JPH03283352A - Incandescent lamp - Google Patents

Abstract

PURPOSE:To utilize light of a wide angle range by containing colored metal ionic oxide in at least either high or low refractive index layer of an interference filter film comprising high refractive index layers and low refractive index layers alternately stacked one on the other. CONSTITUTION:An interference filter film 2 comprising high refractive index layers 2H and low refractive index layers 2L alternately stacked one on the other is formed on at least either one of the inner and outer surfaces of a glass bulb 1 having a filament 6 sealed therein and colored metal ionic oxide is contained in either one of the high refractive index layers 2H and the low refractive index layers 2L. Therefore the light-cut rate of the interference filter film 2 is enhanced, and even when the angle of incidence becomes greater and the cut wavelength range of the interference filter film 2 is shifted to the shorter wavelength side light of this cut wavelength range is absorbed by the colored metal ions so that lowering of the cut rate of desired wavelength range is restrained. Dependence of optical characteristics of an incandescent lamp on the angle of incidence is thereby restrained and light of a wider range of angle of incidence is used.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is an incandescent light bulb that improves the interference filter film formed on the bulb to cut unnecessary light and obtain a desired light color. It is.

(Conventional technique v#) Conventionally, titanium oxide (Tj, 0□) was used on the outer surface of the incandescent bulb bulb.
An interference filter film is formed by alternately laminating a high refractive index layer made of silica (SiO□), etc., and a low refractive index layer made of silica (SiO□), etc., to cut out undesired light such as blue light. A light source for copying machines with a wavelength distribution tailored to the degree of
30408) and yellow fog lamps for automobiles.

(Problem to be solved by the invention) In principle, in such an incandescent light bulb, some of the unnecessary light reflected by the interference filter film and back into the bulb is absorbed by the filament, support, etc. inside the bulb. However, the remaining part is reflected several times between the interference filter films of the bulb, and during this time a considerable proportion leaks out, resulting in an insufficient cut rate in the actual lamp compared to the cut rate of the interference filter film itself. Become. For this reason, even if you try to completely cut out red light, for example, 70%
It can be cut up to about 80%, but it cannot be cut beyond that.

Furthermore, as the incident angle of the transmitted light increases, the interference filter film passes through each layer more obliquely, so the distance it passes through the layers becomes longer, and the thickness of each layer becomes substantially thicker. Furthermore, since the wavelength range to be transmitted or reflected shifts to the shorter wavelength side and the reflectance decreases, the range of incident angles suitable for use is narrow and adjustment with instruments is difficult.

Therefore, the problem of the present invention is to improve the interference filter film so that it is possible to cut a specific color of light as desired, while also easing the dependence of the optical characteristics on the angle of incidence, and widening the angle of incidence (the direction in which the outgoing light is normal to the An object of the present invention is to provide an incandescent light bulb that can be used up to a corner (even at a corner).

[Structure of the invention]

(Means for Solving the Problems) The present invention provides an interference filter film formed by alternately laminating high refractive index layers and low refractive index layers on at least one of the inner and outer surfaces of a glass bulb sealed with a filament. In incandescent light bulbs, by incorporating colored metal ion oxides into at least one of the high refractive index layer and the low refractive index layer, the cut rate of the interference filter film is improved, and the angle of incidence is increased, making it possible to improve the interference filter. Even if the cut wavelength range of the film shifts to the shorter wavelength side, the cut rate in the desired wavelength range is not significantly reduced due to absorption of colored metal ions.

(Function) Oxides of colored metal ions form a solid solution in the metal compounds constituting the high refractive index layer or the low refractive index layer, and the colored metal ions exhibit a unique ionic color. The absorption rate of a specific wavelength by colored metal ions is proportional to the ion concentration and proportional to the substantial thickness of the layer. Furthermore, this absorption rate is not affected by mutual reflection between opposing interference filter films within the light bulb. Furthermore, even if the angle of incidence (output angle) on the interference filter film increases, the absorption wavelength range of colored metal ions does not change, so the color shift caused by the shift in the reflection wavelength range of the interference filter film can be corrected and the desired wavelength can be adjusted. You can cut the light in the area as desired.

