JPH08203477A - Incandescent lamp, reflection type lighting system using this, and vehicle headlight - Google Patents

Abstract

PURPOSE: To provide an incandescent lamp, a reflection type lighting system using this incandescent lamp, and a headlight for a vehicle capable of limiting the emission of light from the edge of a light emitting part and preventing color difference of light emitted from the lamp. CONSTITUTION: An infrared radiation reflecting film 5 is formed on the surface of a bulb 2 in which a filament 6 is accommodated, a shielding plate 15 for shielding light in the specified direction is set in the vicinity of the filament, and a light regulating part 17 which regulates light emitted from the filament so as not to proceed to the edge of the light emitting part is arranged in the shielding plate. The light regulating part 17 shuts off or reduce light proceeding to the edge of the light emitting part, regulates light going out to the outside from the edge of the light emitting part, and irregular color is eliminated.

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.

When 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, thus incandescent filament. Is promoted, the 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.

[0004]

However, in the incandescent lamp having the infrared reflecting film formed as described above, when the light emitting portion has a spherical shape or a shape similar thereto, for example, an elliptic sphere, the light emitting portion is formed on the surface. The film thickness of the infrared reflective film may not be uniform over the whole. That is, when an infrared reflection film is formed on the surface of the bulb, a method is employed in which the bulb is immersed in a solvent for the coating and pulled up to apply the solvent to the surface of the bulb and then to dry and solidify the solvent. In this case, a difference in film thickness of the coating film occurs between the central bulge portion of the valve and the wraparound portion of the end portion depending on the flow rate of the solvent.

That is, in the light emitting portion, there is a tendency that the thickness of the infrared reflecting film becomes thinner at the curved portion at the end portion than at the central spherical portion. In such a case, the light emitted to the outside of the bulb is the color of the light emitted from the central spherical portion of the light emitting portion,
There is a problem that a difference in color of light emitted from the end portion occurs and so-called color unevenness occurs when projected onto an irradiation surface.

In order to prevent such a difference in emission color due to a difference in location, it has been proposed to form a light-shielding film on the end portion of the bulb. However, in this case, the end portion of the bulb absorbs light. Occurs, and there is a problem that the amount of light decreases.

The present invention has been made in view of the above circumstances, and an object thereof is to limit the light emitted from the end of the light emitting portion and prevent the color difference of the light emitted from the lamp. An incandescent light bulb, a reflective lighting device using the same, and a vehicle headlamp are provided.

[0008]

According to a first aspect of the present invention, 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 surface of the bulb are provided. An infrared reflection film that is formed and reflects the light emitted from the filament and returns it to the filament, and is provided in the vicinity of the filament and regulates the light distribution by irradiating the light emitted from the filament only in a predetermined direction. The incandescent light bulb is characterized by comprising: a light-shielding plate; and a light-blocking part formed on the light-shielding plate, which restricts light emitted from the filament from going to the end of the light-emitting part.

According to a second aspect of the present invention, the light control portion is ± 45 ° to ± 13 on the bulb end side with respect to the center of the filament.
The incandescent light bulb according to claim 1, wherein light directed to a region of 5 ° or less is blocked.

According to a third aspect of the present invention, the light-shielding plate has a curved reflecting surface that reflects the light emitted from the filament and returns the light to the filament. It is an incandescent light bulb.

An invention according to claim 4 is the incandescent lamp according to any one of claims 1 to 3, characterized in that the light shielding plate is formed of tungsten or a tungsten alloy.

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 a 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, A traveling beam filament, an infrared reflection film formed on the surface of the bulb, which reflects the light emitted from the filament and returns it to the filament, are provided in the vicinity of the low beam filament, and exit from the low beam filament. A light-shielding plate that regulates light distribution by irradiating light only in a predetermined direction, and a light-shielding plate that is formed on the light-shielding plate and regulates light emitted from the filament toward the end of the light-emitting portion. An incandescent light bulb for a headlight, comprising: a light section.

