JPH0896776A - Lamps and lamp units with protective coating - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a lamp with a protective coating and a lamp device in which a protective coating is formed on the bulb so as to improve the strength of the sealing portion side of the glass bulb and improve the light distribution. To do. A lamp L with a protective coating and a reflecting mirror in which a protective coating 7 is formed on the surface of a bulb 1 in which a light emitting member is sealed inside so that the film thickness on the sealing portion 1s side is larger than the top portion 1t of the bulb 1. This is a lamp device in which this lamp L is attached to R. [Effect] Since the protective film thickness of the bulb is thick on the sealing part side and thin on the top part side, the film complements the weaker part and the top part side which is the main part for light emission etc. Light absorption loss is small, and strength such as impact resistance and pressure resistance and luminous efficiency can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamp, such as a flash bulb, which has a protective coating formed on the surface of a glass bulb for preventing the bulb from bursting or scattering.

[0002]

2. Description of the Related Art For example, a flash bulb is constructed by enclosing a flammable luminescent material made of foil or strip of zirconium or aluminum and a combustion supporting gas such as oxygen in a glass bulb. When the flash light is emitted, the inside of the bulb is pressurized to several to several tens of atmosphere by the combustion of a light-emitting material such as aluminum or zirconium or oxygen gas that can obtain a higher amount of light at a higher pressure. The glass bulb breaks and scatters.

Further, in the high pressure discharge lamp, when the inner tube constituting the arc tube bursts, the fragments and the pressure directly hit the outer tube and the outer tube bulb sometimes breaks and scatters.

Further, lamps using these glass bulbs sometimes cause scratches or cracks when they come into contact with each other during transportation or storage.

Therefore, a transparent protective coating is formed on the outer surface of the glass bulb as a means for coping with the internal pressure, the impact from the inside, the thermal effect, and the impact from the outside, and the glass bulb is damaged by any chance. However, the coating catches the debris and prevents it from scattering and falling.

[0006]

Conventionally, a vinyl chloride resin is often used as the protective coating material, and recently, a urethane resin or a polyester resin is also used due to the problem of post-treatment of the vinyl chloride resin. Is becoming more common.

The coating of these resins on the outer surface of the glass bulb of the flash bulb is carried out as follows. First, a resin coating solution is prepared and the valve is preheated to about 170 ° C. in a preheating furnace. Next, the temperature-increased valve is immersed in a resin coating liquid tank, pulled up, and baked at about 190 ° C. to obtain a film.

When the valve is dipped in the coating liquid to form a film in this way, undesired electrical insulation is not achieved if the film is present on the mouthpiece, and therefore the mouthpiece is generally not covered. It is immersed in the coating liquid with the valve top side facing downwards.

However, the protective coating formed on the surface of the valve may vary in film thickness due to nonuniform flow of the coating film. If the thin part of the coating is weak and can not maintain the internal pressure even if it is left intact, or if there is a scratch when something touches this part, the strength will decrease and it will not be able to withstand the internal pressure. However, there is a problem that the illuminance distribution is not uniform when the bulb is broken and glass pieces scatter, or when there is a large variation in film thickness.

Further, in dip coating, the coating liquid adhering to the upper portion of the valve flows downward, and when the valve is pulled up from the coating liquid, a large amount of coating liquid remains on the valve top portion, and the coating liquid on the valve top side is larger than that on the sealing portion side. The coating film thickness was thick.

Further, in the glass bulb of the flash bulb or the like, a sealing portion is formed at the end portion on the side opposite to the bulb top portion by heat processing, so that the sealing portion has a distortion or a thick wall. The strength is weak due to the occurrence of a thin portion, and it has been sometimes desired to thicken the coating in order to increase the strength on the sealed portion side.

Therefore, an object of the present invention is to provide a lamp with a protective coating and a lamp device in which a protective coating is formed on the bulb so that the strength of the glass bulb on the sealing portion side is improved and the light distribution is improved.

[0013]

A lamp with a protective coating according to claim 1 of the present invention comprises a bulb, a light emitting member disposed inside the bulb, a surface of the bulb, and a top portion of the bulb. The protective film is formed so that the film thickness on the sealing portion side becomes thicker.