(Example) Hereinafter, the details of the present invention will be explained with reference to Examples. FIG. 1 shows an example of a halogen light bulb to which the present invention is applied;
1) is a cylindrical hard glass bulb with a closed end, (2) is an interference filter film formed on the outer surface of this bulb (1), (
3) is a sealing portion formed by crushing and sealing the end of the valve (1);
(4), (4) are a pair of tungsten inner conductors whose bases are sealed to this sealing part (3) and whose tips extend into the bulb (1); (5) are these inner conductors ( 'I), a bridge glass that binds (4), (6) a tungsten coil filament (7) installed between the inner conductors (4), (4) and located at the center line of the bulb (1);

(7) is connected to the inner conductors (4), (4) and the sealing part (3)
) is the nickel outer conductor extending outward. The valve (1) is filled with a necessary halogen along with an inert gas such as argon.

As shown schematically and enlarged in FIG. 2, the interference filter film (2) is formed of titanium oxide (TiO2), tantalum oxide (ya
zos), zirconium oxide (ZrO A total of 9 to 15 layers (rehatching) are alternately laminated. The characteristic of the incandescent lamp of this example is that the high refractive index layer (2H) is made of titanium oxide (Ti).
O□) and chromium oxide (Cr, 03)
It contains 10 to 20% of heavy electric current.

Next, the action of this interference filter film (2) will be explained. When light enters this interference filter film (2), it passes through the high refractive index layer (2H) and the low refractive index layer (2L) alternately. Then, light interference occurs, allowing light in a specific wavelength range to pass through and reflecting and blocking light in a specific wavelength range. The wavelength range that is transmitted or reflected by the interference filter film (2) is
11), determined by the thickness of (2L) 6 In addition, if the angle of incidence (e, which may be expressed as a derived angle) when light passes through the interference filter film (2) is large, the light will pass through the layer (211).
, (2L), the path becomes longer, resulting in the same result as if one layer (2H) and (2L) were thicker, and the wavelength range to be transmitted or reflected shifts to the shorter wavelength side.

In addition, the high refractive index layer (2■) is made of colorless titanium oxide (TjO
Chromium oxide (crzoa) exists as a solid solution in chromium oxide (□), and trivalent chromium ions ((r
+3), it absorbs 400 to 5000 square meters of transmitted light and exhibits a yellow-red color. In this absorption characteristic, the absorption wavelength range is not affected by the thickness or number of layers of the high refractive index layer (211), nor is it affected by the angle of incidence on the interference filter film (2), but the absorption rate of the layer It is influenced by the thickness of (2), the number of layers, or the angle of incidence.

Next, the spectral transmittance was measured for both an interference filter film (2) similar to the halogen bulb of the above example but not containing chromium oxide and a titanium oxide layer (2 days) containing chromium oxide. This result is shown in Figure 3. In Figure 6, the horizontal axis shows the wavelength in nm, the vertical axis shows the transmittance in %, and the solid line is the titanium oxide layer containing the above-mentioned chromium oxide,
The broken lines indicate the respective spectral transmittance curves of the aforementioned alternating layers of titanium oxide and silica. In this graph, both have a cut wavelength range in the range of 400 to 500 nm,
When the incident angle of light increases, the cut wavelength range of the interference filter film shifts to the shorter wavelength side and the cut rate (reciprocal of transmittance) decreases, whereas with chromium oxide, the cut wavelength range remains the same and the cut rate improves. have a property.

In the above-described halogen light bulb, since the interference filter film (2) is formed on the entire circumferential surface of the bulb, the interference filter film (2) on the negative side of the bulb (1) has a
Light in the wavelength range of ~500 nm is reflected, and this is reflected by the bulb (1
) enters the interference filter film (2) on the other side and is reflected again, repeating the reflection many times in this way.

