JPH06181048A - Bulb and coat forming method on bulb thereof - Google Patents

Abstract

PURPOSE:To form a coat with uniform thickness on a bulb including the bulb part near the sealing part wherein the bulb has the sealing part at one end. CONSTITUTION:A filament 2 or a discharge electrode is sealed in the inside of a bulb 1 and a sealing part 4 is formed at the terminal part and at the same time a coating 7 is formed on the outer surface of the bulb 1. Regarding the bulb L, the sealing part is thinned gradually toward the periphery from the center or a cut part 8 is formed in the joining part between the bulb 1 part and the sealing part 4. The coat 7 is formed on the outer surface of the bulb 1 while the tubular bulb L having the sealing part 4 is supported in a chamber BX horizontally or on the tilt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bulb in which a glass bulb such as a halogen bulb is coated with a coating such as a multilayer interference film such as a visible light transmitting infrared reflecting film, and a method for producing the bulb. More particularly, the present invention relates to the structure of the sealing portion of the tube or the method for forming a film on the tube having the sealing portion.

[0002]

2. Description of the Related Art Various efforts have been made in the field of bulbs as part of energy saving. For example, in a halogen bulb, a visible light transmitting infrared reflecting film is formed on the outer surface of a bulb to emit light from a filament. It is known that infrared rays are reflected by this reflective film and returned to the filament, thereby heating the filament and increasing the luminous efficiency. Such a visible light transmitting / infrared reflecting film is formed by alternately stacking a high refractive index layer made of titanium oxide (TiO2) and a low refractive index layer made of silicon oxide (SiO2) to form a multi-layer structure. By appropriately selecting the layer thickness, light interference is used to selectively transmit and reflect light in a desired wavelength range.

In this light bulb, the larger the number of layers of the film, the higher the reflectance of infrared rays and the greater the effect of power saving.

As a method of forming this visible light transmitting infrared reflecting film, there are an immersion method, a vapor deposition method, an ion plating method, a sputtering method and the like.

As a method for forming these films, a method of immersing a valve in a solution for forming a film and pulling it up is often adopted because of its simple and low cost. However, when a strict film thickness is required or the valve is used, When the film is not straight but has a curved surface or a concavo-convex surface, the film thickness of the formed coating film may be non-uniform, or a portion where the film is not formed may occur, so that predetermined characteristics may not be obtained.

When forming a film on a valve having a curved surface or an uneven surface as described above by a vapor deposition method or the like, it is necessary to coat the valve while rotating the valve to be processed in order to obtain a uniform film thickness. Is being carried out.

However, for example, in a halogen bulb of the one-end sealed type, a curved surface is formed in the vicinity where the end is melted and crushed, and a sealing body such as molybdenum foil is embedded in the crushed part, so that the flattened shape is almost flat. A rectangular parallelepiped sealing portion is formed. Therefore, even if an attempt is made to form a film while rotating such a light bulb by a vapor deposition method or the like, the corners of the crushed sealing part obstruct and prevent the film material from flying to the curved surface part, and the entire outer surface of the valve. It is difficult to form a film having a uniform thickness.

Further, in the case of such a method, since the film material is usually evaporated at one place and does not fly from all directions around the valve, the evaporation source of the film material is arranged below the valve and the central axis of the valve is arranged. Even if the valve is horizontally fixed and the valve is rotated, the corners of the crushed sealing part at the valve end block and create a shadow that interferes with the coating on the curved surface near the sealing part, and This causes deterioration of the lamp characteristics.

[0009]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention has been made to solve the problem by changing the shape of the collapsible sealing portion of the tube.
It has a shape as seen in Japanese Patent No. 281,654.
What is disclosed in this publication is that the crushing sealing portion in the direction intersecting with the valve axis has a rectangular shape with a substantially equal thickness in a normal tube, whereas the central portion has a thicker end. It is thin as it goes to the department side. However, the one disclosed in Japanese Patent Application Laid-Open No. 1-281654 is made in order to prevent problems such as bending of the electrode shaft due to the molten glass undesirably pressing the molybdenum foil when molding the sealing portion. No consideration is given to forming a film on the surface of the bulb bulb.