The lamp with a protective coating according to a second aspect of the present invention is characterized in that the protective coating is made of an epoxy resin or a polyester resin.

The lamp with a protective film according to a third aspect of the present invention is characterized in that the film thickness of the protective film made of an epoxy resin formed on the top of the bulb is 0.3 mm or more.

The lamp with a protective coating according to a fourth aspect of the present invention is characterized in that the protective coating made of polyester resin formed on the top portion of the bulb has a thickness of 0.4 mm or more.

The lamp with a protective coating according to a fifth aspect of the present invention is characterized in that it is any one of a flash bulb, an incandescent bulb and a high pressure discharge lamp.

A lamp device according to claim 6 of the present invention comprises:
It is characterized by comprising a reflecting mirror and the lamp according to any one of claims 1 to 5 arranged in the reflecting mirror.

The lamp device according to claim 7 of the present invention comprises:
The inner surface of the reflecting mirror is characterized by an uneven surface.

[0020]

In the lamp with a protective coating according to claims 1, 3 and 4, the protective coating formed on the bulb is thick on the sealing portion side where the strength is weak and the luminous efficiency is not lowered on the top side. It is thinly formed.

In the lamp with the protective coating according to the second aspect, the protective coating is made of epoxy resin or polyester resin and is excellent in elasticity and spreadability, and also has excellent heat resistance and abrasion resistance, and is resistant to impact from inside or outside. On the other hand, it strongly protects the glass bulb, and even if the bulb is damaged, it is possible to prevent the glass pieces from scattering and falling.

The protective coating according to claim 5 is a fluorescent lamp,
It can be formed into bulbs such as light bulbs and discharge lamps for increased strength.

In the lamp device according to the sixth and seventh aspects, the lamp having an improved bulb strength can be turned on with good light distribution characteristics.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a partially sectional front view showing a flash bulb L for copying and taking photographs. In the figure, 1 is a bulb made of soda lime glass, and 2 is a stem sealed in a sealing portion 1s at the end of the bulb 1. Reference numerals 3 and 3 denote a pair of internal lead wires that are hermetically implanted in the stem 2, and reference numeral 4 denotes a tungsten filament connected between the internal lead wires 3 and 3, which is not shown in the connection portion. zirconium,
An ignition agent (primer) composed of a mixture of aluminum and potassium perchlorate is applied. Reference numeral 5 denotes a cap joined to the sealing portion 1s at the end of the valve 1 via an adhesive 5a, to which external lead wires connected to the internal lead wires 3 and 3 are connected (not shown).

Further, a thin foil of zirconium, aluminum or the like, or a thin strip or filament obtained by cutting the thin foil as a flammable luminescent material 6 is enclosed in the bulb 1 together with oxygen of several atmospheres as a combustion gas. is there. Further, the entire outer surface of the valve 1 extending from the top part 1t of the valve 1 to the vicinity of the sealing part and the vicinity of the peripheral surface of the opening of the base 5 are mainly composed of an epoxy resin formed by powder coating described later. Is provided with a protective coating 7 in which calcium carbonate is mixed. Further, in the above-mentioned valve 1, the sealing portion 1s in which the stem 2 is sealed by heat processing is vulnerable to shock and pressure if there is a large amount of residual strain or there is a thin portion, so the protective coating of this portion The thickness of 7 is the valve top part 1
It is formed thicker than t.

The flash bulb L having such a structure is mounted in a socket (not shown) in the reflecting mirror R of the flash light emitter F such as in the copying machine shown in FIG. A current flows through the filament 4 for ignition through the external lead wire and the internal lead wires 3 and 3, the filament 4 is heated, and the luminescent material 6 is instantaneously burned by the igniting agent (primer) to emit a strong flash.

Due to this combustion, the pressure in the valve 1 becomes high, and the valve 1 which has been directly hit with a high pressure breaks and becomes an infinite number of broken glass pieces and tries to scatter outward, but in the case of the present invention. A protective coating 7 formed on the outer surface of the bulb 1 so as to cover the bulb 1 and containing epoxy resin as a main component holds down the glass piece that is about to fly outward. Of course, if the protective film 7 is not formed, the glass pieces forming the bulb 1 and the stem 2 will be shattered and scattered, and it is very dangerous to hit the surrounding objects or human body and be damaged. This is not the case, since it has been formed.

