JPH06310108A - Bulb and bulb with reflecting mirror - Google Patents

Abstract

PURPOSE:To provide a bulb of a long lifetime where a quantity of infrared rays returning to the center of a filament can be reduced by reducing the globular portion of the bulb because a hot spot is likely generated in a filament of a bulb, the whole surface of which is formed into a globular shape. CONSTITUTION:A bulb with a reflecting mirror comprises a bulb 1 formed into a complex shape consisting of a globular center portion 1a and conical ends 1b, a filament 2 disposed inside the bulb 1 along the center axis of the bulb, and a visible light transmitting infrared reflecting film 8 formed on the bulb 1. With this constitution, an infrared ray reflected on the visible light transmitting infrared reflecting film is concentrated on the center of the filament and is not returned, while infrared rays reflected at the conical ends are dispersed. Consequently, it is possible to provide the bulb of a long lifetime where a hot spot of a high temperature cannot be generated in the filament, a temperature in the center portion is decreased so that local superheating can be prevented, local vaporization of tungsten can be prevented, and early breakage due to narrowing can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light bulb in which a multilayer bulb such as a visible light transmitting infrared reflecting film is formed on the surface of a glass bulb such as a halogen bulb.

[0002]

2. Description of the Related Art Various efforts have been made in the field of light bulbs as part of energy saving. For example, in a halogen light bulb, an infrared ray radiated from a filament is formed by forming a visible light transmitting infrared ray reflecting film on the surface of a bulb. Is reflected by this reflective film and returned to the filament,
It is known that this heats the filament to increase the luminous efficiency.

As such a visible light transmitting infrared reflecting film, a high refractive index layer film made of titanium oxide (TiO2) and a low refractive index layer film made of silicon dioxide (SiO2) are alternately laminated to form a multilayer. By appropriately selecting the number of layers and the thickness of the layers, 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.

There are halogen bulbs that use a spherical bulb to further increase the reflectance. However, in this light bulb, the light emitted from the filament is incident on the visible light transmitting infrared reflecting film formed on the surface of the bulb, is reflected and returns to the central portion of the filament, and a hot spot is generated at this central portion. The occurrence of this hot spot is that the central part of the filament is overheated to a high temperature, so that the tungsten of this part forming the filament is sputtered, and it may become thinner earlier than other parts and may be broken early. It was

Therefore, in order to extend the life of the light bulb, it is necessary to prevent the hot spot from occurring.

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, but when a strict film thickness is required or When the valve is not straight and has a curved surface or a concavo-convex surface, the film thickness of the formed coating film may become uneven.

Further, in the case of such a method, since the membrane material is usually supplied from one place and does not fly from all directions around the valve, a supply source of the membrane material is arranged below the valve and the central axis of the valve is arranged. Even if the valve is rotated horizontally or tilted, it is difficult to form a film with a uniform thickness on the irregular curved surface near the crushed seal at the end of the valve. Was that.

Therefore, conventionally, the film has been formed by setting the film thickness such that the central wavelength is 1000 to 1100 nm with reference to the vicinity of the maximum diameter part of the bulb bulb and the substantially central part of the bulb length.

[0010]

DISCLOSURE OF THE INVENTION According to the present invention, in a bulb having a visible light transmitting and infrared reflecting film formed on a bulb, a bulb having a spherical surface has hot spots on the filament. An object is to provide a long-life light bulb in which the amount of infrared rays returning to the center of the filament is reduced.

[0011]

According to a first aspect of the present invention, there is provided a bulb having a composite shape in which a central portion has a spherical shape and both end portions have a conical shape, and a central axis of a halve is provided in the bulb. It is characterized in that it is provided with a filament arranged along the line and a visible light transmitting infrared reflecting film formed on the surface of the bulb.

A light bulb according to a second aspect of the present invention is characterized in that the bulb portion of the bulb is within a range of 60 to 90 degrees from the center of the bulb, and the conical portion forms the remaining portion.

According to a third aspect of the present invention, in the visible light transmitting / infrared reflecting film formed on the bulb, the conical portion closer to the sealing portion than the spherical portion is a thick film and has a center wavelength of 100.
The feature is that the thickness is set to 0 to 1100 nm.