According to the present invention, in a bulb having a sealing portion formed on at least one end of a valve having a coating formed on the surface thereof, a bulb having a coating formed on the surface of the valve includes a valve portion near the sealing portion. It is an object of the present invention to provide a tube capable of forming a coating film having a uniform thickness and a coating forming method capable of making a film thickness uniform.

[0011]

According to a first aspect of the present invention, a filament or a discharge electrode is enclosed inside a bulb to form a sealing portion at an end and a film is formed on the outer surface of the bulb. In the tube formed as described above, the sealing portion is characterized in that the central portion has the maximum thickness portion and the thickness is reduced toward the peripheral edge parallel to the valve axis.

A second invention according to claim 2 of the present application is a tube in which a filament or a discharge electrode is enclosed inside a bulb, a sealing portion is formed at an end portion, and a film is formed on the outer surface of the bulb. The sphere is characterized in that a notch is formed at a connecting portion between the bulb portion enclosing the filament or the discharge electrode and the sealing portion.
Further, a third invention according to claim 3 of the present application is characterized in that a cross section of the sealing portion in a direction orthogonal to the valve axis is a circular shape, a flat oval shape or an oblong shape. There is.

The fourth invention of claim 4 of the present application is characterized in that the bulb portion enclosing the filament or the discharge electrode has a curved surface portion such as a spherical shape or a circular shape.

Furthermore, a fifth invention according to claim 5 of the present application is to provide a tube having the sealing portion according to any one of claims 1 to 4 in a chamber, the tube being horizontal or inclined. It is characterized in that a coating is formed on the outer surface of the valve.

[0015]

According to the invention described in claims 1 to 4, since the bulb valve including the sealing portion has no convex portion or the like for preventing the progress of the flying material due to evaporation or spray atomization, the valve is The film thickness of the coating film of the multilayer interference film such as the visible light transmitting infrared reflecting film formed on the outer surface of the can be made substantially uniform, and the characteristics of the bulb can be improved. Further, in the invention according to claim 5 of the present application, since the bulb valve including the sealing portion has no corners or the like that obstruct the progress of the material that has flown due to evaporation or spray atomization, the material scattered toward the valve. Most of these are deposited on the valve, and the film thickness of the multilayer interference film such as a visible light transmitting infrared reflecting film for the valve can be made substantially uniform.

[0016]

Embodiments of the first to fifth inventions of the present application will be described below with reference to the drawings. 1 (a) and 1 (b) are partially sectional front views of a halogen light bulb L for small light projection, FIG. 2 (a),
FIG. 1B is a bottom view of the collapsed sealing portion of the light bulb L of FIG.

In the electric bulb L of FIG. 1A, a filament 2 and an inert gas such as argon containing halogen are enclosed in a bulb 1 made of quartz glass and having a substantially spherical shape.
The internal conducting wires 3 and 3 supporting the filament 2 are connected to molybdenum foils 5 and 5 sealed in a sealing portion 4 formed by crushing one end of the bulb 1. In addition, external conductors 6 and 6 are connected to the other ends of the molybdenum foils 5 and 5, respectively. A multilayer interference film 7 is a film formed on the outer surface of the bulb 1, for example, a visible light transmitting infrared reflecting film.

The cross section of the crush seal portion 4 in the direction intersecting with the axis of the valve 1 has a flat elliptical shape (a) or an oblong shape (b) as shown in FIG.

Further, FIG. 1B shows a light bulb L showing another embodiment, and the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. This light bulb L is provided with notches 8, 8 that cut into the sealing portion 4 at the connecting portion between the bulb-shaped portion 1 having a spherical shape and the crushing sealing portion 4.

A method of forming the multilayer interference film 7 on the bulb 1 of the electric bulb L shown in FIGS. 1A and 2 by the ion plating method will be described with reference to FIG.

