JPH0945295A - Incandescent lamp, reflection type lighting system using same, and vehicle headlight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an incandescent lamp which, when provided with infrared reflection films, solves problems of formation of color nonuniformity of transmitted visible light due to a difference in film thickness, a reflection type lighting system using the same, and a vehicle headlight. SOLUTION: A bulb 2 having a spherical or elliptical light emitting part 3 has a filament 6 stored in the light emitting part, an infrared reflection film 5 is formed over the surface of the bulb 2, and a light diffusion film 15 controlling visible light is formed at the end of the light emitting part 3. The infrared reflection film 5 is so formed that its maximum thickness is located within a range of not less than +15 deg. and not more than +30 deg. from the center of the light emitting part 3 toward a sealed part, and that it has a boundary located within a range of not less than -40 deg. and not more than -45 deg. from the center of the light emitting part 3 toward an end, so that it is located in an end area beyond the boundary.

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 an infrared reflecting film is provided on the surface of a bulb and infrared rays emitted from a filament contained in the bulb are reflected by the infrared reflecting membrane and returned to the inside of the bulb. The present invention relates to a reflective lighting device and a vehicle headlight using the same.

[0002]

2. Description of the Related Art Generally, an incandescent light bulb including a halogen light bulb is a light source that utilizes light emission due to the incandescence of a filament, so that it has a relatively 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 case of the incandescent lamp having the infrared reflecting film as described above, in order to effectively return the infrared rays to the filament, the shape of the light emitting portion is spherical or elliptical or similar. Although it is desirable that the infrared reflective film formed on the surface have a non-uniform thickness over the entire surface in the case of such a spherical shape. That is, when the infrared reflecting film is formed on the surface of the valve, there are the CVD method, the PVD method, the DIP method of applying the solvent to the valve surface by immersing the valve in a solvent and pulling it up. It is difficult to obtain a uniform film thickness over the entire length, and a film thickness difference occurs depending on the flow condition of the solvent. That is, in the case of a shape close to a sphere, there is a tendency that the film thickness of the central maximum diameter part (equatorial part) becomes the maximum film thickness, and the film thickness of the end part becomes thinner than this.

When such a film thickness difference occurs, a difference occurs in the visible light transmission characteristics, and the color of visible light that goes out changes. That is, there is a problem that a color difference between light emitted from a thick portion and light emitted from a thin portion causes color unevenness when projected onto an irradiation surface.

In order to prevent such a difference in luminescent color, a light-shielding film or the like is formed at both ends where the diameter of the spherical portion becomes small,
Although proposals have been made to block out light with large color shifts, the structure in which light-shielding films are formed on both ends of the spherical portion requires separate coating of these light-shielding films in different areas, so work It takes time and labor, and if light-shielding films are formed on both ends, the light-shielding effect reduces the amount of light emitted to the outside.

The present invention has been made in view of the above circumstances. An object of the present invention is to form a light-shielding portion such as a light-shielding film or a diffusion film only on the tip of the bulb. (EN) An incandescent lamp capable of simplifying the work of forming a part and preventing the difference in color of light emitted from a lamp, a reflective lighting device using the same, and a vehicle headlamp. .

[0008]

According to a first aspect of the present invention, there is provided a bulb having a light emitting portion having a spherical shape, an elliptic spherical shape or a shape similar thereto; a filament accommodated in the light emitting portion; and a surface of the bulb. And an infrared reflection film for reflecting infrared rays emitted from the filament to return to the inside of the bulb, and a light control section formed at the tip of the light emitting section for controlling visible light toward the tip. The maximum film thickness portion of the infrared reflecting film is formed in a region of + 15 ° or more and + 30 ° or less from the center of the light emitting portion toward the sealing portion side, and the light blocking portion is -40 ° or more from the center of the light emitting portion toward the tip side -45
The incandescent light bulb is characterized in that it has a boundary in a range of ° or less and is formed in a region on the tip side of the boundary.

In the present invention, the light control section refers to a function of blocking, diffusing, and reflecting light. The invention according to claim 2 is the incandescent lamp according to claim 1, characterized in that the light control portion is formed of a light diffusion film.