A light bulb according to a fourth aspect of the present invention is characterized in that the bulb has a thick portion in a portion other than where the central points of the filaments face each other.

A light bulb with a reflector according to a fifth aspect of the present invention is a light bulb with a reflector, wherein the light bulb according to any of the first to fourth aspects is mounted in the reflector.

[0016]

[Function] The bulb having the visible light transmitting infrared reflecting film is formed into a conical shape following the spherical portion, and the infrared ray amount returning from the reflecting film to the central portion of the filament disposed on the central axis of the bulb is concentrated. By reducing the temperature, the temperature of the central part of the filament is lowered to prevent partial overheating.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially sectional front view of a small-sized light bulb H for projecting light, and FIG. 2 is an enlarged front view of a bulb portion. The bulb 1 is made of quartz glass and has a spherical central portion 1a,
The part (U-U
Line, line D-D) and the conical 1b portion are continuously formed. And this spherical portion 1a is a portion (U-) which is 30 to 45 degrees vertically and 60 to 90 degrees in total when viewed from the center point of the sphere.
It is cut by U line and D-D line).

Further, the filament 2 is provided inside the bulb 1.
And an inert gas such as argon containing halogen is enclosed. The filament 2 is supported by the inner conductors 3 and 3 and is arranged along the central axis of the bulb 1. The other ends of the internal conductors 3 and 3 are connected to molybdenum foils 5 and 5 sealed in a sealing portion 4 formed by crushing one end of the valve 1. Also, each molybdenum foil 5,5
External conductors 6 and 6 are connected to the other end side of the. Reference numeral 7 is an exhaust pipe provided at the other end of the bulb 1, and 8 is a visible light transmitting infrared reflecting film (hereinafter referred to as red anti-reflection film) formed on the outer surface of the bulb 1 and made of, for example, a multilayer interference film. is there.

When the light bulb L having such a structure is turned on, visible light of the light emitted from the filament 2 arranged on the central axis of the bulb 1 passes through the bulb 1 and the red anti-reflective membrane 8 and goes outside the bulb 1. Is emitted to. Further, the infrared rays emitted from the filament 2 are reflected by the red anti-reflection film 8 and returned to the filament 2, and the infrared rays are emitted from the filament 2 and reflected by the red anti-reflection film 8 repeatedly.

However, in the present invention, the bulb 1 having the red anti-reflection film 8 has a spherical shape in the central portion but has conical surfaces on both sides thereof. Therefore, the infrared rays reflected from the red anti-reflection film 8 are reflected by the filament 2. Those from the conical surface are not concentrated and returned to the central part, but are dispersed, no high-temperature hot spots are generated in the filament 2, and the temperature of the central part can be lowered to prevent partial overheating.

Therefore, there is no local evaporation of tungsten, which is the material of the filament 2, and it is possible to prevent the thinning and breaking of the wire early, and it is possible to provide the long-life light bulb L. Next, the red anti-reflective film 8 is subjected to ion plating PV.
A forming method using the D device will be described with reference to FIG.

In FIG. 3, BX is a chamber, and an exhaust pipe E connected to a vacuum pump VP, an argon gas supply pipe A for supplying an argon gas Ar, to the chamber BX,
An oxygen gas supply pipe O for supplying oxygen gas O ₂ is connected, and a valve E is connected to each of these pipes E, A and O.
C, AC and OC are provided.

A crucible R for accommodating 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 the visible light transmitting / infrared reflecting film 8 having a plurality of layers has the bulb axis inclined by θ (0 to 30 degrees) by a jig (not shown). It is supported by a drive device (not shown) so as to rotate in the direction of arrow X and revolve in the direction of arrow Y.

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

Bulb 1 of light bulb L using such a device
A method for forming a film on the outer surface will be described. First, the surface treatment before forming the coating on the bulb 1 is performed by using a jig (not shown) in the chamber BX and inserting the bulb 1 of the bulb L into the bulb axis θ degree (0 to 30).
Degree) 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.

After that, the valve 1 is rotated in the direction of arrow X and revolved in the direction of 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. Argon gas Ar pressure in this chamber BX is 1.0 × 10 ^{−2 to} 1.0 × 10 ^−1.
Let's say Thor.

In this state, high frequency power of about 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.

