JPH0945294A - Incandescent lamp and vehicle headlight using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an incandescent lamp which has a visor provided near a filament and whose efficiency of utilizing visible light is enhanced through the enhancement of the efficiency of reflecting visible light by preventing the visible light from being absorbed into the visor and to provide a vehicle headlight using the same. SOLUTION: In this incandescent lamp which uses a visor 12 provided near a filament 7 to block part of light emitted from the filament 7 and allows other light to go out of a bulb, a reflection film 13 which reflects at least visible light is formed over the surface of the visor 12 opposite to the filament 7. The visible light going toward the visor from the filament is therefore reflected by the reflection film 13 and emitted to the outside of the bulb, resulting in enhancement of the efficiency for utilizing the visible light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incandescent light bulb in which a light-shielding plate is provided in the vicinity of a filament accommodated in a bulb and the direction of light emitted from the filament is regulated by the light-shielding plate, and a vehicle front using the same. Regarding lighting.

[0002]

2. Description of the Related Art Generally, a halogen bulb used for an H4 type vehicle headlight has a filament for a passing beam and a filament for a traveling beam in the same bulb as disclosed in Japanese Patent Laid-Open No. 4-19956. The traveling beam and the passing beam are selectively used by accommodating and switching these filaments to light.

In this case, since the passing beam emitted from the passing beam filament is required to have a light distribution characteristic that does not give glare to an oncoming vehicle, a shading plate is provided in the vicinity of the passing beam filament. The irradiation of light in an undesired direction is restricted.

[0004]

Such a shading plate is made of a refractory metal, which is resistant to the heat radiated from the filament.
For example, it is formed of molybdenum Mo or tungsten W, and the surface of the light shielding plate facing the filament is a surface in which the metal surface is exposed in the conventional case.
The reflex effect was extremely poor. Such a metal surface has a property of absorbing visible light, that is, the reflectance of visible light is 60% or less. For this reason, the conventional light-shielding plate has an effect of blocking light traveling in a specific direction, but has a problem that it blocks some light and at the same time absorbs part of this light.

For this reason, countermeasures such as chemical polishing of the inner surface of the light shielding plate to give a mirror finish have been studied.
Even with such a mirror finish, the reflectance is limited to about 70%, and about 30% or more is absorbed. Therefore,
There is a problem that all the light emitted from the filament cannot be effectively used as a beam light and the utilization efficiency is low.

An object of the present invention is to provide an incandescent light bulb in which visible light is positively reflected by a reflecting surface of a light shielding plate provided in the vicinity of a filament, and utilization efficiency of light emitted from the filament is improved, and the incandescent lamp. It is intended to provide the used vehicle headlight.

[0007]

According to a first aspect of the present invention, there is provided a bulb; a filament housed in the bulb; provided in the vicinity of the filament so that light emitted from the filament irradiates only in a predetermined direction. An incandescent light bulb comprising: a light-shielding plate that is regulated according to the above; and a reflective film that is formed on a surface of the light-shielding plate that faces the filament and that reflects at least visible light.

According to a second aspect of the present invention, a bulb having a spherical portion having a spherical shape or a shape similar to a spherical shape and a cylindrical portion continuous with the spherical portion; a filament for a low beam which is housed in each of the spherical portion and the cylindrical portion; A traveling beam filament; a light shielding plate which is provided in the vicinity of the low beam filament, and which restricts light emitted from the low beam filament so that the light is emitted only in a predetermined direction; An incandescent light bulb for a headlight, comprising: a reflective film formed on a surface facing the filament and reflecting at least visible light.

The invention according to claim 3 is the incandescent lamp according to claim 1 or 2, wherein the reflection film is formed by directly binding fine particle oxides directly to each other. is there.

The invention of claim 4 is characterized in that the reflective film is made of at least one of aluminum oxide, zirconium oxide, hafnium oxide, calcium oxide, strontium oxide, and magnesium oxide. It is an incandescent light bulb.

According to a fifth aspect of the present invention, the reflection film has a visible light reflectance of 80% or more.
The incandescent light bulb according to claim 4.
The invention according to claim 6 is the incandescent light bulb according to any one of claims 1 to 5, wherein the thickness of the reflective film is 0.5 μm or more and 10 μm or less.

According to a seventh aspect of the present invention, the light shielding plate is made of tungsten, molybdenum, or at least one of them.
The incandescent light bulb according to any one of claims 1 to 6, which is formed of an alloy containing a seed.