In FIG. 3, BX is a chamber, an exhaust pipe E connected to a vacuum pump VP, an argon gas supply pipe A for supplying an argon gas Ar, and a chamber BX.
An oxygen gas supply pipe O for supplying oxygen gas O2 is connected, and a valve E is connected to each of these pipes E, A and O.
C, AC and OC are provided.

Further, a crucible R for containing a vapor deposition substance is provided at the bottom of the chamber BX, and a spiral high-frequency coil C is arranged above the crucible R. Above the high frequency coil C, the bulb 1 of the electric bulb L for forming a visible light transmitting infrared reflecting film consisting of a plurality of layers has a bulb axis inclined by θ (0 to 30 degrees) by a jig (not shown). And is supported by a drive device (not shown) so as to rotate in the arrow X direction and revolve in the arrow Y direction.

Further, HF is connected to the high frequency coil C through a matching box M by a high frequency oscillator,
ES is a variable DC power source, and the negative electrode side is connected to the valve 1. In addition, H is a heater provided above the chamber BX.

A method of forming a coating on the outer surface of the bulb 1 of the light bulb L using the above apparatus will be described. First, the surface treatment before forming a film on the bulb 1 is performed by using a jig (not shown) in the chamber BX, in which the bulb 1 of the bulb L has a bulb axis of θ degrees (0 to 30 degrees).
Support it in a tilted state. In this state, the valve EC is opened and the inside of the chamber BX is evacuated through the exhaust pipe E to a predetermined degree of vacuum.

Thereafter, the valve 1 is rotated in the direction of the arrow X and revolved in the direction of the arrow Y through the drive unit, and the outer surface temperature of the valve 1 is set to 300 by the heater H provided above the chamber BX. Heat to about 350 ° C.

Next, the valve EC is closed, the valve AC is opened, and the argon gas Ar is supplied into the chamber BX through the argon gas supply pipe A. The argon gas Ar pressure in the chamber BX is 0.01 to 0.1 Torr.

In this state, high frequency power of 1 to 20 MHz and 0.5 to 2 KW is supplied from the high frequency oscillator HF to the high frequency coil C.

Then, the argon gas A in the chamber BX
The r is ionized by the high frequency plasma, and the argon ions are attracted to the surface of the valve 1 that is negatively charged and collide with the outer surface of the valve 1. The outer surface of the bulb 1 is etched by the kinetic energy due to the collision of the argon ions, the dust adhering to the surface is removed, and the convex surface is eroded, so that the surface becomes a highly accurate smooth surface, and thus the surface of the valve 1 Processing is done.

When this process is completed, the visible light transmitting infrared reflecting film consisting of the multilayer interference film 7 is formed on the surface of the bulb 1. First, for example, metallic titanium (Ti) is contained in the crucible R as a material for forming the high refractive index layer film 7H as the first layer of the multilayer interference film 7.

Similarly, the valve 1 is rotated in the direction of arrow X and revolved in the direction of arrow Y via a drive device (not shown), and a heater H provided in the upper part of the chamber BX.
To heat the outer surface temperature of the bulb 1 to about 300 to 350 ° C. Then, the valve OC is opened and the oxygen gas O2 is supplied into the chamber BX through the oxygen gas supply pipe O so that the partial pressure of oxygen O2 in the chamber BX is 2.0 × 10.
-Set to about 4 torr. In this state, high frequency power of about 13.56 MHz and 300 W is supplied from the high frequency oscillator HF to the high frequency coil C.

In this way, the T vaporized in the crucible R is
The vapor of i is ionized by the high frequency plasma, and the ions are attracted to the surface of the valve 1 which is negatively charged,
A vapor-deposited film of TiO2 adheres to the outer surface of the valve 1.

