JPH06318450A - Tubular bulb provided with diffusing film - Google Patents

Abstract

PURPOSE:To provide a tubular bulb in which illuminance irregularity is not generated in an irradiated surface by forming a diffusing film out of a cloudy film comprising metal oxide/nirtide througu a CVD method, and forming the film thickness and the film structure uniform. CONSTITUTION:A semi-fabricated product with quartz surface a glass bulb 1 cleaned is put into a CVD reaction chamber, the inside of the reaction chamber is made vacuum, and the bulb 1 is heated until its surface reaches a specified temperature. Next, gas generated by the use of tetraisopropoxy titanium and oxygen gas are introduced into the reaction chamber simultaneously at a specified flow rate. A gas introducing time is regulated in accordance with required cloudiness of the film. After that, nitrogen gas is introduced into the reaction chamber, and the sewi-fabricated product is taken out. Respective surfaces of a head top part 11, a sealing part 12, and a boundary range 13 between them are thus coated with a drffusing film of the desired cloudiness having the uniform film thickness and the film structure in addition to the external surface of a straight tube part 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube having a light diffusing film.

[0002]

2. Description of the Related Art A technique for forming a film having a property of scattering light, that is, a light-scattering film on the surface of a light-transmitting substrate is already known. In addition, in tubes such as light bulbs and discharge lamps, in order to make the illuminance distribution uniform, a translucent member that surrounds the light source part of the tube, for example, a product in which a light diffusion film is formed on the surface of a glass bulb is already known. Has been.

In order to provide a uniform illuminance distribution in any irradiation direction, it is desirable to form a light-scattering film on the entire surface of the glass bulb of the tube, but as a conventional technique that meets this purpose, immersion firing is used. There is a method, the film formation is easy, and the method can be performed at low cost, so it is the most suitable method. As a typical example of the immersion firing method, there is a method disclosed in JP-A-59-221968. In this method, a substrate is immersed in an organometallic compound solution, pulled up in an atmosphere having a humidity of 95% or more, dried, and baked in air at a temperature of 300 ° C. or more to form a light-scattering metal oxide film. Is.

[0004]

If the immersion firing method is applied to, for example, a glass bulb of a single-ended type halogen bulb, first, the glass bulb is immersed in an organometallic compound solution in a posture in which the crown of the glass bulb faces downward. When the glass bulb is pulled up, a liquid pool is formed on the crown after the glass bulb comes out of the liquid surface. Therefore, after baking, a diffuser film with a uniform film thickness is formed on the surface of the straight tube portion of the glass bulb, but there is unevenness in the film thickness at the crown and its surroundings, and among them, the liquid pool at the tip of the crown is burned At the location where the metal oxide powder is changed, the film thickness becomes extremely thick, or the film cannot be formed. Also, in terms of structure, the distribution of the metal oxide is uneven, so that a homogeneous structure cannot be obtained. The same is true when the glass bulb is immersed and pulled up with the top of the glass bulb facing upward, and in addition to the top of the head, the film thickness and film are also formed on the surface of the boundary region between the straight pipe portion and the sealing portion. Unevenness occurs in terms of structure.

Further, since the light diffusing film on such a curved surface has weaker adhesiveness to the substrate than the light diffusing film on a flat surface, the film strength is lowered and it is easily peeled off or damaged. Also has. Therefore, if such a halogen bulb is used, the method of diffusing the transmitted light of the diffuser film layer differs depending on the difference in the film thickness and film structure of the diffuser film or the presence or absence of a missing portion due to peeling, etc. This causes a problem of uneven illuminance on the surface.

The above-mentioned problem is that in the immersion firing method, when the glass bulb is pulled out of the liquid, even if a measure such as finely controlling the pulling rate according to the surface shape is taken, a uniform film thickness and a uniform thickness can be obtained in the curved surface portion. Since the membrane structure cannot be realized, it has not been solved until now. Further, the above problems are not peculiar to the light-diffusing film formed on the glass bulb of the single-ended die halogen light bulb, but the unevenness of complicated shapes such as the glass bulb of the double-ended die halogen bulb, the arc tube of the discharge lamp, etc. This is a problem common to all diffuser films formed on a substrate having a curved surface composed of planes.

In addition to the halogen bulb described above, in the already known bulb with a light diffusing film, the light diffusing film is firm and has a uniform film thickness and film structure. It is limited to the case where the forming surface is a flat surface, a cylindrical surface (straight tube portion) or a conical surface, and is composed of a concavo-convex surface with a complicated shape, such as the crown of a glass bulb of a single-ended halogen bulb. Up to now, there has not been a tube in which the diffuser film is firm and the film thickness and the film structure are uniform on all the surfaces including the curved surface where the diffuser film is formed.