An invention according to claim 3 is the incandescent lamp according to claim 1, characterized in that the light control portion is formed of a light blocking film. In the invention of claim 4, the infrared reflection film is
The incandescent lamp according to any one of claims 1 to 3, wherein the incandescent lamp is formed of a multilayer interference film in which a high refractive index layer and a low refractive index layer are laminated.

The invention of claim 5 comprises the incandescent lamp according to any one of claims 1 to 4; and a reflector to which the incandescent lamp is attached; It is a device.

According to a sixth aspect of the present invention, there is provided a bulb having a light emitting portion having a spherical shape, an elliptic spherical shape, or a shape similar thereto and a cylindrical portion continuous with the light emitting portion; and the light emitting portion and the cylindrical portion, respectively. A low beam filament and a traveling beam filament; an infrared reflection film formed on the surface of the bulb to reflect the infrared rays emitted from the filaments back into the bulb; and an infrared reflection film formed at the tip of the light emitting portion. A light-controlling portion for controlling visible light toward the tip portion; and the maximum film thickness portion of the infrared reflecting film is + 15 ° or more and + 30 ° or less from the center of the light emitting portion toward the sealing portion side. In addition to being formed in the region of, the light control section has a boundary in a range of −40 ° to −45 ° from the center of the light emitting section toward the tip side, and beyond this. A headlights incandescent bulbs before, characterized in that formed on the side of the region. The invention of claim 7 is a headlight for a vehicle, comprising: the incandescent lamp for a headlight according to claim 6; and a reflector incorporating the incandescent lamp.

[0013]

According to the invention of claim 1, since the maximum film thickness portion of the infrared reflecting film is formed at a position deviated to the sealing portion side from the center of the light emitting portion, the thin film portion is exposed to light. It occurs only on the tip side of the discharge part. For this reason, if the light control portion is formed in the thin portion of the tip portion, it is possible to suppress the occurrence of color unevenness.

In this case, the maximum film thickness portion is preferably formed within a region of + 15 ° or more and + 30 ° or less from the center of the light emitting portion toward the sealing portion side, and is a region of less than + 15 °. As a result, a portion having a small film thickness that causes color unevenness is formed on the sealing portion side of the valve. Further, if the area exceeds + 30 °, the thin portion formed at the tip of the light emitting portion is formed over a wide area and must be covered with a light control portion such as light shielding or diffusion. Light is lost and the amount of light emitted to the outside is reduced.

Further, the boundary of the light control portion formed at the tip of the light emitting portion is closer to the tip side than the center of the light emitting portion.
The range of 40 ° or more and −45 ° or less is preferable, and if it is less than −40 °, the area covered by the light control portion becomes too wide, causing optical loss and reducing the amount of light emitted to the outside. Also, -45 °
If it exceeds, the thin portion of the infrared reflective film cannot be completely covered and color unevenness occurs.

According to the second aspect of the present invention, since the light control portion is formed of the light diffusing film, the light directed to this portion is diffused, so that the occurrence of color unevenness can be eliminated. it can.

According to the third aspect of the invention, since the light control portion is formed of the light blocking film, the light directed to this portion is blocked, and the occurrence of color unevenness can be prevented. According to the invention of claim 4, since the infrared reflection film is formed of a multilayer interference film formed by laminating a high refractive index layer and a low refractive index layer, such a multilayer interference film has a variation in film thickness. When the invention according to any one of claims 1 to 3 is applied to an incandescent light bulb having such an infrared reflection film, the effect is effectively exhibited.

According to the invention of claim 5, the advantage of the incandescent lamp according to any one of claims 1 to 4 can be utilized, and an efficient reflection type illumination device can be provided. According to the invention of claim 6, since the passing beam filament is arranged in the light emitting portion having a spherical shape, an elliptic spherical shape, or a shape similar to the spherical shape, the infrared ray reflected by the infrared reflecting film is frequently reflected on the passing beam filament which is frequently used. Can be effectively returned. In this case, since the maximum film thickness portion of the infrared reflecting film is formed at a position closer to the sealing portion side than the center of the light emitting portion, the thin film portion is formed only on the tip side of the light emitting portion. Therefore, if the light control portion is formed in the thin portion of the tip portion, it is possible to suppress the occurrence of color unevenness. The invention according to claim 7 can utilize the advantages of the incandescent lamp according to claim 6, and can provide a vehicle headlamp with less color unevenness in the light distribution characteristics of irradiation light.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the first embodiment shown in FIGS. This embodiment shows an example applied to a reflection type illumination device, FIGS. 1 and 2 show the structure of a halogen bulb used as a light source, FIG. 3 is a film thickness distribution diagram, FIG. 4 is a chromaticity distribution diagram, FIG. 5 is a sectional view of the entire lighting device.