Next, as a material for forming the low refractive index layer film 7L, if SiO2 powder is contained in the crucible R and the SiO2 is evaporated in the same manner as above, the evaporated film 7L of SiO2 is formed on the evaporated film 7H of TiO2. Is attached. .. and TiO2 for forming the high refractive index layer films 7H, ... and SiO2 for forming the low refractive index layer films 7L, .. As a result, the halogen bulb L having the number 7 is obtained.

The coating 7 thus formed is shown in FIG.
In the light bulb L shown in (a), since the end portion of the crushing sealing portion 4 is thin, a protruding corner that shields the coating material M that evaporates and flies as shown in FIGS. 4 (a) and 4 (b). There is no portion, and the gaseous coating material M evaporated from the lower crucible R evenly flows to the outer surface of the valve 1 including the sealing portion 4 to form a coating having a uniform thickness. In this type of light bulb L, the multilayer interference film 7 attached to the crushing sealing portion 4 does not significantly affect the characteristics of the light bulb L, and the sealing portion 4 is
The uniformity of the coating 7 can be ignored, and the coating 7 need not be coated.

In the above embodiment, the coating materials are alternately placed in one crucible R, but a plurality of crucibles R in which different coating materials are previously placed in the chamber BX are prepared so as to be evaporated alternately. You may

In the above embodiment, the high refractive index layer film 7H,
Although metallic titanium (Ti) is used as the material, titanium oxide (TiO2) may be used. However, when titanium (Ti), which is easily ionized, is used, the crystallinity, compactness, and adhesion of the TiO2 layer having high reactivity and high ionization degree are high. In addition, as shown below, a high refractive index can be obtained even if the transmittance is almost the same.

By the way, the case of using metallic titanium (Ti) as the material for the high refractive index layer film 7H, ...
Compared with the case of using O2, titanium oxide (Ti
The refractive index or transmittance of O2) is 2.40 and 9 respectively.
It is 3.7%, whereas it is 2.40 and 93.7% for metallic titanium (Ti), respectively. The initial cut rate or cut width of titanium oxide (TiO2) is 92.6% and 250 nm, and the cut rate and cut width after heat treatment are 94.6% and 238 nm, respectively. For (Ti), the initial cut rate or cut width is 96.2%, 280 nm, and the cut rate or cut width after heat treatment is 9%, respectively.
It becomes 7.1% and 260 nm. (Note that the cut rate is 1
-The minimum transmittance and the cut width refer to the width of the valley of the transmittance curve at the position of 1/2 of the maximum transmittance. ) In the case where the visible light transmitting infrared reflecting film is composed of the above film material forming the high refractive index layer and SiO2 forming the low refractive index layer, metal titanium (T
The use of i) is superior to the use of titanium oxide (TiO2) in the cutting rate and the cutting width both in the initial stage and after the heat treatment. Therefore, metallic titanium (Ti)
By forming a visible-light-transmitting infrared reflective film using, it is possible to provide a halogen bulb that has excellent heat resistance and cuts many heat rays by reflecting many wavelengths in the infrared region and returning it to the filament. .

In the experiments conducted by the present inventors, various characteristics of the halogen bulb L in which 10 layers of visible light transmitting / infrared reflecting film are formed by changing the film material forming the high refractive index layer are as follows. Metal titanium (Ti) The light bulb L using was excellent. That is, the power ratio (%) and luminous flux ratio (%) when there is no coating material
Or efficiency ratio (%) is 100%, 100%, 1 respectively
In the case of titanium oxide (TiO2), it is 96.8%, 132.0% to 136.4%, respectively.
%, Whereas that of metallic titanium (Ti) is 94.
6%, 148.3% to 156.8%.

Further, in the light bulb L shown in FIG. 1B, when a film is formed by the same apparatus and method as described above,
The spherical bulb 1 portion where the vaporized film material flows into the notches 8 and 8 provided by cutting into the connecting portion between the spherical bulb 1 portion and the crushing seal portion 4 and the notches 8 and 8 actually emit light. Therefore, the area of the light bulb will be increased and the efficiency of the light bulb will be improved.