Further, this protective film 7 is rich in elasticity and spreadability and is strong against pressure from the inside and impact from the outside, and there is no problem in quality. Also, the internal pressure of the light bulb L is controlled by the bulb 1.
The sealing portion 1s, which is evenly applied to the inner wall of the sealing portion 1s, is thinner than the valve top portion 1t and has a large amount of strain, is expected to have cracks or other cracks first. Since it is a thicker film than the portion of (1), the glass portion of the sealing portion 1s is reinforced so that the sealing portion 1a hardly cracks first, and the valve 1 almost simultaneously produces uniform cracks on almost the entire surface. There is no chance that glass fragments will scatter locally.

Further, since the thickness of the protective coating 7 is small on the side of the top portion 1t of the bulb 1 which is the main portion of light emission during light emission, the light absorption of the coating 7 is small and the luminous efficiency is not lowered.

Further, the epoxy resin does not generate toxic gas when decomposed and incinerated after being used after being used or during the manufacturing process and decomposed when it becomes unnecessary after testing, and there is no problem in environmental hygiene. Furthermore, when the glass bulb 1 is left to stand, "fog" called a weathering phenomenon occurs on the outer surface of the glass bulb 1 to lower the light transmittance, but a protective coating 7 containing this epoxy resin as a main component is formed. If this is done, this weathering phenomenon does not occur, and even if it is used after long-term storage, the luminous efficiency does not decrease and the appearance does not deteriorate.

Next, the formation of the protective film 7 will be described.

Epoxy resin (melting point: about 80 ° C.) powder as a main component (about 95% by weight) is used as a protective film material, and calcium carbonate (decomposition temperature 1340 ° C.) powder (about 5% by weight) having almost the same diameter as this is used. A powder prepared by adding and mixing is prepared.

Then, the flow protection film 7 is formed on the light bulb L in accordance with the process shown by the arrow in FIG. 2 (flow from top to bottom). First, in FIGS. 2A to 2C,
11 is a preheating furnace, 21 is a sealed tank, 22 is this tank 2
1 is a perforated plate or a net having a large number of holes provided in 1, a reference numeral 23 is an air supply pipe provided at the lower side wall or a lower surface wall of the tank 21, and 24 is an exhaust pipe. Further, 31 is a heating furnace.

First, the light bulb L (bulb 1) is preheated for about 1 minute at a temperature of about 190 ° C. in the preheating furnace 11 whose inside is heated in the preheating step of FIG. 2 (a). At this time, the temperature distribution of the bulb L (bulb 1) in the preheating furnace 11 is higher in the sealing portion 1s than in the bulb top portion 1t by introducing the outside air to the upper side with the heat source on the lower side. To preheat. Then, as shown in FIG.
The powder 71 containing the epoxy resin as a main component is placed on the inside porous plate 22 and the high temperature light bulb L (bulb 1) heated in the preheating furnace 11 is arranged above the powder 71. Then, when the hermetically sealed tank 21 is almost hermetically sealed, the tank 21 is connected to the side wall of the tank 21 through the air supply pipe 23.
A high-pressure dry gas such as high-pressure air is supplied into the inside. Powder 71 containing epoxy resin as a main component in the tank 21
The powder 71 that has received the high-pressure gas and has flowed up (bubbled) to come into contact with the surface of the valve 1 in a high temperature state receives the heat of the valve 1 and a part or most of it melts to the valve 1. Adhere to.

The dwell time of the light bulb L (bulb 1) in the hermetically sealed tank 21 is about 1 second, and the light bulb L (bulb 1) taken out from the hermetically sealed tank 21 is immediately shown in FIG.
It is placed in the heating furnace 31 shown and heated at a temperature of about 190 ° C. for about 5 minutes. Due to this heating, the powder 71 which remains in the original grain shape or partially melts and adheres to the surface of the valve 1
Is completely melted and fused with the surrounding powder 71 to form the valve 1
To the vicinity of the surface around the opening of the die 5 as a coating 7.

