JP2585986B2 - Tube ball - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bulb utilizing a light interference film formed on a bulb surface.

2. Description of the Related Art In recent years, a filament is disposed at the center of a tubular valve, and a visible light transmitting infrared reflecting film is provided on the valve surface. There is known a halogen bulb in which the filament is heated to thereby increase the luminous efficiency by heating the filament and reduce infrared rays in the emitted light. Such a visible light transmitting infrared reflecting film is made of titanium oxide (T
High refractive index layer made of iO2) and silica (SiO2)
5-7 layers of low-refractive-index layers composed of layers, etc., are alternately layered. Light of a desired wavelength is selectively transmitted or reflected by using the interference of light by regulating the thickness of the layer. Things. Therefore, such a film is generally referred to as a light interference film.

However, the temperature of the light interference film of this light bulb during lighting is extremely high at about 400 ° C. In addition, the light bulb with the light interference film has a long service life of typically 2,000 hours. Furthermore, during the life of 2000 hours, for example, in the case of store lighting, blinking is repeated about 200 times. As described above, the light interference film formed on the light bulb is used under extremely severe conditions as compared with conventionally known uses of the light interference film such as a cold mirror and a filter. For this reason, the light interference film formed on the light bulb is more prone to cracking or peeling off during the life of the light interference film than the cold mirror or the filter. This significant difference is interpreted as follows. That is, first, the optical interference film and the glass bulb are originally different in the coefficient of thermal expansion. Therefore, 4
The light interference film is always under stress during lighting during heating to around 00 ° C. Second, because the heat cycle from normal temperature to around 400 ° C is repeated,
Cracking and peeling are more likely to occur than in the case of continuous lighting. In addition, this cracking and peeling is because the light interference film is formed on the surface of the glass bulb having a relatively small diameter, that is, a large curvature,
This is more likely to occur than when formed on a conventional cold mirror or filter. Further, it was found that when a chip-off portion was formed in the light bulb and the light interference film was formed in this portion, cracking and peeling were more likely to occur in this portion than in the portion. This is because the temperature gradient is the largest in the vicinity of the chip-off portion, so that stress tends to concentrate. Since the tip-off portion has a larger curvature, the tensile stress acting on the optical interference film is larger than the tensile stress acting on the optical interference film on a plane. This is presumed to be the reason that the optical interference film near the chip-off portion is liable to crack or peel off. In order to reduce such cracking and peeling, for example, Japanese Patent Application Laid-Open No.
No. 124301, silica (SiO
2) and aluminum oxide (Al2O)
3) in an optical interference film in which a high refractive index layer made of at least one of zirconium oxide (ZrO2) and titanium oxide (TiO2) is alternately layered, at least tin and zirconium (both element names) are added to silica. It is known that the inclusion of one kind improves the stability of the light interference film and reduces cracking and peeling.
However, when this light interference film is applied to a bulb having a bulb made of hard glass such as quartz glass or borosilicate glass, such as a halogen bulb, a heat cycle due to frequent blinking and a long cycle under a high temperature of 400 ° C. Cracks and peeling of the light interference film are also caused by the combined effects of tube-specific factors such as time lighting, film formation on the surface of a glass bulb with a relatively small diameter, that is, a large curvature, and film formation in a place with a large temperature gradient. May occur, which is insufficient for application to such a bulb. Therefore, as a result of further investigation and research, the volumetric shrinkage when the organosilicon compound is thermally decomposed to form a silica layer varies depending on the type and amount of the vitreous additive, but is considerably large, and That there is a large difference in the coefficient of thermal expansion between the high refractive index layer and the low refractive index layer,
Focusing on the fact that titanium oxide and silica do not form a solid solution and the bonding between the layers is insufficient, the results of exploring excellent additives to reduce the difference in thermal expansion and strengthen the bonding between the layers The present invention has been completed. The present invention
An object of the present invention is to provide a tube in which cracking and peeling of an optical interference film are reduced.