The invention according to claim 8 is characterized by comprising: the incandescent lamp according to any one of claims 1 to 7; and a reflector incorporating the incandescent lamp. It is a light.

The incandescent light bulb of the present invention includes a halogen light bulb. Further, in order to effectively use the infrared rays emitted from the filament, an infrared reflecting film is provided on the inner or outer surface of the bulb, and the infrared rays reflected by the infrared reflecting film are returned to the filament, or A light bulb without an infrared reflection film may be used.

[0015]

According to the first aspect of the invention, the visible light emitted from the filament toward the light shield plate is reflected by the reflective film formed on the inner surface of the light shield plate and reflecting at least the visible light. Less light is absorbed in the filaments, so most of the light emitted from the filament is directed out of the bulb. Therefore, the utilization efficiency of visible light is increased and the luminous flux is increased.

According to the invention of claim 2, since it is applied to a light bulb provided with a light shielding plate in the vicinity of the low beam filament in an incandescent light bulb for headlights, most of the light emitted from the filament is used as low beam light. The light flux of the low beam can be increased, and the low beam can be brightened.

According to the third aspect of the invention, since the reflecting film is formed by directly binding the fine particle oxides directly to each other, the reflecting film serves as a diffusive reflecting surface so that the light emitted from the filament is diffused and reflected. Thus, the light is evenly distributed and radiated to the outside except the direction of the light shielding plate. Therefore, there is no concentrated reflection toward one place, and when the vehicle headlight or the like is used, it is easy to control the irradiation light.

According to the invention of claim 4, the reflecting film is
Since it is formed from at least one of aluminum oxide, zirconium oxide, hafnium oxide, calcium oxide, strontium oxide, and magnesium oxide, it has excellent reflection efficiency in the visible region to the infrared region and is easy to form a film.

According to the invention of claim 5, the reflectance of the visible light of the reflective film is 80% or more, so that the reflectance becomes higher than that of the conventional one, and the effective utilization rate of the visible light becomes high. Claim 6
According to the invention, the thickness of the reflective film is 0.5 μm or more and 10 μm or more.
Since it is m or less, the reflection characteristics from the visible region to the infrared region are good. If the film thickness of the reflective film is less than 0.5 μm, the reflecting action in the visible region is insufficient, and if it exceeds 10 μm, peeling or cracking of the film is likely to occur.

According to the invention of claim 7, the light shielding plate is made of tungsten, molybdenum, or at least one of them.
Since it is formed of an alloy containing seeds, it is excellent in heat resistance, has little reaction with halogen, and has improved durability. The invention of claim 8 can utilize the advantages of the incandescent lamp according to any one of claims 1 to 7, and can provide an efficient vehicle headlamp.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on an embodiment applied to an H4 type vehicle headlamp shown in the drawings. 1 and 2 show the structure of a halogen bulb used as a light source, and FIG. 3 is a structural diagram of an infrared reflecting film,
FIG. 4 is a sectional view of the light shielding plate, and FIG. 5 is a sectional view of the entire headlamp.

The halogen bulb 1 shown in FIGS. 1 to 3 is
It has a one-sided sealing structure in which a crushing sealing portion 3 is formed at one end of an arc tube bulb 2 made of quartz glass. This valve 2
A spherical portion 4 having a shape similar to a spherical shape such as a spherical shape or an elliptic spherical shape is formed at the tip of the spherical shape portion 4.
The cylindrical portion 5 is continuously formed in the vicinity of the crushing sealing portion 3 so as to communicate therewith.

A visible light transmitting infrared reflecting film 6 is formed on the outer surface (or inner surface) of the bulb 2. As shown in FIG. 3, the infrared reflective film 6 is made of, for example, titanium oxide (TiO 2).
₂ ), tantalum oxide (Ta ₂ O ₅ ), zirconium oxide (ZrO ₂ ), zinc sulfide (ZnS) and other high refractive index layers 61, silicon oxide (silica = SiO ₂ ), magnesium fluoride (MgF _2). ) Etc. low refractive index layer 6
2 and the like are alternately formed as a multilayer film having, for example, 9 to 35 layers in total. Such an infrared reflection film 6 has a function of reflecting infrared rays by a multilayer interference effect, but transmitting visible light.