The present invention has been made in view of the above points, and is a tube having a light diffusing film for diffusing transmitted light equally in any part of the surface on which the light diffusing film is formed. It is an object of the present invention to provide a bulb that does not cause unevenness in illuminance and always retains such characteristics.

[0009]

According to the present invention, in order to solve the above-mentioned problems, in a tube having a light diffusing film formed on the surface of a light-transmissive member constituting the tube, at least the surface is a flat surface or a cylinder. The diffuser film is formed on the surface of the curved surface of the surface, the conical surface or more, and the film thickness and the film structure are uniformly configured in any portion where the diffuser film is formed. The diffuser film is a cloudy film made of a metal oxide and / or a metal nitride, and is formed from a raw material such as an organometallic compound by a chemical vapor deposition method (hereinafter abbreviated as “CVD method”).

The CVD method has a feature that it is excellent in the covering property of the film substance with respect to the substrate. Since the film forming method is performed by introducing the raw material gas into the reaction chamber in which the substrate is placed and uniformly filling the reaction chamber, the substrate surface of any shape including the curved surface is irrespective of the substrate arrangement. Also, the raw material gas can be uniformly adsorbed. As a result, by using the CVD method, a thin film having a uniform film thickness and a uniform film structure can be formed on any part of the substrate surface.

During the formation of the diffuser film, the temperature of the substrate on which the diffuser film is to be formed, the reaction pressure, and the flow rate of the gas of the source material are adjusted so that the diffuser film layer made of metal oxide and / or metal nitride becomes cloudy. Select the conditions related to film formation such as. The degree of white turbidity of the light-scattering film layer is achieved by adjusting these film forming conditions appropriately.

[0012]

Since the light diffusing film in the tube of the present invention is formed by the CVD method, the film thickness and the film structure of the light diffusing film are uniform on any part of the film forming surface. In particular, a diffuser film having a uniform film thickness and a film structure is formed on the surface of a curved surface composed of a concavo-convex surface having a complicated shape, like the surface of other portions. Therefore, in the bulb of the present invention, the light transmitted through the light diffusing film is uniformly diffused on any film forming surface, so that there is no uneven illuminance on the surface to be illuminated. or,
Since the light diffusing film in the tube of the present invention has excellent film strength on any film forming surface, there is no place where the light diffusing property is lost due to peeling or the like, and the tube always maintains a uniform illuminance distribution. .

[0013]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a single-ended halogen bulb having a light-scattering film, in which the light-scattering film is uniformly formed on the entire outer surface of the glass bulb exposed to the outside. Reference numeral 1 indicates a quartz glass bulb, and 2 indicates a light diffusing film. Figure 2
FIG. 6 is an enlarged view of a portion where a light-scattering film is formed. FIG. 3 shows the halogen bulb in the semi-finished product stage before the base part 7 is attached.

Next, a method of manufacturing the above halogen bulb will be described. First, the quartz glass bulb 1, the tungsten filament 3, the inner lead wire 4, the support member 5, the stem glass 6, the metal foil conductor 8, the outer lead wire 9 and other materials, and a rare gas and a halide at a predetermined pressure are enclosed. From the object, by a known method, as shown in FIG.
The semi-finished product of halogen bulbs in a state without Then
The above semi-finished product is placed in the CVD reaction chamber, and under predetermined conditions,
A cloudy thin film of metal oxide and / or metal nitride, that is, a light scattering film is formed on the outer surface of the quartz glass bulb 1. The semi-finished product with a diffuser film taken out from the CVD reaction chamber is processed into a finished product (FIG. 1) by processing the external lead wire 9 and attaching the base part 7 to the sealing part 12 by a known method.

The method for forming the film will be described in detail, taking the case of forming the light-scattering film made of titanium oxide (TiO ₂ ) by the CVD method as an example. For example, using tetraisopropoxytitanium (hereinafter abbreviated as “TPT”) as a raw material, CV is performed under reduced pressure.
The following is the procedure for carrying out the D reaction. A semi-finished product, in which the surface of the quartz glass bulb 1 has been washed in advance by a known method, is put into a CVD reaction chamber in which a heating mechanism is arranged on the outer periphery, and the reaction chamber is evacuated to a pressure of about 70 to 250 Pa, The heating mechanism heats the semi-finished product so that the surface temperature of the glass bulb is 550 to 600 ° C. Then, a gas generated from TPT heated to about 70 ° C. is introduced into the CVD reaction chamber at a flow rate of 300 to 500 ml / min and an oxygen gas at a flow rate of 500 to 2000 ml / min for several minutes at the same time. This gas introduction time is adjusted according to the required white turbidity of the film. Then, nitrogen gas is introduced into the CVD reaction chamber to return to atmospheric pressure, and then the semi-finished product is taken out of the CVD reaction chamber.

