through the filament 6 and the filament 6 emits light. This light is emitted to the surroundings, and a part of it is blocked by the light shielding plate 15. The visible light and infrared rays that reach the light shield plate 15 are reflected by the inner reflection surface 16 of the light shield plate 15 and returned to the filament 6. In this case, since the reflecting surface 16 is a spherical surface, the reflected infrared rays are condensed on the filament 6 and are effectively returned to the filament 6.

The rest of the light emitted from the filament 6 passes through the spherical portion 3 of the bulb 2 and is emitted to the outside.
When this light passes through the infrared reflection film 5 formed on the outer surface of the spherical portion 3, visible light is transmitted, but infrared light is reflected.

The transmitted visible light is reflected by the reflecting surface 21 of the reflector 22 and heads forward, and the front lens 23 attached to the front opening of the reflector 22 controls the light distribution to illuminate the front. In this case, since the light passing through the front lens 23 and traveling forward is blocked by the light shielding plate 15 toward the predetermined region, the light distribution of the forward irradiation light is biased, and it is a so-called passing beam. It does not give glare to oncoming vehicles.

Then, the infrared rays reflected by the infrared reflecting film 5 formed on the surface of the bulb 2 are returned to the inside of the bulb 2, and the returned infrared rays heat the filament 6.
In this case, the central portion of the coil of the filament 6 is arranged at substantially the center of the spherical portion 3 forming a spherical surface, and the infrared rays reflected by the entire surface of this spherical surface are condensed at the center of the bulb.
It effectively returns to the central portion of the filament 6.

From this fact, the infrared rays emitted from the filament 6 are finally reflected by the reflection surface 16 of the light shielding plate 15 and the infrared reflection film 5 formed on the bulb surface, so that all the infrared rays emitted in all directions. It will be returned to the filament 6 from the direction. Therefore, the return rate of infrared rays returned to the filament 6 becomes high, and the rate of heating the filament 6 by the reflected infrared rays becomes high.

As a result, the filament 6 is given thermal energy not only by the electric energy supplied from the power source but also by the infrared rays reflected by the infrared reflecting film 5, so that the temperature rise is promoted and the incandescence is promoted. Therefore, if the emission intensity is made to be at the same level as when the infrared reflection film is not provided, the power energy supplied from the power source can be reduced by the amount of the heat energy reflected by the infrared reflection film 5, thus consuming less energy. Power can be saved.

On the surface of the bulb 2, the light shielding plate 15
The infrared reflection film 5 is formed except for the area shielded by the infrared reflection film 5.
It is possible to save the coating material without forming a wasteful coating such as the above.

With the floodlighting device using such a halogen bulb 1 as a light source, the lamp efficiency of the halogen bulb 1 is improved, so that the advantage can be utilized and the illumination device with excellent efficiency is obtained. Becomes

In the above embodiment, the passing beam headlamp in the four-lamp type vehicle headlamp has been described, but the illumination device shown in FIG. 5 is not limited to the vehicle headlamp.
The present invention can be applied to a reflection type illuminating device in the case of obtaining a light beam with a light distribution in which the irradiation light is biased. Further, the shape of the light emitting portion of the bulb 2 is not limited to the spherical portion 3 and may be an elliptic spherical shape.

Next, a second embodiment shown in FIGS. 6 to 8 will be described. This embodiment shows an example applied to an H4 type vehicle headlight, FIGS. 6 and 7 show a halogen light bulb used as a light source, and FIG. 8 is a sectional view of the whole headlight.

Halogen bulb 100 shown in FIGS. 6 and 7.
Is composed of an arc tube bulb 102 and a flanged cap 120. The bulb 102 is made of quartz glass and has a one-sided sealing structure in which the base end is crushed and sealed (not shown). A spherical portion 103 is formed at the tip of the valve 102, and a cylindrical portion 104 is continuously formed integrally with the spherical portion 103 toward the base end.

A visible light transmitting infrared reflecting film 105 is formed on the outer surface (or inner surface) of the bulb 102. The infrared reflection film 105 has a multilayer structure in which high refractive index layers 51 ... And low refractive index layers 52 ... Are alternately laminated in the same manner as shown in FIG. Membrane 1
Reference numeral 05 has a function of reflecting infrared rays by a multilayer interference effect, but transmitting visible light. Also in the case of the present embodiment, the bulb 10 in the region corresponding to the back surface of the light shielding plate 111 described later.
The infrared reflection film 105 is not formed on the surface 2.