In the bulb 2, two filaments 7 and 8 each made of tungsten W are housed. These filaments 7 and 8 are a low beam filament and a traveling beam filament. The low beam filament 7 is located in the spherical portion 4 of the bulb 2 so that the center of the coil coincides with the substantially center of the spherical shape. And the traveling beam filament 8 is the above-mentioned passing beam filament 7
It is arranged in the cylindrical portion 5 on the crushing sealing portion 3 side.

The passing beam filament 7 is connected to the inner lead wires 9 and 10, and the traveling beam filament 8 is connected to the one inner lead wire 9 and the other inner lead wire 11. There is. Therefore, the internal lead wire 9 is a common internal lead wire.

A light shielding plate 12 is arranged in the vicinity of the passing beam filament 7. This shading plate 12
Is for blocking the visible light emitted from the low beam beam 7 from going in a certain direction, that is, for preventing the oncoming vehicle from being dazzled when it becomes a low beam. Therefore, the light shielding plate 12
A light-shielding region of visible light emitted from the passing beam filament 7 is predetermined. This shading plate 12
Is formed of tungsten W or molybdenum Mo, or an alloy containing at least one of tungsten W and molybdenum Mo, and is composed of molybdenum in this embodiment.

The light shielding plate 12 has a curved surface such as a spherical surface or an elliptic surface in cross section, and the surface facing the low beam filament 7 mainly reflects light in the visible region to the infrared region. The reflective film 13 is formed.
The reflective film 13 is made of, for example, aluminum oxide Al ₂ O.
₃ , zirconium oxide ZrO ₂ , hafnium oxide HfO
₂ , calcium oxide CaO, strontium oxide Sr
It is formed of a fine particle oxide composed of at least one of O and magnesium oxide MgO. For example, aluminum oxide powder is made into a colloidal solution, and this solution is applied to the reflecting surface of the light shielding plate 12 made of molybdenum. 300
It is obtained by firing at a temperature of 400 ° C. Such a reflective film 13 has a structure in which the fine particle oxides are directly adhered to each other without a special binder to form a continuous sintered film, which diffuses and reflects light in a wide range from the visible region to the infrared region. It is a film that makes it.

The fine particle oxide has an average particle size of 0.05 to
A fine particle powder of about 0.10 μm is used to form the reflective film 13 having a film thickness t of 0.5 μm or more and 10 μm or less.

As a result, the reflectance of the reflective film 13 in the visible region to the infrared region exceeds 80%. Such a light shielding plate 12 is supported by one of the inner lead wires 10 via a holder 14. In addition, in the valve 2,
Halogen gas is enclosed.

Each of the internal lead wires 9, 10 and 11 described above
Are connected to metal foil conductors 15, 16 and 17 made of Mo or the like and sealed to the crushing seal portion 3 at the end of the valve 2, respectively, and these metal foil conductors 15, 16 and 17 are connected.
Are connected to external lead wires 18 ...

The crushing sealing portion 3 of the valve 2 is attached to the flanged base 20. The flanged base 20 is provided with a flange 22 on a cylindrical base body 21, and
Three leg terminals 23, 24, 25 are provided at the ends, and the crushing seal portion 3 of the valve 2 is inserted into the cylindrical base body 21. The crushing seal portion 3 and the cylinder are The die base body 21 is joined by an adhesive (not shown).

The leg terminals 23 to 25 correspond to the valve 2
Are respectively connected to the external lead wires 18 led out from the sealing portion 3 of
Electrically connected to 10 and 11. The common internal lead wire 9 is electrically connected to the common leg terminal 23.

The halogen bulb 1 having such a flanged base 20 is housed in a reflector 30 as shown in FIG. The reflector 30 is composed of a reflector 32 having a reflecting surface 31 and a front lens 33 attached to the front opening of the reflector 32.
A mounting hole 34 is formed at the top of the back surface of the. Mounting hole 3
4, the halogen bulb 1 is inserted, and the flanged cap 20 capped on the sealing portion 3 of the halogen bulb 1 has its flange 22 fixed to the periphery of the mounting hole 34. , This halogen bulb 1 has a reflector 3
It is mounted at a predetermined position with respect to 2.

The operation of the embodiment having such a structure will be described. The headlamp assembled as shown in FIG.
12V DC between the common leg terminal 23 and one leg terminal 25
When it is connected to the power source, a potential difference is applied between the common inner lead wire 9 and one inner lead wire 10, and the low beam filament 7 is energized. Therefore, the passing beam filament 7 emits light, and this light is emitted to the surroundings.