Thus, in addition to the outer surface of the straight pipe portion 10 of each portion of the surface of the quartz glass bulb 1 of FIG. 3, the film thickness and the film structure are uniformly formed by the conventional method such as the immersion firing method. The surface of the crown 11, the sealing portion 12, and the boundary region 13 between the straight tube portion 10 and the sealing portion 12, which were not possible, are all diffused films having a desired white turbidity and having a uniform film thickness and film structure. To be covered. That is, the entire surface of the quartz glass bulb 1 is covered with a diffuser film having a uniform film thickness and a film structure.

As the raw material for the light-scattering film made of TiO ₂ , titanium alkoxide such as tetraisobutoxytitanium is suitable in addition to TPT in the above-mentioned embodiment. The material constituting the diffuser film, in addition to TiO _2, other metal oxides such as tantalum oxide (Ta ₂ O _5), titanium nitride (Ti
N) or the like, a mixture of metal oxide and metal nitride, or a metal oxynitride such as titanium oxynitride (TiON).

As the mode of the CVD reaction, in addition to the CVD method performed under reduced pressure as in the above embodiment, CV performed under normal pressure
D method may be used, or plasma CVD method or photo CVD method.
The method may be used. A substrate on which a light-scattering film can be formed is
Not limited to the glass bulb of the halogen bulb as in the above embodiment, among the translucent member that constitutes the bulb,
Any member can be targeted.

The white turbidity of the light diffusing film depends on the substrate temperature, reaction pressure,
It can be changed by adjusting the film forming conditions such as the raw material gas flow rate. The formation of an opaque film by the CVD reaction is considered to be due to the fact that the gas of the raw material substance undergoes rapid chemical decomposition on the surface of the substrate and changes into a film substance such as an oxide. Often in this cloudy film, the film material is amorphous without forming a particle structure.

Next, a single-ended halogen bulb with the same specifications was prepared, and a light-scattering film was formed on the outer surface of the quartz glass bulb by two methods, and the strength of the light-scattering film was compared and examined by the difference in the forming method. . In the film strength test, a sample of a halogen bulb with a diffuser film is subjected to a heat treatment of leaving it in the air at 600 to 800 ° C for 100 hours, and before and after that, the film surface is strongly shaved with a steel blade to damage the film. It is to check the condition.

As a result, the diffuser film in the halogen bulb of the present invention was hardly damaged on any film forming surface before and after the heat treatment. On the other hand, in the case of the conventional halogen light bulb in which the light diffusion film is formed by the immersion firing method, there is almost no damage to the film of the straight tube portion of the glass bulb, and the light diffusion of the halogen light bulb of the present invention by the CVD method. Although the film strength was equivalent to that of the film, the film on the crown of the glass bulb, the sealing part, and the surface of the boundary area between the straight pipe part and the sealing part was damaged significantly, and the film on the surface of the crown was especially damaged by the blade. It was easy to scrape off.

In the above-mentioned embodiment, the case of the single-ended type halogen bulb is explained, but it has a complicated shape such as a glass bulb of a double-ended type halogen bulb, an arc tube for a discharge lamp such as a metal halide lamp, or the like. It can also be applied to a substrate having a curved surface composed of an uneven surface.

[0023]

As described above, in the bulb of the present invention having the light diffusing film on the surface of the light transmitting member, the light diffusing film is formed by the CVD method. It is uniform on any part of the formation surface, and the light transmitted through the light-transmissive member on which the light-scattering film is formed is equally diffused on any film formation surface, so uneven illumination does not occur on the irradiated surface. , It has a unique effect that has never been seen before. In addition, the tube of the present invention has excellent film strength on any film forming surface, including a curved surface of a diffuser film having a complicated shape.
It also has an effect of always maintaining a uniform illuminance distribution on the surface to be illuminated, without causing a spot of lack of light diffusion due to peeling or the like.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an embodiment of a tube according to the present invention.

FIG. 2 is a schematic enlarged cross-sectional view of a part of the glass bulb of the bulb of FIG.

3 is a schematic cross-sectional view of the tube of FIG. 1 at a stage of a semi-finished product before attaching a base part.

[Explanation of symbols]

 1 Quartz glass bulb 2 Diffusing film 3 Tungsten filament 7 Base part 10 Straight pipe part 11 Top part 12 Sealing part 13 Boundary region

Claims (1)

[Claims] 1. A tube in which a light-scattering film is formed on the surface of a light-transmissive member forming the tube, wherein the light-scattering film is a cloudy film made of a metal oxide and / or a metal nitride, The diffuser film is formed on at least the surface of a curved surface other than a flat surface, a cylindrical surface, or a conical surface by the vapor deposition method (CVD method), and the film is formed on any part where the diffuser film is formed. A tube having a light-scattering film having a uniform thickness and a uniform film structure.