According to a seventh aspect of the present invention, the light-shielding plate has a curved reflecting surface that reflects the light emitted from the filament and returns the light to the filament. It is an incandescent light bulb.

The invention of claim 8 comprises the incandescent lamp according to any one of claims 1 to 4, claim 6 and claim 7, and a reflector incorporating this incandescent lamp. This is a vehicle headlight.

[0016]

In general, a vehicle headlamp has a lamp for irradiating a passing beam and a lamp for irradiating a traveling beam, or 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. The traveling beam and the passing beam can be selectively used by switching and lighting these lamps or filaments. In this case, the low beam emitted from the low beam filament is required to have a light distribution characteristic that does not give glare to an oncoming vehicle. Therefore, a light shielding plate is provided in the vicinity of the low beam filament. The irradiation of light in an undesired direction is restricted.

In the invention according to claim 1 of the present invention, since the light-shielding plate is provided with the light-shielding portion for restricting the light emitted from the filament from going to the end portion of the light-emitting portion, the light-shielding portion is provided. Controls the light toward the end of the light emitting portion such as blocking or dimming the light. Therefore, the emission of light from the end portion of the light emitting portion is regulated, the difference between the light color of this portion and the color of light emitted from the central portion becomes inconspicuous, and uneven color is eliminated.

According to the second aspect of the invention, the light control portion is ± 45 ° or ± 1 on the bulb end side with respect to the center of the filament.
It blocks light that goes to the area below the range of 35 °. The region where the film thickness of the infrared reflective film changes is less than ± 45 ° to ± 135 ° on the bulb end side with respect to the center of the filament. The unevenness is eliminated.

According to the third aspect of the present invention, the visible light and infrared rays radiated from the filament toward the light shielding plate are:
The light is 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.

According to the fourth aspect of the present invention, the light shielding plate is made of tungsten or a tungsten alloy, so that the durability is improved.

According to the invention of claim 5, the advantages of the incandescent lamp according to any one of claims 1 to 4 can be utilized, and a lighting device with less uneven color of irradiation light and high lamp efficiency is provided. be able to.

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, since the light-shielding plate provided in the vicinity of the filament for the passing beam is provided with the light-blocking part that restricts the light emitted from the filament from going to the end of the spherical part, this light-blocking part is provided at the end of the spherical part. Limit the light going to the department. Therefore, the light emitted from the end of the spherical portion is restricted, the difference from the color of the light emitted from the central portion becomes inconspicuous, and the uneven color is eliminated.

According to the incandescent light bulb for headlights recited in claim 7, 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. Like
Therefore, the infrared return efficiency is improved and the lamp efficiency is improved.

According to the invention of claim 8, the advantages of the incandescent lamp according to any one of claims 1 to 4, claim 6 and claim 7 can be utilized, the color unevenness of the irradiation light is small, and the lamp. It is possible to provide an efficient vehicle headlight.

[0025]

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 floodlight illumination device for a low beam in a four-lamp type vehicle headlight, FIGS. 1 to 5 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 3 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. 5, 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 contained 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.

On one side of the filament 6, the shading plate 1
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.

The light shielding plate 15 directs the light emitted from the filament 6 in an undesired direction so that when the halogen bulb 1 is used as a headlight of a vehicle, it emits a passing beam having a predetermined light distribution. 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
Has the above-mentioned light-shielding region, and as shown in FIG. 4, its cross-sectional shape is a curved surface such as a spherical surface or an elliptical surface,
A reflective surface 16 that reflects visible light and infrared light is formed on the surface facing the filament 6. This reflective surface 16
The filament 6 is arranged at the center (focus) of the. 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.