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

On the outer surface (or inner surface) of the valve 2,
A film 5 that transmits visible light and reflects infrared light is formed over the entire surface of the crushing sealing portion 4 except for the outer surface thereof, that is, over the entire surface of the light emitting portion 3. As shown in FIG. 2, the infrared reflective film 5 is made of, for example, titanium oxide (TiO ₂ ) or tantalum oxide (T
a 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, but is visible. It has the effect of transmitting light.

Such an infrared reflecting film 5 is formed by the CVD method,
It is formed by a PVD method or a DIP method, but in this embodiment, it is formed by a DIP method in which the valve 2 is immersed in a solvent and pulled up to apply the solvent to the surface of the valve. In this case, the film thickness is controlled by controlling the pulling speed at which the valve 2 is pulled up from the solvent, and the maximum film thickness portion of the infrared reflecting film 5 is closer to the sealing portion 4 side than the maximum diameter portion of the light emitting portion 3. It is formed in a deviated place.
That is, when the position is set at an angle with the center of the largest diameter portion (equator portion) of the light emitting portion 3 as a reference, the sealing portion 4 side is plus (+), and the tip end side is minus (-), from the equator. The maximum film thickness portion of the infrared reflection film 5 is formed in a region of + 15 ° or more and + 30 ° or less toward the sealing portion 4 side. This state is shown in FIG. 3, and when the maximum film thickness portion of the infrared reflecting film 5 is formed at a position of + 20 °, the sealing portion 4 side (plus direction) and the tip end side (minus direction) are further than this. As the transfer progresses, the film thickness of the infrared reflective film 5 becomes thinner. This is due to the flow of the solvent attached by immersion, and the smaller the diameter is, the smaller the film thickness tends to be.

As described above, when the maximum film thickness portion of the infrared reflecting film 5 is provided in the region deviated from the equator to the sealing portion 4 side, the film thickness of the infrared reflecting film 5 is increased in the tip that is located away from this. Becomes thin. When the film thickness difference is, for example, 10% or more, the transmission characteristics of visible light are changed and a color difference occurs in the transmitted light, causing so-called color unevenness. In order to prevent this, a light control film 15 is formed at the tip of the light emitting portion 3 so as to overlap the infrared reflection film 5. The light control film 15 may be a light shielding film or a reflection film, but in the present embodiment, the light diffusion film 1 is used.
5 is formed. The light diffusion film 15 is made of aluminum oxide Al ₂ O ₃ , silicon oxide SiO ₂ , calcium oxide Ca.
It is formed of a fine particle oxide including at least one of O and magnesium oxide MgO, and diffuses and transmits visible light. The region where the light diffusing film 15 is formed, that is, the boundary of the light diffusing film 15 is located in the range of −40 ° or more and −45 ° or less from the equator toward the tip side.
That is, the light diffusion film 15 is -4 from the equator toward the tip side.
It starts from the range of 0 ° to −45 ° and covers the entire front end.

Although the thickness of the infrared reflection film 5 is reduced from the equator toward the sealing portion 4 side, the maximum film thickness portion of the infrared reflection film 5 is deviated to the sealing portion 4 side. Even at the beginning of the sealing portion 4, the film thickness difference does not exceed 10%, so that it is not necessary to form a light diffusion film on the sealing portion 4 side.

A filament 6 made of tungsten W is housed in the bulb 2 having such a structure. The filament 6 is composed of a single or double coil, and its coil axis is arranged so as to coincide with the center line of the bulb, so that the center of the coil substantially coincides with the center point of the light emitting portion 3. It is arranged. 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. And these M
o The foils 9 and 10 are connected to the external lead wires 11 and 12, respectively. A halogen gas is enclosed in the bulb 2.