During this many round trips, the light in the 400~b long range should be transmitted little by little and radiated to the outside world, but in this example, trivalent chromium is present in the high refractive index layer (211). Since ions exist and absorb light in the wavelength range of 400 to 500 nm, when light in this wavelength range is reflected by the interference filter film (2), a considerable proportion of the reflected light is absorbed and does not go back and forth many times. It will disappear within us.

Therefore, in this embodiment, the cutting rate is significantly improved.

In addition, in the halogen light bulb of this example, since the interference filter film (2) is formed over the entire length of the bulb (1), the light incident from the filament (6) The incident angle of light is approximately Oe, whereas the incident angle of light incident from the filament (6) on the side surface of the bulb (1) in the direction of the top and the direction of the sealing part (3) is considerably large. but.

In this example, the interference filter film (2) includes chromium oxide in the high refractive index layer (2H), and trivalent chromium ions absorb light in the wavelength range of 400 to 500 nm. The light that passes through the interference filter film (2) is almost completely cut off in the vicinity of 500 nm by the interference filter film (2), but on the other hand, the light in the wavelength range of 400 to 500 nm is cut off due to trivalent chromium ions. Since the light is absorbed, leakage of light around 50On+n is extremely small. In particular, as the incident angle increases, the shift in the reflected wavelength range increases, but since the absorption of chromium ions also increases, the color shift does not become large.

Therefore, in this embodiment, the light bulb can be used without color shift even in a considerably large range of incident angles (output angles), and the efficiency of the light bulb is improved.

Next, in the above embodiment, the interference filter film (2)
High refractive index layer (2 days) of chromium oxide 10 in titanium oxide
The spectral light intensity of the emitted light was investigated at various derivation angles (the angles that the light derived from the bulb makes with the normal line) with a focus of 20% and 20%. For comparison, a conventional example having the same structure but containing no chromium oxide in the high refractive index layer was prototyped, and the spectral light intensity was similarly measured at various extraction angles. These results are shown in FIGS. 4 to 6. In other words, Fig. 4 shows the content of chromium oxide in the high refractive index layer 10%, Fig. 5 shows the same <20%, and Fig. 6 shows the conventional example that does not contain chromium oxide. The horizontal axis shows the wavelength in nm, and the vertical axis shows the relative light intensity.The solid line is the derived angle 0°1.The dotted line is the same <15°, the dashed line is the same <30°, and the dashed line is the same 45°.
Indicates the light intensity in the direction of As is clear from these figures, when chromium oxide is contained (Figures 4 and 5), the cut of the emitted light is due to the reduction in the cut rate due to the above-mentioned round-trip reflection of the interference filter film and the improvement in the cut rate due to chromium ions. The results show that they cancel each other out, and on the other hand, when there is no chromium ion (FIG. 6), the cutting rate is extremely low. Furthermore, in the absence of chromium ions (FIG. 6), as the derivation angle increases, the cut wavelength shifts rapidly to the shorter wavelength side, and furthermore, as the derivation angle increases, the cut rate rapidly decreases. On the other hand, when the chromium oxide content is 10% by weight (FIG. 4), even if the derivation angle becomes large, the shift in the cut wavelength is not so large and the decrease in the cut rate is also small. Further, when the chromium oxide content is 20% (FIG. 5), even if the extraction angle becomes large, the shift in wavelength is extremely small, and the reduction in cut rate is even smaller.

As a result, while the conventional one (Fig. 6), which does not contain chromium ions, does not enter the yellow range when the derivation angle is ±30° or more, the one of this example (Figs. 4 and 5) A much wider range than this, e.g. chromium oxide 10% by weight
It can be used up to 0°±30° with chromium oxide, and 0°±45° or more with 20% chromium oxide, greatly improving the efficiency of the equipment.