In the bulb 102, two filaments 106 and 107 each made of tungsten are provided.
Is housed. These filaments 106 and 1
Reference numeral 07 denotes a low beam filament and a low beam filament, and a low beam filament 1
06 is arranged in the spherical portion 103 of the bulb 102 such that the coil center coincides with the substantially center of the spherical shape, and the traveling beam filament 107 is closer to the base end than the passing beam filament 106. Are arranged in the cylindrical portion 104.

The passing beam filament 106 is connected to the inner lead wires 108 and 109, and the traveling beam filament 107 is connected to the one inner lead wire 108 and the other inner lead wire 110. Has been done. Therefore, the internal lead wire 108 is a common internal lead wire. Further, a light shielding plate 111 is arranged near the low beam filament 106. The light shielding plate 111 shields light traveling toward a predetermined area and has a curved surface such as a spherical surface or an elliptic surface in cross section.
A reflective surface 112 that reflects visible light and infrared light is formed on the surface facing 6. The passing beam filament 106 is arranged at the center (focus) of the reflecting surface 112. Therefore, this shading plate 111 also regulates the irradiation of the light emitted from the filament 106 in a direction other than the predetermined direction, and reflects the visible light and infrared rays that have traveled toward this shading plate 111 at the reflecting surface 112, and The effect of returning to 106 is produced. The light shielding plate 111 is supported by the one inner lead wire 109 via the holder 113. The above valve 10
A halogen gas is enclosed in the inside 2.

The internal lead wires 108, 109 and 110 are connected to Mo foils respectively sealed to a crushing seal portion (not shown) formed at the end of the valve 102, and these Mo foils are externally connected to each other. It is connected to the lead wire.

The flanged cap 120 is attached to a sealing portion at one end of the valve 102. Mouthpiece with collar 120
Is a cylindrical base body 121 provided with a flange 122 and three leg terminals 123, 124, 125 at the ends thereof. The cylindrical base body 121 is put on the crushed seal portion of the valve 102. , Which are joined by an adhesive (not shown).

The leg terminals 123 to 125 are connected to external lead wires (not shown) led out from the sealing portion of the valve 102, and the internal lead wires 10 are respectively connected.
It is electrically connected to 8, 109 and 110. The common internal lead wire 108 is connected to the common leg terminal 1
It is electrically connected to 23.

The halogen bulb 100 having the above structure is housed in the reflector 130, as shown in FIG. Reflector 1
30 is a reflector 132 having a reflecting surface 131,
The front lens 133 is attached to the front opening of the reflector 132, and a mounting hole 134 is formed at the top of the back of the reflector 132. The halogen bulb 100 is inserted into the mounting hole 134, and the halogen bulb 100 is positioned at a predetermined position with respect to the reflector 132 by fixing the flange 122 provided on the base 120 to the peripheral edge of the mounting hole 134. Installed.

Regarding the second embodiment having such a structure,
The operation will be described. The headlamp assembled as shown in FIG. 8 has the common internal lead wire 108 when the common leg terminal 123 and the other leg terminal 124 are connected to a DC 12V power source.
Since a potential difference is applied between this and another internal lead wire 109, a current flows through the traveling beam filament 107, and this traveling beam filament 107 emits light.
This light is emitted to the surroundings and the bulb 103 of the bulb 102 is
And is radiated to the outside from the cylindrical portion 104. When this light passes through the infrared reflection film 105 formed on the outer surfaces of the spherical portion 103 and the cylindrical portion 104, visible light is transmitted and infrared rays are reflected.

The visible light that has been transmitted is reflected by the reflecting surface 131 of the reflector 132 toward the front, and is reflected by the reflector 13
The light distribution is controlled by the front lens 133 attached to the front opening of No. 2 to illuminate the front. In this case, the traveling beam is such that a strong beam reaches far away.

The infrared rays reflected by the infrared reflecting film 105 are returned to the inside of the bulb 102, and the returned infrared rays heat the traveling beam filament 107. In this case, since the traveling beam filament 107 is housed in the cylindrical portion 104 of the bulb 102, the infrared rays mainly reflected by the infrared reflection film 105 formed on the cylindrical portion 104 are returned to the traveling beam filament 107. Therefore, the traveling beam filament 107 is given not only the electric energy supplied from the power source but also the thermal energy due to the infrared rays reflected by the infrared reflecting film 105, so that the temperature rise is promoted and the incandescence is favorably achieved. In this case, if the emission intensity is set to the same level as when the infrared reflection film is not provided, the infrared reflection film 105
The power energy supplied from the power source can be reduced by the amount of the heat energy reflected by the power source, and thus the power consumption can be saved.