As shown in FIG. 5, the halogen bulb 1 having the above-described structure is used by being housed in the reflector 20. The reflector 20 includes a reflector 22 having a reflecting surface 21, and
The front lens 23 is attached to the front opening of the reflector 22, 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 crush seal portion 4 of the halogen bulb 1 is made of an adhesive 25 such as insulating cement.
Is joined to the mounting hole 24 by. 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 configuration,
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 light emitting 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 light emitting 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 goes forward, and the front lens 23 attached to the front opening of the reflector 22 controls the light distribution to illuminate the front.

On the other hand, 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 point of the light emitting portion 3 having a spherical surface, and since the infrared rays reflected by the entire surface of this spherical surface are condensed at the center of the bulb, Effectively return to the department. Therefore, the infrared rays emitted from the filament 6 are eventually reflected by the infrared reflection film 5 formed on the surface of the bulb and returned to the filament 6. Therefore,
The return rate of infrared rays returned to the filament 6 becomes high,
The ratio of heating the filament 6 by the reflected infrared rays increases.

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 incandescent heat 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.

The infrared reflecting film 5 having such an action has a variation in film thickness, and conventionally, as shown by a broken line in FIG. 3, the maximum diameter portion of the light emitting portion 3, that is, the equator portion (the portion at 0 °). ), The maximum film thickness portion was formed. However, in this case, the thickness of the light emitting portion 3 becomes thinner toward the end portion on the sealing portion side and the end portion on the front end side, and the thickness difference at both ends may exceed 10%. Thickness difference is 10
%, The color of the visible light that is transmitted changes drastically, so that the light emitted in a certain direction of the emitted light changes color, and color unevenness occurs as a whole. In order to prevent this, conventionally, a device such as providing a light diffusion film at both the end of the light emitting portion 3 on the sealing portion side and the end of the light emitting portion 3 has been devised.

On the other hand, in this embodiment, the infrared reflection film 5
As shown by the solid line in FIG. 3, the maximum film thickness portion is formed in the region of + 15 ° or more and + 30 ° or less from the equator toward the sealing portion 4 side. Therefore, the film thickness difference on the sealing portion 4 side can be kept within a range of 10% or less.
It is not necessary to provide a light diffusion film on the end portion on the sealing portion side.

On the other hand, since the maximum film thickness part of the infrared reflecting film 5 is deviated from the equator to the sealing part 4 side, the film thickness difference is enlarged at the tip part, but this part is covered with the light diffusing film 15. Therefore, the visible light that reaches here is diffused and transmitted.
Therefore, as can be seen from the chromaticity distribution chart shown in FIG. 4, color unevenness is reduced.

The maximum film thickness portion of the infrared reflecting film 5 is + 15 ° or more +30 from the center of the light emitting portion 3 toward the sealing portion side.
It is preferably formed in a region of less than or equal to 0 °, and in the region of less than + 15 °, a thin film portion that causes color unevenness is formed on the sealing portion side of the valve 2. Also, +30
If the area is more than 0 °, the thin film thickness portion formed at the tip of the light emitting portion 3 spreads.
The light diffusion film 15 must be covered with a wide area.
Since it is covered with, light loss occurs and the amount of light emitted to the outside is reduced.

The boundary of the light diffusion film 15 formed at the tip of the light emitting portion 3 is preferably in the range of -40 ° to -45 ° from the center of the light emitting portion 3 toward the tip side. -4
If the angle is less than 0 °, the area covered by the light diffusion film 15 becomes too large and light loss occurs, and the amount of light emitted to the outside decreases.
On the other hand, when the angle exceeds −45 °, the thin portion of the infrared reflective film 5 cannot be covered completely, and color unevenness occurs.

In the case of the reflection type lighting device using the halogen bulb 1 as a light source as shown in FIG. 5, the lamp efficiency is improved by the effective use of infrared rays in the halogen bulb 1, so that the advantage can be utilized. The illuminating device can be made excellent in efficiency. Moreover, since the visible light emitted from the halogen bulb 1 has less color unevenness, the color unevenness of the irradiation light is also reduced.

