JPS59169054A - Bulb - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to the improvement of a light bulb in which a visible light transmitting infrared reflective film is provided on the bulb surface. It is.

[Technical background of the invention]

In recent years, a halogen light bulb with a visible light-transmissive infrared reflective film on the outside of a transparent glass bulb has been released. This infrared reflecting film is made by alternately layering a metal oxide with a low refractive index and a metal oxide tube with a high refractive index, and utilizes light interference to transmit visible light and reflect infrared rays. In order to maximize visible light transmittance in this film, each layer is made transparent.

[Problems with background technology]

When this halogen bulb is used in combination with a reflecting mirror, an optical image of the fine structure of the filament, such as each turn of a coiled filament, appears on the irradiated surface Vc, making it impossible to obtain a uniform irradiated surface.

[Purpose of the invention]

To provide a light bulb that provides good light distribution even when used in combination with a reflecting mirror.

[Summary of the invention]

At least one layer of high refractive index metal oxide, - average grain size 1
By crystallizing it to a size of 0.08 to 1 μm, transmitted light is diffused and formation of filament images is prevented.

[Embodiments of the invention]

The details of the present invention will be explained by referring to the embodiment shown in the first figure. Figure a shows a 100 V Zoo W rated Norogen bulb, in which (1) is a T-shaped bulb and (2) is this bulb (
a visible light transmitting infrared reflective film formed on the outer surface of (1);
) is a sealing part formed by crushing and sealing the base of the valve (1), (
4).

(4) is the molybdenum-introduced foil embedded in this sealing part (3), (5), (5) is the molybdenum-introduced foil (41, +4)
A pair of inner conductors (6) connected to VC and introduced into the valve (1) are installed between these inner conductors (5) and (5) and connected to the center line of the valve (1). The tungsten/filament (7) is located at the introducing foil (4).

(4) is a cap attached to the proximal end of the valve (1) and electrically connected to the valve (4). Then, the required halogen is sealed in the bulb (1) along with an inert gas such as argon.

The above bulb (1) is made of transparent heat-resistant glass such as quartz glass or hard glass, and has an infrared reflective film (2) on its outer surface.
is formed.

As shown in FIG. 2, the visible light transmitting infrared reflective film (2) is a metal oxide layer QD (
A metal oxide layer with a high optical refractive index such as titanium oxide (22) (lower left hatching) is alternately layered), and each layer is usually 5 to 9 layers with a thickness of 1000 to 3000 λ. ing. A feature of the present invention is that at least the high refractive index layer (23) is crystallized. In order to obtain the infrared reflective film (2), for example, after forming an alternating multilayer film of 7 Lika and titanium oxide on the outer surface of the bulb (1) by a normal method, the bulb (1) is treated at a high temperature of 1100°C or higher. The titanium oxide may be crystallized by using this treatment.It is not necessary that silica be crystallized at all by this treatment.

Next, the operation of this halogen light bulb will be explained with reference to FIG. When this light bulb is turned on, the filament (6) emits light, and this light passes through the bulb (1) and infrared reflective film (2).
) K is incident. Of the incident light, infrared rays are reflected by this reflective film (2) and returned to the filament (6) to heat it, helping to improve luminous efficiency, while visible light is transmitted through this reflective film (2). do. At this time, visible light is repeatedly reflected and refracted at the boundaries of crystal grains, and as a result, the reflective film (2
), it diffuses well when transmitted. Therefore, even though the halogen bulb (1) is transparent and has a smooth surface, the emitted visible light is diffused, and even when used in combination with a reflector, the optical image of the filament (6) is transferred to the illuminated surface. Uniform light irradiation can be obtained without any projection.

In addition, when titanium oxide crystallizes, its optical refractive index is 20 to 50.
%, this has the effect of improving the infrared reflectance of this reflective film (2) and expanding the reflection wavelength range. The results are shown in FIG. In the diagram, the horizontal axis shows the wavelength in units of μ, and the vertical axis shows the transmittance in units of (ch). The film and the curve (R1 each represent the spectral light transmittance characteristics of the infrared reflective film of the present invention in which silica is amorphous and titanium oxide is crystallized.

As described above, in the above-described embodiment, although the particle size of the titanium oxide crystal grains is much smaller than the wavelength of visible light, visible light is well diffused. However, when the average particle size of the titanium oxide crystal grains is less than 100A, there is no light diffusing property and the present invention is not effective, and when the average particle size exceeds 1μ, the coating strength is insufficient and it is easy to peel off, making it impractical. do not have. Then,
The grain size in the thickness direction of the coating is limited by the thickness of the titanium oxide layer, and depending on the thickness of the layer, the crystal grains may become flat. Therefore, in the present invention, the average grain size of the crystal grains is set to 10
It was limited to a range of 0 A to 1 μ.

In the above embodiments, silica was used as an example of a metal oxide with a low optical refractive index, but in the present invention, magnesia MgO, alumina AJ, 03, etc. may also be used, or it may be partially crystalline.

Further, in the above embodiment, titanium oxide was used as an example of a metal oxide with a high optical refractive index, but in the present invention, zirconium oxide ZrO, tantalum oxide Ta20g, cerium oxide OeO, etc. may also be used, and the crystallization rate may be Even if it is not 100% effective, there is some effect. Thus, the thickness of each layer of the infrared reflective film is free within the range that does not harm the purpose of the present application.

Furthermore, the present invention is applicable not only to halogen light bulbs but also to ordinary incandescent light bulbs. The infrared reflecting film may be provided on either the inner or outer surface of the bulb, or may be provided on both surfaces.

〔Effect of the invention〕

The light bulb of the present invention is formed by alternately layering a metal oxide with a low refractive index and a metal oxide with a high refractive index on the surface of a transparent glass bulb, and at least one layer of the metal oxide with a high refractive index has an average grain size. Since we have provided a crystallized visible light transmitting infrared reflective film with a diameter of 1008 to 1 μm, it diffuses visible light and does not form an optical image of the filament on the illuminated surface even when combined with a reflecting mirror. Improved reflectance and expanded reflection wavelength range can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the light bulb of the present invention, FIG. 2 is an enlarged sectional view of the main part, FIG.
The figure is also a graph of spectral light transmittance characteristics. (1)...Bulb (2)...Infrared reflective film (6)...Filament Qυ...Metal oxide with a small optical refractive index (2)...Metal oxide cylinder with a large optical refractive index 1 Figure 2

Claims (1)

[Claims] A visible light transmitting and infrared reflecting film formed by alternating layers of a metal oxide with a low refractive index and a metal oxide with a high refractive index is provided on the surface of the transparent glass bulb. A light bulb characterized in that one layer of is crystallized with an average particle size of 100A to 1μ.