FIG. 6 shows the formation of a film by the parallel capacitive coupling plasma CVD method. In the figure, the same parts as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 6, a pair of discharge electrodes ER, ER are provided facing each other in the chamber BX. One end of T1 is connected to an argon gas Ar cylinder (not shown),
At the other end, T2 is an air supply pipe inserted in a container MC containing a film forming material such as Ti (OR) 4 forming a high refractive index layer or Si (OR) 4 forming a low refractive index layer. A material supply pipe that connects the container MC and the chamber BX. Further, HF is a high frequency power source for plasma generation connected to the discharge electrodes ER and ER, and TO is an oxygen gas supply pipe for supplying oxygen gas Q2 into the chamber BX.

The bulb L, on which the coating is to be formed between the pair of discharge electrodes ER, ER facing each other, is tilted with the bulb 1 axis with respect to the direction in which the film material M is fed. Support). Next, while rotating and revolving the light bulb L around the bulb 1 axis and the sealing portion 4, an argon gas Ar is caused to flow from the air supply pipe T1 and, for example, Ti (OR) 4 in the container CM is sucked up to feed the material supply pipe T2.
A gaseous material is introduced into the chamber BX through. At this time, the pressure in the chamber BX is kept at several torr to several 100 torr. In this state, a high frequency voltage is applied to the electrodes ER, ER to perform high frequency glow discharge. At this time, a quasi-equilibrium plasma state in which the gas temperature and the electron temperature greatly differ is generated. This glow discharge energy causes Ti (OR) 4
Is decomposed, and Ti is deposited on the outer surface of the bulb 1 of the light bulb L to form a Ti film.

After that, instead of Ti (OR) 4, oxygen O2 is supplied from the oxygen gas supply pipe TO into the chamber BX, and high frequency glow discharge is performed in the same manner as described above to form a TiO2 film on the outer surface of the valve 1. 7H is formed.

Then, in the same manner as described above, this time, the film material M is changed to Si (OR) 4 forming the low refractive index layer to form a film. Then, as shown in FIG. 5, the films of Ti (OR) 4 7H, ... Forming the high refractive index layer and Si (OR) 4 7L ,. To complete the halogen bulb L.

The light bulb L having the film thus formed is also
Since the end portion of the crushed sealing portion 4 is thin, there is no protruding corner portion for shielding, and the gaseous coating material flows evenly over the outer surface of the valve 1 including the sealing portion 4 and has a uniform thickness. Is formed.

With this method (apparatus), the bulb of which the shape of the sealing portion of the halogen bulb is shown in FIG.
When 8 layers of visible light transmitting / infrared reflecting film consisting of 2 were formed, 18% efficiency improvement was obtained compared to 12% efficiency improvement in the conventional sealed part type light bulb compared to a light bulb without any film formation. .

When a visible light transmitting / infrared reflecting film made of TiO2 --SiO2 is formed on the bulb having the shape of the sealing portion as shown in FIG. 7 (b), the flat sealing portion of the prior art is compared with a bulb having no film. The shape has a 22% improvement in efficiency and the encapsulation temperature of 320 ° C, while the efficiency improvement is 29% and the encapsulation temperature can be lowered to 295 ° C. Cracks in the encapsulation and oxidation of external conductors. A high quality light bulb with less energy loss was obtained.

The invention of the present application is not limited to the above embodiment. For example, the lamp is not limited to a halogen bulb in which a sealing portion is formed at one end of the bulb, but may be a bulb for other purposes or a discharge lamp, or the sealing portion may be provided at both ends of the bulb.