In the above embodiment, the light emitting portion 3 of the bulb 2 has a spherical shape, but the light emitting portion 3 may have an elliptic spherical shape. In addition, in the case of the above-described embodiment, since the light control portion is formed by the light diffusion film 15, not only the uneven color is eliminated, but also visible light is emitted to the outside, so that the decrease in the light amount is reduced, but the light control is suppressed. The portion may be formed of a light blocking film, and in this case, the light in a portion where the color unevenness is remarkable is cut off and not emitted to the outside, so that the occurrence of the color unevenness can be prevented. Further, the light control portion may be formed of a visible light reflecting film. In this case, since the visible light is returned to the inside of the bulb 2, this visible light can be emitted to the outside from other places, and the decrease of the light quantity is suppressed. can do.

Next, a second embodiment in which the present invention is applied to an H4 type vehicle headlamp will be described with reference to FIGS. 6 to 9. 6 and 7 show a halogen bulb used as a light source, FIG. 8 is a perspective view of a light shielding plate, and FIG. 9 is a sectional view of the entire headlamp.

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 hard glass and has a one-side sealing structure in which the base end is sealed. This valve 102
A light emitting portion 103 having a spherical shape is formed at the tip of the, and a cylindrical portion 104 is integrally formed continuously with the light emitting portion 103 near the sealing portion.

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 multi-layer 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.

Although not shown in detail, the maximum thickness of the infrared reflection film 105 is sealed with the maximum diameter portion (equator portion) of the light emitting portion 103 as a reference, as in the first embodiment. It is formed in a region of + 15 ° or more and + 30 ° or less toward the part side.

A light diffusing film 115 is formed on the tip of the light emitting portion 103 as a light blocking portion, as in the first embodiment. The boundary of the light diffusion film 115 is −40 ° or more from the center of the light emitting portion 103 toward the tip side.
It is regulated within the range of 45 ° or less.

In the bulb 102, two filaments 106 and 107 each made of tungsten are provided.
Is housed. One filament 106 is a filament for a low beam, and the filament 106 for a low beam is the light emitting portion 10 of the bulb 102.
3, the center of the coil is arranged so as to substantially coincide with the center of the sphere, and the other filament 107 is a traveling beam filament. This traveling beam filament 107 is the above-mentioned passing beam filament 10.
It is located closer to the sealing portion than 6 and is arranged in the cylindrical portion 104.

The passing beam filament 106
Is connected to internal leads 108 and 109,
The traveling beam filament 107 is connected to the one inner lead wire 108 and the other inner lead wire 110. 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 is made of tungsten, molybdenum, or the like, and has a curved surface such as a spherical surface or an elliptic surface in cross section.
It has a function of blocking light traveling in a predetermined direction out of the light emitted from the device.

Getters 11 are provided at both ends of the light shielding plate 111.
2, 112 are attached. The getter 112 is made of zirconium Zr, titanium Ti, nickel Ni, tantalum Ta, or an alloy thereof, and in this embodiment, a rod-shaped getter made of tantalum Ta is used because it has excellent heat resistance. These getters-11
As shown in FIG. 8, the reference numerals 2 and 112 are fixed to both ends of the light shielding plate 111 by, for example, bending and sandwiching both ends of the light shielding plate, or welding to both ends of the light shielding plate. The getter is plated on the inner surface of the light shielding plate 111.
It may be attached by means such as sputtering or vacuum evaporation.

The getters 112, 112 as described above are used for the impurities remaining in the bulb 102, the bulb, the filament,
Impurities such as water, which are absorbed in the lead wires and the light shielding plate and are discharged into the bulb 102 during lighting, are adsorbed, so that deterioration of the filament and the like is prevented. In particular, when water is released, it may be decomposed into oxygen and hydrogen in the vicinity of the filament, and the hydrogen and the tungsten filament may react with each other, leading to early disconnection of the filament. Further, when the bulb shape is spherical or ellipsoidal as described above and the infrared reflection film 105 is formed on this bulb, the bulb is easily distorted, so that the bulb cannot be baked sufficiently and the bulb is not illuminated. As the temperature inside the valve 102 increases, the amount of impure gas released into the valve increases. However, if the getters 112, 112 as described above are provided, the getters react with impurities, particularly hydrogen of water, and take in the impurities, so that early breakage of the filament is prevented and it is effective for improving the life characteristics.