According to a first aspect of the present invention, there is provided a lamp body including a glass bulb and a light emitting means sealed inside the glass bulb; and at least one of titanium oxide, tantalum oxide and zirconium oxide. A high-refractive-index layer containing a seed as a main component, and a light interference film formed by alternately forming a low-refractive-index layer containing silica as a main component and containing at least one of phosphorus and boron. It is characterized by having. The bulb is, for example, a halogen bulb provided with a visible light transmitting infrared reflecting film, a light bulb formed with a light interference film that frequently flashes like a signal light, a reflective light bulb having a visible light reflecting infrared transmitting film, an arc tube. And a metal halide lamp having a light interference film formed on an outer tube or the like.

According to the first aspect of the present invention, the light interference film has a heat cycle due to frequent flickering, a severe environment in which the light interference film is lit for a long time at a high temperature of 400.degree. Even if a three-dimensional curved surface is formed and the temperature gradient at that portion is large, the low refractive index layer forming the light interference film contains an appropriate additive, so that the interlayer between the layers forming the light interference film is formed. The strain caused by the coefficient of thermal expansion is alleviated and the suturing force between the layers is enhanced, and as a result, cracking and peeling of the optical interference film are reduced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a bulb provided with a light interference film of the present invention, specifically, one embodiment of a halogen lamp will be described with reference to the drawings. FIG. 1 is a partially cutaway front view of a halogen bulb. In the figure,
(1) is a heat-resistant tubular glass bulb made of quartz glass, alumina silicate glass, or the like, and (2) is formed on at least one of the inner and outer surfaces of the glass bulb (1), such as the outer surface, and transmits visual light. A light interference film that reflects infrared light, (3) is a sealing portion obtained by crushing and sealing the end of the glass bulb (1), and (4) and (4) are embedded in the sealing portion (3). Molybdenum-introduced foils, (5) and (5) are inner conductors connected to these introductory foils (4) and (4) and introduced at both ends in the glass bulb (1), and (6) is a light-emitting means. The coil filament is mounted between the inner conductors (5) and (5) along the center line of the glass bulb (1).
(7) is a base attached to the end of the glass bulb (1). A required halogen is sealed in the glass bulb (1) together with an inert gas such as argon. The glass bulb (1), the coil filament (6), and an inert gas such as argon in the glass bulb (1) constitute the tube body. FIG. 2 is an enlarged schematic view of the light interference film (2). The light interference film (2) is made of titanium oxide (TiO2) or tantalum oxide (Ta2O5) on the surface of the glass bulb (1).
And at least one of zircon oxide (ZrO2) and phosphorus (P), boron (B), arsenic (As), antimony (Sb), tin (Sn), zinc (Zn), lead (Pb), potassium (K), nickel (N
i) and a high refractive index layer (21) containing at least one of cobalt (Co) and silica (SiO)
A low refractive index layer (22) containing 2) as a main component and at least one of phosphorus and boron is alternately laminated. By making the thicknesses of the high refractive index layer (21) and the low refractive index layer (22) appropriate, a property that most of visible light is transmitted and most of infrared light is reflected by light interference. Having. Next,
An example of a method for forming the light interference film (2) will be described. First, one or more organic compounds of titanium, tantalum or zircon are taken and dissolved in an alcoholic organic solvent. Next, add phosphorus, boron, arsenic,
A coating solution is prepared by adding an appropriate amount of at least one alcohol-soluble compound of antimony, tin, zinc, lead, potassium, nickel or cobalt (the compound only needs to be soluble enough to dissolve the required amount). Thereafter, the coating solution is applied to the outer surface of the glass bulb (1), dried, and baked at about 500 to 600 ° C. for about 10 minutes in the air to obtain a high refractive index layer (2).
Form 1). Next, an alcohol-based solution of alkoxysilane was reacted and the concentration converted to SiO2 was 5.0.
Wt.% Of a dense solution of an alkoxysilane condensate, and an appropriate amount of at least one alcohol-soluble compound of phosphorus and boron is added to the denatured solution to prepare a coating solution. 21) Apply to the surface, and after drying, bake in air at about 500 to 600 ° C. for several tens of minutes to form a low refractive index layer (22). Thus, the desired light interference film (2) can be obtained by alternately repeating the formation of the high refractive index layer (21) and the formation of the low refractive index layer (22) a desired number of times.
The halogen bulb obtained in this manner is a light emitting member (6)
The visible light of the light emitted from the light transmitting member is transmitted through the light interference film (2) and emitted to the outside, and the infrared light is reflected by the light interference film (2) and returns to the light emitting member (6) to emit the light emitting member (6). Is reheated to improve luminous efficiency. Therefore, this halogen bulb has high efficiency and less infrared rays in the emitted light. Then
In the halogen bulb, the glass bulb (1) is heated to a very high temperature during lighting. In the bulb of this embodiment, the above-mentioned phosphorus or boron is added to the low refractive index layer (22) constituting the light interference film (2). Both layers (21), (22)
Since the distortion caused by the difference in thermal expansion between the layers is reduced, and the bonding force of the additive contained in the low refractive index layer (21) can be expected, both layers (21) constituting the light interference film (2) can be used.
Even when the number of layers of (22) is about six, cracks and peeling of the light interference film (2) are reduced, and the light interference film (2) can withstand long-term lighting. In particular, in the above embodiment, at least one appropriate additive of phosphorus, boron, arsenic, antimony, tin, zinc, lead, potassium, nickel or cobalt is added to the high refractive index layer (21). Therefore, the distortion caused by the difference in thermal expansion between the two layers (21) and (22) is further reduced, and the bonding force of the additive contained in the high refractive index layer (21) can be expected. (2) The number of cracks and peeling is further reduced, and the lamp can withstand long-term lighting. Next, the first
With respect to the halogen lamps shown in the figures, those having the light interference film of the present invention and a comparative example having the light interference film similar thereto were produced, and flickered repeatedly to examine the peeling state. Table 1 shows the results. In the table, the amount of phosphorus added is 3% by weight in terms of phosphorus trioxide (P2O3).