In this case, since the light shielding plate 12 is provided in the vicinity of the passing beam filament 7, the light traveling toward the light shielding plate 12 is blocked. The visible light and infrared rays that reach the light shield plate 12 are diffused and reflected by the reflection film 13 formed on the inner surface of the light shield plate 12.

The reflected light and infrared rays diffusely reflected by the reflection film 13 of the light shielding plate 12 and the light emitted from the low beam filament 7 in a direction other than the light shielding plate 12 are the spherical portion 4 and the cylinder of the bulb 12. It is radiated from the part 5 to the outside. When this light passes through the infrared reflecting film 6 formed on the outer surfaces of the spherical portion 4 and the cylindrical portion 5, visible light is transmitted and infrared rays are reflected.

The transmitted visible light is reflected by the reflecting surface 31 of the reflector 32 and heads forward, and the front lens 33 controls the light distribution to illuminate the front. In this case, due to the light-shielding action of the light-shielding plate 12, 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 road surface that is relatively close to the vehicle is illuminated, the brightness may be lower than that in the case of the traveling beam, and therefore, normally,
Unlike the traveling beam filament 8, the rated power of the beam filament 7 is made smaller. For example, in the standard, in the case of a 4H type halogen bulb, the power supply voltage is 12V.
On the other hand, the traveling beam filament is 60 W, and the difference beam filament is 55 W.

However, the light-shielding plate 12 having the above-mentioned structure is used for the reflecting film 1.
Since 3 is formed, 80%, specifically 90% or more, of the light directed to the light shielding plate 12 is reflected by the reflection action of the reflection film 13. Therefore, the conventional 30-40
The visible light absorbed at a rate of% is reflected in a direction other than the light shielding plate 12, and the light amount of the passing beam increases. Therefore, the brightness of the low beam can be increased, and the utilization efficiency of the visible light emitted from the low beam filament 7 is increased.

The infrared light reflected by the infrared reflecting film 6 is returned to the inside of the bulb 2. In this case, since the coil center portion of the passing beam filament 7 is arranged at the substantially central point of the spherical portion 4 of the bulb 2, the infrared rays reflected by the infrared reflection film 6 of the spherical portion 4 are passed to the passing beam filament 7. Return effectively. Therefore, the feedback rate of the infrared rays returned to the filament 7 becomes high, and the infrared rays returned in this manner heat the filament 7, so that the filament 7 has the above-mentioned infrared reflection film 6 in addition to the power energy supplied from the power source. Since thermal energy is given by the infrared rays reflected by, the temperature rise is promoted and the incandescence is promoted. In this case, if the emission intensity is set to the same level as that in the case where the infrared reflecting 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 reflecting film 6. Power consumption can be saved.

Moreover, in general, a vehicle has more opportunities to travel on a passing beam than when traveling on a traveling beam. Therefore, if the passing beam filament 7 is housed in the spherical portion 4, the energy efficiency for the frequently used passing beam filament 7 can be increased. Therefore, if the traveling beam filament 8 is housed in the spherical portion 4. Compared with, the electric energy of the entire lamp can be significantly reduced and the lamp efficiency can be improved.

The common leg terminal 23 and the other leg terminal 2
4 is connected to a DC 12V power source, a potential difference is given between the common inner lead wire 9 and the other inner lead wire 11, so that a current flows through the traveling beam filament 8 and the traveling beam filament 8 emits light. . This light is emitted to the surroundings and emitted from the spherical portion 4 and the cylindrical portion 5 of the bulb 2 to the outside. Visible light transmitted through the spherical portion 4 and the cylindrical portion 5 is reflected by the reflecting surface 31 of the reflector 32 and directed forward, and the front lens 33 attached to the front opening of the reflector 32 controls the light distribution to illuminate the front. To do. In this case, the traveling beam is such that a strong beam reaches far away from the vehicle.

Then, the infrared rays reflected by the infrared reflecting film 6 are returned to the inside of the bulb 2, and the returned infrared rays heat the traveling beam filament 8. Therefore, the traveling beam filament 8 is provided with the thermal energy by the infrared rays reflected by the infrared reflecting film 6 in addition to the electric energy supplied from the power source, so that the temperature rise is promoted and the power consumption can be saved. it can.

According to the vehicle headlamp using the halogen bulb 1 as a light source, the lamp efficiency of the halogen bulb 1 is improved, so that the advantage thereof can be utilized and the front lamp having 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 implemented as a light bulb in which a filament and a light shielding plate are housed in a spherical or elliptical bulb.