During the coating, a part or most of the powder 71 that hits the high temperature valve 1 is fused to the valve 1,
If the temperature of the fused powder 71 drops too much, the powder 71 that hits the fused powder 71 later will be the previous powder 7
It does not adhere on 1. The thickness of the coating film 7 to be formed is adjusted by changing the preheating temperature of the valve 1,
For example, when a thick film is desired, if the temperature of the valve 1 is kept high, the powders 71, 71, ... Will be fused one after another until the temperature of the valve 1 drops to a certain temperature. The film thickness can be increased.

Therefore, when the valve 1 is preheated as described above, the temperature in the vicinity of the sealing portion 1s, which is weak in strength, is kept at the top portion 1
If it is set higher than the t side, the adhesion amount of the powder 71 can be increased, and the protective film 7 having a predetermined changed film thickness can be obtained.

At this time, substantially from the sealing portion 1s of the valve 1 through the central portion 1c to the top portion 1t,
The film was formed so that the film thickness gradually decreased.

As described above, in the flash bulb L, etc., the strength of the sealing portion 1s at the end of the bulb 1 is weak,
The film thickness of each part of the protective film 7 covering the glass bulb 1 is as shown in FIG. In FIG. 3, the vertical axis represents the film thickness (μm) of the protective film 7, and the horizontal axis represents the portion of the flash bulb L.

According to an experiment conducted by the present inventor, the protective film 7 made of the epoxy resin material of the present invention has a solid line (○) in FIG.
3), and the one formed of a conventional vinyl chloride material was as shown by the dotted line (Δ) in FIG. This is because the protective film 7 formed of an epoxy resin material instead of the vinyl chloride material has high pressure resistance even when the film thickness is thin, and the total amount of film forming material used is about 30% compared to the conventional product.
%.

Further, the flash bulb L is manufactured by enclosing oxygen gas in the glass bulb 1 by increasing it by 120% more than usual, and by changing the film thickness of the protective coating 7 made of the epoxy resin of the present invention variously, flight resistance and light emission. The appearance such as the softening of the coating at the time and the scorched state of the coating after light emission was examined. The results are shown in Table 1. The film thickness is the value of the top portion 1t of the valve 1.

[0042]

[Table 1] The protective coating 7 of the present invention is not limited to the above-mentioned epoxy resin material, and may be a polyester resin as a main component, and the material added to this main component is not limited to calcium carbonate. Alternatively, even if silica, alumina, a metal compound organic substance, or the like is used, the same effect as described above can be obtained.

Table 2 shows the results of examining the flight resistance and the appearance after light emission of the flash bulb in which the protective coating 7 was formed of polyester resin. The structure and film thickness of the flash bulb are the same as those in Table 1.

[0044]

[Table 2] The present invention is not limited to the above embodiment. For example,
As a lamp, I explained about flash bulbs in which almost all of the bulbs crack when igniting, but it is not limited to explosion-proof flash bulbs, but the internal pressure at the time of lighting is over atmospheric pressure by enclosing inert gas etc. in the bulb. It can be applied to the prevention of scattering due to bulb rupture in other types of light bulbs or the prevention of scattering of outer bulb due to rupture of arc tube in high pressure discharge lamps such as metal halide lamps. In addition, it can be applied to various lamps to prevent scratches and cracks that occur when the bulbs come into contact with each other during transportation or storage of the lamps. Further, the lamp is not limited to one having a base, and a protective coating may be formed on a lamp having no base.

In the case of a flash bulb, the thickness of the valve top portion, which is the thickest film, should be 0.3 mm or more for epoxy resin and 0.4 mm or more for polyester resin.
The thickness is not limited to the flash bulb and may be appropriately determined according to the internal pressure applied to the glass bulb.

The film thickness of the coating film may be a thick film on the sealing portion side and a thin film on the top portion side. Even if the film thickness from the sealing portion side to the top portion side changes linearly, it has a wavy shape. It may change gradually.

