JP2000215858A - Electric bulb with wavelength-selective reflecting film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the temperature of a filament, to increase the generated quantity of visible light for improved visibility, to prolong the durability of a vehicle luminaire and to improve reliability by reflecting a wavelength band in a proper range below a specific value and a wavelength band in a proper range above a specific value with a wavelength-selective reflecting film. SOLUTION: A wavelength-selective reflecting film 4 is provided on the outer face side of a bulb 3, and it is laminated with high-refraction factor films and low-refraction factor films in turn. The film thickness is set to 100 nm from a first layer to a seventh layer, and the center wavelength of reflection is set to 400 nm (blue to purple). The film thickness is set to 250 nm from a ninth layer to a fifteenth layer, and the center wavelength of reflection is set to 1000 nm (infrared ray). Luminous efficiency can be improved by the feedback of the reflected infrared rays to a filament 2, and the deterioration of a housing, a reflecting mirror or a lens which is made of a resin member by ultraviolet rays can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incandescent lamp, and more particularly, to installing a wavelength-selective reflective film on the surface of a bulb so as to collect a heat ray radiated from a filament such as a halogen lamp and to return it to the filament again. The present invention relates to a configuration of an incandescent light bulb for further improving efficiency.

[0002]

2. Description of the Related Art FIG. 3 shows an example of the structure of a conventional bulb 90 of this type. As shown in Table 2, the surface of a bulb 91 is made of, for example, TiO ₂ (refractive index = 2.1). ) And a low-refractive-index film made of, for example, SiO ₂ (refractive index = 1.4).

[0003]

[Table 2]

At this time, the wavelength-selective reflection film 92
Is set so that both the high-refractive-index film and the low-refractive-index film are 膜厚 wavelength of the wavelength (typically, infrared light) of the light beam whose thickness is to be reflected. 260 thick
nm, as shown in FIG. 4 as a wavelength-transmittance characteristic T92, an infrared ray in a range of approximately 800 nm to 1400 nm is reflected.

By providing the wavelength-selective reflective film 92 in this manner, the visible light range of the light emitted from the filament 93 is transmitted through the wavelength-selective reflective film 92 and radiated to the outside. The infrared light in the above-mentioned wavelength range is reflected by the wavelength-selective reflection film 92, and the filament 9
It returns to 3 and performs heating.

Therefore, the temperature of the filament 93 is further increased by the return of the infrared rays, so that the filament 93 becomes incandescent and the ratio of visible light in the total emitted energy increases. Conversion efficiency) is improved.

[0007]

However, in the above-mentioned conventional light bulb 90, the luminous efficiency can be certainly improved, but the color temperature of the visible light emitted by the temperature rise of the filament 93 is not so high. It rises further and contains much energy near the short wavelength, such as blue.

Considering the situation when the above-described light bulb 90 is used as a light source of a headlamp for an automobile, if the above-mentioned component near the short wavelength increases, rain, fog, dust, etc. Scattering and absorption due to such factors become remarkable, causing a problem that visibility under bad weather as described above becomes insufficient.

[0009] In addition, as described above, as the component near the short wavelength increases, the emission amount of ultraviolet rays also increases, and in the current situation of recent vehicle lamps in which not only the housing but also the lens are made of resin, The deterioration of the resin member due to ultraviolet rays becomes remarkable, causing a problem in durability, etc., and solving these points has been an issue.

[0010]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, a high refractive index film and a low refractive index film whose film thickness is adjusted are alternately laminated. In a light bulb with a wavelength-selective reflective film, wherein a wavelength-selective reflective film for reflecting a predetermined wavelength is provided on a bulb, the wavelength-selective reflective film has an appropriate wavelength band of 450 nm or less;
An object of the present invention is to solve the problem by providing a light bulb with a wavelength-selective reflective film, which is characterized in that it has a characteristic of reflecting an appropriate wavelength band of 00 nm or more.

[0011]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. 1 is a light bulb with a wavelength-selective reflective film according to the present invention (hereinafter, bulb 1).
The light bulb 1 selects light emitted from the filament 2 between light emitted outside by the wavelength-selective reflection film 4 provided on the bulb 3 and light reflected internally. Is similar to that of the conventional example.

Here, the present invention relates to the wavelength-selective reflection film 4.
Focuses on the fact that it has the same function as a bandpass filter in an electric circuit, and in addition to the infrared region that also reflects in the conventional example, it also partially reflects the ultraviolet region including the visible light region It is also intended to improve visibility and durability.