Light-shielding portions 17, 17 are formed at the front and rear ends of the light-shielding plate 15. These light control units 17,
Reference numeral 17 is a tongue shape formed by integrally extending from the curved light-shielding plate 15, and is formed from the filament 6 to the bulb 2
It is formed so as to block light traveling toward the chip portion 6a and light traveling from the filament 6 toward the root portion of the sealing portion 7. These tongue-shaped light-shielding parts 17, 17 are + 45 ° to ++ from the filament 6 at the end of the spherical part 3 shown in FIG.
It is desirable to block light traveling in the range of 135 ° and in the range of −45 ° to −135 °, but at least the boundary between the spherical portion 3 and the tip portion 6a in the bulb 2, and the spherical portion 3 and the sealing portion. It is formed so as to block the light traveling toward the boundary with 7. The shading plate 15 is joined to a holder 18 made of tungsten wire or the like by means of welding or the like, and the holder 18 is welded to one of the inner lead wires 7.

The halogen bulb 1 having the above-mentioned 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, passes through the spherical portion 3 of the bulb 2, and is emitted to the outside. Then, when this light passes through the infrared reflection film 5 formed on the outer surface of the spherical portion 3, visible light is transmitted,
Infrared is reflected. The infrared rays reflected by the infrared reflecting film 5 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 approximately the center point of the spherical portion 3 forming the spherical surface, and the infrared rays reflected by the entire surface of this spherical surface are condensed at the center of the bulb. Effectively return to. 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 amount of emitted light is made equal to 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 thermal energy reflected by the infrared reflecting film 5, thus consuming Power can be saved.

On the other hand, the visible light transmitted through the infrared reflecting film 5 is reflected by the reflecting surface 21 of the reflector 22 and goes forward, and the light distribution is controlled by the front lens 23 attached to the front opening of the reflector 22 so that the visible light goes forward. Irradiate.

In this case, since the shading plate 15 is arranged on one side of the filament 6, the filament 6 is cut off from the shading plate 1.
The light traveling in the direction 5 is blocked by the light shielding plate 15 and is prevented from being transmitted in this direction. For this reason, since the light reflected by the reflecting surface 21 of the reflector 22 and traveling forward is blocked by the light shielding plate 15 toward the predetermined area, the light distribution of the forward irradiation light is biased, which is so-called. It becomes a passing beam and does not give glare to oncoming vehicles.

By the way, the infrared reflecting film 5 formed on the surface of the bulb 2 has a film thickness difference between the central portion and the end portion of the spherical portion 3, and the difference in the color of light transmitted therethrough due to the difference in interference action. Occurs. However, in this embodiment, the tongue-shaped light-blocking parts 17, 17 are formed at the end of the light-shielding plate 15, and these light-blocking parts 17,
Since 17 blocks the light traveling from the filament 6 toward the tip portion 6a of the bulb 2 and the light traveling from the filament 6 toward the root portion of the sealing portion 7, the light traveling toward the thin film portion is blocked or reduced. Be illuminated. Therefore, the problem that the light emitted from the bulb 2 has a different light color depending on the place is eliminated, and the problem that the light distribution reflected by the reflecting surface 21 of the reflector 22 toward the front causes unevenness in color is eliminated. It

The region of the bulb 2 where the infrared reflective film 5 is thin is +45 at the end of the spherical portion 3 shown in FIG.
In the range of ° to + 135 °, and in the range of −45 ° to −135 °, so that the tongue-shaped light controlling parts 17, 17 are + from the filament 6 to the end of the spherical part 3 shown in FIG.
45 ° to + 135 ° range, and −45 ° to −135
It is better to block the light going to the range of °, but if the light-shielding range is wide, the amount of light emitted from the lamp will be small, so at least the boundary between the spherical portion 3 and the tip portion 6a of the bulb 2, and the spherical portion 3 and the sealing portion. It is preferably formed so as to block light traveling toward the boundary with the stop 7. The tongue-shaped light-blocking parts 17, 17 can be formed integrally or integrally with the light-shielding plate 15, and can be implemented with a simple structure.