On the other hand, when the common leg terminal 123 and the other leg terminal 125 are connected to a DC 12V power source, a potential difference is given between the common internal lead wire 108 and the other internal lead wire 110, and in this case, they pass each other. The beam filament 106 is energized. Therefore, the low beam filament 106 emits light, and this light is emitted to the surroundings.

In this case, since the light shielding plate 111 is provided in the vicinity of the low beam filament 106, the light traveling in the direction of the light shielding plate 111 is blocked. Shading plate 1
The visible light and infrared rays reaching 11 are reflected by the inner reflection surface 112 of the light shielding plate 111 and returned to the filament 106. In this case, the reflecting surface 112 is a spherical surface,
The reflected infrared light is condensed on the filament 106, and is effectively returned to the filament 106.

Light radiated in a direction other than the light shielding plate 111 is spherical portion 103 and cylindrical portion 104 of the bulb 102.
Is emitted from the outside. Then, this light is reflected by the spherical portion 103.
And the infrared reflection film 10 formed on the outer surface of the cylindrical portion 104.
When passing through 5, visible light is transmitted and infrared rays are reflected.

The visible light that has been transmitted is reflected by the reflecting surface 131 of the reflector 132 and travels forward, and the front lens 13
The light distribution is controlled by 3 to illuminate the front. in this case,
Due to the action of the light blocking plate 111, a part of the light traveling forward is cut off, and the light traveling in the upper right direction is blocked or dimmed to reduce glare to the oncoming vehicle. Further, in this case, since the comparatively close road surface is illuminated, the brightness may be lower than that of the traveling beam, and therefore, normally,
Unlike the traveling beam filament 107, the rated power of the beam filament 10 is made smaller. For example, in the standard, in the case of a 4H type halogen light bulb, the traveling beam filament is 60 W and the difference beam filament is 55 W for a power supply voltage of 12V.

The infrared light reflected by the infrared reflecting film 105 is returned to the inside of the bulb 102. In this case, since the center of the coil of the low beam filament 106 is located at the substantially central point of the spherical portion 103 of the bulb 102, the infrared rays reflected by the infrared reflection film 105 of the spherical portion 103 are reflected by the low beam filament 106. Return effectively.

From the above, infrared rays emitted from the low beam filament 106 are shielded from the light shielding plate 11.
The infrared rays radiated in all directions are returned to the filament 106 from all directions because they are reflected by the infrared reflecting film 105 formed on the reflecting surface 112 of No. 1 and the bulb surface. Therefore, the return rate of infrared rays returned to the filament 106 becomes high, and the rate of heating the filament 106 by the infrared rays returned in this way becomes high. By the way, as compared with the case where the light shielding plate has a flat plate shape, the infrared feedback rate is improved by 25 to 50%.

Therefore, the passing beam filament 1
In addition to the electric power energy supplied from the power source, the thermal energy of 06 is given by the thermal energy of the infrared rays reflected by the infrared reflecting film 105, so that the temperature rise is promoted and the incandescence is promoted. Also in this case, if the emission intensity is set to the same level as in the case where the infrared reflective film is not provided, the power energy supplied from the power source can be reduced by the amount of the thermal energy reflected by the infrared reflective film 5. Therefore, power consumption can be saved.

In addition, in general, the vehicle has more opportunities to travel with the passing beam than to travel with the traveling beam. Therefore, the low beam filament 106
If the traveling beam filament 107 is housed in the spherical portion 103, the energy efficiency of the passing beam filament 106 that is frequently used can be increased. Electric power energy can be significantly saved and lamp efficiency can be increased.

According to the vehicle headlamp using the halogen light bulb 100 as a light source, the efficiency of the halogen light bulb 100 is improved, so that the advantage thereof can be utilized and the headlamp with excellent efficiency can be utilized. It becomes a light.

The incandescent light bulb of the present invention is not limited to a halogen light bulb, and may be any light bulb in which a filament is contained in a bulb having a spherical or elliptic spherical shape.