For example, the lamp life was 500 hours when the getters 112 and 112 were not provided, but it has been confirmed that the lamp life is extended to 800 hours when the getters 112 and 112 are provided.

The light shielding plate 111 is a holder 113.
It is supported by one of the internal lead wires 109 via.
A halogen gas is enclosed in the bulb 102. Each of the above internal leads 108, 109 and 1
10 is sealed by a not-shown sealing portion formed at the end portion of the valve 102, and is connected to each external 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 fixed to the reflector 132 by fixing the flange 122 provided on the base 120 to the periphery of the mounting hole 134 of the reflector 130. It is positioned and installed in position.

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. Shield plate 1
The visible light and infrared rays reaching 11 are reflected by the inner reflecting surface of the light shielding plate 111 and 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.
Radiated to 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 radiated in the front is cut off, and the light directed to the upper right direction is blocked or dimmed to reduce the glare to the oncoming vehicle.

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 reflected by the infrared reflection film 105 formed on the bulb surface and returned to the filament 106. The filament 106 is heated. Therefore,
The passing beam filament 106 has the infrared reflective film 105 in addition to the electric 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. 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.

In this embodiment, the infrared reflecting film 105
+ 15 ° from the equator to the sealing side
Since it is formed within the region of + 30 ° or less, the film thickness difference on the sealing portion side can be suppressed within the range of 10%, so that it is not necessary to provide the light diffusion film on the sealing portion side.

As described above, since the maximum film thickness portion of the infrared reflecting film 105 is deviated from the equator to the sealing portion side, the film thickness difference is enlarged at the tip portion, but this portion is formed by the light diffusion film 115. Since it is covered, visible light that reaches here is diffused and transmitted. For this reason, the color of the light emitted from here does not significantly change as compared with other places, and the color unevenness is reduced.

Also in this case, it is preferable that the maximum film thickness portion of the infrared reflecting film 105 is formed within a region of + 15 ° or more and + 30 ° or less from the center of the light emitting portion 103 toward the sealing portion side. If the area is less than + 15 °, a thin portion that causes color unevenness is formed on the sealing portion side of the valve 102. Further, in the region exceeding + 30 °, the thin film portion formed at the tip of the light emitting portion 103 spreads, and this must be covered with the light diffusing film 115, and a wide range is covered. Since it is covered with 115, light loss occurs and the amount of light emitted to the outside is reduced.

The boundary of the light diffusion film 115 formed at the tip of the light emitting portion 103 is preferably in the range of −40 ° to −45 ° from the center of the light emitting portion 103 toward the tip side. If the angle is less than −40 °, the area covered with the light diffusion film 115 becomes too large and light loss occurs, and the amount of light emitted to the outside decreases. On the other hand, when the angle exceeds −45 °, the thin portion of the infrared reflection film 105 cannot be covered completely, and color unevenness occurs.

According to the vehicle headlamp using such a halogen light bulb 100 as a light source, the efficiency of the halogen light bulb 100 is improved, so that the headlight is excellent in efficiency, and furthermore, the halogen light bulb 100 emits light. Since the color unevenness of the light is reduced, the headlight has less color unevenness of the irradiation 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 housed in a bulb having a spherical or elliptic spherical shape.

[0067]

As described above, according to the invention of claim 1, since the maximum film thickness portion of the infrared reflecting film is formed at a position closer to the sealing portion side than the center of the light emitting portion, the film thickness can be reduced. The thin portion occurs only on the tip side of the light emitting portion. For this reason, if the light control portion is formed in the thin portion of the tip portion, it is possible to suppress the occurrence of color unevenness. Therefore, the light control portion may be formed only on the tip portion, and the manufacturing is easy.

According to the invention of claim 2, since the light control portion is formed of the light diffusing film, the light directed to this portion is diffused, so that the occurrence of color unevenness can be eliminated. As well as being able to do this, there is no reduction in the amount of light because light is emitted from this part.