Further, the above resin coating does not cause a decrease in light transmittance even if it is used for a long period of time, and it may be used as a colored coating by dispersing a pigment also as a protective coating for preventing bursting. Further, the material of the glass bulb is not limited to soft glass such as soda lime and lead glass, and even a semi-hard or hard glass bulb can be covered with the same effect.

Further, in the above embodiment, the coating is formed on the outer surface of the glass bulb, but it is not limited to the outer surface and may be formed on both the inner and outer surfaces.

Further, in the case where a coating is formed for protecting the bulb during transportation of the lamp and the coating is peeled off when the lamp is used, a protective coating may be formed on the entire surface from the bulb to the base. Further, in the case of a lamp such as an example in which the coating is not peeled off, it is not preferable to form the coating on the terminal portion of the base in forming the coating after the base is attached. It is good to work, and it is possible to form a film before attaching the base and then attach the base.

Further, in the powder coating, the coating may be formed by using a plurality of lamps at the same time. Further, the means for forming the coating is not limited to powder coating, and other means may be used. Furthermore, the shape of the reflecting mirror of a copying machine or the like on which the lamp is mounted is not limited to the rectangular shape shown in FIG. 4, and may be a bowl shape or an oval shape, and the reflecting surface inside the reflecting mirror is smooth. The surface is not limited to the one described above, and may be an uneven surface. If the uneven surface is used, the reflected light is diffused and uniform light emission can be performed in a wide range to improve the light distribution characteristics.

[0051]

As described in detail above, the present invention provides claim 1,
In the lamps with protective coatings described in 3 and 4, since the protective coating is thick on the sealing portion side and thin on the top portion side, the coating complements the weak portion and the main portion of light emission etc. There is little light absorption loss on the side of the top part forming the part, and strength such as impact resistance and pressure resistance and luminous efficiency can be improved.

In the lamp with the protective film according to the second aspect, the protective film is made of an epoxy resin or a polyester resin, which is rich in elasticity and spreadability, and is excellent in heat resistance and abrasion resistance.
In addition, the glass bulb is strongly protected against impacts from inside and outside, and even if the bulb is damaged, it is possible to prevent the glass pieces from scattering and falling. In addition, when the above resin material is incinerated, no harmful gas is generated, safety and health are not a problem, and environmental hygiene can be improved.

The protective coating according to claim 5 is a fluorescent lamp,
It can be formed in bulbs of light bulbs and discharge lamps for increased strength.

In the lamp device according to the sixth and seventh aspects, it is possible to turn on a lamp having improved bulb strength with good light distribution characteristics.

[Brief description of drawings]

FIG. 1 is a partially sectional front view of a flash bulb showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing a film forming step of the present invention.

FIG. 3 is a graph showing the ideal film thickness of the protective film, the film thickness according to the present invention, and the film thickness of the conventional product in comparison with each other in each part of the flash bulb.

FIG. 4 is a perspective view of a reflecting mirror in a lamp device showing an embodiment of the present invention.

[Explanation of symbols]

 L: Flash light bulb (lamp) 1: Glass bulb 1s; Sealing part 1t; Top part 7: Protective coating 71: Powder R: Reflecting mirror

Claims (7)

[Claims] 1. A bulb; a light-emitting member disposed inside the bulb; and a protective coating formed on the surface of the bulb so that the film thickness on the sealing portion side is larger than the top portion of the bulb. A lamp with a protective coating, characterized by comprising: 2. The lamp with a protective coating according to claim 1, wherein the protective coating is made of an epoxy resin or a polyester resin. 3. The lamp with a protective coating according to claim 1, wherein the protective coating made of epoxy resin formed on the top of the bulb has a thickness of 0.3 mm or more. 4. The lamp with a protective coating according to claim 1, wherein the protective coating formed of a polyester resin on the top of the bulb has a thickness of 0.4 mm or more. 5. The lamp is any one of a flash bulb, an incandescent bulb, and a high-pressure discharge lamp.
A lamp with a protective coating according to claim 4. 6. A lamp device comprising a reflecting mirror and the lamp according to any one of claims 1 to 5, which is arranged in the reflecting mirror. 7. The lamp device according to claim 6, wherein an inner surface of the reflecting mirror is an uneven surface.