Further, the shape of the sealing portion is not limited to the flat shape as shown in FIG. 7 (a) and 7 (b) are for large currents and valves in which the molybdenum foils 5 and 5 are layered to narrow the width of the sealing portion 4 so that the cross section has a circular shape (a) or a substantially circular shape (b). Is applied to a tube having a small diameter, and the sealing portion 4 of the tube can be made smaller than the diameter of the valve 1. Therefore, when forming a film on the outer surface of the valve 1, the flow of the membrane material is obstructed. The film thickness can be made uniform without causing Further, in this type, when the bulb 1 is formed between the molybdenum foils 5 and 5, a glass plate of the same material is interposed, and there is no fear of leakage or electrical conduction between the molybdenum foils 5 and 5. Absent.

Further, the bulb shape of the tube of the present invention is not limited to that shown in the figure, and may be other shape such as tubular shape or elliptical shape, and the material thereof is not limited to quartz glass and may be glass of other material. However, in the above embodiment, the multilayer interference film was formed after treating the outer surface of the valve in advance.
Preliminary outer surface treatment of the valve is not essential.

Further, in the above embodiment, the case where the multilayer interference film acting as a visible light transmitting infrared reflecting film is formed on the outer surface of the bulb has been described, but the present invention is a multilayer interference film performing another function, that is, a simple light. Of course, it can be applied to the case of forming a heat reflection film, a coloring film, or the like.

Furthermore, the film forming method is not limited to the above-mentioned method, and a method such as a vapor deposition method or a sputtering method may be used.

[0052]

As described above in detail, in the first to fourth inventions of the present application, the tube valve including the sealing portion is provided with the convex portion or the like for preventing the progress of the material flying due to evaporation or spray atomization. Therefore, the film thickness of the multilayer interference film such as the visible light transmitting infrared reflecting film formed on the outer surface of the bulb can be made substantially uniform and the characteristics of the bulb can be improved. Further, in the fifth invention of the present application, since the bulb valve including the sealing portion does not have a corner portion or the like which prevents the progress of the material flying by evaporation or jet atomization, most of the material scattered toward the valve is The film thickness of the multilayer interference film, such as a visible light transmitting infrared reflecting film, which is deposited on the valve, can be made substantially uniform.

[Brief description of drawings]

FIG. 1A is a front view of a halogen bulb for light projection in both FIGS.

2 (a) and 2 (b) are enlarged cross-sectional views taken along line ZZ in FIG.

FIG. 3 is an explanatory diagram of an apparatus for forming a coating film on a tube.

4 (a) and 4 (b) are explanatory views showing a film formation process.

FIG. 5 is a sectional view of a coating formed on the outer surface of the bulb of the bulb.

FIG. 6 is an explanatory view of a film forming apparatus of another embodiment.

7 (a) and 7 (b) are enlarged cross-sectional views of the sealing portion of the tube of another embodiment.

[Explanation of symbols]

L ... Tube (light bulb), 1 ... Bulb, 2 ... Filament (discharge electrode), 4 ... Sealing part 7 ... Coating (multilayer interference film), 8 ... Notch, BX ... Chamber.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H01K 1/32 B 9172-5E

Claims (5)

[Claims] Claim: What is claimed is: 1. A bulb comprising a filament or a discharge electrode enclosed inside a bulb, a sealing portion formed at an end portion, and a film formed on the outer surface of the bulb, wherein the sealing portion has a maximum thickness in the central portion. A tube characterized in that the portion is thinned toward the peripheral edge parallel to the valve axis. 2. A bulb formed by enclosing a filament or a discharge electrode inside a bulb and forming a sealing portion at an end and forming a coating on the outer surface of the bulb, and a bulb portion enclosing the filament or the discharge electrode. A tube characterized in that a notch is formed at a connecting portion with the sealing portion. 3. The cross section of the sealing portion in a direction orthogonal to the valve axis is circular, flat elliptical or rhomboid, according to claim 1 or 2. Tube. 4. The bulb according to claim 1, wherein the bulb portion enclosing the filament or the discharge electrode has a curved surface portion such as a spherical shape or a circular shape. 5. A tube having the sealing portion according to any one of claims 1 to 4 is supported horizontally or inclined in the chamber to form a coating on the outer surface of the valve. A method for forming a coating film on a tube characterized by the above.