[0064]

As described above, according to the invention of claim 1,
Visible light and infrared rays emitted from the filament toward the light shielding plate are reflected by the reflection surface of the light shielding plate and returned to the filament. Therefore, the infrared return efficiency is improved and the lamp efficiency is improved. Moreover, in the bulb, since there is no infrared reflection film on the back surface of the light shielding plate, it is not necessary to form an extra coating.

According to the second aspect of the present invention, since the reflecting surface of the light shielding plate has an elliptical spherical shape surrounding the filament, the visible light and infrared rays reflected by the reflecting surface are favorably returned to the filament.

According to the third aspect of the present invention, since the light shielding plate surrounds the area of 180 ° or less around the filament,
It is effective for obtaining the passing beam light.

According to the invention of claim 4, since the light shielding plate is made of tungsten or a tungsten alloy, the reaction with halogen is small and the durability is improved.

According to the invention of claim 5, the advantages of the incandescent lamp described in claim 1 can be utilized, and an efficient lighting device can be provided.

In the incandescent light bulb for headlights according to claim 6, since the filament for the low beam which is frequently used is housed in the spherical portion, the spherical portion has an excellent effect of returning infrared rays to the filament and has a high return efficiency. Moreover, also in this case, the visible light and infrared rays emitted from the low beam filament toward the light shielding plate are reflected by the light shielding plate and returned to the low beam filament. Therefore, the infrared return efficiency is improved and the lamp efficiency is improved. Moreover, in the bulb, since there is no infrared reflection film on the back surface of the light shielding plate, it is not necessary to form an extra coating.

According to the invention of claim 7, the advantages of the incandescent lamp described in any one of claims 1 to 4 and claim 6 can be utilized, and an efficient vehicle headlamp can be provided. it can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a halogen light bulb according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a cross-sectional view illustrating the configuration of the infrared reflective film of the example.

FIG. 5 is a cross-sectional view of a floodlighting device using the halogen bulb of the embodiment as a light source.

FIG. 6 is a side view of a halogen bulb according to a second embodiment of the present invention.

FIG. 7 is a plan view of the halogen bulb of the example.

FIG. 8 is a sectional view showing a vehicle headlamp using the halogen bulb of the embodiment as a light source.

[Explanation of symbols]

1 ... Halogen bulb 2 ... Bulb 3 ... Spherical part 4 ... Sealing part 5, 105 ... Infrared reflecting film 6, 6a, 106 ... Filament 15, 111 ... Shading plate 16, 112 ...
Reflective surface 20, 130 ... Reflector 22, 132 ...
Reflector

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01K 9/08 A 9508-2G

Claims (7)

[Claims] 1. A bulb having a light emitting portion having a spherical shape or a shape similar to a spherical shape, a filament accommodated in the light emitting portion of the bulb, and a light provided from the filament provided near the filament. The light-shielding plate is provided with a curved reflecting surface that regulates the light emitted from the filament and reflects the light emitted from the filament and returns it to the filament, and the surface of the bulb that is not shielded by the light-shielding plate. An incandescent light bulb, comprising: an infrared reflection film formed, which reflects the light emitted from the filament and returns it to the filament. 2. The incandescent lamp according to claim 1, wherein the reflection surface of the light shielding plate has an elliptical spherical shape surrounding the filament. 3. The light-shielding plate is formed around the filament 18
The incandescent light bulb according to claim 1 or 2, which surrounds a region of 0 ° or less. 4. The incandescent lamp according to claim 1, wherein the light shielding plate is made of tungsten or a tungsten alloy. 5. A reflection-type lighting device comprising: the incandescent lamp according to claim 1; and a reflector incorporating the incandescent lamp. 6. A bulb in which a spherical portion having a spherical shape or a shape similar to a spherical shape and a cylindrical portion continuous with the spherical portion are formed, and a filament for a low beam and a filament for a traveling beam housed in the spherical portion and the cylindrical portion, respectively. Provided near the filament for the low beam,
A light-shielding plate formed with a curved reflecting surface that regulates the light emitted from the low beam filament only in a predetermined direction and reflects the light emitted from the low beam filament to return to the filament. And an infrared reflection film formed on the surface of the bulb in a region where the light is not shielded by the reflection plate and reflecting the light emitted from each filament and returning it to these filaments. light bulb. 7. Any one of claims 1 to 4,
Alternatively, a vehicle headlight comprising the incandescent lamp according to claim 6 and a reflector incorporating the incandescent lamp.