With the kinetic energy due to the collision of the argon ions, the outer surface of the bulb 1 is etched and 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 Valve 1
Surface treatment is performed.

After this process is completed, the red anti-reflection film 8 made of a multilayer interference film is formed on the surface of the valve 1.
First, for example, the high refractive index layer film 8 is used as the first layer of the red film 8.
Metal titanium (Ti) is contained in the crucible R as a material for forming H.

Then, similarly to the above, the valve 1 is rotated in the direction of the arrow X and revolved in the direction of the arrow Y via a driving device (not shown), and the heater H provided in the upper part of the chamber BX is used to move the valve 1 in the same direction. Outer surface temperature is about 300 ~
Heat to 350 ° C. Then, the valve OC is opened and the oxygen gas O ₂ is supplied into the chamber BX through the oxygen gas supply pipe O so that the partial pressure of oxygen O ₂ in the chamber BX becomes about 2.0 × 10 ⁻⁴ Torr. In this state, from the high frequency oscillator HF to the high frequency coil C, 13.56 MHz, 3
A high frequency power of about 00 W is supplied.

In this way, the vapor of Ti vaporized in the crucible R is ionized by the high frequency plasma, the ions are attracted to the surface of the valve 1 which is negatively charged, and the TiO is formed on the outer surface of the valve 1. The deposited film of ₂ adheres.

Next, accommodates the SiO ₂ powder in the crucible R as a material for making a low refractive index layer film 8L, SiO ₂ in the same manner as described above if caused to evaporate SiO ₂ of the TiO ₂ deposited film 8H 8L of vapor deposition film is attached.

Thus, TiO ₂ for forming the high refractive index layer films 8H, ... And SiO ₂ for forming the low refractive index layer films 8L, ... , Fig. 4
A halogen light bulb L having a red anti-reflection film 8 as its main part is obtained.

The bulb 1 of the bulb L of the present application has a film thickness distribution as shown in FIG. 5 for the film 8 of each portion formed on the outer surface thereof.

In FIG. 5, the vertical axis represents the ratio (%) to the maximum film thickness.
Is the center point of the spherical portion 1a forming the bulb 1 on the horizontal axis (=
Angles taken from the central point of the filament 2) are taken. Curve A shows the film thickness of the above-described product of the present invention, where the maximum film thickness (100%) is about 92% at the tip of the valve 1 at 45 °, and about 86% at 60 °. Approximately 90% at 45 degrees on the side of the section, about 82 at 60 degrees
% Bulb 1 compared to bulbs that are wholly spherical (curve X)
About 9% at the tip of 45 degrees and about 7 at 60 degrees
%, About 5% at the sealing portion side 45 °, and about 12% at the portion 60 °, the film thickness could be increased.

It is considered that this is because the end portion side of the valve 1 is a conical surface, and therefore the curvature of the outer surface is larger than that of the spherical surface, so that the uniformity of the film thickness is improved, and the deformation of the valve 1 is particularly large. This can also be estimated from the fact that the amount of change in the film thickness on the sealing portion 4 side is large. As is apparent from FIG. 5, the elevation angle from the spherical center of the bulb 1 (= the center point of the filament 2) is in the range of 30 to 60 degrees (60 to 120 degrees in total), preferably 30 to 50 degrees (60 in total). ~ 100
Range), that is, the film thickness of the curved surface that becomes irregular due to the formation of the sealing portion 4 is increased to 1000
If the wavelength of ˜1100 nm is reflected, the incidence of infrared rays at this portion is reduced, the multiple reflection of infrared rays within the wall thickness of the glass bulb 1 is also reduced, and the temperature rise of the sealing portion 4 is also reduced. The occurrence of cracks and leaks in the stopper 4 is reduced, and the service life can be extended.

Next, Table 1 shows characteristics of the conventional light bulb and the light bulb of the present invention in comparison.

The bulb is a halogen bulb for projection with a rating of 100V85W.