[Table 1] Next, similarly to the above, one having another example of the light interference film of the present invention and a comparative example having a light interference film similar to this were prepared, and flickering was repeated to investigate the peeling state. Table 2 shows the results. In the table, the addition amount when Co is added is 2% by weight, and when B is added, the addition amount is 3% by weight in terms of B2O3.

[Table 2] As shown in Tables 1 and 2, in each of the examples, since the additive was contained in the low refractive index layer (22), both of the layers (21) and (22) were included. As compared with the comparative example containing no additive, it was found that the adhesion strength of the light interference film (2) was improved, and cracks and peeling could be reduced even when the number of layers was increased. Further, as shown in Tables 1 and 2, when an additive is contained in both the high refractive index layer (21) and the low refractive index layer (22), the adhesion strength of the light interference film (2) is reduced. It was found to be much improved. This means that the light interference film (2)
It is suggested that the additives contained in at least the low refractive index layer (21), and in some examples, the high refractive index layer (22) are bonded to each other.

According to the present invention, the strain caused by the coefficient of thermal expansion between the layers constituting the optical interference film is alleviated and the bonding force between the layers is strengthened, and as a result, cracking and peeling of the optical interference film can be reduced. A stable quality tube is obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view of one embodiment of a tube of the present invention.

FIG. 2 is a schematic enlarged sectional view of the optical interference film.

[Explanation of symbols]

 (1) Glass bulb (2) Light interference film (21) High refractive index layer (22) Low refractive index layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoji Yuge 1-12-1 Funakoshi-cho, Yokosuka City, Kanagawa Prefecture Inside Yokosuka Plant, Toshiba Corporation (72) Inventor Akira Kawakatsu 201-1-1, Funakoshi-cho Yokosuka City, Kanagawa Prefecture Company Toshiba Yokosuka Plant (72) Inventor Tokuyoshi Saito 2-4 Ariakidai, Ichihara-shi, Chiba Examiner Hiroshi Ogawa (56) References JP-B 7-109758 (JP, B2)

Claims (1)

(57) [Claims] A bulb body including a glass bulb and a light emitting means sealed inside the glass bulb; titanium oxide;
A high refractive index layer containing at least one of tantalum oxide and zirconium oxide as a main component and a low refractive index layer containing silica as a main component and containing at least one of phosphorus and boron are alternately formed. And a light interference film formed.