The light-shielding plate 15 may have a flat shape, but if the reflecting surface 16 of the light-shielding plate 15 is formed into a curved surface such as a spherical surface or an elliptical cross-section, the visible light reaching the light-shielding plate 15 is reached. The internal reflection surface 16 of the light shielding plate 15 for light and infrared rays
It is reflected by and is condensed on the filament 6. Therefore, the infrared rays are effectively returned to the filament 6, which is effective for heating 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,
Infrared rays emitted in all directions are returned to the filament 6 from all directions. 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.

In the case of a floodlighting device using such a halogen bulb 1 as a light source, the tongue-shaped light control unit 1 is used.
Due to the formation of Nos. 7 and 17, there is no color unevenness in the distribution of the irradiation light, and moreover, since the shape of the light shielding plate 15 is made into a curved shape, the lamp efficiency of the halogen light bulb 1 is improved, so that the advantages can be utilized for these. The resulting lighting device is excellent in light color and efficiency.

In the above embodiment, the passing beam headlamp in the four-lamp type vehicle headlamp has been described, but the lighting device shown in FIG. 6 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. 7 to 9 will be described. This embodiment shows an example applied to an H4 type vehicular headlamp, FIGS. 7 and 8 show a halogen bulb used as a light source, and FIG. 9 is a sectional view of the entire headlamp.

Halogen bulb 100 shown in FIGS. 7 and 8.
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.

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 tongue-shaped light blocking portions 113, 113 are integrally formed on the light blocking plate 111. These tongue-shaped light control units 11
Reference numerals 3 and 113 are formed so as to block light from the filament 6 toward at least the boundary between the spherical portion 3 and the tip portion 6a of the bulb 2 and the boundary between the spherical portion 3 and the sealing portion 7. . Such a light shielding plate 111 is supported by one inner lead wire 109 via a holder 114. A halogen gas is enclosed in the bulb 102.

Each of the internal lead wires 108, 109 and 110 is connected to a Mo foil sealed in a crushing sealing 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 base 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 each of the internal lead wires 10 is 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.

With respect to the second embodiment having such a structure,
The operation will be described. The headlamp assembled as shown in FIG. 9 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 and travels forward, so that 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 light reflected by the infrared reflecting film 105 is returned to the inside of the bulb 102, and the returned infrared light heats 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 blocking plate 111 is provided in the vicinity of the low beam filament 106, the light traveling toward the light blocking 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.

The light radiated in the direction other than the light shielding plate 111 is a spherical portion 103 and a 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, according to the standard, in the case of an H4 type halogen 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, the infrared rays emitted from the low beam filament 106 are shielded by 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.

Moreover, 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.

Also in the case of this embodiment, the tongue-shaped light-blocking parts 113, 113 are formed at the ends of the light-shielding plate 111, and these light-blocking parts 113, 113 allow light from the filament 6 to reach the tip part 6a of the bulb 2. Since the light traveling from the filament 6 toward the base of the sealing portion 7 is blocked, the light traveling toward the thin portion is shielded or dimmed. Therefore, the problem that the light color is different depending on the location of the light emitted from the bulb 102 is eliminated, and the problem that the light distribution reflected by the reflecting surface 131 of the reflector 132 and traveling forward is uneven is solved. It

According to the vehicular headlamp using such a halogen light bulb 100 as a light source, color unevenness is eliminated by the distribution of the emitted light and the efficiency of the halogen light bulb 100 is improved. You can take advantage of this advantage,
The headlight has excellent light color distribution and efficiency.

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

[0066]

As described above, according to the invention of claim 1, since the light shielding plate is provided with the light control portion for restricting the light emitted from the filament from going to the end portion of the light emitting portion, this light control portion is provided. The light portion blocks or diminishes the light toward the end of the light emitting portion.
Therefore, the light emitted from the end of the light emitting portion is regulated, the difference between the light color of this portion and the color of the light emitted from the central portion becomes inconspicuous, and the occurrence of color unevenness can be eliminated.
Moreover, since the light control portion is provided on the light shielding plate, it is possible to suppress the occurrence of color unevenness with a simple structure.