[0041]

[Table 1] As is clear from Table 1, the bulb of the present invention having a bulb having a composite shape of a spherical portion and a conical portion was able to improve the efficiency ratio by about 1.7% as compared with the conventional bulb bulb. . (It should be noted that the characteristic ratios are all compared with a clear light bulb in which a multilayer interference film using a spherical bulb is not formed as 100%.) In addition, the present invention, as described above, has the sealing portion 4.
Since the deformation of the valve 1 due to the molding is large, the maximum film thickness portion of the red varnish film 8 is formed near 35 degrees closer to the sealing portion 4 than the spherical center of the valve 1 (other portions are curved in FIG. 5). A line B is shown), and a bulb having the same rating as above was manufactured and the characteristics were compared.

The results are shown in Table 2, and the efficiency ratio was improved by about 1.4% as compared with the conventional product.

[0043]

[Table 2] FIG. 6 shows another embodiment of the present invention. FIG. 6 shows a halogen light bulb integrated with a reflecting mirror. Since the light bulb L has the same shape as that in FIG. 1, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In the figure, 10 is a reflecting mirror having a reflecting surface such as a paraboloid of revolution, a spheroid, etc. formed of hard glass, heat-resistant synthetic resin, metal or the like, and aluminum, chrome, silver on the inner surface. A visible / light-reflective infrared ray transmissive film 11 such as a light / heat reflective film 11 or a dichroic film is formed, and a recess 13 for accommodating the collapsible sealing portion 4 of the light bulb L is formed in the base 12 at the center thereof. Have Then, a heat-resistant adhesive 14 such as a silicon-based adhesive is injected in a state where the collapsed sealing portion 4 of the light bulb L is placed in the recess 13, and the reflective surface 11
When the focusing of the position of the filament 2 with respect to is completed, the adhesive 14 is solidified and both are integrated.

When the light bulb L in FIG. 6 is turned on,
Since the characteristics of the light bulb L itself are increasing, the reflector 1
The light emission characteristics from 0 can also be improved.

FIG. 7 shows another bulb of the present invention. 7 is similar to that of the above embodiment so that the visible light transmitting infrared reflecting film 8 can be easily formed on the outer surface of the bulb 1, but the construction of the bulb 1 on the inner surface side is different. That is,
The thickness of the glass forming the bulb 1 is partially thick, and the thickness of the portion 1c facing the filament 2 connected along the center of the bulb 1 axis is normal. From the vicinity of the filament 2 and the detached portion 1d, it is thick.

When the light bulb L is turned on, the light emitted from the filament 2 to the reflecting mirror 10 is taken as an example, but the light emitted from the center of the light is not changed, but the light from the thick portion 1d is refracted to the outside by the lens effect. Be done. That is, the reflecting mirror 1
The light going to 0 becomes longer, but if it is not refracted, it is the same as the length of the filament 2 shortened by that much. In the combination with the reflecting mirror, the dispersion of the beam becomes small and the light distribution becomes good, and the center plane loss is reduced. Less efficient.

For example, the maximum diameter is 10 mm, the thickness of the central portion is 0.8 mm, and the thickness is thicker toward the ends (R = 10 mm).
Bulb 1 is molded with quartz glass so that the filament 2 with a coil length of 4.2 mm and Ar + Ch ₂ Br ₂
A 12V 75W (efficiency 18Lm / W) spot type halogen light bulb L is manufactured by enclosing the gas described in (1), and this light bulb L is formed as a spheroid and a dichroic reflection surface is provided on the reflecting mirror 10 (focal length f: 21. 7 mm), a mounting characteristic test was conducted, and the results shown in Table 3 were obtained.

As a comparison (conventional product), bulb 1 having a wall thickness of about 1.0 mm on the entire surface (others are the same as above) was manufactured and measured at the same time.

[0050]

[Table 3] As is clear from Table 3, good characteristics were obtained by correcting the light distribution variation due to the coil length by the lens effect of the bulb 1.

It should be noted that the film thickness of the visible light transmitting / infrared reflecting film formed of the multilayer interference film in the present invention means the actual thickness of the film formed on the wall surface of the bulb or that it is formed on the same glass bulb. To optical film thickness (actual film thickness x refractive index)
The thickness may be said to be.

Further, when forming a visible light transmitting infrared reflecting film composed of a multilayer interference film, in the case of a dipping method or the like, if the sealing portion side is located below the upper side, the film material before drying is a flow film. It is preferable because it becomes thick.