In the above embodiment, the high refractive index layer of the interference filter film is made of titanium oxide, which contains chromium oxide (CrzOW) to utilize the blue absorption effect of trivalent chromium ions (Cr+3). The invention is not limited to this, for example,
The high refractive index layer may be made of tantalum oxide, zirconium oxide, etc., and the colored metal ion oxides may be praseodymium oxide (PrGO□□), iron oxide (Fe, 03), cerium oxide (CeO), etc. P
You may use the action of r'+ or P'2+, Fe3+, and Ce2+, all of which have the effect of absorbing light in the wavelength range of 500 nm or less.Also, if you want to cut the wavelength range of 500 to 600 nm, , the thickness of the high refractive index layer and the low refractive index layer of the interference filter film is made appropriate, and cobalt oxide (Cod) and neodymium oxide (Nda) are added to the high refractive index layer.
03) etc., and the light of 500 to 600 nm may be cut by C021 or Nd''.Furthermore, a colored metal ion oxide may be contained in the low refractive index layer, but the colored metal ion oxide Generally, since it has a high refractive index, if it is contained in a large amount, it will increase the refractive index of the low refractive index layer, so there is a limit to the amount that can be added.

Furthermore, the incandescent light bulb to which the present invention is applied may be a regular light bulb or a floodlight bulb, and there is no limitation on the shape of the glass bulb.Furthermore, there is no limitation on the cut wavelength range of the interference filter film. It is sufficient that the cut wavelength range due to optical interference of the film corresponds to the absorption wavelength range of metal ions. The interference filter film may be formed on at least one of the inner and outer surfaces of the bulb.

〔Effect of the invention〕

As described above, the incandescent light bulb of the present invention is provided with an interference filter film formed by alternately laminating high refractive index layers and low refractive index layers on at least one of the inner and outer surfaces of a glass bulb sealed with a filament. , because at least one of the high refractive index layer and the low refractive index layer contains an oxide of colored metal ions, the cut rate caused by the light reflected by the interference filter film leaking out sequentially while going back and forth within the bulb. The decrease in the amount of light is compensated for by absorption of light in a specific wavelength range by colored metal ions, and as a result, the desired cut rate can be obtained. Also,
The cut wavelength range due to optical interference of the interference filter film shifts to the shorter wavelength side and the cut rate decreases as the incident angle (also expressed as the derivation angle) of the light increases. This is compensated for by light absorption in a specific wavelength range that is unaffected by the incident angle of colored metal ions.As a result, the desired cut rate is obtained at the desired cut wavelength, the deviation of the cut wavelength is reduced, and as a result, a wider angle can be obtained. Light within a wide range can be used, improving equipment efficiency.

[Brief explanation of drawings]

FIG. 1 is a front view of an embodiment of the incandescent light bulb of the present invention, FIG. 2 is a schematic enlarged sectional view of an interference filter film, which is the main part, and FIG.
The figure is a graph showing the spectral transmittance curve due to optical interference and the spectral transmittance curve due to light absorption of colored metal ions in the above-mentioned interference filter film. A graph of the spectral light intensity curve at the derivation angle, Figure 5 is also 20% by weight of chromium oxide.
FIG. 6 is a graph of a spectral light intensity curve at each derivation angle of a conventional interference filter film containing no colored metal ion oxide. (1)...Valve, (2)...Interference filter membrane. (21()...High refractive index layer, (2L)...Low refractive index layer. (3)...Sealing portion, (4)...Inner conducting wire. (6)...Filament.

Claims (1)

[Claims] In an incandescent light bulb, an interference filter film formed by alternately laminating a high refractive index layer and a low refractive index layer is provided on at least one of the inner and outer surfaces of a glass bulb sealed with a filament. An incandescent light bulb characterized in that at least one of the refractive index layers contains an oxide of a colored metal ion.