JPH04349339A - Colored electric bulb - Google Patents

Abstract

PURPOSE:To solve such a problem that color uneveness occurs caused by e.g. irregular reflection inside a bulb in a colored electric bulb having specified illunination colors through formation of multilayered interference film formed of alternate lamination of low refraction index film and high refraction index film with proper thickness applied on the outer surface of a conventional valve. CONSTITUTION:At least one of low refraction index film 3a and high refraction index film 3b of multilared interference film 3 formed on the outer face of a bulb, e.g. the film 3a is formed of material absorbing the short wavelength of visible light to form a colored electric bulb 1. With such a constitution, wavelength selecting characteristic by absorption is given to the layer 3 to prevent transmission of light with the wavelength other than the specified to solve such a problem.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to incandescent light bulbs and halogen light bulbs used as light sources for vehicle lighting equipment such as headlamps and fog lamps. Specifically, the present invention relates to a multilayer interference light bulb for obtaining a predetermined luminescent color such as yellow. It concerns a colored light bulb in which a membrane is formed on the outer surface of the bulb.

0002

2. Description of the Related Art Examples of a conventional colored light bulb 90 of this type are shown in FIGS. 6 and 7, and the bulb 9 of this colored light bulb 90 is
1, appropriate layers of low refractive index films 92a and high refractive index films 92b of appropriate thickness are alternately laminated to form a multilayer interference film 92.
is formed, and reflects light other than the predetermined wavelength to the bulb 9.
By preventing light from passing outside of 1, a desired luminescent color such as yellow can be obtained.

0003

[Problems to be Solved by the Invention] However, the multilayer interference film 92 employed in the conventional colored light bulb 90 described above
In this case, when light is incident on each of the low refractive index film 92a or the high refractive index film 92b in a predetermined direction, that is, at right angles, the low refractive index film 92a or the high refractive index film 92b has a predetermined thickness. It reflects light of the same wavelength and obtains the desired characteristics, but when light enters from an oblique direction due to diffused reflection inside a light bulb, for example, an effect equivalent to thinning the film occurs and the desired characteristics are obtained. characteristics cannot be obtained.

[0004] For the above reasons, the colored light bulb 90 cannot provide a completely desired emitted color, and when used as a light source for a fog lamp, for example, the color of the light may change depending on the viewing direction. This has caused problems such as color unevenness being detected, resulting in insufficient characteristics, and it has been a challenge to solve this problem.

[0005]

[Means for Solving the Problems] As a specific means for solving the above-mentioned conventional problems, the present invention provides alternate layers of low refractive index films and high refractive index films of suitable thickness on the outer surface of the bulb. In a colored light bulb that is laminated to form a multilayer interference film to obtain a predetermined emission color, at least a portion of the low refractive index film and the high refractive index film are formed of a material that absorbs short wavelength regions of visible light. By providing a colored light bulb characterized by this, the above-mentioned conventional problems can be solved as a multilayer interference film that does not transmit light other than a predetermined wavelength.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained in detail based on an embodiment shown in the drawings. What is shown in FIGS. 1 and 2 is a first embodiment of a colored light bulb 1 according to the present invention, and on the outer surface of a bulb 2 of this colored light bulb 1, a low refractive index film 3a and a high refractive index film 3b are arranged alternately. This is similar to the conventional example in that a laminated multilayer interference film 3 is formed to emit light of a desired color, such as yellow.

However, according to the present invention, in the first embodiment, as shown in FIG. 2, silicon dioxide (SiO2) is used as a base material for the transparent member forming the low refractive index film 3a of the multilayer interference film 3. This is made into a transparent member by adding an appropriate amount of additives, and the low refractive index film 3a is given wavelength selectivity to absorb light on the short wavelength side, thereby making the low refractive index film 3a a filter. It has the function of At this time, it is not necessarily necessary to provide wavelength selectivity to all of the low refractive index films 3a, and an appropriate number may be provided.

Next, the function and effect of the colored light bulb 1 of the present invention having the above structure will be explained. After the light emitted from the filament of this colored light bulb 1 passes through the bulb 2, it passes through the high refractive index film 3b, for example. Light of a wavelength set as the thickness of the high refractive index film 3b enters the high refractive index film 3b, reaches the low refractive index film 3a, and is transmitted therethrough.

At this time, even if there is light that passes through the high refractive index film 3b obliquely and light with a wavelength other than the above setting is present in the transmitted light, the low refractive index film 3b Light having a wavelength other than the set wavelength is absorbed when it passes through the film 3a, and by repeating this process with the multilayer interference film 3 that is alternately laminated, the set wavelength is selected from among the light that passes through the multilayer interference film 3. Light with other wavelengths will be completely removed.