That is, in the present invention, the wavelength-selective reflection film 4 is used.
The wavelength range reflected by the light source is 800
In addition to setting the infrared region above
The wavelength range of the visible light radiated from the bulb 3 to the outside is set to 450 to 8 between them.
It is to be limited to 00 nm. Incidentally, since the range of the visible light is said to be approximately 400 to 800 nm, the wavelength-selective reflective film of the present invention reflects part of the visible light on the short wavelength side and does not emit it to the outside. And

[0014]

[Table 1]

Table 1 shows the structure of the wavelength-selective reflection film 4 according to the present invention in detail. In this embodiment, the film is provided on the outer surface side of the bulb 3. Therefore, in this description, the side in contact with the valve 3 will be described as the first layer in the order of film formation. In the present invention, the superselective reflection film 4 is also basically formed by alternately laminating a high refractive index film and a low refractive index film.

The first layer has a high refractive index film, and the second layer has a low refractive index film.
It is formed as nm. Here, since the film thickness is set as ４ of the wavelength of light to be reflected, the first to seventh layers have a center wavelength of 400 nm (blue to purple) when performing reflection. ).

In the present invention, the ninth layer to the fifteenth layer are alternately arranged such that the ninth layer has a high refractive index film thickness of 250 nm and the tenth layer has a low refractive index film thickness of 250 nm. Seven layers are formed. Therefore, the ninth layer to the fifteenth layer have a center wavelength set to 1000 nm (infrared ray).

In the eighth layer, the film thickness changes suddenly between the groups from the first layer to the seventh layer and the group from the ninth layer to the fifteenth layer. A low-refractive-index film having a film thickness of 175 nm, which is substantially intermediate between them, is provided so as not to occur, and the outermost sixteenth layer has a thickness (波長 wavelength) of half of the fifteenth layer. A low refractive index film is provided to match with the atmosphere.

FIG. 2 shows a wavelength-transmittance characteristic T4 of the wavelength-selective reflection film 4 of the present invention having the above-described structure.
As described above, visible light near the short wavelength near 400 nm and infrared light with the wavelength of 800 nm or more are reflected without transmitting.

Therefore, according to the present invention, by returning the reflected infrared rays to the filament 2, the temperature of the filament 2 rises to improve the luminous efficiency, and visible light which is remarkably scattered by, for example, raindrops or fog. The present invention makes it possible to provide a vehicular lamp having excellent visibility under any conditions by removing a portion closer to a short wavelength.

The emission color of the vehicle lamp at this time is an amber color, which is a color that has been conventionally used as a vehicle illumination lamp, so that the driver may feel uncomfortable or It does not cause performance problems such as impairing visibility.

In addition, according to the present invention, it is possible to prevent a part of the ultraviolet light from radiating to the outside together with a part near the short wavelength of the visible light.
In recent years, a reflection mirror, a lens, and the like are often formed of a resin member, so that the influence on a portion easily deteriorated by ultraviolet rays can be reduced.

[0023]

As described above, according to the present invention, the wavelength-selective reflection film reflects a wavelength in a proper range of 450 nm or less and a wavelength in a proper range of 800 nm or more. By using a light bulb with a reflective film,
Infrared rays that are not included in luminosity even when radiated to the outside and are not involved in visibility at all are returned to the filament again to improve the temperature of this filament and increase the amount of visible light generated. This makes it possible to achieve the effect of improving visibility as before.

In addition, according to the present invention, the luminous efficiency is improved, and the ratio is remarkably increased.
This type of bulb is used to control the light in the portion near the short wavelength of visible light, which is easily scattered by fog, dust, etc. An extremely excellent effect is achieved in improving the performance of the vehicle lamp. Further, in addition to the above, it is possible to prevent ultraviolet rays that easily cause deterioration of the resin member, which is a member on which the vehicle lamp is formed, from being emitted outside the bulb, thereby extending the durability of the vehicle lamp and improving reliability. It also has an extremely excellent effect in improving the quality.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a light bulb with a wavelength-selective reflective film according to the present invention in a partially broken state.

FIG. 2 is a graph showing wavelength-transmittance characteristics of the same embodiment.

FIG. 3 is a side view showing a conventional example in a partially broken state.

FIG. 4 is a graph showing wavelength-transmittance characteristics of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Light bulb with wavelength selective reflection film 2 ... Filament 3 ... Valve 4 ... Wavelength selective reflection film

Claims (1)

[Claims] 1. A bulb with a wavelength-selective reflective film, wherein a high-refractive-index film and a low-refractive-index film whose thickness is adjusted are alternately laminated and a wavelength-selective reflective film for reflecting a predetermined wavelength is provided in a bulb. 3. The light bulb with a wavelength-selective reflective film according to claim 1, wherein the wavelength-selective reflective film has a characteristic of reflecting an appropriate wavelength band of 450 nm or less and an appropriate wavelength band of 800 nm or more.