The present invention is not limited to the above embodiment. For example, the lamp is not limited to a light-emitting halogen bulb in which a sealing portion is formed at one end of the bulb, but may be a bulb of a type that does not contain halogen for other purposes, and the sealing portion is at both ends of the bulb. It may be provided. Further, the sealing portion is not limited to crush sealing, and may be a sealing portion formed by contracting a valve, and is not limited to a metal foil such as molybdenum foil,
A linear sealing member may be used.

In the bulb shape, a spherical portion is provided with a conical portion such as an ellipse or an ellipse, which is longer than the original spherical portion (shown by a dotted line in FIG. 2). It goes without saying that it belongs to Further, the glass material of the bulb is not limited to quartz glass, and any other hard or soft glass material may be used as long as it has the required translucency, optical refractive index and heat resistance. Further, in the above-described embodiment, the outer surface of the valve is previously treated and then the multilayer interference film is formed, but the outer surface treatment of the valve is not essential. further,
In the above-mentioned embodiment, the case where the visible light transmitting infrared reflecting film consisting of the multilayer interference film is formed on the outer surface of the valve by the ion plating method is described, but the method is not limited to this method, but the dipping method, the vapor deposition method, the sputtering method or the like. But it's okay. Further, the visible light transmitting / infrared reflecting film is not limited to the outer surface of the bulb, but may be the inner surface of the bulb, or may be formed on at least one of the inner and outer surfaces.

[0055] Further, in the above embodiment the titanium dioxide in the high refractive index layer film (TiO _2), was used a low refractive index layer film of silicon dioxide (TiO _2), as a high refractive index layer film is not limited thereto _{May be} tantalum pentoxide (Ta ₂ O ₅ ), zirconium dioxide (ZrO ₂ ), zinc dioxide (ZnO ₂ ), etc., and the low refractive index layer film may be magnesium fluoride (MgF) etc.

Furthermore, the light bulb with a reflector is not limited to one in which both are integrated with an adhesive, and the light bulb is attached to a reflector with a socket or a device in which the socket and the reflector are separate bodies. It does not matter if there is.

[0057]

As described above in detail, according to the present invention, the infrared rays reflected from the visible light transmitting infrared reflecting film are not concentrated and returned to the central portion of the filament, but those from the conical surface are dispersed.
There are no hot spots on the filament,
It is possible to provide a long-life bulb that lowers the temperature of the central portion, prevents partial overheating, does not locally evaporate tungsten, and does not become thin and break quickly.

[Brief description of drawings]

FIG. 1 is a partially sectional front view of a halogen light bulb for floodlight showing an embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of a valve portion in FIG.

FIG. 3 is an explanatory diagram of a valve film forming apparatus.

FIG. 4 is an enlarged cross-sectional view of a main part of the light bulb shown in FIG.

FIG. 5 is an explanatory diagram showing the film thickness of each part of the light bulb of the present invention.

FIG. 6 is a partial cross-sectional front view of a halogen light bulb with a reflecting mirror showing an embodiment of the present invention.

FIG. 7 is a cross-sectional front view of a main part of a halogen light bulb with a reflecting mirror showing another embodiment of the present invention.

[Explanation of symbols]

 L: Light bulb 1: Bulb 1a: Spherical part 1b: Conical part 2: Filament 4: Sealing part 8: Visible light transmitting infrared reflecting film (multilayer interference film)

Claims (5)

[Claims] 1. A bulb having a complex shape in which a central portion is spherical and both ends thereof are conical, a filament arranged along the central axis of the hull in the bulb, and a visible material formed on the surface of the bulb. A light bulb comprising a light-transmitting infrared reflecting film. 2. The bulb has a spherical portion of 60 to 60 mm from the center of the sphere.
The light bulb according to claim 1, wherein the conical portion forms the remaining portion in the range of 90 degrees. 3. The visible light transmitting / infrared reflecting film formed on the bulb is such that the conical portion on the sealing portion side of the spherical portion is a thick film and has a center wavelength of 1000 to 1100 nm. The electric bulb according to claim 1 or 2, characterized in that. 4. The light bulb according to claim 1, wherein the bulb has a thick portion formed in a portion other than the center of the light source facing the bulb. 5. The above-mentioned claim 1 to claim 4 in a reflecting mirror.
A light bulb with a reflector, characterized in that the light bulb described in (4) is attached.