The one shown in FIG. 3 is also a second embodiment of the present invention, and while the previous first embodiment had wavelength selectivity due to absorption on the low refractive index film 3a side, this embodiment In the second embodiment, the high refractive index film 3b is made of titanium dioxide (TiO2) as a base material, and an appropriate amount of additive material is added to this to give it wavelength selectivity to absorb short wavelengths. The index film 3b has both wavelength selectivity due to film thickness and wavelength selectivity due to absorption, and the same functions and effects as described in the first embodiment can be obtained.

Although not shown in the drawings, it goes without saying that both the low refractive index film 3a side and the high refractive index film 3b side may have wavelength selectivity due to absorption. In short, it is sufficient to select and implement any of the above methods so as to obtain the desired effect.

What is shown in FIG. 4 is also a third embodiment of the present invention, and both of the first and second embodiments described above are laminated with a low refractive index film 3a and a high refractive index film 3b. In contrast, in this third embodiment, the setting of the multilayer interference film 3 is This design adds infrared reflection characteristics, and since it is difficult to achieve satisfactory pale yellow light emission with this design, a short wavelength absorption film 4 with a low refractive index that absorbs the short wavelength side of visible light is inserted to create a multilayer structure. The desired light yellow color can be obtained without impairing the properties of the interference film 3.

The graph shown in FIG. 5 shows the graph when the short wavelength absorption film 4 is added to the first embodiment or the second embodiment, that is, when the multilayer interference film 3 and the short wavelength absorption film 4 are laminated. Infrared rays having wavelengths longer than approximately 1000 nm are reflected by the short wavelength absorption film 4 and are not emitted to the outside of the colored light bulb 1.

What should be noted in FIG. 5 is the transmittance of visible light in the wavelength range of 500 nm to 1000 nm, whereas the transmittance of the ordinary multilayer interference film 3 is about 92%. By laminating the short wavelength absorption film 4, the transmittance can be significantly improved to about 98%.

The inventor's consideration for the above-described improvement in transmittance is that by providing the short-wavelength absorbing film 4, a transmittance-enhancing effect similar to that seen in photographic lenses can be obtained in the visible light region. It is thought that the At the same time, colored light bulb 1
The short wavelength absorption film 4 provided on the bulb 2 causes the infrared rays to be reflected and returned to the inside of the bulb 2, causing a temperature rise in the inside of the bulb 2, that is, the filament, and causing the colored bulb 1 to emit light. It will improve efficiency,
This may also have the effect of improving the apparent transmittance of the multilayer interference film 3.

In addition, in the case of only the multilayer interference film 3 or in the case of providing the short wavelength absorption film 4, the total film thickness can be formed as 2 μm or less in either case, so it is flexible, and the colored light bulb Even if bulb 1 is a halogen bulb and quartz glass is used as bulb 2, or if it is an incandescent bulb and alumina silicate glass is used, it will fit well, and peeling may occur due to differences in thermal expansion. It becomes something that does not exist.

[0017]

[Effects of the Invention] As explained above, according to the present invention, at least one of the low refractive index film and the high refractive index film constituting the multilayer interference film is formed of a material that absorbs short wavelength range of visible light. By using a colored light bulb, emitted light other than the predetermined wavelength that is generated due to diagonal transmission through the multilayer interference film, for example, is eliminated by absorption, thereby preventing the occurrence of color unevenness. , which has an excellent effect on improving the quality of this type of colored light bulb.

Furthermore, by providing an infrared reflecting film laminated on the multilayer interference film, the transmission efficiency of the multilayer interference film can be improved by a transparent action or the like, and the effective amount of light radiated to the outside of the bulb can be increased. It also has an excellent effect on improving the performance of this type of colored light bulb.

[Brief explanation of drawings]

FIG. 1 is a side view showing a first embodiment of a colored light bulb according to the present invention.

FIG. 2 is an enlarged sectional view of section A in FIG. 1.

FIG. 3 is a sectional view showing the main parts of a second embodiment of the present invention.

FIG. 4 is a sectional view showing the main parts of a third embodiment of the present invention.

FIG. 5 is a graph showing the characteristics of the third embodiment.

FIG. 6 is a side view showing a conventional example.

FIG. 7 is an enlarged sectional view of section B in FIG. 6.

[Explanation of symbols]

1... Colored light bulb 2... Bulb 3... Multilayer interference film 3a... Low refractive index film, 3b... High refractive index film 4... Short wavelength absorption film

Claims (3)

[Claims] 1. A colored light bulb in which a multilayer interference film is formed by alternately laminating suitable layers of low refractive index films and high refractive index films on the outer surface of the bulb to obtain a predetermined pale yellow light emission, 1. A colored light bulb, wherein at least a portion of the refractive index film and the high refractive index film are formed of a material that absorbs short wavelength range of visible light. 2. The colored light bulb according to claim 1, wherein the first layer on the outer surface of the bulb is a low refractive index film that absorbs visible light in the short wavelength range. 3. The multilayer interference film is characterized in that an infrared reflective film and a blue reflective film are laminated.
3. The colored light bulb according to claim 2.