[0044]

As described above, according to the first aspect of the invention, the visible light emitted from the filament toward the light shielding plate is reflected by the reflection film formed on the reflection surface of the light shielding plate. Less light is absorbed in the filaments, so most of the light emitted from the filament is directed out of the bulb. Therefore, the utilization efficiency of visible light is increased and the luminous flux is increased.

According to the invention of claim 2, most of the light emitted from the filament for low beam in the incandescent light bulb for headlight can be used as low beam.
The luminous flux of the low beam light increases, and the low beam light can be brightened.

According to the third aspect of the invention, since the reflection film is the diffuse reflection surface formed of the fine particle oxide, the light emitted from the filament is diffused and reflected, and the direction of the light shield plate. Other than that, it will be evenly distributed and radiated toward the outside.

According to the invention of claim 4, the fine particle oxide is formed of at least one of aluminum oxide, zirconium oxide, hafnium oxide, calcium oxide, strontium oxide and magnesium oxide. It has excellent light reflection efficiency and is easy to form a film.

According to the fifth aspect of the invention, since the reflectance of the reflective film is 80% or more, the reflection characteristics are excellent and the effective use of visible light is enhanced. According to the invention of claim 6, the thickness of the reflective film is set to 0.5 μm or more and 10 μm or less, so that the visible light reflection characteristic is good.

According to the invention of claim 7, the light shielding plate is made of tungsten, molybdenum, or at least one of them.
Since it is formed of an alloy containing seeds, it is excellent in heat resistance, has little reaction with halogen, and has improved durability. The invention of claim 8 can utilize the advantages of the incandescent lamp according to any one of claims 1 to 7, and can provide an efficient vehicle headlamp.

[Brief description of drawings]

FIG. 1 is a side view of a halogen light bulb showing an embodiment of the present invention.

FIG. 2 is a front view of the halogen bulb of the embodiment.

FIG. 3 is a cross-sectional view illustrating the configuration of the infrared reflective film of the example.

FIG. 4 is a cross-sectional view showing the structures of a light shielding plate and a reflective film of the same embodiment.

FIG. 5 is a sectional view showing a vehicle headlamp using the halogen bulb of the embodiment as a light source.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Halogen bulb 2 ... Bulb 3 ... Sealing part 4 ... Spherical part 5 ... Cylindrical part 6 ... Infrared reflecting film 7 ... Diffusion beam filament 8 ... Traveling beam filament 9, 10, 11 ... Internal lead wire 12 ... Shading plate 23 ... Reflective film 30 ... Reflector 32 ... Reflector

Claims (8)

[Claims] 1. A bulb; a filament housed in the bulb; a light-shielding plate which is provided in the vicinity of the filament and regulates the light emitted from the filament so that the light is emitted only in a predetermined direction; An incandescent light bulb, comprising: a reflective film formed on a surface of the plate facing the filament, the reflective film reflecting at least visible light. 2. A bulb having a spherical portion, an elliptic spherical portion, or a spherical portion having a similar shape and a cylindrical portion continuous with the spherical portion; a filament for a low beam and a traveling beam housed in the spherical portion and the cylindrical portion, respectively. Filament for use; a light-shielding plate that is provided in the vicinity of the filament for low-beam and regulates light emitted from the filament for low-beam to irradiate only in a predetermined direction; and a surface of the light-shielding plate that faces the filament. An incandescent light bulb for a headlight, comprising: a reflective film that is formed and reflects at least visible light. 3. The incandescent lamp according to claim 1, wherein the reflective film is formed by directly binding fine particle oxides directly to each other. 4. The incandescent lamp according to claim 3, wherein the reflective film is made of at least one of aluminum oxide, zirconium oxide, hafnium oxide, calcium oxide, strontium oxide, and magnesium oxide. 5. The reflective film has a visible light reflectance of 80%.
The above is the incandescent light bulb according to any one of claims 1 to 4. 6. The thickness of the reflective film is 0.5 μm or more and 1
The incandescent lamp according to any one of claims 1 to 5, wherein the incandescent lamp has a diameter of 0 µm or less. 7. The incandescent lamp according to claim 1, wherein the light shielding plate is made of tungsten, molybdenum, or an alloy containing at least one of them. . 8. A vehicle headlight comprising: the incandescent lamp according to claim 1; and a reflector incorporating the incandescent lamp.