According to the third aspect of the invention, since the light control portion is formed of the light blocking film, the light directed to this portion is blocked, and the occurrence of color unevenness can be prevented. According to the invention of claim 4, since the infrared reflection film is formed of a multilayer interference film formed by laminating a high refractive index layer and a low refractive index layer, variation in film thickness is likely to occur. If the invention according to any one of claims 3 to 3 is applied, the occurrence of color unevenness can be reduced.

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 an efficient reflection type illumination device can be provided. According to the invention of claim 6, since the passing beam filament is arranged in the light emitting portion having a spherical shape, an elliptic spherical shape, or a shape similar to the spherical shape, the infrared ray reflected by the infrared reflecting film is frequently reflected on the passing beam filament which is frequently used. Can be effectively returned. In this case, since the maximum film thickness portion of the infrared reflecting film is formed at a position closer to the sealing portion side than the center of the light emitting portion, the thin film portion is formed only on the tip side of the light emitting portion. Therefore, if the light control portion is formed in the thin portion of the tip portion, it is possible to suppress the occurrence of color unevenness. The invention according to claim 7 can utilize the advantages of the incandescent lamp according to claim 6, and can provide a vehicle headlamp with less color unevenness in the light distribution characteristics of irradiation light.

[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 cross-sectional view illustrating the configuration of an infrared reflective film of the example.

FIG. 3 is a diagram showing distribution characteristics of film thickness.

FIG. 4 is a characteristic diagram showing a chromaticity distribution.

FIG. 5 is a sectional view of an illumination 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 perspective view of the light shielding plate according to the embodiment.

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]

 DESCRIPTION OF SYMBOLS 1 ... Halogen bulb 2 ... Bulb 3 ... Light emission part 4 ... Sealing part 5 ... Infrared reflection film 6 ... Filament 15 ... Light diffusion film (light control part) 100 ... Bulb 103 ... Light emission part 104 ... Cylindrical part 105 ... Infrared ray Reflecting film 106 ... Filament for passing beam 107 ... Filament for traveling beam 111 ... Shading plate 112 ... Getter 115 ... Light diffusing film (light control part) 20, 130 ... Reflector 22, 132 ... Reflector

Claims (7)

[Claims] 1. A bulb having a light emitting portion having a spherical shape, an elliptic spherical shape or a shape similar to these; a filament contained in the light emitting portion; and infrared rays emitted from the filament formed on the surface of the bulb. An infrared reflection film for reflecting the light back into the bulb; and a light control part formed at the tip of the light emitting part for controlling visible light toward the tip, the maximum film thickness part of the infrared reflection film. Is formed in a region of + 15 ° or more and + 30 ° or less from the center of the light emitting portion toward the sealing portion side, and the light blocking portion is located on the tip side from the center of the light emitting portion. An incandescent light bulb having a boundary in the range of -40 ° to -45 ° toward the front side and being formed in a region on the tip side of the boundary. 2. The incandescent lamp according to claim 1, wherein the light control unit is formed of a light diffusion film. 3. The incandescent lamp according to claim 1, wherein the light control unit is formed of a light blocking film. 4. The infrared reflection film is formed of a multilayer interference film in which a high refractive index layer and a low refractive index layer are laminated, according to any one of claims 1 to 3. Incandescent light bulb. 5. A reflection type lighting device comprising: the incandescent lamp according to claim 1; and a reflector to which the incandescent lamp is attached. 6. A bulb in which a light emitting portion having a spherical shape or an elliptic spherical shape or a shape similar thereto and a cylindrical portion continuous with the light emitting portion are formed; a filament for a low beam which is accommodated in each of the light emitting portion and the cylindrical portion; A traveling beam filament; an infrared reflection film formed on the surface of the bulb to reflect the infrared rays emitted from the filaments and return it to the bulb; a visible light formed on the tip of the light emitting portion and directed toward the tip A light control portion for controlling light, and the maximum film thickness portion of the infrared reflection film is formed in a region of + 15 ° or more and + 30 ° or less from the center of the light emitting portion toward the sealing portion side. In addition, the light control section has a boundary in the range of −40 ° to −45 ° from the center of the light emitting section toward the tip side, and is formed in the region on the tip side. Headlights incandescent light bulb before, characterized in that it has been. 7. An incandescent lamp for headlights according to claim 6;
A vehicle headlight, comprising: a reflector incorporating the incandescent light bulb;