According to the second aspect of the present invention, the light control portion is ± 45 ° or ± 1 on the bulb end side with respect to the center of the filament.
It blocks light that goes to the area below the range of 35 °. The region where the film thickness of the infrared reflective film changes is less than ± 45 ° to ± 135 ° on the bulb end side with respect to the center of the filament. The unevenness is eliminated.

According to the third aspect of the present invention, the visible light and infrared rays radiated from the filament toward the light shielding plate are:
The light is 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.

According to the invention of claim 4, the light shielding plate is formed of tungsten or a tungsten alloy, so that the durability is improved.

According to the invention of claim 5, the advantages of the incandescent lamp according to any one of claims 1 to 4 can be utilized, and the illumination device with less uneven color of irradiation light and high lamp efficiency is provided. be able to.

In the incandescent light bulb for headlights according to the sixth aspect, 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, since the light-shielding plate provided in the vicinity of the filament for the passing beam is provided with the light-blocking part that restricts the light emitted from the filament from going to the end of the spherical part, this light-blocking part is provided at the end of the spherical part. Limit the light going to the department. Therefore, the light emitted from the end of the spherical portion is restricted, the difference from the color of the light emitted from the central portion becomes inconspicuous, and the uneven color is eliminated.

According to the incandescent lamp for a headlight of claim 7, visible light and infrared rays radiated from the low beam filament toward the light shielding plate are reflected by the light shielding plate and returned to the low beam filament. Like
Therefore, the infrared return efficiency is improved and the lamp efficiency is improved.

According to the invention of claim 8, the advantages of the incandescent light bulb described in any one of claims 1 to 4, claim 6 and claim 7 can be utilized, the color unevenness of the irradiation light is small, and the lamp It is possible to provide an efficient vehicle headlight.

[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 perspective view showing the shape of a light shielding plate of the embodiment.

FIG. 5 is a cross-sectional view illustrating the configuration of the infrared reflective film of the example.

FIG. 6 is a cross-sectional view of a floodlighting device using the halogen bulb of the embodiment as a light source.

FIG. 7 is a side view of a halogen bulb according to a second embodiment of the present invention.

FIG. 8 is a plan view of the halogen bulb of the example.

FIG. 9 is a cross-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 17,113 ... Tongue-shaped light control unit 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 (8)

[Claims] 1. A bulb having a light emitting portion having a spherical shape or a shape similar to a spherical shape, a filament housed in the light emitting portion of the bulb, and a light beam emitted from the filament formed on the surface of the bulb. And an infrared reflection film for returning the filament to the filament, a light shielding plate provided in the vicinity of the filament and for controlling the light distribution by regulating the light emitted from the filament only in a predetermined direction, and formed on the light shielding plate. An incandescent light bulb comprising: a light control unit that restricts the light emitted from the filament from going to the end of the light emitting unit. 2. The light control unit blocks light directed to a region within a range of ± 45 ° to ± 135 ° on the bulb end side with respect to the center of the filament.
Incandescent light bulb as described in. 3. The incandescent lamp according to claim 1, wherein the light shielding plate has a curved reflecting surface that reflects the light emitted from the filament and returns it to the filament. 4. The incandescent light bulb according to claim 1, wherein the light shield 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. An infrared reflection film formed on the surface of the bulb, which reflects the light emitted from the filament and returns it to the filament, and is provided in the vicinity of the low beam filament.
A light-shielding plate that controls the light distribution by regulating the light emitted from the low beam filament only in a predetermined direction, and the light emitted from the filament, which is formed on the light-shielding plate, is the end of the light emitting portion. An incandescent light bulb for headlights, comprising: a light control section that restricts the light from going to the section. 7. The incandescent lamp for a headlight according to claim 6, wherein the light shielding plate has a curved reflecting surface that reflects light emitted from the filament and returns the light to the filament. 8. An incandescent lamp according to any one of claims 1 to 4, 6 and 7, and a reflector incorporating the incandescent lamp. Vehicle headlights.